JP4861003B2 - Rack bar and steering device - Google Patents

Description

  The present invention relates to a steering device, and more particularly to a rack bar of a rack and pinion type steering device.

Conventionally, in the power steering device disclosed in Patent Document 1, a portion where rack teeth are formed is formed solidly, and a portion where rack teeth are not formed is hollowed to reduce the weight of the entire device.
JP 2003-291831 A

  However, it is very difficult to form a hollow member by forming a hole in a solid material which is a thin bar like this, and requires time and cost. In order to solve this problem, there is a method of forming a rack bar by forming a member on the rack tooth side with a solid material and press-contacting a hollow pipe material thereto. By performing this pressure contact, a lightweight rack bar can be obtained without forming a drill hole in the member on which the rack teeth are not formed, and sufficient strength can also be obtained at the joint portion.

  Although this press-contact portion can obtain a sufficient hardness, it becomes brittle in terms of metal composition, and thus quenching and tempering processes are required. Moreover, in order to improve the intensity | strength of a rack tooth, a separate quenching and tempering process is needed for the part in which a rack tooth is formed. Although the quenching conditions are different between the rack teeth and the pressure contact portion, there is a problem in that a desired strength may not be obtained when the heat effect in one quenching process affects the other site.

  The present invention has been made paying attention to the above-mentioned problems, and its object is to form a lightweight rack bar by forming a member on the rack tooth side from a solid material and connecting a hollow member to the member. It is an object of the present invention to provide a rack bar capable of preventing the influence of quenching on the rack tooth side from reaching the connection portion and obtaining a sufficient strength of the connection portion.

    In order to achieve the above object, a rack bar of the present invention is formed of a solid material and is formed at a rack tooth side member formed with rack teeth meshing with a pinion gear, and at an axial end of the rack tooth side member. The rod side which is formed of a small diameter portion whose outer diameter is smaller than the portion where the rack teeth are formed, and a hollow material whose outer diameter is smaller than the portion where the rack teeth are formed, and which is connected to the small diameter portion by pressure contact A member, an axial hole that opens at the end of the small-diameter portion of the rack tooth side member, is formed closer to the rod side member than the rack teeth, and the rack tooth side member and the rod side member A first quenching treatment portion that is provided near the connecting portion and after these members are pressure-welded, and a second quenching that is provided in an area that includes the rack teeth and does not reach the axial hole. And having a processing unit

  Therefore, in the lightweight rack bar formed by forming the rack tooth side member with a solid material and connecting the hollow member to this, the effect of quenching on the rack tooth side is prevented from reaching the connection part. The connection portion can obtain a sufficient strength.

  Hereinafter, the best mode for realizing the rack bar and the steering device of the present invention will be described with reference to the drawings.

[Configuration of steering device]
FIG. 1 is an external view of the steering apparatus according to the first embodiment. This steering device has a steering wheel 1, a steering shaft 2, a rack and pinion gear 3, and a tie rod 4.

  The steering wheel 1 is connected to a steering shaft 2, and the steering shaft 2 is connected to a pinion shaft 22 via an intermediate joint 21. The rotation of the steering wheel 1 is transmitted to the pinion shaft 22 via the steering shaft 2 and the intermediate joint 21.

  The rack and pinion gear 3 has a pinion gear 22a formed at the tip of the pinion shaft 22 and a rack bar 30 as described later (see FIG. 2). Rack teeth 31a are formed on the rack bar 30, and the pinion gear 22a meshes with the rack teeth 31a (see FIG. 2).

  When the pinion gear 22a is rotated by the operation of the steering wheel 1, this rotation is changed to a lateral linear motion of the rack bar 30 via the rack teeth 31a. This linear motion steers a front wheel (not shown) via tie rods 4a and 4b attached to both ends of the rack bar 30.

(Configuration of rack and pinion gear)
FIG. 2 is a cross-sectional view of the rack and pinion gear 3. FIG. 2 is a view of the rack and pinion gear 3 cut through the central axis of the rack bar 30 and viewed from the axial direction of the pinion shaft 22. For description, the x-axis is defined in the axial direction of the rack bar 30 and the tie rod 4b side is defined as the positive direction. FIG. 2 shows a state where the steering wheel 1 is not operated and the rack bar 30 is in the neutral position (neutral state).

  The rack and pinion gear 3 includes a pinion gear 22 a formed at the tip of the pinion shaft 22, a rack bar 30, a steering gear housing 33 for housing them, and joint portions 40 a and 40 b attached to both ends of the rack bar 30 in the axial direction. Have.

