JP6360291B2 - Buffer valve structure - Google Patents

Description

  The present invention relates to a valve structure of a shock absorber.

The shock absorber is used for a vehicle, a device, a structure, or the like to generate a damping force and suppress vibrations, and includes various valve structures to obtain a desired damping force. The valve structure is, for example, as shown in FIG. 8 (a), the shock absorber has been embodied as a piston valve P2 held in the piston rod, hydraulic oil is filled are formed in sheet cylinder 6 A piston (valve disk) 8 that divides the working chamber R into two chambers R1 and R2, a damping valve 3C comprising a plurality of annular plate-like leaf valves 2i to 2k stacked on the piston 8, and the damping An annular plate-like spacer 4C stacked on the valve 3C is provided.

  The piston 8 is formed with a flow path 80 that communicates the two chambers R1 and R2, a window 81 that communicates with the flow path 80, and a valve seat 82 that surrounds the window 81. The outer periphery of the valve 3C can be seated. The spacer 4C is in contact with the inner peripheral portion of the damping valve 3C, and the damping valve 3C deflects the outer peripheral portion toward the anti-piston side with the outer peripheral edge of the spacer 4C as a fulcrum, thereby opening the flow path 80. be able to. Further, a notch 20 forming an orifice is formed on the outer periphery of the first leaf valve 2i constituting the damping valve 3C.

  With such a configuration, when the piston valve P2 moves upward in FIG. 8, the hydraulic oil in one chamber R1 pressurized by the piston valve P2 is notched until the damping valve 3C is opened. Since it passes through 20 and moves to the other room R2, the shock absorber generates a damping force having a square characteristic peculiar to the orifice, and the damping coefficient (ratio of the damping force increase amount to the piston speed increase amount) at this time is It becomes relatively large.

  Subsequently, when the piston speed increases and the pressure in one chamber R1 reaches the valve opening pressure of the damping valve 3C, the outer periphery of the damping valve 3C bends to the anti-piston side, and the hydraulic oil in the one chamber R1 becomes the damping valve. Since it passes through the gap formed between 3C and the valve seat 82 and moves to the other chamber R2, the shock absorber generates a damping force having a valve characteristic. At this time, the gap formed between the damping valve 3C and the valve seat 82 increases as the pressure in the one room R1 increases, so the damping coefficient becomes relatively small.

  As shown in FIG. 8B, when the outer periphery of the spacer 4C is a true circle having a center on the axial center line x1 of the shock absorber, when the piston speed reaches a predetermined speed, the outer periphery of the damping valve 3C As shown in FIG. 9 (a), the damping force characteristic changes suddenly when the damping valve 3C is opened, so that the rider feels comfortable riding of the vehicle. May give the impression that it is bad.

  Therefore, in Patent Document 1, as shown in FIG. 8 (c), the outer periphery of the spacer 4C is formed so as not to be a true circle having a center on the axial center line x1, and a part in the circumferential direction of the damping valve 3C. A portion having a small contact width with the spacer 4C is provided. By doing in this way, a part of the damping valve 3C in the circumferential direction starts to bend in advance, and thereafter, the range of bending is operated so as to spread all around. For this reason, as shown by the solid line in FIG. 9B, the connection between the damping characteristic of the orifice characteristic before opening the damping valve and the damping characteristic of the valve characteristic after opening the damping valve is smoothed to make the vehicle smooth. Riding comfort can be improved.

Japanese Utility Model Publication No. 60-99341

  In order to obtain a damping force characteristic as shown by a solid line in FIG. 9C, in which the connection between the damping force of the orifice characteristic and the damping force of the valve characteristic is made smoother, the valve is opened in advance in the damping valve 3C. It is preferable to reduce the width w from the outer peripheral edge to the inner peripheral edge of the spacer 4C corresponding to the portion. The spacer 4C is generally formed by punching a steel plate, and the manufacturing method is inexpensive and capable of mass production, and is excellent in mass productivity. However, if the width w is too narrow, it may be cracked or distorted, and even if it is changed to another manufacturing method with excellent mass productivity, such as sintering, forging, press molding, etc., the above problems are solved. I can't. If laser cutting is performed, defects such as cracking and distortion are eliminated, but the cost is extremely high, and it is not suitable for mass production and is not suitable for mass production.

