Valve devices and buffers

Abstract

The buffer (D) comprises: a shaft component (2); a valve seat component (3) mounted on the outer periphery of the shaft component (2); a main valve assembly (A), which is annular, stacked on the valve seat component and having a first valve (4) and a second valve (5); a bypass passage (P) disposed on the shaft component (2) and communicating with the extension side chamber (R1) and the compression side chamber (R2); and a secondary valve (B) having a secondary valve disc (6) and a secondary valve body (7), the secondary valve disc (6) having a valve body mounted on the shaft component (2). The auxiliary valve body (7) is mounted on the outer periphery of the shaft component (2) and faces the inner periphery of the seat (6c); the auxiliary valve disc (6) has a recess (6d) that opens from the inner periphery of the disc (6a) and communicates with the opening (2f) to form part of the bypass channel (P).

Description

Technical Field

[0001] This invention relates to a valve device and a buffer. Background Technology

[0002] A damper, for example, is installed between the vehicle body and the wheels to apply resistance to the flow of fluid generated during expansion and contraction, thereby generating a damping force and suppressing the vibration of the vehicle body.

[0003] Such buffers are constantly being improved to achieve damping force characteristics that can further enhance the ride comfort of vehicles. Sometimes, the following type of buffer is required: when the buffer's extension and retraction speed is in the low-speed range, the damping force is rapidly increased relative to the extension and retraction speed, but in the low-speed range, the damping coefficient is reduced to avoid excessive damping force. In the high-speed range, the damping coefficient is further reduced to exert damping force proportional to the extension and retraction speed. This effectively attenuates wheel vibration in the low-speed range and achieves damping force characteristics that can improve the ride comfort of vehicles in other speed ranges.

[0004] For example, as shown in JP2022-13974A, a damper that achieves this damping force characteristic includes a cylinder, a piston rod that can be freely inserted into the cylinder, and a valve device mounted on the piston rod. Furthermore, the valve device comprises the following components: a piston mounted on the outer periphery of the piston rod's front end, dividing the cylinder into an extension-side chamber and a compression-side chamber; an extension-side vane valve and a compression-side vane valve, both annular in shape, with their inner peripheries fixed to the piston rod, opening and closing ports located on the piston; a bypass passage that connects the extension-side chamber and the compression-side chamber via the ports inside the piston rod; and a secondary valve located in the bypass passage.

[0005] Based on the above configuration, since the bypass channel with the auxiliary valve connects the extension side chamber and the compression side chamber via the bypass port, the following phenomena will not occur: the flow area of ​​the auxiliary valve becomes a bottleneck; the resistance of the auxiliary valve is greater than the resistance exerted by the extension side vane valve and the compression side vane valve on the flow of hydraulic oil; the characteristics of the auxiliary valve exceed the characteristics of the extension side vane valve and the compression side vane valve, resulting in excessive damping force; thereby improving the ride comfort of the vehicle.

[0006] Existing technical documents Patent documents Patent Document 1: JP2022-13974A Summary of the Invention The problem the invention aims to solve In the past, when a secondary valve was installed in a valve device through a bypass channel connecting the extension side chamber and the compression side chamber inside the piston rod, a valve bracket was installed at the front end of the piston rod to hold the secondary valve in order not to interfere with the extension side vane valve and the compression side vane valve.

[0007] Specifically, the auxiliary valve comprises the following components: a valve support having a retaining shaft, a nut portion connected to the retaining shaft and threadedly engaged with the front end of the piston rod, a flange disposed from between the retaining shaft and the nut portion toward the outer periphery, and a cylindrical annular portion with an annular protrusion on its inner periphery that rises vertically from the outer periphery of the flange toward the opposite side of the piston, and is mounted on the front end of the piston rod; and an annular valve body, which is annular, fixed to the outer periphery of the retaining shaft of the valve support, allowing the outer periphery to bend, and the outer periphery facing the annular protrusion.

[0008] Thus, in conventional valve devices, a valve support with a retaining shaft for holding the annular valve body is installed at the front end of the piston rod, resulting in an increased overall length. To ensure the stroke length of the buffer, the overall length of the buffer also needs to be increased.

[0009] The purpose of this invention is to provide a valve device and a damper that improves the ride comfort of a vehicle without causing an increase in overall length.

[0010] Problem-solving methods The valve device for solving the above-mentioned problem includes: a shaft member; a main valve assembly including: a valve seat member, which is annular and mounted on the outer periphery of the shaft member to separate two working chambers, and having a first main channel and a second main channel respectively communicating with the working chambers; a first valve, which is annular and mounted on the outer periphery of the shaft member, and stacked on one side of the valve seat member to open and close the first main channel; and a second valve, which is annular and mounted on the outer periphery of the shaft member, and stacked on the other side of the valve seat member to open and close the second main channel; and a bypass channel provided on the shaft member, communicating with one of the working chambers and the other working chamber, and located on the side of the shaft member and An opening is located on the side of the working chamber closer to the main valve assembly; and a secondary valve has a secondary valve disc and a secondary valve body. The secondary valve disc has a circular disc portion that is annular and mounted on the outer periphery of the shaft component and stacked on the main valve assembly, a cylindrical portion that rises vertically from the outer periphery of the circular disc portion, and an annular seat portion located on the inner periphery of the cylindrical portion. The secondary valve body is annular, mounted on the outer periphery of the shaft component and stacked on the circular disc portion, and allows the outer periphery to bend so that the outer periphery faces the inner periphery of the seat portion. The secondary valve disc has a recess that extends from the inner periphery opening to the outer periphery on the secondary valve body side of the circular disc portion and communicates with the opening to form part of a bypass channel.

[0011] In a valve device constructed in this way, the auxiliary valve disc does not need to function as a nut to fix the main valve assembly to the shaft component, nor does it need to have a retaining shaft to hold the auxiliary valve body. The main valve assembly and the auxiliary valve can be sequentially fitted into the shaft component and fixed with a nut, which can shorten the overall length.

[0012] In addition, according to the valve device, the bypass channel is parallel to the first main channel and the second main channel, so it can suppress the overload caused by the pressure loss generated by the auxiliary valve being superimposed on the pressure loss of the first or second valve, which would result in excessive damping force.

[0013] Furthermore, the damper of the present invention is characterized by comprising a cylinder, a piston rod inserted into the cylinder, and a valve assembly, wherein a shaft component serves as the piston rod, a valve seat component is slidably inserted into the cylinder, the cylinder is divided into an extension side chamber and a compression side chamber, and a damping force regulating valve with an adjustable flow path area is provided in the bypass channel. According to the damper constructed in this manner, the main valve assembly and the auxiliary valve can be sequentially fitted into the shaft component and fixed with a nut, which shortens the overall length of the valve assembly, thus preventing an increase in overall length. This suppresses the overload caused by the pressure loss generated by the auxiliary valve superimposed on the pressure loss of the first or second valve, resulting in excessive damping force. This allows the damper used in vehicles to generate optimal damping force, thereby improving vehicle ride comfort. Attached Figure Description

[0014] Figure 1 This is a longitudinal cross-sectional view of a buffer according to one embodiment of the present invention.

[0015] Figure 2 This is a partially enlarged cross-sectional view of a buffer according to one embodiment of the present invention.

[0016] Figure 3 (a) is a top view of the auxiliary valve disc. Figure 3 (b) is a cross-sectional view of the auxiliary valve disc.