(Configuration of steering gear housing)
The steering gear housing 33 includes a retainer 331 that supports the rack bar 30 and an end bush 333, and accommodates the rack bar 30 so as to be movable in the x-axis direction. Further, a bearing (not shown) for supporting the pinion shaft 22 and a bracket portion 330 for attaching the entire rack and pinion gear 3 to the vehicle are provided.

  When the rack bar 30 is in a neutral state as shown in FIG. 2, the position of the rack teeth 31 a in the x-axis direction is provided to overlap the position of the bracket portion 330 in the x-axis direction. Specifically, the range of the bracket portion 330 in the x-axis direction overlaps the range of the rack teeth 31a on the x-axis positive direction side with the pinion gear 22a as a boundary.

  The bracket portion 330 is provided at a position adjacent to the pinion gear 22a. Specifically, it is provided on the steering gear housing 33 near the pinion gear 22a on the x-axis positive direction side when viewed from the pinion gear 22a.

  The retainer 331 is provided at a position facing the pinion gear 22a with the rack bar 31 interposed therebetween, and has a compression coil spring 332. The retainer 331 urged by the compression coil spring 332 presses the rack bar 31 from the back side of the rack teeth 31a, and presses the rack teeth 31a of the rack bar 31 against the pinion gear 22a. Thereby, the meshing between the rack teeth 31a and the pinion gear 22a is ensured.

  The rack bar 30 is supported in the steering gear housing 33 at two locations of the retainer 331 (and the meshing portion of the rack teeth 31a and the pinion gear 22a) and the end bush 333. Therefore, various loads applied to the rack bar 30 are received by these two places.

(Composition of joint part)
The joint portions 40a and 40b are interposed between the rack bar 30 and the tie rods 4a and 4b and connect them. In the rack bar 30, fitting holes 41a and 41b for attaching the joint portions 40a and 40b are formed at both ends on the x-axis direction side. The joint portions 40a and 40b are coupled to the rack bar 30 with screws in the fitting holes 41a and 41b.

  The reaction force from the front wheel is transmitted to the rack bar 30 via the tie rods 4a and 4b and the joint portions 40a and 40b. Conversely, the torque input to the pinion shaft 22 generates a force in the x-axis direction that acts on the rack bar 30 via the pinion gear 22a. This force is transmitted to the front wheel via the joint portions 40a and 40b and the tie rods 4a and 4b.

(Rack bar configuration)
FIG. 3 is a cross-sectional view passing through the central axis of the rack bar 30. It is the figure seen from the axial direction of the pinion shaft 22 like FIG.

  The rack bar 30 includes a rack tooth side member 31 and a rod side member 32, and these members 31 and 32 are formed by being joined in a coaxial direction by pressure welding. The rack tooth side member 31 is made of a solid material, and the rod side member 32 is made of a hollow material.

(Configuration of rack tooth side member)
The rack tooth side member 31 has a rack tooth forming part 31b, a taper part 31c, and a small diameter part 31d in order from the negative x-axis direction.

  Rack teeth 31a are formed in the rack tooth forming portion 31b. In FIG. 3, the rack tooth 31a is viewed from the direction perpendicular to the tooth surface.

  The tapered portion 31c is formed so that its outer diameter gradually decreases from the rack tooth forming portion 31b side toward the small diameter portion 31d side.

  The small diameter portion 31d is provided with an outer diameter smaller than that of the rack tooth forming portion 31b. The small diameter portion 31d is provided with an axial hole 31e. The axial hole 31e opens at the x-axis positive direction end of the small-diameter portion 31d and is formed on the x-axis positive direction side with respect to the rack teeth 31a. Specifically, the axial hole 31e is formed in the small diameter portion 31d and does not reach the tapered portion 31c.

(Configuration of rod side member)
The rod side member 32 is formed of a hollow material having an outer diameter smaller than that of the rack tooth forming portion 31b. The x-axis negative direction end of the rod side member 32 is joined to the x-axis positive direction end of the small diameter portion 31d by pressure contact. Let this junction be β.

  The outer diameter of the small diameter portion 31d and the outer diameter of the rod side member 32 are substantially equal, and the inner diameter of the axial hole 31e of the small diameter portion 31d and the inner diameter of the rod side member 32 are substantially equal.

