Steering device

Abstract

Steering device comprising: a steering gear mountable on a vehicle frame (2) and including a hollow cylindrical portion (11) having a rack shaft (3) slidably fitted therein, the rack shaft (3) being reciprocated by rotation of a pinion mounted on a lower end of a steering shaft (5); Vehicle mounting boss portions (16, 17) formed at both a pinion-side end and an end opposite the pinion side of the hollow cylindrical portion (11) of the steering gear so as to protrude from an outer periphery (15) of the hollow cylindrical portion (11) in a longitudinal direction of the vehicle, and in which mounting holes (161; 171) are formed in a vertical direction of the vehicle for mounting the steering gear to the vehicle frame; and a first rib (61) formed at a connecting portion between the hollow cylindrical portion (11) and the vehicle mounting boss portion (17) of the pinion-side opposite end so as to connect the outer periphery (15) of the hollow cylindrical portion (11) to the vehicle mounting boss portion (17) of the pinion-side opposite end, wherein the first rib (61) includes two ribs (61a, 61b), characterized in that the two ribs are formed in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion (11) and are spaced apart from each other at a position connected to the vehicle mounting boss portion (17) of the end opposite to the pinion side.

Description

Technical area

[0001] The present invention relates to a steering device according to the preamble of claim 1.

[0002] JP 2001-239 945 A shows such a generic steering device. Technical background

[0003] A steering gear absorbs a steering reaction force transmitted from a running wheel during a steering operation. Therefore, to absorb the steering reaction force, an elastic member, such as a cylindrical rubber bushing, is interposed between a bolt and a mounting hole for attaching the steering gear to the vehicle frame.

[0004] However, in such a method in which the steering gear is mounted to the vehicle frame by interposing the elastic member therebetween, when a pinion gear meshed with a rack shaft starts rotating, the steering gear moves by an amount equal to the elastic deformation of the elastic member before the rack shaft moves, thus causing a delay in the steering operation. In order to achieve steering accuracy by eliminating the delay in the steering operation, a steering gear having a rigid structure in which an iron bushing is inserted instead of the elastic sleeve (Patent Document 1) or a steering gear having a rigid structure in which the sleeve formed of the elastic member is omitted have been increasingly used in recent years.

[0005] Fig. 2 to 4 illustrate a main part of the steering gear of the known steering device with a vehicle mounting structure formed as a rigid structure, wherein Fig. 2 is a front view, Fig. 3 is a front view illustrating a state of receiving the steering reaction force transmitted from a running wheel in a steering operation, and Fig. 4 a view from the direction of the Fig. 2, which represents a state in which the steering reaction force transmitted from the running wheel during the steering operation is absorbed.

[0006] A steering gear 10 is, as in Fig. 2, attached to a vehicle frame 2, such as a front subframe. In Fig. 2, the upward direction is referred to as a vehicle-upward direction, and the downward direction is referred to as a vehicle-downward direction. In Fig. 2, the transverse direction is referred to as a vehicle transverse direction. In Fig. 2, a direction perpendicular to a paper surface is called a vehicle longitudinal direction.

[0007] A rack shaft 3 is in the Fig. 2, is slidably fitted into an inner periphery 12 of a hollow cylindrical portion 11 of the steering gear 10. Tie rods 41 and 42 are connected to both ends of the rack shaft 3, and the tie rods 41 and 42 are connected to a running wheel via a tie rod arm (not shown).

[0008] A cylindrical pinion insertion hub 13 is formed integrally with the left end of the hollow cylindrical portion 11 so as to protrude upward from an outer periphery 15 of the hollow cylindrical portion 11. A pinion (not shown) that engages with the rack shaft 3 is formed at the lower end of a pinion shaft 5 that is inserted into the cylindrical pinion insertion hub 13. The upper end of the pinion shaft 5 is connected to the lower end of the steering shaft (not shown) connected to the steering wheel.

[0009] A cylindrical rack guide insertion hub 14 is integrally formed with the left end of the hollow cylindrical portion 11 so as to be adjacent to the cylindrical pinion insertion hub 13 and protrude from the outer periphery 15 of the hollow cylindrical portion 11 in the vehicle longitudinal direction (a front-side direction perpendicular to a paper plane). A rack guide (not shown) is inserted into the cylindrical rack guide insertion hub 14 so as to guide the rear side (a side opposite a rack tooth surface) of the rack shaft 3 using a roller and so on, and to prevent deformation of the rack shaft 3 caused by a reaction force upon engagement with the pinion, allowing the rack shaft 3 to slide smoothly thereon.

