JP2017078502A - Damper device and steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper device capable of efficiently increasing the bending strength of an impact receiving member which directly receives impact, of members used for an impact absorption member of the damper device, and to provide a steering device.SOLUTION: An impact absorption member (53) which is mounted between an abutment end face (51a) of a large diameter part (51) and a restriction face (52b) in an axial direction (A) of a damper device (50) includes: an impact receiving member (53a) having a disc part (532) capable of coming into contact with the abutment end face (51a); and an elastic body (53b) arranged between the restriction face (52b) and the disc part (532). The disc part (532) includes an inner periphery side region (IN) which comes into contact with the large diameter part (51) when the large diameter part (51) imparts impact force to the disc part (532), and an outer periphery side region (OUT) located radially outward of the inner periphery side region (IN), which does not come into contact with the large diameter part (51). The thickness of the outer periphery region (OUT) is smaller than a thickness (T) at a boundary position ((B) between the inner periphery side region and the outer periphery side region.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a damper device and a steering device using the damper device.

In a vehicle steering device, the direction of a steered wheel is changed by reciprocating a steered shaft connected to a steered wheel (tire) via a tie rod in the axial direction. The steered shaft is slidably accommodated in the housing. When the turning shaft reaches the limit of the reciprocating movement range, the large diameter portion formed at the end of the turning shaft collides with the housing, and the moving range of the turning shaft is physically restricted. Specifically, in accordance with the operation of the steering wheel by the driver, a force that moves the steered shaft in the axial direction is input (positive). Alternatively, an excessive force that moves the steered shaft in the axial direction from the steered wheel to the steered shaft is input (reverse) by an action such as the steered wheel climbing on the curb. When the steered shaft moves in the axial direction until the large-diameter portion collides with the housing with forward and reverse inputs, “end contact” occurs.
In the steering device, a shock is applied to the end contact portion by using a damper device. As such a damper device, one having an impact absorbing member interposed between the end surface of the large-diameter portion and the housing in a state surrounded by the housing is known.

  The steering device of Patent Document 1 includes stopper means (impact absorbing member) interposed between an axial joint (large diameter portion) and a housing. When the large-diameter portion is about to collide against the housing, the impact absorbing member receives the collision from the large-diameter portion and absorbs the impact shock by the elastic following material (elastic member). The impact absorbing member has a flange (impact receiving member) that contacts the large diameter portion and receives a collision impact.

Japanese Patent No. 4255632

  However, in the impact absorbing member according to the steering device of Patent Document 1, the axial joint (large diameter portion) contacts the flange of the L-shaped impact receiving member. The impact is absorbed by the deformation of the elastic member interposed between the flange and the regulating surface of the housing. In order to increase the impact absorption force, it is necessary to increase the volume of the elastic member. In this case, the inner peripheral side of the end face of the flange is in contact with the axial joint (large diameter part), and the outer peripheral side of the end face of the flange is not in contact with the axial joint (large diameter part). In such a case, when the elastic member is compressively deformed, the flange may be bent and deformed by a load received from the elastic member.

  The present invention has been made in view of the above problems, and among the members used for the shock absorbing member of the damper device, a damper device capable of efficiently increasing the bending strength of the shock receiving member that directly receives an impact, and An object is to provide a steering device.

  The damper device of the present invention is formed in a cylindrical shape with a shaft having a shaft portion and a large-diameter portion, and is inserted into the shaft so as to be relatively movable in the axial direction, and is opposed to the end surface of the large-diameter portion in the axial direction. A damper device comprising: a housing including a restriction surface; and an impact absorbing member that is inserted through the shaft portion and interposed between the end surface of the large diameter portion and the restriction surface. The impact absorbing member is disposed between the impact receiving member having a disc-shaped portion that can contact the end surface of the large-diameter portion, and between the regulating surface and the disc-shaped portion, and has a rubber material or rubber-like elasticity. An elastic body formed of a synthetic resin material, and the disk-shaped portion is an inner peripheral region that comes into contact with the large-diameter portion when the large-diameter portion imparts an impact force to the disk-shaped portion. And an outer peripheral side region that is located radially outward from the inner peripheral side region and does not contact the large diameter portion Comprises a thickness of the outer peripheral side region, than the thickness of the boundary position between the inner peripheral side region and the outer circumferential region is thinner.

  The steering device of the present invention is a steered shaft that includes the damper device of the present invention, both ends of which are coupled to the steered wheels via tie rods and that reciprocates in the axial direction to steer the steered wheels. The shaft including the large-diameter portion that is swingably coupled to the tie rod, the housing that houses the steered shaft, and the impact absorbing member.

  According to the damper device or the steering device of the present invention, when the large diameter portion imparts an impact force to the impact receiving portion, the elastic body to be compressed is compressed in the outer peripheral side region of the disk-shaped portion that does not contact the large diameter portion. Internal pressure acts. That is, the bending moment due to the internal pressure of the elastic body acts on the outer side region of the disk-shaped portion with the boundary position between the inner peripheral side region contacting the large diameter portion and the outer peripheral side region not contacting as a support point. In this case, the boundary position between the inner peripheral region and the outer peripheral region corresponds to the support point of the bending moment. Therefore, the bending moment is supported by forming the thickness of the plate-like portion in the outer peripheral region thinner than the thickness of the boundary position between the inner peripheral region and the outer peripheral region, that is, by forming the thickness of the boundary position relatively thick. The rigidity of the disk-shaped part at the position corresponding to the point can be increased. For example, when compared with a measure for bending strength in which the thickness of the disk-shaped part is formed over the entire surface, the bending strength of the impact receiving member having the disk-shaped part can be efficiently increased with the minimum necessary method. .

