JP5294007B2 - Rack shaft support device and vehicle steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small rack shaft support device for restraining rattle sound for a long time. <P>SOLUTION: A cam 20 and a cam follower 21 are interposed between a support yoke 18 and a sealing member 19 in slide contact with a rack shaft 8. The cam 20 can rotate around a central axial line C1 of a holding hole 16. An inner end 31 of a spiral spring 23 is engaged with a first engagement part 33 of the cam 20, and an outer end 32 of the spiral spring 23 is engaged with a second engagement part 34 of a rotary arm 37 of a torsion amount adjusting member 24 mounted to the sealing member 19 so that its position can be adjusted. When abrasion of a sliding portion of the support yoke 18 and the rack shaft 8 proceeds, the cam 20 rotates due to twist return of the spiral spring 23, so as to move the cam follower 21 toward the support yoke 18. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rack shaft support device and a vehicle steering device including the same.

A rack and pinion type steering device is typically provided with a rack shaft support device for removing backlash between the rack and the pinion (see, for example, Patent Document 1).
In the rack shaft support device, a support yoke that is slidable back and forth and a compression coil spring that biases the support yoke are housed in a holding hole provided in the housing. The support yoke urged by the compression coil spring supports the rack shaft so as to be slidable in the axial direction and presses the rack shaft toward the pinion shaft.
JP 2007-238089 A

However, if wear of the sliding portion of the rack shaft and the support yoke progresses due to long-term use, the support yoke becomes unstable in the depth direction of the holding hole, and as a result, rattle noise may occur. .
The present invention has been made in view of the above problems, and an object thereof is to provide a small rack shaft support device and a vehicle steering device that can suppress the generation of noise over a long period of time.

In order to achieve the above object, the present invention is accommodated in the holding hole (16) formed in the housing (17) so as to be slidable in the depth direction (X1) of the holding hole and sliding the rack shaft (8). A rack shaft support member (18) that is movably supported, a sealing member (19) fixed to the inlet of the holding hole, and a cam (20, 20A) interposed between the rack shaft support member and the sealing member. ) And the cam follower (21, 21A), the mainspring spring (23) whose one end (31) is engaged with the cam, and the other end (32) of the mainspring spring, thereby adjusting the position of the sealing member. And a torsion amount adjusting member (24) that adjusts the torsion amount of the mainspring spring in accordance with the position adjustment, and the cam is received by the sealing member, and the central axis of the holding hole (C1) can rotate around the cam The follower receives the rack shaft support member, is slidable in the depth direction of the holding hole, and is not rotatable, and the rotational force of the cam caused by the twisting back of the mainspring spring causes the cam follower to move to the rack shaft support member side. The sealing member includes a cylindrical part (27) that houses the mainspring spring, and an end wall (28) that closes one end of the cylindrical part, and the cylinder The outer periphery of the shaped portion is screwed into the inner periphery of the holding hole, and the twist amount adjusting member is an adjustment screw (36) screwed into a screw hole (35) formed in the end wall; A rotating arm (37) that rotates together with the adjusting screw, and an inner end (31) as one end of the mainspring spring is provided at a first engaging portion (at the rotation center (C2) of the cam ( 33) and the outer end (32) as the other end of the mainspring spring is a rotating arm. Characterized in that it engages the distal end a second engagement portion provided in (37a) (34), to provide a rack shaft supporting device (15).

  According to the present invention, the mainspring spring for applying a rotational force to the cam rotatable around the central axis of the holding hole does not take a place in the depth direction of the holding hole. This rack shaft support device can be remarkably miniaturized. Further, the torsion amount of the mainspring spring can be adjusted by the torsion amount adjusting member attached to the sealing member so that the position of the mainspring spring can be adjusted. Therefore, the torsion torque generated by the mainspring spring can be managed with high accuracy. be able to. Therefore, it is possible to suppress variation in the pressing force of the meshing portion between the rack and the pinion. Then, as the wear of the sliding portion between the rack shaft support member and the rack shaft progresses, the cam is rotated by the mainspring spring. As a result, since the cam follower pushes the rack shaft support member toward the rack shaft, the pressing force of the meshing portion between the rack and the pinion can be maintained substantially constant.

