JP3041129B2 - Constant velocity joint for steering system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double cardan type constant velocity joint, and more particularly to a constant velocity joint for a steering device of an automobile or the like.

[0002]

2. Description of the Related Art As one of double-cardan type constant velocity joints, two rotating shafts are drivingly connected so that their axes form a predetermined intersection angle (referred to as a bending angle in this specification). As described in Japanese Patent Publication No. 50-21610, a pair of flange yokes having an annular flange portion and two arm portions separated from each other and fastened and fixed to each other at the flange portion, and connected to a rotating shaft. A pair of pin yokes each having a connecting portion, a spherical protrusion, and two arms that are separated from each other and integrally connect the connecting portion and the spherical protrusion, two arm portions of a flange yoke, and two arm portions of a pin yoke. A pair of crosspieces that pivotally connect
A centering disk having a substantially disk-shaped socket portion at the center portion for receiving the spherical projections of a pair of pin yokes, and a pair of thin annular plates disposed on both sides of the centering disk in close contact with the centering disk An outer peripheral edge of the ring disk is disposed in an annular groove defined by the flanges of the pair of flange yokes, and substantially substantially slidably contacts the flange over the entire circumference. Speed joints are conventionally known.

According to such a constant velocity joint, the spherical projections of the pair of pin yokes are maintained in alignment with each other by the sockets of the centering disk, so that compared to a double cardan joint having no centering disk. The annular groove defined by the flange portions of the pair of flange yokes is closed from the outside by the centering disk and the pair of ring disks disposed on both sides thereof. Therefore, it is possible to reduce the possibility that foreign matter such as dust enters the annular groove.

[0004]

However, in the conventional constant velocity joint as described above, the ring disk frictionally slides with both the centering disk and the flange portion of the flange yoke when the constant velocity joint is operated. Therefore, rattling of the rotating shaft and fluctuation of the rotating torque are likely to occur. Also, since the centering disk is supported by the flange portion of the flange yoke via a pair of ring disks, the rotation shaft rattling and the rotation torque due to an assembly error, a ring disk bending, and the like are caused. Fluctuation is likely to occur. Furthermore, the centering disc has a socket portion in the center portion for receiving the spherical projection of the pin yoke, and even when the constant velocity joint has a small bending angle, the centering disc is relatively eccentric with respect to the flange portion of the flange yoke. As the bending angle of the two rotating shafts connected by the constant velocity joint increases, the amount of eccentricity of the centering disk with respect to the flange portion of the flange yoke further increases, and the outer peripheral edge of the centering disk has a pair of flanges. Since it interferes with the bottom wall of the annular groove defined by the portion, the bending angles of the two rotating shafts cannot be increased.

[0005] Therefore, when the conventional constant velocity joint as described above is incorporated in a steering device, there is a problem that the steering feeling is liable to be deteriorated because the backlash of the steering shaft and the fluctuation of the rotational torque are apt to occur. The angle between the axis of the upper shaft carrying the steering wheel at one end and the axis of the pinion gear shaft of the steering gear box cannot be increased. The problem is that two or more constant velocity joints have to be incorporated between them.

The present invention has been made in view of the above-described problems in the conventional constant velocity joint as described in the above-mentioned publication and improves steering feeling with less rattling of the steering shaft and fluctuations in the rotational torque. It is an object of the present invention to provide an improved constant velocity joint for a steering device, which is capable of connecting two steering shafts at a large bending angle.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a lower shaft connected at one end to the pinion gear shaft of a steering gear box at the other end and at one end of an upper shaft carrying a steering wheel. A constant velocity joint that connects the other end of the pair at a bending angle within a predetermined range, and has a ring-shaped flange portion and two arm portions that are spaced apart from each other, and a pair of fastening portions fixed to each other by the flange portion. A pair of pin yokes each having a flange yoke, two arm portions spaced apart from each other and a connecting portion and the spherical protrusion, and integrally connecting the connecting portion and the spherical protrusion, and two arm portions of the flange yoke and the pin yoke A pair of crosspieces pivotally connecting the two arm portions, and a socket portion receiving the spherical projection of the pair of pin yokes at an eccentric position. To and a centering disc, as the outer peripheral edge of the centering disc sliding contact with the flange portion over the arranged KakuJo is an annular groove by the flange portion且全periphery of said pair of flanges yoke This is achieved by a constant velocity joint characterized by being constituted.

