JP2002013545A - Universal joint of steering system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain proper fitting between a bearing bore and a journal member, and to reduce manufacturing cost by cutting working man-hours and assembly management man-hours. SOLUTION: A rolling roller element 7 can slightly be deformed elastically since at least one of the rolling roller elements 7 is formed in hollow or is formed from a porous body. Therefore, when the rolling roller elements 7 are interposed between a bearing bore 4 of a yoke 1 and a journal member 5 of a spider 3, variations in dimensions of an inside diameter of the bearing bore 4 and an outside diameter of the journal member 5 can be accommodated due to the slight, elastic deformation of the rolling roller elements 7. Accordingly, play and bending torque in the rotational direction can be brought within predetermined control values while maintaining the proper fitting between the bearing bore 4 and the journal member 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a universal joint for a vehicle steering device for transmitting torque between a lower shaft and an upper shaft of a steering shaft while bending and connecting the two shafts.

[0002]

2. Description of the Related Art In a vehicle steering system, since it is necessary to transmit torque while bending a steering shaft at an appropriate position, the steering shaft is divided into a lower shaft, an intermediate shaft, an upper shaft, and the like. The divided shafts are connected by a universal joint.

In such a universal joint,
A pair of yokes are connected by a spider, a pair of shafts of the spider are inserted into a pair of bearing holes of each yoke, and a number of roller rolling elements are inserted between the bearing holes and the shaft via a bearing cup. Is interposed. This conventional roller rolling element is made of solid steel.

At the time of this assembling, since there is dimensional variation in the inner diameter of the bearing hole, etc., the work of adjusting the outer diameter of the shaft portion is performed, and then, while a large number of roller rolling elements are interposed, the bearing hole is inserted into the bearing hole. The shaft is fitted. Thereby, the fitting between the bearing hole and the shaft portion is made appropriate, and the play in the rotating direction and the bending torque are kept within predetermined management values.

[0005]

However, when the fit is too large, no rattling occurs,
On the other hand, when the bending torque is too large, when the fitting is too small, the bending torque is small but rattling may occur.

In view of the above, it is necessary to improve the machining accuracy of the inner diameter of the bearing hole or the outer diameter of the shaft, to prepare a large number of shafts having different outer diameters, and to assemble and control the assembly. By taking measures such as taking time, the fitting between the bearing hole and the shaft is properly maintained. However, on the other hand, the number of processing steps and the number of man-hours for assembling management are large, which may cause a rise in manufacturing costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can appropriately maintain the fitting between a bearing hole and a shaft portion, and can reduce the number of processing steps and assembly control steps. It is an object of the present invention to provide a universal joint for a vehicle steering device that can reduce the manufacturing cost.

[0008]

In order to achieve the above object, a universal joint for a vehicle steering system according to the present invention comprises a pair of yokes connected by a cross-shaped spider and a pair of bearing holes of each yoke. A universal joint of a vehicle steering device, in which a pair of shaft portions of a spider is inserted, and between each bearing hole and the shaft portion, a number of roller rolling elements are interposed via a bearing cup; The roller rolling element is characterized in that it is formed hollow or formed of a porous body.

As described above, according to the present invention, since the roller rolling element is formed hollow or formed of a porous body, the roller rolling element can be slightly elastically deformed. Therefore, when the roller rolling element is interposed between the bearing hole of the yoke and the shaft part of the spider, the roller rolling element is slightly elastically deformed, thereby absorbing dimensional variations in the inner diameter of the bearing hole or the outer diameter of the shaft part. can do. Therefore, the fitting between the bearing hole and the shaft portion is appropriately maintained, and the play in the rotating direction and the bending torque can be kept within the predetermined management values.

[0010] In addition, since it is not necessary to take countermeasure work such as increasing the machining accuracy of the dimensions of the bearing hole or the shaft portion and taking time for assembling management as in the related art, the number of machining steps and the assembly time are reduced. The number of management steps can be reduced, and the manufacturing cost can be reduced.

Further, as described above, when the backlash in the rotating direction or the bending torque is within a predetermined management value, the steering feeling is improved in a small steering angle range of the steering wheel. And the hitting sound can be reduced.

Further, since the roller rolling member is formed in a hollow or formed of a porous material, the weight of the universal joint can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a universal joint of a vehicle steering system according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a side view of a universal joint of a vehicle steering system according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view of the universal joint shown in FIG. 1A. FIG. 1 is a cross-sectional view of a shaft portion of a spiral spider, showing a case where a roller rolling element is formed hollow;
(C) is a sectional view of a shaft portion of the spider, showing a case where a roller rolling element is formed from a porous body.

As shown in FIG. 1A, in a universal joint of a steering shaft, a pair of yokes 1 and 2 are connected by a cross-shaped spider 3, and a pair of bearing holes 4 and 4 of the yoke 1 In each case, a pair of shaft portions 5 and 5 of the spider 3 are inserted.

