JP2016070459A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper capable of improving its assembly characteristic and improving durability of a check valve even if an orifice for use in generating attenuation for in a low speed region is effective at one side with a check valve.SOLUTION: A damper D comprises: the first relief valve 40 formed with a passage 2A formed at a piston 1 to communicate with the two chambers and a hole 40a laminated at the piston 1 to open or close the passage 2A and communicated with the passage 2A; an annular ring 43 arranged at the rear surface side of the first leaf valve 40 and enclosing a space SA communicating with the hole 40a; the second leaf valve 41 laminated at the rear surface side of the first leaf valve 40 and sat on a ring 43; a recess 41a formed at either the ring 43 or the second leaf valve 41 to communicate with the inner peripheral side and the outer peripheral side of the ring 43; an orifice arranged in the midway part of a branch passage 20 passing through the hole 40a, the space SA and the recess 41a; and a check valve 9A arranged at the inner peripheral side of the ring 43 to open or close the hole 40a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a shock absorber.

  The shock absorber includes a cylindrical cylinder, a piston that is a valve disk inserted in the cylinder so as to be movable in the axial direction, a rod that is connected to the piston and that has one end extending outside the cylinder, and a piston. Two chambers that are partitioned and filled with hydraulic oil, a passage that communicates with these chambers, and a leaf valve that is stacked on the piston in a state in which bending on the outer periphery side is allowed, the outer peripheral side of the leaf valve There is one that opens and closes a passage by being seated on a seat formed on a piston. When such a shock absorber expands and contracts, a leaf valve provides resistance to the flow of fluid that passes through the passage and passes between the chambers, creating a pressure difference between the two chambers and generating a damping force.

  In particular, when a shock absorber is used for damping a vehicle body in a vehicle, a damping characteristic (a shock absorber) in which a damping force rises relatively large when the piston speed is in a low speed region, for example, because it can improve riding comfort. It is preferable to realize a characteristic of a damping force generated with respect to the piston speed. Therefore, the bending rigidity of the leaf valve is set so as not to open in the low speed region, and a restriction is provided on the leaf valve itself or the seat. By doing in this way, until the leaf valve is opened, the shock absorber generates a damping force due to resistance when the fluid passes through the throttle (for example, Patent Documents 1 and 2). Further, some shock absorbers are configured such that a throttle is opened and closed by a check valve, and attenuation characteristics in a low speed region can be set independently and independently in an extension stroke and a compression stroke (for example, Patent Document 3).

JP 2003-42213 A JP 11-294515 A JP 2010-112464 A

  Here, the shock absorber disclosed in FIG. 1 of Japanese Patent Application Laid-Open No. 2010-112464 includes a piston that is a valve disk that partitions an upper chamber and a lower chamber. The piston is formed with an expansion side port and a pressure side port, which are passages that connect the upper chamber and the lower chamber. Then, the extension side port is opened and closed by the extension side laminated leaf valve laminated on the lower side of the piston, and the pressure side port is opened and closed by the pressure side laminated leaf valve laminated on the upper side of the piston. The extension side laminated leaf valve is composed of a plurality of extension side leaf valves, and the pressure side laminated leaf valve is constituted of a plurality of pressure side leaf valves.

  An arc-shaped cut is formed in the first pressure side leaf valve from the piston side, and the inside of this cut is a valve body (check valve). The second pressure side leaf valve is formed with a throttle that can be opened and closed by the valve body and communicated with the pressure side port. This aperture is set to always communicate with the upper chamber. Then, the valve body is bent toward the piston side in the expansion stroke of the shock absorber, and is separated from the second pressure side leaf valve to open the throttle.

  On the other hand, an annular plate including an annular outer ring and a valve body (check valve) protruding from the outer ring to the inner peripheral side is interposed between the first extension leaf valve and the piston from the piston side. ing. Further, the first leaf-side leaf valve is formed with a throttle that can be opened and closed by the valve body and communicated with the stretching-side port. This aperture is set to always communicate with the lower chamber. Then, the valve body is bent toward the piston side in the compression stroke of the shock absorber and is separated from the first extension side leaf valve to open the throttle.

  According to the above configuration, in the expansion stroke when the piston speed is in the low speed region, the throttle side leaf valve throttle communication is blocked and the compression side leaf valve throttle communication is allowed. Passes only through the leaf valve throttle. On the contrary, in the compression stroke when the piston speed is in the low speed region, the communication of the throttle of the compression side leaf valve is blocked and the communication of the throttle of the extension side leaf valve is allowed, so that the hydraulic oil is expanded. Pass only through the aperture. For this reason, in the low speed region, the shock absorber generates a damping force due to the resistance of the throttle of the compression side leaf valve in the expansion stroke, and generates a damping force due to the resistance of the throttle of the expansion side leaf valve in the compression stroke. In other words, according to the above configuration, the diaphragm can be used in one effect, and the attenuation characteristics in the low speed region can be set independently and independently in the expansion stroke and the compression stroke. However, the following problems can occur in the above configuration.

  First, in the conventional configuration, the valve body is a portion protruding to the inner side of the notch or the inner peripheral side of the annular plate, and one throttle is opened and closed by one valve body. . And if a throttle and a valve body shift | deviate in the circumferential direction, a throttle will always be connected and it will not become one effect. For this reason, it is necessary to position the valve body (check valve) in the rotational direction so that the valve body does not shift with respect to the throttle. Therefore, when the diaphragm is set to one effect using the conventional configuration, positioning in the rotational direction is required and the assembling property is deteriorated.

  Secondly, the seat has an arcuate outer seat part, such as an independent port structure in which the passage is individually enclosed by the seat, and two pieces extending from the circumferential ends of the outer seat part toward the center axis of the piston. And a pair of intermediate seat portions, one outlet of the extension side port and the compression side port is provided inside the seat, and the other inlet of the extension side port and the compression side port is provided outside the seat. Since the valve cannot be opened when the body overlaps the intermediate seat portion, the width of the valve body is limited and the valve body cannot be enlarged. If the deformation of the valve body is large, stress concentrates on the deformed portion, so that the durability of the valve body may be lowered depending on the flow rate of the fluid passing through the throttle.

  The first and second problems described above are not limited to the case where the valve disk is made of a piston. The first and second problems described above may also occur when only one of the throttle that works in the expansion stroke and the throttle that works in the compression stroke is provided.

  Therefore, the object of the present invention is to solve the first and second problems and improve the assemblability even when the throttle for generating the damping force in the low speed region is made one-sided with the check valve. Another object of the present invention is to provide a shock absorber capable of improving the durability of the check valve.

  Means for solving the above-described problems include a valve disc that divides two chambers, a passage formed in the valve disc and communicating with the two chambers, and stacked on the valve disc to open and close the passage. A first leaf valve in which a hole communicating with the passage is formed, an annular ring provided on the back side of the first leaf valve and surrounding a space communicating with the hole, and on the back side of the first leaf valve A second leaf valve stacked and seated on the ring; a notch formed on the ring or the second leaf valve and communicating between an inner peripheral side and an outer peripheral side of the ring; the hole, the space, and the notch And a check valve provided on the inner peripheral side of the ring for opening and closing the hole.

  According to the present invention, even if the throttle for generating the damping force in the low speed region is made one-sided by the check valve, the assemblability can be improved and the durability of the check valve can be improved.

It is the front view which notched and showed the principal part of the buffer which concerns on one embodiment of this invention. It is the top view which expanded and showed the piston of the buffer which concerns on one embodiment of this invention. It is the bottom view which expanded and showed the piston of the buffer which concerns on one embodiment of this invention. It is the figure which expanded and showed a part of FIG. It is the figure which expanded and showed other one part of FIG. It is the top view which decomposed | disassembled and showed the expansion side valve body of the buffer which concerns on one embodiment of this invention. It is the top view which decomposed | disassembled and showed the pressure side valve body of the buffer which concerns on one embodiment of this invention. It is the top view which showed the example of a change of the 1st leaf valve in the buffer which concerns on one embodiment of this invention.

