JP2015017628A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper which can suppress the bowing of a coil spring, and can suppress the generation of noise.SOLUTION: In a damper D which comprises a piston rod 2 inserted into a cylinder 1, and a rebound member A which is compressed between a rod guide 3 fixed to the cylinder 1 and a stopper member 4 fixed to the piston rod 2, and alleviates an impact at ultimate elongation, and in which the rebound member A comprises a coil spring 5, and a pair of holders 6, 7 fixed to both ends of the coil spring 5 in the axial direction, one or both of the holders 6, 7 have annular support bases 70 for supporting one end of the coil spring 5, annular fixed parts 71 which erect from peripheral portions of the support bases 70, and to which the coil spring 5 is pressure-inserted and fixed, cylindrical guide parts 72 extending toward a center of the axial direction of the coil spring 5 from the fixed parts 71, and internal peripheral protrusions 73 which are formed at internal peripheries of the guide parts 72, and slide-contact with or pressure-contact with an external peripheral face of the piston rod 2. The holders are oscillatory with the internal peripheral protrusions 73 as fulcrums.

Description

  The present invention relates to a shock absorber.

  Generally, a shock absorber is used in vehicles, equipment, structures, etc., and includes a cylinder and a piston rod that enters and exits the cylinder, and a damping force that suppresses relative movement of the cylinder and the piston rod in the axial direction. Is supposed to occur. In addition, in such a shock absorber, in order to alleviate the impact when the piston rod is fully retracted from the cylinder, it is fixed to the extension restriction member fixed to the cylinder and the outer periphery of the piston rod. Some have a rebound member between the stopper member.

  As shown in FIG. 7, when the rebound member B includes the coil spring 5 and a pair of holders 600 and 700 fitted to both ends of the coil spring 5 in the axial direction, the rebound member B Is moved freely in the axial direction with respect to the piston rod 2, the rebound member B is separated from and seated on the stopper member 4 to make a contact sound. Therefore, an inner peripheral projection 702 is provided on the inner peripheral surface of the lower holder 700, and the lower holder 700 is press-fitted and fixed to the outer periphery of the piston rod 2, and is maintained in contact with the stopper member 4. (For example, paragraph 0028 of Patent Document 1).

JP 2005-265092 A

  In the conventional rebound member B, when the coil spring 5 is compressed, the lower end thereof is restrained by the piston rod 2 via the holder 700, and the fitting portion 701 between the holder 700 and the coil spring 5 cannot move in the radial direction. It is like that. For this reason, as shown by a two-dot chain line in FIG. 7, the coil spring 5 has the upper holder 600 and the fitting portion 601 of the coil spring 5, and the lower holder 700 and the fitting portion 701 of the coil spring 5 as fulcrums. When the torsion occurs, the coil spring 5 may come into contact with the cylinder 1 and an abnormal noise may be generated. (The distance between the fulcrum points of the above-mentioned body bending is indicated by M in FIG. 7).

  Even if such a torsion occurs, if the clearance between the coil spring 5 and the cylinder 1 is sufficiently ensured, the contact between the coil spring 5 and the cylinder 1 is avoided and the generation of abnormal noise is prevented. It seems to be possible.

  However, for example, in a coil spring of a rebound member used for a strut-type shock absorber that also functions as a vehicle wheel positioning post, in recent years, the roll rigidity is increased by increasing the spring constant while increasing the axial direction. Trying to raise and restrain the vehicle roll. In this way, when the coil spring becomes longer, it becomes easier to cause torsion, and when the wire diameter of the coil spring is increased in order to increase the spring constant, the clearance with the cylinder is reduced, and the coil spring that has been allowed in the past is now acceptable. Even when the body is bent due to compression, the coil spring and the cylinder may rub against each other, generating abnormal noise.

  As described above, the generation of abnormal noise due to the bending of the coil spring may occur in the same manner regardless of whether it is a strut-type shock absorber or another shock absorber.

  Therefore, an object of the present invention is to provide a shock absorber capable of suppressing the torsion of a coil spring and suppressing the generation of abnormal noise.