  Accordingly, an object of the present invention is to provide a valve structure of a shock absorber that can reduce the contact width between a spacer and a damping valve as compared with the conventional one and is excellent in mass productivity.

Means for solving the above problems include an annular valve disk that divides two chambers, a flow path that is formed in the valve disk and communicates with the two chambers, and is laminated on the valve disk and is connected to the flow path. A damping valve composed of one or more ring-plate-like leaf valves that block the ring, a ring-plate-shaped spacer stacked on the anti-valve disk side of the attenuation valve, and a stack on the anti-damping valve side of the spacer The valve disc, the damping valve, the spacer, and the valve stopper are held on the outer periphery of a shaft member that passes through the shaft hole, and the damping valve In the valve structure of the shock absorber, in which the inner peripheral portion is supported by a seat and the outer peripheral portion is bent to the opposite valve disc side to open the flow path, one end of the spacer facing the damping valve side is at one end. , A support surface that is in contact with the damping valve and is formed so that the shaft hole is opened and the outer periphery does not become a true circle centered on the shaft center line, and the support surface extends from the support surface to the outer periphery. A stepped surface having a step in between and spaced from the damping valve is formed.

  According to the valve structure of the shock absorber of the present invention, the contact width between the spacer and the damping valve can be made smaller than before, and the mass productivity is excellent.

It is the longitudinal cross-sectional view which expanded and showed the piston valve part by which the valve structure of the buffer which concerns on one embodiment of this invention was embodied. (A) is a top view of the spacer of FIG. (B) is the x2-x2 sectional view taken on the line of (a). It is the top view which showed the 1st modification of the spacer in the valve structure of the buffer which concerns on one embodiment of this invention. It is the top view which showed the 2nd modification of the spacer in the valve structure of the buffer which concerns on one embodiment of this invention. It is the top view which showed the 3rd modification of the spacer in the valve structure of the buffer which concerns on one embodiment of this invention. (A) is the top view which showed the 4th modification of the spacer in the valve structure of the buffer which concerns on one embodiment of this invention. (B) is the x3-x3 sectional view taken on the line of (a). It is the figure which showed the damping force characteristic of the buffer in the case of providing the spacer of FIG. (A) is the longitudinal cross-sectional view which showed the piston valve part by which the valve structure of the conventional shock absorber was embodied. (B) is the top view which showed the spacer of (a). (C) is the top view which showed the spacer disclosed by patent document 1. FIG. (A) is the figure which showed the damping force characteristic of the buffer in the case of providing the spacer of FIG.8 (b). (B) is the figure which showed the damping force characteristic of the buffer in the case of providing the spacer of FIG.8 (c). (C) is a diagram showing damping force characteristics to be realized by the present invention.

  Hereinafter, a valve structure of a shock absorber according to an embodiment of the present invention will be described 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 valve structure of the shock absorber D according to the present embodiment is embodied as a piston valve P1, and includes an annular piston (valve disk) 1 that partitions two chambers R1 and R2, and Flow paths 11 and 12 that are formed in the piston 1 and communicate with the two chambers R1 and R2, and one or more annular leaf valves 2a that are stacked on the piston 1 and close the flow paths 11 and 12. Are provided with damping valves 3A and 3B composed of ˜2d and 2e to 2h, and ring-plate-shaped spacers 4A and 4B stacked on the damping valves 3A and 3B, and the piston 1 and the damping valves 3A and 3B. The spacers 4A and 4B are held on the outer periphery of a piston rod (shaft member) 5 inserted through the shaft holes 10, 30, and 40, and the damping valves 3A and 3B are connected to the spacers 4A and 4B. 4B inside Supported the parts, the outer peripheral portion is bent to the opposite piston side opens the passage 11, 12. In addition, at one end of the spacers 4A and 4B facing the damping valve side, the abutting against the damping valves 3A and 3B, the shaft hole 40 is opened, and the outer periphery is a true center having the center on the shaft center line x1. A support surface 41 formed so as not to be circular, and a step surface 43 extending from the support surface 41 to the outer peripheral side and having a step 42 between the support surface 41 and spaced from the damping valves 3A and 3B. Is formed.

