JP2014114872A - Buffer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of foreign noise by correcting inclination of a coil spring constituting a rebound member, in a buffer including the rebound member.SOLUTION: A buffer D which includes a cylinder 1, a piston rod 2 axially movably inserted into the cylinder 1, a rod guide 3 fixed to the cylinder 1, a stopper member 4 fixed to an outer periphery of the piston rod 2, and a rebound member 5 mounted on an outer periphery of the piston rod 2, and absorbs impact shock when it is fully expanded, by being compressed between the stopper member 4 and the rod guide 3 in fully expansion, and in which the rebound member 5 includes a coil spring 50, and a first holder 51 fixed to one side end portion of the coil spring 50, and can be brought into contact with the stopper member 4, further includes inclination correcting means 6 disposed between the coil spring 50 and the first holder 51, or between the first holder 51 and the stopper member 4, and inclining a center line X2 of the coil spring 50 in the direction to be aligned to a center line X1 of the piston rod 2.

Description

  The present invention relates to an improvement of a shock absorber.

  Generally, the shock absorber is used for a vehicle, a device, a structure, or the like, and includes a cylinder and a piston rod that is inserted into the cylinder so as to be able to appear and retract. When vibration is input, the shock absorber expands and contracts to generate a damping force and suppress the vibration.

  Further, the shock absorber is provided with an expansion limit restricting member fixed on the cylinder side, a stopper member fixed on the piston rod side, and a stopper member and an extension limit restricting member when extended to alleviate an impact at the time of extension. And a rebound member that is compressed and generates a predetermined reaction force.

  For example, as shown in FIG. 6, in the shock absorber disclosed in Patent Document 1, the extension restricting member is fixed to one end of the cylinder 1 so that the piston rod 2 is axially movable. The rebound member 500 includes a coil spring 501 formed by winding a rectangular column-shaped element wire, and a first member fixed to a lower end portion of the coil spring 501 and in contact with the stopper member 4. A holder 502 and a second holder 503 fixed to the upper end portion of the coil spring 501 and capable of contacting the rod guide 3 are provided.

  Further, the first and second holders 502 and 503 are formed in an annular shape, and the piston rod 2 is inserted inside the coil spring 501 and the first and second holders 502 and 503. When the rod guide 3 and the stopper member 4 approach each other when the shock absorber is fully extended, the coil spring 501 is compressed to generate a predetermined reaction force, and the impact at the time of full extension can be absorbed.

  The coil spring 501 has a shape in which a plurality of coil portions 501a, 501a,. And since the cross-sectional shape of a strand becomes a square shape and the coiled wire 501 is formed by winding a square pillar-shaped strand, as shown in FIG. The coil portions 501a to be brought into surface contact with each other. Therefore, when the coil spring 501a is compressed most, the coil portions 501a slip and part of the coil portions 501a are displaced in the diametrical direction, and the displaced coil portion 501a hits the outer peripheral surface of the piston rod 2 or the inner peripheral surface of the cylinder 1. Generation of abnormal noise can be suppressed.

JP 2005-16632 A

  However, when a coil spring is formed by winding an element wire, the coil spring may be formed in an inclined state under the influence of stress or the like. Further, in particular, when a coil spring is formed by winding a square pillar-shaped element wire as in the conventional shock absorber, the coil spring is likely to be inclined. And when this coil spring is formed in an inclined state, the coil spring is attached in a state of being off-axis from the piston rod, so that when it is compressed, the coil spring is bent and the bent portion of the piston rod is There is a risk that abnormal noise may be generated by hitting the outer peripheral surface or the inner peripheral surface of the cylinder.

  Accordingly, an object of the present invention is to provide a shock absorber capable of suppressing the generation of abnormal noise even when an inclined coil spring is used.

