JPH0392419A - Stabilizer link for automobile and manufacture thereof - Google Patents

Abstract

PURPOSE:To simply obtain a high-performance stabilizer link by molding a link main body with synthetic resin, and setting the undercut ratio of the opening section of a socket section to the preset ratio or above. CONSTITUTION:A link main body 1 is integrally molded with synthetic resin, and the undercut ratio U which is the ratio between the value L-S subtracted with the diameter S of an opening section from the maximum diameter L of a recess coupled with the ball section 5 of a socket section 3 and the maximum diameter L of the recess is set to 10% or above. A mold with a cavity formed in the whole protruded shape of the link main body 1 having socket sections 3 and 3 on both the right and left ends of a connecting rod 2 is formed by the general technology. An insertion core section forming the socket section 3 is formed with the noncrystalline synthetic resin thermally deformed at 90 deg.C or above as a throwaway core. The link main body 1 is molded with this cavity and cores and can be simply molded.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention utilizes a synthetic resin for a part of the stabilizer link, which is a part of an automobile stabilizer installed to improve the running stability of an automobile, etc. , relates to technology that aims to reduce weight, reduce costs, and improve weather resistance.

"Prior Art" As shown in Fig. 7, a conventional stabilizer link for an automobile has a link body C having socket parts B, B at both left and right ends of a connecting rod A, and a ball part D in the socket parts B, B. ，
A ball joint body F, F consisting of a ball joint D and mounting support arms E and E extending from the ball part D is fitted so that the ball part D can be relatively displaced, and the mounting support arm E extending from the ball part D is fitted. It is attached so that it can be changed freely within a predetermined effective angle range.

All of the parts of conventional automobile stabilizer links were usually made of metal. Therefore, many manufacturing processes such as metal cutting, pressing, assembly, and welding are required, which results in high manufacturing costs and heavy weight, so improvements in this respect have been requested. For this reason, attempts are being made in various fields to make some of the parts synthetic resin. As a result, research and development is currently underway to mold the entire link body C out of synthetic resin.

However, since the resin products developed to date are manufactured using conventional resin molding methods, they have not yet reached the point where they meet the required values in terms of both cost and performance. "Problems to be Solved by the Invention" That is, the stabilizer link for an automobile has a socket part B, a ball joint body F in B, a ball part D of F,
There is a so-called ball-and-socket joint structure where D is fitted into E and H so that they can be relatively displaced, but these fitting parts E and E have an undercut structure so that they will not be inadvertently applied even if a load exceeding a predetermined value is applied. Make sure that the ball part does not come off.

The design requirement is a pull-out load of 140kg to 250kg.
g, tensile load/compressive load in the connecting rod direction is 200~
500 kg, ASSY fatigue test over 100,000 times without damage. In addition, the conventional metal stabilizer link shown in Fig. 7 (ball diameter 18mmφ
), the pullout load/compression load is 200 to 213k.
g, tensile load and compressive load in the connecting rod direction are 200 to 5
00kg, ASSY fatigue test over 150,000 times without damage,
It becomes.

In order to satisfy these requirements even with synthetic resin molded products and to be able to press-fit the ball part in the final process,
The undercut ratio U (diameter L of the ball - diameter S of the opening / diameter L of the ball) at the opening of the socket part is set to 10 to
20% (preferred general-purpose undercut skewer U12-15%
). However, when an insert core is forcibly extracted from a conventional synthetic resin undercut structure, the undercut ratio U7.5% is usually the upper limit. For this reason, it has been said that resin stabilizer links for automobiles molded using conventional manufacturing methods cannot sufficiently meet the required durability performance against pull-out loads and tensile loads due to the low undercut ratio.

The undercut rate is reduced to 10% using existing resin molding methods.

In order to increase the size, the core must be constructed so that it can be disassembled, the joints must be finished, and accuracy cannot be maintained.
Moreover, the assembly work of the core part, the disassembly work, the repair work after molding, etc. are too time-consuming, resulting in a very high cost. As a result, there is no point in changing the material of conventional metal products to synthetic resin molded products. The present invention solves the above-mentioned technical problem by using a thermosetting resin material for the cavity part and using a thermally deformable material for the 7 part, and utilizing the difference in the properties of the two when heated. 1
Even with a 0% to 20% undercut structure, the inserted core part can be easily removed from the socket part, making it possible to easily, low-cost, and high-performance synthetic resin molding of automotive stabilizer links. This allows for the manufacture of products.

