JPH07256660A - Insert molded product and production thereof - Google Patents

Abstract

PURPOSE:To prevent the generation of a weld mark by providing a plurality of holes each having a tapered surface becoming a small diameter on the side of the end surface of an insert member to the connection wall part of the insert molded product main body bonded to the end surface of the insert member. CONSTITUTION:An insert molded product, for example, an oil seal 1 is constituted by embedding a metal ring 3 being an annular insert member in an annular molded product main body 2. A seal lip part 6 is integrally bonded to the inner peripheral end of the metal ring main body part 4 of the metal ring 3 and an outer peripheral fitting part 7 is integrally bonded to the outer peripheral part of the annular bent part 5 of the metal ring 3 and the elastomer 8 continuing to the outer peripheral fitting part 7 is also integrally bonded to the inner peripheral surface of the annular bent part 5. Further, the outside connection wall part 9 connecting the seal lip part 6 and the outer peripheral fitting part 7 is integrally bonded to the outside end surface of the metal ring main body part 4 and the inside connection wall part 10 connecting the seal lip part 6 and the elastomer 8 is integrally bonded to the inside end surface thereof. A plurality of holes 14 each having a tapered surface part becoming a small diameter on the side of the end surface of the metal ring main body part 4 are provided on the circumferences of the outside and inside connection wall parts 9, 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various insert molded products such as oil seals and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a conventional insert molded product, there is an oil seal 100 as shown in FIG. 5, for example. The oil seal 100 includes a metal ring 102 as an annular insert member in an annular molded product body 101 to be molded.
The metal ring 102 includes a metal ring main body 103 and an annular bend that is bent from the outer periphery of the metal ring main body 103 at a substantially right angle to the metal ring main body 103. It is configured by the unit 104. Then, a seal lip portion 105 as an inner peripheral wall portion is formed on the inner peripheral side of the metal ring main body portion 103 in close contact with a fitting hole (not shown) of a mating attachment member on the outer peripheral surface of the annular bent portion 104. The outer peripheral fitting portion 106 to be fitted is also the elastic body portion 1 on the inner peripheral surface.
06 'are respectively joined and the metal ring body 1
03 has a seal lip portion 105 and an outer peripheral fitting portion 1 on the outer end surface thereof.
06, and an inner connecting meat portion 107 'that connects the seal lip portion 105 and the elastic body portion 106' to the inner end surface.

The oil seal 100 is molded by opening a pair of molds 108 and 109 which can be opened and closed to each other, and then the annular wall 1 assembled to the outer peripheral portion of one of the first molds 108.
The first mold 10 with a predetermined gap from the inner peripheral surface of the first mold 10.
The metal ring 102 is placed on the placing portion 111 of FIG.
That is, the inner peripheral surface of the annular bent portion 104 of the metal ring 102 is engaged with the outer peripheral surface of the mounting portion 111, and a plurality of inner end surfaces of the metal ring main body portion 103 are circumferentially provided on the end surface of the mounting portion 111. It is pressed by the pressing projection 112. Then, the mold is closed and a plurality of pressing protrusions 1 are provided on the second mold 109 in the circumferential direction.
By pressing the outer end surface of the metal ring main body portion 103 of the metal ring 102 at 13, and filling the molding material 114 on the inner peripheral side of the mounting portion 111 and pressurizing and heating, both end surfaces of the metal ring main body portion 103 are pressed. Pressing protrusions 112 and 11 for pressing down
It was designed to flow from the inner peripheral side of the metal ring main body portion 103 to the outer peripheral side of the annular bent portion 104 via 3 to form a predetermined shape.

As a result, the molded oil seal 10 is formed.
A plurality of holes 115 are formed in the outer and inner connecting wall portions 107, 107 'of 0 in the circumferential direction.

