JP2007223541A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device of simple structure capable of surely fixing a dust cover to the periphery of a cylinder pipe without increasing the number of part items, in a steering device which houses a rack shaft so as to be movable in the cylinder pipe provided in a steering gear housing. <P>SOLUTION: In the steering device 10, one end fitting part 71 of the dust cover 70 is fitted in a recessed part 90 pinched by an outer end flange 14A of a cylinder end 14 and a holding part 51 of a fitting 40 in at periphery of the cylinder pipe 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a steering device.

  In the rack and pinion type steering device, as described in Patent Document 1, a rack shaft interlocked with a steering input shaft is movably accommodated in a steering gear housing, and protrudes to the outside from a bush support member provided at an opening end of the steering gear housing. A tie rod is connected to the end of the rack shaft through a joint, and one end mounting portion of the dust cover covering the joint is held on the outer periphery of the steering gear housing, and the other end mounting portion of the dust cover is held on the outer periphery of the tie rod. There is something to wear. In the steering device of Patent Document 1, the outer end flange of the bush support member positioned outside the opening end of the steering gear housing is abutted against the opening end surface of the steering gear housing, and is made larger than the outer diameter of the steering gear housing. The outer end flange of the bush support member is an assembly position restricting portion for the one end mounting portion of the dust cover.

In the steering device of Patent Document 2, the steering gear housing is made of an aluminum casting, and two annular shoulders are formed on the outer periphery of the steering gear housing so as to bulge and are sandwiched between the two annular shoulders. The one end mounting portion of the dust cover can be fitted into the recess.
5-49566 JP 7-259996

  In the dust cover mounting structure of the steering device disclosed in Patent Document 1, only the outer end flange of the bush support member positioned outside the opening end of the steering gear housing is used as the dust cover assembly position restricting portion. The attachment position can only be restricted in one direction. The dust cover may be displaced in the other direction.

  In the dust cover mounting structure of the steering device of Patent Document 2, the assembly position of the dust cover can be regulated in both directions by the two annular shoulder portions on the outer periphery of the steering gear housing. However, in order to reduce the weight of the steering gear housing, a cylinder pipe made of a steel pipe or the like is provided in the steering gear housing, this cylinder pipe is provided, and the rack shaft is movably accommodated in this cylinder pipe. There is a lot of waste and difficulty in bulging and forming two annular shoulders for attaching a dust cover to the outer periphery of the pipe.

  An object of the present invention is to securely fix a dust cover to the outer periphery of a cylinder pipe with a simple configuration without increasing the number of parts in a steering device that movably accommodates a rack shaft in a cylinder pipe provided in a steering gear housing. There is to do.

  According to the first aspect of the present invention, a rack shaft interlocking with the steering input shaft is movably accommodated in a cylinder pipe provided in the steering gear housing, and the rack projects outside through a cylinder end provided at the opening end of the cylinder pipe. A tie rod is connected to the end of the shaft via a joint, and one end mounting portion of the dust cover covering the joint is embraced on the outer periphery of the cylinder pipe, and the other end mounting portion of the dust cover is embraced on the outer periphery of the tie rod. In this steering device, the outer end flange of the cylinder end located outside the opening end of the cylinder pipe is abutted against the opening end surface of the cylinder pipe, and is made larger than the outer diameter of the cylinder pipe, and the cylinder pipe is held and held. A holding part of a fixture for attaching the cylinder pipe to the vehicle body side is provided on the outer periphery of the cylinder pipe, Te, the recess sandwiched holding portion of the outer end flange and fitting of the cylinder end, is obtained by the so formed by fitting the end mounting portion of the dust cover.

(Claim 1)
In the steering device, the one end mounting portion of the dust cover is fitted into a recess that is sandwiched between the outer end flange of the cylinder end and the holding portion of the mounting tool on the outer periphery of the cylinder pipe. On the outer periphery of the cylinder pipe, one shoulder that regulates the assembly position for one end mounting part of the dust cover is formed by the outer end flange of the cylinder end, and the other shoulder is formed by the holding part of the mounting tool. Yes, the dust cover can be securely fixed to the outer periphery of the cylinder pipe with a simple configuration without increasing the number of parts.