  Means for solving the above problems are a cylinder, a piston rod inserted into the cylinder so as to be movable in the axial direction, an extension regulating member fixed to the cylinder, and an outer periphery of the piston rod. And a rebound member that is attached to the outer periphery of the piston rod and that is compressed between the stopper member and the expansion limit restricting member when extended to relieve an impact when extended. Is a shock absorber provided with a coil spring and a first holder fixed to one end of the coil spring and capable of contacting the stopper member, between the coil spring and the first holder or the It is arranged between the first holder and the stopper member, and is inclined in a direction to align the center line of the coil spring with the center line of the piston rod. It is to comprise the oblique correction means.

  According to the present invention, since the inclination of the coil spring can be corrected by the inclination correction means, 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 longitudinal cross-sectional view which expanded and showed the coil spring which comprises a rebound member in the buffer which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which expanded and showed the state which attached the inclination correction means to the rebound member of the buffer which concerns on one embodiment of this invention. It is the perspective view which expanded and showed the coil spring and inclination correction means which comprise a rebound member in the buffer which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which expanded and showed the inclination correction means part of the buffer which concerns on one embodiment of this invention, (a) shows the 1st modification of an inclination correction means, (b) A second modification of the inclination correction means is shown, and (c) shows a third modification of the inclination correction means. It is the front view which notched and showed the principal part of the conventional shock absorber. It is the longitudinal cross-sectional view which expanded and showed the most compressed state of the coil spring which comprises a rebound member in 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 control member) 3, a stopper member 4 fixed to the outer periphery of the piston rod 2, and attached to the outer periphery of the piston rod 2 between the stopper member 4 and the rod guide 3 when extended. A rebound member 5 that is compressed and relieves an impact when fully extended, and the rebound member 5 is fixed to a coil spring 50 and one end portion (lower end portion in FIG. 1) of the coil spring 50 and the stopper. And a first holder 51 capable of contacting the member 4.

  Further, the shock absorber D is disposed between the coil spring 50 and the first holder 51 in a direction to align the center line X2 (FIG. 2) of the coil spring 50 with the center line X1 of the piston rod 2. Tilt correction means 6 for tilting is provided.

  Hereinafter, in detail, in the present embodiment, the shock absorber D is an upright, multi-cylinder hydraulic shock absorber interposed between a vehicle body and a wheel of an automobile, and oil as a working fluid. Contains liquids such as water and aqueous solutions. The configuration of the shock absorber D is well known and not shown in detail, but the shock absorber D includes an outer cylinder 10 that is connected to the wheel side and forms a well-known reservoir R with the cylinder 1. . The cylinder 1 is an inner cylinder disposed concentrically on the inner side of the outer cylinder 10.

  Further, in the shock absorber D, the piston rod 2 inserted into the cylinder 1 so as to be movable in the axial direction is connected to the vehicle body side and is an annular rod attached to the vehicle body side open end 1a. It is inserted inside the guide 3 and is supported by an annular bearing 30 fitted to the inner periphery of the rod guide 3 so as to be movable in the axial direction.

  In the present embodiment, the rod guide 3 is an extension regulating member in the present invention, the inner peripheral portion 3a is inserted inside the vehicle body side opening end portion 1a of the cylinder 1, and the outer peripheral portion 3b is a cylinder. Projecting from 1 to the outer cylinder side. Further, a well-known seal member 31 is laminated on the non-cylinder side of the rod guide 3 (upper side in FIG. 1), and the rod guide 3 is secured by caulking the vehicle body side end portion 10a of the outer cylinder 10 inward. It is fixed to the cylinder 1 together with the seal member 31.

  Returning, the piston 20 and the stopper member 4 are attached to the outer periphery of the piston rod 2 side by side in the axial direction. The piston 20 is formed in an annular shape, and is fixed to the tip end portion (lower end portion in FIG. 1) of the piston rod 2 with a nut 21. The piston 20 is in sliding contact with the inner peripheral surface of the cylinder 1 and axially passes through the cylinder 1. It is divided into.

