JP2006035844A - Mold and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold capable of ensuring sealing performance at a sliding portion between an ejector pin and a mold and a method for manufacturing the same.
SOLUTION: A mold 30 including a fixed side mold 31, a movable side mold 32, and an ejector pin 36A protruding from the movable side mold 32. The movable side mold 32 includes an ejector pin 36A. A sliding hole 61 is provided in such a manner that the sliding hole 61 can be moved forward and backward, and an expansion space 62 is provided in a part of the sliding hole 61 so that the hole is expanded radially outward. A seal member 63 made of rubber is formed.
[Selection] Figure 7

Description

  The present invention relates to a mold and a manufacturing method thereof, and more particularly, to an injection molding mold capable of performing injection molding while keeping a cavity and a resin material in a vacuum state and a manufacturing method thereof.

2. Description of the Related Art Conventionally, vacuum forming molds that can evacuate the cavity after the molds are clamped are known (see, for example, Patent Documents 1 and 2).
In the molds of Patent Documents 1 and 2, an O-ring is disposed on the parting surface of the mold in order to keep the inside of the cavity in a hermetically sealed state. A ring is provided, and the O-ring and the ejector pin are in elastic contact with each other.

JP 2002-225096 A JP 2001-129833 A

However, since the molds of Patent Documents 1 and 2 use an O-ring in order to maintain airtightness at the location where the ejector pin is disposed, the O-ring is in sliding contact with the ejector pin as molding is repeated. There was a problem that it was worn out.
For this reason, conventionally, it has been troublesome to inspect the O-ring regularly.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a mold capable of ensuring sealing performance at a sliding portion between an ejector pin and a mold and a method for manufacturing the same.

  According to the present invention, the object is a mold including a fixed mold and a movable mold, and an ejector pin protruding from the movable mold, and the movable mold includes the A slide hole is provided in which the ejector pin can be moved forward and backward. An extension space portion is provided in a part of the slide hole, the hole being expanded radially outward. The extension space portion is made of silicon rubber. This is solved by forming a sealing member.

  Thus, in the present invention, in order to ensure the airtightness of the cavity of the mold, the seal member is provided in the sliding hole of the ejector pin. Since the seal member is made of silicon rubber, it is possible to maintain high adhesion with the ejector pin.

  In addition, the seal member is made of silicon rubber, and it is not a structure that deforms and elastically contacts like a conventional O-ring, so it does not crush or wear like an O-ring, and is molded Even if it repeats, it is possible to maintain a sealing performance.

  In addition, when the lubricant is disposed in the expansion space portion, the sliding between the ejector pin and the seal member can be made smooth, and the lubricant enters between the ejector pin and the seal member, so that High adhesion can be obtained, which is preferable.

More specifically, the expansion space is provided on the back plate side that supports the fixed mold or the movable mold from the back.
The seal member is in surface contact with the outer peripheral surface of the ejector pin and maintains high airtightness.

The manufacturing method of the metal mold | die which concerns on Claim 5 is as follows.
A method of manufacturing a mold comprising: a fixed side mold and a movable side mold; and an ejector pin disposed in a sliding hole provided in the movable side mold so as to freely advance and retract. Forming an expanded space part having a hole radially expanded in a part thereof, positioning the ejector pin in the sliding hole, and injecting liquid silicon rubber into the expanded space part; And a step of curing the silicon rubber.

  Thus, according to the mold manufacturing method of the present invention, the expansion space is formed in a part of the sliding hole of the ejector pin, and silicon rubber is injected with the ejector pin positioned in the expansion space. Thus, since the seal member is formed, it is possible to form the seal member in a state where the seal member is always in surface contact with the ejector pin.

  In addition, if a step of applying a release agent to the ejector pin is provided before the step of positioning the ejector pin in the sliding hole, the ejector pin is peeled from the silicon rubber after the silicon rubber is cured. It becomes easy and is suitable.

  Moreover, if the step of injecting a lubricant into the expansion space portion is provided after the step of curing the silicon rubber, sliding of the ejector pin can be made smooth. Further, it is preferable that the lubricant enters between the ejector pin and the seal member, thereby improving the adhesion.

  According to the mold of the present invention, an expansion space is provided in a part of the sliding hole of the ejector pin disposed in the movable mold, and a seal member made of silicon rubber is provided in the expansion space. Therefore, high adhesion between the ejector pin and the seal member is obtained, and the airtightness of the cavity is maintained.

  Since the seal member is made of silicon rubber and does not have a structure that deforms and abuts elastically like a conventional O-ring, a long sealing performance can be ensured. Therefore, it is possible to improve the manufacturing efficiency without taking time and labor for inspection and the like as in the prior art.

  Furthermore, when the lubricant is disposed in the expansion space, the sliding between the ejector pin and the seal member can be smoothed, and the lubricant can enter between the ejector pin and the seal member to obtain higher adhesion. It becomes possible.

  Thus, in the mold of the present invention, airtightness in the cavity is maintained, and when performing injection molding, the resin material can be melted while being kept in a vacuum state and injected into the cavity. It becomes possible to manufacture a high-quality molded product that does not contain bubbles or the like.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

  1 to 15 relate to an embodiment of the present invention, FIGS. 1 to 3 are explanatory views of a mold, FIG. 4 is a cross-sectional explanatory view of a mold sealing member, and FIG. 5 is an explanatory view of the mold sealing member. FIG. 6 is an explanatory view showing a forming method, FIG. 6 is an explanatory sectional view of a sliding seal portion, FIG. 7 is an explanatory view showing a forming method of a sliding seal member, and FIGS.

  11 to 15 relate to another embodiment of the present invention, FIG. 11 is an explanatory view of a mold, FIG. 12 is an explanatory view of a cross section of the mold seal member, and FIG. 13 is a formation of the mold seal member. Explanatory drawing which shows a method, FIG. 14, FIG. 15 is sectional explanatory drawing of a metal mold | die seal | sticker part.

  The mold 30 of this example is used, for example, for injection molding. As shown in FIGS. 1 and 2, the fixed-side mounting plate 33A and the fixed-side mold 31 attached to the fixed-side mounting plate 33A , A movable mold 32 disposed opposite to the fixed mold 31, a back plate 34 supporting the movable mold 32 from the back, and a movable side connected to the back plate 34 via a spacer block. The main components are an attachment plate 37A, an ejector plate 35 movably disposed between the back plate 34 and the movable side attachment plate 37A, and an ejector pin 36A having a base fixed to the ejector plate 35. And the cavity 30a for shape | molding a molded article is formed by clamping the fixed side metal mold | die 31 and the movable side metal mold | die 32. FIG.