  1 is an overall cross-sectional view showing a power steering device, FIG. 2 is a cross-sectional view showing a steering gear housing, FIG. 3 is a cross-sectional view of the main part of FIG. 1, FIG. 4 is a dust cover mounting structure, and FIG. FIGS. 5A and 5B are enlarged views of the main part of FIG. 5A, and FIG.

  As shown in FIGS. 1 to 3, the hydraulic power steering apparatus 10 is provided with a cylinder pipe 13 made of a steel pipe or the like in a rack shaft housing portion 11 </ b> A of the steering gear housing 11 by press fitting or the like, and the rack shaft 12 is linearly connected to the cylinder pipe 13. Contain movably. The rack shaft 12 is press-fitted into a rack guide (not shown) built in the rack shaft housing portion 11A of the steering gear housing 11 and an inner circumference of a cylinder end 14 provided by screwing or the like on the opening end of the cylinder pipe 13. The bush 15 is slidably supported.

  The rack shaft 12 located inside the cylinder pipe 13 is provided with a piston 12A, and a first chamber 16A and a second chamber 16B are formed between the left and right oil seals 13A, 13B inside the cylinder pipe 13 and the piston 12A. Yes. The hydraulic power steering device 10 is connected to the cylinder pipe 13 of the steering gear housing 11 and the left and right ends of the rack shaft 12 projecting outward from the open ends of the rack shaft housing portion 11A via joints 17A and 17B. , 18B are coupled to assist the steering force of the steering wheel by the driver.

  In the hydraulic power steering apparatus 10, a valve body 21 of a control valve 20 is fixed to a steering gear housing 11. The control valve 20 pivotally supports an input shaft 22 that rotates in conjunction with the steering wheel on the valve body 21, and includes a circular rotor (not shown) integrated with the input shaft 22 and a torsion bar 22 </ b> A fixed to the input shaft 22. A circular sleeve (not shown) fixed together with a pinion (not shown) at the tip is coaxially arranged so as to be relatively displaceable by elastic torsional deformation of the torsion bar 22A in response to the steering torque applied to the steering wheel, and the first chamber 16A. The pump-side supply flow path and the tank-side return flow path are switched and connected to the first and second supply / discharge flow paths 19A, 19A connected to the second chamber 16B according to the steering operation. A pinion (not shown) fixed to the sleeve (not shown) is meshed with the rack teeth of the rack shaft 12.

  The hydraulic power steering device 10 includes mounting portions 31 and 32 on one side along the longitudinal direction of the rack shaft housing portion 11A of the steering gear housing 11, and includes a mounting tool 40 on the other side. In the hydraulic power steering apparatus 10, the attachment portions 31 and 32 are integrally formed when the steering gear housing 11 is cast, and bolts inserted into the attachment holes 31A and 32A are screwed to the support portions (screw holes) of the vehicle body frame. At the same time, the cylinder pipe 13 is held by the fixture 40, and the bolt inserted into the mounting hole 40A is screwed into the support portion (screw hole) of the vehicle body frame. As a result, the steering gear housing 11 is fixedly mounted at a predetermined mounting position with respect to the vehicle body frame. Hereinafter, the fixture 40 will be described.

  The fixture 40 has a bracket 50 and a collar 60 as shown in FIG. The bracket 50 includes a substantially annular C-shaped holding portion 51 that holds the cylinder pipe 13 of the steering gear housing 11, and extends outward from both ends of the C-shape of the holding portion 51 to each other. A pair of joining pieces 52 are provided so as to be parallel to each other. The bracket 50 can be formed by pressing a plate material having a constant plate width. The collar 60 is made of a pipe material and is inserted into holes 52 </ b> A provided in the pair of joining pieces 52 of the bracket 50.