  Means for solving the above-mentioned problems are a cylinder, a piston rod inserted into the cylinder so as to be movable in the axial direction, an extension restriction member fixed to the cylinder, and an outer periphery of the piston rod. And a rebound member that is compressed between the extension restriction member and the stopper member when extended to relieve an impact when extended, and the rebound member includes the piston rod inside. In the shock absorber comprising a coil spring through which the coil spring is inserted and a pair of holders fixed to both ends of the coil spring in the axial direction, one or both of the holders is an annular support base that supports one end of the coil spring An annular fixed portion that is raised from the inner peripheral portion of the support base and into which the coil spring is press-fitted and fixed, and an axial center of the coil spring from the fixed portion And a cylindrical guide portion extending toward the inner periphery of the guide portion, and an inner peripheral protrusion that is slidably or pressure-contacted with the outer peripheral surface of the piston rod, and swings around the inner peripheral protrusion as a fulcrum. It is possible.

  According to the shock absorber of the present invention, it is possible to suppress the bending of the coil spring and suppress the generation of abnormal noise.

It is the longitudinal cross-sectional view which showed the principal part of the buffer which concerns on one embodiment of this invention. It is the front view which notched and showed a part of shock absorber concerning one embodiment of the present invention. (A) is the partial notch expansion perspective view which showed the holder by the side of the stopper member of the buffer which concerns on one embodiment of this invention. (B) is the enlarged plan view which showed the holder by the side of the stopper member of the buffer which concerns on one embodiment of this invention. (A) is the longitudinal cross-sectional view which expanded and showed the internal peripheral protrusion part of the buffer which concerns on one embodiment of this invention. (B) is the figure which showed the modification of the internal peripheral protrusion of the buffer which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which showed the principal part of the buffer which concerns on other embodiment of this invention. It is the longitudinal cross-sectional view which showed the principal part of the buffer which concerns on other embodiment of this invention. It is the longitudinal cross-sectional view which showed the principal part of the conventional shock absorber.

  A shock absorber according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the shock absorber D according to the present embodiment includes a cylinder 1, a piston rod 2 that is movably inserted in the cylinder 1 in the axial direction, and a rod guide that is fixed to the cylinder 1. (Extension restriction part) 3, stopper member 4 fixed to the outer periphery of the piston rod 2, and compression between the rod guide 3 and the stopper member 4 when fully extended to alleviate the impact when fully extended The rebound member A includes a coil spring 5 through which the piston rod 2 is inserted, and a pair of holders 6 and 7 fixed to both ends of the coil spring 5 in the axial direction. And.

  The lower holder 7 in FIG. 1 includes an annular support base 70 that supports one end of the coil spring 5 and an annular shape on which the coil spring 5 is press-fitted and fixed from an inner peripheral portion of the support base 70. Fixed portion 71, a cylindrical guide portion 72 extending from the fixed portion 71 toward the axial center of the coil spring 5, and provided on the inner periphery of the guide portion 72 on the outer peripheral surface of the piston rod 2. And an inner peripheral protrusion 73 that is pressed against the inner peripheral protrusion 73, and can swing about the inner peripheral protrusion 73 as a fulcrum.

  Hereinafter, when it demonstrates in detail, the buffer D which concerns on this Embodiment is a strut type buffer, and is utilized as the support | pillar for wheel positioning of a motor vehicle. Since the structure of the strut type shock absorber is well known, although not shown in detail, as shown in FIG. 2, a shock absorber body d1 including an outer cylinder 10 and a piston rod 2 that goes in and out of the outer cylinder 10, A suspension spring receiver 11 that supports the lower end of a suspension spring (not shown) that is fixed to the outer periphery of the outer cylinder 10 and elastically supports the vehicle body, and a knuckle (not shown) that is fixed to the outer periphery of the lower end of the outer cylinder 10 and supports the wheels. ) And a knuckle bracket 12 connected thereto. The shock absorber D according to the present invention may be used for suspensions other than struts, and may be used for other than vehicles.

