CN111810573B - Buffer device - Google Patents
Buffer device Download PDFInfo
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- CN111810573B CN111810573B CN202010080083.5A CN202010080083A CN111810573B CN 111810573 B CN111810573 B CN 111810573B CN 202010080083 A CN202010080083 A CN 202010080083A CN 111810573 B CN111810573 B CN 111810573B
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- Prior art keywords
- wall portion
- soft
- hard
- wall
- cylindrical
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F13/00—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs
- F16F13/04—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a plastics spring and a damper, e.g. a friction damper
- F16F13/06—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a plastics spring and a damper, e.g. a friction damper the damper being a fluid damper, e.g. the plastics spring not forming a part of the wall of the fluid chamber of the damper
- F16F13/08—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a plastics spring and a damper, e.g. a friction damper the damper being a fluid damper, e.g. the plastics spring not forming a part of the wall of the fluid chamber of the damper the plastics spring forming at least a part of the wall of the fluid chamber of the damper
- F16F13/085—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a plastics spring and a damper, e.g. a friction damper the damper being a fluid damper, e.g. the plastics spring not forming a part of the wall of the fluid chamber of the damper the plastics spring forming at least a part of the wall of the fluid chamber of the damper characterised by features of plastics springs; Attachment arrangements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60G—VEHICLE SUSPENSION ARRANGEMENTS
- B60G15/00—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type
- B60G15/02—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring
- B60G15/06—Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type having mechanical spring and fluid damper
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/14—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect
- F16F9/16—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts
- F16F9/18—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts with a closed cylinder and a piston separating two or more working spaces therein
Abstract
The present invention provides a buffer device, which comprises: a holding member having a cylindrical wall portion and a bottom portion that closes one end in an axial direction of the wall portion; a hard portion made of an elastomer, located radially inward of the wall portion, and held by the holding member in a state of contacting the bottom portion; and a soft portion made of an elastic material and having a first end and a second end in an axial direction, the first end being held by the hard portion, and the soft portion being softer than the hard portion, wherein the hard portion includes: a base end portion sandwiched between the bottom portion and the first end; and a cylindrical portion extending from the base end portion to the second end side and disposed between the wall portion and an outer peripheral surface of a portion of the soft portion on the first end side, the outer peripheral surface of the cylindrical portion including: a first surface facing the inner peripheral surface of the wall portion with a gap provided therebetween in a state where the soft portion and the hard portion are not compressed in the axial direction; and a second face located closer to the second end side than the first face and contacting the inner peripheral face of the wall portion.
Description
Technical Field
The present invention relates to a shock absorber, and more particularly to a shock absorber that can prevent abnormal noise from being generated when a soft portion and a hard portion expand and contract.
Background
There is known a damper device including: a cup-shaped holding member; a hard portion made of an elastic material and held inside the holding member; the soft portion is made of an elastic material, one end side of the outer peripheral surface of the soft portion is held by the tube portion of the hard portion, and the soft portion protrudes from the hard portion and is softer than the hard portion. According to this shock absorber, when the compression amount of the soft portion is small, the soft spring characteristic due to the compression deformation of the soft portion can be exhibited, and when the compression amount of the soft portion is large, the hard spring characteristic due to the compression deformation of the soft portion and the hard portion can be exhibited
In addition, in the shock absorber, the cylindrical wall portion of the holding member is positioned radially outward of the cylindrical portion, so that when the amount of compression of the soft portion and the hard portion is large, the soft portion and the cylindrical portion can be prevented from excessively expanding radially outward and the hard spring characteristic can be reliably exhibited. In the technique disclosed in patent document 1, a gap is provided between the cylindrical portion and the wall portion over substantially the entire length in the axial direction.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2001-173709
Disclosure of Invention
Technical problem to be solved
However, the technique of patent document 1 has a problem that, after the tube portion that expands radially outward is brought into close contact with the wall portion as the soft portion and the hard portion expand and contract, if the tube portion and the wall portion are separated at once, abnormal noise is generated due to the impact of air entering the portion that has been brought into close contact with each other by a rush.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a shock absorber which can prevent abnormal noise from being generated when a soft portion and a hard portion expand and contract.
(II) technical scheme
In order to achieve the above object, a shock absorber according to the present invention includes: a holding member having a cylindrical wall portion and a bottom portion that closes one end in an axial direction of the wall portion; a hard portion made of an elastomer, located radially inward of the wall portion, and held by the holding member in a state of contacting the bottom portion; and a soft portion made of an elastomer and having a first end and a second end in the axial direction, the first end being held by the hard portion, and the soft portion being softer than the hard portion, wherein the hard portion includes: a base end portion sandwiched between the bottom portion and the first end; and a cylindrical portion extending from the base end portion to the second end side and disposed between an outer peripheral surface of a part of the first end side of the soft portion and the wall portion, the outer peripheral surface of the cylindrical portion including: a first surface facing the inner peripheral surface of the wall portion with a gap provided therebetween in a state where the soft portion and the hard portion are not compressed in the axial direction; and a second face located closer to the second end side than the first face and contacting an inner peripheral surface of the wall portion.
