JP2015231823A - Rack-and-pinion type steering gear unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a structure which can improve the durability of a slide bearing 26a in an assembled state, and can improve the workability of the assembling work of the slide bearing 26a and the confirmation work of the assembled state.SOLUTION: A non-continuous part 25a of a slide bearing 26a is arranged in a non-load area which does not bear a radial load based on a pressing force of a pressing mechanism 21a. Furthermore, positioning notches 34a, 34b for performing positioning with respect to a circumferential direction of the slide bearing 26a at assembling are formed at axial both side faces of the slide bearing 26a.

Description

  The present invention relates to an improvement of a rack and pinion type steering gear unit that constitutes a steering device for giving a steering angle to a steering wheel of an automobile.

  A steering device including a rack and pinion type steering gear unit that uses a rack and pinion as a mechanism for converting a rotational motion input from a steering wheel into a linear motion for giving a steering angle is disclosed in, for example, Patent Document 1 For example, it has been widely known. In addition, the rack and pinion type steering gear unit can be configured to be small and light, and since it has high rigidity and a good steering feeling, it is actually widely used. 17 to 19 show an example of a steering apparatus incorporating such a rack and pinion type steering gear unit. In this steering device, the movement of the steering shaft 2 that rotates in accordance with the operation of the steering wheel 1 is transmitted to the pinion shaft 6 that is the input shaft of the steering gear unit 5 through the universal joints 3 and 3 and the intermediate shaft 4. To do. In addition, the up-down direction of the said FIGS. 18-19 does not necessarily correspond with the up-down direction in use condition. The vertical direction is appropriately selected depending on the state of assembly in the vehicle, and in general, the pinion shaft 6 is installed in an inclined state with respect to the vertical direction.

The steering gear unit 5 as described above is formed by engaging pinion teeth 7 provided on the outer peripheral surface of the intermediate portion in the axial direction of the pinion shaft 6 with rack teeth 9 provided on the front surface of the rack shaft 8.
The pinion shaft 6 and the rack shaft 8 are partly housed in a casing 10. The casing 10 includes a first storage portion 11 and a second storage portion 12 each having a cylindrical shape. Of these, the first storage part 11 is open at both ends. The second storage portion 12 is provided on a part of the first storage portion 11 and is open at one end. The central axis of the first storage part 11 and the central axis of the second storage part 12 are in a twisted positional relationship with each other. The rack shaft 8 is inserted into the first storage portion 11 of the rack shaft 8 so as to be axially displaceable, and both end portions are protruded from the first storage portion 11. Further, a pair of rack guides (sliding bearings) 13 and 13 supported on both ends of the inner peripheral surface of the first storage portion 11 are brought into sliding contact with the outer peripheral surface of the rack shaft 8 so that the rack shaft 8 However, the first storage part 11 can be displaced in the axial direction without rattling. The base ends of the tie rods 15 and 15 are coupled to both ends of the rack shaft 8 through spherical joints 14 and 14, respectively. The tip portions of both tie rods 15 and 15 are connected to the tip portions of knuckle arms (not shown) by pivots. The rack shaft 8 does not rotate around its own central axis due to the engagement of the pinion teeth 7 and the rack teeth 9.

  The pinion shaft 6 supports the tip half of the pinion teeth 7 in the second storage portion 12 so as to be rotatable only. For this purpose, the insertion part 16 provided at the tip of the pinion shaft 6 is supported by a radial support bearing 17 in a bottomed cylindrical support recess 17 formed at the back end of the second storage part 12. . A radial load and a thrust load are applied to the intermediate portion of the pinion shaft 6 near the opening of the second storage portion 12 by a single row ball bearing 19 such as a deep groove type, a three-point contact type, or a four-point contact type. It is supported so as to be able to be supported (rotation is possible while preventing displacement in the axial direction).

  Further, the casing 10 is provided with a cylinder portion 20 at a portion opposite to the second storage portion 12 in the diameter direction of the first storage portion 11. A pressing mechanism 21 is provided in the cylinder portion 20. The pressing mechanism 21 includes a pressing block 22 that is fitted to the rack shaft 8 so as to be able to move to and away from the rack shaft 8, a lid body 23 that is screwed into the opening of the cylinder portion 20, and the lid body 23 and the pressing block. And a coil spring 24 which is an elastic member provided between them. By the pressing mechanism 21 configured in this manner, the rack shaft 8 is elastically pressed toward the pinion shaft 6 to apply a preload to the meshing portion between the pinion teeth 7 and the rack teeth 9. The meshing state of the meshing portion is appropriately maintained.

  In the case of the steering gear unit 5 described above, the tip end portion (insertion portion 16) of the pinion shaft 6 is supported by the support recess 17 of the second storage portion 12 by a radial needle bearing 18. On the other hand, Patent Document 2 and the like disclose a technique in which the tip portion (insertion portion 16) of the pinion shaft 6 is supported on the inner diameter side of the support recess 17 by a slide bearing instead of a radial needle bearing. If such a sliding bearing is used, it is possible to improve quietness and save space. However, Patent Document 2 does not describe a specific structure and arrangement state of the sliding bearing.

  As described above, the sliding bearing for supporting the tip end portion (insertion portion 16) of the pinion shaft 6 on the inner diameter side of the support recess 17 is shown in FIGS. It is advantageous from the viewpoint of component cost to use a cylindrical slide bearing 26 having a discontinuous portion 25 at one position in the circumferential direction. Such a sliding bearing 26 is formed by punching a plate-like material made of a slippery material such as an oil-impregnated metal so that a plate-like intermediate member (band-like shape) as shown in FIGS. After the material 27 is obtained, the plate-like intermediate member 27 is bent. 20B, 20A, and 20B show the free state of the slide bearing 26. FIG. Then, the assembly jig (not shown) holds the axial end portion of the sliding bearing 26 in the free state, and reduces the circumferential interval of the discontinuous portion 25 (contacts or closes both circumferential end surfaces). By doing so, the sliding bearing 26 is fitted (inserted) into the inner peripheral surface of the support recess 17 in a state where the diameter is reduced as shown in FIG.