  Resin is supplied to the mold 30 from the injection machine. The injection machine shown in FIG. 1 is of a screw-in-line type, and includes a cylinder 11, a nozzle 13, and a drive unit 14, and is connected to a material supply means (not shown). Supplied. The cylinder 11 is heated by a band heater 15.

  The drive unit 14 includes a rotation drive unit 14a including a motor and a speed reduction mechanism that rotate the screw 12 in the cylinder 11, an injection cylinder device 14b that extrudes the screw 12 and injects molten resin in the cylinder 11 into the mold 30, and a cylinder. 11 is provided with a shift cylinder that moves the nozzle 11 in the left-right direction to bring the nozzle 13 into contact with or retract from the sprue.

  The fixed side mold 31 and the movable side mold 32 of this example are made of aluminum alloy. The aluminum alloy mold has a weight as low as about 1/3 as compared with, for example, a mold made of steel S55C, and the injection molding apparatus having the above configuration is reduced in weight and size as a whole.

The aluminum alloy mold is easy to cool because of its good thermal conductivity. Furthermore, it has good machinability, can significantly reduce the processing time of a postcard and the like, and can operate about 1 million shots. Thus, the mold 30 made of the aluminum alloy mold is easy to handle and can reduce the manufacturing cost.
In this example, although the aluminum alloy mold is used for the fixed mold 31 and the movable mold 32, a mold made of steel can also be used.

  Mold vacuum valves 40 and 50 are incorporated in the fixed-side mold 31. The mold vacuum valves 40 and 50 are connected to a vacuum exhaust means (not shown), and the cavity 30a is exhausted to a vacuum state by the vacuum exhaust means. The fixed side mold 31 is provided with a recess 31e on the side surface in contact with the fixed side mounting plate 33A, and the mold vacuum valve 40 is attached to the recess 31e. The mold vacuum valve 40 is configured so that the gate 31d of the fixed mold 31 can be switched between communicating with a material supply nozzle or communicating with a vacuum exhaust means (not shown). ing. The mold vacuum valve 50 is disposed in the recess 32e and the recess 32f formed in the movable mold 32, and is configured to be able to switch whether the cavity 30a communicates with the evacuation means side. ing.

  Further, an electromagnetic valve 59b is provided in a pipe 59 extending from the mold vacuum valves 40, 50 to the vacuum exhaust means, and the electromagnetic valve 59b is provided between the mold vacuum valves 40, 50 and the vacuum exhaust means. Can communicate or occlude. A pipe 59 between the electromagnetic valve 59b and the mold vacuum valves 40 and 50 is provided with a vacuum sensor 59a and a digital vacuum meter 59c. The pressure in the cavity 30a communicated with the pipe 59 and the pipe 59 is measured. Measuring. The vacuum sensor 59a displays the internal atmospheric pressure on the display unit. The vacuum meter 59c sends a detection signal representing an internal atmospheric pressure value to a control means (not shown). The control means includes a control unit, a display unit, an operation unit, and the like, and a control program necessary for performing molding. The control means receives such a detection signal and performs a process of sending an operation signal to a solenoid valve, a drive unit or the like.

  The mold clamping means 80 includes a fixed die plate 81 fixed to the end of the tie bar 83, a mold clamping mechanism 86, and a movable die plate 82 that can move forward and backward with respect to the fixed die plate 81 by the mold clamping mechanism 86. And a drive unit 87 for driving the mold clamping mechanism 86 and the like.

The fixed side die plate 81 supports the fixed side mounting plate 33A, and the movable side die plate 82 supports the movable side mounting plate 37A.
The mold clamping mechanism 86 is configured by a link mechanism or the like, and is configured so that the position of the movable mold 32 can be adjusted by being driven by the drive unit 87.

  The mold clamping means 80 is provided with a position detection switch 88 for detecting the position of the movable mold 32. The position detection switch 88 detects that the movable mold 32 is in the mold clamping position. The position detection signal is sent to the control means.

  Further, the drive unit 87 can move the ejector plate 35 forward and backward toward the movable mold 32 side. After the mold opening, when the drive unit 87 is driven and the ejector plate 35 advances to the movable mold 32 side, the molded product is removed from the mold surface of the movable mold 32 by the ejector pins 36A.

(Parting surface seal structure)
Next, the structure which seals between the fixed side metal mold | die 31 and the movable side metal mold | die 32 of this example is demonstrated based on FIGS. Note that the illustration of the mold vacuum valve 50 is omitted for easy understanding.

  The movable mold 32 of this example is provided with a convex mold seal member 36 made of silicon rubber, and the fixed mold 31 is a mold seal in which the mold seal member 36 is inserted when the mold is clamped. A groove 37 is formed. The mold 30 of this example is configured such that when the mold is clamped, the mold seal member 36 and the mold seal groove 37 are engaged to seal the cavity 30a.

  As shown in FIG. 3A, the movable mold 32 includes a contact surface (parting surface) 32b with the fixed mold 31, a product forming surface 32a for forming the cavity 30a, and a product. A mold seal portion 32c is formed so as to surround the formation surface 32a.

  As shown in FIG. 3B, the fixed mold 31 includes a contact surface (parting surface) 31b with the movable mold 32, and a product forming surface 31a for forming the cavity 30a. A mold seal contact portion 31c is formed so as to surround the product forming surface 31a.

FIG. 4 is a cross-sectional view of the mold seal contact portion 31c and the mold seal portion 32c.
As shown in FIGS. 3 and 4, the mold seal portion 32 c includes an annular groove 33 formed so as to surround the cavity 30 a, and a contact surface 31 b that continues from the annular groove 33 and crosses the contact surface 31 b. An injection groove 33a and a suction groove 33b communicating with the side portions, and an elastic silicon rubber mold seal member 36 disposed so as to protrude from the annular groove 33 toward the fixed side mold 31 are provided. The injection groove 33 a and the suction groove 33 b are formed outward from different portions of the annular groove 33.

  The annular groove 33 of this example is formed with a depth of about 10 mm and a width of about 10 mm. The injection groove 33a and the suction groove 33b have a width of about 10 mm and have a substantially semicircular cross section. The fitting portion 36a protruding from the contact surface 32b of the silicon rubber mold seal member 36 has a width of about 6 mm and a height of about 8 mm from the contact surface 32b. The cross section of the tip portion of the fitting portion 36a is substantially semicircular.

