buffer

Abstract

The damper (D) of the present application is provided with: a cylinder (1); a cylindrical piston rod (2) which is axially movably inserted into the cylinder (1); a piston (3) which is coupled to the piston rod (2), is axially movably inserted into the cylinder (1), and divides the cylinder (1) into an extension side chamber (R1) and a compression side chamber (R2); a cap (10) which closes the compression side chamber side end of the cylinder (1); a cylindrical inner rod (4) which extends from the cap (10) to be inserted into the compression side chamber (R2), and is slidably fitted into the piston rod (2); a main damping passage (M) which exerts resistance to the flow of liquid which goes back and forth between the extension side chamber (R1) and the compression side chamber (R2); a bypass passage (B) which bypasses the main damping passage (M), and connects the extension side chamber (R1) and the compression side chamber (R2) via the inside of the piston rod (2) and the inside of the inner rod (4); and a damping force adjusting valve (21) which is provided in the bypass passage (B).

Description

Technical Field

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

[0002] A damper is used, for example, between the body and wheels of a suspension straddle-type vehicle, to suppress vibrations of the body and wheels by utilizing the damping force generated during extension and retraction.

[0003] For example, as shown in JP2020-143685A, this type of buffer is constructed with the following components: a cylinder; a piston, movably inserted into the cylinder, dividing the cylinder into an extension side chamber and a compression side chamber filled with hydraulic oil; a piston rod, movably inserted into the cylinder and connected to the piston; a reservoir for storing hydraulic oil; a rigid side damping element disposed on the piston, connecting the extension side chamber and the compression side chamber and applying resistance to the flow of hydraulic oil; a bypass channel, bypassing the rigid side damping element, connecting the extension side chamber and the compression side chamber; and a solenoid valve and a soft side damping element, connected in series with the bypass channel.

[0004] In a buffer constructed in this way, the opening area of ​​the bypass channel is adjusted by using a solenoid valve, thereby adjusting the distribution ratio of hydraulic oil flow through the hard-side damping element and the soft-side damping element. This expands the damping force adjustment range and outputs the damping force most suitable for suppressing vehicle vibration.

[0005] Existing technical documents Patent documents Patent Document 1: JP2020-143685A Summary of the Invention The problem the invention aims to solve The conventional shock absorber has the following structure: a housing is provided around the cylinder, a bypass channel is provided between the cylinder and the housing to connect the extension side chamber and the compression side chamber outside the cylinder, and a solenoid valve and a soft side damping element are provided in the bypass channel.

[0006] Therefore, conventional shock absorbers need to cover the large-diameter housing of the cylinder when forming the bypass channel, resulting in larger shock absorbers, increased weight, and increased manufacturing costs. When the shock absorber is larger, it may be difficult to install due to the limited space, depending on the vehicle. The increased weight will lead to increased fuel consumption. Therefore, there is a need to reduce the weight of the shock absorber.

[0007] The purpose of this invention is to provide a small, lightweight shock absorber that reduces manufacturing costs and improves vehicle mounting performance.

[0008] Problem-solving methods To address the aforementioned issues, the buffer of the present invention comprises: a cylinder; a cylindrical piston rod axially movable and inserted into the cylinder; a piston connected to the piston rod, axially movable and inserted into the cylinder, dividing the cylinder into an extension side chamber and a compression side chamber; a cover sealing the compression side chamber end of the cylinder; a cylindrical inner rod extending from the cover and inserted into the compression side chamber, slidably fitted into the piston rod; a main damping channel that applies resistance to the flow of liquid traveling back and forth between the extension side chamber and the compression side chamber; a bypass channel bypassing the main damping channel and communicating with the extension side chamber and the compression side chamber via the piston rod and the inner rod; and a damping force regulating valve disposed in the bypass channel.

[0009] In a buffer constructed in this manner, the bypass channel bypasses the main damping channel and connects the elongation side chamber and the compression side chamber via the piston rod and the inner rod inserted into the piston rod. The cylinder is provided with a bypass channel, so it is not necessary to cover the large-diameter outer shell of the cylinder when forming the bypass channel. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of a buffer in one implementation.