Further , by adjusting the rotational position of the rotating arm while screwing the adjusting screw of the torsion amount adjusting member into the screw hole of the end wall, the engaging portion is engaged with the second engaging portion at the tip of the rotating arm. The position of the outer end as the other end of the mainspring spring can be adjusted. Thereby, the amount of twist of the mainspring spring can be easily adjusted. Further, since the inner end as one end of the mainspring spring is engaged with the first engaging portion provided at the rotation center of the cam, the cam can be smoothly rotated by twisting back the mainspring spring. Can do.

Further, first and second support shafts (43, 44) projecting on both sides of the cam correspond to corresponding support holes (47, 48) provided in the cam follower and the base end (37b) of the rotating arm, respectively. ) May be fitted so as to be relatively rotatable (claim 2 ). In this case, the cam is supported at both ends by the torsion amount adjusting member and the cam follower, and the rotation of the cam is stabilized.

Further, an engagement groove as the first engagement portion may be formed on the second support shaft (claim 3 ). In this case, the structure can be simplified.
Further, there may be provided an urging member (22) interposed between the rack shaft support member and the cam follower and elastically urging the rack shaft support member toward the rack shaft side (claim 4 ). In this case, the rack shaft support member can be elastically biased toward the rack shaft by the biasing member.

Further, the present invention provides a vehicle steering system (1) for slidably supporting the rack shaft in the axial direction with the rack shaft supporting device (claim 5). The present invention achieves a vehicle steering apparatus that can reliably prevent the generation of rattle noise.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Referring to FIG. 1, a vehicle steering apparatus 1 includes a steering shaft 3 connected to a steering member 2 such as a steering wheel, an intermediate shaft 5 connected to the steering shaft 3 via a universal joint 4, an intermediate shaft 5 A rack as a steering shaft having a pinion shaft 7 connected to the shaft 5 through a universal joint 6 and a rack 8a meshing with the pinion 7a provided in the vicinity of the end of the pinion shaft 7 and extending in the left-right direction of the automobile And a shaft 8. The pinion shaft 7 and the rack shaft 8 constitute a rack and pinion mechanism A as a steering mechanism.

  The rack shaft 8 is supported in a rack housing 9 fixed to the vehicle body through a plurality of bearings (not shown) so as to be linearly reciprocable along the axial direction Z1. Both end portions of the rack shaft 8 protrude to both sides of the rack housing 9, and tie rods 10 are coupled to the respective end portions. Each tie rod 10 is connected to a corresponding steered wheel 11 via a corresponding knuckle arm (not shown).

When the steering member 2 is operated and the steering shaft 3 is rotated, this rotation is converted into a linear motion of the rack shaft 8 along the left-right direction of the automobile by the pinion 7a and the rack 8a. Thereby, the turning of the steered wheel 11 is achieved.
With reference to FIG. 2, the pinion shaft 7 is rotatably supported in the pinion housing 14 by a first bearing 12 made of, for example, a ball bearing and a second bearing 13 made of, for example, a cylindrical roller bearing. . The pinion 7 a of the pinion shaft 7 and the rack 8 a of the rack shaft 8 are meshed with each other in the pinion housing 14.

  The vehicle steering device 1 is equipped with a rack shaft support device 15. The rack shaft support device 15 includes a housing 17 having a holding hole 16 formed of a circular hole, and is accommodated in the holding hole 16 so as to be slidable along the depth direction X1 of the holding hole 16 and the rear surface of the rack 8a of the rack shaft 8. A support yoke 18 as a rack shaft support member that slidably supports 8b, and a hollow sealing member 19 that is screwed into and fixed to the inlet of the holding hole 16 are provided.