[0017] Figure 4 This is a graph showing the damping force characteristics of a buffer according to one embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described based on the illustrated embodiments. Figure 1 and Figure 2 As shown, in one embodiment, the valve device V is composed of the following components: a piston rod 2 as a shaft component, a piston 3 having a piston mounted on the outer periphery of the piston rod 2, a main valve assembly A having a compression-side vane valve 4 and an extension-side vane valve 5, a bypass passage P, and a secondary valve B having a secondary valve disc 6 and a secondary valve body 7 mounted on the outer periphery of the piston rod 2, which is applied to the piston portion of the buffer D.

[0019] The following is a detailed description of each part of the valve assembly V and the buffer D. For example... Figure 1As shown, the damper D includes: a cylinder 1; a piston rod 2 movably inserted into the cylinder 1; a piston 3 mounted on the piston rod 2 and slidably inserted into the cylinder 1, dividing the cylinder 1 into an extension side chamber R1 and a compression side chamber R2; and a valve device V, using the piston rod 2 as a shaft component and the piston 3 as a valve seat component. Although not shown, the damper D is, for example, installed between the body and the rear wheel of a suspension straddle-type vehicle such as a motorcycle, generating a damping force during extension and retraction to suppress vehicle vibration. Furthermore, the damper D can be used in vehicles other than suspension straddle-type vehicles, and also in equipment other than vehicles.

[0020] like Figure 1 As shown, cylinder 1 is cylindrical. Figure 1 The upper and middle parts are sealed by cover 11. Additionally, in cylinder 1... Figure 1 An annular guide 10 is installed at the lower end for the piston rod 2 to pass through. The guide 10 has an annular sealing member 10a and an annular bushing 10b on its inner circumference that slide in contact with the outer circumference of the piston rod 2. The sealing member 10a seals the outer circumference of the piston rod 2 to seal the inside of the cylinder 1, and the bushing 10b guides the piston rod 2 to move axially.

[0021] The cylinder 1 is divided into an elongation chamber R1 filled with liquid and a compression chamber R2 by a piston 3, which serves as a valve seat component and is mounted on the outer periphery of the front end of the piston rod 2. Furthermore, in this embodiment, the liquid is hydraulic oil, but other liquids such as water or aqueous solutions may also be used.

[0022] Piston rod 2 is cylindrical and hollow inside. Figure 1 The lower-middle guide member 10 protrudes outward from the cylinder 1. For example... Figure 2 As shown, the outer diameter of the upper part of the piston rod 2 is smaller than that of the lower part, and it has a small-diameter section 2a that functions as a shaft component. Figure 2 The large-diameter portion 2b on the lower middle side, the stepped portion 2c formed on the outer periphery at the boundary between the small-diameter portion 2a and the large-diameter portion 2b, and the portion in the small-diameter portion 2a... Figure 2 The upper part of the piston rod 2 has a threaded portion 2d on its outer periphery, and has two transverse holes 2e that open from the side of the large-diameter portion 2b and communicate with the elongation side chamber R1 and the piston rod 2, and two transverse holes 2f that are located near the threaded portion 2d of the small-diameter portion 2a. The piston rod 2 communicates with the elongation side chamber R1 through the transverse holes 2e and with the compression side chamber R2 through the transverse holes 2f, thus using the piston rod 2 as part of the bypass passage P.

[0023] In addition, piston rod 2 Figure 2 The opening at the upper middle end is sealed by the plug 20, and the piston rod 2 communicates with the compression side chamber R2 through the transverse hole 2f. Additionally, in the piston rod 2... Figure 1At the lower middle end, a bracket 12 is mounted to rotatably hold the wheels of the straddle-type vehicle out of the figure and is connected to a swing arm mounted on the vehicle body that can swing vertically. An annular spring seat 14 is mounted on the outer periphery of the bracket 12. Furthermore, an annular spring seat 17 is mounted on the outer periphery of the cylinder 1, and a suspension spring 19 that applies force to the buffer D in the extension direction is installed between the spring seats 14 and 17.

[0024] The piston 3 is annular and mounted on the outer periphery of the small-diameter portion 2a of the piston rod 2. It has a compression-side port 3a, serving as a first main channel, and an extension-side port 3b, serving as a second main channel, connecting the elongation-side chamber R1 and the compression-side chamber R2 in parallel. On one side of the piston 3... Figure 2 On the lower middle side, a compression-side vane valve 4, which is annular and installed on the outer periphery of the small-diameter portion 2a to open and close the compression-side port 3a, serves as the first valve. Additionally, on the other side of the piston 3... Figure 2 On the upper side, there is an extended side vane valve 5, which is annular and installed on the outer periphery of the small diameter portion 2a to open and close the extended side port 3b, serving as a second valve. Furthermore, the piston 3, the compression side vane valve 4, and the extended side vane valve 5 are fitted into the outer periphery of the small diameter portion 2a of the piston rod 2, and are fixed to the piston rod 2 by a piston nut 13 screwed onto the upper end of the small diameter portion 2a.

[0025] In the valve device V of this embodiment, the compression-side vane valve 4 is configured as a stacked vane valve as follows: On the piston 3 facing the elongation-side chamber R1... Figure 2 The buffer D is constructed by overlapping multiple annular plates at its lower end. The inner circumference is fixed to the piston rod 2, allowing bending of the outer circumference. When the pressure in the compression chamber R2 causes the outer circumference to bend, the compression port 3a opens, simultaneously applying resistance to the flow of liquid through the compression port 3a. Furthermore, when the buffer D extends, the pressure in the extension chamber R1 is higher than the pressure in the compression chamber R2, causing the compression side vane valve 4 to close and block the compression port 3a. Additionally, the compression side vane valve 4 is a valve that applies resistance to the flow of liquid from the compression chamber R2 towards the extension chamber R1 when the buffer D contracts, but it can also be a check valve that does not apply resistance. Furthermore, in the compression side vane valve 4… Figure 2 In the lower middle part, there is a small-diameter gasket 15 with an annular shape and an outer diameter smaller than the outer diameter of the annular plate opposite to the piston of the compression-side vane valve 4, and forming the bending fulcrum of the compression-side vane valve 4 at the outer periphery, as well as a valve stop 16 to limit the excessive bending of the compression-side vane valve 4, and is installed on the outer periphery of the piston rod 2.

[0026] In the valve device V of this embodiment, the elongation-side vane valve 5 is configured as a stacked vane valve as follows: When the piston 3 faces the compression-side chamber R2... Figure 2The upper and middle sections are constructed from multiple annular plates. The inner circumference is fixed to the piston rod 2, allowing bending of the outer circumference. When the pressure in the extension chamber R1 causes the outer circumference to bend, the extension port 3b is opened, simultaneously applying resistance to the flow of liquid through the extension port 3b. Additionally, when the buffer D contracts, the pressure in the compression chamber R2 is higher than the pressure in the extension chamber R1, causing the extension vane valve 5 to close and block the extension port 3b.

[0027] Additionally, on the extended side of the vane valve 5... Figure 2 Multiple annular septum plates 18 are provided in the upper middle section. Their outer diameter is smaller than that of the annular plate on the opposite side of the piston of the extended side vane valve 5, which adjusts the axial position of the auxiliary valve disc 6 relative to the piston rod 2. Furthermore, the number of septum plates 18 can be arbitrarily changed as long as the auxiliary valve disc 6 can be positioned appropriately.

[0028] The aforementioned piston 3 functions as a valve seat component in a valve device V having a compression side port 3a as a first main channel and an extension side port 3b as a second main channel. The compression side vane valve 4 functions as a first valve for opening and closing the first main channel, and the extension side vane valve 5 functions as a second valve for opening and closing the second main channel. These pistons 3, compression side vane valves 4, and extension side vane valves 5 constitute the main valve assembly A.