The mold seal contact portion 31c of this example includes a mold seal groove 37 formed at a position facing the mold seal member 36, an injection groove 37a, and a suction groove 37b. The injection groove 37a and the suction groove 37b are formed at positions facing the injection groove 33a and the suction groove 33b, respectively.
The mold seal groove 37 of this example has a depth of about 8 mm and a width of about 6 mm, and the cross-sectional shape is substantially the same as the cross-sectional shape of the fitting portion 36a. The injection groove 37a and the suction groove 37b have a width of about 10 mm and have a substantially semicircular cross section.

  The width of the mold seal groove 37 is set to be narrower than the width of the annular groove 33, thereby forming a shoulder portion 36c of the mold seal member 36 in the process of forming the mold seal member 36 described later. Yes.

  In the mold seal contact portion 31c and the mold seal portion 32c of this example, the dimensions of the mold seal member 36 and the mold seal groove 37 are not limited to the above dimensions, and are appropriately determined according to the size of the mold. It is good to set. For example, the depth of the mold seal groove 37 and the height of the mold seal member 36 may be set in a range of about 5 mm to 50 mm.

  When set in such a range, as will be described later, an area where the mold seal member 36 and the mold seal groove 37 are in close contact with each other is ensured, and the space between the fixed side mold 31 and the movable side mold 32 is ensured. Can be sealed.

  In addition, although the example in which the width of the mold seal groove 37 is set narrower than the width of the annular groove 33 is shown, the width of the mold seal groove 37 and the annular groove 33 may be set to be substantially the same.

  In this example, the mold seal part is formed on the movable mold 32 and the mold seal contact part 31c is formed on the fixed mold 31. However, the present invention is not limited to this. It may be formed on the mold 31 and the mold seal contact part 31 c may be formed on the movable side mold 32.

Next, a method for forming the mold seal contact portion 31c and the mold seal portion 32c will be described.
First, as shown in FIG. 5A, the contact surface 32b of the movable mold 32 is cut to form an annular groove 33 so as to surround the product forming surface 32a. An injection groove 33 a and a suction groove 33 b are formed so as to communicate with the side portion of the mold 32.

As for the fixed side mold 31, as shown in FIG. 5B, the contact surface 31b is cut to form a mold seal groove 37, an injection groove 37a, and a suction groove 37b. The mold seal groove 37 is formed in an annular shape so as to face the annular groove 33 when the mold is clamped. The injection groove 37 a and the suction groove 37 b are formed so as to communicate from the mold seal groove 37 to the side portion of the fixed mold 31.
In addition, since the movable mold 32 and the fixed mold 31 of this example are made of an aluminum alloy, the machinability is good and the grooves can be easily formed.

  A mold release agent is applied in and around the mold seal groove 37 formed in the fixed side mold 31. In this example, KF412SP (Shin-Etsu Silicone Paintable Silicone Release Agent) was used as the release agent.

  Then, as shown in FIG. 5C, the fixed side mold 31 and the movable side mold 32 are clamped with a predetermined clamping pressure. When the mold is clamped, the injection groove 33a and the injection groove 37a, and the suction groove 33b and the suction groove 37b form an injection hole 30c and a suction hole 30d having a substantially circular cross section, respectively. The annular groove 33 and the mold seal groove 37 form an annular space 30b that communicates with the injection hole 30c and the suction hole 30d.

Prior to mold clamping, liquid silicone rubber is defoamed with sufficient time.
In this example, KE-1314 (silicone RTV rubber for mold making manufactured by Shin-Etsu Silicone), which is a two-part silicone rubber, was used as the silicone rubber. As a curing agent, 10.0% of CAT-1314S (Shin-Etsu Silicone Co., Ltd. curing agent) was added. As for the characteristics after curing of the silicone rubber KE-1314, the hardness (durometer A) is about 44 degrees, the tensile strength is 5.8 (MPa), and the operating temperature range is −60 ° C. to 250 ° C.

Further, before clamping, the shorter part of the annular groove 33 sandwiched between the injection groove 33a and the suction groove 33b and the shorter part of the mold seal groove 37 sandwiched between the injection groove 37a and the suction groove 37b. In this part, liquid silicon rubber that has been subjected to detreatment is placed in advance. In this way, in the silicon rubber injection step described below, the liquid silicon rubber injected from the injection hole 30c is allowed to pass through a long portion sandwiched between the injection groove 37a and the suction groove 37b in the annular space 30b. , Can be led to the suction hole 30d.
However, it is not always necessary to deposit silicon rubber in the shorter part of the mold seal groove 37 sandwiched between the injection groove 37a and the suction groove 37b.

With the mold clamped, as shown in FIG. 5C, an injection hose for pressure-injecting liquid silicon rubber is connected to the injection hole 30c, and a suction hose connected to a vacuum pump is connected to the suction hole 30d. Link.
Then, liquid silicon rubber is injected into the annular space 30b through the injection hose while sucking out the air in the annular space 30b with a vacuum pump through the suction hose. Thereby, the defoamed liquid silicon rubber is pumped from the injection hole 30c through the annular space 30b toward the suction hole 30d.

  When the silicon rubber overflows from the suction hole 30d, the pressure feeding by the injection hose and the suction by the suction hose are stopped. In this way, the annular space 30b, the injection hole 30c, and the suction hole 30d can be filled with liquid silicon rubber. Then, the silicone rubber is cured and the mold is opened.

  When the mold is opened, the cured silicon rubber is peeled off from the fixed mold 31 to which the release agent is applied, and is adhered to the movable mold 32. Thereby, the mold seal member 36 can be formed in a state where it is adhered to the movable mold 32.

  The mold seal member 36 includes an insertion portion 36a and a base portion 36b. The fitting portion 36 a is formed by the mold seal groove 37 and has substantially the same shape as the mold seal groove 37. The base portion 36 b is formed by the annular groove 33 and has substantially the same shape as the annular groove 33. The base portion 36b exposes a shoulder portion 36c between the lower end portion of the fitting portion 36a and the upper end portion of the annular groove 33 to the outside.

  In this example, the injection groove and the suction groove are formed in the fixed mold 31 and the movable mold 32, respectively. However, the injection groove and the suction groove are provided on either the fixed mold 31 or the movable mold 32. You may make it form in. Even in this case, it is possible to form the injection hole and the suction hole communicating with the annular space 30b when the mold is clamped.

  The mold seal part 32c and the mold seal contact part 31c can be formed by the simple operation as described above. The formed insertion portion 36a of the mold seal member 36 is obtained by transferring the surface shape of the mold seal groove 37. When the mold is clamped, the mold seal groove 37 is formed on the entire inner surface. In contact with the fitting portion 36a.

The shoulder portion 36c is a transfer of the surface shape of the contact surface 31b. When the mold is clamped, the shoulder portion 36c comes into surface contact with the contact surface 31b.