[0008]

According to the construction described above, the outer peripheral edge of the centering disk is disposed in the annular groove defined by the flanges of the pair of flange yokes, and is substantially densely disposed on the flange over the entire circumference. It comes into sliding contact. Therefore, the thin annular disk-shaped ring disk incorporated in the above-mentioned conventional constant velocity joint is unnecessary, and the number of parts is reduced and the number of friction sliding parts is reduced. Shafts of the shaft and fluctuations of the rotational torque due to assembly errors are reduced, thereby improving the steering feeling and an annular groove defined by a pair of flanges without providing a ring disk. Foreign matter such as dust is effectively prevented from entering the inside.

Since the socket for receiving the spherical projection of the pin yoke is provided at a position eccentric from the center of the centering disk, the above-mentioned conventional constant velocity joint in which the socket is provided at the center of the centering disk is provided. It is possible to increase the amount of eccentricity of the centering disk with respect to the flange portion as compared with the case of (1), and the centering disk slides substantially tightly on the flange portion over the entire periphery at the outer peripheral edge thereof. In this state, the bending angle can be increased as compared with the related art without causing the backlash of the shaft and the fluctuation of the rotation torque.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 1 is a schematic structural view showing a steering device in which one embodiment of a constant velocity joint according to the present invention is incorporated. FIGS. 2 and 3 show the constant velocity joint shown in FIG. FIG. 4 is an enlarged cross-sectional view showing a maximum bending angle.

In FIG. 1, reference numeral 10 denotes an upper shaft which carries a steering wheel 12 at one end.
The upper shaft 10 is rotatably supported around an axis 16 by a steering post 14. By being secured to the mounting bracket 24 Gabo de chromatography member 20 together with the steering post 14 is supported by the flange 18 Gabo de chromatography member (Instrumental reinforcement of the instrument panel) bracket 22 fixed to 20 fixed thereto It is fixedly supported by the body member.

In FIG. 1, reference numeral 26 denotes a steering gear box fixed to a body member (suspension member) 28 in a known manner, and a pinion gear shaft 30 of the steering gear box 26 has a well-known elasticity. It is connected to one end of a lower shaft 34 by a joint 32. In the embodiment shown, the lower shaft 34 is an adjustable length sliding shaft, the axis 36 of which is substantially aligned with the axis 38 of the pinion gear shaft 30.

The other end of the upper shaft 10 and the other end of the lower shaft 34 are mutually connected by a constant velocity joint 40 according to the present invention so that torque can be transmitted. The constant velocity joint 40 includes a pair of flange yokes 42 and 44, a pair of pin yokes 46 and 48, a pair of crosspieces 50 and 52, and a centering disk 54, as shown in FIGS. doing.

The flange yokes 42 and 44 are respectively radially spaced from and correspond to the substantially annular plate-like flange portions 42A and 44A extending perpendicularly to the axes 56 and 58, respectively. And two arm portions 42B and 44B extending along the axis from the flange portion. The flange yoke 42 and 44, Joy
In order to ensure the uniformity of the port 40, the axes 56 and 58 are inserted into the flanges 42A and 44A with the arms 42B and 44B aligned with each other along the axis. The bolts 60 and the nuts 62 which are screwed thereto are fastened and fixed to each other .
Shows the arm portions 42B and 44B around the axis for the purpose of explanation.
Are shown 90 ° apart from each other . Each arm portion 42B and 44B is provided with a hole 64 and 66 respectively aligned with each other, and the common axes 68 and 70 of the holes 64 and 66 intersect the axes 56 and 58 at the intersections Pa and Pb, respectively. I have.

The pin yokes 46 and 48 are at the intersection P
connecting portions 46A, 48A extending along the axes 72, 74 passing through a and Pb, and spherical projections 46B, 48 projecting away from the connecting portions along the axes 72, 74, respectively.
B and the corresponding connecting portions 46A, 48A and the spherical projections 46B, 4B which are spaced from each other on both sides of the axes 72, 74, respectively.
8B are integrally connected to each other. Each arm 46C and 48C is provided with a hole 76 and 78 respectively aligned with each other, and the common axes 80 and 82 of the holes 76 and 78 intersect the axes 72 and 74 at the intersections Pa and Pb, respectively. I have.
The connecting portions 46A and 48A have holes 84 and 86 extending along the axes 72 and 74, respectively, into which the shaft portions of the connecting members 88 and 90 (see FIG. 1) are fitted and welded. The connecting portions 46A and 48A are fixed by the connecting members 88 and 90, respectively,
The lower shaft 34 and the other end of the lower shaft 34 are rigidly connected to each other.