By the way, in the case of a structure in which the tip end portion (insertion portion 16) of the pinion shaft 6 is supported on the inner diameter side of the support recess 17 by the slide bearing 26 having the above-described configuration, depending on the state of incorporation of the slide bearing 26. May cause the following problems from the viewpoint of durability.
That is, there is a case where there is a sag associated with the punching process at both ends in the circumferential direction of the slide bearing 26 (in the vicinity of the discontinuous portion 25). May be low. Such circumferential ends (discontinuous portions 25) of the sliding bearing 26 are, for example, reaction forces based on preload applied to the meshing portions of the pinion teeth 7 and the rack teeth 9, or the meshing portions Based on the meshing reaction force, if it is arranged in a portion that supports most of the radial load applied to the pinion shaft 6, it will be excessive on the inner peripheral surface of both ends (discontinuous portion 25) in the circumferential direction of the slide bearing 26. There is a possibility that durability of the sliding bearing 26 may be reduced due to, for example, excessive wear. The meshing reaction force is considerably larger than the reaction force based on the preload. Therefore, most of the radial load is generated based on the meshing reaction force.

The direction of the meshing reaction force of the meshing portion applied to the pinion shaft 6 is influenced by the rotation state of the pinion shaft 6 or the pressure angle applied to the pinion teeth 7 and the rack teeth 9. As shown in FIG. 3, when the pinion shaft 6 rotates in one direction (counterclockwise in FIG. 3), the pressure angle of the meshing portion between the pinion teeth 7 and the rack teeth 9 at this time is expressed by β _a When the direction of the meshing reaction force, the center line O ₆ of the pinion shaft 6 through _(see FIG. 3), and, (vertical direction in FIG. 3) direction of pressing the rack shaft 8 by the pressing mechanism 21 ₃ from the imaginary plane α ₁ existing in FIG. 3 by an angle β ₁ (β ₁ = 90−β _a ). On the other hand, when the pinion shaft 6 rotates in the other direction (clockwise in FIG. 3), if the pressure angle of the meshing portion between the pinion teeth 7 and the rack teeth 9 at this time is β _b , The direction of the force is a position shifted from the virtual plane α ₁ by the angle β ₂ (β ₂ = 90−β _b ) in the clockwise direction in FIG. As described above, the direction of the meshing reaction force is influenced not only by the pressure angle but also by the rotation state of the pinion teeth 7 and the like. For this reason, the direction of the meshing reaction force can be obtained by simulation or experiment.

  Further, in the case of the sliding bearing 26 having the above-described structure, the circumferential position of both ends (discontinuous portion 25) of the sliding bearing 26 in the circumferential direction is regulated (the discontinuous portion 25 is engaged with the circumferential direction). Therefore, it is necessary to confirm the position of the discontinuous portion 25 by visual observation or the like. However, since the width dimension in the circumferential direction of the discontinuous portion 25 is zero or almost zero when the sliding bearing 26 is assembled or in a state in which the sliding bearing 26 is assembled, it is viewed from the axial direction. Inconspicuous if For this reason, the work of visually confirming the position of the discontinuous portion 25 is troublesome, and workability may be reduced.

JP 2009-184591 A JP 2010-023796 A

  In view of the circumstances as described above, the present invention provides a slide having a discontinuous portion at one circumferential position on the inner diameter side of the support concave portion of the second storage portion constituting the casing of the pinion shaft. A rack and pinion type steering gear unit that can improve the durability of the sliding bearing by regulating the position of the discontinuous portion of the sliding bearing in the assembled state in a structure that is rotatably supported via the bearing. Invented to realize the above.

The rack and pinion type steering gear unit of the present invention includes a casing, a rack shaft, a pinion shaft, a pressing mechanism, and a sliding bearing.
Of these, the casing has a first storage portion and a second storage portion in which the inner spaces communicate with each other.
The rack shaft has rack teeth on the front surface, and is supported on the inner diameter side of the first storage portion so as to be axially displaceable.
The pinion shaft has pinion teeth on a part of the outer peripheral surface in the axial direction, and is supported on the inner diameter side of the second storage portion in a state where the pinion teeth are engaged with the rack teeth.
The pressing mechanism is for pressing a part of the back surface of the rack shaft toward the pinion shaft.
Furthermore, the sliding bearing is formed in a cylindrical shape having a discontinuous portion at one position in the circumferential direction by, for example, rounding (bending) a plate-shaped material, and the second storage The inner end of the bottomed cylindrical support recess formed inside the portion is fitted inside, and the tip end portion of the pinion shaft is rotatably supported with respect to the second storage portion on the inner diameter side thereof. ing.

In particular, in the rack-and-pinion type steering gear unit of the present invention, the discontinuous portion has a reaction force applied from the rack shaft to the pinion shaft when the pinion shaft rotates in one direction with respect to the circumferential direction. Of the range defined by the direction and the direction of the reaction force when it rotates to the other side, it is arranged in the range on the meshing part side of the pinion teeth and the rack teeth.
In carrying out the present invention as described above, preferably, as in the invention described in claim 2, at least an end face disposed on the opening side of the support recess among the axial end faces of the slide bearing. At the time of assembly, a positioning portion (for example, a concave portion or a convex portion) is formed for positioning the sliding bearing in the circumferential direction.
Preferably, the discontinuous portion is arranged in a half portion on the side of the meshing portion between the pinion teeth and the rack teeth in the circumferential direction.

In carrying out the invention described in claim 2 as described above, preferably, as in the invention described in claim 3, the positioning portion is arranged such that the discontinuous portion of the axial end surface of the sliding bearing is the discontinuous portion. To 90 degrees in the circumferential direction.
Further, when carrying out the invention described in claims 2 to 3 as described above, more preferably, as in the invention described in claim 4, the positioning portion is a meshing portion of the pinion teeth and rack teeth. Form on the side half.
Further, when carrying out the invention described in claims 2 to 4 as described above, preferably the positioning portion is punched into the plate material as in the invention described in claim 5. Thus, it is formed when a belt-like plate-like intermediate member is made.
When the present invention as described above is carried out, preferably, as in the invention described in claim 6, the sliding bearing is fitted in the support recess, and the circumferential direction of the sliding bearing is set. The gap between the both end faces is configured to exist in the circumferential direction.
In carrying out the present invention as described above, a positioning convex portion is preferably formed on the inner peripheral surface of the supporting concave portion as in the seventh aspect of the present invention. And the said positioning convex part is arrange | positioned in the part between the circumferential direction both end surfaces of the said sliding bearing. In addition, the said positioning convex part is made into the protrusion long in an axial direction, for example.