  Therefore, when the mold is clamped, the fitting portion 36a and the shoulder portion 36c are brought into close contact with the mold seal groove 37 and the contact surface 31b, respectively, and the parting surface can be sealed. Thereby, the contact area can be increased in the mold seal part 32c and the mold seal contact part 31c of this example.

  Further, when the cavity 30a is exhausted as will be described later in a state where the fitting portion 36a and the mold seal groove 37 are in close contact with each other, elasticity (hardness (durometer A) is about 44 degrees due to a pressure difference between the outside and the cavity 30a. The mold seal member 36 made of silicon rubber having the above is sucked into the cavity 30a. Thereby, the mold seal member 36 and the mold seal groove 37 can be further in surface contact with each other to improve the sealing performance.

  In this example, since the mold seal member 36 is made of silicon rubber, the adhesion with the metal is good. Moreover, since silicon rubber is excellent in durability, the sealing performance does not deteriorate even when used for a long time.

  In addition, in a mold with a structure that secures the seal between the cavity and the outside by installing an O-ring, the O-ring may be crushed or the elasticity of the O-ring may be reduced during repeated molding. As a result, the sealing performance may be reduced, and the sealed state may not be maintained. For this reason, it takes time and labor to periodically inspect the O-ring and the like.

  However, in the mold 30 of this example, the fitting portion 36a of the mold seal member 36 is fitted into the mold seal groove 37 and brought into surface contact. Further, by evacuating the cavity 30a, the mold seal member 36 is sucked against the inner wall of the mold seal groove 37 by an atmospheric pressure difference, and is hermetically adhered to ensure sealing performance.

  Thus, even when the mold is clamped and the sealing performance is ensured, the mold seal member 36 does not receive a large deformation force. Therefore, the mold seal member 36 can reliably ensure the sealing performance by surface contact, and even if the molding is repeated, there is no inconvenience that the mold seal member 36 is crushed or its elasticity is reduced. Can be reduced.

  Further, in the mold 30 of this example, since the cavity 30a and the outside are sealed by surface contact between the mold seal member 36 and the mold seal groove 37, it is related to the size of the mold 30. Even if the mold 30 is enlarged, it is easy to ensure the sealing performance.

(Sliding part seal structure)
Next, the sliding seal portion 60 for securing the sealing performance in the sliding hole 61 will be described with reference to FIGS. The movable side mold 32 is formed with a sliding hole 61 as a through hole so as to communicate the cavity 30a with the outside (back plate 34) side. This ejector pin 36A is slidable in a reciprocating manner.

  As shown in FIG. 6, the sliding seal portion 60 is formed on the back plate 34 side of the movable mold 32. The sliding seal portion 60 is disposed in the expansion space portion 62 and the expansion space portion 62 formed from the outer end portion of the sliding hole 61 to a predetermined depth so as to expand the cross section of the sliding hole 61. The sliding seal member 63 and the paste-like grease 64 are provided.

  The sliding seal member 63 is made of silicon rubber in an annular shape, and a through hole 63b for allowing the ejector pin 36A to penetrate is formed in the main body 63a. The sliding seal member 63 is formed from the bottom of the expansion space 62 to the vicinity of the opening on the back plate 34 side. The outer peripheral surface of the main body 63 a is bonded and fixed to the inner peripheral surface of the expansion space 62.

  In the sliding seal portion 60 of this example, the outer peripheral surface of the ejector pin 36A is slidable with the inner peripheral surface 63ba of the through hole 63b, and is slidable with respect to the sliding seal member 63. In a state where the inner peripheral surface 63ba is in surface contact with the outer peripheral surface of the ejector pin 36A, the sealing performance between the cavity 30a side and the outside can be secured.

  Further, in the sliding seal portion 60 of this example, paste-like grease 64 is applied between the sliding seal member 63 and the back plate 34. For the grease 64 of this example, KS-61 (Shin-Etsu Silicone's lubricant release agent) is used.

  In the sliding seal portion 60 of this example, the grease 64 can smooth the sliding between the ejector pin 36 </ b> A and the sliding seal member 63, and the adhesion between the ejector pin 36 </ b> A and the sliding seal member 63. To improve the sealing performance.

Based on FIG. 7, the formation method of the sliding seal | sticker part 60 is demonstrated.
FIG. 7A shows a state where the sliding hole 61 is formed in the movable mold 32. Then, as shown in FIG. 7 (B), the sliding hole 61 is processed with a reamer or the like, and the diameter of the sliding hole 61 is expanded from the end on the outer side (back plate 34 side) to a predetermined depth. An expansion space 62 is formed.

  In this example, the diameter of the sliding hole 61 is about 10 mm, the diameter of the expansion space 62 is set to about 20 mm, and the depth is set to about 30 mm. In addition, according to the diameter of the sliding hole 61, it is good to set the depth of the expansion space part 62 in the range of about 10-50 mm suitably.

  In this example, the expansion space 62 is formed in a circular cross section. However, the present invention is not limited to this, and if the periphery of the sliding hole 61 is cut and the diameter of the sliding hole 61 is increased, It is not limited to a circular cross section.

After the expansion space 62 is formed, a release agent is applied to the outer peripheral surface of the ejector pin 36A, and the ejector pin 36A is inserted into the sliding hole 61 as shown in FIG.
In a state where the ejector pin 36A is inserted, the liquid silicon rubber 2 is injected into the expansion space 62 from the outside. At this time, the silicon rubber 2 is injected up to about 2/3 of the expansion space 62 (about 20 mm from the bottom).

  For the silicon rubber 2 of this example, the above-mentioned KE-1314 was used. Moreover, not limited to this, KE45 (manufactured by Shin-Etsu Silicone), which is a one-component RTV rubber, may be used. The KE45 is in a paste form before being cured, and the injection work into the expansion space 62 is easy.

  After the injection, the sliding seal member 63 can be formed by curing the silicon rubber 2. Furthermore, grease 64 is injected into the upper portion of the sliding seal member 63 so as not to overflow from the expansion space 62 by a thickness of about 10 mm.

  The through hole 63b of the sliding seal member 63 formed in this way has an inner diameter that is substantially the same as the diameter of the ejector pin 36A that slides relative to the sliding hole 61.

  Therefore, the sliding seal member 63 is always in surface contact with the ejector pin 36A and can maintain the sealing performance. Furthermore, the grease 64 improves the slipperiness and adhesion between the sliding seal member 63 and the ejector pin 36A, so that it can be reliably sealed.

Further, since the sliding seal member 63 of this example does not have a structure that deforms and elastically contacts like an O-ring, it does not collapse or wear like an O-ring.
Further, since the sliding seal member 63 is made of silicon rubber, the durability and wear resistance are good, and the ejector pin 36A can be smoothly slid while being in close contact with the ejector pin 36A.

