JP2008051159A - Universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a universal joint capable of minimizing restrictions on a layout in spite of a structure capable of preventing the transmission of vibration caused on one shaft side to the other shaft side, and making torque fluctuation which is caused by the geometric change of one shaft hard to occur. <P>SOLUTION: The universal joint comprises a first yoke 11, a second yoke 12 and a cross shaft 10. The cross shaft 10 is halved to a first joint shaft 21 double-supported by the first yoke 11 and a second joint shaft 22 double-supported by the second yoke 12, and the first joint shaft 21 is connected to the second joint shaft 22 so as to be mutually rockable about an axial center. An elastic member 18 is interposed between the first joint shaft 21 and the second joint shaft 22 in the rocking direction of the first and second joint shaft 21 and 22 to perform the transmission of a rotating force between a first shaft 4 and a second shaft 5 through the elastic member 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a first yoke fixed to the shaft end of the first shaft, a second yoke fixed to the shaft end of the second shaft, and a cross shaft connecting the first yoke and the second yoke. The present invention relates to a universal joint that connects the first shaft and the second shaft having an angular difference so as to be able to transmit a rotational force, and more particularly to a universal joint that is suitable for use in an automobile steering system.

  As an example, this type of universal joint is interposed between a shaft end of a steering shaft (first shaft) of a steering apparatus for an automobile and a shaft end of a pinion shaft (second shaft) of a steering gear box. . Conventionally, the cross shaft of the universal joint is configured by integrally providing the first joint shaft and the second joint shaft so that they cannot be displaced relative to each other.

  Steering devices for automobiles are composed of a steering wheel, steering shaft, steering gear box, etc., and the steering wheel and steering wheel (hereinafter referred to as “steering wheel”) are mechanically connected. The vibration applied to the steering wheel is transmitted to the steering wheel via the universal joint, the steering shaft, etc., and it is easy for the operator to feel uncomfortable. In view of this, a first technique has been proposed in which an elastic joint is provided in the longitudinal intermediate portion of the steering shaft to absorb the above vibration.

As shown in FIG. 5, this elastic joint has a disk formed by an elongated first flange 51 provided at one end of one steering shaft portion 50 and an elongated second flange 52 provided at one end of the other steering shaft portion. A thick rubber plate 53 is sandwiched and fixed. Reference numeral 54 denotes a first holding plate elongated in a direction perpendicular to the first flange 51, 55 denotes a clamping bolt for clamping and fixing, and 56 denotes a nut. In addition to the first technique, the steering shaft is divided into two in the longitudinal direction, and both divided ends are connected via a bush made of a rubber material between the inner and outer cylinders and the inner and outer cylinders. As disclosed in Document 1 and Patent Document 2, there is also a third technique in which a cylindrical rubber material is interposed between the four ends of the cross shaft and the four mounting holes of the yoke. is there.
Japanese Utility Model Publication No. 4-83978 JP-A-9-72348

  However, when the first technique is adopted, the rubber plate has a large diameter, so that a space for disposing the elastic joint is required, which increases layout restrictions. And the number of parts of an elastic joint increases, a structure becomes complicated, and a man-hour (work) is required for an assembly. When the second technique is adopted, the bushing has a large diameter, so that a space for arranging the bushing is required, which increases layout restrictions. In any of the first to third techniques, the structure has elasticity not only in the rotation direction (twisting direction) of the steering shaft but also in the axial direction, so that the center of the universal joint moves in the axial direction. As a result, the geometry of the steering shaft changes, which may cause torque fluctuations.

  As described above, the steering device for an automobile provided with the universal joint having the conventional structure has been described. Even when the universal joint having the conventional structure is provided in another part of the automobile or an apparatus other than the automobile, There may be a problem caused by transmitting the vibration generated on the shaft side to the other shaft side or the above-mentioned problems.