  In the present specification, the “elastic body” refers to a member formed of a material material that expresses a generally defined “rubber-like elasticity”, and is not limited thereto. As the elastic body, a rubber material or a synthetic resin material having rubber-like elasticity can be suitably used.

It is the schematic which shows the steering device of this embodiment. It is sectional drawing which shows the damper apparatus of this embodiment. It is a figure which shows the arrangement | positioning relationship of the impact receiving member of FIG. 2, and a large diameter part along a radial direction. FIG. 4 is a cross-sectional view taken along line X-X in FIG. 3, showing an arrangement relationship between the impact receiving member and the large diameter portion along the axial direction. It is sectional drawing explaining the damper apparatus before and behind "end contact".

  Hereinafter, a damper device of the present invention will be described with reference to the drawings based on a specific embodiment of a steering device of the present invention using the damper device. The steering device of the present invention can be applied to an electric power steering device, a rear wheel steering device, a steer-by-wire device, and the like. In FIG. 1, the steering device ST includes a steering mechanism 10, a steering mechanism 20, and a damper device 50.

(1. Configuration of steering device)
As shown in FIG. 1, the steering mechanism 10 includes a steering wheel 11 and a steering shaft 12. The steering wheel 11 is fixed to the end of the steering shaft 12. The steering shaft 12 transmits a steering torque applied to the steering wheel 11 in order to steer the steered wheels 26. The steering shaft 12 is configured by connecting a column shaft 13, an intermediate shaft 14, and a pinion shaft 15. The pinion shaft 15 includes an input shaft 15a, an output shaft 15b, and a torsion bar 15c. The output side portion of the intermediate shaft 14 is connected to the input side portion of the input shaft 15a, and pinion teeth 15d are formed on the output side portion of the output shaft 15b.

  The turning mechanism 20 includes a turning shaft 21 and a housing 22 formed in a substantially cylindrical shape. The steered shaft 21 is housed and supported in a housing 22 so as to be linearly reciprocable along the axial direction A. The housing 22 includes a first housing 22a and a second housing 22b fixed to the left side of the first housing 22a in the axial direction A in FIG.

  The pinion shaft 15 is rotatably supported in the first housing 22a. Rack teeth 21 a are formed on the steered shaft 21, and the rack teeth 21 a and the pinion teeth 15 d are engaged with each other to form a rack and pinion mechanism 23. A rack and pinion mechanism 23 is accommodated in the first housing 22a.

  The steered shaft 21 has large diameter portions 51, 51 at both ends of the shaft portion 211. The large diameter portions 51 and 51 are formed by expanding the diameter of the shaft portions 211 at both ends of the steered shaft 21. The large-diameter portion 51 accommodates a ball stud 27 and forms a ball joint. Tie rods 24, 24 are connected to both ends of the ball studs 27, 27, and the tips of the tie rods 24, 24 are connected to a knuckle on which the steered wheels 26 are assembled. Thus, when the steering wheel 11 is steered, the steering torque is transmitted to the steering shaft 12, and the pinion shaft 15 is rotated. The rotation of the pinion shaft 15 is converted into a linear reciprocating movement of the steered shaft 21 by the pinion teeth 15d and the rack teeth 21a. Then, the movement along the axial direction A is transmitted to the knuckle via the tie rods 24, 24, whereby the steered wheels 26, 26 are steered, and the traveling direction of the vehicle is changed. Reference numeral 25 denotes a boot for maintaining the airtightness of the accommodation space of the steering mechanism 20 including the inside of the housing 22.

  At both ends of the housing 22, shock absorbing members 53, 53 described later are provided. The shock absorbing members 53 and 53 are accommodated in large-diameter housings 52 and 52 formed at one end of the first housing 22a and the other end of the second housing 22b. It is mounted (see FIG. 2). The shock absorbing members 53 and 53 are interposed between the large diameter portions 51 and 51 and the regulating surfaces 52b and 52b so as to face the large diameter portions 51 and 51 for stopping the linear movement of the steered shaft 21. Is done. When the steered shaft 21 moves in the axial direction A and the steered wheels 26 and 26 reach the maximum steering angle, an “end contact” occurs in which the large diameter portion 51 collides with the impact absorbing member 53. The impact absorbing member 53 absorbs the impact of the collision at this time.

(2. Damper device)
The damper device 50 described above will be further described with reference to FIG. In the damper device 50, the large diameter portion 51 is used for the large diameter portion in accordance with the normal input accompanying the steering of the driver or the reverse input from the outside of the vehicle via the steered wheels 26 to the steered shaft 21. This is a device for absorbing the impact caused by the impact absorbing member 53 when it is about to collide with the regulating surface 52 b of the housing 52. As shown in FIG. 2, the damper device 50 includes a steered shaft 21 that includes a large-diameter portion 51, a large-diameter portion housing 52, and an impact absorbing member 53.

  Note that the damper device 50 of the embodiment is mounted at two places on the left and right sides in the axial direction A of the steering device ST. In the following description, in FIG. 1, the right side in the axial direction A is the “one” side and the left side is the “other” side, and unless otherwise noted, the other side of the damper device 50 mounted at two locations. The configuration of the damper device 50 will be mainly described.

  The steered shaft 21 includes a shaft portion 211 and a large diameter portion 51 connected to the shaft portion 211. The steered shaft 21 connects the shaft portion 211 formed with the rack teeth 21a on one side along the axial direction A, and connects the shaft portion 271 of the ball stud 27 via the large diameter portion 51 on the other side. To do.