  Embodiments 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 FIGS. 1, 4, and 5, a shock absorber D according to an embodiment of the present invention includes a piston (valve disk) 1 that partitions an extension side chamber L1 and a compression side chamber L2 (two chambers), and the piston. Passages 2A and 2B that are formed in the passage 1 and communicate with the extension side chamber L1 and the compression side chamber L2, and holes 40a and 50a that are stacked on the piston 1 to open and close the passages 2A and 2B and communicate with the passages 2A and 2B. The first leaf valves 40, 50, and the annular rings 43, 53 provided on the back side of the first leaf valves 40, 50 and surrounding the spaces SA, SB communicating with the holes 40a, 50a, The second leaf valves 41 and 51 are stacked on the back side of the first leaf valves 40 and 50 and are seated on the rings 43 and 53, and the second leaf valves 41 and 51 are formed on the rings 43 and 53. Circumferential side Notches 41a, 51a communicating with the outer peripheral side, throttles provided in the middle of the branch passages 20, 21 passing through the holes 40a, 50a, the spaces SA, SB and the notches 41a, 51a, and the rings 43, 53 Check valves 9A and 9B are provided on the inner peripheral side to open and close the holes 40a and 50a.

  Hereinafter, in detail, the shock absorber D according to the present embodiment is interposed between the vehicle body and the wheel of the automobile and used for damping the vehicle body. As shown in FIG. 1, the shock absorber D includes a cylindrical cylinder C, a piston 1 slidably inserted into the cylinder C, one end connected to the piston 1 and the other end outside the cylinder C. And a free piston 7 slidably inserted into the inner peripheral surface of the cylinder C on the opposite rod side. In the cylinder C, two chambers (L1, L2) partitioned by the piston 1 and filled with hydraulic oil, and the chamber (L2) on the piston 1 side of these chambers (L1, L2) are free. An air chamber G defined by the piston 7 and filled with gas is formed. Hereinafter, of the two chambers (L1, L2) filled with hydraulic oil, the chamber on the rod 6 side which is the upper side in FIG. 1 is the expansion side chamber L1, and the chamber on the piston 1 side which is the lower side in FIG. And

  In this embodiment, the cylinder C is connected to the wheel side, the other end of the rod 6 protruding from the cylinder C is connected to the vehicle body side, and the shock absorber D is set upright. When the shock due to is input to the wheel, the rod 6 enters and exits the cylinder C and the shock absorber D expands and contracts. Further, the change in volume in the cylinder corresponding to the rod protruding and retracting volume when the shock absorber D expands and contracts can be compensated by the expansion and contraction of the air chamber G accompanying the movement of the free piston 7, and the shock absorber D is a single cylinder type. Is set to

  The configuration of the shock absorber D is not limited to the above, and can be changed as appropriate. For example, the cylinder C may be connected to the vehicle body side and the rod 6 may be connected to the wheel side so that the shock absorber D is set upside down. In addition, an outer cylinder is provided on the outer periphery of the cylinder C so that the shock absorber D is set to a double cylinder type, and hydraulic oil and gas are sealed in a reservoir formed between the cylinder C and the outer cylinder, and the rod extends and retracts in the reservoir. A change in the cylinder volume corresponding to the volume may be compensated. As described above, when the shock absorber D is set to a double cylinder type, the reservoir and the pressure side chamber L2 may be partitioned by the valve disk according to the present invention. Further, in the present embodiment, the hydraulic oil is used for generating the damping force, but a liquid or gas other than the hydraulic oil may be used.

  Subsequently, in the present embodiment, the piston 1 slidably inserted into the cylinder C is the valve disk according to the present invention, and as described above, the two chambers of the expansion side chamber L1 and the compression side chamber L2 are partitioned. doing. The piston 1 is formed in an annular shape with a center hole 10 (FIGS. 2 and 3) that allows the rod 6 to be inserted, and the rod 6 is mounted together with valve bodies 4 and 5 that are stacked on the top and bottom of the piston 1, respectively. The outer periphery of the portion 60 is held by a nut 61.

  As shown in FIGS. 2 and 3, passages 2 </ b> A and 2 </ b> B that penetrate the piston 1 in the axial direction are formed in the piston 1. There are two types of passages 2A and 2B: a passage 2A that opens in the expansion stroke and a passage 2B that opens in the compression stroke. In order to distinguish these, the former is hereinafter referred to as the expansion side passage 2A and the latter is referred to as the compression side passage 2B. Further, among the valve bodies 4 and 5, the valve body 4 that opens and closes the expansion side passage 2 </ b> A is referred to as the expansion side valve body 4, and the valve body 5 that opens and closes the pressure side passage 2 </ b> B is referred to as the pressure side valve body 5.

  The extension side passages 2A and the pressure side passages 2B are formed three by three alternately in the circumferential direction. In the extension side passages 2A and the pressure side passages 2B, the island portions 11 each have a central axis X of the piston 1. It protrudes from the side toward the outer peripheral side.

  As shown in FIG. 3, a seat 3 </ b> A surrounding the outlet 12 of the extension side passage 2 </ b> A and a boss portion 8 </ b> A provided inside the seat 3 </ b> A are formed in the lower portion of the piston 1, while As shown in FIG. 2, a sheet 3B that surrounds the outlet 15 of the pressure side passage 2B and a boss portion 8B provided inside the sheet 3B are formed. Hereinafter, in order to distinguish between the sheets 3A and 3B, the sheet 3A surrounding the outlet of the extension side passage 2A is referred to as the extension side sheet 3A, and the sheet 3B surrounding the outlet of the compression side passage 2B is referred to as the compression side sheet 3B.

  The pressure side sheet 3B and the boss portion 8B formed on the upper portion of the piston 1 protrude upward, the stretch side sheet 3A and the boss portion 8A formed on the lower portion of the piston 1 protrude downward, and the island portion 11 protrudes up and down. Yes. As shown in FIG. 5, the top side of the pressure side sheet 3 </ b> B, the boss portion 8 </ b> B, and the island portion 11 protruding upward is disposed on the same plane orthogonal to the central axis X of the piston 1. The extending side sheet 3 </ b> A, the boss 8 </ b> A, and the top of the island 11 are arranged on the same plane orthogonal to the central axis X of the piston 1. In other words, in the present embodiment, the extension side valve body 4 and the pressure side valve body 5 stacked on the piston 1 are set so as not to be initially bent. However, in the extension side sheet 3A and the pressure side sheet 3B, the piston 1 An outer sheet portion 30 to be described later arranged on the outer peripheral side may protrude from the boss portions 8A and 8B and give initial deflection to both or one of the extension side valve body 4 and the pressure side valve body 5.

  As shown in FIGS. 2 and 3, the compression side sheet 3 </ b> B and the extension side sheet 3 </ b> A formed on the upper and lower sides of the piston 1 are each composed of three arcuate outer sheet portions 30 and circumferential directions of these outer sheet portions 30. A total of six linear intermediate sheet portions 31 extending from both ends to the central axis X side of the piston 1 and adjacent to each other extending from the central axis X side ends of these intermediate sheet portions 31 toward the opposite outer sheet portion side in the circumferential direction. A linear inner sheet portion 32 that connects the intermediate sheet portion 31 is provided, and the shape is like a closed ring.

  As shown in FIG. 3, in the stretch side sheet 3 </ b> A formed in the lower part of the piston 1, the stretch side passage is formed between the intermediate sheet portion 31 connected to the inside of the stretch side sheet 3 </ b> A and the outer sheet portion 30. An outlet 12 of 2A is provided, and an inlet 13 of the pressure side passage 2B is provided between the intermediate sheet portion 31 that is connected to the outer side of the stretched sheet 3A and the inner sheet portion 32.