[0029] Furthermore, when the main valve assembly A constructed in this manner is installed on the outer periphery of the small diameter portion 2a of the piston rod 2, which is a shaft component, the transverse hole 2f, which opens from the side of the small diameter portion 2a of the piston rod 2, opens on the compression side chamber side, which is further away from the main valve assembly A. Therefore, the bypass passage P communicates with the compression side chamber R2 through the transverse hole 2f.

[0030] Next, the auxiliary valve B is deposited on the main valve assembly A via the septum liner 18. Figure 2 The compression chamber at the upper center is mounted on the outer periphery of the piston rod 2. The auxiliary valve B includes an annular auxiliary valve disc 6, a valve stop 8 stacked on the auxiliary valve disc 6, a gasket 30 stacked on the valve stop 8, an auxiliary valve body 7 stacked on the gasket 30, a gasket 31 stacked on the auxiliary valve body 7, and a valve stop 9 stacked on the gasket 31. It is clamped and fixed to the piston rod 2 together with the main valve assembly A through the piston nut 13 threadedly engaged with the threaded portion 2d formed on the upper outer periphery of the small diameter portion 2a and the stepped portion 2c of the piston rod 2.

[0031] The auxiliary valve disc 6 includes: a disc portion 6a, which is annular and mounted on the outer periphery of the small-diameter portion 2a, and is deposited on the opposite side of the piston of the main valve assembly A via a stencil 18; and a cylindrical portion 6b, which extends from the outer periphery of the disc portion 6a towards... Figure 2 The upper middle part, i.e., the opposite side of the piston, rises vertically; the annular seat 6c extends from the cylindrical part 6b. Figure 2The inner circumference of the upper middle part protrudes radially inward; and the recess 6d is located in the disk portion 6a. Figure 2 The upper middle side, i.e. the side of the auxiliary valve body, opens from the inner circumference and extends to the outer circumference; the auxiliary valve disc is fitted into the outer circumference of the small diameter portion 2a of the piston rod 2.

[0032] like Figure 2 and Figure 3 As shown, the disk portion 6a is annular and has the following features: Figure 2 The annular recess 6d1, which opens from the inner circumference on the upper side of the valve body side of the secondary valve, and four interconnected recesses 6d2, which extend radially from the outer circumference of the annular recess 6d1 on the upper side of the valve body side of the secondary valve.

[0033] An annular recess 6d1 is formed at a depth near the center, extending axially from the upper end of the disc portion 6a, when the auxiliary valve disc 6 is deposited on the main valve assembly A with the gap filler plate 18 in between. Figure 2 When the piston rod 2 is in the upper middle position, it faces the transverse hole 2f that opens to the side of the small diameter portion 2a of the piston rod 2. The connecting recess 6d2 communicates with the annular recess 6d1, and the transverse hole 2f that forms the opening in the bypass channel P communicates with the compression chamber R2 through the annular recess 6d1 and the connecting recess 6d2. Thus, the annular recess 6d1 and the connecting recess 6d2 form a recess 6d that extends from the inner circumference to the outer circumference of the disc portion 6a. Even when the auxiliary valve disc 6 is installed on the outer circumference of the piston rod 2, the opening of the bypass channel P communicates with the compression chamber R2 through the recess 6d. As described above, the bypass channel P is formed by the transverse hole 2e provided in the piston rod 2, which is a shaft member, the transverse hole 2f that is the opening in the piston rod 2, and the recess 6d provided in the auxiliary valve disc 6. Thus, the recess 6d provided in the auxiliary valve disc 6 constitutes a part of the bypass channel P.

[0034] In this embodiment, the auxiliary valve disc 6 has an annular recess 6d1 on the inner circumference of the disc portion 6a. Therefore, when the annular recess 6d1 is axially fitted onto the outer circumference of the small-diameter portion 2a of the piston rod 2 at a position opposite to the transverse hole 2f, the transverse hole 2f and the annular recess 6d1 will necessarily be aligned even without circumferential positioning, thus reliably connecting the bypass passage P to the compression side chamber R2. Furthermore, the depth from the upper end of the disc portion 6a to the bottom of the four connecting recesses 6d2 is less than the depth of the annular recess 6d1, but the total cross-sectional area of ​​the four connecting recesses 6d2 viewed from the center of the disc portion 6a is [missing information]. Figure 2The cross-sectional area of ​​the annular recess 6d1 is greater than or equal to the cross-sectional area of ​​the ring recess 6d1. The total cross-sectional area of ​​the four connecting recesses 6d2, viewed from the center of the disc portion 6a, is equal to the effective flow path area when the liquid passes through the connecting recesses 6d2. Therefore, by setting the cross-sectional area as described above, it is considered that the connecting recesses 6d2 will not narrow the flow path within the recess 6d. Furthermore, in this embodiment, the connecting recesses 6d2 are formed by longitudinal grooves extending radially from the outer periphery of the annular recess 6d1. However, since it is only necessary to connect the annular recess 6d1 to the compression side chamber R2, which is the other side of the working chamber, the shape and structure can be arbitrarily designed and changed. Moreover, as long as the total cross-sectional area of ​​the aforementioned connecting recesses 6d2 is greater than or equal to the cross-sectional area of ​​the annular recess 6d1, the number of connecting recesses 6d2 can also be arbitrarily designed and changed.

[0035] Next, the cylindrical portion 6b is separated from the disc portion 6a. Figure 2 Outer periphery of the middle and upper end Figure 2 It stands upright at the top center. Figure 2 The upper inner circumference has an annular seat 6c that protrudes radially inward in a flange-like manner. The seat 6c faces the outer circumferential surface of the secondary valve body 7, which is located on the inner circumferential side, through a small gap, thus functioning as a valve seat in the secondary valve B. Furthermore, when the secondary valve body 7 bends and shifts axially, the area of ​​the gap between the seat 6c and the secondary valve body 7 increases rapidly, thereby narrowing the axial width of the inner circumferential surface of the seat 6c, and the seat 6c... Figure 2 The upper and lower parts are tapered, and the axial width narrows towards the inner circumference. Furthermore, if only the axial width of the inner circumferential surface of the seat 6c is made extremely narrow, the strength of the front end side of the seat 6c will decrease. Therefore, in the cylindrical part 6b... Figure 2 Eight ribs 6e, connected to the base 6c, are intermittently arranged along the circumferential direction at the upper middle part to ensure the strength of the base 6c. In addition, the arrangement of the ribs 6e is arbitrary, and the number and circumferential width can also be changed arbitrarily.

[0036] When the auxiliary valve disc 6, constructed in this manner, is stacked above the main valve assembly A via the filler plate 18, as described above, the annular recess 6d1 faces the transverse hole 2f, and the bypass passage P is not blocked by the auxiliary valve disc 6 but communicates with the compression side chamber R2 via the recess 6d. Furthermore, by adjusting the number of stacked filler plates 18 between the main valve assembly A and the auxiliary valve disc 6, the axial position of the auxiliary valve disc 6 relative to the piston rod 2 can be adjusted, thus allowing the number of stacked filler plates 18 to be adjusted so that the recess 6d and the transverse hole 2f are radially aligned.

[0037] The valve stop 8 is annular, with an outer diameter smaller than the inner diameter of the seat 6c of the auxiliary valve disc 6, and can be inserted into the cylindrical part 6b, accumulating on the disc part 6a. Figure 2 The upper middle part is fitted into the outer periphery of the small diameter portion 2a of the piston rod 2. When the outer periphery of the auxiliary valve body 7 is at... Figure 2When the valve body 8 bends axially downwards by a predetermined amount, the valve stop 8 abuts against the secondary valve body 7 to prevent the secondary valve body 7 from bending excessively.

