JPH0456164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for applying a ball joint used in suspension systems, steering systems, etc. of automobiles.

Conventional technology As a method for applying this type of ball joint,
As in No. 48-26105, the socket is fixed and the ball stud is forcibly rotated relative to the socket, and the frictional heat generated at this time melts the inner peripheral surface of the thermoplastic polymer compound catch and forms a ball. There is a method that stabilizes the stud swing torque to a desired low torque.

Problems to be Solved by the Invention According to the above conventional method, the conditions for reducing the ball stud swing torque to a desired value are extremely delicate, and the ball stud swing torque after the ball stud starts to hit varies widely. There are drawbacks.

Means for solving the problem The ball joint is forcibly cooled from the outer periphery during the forced relative movement between the socket and the ball stud bulb.

Effect This is thought to be due to the fact that the frictional heat generated by the ball joint is quickly dissipated during the start-up of the ball joint, eliminating abnormal melting of the sheet.

Embodiments The present invention will be described below with reference to drawings of embodiments. The ball joint J is composed of a socket 1, a seat 2 made of a thermoplastic polymer compound that is press-fitted into the socket, and a ball stud 3 having a spherical portion 4 that is fitted into the seat 2. A tongue piece 5 for preventing the ball stud 3 from falling out is formed on one opening edge of the socket 1, and a tongue piece 7 for crimping a closing plate 6 is formed on the opposite opening edge. .

As shown upside down in FIG. 2, the catch seat 2 is made of a thermoplastic polymer compound to have a spherical inner circumferential surface and a substantially cylindrical outer circumferential surface, and has several cuts on its periphery. Grooves 7, 7, . . . are formed at intervals in the longitudinal direction, and are sized to have a large interference so that the socket can be press-fitted with a large internal stress.

Then, the spherical part 4 of the ball stud is attached to the catch seat 2.
After fitting and press-fitting the seat 2 into the socket 1, the closing plate 6 is inserted from below the socket 1 and the tongue pieces are crimped to assemble the ball joint J.

In this assembled state, the seat 2 is press-fitted into the socket 1 with a large interference, and the spherical portion 4 of the ball stud 3 is held by the seat 2 with a strong tightening force.

Then, the ball joint J assembled as described above is brought out by a forced leveling device, which will be described in detail below, so as to allow relative movement between the seat 2 and the ball stud spherical portion 4.

The configuration of this forced leveling device will be explained below. A blind hole 11 is formed on one side of a support 10 set up on a bed 9, and the base end of a connecting rod 12 can freely move inside the blind hole 11. The key 14, which is fixed to the connecting rod 12 and inserted with a predetermined play 13, is inserted into the keyway 15 in the blind hole 11 with some play, and the tip of the connecting rod 12 is free. Although it can move freely, it cannot rotate with respect to the support body 10.

A socket holder 16 having a fitting hole 17 into which the socket 1 can be fitted has a socket holder 16 on one side thereof.
The tip of the connecting rod 12 is screwed, and the tightening screw 18 of the socket 1 is screwed onto the other side.

Below the socket holder 16, a chuck body 19 for holding the ball stud 3 is rotatably supported on the bed 9.

Reference numeral 20 denotes a coolant pipe which supplies a coolant 21 such as air or water to the ball joint J by a coolant supply means such as a blower (not shown).

Further, the pipe line leading to the outlet of the coolant pipe 20 is appropriately provided with means (not shown) for controlling the supply of the coolant 21, such as a flow rate regulating valve and an electromagnetic valve.

When the ball joint J assembled as described above is to be brought into contact, the socket 1 is
As shown in the figure, the ball stud 3 is fitted into the fitting hole 17 of the socket holder 16 and fixed by the screw 18, and the ball stud 3 is fixed by the chuck body 8.

Here, when the ball stud 3 is forcibly rotated relative to the seat 2, friction is generated on their sliding surfaces, and the temperature rise due to the frictional heat causes the seat 2, which is made of a thermoplastic polymer compound, to The inner circumferential surface of the ball stud is melted and flows into the several grooves 7, 7, .

By the way, while the ball stud 3 is rotating relative to the seat 2, the coolant 21 is supplied from the coolant pipe 20 toward the ball joint J for an appropriate period of time according to the desired ball stud rocking torque. , the ball joint J is forcibly cooled from the outer periphery.

As a result of performing hitting while performing forced cooling in this way, as shown in Fig. 3, the products B and C in which forced cooling was performed are compared to the product A in which hitting was performed without forced cooling using the conventional method. Variations in ball stud swing torque between products have been reduced.
It was also found that even if the coolant supply time was changed, the variation in torque between products did not change much compared to the change in torque level.

Figure 3 shows the case where the diameter of the spherical part is 24 mm and the catch is made of polyacetal, and each data A, B,
The length in the vertical direction of C represents the magnitude of variation, and the numbers attached to each data are the maximum and minimum values (unit: Kgm) of the rocking torque measured after the hitting experiment, and the values in parentheses indicate the difference. show.

In the above manufacturing process, a lubricant such as grease is filled in the socket 1 in advance.

In addition, in the above embodiment, the catch seat 8 has several grooves 9,
9... are formed, but a plurality of recesses may be formed instead.

Furthermore, the coolant may be sprayed not only from the closing plate 6 but also from one or several locations on each outer circumference of the ball joint, and temperature detection means for detecting the temperature at appropriate locations on the outer circumferential surface of the ball joint may be provided for forced cooling. The state may also be controlled.

Effects As described above, according to the present invention, by cooling the ball joint from the outer periphery during forced relative movement between the socket and the ball, the ball stud swinging torque can be easily controlled, and the ball stud swinging torque can be easily controlled. Variations in dynamic torque are significantly reduced compared to conventional hitting methods.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a longitudinal sectional side view of a striking device. FIG. 2 is a perspective view of the ball catch. FIG. 3 is a measured torque diagram showing the result of hitting. (Explanation of symbols), J...Ball joint. 2...Ukeza.
3...Ball studs. 4... Spherical part. 8...
groove. 20... Coolant pipe. 21...coolant.

Claims (1)

[Claims] 1 The spherical part 4 is fitted into the seat 2 made of a thermoplastic polymer compound, and the seat 2 is press-fitted into the socket 1 with a large interference to create a large internal stress in the seat. 1 and the spherical part 4 to generate frictional heat on the sliding surface of the spherical part and the seat 4, and this frictional heat melts the inner circumferential surface of the seat 2. Place the dissolved polymer compound on the receiving plate 2.
A method for producing a ball joint in which the flow is caused to flow into a groove 8 or a recess formed in the ball joint J, characterized in that the ball joint J is forcibly cooled from the outer periphery at least during the relative movement.