  And the exit 12 of the extension side passage 2A opens to a window 14 formed around the boss portion 8A and the island portion 11 protruding into the extension side passage 2A up to the inner peripheral end of the extension side sheet 3A. When the extension side valve body 4 is seated on the extension side seat 3A, the extension side valve body 4 closes the window 14, and thereby the extension side passage 2A is closed. At this time, the area of the portion facing the window 14 becomes the pressure receiving area of the expansion side valve body 4, and the expansion side valve body 4 receives the pressure of the expansion side chamber L1 and opens the expansion side passage 2A. The inlet 13 of the pressure side passage 2B is not blocked by the extension side valve element 4 even when the extension side valve element 4 is seated on the extension side seat 3A, and is always in communication with the compression side chamber L2. ing.

  On the other hand, as shown in FIG. 2, in the pressure side sheet 3 </ b> B formed on the upper part of the piston 1, the outlet of the pressure side passage 2 </ b> B is interposed between the intermediate sheet part 31 connected to the inner side of the pressure side sheet 3 </ b> B and the outer sheet part 30. 15 is provided, and the inlet 16 of the extension side passage 2A is provided between the intermediate sheet portion 31 that is outside the compression side sheet 3B and connected by the inner sheet portion 32.

  The outlet 15 of the pressure side passage 2B opens to a window 17 formed up to the inner peripheral end of the pressure side seat 3B around the island portion 11 protruding into the boss portion 8B and the pressure side passage 2B. When 5 is seated on the pressure side seat 3B, the window 17 is closed by the pressure side valve body 5, and the pressure side passage 2A is thereby closed. At this time, the area of the portion facing the window 17 becomes the pressure receiving area of the pressure side valve body 5, and the pressure side valve body 5 receives the pressure of the pressure side chamber L2 and opens the pressure side passage 2B. The inlet 16 of the extension side passage 2A is not blocked by the pressure side valve body 5 even when the pressure side valve body 5 is seated on the pressure side seat 3B, and is always in communication with the extension side chamber L1. .

  In the present embodiment, the inlet 16 and the outlet 12 of the expansion side passage 2A are opposed to the upper and lower sides of the piston 1, and similarly, the outlet 15 and the inlet 13 of the compression side passage 2B are opposed to the upper and lower sides of the piston 1. As a result, the extension-side passage 2A and the compression-side passage 2B can be formed straight along the central axis X of the piston 1, so that the piston 1 can be easily formed.

  Further, in the present embodiment, the inner sheet portion 32 of the stretch side sheet 3A and the inner sheet portion 32 of the compression side sheet 3B both have a linear shape, and are disposed on both sides of the inner sheet portion 32. It is provided along the straight line y on the straight line y connecting the ends of the intermediate sheet portion 31 on the central axis X side. By the way, the extension side passage 2A can be expanded to the outer end of the inner sheet portion 32 of the compression side sheet 3B, and the compression side passage 2B can be extended to the outer end of the inner sheet portion 32 of the extension side sheet 3B. For this reason, as above-mentioned, the flow path area of the expansion side channel | path 2A and the pressure side channel | path 2B can be enlarged by setting it as the structure which the inner side sheet | seat part 32 does not protrude to the outer peripheral side of the piston 1 exceeding the straight line y.

  Subsequently, the boss portion 8A provided inside the stretch side sheet 3A and the boss portion 8B provided inside the compression side sheet 3B are both formed in an annular shape so as to surround the center hole 10 of the piston 1, and the boss portion The widths of 8A and 8B, that is, the width from the inner peripheral end to the outer peripheral end are formed to be partially narrow or wide. Specifically, the outer peripheral shape of the boss portions 8A and 8B is a triangular shape with rounded corners, the rounded apex portion faces the outer sheet portion 30, and the linear side portion is the inner sheet portion. 32. Since the center hole 10 of the piston 1 is a perfect circle according to the outer peripheral shape of the mounting portion 60 of the rod 6, the width of the portion a facing the outer sheet portion 30 in the boss portions 8A and 8B is the inner sheet. It becomes wider than the width of the part b facing the part 32.

  According to the above configuration, the expansion valve body 4 is supported in the boss portion 8A, the area of the portion that receives the load when the piston is fixed is secured, and the distance between the boss portion 8A and the inner seat portion 32 is reduced, so that the hydraulic oil Can be prevented from passing. Similarly, the pressure side valve element 5 is supported in the boss portion 8B, and the area of the portion that receives the load at the time of fixing the piston is secured, and the interval between the boss portion 8B and the inner seat portion 32 is narrowed so that the hydraulic oil does not easily pass. Can be prevented.

  Further, as in the present embodiment, the extension side passage 2A, the compression side passage 2B, the outer sheet portion 30 and the inner sheet portion 32 of the extension side sheet 3A, and the outer sheet portion 30 and the inner sheet portion 32 of the compression side sheet 3B. If the number is the same, and the number is n, the shape of the bosses 8A and 8B is an n-corner with rounded corners, the curved apex portion is opposed to the outer sheet portion 30, and a straight side portion is formed. By facing the inner sheet portion 32, the same effect as described above can be obtained. If n is increased, the flow passage area of the extension side passage 2A and the pressure side passage 2B is reduced, and the damping coefficient when the piston speed is in the medium to high speed region is increased. n = 2 to 4 is preferable, and n = 3 is most preferable, but the value of n can be changed as appropriate.

  Subsequently, a total of six island portions 11 projecting into the extension side passage 2A and the pressure side passage 2B are arranged on the same circumference and alternately arranged with the intermediate sheet portion 31. And the pressure side valve body 5 laminated | stacked on the upper side of the piston 1 is supported by the upper part of each said island part 11, and while preventing this pressure side valve body 5 from cracking by back pressure, the lower part of each island part 11 of piston 1 The extension side valve body 4 stacked on the lower side is supported, and the extension side valve body 4 is prevented from being broken by back pressure.

  As shown in FIGS. 4 and 6, the expansion side valve element 4 includes a first leaf valve 40 which is seated on the extension side seat 3 </ b> A of the piston 1 and has a hole 40 a, and a rear side (anti-piston) of the first leaf valve 40. A laminated leaf valve including a second leaf valve 41 having a notch 41a and a plurality of normal leaf valves 42a, 42b and 42c which are sequentially laminated on the back side of the second leaf valve 41. V1 is provided. An annular ring 43 is provided between the outer peripheral part of the first leaf valve 40 and the outer peripheral part of the second leaf valve 41, and the inner peripheral side of the first leaf valve 40 on the inner peripheral side of the ring 43. An annular spacer 44 is provided between the inner peripheral portions of the second leaf valve 41, and a check valve 9 </ b> A is provided on the inner peripheral side of the ring 43 and on the outer peripheral side of the spacer 44.

  In addition, an annular spacer 45 is stacked on the lower side of the extension side valve body 4 in FIG. 4, and the extension side valve body 4 is sandwiched between the spacer 45 and the boss portion 8A on the inner peripheral side. Is fixed. And the expansion side valve body 4 opens the expansion side channel | path 2A by deflecting the outer peripheral side rather than the spacer 45 to the lower side in FIG. 4 in the expansion process of the buffer D, and passes through the said expansion side channel | path 2A. Provides resistance to hydraulic fluid flow. On the contrary, in the compression stroke of the shock absorber D, the expansion side valve body 4 closes the expansion side passage 2A, and the first leaf valve 40 is maintained in a state of being seated on the expansion side seat 3A.