  Hereinafter, in detail, the shock absorber D is interposed between a vehicle body and a wheel of a vehicle such as an automobile, and a cylinder 6 in which a working chamber R filled with hydraulic oil is formed, A piston rod 5 that enters and exits the cylinder 6, a piston valve P1 that is held at the tip of the piston rod 5 and divides the working chamber R into two chambers R1 and R2 on the expansion side and the pressure side, a free piston and a bladder And an air chamber (not shown) which is partitioned from the working chamber R and in which gas is enclosed. Moreover, although not shown in figure, the attachment part is each provided in the lower end part in FIG. 1 of the cylinder 6 located in the both ends of the shock absorber D, and the upper end part in FIG. 1 of the piston rod 5, and one attachment part is provided. It is connected to the vehicle body side, and the other mounting portion is connected to the wheel side. For this reason, when an impact due to road surface unevenness is input, the piston rod 5 enters and exits the cylinder 6 and the shock absorber D expands and contracts. Further, the change in volume in the cylinder corresponding to the piston rod in / out and the change in volume of the hydraulic oil due to the temperature change can be compensated for in the air chamber.

  That is, in the present embodiment, the shock absorber D is a single-rod single-tube shock absorber, but the configuration of the shock absorber D can be changed as appropriate. For example, it may be a double rod type shock absorber in which a piston rod extends on both sides of the piston valve P1, an outer cylinder standing on the outer periphery of the cylinder 6 and forming a reservoir between the cylinder 6 and a chamber on the piston side. It may be a multi-cylinder shock absorber provided with a base valve that partitions R2 and the reservoir. Thus, when the shock absorber D is a double cylinder type, the present invention may be embodied as a base valve. Further, in the present embodiment, the shock absorber D is a hydraulic shock absorber that uses hydraulic oil as a working fluid. However, a liquid other than the hydraulic oil or a gas may be used as the working fluid. Further, the shock absorber D may be used other than the vehicle.

  The piston rod 5 is pivotally supported by an annular rod guide (not shown) that closes the upper open end of the cylinder 6 in the drawing, and is inserted into the cylinder 6 so as to be movable in the axial direction. A main body portion 50 that is pivotally supported at the shaft, a holding portion 51 that is coaxially connected to the main body portion 50 and disposed in the cylinder 6, and a screw groove is formed on the outer periphery of the holding portion 51 on the opposite side of the holding portion 51. Screw portion 52. The holding part 51 has an outer diameter that is smaller than the outer diameter of the main body part 50, and a step 53 is formed at the boundary between the main body part 50 and the holding part 51.

The piston valve P1 includes a piston 1 that is a valve disk, an extension-side damping valve 3A, an extension-side spacer 4A, and an extension-side valve stopper 7A that are stacked in order from the piston side to the lower side of the piston 1 in FIG. And a pressure-side damping valve 3B, a pressure-side spacer 4B, and a pressure-side valve stopper 7B, which are stacked in order from the piston side on the upper side of the piston 1 in FIG. Each member constituting the piston valve P1 is formed in an annular shape and includes shaft center holes 10, 30, 40, and 70, respectively. The pressure side valve stopper 7B, the pressure side spacer 4B, the pressure side damping valve 3B, the piston 1, the extension side damping valve 3A, the extension side spacer 4A, and the extension side valve stopper 7A are arranged in this order. By inserting the holding portion 51 into the core holes 10, 30, 40, 70 and screwing the nut N into the screw portion 52, the piston valve P 1 is sandwiched between the nut N and the step 53, and the piston rod 5 It is held on the outer periphery. Although not shown, a cylindrical spacer is interposed between the nut N and the piston 1, and an extension-side damping valve 3A, an extension-side spacer 4A, and an extension-side valve stopper 7A are provided on the outer periphery of the spacer. Attached so as to be slidable, a spring may be interposed between the nut N and the valve stopper 7A, and the extension side damping valve 3A, spacer 4A and valve stopper 7A may be urged to the piston side by this spring. .

