JP2013199158A - Method for fixing adjusting screw of steering device, and steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering device in which the occurrence of back rush of a rack and a pinion is prevented and the change of the sliding force of the rack is prevented, and to provide a method for fixing an adjusting screw.SOLUTION: A method for fixing an adjusting screw of a steering device 1 having a rack guide 8, an elastic member 9 and the adjusting screw 10 includes a first step of screwing the adjusting screw 10 to a cylindrical part 7 of a housing 2, a second step of caulking an axial directional side end surface of one of the adjusting screw 10 and the cylindrical part 7 to bridge a gap between a screw part 10a of the adjusting screw 10 and a screw part 7a of the cylindrical part 7, a third step of adjusting pressing force to press a rack guide 8 to a rack 3 and a forth step of locking the adjusting screw 10 by caulking remaining another one of the axial directional side end surface of the adjusting screw 10 and the cylindrical part 7 and the adjusting screw 10 is fixed to the housing 2 by successively carrying out from the first step to the forth step.

Description

  The present invention relates to a rack and pinion type steering device and an adjusting screw fixing method.

2. Description of the Related Art Conventionally, as a rack-and-pinion type steering device for a vehicle, an apparatus including a preload mechanism that applies a predetermined pressing force (preload) to a rack in a housing is known. In general, the preload mechanism includes a rack guide that supports the rack, a preload spring that presses the rack guide against the rack, and an adjustment screw that is screwed into the housing to support the preload spring.
In recent years, a steering device has been proposed in which the housing is crimped and a part of the housing is inserted into a recess formed on the outer peripheral surface of the adjustment screw to prevent the adjustment screw from loosening (for example, Patent Document 1). See).
In addition, a steering device has also been proposed in which the adjustment screw is prevented from loosening by crimping the housing and crimping a part of the housing to the screw portion without plastic deformation of the screw portion of the adjustment screw (for example, (See Patent Document 2).

JP-A-11-227616 JP 2005-170109 A

However, in the conventional steering device as in Patent Document 1, a gap is generated between the screw portion of the adjustment screw and the screw portion of the housing. For this reason, when an excessive load is applied to the rack, the position of the adjusting screw screwed into the housing is shifted, and the preload is reduced. As the preload decreases, rack and pinion backlash occurs, and the rack sliding force decreases excessively. The rack sliding force is a force required to slide the rack with respect to the rack guide, and affects the operational feeling of the steering wheel connected to the pinion.
Further, in the conventional steering device such as Patent Document 2, after adjusting the preload, the housing is crimped with a gap left between the screw portion of the adjustment screw and the screw portion of the housing. For this reason, the position of the adjusting screw is shifted by the gap and the preload increases, and the rack sliding force increases.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a steering device and an adjusting screw fixing method that prevent occurrence of backlash between a rack and a pinion and prevent changes in rack sliding force. And

In order to solve the above problems, the present invention
A rack guide inserted into a cylindrical portion provided in the housing to support the rack; an elastic member for pressing the rack guide against the rack; and an adjustment screw screwed into the cylindrical portion to support the elastic member; An adjustment screw fixing method for a steering device having
A first step of screwing the adjustment screw into the cylindrical portion;
A second step of performing caulking on one of the adjustment screw and the cylindrical portion on an axial end surface thereof to narrow a gap between the screw portion of the adjustment screw and the screw portion of the cylindrical portion;
A third step of adjusting a force of pressing the rack guide against the rack by rotating the adjustment screw within the cylindrical portion;
Including a fourth step of caulking the remaining one axial side end surface of the adjustment screw and the cylindrical portion and preventing the adjustment screw from loosening,
An adjustment screw fixing method for a steering apparatus is provided, wherein the adjustment screw is fixed to the cylindrical portion of the housing by sequentially performing the first step to the fourth step.

The present invention also provides
A rack guide inserted into a cylindrical portion provided in the housing to support the rack; an elastic member for pressing the rack guide against the rack; and an adjustment screw screwed into the cylindrical portion to support the elastic member; A steering device having
Between the adjustment screw and the cylindrical portion, the gap between the screw portion of the adjustment screw and the screw portion of the cylindrical portion is narrowed by caulking to any one axial end surface,
In a state where the force for pressing the rack guide against the rack is adjusted, the adjustment screw and the cylindrical portion are prevented from loosening to the cylindrical portion by caulking to the remaining axial end surface of the cylindrical portion. Provided is a steering apparatus characterized by the above.