  In this example, the example in which the ejector pin 36A is used as the sliding member has been described. However, the present invention is not limited to this, and the sliding member may be a shaft or the like connected to the slide core. In this case, the shaft is further connected to an external driving means, and the driving means is operated to drive the shaft, whereby the slide core is moved forward and backward with respect to the mold 30.

(Cavity evacuation structure)
Next, the mold vacuum valve 40 of this example will be described with reference to FIG.
FIG. 8 is an explanatory sectional view of the mold vacuum valve 40 as viewed from the nozzle 13 side.

  The mold vacuum valve 40 of this example includes a main body portion 40a, a valve body 47 that slides within the main body portion 40a, a coil spring 48 as an urging means for urging the valve body 47, and a main body portion 40a. Are connected to the end portions of the operating hose 43a and the exhaust hose 44a. The connecting portion 42 communicates with the operation hose 43a and the exhaust hose 44a, and a pipe 59 is connected to the outside.

  A sprue 41 is formed in the main body portion 40a so as to penetrate the main body portion 40a. A bottomed actuation hole 43 is formed in a direction substantially orthogonal to the sprue 41 from the side surface of the main body 40a. The operating hole 43 communicates with the sprue 41 through an exhaust hole 41 a formed on the side surface of the sprue 41. An operation hose 43 a is connected to the operation hole 43.

  Further, a bottomed exhaust hole 44 is formed in the main body portion 40 a in parallel with the operation hole 43, and the exhaust hole 44 and the operation hole 43 communicate with each other through a communication hole 45. . The communication hole 45 is formed on the side close to the sprue 41 (that is, the side close to the bottom). An exhaust hose 44 a is connected to the exhaust hole 44. The exhaust hole 44 is formed to have a smaller diameter than the operation hole 43.

  The valve body 47 is disposed in the operating hole 43, and includes a disc portion 47b, a cylindrical cap portion 47a formed so as to penetrate the disc portion 47b, and a cap portion 47a from the rear side of the cap portion 47a. The sliding portion 47c is formed so as to extend in the length direction.

  The cap part 47a is a member for closing the exhaust hole 41a. The operation hole 43 has a tapered shape at a portion communicating with the exhaust hole 41a, and the tip portion 47aa of the cap portion 47a is also tapered in accordance with the taper portion 43c. The cap portion 47a is urged toward the exhaust hole 41a, and the tapered tip portion 47aa enters the tapered portion 43c on the exhaust hole 41a side, so that the operation hole 43 can be airtightly closed.

  The operation hole 43 is formed in a circular cross section on the sprue 41 side, and is further provided with grooves 43b at two locations so as to expand the operation hole 43 along a direction orthogonal to the sprue 41. The disk portion 47b is a circular member having an outer diameter substantially the same as the inner diameter of the actuation hole 43, and is substantially the same shape as the two grooves 43b formed in the actuation hole 43. The engaging piece 47ba to be engaged is formed to extend in the radial direction.

The disc portion 47b is disposed so as to be movable back and forth in the length direction of the actuation hole 43 in a state where the engagement piece 47ba is engaged with the groove 43b.
A support portion 46 that slidably holds the sliding portion 47 c is fixed to the operating hole 43 so as to close the operating hole 43. The support portion 46 is formed with a plurality of through holes 46a that penetrate in the sliding direction and allow air movement.

  A coil spring 48 is disposed between the rear surface of the disk portion 47 b and the support portion 46. The coil spring 48 is inserted into the cap portion 47 a from the rear side of the valve body 47. The coil spring 48 urges the valve body 47 toward the sprue 41 side.

  When the valve body 47 is urged by the coil spring 48 and the tip of the cap portion 47a closes the exhaust hole 41a (closed position), the communication hole 45 is closed by the side surface of the disk portion 47b. It has become.

Next, the operation of the mold vacuum valve 40 will be described.
As shown in FIG. 8A, when the solenoid valve 59b is closed and the mold vacuum valve 40 is not in communication with the vacuum exhaust means, the valve spring 47 is biased toward the sprue 41 by the coil spring 48. Thus, the exhaust hole 41a is closed by the tip of the cap portion 47a (closed position).

  On the other hand, when an open signal is sent from the control means to the electromagnetic valve 59b, the electromagnetic valve 59b is opened, and the mold vacuum valve 40 communicates with the vacuum exhaust means. Thereby, as shown in FIG. 8B, the air in the operation hole 43 and the exhaust hole 44 is exhausted by the vacuum exhaust means.

  At this time, since the operating hole 43 has a larger diameter than the exhaust hole 44, a large suction force acts on the disk portion 47b, and the valve body 47 moves away from the sprue 41 against the biasing force. Slide. The valve body 47 is held at a position (exhaust position) away from the sprue 41 while the air in the cavity 30a is being exhausted.

When the valve body 47 is held at the exhaust position, the exhaust hole 41 a is opened, the communication hole 45 is also opened, and the sprue 41 and the exhaust hole 44 are in communication with each other via the communication hole 45.
When the sprue 41 communicates with the exhaust hole 44, the cavity 30a communicates with the vacuum exhaust means via the mold vacuum valve 40, and the cavity 30a is exhausted to a vacuum state by the vacuum exhaust means.

The control means sends a close signal to the electromagnetic valve 59b after a predetermined time when the cavity 30a is in a vacuum state to make it close. When the pressure in the cavity 30a and the pipe 59 becomes substantially the same, or when the electromagnetic valve 59b is closed, the valve body 47 is forced by the urging force of the coil spring 48 when the air flow from the cavity 30a disappears. Returning to the closing position, the cap 47a closes the exhaust hole 41a.
As described above, the mold vacuum valve 40 of the present example can exhaust the cavity 30a through the sprue 41 by opening and closing the electromagnetic valve 59b.
The mold vacuum valve 40 of the present example is easy to mount because the recess 31e is formed in the stationary mold 31 and is positioned and fixed. Further, the mold vacuum valve 40 of this example can be easily controlled because the flow path can be switched only by connecting the pipe 59 and reducing the pressure in the pipe 59.

  In the above embodiment, the case where the mold 30 is a two-plate type is shown, but a three-plate type may be used.

Next, the mold vacuum valve 50 of this example is demonstrated based on FIG. 9, FIG.
FIG. 9 is a cross-sectional explanatory view of the mold vacuum valve 50 as viewed from the side of the mold 30.
As shown in FIG. 2, the mold vacuum valve 50 of this example includes a recess 32e formed from the end of the product forming surface 32a of the movable side mold 32 to the contact surface 32b, and the recess 32e and the movable side mold. 32 is provided in a recess 32 f that communicates between the side portions of 32.