  The piston 1 is in sliding contact with the inner peripheral surface of the cylinder 6 via a piston ring 13, and divides the working chamber R into chambers R1 and R2 on the expansion side and pressure side. The piston 1 is formed with two types of flow paths 11 and 12 that extend between the expansion side and the pressure side chambers R1 and R2 and communicate with the expansion side and the pressure side. A lower side of the piston 1 in FIG. 1 is a window 14 with a flow path 11 on the extended side, a valve seat 15 surrounding the window 14, and an outer side of the valve seat 15 which opens to the pressure side chamber R2. An opening window 16 is formed in which the pressure-side flow path 12 is continuous. On the other hand, on the upper side of the piston 2 in FIG. 1, a window 17 having a pressure-side flow passage 12 connected thereto, a valve seat 18 surrounding the window 17, and an outside of the valve seat 18, which opens to the extension-side chamber R <b> 1. An opening window 19 is formed in which the stretch-side flow path 11 is continuous.

  The extension-side damping valve 3A stacked on the piston 1 includes four leaf valves 2a to 2d formed in an annular plate shape and stacked in the axial direction. The first leaf valve 2a from the piston side that constitutes the extension-side damping valve 3A can be seated on the lower valve seat 15 in FIG. 1, and when it is seated, the window 14 is closed. However, the opening window 16 is not blocked. On the other hand, the compression side damping valve 3B laminated on the opposite side of the expansion side damping valve 3A is formed in an annular plate shape and laminated in the axial direction in the same manner as the expansion side damping valve 3A. 4 leaf valves 2e to 2h. The first leaf valve 2e from the piston side constituting the pressure-side damping valve 3B can be seated on the valve seat 18 on the upper side in FIG. 1 and closes the window 17 when seated. The window 19 is not blocked. Therefore, when the expansion-side chamber R1 is pressurized, the pressure in the chamber R1 acts in the direction of opening the expansion-side damping valve 3A through the opening window 19 and the expansion-side flow path 11, but The damping valve 3B acts on the valve seat 18 to close the valve. On the other hand, when the pressure-side chamber R2 is pressurized, the pressure in the chamber R2 acts in the direction of opening the compression-side damping valve 3B through the opening window 16 and the pressure-side flow path 12, but the expansion-side damping. The valve 3A is pressed against the valve seat 15 to act as a valve closing direction.

  Further, notches 20 are formed in the outer peripheral portions of the first leaf valves 2a and 2e, respectively, to form a known orifice. The orifice may be formed by forming grooves in the valve seats 15 and 18. In the present embodiment, the expansion side and compression side damping valves 3A and 3B have the same configuration, but may have different configurations, and the number of stacked leaf valves 2a to 2d and 2e to 2h is also appropriate. It is possible to change.

  As shown in FIG. 2, the extension side and pressure side spacers 4A and 4B stacked on the damping valves 3A and 3B are in contact with the damping valves 3A and 3B at one end facing the damping valve side, respectively. A support surface 41 in which the axial hole 40 is opened and a step surface 43 extending from the support surface 41 to the outer peripheral side and having a step 42 between the support surface 41 and spaced from the damping valves 3A and 3B are formed. Yes. The support surface 41 is a cut-out circular shape in which a part of a circle is cut out with a straight line, and the outer periphery thereof does not become a true circle having a center on the axial center line x1 of the shock absorber D. Further, the axial hole 40 is a true circle having a center on the axial center line x1 of the shock absorber D. From the outer peripheral edge to the inner peripheral edge of the support surface 41 in a part in the circumferential direction of the spacers 4A and 4B. A portion where the width w is smaller than other portions is formed. Further, since the spacers 4A and 4B have a stepped surface 43 continuous to the outer peripheral side of the support surface 41, the space w for the damping valves 3A and 3B is secured and the width w is made smaller than the conventional one. However, the strength of this portion can be increased, and the portion can be produced by a method excellent in mass productivity such as sintering, forging and press molding.

  Further, the other side end of each spacer 4A, 4B has a point-symmetrical shape with respect to the one side end, and when the other side end is assembled with the other side end facing the damping valve side, the damping valve 3A. , 3B and a support surface 44 in which the axial hole 40 opens, and a step surface extending from the support surface 44 to the outer peripheral side and having a step 45 between the support surface 44 and spaced apart from the damping valves 3A, 3B 46 is formed. By doing in this way, there is no front and back in the spacers 4A and 4B, and there is no fear of wrong assembly in which the front and back of the spacers 4A and 4B are mistakenly assembled. Further, as described above, since the support surfaces 41 and 44 are not circular, when the both ends of the spacers 4A and 4B are point-symmetrical, the step surfaces 43 and 46 are positioned at both ends in the diameter direction. Do not overlap. When the step surfaces 43 and 46 overlap, it is necessary to increase the thickness of the spacers 4A and 4B in order to ensure the thickness of this portion.