According to the present invention as described above, the durability of the sliding bearing can be improved.
The reason for this is that the discontinuous part of the sliding bearing is related to the direction of the reaction force applied to the pinion shaft from the rack shaft when the pinion shaft rotates in one direction and the reaction force when the pinion shaft rotates in the other direction. This is because, in the range defined by the direction, the pinion teeth and the rack teeth are arranged in the range on the meshing portion side. In other words, as described above, there are cases in which there are sagging or the like at both ends (discontinuous portions) in the circumferential direction of the slide bearing, and there is a possibility that the durability will be lower than other portions. Therefore, in the case of the present invention, by disposing the circumferential end portions (discontinuous portions) of the sliding bearing at the above-described positions, the inner peripheral surfaces of the circumferential end portions of the sliding bearing and the pinion shaft A large radial load based on the meshing reaction force of the meshing portion between the pinion tooth and the rack tooth is prevented from being applied to the sliding contact portion with the outer peripheral surface of the insertion portion. As a result, it is possible to prevent the sliding contact portion from being worn and prevent the durability of the sliding bearing from being lowered.

Further, according to the invention described in claim 2, the workability when the sliding bearing is incorporated can be improved.
That is, a positioning portion for positioning the sliding bearing in the circumferential direction at the time of assembling at least the end surface arranged on the opening side of the support recess in the assembled state among the axial end surfaces of the sliding bearing. It is because it forms. That is, when the sliding bearing is assembled into the support recess, the positioning in the circumferential direction of the sliding bearing is reliably and easily performed by incorporating the positioning portion and the jig constituting the assembling device in an engaged state. You can plan.
Further, in the state in which the sliding bearing is incorporated in the support recess, the positions of both ends (discontinuous portions) in the circumferential direction of the sliding bearing can be determined with reference to the positioning portion. For this reason, the operation | work which confirms the assembly state of a slide bearing can be performed efficiently. In the invention described in claim 7 as well, when the slide bearing is incorporated into the support recess, the positioning projection formed in the support recess is formed in a portion (discontinuous portion) between both circumferential end surfaces of the slide bearing. By incorporating in a state in which the portion is arranged, positioning in the circumferential direction of the slide bearing at the time of incorporation and use can be achieved reliably and easily.

The fragmentary sectional view equivalent to the A section of FIG. 17 which shows the 1st example of embodiment of this invention. Similarly, the II sectional view of FIG. Similarly, the roll sectional view of FIG. Similarly, a plan view (A) (a) of the plate-shaped intermediate member, a side view (A) (b), and a view of the periphery of the discontinuous portion of the slide bearing as viewed from the outside in the radial direction (B) (a) (B) and (b) as seen from the axial direction. Similarly, it is a figure which shows the slide bearing of the state integrated in a support recessed part, Comprising: The figure (a) which looked at the discontinuous part periphery from the radial direction outer side, and the figure (b) seen from the axial direction. The figure similar to FIG. 2 which shows the 2nd example of embodiment of this invention. The top view (a) of a plate-shaped intermediate member which shows the same 3rd example, and the figure (b) which looked at the discontinuous part periphery of a slide bearing from the radial direction outer side. The figure similar to FIG. 7 which shows the 4th example. The figure similar to FIG. 7 which shows the said 5th example. The figure similar to FIG. 7 which shows the 6th example. The figure similar to FIG. 7 which shows the said 7th example. The figure similar to FIG. 7 which shows the said 8th example. The figure similar to FIG. 5 which shows the 9th example. The figure similar to FIG. 13 which shows the 10th example. The figure similar to FIG. 2 which shows the 11th example. Similarly, the same figure as FIG. The partial cutting side view which shows an example of the steering device for motor vehicles incorporating the rack and pinion type steering gear unit. FIG. 18 is a cross-sectional view of FIG. FIG. 19 is a sectional view of the knee of FIG. 18. It is a figure for demonstrating the plain bearing of conventional structure, Comprising: The top view (A) (a) of a plate-shaped intermediate member, a side view (A) (b), and the periphery of the discontinuous part of a slide bearing The figure (B) (a) seen from radial direction outward, and the figure (B) (b) seen from the axial direction. Similarly, it is a figure which shows the slide bearing of the state integrated in a support recessed part, Comprising: The figure (a) which looked at the periphery of a discontinuous part from radial direction outward, and the figure (b) seen from the axial direction.

[First example of embodiment]
1 to 5 show a first example of an embodiment of the present invention. The feature of this example is that it is incorporated in the inner diameter side of the support concave portion 17a of the second storage portion 12a constituting the casing 10a, and is a sliding bearing 26a for supporting the tip portion (insertion portion 16) of the pinion shaft 6. It is in the point which devised structure and arrangement situation. Hereinafter, the rack and pinion type steering gear unit 5a of this example will be described.

The rack and pinion type steering gear unit 5a of this example includes a casing 10a, a rack shaft 8, a pinion shaft 6, a pressing mechanism 21a, and a sliding bearing 26a.
Of these, the casing 10a is made of an aluminum alloy and is made by a casting method such as die casting. Such a casing 10a includes a first storage portion 11a, a second storage portion 12a, and a pair of mounting flange portions 28a and 28b, each of which is cylindrical.
Of these, the first storage portion 11a is open at both ends, and a cylinder portion 20a is provided on the opposite side of the second storage portion 12a, which will be described later, in the diameter direction of the first storage portion 11a.

  The second storage portion 12a is provided on a side of a part of the first storage portion 11a in a state in which the central axis thereof is twisted with respect to the central axis of the first storage portion 11a. ing. The second storage portion 12a is open at one end, and a support recess 17a for supporting the tip end portion of the pinion shaft 6 is formed at the other end (back end). The support recess 17a has a bottomed cylindrical shape that is open only on one end side (the side on which the tip end of the pinion shaft 6 is inserted and the right side in FIG. 2).

  Further, both the mounting flange portions 28a and 28b are provided on the outer peripheral surfaces of the both ends in the axial direction of the first storage portion 11a so as to protrude radially outward, and mounting holes 29 are formed in the center portion. Has been. Such mounting flange portions 28a and 28b are for mounting the casing 10a to the vehicle body with bolts (not shown) inserted through the mounting holes 29.

  The rack shaft 8 has rack teeth 9 formed on a part of the front surface in the axial direction, and is inserted into the first storage portion 11a so as to be axially displaceable. It protrudes from the part 11a. Also in the case of the present invention, a pair of rack guides 13 and 13 (see FIG. 18) supported on both ends of the inner peripheral surface of the first storage portion 11a are brought into sliding contact with the outer peripheral surface of the rack shaft 8. Thus, the rack shaft 8 can be displaced in the axial direction without rattling with respect to the first storage portion 11a. The base ends of the tie rods 15 and 15 are coupled to both ends of the rack shaft 8 through spherical joints 14 and 14, respectively. The tip portions of both tie rods 15 and 15 are respectively connected to the tip portions of knuckle arms (not shown) by pivots. The rack shaft 8 does not rotate around its own central axis due to the engagement of the pinion teeth 7 and the rack teeth 9.

