JPH03125022A - Assembly of ball type universal joint - Google Patents

Abstract

PURPOSE:To mitigate striking sound, and to reduce rattling between a yoke and a spherical body by performing assembly by making relative interval between respective flat surfaces of two hemispherical bodies smaller than that between respective points of fitting parts of yokes through the deformation caused by heating or cooling. CONSTITUTION:A spherical body C for which hemispherical bodies 3, 4 are put together at combination surfaces 5, 6 is inserted into a yoke A in such a way that the spherical body C is sandwiched between flat surfaces 9 and 10 at a point of a fitting part 1 of the yoke A. By cooling the spherical body C, relative interval between the respective flat surfaces 9, 10 is further shortened due to the contraction. By heating the yokes A, B, relative interval between the respective points of fitting parts 1, 2 is elongated due to the expansion. Workability is improved thereby, and a striking sound generated between the respective combination surfaces can be mitigated, and rattling between the yoke and the spherical body in a direction of rotational shaft can thus be improved.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for assembling a ball-shaped universal joint.

(Prior Art) A conventional method of assembling a ball-shaped universal joint will be described below with reference to FIGS. 3 to 7.

FIG. 3 is a perspective view showing an exploded state of the ball-shaped universal joint. Symbols A and B are metal yokes with a trapezoidal cross section and a U-shaped fitting part (lH) with a part of the circle cut out.
2) is formed, and the inner surface of this fitting $m(2) is formed into a partially spherical shape. Symbols (3) and (4) are hemispherical bodies made of synthetic resin, which are combined to form a sphere C with their flat surfaces (5) and (G) facing each other, and on the outer peripheral surface of the sphere C. Two trapezoidal yoke fitting grooves (7) and (8) orthogonal to each other are formed in the centers of the two hemispheres, and the above-mentioned Flat surface (9) (1θ
) is formed on the combined surface of each hemisphere (3) (4) (
5) Elastic body housing recesses (II) (12) are formed in (6) so as to face each other, and the recesses (II) (12)
Small holes (13) and (14) are provided at predetermined positions on the bottom periphery of 2). The small holes (13) (14) are hemispheres (3)
(4) are arranged so as to be offset in the circumferential direction when they are butted against each other.

Reference numeral (15) indicates a coiled spring as an elastic body, and one end of the coiled spring (15) is fitted into the small hole (13), and the other end is fitted into the small hole (14) and inserted into the recess (11). ) (12).

The flat surfaces of the two hemispheres (3) and (4) forming the sphere C (
9) The mutual spacing in (10) is the fitting part of each yoke A and B (
1) It is set slightly smaller than the mutual spacing between the tips in (2).

Next, the assembly method will be explained below.

First, as shown in Fig. 4, the hemispheres (3) and (4) are combined with the combination surfaces (5 and 8) to form a sphere C, and the flat surface ( 9) Insert the sphere C between the fitting parts (1) and (2) of the yoke A so as to sandwich (10) therebetween. Next, by rotating the yoke A by θ0 degrees in the direction of the arrow with the sphere C fixed, the fitting part (1) of the yoke A is inserted into the yoke fitting groove (1) of the sphere C, as shown in FIG.
8) is fitted.

Yoke B is then assembled with sphere C fitted into yoke A in FIG. That is, the yoke B passes through the recess (16) formed in the center of the fitting part (1) of the yoke A, and touches the flat surfaces (9) (10) of the sphere C at the tip of the fitting part (2) of the yoke B. ) is assembled with the sphere C (not shown). Furthermore, by rotating yoke B 90 degrees in the axial direction opposite to said yoke A with yoke A fixed, the fitting part (2) of yoke B fits into the yoke fitting groove (7) of sphere C. and assembled into a ball-shaped universal joint (17) as shown in FIG.

FIG. 7 is a cross-sectional view taken along the line E-E in FIG.
The yoke A applies a twisting force to the hemispheres (3) and (4) in the arrow X or arrow Y direction depending on the positional relationship between the yoke A and the small hole (14) of the hemisphere (4).

This prevents rattling in the rotational direction between the fitting portions (1) and (2) of B and the sphere C. Furthermore, the coiled spring (I5) provides a repulsive force to repel the hemispheres (3) and (4), and is designed to prevent axial wobbling between the yoke A and the yoke 8. It is configured. At this time, as shown in Figure 8, the space between the hemisphere (3) and the hemisphere (4) is pushed apart by the repulsive force of the coiled spring (15), and a gap Z is created between the mating surfaces (5) and (Ei). The above-described assembly of the ball-shaped universal joint is performed with the yokes A, B, and the sphere C at room temperature (problem to be solved by the invention) However, the conventional method of assembling the ball-shaped universal joint described above When an axial load greater than the spring force acts on the coiled spring (15) in the ball-shaped universal joint based on (4
) approach each other, the combination surface (5) and the combination surface (6) come into contact and a hammering sound is generated, and the twisting force in the rotational direction of the coiled spring (15) is canceled out, causing a problem between the yoke and the sphere. There was a problem in that rattling occurred in the rotational direction. When a ball-shaped universal joint in such a state is used, for example, in a wheel steering section of an automobile, the steering force may become heavy or light, resulting in a poor steering feel. Furthermore, if the fit between the yokes A and B and the sphere C is made tight in order to make the gap Z as small as possible, it will be difficult to assemble and the workability will be poor.

