JPS60239215A - Molding method of different materials - Google Patents

Abstract

PURPOSE:To prevent production of burr by using a slide pin having a taper section in a molding method of a second plastic material under said open recess of a first molding base which has a open recess. CONSTITUTION:A first molding base 2 having a open recess 1 is molded under projecting a first resin in a cavity 13 which is molded by a fixed side mold section 11, a moving side mold section 12, a fixed pin 14, and the slid pin 5 having the taper section 6, said base 2 is displaced to a second fixed side mold section 15 together with the moving side mold section 12, and the second plastic material 4 is injected integral during the slide pin is raised somewhat. The production of the burr may be prevented, since a clearance (a) produced when the base 2 is molded will be closed by a displacement of the slide pin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technique for manufacturing an integrally molded product by sequentially molding two types of synthetic resin materials.

[Background Art 1] As a conventional example, FIGS. 11 and 12 show a case in which a motor is attached by integrally molding a sealing material 8 on a base 10 using a dissimilar material molding method.

That is, first, as shown in FIG. 11, the base 2 is molded by injecting the thermosetting first synthetic resin material 3 into the cavity 13 between the stationary mold part 11 and the movable mold part 12. , At this time, the fixed pin 14 inserted into the fixed side mold 'H11 and the movable side mold part 1
2 and the slide pin 5 inserted into the base 2.
An opening recess 1 is formed. After that, the first synthetic resin material 3 is cooled by a cooling method, the stationary mold part 11 and the movable mold part 12 are separated, and the molded base 2 is transferred to the movable mold part 1.
2 and moved to another fixed side mold part 15, where the mold is clamped again, and at this time, the slide pin 5 retreats and the fixed pin 16 in the fixed side mold part 15 protrudes into the opening recess 1. A space for molding the sealing material 8 was created between the slide pin 5 and the inner periphery of the opening recess 1 .

However, in such a conventional example, the slide pin 5
Although there are irregularities 17 on the outer periphery of the tip of the slide pin 5 for knurling in the circumferential direction, the slide pin 5 has a slate in the axial direction, which cools the first synthetic resin material 3 as shown in FIG. When the first synthetic resin material 3 is molded and stretched toward the center of the base 2 (on the opposite side, the slide pin 5
I can't move because it's blocked by. ), a gap A is created between the slide pin 5 and the inner periphery of the base 2 on the side closer to the center of the base 2, so in the second step, the second synthetic resin material 4 is injected as shown in Figure 12. When this happens, the second synthetic resin material 4 flows out from the gap A, creating a burr 18 between the slide pin 5 and the movable mold part 12. There were also secondary problems such as the inability to do so.

[Objective of the Invention 1 The present invention has been made in view of the technical background described above, and its purpose is to provide a unique method in which a second synthetic resin material is integrally molded on the inner periphery of the opening recess of the base. In material forming,
To provide a method that can perform molding of different materials without causing swelling.

[Disclosure of the Invention] The dissimilar material molding method of the present invention includes forming a base 2 having four openings 1 from a first synthetic resin material 3, and forming a second base 2 at a position lower than the edge of the opening in the opening recess 1. In the dissimilar material molding method for molding the synthetic resin material 4, a tapered portion 6 is formed on the side surface of the slide pin 5 inserted into the opening 1 during molding of the base 2, and the taper portion 6 is formed on the side surface of the slide pin 5 to be inserted into the opening 1. An inclined portion 7 is formed on a surface near the center of the stand 2 so as to protrude toward the opening edge of the opening recess 1.
, and when molding the second composite I & resin material 4, the slide pin 5 is moved to the opening edge side of the opening 4 part 1 to form the opening recess 1.
This is characterized by molding the second synthetic resin material 4 in the space created between the inner periphery and the slide pin 5, thereby achieving the above object.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1st
In the figure and FIG. 2, 12 is the moving side mold part, 11 is the first mold part.
A fixed side mold part 15 is used in the second process, and a slide pin 5 is slidably inserted into the movable mold part 12. Fixing pins 14 and 16 having different tip shapes are slidably inserted into the side mold parts 11 and 15, respectively.