[0011] Figure 2 This is a graph showing the damping force characteristics of a buffer in one implementation. Detailed Implementation

[0012] The present invention will now be described based on the illustrated embodiments. Figure 1 As shown, in one embodiment, the buffer D is configured with the following components: a cylinder 1; a cylindrical piston rod 2, which is axially movable and inserted into the cylinder 1; a piston 3, connected to the piston rod 2, which is axially movable and inserted into the cylinder 1, and divides the cylinder 1 into an extension side chamber R1 and a compression side chamber R2; a cover 10, which closes the compression side chamber of the cylinder 1; a cylindrical inner rod 4, which extends from the cover 10 and passes through the compression side chamber R2, and is slidably fitted into the piston rod 2; a main damping channel M, which applies resistance to the flow of liquid traveling back and forth between the extension side chamber R1 and the compression side chamber R2; a bypass channel B, which bypasses the main damping channel M and connects the extension side chamber R1 and the compression side chamber R2 via the piston rod 2 and the inner rod 4; and a damping force regulating valve 21, which is provided in the bypass channel B.

[0013] Furthermore, although not illustrated, this damper D is used between the body and rear wheel of a suspension straddle-type vehicle such as a motorcycle to suppress vibrations of the body and rear wheel. Additionally, the damper D can also be used to suppress vibrations in vehicles other than those in suspension straddle-type vehicles.

[0014] The following will describe in detail the various parts of buffer D. For example... Figure 1 As shown, cylinder 1 is cylindrical. Figure 1The upper and middle parts are closed by guide 17, and Figure 1 The lower middle section is sealed by cover 10. Additionally, in cylinder 1... Figure 1 A threaded portion 1a is provided at a position slightly above the lower middle end. The cover 10 is threadedly engaged with the threaded portion 1a and installed on the cylinder 1. Figure 1 Lower middle section.

[0015] In addition, fitted into cylinder 1 Figure 1 The guide 17 at the upper inner circumference is annular, with an annular sealing ring 17a on its outer circumference that is in close contact with the inner circumference of the cylinder 1, and an annular sealing ring 17b and an annular bushing 17c on its inner circumference that are in sliding contact with the outer circumference of the piston rod 2. Furthermore, the guide 17 is mounted on the cylinder 1... Figure 1 The C-shaped ring 24 on the inner circumference of the upper middle part restricts the direction relative to cylinder 1. Figure 1 Move to the upper middle.

[0016] In this way, the piston rod 2, which is movably inserted into the cylinder 1, is inserted through the sealing ring 17b and bushing 17c of the guide member 17 installed on the inner circumference of the cylinder 1. The guide member 17 supports the piston rod 2 via the bushing 17c, guides the piston rod 2 to move axially relative to the cylinder 1, and seals the outer circumference of the piston rod 2 via the sealing ring 17b. Furthermore, the sealing ring 17a is in close contact with the inner circumference of the cylinder 1, sealing it and preventing liquid leakage between the guide member 17 and the cylinder 1. As the front end of the piston rod 2... Figure 1 The upper and middle ends are guided by the inner circumference of the guide 17 from the cylinder 1. Figure 1 The upper and middle parts protrude outwards.

[0017] The piston rod 2 is cylindrical and includes: a small-diameter portion 2a, which is located at... Figure 1 The lower part has a smaller outer diameter than the upper part and a piston 3 is mounted on its outer circumference; the threaded part 2b is located on the smaller diameter part 2a. Figure 1 The lower outer periphery; and the through hole 2c, which is radially penetrating and closer to the smaller diameter portion 2a. Figure 1 The upper middle side. Additionally, on piston rod 2... Figure 1 The upper middle section is equipped with a bracket 6 that can be connected to the body of a suspension straddle-type vehicle.

[0018] A piston 3, mounted on a piston rod 2, is axially movable inside a cylinder 1. The cylinder 1 is divided by the piston 3 into an elongation-side chamber R1 above the piston 3 and a compression-side chamber R2 below the piston 3. Both the elongation-side chamber R1 and the compression-side chamber R2 are filled with a liquid such as hydraulic oil. In this embodiment, the liquid is hydraulic oil, but other liquids such as water or an aqueous solution may also be used. The through-hole 2c of the piston rod 2 is located further than the small-diameter portion 2a where the piston 3 is mounted. Figure 1 The piston rod 2 has an opening at the top and faces the elongated side chamber R1, so the piston rod 2 communicates with the elongated side chamber R1 through the through hole 2c.

