JP3917315B2 - Wire seal and manufacturing method of wire seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire seal for sealing a wire outlet of a connector housing and a method for manufacturing the wire seal.
[0002]
[Prior art]
As a connector used as a connection means in wiring of automobiles and the like, a waterproof multipolar connector having a sealing structure that accommodates a plurality of connection terminals in the housing and prevents moisture from entering the housing is widely used. It has been. In this connector, a plurality of wires (electric wires) connected to the respective connection terminals are drawn out from the housing, and a wire seal is attached to a drawing position of the wires. As shown in FIG. 12, the wire drawing structure provided with the wire seal is formed by dividing a plurality of wire drawing holes in the housing and pulling out one wire from the wire drawing hole through the wire seal. It has been known. The connector A in FIG. 12 is configured by fitting the female housing F to the male housing D via the connector seal E so that the male terminal B is connected to the female terminal C. Each has a plurality of small-sized wire lead-out holes G, H formed in a row (one by one shown in the figure), and the outer and inner peripheral surfaces of the wire lead-out holes G, H are uneven. One wire K, L to which cylindrical wire seals I, J formed in a shape are attached is drawn out.
[0003]
However, in the connector of FIG. 12, it is necessary to fit a small cylindrical seal to each wire, and to insert the cylindrical seal into the wire extraction hole when passing the wire through the wire extraction hole. not good. Therefore, in order to eliminate such inconvenience, a single wire seal in which a plurality of wire insertion holes are formed is fitted into the housing so as to block the housing opening, which is a wire outlet, and each wire insertion hole is inserted. A wire drawing structure in which the wire is drawn through and pulled out is also employed. And this single wire seal also has sufficient adhesiveness due to the flexible restoring force of the ridge portion of the concavo-convex shape, in which the outer peripheral surface and the inner peripheral surface of the wire insertion hole are formed in the concavo-convex shape. The necessary sealing performance is secured.
[0004]
[Problems to be solved by the invention]
By the way, such a single wire seal usually has one split mold having a molding surface on which undulations corresponding to the concavo-convex shape to be formed on the outer peripheral surface and the concavo-convex shape to be provided in the wire insertion hole. Molded with a rubber material using an injection mold composed of the other split mold having a plurality of core pins on which corresponding undulations are formed, but it is easy to remove the molded wire seal. In order to automate the configuration, it is necessary that the core pin comes out of the wire insertion hole and the wire seal is held in one of the divided molds when the mold is opened. In particular, when a middle mold is used as one split mold and a wire seal is formed by combining this middle mold with an upper mold and a lower mold, the wire seal is changed to the middle mold when the mold is opened by the protruding strip portion of the outer peripheral surface as an undercut. If held, the wire seal can be easily demolded by pressing the surface of the wire seal with a pressing member having a simple structure. However, in such a wire seal, the protruding portion of the wire insertion hole is usually undercut, so even if the number of wire insertion holes formed is small, the wire seal is not necessarily held in the middle mold when the mold is opened. Not limited to this, when there are a large number of wire insertion holes to be formed, the resistance of the undercut of all the insertion holes is larger than the resistance of the undercut of the outer peripheral surface, and the wire seal is attached to the core pin. End up. For example, the core pin needs to be provided entirely on the molding surface of the lower mold and without a large gap. Therefore, a simple protrusion mechanism that is a simple and effective demolding device is configured on the split mold on the core pin side. It is difficult to do. Therefore, it is not preferable in terms of molding work efficiency that the wire seal is attached to the core pin when the mold is opened.
[0005]
Therefore, an object of the present invention is to provide a wire seal having a structure that can be automatically removed with a simple configuration at the time of molding and can improve productivity.