(Means for solving the problem) A pair of metal yokes A and B, each having a U-shaped fitting part with a trapezoidal cross section and a partially cut out circle at its tip. and a sphere C made of synthetic resin that connects them, and the sphere C is formed by combining two hemispheres with their combined surfaces facing each other to form a spherical shape. Two trapezoidal yoke fitting grooves (7) and (8) orthogonal to each other are formed at the center of the two hemispheres,
A flat surface parallel to the combination surface is formed at the intersection of the two grooves (7) and (8) of each hemisphere, and an elastic body accommodation recess is formed in the combination surface of each hemisphere.
An elastic body for urging each hemisphere to both sides in the axial direction is housed in the concave portion, and the first yoke A is arranged such that the flat surface of the sphere C is sandwiched between the distal end of the fitting portion of the yoke A. After inserting the sphere C, by tilting it 90 degrees, it is fitted into the first yoke fitting groove (7) of the sphere C, and the second yoke B is fitted into the first yoke fitting groove (7).
By inserting the sphere C through the recess formed in the center of the fitting part of the yoke A so that the flat surface of the sphere C is sandwiched between the tips of the fitting part of the yoke B, and then tilting it 90 degrees.
In the method for assembling a ball-shaped universal joint that is assembled by being fitted into the second yoke fitting groove (8) of the sphere C, at least one of the yokes A, B or the sphere C is deformed in advance by heating or cooling. As a result of this deformation, the distance between the flat surfaces of the two hemispheres is made smaller than the distance between the ends of the fitting portions of the yokes A and B when assembled.

(Function) The function of the structure of the present invention is as follows. By cooling the sphere C in which the hemispheres (3) and (4) are joined together at the combination surfaces (5 and e), the flat surface (9) (
10) becomes smaller due to contraction. Also, by heating the yokes A and B, the fitting parts (1) and (2)
The mutual spacing between the tips of each increases due to expansion. As a result, when the sphere C is inserted into the yoke A or yoke B, the distance between the tip of the yoke A or yoke B and the flat surfaces (3) and (10) becomes larger, improving work efficiency.

In addition, in the method for assembling a ball-shaped universal joint of the present invention, the mutual spacing ΔX of the flat surfaces (9) and (10) is reduced by cooling the sphere C, and the yokes A and B are heated. An enlarged interval Δy is generated in the mutual spacing between the tips of the fitting portions (1) and (2), and an enlarged interval of ΔX+Δy is obtained in total. By this, hemispheres (3) (4) at room temperature
) are combined with the combination surfaces (5) and (6) to form a sphere C, and the mutual distance between the flat surfaces (9) and (10) is defined as the enlarged distance △
Only X+Δy can be set larger than before. With this setting, when the ball-shaped universal joint made by the assembly method of the present invention is returned to room temperature, that is, when the ball-shaped universal joint is actually used, the gap (1G) between the hemispheres (3) and (4) is
) becomes smaller by ΔX+Δy. Therefore, when an axial load greater than the spring force is applied to the coiled spring (15), the hitting noise generated between the combination surfaces (5) (!li) can be reduced, and the rotational axis direction between the yaw and the sphere can be reduced. Embodiment of the present invention will be described below with reference to FIGS. 1 and 2, focusing on the differences from the conventional example. Further, the same reference numerals as those shown in FIGS. 3 to 7 indicate parts having the same names. In this embodiment, a case will be described in which the sphere C is cooled, the yokes A and B are heated, and these are assembled into a ball-shaped universal joint.

FIG. 1 shows the hemispheres (3) (4) and
li) and the fitting part (1) of the yoke A.
) is inserted into the yoke A with the flat surfaces (9) and (10) sandwiched therebetween. Here, the hemisphere (3
)(4) is a flat surface (9H10
), the scrap portion is omitted, the solid line shows the shape at room temperature, and the broken line shows the shape when contracted by cooling. Here, the mutual spacing between the flat surfaces (9) (to) changes from xl at room temperature to X2 when cooling, xl - x2 (=ΔX)
It's only smaller.

Next, in yoke A, the solid line shows the shape at room temperature,
The broken line shows the shape when expanded by heating.
The distance between the ends of the fitting part (1) of the yoke A is y at room temperature.
It changes from t to y2 during heating and expands by y2-yl (=Δy).

As a result of the above, the mutual distance between the sphere C, the flat surfaces (9) and (10), and the tip of the fitting part (1) of the yoke A is △
It is enlarged by X+Δy, and the workability when inserting the sphere C into the yoke A is improved.

Next, as shown in FIG. 4, after inserting the sphere C into the yoke A to a predetermined position, the yoke A is rotated 90 degrees in the direction of the arrow with the sphere C fixed, and as shown in FIG. As shown, the fitting part (1) of the yoke A is fitted into the yoke fitting groove (8) of the sphere C.