  The mold vacuum valve 50 of this example includes a main body 50a, a valve body 57 that slides within the main body 50a, a coil spring 58 as a biasing means for biasing the valve body 57, and a main body 50a. And an operation hose 53a and an exhaust hose 54a connected to each other, and a connection portion 52 connected to the ends of the operation hose 53a and the exhaust hose 54a. The connecting portion 52 is connected to the pipe 59 and communicates with the operation hose 53a and the exhaust hose 54a.

  The main body 50a is fixed in the recess 32e so that the side surface 50c on the fixed mold 31 side is flush with the contact surface 32b. The operating hose 53a and the exhaust hose 54a are connected to the main body 50a through the recess 32f.

The main body 50 a is formed with an operation hole 53 to which the operation hose 53 a is connected, and an exhaust hole 54 having a smaller diameter than the operation hole 53 in parallel with the operation hole 53.
As shown in FIG. 10, the side surface 50c of the main body 50a is formed with a recess 50b in which the end on the product forming surface 32a side is partially cut away, and the operation hole 53 communicates with the recess 50b. ing.
Further, the recess 50 b and the exhaust hole 54 communicate with each other through a communication hole 55.

  The valve body 57 is disposed in the recess 50b. The closing member 57a slides in the recess 50b in a direction orthogonal to the clamping direction, and the end is attached to the closing member 57a and extends in the sliding direction. And a sliding portion 57c.

  The closing member 57a is slidable with the side surface 57aa on the cavity 30a side being flush with the contact surface 32b and the side surface 50c. The thickness of the side surface 57aa in the sliding direction is set larger than the width of the end 30e of the cavity 30a (the thickness of the end of the molded product). In FIG. 10, a curve Y substantially parallel to the curve X at the end of the product forming surface 32a is a curve at the end of the product forming surface 31a of the fixed mold 31 when the mold is clamped. That is, the end of the cavity 30a is between the curve X and the curve Y.

  As shown in FIGS. 9A and 10, when the closing member 57a is urged and is in contact with the side surface of the recess 32e on the product forming surface 32a side, the recess 57e is recessed from the end 30e of the cavity 30a by the side surface 57aa. The opening 30f communicating with 50b can be closed.

  A support portion 56 that slidably holds the sliding portion 57 c is fixed to the operating hole 53 so as to close the operating hole 53. The support portion 56 is formed with a plurality of through holes 56a that penetrate in the sliding direction and allow air movement.

  A coil spring 58 is disposed between the rear surface of the closing member 57 a and the support portion 56. The coil spring 58 is inserted into the sliding portion 57 c from the rear side of the valve body 57. The coil spring 58 biases the valve body 57 toward the center side of the movable mold 32.

  When the valve body 57 is urged by the coil spring 58 and the side surface 57aa of the closing member 57a closes the opening 30f of the end 30e of the cavity 30a (closed position), it opposes the side surface 57aa of the closing member 57a. The communication hole 55 is blocked by the side surface 57ab.

Next, the operation of the mold vacuum valve 50 will be described.
As shown in FIG. 9A, when the electromagnetic valve 59b is closed and the mold vacuum valve 50 is not in communication with the evacuation means, the valve spring 57 is moved to the movable side mold 32 by the coil spring 58. It is biased toward the center, and the opening 30f is closed by the side surface 57aa of the closing member 57a (closed position).

  On the other hand, when an open signal is sent from the control means to the electromagnetic valve 59b, the electromagnetic valve 59b is opened, and the mold vacuum valve 50 communicates with the vacuum exhaust means. Thereby, as shown in FIG. 9B, the air in the operation hole 53 and the exhaust hole 54 is exhausted by the vacuum exhaust means.

  At this time, since the operating hole 53 has a larger diameter than the exhaust hole 54, a large suction force acts on the closing member 57a, and the valve body 57 resists the urging force of the movable mold 32. Slide to the side. The valve body 57 is held at a position (exhaust position) moved to the side surface side of the movable mold 32 while the air in the cavity 30a is being exhausted.

  When the valve body 57 is held at the exhaust position, the opening 30f opens and the communication hole 55 also opens. In addition, a flow path is formed between the closing member 57a and the side surface of the recess 32e. The cavity 30 a is in communication with the exhaust hole 54 through the flow path and the communication hole 55.

  As a result, the cavity 30a communicates with the vacuum evacuation means via the mold vacuum valve 50, and the cavity 30a is evacuated to a vacuum state by the vacuum evacuation means.

The control means sends a close signal to the electromagnetic valve 59b after a predetermined time when the cavity 30a is in a vacuum state to make it close. When the electromagnetic valve 59b is closed or the air flow from the cavity 30a is lost, the valve body 57 returns to the closed position by the urging force of the coil spring 58 and closes the opening 30f by the closing member 57a.
As described above, the mold vacuum valve 50 of this example can exhaust the cavity 30a by opening and closing the electromagnetic valve 59b.
The mold vacuum valve 50 of the present example is easy to mount because the recesses 32e and 32f are formed in the movable mold 32 and only fixed in the recesses 32e and 32f. In addition, the mold vacuum valve 50 of this example can be easily controlled because the flow path can be switched only by connecting the pipe 59 and reducing the pressure in the pipe 59.

  As described above, in the injection molding apparatus of this example, the cavity 30a is in a vacuum state at the time of injection. At this time, the mold 30 of this example has a seal structure, so that the vacuum state is suitably maintained. Is possible. By making the cavity 30a in a vacuum state, there is almost no air resistance during molding, and the molten resin can be spread quickly and uniformly to every corner of the cavity 30a with a small injection pressure.

Therefore, uneven color, cracks, sink marks, burns, weld lines, shorts, etc. do not occur in the molded product. For example, even if the molded product is a long deep object such as a reinforcing rib or a fine mesh (lattice), insufficient filling does not occur.
Moreover, in the injection molding apparatus of this example, since the molten resin is filled quickly and uniformly as described above, a molded product with extremely small internal stress can be molded.

Moreover, in the injection molding apparatus of this example, since the inside of the cavity 30a is in a vacuum state at the time of injection, the injection pressure of the molten resin into the mold 30 can be reduced as compared with the conventional case. As a result, the mold clamping pressure can be reduced, so that the mold clamping means 80 can be changed to a small output.
As described above, in the injection molding apparatus of this example, the injection pressure and the mold clamping pressure can be reduced, so that energy saving and cost reduction are possible as compared with the conventional injection molding apparatus.