"Means for Solving the Problems" Means for solving the above problems of the present invention are as follows.

The first invention to be patented is a ball joint body consisting of a link body having socket parts at both left and right ends of a connecting rod, a ball part in the socket part, and a mounting support arm extending from the socket part. In the automobile stabilizer link, the ball part is fitted so as to be relatively displaceable, and the mounting support arm extending from the ball part is attached so as to be able to change freely within a predetermined effective angle range. The main body is molded from synthetic resin, and the undercut ratio of the opening in the socket part is set to 10.
% or more.

The present invention is characterized in that the link body portion is integrally molded from synthetic resin, and that the socket portion, which cannot be molded using normal resin molding methods, has an undercut ratio of 10% or more.

The second invention to be patented is a ball joint body consisting of a link body having socket parts at both left and right ends of a connecting rod, a ball part in the socket part, and a mounting support arm extending from the socket part. In the automobile stabilizer link, the ball part is fitted so as to be relatively displaceable, and the mounting support arm extending from the ball part is attached so as to be able to change freely within a predetermined effective angle range. The connecting rod is formed of a hard material such as metal, the socket part is molded of synthetic resin, and the two are connected to form a link body, and the undercut ratio of the opening in the socket part is 10% or more. This is an automotive stabilizer link that is characterized by: In this second invention, only the socket part of the link body is integrally molded with synthetic resin, and when the span of both the left and right socket parts is long, the flexure rate of the connecting rod increases due to the physical properties of the synthetic resin material. This is effective when trying to make corrections or reduce costs. The third invention for which a patent is sought is a ball joint consisting of a link body having socket portions at both left and right ends of a connecting rod, a ball portion in the socket portion of the link body, and a mounting support arm extending from the ball portion. A stabilizer link for an automobile, wherein the body is fitted with the ball part such that the ball part can be relatively displaced, and the mounting support arm extending from the ball part can be freely changed within a predetermined effective angle range. A method for manufacturing a stabilizer/riser link for an automobile, characterized in that it is manufactured by the following means (a) to (ii). (a) A cavity part is formed as a mold by molding the entire convex shape of the link body which has socket parts at both left and right ends of the connecting rod, and a recess of the socket part with an undercut structure of the link body. The core part for the insert is molded with a cavity shape that allows the shape and mounting support arm to change freely within a predetermined effective angle range, and is molded using an amorphous synthetic resin material that is thermally deformed at a high temperature of 90°C or higher. I'll keep it.

(b) Next, a mold for forming a link body is made by combining the cavity part and the core part for insert, and a mold having a heat deformation temperature (90°C) or higher of the core part for insert is placed in the mold for forming link body. A crystalline synthetic resin material whose physical properties do not deteriorate even at high temperatures is poured and hardened to form a link body intermediate molded product in which an insert core part is embedded in a socket part with an undercut structure.

(C) Next, the entire link body intermediate molded product is heated at a temperature higher than the heat distortion temperature (90°C) of the insert core part and within a range where the material properties of the crystalline synthetic resin material of the cavity part do not deteriorate. The insert core is heated to a high temperature and is pulled out from the undercut opening of the socket while being thermally deformed to form a link body made of synthetic resin.

(2) Thereafter, the ball part of the ball joint body is press-fitted into the socket part of the link body from the opening thereof, and the ball part is fitted so as to be relatively displaceable, and the mounting support arm is rotated at a predetermined effective angle. It is attached so that it can be changed freely within the range of . That is, the third invention is a method for manufacturing the automobile stabilizer link according to the first invention. The fourth invention to be patented is a ball joint consisting of a link body having socket parts at both left and right ends of a connecting rod, a ball part in the socket part of the link body, and a mounting support arm extending from the socket part. An automobile stabilizer link is attached to the body so that the ball part is fitted so as to be relatively displaceable, and the mounting support arm extending from the ball part can be freely changed within a predetermined effective angle range. A method for manufacturing an automobile stabilizer link, characterized in that it is manufactured by the following means (a) to (e). (a) A cavity part molded in the shape of the convex part of the socket part with the connecting part is formed as a mold, and the shape of the concave part of the socket part with an undercut structure and the mounting support arm are within a predetermined effective angle range. The core part for the insert, which has a shape of the void that can be freely changed, is molded using an amorphous synthetic resin material that can be thermally deformed at a high temperature of 90° C. or higher.