Moreover, an object of this invention is to provide the manufacturing method which can manufacture a wire seal efficiently.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the wire seal of the present invention has a plurality of wire insertion holes whose inner peripheral surface is formed in an uneven shape, and the uneven outer peripheral surface is in contact with the housing inner surface of the connector in a sealed state. Further, it is a wire seal made of an elastic material fitted in the housing, and is formed integrally from an inner part in which the wire insertion hole is formed and an outer peripheral part including the outer peripheral surface and surrounding the inner part. The outer peripheral portion is formed of a first elastic material, and the inner portion is formed of a second elastic material, and the first elastic material has a hardness higher than that of the second elastic material. It is what has. On the inner peripheral surface of the wire insertion hole and the outer peripheral surface of the main body, a concavo-convex shape such as a wavy shape, a square wave shape or a sawtooth shape is provided, and the ridge is Usually, a plurality of annular ridges are formed along the outer circumferential surface and the inner circumferential surface of the wire insertion hole, but the number of ridges on the outer circumferential surface may be larger than the number of ridges on the wire insertion hole. In addition, the height of the ridges on the outer peripheral surface can be made larger than the ridges of the wire insertion holes. In addition, the concavo-convex shape of the outer peripheral surface may be a shape that protrudes perpendicularly (for example, a square wave shape), and the concavo-convex shape of the wire insertion hole may be a shape that is gently curved (for example, a gradual waveform shape). is there. Normally, all the wire insertion holes are formed on the inner side, and no wire insertion holes are formed on the outer peripheral part. As the elastic material, a rubber material such as silicon rubber, nitrile rubber (NBR) and acrylic rubber, or a thermoplastic elastomer material can be used. Usually, the same material is used for the first elastic material and the second elastic material. However, it is possible to use different materials. The hardness range of the first elastic member or the outer peripheral portion is preferably Hs30 to 70. If the hardness exceeds Hs70, the hardness of the ridges on the outer peripheral surface becomes too large to secure a sealing property by a sufficient restoring force, and if it is below Hs30, a sufficient hardness difference from the second elastic material is obtained. It cannot be secured. The hardness range of the second elastic member or the inner portion is preferably Hs 10 to 50, but a hardness difference of 20 to 60 should be generated between the second elastic member and the first elastic member. The inner part and the outer peripheral part are integrated by, for example, vulcanization bonding.
[0007]
In order to manufacture such a wire seal, first, the outer periphery of the wire seal is molded from the first molding material using the first molding die. Then, a molding space for the inner part of the wire seal is formed inside the outer peripheral part using the second molding die, and the second molding material is filled in the molding space to be integrated with the outer peripheral part, and A wire seal is formed by forming an inner portion having a smaller hardness than the outer peripheral portion. Here, if the mold is opened so that the protrusions on the outer peripheral surface of the wire seal and the protrusions of the wire insertion hole formed on the inner side are undercut, the protrusions on the outer peripheral surface are hard and have high resistance to slipping. The outer peripheral surface is held in the split mold without being released. Then, the wire seal whose outer periphery is supported is removed from the split mold using a pressing mechanism or a protruding mechanism. More specifically, the first molding die includes a split die having a molding surface of the outer peripheral surface of the wire seal, and the first molding die is held by the split die. Open the mold. The second molding die is configured using a split mold with an outer peripheral part as it is, and a core pin for a wire insertion hole is arranged inside the outer peripheral part to form a molding space inside the wire seal. Then, after the inner part of the wire seal is molded, the second molding die is opened so that the core pin comes out of the wire insertion hole and the wire seal is held accompanying the split mold. Preferably, the first molding die has a molding surface of the outer peripheral surface of the wire seal, in particular, a middle die having only a molding surface for the outer peripheral surface, and a first upper and lower parts disposed with the middle die interposed therebetween. The second mold is composed of this middle mold and a second upper and lower mold disposed with the middle mold in between. The second upper and lower molds are provided with a plurality of fixed core pins for forming wire insertion holes. Here, a pin portion is provided on both the upper die and the lower die, and both the pin portions are brought into contact with each other when the mold is clamped to form a core pin, and corresponds to the protrusions to be formed in the wire insertion hole. If the concave portions to be distributed are provided in the respective pin portions, the pull-out resistance on the wire insertion hole side becomes sufficiently small both when the upper die is separated from the middle die and when the lower die is separated. Although the seal can be securely held in the middle mold, burrs are generated on the inner peripheral surface of the wire insertion hole at the contact position of the pin portion in such a configuration of the core pin. The work which removes this burr | flash which arose was needed. Therefore, in order to minimize the occurrence of burrs, or to prevent burrs from being generated at positions that are difficult to remove, the core pin is either an upper die or a lower die (usually a movable lower die). It is preferable to provide only. And, when the second molding die is opened, the outer periphery of the wire seal is sufficiently harder than the inner portion, or the inner portion is made to be larger than the pull-out resistance on the outer peripheral surface side of the main body. Molded sufficiently softer than the outer periphery. More specifically, the total pull-out resistance in the length direction of the core pin between the inner peripheral surface of the wire insertion hole and the core pin (more specifically, an integral or non-divided core pin) is divided from the outer peripheral surface of the main body. The outer periphery of the wire seal is harder than the inner part or the inner part is softer than the outer part so as to be smaller than the resistance in the thickness direction between the outer peripheral surface molding surface of the mold (more specifically, the middle mold) Mold it.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
FIG. 1 is an exploded perspective view of a connector having a wire seal according to the present invention, and FIG. 2 is a sectional view of the connector assembly.