The pinion shaft 6 has pinion teeth 7 formed on the outer peripheral surface of the intermediate portion in the axial direction, and the front half including the pinion teeth 7 is supported in the second storage portion 12a so as to be rotatable only. ing. For this purpose, the insertion portion 16 having a cylindrical outer peripheral surface formed at the tip of the pinion shaft 6 is supported by the support recess 17a of the second storage portion 12a via the slide bearing 26a. . The insertion portion 16 is fitted in a state where there is no gap over the entire circumference on the inner diameter side of the sliding bearing 26a or a state where a slight gap is provided.
A radial load and a thrust load are applied to the intermediate portion of the pinion shaft 6 near the opening of the second storage portion 12a by a single row ball bearing 19 such as a deep groove type, a three-point contact type, or a four-point contact type. It is supported so as to be able to be supported (rotation is possible while preventing displacement in the axial direction).
Further, in order to support the ball bearing 19 at a predetermined position of the casing 10 a, a holding screw cylinder 30 is screwed to the casing 10 a, and an inner circumferential surface of the holding screw cylinder 30 and an outer circumferential surface of the pinion shaft 6. Is sealed with a seal ring 31.

The pressing mechanism 21a includes a pressing block 22a, a lid body 23a, and a coil spring 24a provided in the cylinder portion 20.
Of these, the pressing block 22a is formed with a partial cylindrical concave concave portion 32 that matches the back shape of the rack shaft 8 on one end surface (the upper end surface in FIG. 2). Further, a rack receiving sheet 33 made of a synthetic resin that is slippery is attached to the surface of the pressing recess 32. Such a pressing block 22 a is provided in a state where the pressing recess 32 is in contact with the back surface of the rack shaft 8 via the rack receiving sheet 33.

The lid 23 a is screwed into the opening of the cylinder portion 20.
The coil spring 24a is provided between the pressing block 22a and the lid body 23a in a state of being given elasticity.
The pressing mechanism 21 a configured in this manner eliminates backlash at the meshing portion between the pinion teeth 7 and the rack teeth 9 by elastically pressing the rack shaft 8 toward the pinion shaft 6. . Furthermore, the meshing state of the meshing portion is properly maintained regardless of the force in the direction away from the pinion shaft 6 applied to the rack shaft 8 with the transmission of power at the meshing portion between the teeth 7 and 9. I am trying to do it.

  The sliding bearing 26a is, for example, an oil-impregnated metal, a metal material having a high compressive strength, or a synthetic resin that is slippery and formed by lining an alloy such as copper alloy or aluminum alloy on a back metal such as a steel plate It is a cylindrical member which consists of the material which laminated | stacked and the metal, and has the discontinuous part 25a in one place position of the circumferential direction. In addition, as a material configured by laminating a synthetic resin and a metal, for example, a synthetic resin layer is provided on the inner diameter side in use, and an iron-based material such as a cold rolled steel plate (SPCC) is provided on the outer diameter side. An alloy layer having a three-layer structure in which a sintered copper alloy layer is provided between the synthetic resin layer and the iron alloy layer can be used. Such a sliding bearing 26a is formed by punching a plate-like material (not shown) made of the material as described above, thereby forming a belt-like plate as shown in FIGS. 4 (A), (a) and (b). After the plate-shaped intermediate material 27a is obtained, the plate-shaped intermediate material 27a is made by rounding (bending).

In particular, in the rack and pinion type steering gear unit 5a of the present example, a discontinuous portion of one end face {the lower end face in FIG. 4 (B) (a)} among the axial end faces of the sliding bearing 26a. A positioning notch 34a having a triangular shape as viewed from the outside in the radial direction is located at a position shifted by about 40 degrees from one side in the circumferential direction {counterclockwise in FIGS. 4B and 4B} from 25a. Is formed.
On the other hand, of the two axial end surfaces of the slide bearing 26a, the other end surface {the upper end surface in FIG. 4B and FIG. 4A} from the discontinuous portion 25a to the other circumferential side {FIG. 4B and FIG. The position of the positioning notch 34b is the same as the positioning notch 34a. The positioning notch 34b has a triangular shape as viewed from the outside in the radial direction. In the case of this example, the positioning notches 34a and 34b correspond to the positioning portions in the claims.
Each of the positioning notches 34a and 34b as described above is used for punching the plate-like material in order to produce the plate-like intermediate material 27a shown in FIGS. 4 (A), (a) and (b). Are formed at the same time.

Further, in the sliding bearing 26a having the above-described configuration, the discontinuous portion 25a is rotated in one direction (counterclockwise in FIG. 3) with respect to the circumferential direction as shown in FIG. reaction force direction applied from the rack shaft 8 to the pinion shaft 6 when (virtual plane alpha ₁ in FIG. 3, by an angle beta ₁ shifted direction in a counterclockwise direction), similarly the other (clockwise direction in FIG. 3) Of the pinion teeth 7 and the rack teeth 9 in the range defined by the direction of the reaction force when rotated in the direction (the direction shifted by the angle β _{2 in the} clockwise direction from the virtual plane α _{1 in} FIG. 3) In a state of being arranged in the range on the meshing portion side (range indicated by δ ₁ in FIG. 3), it is press-fitted into the inner diameter side of the support concave portion 17a of the second storage portion 12a constituting the casing 10a. Preferably, the range in which the discontinuous portion 25a is disposed is a half portion (range indicated by δ ₂ in FIG. 3) on the meshing portion side of the pinion teeth 7 and the rack teeth 9 in the circumferential direction. In the case of this example, the discontinuous portion 25a is defined as the center line O ₆ (the center line O ₆ (the lower half portion in FIG. 3) of the inner peripheral surface of the support concave portion 17a on the rack shaft 8 side. through see Fig. 3), and are arranged at positions intersecting the virtual plane alpha ₁ that exists in a direction for pressing the rack shaft 8 (the vertical direction in FIGS. 2-3) by the pressing mechanism 21a.