  The large-diameter portion 51 is connected to the steered shaft 21 at one end portion 511 in its own axial direction A, and the one-side end portion 511 of the large-diameter portion 51 has a larger diameter than the shaft portion 211 of the steered shaft 21. Formed. A female screw portion 213 that opens to the other side in the axial direction A is formed on the end surface 212 of the shaft portion 211 of the steered shaft 21. A male screw part 51 b that is screwed into the female screw part 213 of the steered shaft 21 is formed at one end 511 of the large diameter part 51. The male screw portion 51b protrudes along the axial direction A to one side. The ball stud 27 can be connected to the other side of the large-diameter portion 51 with respect to the steered shaft 21 by screwing the male screw portion 51 b and the female screw portion 213.

  In addition, an end face 212 of the steered shaft 21, that is, a large-diameter contact end face 51 a with which the terminal end of the shaft section 211 comes into contact is formed at the root of the male screw portion 51 b. The contact end surface 51a is formed in the radial direction from the root of the male screw portion 51b. The contact end surface 51a corresponds to the end surface of the steered shaft 21, and is a so-called rack end. The abutting end surface 51 a is in contact with the impact receiving member 53 a disposed on the other end surface of the impact absorbing member 53, and is formed so as to be able to be locked to the disk-shaped portion 532. Further, the shock absorbing member 53 is attached to the restriction surface 52b of the housing at one end portion. Therefore, when the contact end surface 51 a is locked to the disk-shaped portion 532, the linear reciprocation of the steered shaft 21 is restricted via the impact absorbing member 53.

Two surfaces for engaging a tool that rotates the one-side end portion 511 with the one-side end portion 511 of the large-diameter portion 51 when the male screw portion 51b is screwed into the female screw portion 213 of the shaft portion 211. A width is formed. Therefore, the shape of the outer peripheral edge portion 51e of the large diameter portion 51 is formed in a non-true circle. As shown in FIG. 3, the shape of the outer peripheral edge portion 51e of the abutting end face 51a abutting against the disc-shaped portion 532, a pair of linear portions 51c corresponding to the width across flats on the circle of radius R ₁ is formed , opposing distance between the straight line portion 51c in parallel arrangement is 2 × _{R 2.}

  The large-diameter portion 51 connects the ball stud 27 at the other end 512, and connects the steered wheels 26 via the ball stud 27, the tie rod 24, and the knuckle (see FIG. 1). A shaft portion 271 is formed on the other side of the ball stud 27. The other end portion of the shaft portion 271 and the knuckle connecting the steered wheels 26 are connected via a tie rod 24. Accordingly, when the steered shaft 21 moves linearly in the axial direction A, the tie rod 24 is swung around the ball portion 27b attached to the large diameter portion 51 as a rotation center. The steered wheels 26 are steered until the contact end surface 51a is locked to the impact absorbing member 53 mounted on the restricting surface 52b.

  The large-diameter portion housing 52 is formed in a cylindrical shape, passes through the steered shaft 21 so as to be relatively movable in the axial direction A, and is a regulating surface that faces the contact end surface 51a of the large-diameter portion 51 in the axial direction A. 52b. Specifically, the large-diameter portion housing 52 is a part of the housing 22 connected to one end and the other end of each of the first and second housings 22a and 22b, and rolls along the axial direction A. It is formed in a substantially bottomed cylindrical shape that opens to the side where the steering wheel 26 is disposed.

  Inside the large-diameter portion housing 52, a shaft accommodating portion 52e that accommodates the shaft portion 211 of the steered shaft 21 in an inserted state, and opens to the other side along the axial direction A. The shaft portion 211 and the large-diameter portion A large-diameter portion accommodating portion 52a capable of accommodating 51 is formed. The large-diameter portion accommodating portion 52 a is formed so that the inner diameter is maintained substantially constant, and the bottom surface forming the bottom wall forms a regulating surface 52 b that faces the contact end surface 51 a of the large-diameter portion 51. The regulating surface 52b is a surface that physically abuts the linear movement range by bringing the abutting end surface 51a, which is the terminal end of the steered shaft 21, into contact with the shock absorbing member 53 mounted on the regulating surface 52b.

  Further, it is a part of the inner peripheral surface 52c of the large-diameter portion housing, and the bottom corner standing from the restriction surface 52b is radially outward so as to be flush with the restriction surface 52b. An annular groove 52d that is recessed toward the surface is formed. It is a recess for fitting the shock absorbing member 53 to the regulation surface 52b by fitting with the annular projection 536 of the elastic body.

(3. Shock absorbing member)
The shock absorbing member 53 is inserted between the axial direction A between the contact end surface 51 a of the large diameter portion 51 and the regulation surface 52 b of the large diameter portion housing 52 through the shaft portion 211. The impact absorbing member 53 is an elastic body disposed between the impact receiving member 53a including the disc-shaped portion 532 that can contact the contact end surface 51a of the large-diameter portion 51, and the regulating surface 52b and the disc-shaped portion 532. 53b. The shock absorbing member 53 has a substantially circular columnar shape in which the cylindrical portion 531 of the shock receiving member 53a is inserted into the through hole of the elastic body 53b, and the other end surface 533a of the elastic body 53b is bonded to the shock receiving member 53a. And integrated. The shock absorbing member 53 is mounted on the regulating surface 52b of the housing 52 so that the abutted end surface 532a on the other side of the impact receiving member 53a is disposed opposite to the abutting end surface 51a of the large diameter portion 51. The impact absorbing member 53 is a member that absorbs a collision impact during “end contact”.