  According to the present invention, it is possible to provide a steering device and an adjustment screw fixing method that prevent the occurrence of backlash between the rack and the pinion and prevent the change of the rack sliding force.

It is sectional drawing which looked at a part of steering device concerning an embodiment of the present invention from the side, and is a figure showing a rack in a housing, a pinion, and a preload mechanism. It is a figure which shows the mode of the procedure 1 of the adjustment screw fixing method, (a) is a top view of a housing, (b) is sectional drawing of a housing, (c) is the elements on larger scale of (b). It is a figure which shows the mode 2 of the adjustment screw fixing method, (a) is a top view of a housing, (b) is sectional drawing of a housing, (c) is the elements on larger scale of (b). It is a figure which shows the mode 3 of the adjustment screw fixing method, (a) is a top view of a housing, (b) is sectional drawing of a housing, (c) is the elements on larger scale of (b). It is a figure which shows the mode of the procedure 4 of an adjustment screw fixing method, (a) is a top view of a housing, (b) is sectional drawing of a housing, (c) is the elements on larger scale of (b), (d) is adjustment The figure which shows the external appearance of a screw, (e) is the elements on larger scale of (d).

A steering device and an adjustment screw fixing method according to an embodiment of the present invention will be described with reference to the accompanying drawings.
A steering apparatus 1 according to this embodiment shown in FIG. 1 is a rack and pinion type steering apparatus for a vehicle. In the steering device 1, a rack 3, a pinion 4, and a preload mechanism 5 that applies preload to the rack 3 are provided in a housing 2 fixed to a vehicle body frame (not shown).

  The pinion 4 is composed of a cylindrical member on which pinion teeth 4a are formed. The pinion 4 extends in the left-right direction in FIG. 1 and is rotatably supported by the housing 2 via a bearing 6. Note that an end portion (not shown) of the pinion 4 is connected to a steering wheel (not shown) via a steering shaft (not shown).

  The rack 3 is composed of a cylindrical member on which rack teeth 3a are formed. The rack 3 extends in a direction perpendicular to the paper surface of FIG. 1, and is supported by the housing 2 so as to be reciprocally movable in the axial direction. The rack 3 is disposed in the housing 2 so that the rack teeth 3a face downward and intersect with the pinions 4, and the rack teeth 3a and the pinion teeth 4a mesh with each other. Further, both end portions (not shown) of the rack 3 are connected to wheels (not shown) via tie rods (not shown).

  The housing 2 has a cylindrical portion 7 extending from the crossing position of the pinion 4 and the rack 3 toward the upper direction. A female screw portion 7 a is formed on the inner peripheral surface of the cylindrical portion 7. In the cylindrical portion 7, a rack guide (pressure pad) 8, a preload spring 9, and an adjustment screw 10 are sequentially inserted, and the preload mechanism 5 is configured by these. The housing 2 is made of aluminum die cast.

  The rack guide 8 supports the rack 3 from above, and is made of a sintered metal columnar member that fits inside the cylindrical portion 7 of the housing 2. The rack guide 8 is provided so as to be movable in the axial direction of the cylindrical portion 7, and a curved portion corresponding to the rear surface of the rack 3 (the upper surface of the rack 3 on which the rack teeth 3 a are not formed) is curved on the lower surface thereof. Is formed. A sliding spacer 13 made of a resin sheet is disposed between the curved portion and the back surface of the rack 3 in order to reduce the frictional resistance between the rack guide 8 and the rack 3.

  The adjustment screw 10 is a lid member made of iron or zinc for adjusting the preload and closing the cylindrical portion 7 of the housing 2, and has a substantially cylindrical shape fitted inside the cylindrical portion 7. A male screw portion 10 a is formed at the upper part of the outer peripheral surface of the adjustment screw 10, and is screwed with the female screw portion 7 a of the cylindrical portion 7. A hexagonal columnar nut portion 10d extending in the axial direction of the cylindrical portion 7 is provided at the center of the upper surface of the adjustment screw 10, and the adjustment screw 10 can be rotated using a spanner or the like. The nut portion 10d is formed with a through hole penetrating in the axial direction of the cylindrical portion 7 so that the gap amount between the adjusting screw 10 and the rack guide 8 can be directly measured. After the adjustment, the preload spring 9 is positioned concentrically with the adjustment screw 10 and a spring seal component 14 for sealing the through hole is fitted. An O-ring 15 is disposed between the adjustment screw 10 and the inner peripheral surface of the cylindrical portion 7 and between the rack guide 8 and the inner peripheral surface of the cylindrical portion 7 for soundproofing and preventing grease leakage. Has been.