[0010] When a user turns a steering wheel (not shown), the pinion of the pinion shaft 5 rotates, and then the rack shaft 3 slidably moves left and right according to the rotation of the pinion, thus changing the steering angle of a running wheel.

[0011] Vehicle mounting boss portions 16 and 17 are formed at the left end (a pinion side end) of the hollow cylindrical portion 11 and the right end (an end opposite the pinion side) of the hollow cylindrical portion 11, respectively, so as to protrude from the outer periphery 15 of the hollow cylindrical portion 11 in the longitudinal direction of the vehicle (the front side direction perpendicular to a paper plane). Circular mounting holes 161 and 171 are formed in the vehicle mounting boss portions 16 and 17, respectively, in the vertical direction of the vehicle (which is Fig. 2 shown vertical direction).

[0012] The steering gear 10 is mounted to the vehicle frame 2 in a rigid structure (a rigid body structure) without the sleeve composed of the elastic member therebetween by inserting bolts 163 and 173 into the mounting holes 161 and 171 and then firmly tightening the bolts 163 and 173 to the vehicle frame.

[0013] When the steering device having such a steering gear 10 of a rigid structure is used for steering and then a steering reaction force F transmitted from a running wheel acts on the steering gear 10, the steering reaction force acts directly on the vehicle mounting hub portions 16 and 17.

[0014] This deforms, as in Fig. 3, the steering gear 10 is deformed around the mounting holes 161 and 171 of the vehicle mounting hub portions 16 and 17, thereby deforming in the vertical direction of the vehicle. Furthermore, the steering gear 10 is deformed as shown in Fig. 4, around the mounting holes 161 and 171 of the vehicle mounting boss portions 16 and 17, thereby causing deformation in the longitudinal direction of the vehicle.

[0015] Specifically, unlike the vicinity of the vehicle-mounting boss portion 17 at the right end (the end opposite the pinion side) of the hollow cylindrical portion 11, the vicinity of the vehicle-mounting boss portion 16 at the left end (in the pinion side end) of the hollow cylindrical portion 11 is not provided with the cylindrical pinion insertion boss 13 or the cylindrical rack guide insertion boss 14. Accordingly, the rigidity in the vicinity of the vehicle-mounting boss portion 17 at the end opposite the pinion side is low, and the deformation in the vicinity of the vehicle-mounting boss portion 17 becomes large when the steering reaction force F occurs. This poses a problem in that the steering stability decreases.

[0016] Thus, in order to prevent the deformation in the vicinity of the vehicle mounting boss portion 17 at the end opposite to the pinion side, as shown in Fig. 2, the vehicle mounting boss portion 17 at the pinion-side end is connected to the outer periphery 15 of the hollow cylindrical portion 11, and ribs 18a and 18b are formed parallel to the central axis line of the hollow cylindrical portion 11. Furthermore, in order to prevent deformation in the vicinity of the vehicle mounting boss portion 16 at the pinion-side end, the vehicle mounting boss portion 16 at the pinion-side end is connected to the outer periphery 15 of the hollow cylindrical portion 11, and ribs 19a and 19b are formed parallel to the central axis line of the hollow cylindrical portion 11. However, such parallel ribs 18a, 18b, 19a and 19b do not have sufficient rigidity to prevent the deformation of the vehicle mounting hub portions 16 and 17.