(b) Next, a mold for forming a socket part with a connecting part is made by combining the cavity part and the core part for insert, and the thermal deformation of the core part for insert is placed in the mold for forming a socket part with a connecting part. A crystalline synthetic resin material whose physical properties do not deteriorate even at high temperatures is poured and cured to create an intermediate molded socket part with a connecting part in which the core part for the insert is embedded in the socket part with an undercut structure. Form. (c) Next, the entire socket intermediate molded product with the connecting part is heated at a temperature higher than the heat deformation temperature of the insert core part and within a range where the material properties of the crystalline synthetic resin material of the cavity part do not deteriorate. The insert core is heated to a high temperature and is thermally deformed while being pulled out from the undercut opening of the socket to form a synthetic resin socket with a connecting part. (2) A connecting rod with connecting parts at both left and right ends is formed of a hard material such as metal, and the connecting rod with connecting parts and a socket with connecting parts molded from synthetic resin are connected to each other. The link body is formed by continuously extending through the connecting portion.

(e) Thereafter, the ball part of the ball joint body is press-fitted into the socket part of the link body from the opening thereof, and the ball part is fitted so as to be relatively displaceable, and the mounting support arm is fitted at a predetermined effective angle. It is attached so that it can be changed freely within the range of . That is, the fourth invention is a method for manufacturing the automobile stabilizer link according to the second invention. "
Embodiment 1 [Embodiment 1] The present invention will be described in detail below based on illustrated embodiments.

1 and 2 are front views showing a stabilizer link for an automobile according to the first invention of the present application, and FIG. 3 is a side view of a main part cut away from FIG. 1. In the figure, 1 is a link body having socket parts 3.3 at both left and right ends of the connecting rod 2, and 4.4 is a link body comprising a ball part 5.5 and mounting support arms 6, 6 extending from the ball part 5.5. It is a ball joint body.

The socket portion 3.3 of the link body 1 has a ball portion 5.
．． 5 are fitted together so that they can be relatively displaced, and the mounting support arm 6.6 extending from the ball part 5.5 is attached so that it can be freely changed within a predetermined effective angle range 7. It is. The features of the present invention are that the link body 1 is integrally molded from synthetic resin, and that the undercut ratio of the opening in the socket portion 3 is approximately 10% or more. Here, the undercut ratio U is calculated by calculating what percentage of the maximum diameter L of the recess is the value obtained by subtracting the diameter S of the opening from the maximum diameter L of the recess into which the ball part fits. , refers to the narrowing ratio of the opening.

A synthetic resin molded product with an undercut rate of approximately 10% or more is a shape that cannot be manufactured using conventional synthetic resin molding methods, and it was not until the new molding method described below was developed that molding was possible. This is a new shape that has become possible.

Note that the undercut rate that can be conventionally molded is limited to 7.5%, which allows forcible removal of the insert core.

In the case of the present invention, the undercut rate is approximately 10 to 20%.
It is desirable to do so. Because the undercut rate is 1
This is because if it is less than 0%, the pullout strength, tensile strength, impact strength, etc. may not meet the required values. Furthermore, if the undercut ratio is set to 20% or more, it will become more difficult than necessary to fit the ball portion of the ball joint body later. In the case of medium-sized and small-sized passenger cars, an undercut rate of 12 to 15% is a versatile and preferable value, in order to ensure that the required strength value is met and to improve manufacturing efficiency. .

In addition, in consideration of strength, rigidity, chemical resistance, sliding/friction/wear properties, manufacturing method, etc., preferable synthetic resins for manufacturing the link body 1 include Duracon, Delrin, polyethylene, Ubital, etc. Any polyacetal resin may be used.