  As shown in FIG. 6, the first leaf valve 40 is formed with four arc-shaped holes 40 a penetrating the wall thickness. Four of these holes 40a are arranged side by side on the same circumference. When the first leaf valve 40 is overlapped with the piston 1, all of the holes 40a are opposed to the inside of the extended side seat 3A. Here, when the number of holes 40a is reduced, each hole 40a can be enlarged, but when the first leaf valve 40 is bent, stress tends to concentrate between the holes 40a and 40a, and the first leaf valve 40 There is a tendency to lower the durability. On the other hand, when the number of holes 40a is increased, each hole 40a becomes smaller. However, since the stress can be dispersed when the first leaf valve 40 is bent, the durability of the first leaf valve 40 is improved. Can be increased. Therefore, when the hole 40a is not used as a throttle as in the present embodiment, four holes 40a are formed to increase the opening amount of the hole 40a and ensure the durability of the first leaf valve 40. It is preferable to do. However, the number, shape, and size of the holes 40a are not limited to the above and can be arbitrarily changed.

  As described above, since the shape of the boss portion 8A is a triangular shape with rounded corners, the area where the boss portion 8A and the hole 40a overlap is reduced, and the opening area of the hole 40a can be increased as much as possible.

  A ring 43 provided between the outer peripheral part of the first leaf valve 40 and the outer peripheral part of the second leaf valve 41 is fixed to the outer peripheral part on the back side of the first leaf valve 40. The ring 43 and the first leaf valve 40 can be fixed by any method as long as the ring 43 does not move from a predetermined position of the first leaf valve 40, such as adhesion, welding, and integral formation.

  Further, the spacer 44 provided between the inner peripheral portion of the first leaf valve 40 and the inner peripheral portion of the second leaf valve 41 is sandwiched and fixed between the spacer 45 and the boss portion 8A. The outer diameter of the spacer 44 is smaller than the inner diameter of the ring 43, the first leaf valve 40 and the second leaf valve 41 are separated by the ring 43 and the spacer 44, and the inner periphery side of the ring 43. A space SA for accommodating the check valve 9A is formed. The inner diameter of the ring 43 is formed to be larger than the diameter of a circle connecting the outer peripheral ends of the hole 40a of the first leaf valve 40, and the hole 40a and the space SA are communicated with each other.

  Further, in the present embodiment, the thickness of the ring 43 is equal to the thickness of the spacer 44, and is set so as not to give initial deflection to the leaf valves 42a, 42b, 42c after the second leaf valve 41. However, the ring 43 may be set to be thicker than the spacer 44 so as to apply initial deflection to the leaf valves 42a, 42b, and 42c after the second leaf valve 41.

  Subsequently, the second leaf valve 41 stacked on the back side of the first leaf valve 40 has an inner peripheral portion thereof stacked on the spacer 44 and an outer peripheral portion seated on the ring 43. The second leaf valve 41 is formed with four notches 41a from the outer peripheral end toward the center. As shown in FIG. 4, the notch 41 a is set to a length that traverses the ring 43 in the radial direction, and a space SA formed on the inner peripheral side of the ring 43 and a pressure side chamber formed on the outer peripheral side of the ring 43. Communicate with L2. As described above, the space SA can communicate with the extension side passage 2A through the hole 40a and the window 14, and the hydraulic oil in the extension side passage 2A passes through the branch passage 20 passing through the hole 40a, the space SA, and the notch 41a. It can move to pressure side chamber L2.

  In the present embodiment, the leaf valve 42a stacked on the back side of the second leaf valve 41 has an outer diameter substantially the same as the outer diameter of the second leaf valve 41, and closes the lower side of the notch 41a. Is set to In the present embodiment, the notch 41a is narrowed to form a throttle, and a known orifice is formed by the notch 41a. In addition, the notch 41a which connects the inner peripheral side and the outer peripheral side of the ring 43 may be provided in the ring 43, and the position where the notch 41a is provided and the shape of the notch 41a can communicate the space SA and the pressure side chamber L2. As long as it can be changed arbitrarily. In the present embodiment, the notch 41a is a throttle, but the position where the throttle is provided can be arbitrarily changed as long as it is in the middle of the branch passage 20.

  Subsequently, the check valve 9A provided on the inner peripheral side of the ring 43 is thinner than the ring 43 and the spacer 44, is in sliding contact with the outer peripheral surface of the spacer 44, and can move up and down in FIG. And a plurality of urging portions 91 that urge the valve portion 90 in a direction in which the valve portion 90 is pressed against the first leaf valve 40. The valve portion 90 is set so as to close all the holes 40a when pressed against the first leaf valve 40 according to the urging force of the urging portion 91. The urging portion 91 extends radially from the outer periphery of the valve portion 90, rises obliquely from the outer periphery of the valve portion 90 toward the second leaf valve 41, and is bent at the end toward the first leaf valve 40 side. It has been. The check valve 9A has elasticity, and by changing or returning the inclination angle of the urging portion 91, the valve portion 90 is allowed to move up and down, and the hole 40a can be opened and closed.

  Then, the check valve 9A moves the valve portion 90 downward in FIG. 4 in the extension stroke of the shock absorber D to open the hole 40a, and allows the flow of hydraulic oil from the hole 40a toward the space SA. For this reason, in the extension stroke of the shock absorber D, the check valve 9A opens the hole 40a even if the first leaf valve 40 is seated on the extension side seat 3A until the valve opening pressure of the extension side valve body 4 is reached. When opened, the hydraulic oil in the extension side passage 2A passes through the branch passage 20 in the order of the hole 40a, the space SA, and the notch 41a and moves to the compression side chamber L2. On the contrary, in the compression stroke of the shock absorber D, the check valve 9A closes the hole 40a, so that the communication of the branch passage 20 is blocked. According to the above-described configuration, the throttle formed by the notch 41a in the middle of the branch passage 20 can be a one-effect throttle that works only in the extension stroke of the shock absorber D, until the extension-side valve element 4 is opened. In the meantime, the shock absorber D can generate a damping force due to the resistance of the throttle (notch 41a).

  In the present embodiment, the deformation amount of the check valve 9A is regulated by the second leaf valve 41, and the opening amount of the check valve 9A is maximized when the valve portion 90 contacts the second leaf valve 41. In this way, by restricting the deformation amount of the check valve 9A by the second leaf valve 41, the deformation amount of the check valve 9A can be prevented from becoming excessive, and the durability of the check valve 9A can be improved. In addition, according to the above configuration, the size of the check valve 9A is not restricted by the sheet shape of the extended side sheet 3A, and the check valve 9A can be enlarged, so that the deformation amount of the check valve 9A becomes excessive. This can prevent this and improve the durability of the check valve 9A.

  Further, according to the above configuration, even if the check valve 9A and the first leaf valve 40 are relatively rotated in the circumferential direction, there is no problem even if the check valve 9A and the second leaf valve 41 are relatively rotated in the circumferential direction. Even if the (notch 41a) is set to be one-sided, positioning in the rotational direction of the check valve 9A is not required, and the assemblability can be improved.

  Subsequently, as shown in FIGS. 5 and 7, the pressure-side valve body 5 includes a first leaf valve 50 that is separated from and seated on the pressure-side seat 3 </ b> B of the piston 1 and has a hole 50 a, and a back surface side (reverse side) A laminated leaf including a second leaf valve 51 laminated on the piston 1 side and having a notch 51a, and a plurality of normal leaf valves 52a, 52b, 52c laminated in order on the back side of the second leaf valve 51. A valve V2 is provided. An annular ring 53 is provided between the outer peripheral portion of the first leaf valve 50 and the outer peripheral portion of the second leaf valve 51, and a check valve 9 </ b> B is provided on the inner peripheral side of the ring 53.