[0038] Additionally, from valve stop 8 Figure 2 The lower part, i.e., the radial middle portion opposite to the valve body of the auxiliary valve, has an inclined surface 8a formed towards the outer periphery, away from the disc portion 6a. The inner diameter of the inclined surface 8a is larger than the outer diameter of the annular recess 6d1. A flat surface 8b, which is further inward than the inclined surface 8a at the lower end, abuts against the outer periphery of the annular recess 6d1 of the disc portion 6a. Therefore, the flat surface 8b of the valve stop 8 does not enter the annular recess 6d1, but rather is in contact with the outer periphery of the disc portion 6a. Figure 2 The upper and middle surfaces abut and are supported.

[0039] Thus, the valve stop 8 has an inclined surface 8a on the outer periphery opposite to the secondary valve body, and the recess 6d has a communicating recess 6d2 that extends radially from the outer periphery of the annular recess 6d1 and whose front end reaches the outer periphery more than the flat surface 8b. An annular gap is created between the disc portion 6a and the inclined surface 8a, so that even when the valve stop 8 is housed within the cylindrical portion 6b and placed on the disc portion 6a... Figure 2 The upper middle section, the recess 6d, will not be sealed, so there is no need to worry about the bypass channel P being cut off from the compression side chamber R2.

[0040] In this embodiment, such as Figure 2 As shown, the secondary valve body 7 is composed of three stacked, elastic vane valves 7a, 7b, and 7c, whose inner circumference is fixed to the outer circumference of the small-diameter portion 2a of the piston rod 2. Furthermore, among the three vane valves constituting the secondary valve body 7, the outer diameter of the central vane valve 7b is larger than the outer diameters of the vane valves 7a and 7c located at the upper and lower ends. Moreover, the number of vane valves constituting the secondary valve body 7 can be arbitrarily set according to the damping force generated by the buffer D by the valve device V; it can be either multiple or a single vane valve.

[0041] Furthermore, the outer diameter of the central vane valve 7b in the secondary valve body 7 is slightly smaller than the inner diameter of the annular seat 6c of the secondary valve disc 6. The secondary valve body 7 is positioned with the outer circumferential surface of the vane valve 7b facing the inner circumferential surface of the seat 6c, and is fixed to the small-diameter portion 2a. Additionally, in Figure 2 Between the lower center vane valve 7c and the valve stop 8, and Figure 2 Between the upper vane valve 7a and the valve stop 9, annular gaskets 30 and 31 are respectively installed. The outer diameters of gaskets 30 and 31 are smaller than the outer diameters of vane valves 7a and 7c. Therefore, the auxiliary valve body 7 can use the outer periphery of the auxiliary valve body side of gaskets 30 and 31 as a fulcrum to make the outer periphery... Figure 2 It bends in the vertical direction.

[0042] Furthermore, when the outer periphery of the central vane valve 7b is aligned with the inner periphery of the annular seat 6c of the secondary valve disc 6, with the secondary valve body 7 not bent, there is almost no gap between the outer periphery of the vane valve 7b and the inner periphery of the seat 6c, and the secondary valve B is in a closed state. The gap between the secondary valve body 7 and the seat 6c communicates with the compression side chamber R2, and communicates with the extension side chamber R1 via the inner cavity of the cylindrical portion 6b of the secondary valve disc 6, the recess 6d, the transverse hole 2f, the inner cavity of the piston rod 2, and the transverse hole 2e. Thus, the secondary valve B functions as a valve for opening and closing the bypass passage P. When the damping force regulating valve 40 provided in the bypass passage P is open and liquid can pass through the bypass passage P, when the secondary valve B is in a closed state, it applies a large resistance to the flow of liquid passing through the bypass passage P. Therefore, in the extremely low speed range where the piston speed is close to 0, such as when the buffer D starts, the secondary valve body 7 will not bend and will remain closed. Figure 2 The image shows the initial state of the installation.

[0043] On the other hand, when the outer periphery of the auxiliary valve body 7 is lateral Figure 2 When the vane valve 7b is bent at the upper or lower part, the outer periphery of the vane valve 7b is offset axially upward or downward relative to the inner periphery of the seat 6c. As a result, the area of ​​the annular gap between the outer periphery of the vane valve 7b and the inner periphery of the seat 6c increases, and the auxiliary valve B becomes open, applying resistance to the flow of liquid through the gap in accordance with the size of the gap.

[0044] Furthermore, when the liquid can pass through the bypass channel P, the differential pressure between the extended side chamber R1 and the compression side chamber R2 when the secondary valve body 7 bends and leaves the seat 6c to open the valve, i.e., the opening pressure of the secondary valve B, is lower than the opening pressure of the compression side vane valve 4 and the extended side vane valve 5. When the piston speed is in the low speed range, the secondary valve B opens as described above, but the compression side vane valve 4 and the extended side vane valve 5 do not open, and the liquid only passes through the bypass channel P.

[0045] Valve stop 9 is annular and is disposed on the auxiliary valve body 7. Figure 2 The upper middle side is fitted into the outer periphery of the small diameter portion 2a of the piston rod 2. When the outer periphery of the auxiliary valve body 7 is... Figure 2 When the valve body bends axially upwards by a predetermined amount, the valve stop 9 abuts against the secondary valve body 7 to prevent excessive bending of the secondary valve body 7. The valve stop 9 does not need to be housed within the cylindrical portion 6b but is positioned on the cylindrical portion 6b towards the axial direction. Figure 2 The outer diameter is offset to the upper middle position, so it can be larger than the inner diameter of the cylinder 6b. However, if it is larger than the inner diameter of the cylinder 6b, the gap between the cylinder 6b and the valve stop 9 will become narrower, which may sometimes impose unexpected resistance on the flow of liquid through the bypass channel P. Therefore, the outer diameter needs to be set to a level that does not impose resistance.

[0046] Additionally, from valve stop 9 Figure 2An inclined surface 9a is formed from the radial middle portion on the opposite side of the secondary valve body 7 at the upper middle end to the outer periphery, away from the secondary valve body 7. However, the inclined surface 9a may not be provided. However, if the inclined surface 9a is provided, the valve stop 9 and the valve stop 8 can be used as common parts, which makes the parts management and manufacturing of the valve device V easier.

[0047] The gasket 30 is composed of multiple small-diameter annular plates. Adjusting the axial position of the secondary valve body 7 ensures that the outer circumference of the secondary valve body 7 is aligned with the inner circumference of the seat portion 6c of the secondary valve disc 6. The gasket 30 fits into the outer circumference of the small-diameter portion 2a, even if it accumulates on a layer closer to the gasket 30. Figure 2 The components in the lower middle section have dimensional errors. By changing the number of layers in the shim 30, the axial position of the secondary valve body 7 can be adjusted to an appropriate position. Furthermore, the shim 30 not only serves as a bending fulcrum for the secondary valve body 7 but also adjusts the axial distance between the secondary valve body 7 and the valve stop 8. Therefore, when the outer circumference of the secondary valve body 7... Figure 2 When the valve body 7 bends downwards and abuts against the valve stop 8, it can limit further bending of the secondary valve body 7, suppress excessive bending of the secondary valve body 7, thereby protecting the secondary valve body 7. The maximum bending amount of the secondary valve body 7 can be adjusted by the number of stacked pieces of the gasket 30.

