JP2911340B2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold for molding a molded product having an undercut portion.

[0002]

2. Description of the Related Art A cooling water circuit is provided inside an injection mold for temperature control. Cooling water may flow through the core as well as the mold body. The example is shown in
It can be seen in JP-A-187022 and JP-A-63-6154.

[0003]

The molded product ejection pin is normally slid parallel to the mold opening / closing direction, but may be slid obliquely to the mold opening / closing direction in some cases, and an undercut portion is formed on the molded product. Sometimes used to form. If the undercut portion is large, it will have a block shape instead of a pin shape. The present invention seeks to pass cooling water through such a protruding block.

[0004]

SUMMARY OF THE INVENTION A cooling water passage is formed in a protruding block, and the cooling water passage is connected to a relay conduit provided in an ejector plate through a water conduit at least partially formed of an elastic portion. Connected.

A slide block that slides at right angles to the mold opening / closing direction in synchronization with the protrusion block is disposed on the ejector plate, and the cooling water of the protrusion block is connected to a relay conduit provided on the slide block via a water guide pipe. The passage was connected.

[0006]

The cooling water flows into the protruding block via the relay pipe on the ejector plate side, and is discharged again via the relay pipe. The positional relationship between the ejector plate and the protruding block is invariable with respect to the mold opening and closing direction, but in the direction perpendicular to the mold opening, a displacement occurs due to the protruding. This displacement is absorbed by expansion and contraction or bending of the elastic portion of the water pipe. Alternatively, it is absorbed by the slide of the slide block having the relay conduit.

[0007]

【Example】

(First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. In the drawing, 1 is a molded product, 2 is a movable die, 3 is a protruding block provided inside the movable die 2, 4 is an ejector plate, 5 is one end fixed to the ejector plate 4 and the other end is protruded. It is a rod connected to the block 3. The protruding block 3 is attached along the slope 6 of the movable mold 2 so as to slide diagonally with respect to the mold opening and closing direction.
The rod 5 is connected so as to be able to shift at right angles to the mold opening and closing direction. The surface of the protruding block 3 opposite to the surface attached to the slope 6 is an undercut forming portion 7, and the undercut portion 8 is formed on the molded product 1 in combination with the cavity shape of the movable mold 2. .

The projecting block 3 has a cooling water passage (not shown) therein. The ejector plate 4 is provided with a relay conduit 10 for distributing water to the cooling water passage. A water pipe 11 connects the relay pipe 10 and the protruding block 3. The water pipe 11 includes a metal pipe 12 protruding from the protruding block 3, and the metal pipe 12 and the relay pipe 1.
0 is connected to a rubber flexible hose 13. The relay conduit 10 is connected to an external cooling water source by a flexible hose (not shown). One set of the relay conduit 10 and one set of the water guide pipe 11 are required for water supply and drainage, but only one for water supply is shown because they overlap in the depth direction of the paper. As for the connection of the water pipe 11, a through hole 14 is formed in the ejector plate 4, and the end of the metal pipe 12 and the flexible hose 13 are accommodated therein. The through hole 14 is
It becomes a service hole when replacing the space 13.

In the mold having the above structure, the temperature of the protruding block 3 is adjusted by the cooling water distributed through the relay conduit 10 and the water conduit 11. After the mold is opened, the ejector plate 4 is pushed by a rod (not shown) to eject the molded article 1. When the ejected block 3 projects the molded article 1, the eject block 3 is displaced at right angles to the mold opening / closing direction, thereby undercutting. The escape of the part 8 is enabled. This is the state of FIG. As the protruding block 3 is displaced with respect to the ejector plate 4, the metal pipe 12 approaches the relay line 10, but this movement is caused by the compression of the flexible hose 13 and the deflection of the metal pipe 12 to some extent. Is absorbed by

(Second Embodiment) FIGS. 3 and 4 show a second embodiment. Elements common to the first embodiment are denoted by the same reference numerals,
Description is omitted. Here, the protruding block 3 and the relay conduit 10 are directly connected by a rubber flexible hose 13. The displacement of the protruding block 3 is mainly absorbed by the deflection of the flexible hose 13 as shown in FIG.

(Third Embodiment) FIGS. 5 and 6 show a third embodiment. Elements common to the first embodiment are denoted by the same reference numerals,
Description is omitted. Here, a slide block 15 is disposed in front of the ejector plate 4 and a relay conduit 10 is provided in the slide block 15. The slide block 15 slides at right angles to the mold opening / closing direction, and is given a movement by an angular pin 16 protruding from the movable mold 2.
The angle θ of the angular pin 16 is made equal to the angle θ of the slope 6. Ejector plate 4 has angular pin 1
6 is provided. When the mold is opened and the molded product 1 is ejected, the ejection block 3 and the slide block 15 slide synchronously as shown in FIG. Therefore, it is not necessary to use the compression or bending of the water pipe 11 to absorb the displacement of the protruding block 3, and the slope angle θ can be made larger than in the first embodiment, and a deep undercut can be formed. It is.

[0012]

According to the present invention, it is possible to supply cooling water to a projecting block projecting obliquely from a mold, and to improve the quality of a molded product requiring an oblique projecting block for forming an undercut portion. I was able to.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment.

FIG. 2 is a cross-sectional view of main parts of the first embodiment showing different operation states.

FIG. 3 is a sectional view of a main part of a second embodiment.

FIG. 4 is a sectional view of a main part of a second embodiment showing different operation states.

FIG. 5 is a sectional view of a main part of a third embodiment.

FIG. 6 is a sectional view of a main part of a third embodiment showing different operation states.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molded product 2 Mobile type 3 Projection block 4 Ejector plate 10 Relay line 11 Water pipe 12 Metal pipe 13 Flexible hose 15 Slide block

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 45/26-45/44 B29C 45/73 B29C 33/00-33/76 B22D 17/22

Claims (4)

(57) [Claims] 1. An undercut portion of a molded product is formed by a protruding block which slides obliquely to a mold opening and closing direction, and the molded product is protruded. A cooling water passage is formed in the protruding block. An injection mold, wherein the cooling water passage is connected to a relay conduit provided on the ejector plate via a water guide tube at least partially formed of an elastic portion. 2. The water guide pipe comprises a metal pipe projecting from the protruding block, and a flexible hose connecting the metal pipe and the relay pipe, and the flexible hose plays a role of an elastic part. The injection mold according to claim 1, wherein 3. A water transmission pipe comprising a flexible hose connecting the protruding block and the relay pipe, wherein the flexible hose plays a role of an elastic part. 2. The injection mold according to 1. 4. An apparatus according to claim 1, wherein a projecting block which slides obliquely to a mold opening and closing direction forms an undercut portion of the molded product and projects the molded product, wherein a cooling water passage is formed in the projecting block. At the same time, a slide block that slides at right angles to the mold opening and closing direction in synchronization with the protruding block is disposed on the ejector plate, and the cooling water passage is connected to a relay conduit provided on the slide block via a water conduit. An injection molding die characterized by the following.