Arm 4 of flange yokes 42 and 44
A pair of shaft portions 50A and 52A of crosspieces 50 and 52 having a substantially cross shape are inserted into holes 64 and 66 provided in 2B and 44B, respectively, so as to be relatively rotatable with respect to the corresponding arm portions. Crosspieces 50 and 5
The other pair of shaft portions 50B and 52B are the arm portions 46C and 48 of the corresponding pin yokes 46 and 48, respectively.
It is rotatably inserted into holes 76 and 78 provided in C. Thus, the flange yoke 42 and the pin yoke 46
Are connected to each other by a crosspiece 50 at an intersection Pa as a pivot point, and the flange yoke 44 and the pin yoke 48 are connected to each other by a crosspiece 52 at an intersection Pb as a pivot point.

The flange portions 42A and 44A of the flange yokes 42 and 44 cooperate with each other to define an annular groove 92 extending along a plane perpendicular to the axes 56 and 58, wherein the annular groove 92 is radial. It opens inward and extends annularly about axes 56 and 58. The annular groove 92 in the outer peripheral edge of the centering disc 54 has been inserted, the outer peripheral portion is in contact side wall and substantially close sliding of Wataru Liwa shaped groove all around it.

The centering disk 54 is substantially disk-shaped, and has spherical projections 46B and 48 of pin yokes 46 and 48.
It has a socket 94 for receiving B in a pivotally tight manner.
The socket 94 is connected to the axis 5 even when the constant velocity joint 40 is at the minimum bending angle as shown in FIGS.
6 and 58, and is formed in a cylindrical shape extending along an axis 96 parallel to the axes 56 and 58, whereby the centers Oa and Ob of the spherical projections 46B and 48B are formed. To axes 56 and 5, respectively.
8 and is positioned at an equidistant position.
Also, when the constant velocity joint is at the maximum bending angle as shown in FIG.
b has a length located inside of both ends of the socket.

Further, the intersection Pa between the axes 68 and 80 and the intersection Pb between the axes 70 and 82 are defined by the flanges 42A and 44A.
Are positioned equidistant from the plane 98 of the mating surface of.
The centers Oa and Ob of the spherical projections 46B and 48B are also located at the same distance from the plane 98 of the mating surface. Therefore, as shown in FIG.
Is the minimum value, the bending angle θ is the maximum value as shown in FIG. 3, and the bending angle is a value between the minimum value and the maximum value. In addition, the intersection P between the axes 72 and 74 is always located on the plane 98 of the mating surface.

In the embodiment shown, when the steering shaft 12 is steered to rotate the upper shaft 10 about the axis 16, the rotation of the upper shaft is controlled by the connecting member 88 about the axis 72. The rotation is transmitted to the pin yoke 46. The rotation of the yoke 46 is transmitted by the crosspiece 50 as rotation about the axis 56 to the flange yoke 42, thereby rotating the flange yoke 44 about the axis 58. The rotation of the flange yoke 44 is transmitted by the crosspiece 52 as rotation about an axis 74 to the pin yoke 48, and the rotation of the pin yoke is transmitted by the connecting member 90 as rotation about the axis 36 to the lower shaft 34, whereby the elastic joint 32 Through which the pinion gear shaft 30 is rotated about an axis 38. The rotation of the pinion gear shaft 30 about the axis 38 is transmitted to the steering wheel 12 in a manner opposite to the above-described manner.

In this case, the flange yokes 42 and 44
The arms 44B are aligned with each other along the axis.
Regardless of the magnitude of the bending angle θ, the centers Oa and Ob of the spherical projections 46B and 48B are maintained at positions equidistant from the axes 56 and 58, respectively, and the centers Oa, Ob and the intersections Pa, P
Since b is maintained at a position equidistant from the flat surface 98 of the mating surface, the rotational torque is transmitted between the pin yoke 46 and the pin yoke 48 while maintaining the constant velocity.

Thus, according to the illustrated embodiment, the outer peripheral edge of the centering disk 54 is always substantially in sliding contact with the wall surface of the annular groove 94, which is the same as the conventional constant velocity joint described above. Because it is not supported by the flange portion of the flange yoke via a thin annular disk-shaped ring disk as such, the shafts connected to each other by the constant velocity joint and the rotational torque are compared with the conventional case. Can be reduced, whereby the steering feeling can be improved.