  Hereinafter, the operation of the piston valve P1 of the shock absorber D according to the present embodiment will be described.

  The piston rod 5 is retracted from the cylinder 6 and the expansion valve R1 is pressurized by the piston valve P1. During the expansion of the shock absorber D, the expansion valve 3A is opened until the expansion valve 3A is opened. Since the pressurized hydraulic fluid in the chamber R1 on the extension side passes through the notch 20 and moves to the chamber R2 on the compression side, the shock absorber D generates a damping force having a square characteristic peculiar to the orifice. The damping coefficient (ratio of the damping force increase amount to the piston speed increase amount) at this time is relatively large.

  Subsequently, when the piston speed increases and the pressure in the expansion-side chamber R1 reaches the valve opening pressure of the expansion-side damping valve 3A, the outer peripheral portion of the expansion-side damping valve 3A bends toward the anti-piston side, Since the hydraulic oil in the room R1 passes through the gap formed between the extension side damping valve 3A and the valve seat 15 and moves to the pressure side room R2, the shock absorber D generates a damping force having a valve characteristic. At this time, the gap formed between the extension-side damping valve 3A and the valve seat 15 becomes larger as the pressure in the extension-side chamber R1 increases, so the damping coefficient becomes relatively smaller.

  Further, in the present embodiment, a portion with a small contact width with the extension side spacer 4A is provided in a part of the extension side damping valve 3A in the circumferential direction, and this contact width is smaller than the conventional one. Yes. For this reason, when the expansion side damping valve 3A is opened, a part of the circumferential direction starts to bend in advance from the stage where the piston speed is lower than the conventional one, and thereafter, the bending range operates so as to spread over the entire circumference. . For this reason, as shown in FIG.9 (c), the connection at the time of changing from the damping force of an orifice characteristic to the damping force of a valve characteristic can be made smoother than before.

  On the contrary, when the shock absorber D in which the piston rod 5 enters the cylinder 6 and the pressure side chamber R2 is pressurized by the piston valve P1, the compression side damping valve 3B is the same as the expansion side damping valve 3A. Since it exhibits an operation, detailed description is omitted.

  Hereinafter, the effect of the valve structure of the shock absorber D according to the present embodiment will be described.

  In the present embodiment, the spacers 4A and 4B are formed by sintering.

  The manufacturing method is a manufacturing method excellent in mass productivity, and the spacers 4A and 4B can be easily formed in the shape described above. However, the method of forming the spacers 4A and 4B is not limited to the above, and can be changed as appropriate.

  Moreover, in this Embodiment, the support surfaces 41 and 44 are circular.

  According to the above configuration, when both ends in the axial direction of the spacers 4A and 4B are point-symmetric, the stepped surfaces 43 and 46 at both ends do not overlap. Therefore, since the thickness of the portion where the step surfaces 43 and 46 overlap is ensured, it is possible to prevent the thickness of the spacers 4A and 4B from increasing. In the present embodiment, the support surfaces 41 and 44 have a shape in which a part of the circle is cut out with a straight line, but as shown in FIG. It may be. Moreover, the shape of the support surfaces 41 and 44 should just be formed so that outer periphery may not become a perfect circle centered on the axial center line x1, for example, an ellipse as shown in FIG. It may be a triangle as shown.

  Moreover, in this Embodiment, the other side edge of spacer 4A, 4B has a point-symmetrical shape with one side edge.

  According to the above configuration, the spacers 4A and 4B do not have the front and back sides, so that it is possible to prevent erroneous assembly and to facilitate assembly work. However, both ends of the spacers 4A and 4B may not be point-symmetrical, and the support surface 41 and the step surface 43 may be formed only at one end facing the piston side.