  The preload spring 9 is composed of a coiled compression spring and biases the rack guide 8 toward the rack 3. By this preload spring 9, the rack guide 8 supports the rack 3 while applying a preload from the back side at a position intersecting the pinion 4. With such a configuration, the rack 3 can be appropriately pressed against the pinion 4 while allowing the rack 3 to reciprocate in the axial direction. That is, backlash between the rack 3 and the pinion 4 can be prevented while the rack sliding force is moderately lightened. The preload can be adjusted by rotating the adjusting screw 10 to change the axial position in the cylindrical portion 7.

  With the above configuration, in the steering device 1 according to the present embodiment, when the driver of the vehicle rotates a steering wheel (not shown), the pinion 4 rotates and the rotation is transmitted to the rack 3. As a result, the rack 3 moves in the axial direction, that is, in the vehicle width direction, and a wheel (not shown) turns to achieve steering of the vehicle.

  Here, in the steering device 1 according to the present embodiment, the adjustment screw 10 is attached to the cylindrical portion 7 of the housing 2 according to the following adjustment screw fixing method. When the operator performs the adjustment screw fixing method, as shown in FIG. 2 (b), the rack 3 or the like is incorporated in the housing 2 in advance, and the rack guide 8 and the preload spring 9 are installed in the cylindrical portion 7 of the housing 2. Is inserted.

  Procedure 1: As shown in FIG. 2B and FIG. 2C, the operator inserts the adjusting screw 10 into the cylindrical portion 7 of the housing 2 and rotates the adjusting screw 10 to rotate the male screw portion of the adjusting screw 10. 10 a and the female screw portion 7 a of the cylindrical portion 7 are screwed together, and the adjustment screw 10 is seated on the rack guide 8. At this time, the operator tightens the adjusting screw 10 to a specified torque. Thereby, an appropriate axial force can be generated in the adjusting screw 10 and the axial backlash between the male screw portion 10a and the female screw portion 7a can be reduced. That is, as shown in FIG. 2B, each screw thread of the male screw portion 10a is appropriately supported by each screw thread of the female screw portion 7a.

Procedure 2: As shown in FIGS. 3 (a) to 3 (c), the operator can place 6 at regular intervals along the circumferential direction in the vicinity of the female screw portion 7a on the ring-shaped upper surface 7b of the cylindrical portion 7. Perform location caulking. Caulking means that an object is locally pressed and plastically deformed using a caulking tool or the like. In this procedure 2, caulking is performed using a caulking tool having a wedge shape, more specifically, a shape in which the tip of a half cone is notched.
As shown in FIG. 3C, the caulking in this procedure 2 forms a recess 7c on the upper surface 7b of the cylindrical portion 7, and the first thread of the female thread 7a, that is, the thread on the uppermost surface 7b side is Press contact with the male screw portion 10a. Specifically, the peripheral portion of the recess 7c protrudes in the inner diameter direction of the cylindrical portion 7 and is filled in the thread groove of the male screw portion 10a, thereby achieving gap filling in the radial direction and the axial direction of the male screw portion 10a and the female screw portion 7a. (Hereinafter simply referred to as “filling gaps”). In addition, it is preferable that the depth of the recess 7c is not less than one pitch of the female screw portion 7a in order to appropriately press the first thread of the female screw portion 7a against the male screw portion 10a (FIG. 3 (c). (See depth L in the middle.) Further, in this procedure 2, only the female screw portion 7a needs to be deformed, that is, the male screw portion 10a does not need to be deformed. Therefore, the caulking load per place is smaller than the caulking of procedure 4 described later.

  Note that the caulking tool used in this procedure 2 is not limited to the above-described one, and may be any tapering substantially wedge shape, for example, a shape obtained by equally dividing a cone, a triangular pyramid, a square pyramid, or the like. Further, in place of the caulking in the procedure 2, it is conceivable to form the depression 7c in the cylindrical portion 7 in advance with a mold when casting the housing 2, but the effect of filling the gap as in the procedure 2 cannot be achieved.