  Further, the rack shaft support device 15 is interposed between the support yoke 18 and the sealing member 19 and between the cam follower 21 and the support yoke 18 and elastically moves the support yoke 18 toward the rack shaft 8. And an urging member 22 made of, for example, a compression coil spring. The cam 20 can rotate around the central axis C <b> 1 of the holding hole 16. The cam follower 21 is slidable in the holding hole 16 in the depth direction X1 of the holding hole 16 and is held non-rotatable. A gap for fluctuation absorption is secured between the cam follower 21 and the rear surface 18b of the support yoke 18.

The rack shaft support device 15 also includes a mainspring spring 23 for applying a rotational force to the cam 20 and a torsion amount adjusting member 24 for adjusting the torsion amount of the mainspring spring 23.
The housing 17 of the rack shaft support device 15 is formed integrally with the pinion housing 14 and is disposed on the opposite side of the pinion shaft 7 with the rack shaft 8 therebetween. The pinion housing 14 and the housing 17 are manufactured by die casting, for example.

  The support yoke 18 as a rack shaft support member has a front surface 18a facing the rack shaft 8, a rear surface 18b as a facing surface facing the cam follower 21, and an outer peripheral surface 18c made of a cylindrical surface. On the front surface 18 a of the support yoke 18, a concave surface 25 that substantially matches the shape of the back surface 8 b of the rack shaft 8 is formed. A sliding contact plate 26 is attached along the concave surface 25, and the sliding contact plate 26 is in sliding contact with the back surface 8 b of the rack shaft 8. As the sliding contact plate 26, a plate having a low friction coefficient is preferably used. For example, a metal plate or a metal plate coated with a fluororesin can be used.

The sealing member 19 includes a cylindrical portion 27 and a circular end wall 28 that closes one end of the cylindrical portion 27. A male screw 29 is formed on the outer periphery 27 a of the cylindrical portion 27. A female screw portion 16b is formed on the inner peripheral surface 16a of the holding hole 16 corresponding to the inlet of the holding hole 16, and the male screw 29 of the sealing member 19 is screwed and fixed to the female screw portion 16b. .
With reference to FIGS. 2 and 3, the lock member 30 screwed to the male screw 29 on the outer periphery of the sealing member 19 is pressed against the end surface of the housing 17, so that the sealing member 19 is stopped on the housing 17. It has been determined.

As shown in FIG. 2, the cam 20 is received by the other end of the cylindrical portion 27 of the sealing member 19, whereby the cam 20 moves rearward (moving away from the support yoke 18). Is regulated.
The mainspring spring 23 is accommodated in the sealing member 19. That is, the mainspring spring 23 is disposed between the cam 20 and the end wall 28 of the sealing member 19. The mainspring spring 23 has an inner end 31 as one end and an outer end 32 as the other end. An inner end 31 of the mainspring spring 23 is locked to a first engagement portion 33 provided on the cam 20. An outer end 32 of the mainspring spring 23 is locked to a second engaging portion 34 provided on the torsion amount adjusting member 24.

The torsion amount adjusting member 24 includes an adjusting screw 36 screwed into a screw hole 35 formed in the end wall 28 of the sealing member 19, and a rotating arm 37 that rotates along with the adjusting screw 36. The center of the screw hole 35 coincides with the center of the cylindrical portion 27 of the sealing member 19. The rotating arm 37 extends in a direction orthogonal to the central axis of the adjustment screw 36 (matching the central axis of the screw hole 35).
A second engagement portion 34 that locks the outer end 32 of the mainspring spring 23 is provided at the distal end 37 a of the rotating arm 37. As shown in FIG. 4, the second engaging portion 34 is provided at, for example, the tip 37 a of the rotating arm 37, and includes a shaft that extends toward the cam 20 side in parallel with the central axis of the adjustment screw 36. The shaft as the second engaging portion 34 hooks and locks the outer end 32 having a hook shape, for example.