The impact receiving member 53a is substantially L-shaped in cross-section along the axial direction A, and the L-shaped corner portion has a circular arc concave shape, and the L-shaped corner portion has a right-angle shape. The cylindrical portion 531 forms one side along the L-shaped axial direction A, and the disk-shaped portion 532 forms another side along the radial direction perpendicular to the axial direction A. As shown in FIG. 4, the radius of curvature of the concave arc shape at the L-shaped corner of the impact receiving member 53 a is “r”. The radius of curvature r is formed slightly larger than the length up to the boundary position B ₁ from the inner end position 532e in the radially outer side of the disc-shaped portion 532 to be described later. The impact receiving member 53a is a member that receives an impact force due to contact or collision from the contact end surface 51a of the large-diameter portion 51 in the disk-shaped portion 532, and transmits and attenuates the impact while applying a compressive force to the elastic body 53b. .

  The cylindrical portion 531 is substantially straight along the axial direction A on the inner peripheral surface 531a, is straight at one end portion 531c on the outer peripheral surface 531b, and is directed radially outward at the other end portion. Thus, it is continuously formed in the disk-shaped part 532 with a circular arc concave shape. The inner peripheral surface 531 a of the cylindrical portion 531 forms a through-hole for inserting the shaft portion 211 in a state of being attached to the large-diameter portion housing 52. The outer peripheral surface 531b of the cylinder part 531 is formed in the outer diameter which can loosely insert the inner peripheral surface 534 of the elastic body 53b. The length of the cylindrical portion 531 along the axial direction A is formed corresponding to a displacement X described later of the shock absorbing member 53. The cylindrical part 531 is a part for restricting the deflection at the time of compressive deformation of the inner peripheral surface 534 of the elastic body 53b so as to be along the axial direction A, and the elastic body 53b exceeds the cylindrical part 531 in the radial direction. To prevent it from protruding and deforming.

  The disc-shaped portion 532 has a substantially annular plate shape extending radially outward from the cylindrical portion 531, and is arranged coaxially with the contact end surface 51 a of the large-diameter portion 51 along the axial direction A. The outer diameter of the disk-shaped portion 532 is formed to be slightly smaller than the inner diameter of the inner peripheral surface 52 c of the large-diameter portion housing 52. The disk-shaped portion 532 forms a uniform flat contacted end surface 532 a that allows the other surface (end surface) of the annular plate to contact the contact end surface 51 a of the large-diameter portion 51. The back surface 532b of the abutted end surface 532a includes a radially inner surface formed in a curved surface continuously from the outer peripheral surface 531b of the cylindrical portion, and a radially outer surface formed in a flat shape. , Along the radial direction.

  When the surface on which the impact receiving member 53a contacts the large-diameter portion 51, that is, the contacted end surface 532a of the disk-shaped portion 532, is the front surface, the cylindrical portion 531 is assumed to be straight when viewed from the back side. When the disk-shaped part 532 is formed in a flat plate shape, the disk-shaped part is radially expanded with respect to the cylindrical part, and the diameter of the right-angled corner that becomes the root extending vertically is formed. The direction position is defined as an inner end position 532e of the disk-shaped portion (see FIG. 4). On the back surface 532b of the disk-shaped portion, an arc concave surface portion 532r having a radius of curvature r that is continuous with the radially outer plane is formed in contact with the inner end position 532e extending to one side along the axial direction A. The Therefore, the disk-shaped portion 532 is gradually formed radially outward in the region of the arc-shaped concave surface portion 532r that does not exceed “r” radially outward from the inner end position 532e. It is formed so that the plate thickness of 532 becomes thin.

Next, the elastic body 53b will be described. In the following description of the elastic body, unless otherwise specified, the non-deformed elastic body 53b will be described. The elastic body 53b includes a substantially drum-shaped main body portion 53c formed with a constricted concave portion 535c in the central portion in the axial direction A of the outer peripheral surface 535, and a flange-shaped annular convex portion 536 at one end portion in the axial direction A. Forms an overall shape projecting radially outward. The main body portion 53c of the elastic body 53b has the annular convex portion 536 fitted in the annular concave groove 52d of the housing extending radially outward from the restricting surface 52b, and in the radial direction with respect to the inner peripheral surface 52c of the housing. In the state where the gap S ₁ is interposed, the inner peripheral surface 52 c of the large-diameter portion housing, the regulating surface 52 b, the outer peripheral surface 531 b of the cylindrical portion, and the initial space S ₀ formed by the disc-shaped portion 532 are disposed. .

  The other end surface 533a of the elastic body 53b is bonded over the entire back surface 532b of the disk-shaped part. The other side end surface 533a forms an end surface along a uniformly flat back surface radially outward from the arc concave surface portion 532r and the arc concave surface portion 532r of the back surface 532b. If the other side end surface 533a of the elastic body and the back surface 532b of the disk-shaped part are bonded to each other, a rubber material can be vulcanized and bonded.

The outer peripheral surface 535 of the elastic body 53b is formed so that the outer diameter of the outer peripheral surface 535 along the axial direction A is large at the corner portion 535a on the other side and the corner portion 535b on the one side, and is minimized toward the central portion. The drum is gradually reduced in diameter. A constricted recess 535c is formed at the center in the axial direction A. Between the inner circumferential surface 52c of the housing opposite to the outer peripheral surface 535 and outer circumferential surface 535 of the elastic body, a gap S ₁ is formed.