(III) advantageous effects
According to the shock absorber of the first aspect, since the gap is provided between the first surface of the outer peripheral surface of the tube portion and the inner peripheral surface of the wall portion in the state where the soft portion and the hard portion are not compressed, the tube portion can be expanded toward the wall portion when the soft portion and the hard portion are compressed in the axial direction. This makes it possible to alleviate the load rise of the load-deflection curve during compression deformation of the soft portion and the hard portion, thereby ensuring the cushioning performance of the cushioning device
Further, after the cylindrical portion of the hard portion compressed in the axial direction expands outward in the radial direction and the outer peripheral surface of the cylindrical portion comes into close contact with the inner peripheral surface of the wall portion, when the compression is released, the first surface having the gap before the compression and the wall portion are separated at once, and air enters vigorously to generate abnormal noise. When the compression is released, the wall portion vibrates with the end portion on the second end side of the wall portion as a free end, thereby generating abnormal noise. However, since the second surface located closer to the second end side than the first surface can be brought into contact with the wall portion to reduce the volume of the gap, the amount of air entering the gap can be reduced and abnormal noise is less likely to be generated. Further, since the second surface and the wall portion can be brought into contact with each other to suppress vibration of the wall portion, abnormal noise generated by the vibration of the wall portion can be suppressed. As a result, abnormal noise can be prevented from being generated when the soft portion and the hard portion expand and contract.
According to the damper device of the second aspect, in addition to the effects of the damper device of the first aspect, the following effects can be obtained. The protruding portion protrudes radially inward from the inner peripheral surface of the cylindrical portion, and the fitting portion of the soft portion is fitted to a portion of the cylindrical portion closer to the base end portion side than the protruding portion, so that the soft portion is held by the hard portion. At least a part of the second surface that contacts the wall portion is located in a region in which the protruding portion is projected outward in the radial direction, and therefore the protruding portion can be prevented from being excessively expanded outward in the radial direction. This makes it possible to prevent the fitting portion from falling off from the protruding portion, and to easily maintain the soft portion in the hard portion.
According to the damper device of the third aspect, in addition to the effects of the damper device of the first aspect, the following effects can be obtained. The end portion on the second end side of the wall portion is a bent portion that is bent radially outward from a portion of the wall portion that contacts the second surface. Since the tube portion extends to the second end side of the curved portion, the soft portion expanding radially outward due to compression deformation can be prevented from abutting against the wall portion by the tube portion, and the tube portion expanding radially outward can be prevented from sinking into the end portion on the second end side of the wall portion by the curved portion, thereby reducing the durability of the tube portion.
Further, when the soft portion and the hard portion are compressed and deformed, the curved portion that is curved outward in the radial direction is less likely to be firmly adhered to the cylindrical portion in the radial direction, and therefore, it is possible to suppress generation of abnormal noise due to separation after the cylindrical portion comes into contact with the wall portion (curved portion) closer to the second end side than the second surface. This makes it possible to ensure the durability of the soft portion and the hard portion and to prevent abnormal noise from being generated when the soft portion and the hard portion expand and contract.
According to the buffer device of the fourth aspect, in addition to the effects of the buffer device of the first aspect, the following effects can be obtained. The second surface that contacts the inner peripheral surface of the wall portion is provided on the entire periphery of the cylindrical portion. Thus, the cylindrical portion, which tends to expand radially outward when the soft portion and the hard portion are compressed in the axial direction, can compress air in the gap between the first surface and the wall portion, the second surface of which is closer to the bottom side. Further, when the compression of the soft portion and the hard portion is released, the air compressed between the first surface and the wall portion expands again, so that the amount of air entering the gap between the first surface and the wall portion can be further reduced, and abnormal noise caused by the entry of the air can be made less likely to occur. As a result, abnormal noise can be made less likely to occur when the soft portion and the hard portion expand and contract.
According to the buffer device of the fifth aspect, in addition to the effects by the buffer device of the first aspect, the following effects can be obtained. The wall portion is separated from the cylindrical portion from a portion in contact with the second surface to a distal end of the wall portion in the axial direction on the second end side. The axial length from the portion of the wall portion in contact with the second surface to the distal end on the second end side is shorter than the axial length of the second surface. This can reduce the volume of the gap between the tube portion and the wall portion on the second end side of the second surface, and can reduce the occurrence of abnormal noise caused by air entering the gap.
According to the shock absorber of the sixth aspect, in addition to the effects of the shock absorber of the first aspect, the following effects can be obtained. The axial tip of the second end of the wall portion is located in a region where the protruding portion is projected outward in the radial direction. Thus, the wall portion can prevent the projection from being excessively expanded outward in the radial direction, and the fitting portion can be made less likely to fall off from the projection, so that the soft portion can be easily maintained in the state of being held by the hard portion.
According to the buffer device of the seventh aspect, in addition to the effects brought by the buffer device of any one of the first to sixth aspects, the following effects can be obtained. The wall portion includes a convex portion that protrudes radially inward from the inner peripheral surface. Since the convex portion pre-compresses the second surface in the radial direction, the second surface can be suppressed from being separated from the convex portion by the force when the axial compression of the buffer member is released and the expansion in the radial direction is restored. As a result, the hitting sound can be made less likely to occur when the second surface and the convex portion are separated and then brought into contact again.
Drawings
Fig. 1 is a sectional view of a shock absorber according to a first embodiment.
Fig. 2 is a partially enlarged cross-sectional view of the shock absorber shown in fig. 1 in which a portion indicated by II is enlarged.