  Referring again to FIG. 2, the adjustment screw 36 is connected to the first end 38 exposed to the outside from the end wall 28 of the sealing member 19 and the base end 37 b of the rotating arm 37 in the sealing member 19. Second end 39 formed. As shown in FIGS. 2 and 3, the first end portion 38 is provided with an operation portion 40 for operating the adjustment screw 36. The operation unit 40 is formed of, for example, a hexagonal hole formed in the first end portion 38.

When the lock nut 41 screwed onto the outer periphery of the first end portion 38 of the adjustment screw 36 is pressed against the end wall 28 of the sealing member 19, the adjustment screw 36 is fixed to the sealing member 19. Yes.
As shown in FIG. 2, the cam 20 is supported by the torsion amount adjusting member 24 and the cam follower 21 so as to be rotatable around the central axis C <b> 1 of the holding hole 16. As shown in FIG. 5, the cam 20 includes a main body 42 formed of an annular plate, and first and second support shafts 43 and 44 that protrude from the central portion of the main body 42 to both sides.

The main body 42 of the cam 20 has a first surface 45 that faces the cam follower 21, and a second surface 46 that faces the end wall 28 of the sealing member 19. The first support shaft 43 is formed so as to protrude from the central portion of the first surface 45 of the main body 42. The first support shaft 43 is fitted in a first support hole 47 provided at the center of the cam follower 21 so as to be relatively rotatable.
The second support shaft 44 is formed so as to protrude from the center of the second surface 46 of the main body 42. The 1st engaging part 33 which latches the inner end 31 of the mainspring spring 23 consists of an engaging groove formed in the 2nd spindle 44 (refer FIG. 9). The second support shaft 44 is fitted in a second support hole 48 (see FIG. 4) provided in the base end 37b of the rotation arm 37 of the torsion amount adjusting member 24 so as to be relatively rotatable. . As shown in FIG. 5, the cam 20 is supported in a doubly supported manner by first and second support holes 47 and 48 via first and second support shafts 43 and 44.

A tapered portion 49 is provided on the outer edge of the second surface 46 of the main body 42 of the cam 20. The tapered portion 49 is received by the tapered portion 50 provided at the tip of the cylindrical portion 27 of the sealing member 19 so as to be relatively rotatable.
5 and 7, a plurality of cam protrusions 51 having a V-shaped cross section extending in the circumferential direction of the main body 42 are formed near the outer edge of the first surface 45 of the main body 42 of the cam 20. The plurality of cam protrusions 51 are arranged at equal intervals in the circumferential direction of the main body 42 of the cam 20. The height of the cam protrusion 51 from the first surface 45 is changed in accordance with the circumferential position of the cam 20.

  Referring to FIGS. 5 and 8, cam follower 21 is made of an annular plate, and has a first surface 52 that faces cam 20 and a second surface 53 that faces support yoke 18. Near the outer edge of the first surface 52, a plurality of pairs of concentric ridges 54 extending in the circumferential direction of the cam follower 21 are formed. The plurality of pairs of ridges 54 are arranged at equal intervals in the circumferential direction of the cam follower 21.

As shown in FIG. 6, cam follower grooves 55 having a V-shaped cross section are formed between the pair of protruding ridges 54, and corresponding cam protrusions 51 of the cam 20 are engaged with each cam follower groove 55. doing. The depth of the cam follower groove 55 is changed in accordance with the circumferential position of the cam follower 21.
The tops of the cam protrusions 51 are not engaged with the bottoms of the cam follower grooves 55, and the pair of side surfaces 510 of the cam protrusions 51 having a V-shaped cross section are formed on the pair of inner side surfaces 550 of the cam follower grooves 55 having a V-shaped cross section. By engaging, a cam operation is performed. That is, the cam 20 and the cam follower 21 achieve a stable cam operation in a state where the cam 20 and the cam follower 21 restrain each other in the radial direction via the cam protrusion 51 and the cam follower groove 55 fitted to each other.