  Further, in the injection molding apparatus of this example, the molten resin can be surely spread in the mold 30, so that the cavity of the mold 30 can be faithfully and reliably transferred at the mold design stage. Thus, there is no deviation between the molded product planned in step 1 and the molded product actually formed by the mold 30. Since no deviation occurs in this way, the mold design is facilitated, and the mold manufacturing time can be shortened.

  Further, as described above, in the injection molding apparatus of this example, the mold clamping pressure can be set small, so that a hydraulic apparatus that enables a large mold clamping pressure as in the prior art, and a large-sized mold having durability. Therefore, the apparatus can be downsized. This makes it possible to manufacture the device at a low cost. Further, as the injection molding apparatus is reduced in size and weight, the tonnage of the total grain of the factory equipment to be deployed is preferably small.

Further, in the conventional injection molding apparatus, the size of the molded product is adjusted in units of 1 mm. However, in the injection molding apparatus of this example, the molten resin can be surely distributed to the cavity in the mold 30. Therefore, fine adjustment in units of 0.1 mm is possible.
Therefore, even when thin-wall processing is performed or when the shape of the mold 30 is complicated, it can be molded well, so that a desired molded product can be molded without being limited to the shape and thickness. It becomes possible to do.

For example, in the past, a molded product with a thickness of 1 mm was the limit, but with the injection molding apparatus of this example, it is possible to create a molded product with a thickness of 0.1 mm, which is about 1/10 of the conventional one. . In addition, the size of the molded product itself can be reduced to about 1/10 compared to the conventional size.
According to the injection molding apparatus of this example, since the molded product can be made thinner than before, the amount of injected resin can be reduced, the injection time and the cooling time can be shortened, and the molding cycle can be shortened. It becomes possible. Thereby, energy saving can be achieved and productivity can be improved. For example, in the injection molding apparatus of this example, the molding cycle time can be shortened to 1/2 to 1/3.

  Moreover, in the injection molding apparatus of this example, a molded product having the same thickness as that of a conventional injection molding machine can be molded for a thick molded product.

(Parting surface seal structure: other examples)
Next, another embodiment of the sealing structure for sealing the parting surface will be described with reference to FIGS. The same components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 11A shows the contact surface 32 b of the movable mold 32. The mold seal portion 132c of this modified example is formed along the outer periphery of the contact surface 32b so as to surround the product formation surface 32a. FIG. 11B shows the contact surface 31 b of the fixed mold 31. The mold seal contact portion 131c is formed along the outer periphery of the contact surface 31b, like the mold seal portion 32c.

  As shown in FIG. 12, the mold seal portion 132c includes an injection groove 133 as a first groove formed so as to surround the cavity 30a, a partition wall 134 that forms the inner and outer sides of the injection groove, and a partition wall. An escape groove 135 as a second groove formed adjacent to the injection groove 133 via 134 and an elastic silicon rubber disposed so as to protrude from the injection groove 133 toward the fixed mold 31 side. A mold seal member 136 is provided. Further, at the bottom of the injection groove 133, a retaining groove 133a for holding the mold seal member 136 so as not to come out is formed.

Further, a mold seal groove 137 is formed at a position facing the mold seal member 136 in the mold seal abutting portion 131c of this modification.
The injection groove 133, the escape groove 135, and the mold seal groove 137 are formed by cutting the mold surface.

  In the mold seal portion 132c of this modification, the escape groove 135 is formed with a depth of about 22 mm and a width of about 4 mm, the partition wall 134 is formed with a height of about 18 mm, a width of 2 mm, and the injection groove 133 with a width of about 15 mm. Thereby, when the mold is clamped, a gap 134a of about 4 mm is formed between the partition wall 134 and the contact surface 31b.

The mold seal member 136 is formed so as to protrude about 15 mm from the contact surface 32 b toward the fixed mold 31. The tip portion of the mold seal member 136 is formed in a semicircular cross section.
The mold seal groove 137 of the mold seal contact portion 131c has a depth of about 15 mm and a width of about 15 mm, and the bottom surface is formed in a semicircular cross section having substantially the same shape as the tip portion of the mold seal member 136. ing. The width is set to be the same as the width of the injection groove 133.

  In addition, in the mold seal contact part 131c and the mold seal part 132c of this modification, the width of the injection groove 133 and the mold seal groove 137 is set to about 15 mm. It is good to set to the range of about 10 mm-50 mm according to a magnitude | size. When set in such a range, as will be described later, an area where the mold seal member 136 and the mold seal groove 137 are in close contact with each other is secured, and the space between the fixed side mold 31 and the movable side mold 32 is ensured. Can be sealed.

Next, a method for forming the mold seal member 136 will be described with reference to FIG.
First, as shown in FIG. 13A, an injection groove 133, a partition wall 134, a relief groove 135, and a mold seal groove 137 having the above dimensions are formed in the fixed mold 31 and the movable mold 32 by cutting. Form. At this time, the injection groove 133 and the mold seal groove 137 are formed at opposing positions.

  After the contact surfaces 31b and 32b are processed in this way, liquid silicon rubber 2 is injected into the injection groove 133 as shown in FIG. At this time, the silicon rubber 2 is poured so as to rise from the tip of the partition wall 134 toward the fixed mold 31 side. In the case of this modification, specifically, it is in a state of being raised by about 15 mm to 20 mm from the contact surface 32b.

  In this modification, KE45 (manufactured by Shin-Etsu Silicone), which is a one-component RTV rubber, was used as the silicone rubber.

  Then, a mold release agent is applied to the mold seal groove 137 so that the mold seal groove 137 can be easily separated from the cured silicon rubber 2. After the mold release agent is applied and before the silicon rubber 2 is cured, the movable side mold 32 and the fixed side mold 31 are clamped as shown in FIG. 13C, and the silicon rubber 2 is cured in this state. Let At this time, the silicon rubber 2 comes into contact with the bottom and side surfaces of the mold seal groove 137, and the silicon rubber 2 that does not fit into the mold seal groove 137 passes through the gap between the contact surface 31 b and the tip of the partition wall 134. It is pushed out into the escape groove 135.

  When the escape groove 135 is not formed on the side of the injection groove 133, the silicon rubber 2 enters between the contact surfaces 31 b and 32 b, and between the fixed side mold 31 and the movable side mold 32. There is a possibility that the sealing performance of the material cannot be secured.

  However, in the modified mold 30, the excess silicon rubber 2 is pushed out into the escape groove 135 formed in parallel with the side of the injection groove 133, so that the silicon rubber 2 is formed on the contact surfaces 31 b and 32 b. It is possible to prevent the penetration and secure the sealing property between the fixed side mold 31 and the movable side mold 32.