In other words, the synthetic resin that can be used is any crystalline synthetic resin material whose physical properties do not deteriorate even at a certain high temperature. In addition, 8 in the figure is a cover dust that seals to protect the relative displacement part between the socket part 3.3 and the ball joint body 4.4. In the embodiment shown in FIG. 2, the orientations of the ball joint bodies 4, 4 attached to the link body 1 are different on the left and right sides. The design can be changed to suit the structure of the vehicle and the installation location. Therefore, if necessary, the sixth
As shown in the figure, a plurality of socket parts 3a and 3b are provided at one end,
Each ball joint body 4a. 4b may be attached.

The results of a performance evaluation test of the automotive stabilizer link according to the present invention shown in Figure 1 were as follows. ASSY fatigue test for stabilizer> relative displacement 42m
I rubbed it over 150,000 times with m, but the ASSY
There is no abnormality in the condition, and there is no abnormal wear such as rattling. This is similar to the test results for conventional metal products.

In other words, the required value is that the product should not be damaged even after being used 100,000 times or more, so this performance evaluation is passed.

Low-temperature impact load test> After cooling to -35°C, an impact load of 380 kg was applied 10 times in the axial direction at room temperature, but no abnormalities such as damage or cracks were observed.

That is, the required value is such that no abnormality is observed under an impact load of 250 kg or more, so the performance evaluation in this aspect is also passed.

Pull-out strength test> In the direction of the opening in the socket part 3, which is the mounting
A pull-out test was conducted under a load of 50 kg, but no breakage occurred.Although a load of 500 kg was applied in the direction of pressing the mounting support arm against the socket part 3, no breakage occurred. In other words, the required value is a pull-out load of 100 kg to 1
Since the weight is supposed to be 50 kg or more, the product of the present invention fully satisfies this required value. Tensile/compression load test〉 When the connecting rod was pulled with a load of 250 kg in the axial direction of the connecting rod and compressed, no abnormalities such as damage or cracks were observed in the ball-and-socket joint structure. However, due to the elasticity of the material, there is a tendency for the deflection under load to appear slightly larger than for metal products, so care must be taken when designing the shape depending on the length of the connecting rod. <Lace link strength test> We observed the state of change in the ball and socket joint structure when the connecting rod was gradually pulled and compressed to a load of 1,000 kg in the axial direction, and in the case of the present invention, 730 kg.
A part of the resin part buckled due to the tensile or compressive load of 950 kg, and the ball part of the ball joint body fell off from the socket part due to the compressive load of 950 kg. When the same test was conducted on a conventional metal product, the connecting rod buckled under a compressive load of 920 kg, and the ball portion of the ball joint body 4 fell out of the socket portion under a tensile load of 980 kg. As a result, although the parts and order in which damage begins to occur under high loads are different between this @invention product and conventional metal products, both
It can withstand up to around 100 kg, so there is no practical problem.

<Chemical resistance test> Oil resistance, anti-rust wax resistance, grease resistance, etc. were tested as follows.

(a) First, the oil resistance test was performed by applying all-season type oil to the entire surface and leaving it at 80±2℃ for one week.
When the above-mentioned pull-out test was conducted, there was no change in the performance evaluation, and there were no abnormalities such as deformation or cracks in the resin part.

(b) Next, the anti-rust wax property test was conducted using CC oil (
Nippon Paint Co., Ltd.) was applied to the entire surface and left at 40±2° C. for 24 hours, and then subjected to the above-mentioned pull-out test. There was no change in the performance evaluation, and there were no abnormalities such as deformation or cracks in the resin part.

(c) Furthermore, in the grease resistance test, the above-mentioned pull-out test was performed after coating the entire automobile wheel bearing and leaving it for 24 hours at 40 ± 2 ° C. There was no change in performance evaluation, and no deformation of the resin part. There were no abnormalities such as cracks.

As a result, it was found that the present invention had no problems with chemical resistance.

[Embodiment 2 The stabilizer link for an automobile shown in FIG. 8 is an embodiment of the second invention of the present application.

In this embodiment, the link body 1 is not entirely made of resin, but the connecting rod 2 is made of a hard material such as metal, and connecting portions 2a, 2a are provided at both left and right ends of the connecting rod 2. Further, the socket portion 3.3 is molded from a composite resin and has connecting portions 3a, 3a.