[0019] The piston 3 is annular and mounted on the outer periphery of the small-diameter portion 2a of the piston rod 2. It has an elongation-side port 3a and a compression-side port 3b that allow the elongation-side chamber R1 and the compression-side chamber R2 to communicate side-by-side, respectively. In the piston 3... Figure 1 At the lower middle end, an extension-side main damping valve 13, which is annular and installed on the outer periphery of the small-diameter portion 2a, is present to open and close the extension-side port 3a. Furthermore, in the piston 3... Figure 1 At the upper middle end, a compression-side main damping valve 14, which is annular and installed on the outer periphery of the small-diameter portion 2a, is stacked to open and close the compression-side port 3b. Furthermore, the piston 3, the extension-side main damping valve 13, and the compression-side main damping valve 14 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 15 screwed to the lower end of the small-diameter portion 2a.

[0020] In the buffer D of this embodiment, the elongation-side main damping valve 13 is a stacked vane valve, which is located on the piston 3. Figure 1 The buffer D is constructed by stacking multiple annular plates at its lower end. The inner circumference is fixed, and the extension port 3a opens when the outer circumference bends due to pressure in the extension chamber R1. The extension-side main damping valve 13 can open and close the extension port 3a. It opens when the buffer D extends, resisting the flow of liquid from the extension chamber R1 towards the compression chamber R2 through the extension port 3a, and closes when the buffer D contracts, blocking the extension port 3a. Furthermore, the extension-side main damping valve 13 can be any damping valve capable of resisting the flow of liquid from the extension chamber R1 towards the compression chamber R2 and exerting a damping force that hinders the extension of the buffer D when it extends; therefore, it can be a damping valve other than a stacked vane valve.

[0021] In contrast, in the buffer D of this embodiment, the compression-side main damping valve 14 is a stacked vane valve, which is located on the piston 3. Figure 1 The upper and middle sections are constructed by stacking multiple annular plates, with the inner circumference fixed. When the outer circumference bends due to the pressure in the compression chamber R2, the compression port 3b opens. The compression-side main damping valve 14 can open and close the compression port 3b. When the buffer D contracts, the valve opens to resist the flow of liquid from the compression chamber R2 toward the extension chamber R1 through the compression port 3b, and closes to block the compression port 3b when the buffer D extends. Furthermore, the compression-side main damping valve 14 can be any damping valve capable of resisting the flow of liquid from the compression chamber R2 toward the extension chamber R1 and exerting a damping force that hinders the contraction of the buffer D when it contracts; therefore, it can be a damping valve other than a stacked vane valve. Additionally, although not shown, a throttling orifice is provided alongside the extension-side main damping valve 13 and the compression-side main damping valve 14. The throttling orifice is formed, for example, by a notch provided on the annular plate constituting the elongation-side main damping valve 13 and the compression-side main damping valve 14, or by an engraving provided on the valve seat of the piston 3 for the annular plate to disengage and sit on.

[0022] Thus, the extension-side port 3a and compression-side port 3b of piston 3 connect the extension-side chamber R1 and the compression-side chamber R2. Furthermore, for the flow of liquid traveling back and forth between the extension-side chamber R1 and the compression-side chamber R2 via the extension-side port 3a and the compression-side port 3b, resistance is applied by the aforementioned throttling orifice when the extension-side main damping valve 13 and the compression-side main damping valve 14 are closed. When the extension-side main damping valve 13 and the compression-side main damping valve 14 are open, the extension-side main damping valve 13 resists the flow of liquid through the extension-side port 3a, and the compression-side main damping valve 14 resists the flow of liquid through the compression-side port 3b. In this embodiment, these extension-side ports 3a, compression-side ports 3b, throttling orifices, extension-side main damping valve 13, and compression-side main damping valve 14 constitute a main damping channel M that resists the flow of liquid moving between the extension-side chamber R1 and the compression-side chamber R2. Alternatively, the main damping channel M may be configured with only a single channel and a bidirectional valve such as a throttle or choke ring that applies resistance to the flow of liquid traveling back and forth between the elongation side chamber R1 and the compression side chamber R2.

[0023] The cover 10 has a cylindrical part 10a and a bottom 10b that closes the lower end of the cylindrical part 10a. It is a bottomed cylindrical shape. The lower end of the cylinder 1 is inserted into the cylindrical part 10a, and the threaded part 10a1 on the inner circumference of the cylindrical part 10a is threadedly engaged with the threaded part 1a on the outer circumference of the cylinder 1 to fix it to the cylinder 1.