In other words, the discontinuous portion 25a has a direction (from the rack shaft 8 to the pinion shaft 6 when the pinion shaft 6 rotates to one side of the inner peripheral surface of the support recess 17a ( When the pinion shaft 6 rotates to the other position at a position that intersects the virtual plane α _{1 in} FIG. 3 with a direction shifted by an angle β ₁ counterclockwise, the rack shaft 8 is opposed to the pinion shaft 6. (from the virtual plane alpha ₁ in FIG. 3, the angle beta ₂ shifted direction counterclockwise) direction force is applied are arranged on the inner diameter side of the farthest position from the position intersecting the. Further, in the present example, each of the positioning notches 34a, 34b are also in the circumferential direction, the halves of the coupling portion between the pinion teeth 7 and the rack teeth 9 (range shown by in FIG. 3 [delta] ₂₎ Has been placed.

According to the rack and pinion type steering gear unit 5a of this example as described above, the durability of the sliding bearing 26a can be improved, and workability when the sliding bearing 26a is assembled and when the assembled state is confirmed. Can be improved.
First, the reason why the durability can be improved is that the range in which both ends (discontinuous portions 25a) in the circumferential direction of the sliding bearing 26a are arranged is restricted to the above-described range. That is, there is a case where there is a sacrificial portion or the like accompanying the punching process at both ends (discontinuous portion 25a) in the circumferential direction of the slide bearing 26a, and there is a possibility that durability is lowered as compared with other portions. Therefore, in the case of this example, by restricting both ends (discontinuous portions 25a) in the circumferential direction of the sliding bearing 26a to the above-described range, the inner peripheral surfaces at both ends in the circumferential direction of the sliding bearing 26a, A large radial load based on the meshing reaction force of the meshing portion of the pinion tooth 7 and the rack tooth 9 is prevented from being applied to the sliding contact portion of the pinion shaft 6 with the outer peripheral surface of the insertion portion 16. As a result, it is possible to prevent the sliding contact portion (in particular, the inner peripheral surfaces of both ends in the circumferential direction of the sliding bearing 26a) from being worn and prevent the durability of the sliding bearing 26a from being lowered.
In the case of this example, the range in which the positioning notches 34a and 34b are formed is also restricted to the above range. For this reason, the radial load can be supported in a portion having a sufficiently large area in which the positioning notches 34a and 34b are not formed in the sliding bearing 26a. As a result, the performance and durability of the sliding bearing 26a are not impaired.

The reason why the workability when incorporating the slide bearing 26a can be improved is that each of the positioning notches for positioning the slide bearing 26a at the time of assembly on both axial end surfaces of the slide bearing 26a. This is because 34a and 34b are formed. That is, when the sliding bearing 26a is assembled into the support recess 17a, the sliding notches 34a and 34b are engaged with the jigs constituting the assembling device, so that the circular bearing 26a has a circular shape. Positioning in the circumferential direction can be achieved reliably and easily.
In the case of this example, the positioning notches 34a and 34b are formed on both end surfaces in the axial direction of the sliding bearing 26a. For this reason, when the slide bearing 26a is incorporated into the support recess 17a, the direction of the slide bearing 26a in the axial direction is not taken into consideration, and the assemblability can be improved.
Further, in the state in which the slide bearing 26a is incorporated in the support recess 17a, the position of the discontinuous portion 25a of the slide bearing 26a can be determined based on the positioning notches 34a and 34b. Therefore, the workability of this confirmation work can be improved.

[Second Example of Embodiment]
FIG. 6 shows a second example of the embodiment of the present invention. In the case of the rack and pinion type steering gear unit 5b of this example, the structure and arrangement of the sliding bearing 26a are the same as those of the first example of the embodiment described above.
On the other hand, in the case of this example, the discontinuous portion 25a of the sliding bearing 26a in the circumferential direction among the half portion on the rack shaft 8 side of the inner peripheral surface of the support recess 17b of the second storage portion 12b constituting the casing 10b. A vent groove 35 is formed at a position aligned with. The vent groove 35 is formed at the same time as the casing 10b is die-cast.

  The vent groove 35 as described above has a substantially semicircular cross-sectional shape and is linear (parallel to the central axis of the pinion shaft 6), and one end (the right end in FIG. 6) of the support recess 17b. While opening to the periphery of one end, the other end is located closer to the back end side of the support recess 17b than the other end of the sliding bearing 26a. That is, when the tip portion (insertion portion 16) of the pinion shaft 6 is inserted into the inner diameter side of the slide bearing 26a incorporated in the support recess 17b, the vent groove 35 is inserted into the support recess 17b and the slide bearing. The inner space 36 defined by the inner surface of the pinion shaft 6 and the tip end surface of the pinion shaft 6, and the outer peripheral surface of the portion near the tip of the pinion shaft 6 that is not located on the inner diameter side of the support recess 17b ( The insertion portion 16 and the outer space 37 existing around the pinion tooth 7 side of the insertion portion 16 are communicated with each other. In other words, the internal space 36 communicates with an outer space 37 for storing the pinion teeth 7 having a larger diameter than the portion for storing the insertion portion 16 in the second storage portion 12b. Yes. In addition to the shape (substantially semicircular shape) of the present example, for example, various shapes such as a substantially rectangular shape and a substantially triangular shape can be adopted as the cross-sectional shape of the vent groove 35.

  In the case of the rack and pinion type steering gear unit 5b of the present example having the above-described configuration, the vent groove 35 is formed on the inner peripheral surface of the support recess 17b of the second storage portion 12b constituting the casing 10b. By doing so, the inner space 36 and the outer space 37 are communicated. For this reason, when the distal end portion (insertion portion 16) of the pinion shaft 6 is inserted into the inner diameter side of the slide bearing 26a incorporated in the support recess 17b, the inner space 36 is increased as the insertion of the pinion shaft 6 proceeds. When the volume of the air becomes smaller, as indicated by a one-dot chain line γ in FIG. 6, the air present in the inner space 36 moves (is pushed out) to the outer space 37 through the vent groove 35. Therefore, the air in the inner space 36 is not compressed, and the internal pressure of the inner space 36 does not become so high as to push the pinion shaft 6 back. As a result, the pinion shaft 6 can be smoothly inserted into the inner diameter side of the sliding bearing 26a incorporated in the support recess 17b, and the assemblability of the pinion shaft 6 can be improved. In the case of this example, in the assembled state of the slide bearing 26a, the width dimension in the circumferential direction of the discontinuous portion 25a of the slide bearing 26a is zero or almost zero. For this reason, the amount of the air in the inner space 36 moving to the outer space 37 through the discontinuous portion 25a as the insertion of the tip end portion (insertion portion 16) of the pinion shaft 6 proceeds is small. is there.