  The chamber defined by the piston 20 includes an extension side chamber A formed on the piston rod side (upper side in FIG. 1) of the piston 20 and a pressure side formed on the anti-piston rod side (lower side in FIG. 1) of the piston 20. This is the chamber B, and the expansion side chamber A and the compression side chamber B are filled with working fluid. Further, the piston 20 is formed with an extension side channel 20a and a pressure side channel 20b communicating the extension side chamber A and the pressure side chamber B, and the extension side channel on the pressure side chamber side (lower side in FIG. 1). An extension side leaf valve V1 that closes the outlet of 20a so as to be opened and closed is stacked, and a pressure side leaf valve V2 that closes the outlet of the pressure side channel 20b so as to open and close is stacked on the extension side chamber side (upper side in FIG. 1).

  Next, the stopper member 4 attached to the outer periphery of the piston rod 2 as with the piston 20 is disposed on the rod guide side (upper side in FIG. 1) of the piston 20, and is an annular shape fixed to the outer periphery of the piston rod 2. A support portion 4a and a disc-shaped flange portion 4b projecting from the upper end of the support portion 4a to the outer peripheral side are provided, and the rebound member 5 is supported by the flange portion 4b.

  The rebound member 5 is attached to the outer periphery of the piston rod 2, and includes a coil spring 50, a first holder 51 fixed to one end (lower end in FIG. 1) of the coil spring 50, and the coil And a second holder 52 fixed to the other end portion (upper end portion in FIG. 1) of the spring 50. The rebound member 5 is arranged with the first holder 51 facing the stopper member (lower side in FIG. 1) and the second holder 52 facing the rod guide side (upper side in FIG. 1).

  As shown in FIG. 2, the coil spring 50 is formed by winding a rectangular pillar-shaped element wire. When the coil portion 50a is one volume of the strand, the coil spring 50 has a shape in which a plurality of coil portions 50a, 50a,... Are arranged in the axial direction and connected to the center of the coil portion 50a. The center line X2 is inclined. That is, the coil spring 50 is formed in an inclined state.

  Subsequently, as shown in FIG. 3, the first holder 51 is formed in an annular shape, and has a plurality of protrusions 51 a and 51 a protruding to the inner peripheral side, and is press-fitted into the outer periphery of the piston rod 2. The stopper member 4 is positioned and fixed while being supported by the flange portion 4b. The first holder 51 includes an annular holding portion 51b that is press-fitted inside one end (lower side in FIG. 3) of the coil spring 50, and an anti-coil spring side (in FIG. 3) of the holding portion 51b. An annular bearing portion 51c that is connected to the lower side) and has an outer diameter larger than the outer diameter of the holding portion 51b, and an annular seat surface on the coil spring side (upper side in FIG. 3) of the bearing portion 51c. 51d is formed.

  The seat surface 51d is disposed substantially horizontally (perpendicular to the center line X1 of the piston rod 2) when the first holder 51 is attached to the piston rod 2. For this reason, when the coil spring 50 is attached to the piston rod 2 via the first holder 51, if one end (the lower end in FIG. 3) of the coil spring 50 is brought into contact with the seat surface 51d as it is, the coil spring 50 is As shown in FIG. 2, the center line X <b> 1 of the piston rod 2 passes through the center of the lower end of the coil spring 50, but the center line of the coil spring 50 extends toward the upper end of the coil spring 50. X2 and the center line X1 of the piston rod 2 are shifted in the arrow Y direction.

  Therefore, in the present embodiment, as shown in FIG. 3, an annular plate washer is formed between the sheet surface 51 d of the first holder 51 and one end (lower end in FIG. 3) of the coil spring 50. The inclination correction means 6 is interposed to correct the inclination of the coil spring 50. The inclination correction means 6 is set so that the center line X2 (FIG. 2) of the coil spring 50 can be moved in the direction opposite to the arrow Y to match the center line of the piston rod 2.