[0017] Patent Document 1: Unexamined Japanese Patent Publication No. JP 2001-80528A. Disclosure of the inventionProblem the invention is intended to solve

[0018] An object of the invention is to provide a steering device that prevents deformation in the vicinity of a vehicle-mounting boss portion of a steering gear so as to improve steering stability with a simple rib structure. Means to solve the problem

[0019] The object is achieved with the features of claim 1. According to a first aspect of the invention, a steering device is provided which includes: a steering gear mountable on a vehicle frame and including a hollow cylindrical portion having a rack shaft slidably fitted therein, the rack shaft being reciprocated by rotation of a pinion mounted on a lower end of a steering shaft; Vehicle mounting boss portions formed at both a pinion-side end and an end opposite the pinion-side of the hollow cylindrical portion of the steering gear so as to protrude from an outer periphery of the hollow cylindrical portion in a longitudinal direction of the vehicle, and in which mounting holes are formed in a vertical direction of the vehicle for mounting the steering gear to the vehicle frame; and a first rib formed at a connecting portion between the hollow cylindrical portion and the vehicle mounting boss portion of the end opposite the pinion side so as to connect the outer periphery of the hollow cylindrical portion to the vehicle mounting boss portion of the end opposite the pinion side, where the first rib contains two ribs, and the two ribs are formed in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the end opposite to the pinion side.

[0020] According to a second aspect of the invention, in the steering device described in the first aspect, a second rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on an upper outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0021] According to a third aspect of the invention, in the steering device described in the first aspect, a third rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on a lower outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0022] According to a fourth aspect of the invention, in the steering device described in the first aspect, a second rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on an upper outer periphery of the hollow cylindrical portion at the pinion side opposite end; and a third rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on a lower outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0023] According to a fifth aspect of the invention, in the steering device described in the first aspect, a fourth rib is formed at a connecting portion between the hollow cylindrical portion and the vehicle-mounting boss portion of the pinion-side end so as to connect the outer periphery of the hollow cylindrical portion to the vehicle-mounting boss portion of the pinion-side end, where the fourth rib contains two ribs, and the two ribs are formed substantially in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion side end.

[0024] According to a sixth aspect of the invention, in the steering device described in the second aspect, a fourth rib is formed at a connecting portion between the hollow cylindrical portion and the vehicle-mounting boss portion of the pinion-side end so as to connect the outer periphery of the hollow cylindrical portion to the vehicle-mounting boss portion of the pinion-side end, where the fourth rib contains two ribs, and the two ribs are formed substantially in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion side end.

[0025] According to a seventh aspect of the invention, in the steering device described in the third aspect, a fourth rib is formed at a connecting portion between the hollow cylindrical portion and the vehicle-mounting boss portion of the pinion-side end so as to connect the outer periphery of the hollow cylindrical portion to the vehicle-mounting boss portion of the pinion-side end, where the fourth rib contains two ribs, and the two ribs are formed substantially in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion side end.

[0026] According to an eighth aspect of the invention, in the steering device described in the fourth aspect, a fourth rib is formed at a connecting portion between the hollow cylindrical portion and the vehicle-mounting boss portion of the pinion-side end so as to connect the outer periphery of the hollow cylindrical portion to the vehicle-mounting boss portion of the pinion-side end, where the fourth rib contains two ribs, and the two ribs are formed substantially in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion side end. Advantage of the invention

[0027] In the steering device according to the first aspect of the invention, two ribs constitute the first rib for connecting the outer periphery of the hollow cylindrical portion to the vehicle mounting boss portion of the pinion-side opposite end. The two ribs are formed in a V-shape so that they intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion-side opposite end.

[0028] Accordingly, the first rib forms a closed loop with the vehicle mounting boss portion and the two ribs formed in a V shape. Therefore, it is possible to effectively prevent the deformation of the vehicle mounting boss portion of the pinion-side opposite end in both the vertical and longitudinal directions of the vehicle, thereby improving steering stability.

[0029] In the steering device according to the second aspect of the invention, the second rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on the upper outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0030] Accordingly, the second rib assists the first rib in preventing the deformation of the vehicle mounting boss portion of the pinion side opposite end in the vertical direction of the vehicle, thus further improving the steering stability.

[0031] In the steering device according to the third aspect of the invention, the third rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on the lower outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0032] Accordingly, the third rib assists the first rib in preventing the deformation of the vehicle mounting boss portion of the end opposite to the pinion side in the vertical direction of the vehicle, thus further improving the steering stability.

[0033] In the steering device according to the fourth aspect of the invention, the second rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on the upper outer periphery of the hollow cylindrical portion at the pinion side opposite end, and the third rib is formed in the vicinity of the vehicle mounting boss portion of the pinion side opposite end on the lower outer periphery of the hollow cylindrical portion at the pinion side opposite end.