  Further, the inner peripheral surface 534 of the elastic body 53b is loosely inserted into the cylindrical portion 531 with a slight gap. That is, the inner peripheral surface 534 of the elastic body 53 b is not bonded to the outer peripheral surface 531 b of the cylindrical portion 531. Further, a diameter-enlarged portion 534a that increases in diameter toward the regulating surface 52b is formed at a corner portion of the inner circumferential surface 534 of the elastic body 53b on the side disposed on the regulating surface 52b. The diameter-enlarged portion 534a is formed to be inclined so as to increase in diameter from the position on the disc-like portion 532 side slightly toward the regulating surface 52b than the end portion 531c of the cylindrical portion 531. Thereby, the main-body part 53c at the time of compressive deformation can be prevented from being bitten in the opening part 53d.

The elastic body according to the present invention is not particularly limited as long as it is a member molded to exhibit rubber-like elasticity, but can be molded using a material such as a crosslinked rubber, a thermosetting or thermoplastic synthetic resin elastomer, or the like. . As the crosslinked rubber, hydrogen is added to diene rubbers such as natural rubber, butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber (hereinafter also referred to as NBR), and unsaturated bond portions thereof. As the thermosetting synthetic resin elastomer, olefin rubber such as ethylene-propylene rubber, butyl rubber, acrylic rubber, urethane rubber, silicon rubber, fluorine rubber, etc., as the thermoplastic synthetic resin elastomer, Examples of the elastomer include styrene, olefin, polyester, polyurethane, polyamide, and vinyl chloride.
In the present embodiment, the elastic body 53b used for the impact absorbing member 53 mounted on the large-diameter portion housing 52 of the steering device ST is NBR, chloroprene rubber, butyl rubber, ethylene from the viewpoint of heat resistance, cold resistance, and weather resistance. -From the viewpoint of oil resistance, propylene rubber and the like, NBR having a polar group, chloroprene rubber and the like can be preferably used.

(4. Action explanation)
In the damper device 50 according to the present embodiment, when the large-diameter portion 51 imparts an impact force to the disc-shaped portion 532, the disc-shaped portion 532 is in contact with the inner peripheral side region IN, and An outer peripheral side region OUT that is located radially outward from the inner peripheral side region IN and does not contact the large-diameter portion 51, and the outer peripheral side region OUT has a thickness between the inner peripheral side region IN and the outer peripheral side region OUT. than the thickness of the B _1, it has a feature configured to be thin. With this configuration, when the shock absorbing member 53 receives an impact and compressively deforms, the disk-like portion 532 has an action against an increase in internal pressure due to the elastic body 53b, which will be described below.

  FIG. 3 is a diagram mainly illustrating the radial arrangement of the abutting end surface 51a of the large-diameter portion 51 and the abutted end surface 532a of the disc-like portion 532, and the shock absorbing member 53 is arranged in the Y direction (FIG. 2). FIG. 4 is a cross-sectional view taken along the line XX of FIG. 3, and is a diagram for mainly explaining the thickness according to the radial position of the disk-like portion 532. 3 and 4 are diagrams showing the arrangement and working position of each member, and therefore the illustration of the steered shaft, the housing, and hatching is omitted.

As shown in the drawing, the shape of the outer peripheral edge portion 51e of the abutting end surface 51a of the large diameter portion is a non-true circle having a pair of straight portions 51c having a two-surface width, as indicated by a thick line E. The outer peripheral edge portion 51e is arranged radially inward than the circumscribed circle of radius R _1, and is arranged radially outward of the inscribed circle of the radius R _2.

When the large-diameter portion 51 gives an impact force to the disc-like portion 532, the contact end surface 51a corresponding to the outer peripheral edge 51e along the true circumference and the contacted end surface 532a are in contact with each other. , the boundary of the boundary position B _1, and the inner side area iN of the inner contact with the abutment end face 51a, the outer peripheral side region OUT outside without abutting against the abutment end face 51a is formed. Boundary position _{B 1} represents overlap a portion along the radial direction position _{P 1} of circumscribed circle of radius _{R 1,} circumscribing thick line E (the outer peripheral edge portion 51e).

The portion of the abutting end face 51a corresponding to an outer circumferential portion 51e along the straight portion 51c and the abutted end surface 532a abuts a boundary of the linear boundary position B _2, those on the abutting end face 51a An inner peripheral side region IN that contacts and an outer peripheral side region OUT that does not contact the contact end surface 51a are formed. Boundary position _{B 2} is inscribed in an inscribed circle of a radius _{R 2.} Boundary position B ₂ is divided and the inner peripheral side area IN of the width smaller than the true circle portion, the outer circumferential region OUT of wider width than the true circumference section. As shown in FIG. 3, the entire circumference of the outer peripheral edge portion 51e is formed by continuously forming boundary positions B ₁ → B ₂ → B ₁ → B _{2 and} is radially inward from the radial position P ₁ along the circumscribed circle. a is better, it is arranged in the region of the radially outward than the radial position P ₂ along the inscribed circle. With the bold line E as a boundary, the radially outer side is divided into the outer peripheral side region OUT, and the radial inner side is divided into the inner peripheral side region IN.

An arc concave surface portion 532r having a radius of curvature r is formed on the back surface 532b of the disk-shaped portion. The radius of curvature r is larger than the length from the inner end position 532e of the disk-shaped portion 532 up to the radially outer side of the boundary position B _1. Therefore, starting from the inner end position 532e, further comprising an area for the "r" radially outward by, in the range of the area extending to the outer peripheral side region OUT passing through the boundary position B _1, radially outwardly The thickness of the disk-shaped portion 532 corresponding to the arc-shaped concave surface portion 532r is gradually reduced toward the direction (indicated by a thick arrow along the radial direction as “H” region in FIG. 3). Therefore, the disc-shaped portion 532 thickness T ₀ in the outer peripheral side region OUT radially outward from the boundary position B ₁ is the radius R _{1 of} the entire peripheral boundary positions B ₁ and B ₂ corresponding to the outer peripheral edge portion 51e. Is thinner than the thinnest thickness T _{1 at} the radial position P ₁ of the circumscribed circle. In addition, the thickness of the disc-shaped portion 532 in the region including the entire perimeter of the boundary positions B _{1 to} B ₂ radially inward from the outer peripheral side region OUT is the thickness at the radial position P ₁ along the circumscribed circle. becomes thin, the thickness in the radial direction position P ₂ along the inscribed circle is the thickest. That is, the thickness of the disk-shaped part 532 at the boundary positions B _{1 to} B ₂ is along the circumscribed circle at the boundary position B ₁ than the thickness T _{2 at} the radial position P ₂ along the inscribed circle at the boundary position B ₂ . the thickness T ₁ way of radial position P ₁ has is formed thinly.