[0005]

However, in the case of the above-mentioned conventional technique, the mounting portion 11 of the first die 108 is used.
1. The metal ring main body portion 1 provided on the end face 1 and the second mold 109.
Pressing projections 112 and 11 for pressing the respective end surfaces of 03.
As shown in FIG. 6B, the shape of 3 is a rectangular shape, that is, a so-called rectangular parallelepiped. Therefore, when the fluidized molding material 114 flows from the inner peripheral side to the outer peripheral side of the projections 112 and 113, the flow resistance is increased. The molding material 114 is large and the projections 112, 1
When the inner peripheral surface of 13 is contacted and the outer peripheral surface passes through both end surfaces, it may not be possible to completely fuse,
There were cases where weld marks M were generated as shown in FIG.

Therefore, in order to reduce the flow resistance, it is conceivable to reduce the shape of the projections 112 and 113, but this time, the force for pressing the end face of the metal ring main body 103 becomes weaker, and the molding material 114 becomes a metal ring. The metal ring 102 may move due to the pressure when flowing from the inner peripheral side to the outer peripheral side of 102, which may cause defective molding.

The present invention has been made to solve the above-mentioned problems of the prior art. An object of the present invention is to provide an insert-molded article and a manufacturing method therefor capable of improving the quality by preventing the occurrence of weld marks. To do.

[0008]

In order to achieve the above object, in the present invention, an annular insert member is embedded in an annular molded article body to be molded, In the insert molded article in which the meat of the molded article body is joined to the inner peripheral side and the outer peripheral side of the insert member, and the connecting meat portion that connects the inner peripheral wall portion and the outer peripheral wall portion to the insert member end surface is joined, A plurality of holes having a tapered surface such that the end surface side of the insert member has a small diameter are provided in the connecting wall portion of the molded product body joined to the end surface of the insert member.

Further, when a pair of molds which can be opened and closed with respect to each other is opened, an insert member is inserted, and then the mold is closed,
The insert member end surface is pressed by a pressing projection provided on at least one of the molds, the molding material is flown to the inner peripheral side and the outer peripheral side of the insert member through the pressing projection of the insert member end surface, and the inner surface is inserted at the insert member end surface. In the method of manufacturing an insert-molded product in which a peripheral wall portion and an outer peripheral wall portion are connected to each other to form an insert-molded product having a predetermined shape, the pressing projection on the end surface of the insert member has a tapered surface such that the end surface of the insert member has a small diameter. It is characterized by having.

Further, a first die into which the annular insert member is inserted, and a second die which closes the first die to form a cavity having a predetermined shape between mating surfaces. A mold having at least one of the first and second molds provided with a pressing projection for pressing the end surface of the insert member, wherein the pressing projection of the insert member is an insert member. It is characterized by having a tapered surface such that the end surface side has a small diameter.

[0011]

According to the insert-molded product and the method of manufacturing the same having the above-described structure, the pressing projection for pressing the end surface of the insert member has a tapered surface having a small diameter on the end surface side of the insert member. When the above molding material flows from the inner peripheral side to the outer peripheral side, the flow resistance becomes small and the flow path between the pressing protrusions can be made large. This allows for smooth flow from the inner circumference to the outer circumference,
Since the flows are completely fused on the outer peripheral side, a weld mark does not occur on the outer peripheral side portion of the hole in the insert-molded product as in the prior art.

Further, since the base of the pressing projection has a large diameter, the force for pressing the end surface of the insert member does not decrease, so that the end surface of the insert member can be pressed reliably.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments. FIG. 1 shows an oil seal 1 as an insert molded product according to an embodiment of the present invention, in which a metal ring 3 as an annular insert member is generally embedded in an annular molded product body 2 to be molded. Is configured.

The metal ring 3 is a ring-shaped member having an L-shaped cross section, and has a washer-shaped metal ring body 4 and a tubular shape extending from the outer circumference of the metal ring body 4 to the metal ring body 4 at a right angle. It is constituted by an annular bending portion 5 that can be bent.