  The fixture 40 is held at each of a plurality of circumferential positions (four positions in this embodiment) of the holding portion 51 in a state where the holding portion 51 of the bracket 50 is held on the cylinder pipe 13 of the steering gear housing 11. Laser beam welding (or arc welding is possible) of the inner surface of the slit 51A extending in the plate width direction of the holding portion 51 to the outer periphery of the cylinder pipe 13 (welding portion 53). In addition, the fixture 40 is a state in which the collar 60 is inserted into each hole 52A of the pair of joining pieces 52 of the bracket 50, and the outwardly facing surfaces of the joining pieces 52 (the steering gear housing 11 is vertically arranged as shown in FIG. 5). The upper surface of the upper joint piece 52 and the lower surface of the lower joint piece 52 as viewed in FIG. 2 are laser beam welded (or arc welded) to the outer periphery of the collar 60 (welded portion 54). The welded portions 54 are provided at a plurality of circumferential positions along the outer periphery of the collar 60 (or the entire circumference is acceptable).

  As shown in FIG. 3, a mounting bush 61 is fitted on the inner periphery of the collar 60, and the mounting bush 61 has the mounting hole 40A as described above. The bracket 50 of the fixture 40 holds the outer diameter portion of the cylinder pipe 13 where the cylinder end 14 is inserted.

Hereinafter, a procedure for providing the fixture 40 on the steering gear housing 11 will be described.
(1) The holding part 51 of the bracket 50 of the fixture 40 is attached to the cylinder pipe 13 of the steering gear housing 11.

  (2) The pair of joining pieces 52 of the bracket 50 are sandwiched by applying pressure from both sides, and the holding portion 51 is brought into close contact with the cylinder pipe 13 without a gap. In this state, the inner surfaces of the two slits 51 </ b> A on the upper half circumference side of the holding portion 51 are welded to the cylinder pipe 13 by the welding portion 53. Subsequently, the upper joining piece 52 is welded to the outer periphery of the collar 60 at the welding portion 54.

  (3) With the steering gear housing 11 reversed or not reversed, the pair of joining pieces 52 of the bracket 50 are sandwiched by pressurizing from both sides, and the holding portion 51 is inserted into the cylinder pipe 13 without a gap. Adhere closely. In this state, the inner surfaces of the two slits 51 </ b> A on the lower half circumference side of the holding part 51 are welded to the cylinder pipe 13 by the welding part 53. Subsequently, the upper joining piece 52 is welded to the outer periphery of the collar 60 at the welding portion 54.

  When the steering gear housing 11 is inverted in the above (3), the lower half circumference welding of the holding portion 51 and the lower joining piece 52 can be welded downward. When the steering gear housing 11 is not reversed, the lower half circumferential side welding of the holding portion 51 and the lower joining piece 52 are welded upward.

  However, in the hydraulic power steering apparatus 10, the cylinder pipe 13 of the steering gear housing 11 and the left and right ends of the rack shaft 12 projecting outside from the opening end of the rack shaft accommodating portion 11A are connected via joints 17A and 17B. When connecting the tie rods 18A and 18B, rubber bellows-like dust covers 70 and 80 are provided to cover the joints 17A and 17B. The dust covers 70 and 80 prevent muddy water and foreign matter from entering the cylinder pipe 13 and the rack shaft housing 11A of the steering gear housing 11 and the joints 17A and 17B.

  Hereinafter, as shown in FIGS. 2 and 4, the dust around the joint 17 </ b> A provided at one end of the rack shaft 12 that penetrates the cylinder end 14 provided at the opening end of the cylinder pipe 13 of the steering gear housing 11 and protrudes to the outside. The attachment structure of the cover 70 will be described.

