JP2004181637A - Method for manufacturing waterproof connector housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To integrally mold a ring-shaped sealing part in a connector part continuously even in the case of a small-sized waterproof connector and to reduce deburring steps. <P>SOLUTION: A slit 15 is formed to the bottom part of a hood part and the remaining mold part is replaced with a rubber mold with a runner part 80 which allows the injection of a molding material in a direction parallel to the mold opening/closing direction in such a state that the obtained primary molded body is held to an intermediate mold part 6 to inject an unvulcanized rubber in a ring-shaped cavity 70 from the runner part 80 through the slit 15. Since the runner part 80 is arranged so that the molding material can be injected in the direction parallel to the mold opening/closing direction, the trouble causing the interference between a molding machine and the runner part 80 can be avoided. Further, the interference between the primary molded body and the runner part 80 can be avoided by the presence of the slit 15. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides an integral and continuous waterproof connector having a male connector portion inserted and coupled inside a cylindrical connector as a mating member, and having a ring-shaped elastic seal portion elastically contacting and sealing the mating member. The present invention relates to a manufacturing method that can be manufactured in a uniform manner.
[0002]
[Prior art]
The waterproof connector is generally composed of a pair of a male type and a female type, and a seal is generally ensured by interposing a ring-shaped packing as a separate component on the fitting surface. However, there is a problem that the number of steps for mounting the packing is large and the number of parts is increased. Therefore, it is desirable that the ring-shaped packing is also formed by molding.
[0003]
The ring-shaped packing needs to have elasticity, and is desirably formed from a rubber material. However, since resin and oil bleeding rubber material particularly suitable for waterproofness have low adhesion, if a ring-shaped packing is formed from a rubber material on the surface of a connector formed of resin, the ring-shaped packing falls off the connector. There is a problem.
[0004]
Therefore, for example, in Japanese Patent Application Laid-Open Nos. 63-221568 and 08-222316, after a housing having a male connector portion is molded from resin, a ring-shaped packing is integrally formed from a rubber material on the outer peripheral surface of the connector portion. It is described that a through hole continuous with the packing molding cavity is formed on the side surface of the housing, and a groove continuous with the packing molding cavity is formed on the bottom of the housing. With this configuration, when the ring-shaped packing is formed, the rubber material continuous with the packing fills the through-holes and grooves, and acts as a locking projection, thereby preventing the packing from dropping from the connector portion. .
[0005]
Japanese Patent Application Laid-Open No. 05-47436 describes that the ring-shaped packing is formed from silicone rubber, and a primer layer is formed on the surface of the connector to improve the bonding strength of the packing to the connector. Have been. By doing so, it is possible to prevent adhesion to the mold, but there is a problem that the number of steps for forming the primer layer increases.
[0006]
Japanese Patent Application Laid-Open No. 09-165517 describes a waterproof connector in which a ring-shaped packing is integrally formed from a special silicone rubber. If this silicone rubber is used, it is excellent in adhesion to the resin without adhering to the mold, so that the formation of the primer layer and the locking projection of the ring-shaped packing are unnecessary, so that it can be integrally molded.
[0007]
By the way, in order to form a waterproof seal portion from a rubber material, it is necessary to perform injection molding using unvulcanized rubber, and then vulcanize and cure by heating. Therefore, in order to improve the yield of the rubber material and reduce the number of steps for deburring, it is preferable that the runner portion immediately before the cavity is always in an unvulcanized state, and the rubber molding machine has a cold runner with a built-in cooling mechanism. It is effective to use a runner part such as this. However, such a cold runner or the like often has a larger diameter than a normal runner portion, and when molding a small waterproof connector, it is often difficult to arrange the cold runner or the like.
[0008]
In particular, in a method of manufacturing a connector housing having a shape in which a cylindrical portion for housing a waterproof seal (wire seal) of a harness protrudes from an outer surface of a bottom portion of a hood portion and a connector portion protrudes from an inner surface, When injecting unvulcanized rubber to form a waterproof seal part (connector seal) on the outer peripheral surface, it is necessary to avoid interference between the runner part such as a cold runner and the cylindrical part, and there is a great restriction on the arrangement of the runner part. Had occurred. Further, the position of the runner portion has an adverse effect on the injection pressure of the unvulcanized rubber, and there has been a quality problem. In addition, if an injection gate having a cold runner or the like is arranged on the side of the hood, interference with the molding machine occurs when opening and closing the mold or removing the molded product, or when a normal runner is arranged, the runner remains as burrs Thus, it has been difficult to use a known technique for forming a waterproof connector housing using a cold runner or the like.