The molded product body 2 has a substantially U-shaped cross section and has a metal ring 3
A seal lip portion 6 as an inner peripheral wall portion slidably in contact with an outer peripheral surface of a shaft (not shown) is attached to an inner peripheral end of the metal ring main body portion 4 which is an inner peripheral side of the metal ring 3. Outer peripheral fitting as an outer peripheral wall portion that is fitted in close contact with the inner peripheral surface of the mating hole (not shown) of the mating attachment member as the outer peripheral wall portion on the outer peripheral surface of the annular bent portion 5 on the outer peripheral side. The part 7 is also an annular bending part 5
The elastic body portions 8 are continuously joined to the inner peripheral surface of the metal ring 3 continuously with the outer peripheral fitting portion 7, and the outer end surfaces of the end surfaces on both sides of the metal ring body 4 are joined together. , An outer connecting meat portion 9 that connects the seal lip portion 6 and the outer peripheral fitting portion 7, and an inner connecting meat portion 10 that connects the seal lip portion 6 and the elastic body portion 8 to the inner end surface are integrally formed. It is joined.

The seal lip portion 6 of the molded product body 2 extends substantially parallel to the axial annular bent portion 5 from the inner peripheral end of the metal ring body portion 4, and the inner peripheral end thereof has a wedge-shaped cross section. 11 and a dust lip 12 that extends from the inner peripheral end of the metal ring body 4 to the side opposite to the axial seal lip 11 and inclines radially inward. In addition, a semicircular cross section for accommodating a spring (not shown) for applying a tightening force to the outer peripheral surface of the shaft on the outer periphery of the lip tip 11A having a wedge-shaped cross section of the seal lip 11. A spring holder 13 having a shape is provided.

The outer and inner connecting wall portions 9 and 10 are provided with a plurality of holes having a tapered surface portion such that the end surface side of the metal ring main body portion 4 has a small diameter, that is, a so-called truncated cone-shaped hole 14 on the circumference. They are evenly distributed.

FIG. 2 shows a molding die for molding the oil seal 1. That is, this molding die 20
Is a first mold 21 on which the metal ring 3 is arranged, and the first mold 21.
Second mold 23 for forming a cavity 22 having a predetermined shape between the mating surfaces by closing the mold 21.

The first mold 21 includes a first mold A21A having a mounting portion 24 on which the metal ring 3 is mounted, and a first mold A21.
21A of 1st annular mold B2 assembled | attached to the outer peripheral part
It consists of 1B. The outer peripheral surface of the mounting portion 24 and the inner peripheral surface of the first mold B21B have a predetermined distance.

The mounting portion 24 of the first die A21A
On the end face of the metal ring 3, a so-called frusto-conical inner pressing protrusion having a tapered surface for pressing the inner end surface of the metal ring body 4 of the metal ring 3 so that the inner end surface side of the metal ring body 4 has a small diameter. 25 are provided at equal intervals on the circumference, and as a pressing protrusion that faces the inner pressing protrusion 25 and presses the outer end surface of the metal ring main body 4 against the second mold 23, the outside of the metal ring main body 4 A plurality of so-called frustoconical outer pressing projections 26 having a tapered surface with a small diameter on the end surface side are provided on the circumference in equal distribution. In the present embodiment, the end faces of the metal ring body 4 are evenly arranged so as to be pressed uniformly, but the present invention is not limited to this, and the end faces may be not evenly arranged as long as the end faces can be securely pressed.

Next, a method of molding the oil seal 1 using the molding die 20 will be described.