The direction of the reaction force applied from the rack shaft 8 to the pinion shaft 6 when the pinion shaft 6 is rotated to one side of the inner circumferential surface of the support recess 17b in the vent groove 35 (see FIG. When the pinion shaft 6 is rotated to the other position at a position that intersects the imaginary plane α _{1 of FIG.} 3 with a direction shifted by an angle β ₁ counterclockwise, the counter-force applied to the pinion shaft 6 from the rack shaft 8 is reversed. (from the virtual plane alpha ₁ in FIG. 3, the angle beta ₂ shifted direction in a clockwise direction) force to form the farthest from the intersection position. For this reason, with the formation of the vent groove 35, the performance of the sliding bearing 26a is not deteriorated (a decrease in performance is minimized), and the above-described assembling property is improved. I can do things.
Further, the vent groove 35 is formed simultaneously with the die casting of the casing 10b. For this reason, there is no need to provide a separate process for forming the vent groove 35. Therefore, it is possible to improve the assemblability as described above without increasing the manufacturing cost of the casing 10b. Other structures, operations and effects are the same as those of the first example of the embodiment described above.

[Third example of embodiment]
FIG. 7 shows a third example of the embodiment of the present invention. In the case of this example, only one end face (the lower end face in FIG. 7B) of both end faces in the axial direction of the sliding bearing 26b has a substantially semicircular positioning notch. 34c is formed.
Also in this example, the positioning notch 34c is formed at a position shifted from the discontinuous portion 25a of the sliding bearing 26b by about 40 degrees in one circumferential direction {left side in FIG. 7B}. doing.

In the sliding bearing 26b as described above, the discontinuous portion 25a has a circumferential surface out of the inner peripheral surfaces of the support recesses 17a and 17b (see FIGS. 2 and 6), as in each example of the embodiment described above. angle with respect to the direction, when the pinion shaft 6 (see FIG. 2 and 6) is rotated in one direction, from the virtual plane alpha ₁ of the reaction force in the direction (Figure 3 applied to the pinion shaft 6 from the rack shaft 8, counterclockwise (the direction shifted by β ₁ ) and the direction of the reaction force when rotated to the other side (the direction shifted by an angle β _{2 in the} clockwise direction from the virtual plane α _{1 in} FIG. 3) In the state arrange | positioned in the inner diameter side of the distant position, it integrates in the inner diameter side of the support recessed parts 17a and 17b of the 2nd accommodating part 12a which comprises the casing 10a.

  In the case of this example as well, the positioning notch 34c and a jig constituting an unillustrated assembling device are engaged to position the sliding bearing 26b in the circumferential direction. It fits into (injects into) the inner peripheral surfaces of the support recesses 17a, 17b. For this reason, of the axial end faces of the sliding bearing 26b, the end face where the positioning notch 34c is formed is disposed on the opening side of the support recesses 17a and 17b.

  If the positioning notch 34c is also formed on the other end surface of the sliding bearing 26b in the axial direction (the upper side in FIG. 7B), the sliding bearing 26b is supported by the supporting recesses 17a and 17b. When assembling the slide bearing 26b, it is possible to improve the assemblability without considering the directionality of the slide bearing 26b in the axial direction. Other structures, operations and effects are the same as those in the first example or the second example of the above-described embodiment.

[Fourth Example of Embodiment]
FIG. 8 shows a fourth example of the embodiment of the present invention. In the case of this example, the position (circle) of the discontinuous portion 25a of the sliding bearing 26c on one end face {the lower end face in FIG. Positioning notches 34d are formed at both ends in the circumferential direction. Such a positioning notch 34d is in a state in which both end surfaces in the circumferential direction of the slide bearing 26c are in contact with each other (a state in which the width dimension in the circumferential direction of the discontinuous portion 25a is zero). The shape seen from the side is triangular. Further, the positioning notch 34d is formed in the short side direction (upper and lower sides in FIG. 8) of both ends of the long side direction (left and right direction in FIG. 8) in plan view of the plate-like intermediate member 27b shown in FIG. Direction) is formed by a portion that is obliquely cut out. Other structures, operations and effects are the same as those of the third example of the embodiment described above.

[Fifth Example of Embodiment]
FIG. 9 shows a fifth example of the embodiment of the present invention. In the case of this example, one end face {the lower end face in FIG. 9B) of both ends in the axial direction of the sliding bearing 26d protrudes in the axial direction from this end face, and the shape viewed from the outside in the radial direction is substantially triangular. A positioning convex portion 38 having a shape is formed. In the case of this example, the positioning convex portion 38 corresponds to the positioning portion in the claims. Also in this example, the positioning convex portion 38 is formed at a position shifted by about 40 degrees from the discontinuous portion 25a of the sliding bearing 26d to one side in the circumferential direction (left side in FIG. 9B). doing. Other structures, operations and effects are the same as those of the third example of the embodiment described above.

[Sixth Example of Embodiment]
FIG. 10 shows a sixth example of the embodiment of the present invention. In the case of this example, the shape seen from the outside in the radial direction at two positions adjacent to each other in the circumferential direction of one end face {the lower end face in FIG. 10B} among the axial end faces of the sliding bearing 26e. Forms the positioning notches 34e and 34f having a substantially triangular shape.
Of these positioning notches 34e and 34f, the positioning notch 34e near the discontinuous portion 25a of the sliding bearing 26e is one side in the circumferential direction from the discontinuous portion 25a {the left side in FIG. 10 (b)}. Is formed at a position shifted by about 40 degrees. On the other hand, the positioning notch 34f is formed at a position slightly shifted (about 10 degrees) to one side in the circumferential direction from the positioning notch 34e. Other structures, operations and effects are the same as those of the third example of the embodiment described above.

[Seventh example of embodiment]
FIG. 11 shows a seventh example of the embodiment of the invention. In the case of this example, positioning notches 34g and 34h are located at two positions adjacent to each other on one end face {the lower end face in FIG. 11 (b)} of both end faces in the axial direction of the sliding bearing 26f. Is forming.
Of these positioning notches 34g and 34h, the positioning notch 34g near the discontinuous portion 25a of the sliding bearing 26f has a triangular shape when viewed from the outside in the radial direction. It is formed at a position shifted by about 40 degrees on one side in the circumferential direction (left side in FIG. 11B). On the other hand, the positioning notch 34h has a substantially semicircular shape when viewed from the outside in the radial direction, and is slightly shifted from the positioning notch 34g to one side in the circumferential direction (about 10 degrees). Formed in position. Other structures, operations and effects are the same as those of the third example of the embodiment described above.