[0009]
[Patent Document 1] Japanese Patent Application Laid-Open No. 63-221568 [Patent Document 2] Japanese Patent Application Laid-Open No. 08-222316 [Patent Document 3] Japanese Patent Application Laid-Open No. 05-47436 [Patent Document 4] Japanese Patent Application Laid-Open No. 09-165517 [ 0010
[Problems to be solved by the invention]
The present invention has been made in view of such circumstances, and even with a small waterproof connector, a waterproof seal portion can be continuously formed integrally with the connector portion using a cold runner or the like, and the number of deburring steps is reduced. The purpose is to do.
[0011]
[Means for Solving the Problems]
The feature of the method for manufacturing a waterproof connector housing of the present invention that solves the above-mentioned problems is that a hood part having a substantially cylindrical shape with a bottom and a substantially cylindrical connector part that projects from the bottom of the hood part into the hood part and is inserted into a mating member And a cylindrical portion communicating with the connector portion and projecting from the outer surface of the hood portion opposite to the connector portion, and a rubber seal portion formed in a ring shape on the outer peripheral surface of the connector portion and elastically contacting a mating member. A method for manufacturing a connector housing, comprising:
A hood, a connector, and a cylinder are molded from a resin material using a mold composed of a plurality of molds, and the front and back surfaces of the bottom of the hood are separated from the outer peripheral surface of the connector in an outer radial direction. A first forming step of forming a through hole therethrough;
At least one molding die used in the first molding step is replaced with a rubber molding die capable of injecting molding material in a direction parallel to the mold opening and closing direction and having a cooling structure around a runner portion, and an outer peripheral surface of a connector portion. Unvulcanized rubber is injected from the runner portion through the through hole into the ring-shaped cavity formed between the rubber mold and the ring-shaped cavity, and the space connecting the ring-shaped cavity with the through-hole. And a second molding step of vulcanizing the unvulcanized rubber filled in the ring-shaped cavity to form a seal portion.
[0012]
The space is preferably a groove that reaches the outer peripheral surface of the connector from the through hole and is formed on the inner surface of the bottom of the hood.
[0013]
Preferably, the space is a slit penetrating the bottom of the hood from the through hole to the outer peripheral surface of the connector.
[0014]
Further, in the method for manufacturing a waterproof connector housing according to the present invention, the plurality of dies are constituted by a movable mold and a fixed mold, and a middle mold arranged between the movable mold and the fixed mold, and the primary molding formed in the first molding step. The body is particularly effective when forming the seal portion while being held by the middle mold during the second molding step.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
In the method for manufacturing a waterproof connector housing according to the present invention, first, in a first molding step, a hood, a connector, and a tube are molded from resin. The hood portion has a substantially cylindrical shape with a bottom covering the outer periphery of the connector portion, and the tubular portion houses a waterproof seal (wire seal) of a harness extending from the inside of the connector portion. In many cases, a locking portion for locking with a mating connector is provided on the outer peripheral surface of the hood portion. Various thermoplastic resins such as PA, PP, PE, ABS, PBT, PPO, PPS, polycarbonate, PET, and acrylic resin can be used as the resin. In the case where a seal portion (connector seal) is formed on the outer peripheral surface of the connector portion from silicone rubber as disclosed in JP-A-09-165517 in the second molding step, ABS and PBT having excellent adhesion to the seal portion are used. Etc. are particularly preferred.
[0016]
In the first molding step, a through-hole is formed through the front and back surfaces of the bottom of the hood at a position spaced apart from the outer peripheral surface of the connector in the outer radial direction.
[0017]
In the second molding step, at least one molding die is replaced with a rubber molding die capable of injecting molding material in a direction parallel to the mold opening / closing direction and having a cooling structure around the runner portion, and the outer peripheral surface of the connector portion and the rubber molding die are replaced. Unvulcanized rubber is injected into the ring-shaped cavity formed between the molding die and the space connecting the through-hole and the ring-shaped cavity from the runner through the through-hole. The unvulcanized rubber filling the cavity is vulcanized to form a seal.
[0018]
At this time, since the pressure of the unvulcanized rubber injected from the runner portion is first received on the surface of the mold that appears in the through-hole, the application of a large force to the primary molded body is suppressed.