[0024] More specifically, such as Figure 1 As shown, the cylindrical portion 10a has a threaded portion 10a1 provided on the inner circumference of the upper end, and an annular sealing groove 10a2 provided on the inner circumference and below the threaded portion 10a1. A sealing ring 20 that is in close contact with the outer circumference of the cylinder 1 is accommodated in the sealing groove 10a2 provided on the inner circumference of the cylindrical portion 10a, and the cover 10 and the cylinder 1 are sealed.

[0025] Then, the bottom 10b of cover 10 is in Figure 1 The upper part has a central recess 10b1, into which a cylindrical inner rod 4 is inserted. Figure 1 The lower middle section. A stop wheel 5 is provided in the recess 10b1 to prevent the inner rod 4 from disengaging from the recess 10b1, and the inner rod 4 is held by the cover 10. In addition, a sealing ring 16 is provided in the recess 10b1 to closely contact the outer periphery of the inner rod 4, and the cover 10 and the inner rod 4 are sealed.

[0026] Thus, the inner rod 4 extends from the bottom 10b of the cover 10 and penetrates the compression chamber R2, and is slidably inserted into the piston rod 2. More specifically, the outer diameter of the inner rod 4 is smaller than the inner diameter of the piston rod 2, and the inner rod 4 can be slidably inserted into the small-diameter portion 2a of the piston rod 2. Figure 1The lower end is within the cylindrical bushing 2d on the inner circumference. Therefore, when the piston rod 2 is displaced relative to the cylinder 1, the piston rod 2 is also displaced relative to the inner rod 4 held in the cover 10. Furthermore, the inner rod 4 is movably fitted into the recess 10b1, and although held on the cover 10 by the stop wheel 5, it allows... Figure 1 The slight radial oscillation at the upper middle end allows it to smoothly move in and out of the piston rod 2 when inserted. The inner rod 4 communicates with the elongated side chamber R1 through the piston rod 2 and the through hole 2c, forming the inner passage Pr of the rod together with the piston rod 2.

[0027] In addition, the cross-sectional area of ​​the annular gap between the inner circumference of cylinder 1 and the outer circumference of piston rod 2 is larger than the cross-sectional area of ​​inner rod 4, that is, the cross-sectional area of ​​the cutting surface formed by transversely cutting inner rod 4.

[0028] Furthermore, at the lower end of the bottom 10b of the cover 10, in Figure 1 A bracket 10c is provided at the lower center, through which the lower end of the buffer D can be connected to the swing arm that holds the rear wheel in the suspension straddle-type vehicle. Furthermore, in this embodiment, it is described that the piston rod 2 is connected to the body of the suspension straddle-type vehicle and the cover 10 is connected to the rear wheel of the suspension straddle-type vehicle. However, conversely, the piston rod 2 can also be connected to the rear wheel of the suspension straddle-type vehicle and the cover 10 can be connected to the body of the suspension straddle-type vehicle.

[0029] Furthermore, the cover 10 includes a liquid tank holding portion 10d extending radially from the side of the bottom 10b and arranged parallel to the cylindrical portion 10a. The liquid tank 18 is cylindrical, and its lower end is integrally connected to the liquid tank holding portion 10d, and it houses an air bladder 19. The liquid tank 18 is divided by the air bladder 19 into a liquid chamber L filled with liquid and a gas chamber G filled with gas. In addition, gas is sealed in the gas chamber G so that the pressure in the gas chamber G is at least atmospheric pressure or higher when the buffer D is at its maximum extension. In addition, the division between the liquid chamber L and the gas chamber G in the liquid tank 18 can be achieved by using an elastic partition wall such as the air bladder 19 or a diaphragm, or by using a free piston.

[0030] Furthermore, in this embodiment, such as Figure 1 As shown, the cover 10 includes: an internal channel Pc, which extends from the bottom 10b through the recess 10b1. Figure 1 The lower end has an opening leading to the end 10b2 of the bottom 10b facing the compression side chamber R2; and the discharge passage EP and the suction passage SP open from the end 10b2 of the bottom 10b and lead to the liquid chamber L of the storage tank 18.

[0031] One end of the inner channel Pc is connected to the elongation side chamber R1 through the inner channel Pr of the rod, and the other end is connected to the compression side chamber R2. Together with the inner channel Pr of the rod, they form a bypass channel B that bypasses the main damping channel M and connects the elongation side chamber R1 and the compression side chamber R2.