Fig. 3 is a partially enlarged sectional view of a shock absorber according to a second embodiment.
Fig. 4 is a partially enlarged sectional view of a shock absorber according to a third embodiment.
Description of the reference numerals
20. 40, 50-buffer means; 21. 41, 51-a holding member; 22-bottom; 23. 42, 52-wall portion; 23 b-a bend; 23 c-front end; 31-a soft portion; 31 a-first end; 31 b-a second end; 32-a fitting portion; 35. 45-a hard portion; 36-base end portion; 37. 46-a barrel portion; 37 a-a first face; 37b, 47-second face; 38-a protrusion; 43-convex part.
Detailed Description
The preferred embodiments are described below with reference to the accompanying drawings. A shock absorber 20, a mounting device 10 for mounting the shock absorber 20, and a shock absorber 1 according to a first embodiment will be described with reference to fig. 1 and 2. In fig. 1, a cross section of a central axis C of a piston rod 4 comprising a shock absorber 1 is shown.
As shown in fig. 1, the damper 1 is a part of a suspension that is mainly used for connecting a wheel (not shown) and a vehicle body (not shown) and that damps vibration from the wheel to the vehicle body. The damper 1 damps vibration of a coil spring (not shown) that supports a vehicle body and absorbs impact from a wheel. The damper 1 mainly includes a cylinder 2 mounted on a wheel side and a piston rod 4 protruding from an axial end surface 3 of the cylinder 2. In the shock absorber 1, the amount of protrusion of the piston rod 4 from the cylinder 2 changes and expands and contracts in accordance with the input of a load from the wheel, thereby damping vibration.
The piston rod 4 is fixed to the vehicle body via a mounting device 10. The mounting device 10 includes: a cylinder portion 11 into which the tip end of the piston rod 4 is inserted and fastened, a circular plate portion 12 extending radially outward from the cylinder portion 11, an elastic portion 13 formed of an elastic body such as rubber or a thermoplastic elastomer and surrounding the circumference of the circular plate portion 12, and a first jig 14 and a second jig 15 that sandwich the elastic portion 13 from both sides in the axial direction of the center axis C.
The first jig 14 and the second jig 15 are metal members fixed to the vehicle body side. The first jig 14 is a plate material located on the opposite side of the cylinder 2 from the elastic portion 13. The second jig 15 has a cylindrical body surrounding the outer peripheral surface of the elastic portion 13, and a plate portion closing one end of the cylindrical body and contacting the cylinder 2 side of the elastic portion 13. A through hole 15a through which the piston rod 4 passes is provided in the center of the plate portion of the second jig 15.
The damper device 20 includes a holding member 21 attached to the second jig 15 of the mounting device 10, and a damper member 30 formed of an elastic body held by the holding member 21. When the shock absorber 1 contracts, the shock absorber 20 absorbs the shock transmitted from the cylinder 2 (wheel side) to the mounting device 10 (vehicle body side) by compressing the shock absorbing member 30 between the axial end surface 3 of the cylinder 2 and the mounting device 10. The damper 20 is formed to be axisymmetrical with respect to the center axis C. Therefore, in the present embodiment, the axial direction of the central axis C and the direction perpendicular to the axial direction are described as the axial direction and the radial direction of each part of the damper device 20, respectively.
The holding member 21 is a metal member having higher rigidity (higher young's modulus) than the cushioning member 30 (hard portion 35), and is formed in a cup shape. The holding member 21 includes a bottom portion 22 attached to overlap with the cylinder 2 side of the plate portion of the second jig 15, and a cylindrical wall portion 23 extending from an outer peripheral edge of the bottom portion 22 toward the cylinder 2 side (a second end 31b side described later).
The bottom portion 22 is a substantially annular plate-like member that closes one axial end of the cylindrical wall portion 23, and the piston rod 4 penetrates the center thereof. The bottom portion 22 is formed substantially perpendicular to the central axis C. The bottom portion 22 is attached to the second jig 15 by inserting a cylindrical body extending from the inner peripheral edge toward the first jig 14 into the through hole 15a and bending the distal end of the cylindrical body radially outward.
The wall portion 23 includes a press-fitting portion 23a formed by bending a part of the inner peripheral surface radially inward, and a bent portion 23b which is an end portion close to the cylinder 2 side and is bent radially outward. The wall portion 23 is formed in a substantially conical tube shape in which the distance from the center axis C gradually increases as the distance from the bottom portion 22 increases, except for the press-fitted portion 23a and the bent portion 23b, and the inner circumferential surface and the outer circumferential surface are formed in a substantially linear shape in a cross section including the center axis C.
The press-fitting portion 23a is an annular portion provided substantially over the entire circumference of the wall portion 23. The buffer member 30 is held by the holding member 21 by pressing the buffer member 30 into the press-fitting portion 23 a. The bent portion 23b is a portion for making the cushioning member 30 less susceptible to breakage when the cushioning member 30 is pressed against the end portion of the wall portion 23 on the cylinder 2 side.