[0034] Accordingly, the second rib and the third rib assist the first rib in preventing the deformation of the vehicle mounting boss portion of the pinion side opposite end in the vertical direction of the vehicle, thus further improving the steering stability.

[0035] In the steering device according to the fifth aspect to the eighth aspect of the invention, two ribs constitute the fourth rib for connecting the outer periphery of the hollow cylindrical portion to the vehicle-mounting boss portion of the pinion-side end. The two ribs are formed in a substantially V-shape so as to intersect each other at a position connected to the hollow cylindrical portion and spaced apart from each other at a position connected to the vehicle-mounting boss portion of the pinion-side end.

[0036] Accordingly, since the fourth rib forms a closed loop with the vehicle mounting boss portion and the two ribs, it is possible to effectively prevent the deformation of the vehicle mounting boss portion of the pinion side end in both the vertical direction and the longitudinal direction, thereby improving the steering stability. Short description of the drawings Fig. 1 is a front view illustrating a main part of a steering gear of a steering apparatus according to an embodiment of the invention. Fig. 2 is a front view showing a main part of a steering gear of a conventional steering device. Fig. 3 is a front view illustrating a deformation state at the time when the steering gear of the known steering device receives a steering reaction force transmitted from a running wheel during a steering operation. Fig. 4 is a view in the direction of the Fig. 2, which represents a deformation state at the time when the steering gear of the known steering device receives a steering reaction force transmitted from the running wheel during the steering operation. Description of reference symbols 10 steering gear 11 hollow cylindrical section 12 inner circumference 13 cylindrical pinion insertion hub 14 cylindrical rack guide insertion hub 15 outer circumference 16, 17 Vehicle mounting hub section 161, 171 mounting hole 163, 173 bolts 18a, 18b rib 19a, 19b rib 2 vehicle frames 3 Rack shaft 41, 42 tie rod 5 pinion shaft 61 first rib 61a, 61b rib 62 second rib 63 third rib 64 fourth rib 64a, 64b rib Best mode for carrying out the invention

[0037] An embodiment of the invention will now be described with reference to the accompanying drawings.

[0038] Fig. 1 is a front view illustrating a main part of a steering gear of a steering device according to an embodiment of the invention. A steering gear 10 according to the embodiment of the invention is, as shown in Fig. 1, attached to a vehicle frame 2, such as a front subframe. In Fig. 1, the upward direction is referred to as a vehicle-upward direction, and the downward direction is referred to as a vehicle-downward direction. In Fig. 1, the transverse direction is referred to as a vehicle transverse direction. In Fig. 1, a direction perpendicular to a paper surface is called a vehicle longitudinal direction.

[0039] A rack shaft 3 is in the Fig. 1, is slidably inserted into an inner periphery 12 of a hollow cylindrical portion 11 of the steering gear 10. Tie rods 41 and 42 are connected to both ends of the rack shaft 3, and the tie rods 41 and 42 are connected to a running wheel via a tie rod arm (not shown).

[0040] A cylindrical pinion insertion hub 13 is integrally formed with the left end of the hollow cylindrical portion 11 so as to protrude upward from an outer periphery 15 of the hollow cylindrical portion 11. A pinion (not shown) meshing with the rack shaft 3 is formed at the lower end of a pinion shaft 5 inserted into the cylindrical pinion insertion hub 13. The upper end of the pinion shaft is connected to the lower end of the steering shaft (not shown) connected to the steering wheel.

[0041] A cylindrical rack guide insertion hub 14 is integrally formed with the left end of the hollow cylindrical portion 11 so as to be adjacent to the cylindrical pinion insertion hub 13 and protrude from the outer periphery 15 of the hollow cylindrical portion 11 in the longitudinal direction of the vehicle (a front-side direction perpendicular to a paper plane). A rack guide (not shown) is inserted into the cylindrical rack guide insertion hub 14 so as to guide the back side (a side opposite the rack tooth surface) of the rack shaft 3 using a roller and so on, and prevent deformation of the rack shaft 3 caused by a reaction force upon engagement with the pinion, so that the rack shaft 3 can slide smoothly thereon.

[0042] When a driver turns a steering wheel (not shown), the pinion of the pinion shaft 5 rotates, and then the rack shaft 3 slidably moves left and right according to the rotation of the pinion, thus changing the steering angle of a running wheel.