  Specifically, as shown in FIG. 4, the inclination correcting means 6 includes a thick part 6 a having a large thickness and a thin thickness disposed so as to face each other across the thick part 6 a and the center hole 6 o. The coil spring side surface 6c of the inclination correcting means 6 is a flat surface that is inclined from the thick part 6a to the thin part 6b. Further, on the coil spring side surface 6c of the inclination correcting means 6, a positioning projection 6d is erected on which the coil spring 50 starts or ends, that is, the tip 50b of the wire constituting the coil spring 50 abuts.

  Then, the coil spring 50 is attached to the piston rod 2 via the first holder 51, and when the center line X1 of the piston rod 2 passes through the center of the lower end of the coil spring 50, the center line X1 is at the upper end of the coil spring 50. The position of the protrusion 6d is set so that the thick portion 6a overlaps with the circumferential position p1 (FIG. 2) that is shifted most away from the center.

  Subsequently, as shown in FIG. 3, the second holder 52 fixed to the other end (the upper end in FIG. 2) of the coil spring 50 is formed in an annular shape and loosely fitted on the outer periphery of the piston rod 2. And an annular holding portion 52a that is press-fitted inside the other end (upper side in FIG. 3) of the coil spring 50, and the outer diameter is held continuously to the anti-coil spring side (upper side in FIG. 3) of the holding portion 52a. And an annular abutting portion 52b formed larger than the outer diameter of the portion 52a. An annular seat surface 52c is formed on the coil spring side (lower side in FIG. 3) of the abutting portion 52b. . The other end (upper end in FIG. 3) of the coil spring 50 is in contact with the seat surface 52c. Further, protrusions 52d, 52d,... Stand up along the circumferential direction on the side of the abutting portion 52b opposite to the coil spring (upper side in FIG. 3). For this reason, when the 2nd holder 52 contact | abuts to the rod guide 3, it can suppress that a working fluid passes between the protrusions 52d and an abnormal noise generate | occur | produces.

  Next, the operation of the shock absorber D of the present embodiment will be described. Since the stopper member 4 is fixed to the piston rod side and the rod guide (extension control member) 3 is fixed to the cylinder side, when the piston rod 2 retracts from the cylinder 1 and the shock absorber D extends, the stopper The member 4 and the rod guide 3 approach each other.

  Further, since the rebound member 5 is fixed to the outer periphery of the piston rod 2 in a state where the first holder 51 is in contact with the stopper member 4, when the shock absorber D continues to expand, the second holder 52 becomes the rod guide. The first holder 51 is pushed up to the rod guide side by the stopper member 4 while the movement of the second holder 52 is regulated by the rod guide 3. For this reason, the coil spring 50 is compressed to generate a predetermined reaction force, and the shock when the shock absorber D is fully extended is alleviated.

  Next, the effect of the buffer D of this Embodiment is demonstrated. The shock absorber D according to the present embodiment 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 control member) 3 fixed to the cylinder 1. And a stopper member 4 fixed to the outer periphery of the piston rod 2 and an impact at the time of extension when attached to the outer periphery of the piston rod 2 and compressed between the stopper member 4 and the rod guide 3 when fully extended. And the rebound member 5 is fixed to a coil spring 50 and one end portion (lower end portion in FIG. 1) of the coil spring 50 and can contact the stopper member 4. One holder 51 is provided.

  Further, the shock absorber D is disposed between the coil spring 50 and the first holder 51 in a direction to align the center line X2 (FIG. 2) of the coil spring 50 with the center line X1 of the piston rod 2. Tilt correction means 6 for tilting is provided.

  For this reason, even if the coil spring 50 is formed in a tilted state due to, for example, being formed by winding a rectangular columnar strand, the tilt correction means 6 causes the center line X2 of the coil spring 50 to be connected to the piston rod. The inclination of the coil spring 50 can be corrected by inclining it so as to match the center line X1 of 2. Therefore, when the shock absorber D is fully extended, the coil spring 50 is compressed along the center line X2 to suppress the torsion of the coil spring 50, and the portion where the torsion is caused is the outer peripheral surface of the piston rod 2. In addition, it is possible to suppress the generation of noise due to contact with the inner peripheral surface of the cylinder 1.