When an impact force is applied to the impact receiving member 53a by the large-diameter portion 51, the elastic body 53b is compressed via the impact receiving member 53a, and an internal pressure Q by the compressed elastic body 53b (see FIG. 4), The disk-like portion 532 acts on a region from the inner end position 532e toward the outer peripheral surface 532d toward the outer side in the radial direction (region with shaded dots in FIG. 3). Further, the outer peripheral side region OUT (region indicated by dark dots in FIG. 3) outside the boundary positions B _{1 to} B ₂ corresponding to the outer peripheral edge portion 51 e of the large-diameter portion 51 hinders the bending of the disk-shaped portion 532. It does not contact (contact) the contact end surface 51a. Therefore, in the outer peripheral side region OUT, the internal pressure Q of the elastic body 53b acts like a cantilever, and the disk-like portion is opposite to the compression direction of the elastic body 53b with the boundary positions B ₁ and B ₂ as support points. A bending moment M that bends 532 acts. The bending moment M increases in proportion to the length along the radial direction from the outer peripheral surface 532d of the disc-shaped portion which is the free end to the predetermined position, and the boundary positions B ₁ and B ₂ (outside It becomes the maximum at the thick line E) corresponding to the peripheral part 51e. Furthermore, it acts most greatly at the radial position P ₂ along the boundary position B ₂ corresponding to the straight line portion 51 c of the large-diameter portion 51 and in contact with the inscribed circle among the boundary positions B ₁ and B ₂ .

As described above, the thickness T ₂ of the disc-shaped portion 532 corresponding to the radial position P ₂ of the inscribed circle is the thickest in the region including the entire circumference of the boundary positions B ₁ and B ₂ , and the cross section The coefficient is large and the bending strength is increased. Further, the thickness of the disk-shaped portion 532 is gradually reduced from the inner end position 532e along the arc concave surface portion 532r and does not change suddenly along the radial direction, so stress due to the bending moment M during this time is concentrated. Hindering the action.

  In the present embodiment, an example in which the arc-shaped concave surface portion 532r is formed on the back surface 532b of the disk-shaped portion 532 is shown, but the present invention is not limited to the shape of the arc-shaped concave surface. The thickness of the disk-shaped portion gradually decreases as it goes radially outward in the range from the radially inner end of the disk-shaped portion to the radial position exceeding the boundary position between the inner peripheral region and the outer peripheral region. If formed in this way, it is not limited to an arc. Moreover, although the example in which the large diameter portion is a non-perfect circle having a two-sided width for engaging the tool has been described, it is not limited to the two-sided width. For example, there is a hexagonal shape as long as it is a shape for engaging a tool. Further, the impact receiving member may have a configuration not having a cylindrical portion, and the same effect is obtained.

In addition, the damper device 50 according to the present embodiment can regulate the relative movement of the impact receiving member 53a with respect to the housing 52 by the volume of the elastic body 53b that has been compressed by a predetermined length due to the collision of the large-diameter portion 51 and has increased rigidity. A shock absorbing member 53 is used. Compressed to fill status in the compression space S _X which is formed by the impact receiving member 53a and the large-diameter portion housing 52, the rubber-like elastic properties of the elastic body 53b interposed, prevent the both metal collide with each other, An impact absorbing member 53 that obtains an impact transmission suppressing effect is used. This will be briefly described below.

For example, in the undeformed state where the shock absorbing member 53 is disposed in the large diameter portion housing 52 as shown in the upper part of FIG. 5, the main body portion 53 c of the elastic body 53 b is the inner peripheral surface of the large diameter portion housing 52. 52 c, the regulating surface 52 b of the housing 52, the outer peripheral surface 531 b of the cylindrical portion 531, and the initial space S ₀ formed by the disc-shaped portion 532. Further, in this state, the elastic body 53b, the cylindrical portion 531 and the inner peripheral surface 52c of the housing are arranged concentrically with respect to the central axis C of the steered shaft 21, respectively. Further, the restricting surface 52b of the housing and the disc-like portion 532 are arranged in parallel along the direction perpendicular to the central axis C of the steered shaft 21, respectively. Further, in an undeformed state before receiving the impact force, the gap D between the end surface of the end portion 531c of the cylindrical portion 531 and the regulating surface 52b is larger than the compression allowance (compression displacement) X along the axial direction A. The opening 53d is formed.

If the large diameter portion 51 does not impart an impact force to the disc-shaped portion 532, the body portion 53c of the elastic body 53b is arranged via a gap S ₁ between the inner circumferential surface 52c of the housing. The main body unit 53c, if the end portion 531c of the cylindrical portion 531 between the outer circumferential surface of the imaginary cylindrical portion at the time of the extending so as to abut against the regulating surface 52 b, are disposed with a gap S ₂ The Elastic body 53b has a volume of its own body portion 53c, is disposed within the initial spatial S ₀ is the sum of the volume of the rotating body clearance S _1, S ₂ is obtained by a central axis C and the rotation axis.