[0048] Similar to gasket 30, gasket 31 is composed of multiple small-diameter annular plates, fitted around the outer periphery of the small-diameter portion 2a. It serves not only as a bending fulcrum for the secondary valve body 7 but also as a means of adjusting the axial distance between the secondary valve body 7 and the valve stop 9. Therefore, when the outer periphery of the secondary valve body 7... Figure 2 When the valve body 7 bends upward and abuts against the valve stop 9, it can limit further bending of the secondary valve body 7, suppress excessive bending of the secondary valve body 7, and thus protect the secondary valve body 7. The maximum bending amount of the secondary valve body 7 can be adjusted by the number of stacked pieces of the gasket 31.

[0049] The auxiliary valve B, main valve assembly A, gasket 15, valve stop 16 and septum 18 constructed in this manner are assembled on the outer periphery of the small diameter portion 2a of the piston rod 2, and then fixed to the piston rod 2, which is a shaft component, by being clamped by the piston nut 13, which is threadedly engaged with the threaded portion 2d formed on the outer periphery of the front end of the small diameter portion 2a and the stepped portion 2c of the piston rod 2.

[0050] Next, within the piston rod 2 and between the transverse holes 2e and 2f forming the bypass passage P, a damping force regulating valve 40, which is a needle valve composed of an annular valve seat 41 and a needle valve body 42, is accommodated. The annular valve seat 41 is fitted and fixed to the inner circumference of the piston rod 2. Furthermore, the needle valve body 42, at its front end... Figure 2 The upper and middle ends have a conical valve needle 42a and serve as the base end. Figure 2 The lower part has a large-diameter sliding part 42b that slides in contact with the inner circumference of the piston rod 2.

[0051] The needle valve body 42 and the annular valve seat 41 together constitute the damping force regulating valve 40, which is activated by the piston rod 2 moving in an axial direction. Figure 2 The needle valve 40 can move up and down, allowing the valve needle 42a to move closer to or further away from the lower opening of the annular valve seat 41, thus adjusting the size of the annular gap between the valve needle 42a and the annular valve seat 41. Therefore, when the needle valve body 42 moves axially, the damping force regulating valve 40 can adjust the size of the flow path area and the magnitude of the resistance applied to the flow of liquid through the bypass channel P. In addition, when the valve needle 42a in the needle valve body 42 is seated at the opening of the annular valve seat 41, the damping force regulating valve 40 can also close the valve, cutting off the connection between the extension side chamber R1 and the compression side chamber R2 realized by the bypass channel P.

[0052] Furthermore, the sliding part 42b is closer to the inner circumference of the piston rod 2 than the transverse hole 2e. Figure 2 The lower middle part has a sliding contact, and a notch 42c is provided along the axial direction on the outer periphery. Furthermore, it is closer to the sliding portion 42b than the needle valve body 42. Figure 2 The outer diameter of the upper part is smaller than the inner diameter of the piston rod 2. When the damping force regulating valve 40 is opened, the liquid can pass between the outer periphery of the sliding part 42b of the needle valve body 42 and the inner periphery of the piston rod 2, and travel back and forth in the bypass channel P.

[0053] In addition, a control rod 43 is inserted into the piston rod 2 to allow the needle valve body 42 to move axially. Figure 1 As shown, with its upper end abutting against the lower end of the sliding portion 42b of the needle valve body 42, the control lever 43 can be axially inserted into the piston rod 2, causing its lower end to protrude downwards from the lower end of the piston rod 2 and abut against the regulator 44, which is rotatably mounted on the bracket 12. Furthermore, when the regulator 44 is rotated, the regulator 44 moves relative to the bracket 12... Figure 1 Lateral movement, via control lever 43, causes needle valve body 42 to move towards the piston rod 2. Figure 2 The displacement is in the vertical direction. Therefore, by rotating the regulator 44, the valve opening of the damping force regulating valve 40 can be adjusted to regulate the flow area in the bypass channel P, and the bypass channel P can be blocked.

[0054] Next, in this embodiment, as Figure 1 As shown, the cover 11 is equipped with a mounting plate on the cylinder 1. Figure 1 The upper and middle part of the cover 11a, the liquid storage tank holding part 11b that holds the liquid storage tank 23, and the connecting part 11c that extends from the side of the cover 11a and is connected to the liquid storage tank holding part 11b.

[0055] The cover 11a is a bottomed cylindrical shape and is mounted on the cylinder 1. Figure 1 The upper middle part, the upper part of the closed cylinder 1, and as the top Figure 1 The upper part has a bracket 11d that can be connected to the body of a suspension straddle-type vehicle not shown in the figure. When the shock absorber D is installed between the body of the suspension straddle-type vehicle and the rear wheel using the bracket 11d of the cover 11 and the bracket 12 installed at the lower end of the piston rod 2, the suspension spring 19 exerts its elastic force to elastically support the body.

[0056] Returning to the liquid tank holding section 11b, a cylindrical liquid tank 23 is installed thereon. A free piston 24 is slidably inserted into the liquid tank 23, dividing the liquid tank 23 into a liquid chamber L filled with liquid and a gas chamber G filled with gas. Furthermore, gas is sealed into the gas chamber G such that the pressure inside the gas chamber G is at least atmospheric pressure when the buffer D is at its maximum extension. In addition to using the free piston 24, the division between the liquid chamber L and the gas chamber G within the liquid tank 23 can also be achieved using partitions or air bladders.

[0057] The liquid chamber L in the storage tank 23 is connected to the compression chamber R2 in the cylinder 1 via the compression-side damping channel 11e and the suction channel 11f located in the connecting part 11c. The compression-side damping channel 11e is provided with a compression-side damping valve 21 that allows only the flow of liquid from the compression chamber R2 toward the liquid chamber L in the storage tank 23 and applies resistance to the flow of liquid. The suction channel 11f is provided with an extension-side check valve 22 that allows only the flow of liquid from the liquid chamber L toward the compression chamber R2.

[0058] The valve device V and the buffer D in this embodiment are configured as described above. The operation of the valve device V and the buffer D in this embodiment will be explained below. First, the operation of the buffer D when the damping force regulating valve 40 is fully open and the flow path area of ​​the bypass channel P is maximized will be explained.

[0059] When the buffer D extends, the piston 3 moves downward within the cylinder 1, compressing the extension-side chamber R1. When the extension speed of the buffer D is in a low-speed range, the pressure in the extension-side chamber R1 rises, but the pressure difference with the compression-side chamber R2 does not reach the opening pressure of the extension-side vane valve 5. Therefore, the extension-side vane valve 5 remains closed, keeping the extension-side port 3b closed. The compression-side vane valve 4 is closed from the back side by the pressure from the extension-side chamber R1. When the extension speed of the buffer D is in a low-speed range, the pressure in the extension-side chamber R1 rises, but the pressure difference with the compression-side chamber R2 does not reach the opening pressure of the auxiliary valve B. Therefore, the auxiliary valve B is closed, and the liquid experiences significant resistance as it passes through the gap between the vane valve 7b and the seat 6c in the auxiliary valve B, causing the pressure in the extension-side chamber R1 to rise rapidly.

[0060] In addition, as the buffer D extends, the piston rod 2 exits from the cylinder 1, resulting in insufficient liquid in the cylinder 1. However, the insufficient liquid is supplied from the reservoir 23 to the cylinder 1 through the opening of the extension side check valve 22, compensating for the volume of the piston rod 2 exiting from the cylinder 1.