The present invention has been made in view of the above circumstances, and its purpose is as follows.
While it is a structure that can prevent vibration and noise generated on one shaft side from being transmitted to the other shaft side, it can reduce layout restrictions and reduce the number of parts. It is in the point of providing a universal joint that can simplify, simplify assembly, hardly change the geometry of one shaft, and make it difficult to cause torque fluctuation,
For example, when used in a steering system of an automobile, it is possible to prevent vibrations and abnormal noises from being generated in the steering force transmission system of the steering mechanism due to vibrations from the steering wheel, thereby making it difficult for the driver to feel uncomfortable. However, the layout constraints of the steering device can be reduced, the number of parts can be reduced, the structure can be simplified, the assembly can be simplified, the steering shaft geometry is less likely to change, the torque It is in providing a universal joint that can be made less likely to cause fluctuations.

The feature of the present invention is that
In the universal joint described in the [Technical Field] section at the beginning,
The cross shaft is divided into two parts: a first joint shaft that is both-end supported by the first yoke via a bearing; and a second joint shaft that is both-end supported by the second yoke via a bearing; A longitudinal central portion of the first joint shaft and a longitudinal central portion of the second joint shaft are pivotably coupled to each other around an axis that is orthogonal to any longitudinal direction of the first and second joint shafts; An elastic member is interposed between the first joint shaft and the second joint shaft in the swinging direction of the first and second joint shafts to transmit the rotational force between the first shaft and the second shaft. It is in the point performed through an elastic member. (Claim 1)

With this configuration, the following effects can be achieved.
(A) In the swinging direction of the first and second joint shafts, an elastic member is interposed between the first joint shaft and the second joint shaft to elastically transmit the rotational force between the first shaft and the second shaft. Since it performs via a member, the vibration of a rotation direction can be absorbed with the said elastic member among the vibrations which arose on the one shaft side. (Claim 1)
(B) Since there is no elastic member between the first joint shaft and the second joint shaft in the axial direction other than the rotational direction, it is possible to prevent a problem that the center of the universal joint changes in the axial direction, and torque fluctuation Can be difficult to cause. (Claim 1)
(C) The cross shaft is divided into two parts, the first joint axis and the second joint axis, and the central part in the longitudinal direction of the first joint axis and the central part in the longitudinal direction of the second joint axis can swing around the axis. And a structure in which an elastic member is interposed between the first joint shaft and the second joint shaft in the swing direction of the first and second joint shafts, so that an increase in the size of the universal joint can be avoided. it can. Thereby, it is possible to avoid a problem that a new space is required by adopting the above configuration, and it is possible to avoid an increase in layout constraints. And compared with the conventional structure which absorbs a vibration with an elastic joint, the increase in a number of parts can be suppressed and a structure can be simplified and an assembly can be simplified. (Claim 1)
(D) According to the above (A), for example, the shaft end of the steering shaft (corresponding to the first shaft) of the steering device for automobiles and the shaft end of the pinion shaft (corresponding to the second shaft) of the steering gear box In the case of a universal joint provided between them, vibrations in the rotational direction (torsional direction) of vibrations applied to the steering wheel when traveling on rough roads can be absorbed by the elastic member and rotate from the steering shaft to the steering wheel. It is possible to prevent the vibration in the direction from being transmitted, and to make it difficult for the driver to feel uncomfortable. (Claim 1)

In the present invention,
A through hole concentric with the shaft core is formed in a longitudinal center portion of the first joint shaft and a longitudinal center portion of the second joint shaft, and the first joint shaft and the second joint shaft are formed in the through hole. When the first and second joint shafts are pivotably connected to each other around the shaft center by inserting a connecting shaft for connecting the two shafts so as to be relatively rotatable, the following effects can be obtained. . (Claim 2)

  The increase in the number of parts can be suppressed, the connection structure of the first joint shaft and the second joint shaft can be further simplified, and the assembly can be further simplified. (Claim 2)