(Range of quenching processing part)
Since the welded joint β is fragile in terms of metal composition, a quenching process after the pressure welding is performed. In addition, since a load is always applied to the rack teeth 31a that are engaged with the pinion gear 22a and to which torque is transmitted from the pinion gear 22a, it is necessary to ensure strength that can counter the load. Accordingly, the rack teeth 31a are quenched.

  Since the quenching conditions are different between the rack teeth 31a and the joint β, the quenching process is performed separately. In this way, in order to specify the range and perform the quenching process, the induction hardening method is used in the first embodiment.

  FIG. 4 shows an outline of a known direct energization method as an example of the induction hardening method. The direct energization method is a heating method in which a component called a contact is pressed against a predetermined position of a rack bar, a high frequency current is applied from an oscillator, and a high frequency current is applied directly to the rack bar to generate heat. In the case of tooth surface quenching, the two contactors, the cooling jacket, and the rack bar themselves constitute a current circuit, and the tooth tip portion is induction heated by forming an induction heating coil. In addition, a tooth root part is heated by direct electricity supply.

  A quenching processing unit applied to the region including the rack teeth 31a is referred to as A. After the pressure contact between the rack tooth side member 31 and the rod side member 32, the quenching processing part applied in the vicinity of the joint β is defined as B. The range of the quenching processing part A is provided so as not to reach the axial hole 31e. The rack teeth 31a may be quenched before or after the press contact between the rack tooth side member 31 and the rod side member 32.

[Operation of the first embodiment]
Next, the operation of the first embodiment will be described.

(Lightening effect)
The rack bar 30 includes a rack tooth side member 31 formed of a solid material and a rod side member 32 formed of a hollow material, and these members 31 and 32 are joined in a coaxial direction by pressure welding. It is formed by. Further, the outer diameter of the rod side member 32 is provided smaller than the outer diameter of the rack tooth forming portion 31 b of the rack tooth side member 31. Thereby, weight reduction of the rack bar 30 is implement | achieved.

(Reinforcement of connecting part by quenching range)
The rack tooth side member 31 has a small diameter portion 31d, and the small diameter portion 31d is provided with an axial hole 31e. The x-axis negative direction end of the rod side member 32 is joined to the x-axis positive direction end of the small diameter portion 31d where the axial hole 31e opens. That is, in the connection part β, the hollow materials are connected to each other.

  On the other hand, since the rack tooth side member 31 and the rod side member 32 are joined by pressure contact, the vicinity of the connection portion β (B) needs to be subjected to a quenching process under a quenching condition different from that of the rack teeth 31a.

  Since the hollow material has a smaller mass than the solid material, the degree of thermal influence in the axial direction is increased. Therefore, when the influence of quenching of the rack teeth 31a reaches the axial hole 31e, there is a high possibility that the influence of the quenching extends to the vicinity of the connection portion β (B) connecting the hollow materials.

  In the first embodiment, by setting the quenching region A of the rack teeth 31a not to reach the axial hole 31e, it is possible to prevent the rack teeth 31a from being affected by the quenching of the rack teeth 31a (B). To do. Thereby, sufficient strength of the connecting portion β is ensured.

(Connecting portion strengthening action by cross-sectional shape)
In the first embodiment, the outer diameter of the small diameter portion 31d and the outer diameter of the rod side member 32 are substantially equal, and the inner diameter of the axial hole 31e of the small diameter portion 31d and the inner diameter of the rod side member 32 are substantially equal.

  By aligning the cross-sectional shapes of the members to be pressure-bonded in this way, the heat capacities near the connection portion β are substantially the same on the small diameter portion 31d side and the rod side member 32 side. Therefore, the heat rise of the connection part β due to the pressure contact is substantially the same in both the members 31d and 32. Therefore, the amount of melting of both the members 31d and 32 is substantially the same amount, so that good pressure contact can be performed, and sufficient strength of the connection portion β is ensured.

(Rack bar strengthening action by taper)
Due to external forces such as road surface reaction force transmitted from the joint portions 40a and 40b and the force in the x-axis direction applied from the pinion gear 22a, a stress in the bending direction is generated on the shaft of the rack bar 30. On the other hand, the outer diameter of the small diameter part 31d of the rack tooth side member 31 is provided smaller than the outer diameter of the rack tooth forming part 31b. Therefore, stress concentration occurs between the portions 31b and 31d having different outer diameters.

  In the first embodiment, a tapered portion 31c is provided between the rack tooth forming portion 31b and the small diameter portion 31d, and the outer diameter is gradually reduced from the rack tooth forming portion 31b side toward the small diameter portion 31d side. did. Since the maximum stress in the bending direction is generated in the outermost diameter portion of the rack bar 30, the taper portion 31c is provided to gradually change the outer diameter of the rack bar 30 to alleviate the stress concentration, thereby increasing the strength of the rack bar 30. It is improving.