The shock absorbing member 30 is a cylindrical elastic body that surrounds the outer periphery of the piston rod 4, and is compressed in the axial direction thereof to absorb shock. The cushion member 30 includes a soft portion 31 made of a soft foam such as a soft urethane foam, and a hard portion 35 made of a rubber interposed between the soft portion 31 and the holding member 21. That is, the soft portion 31 is formed of an elastomer softer than the hard portion 35. The hardness of the soft portion 31 and the hardness of the hard portion 35 are set in accordance with JIS K6253-3: 2012 as standard, measurement was performed using a type a durometer. However, when both the hardness of the soft portion 31 and the hardness of the hard portion 35 measured using the type a durometer show less than 20, the hardness of the soft portion 31 and the hardness of the hard portion 35 are compared using the type E durometer.
The soft portion 31 is a substantially cylindrical portion having a first end 31a and a second end 31b in the axial direction, and the second end 31b faces the axial end surface 3 of the cylinder 2. The soft portion 31 includes a fitting portion 32 at a portion on the first end 31a side. The fitting portion 32 is a portion extending from the outer peripheral surface from the second end 31b side to the first end 31a side in a step shape to the first end 31 a.
The inner peripheral surface of the soft portion 31 is provided with a plurality of dimples continuous over the entire circumference. Further, a plurality of dimples continuous over the entire circumference are provided between the plurality of dimples on the inner circumferential surface of the outer circumferential surface of the soft portion 31. These dimples allow the soft portion 31 to be compressed and deformed so as to be folded in the axial direction.
Further, a groove continuous over the entire circumference is formed on the outer circumferential surface of the soft portion 31 closer to the second end 31b than the plurality of recesses. A ring member 33 made of a material (e.g., synthetic resin) harder than the soft portion 31 and the hard portion 35 is fitted into the groove. When the soft portion 31 is compressed and deformed in the axial direction, the ring member 33 restricts the soft portion 31 in the radial direction so that the second end 31b side of the soft portion 31 does not expand outward in the radial direction.
The hard portion 35 is a cup-shaped portion fitted into and attached to the inside of the cup-shaped holding member 21. The hard portion 35 includes a base end portion 36 axially sandwiched between the bottom portion 22 and the first end 31a of the soft portion 31, and a cylindrical portion 37 extending from the base end portion 36 toward the second end 31 b.
The base end 36 is an annular thick plate through which the piston rod 4 penetrates. The base end portion 36 is press-fitted into the pressed portion 23a, and the base end portion 36 is brought into contact with the bottom portion 22, whereby the hard portion 35 is held by the holding member 21. Further, a gap is provided between the outer peripheral surface of the base end portion 36 and the inner peripheral surface of the wall portion 23 on both sides in the axial direction of the press-fitting portion 23 a.
Since the radial dimension of the base end portion 36 is larger than the radial dimension of the cylindrical portion 37, the elastic force when the base end portion 36 is pushed in the radial direction is larger than the elastic force when the cylindrical portion 37 is compressed in the radial direction. Therefore, the hard portion 35 can be made less likely to be detached from the holding member 21 by press-fitting the base end portion 36 into the press-fitting portion 23a, as compared with the case where the cylindrical portion 37 is press-fitted into the press-fitting portion 23 a.
The cylindrical portion 37 is a cylindrical portion extending from the outer peripheral side of the base end portion 36 toward the second end 31 b. The tube portion 37 is disposed between the outer peripheral surface of the soft portion 31 and the inner peripheral surface of the wall portion 23, in close contact with a part of the outer peripheral surface of the soft portion 31 on the first end 31a side. A projecting portion 38 projecting radially inward is provided on the inner peripheral surface of the cylindrical portion 37. The soft portion 31 is inserted into the tube portion 37 from the first end 31a, and the fitting portion 32 of the soft portion 31 is fitted into a portion of the tube portion 37 closer to the base end portion 36 than the protruding portion 38, whereby the soft portion 31 is held by the hard portion 35.
The cylindrical portion 37 extends to the second end 31b side than the bent portion 23b of the wall portion 23. A cylindrical dust cover 39 extending to the outer periphery of the cylinder 2 is integrally formed at the front end of the tube portion 37 on the second end 31b side. The dust cover 39 is a member that prevents dust from entering the shock absorber 1.
The outer peripheral surface of the cylindrical portion 37 includes: a first surface 37a facing the wall portion 23 with a gap S therebetween in an uncompressed state (hereinafter referred to as an uncompressed state) of the cushioning member 30 (the soft portion 31 and the hard portion 35); a second surface 37b connected to the second end 31b side of the first surface 37a and contacting the inner peripheral surface of the wall portion 23; and a third surface 37c located closer to the second end 31b side than the second surface 37b and projecting radially outward.
In a cross section including the central axis C, the first surface 37a is formed substantially parallel to the inner peripheral surface of the wall portion 23 and is connected to the outer peripheral surface of the base end portion 36. A small part of the first surface 37a is also provided on the second end 31b side and radially inside the bent portion 23b than the second surface 37 b. The second surface 37b is provided over the entire circumference of the cylindrical portion 37, and contacts the wall portion 23 by extending radially outward from the first surface 37a by the gap S.
The third surface 37c is connected to the second end 31b side of the first surface 37a radially opposed to the bent portion 23b, and is axially opposed to the bent portion 23 b. When the hard portion 35 is greatly compressed in the axial direction, the third surface 37c abuts against the curved portion 23b, so that the compression deformation of the hard portion 35 can be restricted.