[Eighth Example of Embodiment]
FIG. 12 shows an eighth example of the embodiment of the present invention. In the case of this example, the positioning convex portion 38a and the positioning are positioned at two positions adjacent to each other in the circumferential direction on one end face {the lower end face in FIG. 12B} of both end faces in the axial direction of the sliding bearing 26g. A notch 34i is formed.
Of these, the positioning convex portion 38a has a triangular shape when viewed from the outside in the radial direction, and is displaced from the discontinuous portion 25a by about 40 degrees to one side in the circumferential direction (left side in FIG. 12). Is formed. On the other hand, the positioning notch 34i has a substantially semicircular shape when viewed from the outside in the radial direction, and is slightly shifted (about 10 degrees) to one side in the circumferential direction from the positioning convex portion 38a. Formed in position. Other structures, operations and effects are the same as those of the third example of the embodiment described above.

[Ninth Embodiment]
FIG. 13 shows a ninth example of the embodiment of the present invention. In the case of this example, the discontinuous portion 25b of the sliding bearing 26h has dimensions in the circumferential direction in a state in which the sliding bearing 26h is fitted in the inner peripheral surface of the support recess 17a (see FIG. 2). In other words, with the sliding bearing 26h fitted in the inner peripheral surface of the support recess 17a, a gap (discontinuous) in the circumferential direction is formed between the circumferential end surfaces of the sliding bearing 26h. Part 25b). Such a discontinuous portion 25b is formed in the state in which the tip end portion (insertion portion 16) of the pinion shaft 6 is inserted (assembled state) on the inner diameter side of the sliding bearing 26h incorporated in the support concave portion 17a. Of the outer space of the inner space 36 (see FIG. 2) defined by the recess 17a and the inner surface of the sliding bearing 26h and the tip end surface of the pinion shaft 6, and the outer peripheral surface of the pinion shaft 6 near the tip, this support recess 17a. The outer space 37 (see FIG. 2) existing around the portion not located on the inner diameter side (the insertion portion 16 and the pinion tooth 7 side portion from the insertion portion 16) is communicated. The position of the discontinuous portion 25b in the circumferential direction in the state in which the sliding bearing 26h is fitted in the inner peripheral surface of the support recess 17a is the same as in each example of the above-described embodiment. is there.

  In the case of this example as described above, the diameter of the sliding bearing 26h is reduced, and a jig constituting the assembling device is engaged between the circumferential ends of the sliding bearing 26h (discontinuous portion 25b). In the combined state, the sliding bearing 26h can be fitted into the inner peripheral surface of the support recess 17a. For this reason, positioning in the circumferential direction of the sliding bearing 26h at the time of incorporation can be achieved reliably and easily.

  In the case of this example, in the state where the sliding bearing 26h is assembled to the support recess 17a, a gap is provided between both circumferential end surfaces of the sliding bearing 26h, so that the tip of the pinion shaft 6 ( When the insertion portion 16) is inserted into the inner diameter side of the slide bearing 26h incorporated in the support recess 17a, the inner space 36 and the outer space 37 are communicated with each other. For this reason, when the distal end portion (insertion portion 16) of the pinion shaft 6 is inserted into the inner diameter side of the sliding bearing 26h incorporated in the support recess 17a, the inner space 36 is advanced as the insertion of the pinion shaft 6 proceeds. When the volume of becomes smaller, the air existing in the inner space 36 moves (is pushed out) to the outer space 37 through the discontinuous portion 25b. Therefore, the air in the inner space 36 is not compressed, and the internal pressure of the inner space 36 does not become so high as to push the pinion shaft 6 back. As a result, the pinion shaft 6 can be smoothly inserted into the inner diameter side of the sliding bearing 26h incorporated in the support recess 17a, and the assemblability of the pinion shaft 6 can be improved. Other structures, operations and effects are the same as those in the first example or the second example of the above-described embodiment.

[Tenth example of embodiment]
FIG. 14 shows a tenth example of the embodiment of the present invention. In the case of this example, of the both end surfaces in the axial direction of the sliding bearing 26i, the position (circle) between the discontinuous portions 25c of the sliding bearing 26i on one end surface {the lower end surface in FIG. 14 (a)}. A pair of positioning notches 34j and 34j are formed at both ends in the circumferential direction. Also in this example, the discontinuous portion 25c of the sliding bearing 26i has a dimension in the circumferential direction in a state where the sliding bearing 26i is fitted in the inner peripheral surface of the support recess 17a. In other words, with the sliding bearing 26i fitted in the inner peripheral surface of the support recess 17a, a gap (discontinuous) in the circumferential direction is formed between the circumferential end surfaces of the sliding bearing 26i. Part 25c). The position of the discontinuous portion 25c in the circumferential direction in the state in which the slide bearing 26i is fitted in the inner peripheral surface of the support recess 17a is the same as in each example of the above-described embodiment. is there.

  In the case of this example as described above, in a state where the diameter of the slide bearing 26i is reduced, both the positioning notches 34j and 34j of the slide bearing 26i are engaged with jigs constituting the assembly device, The sliding bearing 26i is fitted into the support recess 17a. For this reason, positioning in the circumferential direction of the slide bearing 26i at the time of incorporation can be achieved reliably and easily. Other structures, functions and effects are the same as those of the ninth example of the above-described embodiment.

[Eleventh example of embodiment]
15 and 16 show an eleventh example of the embodiment of the invention. In the case of this example, the structure and arrangement of the sliding bearing 26h are the same as in the ninth example of the embodiment described above. That is, also in this example, the discontinuous portion 25b of the sliding bearing 26h has dimensions in the circumferential direction in a state in which the sliding bearing 26h is fitted in the inner peripheral surface of the support recess 17a.

In the case of this example, the rack shaft 8 side half of the inner peripheral surface of the support recess 17c of the inner peripheral surface of the support recess 17c of the second storage portion 12c constituting the casing 10c. Portion (the lower half of FIGS. 15 and 16) passes through the center line O ₆ (see FIG. 16) of the pinion shaft 6 and presses the rack shaft 8 by the pressing mechanism 21a (FIGS. 15 and 16). of a position intersecting the virtual plane alpha ₁ existing in the up-down direction), a long rib 39 in the axial direction is formed. The protrusion 39 is formed over the entire length from the back end to the opening end of the support recess 17c, and the dimension in the circumferential direction is such that the sliding bearing 26h is located on the inner peripheral surface of the support recess 17c. In the fitted state, the sliding bearing 26h is restricted to a circumferential dimension or less of the portion between the circumferential end surfaces (discontinuous portion 25b).