[0010]
A connector housing 3 is integrally formed in the box 1 containing an electronic circuit (not shown) such as a CPU, and a retaining portion 5 is integrally formed on the rear side of the housing 3 or on the box 1 side. The plurality of terminal receiving holes 7 are partitioned. In each terminal receiving hole 7 of the housing 3, the tip end portion of the male terminal 9 fixed and attached to the box 1 extends, and the female terminal 13 attached to one end of the wire 11 exceeds the retaining portion 5. By being fitted in the terminal receiving hole 7, it is connected to the tip of the male terminal 9. The inside of the front end of the housing 3 is formed as a wide seal receiving port 15 (wire drawing port), and an annular seal receiving surface 17 is formed at the rear end of the seal receiving port 15. A rectangular, relatively thick wire seal 19 is accommodated in the seal receiving port 15 so as to contact the seal receiving surface 17, and a cap is provided on the outer side of the front end of the housing 3 so as to hold down the surface side of the wire seal 19. 21 is fitted. The cap 21 is formed of a short cylindrical portion 25 having a rectangular cross section provided with a fitting hole 23 and an inward flange portion 27 integrally formed at the front end of the cylindrical portion 25, and the cylindrical portion 25. A stopper projection 29 on the outer end of the housing 3 is fitted in the fitting hole 23 of the housing 3, and a short axial portion 31 formed at the inner end of the inward flange portion 27 is a wire seal 19. The outer peripheral portion 33 surface is pressed.
[0011]
A large number of wire insertion holes 35 are formed in the wire seal 19, and each wire 11 passes through the wire insertion hole 35, and passes through the center passage opening 37 of the inward flange portion 27 of the cap 21 to the outside. Has been drawn to. The outer peripheral surface 39 of the wire seal 19 is formed in a concavo-convex shape with a square-shaped cross section and has three annular ridges 41, and the inner peripheral surface 43 of the wire insertion hole 35 has a saw-tooth concavo-convex shape with a round cross section. It has two annular ridges 45 formed, and the ridges 41 on the outer peripheral surface 39 are in sealing contact with the inner peripheral surface 47 of the seal housing port 15, and the inner peripheral surface 43 of the wire insertion hole 35 is formed. The ridge 45 is in sealing contact with the wire 11.
[0012]
The outer peripheral portion 33 of the wire seal 19 (outside the region where the wire insertion hole 35 is provided) is formed of silicon rubber with a hardness Hs 50 to 60, and the inner portion 49 (region where the wire insertion hole 35 is provided) is also formed. Although it is also formed of silicon rubber, the hardness of the inner portion 49 is relatively lower than Hs 15 to 30 and the outer peripheral portion 33.
[0013]
FIG. 3 is a schematic perspective view of a middle mold used for molding the wire seal 19, and FIG. 4 is a cross-sectional view of a first mold for injection molding the outer peripheral portion 33 of the wire seal 19 provided with the middle mold. FIG. 3 is a perspective view of the middle mold after the first mold is opened.
[0014]
The middle mold 51 is formed in a plate shape having a plurality of molding holes 55 defined by the annular molding surface 53 of the outer peripheral surface 39 of the wire seal 19 so that the plurality of wire seals 19 can be molded simultaneously. The annular molding surface 53 is provided with three annular recesses or annular grooves 57 corresponding to the ridges 41 to be formed on the outer peripheral surface 39 of the wire seal 19 (see FIG. 3). The middle mold 51 is combined with a first upper mold 59 and a first lower mold 61 having a plurality of molding portions corresponding to the molding holes 55 of the middle mold 51 to form a first molding die 63. The core 65 of the lower mold 61 is disposed in each molding hole 55 to form the cavity 67 of the outer peripheral portion 33 of the wire seal 19. The cavity 67 is filled with the first silicon rubber (first molding material) from the runner 69 and vulcanized at 160 ° C. to 170 ° C. for 5 minutes to mold the outer peripheral portion 33 made of the first elastic material ( (See FIG. 4). Then, when the lower mold 61 and the middle mold 51 are moved downward and separated from the upper mold 59, and then only the lower mold 61 is moved downward and separated from the middle mold 51 to complete the outer layer molding step, the protrusions on the outer peripheral surface 39 are completed. 41 becomes undercut and the outer peripheral part 33 will be in the state adhering to each shaping | molding hole 55 of the intermediate mold 51 (refer FIG. 5).