[0032] Furthermore, at the bottom 10b of the cover 10, there are a damping force regulating valve 21, an extension side low speed valve 22 and a compression side low speed valve 23 disposed in the middle of the cover inner passage Pc which constitutes part of the bypass passage B, a compression side damping valve 30 disposed in the middle of the discharge passage EP, and an intake check valve 31 disposed in the middle of the intake passage SP as an intake side valve.

[0033] The damping force regulating valve 21 is connected in series with the extension side low speed valve 22 and the compression side low speed valve 23 in the bypass channel B, and the extension side low speed valve 22 and the compression side low speed valve 23 are connected in parallel in the bypass channel B.

[0034] In this embodiment, the damping force regulating valve 21 is a solenoid valve, comprising a valve body 21a that can open and close an inner passage Pc forming part of the bypass passage B, a spring 21b that applies force to close the valve body 21a, and a solenoid 21c installed on the side of the bottom 10b that generates a force against the spring 21b and pushes the valve body 21a in the opening direction. The degree of valve opening can be adjusted according to the amount of current supplied to the solenoid 21c, and the valve closes when the current to the solenoid 21c is cut off. Alternatively, the damping force regulating valve 21 can be a solenoid valve that allows adjustment of the valve opening degree in this manner, but it can also be a solenoid valve that allows adjustment of the valve opening pressure, or a damping force regulating valve whose valve opening degree or valve opening pressure can be adjusted by manual operation.

[0035] The low-speed valve 22 on the extension side is a damping valve that opens to resist the flow of liquid from the extension side chamber R1 to the compression side chamber R2 and closes to block the flow of liquid from the compression side chamber R2 to the extension side chamber R1. It is a valve whose opening pressure is lower than that of the main damping valve 13 on the extension side, and whose damping force is generated when the extension speed of the buffer D is low, opens before the main damping valve 13 on the extension side.

[0036] The low-speed valve 23 on the compression side is a damping valve that opens to resist the flow of liquid from the compression side chamber R2 to the extension side chamber R1 and closes to block the flow of liquid from the extension side chamber R1 to the compression side chamber R2. It is a valve whose opening pressure is lower than that of the main damping valve 14 on the compression side, and whose damping force is generated when the buffer D contracts at low speed before the main damping valve 14 on the compression side opens.

[0037] In addition, in this embodiment, the inner channel Pc is provided with an extension-side low-speed valve 22 that only allows liquid to flow from the extension-side chamber R1 to the compression-side chamber R2 and applies resistance to the flow of the liquid passing through, and a compression-side low-speed valve 23 that only allows liquid to flow from the compression-side chamber R2 to the extension-side chamber R1 and applies resistance to the flow of the liquid passing through. These extension-side low-speed valves 22 and compression-side low-speed valves 23 are used as low-speed valves. However, valves that allow the flow of liquid reciprocating between the extension-side chamber R1 and the compression-side chamber R2 and apply resistance to the flow of the liquid passing through can also be used as low-speed valves.

[0038] A compression-side damping valve 30 is provided in the discharge channel EP and is configured as follows: it opens to resist the flow of liquid from the compression-side chamber R2 toward the storage tank 18, and closes to block the flow of liquid from the storage tank 18 toward the compression-side chamber R2, thus blocking the discharge channel EP. A suction check valve 31, serving as the suction-side valve, is provided in the suction channel SP and is configured as follows: it opens to allow the flow of liquid from the storage tank 18 toward the compression-side chamber R2 with almost no resistance, but closes to block the flow of liquid from the compression-side chamber R2 toward the storage tank 18, thus blocking the suction channel SP. Therefore, in this embodiment, the suction-side valve is a suction check valve 31 provided in the suction channel SP that only allows liquid to flow from the storage tank 18 toward the compression-side chamber R2. However, it could also be a damping valve provided in the suction channel SP that resists the flow of liquid from the storage tank 18 toward the compression-side chamber R2.