As the mainspring spring 23 is untwisted, the cam 20 is rotated, whereby the cam projection 51 and the cam follower groove 55 act to rotate the cam 20 (rotational force), causing the cam follower 21 to move toward the support yoke 18. Converted to pushing force. Specifically, the cam follower 21 moves to the support yoke 18.
As shown in FIGS. 2 and 8, a screw hole 56 is formed in the cam follower 21 in parallel with the central axis of the cam follower 21. As shown in FIGS. 2 and 3, a fixing jig insertion hole 57 is formed in the end wall 28 of the sealing member 19. Further, as shown in FIGS. 2 and 7, a fixing jig insertion hole 58 is formed in the cam 20. When the cam 20 is at a predetermined rotational position, the fixing jig insertion hole 57 of the sealing member 19, the fixing jig insertion hole 58 of the cam 20, and the screw hole 56 of the cam follower 21 are aligned on the same axis. Has been.

  As shown in FIGS. 2 and 3, the plug 60 is fitted into the enlarged diameter portion 59 formed at the entrance of the fixing jig insertion hole 57 of the sealing member 19, thereby The entrance is blocked. Specifically, a male screw constituting the plug 60 is screwed into a female screw formed on the inner periphery of the enlarged diameter portion 59. As shown in FIG. 3, a tool engagement hole 61 is provided at the end of the male screw constituting the plug 60 for rotating the male screw.

  In an intermediate process of assembling the rack shaft support device 15 (twisting amount adjusting step of the mainspring spring 23 by the torsion amount adjusting member 24), as shown in FIG. 10, the fixing jig insertion hole 57 and the fixing jig insertion The sealing member 19, the cam 20, and the cam follower 21 can be fixed to each other using a fixing jig 62 screwed into the screw hole 56 through the hole 58. Specifically, the subassembly SA including the fixing jig 62, the sealing member 19, the cam 20, the cam follower 21, the mainspring spring 23 (not shown in FIG. 10), and the torsion amount adjusting member 24 is configured. .

  The fixing jig 62 includes a screw having a head 63 and having a screw part 64 formed at the tip. The fixing jig 62 is inserted through the fixing jig insertion hole 57 of the sealing member 19, and the screw portion 64 at the tip of the fixing jig 62 is screwed into the screw hole 56 of the cam follower 21. The head 63 is received by the bottom of the enlarged diameter portion 59 at the entrance of the fixing jig insertion hole 57 of the sealing member 19. Thereby, the sealing member 19, the cam 20, and the cam follower 21 are fixed by the fixing jig 62.

  In this way, by rotating the adjusting screw 36 of the torsion amount adjusting member 24 by a predetermined amount while the sealing member 19, the cam 20 and the cam follower 21 are fixed by the fixing jig 62, After the torsion amount of the internal mainspring 23 is accurately adjusted, the adjusted adjustment screw 36 is fixed using the lock nut 41, and the fixing jig 62 is removed and the plug 60 is attached. ing.

  According to the present embodiment, the mainspring spring 23 is twisted back as the sliding of the support yoke 18 and the rack shaft 8 progresses, whereby the cam 20 is rotated. As a result, the cam follower 21 is driven toward the support yoke 18 by the action of the cam protrusion 51 and the cam follower groove 55. Thereby, the pressing force of the meshing portion of the rack 8a and the pinion 7a can be maintained substantially constant over a long period of time, and as a result, noise can be reliably suppressed over a long period of time.

Therefore, in the vehicle steering device 1 to which the rack shaft support device 15 is applied, the steering feeling does not deteriorate as the pressing force of the meshing portion between the rack 8a and the pinion 7a becomes excessive. . Moreover, noise can be reliably suppressed.
In particular, a mainspring spring 23 is used to give a rotational force to the cam 20, and the mainspring spring 23 does not take a place in the depth direction X <b> 1 of the holding hole 16. The rack shaft support device 15 can be significantly reduced in size.