[0015]
6 is a cross-sectional view of a second molding die for molding the entire wire seal 19 by injection molding the inner portion, FIG. 7 is a plan view of the lower die of the second molding die, and FIG. FIG. 9 is a diagram conceptually showing a process from mold opening to demolding of the second molding die, and FIG. 10 is a perspective view of the middle mold 51 after the mold opening of the second molding die. It is.
[0016]
The middle die 51 holding the outer peripheral portion 33 in each molding hole 55 is combined with a second upper die 71 and a second lower die 73 having a plurality of molding portions corresponding to the molding holes 55 of the middle die 51, A second molding die 75 that forms a molding space for the inner portion 49 is formed inside the portion 33 (see FIG. 6). A plurality of core pins 77 for the wire insertion holes 35 are attached to the lower die 73 (the lower die 73 and the core pin 77 are shown in an integrated manner in FIG. 6). The core pin 77 is formed from the molding surface of the lower die 73 into a molding space. Projecting in (see also FIG. 7). The outer peripheral surface of each core pin 77 is formed in a concavo-convex shape corresponding to the concavo-convex shape to be formed in the inner peripheral surface 43 of the wire insertion hole 35 and repeated with a large diameter and a small diameter being smoothly connected. The upper die 71 is formed with a plurality of injection holes 79 corresponding to the core pins 77, and the upper end portion 81 of the core pin 77 of the lower die 73 slightly enters the lower end of the injection hole 79 of the upper die 71. An annular gate is formed on the outer periphery of the upper end portion 81 (see FIG. 8). The molding space in which the core pin 77 is disposed is filled with the second silicon rubber (second molding material) from the runner 83 and vulcanized at 160 ° C. to 170 ° C. for 5 minutes, and has a large number of wire insertion holes 35. An inner portion 49 made of a second elastic material having a length of Hs15 to 30 is formed integrally with the outer peripheral portion 33. The outer peripheral portion 33 is again vulcanized for 5 minutes, but has a hardness of Hs 50 to 60. Then, the lower mold 73 and the middle mold 51 are moved downward and separated from the upper mold 71 (FIG. 9a), and then only the lower mold 73 is moved downward and separated from the middle mold 51 to perform mold opening, and the inner layer forming step is performed. Completion (Figure 9b). When separating the lower mold 73 from the middle mold 51, the two protrusions 45 of the wire insertion hole 35 are undercut, but due to the large pull-out resistance due to the three protrusions 41 of the hard outer peripheral portion 33, the wire is opened after the mold is opened. The seals 19 are attached to the respective molding holes 55 of the middle die 51 (see FIG. 10). Then, by pressing the surface of the forming wire seal 19 attached to each forming hole 55 with a pressing member (not shown), the wire seal 19 is removed from the middle die 51 and the demolding process is completed (FIG. 9c). The intermediate mold 51 from which the wire seal 19 has been removed is replaced with the intermediate mold 51 to which the outer peripheral portion 33 formed by the first forming mold 63 is attached, and the first forming mold 63 and the second forming mold are exchanged. The molding process with the mold 75 is repeated.
[0017]
In order to suppress the occurrence of burrs in the forming wire seal 19 as much as possible, the injection holes 79 should be formed in the upper mold 71 so as to correspond to all the core pins 77. Material costs increase because a large amount of molding material must be discarded. Therefore, as shown in FIG. 11, the injection hole 79 is formed so as to correspond to the specific core pin 77 to prevent the generation of burrs in this portion, and at a position corresponding to the other core pin 77 of the upper die 71. It is also possible to reduce the material cost by forming a burr pool 85 and closing the wire insertion hole 35 so that a burr that can be easily removed is formed.
The technique described here can be expressed as follows.
(1) The core pin is provided in one of the upper mold and the lower mold, and an injection hole is formed in the other of the upper mold and the lower mold so as to correspond to at least one of the core pins. A method of manufacturing a wire seal in contact with the injection hole.
(2) The manufacturing method of the wire seal according to (1), wherein the core pin has a tip part slightly inserted into and in contact with the injection hole, and an annular gate is formed on an outer periphery of the tip part of the core pin.