  In the present embodiment, the first holder 51 is connected to the annular holding portion 51b press-fitted inside the coil spring 50, and the anti-coil spring side (lower side in FIG. 3) of the holding portion 51b. And an annular support portion 51c that supports the coil spring 50 and has an outer diameter that is larger than the outer diameter of the holding portion 51b. Further, the inclination correcting means 6 is an annular plate washer interposed between the support portion 51c and the coil spring 50, and has a thick wall portion 6a and a thin wall portion. 6b.

  Therefore, it is possible to easily correct the inclination of the coil spring 50 by using the thickness difference of the inclination correction means 6. Further, since the inclination correcting means 6 is an annular plate washer interposed between the support portion 51c and the coil spring 50, the winding start or end of the coil spring 50 contacting the support portion 51c (coil spring) It is possible to prevent the supporting portion 51c from being pinched with the tip 50b) of the strand forming the wire 50.

  In addition, by forming the tilt correcting means 6 as a single unit without integrally forming the first holder 51 and the stopper member 4, a coil spring that is not tilted, such as being formed by winding a cylindrical wire, is provided. The first holder and the stopper member used in the shock absorber provided can be used as they are, and the versatility is high.

  Further, in the present embodiment, the inclination correcting means 6 includes a positioning projection 6d with which the winding start or winding end of the coil spring 50 (the tip 50b of the strand forming the coil spring 50) abuts.

  Accordingly, when the winding start or end of winding of the coil spring 50 (the tip 50b of the wire forming the coil spring 50) is applied to the positioning protrusion 6d, the positioning protrusion can be corrected so that the inclination of the coil spring 50 can be corrected. If the position of 6d is set, it is not necessary to attach the correction means 6 while confirming the inclination direction of the coil spring 50, and the inclination correction work of the coil spring 50 can be made efficient.

  In addition, when the inclination direction of the coil spring 50 with respect to the winding start or winding end position of the coil spring 50 is changed due to a change in the winding start and winding end positions of the coil spring 50, the inclination correction means 6 is provided with a washer. Therefore, it is only necessary to prepare washers (tilt correction means 6) having different positions of the positioning protrusions 6d, and can easily cope with the coil springs 50 having different tilt directions.

  In the present embodiment, the first holder 51 is formed in an annular shape and is press-fitted into the outer periphery of the piston rod 2, and is fixed in a state of being in contact with the stopper member 4.

  Therefore, it is possible to suppress the rebound member 5 from moving in the axial direction along the piston rod 2, and to suppress the generation of contact sound when the first holder 51 contacts the flange portion 4 b of the stopper member 4.

  Further, when the first holder 51 is press-fitted into the outer periphery of the piston rod 2 in this way, particularly when the coil spring 50 is compressed, one end (the lower end in FIG. 1) of the coil spring 50 is the first end. Since it is fixed to the piston rod 2 through the one holder 51 and cannot be displaced in the diameter direction, it is easy to bend. Therefore, it is particularly effective to provide the inclination correction means 6 and correct the inclination of the coil spring 50.

  Further, in the present embodiment, the coil spring 50 is formed by winding a square columnar strand.

  Therefore, when the coil spring 50 is most compressed, the coil portions 50a can be prevented from slipping, and the shifted coil portion 50a can be prevented from hitting the outer peripheral surface of the piston rod 2 or the inner peripheral surface of the cylinder 1 to generate abnormal noise. .

  However, when the coil spring 50 is formed by winding a square columnar strand, the coil spring 50 may be inclined due to the influence of stress or the like. For this reason, in the coil spring 50 formed by winding a square columnar element wire, it is necessary to provide the inclination correction means 6 to correct the inclination of the coil spring 50.

  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.