(Equipment stabilization effect due to the arrangement of brackets)
As shown in FIG. 2, the center of gravity of the rack bar 30 when the rod side member 32 is a solid material is G1, and the center of gravity of the rack bar 30 when the rod side member 32 is a hollow material is G2. . In the first embodiment, the rod side member 32 of the rack bar 30 is formed of a hollow material. As a result, the center of gravity of the rack bar 30 moves from G1 to G2 on the x-axis negative direction side, that is, the rack tooth 31a side.

  On the other hand, in the first embodiment, the bracket portion 330 is disposed so as to overlap the rack teeth 31a in the x-axis direction when the rack bar 30 is at least in a neutral state (see FIG. 2).

  Therefore, the center of gravity G2 (on the rack tooth 31a side) of the rack bar 30 is in the vicinity of the bracket portion 330 that supports the entire rack and pinion gear 3. Thereby, stability of the whole steering apparatus is improved and vibration is suppressed.

  Further, the rack bar 30 is supported at two locations of the retainer 331 (meshing portion of the rack teeth 31a and the pinion gear 22a) and the end bush 333, and various loads applied to the rack bar 30 are received by these two locations. . In particular, the load concentrates on the meshing portion between the rack teeth 31a and the pinion gear 22a.

  The bracket portion 330 is provided on the steering gear housing 33 at a position adjacent to the pinion gear 22a. Thereby, the load concentrated on the meshing portion is efficiently transmitted to the bracket portion 330.

  That is, this load is transmitted through the two paths of the retainer 331 → the steering gear housing 33 → the bracket portion 330 or the pinion shaft 22 → the bearing (not shown) → the steering gear housing 33 → the bracket portion 330. The distance between the retainer 331 and the bracket portion 330 and the distance between the pinion shaft 22 and the bracket portion 330 are shortened. By efficiently transmitting the load concentrated on the meshing portion to the bracket portion 330, the stability of the entire steering apparatus is enhanced.

[Effect of the first embodiment]
The rack bar 30 of the first embodiment is formed of a solid material, and is formed at a rack tooth side member 31 formed with rack teeth 31a meshing with the pinion gear 22a, and at an axial end of the rack tooth side member 31. A small diameter portion 31d having an outer diameter smaller than that of the rack tooth forming portion 31b, a rod side member 32 formed of a hollow material having an outer diameter smaller than that of the rack tooth forming portion 31b, and connected to the small diameter portion 31d by pressure contact; An opening in the end portion on the small diameter portion 31d side of the side member 31 and an axial hole 31e formed on the rod side member 32 side of the rack teeth 31a, and the vicinity of the connecting portion β between the rack tooth side member 31 and the rod side member 32 The second quenching is performed in a region including the first quenching processing part B and the rack teeth 31a applied after the members 31 and 32 are pressed and not reaching the axial hole 31e. Input processing unit A It was decided to.

  Therefore, in the lightweight rack bar 30 formed by forming the rack tooth side member 31 from a solid material and connecting the rod side member 32 formed from a hollow material thereto, the influence of quenching of the rack teeth 31a is affected. This has the effect of preventing the connection portion β from reaching the connection portion β and obtaining sufficient strength.

  The steering device of the first embodiment includes a rack bar 30 that meshes with the pinion gear 22a, and a steering gear housing 33 that accommodates the rack bar 30 so as to be movable in the x-axis direction and is attached to the vehicle. The rack bar 30 is formed of a solid material, is formed at a rack tooth side member 31 formed with rack teeth 31a meshing with the pinion gear 22a, and is formed at an axial end of the rack tooth side member 31, and has an outer diameter of the rack bar 30. A small diameter portion 31d smaller than the tooth forming portion 31b, a rod side member 32 formed of a hollow material having an outer diameter smaller than that of the rack tooth forming portion 31b and connected to the small diameter portion 31d by pressure contact; and the rack tooth side member 31 An axial hole 31e that opens to the end on the small diameter portion 31d side and is formed closer to the rod side member 32 than the rack teeth 31a, and the rack tooth side member 31 and the lock teeth Near the connecting portion β with the side member 32, a region including the first quenching processing portion B applied after the members 31 and 32 are pressed and the rack teeth 31 a, reaching the axial hole 31 e. The bracket portion 330 of the steering gear housing 33 is provided at a position that overlaps at least the rack teeth 31a in the x-axis direction when the rack bar 30 is in a neutral state. It was decided that

  The center of gravity G2 of the rack bar 30 is in the vicinity of the bracket portion 330 that supports the entire rack and pinion gear 3. This has the effect of increasing the stability of the entire steering apparatus and suppressing vibrations.