  In the present embodiment, the valve structure of the shock absorber includes an annular piston (valve disk) 1 that partitions the expansion side and pressure side chambers R1 and R2, and the piston 1 formed on the expansion side and the compression side. Damping valves comprising flow paths 11 and 12 communicating with the chambers R1 and R2, and one or more annular plate-like leaf valves 2a to 2d and 2e to 2h stacked on the piston 1 and closing the flow paths 11 and 12 3A, 3B and annular plate-like spacers 4A, 4B stacked on the damping valves 3A, 3B. The piston 1, the damping valves 3A, 3B, and the spacers 4A, 4B Are held on the outer periphery of a piston rod (shaft member) 5 inserted through the shaft center holes 10, 30, and 40, and the damping valves 3A and 3B are supported on the inner periphery by the spacers 4A and 4B. Bend the part to the non-piston side Allowed by opening the flow path 11, 12. Further, at one end of the spacers 4A and 4B facing the damping valve side, the abutting against the damping valves 3A and 3B, the shaft hole 40 is opened, and the outer periphery has a center on the shaft center line x1. A support surface 41 formed so as not to be circular, and a step surface 43 extending from the support surface 41 to the outer peripheral side and having a step 42 between the support surface 41 and spaced from the damping valves 3A and 3B. Is formed.

  According to the above configuration, the width w from the outer peripheral edge to the inner peripheral edge of the spacers 4A and 4B corresponding to the portion to be opened in advance in the damping valves 3A and 3B is made smaller than that of the conventional spacer. Even if the contact width between 4A and 4B and the damping valves 3A and 3B is reduced, a manufacturing method with excellent mass productivity, such as sintering, forging, press molding, etc., can be adopted, so that mass productivity is not deteriorated.

  In this embodiment, the spacers 4A and 4B according to the present invention are provided on both sides of the piston (valve disk) 1 in the axial direction, but may be provided only on one side of the piston 1.

  Further, as shown in FIG. 6, a protrusion 47 may be raised on the step surfaces 43 and 46 of the spacers 4 </ b> A and 4 </ b> B, and the bending amount of the damping valves 3 </ b> A and 3 </ b> B may be regulated by the protrusion 47. In this way, after the outer peripheral portions of the damping valves 3A and 3B come into contact with the protrusion 47, the pressure in the chambers R1 and R2 acting in the direction to open the damping valves 3A and 3B increases the piston speed. Even if it rises, the gap formed between the damping valves 3A and 3B and the valve seats 15 and 18 does not become large. Therefore, as shown in FIG. 7, the damping coefficient when the piston speed becomes extremely high is relatively high. Can be bigger.

  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.

D Shock absorber R1, R2 Room x1 Axle 1 Piston (valve disc)
2a to 2h Leaf valve 3A, 3B Damping valve 4A, 4B Spacer 5 Piston rod (shaft member)
DESCRIPTION OF SYMBOLS 10 Piston (valve disc) axial hole 11 and 12 Flow path 30 Damping valve axial hole 40 Spacer axial hole 41 Support surface 42 Level difference 43 Level difference surface

Claims (4)

An annular valve disc that separates the two chambers;
A flow path formed in the valve disc and communicating the two chambers;
A damping valve comprising one or more annular plate-like leaf valves stacked on the valve disk to block the flow path;
An annular plate-like spacer stacked on the valve disc side of the damping valve;
A valve stopper laminated on the anti-damping valve side of the spacer,
The valve disc, the damping valve, the spacer, and the valve stopper are held on the outer periphery of a shaft member that is inserted through the shaft hole,
In the valve structure of the shock absorber, the damping valve supports the inner peripheral portion with the spacer, and deflects the outer peripheral portion to the side opposite to the valve disc to open the flow path.
One end of the spacer facing the damping valve side is formed so as to abut against the damping valve and to open the shaft hole so that the outer periphery does not become a true circle centered on the axis. A shock absorber valve structure, comprising: a support surface; and a step surface extending from the support surface to an outer peripheral side and having a step between the support surface and a distance from the damping valve. The cross-sectional view when the spacer is cut in the radial direction, the other side end of the spacer is point-symmetric with respect to the one side end and the center of the spacer. Item 2. The shock absorber valve structure according to Item 1. The buffer structure for a shock absorber according to claim 1 or 2, wherein the support surface has a circular shape. The valve structure of the shock absorber according to any one of claims 1 to 3, wherein the spacer is a sintered body .

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