Further, the torsion amount of the mainspring spring 23 can be adjusted by the torsion amount adjusting member 24 attached to the sealing member 19 so that the position of the mainspring spring 23 can be adjusted. It can be managed with high accuracy. Therefore, it is possible to suppress variations in the pressing force of the meshing portion between the rack 8a and the pinion 7a.
Further, the outer periphery of the cylindrical portion 27 of the sealing member 19 is screwed into the inner periphery of the holding hole 16, and the sealing member 19 is fixed to the housing 17. Further, an adjustment screw 36 of the torsion amount adjusting member 24 is screwed into the screw hole 35 of the end wall 28 of the sealing member 19, and a rotating arm 37 that can rotate along with the adjustment screw 36 is provided. . Further, the inner end 31 of the mainspring spring 23 is engaged with the first engaging portion 33 provided at the rotation center C2 of the cam 20, and the outer end 32 of the mainspring spring 23 is provided at the tip 37a of the rotating arm. The second engaging portion 34 is engaged.

  Therefore, the second engagement of the tip 37 a of the rotating arm 37 is adjusted by adjusting the rotational position of the rotating arm 37 while screwing the adjusting screw 36 of the torsion amount adjusting member 24 into the screw hole 35 of the end wall 28. The position of the outer end 32 of the mainspring spring 23 engaged with the joint portion 34 can be easily adjusted. Thereby, the amount of twist of the mainspring spring 23 can be easily adjusted. Further, since the inner end of the mainspring spring 23 is engaged with the first engagement portion 33 provided at the rotation center C2 of the cam 20, the cam 20 is smoothly moved by twisting back the mainspring spring 23. Can be rotated.

Further, the first and second support shafts 43 and 44 projecting on both sides of the cam 20 are rotatable relative to first and second support holes 47 and 48 provided in the cam follower 21 and the rotating arm 37, respectively. Since they are fitted, the cam 20 is supported at both ends by the torsion amount adjusting member 24 and the cam follower 21, and the rotation of the cam 20 is stabilized.
Further, with respect to the cam 20 and the cam follower 21, the cam protrusion 51 is formed on the cam 20 and the cam follower groove 55 is formed on the cam follower 21. As a result, the cam protrusion 51 is fitted into the cam follower groove 55. The operation can be made more stable.

Moreover, since the engaging groove as the 1st engaging part 33 is formed in the 2nd spindle 44 of the cam 20, a structure can be simplified.
Further, the support yoke 18 can be elastically biased toward the rack shaft 8 by the biasing member 22 interposed between the support yoke 18 and the cam follower 21.
Further, the torsion amount adjusting member 24 for adjusting the torsion amount of the mainspring spring 23 uses an adjusting screw 36 screwed into the screw hole 35 of the sealing member 19, and the first of the adjusting screw 36 is used. The end portion 38 has an operation portion 40 and is exposed to the outside of the sealing member 19. Therefore, the amount of twist of the mainspring spring 23 can be adjusted by operating the adjusting screw 36 from the outside of the sealing member 19 to rotate the outer end 32 of the mainspring spring 23 along with the rotating arm 37. it can. That is, by adjusting the screwing position of the adjustment screw 36 with respect to the screw hole 35 from the outside, the torsion amount of the mainspring spring 23 can be accurately adjusted.