  For example, in the said embodiment, although the buffer D is the buffer D for motor vehicles, it is good also as being utilized for apparatuses, structures, etc. other than motor vehicles. The type of the shock absorber D is not limited to the above, and although not shown, it may be a single-tube shock absorber or a pneumatic shock absorber that uses gas as a working fluid. Although not shown, the cylinder 1 may be connected to the vehicle body side, the piston rod 2 may be connected to the wheel side, and the shock absorber D may be set upside down.

  Moreover, in the said one Embodiment, it is a washer by which the inclination correction means 6 is interposed between the support part 51c and the coil spring 50. FIG. However, as long as the inclination of the coil spring 50 can be corrected, the configuration of the inclination correction means 6 can be selected as appropriate.

  For example, when the first holder 51 can tilt with respect to the piston rod 2, an inclination correction means 6 </ b> A is provided between the first holder 51 and the stopper member 4 as shown in FIG. May be. In addition, as shown in FIG. 5B, the inclination correcting means 6 </ b> B may be a protrusion integrally formed on the anti-coil spring side (lower side in FIG. 5) of the first holder 51. Further, as shown in FIG. 5C, the sheet surface 51d of the first holder 51 may be inclined, and the sheet surface 51d may be used as the inclination correcting means 6C.

  Moreover, in the said embodiment, although the inclination correction means 6 is provided with the positioning protrusion 6d, you may align the circumferential direction of the coil spring 50 and the inclination correction means 6 by methods other than the positioning protrusion 6d. .

  Moreover, in the said embodiment, although the said 1st holder 51 is formed cyclically | annularly and press-fitted in the outer periphery of the said piston rod 2, and is being fixed to the piston rod 2, you may be in sliding contact with the piston rod 2. .

  In the above-described embodiment, the coil spring 50 is formed by winding a rectangular column-shaped element wire, and thus the coil spring 50 is inclined, but is formed by an element wire other than the rectangular column-shaped element. Also good.

D Shock absorber X1 Piston rod center line X2 Coil spring center line 1 Cylinder 2 Piston rod 3 Rod guide (extension control member)
4 Stopper member 5 Rebound member 6 Inclination correction means 6a Thick portion 6b Thin portion 6d Positioning protrusion 50 Coil spring 50b The tip of the wire forming the coil spring (start or end of winding of the coil spring)
51 First holder 51b Holding part 51c Bearing part

Claims (5)

A cylinder, a piston rod inserted in the cylinder so as to be movable in the axial direction, an extension regulating member fixed to the cylinder, a stopper member fixed to the outer periphery of the piston rod, and an outer periphery of the piston rod And a rebound member that is compressed between the stopper member and the stretch-out regulating member when fully extended and relieves an impact when fully extended,
In the shock absorber, the rebound member includes a coil spring and a first holder fixed to one end of the coil spring and capable of contacting the stopper member.
Inclination correcting means disposed between the coil spring and the first holder or between the first holder and the stopper member and tilting the coil spring in a direction to align the center line of the coil spring with the center line of the piston rod. A shock absorber characterized by that. The first holder includes an annular holding portion that is press-fitted inside the coil spring, and an outer diameter that is connected to the anti-coil spring side of the holding portion and is larger than the outer diameter of the holding portion. An annular support section to support,
The inclination correction means is an annular plate washer interposed between the support portion and the coil spring, and includes a thick portion having a large thickness and a thin portion having a small thickness. The shock absorber according to claim 1.   The shock absorber according to claim 2, wherein the inclination correcting means includes a positioning protrusion with which a winding start or a winding end of the coil spring comes into contact.   The first holder according to any one of claims 1 to 3, wherein the first holder is formed in an annular shape, is press-fitted into an outer periphery of the piston rod, and is fixed in a state of being in contact with the stopper member. The shock absorber according to one item.   The shock absorber according to any one of claims 1 to 4, wherein the coil spring is formed by winding a rectangular pillar-shaped element wire.

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