  Further, an annular spacer 54 is laminated on the upper side of the pressure side valve body 5 in FIG. 5, and the pressure side valve body 5 is fixed with the inner peripheral side being sandwiched between the spacer 54 and the boss portion 8B. ing. And the pressure side valve body 5 opens the pressure side channel | path 2B by deflecting the outer peripheral side rather than the spacer 54 to the upper side in FIG. 5 by the compression process of the buffer D, and the flow of the hydraulic fluid which passes the said pressure side channel | path 2B Give resistance. On the other hand, in the extension stroke of the shock absorber D, the pressure side valve body 5 closes the pressure side passage 2B, and the first leaf valve 50 is maintained in a seated state on the pressure side seat 3B.

  As shown in FIG. 7, the first leaf valve 50 is formed with four arc-shaped holes 50 a penetrating the wall thickness, similarly to the first leaf valve 40. Four of these holes 50a are arranged side by side on the same circumference. When the first leaf valve 50 is overlapped with the piston 1, all of the holes 50a are opposed to the inside of the pressure side seat 3B. Here, when the number of holes 50a is reduced, each hole 50a can be enlarged, but when the first leaf valve 50 is bent, stress tends to concentrate between the holes 50a and 50a, and the first leaf valve 50 There is a tendency to lower the durability. On the other hand, when the number of holes 50a is increased, each hole 50a becomes smaller. However, since the stress can be dispersed when the first leaf valve 50 is bent, the durability of the first leaf valve 50 is improved. Can be increased. For this reason, when the holes 50a are not used as an aperture as in this embodiment, the durability of the first leaf valve 50 is ensured while forming four holes 50a to increase the opening amount of the holes 50a. It is preferable to do. However, the number, shape, and size of the holes 50a are not limited to the above and can be arbitrarily changed.

  Further, as described above, since the boss portion 8B has a triangular shape with rounded corners, the area where the boss portion 8B and the hole 50a overlap is reduced, and the opening area of the hole 50a can be increased as much as possible.

  A ring 53 provided between the outer peripheral portion of the first leaf valve 50 and the outer peripheral portion of the second leaf valve 51 is fixed to the outer peripheral portion on the back side of the first leaf valve 50. The ring 53 and the first leaf valve can be fixed by any method as long as the ring 53 does not move from a predetermined position of the first leaf valve 50, such as adhesion, contact, and integral formation.

  The first leaf valve 50 and the second leaf valve 51 are separated from each other by the ring 53, and a space SB for accommodating the check valve 9B is formed on the inner peripheral side of the ring 53. The inner diameter of the ring 53 is formed larger than the diameter of a circle connecting the outer peripheral ends of the holes 50a of the first leaf valve 50, and the holes 50a and the spaces SB are communicated with each other.

  Subsequently, the second leaf valve 51 stacked on the back side of the first leaf valve 50 is configured such that the outer peripheral portion is seated on the ring 53. The second leaf valve 51 is formed with four notches 51a from the outer peripheral end toward the center. As shown in FIG. 5, the notch 51 a is set to a length that traverses the ring 53 in the radial direction, and a space SB formed on the inner peripheral side of the ring 53 and an extension side chamber formed on the outer peripheral side of the ring 53. Communicate with L1. As described above, the space SB can communicate with the pressure side passage 2B through the hole 50a and the window 17, and the hydraulic oil in the pressure side passage 2B passes through the branch passage 21 passing through the hole 50a, the space SB, and the notch 51a. It can move to the extension side chamber L1.

  In the present embodiment, the leaf valve 52a stacked on the back side of the second leaf valve 51 has an outer diameter substantially the same as the outer diameter of the second leaf valve 51, and closes the upper side of the notch 51a. Is set. In the present embodiment, the notch 51a is narrowed to form a throttle, and a known orifice is formed by the notch 51a. The notch 51a that communicates the inner peripheral side and the outer peripheral side of the ring 53 may be provided in the ring 53. The position where the notch 51a is provided and the shape of the notch 51a are capable of communicating the space SB and the extension side chamber L1. As long as it can be changed arbitrarily. Further, in the present embodiment, the notch 51a is a throttle, but the position where the throttle is provided can be arbitrarily changed as long as it is in the middle of the branch passage 21.

  Subsequently, the check valve 9 </ b> B provided on the inner peripheral side of the ring 53 is a leaf valve having a small diameter whose outer diameter is smaller than the inner diameter of the ring 53 and whose thickness is thinner than that of the ring 53. An intermediate spacer 55 is stacked on the upper side of the check valve 9B in FIG. 5, and the check valve 9B has an intermediate spacer on the inner peripheral side in a state where the outer peripheral side of the intermediate spacer 55 is allowed to bend. 55 and fixed between the boss portion 8B. The check valve 9B is set to close all the holes 50a when seated on the back side of the first leaf valve 50. In the present embodiment, the total thickness of the check valve 9B and the intermediate spacer 55 is equal to the thickness of the ring 53 so that the leaf valves 52a, 52b, and 52c after the second leaf valve 51 are not initially bent. Is set. However, the thickness of the ring 53 is set to be thicker than the total thickness of the check valve 9B and the intermediate spacer 55, and initial deflection is applied to the leaf valves 52a, 52b, and 52c after the second leaf valve 51. Good.

  In the compression stroke of the shock absorber D, the check valve 9B deflects the outer peripheral side of the intermediate spacer 55 upward in FIG. 5 to open the hole 50a, and allows the flow of hydraulic oil from the hole 50a toward the space SB. . For this reason, in the compression stroke of the shock absorber D, even if the first leaf valve 50 is seated on the pressure side seat 3B until the valve opening pressure of the pressure side valve body 5 is reached, the check valve 9B opens the hole 50a. The hydraulic oil in the pressure side passage 2B passes through the branch passage 21 in the order of the hole 50a, the space SB, and the cutout 51a and moves to the extension side chamber L1. On the contrary, in the extension stroke of the shock absorber D, the check valve 9B closes the hole 50a, so that the communication of the branch passage 21 is blocked. According to the above configuration, the throttle formed by the notch 51a in the middle of the branch passage 21 can be a single-effect throttle that works only in the compression stroke of the shock absorber D, and the pressure side valve body 5 is opened. Meanwhile, the shock absorber D can generate a damping force due to the resistance of the throttle (notch 51a).

  In the present embodiment, the deformation amount (deflection amount) of the check valve 9B is regulated by the second leaf valve 51, and the opening amount of the check valve 9B when the outer peripheral side of the check valve 9B comes into contact with the second leaf valve 51. Is the maximum. Thus, by restricting the deformation amount of the check valve 9B with the second leaf valve 51, the deformation amount of the check valve 9B can be prevented from becoming excessive, and the durability of the check valve 9B can be improved. In addition, according to the above configuration, the size of the check valve 9B is not restricted by the seat shape of the compression side seat 3B, and the check valve 9B can be enlarged, so that the deformation amount of the check valve 9B becomes excessive. And the durability of the check valve 9B can be improved.

  Further, according to the above configuration, even if the check valve 9B and the first leaf valve 50 are relatively rotated in the circumferential direction, there is no problem even if the check valve 9B and the second leaf valve 51 are relatively rotated in the circumferential direction. Even if the (notch 51a) is set to be one-sided, positioning in the rotational direction of the check valve 9B is not required, and assemblability can be improved.

  Hereinafter, the operation of the shock absorber D according to the present embodiment will be described. In the following description, the piston speed of the shock absorber D is divided into a low speed region and a medium / high speed region, but the threshold value of each region can be arbitrarily set.

  In the expansion stroke of the shock absorber D in which the piston 1 moves upward in FIG. 1 and the rod 6 retracts from the cylinder C, the hydraulic oil in the expansion side chamber L1 to be reduced moves to the pressure side chamber L2. In the extension stroke of the shock absorber D, when the piston speed is in the low speed region, the hydraulic oil in the extension side chamber L1 pushes down the valve portion 90 of the check valve 9A to open the hole 40a and passes through the branch passage 20 to the pressure side. Move to chamber L2. For this reason, when the piston speed is in the low speed region during the extension stroke, the shock absorber D generates a damping force having an orifice characteristic due to the resistance of the notch 41a serving as a throttle.