[0061] Thus, when the elongation speed of buffer D is in a low-speed range, buffer D mainly generates a damping force to resist elongation through the resistance applied to the liquid by the secondary valve B. Therefore, with the bypass channel P open through the damping force regulating valve 40, the damping force characteristics (the characteristics of the damping force relative to the elongation speed of buffer D) on the elongation side of buffer D when the elongation speed of buffer D is in a low-speed range are as follows: Figure 4 As shown, it exhibits the following characteristics: the damping coefficient is very large and increases significantly with the increase of piston speed.

[0062] When the extension speed of the buffer D exceeds the low-speed range and falls within the low-speed range, the pressure in the extension-side chamber R1 rises. However, the pressure difference between this chamber and the compression-side chamber R2 does not reach the opening pressure of the extension-side vane valve 5. Therefore, the extension-side vane valve 5 remains closed, maintaining the closed extension-side port 3b. The compression-side vane valve 4 is closed from the back side by the pressure from the extension-side chamber R1. When the extension speed of the buffer D is within the low-speed range, the pressure difference between the extension-side chamber R1 and the compression-side chamber R2 exceeds the opening pressure of the auxiliary valve B. Therefore, the auxiliary valve body 7 bends, the auxiliary valve B opens, and the flow area of ​​the gap between the vane valve 7b and the seat 6c increases. Thus, liquid cannot pass through the blocked extension-side port 3b and compression-side port 3a, but will move from the extension-side chamber R1 to the compression-side chamber R2 via the bypass channel P. When the liquid passes through the bypass channel P, it encounters resistance as it passes through the gap between the vane valve 7b and the seat 6c of the open auxiliary valve B. Therefore, when the extension speed of the buffer D is in the low-speed range, the buffer D primarily generates a damping force that opposes its extension through the resistance exerted on the liquid by the auxiliary valve B. Thus, the damping force characteristics of the extension side of the buffer D when its extension speed is in the very low-speed range are as follows: Figure 4 As shown, the following characteristics are observed: due to the opening of the secondary valve B, the slope becomes smaller compared to when the elongation speed is in the low-speed range.

[0063] Furthermore, when the extension speed of the buffer D exceeds the low-speed range and is in the medium-to-high-speed range, the pressure difference between the extension-side chamber R1 and the compression-side chamber R2 reaches the opening pressure of the extension-side vane valve 5. The extension-side vane valve 5 bends and opens, thereby opening the extension-side port 3b. The compression-side vane valve 4, subjected to pressure from the extension-side chamber R1 from the back side, closes the compression-side port 3a. Additionally, when the extension speed of the buffer D is in the medium-to-high-speed range, the pressure difference between the extension-side chamber R1 and the compression-side chamber R2 exceeds the opening pressure of the auxiliary valve B. Compared to when the extension speed is in the low-speed range, the opening degree of the auxiliary valve B becomes greater. Since the liquid can pass through the bypass channel P, but the extension-side port 3b, which serves as the second main channel, is also open, it moves from the extension-side chamber R1 to the compression-side chamber R2 through both. When the elongation speed of buffer D is in the medium-to-high speed range, the flow rate of liquid moving from the elongation-side chamber R1 to the compression-side chamber R2 increases. Therefore, the secondary valve body 7 abuts against the valve stop 9 to restrict bending. The resistance experienced by the liquid through the secondary valve B is greater than the resistance experienced by the liquid through the elongation-side vane valve 5. Consequently, the liquid has difficulty passing through the bypass channel P, and most of the liquid moving from the elongation-side chamber R1 to the compression-side chamber R2 passes through the elongation-side port 3b. Therefore, when the elongation speed of buffer D is in the medium-to-high speed range, buffer D mainly generates a damping force that hinders elongation through the resistance applied to the liquid by the elongation-side vane valve 5. Therefore, the damping force characteristics of the elongation side of buffer D when its elongation speed is in the medium-to-high speed range are as follows: Figure 4 As shown, it has the following characteristics: it is proportional to the extension speed of the buffer D unique to the extension side vane valve 5, but the damping coefficient is further reduced compared to the aforementioned extension speed in the low speed range.

[0064] On the other hand, when the buffer D contracts, the piston 3 moves upward within the cylinder 1, compressing the compression chamber R2. When the contraction speed of the buffer D is in a low-speed range, the pressure in the compression chamber R2 rises, but the pressure difference with the extension chamber R1 does not reach the opening pressure of the compression side vane valve 4. Therefore, the compression side vane valve 4 remains closed, keeping the compression side port 3a closed. The extension side vane valve 5 is closed from the back side by the pressure of the compression chamber R2. When the contraction speed of the buffer D is in a low-speed range, the pressure in the compression chamber R2 rises, but the pressure difference with the extension chamber R1 does not reach the opening pressure of the secondary valve B. Therefore, the secondary valve B is closed, and the liquid is subjected to greater resistance when passing through the gap between the vane valve 7b and the seat 6c in the secondary valve B.

[0065] Furthermore, when the buffer D retracts, the piston rod 2 enters the cylinder 1, causing an excess of liquid within the cylinder 1 due to the volume of liquid entering the cylinder 1. This excess liquid then moves from the cylinder 1 to the reservoir 23 via the compression-side damping valve 21. Consequently, the pressure in the compression-side chamber R2 rises rapidly due to the auxiliary valve B and the compression-side damping valve 21. Additionally, when the buffer D retracts, liquid moves from the cylinder 1 to the reservoir 23 to compensate for the volume of liquid entering the cylinder 1 due to the piston rod 2.

[0066] Thus, when the contraction speed of buffer D is in a low-speed range, buffer D mainly generates a damping force to resist contraction by applying resistance to the liquid through the auxiliary valve B and the compression-side damping valve 21. Therefore, with the bypass channel P open through the damping force regulating valve 40, the damping force characteristics (damping force characteristics relative to the elongation speed of buffer D) of the compression side of buffer D when the contraction speed of buffer D is in a low-speed range are as follows: Figure 4 As shown, it exhibits the following characteristics: the damping coefficient is very large and increases significantly with the increase of piston speed.

[0067] When the contraction speed of the buffer D exceeds the low-speed range and falls within the low-speed range, the pressure in the compression chamber R2 rises. However, the pressure difference between this chamber and the extension chamber R1 does not reach the opening pressure of the compression side vane valve 4. Therefore, the compression side vane valve 4 remains closed, maintaining the closed state of the compression side port 3a. The extension side vane valve 5 is closed from the back side by the pressure of the compression chamber R2. When the extension speed of the buffer D is within the low-speed range, the pressure difference between the compression chamber R2 and the extension chamber R1 exceeds the opening pressure of the auxiliary valve B. Therefore, the auxiliary valve body 7 bends, the auxiliary valve B opens, and the flow area of ​​the gap between the vane valve 7b and the seat 6c increases. Thus, liquid cannot pass through the blocked compression side port 3a and extension side port 3b, but will move from the compression chamber R2 to the extension chamber R1 via the bypass channel P. When the liquid passes through the bypass channel P, it encounters resistance as it passes through the gap between the vane valve 7b and the seat 6c of the open auxiliary valve B. Therefore, when the contraction speed of the buffer D is in the low-speed range, the buffer D mainly generates a damping force that opposes contraction through the resistance applied to the liquid by the auxiliary valve B and the compression-side damping valve 21. Therefore, the damping force characteristics of the compression side of the buffer D when its contraction speed is in the very low-speed range are as follows: Figure 4 As shown, the following characteristics are observed: due to the opening of the secondary valve B, the slope becomes smaller compared to when the contraction speed is in the low-speed range.