[0043] Vehicle mounting boss portions 16 and 17 are formed at the left end (a pinion side end) of the hollow cylindrical portion 11 and at the right end (an end opposite the pinion side) of the hollow cylindrical portion 11, respectively, so as to protrude from the outer periphery 15 of the hollow cylindrical portion 11 in the longitudinal direction of the vehicle (the front side direction perpendicular to a paper surface). Circular mounting holes 161 and 171 are formed in the vehicle mounting boss portions 16 and 17, respectively, in the vertical direction of the vehicle (the Fig. 1 shown vertical direction).

[0044] The steering gear 10 is mounted on the vehicle frame 2 in a strong structure (a rigid body structure) without inserting the sleeve made of the elastic member by inserting bolts 163 and 173 into the mounting holes 161 and 171 and then firmly tightening the bolts 163 and 173 to the vehicle frame 2.

[0045] In order to prevent the deformation in the vicinity of the vehicle mounting boss portion 17 at the end opposite to the pinion side, a first rib 61 connecting the outer periphery 15 of the hollow cylindrical portion 11 with the vehicle mounting boss portion 17 at the end opposite to the pinion side is formed at a connecting portion between the outer periphery 15 of the hollow cylindrical portion 11 and the vehicle mounting boss portion 17 at the end opposite to the pinion side.

[0046] The first rib 61 includes two ribs, that is, an upper rib 61a and a lower rib 61b below the rib 61a, as shown in Fig. 1. The ribs 61a and 61b are formed in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion 11 (on the left side of the Fig. 1), and are spaced apart from each other at a position connected to the vehicle mounting hub portion 17 in the vertical direction of the vehicle.

[0047] The first rib 61 forms a triangular closed loop by the vehicle mounting hub portion 17, the rib 61a, and the rib 61b. This makes it possible to form an effective rib structure whose rigidity resists the deformation of the vehicle mounting hub portion 17 in both the vertical direction and the longitudinal direction of the vehicle.

[0048] A second rib 62 is formed in the vicinity of the vehicle-mounting boss portion 17 at the end opposite the pinion gear side, on the vehicle upper side of the outer periphery 15 of the hollow cylindrical portion 11 at the end opposite the pinion gear side. Additionally, a third rib 63 is formed in the vicinity of the vehicle-mounting boss portion 17 at the end opposite the pinion gear side, on the lower outer periphery 15 of the hollow cylindrical portion 11 at the end opposite the pinion gear side.

[0049] The second rib 62 and the third rib 63 assist a deformation preventing action of the first rib 61 in the vehicle vertical direction with respect to the deformation of the vehicle mounting boss portion 17 at the pinion side opposite end in the vehicle vertical direction.

[0050] Furthermore, in order to prevent the deformation in the vicinity of the vehicle mounting boss portion 16 at the pinion side end, a fourth rib 64 connecting the vehicle mounting boss portion 16 at the pinion side end to the outer periphery 15 of the hollow cylindrical portion 11 is formed at a position where the vehicle mounting boss portion 16 at the pinion side end is connected to the outer periphery of the hollow cylindrical portion 11.

[0051] The fourth rib 64 includes two ribs, ie an upper rib 64a and a lower rib 64b below the upper rib 64a, as shown in Fig. 1. The ribs 64a and 64b are formed in a V-shape so as to be connected to the cylindrical rack guide insertion hub 14 while intersecting each other at a position connected to the hollow cylindrical portion 11 (on the right side of the Fig.1) and are spaced apart from each other at a position connected to the vehicle mounting portion 16 in the vertical direction of the vehicle.

[0052] The fourth rib 64 forms a square-like closed loop by the vehicle mounting boss portion 16, the rib 64a, the rib 64b, and the cylindrical rack guide insertion hub 14. This makes it possible to form an effective rib structure whose rigidity is resistant to the deformation of the vehicle mounting boss portion 16 in the vertical direction of the vehicle and in the longitudinal direction of the vehicle.

[0053] With such a rib structure, when the steering device whose steering gear 1 is rigidly mounted on the vehicle frame 2 is steered, the steering reaction force transmitted from a running wheel acts on the steering gear 10, and then the steering reaction force directly acts on the vehicle mounting boss portions 16 and 17.