According to the above-described shock absorber 20, when the shock absorber 1 contracts and the shock absorbing member 30 is compressed in the axial direction between the bottom portion 22 and the cylinder 2, the soft portion 31 is softer than the hard portion 35, and therefore, the soft portion is compressed in the axial direction first, and after the soft portion 31 is compressed by a predetermined amount, the hard portion 35 is compressed. Further, the soft portion 31 compressed in the axial direction can be restricted from expanding outward in the radial direction by the cylindrical portion 37, and the cylindrical portion 37 can be restricted from expanding outward in the radial direction by the wall portion 23. As a result, when the compression amount of the cushion member 30 is small, the soft spring characteristic by the compression deformation of the soft portion 31 can be exhibited, and when the compression amount of the cushion member 30 is large, the hard spring characteristic by the compression deformation of the soft portion 31 and the hard portion 35 can be exhibited. Therefore, since the shock of the shock absorbing member 30 at the time of compression deformation can be reduced and the contraction of the shock absorber 1 can be reliably restricted by the shock absorbing member 30, the riding comfort of the vehicle can be improved and the steering stability can be ensured.
Further, since the gap S is provided between the first surface 37a of the tube 37 and the wall 23 in the non-compressed state, the first surface 37a of the tube 37 can be expanded toward the wall 23 when the cushioning member 30 is compressed and deformed. This can alleviate the load rise of the load-deflection curve during the compression deformation of the shock-absorbing member 30, thereby ensuring the shock-absorbing performance of the shock-absorbing device 20.
After the outer peripheral surface of the cylindrical portion 37 expanded radially outward at the time of compression deformation is brought into close contact with the inner peripheral surface of the wall portion 23, the first surface 37a having the gap S before compression (non-compressed state) is separated from the wall portion 23 at a stroke at the time of releasing the compression, and air enters abruptly to generate abnormal noise. When the compression is released, the wall portion 23 vibrates with the end portion (the bent portion 23b) of the wall portion 23 on the second end 31b side as a free end, and abnormal noise is generated.
However, in the present embodiment, since the second surface 37b located closer to the second end 31b than the first surface 37a can be brought into contact with the wall portion 23 to reduce the volume of the gap S, the amount of air entering the gap S can be reduced and abnormal noise is less likely to occur. Further, since the second surface 37b and the wall portion 23 can be brought into contact with each other to suppress the vibration of the wall portion 23, the generation of abnormal noise due to the vibration of the wall portion 23 can be suppressed. As a result, abnormal noise can be prevented from being generated when the cushioning member 30 expands and contracts.
In particular, since the second surface 37b that contacts the wall portion 23 is provided over the entire circumference of the tube portion 37, the air in the gap S between the first surface 37a on the bottom portion 22 side of the second surface 37b and the wall portion 23 can be compressed by the tube portion 37 that tends to expand radially outward when the shock-absorbing member 30 is compressively deformed. Further, when the compression deformation of the cushioning member 30 is released, the air compressed between the first surface 37a and the wall portion 23 expands again, so that the amount of air entering the gap S between the first surface 37a and the wall portion 23 can be further reduced, and abnormal noise caused by the entry of the air can be made less likely to occur. As a result, it is possible to make it more difficult for abnormal noise to be generated when the cushioning member 30 expands and contracts.
A part of the second surface 37b in contact with the wall 23 is located in a region a in which the protruding portion 38 is projected radially outward. This prevents the projection 38 from expanding outward in the radial direction too much when the cushioning member 30 is compressively deformed by the wall portion 23. This makes it possible to prevent the fitting portion 32 from easily coming off the protruding portion 38, and thus to easily maintain the state in which the soft portion 31 is held by the hard portion 35.
Since the tube portion 37 extends to the second end 31b side of the bent portion 23b, the soft portion 31 expanding radially outward with the compression deformation of the cushioning material 30 can be prevented from abutting against the wall portion 23 by the tube portion 37, and the bent portion 23b is an end portion of the wall portion 23 on the second end 31b side. It is possible to prevent soft portion 31 from being sunk into the end of wall portion 23 and damaging soft portion 31. Further, since the curved portion 23b is curved radially outward, the relatively hard tube portion 37 expanding radially outward with compression deformation can be made less likely to sink into the curved portion 23b, and the tube portion 37 can be made less likely to be broken. Thus, the durability of the soft portion 31 and the hard portion 35 can be ensured.
Further, when the cushioning member 30 is compressively deformed, the curved portion 23b that is curved radially outward is less likely to be firmly adhered to the tube portion 37 in the radial direction. Further, since the curved portion 23b is curved radially outward from the portion of the wall portion 23 that contacts the second surface 37b, it is possible to suppress generation of abnormal noise due to separation of the tube portion 37 and the wall portion 23 (curved portion 23b) after the tube portion 37 contacts the second end 31b side with respect to the second surface 37 b. This makes it possible to further reduce the generation of abnormal noise when the cushioning member 30 expands or contracts.
The wall portion 23 is separated from the cylindrical portion 37 from a portion in contact with the second surface 37b to the axial distal end 23c on the second end 31b side. In the case where the wall portion 23 has the curved portion 23b, the apex of the curved portion 23b on the second end 31b side is the leading end 23 c. The axial length L2 from the portion of the wall portion 23 that contacts the second surface 37b to the distal end 23c is shorter than the axial length L1 of the second surface 37 b. This can reduce the volume of the gap between the cylindrical portion 37 and the wall portion 23 on the second end 31b side of the second surface 37b, and can reduce the generation of abnormal noise caused by air entering the gap.