  Further, in the expansion stroke of the shock absorber D, when the piston speed becomes high and becomes a medium-high speed region, and the pressure in the expansion side chamber L1 becomes larger than the pressure in the compression side chamber L2, the outer peripheral portion of the expansion side valve body 4 is lowered. And a gap is formed between the first leaf valve 40 of the extension side valve element 4 and the extension side seat 3A, and hydraulic oil passes through the gap and moves from the extension side chamber L1 to the compression side chamber L2. . For this reason, the shock absorber D generates a damping force of the valve characteristic due to the resistance of the expansion side valve body 4 when the piston speed is in the middle to high speed region in the expansion stroke.

  On the other hand, in the compression stroke of the shock absorber D in which the piston 1 moves downward in FIG. 1 and the rod 6 enters the cylinder C, the hydraulic oil in the compression side chamber L2 to be reduced moves to the expansion side chamber L1. In the compression stroke of the shock absorber D, when the piston speed is in the low speed region, the hydraulic oil in the compression side chamber L2 deflects the outer peripheral portion of the check valve 9B upward to open the hole 50a, passes through the branch passage 21, and extends to the extension side chamber. Move to L1. For this reason, when the piston speed is in the low speed region in the compression stroke, the shock absorber D generates a damping force having an orifice characteristic due to the resistance of the notch 51a serving as a throttle.

  Further, in the compression stroke of the shock absorber D, when the piston speed becomes high and becomes a medium-high speed region, and the pressure in the compression side chamber L2 becomes larger than the pressure in the expansion side chamber L1, the outer peripheral portion of the compression side valve element 5 is moved upward. The bending causes a gap between the first leaf valve 50 of the pressure side valve body 5 and the pressure side seat 3B, and hydraulic oil passes through the gap to move from the pressure side chamber L2 to the extension side chamber L1. For this reason, the shock absorber D generates a damping force of the valve characteristic due to the resistance of the compression side valve body 5 when the piston speed is in the middle to high speed region in the compression stroke.

  As described above, in the present embodiment, the notch 41a serving as the throttle can be used for generating a damping force in the extension stroke in the low speed region, and the notch 51a serving as the throttle can also be used for the damping force in the compression stroke in the low speed region. Available. Accordingly, by changing the widths of the notches 41a and 51a and arbitrarily setting the flow passage areas of the throttles, the attenuation characteristics in the low speed region can be set independently for the expansion stroke and the compression stroke. In the present embodiment, the notches 41a and 51a are made to function as a throttle. However, the throttle may be provided anywhere in the branch passages 20 and 21, for example, the holes 40a and 50a may be throttled. You may use as. In the present embodiment, the throttle is made of an orifice, but may be made of a choke passage.

  In the present embodiment, the check valve 9 </ b> A is provided on the back side of the first leaf valve 40 using the space SA formed by the ring 43. By doing so, the check valve 9A can be formed in an annular shape, and the hole 40a can be opened and closed without positioning the check valve 9A in the rotational direction. Therefore, even if the throttle (notch 41a) for generating the damping force in the low speed region is single-effected by the check valve 9A, positioning in the rotational direction of the check valve 9A is not necessary, and the assembling property is improved.

  Further, since the check valve 9A opens in the direction away from the piston 1, that is, on the second leaf valve 41 side, the opening amount of the check valve 9A can be regulated by the second leaf valve 41. For this reason, the deformation amount of the check valve 9A is prevented by the second leaf valve 41, and the durability of the check valve 9A can be improved. Further, according to the above configuration, the size of the check valve 9A is not restricted by the seat 3A, and the check valve 9A can be enlarged. Therefore, even if the check valve 9A is slightly separated from the second leaf valve 41, a large flow rate can be allowed to flow, and this can also suppress an increase in the deformation amount of the check valve 9A.

  Similarly, a check valve 9 </ b> B is provided on the back side of the first leaf valve 50 using a space SB formed by the ring 53. In this way, the check valve 9B can be formed in an annular shape, and the hole 50a can be opened and closed without positioning the check valve 9B in the rotational direction. Therefore, even if the throttle (notch 51a) for generating the damping force in the low speed region is single-effected by the check valve 9B, positioning in the rotational direction of the check valve 9B is not necessary, and the assembling property is improved.

  Further, since the check valve 9B opens in the direction away from the piston 1, that is, on the second leaf valve 51 side, the opening amount of the check valve 9B can be regulated by the second leaf valve 51. For this reason, the deformation amount of the check valve 9B is prevented by the second leaf valve 51, and the durability of the check valve 9B can be improved. Furthermore, according to the above configuration, the size of the check valve 9B is not restricted by the seat 3B, and the check valve 9B can be enlarged. Therefore, even if the check valve 9B is slightly separated from the second leaf valve 51, a large flow rate can be allowed to flow, and this can also suppress an increase in the amount of deformation of the check valve 9B.

  Further, in the present embodiment, the extension side seat 3A on which the extension side valve body 4 is seated and detached is configured to include an outer seat portion 30, an intermediate seat portion 31, and an inner seat portion 32. It has a closed shape like this. For this reason, since the window 14 formed inside the said extending side sheet | seat 3A can be enlarged and the pressure receiving area of the extending side valve body 4 which receives the pressure of the extending side chamber L1 can be enlarged, even if the pressure of the extending side chamber L1 is low, it extends. The side valve body 4 can be opened. Similarly, the pressure side seat 3B to which the pressure side valve body 5 is seated is also configured to include an outer seat portion 30, an intermediate seat portion 31, and an inner seat portion 32, and has a closed shape like a ring. doing. For this reason, since the window 17 formed inside the pressure side seat 3B can be enlarged and the pressure receiving area of the pressure side valve body 5 that receives the pressure of the pressure side chamber L2 can be increased, the pressure side valve body even if the pressure of the pressure side chamber L2 is low. 5 can be opened.

  Further, in the stretch side sheet 3A, the outlet 12 of the stretch side passage 2A is provided between the intermediate sheet portions 31 connected by the outer sheet portion 30, and the pressure side passage 2B is provided between the intermediate sheet portions 31 connected by the inner sheet portion 32. Therefore, without extending the cylinder diameter, the extension side seat 3A can be extended to the outer peripheral side of the piston 1 to increase the diameter of the extension side valve body 4, and the extension side valve body 4 can be easily bent. . Similarly, in the pressure side sheet 3B, the outlet 15 of the pressure side passage 2B is provided between the intermediate sheet portions 31 connected by the outer sheet portion 30, and the extension side passage 2A is provided between the intermediate sheet portions 31 connected by the inner sheet portion 32. Since the pressure side seat 3A is extended to the outer peripheral side of the piston 1 without increasing the cylinder diameter, the diameter of the pressure side valve body 5 is increased and the pressure side valve body 5 can be easily bent.

  Further, in the present embodiment, the inner sheet portion 32 of the stretched side sheet 3A is provided on a straight line y connecting the end of the intermediate sheet portion 31 on the central axis X side. Without projecting to the side, the flow passage area of the pressure side passage 2B can be expanded to the inner peripheral side of the piston 1. Similarly, since the inner sheet portion 32 of the compression side sheet 3B is provided on the straight line y connecting the end of the intermediate sheet portion 31 on the central axis X side, the inner sheet portion 32 may protrude toward the outer peripheral side of the piston 1. In addition, the flow passage area of the extension side passage 2 </ b> A can be expanded to the inner peripheral side of the piston 1.

  According to the said structure, when the piston speed exists in a medium-high speed area | region, the inclination of the curve which shows the characteristic of the damping force with respect to piston speed can be put down, and a damping coefficient can be made small enough. For this reason, when the shock absorber D is used for damping a vehicle body as in the present embodiment, the ride comfort can be improved.