In the present invention,
Forming a first recess opened in a direction perpendicular to the axis perpendicular to the axis while opening to the second joint axis side and being recessed in a direction along the axis, in the longitudinal center of the first joint axis;
Forming a second recess opened in a direction perpendicular to the axis perpendicular to the axis and being recessed in a direction along the axis while being opened toward the first joint axis in the longitudinal central portion of the second joint axis;
The bottom wall inner surface of the first recess and the bottom wall inner surface of the second recess face each other, the bottom wall of the first recess is between both side walls of the second recess, and the bottom wall of the second recess is If the elastic member is fitted between both side walls of the first recess, the following action can be achieved. (Claim 3)

  The first joint shaft and the second joint shaft can be easily assembled, and a cross shaft can be configured by this assembly. (Claim 3)

In the present invention,
Both the side surfaces of the bottom wall of the first recess and the inner surfaces of the side walls of the first recess in the longitudinal direction of the second joint shaft are configured as a first torque transmission surface, and the longitudinal direction of the first joint shaft The two side surfaces of the bottom wall of the second recess and the inner surfaces of the side walls of the second recess are configured as a second torque transmission surface, and the first torque transmission surface and the second torque transmission facing each other. If the elastic member is interposed between the surfaces, the following effects can be obtained. (Claim 4)

  The rotational force can be reliably transmitted from the first rotational force transmission surface to the second rotational force transmission surface or vice versa. (Claim 4)

In the present invention,
A square shape in which both the side surfaces of the bottom wall of the first recess and the inner surfaces of the side walls of the second recess are positioned closer to the center side in the longitudinal direction of the second joint shaft toward the center side in the longitudinal direction of the first joint shaft. Each formed on the inclined surface of
A square shape in which both the side surfaces of the bottom wall of the second recess and the inner surfaces of the side walls of the first recess are positioned closer to the center side in the longitudinal direction of the first joint shaft toward the center side in the longitudinal direction of the second joint shaft. If formed on each of the inclined surfaces, the following effects can be obtained. (Claim 5)

  By forming each of the surfaces serving as the first rotational force transmission surface or the second rotational force transmission surface in a dogleg shape, the rotational force can be transmitted more reliably. (Claim 5)

In the present invention,
When the first joint shaft and the second joint shaft are formed in the same shape and the same size, the following effects can be obtained. (Claim 6)

  The first joint shaft and the second joint shaft become a common part, so that it is not necessary to distinguish between the two, and the productivity can be increased. (Claim 6)

According to the present invention, it is possible to reduce the restrictions on the layout and reduce the number of parts while the structure can prevent the vibration and noise generated on one shaft side from being transmitted to the other shaft side. Therefore, it was possible to provide a universal joint capable of simplifying the structure and simplifying the assembly, making it difficult for changes in the geometry of one of the shafts to occur, and making it difficult for torque fluctuations to occur.
When used in a steering system of an automobile, vibration and abnormal noise can be prevented from being generated in the steering force transmission system of the steering mechanism due to vibrations from the steering wheel, thereby making it difficult for the driver to feel uncomfortable. Although it is a structure, it can reduce constraints on the layout of the steering device, can reduce the number of parts, simplify the structure, simplify assembly, and change the steering shaft geometry less likely to occur, The universal joint which can make it difficult to cause a torque fluctuation was able to be provided.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
FIG. 4 shows the structure of the steering system of an automobile. Reference numeral 1 denotes a steering wheel, and 2 denotes a steering column supported by a steering hanger 3. The steering gear is a rack and pinion type, and a universal joint is provided between the shaft end 4A of the steering shaft 4 (corresponding to the first shaft) and the shaft end 5A of the pinion shaft 5 (corresponding to the second shaft) of the steering gear box. 100 is provided. The rotation of the steering wheel 1 by the operator is transmitted to the steering gear via the steering shaft 4 to give a steering angle to the front wheels which are steering wheels.

  As shown in FIG. 1, the universal joint 100 has a U-shaped first yoke 11 fixed to the shaft end 4A of the steering shaft 4 and a U-shape fixed to the shaft end 5A of the pinion shaft 5 (see FIG. 4). A character-shaped second yoke 12 and a cross shaft 10 connecting the first yoke 11 and the second yoke 12 are provided. The universal joint 100 connects the steering shaft 4 and the pinion shaft 5 that have an angle difference due to the inclination of the axes of each other so that the rotational force can be transmitted.