The front end 23c of the wall 23 is located in a region a obtained by projecting the projection 38 outward in the radial direction. Thus, the fitting portion 32 can be sufficiently made less likely to fall off the protruding portion 38 by the wall portion 23, and the axial length from the portion of the wall portion 23 in contact with the second surface 37b to the distal end 23c can be made shorter than L2. As a result, the soft portion 31 can be easily held by the hard portion 35, and abnormal noise can be further reduced when the cushioning member 30 expands and contracts.
The second surface 37b protrudes outward in the radial direction by the gap S relative to the first surface 37a, and a portion of the inner peripheral surface of the wall portion 23 that is in contact with the second surface 37b and a portion that faces the first surface 37a are formed linearly in a cross section that includes the central axis C. Since the wall portion 23 does not sink into the second surface 37b, when the shock-absorbing member 30 is compressively deformed, the axial compressive deformation of the tube portion 37 near the wall portion 23 can be prevented from being restricted by the wall portion 23 sinking into the second surface 37 b. As a result, the increase in load of the load-deflection curve during compressive deformation of the cushioning member 30 can be further alleviated.
Next, a second embodiment is explained with reference to fig. 3. In the first embodiment, the case where the second surface 37b is extended radially outward from the first surface 37a and the second surface 37b is brought into contact with the wall portion 23 has been described. In contrast, in the second embodiment, a case will be described in which the convex portion 43 that protrudes the wall portion 42 radially inward is brought into contact with the second surface 47 of the cylindrical portion 46. Note that the same portions as those in the first embodiment are denoted by the same reference numerals and will not be described below.
As shown in fig. 3, the damper device 40 includes a holding member 41 attached to the second jig 15 of the mounting device 10 (see fig. 1), and a damper member 44 formed of an elastic body held by the holding member 41. The holding member 41 is a metal member having higher rigidity than the hard portion 45 of the cushioning member 44, and is formed in a cup shape. The holding member 41 includes a bottom portion 22 attached to the second jig 15, and a cylindrical wall portion 42 extending from an outer peripheral edge of the bottom portion 22 toward the cylinder 2 (downward in the plane of the paper in fig. 3).
The wall portion 42 includes a press-fitting portion 23a formed by bending a part of the inner peripheral surface radially inward, a bent portion 23b which is an end portion on the cylinder 2 side and is bent radially outward, and a convex portion 43 which is connected to the bottom portion 22 side of the bent portion 23b and projects the inner peripheral surface radially inward. The wall portion 42 is formed in a substantially conical tube shape in which the distance from the central axis C gradually increases as the distance from the bottom portion 22 increases, except for the pushed-in portion 23a, the bent portion 23b, and the convex portion 43. In a cross section including the center axis C, the inner peripheral surface and the outer peripheral surface are formed substantially linearly. The projection 43 is an annular portion provided substantially over the entire circumference of the wall 42.
The cylindrical portion 46 of the hard portion 45 of the cushioning material 44 is a cylindrical portion extending from the outer peripheral side of the base end portion 36 of the hard portion 45 toward the second end 31b (below the sheet surface of fig. 3), and extends to the second end 31b side of the bent portion 23 b. The cylindrical portion 46 is in close contact with a part of the outer peripheral surface of the soft portion 31 on the first end 31a side, and is disposed between the outer peripheral surface of the soft portion 31 and the inner peripheral surface of the wall portion 42. The soft portion 31 is held by the hard portion 45 by the protruding portion 38 protruding radially inward from the inner peripheral surface of the tube portion 46.
The outer peripheral surface of the cylindrical portion 46 includes: a first surface 37a facing the wall 42 with a gap S therebetween; a second surface 47 connected to the second end 31b side of the first surface 37a and contacting the inner circumferential surface of the convex portion 43 of the wall portion 42; and a third surface 37c located closer to the second end 31b side than the second surface 47 and projecting radially outward.
In the cross section including the central axis C, the first surface 37a and the second surface 47 are formed substantially linearly in a state where the hard portion 45 is not attached to the holding member 41. Since the protruding amount of the convex portion 43 toward the radial inner side is larger than the radial dimension of the gap S, the cylindrical portion 46 is press-fitted into the convex portion 43, and the second surface 47 comes into contact with the convex portion 43. In this way, the base end portion 36 is press-fitted into the press-fitting portion 23a, and the cylindrical portion 46 is press-fitted into the protruding portion 43, so that the hard portion 45 can be made less likely to be detached from the holding member 41.
Further, a part of the second surface 47 pre-compressed in the radial direction by the convex portion 43 is located in a region a in which the protruding portion 38 is projected outward in the radial direction. In this way, since a part of the region a of the cylindrical portion 46 is pre-compressed radially inward, the projecting portion 38 is less likely to expand radially outward when the shock-absorbing member 44 is compressed and deformed. As a result, the fitting portion 32 can be made less likely to fall off from the protruding portion 38, and therefore the state in which the soft portion 31 is held by the hard portion 45 can be maintained more easily.
According to the above-described damper 40, as in the first embodiment, in the non-compressed state of the damper member 44, since the first surface 37a of the tubular portion 46 does not contact the wall portion 42 and the second surface 47 of the tubular portion 46 contacts the wall portion 42, the damping performance of the damper 40 can be ensured and the generation of abnormal noise when the damper member 44 expands and contracts can be made less likely.