  Further, when the cam 20 and the cam follower 21 are in a predetermined rotational position, the screw hole 56 of the cam follower 21, the fixing jig insertion hole 57 of the sealing member 19, and the fixing jig insertion hole 58 of the cam 20 are: Since the rack shaft support device 15 is assembled, the cam follower is inserted through the fixing jig insertion hole 57 of the sealing member 19 and the fixing jig insertion hole 58 of the cam 20 in the process of assembling the rack shaft support device 15. The cam 20 can be prevented from rotating with respect to the sealing member 19 by using a fixing jig 62 screwed into the screw hole 56 of 21. In this state, the torsion amount of the mainspring spring 23 can be accurately adjusted using the adjusting screw 36 attached to the sealing member 19 so as to be position-adjustable.

  That is, when adjusting the torsion amount of the mainspring spring 23 using the adjusting screw 36 of the torsion amount adjusting member 24, the sealing member 19, the cam 20 and the cam follower 21 are rattled by the fixing jig 62. It is fixed without sticking, and the torsion amount of the mainspring spring 23 can be adjusted with high accuracy. In particular, since the fixing jig 62 is screwed into the screw hole 56 of the cam follower 21, and the sealing member 19, the cam 20, and the cam follower 21 are fixed in the axial direction and the rotational direction, the following advantages are obtained.

  Assuming that the sealing member 19, the cam 20, and the cam follower 21 are not fixed in the axial direction, the sealing member 19, the cam 20, and the cam follower 21 may be inclined with respect to each other when the mainspring spring 23 is twisted. There is. When tilted, a gap is generated between the cam projection 51 and the cam follower groove 55 of the cam 20 or the relative phase of the cam 20 and the cam follower 21 is shifted. Therefore, the torsion torque of the mainspring spring 23 is set with high accuracy. become unable.

  In contrast, in the present embodiment, when the mainspring spring 23 is twisted, the sealing member 19, the cam 20, and the cam follower 21 do not tilt each other, and the cam protrusion 51 and the cam follower groove 55 are in close contact with each other. It can be maintained and the relative phase of the cam 20 and the cam follower 21 is not shifted. As a result, the torsion torque of the mainspring spring 23 can be set with high accuracy.

After adjusting the amount of torsion of the mainspring spring 23 with the adjusting screw 36, the fixing jig 62 is removed, and the inlet of the fixing jig insertion hole 57 is closed with the plug 60. And dust does not enter.
Further, the present invention is not limited to the above-described embodiment. For example, an annular elastic member such as rubber is provided between the cam follower 21 and the rear surface 18b of the support yoke 18 in order to restrict the rotation of the cam follower 21. May be interposed. In this case, the annular elastic member functions as an urging member that elastically urges the support yoke 18 toward the rack shaft 8, so the urging member 22 may be eliminated.

  Further, in the above description of the embodiment, the pair of side surfaces 510 of the cam projection 51 formed on the cam 20 engages with the pair of inner side surfaces 550 of the cam follower groove 55 formed on the cam follower 21 to perform cam operation. However, the present invention is not limited to this, and the cam follower groove 55 may be eliminated. For example, as shown in FIG. 11, the top portion 511 of the cam projection 51A formed on the cam 20A and the top portion 551 of the cam follower projection 55A formed on the cam follower 21A are engaged with each other to perform the cam operation. Also good. In this case, there is an advantage that the friction between the top portions 511 and 551 of both the cam projections 51A and 55A can be reduced as compared with the embodiment of FIG. Although not shown, at least one of the cam protrusion 51A and the cam follower protrusion 55A is formed in the same tapered V-shaped shape as the cam protrusion 51 of FIG. 6, and the contact between the top portions 511 and 551 of both the cam protrusions 51A and 55A. The area may be reduced to further reduce the friction.

  In addition, various modifications can be made within the scope of the claims of the present invention.