When the movable side mold part 12 and the fixed side mold part 11 or 15 are matched, a cavity 13 for molding the base 2 is formed between the two mold parts, and the slide pin 5 and the fixed pin 14 or 1 are formed.
6 are matched against each other. Furthermore, an unevenness 17 for knurling is formed on the outer periphery of the tip of the slide pin 5, and a reversely tapered portion 6 is provided on one side. This taper portion 6 is provided in a range of about θ=180°, and the amount of inclination of the taper portion 6 gradually decreases as it goes from the center to both sides (as it goes away from the base 2). In Figure 5, A
I>A2>A3>A4>As>A6... What's going on? Further, at the tip of the fixing pin 16 of the fixed side mold part 15, four ring-shaped parts 19 having a concave curved surface are provided.

First, the movable side mold part 12 and the (first) fixed side mold part 11 are clamped to form a cavity 13 between the two mold parts, and the slide pin 5 and the fixed pin 14 are butted against each other. The four openings 1 of the base 2 are molded, and a thermoplastic synthetic resin such as ABS resin is first filled in the cavity 13.
The synthetic resin material 3 is injected to form the base 2 in the cavity 13. On the inner periphery of the opening recess 1 of the base 2 formed in this manner, a reverse tapered inclined portion 7 is formed in the shape 1# for the tapered portion 6. . Of course, the amount of inclination of this inclined portion 7 is large toward the center of the base 2, and becomes smaller toward the opposite side. When the molded base 2 is cooled, a gap is generated between the molded base 2 and the slide pin 5 on the center side surface of the base 2 due to molding shrinkage. Next, the movable mold part 12 is opened from the first fixed mold part 11, the movable mold part 12 is moved together with the base 2 of the molded product to the second fixed mold part 15, and the movable mold part 12 is moved to the second fixed mold part 15. The part 12 and the stationary side mold part 15 are clamped, and the slide pin 5 is slightly retracted to such an extent that it cannot be pulled out from the opening recess 1. When the slide pin 5 is moved back, the gap A is closed as shown in FIG. 2 due to the taper of the tapered part 6 and the inclined part 7, thereby preventing the occurrence of burrs outside the opening recess 1 of the base 2. are doing. Therefore,
The taper amount of the tapered portion 6 may be such that it comes into pressure contact with the inclined portion 7 when the slide pin 5 retreats. Fixed side mold part 15
The fixed bin 16 protrudes from the opening and hits the slide pin 5, and the opening 1, the lower surface of the slide bin 5, and the fixed pin 16
A space opening for molding the first seal part 20 of the sealing material 8 is formed between the four ring-shaped parts 19 of Cavity 2 for forming second seal portion 21
It is connected to 2. The second synthetic resin material 3 is, for example, a thermoplastic elastomer with elasticity like rubber, and is injected into the cavities 13 and 22, and the sealing material 8 is integrally molded with the base 2.

The molded product thus formed is shown in FIG. 3, which is a component of the waterproof electric shaver 23 shown in FIG. 9, and the motor is mounted on a stand 10. electric razor 23
The casing 26 is composed of a housing 24, a stand 10 for mounting the motor, and a stand 25 for mounting the outer blade.The casing 26 is assembled by inserting the motor mounting stand 10 into the opening between the housing 24 and the outer blade mounting stand 25. It is being A battery storage chamber 27 is provided in the lower part of the housing 24, and a lower opening of the battery storage chamber 27 is closed by a bottom cover 28. The motor 29 is attached to the bottom surface of the base 10 and housed in the upper part of the housing 24.
An inner cutter 31 is attached to the motor shaft 30 that is inserted through the motor shaft 2 . Furthermore, the motor is mounted on base 10 (base 2).
The first seal portion 2 of the sealing material 8 is molded from a different material.
0 is a switch lever 34 for moving the contact fitting 33.
is inserted in a watertight manner. Also, the outer blade is installed on stand 2.
An outer cutter 36 is attached to the outer cutter 5, and the outer cutter 36 can be protected by an outer cutter cover 37. The X section in FIG. 9 is shown enlarged in FIG. 10. The second seal part 21 integrally molded on the base 10 is used for mounting the motor on the base 1.
The second seal portion 21 is fitted into a fixing groove 38 provided annularly on the lower surface thereof, and the tip of the second seal portion 21 projects from the fixing groove 38 . Therefore, the space between the motor mounting base 10 and the housing 24 is watertightly sealed by the second seal portion 21. Further, due to the unevenness 17 of the slide pin 5, a knurling 39.9 is formed on the inner periphery of the opening recess 1 and the outer periphery of the second seal portion 21, and they engage with each other. This is to prevent twisting of the seal portion 20.