  In the present embodiment, the shock absorber main body d1 is fixed to the outer cylinder 10 connected to the wheel side, the cylinder 1 standing on the axial center of the outer cylinder 10, and the upper opening end of the cylinder 1. An annular rod guide 3, a piston rod 2 that is connected to the vehicle body side and is pivotally supported by the rod guide 3 and enters and exits the cylinder 1, and is held by the lower end portion of the piston rod 2 and slides into the cylinder 1. A piston 8 that can be inserted and a base member 9 fixed to the lower opening end of the cylinder 1 are provided.

  An extension side chamber L1 and a pressure side chamber L2 that are partitioned by the piston 8 and filled with hydraulic fluid are formed in the cylinder 1, and between the cylinder 1 and the outer cylinder 10, the pressure side chamber L2 is formed. And a reservoir R that is partitioned by the base member 9 and stores the hydraulic fluid corresponding to the volume of the piston rod that enters and exits the cylinder 1 is formed. Further, the reservoir R is filled with gas on the upper side through the liquid surface of the working fluid.

  The extension side chamber L1 and the pressure side chamber L2 communicate with each other through passages 80 and 81 formed in the piston 8, and the pressure side chamber L2 and the reservoir R communicate with each other through passages 90 and 91 formed in the base member 9. Has been. For this reason, when the piston rod 2 enters and exits the cylinder 1 and the shock absorber D expands and contracts, the working fluid moves from the one chamber (L1 or L2) that expands to the other chamber (L2 or L1) that is contracted, The hydraulic fluid corresponding to the volume of the piston rod entering and exiting the cylinder 1 moves between the pressure side chamber L2 and the reservoir R. The shock absorber D generates a damping force due to the resistance when the hydraulic fluid passes through the passages 80, 81, 90, 91, and the cylinder 1 and the piston rod 2 move in the axial direction. Can be suppressed. In the present embodiment, the shock absorber D is set to a single rod double cylinder type, but the configuration of the shock absorber D can be changed as appropriate. For example, the air chamber that compensates for the change in the cylinder volume corresponding to the volume of the piston rod entering and exiting the cylinder 1 may be a single cylinder type shock absorber that partitions the cylinder 1 with a free piston or a bladder. It may be a double rod type shock absorber in which the piston rod stands.

  Further, in the present embodiment, the shock absorber D includes an extension / restriction restricting means for restricting the further extension of the shock absorber D when the piston rod 2 is retracted from the cylinder 1 by a predetermined amount. Yes. In the present embodiment, the stretch restriction means includes a rod guide 3 as a stretch restriction member fixed to the cylinder 1, a stopper member 4 fixed to the outer periphery of the piston rod 2, and the rod guide 3 when fully extended. And a rebound member A that is compressed between the stopper member 4 and relieves an impact when fully extended.

  As shown in FIG. 1, the rod guide 3 serving as a stretch restriction member has an inner peripheral portion 30 inserted into the cylinder 1 and an outer peripheral portion 31 protruding from the cylinder 1 toward the outer cylinder. Further, a well-known seal member 32 that seals between the outer cylinder 10 and the piston rod 2 is laminated on the upper side of the rod guide 3 in FIG. 1, and the hydraulic fluid stored in the shock absorber D leaks to the outside. There is no such thing. The rod guide 3 and the seal member 32 are fixed in a state where they are stacked on the cylinder 1 by crimping the upper end portion of the outer cylinder 10 inward.

  The stopper member 4 is an outer periphery of the piston rod 2 and has a cylindrical connecting portion 40 fixed between the piston 8 and the rod guide 3, and an annular plate-like flange projecting outward from the upper end of the connecting portion 40. Part 41. And the connection part 40 is being firmly fixed to the outer periphery of the piston rod 2, and the relative movement of the piston rod 2 and the stopper member 4 is prevented.

  The rebound member A is supported by the flange portion 41 of the stopper member 4, and includes a coil spring 5 and a pair of annular holders 6 and 7 that are press-fitted and fixed to both end portions in the axial direction of the coil spring 5. . The piston rod 2 is inserted through the axial center of the coil spring 5 and the pair of holders 6 and 7.