1 is a schematic diagram showing a schematic configuration of a rack and pinion type vehicle steering apparatus according to an embodiment of the present invention. It is sectional drawing of the principal part of the steering apparatus for vehicles to which the rack shaft support apparatus was applied. It is the schematic showing the external appearance of a sealing member and a twist amount adjustment member. It is the schematic of a rotation arm. It is a general | schematic expanded sectional view of the principal part of a rack shaft support apparatus. It is an expanded sectional view of the principal part of a cam and a cam follower. It is a front view of the surface by the side of a cam follower of a cam. It is a front view of the cam side surface of a cam follower. It is a front view of the surface by the side of the sealing member of the cam which latched the mainspring spring. It is a partially broken side view of the subassembly formed in the intermediate process of the assembly of the rack shaft support device. It is sectional drawing of the principal part of the cam of another embodiment of this invention, and a cam follower.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle steering device, 2 ... Steering member, 7 ... Pinion shaft, 7a ... Pinion, 8 ... Rack shaft, 8a ... Rack, 8b ... Back surface, 15 ... Rack shaft support device, 16 ... Holding hole, X1 ... (Holding) Depth direction of hole, 17 ... housing (for rack shaft support device), 18 ... support yoke (rack shaft support member), 19 ... sealing member, 20,20A ... cam, 21,20A ... cam follower, 22 ... with 23 ... Mainspring spring, 24 ... Twist amount adjusting member, 27 ... Cylindrical part, 28 ... End wall, 31 ... Inner end (one end of the mainspring spring), 32 ... Outer end (the other end of the mainspring spring) 33... First engaging portion 34... Second engaging portion 35. Screw hole 36. Adjustment screw 37. Rotating arm 37 a. ... Main body, 43 ... first support shaft, 44 ... second support shaft, 47 ... first support (Corresponding support hole), 48 ... second support hole (corresponding support hole), 51, 51A ... cam projection, 54 ... projection, 55 ... cam follower groove, 55A ... cam follower projection, 56 ... screw hole, 57, 58 ... Fixing jig insertion hole, 60 ... Stopper, 62 ... Fixing jig

Claims (5)

A rack shaft support member that is slidably accommodated in a depth direction of the holding hole in a holding hole formed in the housing and slidably supports the rack shaft;
A sealing member fixed to the inlet of the holding hole;
A cam and a cam follower interposed between the rack shaft support member and the sealing member;
A mainspring spring having one end engaged with the cam;
A torsion amount adjusting member that engages the other end of the mainspring spring, is attached to the sealing member so that the position of the mainspring spring can be adjusted, and adjusts a torsion amount of the mainspring spring in accordance with the position adjustment. The cam is received by the sealing member and is rotatable around the central axis of the holding hole. The cam follower receives the rack shaft support member, is slidable in the depth direction of the holding hole, and is not rotatable. Yes,
The rotational force of the cam due to the twisting back of the mainspring spring is converted into a force that pushes the cam follower toward the rack shaft support member .
The sealing member includes a cylindrical portion that houses the mainspring spring, and an end wall that closes one end of the cylindrical portion, and the outer periphery of the cylindrical portion is screwed into the inner periphery of the holding hole. Together
The torsion amount adjusting member includes an adjusting screw screwed into a screw hole formed in the end wall, and a rotating arm that rotates together with the adjusting screw.
An inner end as one end of the mainspring spring engages with a first engagement portion provided at the rotation center of the cam, and an outer end as the other end of the mainspring spring is provided at the tip of the rotating arm. A rack shaft support device, wherein the rack shaft support device is engaged with the second engaging portion . In Claim 1 , the 1st and 2nd spindle which protrudes on the both sides of the said cam is fitted in the corresponding support hole respectively provided in the base end of the said cam follower and the said rotation arm so that relative rotation is possible. A rack shaft support device characterized by that. The rack shaft support device according to claim 2, wherein an engagement groove as the first engagement portion is formed on the second support shaft. In any one of claims 1 to 3, interposed between the rack shaft support member and the cam follower, characterized in that it comprises a biasing member for biasing the rack shaft supporting member to the rack shaft side rack Shaft support device. 5. A vehicle steering apparatus that supports a rack shaft so as to be slidable in an axial direction by using the rack shaft support device according to any one of claims 1 to 4 .

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