Since the second surface 47 is pre-compressed in the radial direction by the convex portion 43 of the wall portion 42, the second surface 47 can be prevented from separating from the convex portion 43 by the force (the pressure-receiving line い) when the compression in the axial direction of the shock-absorbing member 44 is released and the expansion in the radial direction is restored. This makes it possible to prevent the second surface 47 and the convex portion 43 from being separated from each other and from being again in contact with each other.
Further, since the second surface 47 is pre-compressed by the convex portion 43 over the entire circumference of the cylindrical portion 46, air compressed in the gap S along with the compression deformation of the cushioning material 44 can be made less likely to leak from between the second surface 47 and the convex portion 43. This makes it possible to prevent air from entering the gap S when the compression deformation of the cushioning material 44 is released, and to suppress the occurrence of abnormal noise due to the entry of air. As a result, it is possible to make it more difficult for abnormal noise to be generated when the cushioning member 44 expands and contracts.
Next, a third embodiment is explained with reference to fig. 4. In the first and second embodiments, the case where the base end portion 36 is press-fitted into the press-fitting portion 23a and the hard portions 35 and 45 are held by the holding members 21 and 51 has been described. In contrast, in the third embodiment, a case will be described in which the pushed-in portion 23a is omitted, the cylindrical portion 46 is pushed into the protruding portion 43, and the hard portion 45 is held by the holding member 51. Note that the same portions as those in the first and second embodiments are denoted by the same reference numerals and will not be described below.
As shown in fig. 4, the damper device 50 includes a holding member 51 attached to the second jig 15 of the mounting device 10 (see fig. 1), and a damper member 44 formed of an elastic body held by the holding member 51. The holding member 51 is a metal member having higher rigidity than the hard portion 45 of the cushioning member 44, and is formed in a cup shape. The holding member 51 includes a bottom portion 22 attached to the second jig 15, and a cylindrical wall portion 52 extending from an outer peripheral edge of the bottom portion 22 toward the cylinder 2 (downward in the plane of the paper in fig. 4).
The wall portion 52 is the same as the wall portion 42 except that the pressed portion 23a is omitted from the wall portion 42 of the second embodiment. That is, the wall portion 52 is formed in a substantially conical tube shape in which the distance from the central axis C gradually increases as the distance from the bottom portion 22 to the convex portion 43 increases, and the inner peripheral surface and the outer peripheral surface are formed in a substantially linear shape in a cross section including the central axis C. The rigid portion 45 is held by the holding member 51 by press-fitting the cylindrical portion 46 into the convex portion 43 of the wall portion 52. In other words, since the cylindrical portion 46 can be press-fitted into the convex portion 43, the press-fitted portion 23a of the press-fitted base end portion 36 can be omitted.
By omitting the press-fitted portion 23a, the gap S between the outer peripheral surface of the hard portion 45 on the bottom portion 22 side of the second surface 47 and the inner peripheral surface of the wall portion 52 can be expanded to the bottom portion 22. Accordingly, since the hard portion 45 can be expanded more toward the wall portion 52 when the shock-absorbing member 44 is compressively deformed, the increase in load of the load-deflection curve when the shock-absorbing member 44 is compressively deformed can be further alleviated, and the shock-absorbing performance of the shock-absorbing device 50 can be improved.
The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments at all, and it is easily inferred that various modifications and variations can be made without departing from the scope of the present invention. For example, the shapes and dimensions of the respective portions of the mounting device 10, the holding members 21, 41, 51, and the cushioning members 30, 44 may be changed as appropriate. Dust covers formed separately from the hard portions 35, 45 may be attached to the holding members 21, 41, 51, etc.
In the above embodiment, the case where the shock absorbers 20, 40, and 50 are mounted to the mounting device 10 fixed to the piston rod 4 of the shock absorber 1 has been described, but the present invention is not limited to this. The shock absorbing devices 20, 40, 50 may be attached to the cylinder 2 side, and the shock absorbing members 30, 44 may be compressed and deformed between the cylinder 2 and the attachment device 10. Further, the shock absorbing devices 20, 40, and 50 may be disposed between the shock absorber 1 and two members other than the mounting device 10 (for example, between the plate spring and the vehicle body), and the shock between the two members may be absorbed by the shock absorbing members 30 and 44. In particular, it is preferable to dispose the shock absorbers 20, 40, and 50 between the wheel-side chassis and the vehicle body, so that the shock absorbers 20, 40, and 50 can improve the ride comfort of the vehicle and ensure the steering stability. Further, if there is no member penetrating the center of the shock absorbers 20, 40, 50, the inner peripheral sides of the soft portion 31, the base end portion 36, and the bottom portion 22 may be filled.
In the above embodiment, the case where the soft portion 31 is made of soft foam and the hard portions 35 and 45 are made of rubber has been described, but the present invention is not limited thereto. The types of the elastic bodies of the soft portions 31 may be changed as appropriate as long as they are softer than the elastic bodies of the hard portions 35, 45. For example, the soft portion 31 may be made of a synthetic resin including a thermoplastic elastomer, a rigid polyurethane foam, or the like, or made of rubber, and the hard portions 35 and 45 may be made of a synthetic resin including a thermoplastic elastomer, a rigid polyurethane foam, or the like. The holding members 21, 41, 51 may be made of a synthetic resin having higher rigidity (higher young's modulus) than the hard portions 35, 45.