Also, according to the illustrated embodiment, as long as the bending angle θ is between the minimum value shown in FIG. 2 and the maximum value shown in FIG. Because it is maintained in a closed state over its entire circumference by the peripheral edge,
It is possible to reliably prevent the constant velocity joint 40 from satisfactorily operating due to foreign matter such as dust entering the annular groove.

Further according to the illustrated embodiment, the spherical projection 46
Since the socket 94 for receiving a B and 48 B are provided on the centering disc 54 at a position offset from the center, it is possible to set the bending angle θ to a relatively high extent as 40 ° to 70 °, this Thus, the vehicle interior space can be made larger than before, and the space occupied by the steering device can be reduced as compared with the case of a two-joint or three-joint type steering device. Can be increased.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments may be made within the scope of the present invention. The possibilities will be clear to the skilled person.

For example, the plane 9 of the mating surface with the intersections Pa and Pb
8 is set to be larger than that in the illustrated embodiment, and when the bending angle θ is the minimum value, the upper edge of the outer peripheral edge of the centering disk 54 is substantially equal to the upper edge of the inner edge of the flange portions 42A and 44A. The minimum value of the bending angle θ may be made smaller than that of the illustrated embodiment by being able to be located at the same position.

[0028]

As is apparent from the above description, according to the present invention, the outer peripheral edge of the centering disk is disposed in the annular groove defined by the flanges of the pair of flange yokes and extends all around. The flange is substantially in close sliding contact with the flange portion. Therefore, the thin annular ring-shaped ring disk incorporated in the above-mentioned conventional constant velocity joint is unnecessary, and the number of parts is reduced. Since the number of friction sliding parts is reduced, the rattling of the shaft and fluctuations in rotational torque caused by wear of parts and assembly errors can be reduced, and the steering feeling can be improved. It is possible to effectively prevent foreign matter such as dust from entering the annular groove defined by the pair of flange portions without providing a disk.

Since the socket for receiving the spherical projection of the pin yoke is provided at a position eccentric from the center of the centering disk, the conventional constant velocity joint described above in which the socket is provided at the center of the centering disk. It is possible to increase the amount of eccentricity of the centering disk with respect to the flange portion as compared with the case of (1), and the centering disk slides substantially tightly on the flange portion over the entire periphery at the outer peripheral edge thereof. In this state, the bending angle can be increased as compared with the conventional case without rattling of the shaft and fluctuations in the rotational torque, so that the axis of the upper shaft carrying the steering wheel and the steering wheel can be increased. By increasing the angle between the gearbox and the axis of the pinion gear shaft, the interior space of the vehicle can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a steering device incorporating one embodiment of a constant velocity joint according to the present invention.

FIG. 2 is an enlarged sectional view showing the constant velocity joint shown in FIG. 1 at a minimum bending angle.

FIG. 3 is an enlarged sectional view showing the constant velocity joint shown in FIG. 1 at a maximum bending angle.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is a sectional view taken along the line VV in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Upper shaft 12 ... Steering wheel 14 ... Steering post 20 ... Body member 26 ... Steering gear box 28 ... Body member 30 ... Pinion gear shaft 32 ... Elastic joint 34 ... Lower shaft 40 ... Constant velocity joint 42, 44 ... Flange yoke 42A, 44A: Flange part 42B, 44B: Arm part 46, 48 ... Pin yoke 46A, 48A: Connection part 46B, 48B: Spherical projection 46C, 48C: Arm part 50, 52 ... Cross piece 54 ... Centering disk 92: Annular groove 94 ... socket

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-99244 (JP, A) JP-B 56-19504 (JP, B2) JP-B 50-21610 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) F16D 3/32-3/33

Claims (1)

(57) [Claims] 1. The other end of an upper shaft carrying a steering wheel at one end and the other end of a lower shaft connected to a pinion gear shaft of a steering gear box at one end are connected at a bending angle within a predetermined range. A speed joint, a pair of flange yokes having an annular flange portion and two arm portions separated from each other and fastened and fixed to each other at the flange portion; A pair of pin yokes having two arms that integrally connect the portion and the spherical protrusion, and a pair of crosspieces that pivotally connect the two arms of the flange yoke and the two arms of the pin yoke. A centering disk having socket portions for receiving the spherical protrusions of the pair of pin yokes at eccentric positions. Constant velocity joint periphery, characterized in that it is configured to sliding contact with the flange portion over the arranged KakuJo is an annular groove by the flange portion且全periphery of said pair of flanges yoke.