  Further, in the present embodiment, the pressure receiving area of the expansion side valve body 4 that opens and closes the expansion side passage 2A is increased, but the expansion side valve body 4 is supported by the island portion 11. Even if the pressure in the compression side chamber L2, which is the back pressure of the expansion side valve body 4, increases, it is possible to prevent the expansion side valve body 4 from being bent and cracked by the pressure. Similarly, the pressure receiving area of the pressure side valve element 5 that opens and closes the pressure side passage 2B is increased. However, since the pressure side valve element 5 is supported by the island portion 11, the back pressure of the pressure side valve element 5 is increased. Even if the pressure in the extending side chamber L1 is increased, the pressure side valve element 5 can be prevented from being bent and cracked by the pressure toward the piston 1 side.

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

  In the present embodiment, the piston 1 has a boss portion 8A formed inside the stretched side sheet 3A and a boss portion 8B formed inside the compression side sheet 3B. In each of the boss portions 8A and 8B, the width of the portion a facing the outer sheet portion 30 is formed wider than the width of the portion b facing the inner sheet portion 32.

  According to the above configuration, the overlap between the holes 40a and 50a of the first leaf valves 40 and 50 and the boss portions 8A and 8B can be reduced, and the distance from the boss portions 8A and 8B to the inner seat portion 32 can be increased. Therefore, the resistance when hydraulic fluid moves through the holes 40a and 50a and the windows 14 and 17 can be made as small as possible. Further, by forming the wide portion a in the boss portions 8A and 8B, the area of the portion that receives the load when the piston is fixed and the pressure side valve body 5 is supported, and the load when the piston is fixed. The area of the receiving part can be increased. Note that the shapes of the boss portions 8A and 8B are not limited to those described above, and can be changed as appropriate, and one or both of the pos portions 8A and 8B may have a perfect circle shape.

  Further, in the present embodiment, the intermediate sheet portions 31 are arranged at equal intervals in the circumferential direction.

  According to the said structure, it is easy to make equal the flow area of 2 A of expansion | extension side passages, and the pressure side passage 2B. The arrangement of the intermediate sheet portion 31 can be changed as appropriate. The interval between the intermediate sheet portions 31 connected by the inner sheet portion 32 and the interval between the intermediate sheet portions 31 connected by the outer sheet portion 30 may be different. In this case, the flow area of the extension side passage 2A and the pressure side passage 2B are different. It is possible to make a difference in the flow path area. For example, when the flow passage area of the compression side passage 2B is formed larger than the flow passage area of the expansion passage 2A, the damping force exerted by the shock absorber D when the piston speed is in the middle to high speed region. The damping force exerted by the shock absorber D during compression can be reduced.

  Moreover, the circumferential direction length of the outer sheet | seat part 30 provided with two or more on the same periphery may each differ. In this case, it is possible to make a difference in the flow passage area among the plurality of expansion side passages 2A, or to make a difference in the flow passage area among the plurality of compression side passages 2B, so that it faces the expansion side passage 2A having a large flow passage area. The expansion side valve body 4 can be gradually opened from the portion where the pressure is applied, or the pressure side valve body 5 can be gradually opened from the portion facing the pressure side flow path 2B having a large flow area. For this reason, the change in switching from the damping force of the orifice characteristic when the piston speed is in the low speed region to the damping force of the valve characteristic when the piston speed is in the medium to high speed region can be moderated, further improving the ride comfort of the vehicle Can be made.

  In the present embodiment, the inner sheet portion 32 of the stretch side sheet 3 </ b> A and the inner sheet portion 32 of the compression side sheet 3 </ b> B are provided on a straight line y connecting the ends of the intermediate sheet portion 31 on the central axis X side.

  According to the above configuration, since the inner sheet portion 32 is provided on the straight line y connecting the end of the intermediate sheet portion 31 on the central axis X side, the flow passage areas of the extension side passage 2A and the pressure side passage 2B are set to the center of the piston 1. The damping coefficient when the piston speed is in the medium to high speed region can be made sufficiently small.

  In the present embodiment, the inner sheet portion 32 has a linear shape along the straight line y. However, the inner sheet portion 32 is provided closer to the central axis X than the straight line y, and the straight line y If the inner sheet portion 32 is provided on the straight line y, the same effect can be obtained as long as the inner seat portion 32 does not protrude from the outer peripheral side of the piston 1.

  In the present embodiment, the stretch side sheet 3A and the compression side sheet 3B both extend from the arc-shaped outer sheet portion 30 and the circumferential ends of the outer sheet portion 30 toward the central axis X of the piston 1. A pair of intermediate sheet portions 31 and two inner sheet portions 31 extending from the end on the central axis X side to the opposite outer sheet portion side in the circumferential direction and connecting the adjacent intermediate sheet portions 31 to each other. It is prepared for.

  The outlet 12 of the extension side passage 2A is disposed between the intermediate sheet portions 31 and 31 connected to the outside sheet portion 30 of the extension side sheet 3A inside the extension side sheet 3A. The inlet 13 of the passage 2B is disposed on the outside of the stretched sheet 3A and between intermediate sheet portions 31 and 31 connected by the inner sheet portion 32 of the stretched sheet 3A. The outlet 15 of the pressure side passage 2B is disposed between the intermediate sheet portions 31 and 31 connected to the outer side seat portion 30 of the pressure side sheet 3B inside the pressure side sheet 3B, and the extension side passage. The inlet 16 of 2A is disposed on the outer side of the pressure side sheet 3B and between the intermediate sheet parts 31 and 31 connected by the inner sheet part 32 of the pressure side sheet 3B.

  According to the above configuration, the extension side seat 3 </ b> A and the compression side seat 3 </ b> B have a closed shape like a ring, so that the first leaf valve is larger than the diameter of the circle connecting the inner peripheral ends of the inner peripheral seat 32. If the diameter of the circle connecting the outer peripheral ends of the 40 and 50 holes 40a and 50a is set to be small, the circumferential alignment of the piston 1 and the first leaf valve 40, and the piston 1 and the first leaf valve are set. 50 circumferential alignment is not required. Therefore, according to the stretch side sheet 3A and the pressure side sheet 3B, the assemblability can be further improved.

  Note that the shapes of the stretch side sheet 3A and the compression side sheet 3B are not limited to the above, and can be arbitrarily changed. For example, one or both of the extension side sheet 3A and the compression side sheet 3B may be an annular sheet that collectively surrounds the outlets of the extension side passage 3A or the compression side passage 3B. In this case, the same effect as the stretch side sheet 3A and the pressure side sheet 3B can be obtained. Moreover, when aligning the piston 1 and the first leaf valve 40 in the circumferential direction, an independent port structure in which the outlet of the extension side passage 2A is individually surrounded by the extension side seat 3A may be employed. Similarly, when positioning the piston 1 and the first leaf valve 50 in the circumferential direction, an independent port structure in which the pressure side seat 3B individually surrounds the outlet of the pressure side passage 2B may be employed.

  In the present embodiment, the check valve 9A includes an annular valve portion 90 that opens and closes the hole 40a, and a plurality of urging portions 91 that urge the valve portion 90 in a direction in which the valve portion 90 is pressed against the first leaf valve 40. The urging portion 91 extends radially from the outer periphery of the valve portion 90 and rises obliquely from the outer periphery of the valve portion 90 toward the second leaf valve 41.

  According to the above configuration, it is not necessary to position the check valve 9A in the rotational direction, and the check valve 9A can be easily formed. Moreover, according to the said structure, the axial direction length of 9 A of check valves can be shortened. When the space SA is formed by the ring 43 on the back surface side of the first leaf valve 40 as in the present invention, the vertical width of the space SA becomes narrow, and thus the check valve 9A has such a vertically narrow space SA. Suitable for housing in.