First, the first die A21A is provided with a first outer peripheral portion.
The second mold B21B is assembled to form the first mold 21,
The metal ring 3 is placed on the placing portion 24 of the first die A21A. In this mounting, the inner end surface of the metal ring main body portion 4 of the metal ring 3 is brought into contact with the inner pressing protrusion 25, and the inner peripheral surface of the annular bent portion 5 is engaged with the outer peripheral surface of the mounting portion 24. Then, a rubber material 27 as a molding material is placed on the end surface of the mounting portion 24 of the first die A21A on the inner peripheral side, and the outer pressing protrusions 26 of the second die 23 press the metal ring body 4 By closing the second mold 23 with respect to the first mold 21 so as to press the outer end surface, a predetermined shape is formed between the mold matching surfaces of the first mold 21 and the second mold 23. Cavity 22 is formed.

When the mold is closed, the rubber material 27 is pressurized and heated so as to be fluidized, and the cavity material 22 is filled with the rubber material 27 to be molded into a predetermined shape following the shape of the cavity 22 (see FIG. 3). .

At this time, the fluidized rubber material 27 is pressed from the inner side to the outer side of the metal ring 3 on both side end faces of the metal ring body 4 to hold the outer and inner pressing protrusions (hereinafter simply referred to as pressing protrusions). Flows through 25,26. At this time, since the pressing projections 25 and 26 are frustoconical, that is, the end surface side of the metal ring body 4 is a tapered surface having a small diameter, the fluidized rubber material when the mold is closed. Since the flow resistance of 27 when flowing from the inner peripheral side to the outer peripheral side is small and the peripheral surface is circular, the flow pressing protrusions 25, 2 can be smoothly moved.
6 is easily fused on the outer peripheral side, and the pressing protrusions 25, 2
Since the flow path between the circumferential directions of 6 can be made large, a weld mark does not occur at the outer peripheral side portions of the pressing protrusions 25 and 26 as in the prior art. In addition, in this embodiment, FIG.
As shown in (4), since the pressing projections 25 and 26 are provided in a staggered manner in the radial direction, the flow is facilitated also in the circumferential direction, so that the occurrence of weld marks can be further prevented.

Further, the pressing projections 25 and 26 have a small diameter on the end face side of the metal ring body 4, and conversely, since they have a large diameter toward the base, the metal ring body 4 has a large diameter. The force to hold down is never reduced. That is, since the pressure on the end surface of the metal ring main body 4 can be increased and the metal ring 3 can be firmly fixed (pressed), the metal ring 3 can be fixed by the pressure when the fluidized rubber cloth 27 flows. It does not move and the moldability is improved.

After the rubber material 27 is vulcanized and cured,
The mold is opened and the molded product is released. At this time, the seal lip portion 6, the outer periphery fitting portion 7, and the elastic body portion 8 are integrally joined to the metal ring 3 by the outer connecting wall portions 9 and the inner connecting wall portions 10 on both end surfaces of the metal ring main body portion 4. Therefore, the outer connecting wall portion 9 and the inner connecting wall portion 10 are formed with a truncated cone-shaped hole 14 following the shape of the pressing protrusions 25 and 26. After releasing the mold, the excess rubber material 27 is cut to form the oil seal 1.

In the above embodiment, the pressing protrusion for pressing the end face of the metal ring body 4 of the metal ring 3 as the insert member has a truncated cone shape, but as shown in FIG. Semicircular holding projections 25A, 26A, triangular pyramid holding projections 25B, 26B, or square pyramid holding projections 25.
It may be C or 26C.

Further, the description has been made by taking the case where the first die 21 and the second die 23 are provided with the holding projections respectively to hold the end faces on both sides of the metal ring body 4 as an example. Although the force for pressing the four end faces may be weakened, it may be provided in at least one of the molds.

Further, as the molding method, the case where the fluidized molding material is flowed from the inner peripheral side to the outer peripheral side for molding has been described as an example, but the same applies to the case of molding by flowing from the outer peripheral side to the inner peripheral side. can do.

Although the oil seal has been described as an example of the insert molded product, the present invention is not limited to the oil seal, and various insert molded products in which an annular insert member is embedded in an annular molded product body can also be used. it can.