When the large-diameter portion 51 imparts an impact force to the disc-like portion 532, the main body portion 53c is pressed in the axial direction A by the restricting surface 52b and the disc-like portion 532, whereby the gaps S ₁ and S It compresses and deforms so as to fill the space occupied by ₂ . As shown in the lower part of FIG. 5, finally, the main body portion 53c includes the inner peripheral surface 52c of the large-diameter portion housing 52, the housing regulating surface 52b, the outer peripheral surface 531b of the cylindrical portion, and X in the axial direction A. It is compressed and deformed so as to be in contact with all of the disc-shaped portion 532 after being displaced. At this time, the opening 53d is closed. That is, the main body portion 53c after the compression deformation is disposed in a full state in the compression space S _X after the compression deformation displaced by X in the axial direction A. The volume of the main body 53c after compression deformation has the characteristics of an incompressible fluid because the elastic body 53b has rubber-like elasticity, and is equal to the volume of the main body 53c.

The main body 53c that fills the compression space S _X has no residual space for compressive deformation and is saturated. Further, formed at the large-diameter portion housing 52 and impact receiving member 53a, and inscribed in close contact to the compression space S _X is not essentially free of external and communicating with the gap, for compressive deformation It does not have a place to escape to the compression space S _X outside. Further, by compressing only the predetermined displacement X, it is possible to suppress the rubber-like elasticity and to compress in a cured state with increased rigidity. Elastic body 53b is in the compression space S _X, continues interposed between the regulating surface 52b and the disk-shaped portion 532 filled state, axial shock absorbing member 53 which receives the impact force is more than the displacement X Displacement to A is prevented. The shock receiving member 53a of the shock absorbing member 53 maintains a non-contact arrangement in which the end portion 531c does not collide with the restriction surface 52b, and the relative movement with respect to the large diameter portion housing 52 is restricted. It is possible to avoid collision between the two metals.

As described above, in a state where the elastic body that has been compressed by the predetermined displacement X and has increased rigidity is disposed in the compression space S _X in a full state, the internal pressure Q exerted on the disk-like portion 532 by the elastic body is further increased. Tend to be. The necessity to increase the bending strength of the outer peripheral side region OUT of the disk-shaped part 532 is increased. Therefore, it is preferable to take measures against the bending strength of the disk-shaped portion 532 by the damper device 50 according to the present embodiment.

(5. Effects of the embodiment)
According to the above embodiment, the impact absorbing member 53 includes the impact receiving member 53a including the disc-shaped portion 532 that can contact the contact end surface 51a of the large-diameter portion 51, and the regulation surface 52b and the disc-shaped portion 532. And an elastic body 53b formed of a rubber material or a synthetic resin material having rubber-like elasticity. The disk-shaped portion 532 has a large-diameter portion 51 that imparts an impact force to the disk-shaped portion 532. An outer peripheral side region IN that is in contact with the large diameter portion 51 and an outer peripheral side region OUT that is located radially outward from the inner peripheral side region IN and does not contact the large diameter portion 51. Is formed thinner than the thicknesses of the boundary positions B ₁ and B ₂ between the inner peripheral region IN and the outer peripheral region OUT.

Therefore, when the large-diameter portion 51 imparts an impact force to the disk-shaped portion 532, the outer diameter of the large-diameter portion 51 is increased by the internal pressure Q of the elastic body 53b compressed in the outer peripheral side region OUT that does not contact the large-diameter portion 51. When a bending moment M at which the disk-like portion 532 bends acts with the boundary positions B ₁ and B ₂ (indicated by the thick line E in FIG. 3) corresponding to the peripheral edge portion 51e acting as a support point, the section modulus along this support point Can be increased. The bending strength can be efficiently increased according to the part where the bending strength countermeasure is required.

Further, according to the embodiment, the large-diameter portion 51 and the disk-shaped portion 532 are arranged coaxially in the axial direction A, and the outer peripheral edge portion of the large-diameter portion 51 that contacts the disk-shaped portion 532. Is formed in a non-circular shape, and the boundary positions B ₁ and B ₂ between the inner peripheral side area IN and the outer peripheral side area OUT of the disc-shaped part 532 are the shapes of the outer peripheral edge part 51e of the large diameter part 51. None of the non-round in correspondence with the thickness of the boundary position B _1, B _2, rather than the radial position P ₂ of the inscribed circle at the boundary position B _2, the radial position P of the circumscribed circle of the boundary position B _{1 1} is formed thinner. Therefore, when the disc-like portion 532 is not a perfect circle, the section modulus can be increased in accordance with the accuracy with respect to the portion where the bending moment M due to the elastic body 53b having the internal pressure Q is large. Therefore, it is possible to take an appropriate measure against bending strength.

According to the above embodiment, the thickness of the disc-shaped portion 532, from the inner end position 532e in the radial direction of the disk-shaped portion 532, in a range exceeding the boundary position B _1, B ₂ and the outer peripheral side region OUT It is formed so as to become thinner gradually as it goes outward in the radial direction. Therefore, since the thickness of the disk-shaped part 532 is gradually different and does not change suddenly, it is possible to avoid stress from being concentratedly applied to the sudden change portion due to the sudden change.