  Procedure 3: As indicated by an arrow in FIG. 4 (a), the operator rotates the adjustment screw 10 to change the axial position in the cylindrical portion 7, thereby making the rack sliding force moderately light. The preload is adjusted so that backlash of 3 and pinion 4 can be prevented. At this time, the gaps are narrowed by caulking in the above procedure 2, so that a gap can be prevented from being generated in the male screw portion 10a and the female screw portion 7a. Further, as indicated by arrows in FIG. 4C, the state in which each screw thread of the female screw portion 7a appropriately supports each screw thread of the male screw portion 10a is maintained, so that the adjusting screw 10 is attached to the rack 3. The preload does not change even if the reaction force is received. In addition, by making the preload appropriate in this procedure 3, a space is generated between the adjusting screw 10 and the rack guide 8 as shown in FIG. Thereby, it becomes possible to absorb a dimensional error caused by the tooth accuracy of the rack 3 and the pinion 4.

Procedure 4: As shown in FIGS. 5A to 5C, the operator is a position near the male screw portion 10 a on the upper surface 10 b of the adjustment screw 10, and a position facing the recess 7 c of the cylindrical portion 7. In addition, caulking is performed at three locations at equal intervals along the circumferential direction. In this procedure 4, caulking is performed using a spherical caulking tool.
As shown in FIG. 5C, the caulking of the procedure 4 forms a hemispherical recess 10c on the upper surface 10b of the adjustment screw 10, and the peripheral portion of the recess 10c of the adjustment screw 10 and the recess of the cylindrical portion 7. The peripheral portion of 7c deforms and meshes with each other. Thereby, the frictional resistance between the male screw portion 10a and the female screw portion 7a can be increased, and the locking of the adjusting screw 10 with respect to the cylindrical portion 7 is achieved (hereinafter simply referred to as “loosening prevention”). At this time, the gaps are narrowed by caulking in the above procedure 2, so that a gap can be prevented from being generated in the male screw portion 10a and the female screw portion 7a. Moreover, as shown in FIG.5 (c), the state which each thread of the internal thread part 7a supported each thread of the external thread part 10a appropriately is maintained. For this reason, it is possible to prevent the preload appropriately adjusted in the procedure 3 from being changed by the caulking in the procedure 4.

  In this procedure 4, when the peripheral portion of the depression 7c of the cylindrical portion 7 is deformed by caulking on the upper surface 10b of the adjustment screw 10 at a position facing the depression 7c of the cylindrical portion 7, the peripheral portion is As shown in FIG.5 (c), it can bulge in the hollow 7c and can escape. For this reason, the load of crimping can be made small and the change of the shape of the said peripheral part by crimping can be stabilized. Therefore, it is possible to use a general hard material such as low carbon steel or zinc as the material of the adjusting screw 10, and it is possible to prevent unintended deformation or cracking of the peripheral portion. The caulking does not adversely affect the performance of the steering device 1.

  Further, as shown in FIG. 5A, on the upper surface 10b of the adjusting screw 10, there are three positions that are opposite to the recess 7c of the cylindrical portion 7 and that are not caulked in this procedure 4. Yes. These three places can be used to perform caulking again in this procedure 4 when the above procedure 3 is performed again and the preload is readjusted. When the adjustment screw 10 is rotated for readjustment of the preload, the peripheral portion of the recess 7c of the cylindrical portion 7 meshed with the peripheral portion of the recess 10c of the adjustment screw 10 is bulged into the recess 7c. I can escape. For this reason, there is no possibility of damaging the external thread part 10a and the internal thread part 7a. Therefore, it becomes unnecessary to repair the damaged male screw portion 10a and the female screw portion 7a, and the broken piece enters between the rack 3 and the pinion 4, the rack guide 8 and the rack 3, etc., and the rack sliding force is increased. There is no such thing as a significant increase.

According to the adjustment screw fixing method, the steering device 1 according to the present embodiment can prevent the preload from being changed when the loosening is caulked after the preload adjustment by performing caulking of the gap before adjusting the preload. Therefore, the steering device 1 according to the present embodiment can appropriately set the preload when the adjustment screw 10 is attached to the cylindrical portion 7.
In addition, the steering device 1 according to the present embodiment performs the clearance filling and the locking prevention to prevent the preload from changing even when an excessive load is applied to the rack 3 during driving of the vehicle. Can be prevented. Therefore, the steering device 1 according to the present embodiment can also maintain the preload appropriately set when the adjustment screw 10 is attached to the cylindrical portion 7.
As described above, the steering device 1 according to the present embodiment can prevent the backlash of the rack 3 and the pinion 4 and can prevent the rack sliding force from changing. Further, the adjusting screw fixing method does not require large-scale equipment, and can be used not only at the time of manufacturing the steering device but also at the time of maintenance.