[0019]
The space portion may be a groove that reaches the outer peripheral surface of the connector portion from the through hole and is formed on the inner surface of the bottom portion of the hood portion. If there is room in the space between the mating connector and the mating connector, a groove communicating with the through hole and the ring-shaped cavity may be formed on the mold surface of the rubber molding die, and the groove may be used as a space. The space may be a slit that penetrates the bottom of the hood from the through hole to the outer peripheral surface of the connector. By forming the space portion, the cross-sectional area of the flow path to the cavity forming the ring-shaped seal portion can be increased, and the injection pressure can be reduced. And since the pressure of the unvulcanized rubber injected from the runner part is received on the surface of the mold that appears in the space, the area of the surface of the mold that receives the pressure is large, and a large force acts on the primary molded body. Is further suppressed.
[0020]
Furthermore, when the silicone rubber described in JP-A-09-165517 is used, the surface of the primary molded body exposed in the flow path decreases, and the surface of the mold exposed in the flow path increases. Resistance can be reduced and injection pressure can be reduced. Therefore, it is possible to suppress such a problem that the primary molded body is deformed by the injection pressure in the second molding step.
[0021]
Generally, the runner portion is arranged so as to be able to inject a molding material in a direction parallel to the mold opening and closing direction, so that it is possible to avoid such a problem that interference with a molding machine occurs in a molded product removal step at the time of opening and closing the mold. Further, in the case of using a middle die described later, since it is impossible to form the runner portion on the side surface of the housing (perpendicular to the mold opening and closing direction), it is better to arrange the runner portion in a direction parallel to the mold opening and closing direction. The degree of freedom in design is higher, and this is effective for continuous production.
[0022]
In addition, the presence of the space makes it possible to ensure a distance from the nozzle of the runner to the gate of the ring-shaped cavity formed between the outer peripheral surface of the connector and the rubber molding die. However, it is possible to arrange the runner portion without interfering with the primary molded body.
[0023]
The plurality of molds may be of two types, a fixed mold and a movable mold, or may be composed of a movable mold and a fixed mold, and a middle mold arranged between the movable mold and the fixed mold. In the former case, it is necessary to take out the primary molded body and transfer it to the second molding step, and it is not advisable to use another apparatus such as a take-out device or a protruding mechanism for automation.
[0024]
Therefore, it is desirable to include the medium size as the latter. In this way, by holding the primary molded body in the middle mold and moving it, the primary molded body and the middle mold can be moved together to the position of the rubber molding die, enabling molding in a narrow space and molding. Will also be cheaper.
[0025]
In the second molding step, liquid unvulcanized rubber is injected from the runner portion into the space portion through the through hole in a direction parallel to the mold opening / closing direction, and the molding material is injected into the cavity forming the ring-shaped seal portion through the space portion. Will be filled. Thereafter, the rubber material filling the space and the ring-shaped seal portion is vulcanized by being heated from the mold, and is formed integrally with the primary molded body. However, since the rubber material inside the runner is cooled by the cooling structure, the unvulcanized state is maintained, and the waterproof connector released from the runner does not generate burrs due to the runner, and the unvulcanized rubber remaining in the runner part is left as it is. It can be used for subsequent molding. Therefore, continuous molding with a short molding cycle becomes possible.
[0026]
As the unvulcanized rubber used in the second molding step, rubber used for general sealing may be used, or silicone rubber may be used. When silicone rubber is used, a primer layer may be formed to secure the bonding strength, but it is preferable to use a silicone rubber as disclosed in JP-A-09-165517.
[0027]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples.
[0028]
(Example 1)
1 to 3 show a waterproof connector manufactured in this embodiment. The waterproof connector has a substantially cylindrical bottomed hood 1, a substantially cylindrical connector 2 projecting into the hood 1 and inserted into the connector of the mating member 100 shown in FIG. A rubber seal portion 3 formed in a ring shape on the outer peripheral surface and elastically contacting the inner peripheral surface of the mating member 100.
[0029]
On the outer surface of the bottom part 10 of the hood part 1, a pair of cylindrical parts 11 communicating with the connector part 2 and holding a waterproof seal (wire seal) of the harness is formed, and a rib 12 for supporting the cylindrical part 11 is formed. I have. Further, an engagement groove 13 penetrating the upper side wall is formed, and a pair of guide grooves 14 facing each other are formed on the inner surfaces of the left and right side walls. A slit 15 is formed in the bottom part 10 and penetrates the bottom part 10 and reaches the outer surface of the side wall of the connector part 2. The slit 15 is filled with rubber of the same material as the seal part 3. An air vent 16 penetrating through the bottom 10 is formed in the bottom 10 at a position facing the slit 15 with the cylindrical portion 11 interposed therebetween. The air vent 16 is also filled with rubber of the same material as the seal portion 3.