A number of roller rolling elements 7 are interposed between each bearing hole 4 and the shaft portion 5 via a bearing cup 6. A seal member 8 is provided at an end of the bearing cup 6.

In this embodiment, at least one roller rolling element 7 is formed in a hollow shape as shown in FIG. 1B, or is formed as a porous material as shown in FIG. It is formed from the body. 11 (b) and FIG. 1 (c) show only three roller rolling elements 7 by way of example.

The hollow roller rolling element 7 is formed from a hollow steel tube or the like. On the other hand, the porous rolling element 7 is
For example, it is formed from porous steel such as lotus root, in which bubbles (bore) are elongated and unidirectionally solidified by unidirectionally solidifying a molten raw material in which a large amount of nitrogen gas is dissolved in molten iron. .

As described above, in the present embodiment, since at least one roller rolling element 7 is formed in a hollow or porous body, the roller rolling element 7 is slightly elastically deformed. can do. Therefore, when the roller 7 is interposed between the bearing hole 4 of the yoke 1 and the shaft 5 of the spider 3, the roller 7 is slightly elastically deformed. Can absorb the dimensional variation of the outer diameter. Therefore, the bearing hole 4 and the shaft 5
And the bending torque in the rotation direction can be kept within a predetermined management value by appropriately maintaining the fit with the shaft.

Further, as in the prior art, the bearing hole 4 or the shaft 5
Since it is not necessary to take countermeasure work such as increasing the processing accuracy of the dimensions of the product and taking time for assembly management, it is possible to reduce the number of processing steps and assembly management steps, and to reduce the manufacturing cost. it can.

Further, as described above, when the backlash in the rotating direction or the bending torque is within a predetermined management value, the steering feeling is improved in a small steering angle range of the steering wheel. And the hitting sound can be reduced.

Further, at least one roller rolling element 7
Is formed hollow or made of a porous material, so that the weight of the universal joint can be reduced.

The bearing hole 4 of the yoke 1 and the spider 3
The hollow or porous roller 7 and the solid roller may be interposed between the shaft portions 5.

In this case, the hollow or porous roller 7
If the outer diameter of is formed slightly larger than that of the solid roller rolling element, the hollow or porous roller roller 7 is
When the load is low, the load may be slightly elastically deformed as the load is increased by receiving the load from the shaft portion 5 so as to contact the solid roller elastic body.

Further, a plurality (for example, three) of hollow or porous roller rolling members 7 are symmetrical with respect to the point between the bearing hole 4 and the shaft portion 5, for example, at equal intervals or in the circumferential direction. Both roller rolling elements may be mixed at the same angle.

The present invention is not limited to the above-described embodiment, but can be variously modified.

[0027]

As described above, according to the present invention,
Since the roller rolling element is formed hollow or formed of a porous body, the roller rolling element can be slightly elastically deformed. Therefore, when the roller rolling element is interposed between the bearing hole of the yoke and the shaft part of the spider, the roller rolling element is slightly elastically deformed, thereby absorbing dimensional variations in the inner diameter of the bearing hole or the outer diameter of the shaft part. can do. Therefore, the fitting between the bearing hole and the shaft portion is appropriately maintained, and the play in the rotating direction and the bending torque can be kept within the predetermined management values.

Further, since it is not necessary to take countermeasure operations such as increasing the processing accuracy of the dimensions of the bearing hole or the shaft portion and taking time for the assembly management as in the related art, the number of processing steps and the assembly time are reduced. The number of management steps can be reduced, and the manufacturing cost can be reduced.

Further, as described above, when the backlash in the rotating direction or the bending torque is within a predetermined management value, the steering feeling is improved in a small steering angle range of the steering wheel. And the hitting sound can be reduced.

Furthermore, since the roller rolling elements are formed hollow or formed of a porous material, the weight of the universal joint can be reduced.

[Brief description of the drawings]

FIG. 1A is a side view of a universal joint of a vehicle steering device according to an embodiment of the present invention, and FIG. 1B is a shaft portion of a cruciform spider of the universal joint shown in FIG. FIG. 4 is a cross-sectional view of a case where a roller rolling element is formed in a hollow shape, and FIG. 4C is a cross-sectional view of a shaft portion of a spider, illustrating a case where the roller rolling element is formed of a porous body.

[Explanation of symbols]

 Reference numerals 1 and 2 Yoke 3 Spider 4 Bearing hole 5 Shaft 6 Bearing cup 7 Roller rolling element 8 Seal member

Claims (1)

[Claims] A pair of yokes are connected by a cross-shaped spider, a pair of shafts of the spider are inserted into a pair of bearing holes of each yoke, and a bearing cup is interposed between each bearing hole and the shaft. A universal joint of a vehicle steering device in which a large number of roller rolling elements are interposed, wherein the at least one roller rolling element is formed in a hollow or formed of a porous body. Universal joint of a vehicle steering device.