(3) An injection hole is formed in the other of the upper mold and the lower mold so as to correspond to at least one of the core pins, and a burr reservoir is formed so as to correspond to the remaining core pins. ) Or (2).
(4) The method for manufacturing a wire seal according to (1), wherein an injection hole is formed in the other of the upper mold and the lower mold so as to correspond to all the core pins.
[0018]
【The invention's effect】
As described above, the wire seal of the present invention is suitable for automation of the manufacturing process, and can be efficiently manufactured with a simple configuration by the manufacturing method of the present invention.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a connector provided with a wire seal according to the present invention.
FIG. 2 is a cross-sectional view of the connector assembly.
FIG. 3 is a schematic perspective view of a middle mold used for forming a wire seal.
FIG. 4 is a cross-sectional view of a first molding die for injection molding of the outer periphery of a wire seal provided with a middle mold.
FIG. 5 is a perspective view of the middle mold after the first mold is opened.
FIG. 6 is a cross-sectional view of a second molding die for molding the entire wire seal by injection molding the inner part.
FIG. 7 is a plan view of a lower mold of a second molding die.
FIG. 8 is an enlarged view of a portion X in FIG. 6;
FIG. 9 is a diagram conceptually showing a process from mold opening to mold removal of a second molding die.
FIG. 10 is a perspective view of a middle mold after the second molding die is opened.
FIG. 11 is a diagram showing another configuration of the second molding die.
FIG. 12 is a cross-sectional view showing a conventional wire drawing structure.
[Explanation of symbols]
3 Housing 19 Wire seal 33 Outer peripheral portion 35 Wire insertion hole 39 Outer peripheral surface 41, 45 Convex and convex shaped ridge 43 Inner peripheral surface of wire insertion hole

Claims (4)

A wire seal made of an elastic material, which has a plurality of wire insertion holes with an inner peripheral surface formed in an uneven shape, and is fitted into the housing so that the outer peripheral surface with the uneven shape is in sealing contact with the inner surface of the housing of the connector Because
It is integrally configured from an inner part in which the wire insertion hole is formed and an outer peripheral part that includes the outer peripheral surface and surrounds the inner part,
The outer peripheral portion is formed of a first elastic material, and the inner portion is formed of a second elastic material,
The wire seal according to claim 1, wherein the first elastic member has a hardness higher than that of the second elastic member. The inner circumferential surface has a plurality of wire insertion holes formed in a concavo-convex shape, and the outer peripheral surface is a method for manufacturing a wire seal made of an elastic material formed in a concavo-convex shape
After forming the outer periphery of the wire seal with the first molding material using the first molding die,
Using a second molding die, a molding space is formed in the inner portion of the wire seal having the wire insertion hole inside the molded outer peripheral portion, and a second molding material is placed in the molding space. Filling and molding the wire seal by molding the inner part integral with the outer peripheral part and having a hardness smaller than the outer peripheral part,
Thereafter, the second molding die is opened so that the outer peripheral surface of the wire seal is held,
And demolding the wire seal,
A method of manufacturing a wire seal. The inner circumferential surface has a plurality of wire insertion holes formed in a concavo-convex shape, and the outer peripheral surface is a method for manufacturing a wire seal made of an elastic material formed in a concavo-convex shape,
(1) Using a first molding die having a split mold having a molding surface of the outer peripheral surface of the wire seal, the outer peripheral portion of the wire seal is molded with a first molding material,
An outer layer molding step of performing mold opening of the first molding die so that the molded outer peripheral portion is held by the split mold;
(2) A second molding die is configured by using the split mold holding the outer peripheral portion, and the core pin for the wire insertion hole is disposed inside the outer peripheral portion by the second molding die. Forming a molding space inside the wire seal,
Filling the molding space with a second molding material, molding the wire seal by molding the inner part integral with the outer peripheral part and having a hardness smaller than the outer peripheral part,
An inner layer molding step of opening the second molding die so that the core pin comes out of the wire insertion hole and the wire seal is held by the split mold;
(3) a demolding step of demolding the wire seal from the split mold;
A method of manufacturing a wire seal, comprising: The split mold is an intermediate mold, and the second mold is composed of this intermediate mold, and an upper mold and a lower mold that sandwich the intermediate mold from both sides,
4. The method of manufacturing a wire seal according to claim 3, wherein the core pin is provided on one of the upper mold and the lower mold.

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