Next, the yoke B is connected to the fitting part (
1) through the recess (16) formed in the center of the yoke B.
At the tip of the fitting part (2) of the sphere C, the flat surface (9) (1
0) into the sphere C (not shown).

Furthermore, by rotating yoke B by 90 degrees in the axial direction opposite to said yoke A with yoke A fixed, the fitting part (2) of yoke B is fitted into the yoke fitting groove (7) of sphere C. Together, the ball-shaped universal joint (20) is assembled as shown in FIG. After this, yokes A, B and sphere C
is returned to room temperature. At this time, hemispheres (3) (4) at room temperature
) are combined with the combination surfaces (5) and (G) to form a sphere C, and the mutual distance between the flat surfaces (9) and (10) is the enlarged distance △
Only X+Δy is set larger than before. As a result, the gap Z' becomes smaller than the conventional gap Z by ΔX+Δy.

In the above explanation, the method for assembling the ball-shaped universal joint is described in which the yokes A and B are heated and the sphere C is cooled, but when the yokes A and B are at room temperature and the sphere C is cooled, or The present invention is also applicable to the case where the sphere C is at room temperature and the yokes A and B are heated.

(Effects) As explained above, the method for assembling a globe-shaped universal joint of the present invention improves the workability of assembling a globe-shaped universal joint, and
Since the gap between the mating surfaces of the hemisphere becomes smaller, the hitting noise generated between the mating surfaces when an axial load greater than the spring force is applied to the coiled spring is reduced, and the rotational direction between the yoke and the sphere is reduced. It has the effect of improving dryness.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the assembly method of the embodiment of the present invention, and FIG.
The figure is a front view showing an embodiment of the present invention, FIG. 3 is an exploded perspective view showing the structure of a ball-type universal joint, and FIGS. 4 and 5 are explanatory diagrams showing a conventional method of assembling a ball-type universal joint. FIG. 6 is a front view showing a conventional ball-shaped universal joint, and FIG. 7 is a sectional view taken along the line EE in FIG. 8. A, B... Yoke 1.2... φ fitting part 3.4 Φ... Hemisphere C@ 11 * Sphere 7.8... Yoke fitting groove 15... Elastic body sphere C

Claims (4)

[Claims] (1) A pair of metal yokes A and B, each of which has a U-shaped fitting part with a trapezoidal cross section and a partially cut out circle, and a synthetic resin that connects them. The above-mentioned sphere C is formed by combining two hemispheres with their combined surfaces facing each other to form a spherical shape, and the outer peripheral surface of the sphere C has two hemispheres. Two trapezoidal yoke fitting grooves (7) and (8) orthogonal to each other are formed at the center of the yoke.
A flat surface parallel to the combination surface is formed at the intersection of the two grooves (7) and (8) of each hemisphere, and an elastic body accommodation recess is formed in the combination surface of each hemisphere.
An elastic body for urging each hemisphere to both sides in the axial direction is housed in the concave portion, and the first yoke A is arranged such that the flat surface of the sphere C is sandwiched between the distal end of the fitting portion of the yoke A. After inserting the sphere C, by tilting it 90 degrees, it is fitted into the first yoke fitting groove (7) of the sphere C, and the second yoke B is fitted into the first yoke fitting groove (7).
By inserting the sphere C through the recess formed in the center of the fitting part of the yoke A so that the flat surface of the sphere C is sandwiched between the tips of the fitting part of the yoke B, and then tilting it 90 degrees.
In the method for assembling a ball-shaped universal joint that is assembled by being fitted into the second yoke fitting groove (8) of the sphere C, at least one of the yokes A, B or the sphere C is deformed in advance by heating or cooling. . A method of assembling a ball-shaped universal joint, characterized in that the deformation makes the distance between the flat surfaces of the two hemispheres smaller than the distance between the tips of the fitting portions of each of the yokes A and B. (2) As the sphere C is cooled, the distance between the flat surfaces of the two hemispheres is reduced, and the distance between the flat surfaces of the two hemispheres is reduced to the fitting portion of each yoke A, B. 2. The method of assembling a ball-shaped universal joint according to claim 1, wherein the distance between the tips of the ball-shaped universal joint is smaller than the distance between the tips of the spherical universal joint. (3) By heating the yokes A and B, the distance between the tips of the fitting parts of each yoke A and B expands, and the spherical C
The ball-shaped universal joint according to claim (1), wherein the two hemispheres are assembled so that the distance between the flat surfaces of the two hemispheres is smaller than the distance between the tips of the fitting portions of each of the yokes A and B. How to assemble. (4) As the sphere C is cooled, the distance between the two hemispherical flat surfaces decreases, and the yoke A
, B are heated, the mutual distance between the tips of the fitting parts of each yoke A and B expands, and the mutual distance between the flat surfaces of the two hemispheres of the sphere C increases when the fitting parts of each yoke A and B are heated. 2. The method of assembling a ball-shaped universal joint according to claim 1, wherein the distance between the ends of the joints is smaller than the distance between the ends of the joints.