[0030]
In this waterproof connector, the mating member 100 shown in FIG. 4 is inserted into the hood 1, and the connector 2 is inserted into the cylindrical portion 101 of the mating member 100. A pair of rails 102 projecting in the left-right direction is formed on the mating member 100, and the rails 102 are guided by the guide grooves 14 to perform insertion. At this time, the arm 103 formed on the upper surface of the mating member 100 is elastically deformed by being pressed against the upper side wall of the hood 1, and the claw 104 projecting from the upper surface of the arm 103 reaches the engaging groove 13. By doing so, the arm 103 is restored to its original shape by the elastic reaction force, and the claw 104 is engaged with the end of the engagement groove 13 to prevent the arm 103 from coming off. In this state, the seal portion 3 is in close contact with the inner peripheral surface of the cylindrical portion 101 of the mating member 100, and the connector portion 2 exhibits a high waterproof sealing property.
[0031]
This waterproof connector was manufactured by a molding method described below. First, a mold shown in FIG. 5 is prepared. This mold is composed of a first upper mold 4 and a first lower mold 5, and a middle mold 6 sandwiched between the first upper mold 4 and the first lower mold 5, and is formed on the first lower mold 5. The PBT resin is injected from the spool & runner section 50 to form a primary molded body. The side wall of the hood 1 and the connector 2 are formed by the first upper mold 4 and the middle mold 6, and the bottom 10 and the cylindrical section of the hood 1 are formed by the first upper mold 4, the first lower mold 5 and the middle mold 6. 11 and ribs 12 are formed.
[0032]
When the mold is opened after the injection molding of the primary molded body, the contact area between the middle mold 6 and the primary molded body in the mold opening and closing direction is large, so that the primary molded body is held by the middle mold 6 as shown in FIG. A slit 15 and an air vent 16 are formed in the bottom 10.
[0033]
Next, the part formed by the spool & runner part 50 is removed, and the middle die 6 holding the primary molded body is moved to the secondary molding position. At the primary molding position, an empty middle mold 6 is arranged between the first upper mold 4 and the first lower mold 5, and the next primary molding is performed.
[0034]
As shown in FIG. 7, a second upper mold 7 and a second lower mold 8 are arranged at the secondary molding position, and each is heated to 120 ° C. A cold runner 80 having a nozzle at the position of the slit 15 is disposed in the second lower die 8, and the inside thereof is water-cooled to about 17 ° C.
[0035]
These are closed, and injection molded from a cold runner 80 using an unvulcanized silicone rubber described in JP-A-09-165517. The unvulcanized silicone rubber first fills the slit 15, then fills the ring-shaped cavity 70 formed between the outer periphery of the connector 2 and the second upper mold 7, and finally fills the air vent hole 16. Since the air vent 16 is exposed on the outer surface of the molded product, it is possible to determine the presence or absence of the underfill of the seal portion 3 only by visually checking the filling state of the air vent 16.
[0036]
Although the cold runner 80 has a maximum nozzle portion diameter of about 10 mm, the ring-shaped cavity 70 is filled through the slit 15. Therefore, even if the waterproof connector is a small waterproof connector, the cold runner 80 may interfere with the cylindrical portion 11 and the rib 12. , And injection can be performed in a direction parallel to the mold opening and closing direction. Therefore, there is no interference with the molding machine, and the degree of freedom of the arrangement position of the cold runner 80 is high.
[0037]
The unvulcanized silicone rubber filled in the slit 15, the ring-shaped cavity 70, and the air vent hole 16 is vulcanized and cured by heating from the first upper mold 7 and the second upper mold 8, and a predetermined rubber elasticity is formed in the ring-shaped cavity 70. Is formed. FIG. 8 shows this state. The seal portion 3 has excellent adhesion to the PBT resin and does not adhere to the mold. Further, since the seal portion 3 is soft and has rubber elasticity, no breakage or permanent deformation occurs even if the second upper mold 7 is forcibly removed when the mold is opened. Accordingly, the waterproof connector shown in FIGS. 1 to 3 is obtained by opening the mold and releasing the mold. The obtained waterproof connector has no runner portion adhered and hardly any burrs, so that the deburring process can be omitted at all and the man-hour is small.
[0038]
Since the first upper mold 7, the second upper mold 8 and the middle mold 6 have no adhesion of the PBT resin and the silicone rubber, they can be directly used for the next molding. Further, since the cold runner 80 is cooled, the unvulcanized silicone rubber inside does not cure by vulcanization. Therefore, continuous molding becomes possible, and the production efficiency is greatly improved.