In addition, although the case where different materials are used for the first synthetic resin material 3 and the second synthetic resin material 4 has been described above, the same effect can be obtained even if the same materials in different colors are used. .

[Effect of the Invention 1] Since the present invention is constructed as described above, the gap created when the base is molded from the first synthetic resin material can be closed by moving the slide pin, and the first synthetic resin material can be closed by moving the slide pin. There is an advantage that when the second synthetic resin material is integrally molded, leakage of the second synthetic resin material from the gap and generation of burrs can be prevented. This also eliminates sealing defects due to build-up of the sealant.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing one embodiment of the method of the present invention, FIG. 3 is a cross-sectional view of a molded product molded by the same method, and FIG. 4 is a front view of the slide pin shown in the above. Figure 5 is the fourth
XX cross-sectional view in the figure, Figure 6 is an explanatory diagram showing the gap created between the four openings and the slide pin, and Figure 7 is a part of the base where the motor mounting molded by method 2 is cut out. A perspective view, FIG. 8 is an enlarged perspective view of the Y section in FIG. 7, FIG. 9 is a sectional view of the electric shaver, FIG. 10 is an enlarged sectional view of the Z section of FIG. 9, and FIGS. 11 and 12 are conventional It is a sectional view showing an example of the molding method, in which 1 is the four openings, 2 is the base, 3 is the first synthetic resin material, 4 is the second synthetic resin material, 5 is the slide pin, 6 is the taper part, 7 is an inclined portion. Agent Patent Attorney Ishi 1) Chief Shichibutsu 1 Figure 3 Figure 6 Figure 7 Figure 9 Figure 10 Figure 11 Figure 12 Procedural amendment (method) % formula % 2. Name of the invention Molding of different materials Method 3: Relationship with the person making the amendment Patent applicant address 1048 Kadoma, Kadoma City, Osaka Name (5)
83) Matsushita Electric Works Co., Ltd. Representative Iku Kobayashi 4, Agent postal code 530 5, Date of amendment order July 11, 1980 6, Specification subject to amendment 7, Contents of amendment Specification originally attached to the application As per the engraving appendix of the calligraphy (no change in content)

Claims (4)

[Claims] (1) A base having an opening recess is formed of a first synthetic resin material, and a second base is formed at a position lower than the opening edge in the opening recess.
In the dissimilar material molding method for molding synthetic resin materials, a part of the taper is formed on the side surface of the slide pin inserted into the opening recess when molding the base, and a tapered part is formed on the side surface of the slide pin that is inserted into the opening recess on the inner periphery of the opening recess near the center of the base. The sloped portion is molded so that it protrudes toward the opening edge of the opening recess, and when molding the VK2 synthetic resin material, the slide pin is moved toward the opening edge of the opening recess to create a space between the inner periphery of the opening recess and the slide bin. A method for molding different materials, characterized by molding a second synthetic resin material in the space formed. (2) The second synthetic resin material is a sealing material. A method for forming dissimilar materials according to claim 1, characterized in that: (3) The method for molding different materials according to claim 2, characterized in that a knurling Y is formed on the outer periphery of the second synthetic resin material. (4) The method for molding dissimilar materials according to claim 1, characterized in that the amount of inclination of the inclined portion of the inner periphery of the opening recess is gradually reduced as the distance from the center of the base increases.