  The configuration of the check valve 9A can be arbitrarily changed. In the present embodiment, the check valve 9A is provided on the expansion side valve body 4, but may be provided on the pressure side valve body 5.

  In the present embodiment, the check valve 9B is a leaf valve having an outer diameter smaller than the inner diameter of the ring 53, and the hole 50a is opened by bending the outer peripheral side toward the second leaf valve 51. .

  According to the said structure, while positioning of the check valve 9B in the rotation direction becomes unnecessary, check valve 9B can be formed easily. Moreover, according to the said structure, the axial direction length of the check valve 9B can be shortened. When the space SB is formed by the ring 53 on the back surface side of the first leaf valve 50 as in the present invention, the vertical width of the space SB is narrowed. Therefore, the check valve 9B has such a vertically narrow space SB. Suitable for housing in.

  Note that the configuration of the check valve 9B can be arbitrarily changed. In the present embodiment, the check valve 9B is provided on the compression side valve body 5, but may be provided on the expansion side valve body 4.

  In the present embodiment, the notches 41 a and 51 a are formed in the second leaf valves 41 and 51.

  According to the said structure, it is easy to form the notches 41a and 51a. The notches 41a and 51a may be provided in the rings 43 and 53, but the sizes of the holes 40a and 50a formed in the first leaf valves 40 and 50 and the sizes of the notches 41a and 51a are set individually. The second leaf valves 41 and 51 separated from the first leaf valves 40 and 50 are easier to set.

  In the present embodiment, the notches 41a and 51a are narrowed to form a stop.

  Since the throttles 41a and 51a may be provided in the middle of the branch passages 20 and 21, for example, the holes 40a and 50a of the first leaf valves 40 and 50 may function as a throttle. However, in this case, the pressure receiving area of the check valves 9A and 9B cannot be increased. On the other hand, according to the above configuration, since the opening areas of the holes 40a and 50a can be increased, the pressure receiving area of the check valves 9A and 9B can be increased to reduce the valve opening pressure of the check valves 9A and 9B. it can.

  As described above, the portions other than the notches 41a and 51a may function as a diaphragm. In the present embodiment, both the notch 41a provided in the extension side valve element 4 and the notch 51a provided in the compression side valve element 5 are caused to function as a throttle. However, one of the notches 41a and 51a May function as an aperture.

  In the present embodiment, the shock absorber D includes a piston (valve disk) 1 that partitions the expansion side chamber L1 and the compression side chamber L2 (two chambers), and the extension side chamber L1 and the compression side chamber L2 formed on the piston 1. An extension side passage (passage) 2A and a pressure side passage (passage) 2B that communicate with each other, and a hole 40a that is stacked on the piston 1 to open and close the extension side passage 2A and communicate with the extension side passage 2A are formed. One leaf valve 40, an annular ring 43 provided on the back side of the first leaf valve 40 and surrounding the space SA communicating with the hole 40a, and the ring 43 stacked on the back side of the first leaf valve 40 A second leaf valve 41 seated in the second leaf valve 41, a notch 41a formed in the second leaf valve 41 to communicate the inner peripheral side and the outer peripheral side of the ring 43, the hole 40a, the space SA and the notch A diaphragm provided in the middle of the branch passage 20 through the 1a, provided on the inner peripheral side of the ring 43 and a check valve 9A for opening and closing the hole 40a.

  Further, the shock absorber D is stacked on the piston 1, opens and closes the pressure side passage 2B, and has a first leaf valve 50 in which a hole 50a communicating with the pressure side passage 2B is formed, and a rear surface of the first leaf valve 50. An annular ring 53 surrounding the space SB provided on the side and communicating with the hole 50a; a second leaf valve 51 stacked on the back side of the first leaf valve 50 and seated on the ring 53; and the second leaf A notch 51a that is formed in the valve 51 and connects the inner peripheral side and the outer peripheral side of the ring 53; a throttle provided in the middle of the branch passage 21 that passes through the hole 50a, the space SB, and the notch 51a; and the ring 53 and a check valve 9B provided on the inner peripheral side of 53 for opening and closing the hole 50a.

  According to the above configuration, even if the throttle for generating the damping force in the low speed region is made to be one-sided by the check valves 9A and 9B, the check valves 9A and 9B can be formed in an annular shape. The circumferential alignment of the two-leaf valve 41 and the check valve 9A is not necessary, and the circumferential alignment of the first leaf valve 50, the second leaf valve 51 and the check valve 9B is unnecessary, and the assemblability is excellent. Can be.

  Furthermore, according to the above configuration, the size of the check valve 9A is not restricted by the expansion side seat 3A, and the size of the check valve 9B is not restricted by the compression side seat 9B. 9B can be formed large. In addition, since the deformation amount of the check valve 9A can be regulated by the second leaf valve 41 and the deformation amount of the check valve 9B can be regulated by the second leaf valve 51, the durability of the check valves 9A and 9B can be improved.

  In the present embodiment, the configuration according to the present invention is embodied on both the expansion side chamber L1 side and the compression side chamber L2 side of the piston 1, and a one-effect throttle (notch 41a) that works only in the extension stroke; Both are provided with a single-effect throttle (notch 51a) that works only in the compression stroke, and the damping characteristic in the low speed region can be set independently in the expansion stroke and the compression stroke. However, the present invention may be embodied only in one of the extension side chamber L1 side and the compression side chamber L2 side, and may include only one of the one-effect throttles that are effective only in the extension stroke and the one-effect throttle that is effective only in the compression stroke. .

  In the present embodiment, the cutouts 41 a and 51 a are formed in the second leaf valves 41 and 51, but may be formed in the rings 43 and 53.

  Further, in the present embodiment, the first leaf valves 40 and 50 are formed by opening holes 40a and 50a in an annular plate-like leaf valve body, but as shown in FIG. One or both of the leaf valves 40 and 50 are divided into an annular outer peripheral member 401 to which the rings 43 and 53 are attached and an inner peripheral member 402 inserted on the inner peripheral side of the outer peripheral member 401. The holes 40 a and 50 a may be formed between the inner peripheral members 402.

  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 Buffer L1 Extension side room (room)
L2 compression side room (room)
SA, SB Space 1 Piston (Valve Disc)
2A Extension side passage (passage)
2B Pressure side passage (passage)
9A, 9B Check valve 20, 21 Branch passage 40, 50 First leaf valve 40a, 50a Hole 41, 51 Second leaf valve 41a, 51a Notch 43 Spacer 44, 53 Ring 90 Valve portion 91 Energizing portion

Claims (5)

A valve disc that divides the two rooms,
A passage formed in the valve disk and communicating with the two chambers;
A first leaf valve that is stacked on the valve disk to open and close the passage and to form a hole communicating with the passage;
An annular ring which is provided on the back side of the first leaf valve and surrounds a space communicating with the hole;
A second leaf valve stacked on the back side of the first leaf valve and seated on the ring;
A notch formed in the ring or the second leaf valve to communicate the inner peripheral side and the outer peripheral side of the ring;
A throttle provided in the middle of a branch passage passing through the hole, the space and the notch;
A shock absorber comprising: a check valve provided on an inner peripheral side of the ring for opening and closing the hole. The shock absorber according to claim 1, wherein the notch is narrowed to form the aperture. The shock absorber according to claim 1 or 2, wherein the notch is formed in the second leaf valve. The check valve is a leaf valve having an outer diameter smaller than an inner diameter of the ring, and the hole is opened by bending the outer peripheral side toward the second leaf valve. The shock absorber according to any one of claims 3 to 4. The check valve is
A valve portion that is annularly formed to open and close the hole;
A plurality of urging portions for urging the valve portion in a direction of pressing the first leaf valve;
The urging portion extends radially from the outer periphery of the valve portion, and rises obliquely from the outer periphery of the valve portion toward the second leaf valve. The shock absorber according to one item.

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