A feature of the link body 1 is that these two parts are connected by a connecting fitting 9.9 to form the link body 1. This is practical when the connecting rod 2 is relatively long and the left and right socket parts 3 have a large span. This is because when using elastic synthetic resin materials, if the amount of deflection exceeds the required limit due to the nature of the material, this can be prevented and it is useful for reducing material costs. be.

The automobile stabilizer link according to the second invention is also characterized in that the undercut ratio of the opening in the socket portion 3.3 is 10% or more.
The effect in this respect is almost the same as the first invention, so
It is omitted here.

[Example 3] Next, a manufacturing method of the example of the automobile stabilizer link shown in FIG. 1 will be described.

First step: Manufacture of resin molds for the cavity portion 10 and insert core portion l1.

First, as shown in FIG. 9, a cavity part 10 is formed as a mold in which the entire convex shape of the link body l having the socket parts 3.3 at both left and right ends of the connecting rod 2 is molded. . The method for manufacturing this mold is a general-purpose technology, so it will be omitted here.

At the same time, the core part 11 for the insert, which has been molded to have the recess shape of the socket part 3.3 with the undercut structure of the link body 1 and the shape of the gap that allows the mounting arm to change freely within a predetermined effective angle range, is heated at 90°C. Molded using an amorphous synthetic resin material that is thermally deformed at higher temperatures (No. 10)
Figures (a) (b)). This point is a new technical component that forms the main part of the present invention. That is, unlike conventional molds, the insert core portion 11 is a dummy mold made of synthetic resin that is disposable each time the link body 1 is molded. This is 9
It is characterized in that it does not harden even when heated to a high temperature of 0° C. or higher, and can be easily pulled out even if it is thermally deformed and has an undercut structure.

Second process: Forming the link body intermediate or shaped product.

Next, the cavity part 10 and the insert core part 1 are
A mold for forming a link body is made by combining 1 and 1, and a crystalline synthetic resin material whose physical properties do not deteriorate even at a high temperature higher than the heat deformation temperature of the core portion 11 is poured into the mold and hardened. Then, a link body intermediate molded product is formed in which the insert core part 11 is embedded in the socket parts 3, 3 having an undercut structure.

Third step: Formation of the link body made of two-glue resin.

Next, the entire link body intermediate molded product is heated to a high temperature (for example, 130° C.) that is higher than the heat deformation temperature of the insert core portion 11 and within a range that does not deteriorate the material properties of the crystalline synthetic resin material of the cavity portion. The insert core part 11 is heated to a temperature of 10.degree. C. and pulled out from the undercut opening of the socket part 3.3 while thermally deforming the insert core part 11 to form a link body 1 made of synthetic resin. Fourth step: Installation of the two-ball joint body. Thereafter, the ball portion of the ball joint body 4 is press-fitted into the socket portion 3.3 of the link body 1 through its opening, and the mounting support arm is attached so as to be freely variable within a predetermined effective angle range.

In the manner described above, the automobile stabilizer link of the embodiment shown in FIGS. 1 and 2 is manufactured. [Embodiment 4] Next, a manufacturing method of the embodiment of the automobile stabilizer link of the second invention shown in FIG. 8 will be explained. In this, only the socket part 3.3 of the link body 1 is made of resin,
The connecting rod 2 is characterized by being made of a hard material such as metal. First step: Formation of a synthetic resin mold for the cavity part 10 of the socket part with connecting part and the core part 11 for insert.

A cavity portion having the convex shape of the socket portion with a connecting portion is formed as a mold. At the same time, the core part l1 for the insert, which has been molded with the shape of the concave part of the socket part having an undercut structure and the shape of the gap in which the mounting support arm can freely change within a predetermined effective angle range, is thermally deformed at a high temperature of 90 degrees Celsius or higher. It is molded using an amorphous synthetic resin material. Second process: Formation of intermediate molded product of socket part with connecting part.

Next, a mold for forming a socket part with a connecting part is made by combining the cavity part and the core part for the insert, and the mold is heated to a temperature higher than the heat deformation temperature of the core part in the mold for forming a socket part with a connecting part. A crystalline synthetic resin material whose physical properties do not deteriorate even when exposed to heat is poured and cured to form an intermediate molded socket part with a connecting part in which the core part for the insert is embedded in the socket part with an undercut structure. Third step: Shape the socket with a synthetic resin connecting part.