[0031]

According to the present invention having the above-mentioned structure and operation, the pressing projection for pressing the end surface of the insert member has a tapered surface having a small diameter on the end surface side of the insert member. When the molded molding material flows from the inner peripheral side to the outer peripheral side, the flow resistance between the pressing protrusions can be reduced and the flow path between the pressing protrusions can be increased. As a result, since it smoothly flows from the inner peripheral side to the outer peripheral side and is completely fused on the outer peripheral side, the weld mark does not occur on the outer peripheral side portion of the hole in the insert molded product unlike the prior art, and the quality is improved. Can be improved.

Further, since the base portion of the pressing projection has a large diameter, the force for pressing the end surface of the insert member does not become small. That is, since the pressure on the end surface of the insert member can be increased, the insert member can be reliably fixed to the mold. As a result, the insert member does not move due to the pressure of the fluidized molding material during molding, and the moldability is improved.

[Brief description of drawings]

FIG. 1 is a cutaway perspective view of an oil seal as an insert molded product according to an embodiment of the present invention.

FIG. 2 (a) is a half sectional view showing a mold opening step of a molding die in a method for manufacturing an oil seal as an insert molded article according to an embodiment of the present invention, and FIG. 2 (b) is the same. It is a perspective view of the presser projection part of FIG.

FIG. 3 is a half cross-sectional view showing a mold closing process of the molding die of FIG.

4A and 4B show another mode of the shape of the presser projection. FIG. 4A is a perspective view of the semicircular presser projection, and FIG. 4B is a plan view of the triangular pyramid presser projection. In the figure, FIG. 3C is a plan view of the holding projection of the quadrangular pyramid.

FIG. 5 is a cutaway perspective view of an oil seal as a conventional insert molded product.

FIG. 6 (a) is a half cross-sectional view showing a mold opening step of a molding die in a method of manufacturing an oil seal as a conventional insert molded product, and FIG. 6 (b) is a presser foot of FIG. 6 (a). It is a perspective view of a protrusion.

[Explanation of symbols]

 1 Oil Seal (Insert Molded Product) 2 Molded Product Main Body 3 Metal Ring (Insert Member) 4 Metal Ring Main Body Part 5 Annular Bend Part 6 Seal Lip Part (Inner Circumference Meat Part) 7 Outer Peripheral Fitting Part (Outer Meat Part) 8 Elasticity Body part 9 Outer connecting meat part 10 Inner connecting meat part 11 Seal lip 11A Lip tip 12 Dustrip 13 Spring holder 14 Hole 20 Forming die 21 First die 21A First die A 21B First die B 22 Cavity 23 Second mold 24 Mounting portion 25, 25A, 25B, 25C Inner pressing protrusion 26, 26A, 26B, 26C Outer pressing protrusion 27 Rubber material (molding material)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29L 31:26

Claims (2)

[Claims] 1. A structure comprising an annular insert member embedded in an annular molded product body to be molded, wherein the meat of the molded product body is joined to the inner peripheral side and the outer peripheral side of the insert member. In the insert molded product in which a connecting meat portion that connects an inner peripheral wall portion and an outer peripheral wall portion is joined to the insert member end surface, a connecting meat portion of the molded product body joined to the insert member end surface is an insert. An insert-molded article, characterized in that a plurality of holes having tapered surfaces such that the end surface side of the member has a small diameter are provided. 2. A pair of molds which can be opened and closed with respect to each other are opened, an insert member is inserted, and when the mold is subsequently closed, a pressing projection provided on at least one mold presses the end surface of the insert member, A molding material is caused to flow to the inner peripheral side and the outer peripheral side of the insert member via the pressing protrusions on the end surface of the insert member, and the inner peripheral wall portion and the outer peripheral wall portion are connected at the insert member end surface to form an insert molded product of a predetermined shape. In the method for manufacturing an insert-molded product to be molded, the pressing protrusion on the end surface of the insert member has a tapered surface such that the end surface side of the insert member has a small diameter.