[0039] The buffer D in this embodiment is configured as described above, and the operation of the buffer D will be explained below. When the buffer D extends, the piston rod 2 retracts from the cylinder 1, and the piston 3 compresses the extension-side chamber R1. As a result, the liquid in the extension-side chamber R1 moves to the compression-side chamber R2 through the external throttling orifice in the main damping channel M, the extension-side main damping valve 13 in the main damping channel M, or through the bypass channel B formed by the piston rod 2 and the inner rod 4, and simultaneously through the extension-side low-speed valve 22. Furthermore, the amount of liquid remaining in the cylinder 1 is insufficient after subtracting the displacement volume of the inner rod 4 from the displacement volume of the piston rod 2 retracting from the cylinder 1. Therefore, the suction check valve 31 opens, and the insufficient amount of liquid is supplied to the cylinder 1 from the reservoir 18 via the suction channel SP. As mentioned earlier, the cross-sectional area of ​​the annular gap between the inner circumference of cylinder 1 and the outer circumference of piston rod 2 is larger than the cross-sectional area of ​​inner rod 4. Therefore, when the buffer D extends, the liquid will inevitably move from the extension side chamber R1 to the compression side chamber R2 through the main damping channel M or the bypass channel B.

[0040] The main damping channel M or the low-speed valve 22 on the extension side applies resistance to the flow of liquid from the extension-side chamber R1 to the compression-side chamber R2. Therefore, the buffer D generates a damping force that hinders the extension-side operation due to this resistance. Furthermore, regarding the resistance applied to the liquid as it passes through the main damping channel M, when the extension speed of the buffer D is in the low-speed range, the main damping valve 13 on the extension side remains closed, and resistance to the liquid flow is applied through the unseen throttling orifice. When the extension speed of the buffer D is in the high-speed range, the main damping valve 13 on the extension side opens, and resistance to the liquid flow is applied through the main damping valve 13. Moreover, changing the energizer applied to the damping force regulating valve 21 alters the liquid distribution ratio through the main damping channel M and the low-speed valve 22 on the extension side during the extension operation of the buffer D.

[0041] Specifically, during the extension action of the buffer D, when the damping force regulating valve 21 is open, the liquid passes through the main damping channel M and the extension-side low-speed valve 22. However, when the damping force regulating valve 21 is closed, because the bypass channel B is blocked, the liquid cannot pass through the extension-side low-speed valve 22 and only passes through the main damping channel M, moving from the extension-side chamber R1 to the compression-side chamber R2. Furthermore, when current is supplied to the damping force regulating valve 21 to open it and the amount of current supplied is increased, the opening degree of the damping force regulating valve 21 increases, the flow rate of liquid through the bypass channel B increases, therefore the proportion of liquid passing through the extension-side low-speed valve 22 increases, and the proportion of liquid passing through the main damping channel M decreases. Therefore, as... Figure 2 As shown, when the elongation action occurs and the elongation speed is in the low-speed range, the damping force characteristic generated by the buffer D is adjusted by regulating the current supplied to the damping force regulating valve 21. Figure 2 The dotted line indicates the soft characteristics mainly generated by valve 22 at low speed on the elongation side. Figure 2 The solid line indicates the range of hardness characteristics primarily generated by the main damping channel M. Furthermore, during the elongation operation at high speeds, regardless of the opening degree of the damping force regulating valve 21, the elongation-side main damping valve 13 opens significantly, allowing liquid to preferentially pass through the main damping channel M. Therefore, the damper D generates damping force from the elongation-side main damping valve 13. Additionally, when the suction-side valve replaces the suction check valve 31 as the damping valve, resistance can be applied to the flow of liquid as it moves from the reservoir 18 through the suction channel SP within the cylinder 1, reducing the pressure in the compression-side chamber R2 and generating a higher damping force.

[0042] Conversely, during the retraction of the buffer D, piston rod 2 enters the cylinder 1, and piston 3 compresses the compression chamber R2. As a result, the liquid in the compression chamber R2 moves towards the extension chamber R1 through the external throttling orifice in the main damping channel M, the compression-side main damping valve 14 in the main damping channel M, or through the bypass channel B formed by piston rod 2 and inner rod 4, and simultaneously through the low-speed valve 23 on the compression side. Furthermore, the amount of liquid remaining in the cylinder 1 after subtracting the displacement volume of inner rod 4 from the displacement volume of piston rod 2 entering the cylinder 1 is excessive. Therefore, the excess liquid is discharged from the compression chamber R2 through the compression-side damping valve 30 into the reservoir 18. As mentioned earlier, the cross-sectional area of ​​the annular gap between the inner circumference of cylinder 1 and the outer circumference of piston rod 2 is larger than the cross-sectional area of ​​inner rod 4. Therefore, when the buffer D contracts, the liquid will inevitably be in excess in cylinder 1 and move from cylinder 1 to reservoir 18.