Next, the entire intermediate molded product of the socket part with the connecting part,
The undercut structure of the socket part is formed by heating to a high temperature above the thermal deformation temperature of the core part and within a range in which the physical properties of the crystalline synthetic resin material of the cavity part do not deteriorate, thereby thermally deforming the insert core part. Pull it out from the opening marked with , and form a socket with a synthetic resin connecting part. Fourth step: Forming the link body.

A connecting rod having connecting portions at both left and right ends is formed of a hard material such as metal, and the connecting rod with connecting portions and a socket portion with connecting portions molded from synthetic resin are connected so that the mutual connecting portions are connected. to form a link body.

Fifth step: Installing the ball joint body.

Thereafter, the ball portion of the ballge β point body is press-fitted into the socket portion of the link body from the opening thereof, and the mounting support arm is attached so as to be freely variable within a predetermined effective angle range.

``Effects'' As mentioned above, the manufacturing process can be simplified by making the link body or socket part of an automobile stabilizer link into a synthetic resin, and forming a socket part with an undercut structure in the resin part. As a result, the cost has been significantly reduced compared to conventional metal products, and it has also been made easier to measure. Furthermore, the product of the present invention can provide a high-performance product that is comparable in performance evaluation to conventional metal products.

Further, in the third and fourth inventions of the present application, the insert core part 11 is molded using an amorphous synthetic resin material that is thermally deformed at a high temperature of 90° C. or higher, and the cavity part l○ and the insert core A socket part with an undercut structure is formed by pouring a crystalline synthetic resin material whose physical properties do not deteriorate even at high temperatures into a link body forming mold made by combining the parts 11 and 11, and hardening the material to form a socket part with an undercut structure. After forming an intermediate molded product in which the ball joint body 4 is embedded in the socket portion of the socket, it is heated to a high temperature of 90°C or higher so that only the ball joint body 4 is thermally deformed. The ball joint body 4 can be easily pulled out from the socket part 3 of the structure, and the undercut rate, which was conventionally considered difficult to mold with resin, is 10.
% or more of parts can be easily molded. As a result, manufacturing costs have been significantly reduced and mass production can be carried out efficiently.

[Brief explanation of drawings]

1 and 2 are front views showing a stabilizer link for an automobile according to the first invention of the present application, FIG. 3 is a side view of a cutaway of the main part of FIG. 1, and FIG. FIG. 5 is an explanatory diagram showing the undercut ratio, FIG. 6 is a perspective view of main parts showing another embodiment of the first invention, and FIG. 7 is a perspective view showing how the link is used. FIG. 8(A) is a perspective view showing a conventional automobile stabilizer link.
(A) is a front view showing the embodiment of the second invention, (A) is a front view with a part of the connecting rod that is a component thereof cut away, (
B) is a vertical sectional front view showing a manufacturing method of the socket part with a connecting part, and a front view showing the socket part with a connecting part, and FIG. Figure 10 (a) is an explanatory view showing the state in which the core part for an insert is manufactured, (b) is a front view showing the formed core part for an insert, and Figure 11 is an explanatory diagram showing the state in which the core part for an insert is manufactured. FIG. 12 is a process diagram showing the manufacturing method of the second invention. "Explanation of main symbols" 1...Link body 2...Connecting rod 3...Socket part 4...Ball joint body 5...Ball part 6...Mounting support arm 7...Effective Within the angle range 10... Cavity part 1l... Core part for insert 5 Fig. 6 Fig. 8 Fig. C] 2J4 {Fig. (d) ＾ type stop wide

Claims (4)