In the above adjustment screw fixing method, caulking is performed at six locations on the upper surface 7b of the cylindrical portion 7 of the housing 2 in procedure 2 and at three locations on the upper surface 10b of the adjusting screw 10 in procedure 4, but the number of caulking is not limited to these. Not limited to. For example, in order to make the centering, that is, the adjustment screw 10 and the cylindrical portion 7 concentric, it is preferable to set the number of crimps to three or more in any procedure. In particular, for better centering, it is preferable to perform all the caulking simultaneously in each procedure. Further, if the number of crimps in step 2 is an integer multiple (two or more) of the number of crimps in step 4, it is possible to re-adjust the preload, that is, it is possible to repeatedly perform steps 3 and 4. Specifically, if the number of crimps in step 2 is 12 and the number of crimps in step 4 is 3, it is possible to readjust the preload three times while centering.
In the adjusting screw fixing method, crimping is performed on the cylindrical portion 7 of the housing 2 in the procedure 2, and crimping is performed on the adjustment screw 10 in the procedure 4. However, the present invention is not limited to this, and the adjustment screw 10 may be crimped in the procedure 2 and the cylindrical portion 7 of the housing 2 may be crimped in the procedure 4.

  As described above, according to the present embodiment, it is possible to realize the rack and pinion type steering device and the adjusting screw fixing method which prevent the occurrence of backlash between the rack and the pinion and prevent the change of the rack sliding force.

DESCRIPTION OF SYMBOLS 1 Steering device 2 Housing 3 Rack 4 Pinion 5 Preload mechanism 7 Cylindrical part 7a of housing Female thread part 8 of cylindrical part Rack guide 9 Preload spring 10 Adjustment screw 10a Male thread part of adjustment screw

Claims (6)

A rack guide inserted into a cylindrical portion provided in the housing to support the rack; an elastic member for pressing the rack guide against the rack; and an adjustment screw screwed into the cylindrical portion to support the elastic member; An adjustment screw fixing method for a steering device having
A first step of screwing the adjustment screw into the cylindrical portion;
A second step of performing caulking on one of the adjustment screw and the cylindrical portion on an axial end surface thereof to narrow a gap between the screw portion of the adjustment screw and the screw portion of the cylindrical portion;
A third step of adjusting a force of pressing the rack guide against the rack by rotating the adjustment screw within the cylindrical portion;
Including a fourth step of caulking the remaining one axial side end surface of the adjustment screw and the cylindrical portion and preventing the adjustment screw from loosening,
An adjustment screw fixing method for a steering device, wherein the adjustment screw is fixed to the cylindrical portion of the housing by sequentially performing the first step to the fourth step. In the second step, caulking is performed at three or more locations along the circumferential direction in the vicinity of the screw portion on the axial end surface of the cylindrical portion,
2. The adjustment screw fixing method for a steering device according to claim 1, wherein, in the fourth step, caulking is performed at three or more locations along the circumferential direction in the vicinity of the screw portion on the axial end surface of the adjustment screw. By caulking in the second step, a depression is formed in the axial end surface of the cylindrical portion,
The adjusting screw fixing method for a steering apparatus according to claim 2, wherein, in the fourth step, caulking is performed so as to face the hollow of the cylindrical portion.   The said 2nd step WHEREIN: It caulks using a wedge-shaped caulking tool, The said hollow is formed so that it may become the depth more than 1 pitch of the thread part of the said cylindrical part. Adjustment screw fixing method of steering device.   5. The adjustment screw fixing method for a steering device according to claim 3, wherein the number of crimping locations in the second step is an integral multiple of the number of crimping locations in the fourth step. A rack guide inserted into a cylindrical portion provided in the housing to support the rack; an elastic member for pressing the rack guide against the rack; and an adjustment screw screwed into the cylindrical portion to support the elastic member; A steering device having
Between the adjustment screw and the cylindrical portion, the gap between the screw portion of the adjustment screw and the screw portion of the cylindrical portion is narrowed by caulking to any one axial end surface,
In a state where the force for pressing the rack guide against the rack is adjusted, the adjustment screw and the cylindrical portion are prevented from loosening to the cylindrical portion by caulking to the remaining axial end surface of the cylindrical portion. A steering device characterized in that

Images