In the above embodiment, the case where the second surfaces 37b and 47 that contact the inner circumferential surfaces of the wall portions 23, 42, and 52 are provided on the entire circumferences of the cylindrical portions 37 and 46 has been described, but the present invention is not limited to this. One second surface that contacts the inner circumferential surface of the wall portion 23, 42, 52 may be provided at a part of the cylindrical portion 37, 46 in the circumferential direction, or a plurality of second surfaces may be provided intermittently in the circumferential direction of the cylindrical portion 37, 46.
In the above embodiment, the description has been given of the case where the hard portions 35 and 45 are press-fitted into the press-fitting portions 23a and the convex portions 43 to hold the hard portions 35 and 45 on the holding members 21, 41, and 51, but the present invention is not limited to this. The base end portion 36 may be bonded to the bottom portion 22 with an adhesive to hold the hard portions 35 and 45 to the holding members 21, 41, and 51.
Claims (6)
1. A shock absorber is characterized by comprising:
a holding member having a cylindrical wall portion and a bottom portion that closes one end in an axial direction of the wall portion;
a hard portion made of an elastomer, located radially inward of the wall portion, and held by the holding member in a state of contacting the bottom portion; and
a soft portion made of an elastomer and having a first end and a second end in the axial direction, the first end being held by the hard portion, and the soft portion being softer than the hard portion,
wherein the hard portion includes:
a base end portion sandwiched between the bottom portion and the first end; and
a cylindrical portion extending from the base end portion toward the second end side and disposed between the wall portion and an outer peripheral surface of a part of the soft portion on the first end side,
the outer peripheral surface of the tube portion includes:
a first surface facing the inner peripheral surface of the wall portion with a gap provided therebetween in a state where the soft portion and the hard portion are not compressed in the axial direction; and
a second face located closer to the second end side than the first face and contacting an inner peripheral face of the wall portion,
the tube portion includes: a protruding portion protruding from the inner peripheral surface toward the inner side in the radial direction,
the soft portion includes a fitting portion that fits in a portion of the cylindrical portion closer to the base end portion than the protruding portion,
at least a part of the second surface is located in a region where the protruding portion is projected outward in the radial direction.
2. The cushioning device of claim 1,
an end portion of the wall portion on the second end side is a bent portion bent radially outward from a portion of the wall portion in contact with the second surface,
the barrel portion extends to be closer to the second end side than the bent portion.
3. The cushioning device of claim 1,
the second surface is provided on the entire circumference of the cylindrical portion.
4. The cushioning device of claim 1,
the wall portion is separated from the cylindrical portion between a portion in contact with the second surface and a distal end of the second end in the axial direction,
the axial length from a portion of the wall portion that contacts the second face to the leading end is shorter than the axial length of the second face.
5. The cushioning device of claim 1,
the axial direction leading end of the second end side of the wall portion is located in a region where the protruding portion is projected outward in the radial direction.
6. The damping device according to one of claims 1 to 5,
the wall portion includes a convex portion having an inner peripheral surface protruding inward in the radial direction,
the convex portion pre-compresses the second face in the radial direction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019-076466 | 2019-04-12 | ||
| JP2019076466A JP7199292B2 (en) | 2019-04-12 | 2019-04-12 | shock absorber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111810573A CN111810573A (en) | 2020-10-23 |
| CN111810573B true CN111810573B (en) | 2021-12-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010080083.5A Active CN111810573B (en) | 2019-04-12 | 2020-02-04 | Buffer device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP7199292B2 (en) |
| CN (1) | CN111810573B (en) |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH056259U (en) * | 1991-07-05 | 1993-01-29 | 株式会社イノアツクコーポレーシヨン | Dust cover of shock absorber for vehicle |
| JPH0624222A (en) * | 1992-07-08 | 1994-02-01 | Nippon Mektron Ltd | Bump stopper assmbling structure |
| JP2001173709A (en) * | 1999-12-16 | 2001-06-26 | Nissan Motor Co Ltd | Bearing assembly for supporting strut upper part of suspension device |
| JP4367332B2 (en) * | 2004-12-17 | 2009-11-18 | 東海ゴム工業株式会社 | Bound stopper for suspension device |
| JP5014204B2 (en) * | 2008-03-05 | 2012-08-29 | 東洋ゴム工業株式会社 | Dust cover |
| JP2010007692A (en) * | 2008-06-24 | 2010-01-14 | Toyo Tire & Rubber Co Ltd | Dust cover with bound stopper |
| JP5106293B2 (en) * | 2008-07-29 | 2012-12-26 | カヤバ工業株式会社 | Hydraulic shock absorber |
| JP6532367B2 (en) * | 2015-09-30 | 2019-06-19 | 住友理工株式会社 | Tubular vibration control with bracket |
| JP2018084276A (en) * | 2016-11-23 | 2018-05-31 | 東洋ゴム工業株式会社 | Bump stopper |
-
2019
- 2019-04-12 JP JP2019076466A patent/JP7199292B2/en active Active
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2020
- 2020-02-04 CN CN202010080083.5A patent/CN111810573B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020173007A (en) | 2020-10-22 |
| JP7199292B2 (en) | 2023-01-05 |
| CN111810573A (en) | 2020-10-23 |
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