[0054] As a result, even if bending stress acts on the steering gear 10 around the attachment holes 161 and 171 of the vehicle-mounting boss portions 16 and 17, the deformation in the vicinity of the vehicle-mounting boss portions 16 and 17 in both the longitudinal and vertical directions of the vehicle is reduced because the rigidity against deformation in the vicinity of the vehicle-mounting boss portions 16 and 17 in both the longitudinal and vertical directions of the vehicle is high due to the ribs from the first rib 61 to the fourth rib 64. Accordingly, it is possible to improve the steering stability when the steering reaction force occurs.

[0055] Although the above-described embodiment describes a case where the invention is applied to the steering device without using a steering assist force, it is more effective if the invention is applied to the steering device such as an electric power steering device which has the steering assist force and in which a strong steering reaction force occurs. Industrial applicability

[0056] In the steering device according to the invention, the first rib connecting the outer periphery of the hollow cylindrical portion to the vehicle mounting boss portion of the pinion-side end includes two ribs. The two ribs are formed in a V-shape so that they intersect each other at a position connected to the hollow cylindrical portion and are spaced apart from each other at a position connected to the vehicle mounting boss portion of the pinion-side end in the vehicle vertical direction.

[0057] Accordingly, the first rib forms a closed loop with the vehicle mounting boss portion and the two ribs formed in a V shape. This effectively prevents deformation of the vehicle mounting boss portion of the end opposite the pinion side in both the vertical and longitudinal directions of the vehicle, thereby improving steering stability.

Claims

[1] Steering device comprising: a steering gear mountable on a vehicle frame (2) and including a hollow cylindrical portion (11) having a rack shaft (3) slidably fitted therein, the rack shaft (3) being reciprocated by rotation of a pinion mounted on a lower end of a steering shaft (5); Vehicle mounting boss portions (16, 17) formed at both a pinion-side end and an end opposite the pinion side of the hollow cylindrical portion (11) of the steering gear so as to protrude from an outer periphery (15) of the hollow cylindrical portion (11) in a longitudinal direction of the vehicle, and in which mounting holes (161; 171) are formed in a vertical direction of the vehicle for mounting the steering gear to the vehicle frame; and a first rib (61) formed at a connecting portion between the hollow cylindrical portion (11) and the vehicle mounting boss portion (17) of the pinion-side opposite end so as to connect the outer periphery (15) of the hollow cylindrical portion (11) to the vehicle mounting boss portion (17) of the pinion-side opposite end, wherein the first rib (61) contains two ribs (61a, 61b), characterized by , that the two ribs are formed in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion (11) and are spaced apart from each other at a position connected to the vehicle mounting boss portion (17) of the end opposite to the pinion side. [2] Steering device according to claim 1, further comprising: a second rib (62) formed in the vicinity of the vehicle mounting boss portion (17) of the pinion side opposite end on an upper outer periphery of the hollow cylindrical portion (11) at the pinion side opposite end. [3] Steering device according to claim 1, further comprising: a third rib (63) formed in the vicinity of the vehicle mounting boss portion (17) of the pinion side opposite end on a lower outer periphery of the hollow cylindrical portion (11) at the pinion side opposite end. [4] Steering device according to claim 1, further comprising: a second rib (62) formed in the vicinity of the vehicle mounting boss portion (17) of the pinion-side opposite end on an upper outer periphery of the hollow cylindrical portion (11) at the pinion-side opposite end; and a third rib (63) formed in the vicinity of the vehicle mounting boss portion (17) of the pinion side opposite end on a lower outer periphery of the hollow cylindrical portion (11) at the pinion side opposite end. [5] Steering device according to one of the preceding claims, further comprising: a fourth rib (64) formed at a connecting portion between the hollow cylindrical portion (11) and the vehicle mounting boss portion (16) of the pinion side end so as to connect the outer periphery (15) of the hollow cylindrical portion (11) to the vehicle mounting boss portion (16) of the pinion side end, wherein the fourth rib (64) includes two ribs (64a, 64b), and the two ribs (64a, 64b) are formed substantially in a V-shape so as to intersect each other at a position connected to the hollow cylindrical portion (11) and are spaced apart from each other at a position connected to the vehicle mounting boss portion (16) of the pinion side end.

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