  The second yoke 12 includes a cylindrical connecting tube portion 8 at one end in the axial direction. The connecting tube portion 8 is divided at one place in the circumferential direction, and a pair of fastening flanges 9 facing each other is provided at the divided portion. Yes. Then, the spline formed in the shaft end 5A of the pinion shaft 5 is fitted and connected to the spline hole 12H formed in the connecting cylinder portion 8, and the tightening bolt 7 (see FIG. 4) is connected to the bolt insertion hole 13 formed in the pair of tightening flanges 9. ) Is inserted. The tightening bolt 7 fastens and fixes the connecting cylinder portion 8 to the shaft end 5 </ b> A of the pinion shaft 5.

  As shown in FIGS. 1 and 2, the cross shaft 10 is supported at both ends by a first yoke 11 via a bearing 6 (corresponding to a bearing) and a first joint shaft 21 is supported by a second yoke 12 via a bearing 6. The second joint shaft 22 that is supported by both ends is divided into two. The first joint shaft 21 and the second joint shaft 22 have the same shape and the same dimensions, and both end portions in the longitudinal direction of both joint shafts 21 and 22 are formed in a circular cross section and the intermediate portion in the longitudinal direction is formed in a square block shape. . Further, the central portion in the longitudinal direction of the first joint shaft 21 and the central portion in the longitudinal direction of the second joint shaft 22 are swung around the axis O that is orthogonal to the longitudinal direction of any of the first and second joint shafts 21 and 22. It is connected so that it can move and cannot be displaced relative to the direction along the axis O.

The connecting structure will be described in detail. A first recess 31 that is recessed in the direction along the axis O is formed in the longitudinal center portion of the first joint shaft 21, and the longitudinal direction center portion of the second joint shaft 22 is A second recess 32 that is recessed in the direction along the axis O is formed, the first recess 31 is opened in the longitudinal direction of the second joint shaft 22, and the second recess 32 is opened in the longitudinal direction of the first joint shaft 21. It is. That is, the first recess 31 is opened to the second joint shaft 22 side (the direction in which the second joint shaft 22 is disposed) and is recessed in the direction along the axis O, and is perpendicular to the axis O (in a direction perpendicular to the axis O). The second recess 32 is open to the first joint shaft 21 side (the direction in which the first joint shaft 21 is disposed) and is recessed in the direction along the shaft core O. It is open in the direction perpendicular to the axis perpendicular to the axis (width direction).
More specifically, each of the recesses 31 and 32 is formed to penetrate in a direction perpendicular to the longitudinal direction of each joint shaft. In other words, the first recess 31 is formed by cutting the rectangular block-shaped longitudinal intermediate portion of the first joint shaft 21 into a substantially U shape when viewed from the longitudinal direction of the second joint shaft 22. And side walls 35 on both sides in the longitudinal direction of the first joint shaft 21. The both sides of the first joint shaft 21 in the longitudinal direction are connected by the bottom wall 33 of the first recess 31. Similarly, the second recessed portion 32 is formed by cutting the rectangular block-shaped longitudinal intermediate portion of the second joint shaft 22 into a substantially U shape when viewed from the longitudinal direction of the first joint shaft 21. 34 and side walls 36 on both sides in the longitudinal direction of the second joint shaft 22. Then, both sides in the longitudinal direction of the second joint shaft 22 are connected by the bottom wall 34 of the second recess 32. The concave inner surface 33N of the bottom wall 33 of the first concave portion 31 and the concave inner surface 34N of the bottom wall 34 of the second concave portion 32 are overlapped with each other, and the bottom wall 33 of the first concave portion 31 is placed on both sides of the second concave portion 32. Between the walls 36, the bottom wall 34 of the second recess 32 is fitted between both side walls 35 of the first recess 31 via rubber plates 18 as elastic members. A through hole 14 concentric with the axis O is formed in the longitudinal center (bottom wall 33) of the first joint shaft 21 and the longitudinal center (bottom wall 34) of the second joint shaft 22. A connecting shaft 15 having a circular cross section for connecting the first joint shaft 21 and the second joint shaft 22 is inserted into the through hole 14 so as to be relatively rotatable, whereby the first joint shaft 21 and the second joint shaft 22 are inserted into the axis. O are swingably connected around O. The connecting shaft 15 is a rivet, and penetrates the through holes 14 of the first joint shaft 21 and the second joint shaft 22 and is arranged so as not to come off. The first joint shaft 21 and the second joint shaft 22 can be connected by another fixing means other than riveting.