  The cylinder end 14 provided at the opening end of the cylinder pipe 13 causes the side end surface of the outer end flange 14A located outside the opening end of the cylinder pipe 13 to abut the opening end surface of the cylinder pipe 13, and the outside of the outer end flange 14A. The diameter is made larger than the outer diameter of the cylinder pipe 13.

  As described above, on the outer periphery of the portion of the cylinder pipe 13 where the cylinder end 14 is inserted, the bracket 50 of the fixture 40 that holds the cylinder pipe 13 and attaches the cylinder pipe 13 to the vehicle body side is formed in an annular shape. A holding part 51 is provided.

  Therefore, an annular recess 90 is formed on the outer periphery of the cylinder pipe 13 between the side end surface of the outer end flange 14 </ b> A of the cylinder end 14 and the side end surface of the holding portion 51 of the fixture 40. The one end attaching portion 71 of the dust cover 70 is fitted in the annular recess 90 on the outer periphery of the cylinder pipe 13 and is fastened by the clamp device 71A. The other end mounting portion 72 of the dust cover 70 is attached to the outer periphery of the tie rod 18A and is fastened by the clamp device 72A.

  The one end mounting portion of the dust cover 80 is fitted on the outer periphery of the rack shaft housing portion 11A of the steering gear housing 11 and is fastened by a clamping device, and the other end mounting portion of the dust cover 80 is attached to the outer periphery of the tie rod 18B. And are fastened by a clamping device.

According to the present embodiment, the following operational effects can be obtained.
In the steering device 10, the one end attaching portion 71 of the dust cover 70 is fitted into the annular recess 90 on the outer periphery of the cylinder pipe 13 and sandwiched between the outer end flange 14 </ b> A of the cylinder end 14 and the holding portion 51 of the attachment 40. To wear. On the outer periphery of the cylinder pipe 13, one shoulder for restricting the assembly position for the one end mounting portion 71 of the dust cover 70 is held by the outer end flange 14 </ b> A of the cylinder end 14, and the other shoulder is held by the mounting tool 40. The dust cover 70 can be securely fixed to the outer periphery of the cylinder pipe 13 with a simple configuration without increasing the number of parts.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, the present invention is not limited to the hydraulic power steering apparatus, but can be widely applied to an electric power steering apparatus or other general rack and pinion type steering apparatus.

FIG. 1 is an overall cross-sectional view showing a power steering apparatus. FIG. 2 is a sectional view showing the steering gear housing. 3 is a cross-sectional view of the main part of FIG. 4A and 4B show a dust cover mounting structure, where FIG. 4A is a cross-sectional view and FIG. 4B is an enlarged view of a main part of FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG.

Explanation of symbols

10 Power steering device (steering device)
11 Steering gear housing 12 Rack shaft 13 Cylinder pipe 14 Cylinder end 14A Outer end flange 17A Joint 18A Tie rod 22 Input shaft 40 Mounting tool 51 Holding part 70 Dust cover 71 One end attaching part 72 Other end attaching part 90 Recess

Claims (1)

A rack shaft interlocking with the steering input shaft is movably accommodated in a cylinder pipe provided in the steering gear housing, and a joint is attached to the end of the rack shaft that protrudes outside through the cylinder end provided at the opening end of the cylinder pipe. In the steering device in which the tie rod is connected to each other, the one end mounting portion of the dust cover covering the joint is embraced on the outer periphery of the cylinder pipe, and the other end mounting portion of the dust cover is embraced on the outer periphery of the tie rod.
While the outer end flange of the cylinder end located outside the opening end of the cylinder pipe is abutted against the opening end surface of the cylinder pipe, the outer diameter of the cylinder pipe is larger than the outer diameter.
A holding part of a fixture for holding the cylinder pipe and attaching the cylinder pipe to the vehicle body side is provided on the outer periphery of the cylinder pipe,
A steering device characterized in that one end mounting portion of a dust cover is fitted in a recess which is an outer periphery of a cylinder pipe and is sandwiched between an outer end flange of a cylinder end and a holding portion of a mounting tool.

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