  In the present embodiment, the coil spring 5 is formed by spirally winding a wire having a square cross section. And when the coil spring 5 is compressed most and the coil parts 50 which are one volume of coil springs 5 contact, coil parts 50 come to surface-contact, and some coil parts 50 are. Jumping out in the radial direction is suppressed. By doing in this way, it can control that a part of coil part jumps out to 50 diameter directions, contacts cylinder 1 or piston rod 2, and abnormal noise is generated. The cross-sectional shape of the wire forming the coil spring 5 can be selected as appropriate, and may be circular or elliptical.

  An upper holder 6 disposed on the rod guide side, which is the upper side in FIG. 1, stands up from an annular support base 60 that supports the upper end of the coil spring 5 and an inner peripheral portion of the support base 60. And an annular fixing portion 61 that is press-fitted and fixed to the upper end portion of the head. In addition, there is a clearance between the upper holder 6 and the piston rod 2, and the holder 6 is movable in the axial direction with respect to the piston rod 2 and is movable in the radial direction.

  A lower holder 7 disposed on the stopper member side, which is the lower side in FIG. 1, has an annular support base 70 that supports the lower end of the coil spring 5, and stands up from the inner peripheral portion of the support base 70. An annular fixed portion 71 that is press-fitted and fixed to the lower end portion of the spring 5, a cylindrical guide portion 72 that extends from the fixed portion 71 toward the axial center of the coil spring 5, and an inner periphery of the guide portion 72 And an inner peripheral protrusion 73 that is provided in pressure contact with the outer peripheral surface of the piston rod 2. The pressure contact means a state in which the inner peripheral protrusion 73 is pressed against the outer peripheral surface of the piston rod 2.

  As shown in FIG. 3, the outer diameter of the fixed portion 71 is slightly larger than the outer diameter of the guide portion 72, and even if the inner diameter of the coil spring 5 is uniform in the axial direction, the fixed portion 71 has a coil spring. 5 can be press-fitted and fixed. Further, the guide portion 72 does not hinder expansion and contraction of the coil spring 5, and the lower portion of the coil spring 5 disposed on the outer periphery of the guide portion 72 can be expanded and contracted while being guided by the guide portion 72. Moreover, although the axial direction length of the guide part 72 can be changed suitably, it is preferable to provide over 1/4 or more of the axial direction of the coil spring 5, for example.

  In the present embodiment, the inner peripheral protrusions 73 are provided at three equal intervals in the circumferential direction on the inner periphery of the anti-support base side portion that is the upper portion of the guide portion 72 in FIG. Further, as described above, the inner peripheral protrusion 73 is in pressure contact with the outer peripheral surface of the piston rod 2, and the relative movement in the axial direction between the lower holder 7 and the piston rod 2 is suppressed. Further, as shown in FIG. 4A, the inner peripheral protrusion 73 is formed in a mountain shape, and between the lower holder 7 excluding the pressure contact portion of the inner peripheral protrusion 73 and the piston rod 2. There is a clearance, and the lower holder 7 can swing about the inner peripheral projection 73 as a fulcrum. In addition, as long as the lower holder 7 can be swung, the shape and the shape of the inner peripheral protrusion 73 can be appropriately changed. For example, as shown in FIG. It may be a shape.

  Hereinafter, the operation of the shock absorber D according to the present embodiment will be described.

  When the piston rod 2 retreats from the cylinder 1, the rebound member A moves in the axial direction with respect to the cylinder 1 together with the piston rod 2 while being supported by the stopper member 4, and approaches the rod guide 3. When the upper holder 6 comes into contact with the rod guide 3 and the piston rod 2 continues to retract as it is, the coil spring 5 is compressed to generate a reaction force and relieve the impact when fully extended.