[0043] For the flow of liquid from the compression chamber R2 towards the extension chamber R1, resistance is applied by the main damping channel M or the low-speed valve 23 on the compression side. For the flow of liquid from the compression chamber R2 towards the reservoir 18, resistance is applied by the compression damping valve 30, generating a compression damping force caused by the aforementioned resistances. Furthermore, regarding the resistance applied to the liquid as it passes through the main damping channel M, when the contraction speed of the buffer D is in the low-speed range, the compression main damping valve 14 remains closed, and resistance is applied to the liquid flow through the un-shown throttling orifice. When the contraction speed of the buffer D is in the high-speed range, the compression main damping valve 14 opens, and resistance is applied to the liquid flow through the compression main damping valve 14. Moreover, changing the current applied to the damping force regulating valve 21 alters the liquid distribution ratio through the main damping channel M and the low-speed valve 23 on the compression side during the contraction action of the buffer D.

[0044] Specifically, during the contraction of the buffer D, when the damping force regulating valve 21 is open, the liquid passes through the main damping channel M and the low-speed valve 23 on the compression side. However, when the damping force regulating valve 21 is closed, because the bypass channel B is blocked, the liquid cannot pass through the low-speed valve 23 on the compression side and only passes through the main damping channel M, moving from the compression side chamber R2 to the extension side chamber R1. Furthermore, when current is supplied to the damping force regulating valve 21 to open it and the amount of current supplied is increased, the opening degree of the damping force regulating valve 21 increases, the flow rate of liquid through the bypass channel B increases, therefore the proportion of liquid passing through the low-speed valve 23 on the compression side increases, and the proportion of liquid passing through the main damping channel M decreases. Therefore, as... Figure 2 As shown, during the contraction action and when the contraction speed is in the low-speed range, the damping force characteristics generated by the buffer D are adjusted by regulating the current supplied to the damping force regulating valve 21. Figure 2The dashed line indicates the soft-body characteristics of the fluid being resisted by valve 23 at low speed on the compression side, moving from the compression-side chamber R2 towards the elongation-side chamber R1. Figure 2 The solid line indicates the range of changes in the rigidity of the resistance applied by the main damping channel M. Furthermore, during the contraction action and at high speeds, regardless of the opening degree of the damping force regulating valve 21, the compression-side main damping valve 14 opens significantly. Liquid from the compression-side chamber R2 towards the extension-side chamber R1 preferentially passes through the compression-side main damping valve 14, thus the buffer D generates damping force from the compression-side main damping valve 14. Moreover, during the contraction action of the buffer D, excess liquid in the cylinder 1 flows from the compression-side chamber R2 towards the reservoir 18 through the compression-side damping valve 30. Therefore, the pressure in the compression-side chamber R2 can be increased to a pressure higher than the reservoir pressure using the compression-side damping valve 30, thus enabling the buffer D to generate a higher compression-side damping force than before.

[0045] In addition, in the buffer D of this embodiment, a low-speed valve 22 for the extension side and a low-speed valve 23 for the compression side are provided as low-speed valves. However, the low-speed valve 22 for the extension side and the low-speed valve 23 for the compression side can also be omitted, and the damping force can be adjusted by changing the opening degree of the damping force regulating valve 21.

[0046] As described above, the buffer D of this embodiment includes: a cylinder 1; a cylindrical piston rod 2, which is axially movable and inserted into the cylinder 1; a piston 3, connected to the piston rod 2, which is axially movable and inserted into the cylinder 1, and divides the cylinder 1 into an extension side chamber R1 and a compression side chamber R2; a cover 10, which closes the compression side chamber of the cylinder 1; a cylindrical inner rod 4, which extends from the cover 10 and passes through the compression side chamber R2, and is slidably fitted into the piston rod 2; a main damping channel M, which applies resistance to the flow of liquid traveling back and forth between the extension side chamber R1 and the compression side chamber R2; a bypass channel B, which bypasses the main damping channel M and connects the extension side chamber R1 and the compression side chamber R2 via the piston rod 2 and the inner rod 4; and a damping force regulating valve 21, which is provided in the bypass channel B.

[0047] In the buffer D constructed in this manner, the bypass channel B bypasses the main damping channel M, connects the elongation side chamber R1 and the compression side chamber R2 via the piston rod 2 and the inner rod 4 inserted into the piston rod 2, and is provided within the cylinder 1. Therefore, when forming the bypass channel B, it is not necessary to cover the large-diameter outer shell of the cylinder 1. Thus, the buffer D according to this embodiment is small and lightweight because it does not require an outer shell, which reduces manufacturing costs and allows it to be mounted in vehicles with limited mounting space, thereby improving vehicle mounting performance.