[Claims] (1) A ball joint body consisting of a link body having a socket part at both left and right ends of a connecting rod, a ball part in the socket part, and an attachment support arm extending from the ball part, with the ball part being able to move freely relative to each other. A stabilizer link for an automobile that is fitted so that the mounting support arm extending from the ball portion can be freely changed within a predetermined effective angle range, the link body being molded from synthetic resin; , the undercut ratio of the opening in the socket part is 10
% or more. (2) A ball joint body consisting of a link body having a socket part at both left and right ends of a connecting rod, a ball part in the socket part, and a mounting support arm extending from the ball part, with the ball part being able to move freely relative to each other. In an automobile stabilizer link which is fitted so that the mounting support arm extending from the ball portion can be freely changed within a predetermined effective angle range, the connecting rod is made of a hard material such as metal. and the socket part is molded from synthetic resin, and the two are connected to form a link body, and the undercut ratio of the opening in the socket part is 10% or more. Stabilizer link for. (3) A ball joint body consisting of a link body having socket portions at both left and right ends of the connecting rod, a ball portion in the socket portion of the link body, and an attachment support arm extending from the ball portion, with the ball portion facing each other. An automobile stabilizer link that is attached so that it can be displaceably fitted and that the mounting support arm extending from the ball portion can be freely changed within a predetermined effective angle range is attached as follows (a) to A method for manufacturing an automobile stabilizer link, characterized in that it is manufactured by the method of (d). (a) A cavity part is formed as a mold by molding the entire convex shape of the link body which has socket parts at both left and right ends of the connecting rod, and a recess of the socket part with an undercut structure of the link body. The core part for the insert is molded with a cavity shape that allows the shape and mounting support arm to change freely within a predetermined effective angle range, and is molded using an amorphous synthetic resin material that is thermally deformed at a high temperature of 90°C or higher. I'll keep it. (b) Next, a mold for forming a link body is made by combining the cavity part and the core part for insert, and a mold having a heat deformation temperature (90°C) or higher of the core part for insert is placed in the mold for forming link body. A crystalline synthetic resin material whose physical properties do not deteriorate even at high temperatures is poured and hardened to form a link body intermediate molded product in which an insert core part is embedded in a socket part with an undercut structure. (C) Next, the entire link body intermediate molded product is heated at a temperature higher than the heat distortion temperature (90°C) of the insert core part and within a range where the material properties of the crystalline synthetic resin material of the cavity part do not deteriorate. The insert core is heated to a high temperature and is pulled out from the undercut opening of the socket while being thermally deformed to form a link body made of synthetic resin. (d) Thereafter, the ball part of the ball joint body is press-fitted into the socket part of the link body from the opening thereof, and the ball part is fitted so as to be relatively displaceable, and the mounting support arm is rotated at a predetermined effective angle. It can be attached freely within the range of . (4) A ball joint body consisting of a link body having socket portions at both left and right ends of a connecting rod, a ball portion in the socket portion of the link body, and a mounting support arm extending from the ball portion is connected to An automobile stabilizer link that is attached so that it can be displaceably fitted and that the attachment support arm extending from the ball part can be freely changed within a predetermined effective angle range is manufactured using the following method (a) to (a). e)
A method for manufacturing a stabilizer link for an automobile, characterized in that it is manufactured by the following means. (a) A cavity part molded in the shape of the convex part of the socket part with the connecting part is formed as a mold, and the shape of the concave part of the socket part with an undercut structure and the mounting support arm are within a predetermined effective angle range. The core part for the insert, which has a cavity shape that can be freely changed, is molded using an amorphous synthetic resin material that is thermally deformed at a high temperature of 90° C. or higher. (b) Next, a mold for forming a socket part with a connecting part is made by combining the cavity part and the core part for insert, and the thermal deformation of the core part for insert is placed in the mold for forming a socket part with a connecting part. A crystalline synthetic resin material whose physical properties do not deteriorate even at high temperatures is poured and cured to create an intermediate molded socket part with a connecting part in which the core part for the insert is embedded in the socket part with an undercut structure. Form. (c) Next, the entire socket intermediate molded product with the connecting part is heated to a high temperature that is higher than the heat deformation temperature of the insert core part and within a range that does not deteriorate the material properties of the crystalline synthetic resin material of the cavity part. The insert core is heated to 100° C. and pulled out from the undercut opening of the socket portion while thermally deforming the insert core portion to form a socket portion with a connecting portion made of synthetic resin. (d) A connecting rod having connecting portions at both left and right ends is formed of a hard material such as metal, and the connecting rod with connecting portions and a socket portion with connecting portions molded from synthetic resin are connected to each other. They are connected via a connecting part to form a link body. (e) Thereafter, the ball part of the ball joint body is press-fitted into the socket part of the link body from the opening thereof, and the ball part is fitted so as to be relatively displaceable, and the mounting support arm is moved at a predetermined effective angle. It can be attached freely within the range of .