  When the coil spring 5 is compressed, the lower holder 7 swings around the inner peripheral projection 73 and the fixed portion 71 on which the coil spring 5 is press-fitted and fixed can move in the radial direction with respect to the piston rod 2. The fulcrum of the torsional bending in the coil spring 5 includes the lower holder 7 and the press-fit fixing portion (inner peripheral projection 73 portion) of the piston rod 2, the upper holder 6 and the press-fit fixing portion of the coil spring 5 (upper holder 6). Of the fixing portion 61). That is, the lower bending fulcrum of the coil spring 5 moves to the center side of the coil spring 5 than before, and the distance M between the fulcrum points of the bending becomes shorter, so that the bending of the coil spring 5 can be suppressed.

  Furthermore, in the present embodiment, the lower holder 7 is fixed while the fixing portion 71 of the lower holder 7 to which the lower end portion of the coil spring 5 is press-fitted and fixed is movable in the radial direction with respect to the piston rod 2. Since it does not move in the axial direction with respect to the piston rod 2, it is possible to suppress the generation of contact sound due to the rebound member A being separated from and seated on the stopper member 4.

  Hereinafter, the operational effects of the shock absorber D according to the present embodiment will be described.

  In the present embodiment, the holder 7 on the stopper member side which is the lower side in FIG. 1 includes the inner peripheral protrusion 73, while the holder 6 on the rod guide side (extension regulating member side) which is the upper side in FIG. It is not provided with a circumferential protrusion, is movable in the axial direction with respect to the piston rod 2, and is movable in the radial direction.

  When the upper holder 6 has a tightening margin with respect to the piston rod 2, the upper holder 6 is the rod guide 3 at the upper side in FIG. 1 when the shock absorber D is retracted from the cylinder 1. When the upper holder 6 and the piston rod 2 move relative to each other in the axial direction, the retraction of the piston rod 2 is suppressed by the sliding resistance between the upper holder 6 and the piston rod 2. However, according to the said structure, generation | occurrence | production of such a malfunction can be prevented. The configuration of the upper holder 6 is not limited to the above, and can be changed as appropriate. For example, the upper holder 6 may be in sliding contact with the outer peripheral surface of the piston rod 2.

  Further, in the present embodiment, the inner peripheral protrusion 73 is provided on the side opposite to the support base in the guide portion 72.

  According to the above configuration, the inner peripheral projection 73 serving as the swing fulcrum of the lower holder 7 can be separated from the fixed portion 71 to which the coil spring 5 is press-fitted and fixed. Therefore, the piston rod 2 of the fixed portion 71 The movable range in the radial direction with respect to can be increased. However, the position where the inner peripheral protrusion 73 is provided is appropriately changed as long as it is disposed closer to the axial center side of the coil spring 5 than the press-fit fixing portion (fixing portion 71) of the lower holder 7 and the coil spring 5. Is possible.

  Further, in the present embodiment, the holder 7 on the stopper member side which is the lower side in FIG. 1 includes an inner peripheral protrusion 73, and the inner peripheral protrusion 73 is in pressure contact with the outer peripheral surface of the piston rod 2. .

  According to the above configuration, since the relative movement of the lower holder 7 and the piston rod 2 can be suppressed, the lower holder 7 can be maintained in the state of being seated on the stopper member 4. Therefore, it is possible to suppress the generation of contact sound that occurs when the lower boulder 7 is seated on and away from the stopper member 4. However, the inner peripheral protrusion 73 of the lower holder 7 may be brought into sliding contact with the outer peripheral surface of the piston rod 2.

  In the present embodiment, the shock absorber D includes a cylinder 1, a piston rod 2 inserted into the cylinder 1 so as to be movable in the axial direction, and a rod guide (extension restriction member) fixed to the cylinder 1. ) 3, a stopper member 4 fixed to the outer periphery of the piston rod 2, and a rebound member A that is compressed between the rod guide 3 and the stopper member 4 when fully extended to relieve an impact when fully extended The rebound member A includes a coil spring 5 into which the piston rod 2 is inserted, and a pair of holders 6 and 7 fixed to both ends of the coil spring 5 in the axial direction. .