[Configuration of Example 2]
FIG. 5 is a cross-sectional view passing through the central axis of the rack bar 30 according to the second embodiment. It is the figure seen from the axial direction of the pinion shaft.

  Unlike the first embodiment, the axial hole 31e is formed to overlap to the tapered portion 31c. Specifically, the negative end in the x-axis direction of the axial hole 31e extends beyond the tapered portion 31c to reach the rack tooth forming portion 31b and is positioned on the x-axis positive direction side with respect to the rack tooth 31a. .

  Other configurations of the rack bar 30 of the second embodiment and the configuration of the steering device of the second embodiment are the same as those of the first embodiment.

[Effects of Example 2]
Since the axial hole 31e overlaps the tapered portion 31c, the transition from the rack tooth forming portion 31b to the small diameter portion 31d is a transition from the hollow state to the hollow state. That is, the thickness change before and after the taper portion 31c in the x-axis direction does not change suddenly from the solid state to the hollow state, and is smoother than in the first embodiment. Thereby, the stress concentration in the taper portion 31c can be further relaxed, and the strength of the rack bar 30 can be improved.

  Other functions and effects are the same as those of the first embodiment.

[Configuration of Example 3]
FIG. 6 is an external view of the steering apparatus according to the third embodiment. Unlike the first embodiment, this device is an electric power steering device, and is provided with an electric motor 2a for adding a steering assist force on the steering shaft 2, an assist mechanism 2b such as a speed reducer, and an ECU for controlling the steering assist force. Yes.

  The other configuration of the steering device and the configuration of the rack bar 30 are the same as those in the first embodiment.

[Effects of Example 3]
In the electric power steering apparatus, a steering assist force is applied to the pinion shaft 22 in addition to the human steering force, and the load generated at the meshing portion between the pinion gear 22a and the rack teeth 31a becomes very large.

  In the third embodiment, the center of gravity G2 of the rack bar 30 is brought closer to the bracket part 330, and the positions of the meshing part and the bracket part 330 are made closer to each other. Thereby, the vibration of the whole apparatus can be suppressed. As a result, there is an effect that the force component generated by the vibration is suppressed in addition to the load generated in the meshing portion, and the durability of the tooth surface of the rack tooth 31a is improved.

[Other embodiments]
The best mode for carrying out the present invention has been described based on the first to third embodiments. However, the specific configuration of the present invention is not limited to the first to third embodiments. Design changes and the like within a range that does not depart from the gist are also included in the present invention.

  In addition to the quenching treatment part A and the quenching treatment part B, a quenching process may be performed on the outer circumferential surface on the opposite side in the circumferential direction of the rack teeth 31a within a range not reaching the axial hole 31e.

  Further, regarding the connection between the rack tooth side member 31 and the rod side member 32, in addition to pressure welding, a part of the member may be melted and joined by applying heat from the outside, such as laser welding or arc welding. Good.

  In the third embodiment, an example of a column assist type electric power steering apparatus is shown, but a pinion assist type or rack assist type electric power steering apparatus may be used. Further, in the third embodiment, an example of an electric direct-coupled power steering device is shown, but an electrohydraulic or hydraulic power steering device may be used.

  Further, technical ideas other than claims 1 and 2 that can be grasped from the first to third embodiments will be described together with the effects thereof.

  (A) In the rack bar according to claim 1, the outer diameter is gradually increased from the portion where the rack teeth are formed to the small diameter portion side from the portion where the rack teeth are formed. The rack bar is characterized in that a tapered portion is formed with a small diameter.

  By gradually changing the outer diameter, there is an effect that stress concentration generated between the parts having different outer diameters (rack tooth forming portion 31b, small diameter portion 31d) can be relaxed.

  (B) The rack bar according to (a), wherein the axial hole is formed so as to overlap to the tapered portion.

  By making the wall thickness change before and after the tapered portion 31c smoother, the stress concentration of the tapered portion 31c can be further relaxed.

  (C) The rack bar according to claim 1, wherein the inner diameter of the axial hole and the rod side member is substantially equal, and the outer diameter of the small diameter portion and the outer diameter of the rod side member are substantially equal. Rack bar to be.