[0039]
(Example 2)
In the first embodiment, the slit 15 penetrating the bottom 10 is formed. However, as shown in FIG. 9, when the thickness of the bottom 10 can be sufficiently ensured, the ring-shaped cavity 70 is formed on the inner surface of the bottom 10. A groove 17 (space) communicating with the groove 17 can be formed, and unvulcanized silicone rubber can be injected from the cold runner 80 into the groove 17 through a through hole 18 formed in the bottom 10.
[0040]
(Example 3)
When there is room in the space between the mating member 100 and the bottom part 10 of the hood part 1, a through hole 18 is first formed in the bottom part 10 of the hood part 1 as shown in FIG. A groove 71 (space) communicating the through hole 18 and the ring-shaped cavity 70 is formed in the abutting mold surface. Then, the unvulcanized silicone rubber can be injected from the cold runner 80 to the ring-shaped cavity 70 through the through hole 18 and the groove 71 thereof. In this case, the ridge 19 is formed on the surface of the bottom 10 by the groove 71 formed in the second upper mold 7.
[0041]
However, in consideration of sealing properties, it is needless to say that it is preferable that the mold surface of the second upper mold 7 abutting on the bottom portion 10 be a flat surface as shown in FIGS. 8 and 9.
[0042]
【The invention's effect】
That is, according to the method for manufacturing the waterproof connector housing of the present invention, even in the case of a small waterproof connector, the ring-shaped seal portion can be integrally formed with the connector portion using the cold runner, thereby reducing the number of deburring steps and continuously forming the connector. , The productivity is greatly improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a waterproof connector formed according to an embodiment of the present invention.
FIG. 2 is a front view of the bottom wall side of the waterproof connector formed in one embodiment of the present invention.
FIG. 3 is a front view of an opening side of the waterproof connector formed in one embodiment of the present invention.
FIG. 4 is a perspective view of a mating member of the waterproof connector formed in one embodiment of the present invention.
FIG. 5 is a sectional view of a primary molding die according to an embodiment of the present invention.
FIG. 6 is an explanatory view showing a state where a mold is opened after primary molding in one embodiment of the present invention.
FIG. 7 is an explanatory view showing a state before closing a mold at the time of secondary molding in one embodiment of the present invention.
FIG. 8 is an explanatory view showing a state before opening the mold after the secondary molding in one embodiment of the present invention.
FIG. 9 is an explanatory view showing a second embodiment of the present invention, in which a state before mold opening after secondary molding is omitted, omitting a mold.
FIG. 10 is an explanatory view showing a second embodiment of the present invention and showing a state before opening the mold after secondary molding, omitting a mold.
[Explanation of symbols]
1: Hood section 2: Connector section 3: Seal section 4: First upper mold 5: First lower mold 6: Middle mold 7: Second upper mold 8: Second lower mold 11: Cylindrical section 15: Slit (space section) 17: groove (space) 18: through hole 71: groove (space)

Claims (4)

A hood part having a substantially cylindrical shape with a bottom, a substantially cylindrical connector part which projects from the bottom of the hood part into the hood part and is inserted into a mating member, and which communicates with the connector part and which is opposite to the connector part; A method for manufacturing a waterproof connector housing, comprising: a tubular portion projecting from an outer surface of a hood portion; and a rubber seal portion formed in a ring shape on an outer peripheral surface of the connector portion and elastically contacting a mating member,
The hood, the connector, and the cylindrical portion are formed from a resin material using a mold composed of a plurality of molds, and the hood is separated from the outer peripheral surface of the connector in an outer radial direction. A first forming step of forming a through-hole penetrating the front and back surfaces of the bottom;
At least one molding die used in the first molding step is replaced with a rubber molding die capable of injecting molding material in a direction parallel to the mold opening / closing direction and having a cooling structure around a runner portion. Unvulcanized rubber is injected from the runner portion into the ring-shaped cavity formed between the outer peripheral surface and the rubber mold and the space connecting the through-hole and the ring-shaped cavity from the runner portion. A second molding step of vulcanizing the unvulcanized rubber filling the through-hole, the space, and the ring-shaped cavity to form the seal portion. Production method. 2. The method according to claim 1, wherein the space portion is a groove that reaches the outer peripheral surface of the connector portion from the through hole and is formed on an inner surface of a bottom portion of the hood portion. 3. . 2. The method according to claim 1, wherein the space is a slit that penetrates a bottom of the hood from the through hole to an outer peripheral surface of the connector. 3. The plurality of molds are composed of a movable mold and a fixed mold, and a middle mold arranged between the movable mold and the fixed mold, and the primary molded body formed in the first molding step is formed at the time of the second molding step. The method for manufacturing a waterproof connector housing according to any one of claims 1 to 3, wherein the seal portion is formed while being held by the middle mold.

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