[0068] Furthermore, when the contraction speed of the buffer D exceeds the low-speed range and is in the medium-high speed range, the pressure difference between the elongation side chamber R1 and the compression side chamber R2 reaches the opening pressure of the compression side vane valve 4. The compression side vane valve 4 bends and opens, thereby opening the compression side port 3a. The elongation side vane valve 5 is closed by the pressure from the elongation side chamber R1 from the back side. In addition, when the contraction speed of the buffer D is in the medium-high speed range, the pressure difference between the compression side chamber R2 and the elongation side chamber R1 exceeds the opening pressure of the auxiliary valve B. Compared with the low-speed range, the opening degree of the auxiliary valve B becomes larger. Since the liquid can pass through the bypass channel P, but the compression side port 3a, which is the first main channel, is also open, it moves from the compression side chamber R2 to the elongation side chamber R1 through both. When the contraction speed of buffer D is in the medium-to-high speed range, the flow rate of liquid moving from the compression side chamber R2 to the extension side chamber R1 increases. Therefore, the secondary valve body 7 abuts against the valve stop 8 to restrict bending. The resistance experienced by the liquid through the secondary valve B is greater than the resistance experienced by the liquid through the compression side vane valve 4. Thus, the liquid has difficulty passing through the bypass channel P, and most of the liquid moving from the compression side chamber R2 to the extension side chamber R1 passes through the compression side port 3a. Therefore, when the contraction speed of buffer D is in the medium-to-high speed range, buffer D mainly generates a damping force that hinders contraction by applying resistance to the liquid through the compression side vane valve 4 and the compression side damping valve 21. Therefore, the damping force characteristics of the compression side of buffer D when the contraction speed of buffer D is in the medium-to-high speed range are as follows: Figure 4 As shown, it has the following characteristics: it is proportional to the contraction speed of the buffer D of the compression-side vane valve 4 and the compression-side damping valve 21, but the damping coefficient becomes smaller compared to the aforementioned contraction speed when it is in the low-speed range.

[0069] Furthermore, when the damping force regulating valve 40 is in the fully open state, as described above, by changing the flow area of ​​the bypass channel P using the damping force regulating valve 40, the flow rate of the liquid passing through the bypass channel P can be adjusted, and the damping force of the buffer D's extension and retraction speed can be adjusted from the micro-low speed range to the low speed range.

[0070] Here, the buffer D of this embodiment is configured with the following components: a bypass channel P, which is parallel to the compression side port 3a (serving as the first main channel) and the extension side port 3b (serving as the second main channel), and connects the extension side chamber R1 and the compression side chamber R2; a compression side vane valve 4 for opening and closing the compression side port 3a and the extension side vane valve 5 for opening and closing the extension side port 3b; and a secondary valve B, which opens and closes the bypass channel P, and whose opening pressure is lower than that of the compression side vane valve 4 and the extension side vane valve 5. In the buffer D configured in this way, even if the secondary valve B is restricted from bending by the valve stops 8 and 9, the flow of liquid through the compression side port 3a and the extension side port 3b will not be affected.

[0071] In other words, in the buffer D of this embodiment, there is no bottleneck where the secondary valve B minimizes the flow area of ​​the compression side port 3a (which serves as the first main channel) and the extension side port 3b (which serves as the second main channel). Therefore, even if the extension and retraction speed of the buffer D reaches a high-speed range, most of the liquid in the extension side chamber R1 compressed by the piston 3 will flow through the compression side port 3a or the extension side port 3b. Thus, it is possible to suppress the overload caused by excessive damping force due to the pressure loss generated by the secondary valve B superimposed on the pressure loss in the compression side vane valve 4 or the extension side vane valve 5.

[0072] Furthermore, in the buffer D of this embodiment, the speed range in which the damping force is generated by the auxiliary valve B is set to a low-speed range, and the speed range in which the damping force is generated by the compression-side vane valve 4 and the extension-side vane valve 5 is set to a medium-high speed range. However, the speed ranges of low-speed, medium-high speed can be arbitrarily set by the designer.

[0073] The valve device V of this embodiment includes: a piston rod (shaft component) 2; a main valve assembly A, including: a piston (valve seat component) 3, which is annular and mounted on the outer periphery of the piston rod (shaft component) 2 to separate the extension side chamber (working chamber) R1 and the compression side chamber (working chamber) R2, and having a compression side port (first main channel) 3a and an extension side port (second main channel) 3b that respectively connect the extension side chamber (working chamber) R1 and the compression side chamber (working chamber) R2; a compression side vane valve (first valve) 4, which is annular and mounted on the outer periphery of the piston rod (shaft component) 2, and stacked on one side of the piston (valve seat component) 3 to open and close the compression side port (first main channel) 3a; and an extension side vane valve (second valve) 5, which is annular and mounted on the outer periphery of the piston rod (shaft component) 2, and stacked on the other side of the piston (valve seat component) 3 to open and close the extension side port (second main channel) 3b; and a bypass channel P provided on the piston rod (shaft component) 2. The piston rod (shaft component) 2 connects to the elongated side chamber (one working chamber) R1 and the compression side chamber (the other working chamber) R2, and has a transverse hole (opening) 2f on the side of the piston rod (shaft component) 2 and closer to the compression side chamber (the other working chamber) than the main valve assembly A; and a secondary valve B, having a secondary valve disc 6 and a secondary valve body 7, the secondary valve disc having an annular shape and mounted on the outer periphery of the piston rod (shaft component) 2 and stacked on the disc portion 6a of the main valve assembly A, from the disc portion 6a... The sub-valve disc 6a has an erected cylindrical portion 6b on its outer periphery and an annular seat portion 6c on its inner periphery. The sub-valve body is annular, mounted on the outer periphery of the piston rod (shaft component) 2 and stacked on the disc portion 6a. The outer periphery is allowed to bend so that the outer periphery faces the inner periphery of the seat portion 6c. The sub-valve disc 6 has a recess 6d, which opens from the inner periphery on the sub-valve body side of the disc portion 6a and extends outward to communicate with the transverse hole (opening portion) 2f to form part of the bypass channel P.

[0074] In the valve device V constructed in this manner, the auxiliary valve B is stacked on the main valve assembly A. The main valve assembly A includes a piston (valve seat component) 3 having a compression side port (first main channel) 3a and an extension side port (second main channel) 3b, a compression side vane valve (first valve) 4 stacked on the piston (valve seat component) 3, and an extension side vane valve (second valve) 5 for opening and closing the extension side port (second main channel) 3b. The auxiliary valve B also includes an auxiliary valve disc mounted on the outer periphery of the piston rod (shaft component) 2. The valve assembly V consists of a main valve assembly A and a secondary valve body 7. The disc portion 6a of the secondary valve disc 6 has a recess 6d that is open on its inner circumference and faces the transverse hole (opening portion) 2f of the bypass passage P, so that the bypass passage P communicates with the compression side chamber R2. Therefore, the secondary valve disc 6 does not need to function as a nut to fix the main valve assembly A to the piston rod (shaft component) 2, nor does it need to have a retaining shaft to hold the secondary valve body 7. The main valve assembly A and the secondary valve B can be sequentially fitted into the piston rod (shaft component) 2 and fixed with a piston nut 13. Therefore, the overall length of the valve device V can be shortened.

[0075] Furthermore, according to the valve device V of this embodiment, the bypass passage P is arranged side-by-side with the compression-side port (first main passage) 3a and the extension-side port (second main passage) 3b. Therefore, it can suppress the overload caused by the pressure loss generated by the auxiliary valve B superimposed on the pressure loss in the compression-side vane valve (first valve) 4 or the extension-side vane valve (second valve) 5, which would result in excessive damping force. This allows the damper D used in the vehicle to generate optimal damping force, thereby improving the vehicle's ride comfort. In summary, according to the valve device V, the overall length of the vehicle is not increased, thus improving ride comfort.