  By aligning the cross-sectional shapes of the members 31 and 32 to be joined, good pressure contact can be performed.

  (D) The steering apparatus according to claim 2, wherein the bracket portion is provided adjacent to the pinion gear.

  Since the load is concentrated on a portion of the rack bar 30 that meshes with the pinion gear 22a, the load generated at the meshing portion is efficiently transmitted to the bracket portion 330 by providing the pinion gear 22a and the bracket portion 330 adjacent to each other. It is possible to increase the stability of the entire apparatus.

  (E) The steering apparatus according to claim 2, further comprising an electric motor that applies a steering assist force between the steering wheel and the pinion gear.

  In the electric power steering apparatus to which a steering assist force is applied from the pinion gear 22 a side, the load at the meshing portion between the pinion gear 22 a and the rack teeth 31 a becomes very large, but the center of gravity of the rack bar 30 is brought close to the bracket portion 330. With this configuration, the load generated at the meshing portion can be efficiently transmitted to the bracket portion 330, and the stability of the entire apparatus can be improved.

  (F) The steering apparatus according to (d) above further includes an electric motor that applies a steering assist force between a steering wheel and the pinion gear.

  In the electric power steering apparatus to which the steering assist force is applied from the pinion gear 22a side, the load at the meshing portion between the pinion gear 22a and the rack teeth 31a becomes very large, but the position of the meshing portion and the bracket portion 330 is brought close to each other. On the other hand, the vibration of the entire apparatus can be suppressed by adopting a configuration in which the center of gravity of the rack bar 31a is closer to the bracket portion 330. As a result, there is an effect that the force component generated by the vibration is suppressed in addition to the load generated in the meshing portion, and the durability of the tooth surface of the rack tooth 31a is improved.

It is an external view of the steering device of Examples 1 and 2. It is sectional drawing of the rack & pinion gear 3 of this invention. 3 is a cross-sectional view of a rack bar according to Embodiment 1. FIG. It is the schematic of the induction hardening method of a rack bar. 6 is a cross-sectional view of a rack bar of Example 2. FIG. FIG. 6 is an external view of a steering device according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 2a Electric motor 2b Assist mechanism 3 Rack & pinion gear 4a, 4b Tie rod 22 Pinion shaft 22a Pinion gear 30 Rack bar 31 Rack tooth side member 31a Rack tooth 31b Rack tooth formation part 31c Taper part 31d Small diameter part 31e Axial direction Hole 32 Rod side member 33 Steering gear housing 330 Bracket portion 331 Retainer
A, B Quenching processing part
G1, G2 Rack bar center of gravity position β Connection

Claims (2)

A rack tooth side member formed of a solid material and formed with rack teeth meshing with the pinion gear;
A small-diameter portion formed at the axial end of the rack tooth-side member and having an outer diameter smaller than the portion where the rack teeth are formed;
A rod-side member that is formed of a hollow material having an outer diameter smaller than a portion where the rack teeth are formed, and is connected to the small-diameter portion by pressure contact;
An opening in the end portion on the small diameter side of the rack tooth side member, and an axial hole formed on the rod side member side with respect to the rack tooth;
A first quenching treatment portion that is provided near the connecting portion between the rack tooth side member and the rod side member, and which is subjected to pressure contact with these members;
A rack bar, comprising: a second quenching treatment portion that is an area including the rack teeth and that does not reach the axial hole. A rack bar meshing with the pinion gear;
The rack bar is accommodated so as to be movable in the axial direction, and includes a steering gear housing having a bracket portion for mounting on the vehicle.
The rack bar is
A rack tooth side member formed of a solid material and formed with rack teeth meshing with the pinion gear;
A small-diameter portion formed at the axial end of the rack tooth-side member and having an outer diameter smaller than the portion where the rack teeth are formed;
A rod-side member that is formed of a hollow material having an outer diameter smaller than a portion where the rack teeth are formed, and is connected to the small-diameter portion by pressure contact;
An opening in the end portion on the small diameter side of the rack tooth side member, and an axial hole formed on the rod side member side with respect to the rack tooth;
A first quenching treatment portion that is provided near the connecting portion between the rack tooth side member and the rod side member, and which is subjected to pressure contact with these members;
A second quenching treatment section that is an area including the rack teeth and is provided in a range not reaching the axial hole,
The steering device according to claim 1, wherein the bracket portion of the steering gear housing is provided at a position that overlaps the rack teeth in the axial direction at least when the rack bar is in a neutral state.

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