  The lower holder 7 in FIG. 1 includes an annular support base 70 that supports one end of the coil 5 spring, and an annular shape on which the coil spring 5 is press-fitted and fixed from an inner peripheral portion of the support base 70. Fixed portion 71, a cylindrical guide portion 72 extending from the fixed portion 71 toward the axial center of the coil spring 5, and provided on the inner periphery of the guide portion 72 on the outer peripheral surface of the piston rod 2. And an inner peripheral protrusion 73 that is pressed against the inner peripheral protrusion 73, and can swing about the inner peripheral protrusion 73 as a fulcrum.

  According to the above configuration, the inner peripheral projection 73 serving as the swing fulcrum of the lower holder 7 is arranged closer to the axial center side of the coil spring 5 than the fixing portion 71 to which the coil spring 5 is press-fitted and fixed. The distance M between the fulcrum points of the bending of the coil spring 5 is shortened, and the bending of the coil spring 5 can be suppressed.

  In the present embodiment, only the lower holder 7 can swing with the inner peripheral projection 73 as a fulcrum, but both the upper and lower holders 6 and 7 are fixed as shown in FIG. Cylindrical guide portions 62, 72 extending from the portions 61, 71 toward the axial center of the coil spring 5, and inner peripheral protrusions 63, 73 provided on the inner periphery of the guide portions 62, 72. The inner peripheral projections 63 and 73 may be swingable around the fulcrum. Further, as shown in FIG. 6, the lower holder 7 does not include the inner peripheral projection 73, and only the upper holder 6 extends from the fixing portion 61 toward the axial center of the coil spring 5. The guide part 62 and an inner peripheral protrusion 63 provided on the inner periphery of the guide part 62 may be provided, and the inner peripheral protrusion 63 may be swingable about the fulcrum. As described above, when the upper holder 6 includes the inner peripheral protrusion 63, the inner peripheral protrusion 63 of the upper holder 6 is in sliding contact with the outer peripheral surface of the piston rod 2.

  Although preferred embodiments of the present invention have been described in detail above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

A Rebound member D Shock absorber 1 Cylinder 2 Piston rod 3 Rod guide (extension restriction member)
4 Stopper member 5 Coil spring 6, 7 Holder 60, 70 Support base 61, 71 Fixing part 62, 72 Guide part 63, 73 Inner peripheral projection

Claims (5)

A cylinder, a piston rod movably inserted in the cylinder in the axial direction, an extension restriction member fixed to the cylinder, a stopper member fixed to the outer periphery of the piston rod, and the extension when extended. A rebound member that is compressed between the cut-off regulating member and the stopper member to relieve an impact when fully extended,
In the shock absorber, the rebound member includes a coil spring through which the piston rod is inserted, and a pair of holders fixed to both ends in the axial direction of the coil spring.
One or both of the holders include an annular support base that supports one end of the coil spring, an annular fixed part that is erected from an inner peripheral portion of the support base, and the coil spring is press-fitted and fixed. A cylindrical guide portion extending toward the axial center of the coil spring, and an inner peripheral protrusion provided on the inner periphery of the guide portion and slidably or pressure-contacted with the outer peripheral surface of the piston rod. A shock absorber characterized in that it can swing around the inner peripheral projection as a fulcrum.   The shock absorber according to claim 1, wherein the holder on the stopper member side includes the inner peripheral protrusion, and the inner peripheral protrusion is in pressure contact with the outer peripheral surface of the piston rod.   The shock absorber according to claim 1, wherein the inner peripheral protrusion is provided on a portion of the guide portion opposite to the support base.   While the holder on the stopper member side includes the inner peripheral protrusion, the holder on the stretch restriction member side does not include the inner peripheral protrusion and is movable in the axial direction with respect to the piston rod. The shock absorber according to any one of claims 1 to 3, wherein the shock absorber is movable in a radial direction.   4. The holder according to claim 1, wherein the holder on the side of the stretch restriction member is provided with the inner peripheral protrusion, and the inner peripheral protrusion is in sliding contact with the outer peripheral surface of the piston rod. The shock absorber according to any one of the above.

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