[0076] Furthermore, in the valve device V of this embodiment, the recess 6d provided in the auxiliary valve disc 6 has an annular recess 6d1 located on the inner circumference of the auxiliary valve body side of the disc portion 6a and facing the transverse hole (opening) 2f. According to the valve device V constructed in this manner, since the annular recess 6d1 facing the transverse hole (opening) 2f is provided on the inner circumference of the disc portion 6a, it is easy to align the annular recess 6d1 with the transverse hole (opening) 2f. Even if there are dimensional errors in the setting of the number of stacked plates of the annular plate in the compression-side vane valve (first valve) 4 or the extension-side vane valve (second valve) 5, or in the individual parts of the main valve assembly A, the axial position of the auxiliary valve disc 6 can be easily positioned so that the annular recess 6d1 faces the transverse hole (opening) 2f, without the need for fine adjustment of the number of stacked plates of the sprue 18. Furthermore, regardless of the position of the auxiliary valve disc 6 relative to the piston rod (shaft component) 2 in the circumferential direction, as long as the axial position is aligned, the annular recess 6d1 will necessarily face the transverse hole (opening) 2f. Therefore, there is no need to position the auxiliary valve disc 6 relative to the piston rod (shaft component) 2 in the circumferential direction, reducing the burden of assembling the valve device V.

[0077] Furthermore, in the valve device V of this embodiment, the recess 6d provided in the auxiliary valve disc 6 has a communicating recess 6d2 extending from the annular recess 6d1 and communicating the annular recess 6d1 with the compression side chamber (another working chamber) R2. When viewed from the center of the disc portion 6a, the total cross-sectional area of ​​the communicating recess 6d2 is greater than or equal to the cross-sectional area of ​​the annular recess 6d1. According to the valve device V constructed in this way, even if certain parts attached to the auxiliary valve body 7 (valve stop 8 in this example) are stacked on the disc portion 6a, the communication between the bypass passage P and the compression side chamber R2 can be ensured through the recess 6d. Moreover, the flow path is not narrowed by the communicating recess 6d2 within the recess 6d, which can prevent unnecessary resistance to the flow of liquid through the recess 6d and overload that is useless for the damping force.

[0078] Furthermore, the buffer D of this embodiment includes a cylinder 1, a piston rod 2 inserted into the cylinder 1, and a valve device V. The shaft component serves as the piston rod 2, and the valve seat component is slidably inserted into the cylinder 1, dividing the cylinder 1 into an extension side chamber R1 and a compression side chamber R2. A damping force regulating valve 40 with an adjustable flow path area is provided in the bypass channel P. In the buffer D constructed in this manner, as described above, the main valve assembly A and the auxiliary valve B can be sequentially fitted into the piston rod (shaft component) 2 and fixed with a piston nut 13, which shortens the overall length of the valve device V, thus preventing an increase in overall length. Furthermore, according to the buffer D of this embodiment, the bypass channel P is parallel to the compression-side port (first main channel) 3a and the extension-side port (second main channel) 3b. Therefore, it can suppress the overload caused by the pressure loss generated by the auxiliary valve B superimposed on the pressure loss in the compression-side vane valve (first valve) 4 or the extension-side vane valve (second valve) 5, which would result in excessive damping force. This allows the buffer D used in the vehicle to generate optimal damping force, thereby improving the vehicle's ride comfort. In addition, according to the buffer D, the overall length does not increase, thus improving the vehicle's ride comfort. Furthermore, according to the buffer D of this embodiment, compared to the case where the auxiliary valve B is connected in series with the compression-side port (first main channel) 3a and the extension-side port (second main channel) 3b, where the flow rate increases when the outer diameter of the piston rod 2 is small, the flow rate through the bypass channel P can be reduced. Therefore, the maximum bending amount of the auxiliary valve body 7 can be reduced, preventing the deterioration of the auxiliary valve body 7, and allowing the use of an auxiliary valve body 7 with lower bending stiffness. In addition, according to this embodiment, since the buffer D is provided with a damping force regulating valve 40 in the bypass channel P, the damping force of the buffer D can also be adjusted when the extension and retraction speed is in the low speed range.

[0079] Furthermore, in this embodiment, the valve device V uses the piston rod 2 of the buffer D as a shaft component and the piston 3 as a valve seat component, and is located on the piston part of the buffer D. Alternatively, the compression-side damping channel 11e can be used as the first main channel, the compression-side damping valve 21 as the first valve, the suction channel 11f as the second main channel, the extension-side check valve 22 as the second valve, and the working chamber as the compression-side chamber R2 and the liquid storage tank 23, and is located between the compression-side chamber R2 and the liquid storage tank 23.

[0080] The preferred embodiments of the present invention have been described in detail above, but modifications, variations and alterations can be made without departing from the claims.

[0081] Symbol Explanation 1 cylinder 2. Piston rod (shaft assembly) 2f horizontal hole (opening) 3-piston (valve seat assembly) 3a Compression side port (first main channel) 3b Extended side port (second main channel) 4. Compression-side vane valve (first valve) 5. Extended side vane valve (second valve) 6 valve discs 6a Disc Section 6b cylinder 6c seat 6d recess 6d1 annular recess 6d2 connects the concave part 7 valve bodies A Main Valve Assembly B auxiliary valve D buffer P bypass lane R1 elongated side chamber (working room) R2 compression side chamber (working chamber) V valve device

Claims

1. A valve device comprising: Shaft components; The main valve assembly includes: a valve seat component, which is annular and mounted on the outer periphery of the shaft component to separate two working chambers, and having a first main channel and a second main channel respectively communicating with the working chambers; a first valve, which is annular and mounted on the outer periphery of the shaft component, and stacked on one side of the valve seat component to open and close the first main channel; and a second valve, which is annular and mounted on the outer periphery of the shaft component, and stacked on the other side of the valve seat component to open and close the second main channel; A bypass passage, located on the shaft component, connects one of the chambers and the other chamber, and has an opening on the side of the shaft component, further from the main valve assembly than on the other side of the chamber; and A secondary valve has a secondary valve disc and a secondary valve body. The secondary valve disc has a circular portion that is annular and mounted on the outer periphery of the shaft component and stacked on the main valve assembly, a cylindrical portion that rises vertically from the outer periphery of the circular portion, and an annular seat portion disposed on the inner periphery of the cylindrical portion. The secondary valve body is annular, mounted on the outer periphery of the shaft component and stacked on the circular portion, and allows the outer periphery to be bent so that the outer periphery faces the inner periphery of the seat portion. The secondary valve disc has a recess that extends from the inner circumference opening to the outer circumference on the secondary valve body side of the disc portion and communicates with the opening to form part of the bypass channel.

2. The valve device according to claim 1, wherein... The recess in the secondary valve disc has: An annular recess is provided on the inner circumference of the secondary valve body side of the disc portion and faces the opening.

3. The valve device according to claim 3, wherein, The recess in the secondary valve disc has: A connecting recess extends from the annular recess to connect the annular recess to the other side of the working chamber; When viewed from the center of the disc portion, the total cross-sectional area of ​​the connecting recesses is greater than or equal to the cross-sectional area of ​​the annular recess.

4. A buffer, comprising: cylinder; The piston rod is inserted into the cylinder; and Valve device according to any one of claims 1 to 3; The shaft component is used as the piston rod. The valve seat component is slidably inserted into the cylinder, dividing the cylinder into an extension side chamber and a compression side chamber. A damping force regulating valve with adjustable flow area is installed in the bypass channel.

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