  The bearing 6 is fitted into the pair of mounting holes 17 of the first yoke 11 and the pair of mounting holes 23 of the second yoke 12, and both ends of the first joint shaft 21 and both ends of the second joint shaft 22 are fitted. It is pivotally supported. Reference numeral 16 in the drawing denotes a ring-shaped oil seal 16 that is fitted to both ends of each joint shaft together with the bearing 6 so that foreign matter does not enter the bearing.

  Both the side surfaces 33S of the bottom wall 33 of the first recess 31 on the longitudinal direction side of the second joint shaft 22 and the inner surfaces 35N of the side walls 35 of the first recess 31 are configured as a first rotational force transmission surface, and the second recess Both side surfaces 34S of the bottom wall 34 of the 32 in the longitudinal direction of the first joint shaft 21 and inner surfaces 36N of the side walls 36 of the second recess 32 are configured as second rotational force transmission surfaces. A rubber plate 18 is interposed between the first rotational force transmission surface and the second rotational force transmission surface facing each other. That is, as shown in FIGS. 2 and 3, the rubber plate 18 is interposed between the first joint shaft 21 and the second joint shaft 22 in the swinging direction S of the first and second joint shafts 21 and 22. A rotational force is transmitted between the steering shaft 4 and the pinion shaft 5 via a rubber plate 18.

  Thereby, the vibration in the rotational direction (torsional direction) among the vibrations applied to the steering wheel when traveling on a rough road or the like can be absorbed by the rubber plate 18, and the vibration in the rotational direction is transmitted from the steering shaft 4 to the steering wheel 1. This can prevent the driver from feeling uncomfortable. In addition, since the rubber plate 18 is not interposed between the first joint shaft 21 and the second joint shaft 22 in the axial direction other than the rotation direction, a problem that the center of the universal joint 100 changes in the axial direction can be prevented. Torque fluctuation can be made difficult to cause.

  The first rotational force transmission surface and the second rotational force transmission surface are formed in a plane parallel to the axis O, and both side surfaces 33S of the bottom wall 33 of the first recess 31 and both sides of the second recess 32. The inner surface 36 </ b> N of the wall 36 is formed in a dogleg-shaped inclined surface that is positioned closer to the longitudinal center side of the second joint shaft 22 toward the longitudinal center side of the first joint shaft 21. Similarly, both the side surfaces 34 </ b> S of the bottom wall 34 of the second recess 32 and the inner surfaces 35 </ b> N of the side walls 35 of the first recess 31 are arranged in the longitudinal direction center side of the first joint shaft 21 toward the longitudinal center side of the second joint shaft 22. Are formed on the inclined surfaces of the V-shape located in With this structure, a plurality (four) of the rubber plates 18 are also deformed in the assembled state. The rubber plate 18 is a flat plate that is not bent before assembly, but the rubber plate 18 may be formed in a dogleg shape before assembly.

[Another embodiment]
The present invention can also be applied to the following universal joints (1) to (3).
(1) As shown in FIG. 4, a second universal joint 20 interposed between the upper shaft end of the steering shaft 4 and the second steering shaft 19 in the steering column 2.
(2) A universal joint provided on the propeller shaft of an automobile.
(3) A universal joint provided in devices other than automobiles.