  After the silicon rubber 2 is cured, the mold is opened. Then, as shown in FIG. 13D, the mold seal member 136 is formed by removing the excess silicon rubber 2a which has been pushed into the escape groove 135 and hardened while the mold is open.

  The poured silicon rubber 2 is bonded to the side wall and the bottom surface of the injection groove 133 at the base of the mold seal member 136. In this modification, the excess silicon rubber 2a is removed, but it is not always necessary to remove it.

  Thus, the mold seal member 136 can be formed by a simple operation. The contact portion of the formed mold seal member 136 has a tip portion which is a transfer of the surface shape of the mold seal groove 137. When the mold is clamped, the mold seal groove 137 is formed on the entire inner surface. It abuts on the seal member 136. As described above, the tip portion of the mold seal member 136 and the mold seal groove 137 have substantially the same shape and are easily in close contact with each other and have a large contact area. Furthermore, silicon rubber has good adhesion to metal. Moreover, since silicon rubber is excellent in durability, the sealing performance does not deteriorate even when used for a long time.

For this reason, the fixed mold 31 and the movable mold 32 can ensure the sealing property between the cavity 30 a and the outside by the surface contact between the mold seal member 136 and the mold seal groove 137.
Further, since the mold seal member 136 is fitted into the mold seal groove 137 during mold clamping, the sealing performance can be further improved.

Moreover, in the said embodiment, although the metal mold | die seal | groove groove | channel 137 was substantially semicircular in cross section, not only this but planar shape as shown to FIG. 14 (A), FIG.14 (B), (C) As shown in FIG.
When it is planar as shown in FIG. 14A, the tip portion of the mold seal member 136 is also planar. When the cross section is rectangular as shown in FIGS. 14B and 14C, the tip portion of the mold seal member 136 is also rectangular. However, in any case, when the mold is clamped, the tip portion of the mold seal member 136 is in surface contact with the surface of the fixed mold 31, so that a good sealing property can be ensured.

  In FIG. 14B, the width of the mold seal groove 137 is set to be the same as the width of the injection groove 133, but in the example of FIG. 14C, the width of the mold seal groove 137 is The distance between the outer surfaces of the two escape grooves 135 is set to be the same. In the case of FIG. 14C, the height of the partition wall 134 may be the same as that of the contact surface 32b. That is, when the mold seal member 136 is formed, a gap is formed between the upper end of the partition wall 134 and the bottom surface of the mold seal groove 137 when the mold is clamped. It becomes possible to push into the groove 135.

In the above embodiment, the escape grooves 135 are provided on both sides of the injection groove 133. However, the present invention is not limited to this, and the escape grooves 135 may be provided only on one side of the injection groove 133 as shown in FIG.
FIG. 15A shows an example in which the mold seal groove 137 has the same width as the injection groove 133 and a substantially semicircular cross section, and the escape groove 135 is formed only on one side of the injection groove 133.
FIG. 15B shows an example in which the mold seal groove 137 has the same width as the injection groove 133 and has a rectangular cross section, and the escape groove 135 is formed only on one side of the injection groove 133.

15C, the escape groove 135 is formed only on one side of the injection groove 133, and the width of the mold seal groove 137 is the same as the distance from the outer surface of the injection groove 133 to the outer surface of the escape groove 135. This is an example in which the mold seal groove 137 has a rectangular cross section.
As described above, even if the escape groove 135 is provided only on one side of the injection groove 133, when the mold seal member 136 is formed, the silicon rubber can be pushed out into the escape groove 135 when the mold is clamped. A good contact surface between the member 136 and the mold seal groove 137 can be formed.

It is explanatory drawing of the metal mold | die which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die which concerns on one Embodiment of this invention. It is a section explanatory view of the metallic mold seal member concerning one embodiment of the present invention. It is explanatory drawing which shows the formation method of the metal mold | die sealing member which concerns on one Embodiment of this invention. It is a section explanatory view of the sliding seal part concerning one embodiment of the present invention. It is explanatory drawing which shows the formation method of the sliding seal member which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die vacuum valve which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die vacuum valve which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die vacuum valve which concerns on one Embodiment of this invention. It is explanatory drawing of the metal mold | die which concerns on other embodiment of this invention. It is a section explanatory view of a metallic mold seal member concerning other embodiments of the present invention. It is explanatory drawing which shows the formation method of the metal mold | die seal member which concerns on other embodiment of this invention. It is a section explanatory view of a metallic mold seal part concerning other embodiments of the present invention. It is a section explanatory view of a metallic mold seal part concerning other embodiments of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molded product 2 Silicon rubber 11 Cylinder 12 Screw 30 Mold 30a Cavity 30b Annular space 30e End 30f Opening 31 Fixed side mold 31a Product formation surface 31b Contact surface 31c, 131c Mold seal contact part 31d Gate 31e Recess 32 Movable mold 32a Product forming surface 32b Abutting surfaces 32c, 132c Mold seal portions 32e, 32f Recess 33 Annular groove 33a Injection groove 33b Suction groove 36A Ejector pins 36, 136 Mold seal members 37, 137 Mold seal groove 40 , 50 Mold vacuum valve 41 Sprue 59b Solenoid valve 60 Sliding seal 80 Mold clamping means

Claims (7)

A mold comprising a fixed side mold and a movable side mold, and an ejector pin protruding from the movable side mold,
The movable mold is provided with a sliding hole in which the ejector pin is disposed so as to be movable back and forth.
A part of the sliding hole is provided with an expansion space that expands the hole radially outward,
A mold characterized in that a seal member made of silicon rubber is formed in the expansion space.   The mold according to claim 1, wherein a lubricant is disposed in the expansion space.   2. The mold according to claim 1, wherein the expansion space part is provided on a back plate side that supports the fixed mold or the movable mold from the back.   The mold according to claim 1, wherein the seal member is in surface contact with an outer peripheral surface of the ejector pin. A mold manufacturing method comprising a fixed side mold and a movable side mold, and an ejector pin disposed in a sliding hole provided in the movable side mold so as to freely advance and retract,
Forming a part of the sliding hole in an expanded space part in which the hole is expanded radially outward;
Positioning the ejector pin in the sliding hole;
Injecting liquid silicone rubber into the expansion space,
And a step of curing the silicon rubber.   6. The method for manufacturing a mold according to claim 5, further comprising a step of applying a release agent to the ejector pin before the step of positioning the ejector pin in the sliding hole.   6. The method of manufacturing a mold according to claim 5, further comprising a step of injecting a lubricant into the expansion space after the step of curing the silicon rubber.

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