In addition, according to the above-described embodiment, the impact receiving member 53a has the cylindrical portion 531 facing the inner peripheral surface 52c of the housing, and a circle extending radially outward from the cylindrical portion 531 and facing the regulating surface 52b. and a tabular portion 532, the elastic body 53b is disposed in the initial spatial _{S 0} which is formed inner peripheral surface 52c of the housing, the regulating surface 52 b, the outer peripheral surface 531b and the disc-shaped portion 532 of the cylindrical portion, When the large-diameter portion 51 does not apply an impact force to the disk-like portion 532, the elastic body 53b is disposed between the inner peripheral surface 52c of the housing and the outer peripheral surface 531b of the cylindrical portion via the gaps S ₁ and S _2. When the large-diameter portion 51 imparts an impact force to the disc-like portion 532, the elastic body 53b has a restriction surface 52b, a disc-like portion 532, and a housing so as to fill the gaps S ₁ and S ₂ . It contacts all of the inner peripheral surface 52c and the outer peripheral surface 531b of the cylindrical portion. The impact receiving member 53a is compressed and deformed in the touched state, and the relative movement with respect to the large-diameter portion housing 52 is restricted by the deformed elastic body 53b while maintaining a non-contact state with respect to the restriction surface 52b. Therefore, the elastic body 53b are arranged in the compression space S _X in charging status, even if the increased internal pressure Q Gayori on disc-shaped portion 532, effectively, the bending of the disc-shaped portion 532 Strength can be increased.

  Further, according to the above embodiment, the steering device ST includes the damper device 50 according to any of the above embodiments, and both end portions thereof are connected to the steered wheels 26 via the tie rods 24 and reciprocate in the axial direction A. A steered shaft 21 that moves and steers the steered wheels 26, and includes a steered shaft 21 that includes a large-diameter portion 51 that is swingably coupled to the tie rod 24, and a large-diameter portion that houses the steered shaft 21 A housing 52 and an impact absorbing member 53 are provided. Therefore, the steering device ST having the effect of the above-described damper device can be obtained.

ST ... steering system, S 0 _... initial spatial, S x _... compression space, _{S 1,} S 2 _... gap, IN ... inner circumferential side area, OUT ... outer circumferential region, _{B 1,} B 2 _... boundary position, 21 ... rolling Rudder shaft (shaft), 50 ... damper device, 51 ... large diameter portion, 51a ... abutting end surface, 51e ... outer peripheral edge portion, 52 ... large diameter portion housing (housing), 52b ... regulating surface, 52c ... (housing of the housing) ) Inner peripheral surface, 53... Shock absorbing member, 53 a. Shock receiving member, 532. Disc-shaped portion, 532 e .. inner end position (radial inner end), 53 b.

Claims (5)

A shaft having a shaft portion and a large diameter portion;
A housing that is formed in a cylindrical shape, passes through the shaft so as to be relatively movable in the axial direction, and includes a regulating surface that faces the end surface of the large-diameter portion in the axial direction;
An impact absorbing member inserted through the shaft portion and interposed between the end surface of the large diameter portion and the regulating surface;
A damper device comprising:
The shock absorbing member is
An impact receiving member comprising a disk-shaped portion that can contact the end face of the large-diameter portion;
An elastic body that is disposed between the regulating surface and the disc-shaped portion, and is molded of a rubber material or a synthetic resin material having rubber-like elasticity;
With
The disk-shaped part is positioned radially outward from the inner peripheral side area and an inner peripheral side area that comes into contact with the large diameter part when the large-diameter part imparts an impact force to the disk-shaped part. And an outer peripheral side region that does not contact the large diameter portion,
The thickness of the said outer peripheral side area | region is a damper apparatus formed thinner than the thickness of the boundary position of the said inner peripheral side area | region and the said outer peripheral side area | region. The large diameter portion and the disc-shaped portion are arranged coaxially in the axial direction,
The shape of the outer peripheral edge of the large-diameter portion that contacts the disk-shaped portion is formed in a non-true circle,
The boundary position between the inner peripheral side region and the outer peripheral side region of the disk-shaped part is a non-circular shape corresponding to the shape of the outer peripheral edge of the large diameter part,
2. The damper device according to claim 1, wherein a thickness of the boundary position is formed so that a radial position of a circumscribed circle at the boundary position is thinner than a radial position of the inscribed circle at the boundary position.   The thickness of the disk-shaped portion is such that it goes radially outward in the range from the radially inner end of the disk-shaped portion to the radial position exceeding the boundary position between the inner peripheral region and the outer peripheral region. The damper device according to claim 1, wherein the damper device is formed so as to be gradually thinner. The impact receiving member has a cylindrical portion facing the inner peripheral surface of the housing, and the disk-shaped portion extending radially outward from the cylindrical portion and facing the regulating surface,
The elastic body is disposed in a space formed by the inner peripheral surface of the housing, the regulating surface, the outer peripheral surface of the cylindrical portion, and the disk-shaped portion,
When the large diameter portion does not give an impact force to the disk-shaped portion,
The elastic body is disposed through a gap between at least one of the inner peripheral surface of the housing and the outer peripheral surface of the cylindrical portion,
When the large diameter portion gives an impact force to the disk-shaped portion,
The elastic body is compressed and deformed so as to be in contact with all of the regulating surface, the disc-shaped portion, the inner peripheral surface of the housing and the outer peripheral surface of the cylindrical portion so as to fill the gap.
The damper according to any one of claims 1 to 3, wherein the impact receiving member is restricted in relative movement with respect to the housing by the deformed elastic body while maintaining a non-contact state with respect to the restriction surface. apparatus. A steering device comprising the damper device according to any one of claims 1 to 4,
Both ends are coupled to the steered wheels via tie rods, and are steered shafts that reciprocate in the axial direction to steer the steered wheels, and include the large-diameter portion that is pivotably coupled to the tie rods. The shaft;
The housing that houses the steered shaft;
The shock absorbing member;
A steering apparatus comprising:

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