Exploded perspective view of universal joint Divided perspective view of the cross shaft of the universal joint Front view of the universal joint cross shaft Side view of steering system Perspective view showing conventional structure

Explanation of symbols

4 First shaft (steering shaft)
4A Shaft end of first shaft (steering shaft) 5 Second shaft (pinion shaft)
5A Shaft end 6 of the second shaft (pinion shaft)
10 cross shaft 11 first yoke 12 second yoke 14 through hole 15 connecting shaft 18 elastic member (rubber plate)
21 first joint shaft 22 second joint shaft 31 first recess 32 second recess 33 bottom wall 33N of the first recess bottom wall inner surface 33S of the first recess both side surfaces 34 of the bottom wall of the first recess 34 bottom wall of the second recess 34N Bottom wall inner surface 34S of the second recess Both side surfaces 35 of the bottom wall of the second recess Both side walls 35N of the first recess Both side walls 36 of the first recess Both side walls 36N of the second recess Both surfaces of the both walls of the second recess 100 Universal joint O Shaft core S Oscillating direction

Claims (6)

A first yoke fixed to the shaft end of the first shaft; a second yoke fixed to the shaft end of the second shaft; and a cross shaft connecting the first yoke and the second yoke; A universal joint for connecting the first shaft and the second shaft with the torque to transmit a rotational force;
The cross shaft is divided into two parts: a first joint shaft that is both-end supported by the first yoke via a bearing; and a second joint shaft that is both-end supported by the second yoke via a bearing; A longitudinal central portion of the first joint shaft and a longitudinal central portion of the second joint shaft are pivotably coupled to each other around an axis that is orthogonal to any longitudinal direction of the first and second joint shafts; An elastic member is interposed between the first joint shaft and the second joint shaft in the swinging direction of the first and second joint shafts to transmit the rotational force between the first shaft and the second shaft. Universal joint through an elastic member.   A through hole concentric with the shaft core is formed in a longitudinal center portion of the first joint shaft and a longitudinal center portion of the second joint shaft, and the first joint shaft and the second joint shaft are formed in the through hole. The universal joint according to claim 1, wherein the first joint shaft and the second joint shaft are swingably connected to each other around the axis by inserting a connecting shaft for connecting the two together so as to be relatively rotatable. Forming a first recess opened in a direction perpendicular to the axis perpendicular to the axis while opening to the second joint axis side and being recessed in a direction along the axis, in the longitudinal center of the first joint axis;
Forming a second recess opened in a direction perpendicular to the axis perpendicular to the axis and being recessed in a direction along the axis while being opened toward the first joint axis in the longitudinal central portion of the second joint axis;
The bottom wall inner surface of the first recess and the bottom wall inner surface of the second recess face each other, the bottom wall of the first recess is between both side walls of the second recess, and the bottom wall of the second recess is The universal joint according to claim 1, wherein the universal joint is fitted between both side walls of the first recess via the elastic member.   Both the side surfaces of the bottom wall of the first recess and the inner surfaces of the side walls of the first recess in the longitudinal direction of the second joint shaft are configured as a first torque transmission surface, and the longitudinal direction of the first joint shaft The two side surfaces of the bottom wall of the second recess and the inner surfaces of the side walls of the second recess are configured as a second torque transmission surface, and the first torque transmission surface and the second torque transmission facing each other. The universal joint according to claim 3, wherein the elastic member is interposed between the surfaces. A square shape in which both the side surfaces of the bottom wall of the first recess and the inner surfaces of the side walls of the second recess are positioned closer to the center side in the longitudinal direction of the second joint shaft toward the center side in the longitudinal direction of the first joint shaft. Each formed on the inclined surface of
A square shape in which both the side surfaces of the bottom wall of the second recess and the inner surfaces of the side walls of the first recess are positioned closer to the center side in the longitudinal direction of the first joint shaft toward the center side in the longitudinal direction of the second joint shaft. The universal joint according to claim 4, wherein the universal joint is formed on each of the inclined surfaces.   The universal joint according to any one of claims 1 to 5, wherein the first joint shaft and the second joint shaft are formed in the same shape and the same size.

Images