[0048] Furthermore, in the buffer D of this embodiment, the cross-sectional area of ​​the annular gap between the inner circumference of the cylinder 1 and the outer circumference of the piston rod 2 is larger than the cross-sectional area of ​​the inner rod 4. With the buffer D constructed in this manner, during the extension action, the liquid moves from the extension-side chamber R1 to the compression-side chamber R2, and during the contraction action, the liquid moves from the compression-side chamber R2 to the extension-side chamber R1. Therefore, the flow of the liquid is similar to that of conventional buffers, and the damping force characteristics can be easily set.

[0049] Furthermore, the buffer D of this embodiment includes: a liquid storage tank 18 for storing liquid; a discharge channel EP for connecting the compression side chamber R2 and the liquid storage tank 18; a suction channel SP for connecting the liquid storage tank 18 and the compression side chamber R2; a compression side damping valve 30 provided in the discharge channel EP for applying resistance to the flow of liquid from the compression side chamber R2 toward the liquid storage tank 18; and a suction check valve (suction side valve) 31 provided in the suction channel SP for allowing liquid to flow from the liquid storage tank 18 to the compression side chamber R2.

[0050] The buffer D constructed in this manner not only allows for adjustment of the flow distribution ratio between the main damping channel M and the bypass channel B via the damping force regulating valve 21, ensuring the damping force adjustment range while adjusting the damping force level, but also, because the discharge channel EP is equipped with a compression-side damping valve 30 and the suction channel SP is equipped with a suction check valve (suction-side valve) 31, the pressure in the compression-side chamber R2 can be increased to above the reservoir pressure during contraction, generating a higher damping force than before. Therefore, the buffer D according to this embodiment can achieve a higher damping force during contraction while ensuring the damping force adjustment range.

[0051] Furthermore, in the buffer D of this embodiment, the bypass channel B is equipped with an extension-side low-speed valve 22 and a compression-side low-speed valve 23, which are connected in series with the damping force regulating valve 21 and apply resistance to the flow of liquid moving in the extension-side chamber R1 and the compression-side chamber R2. With the buffer D configured in this way, the damping force regulating valve 21 can be opened to activate the extension-side low-speed valve 22 and the compression-side low-speed valve 23 in the bypass channel B, adjusting the damping force when the extension / retraction speed is in the low-speed range, and generating a damping force suitable for suspension straddle-type vehicles traveling at high speeds on smooth, vibration-free roads with minimal bumps.

[0052] The preferred embodiments of the present invention have been described in detail above, but modifications, variations and alterations are possible as long as they do not depart from the scope of the patent application.

[0053] Symbol Explanation 1 cylinder 2 piston rods 3-piston 4 inner rods 10 caps 18 storage tanks 30 Compression Side Damping Valve 31. Suction Check Valve (Suction Side Valve) B Bypass D buffer EP discharge channel M main damping channel R1 elongated side chamber R2 compression side chamber SP discharge channel

Claims

1. A buffer, comprising: cylinder; A cylindrical piston rod is axially movable and inserted into the cylinder; A piston, connected to the piston rod, is axially movable and inserted into the cylinder, dividing the cylinder into an extension side chamber and a compression side chamber. The cover seals the compression chamber side end of the cylinder; A cylindrical inner rod extends from the cover and inserts into the compression side chamber, and is slidably fitted into the piston rod; The main damping channel applies resistance to the flow of liquid traveling back and forth between the elongation side chamber and the compression side chamber; A bypass channel, bypassing the main damping channel, connects the elongation side chamber and the compression side chamber via the piston rod and the inner rod; as well as A damping force regulating valve is located in the bypass channel.

2. The buffer according to claim 1, wherein The cross-sectional area of ​​the annular gap between the inner circumference of the cylinder and the outer circumference of the piston rod is larger than the cross-sectional area of ​​the inner rod.

3. The buffer according to claim 1 or 2, comprising: Liquid storage tanks are used to store liquids. A discharge channel connects the compression chamber and the liquid storage tank. The suction channel connects the liquid storage tank and the compression side chamber; A compression-side damping valve, located in the discharge passage, applies resistance to the flow of liquid from the compression-side chamber toward the storage tank; as well as An intake-side valve, located in the intake passage, allows liquid to flow from the reservoir to the compression-side chamber.

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