  Then, in a state in which the sliding bearing 26h is fitted in the inner peripheral surface of the support recess 17c, the protrusion 39 is disposed in a portion (discontinuous portion 25b) between both circumferential end surfaces of the sliding bearing 26h. I am letting. In the case of this example, in the assembled state described above, there are gaps in the circumferential direction between the circumferential end faces of the sliding bearing 26h and the circumferential end faces of the ridges 39, respectively. It seems to exist. However, in the assembled state described above, both end surfaces in the circumferential direction of the sliding bearing 26h and both end surfaces in the circumferential direction of the protrusion 39 can be brought into contact with each other.

In the case of this example, the radial dimension (height dimension) of the protrusion 39 is made smaller than the thickness dimension (the radial dimension of the discontinuous portion 25b) in the radial direction of the sliding bearing 26h. Therefore, of the discontinuous portion 25b, the radially inner portion from the tip surface of the protrusion 39 is located on the inner diameter side of the sliding bearing 26h incorporated in the support recess 17c, and the tip portion of the pinion shaft 6 (insertion portion 16). ) Is inserted (assembled state), the inner space 36 defined by the inner surface of the support recess 17c and the sliding bearing 26h and the tip surface of the pinion shaft 6, and the tip of the pinion shaft 6 Communicating with the outer space 37 existing around the portion (the insertion portion 16 and the pinion tooth 7 side portion from the insertion portion 16) that is not located on the inner diameter side of the support recess 17a in the outer peripheral surface of the shift portion. ing.
The dimensions of the ridge 39 in the axial direction, radial direction, and circumferential direction, and the formation position in the circumferential direction are appropriately determined in consideration of the relationship with the discontinuous portion 25b of the sliding bearing 26h. Is. The protrusion 39 is formed simultaneously with the die casting of the casing 10c.

  In the case of this example having the above-described configuration, the diameter of the sliding bearing 26h is reduced, and one end portion (the right end in FIG. 15) of the portion between the circumferential end surfaces of the sliding bearing 26h (discontinuous portion 25b). Part) is engaged with a jig constituting the assembling apparatus. Then, the sliding bearing 26h is inserted into the inner diameter side of the supporting recess 17c (inner side) in a state where the protrusion 39 is disposed between the circumferential ends of the sliding bearing 26h (discontinuous portion 25b). Fit). For this reason, positioning in the circumferential direction of the sliding bearing 26h at the time of incorporation and use can be achieved reliably and easily. Other structures, operations and effects are the same as those of the ninth and tenth examples of the above-described embodiment.

  When carrying out the present invention, the shape of the portion corresponding to the positioning portion described in the claims (the positioning notch and the positioning convex portion) is limited to the structure of each example of the above-described embodiment. It is not a thing. The shape of each example of the embodiment described above and other various shapes can be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 3 Universal joint 4 Intermediate shaft 5, 5a, 5b Steering gear unit 6 Pinion shaft 7 Pinion tooth 8 Rack shaft 9 Rack tooth 10, 10a, 10b, 10c Casing 11, 11a First storage part 12, 12a , 12b, 12c Second storage portion 13 Rack guide 14 Spherical joint 15 Tie rod 16 Insertion portion 17, 17a, 17b, 17c Support recess 18 Radial needle bearing 19 Ball bearing 20, 20a Cylinder portion 21, 21a Press mechanism 22, 22a Press block 23, 23a Lid 24, 24a Coil spring 25, 25a, 25b, 25c Discontinuous part 26, 26a, 26b, 26c, 26d, 26e, 26f, 26g, 26h, 26i Sliding bearing 27, 27a, 27b Plate-shaped intermediate member 28 28b Mounting flange 29 Mounting hole 30 Set screw cylinder 31 Seal ring 32 Pressing recess 33 Rack receiving sheet 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h, 34i, 34j Positioning notch 35 Venting groove 36 Inner space 37 Outer space 38, 38a Positioning projection 39 Projection

Claims (7)

A casing, a rack shaft, a pinion shaft, a pressing mechanism, and a sliding bearing;
Of these, the casing has a first storage portion and a second storage portion that communicate with each other of the inner spaces,
The rack shaft has rack teeth on the front surface, and is supported on the inner diameter side of the first storage portion so as to be capable of axial displacement.
The pinion shaft has pinion teeth on a part of the outer peripheral surface in the axial direction, and is supported on the inner diameter side of the second storage portion with the pinion teeth meshed with the rack teeth.
The pressing mechanism is for pressing a part of the back surface of the rack shaft toward the pinion shaft,
The sliding bearing is formed in a cylindrical shape having a discontinuous portion at one position in the circumferential direction, and is fitted into an inner peripheral surface of a support recess formed in the second storage portion. A rack-and-pinion type steering gear unit that supports the tip of the pinion shaft on the inner diameter side thereof so as to be rotatable with respect to the second storage,
The discontinuous portion is defined by the direction of the reaction force applied from the rack shaft to the pinion shaft when the pinion shaft rotates in one direction and the direction of the reaction force when the pinion shaft rotates in the other direction. A rack-and-pinion type steering gear unit characterized in that it is arranged in a range on the meshing part side of the pinion teeth and the rack teeth among the range formed.   A positioning portion for positioning the sliding bearing in the circumferential direction is formed at least on an end surface arranged on the opening side of the support recess among the axial end surfaces of the sliding bearing. Item 2. A rack and pinion type steering gear unit according to item 1.   The rack and pinion type steering gear unit according to claim 2, wherein the positioning portion is formed at a position within 90 degrees from the discontinuous portion in the circumferential direction in the sliding bearing.   The rack and pinion type steering according to any one of claims 2 to 3, wherein the positioning portion is formed in a half portion on the meshing portion side of the pinion teeth and the rack teeth in the circumferential direction. Gear unit.   The rack and pinion type according to any one of claims 2 to 4, wherein the positioning portion is formed when a plate-shaped intermediate member is made by punching the plate-shaped material. Steering gear unit.   The clearance gap regarding the circumferential direction exists in the part between the circumferential direction both ends of this sliding bearing in the state which fitted the said sliding bearing in the said support recessed part. A rack-and-pinion type steering gear unit according to claim 1. A positioning projection is formed on the inner peripheral surface of the support recess,
The rack-and-pinion type steering gear unit according to any one of claims 1 to 6, wherein the positioning convex portion is disposed between the circumferential end surfaces of the sliding bearing.

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