Suspension device and rear buffer unit

Abstract

This suspension device (S) is provided with: a suspension spring (30) that supports a vehicle body (F) in a vehicle (M); a movable spring holder (31) that supports one end of the suspension spring (30) and is displaceable in the expansion / contraction direction of the suspension spring (30); a housing (32) that allows the movable spring holder (31) to move in the expansion / contraction direction of the suspension spring (30), and that forms a pressure chamber (P) for accommodating a liquid between the housing (32) and the movable spring holder (31); a stopper (33) that prevents the movable spring holder (31) from further moving toward the suspension spring side when the movable spring holder (31) moves toward the suspension spring side with respect to the housing (32) and the pressure chamber (P) is maximized; and an elastic pressurizing mechanism (34) which can pressurize the inside of the pressure chamber (P) by elastic force and can adjust the elastic force.

Description

TECHNICAL FIELD

[0001] The present application relates to a suspension device and a rear cushion unit. BACKGROUND

[0002] The suspension device and the damper main body constitute a rear cushion unit, for example, which is installed between a vehicle body and a rear wheel of a suspension vehicle and elastically supports the vehicle body.

[0003] Further, as disclosed in, for example, JP 2021-11875 A, a rear cushion unit is constituted by a damper main body and a suspension device, the damper main body having: a cylinder; a piston movably inserted into the cylinder and dividing the cylinder into an extension-side chamber filled with hydraulic oil and a compression-side chamber; and a rod member movably inserted into the cylinder and coupled to the piston; and the suspension device being constituted by including a suspension spring installed between a spring support mounted to the outer periphery of the cylinder and a spring support mounted to the outer periphery of the front end of the rod member. The rear cushion unit constituted in this way elastically supports the vehicle body by the suspension spring when installed between the vehicle body and the rear wheel, and the relative movement of the vehicle body and the rear wheel in the up-down direction can suppress the vibration of the vehicle body and the rear wheel by the damping force generated by the damper main body. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] Patent Document 1: JP 2021-11875 A SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] The conventional suspension device can adjust the vehicle height by changing the support position of the suspension spring of the spring support on the cylinder side, but cannot change the spring constant of the suspension spring, and thus there is room for improvement in the ride comfort of the vehicle.

[0006] To address this, the present application aims to provide a suspension device and a rear cushion unit that can improve the ride comfort of a vehicle. TECHNICAL MEANS FOR SOLVING THE PROBLEMS

[0007] To solve the aforementioned problems, the suspension device of the present application has: a suspension spring that supports a vehicle body in a vehicle; a movable spring support that supports one end of the suspension spring and is capable of displacing in the expansion and contraction direction of the suspension spring; a housing that allows the movable spring support to move in the expansion and contraction direction of the suspension spring and forms a pressure chamber that contains a liquid between the movable spring support and the housing; a stopper that prevents the movable spring support from further moving toward the suspension spring side when the pressure chamber is at its maximum as the movable spring support moves toward the suspension spring side with respect to the housing; and an elastic pressure applying mechanism that can apply pressure to the pressure chamber by an elastic force and can adjust the elastic force.

[0008] In the suspension device constructed in this manner, the elastic pressurizing mechanism pressurizes the pressure chamber using its spring force, and one end of the suspension spring is supported by the movable spring holder. Therefore, by adjusting the pressure applied to the pressure chamber by the elastic pressurizing mechanism, the movable spring holder can be fixed at a position restricted by the stopper, while allowing the movable spring holder to be displaced relative to the housing in accordance with the degree of contraction of the suspension spring. Furthermore, since the elastic pressurizing mechanism pressurizes the pressure chamber using its spring force, when the movable spring holder is displaced relative to the housing, the elastic force of the elastic pressurizing mechanism is applied to the movable spring holder, causing it to function as a spring together with the suspension spring, thereby reducing the spring constant of the suspension device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a cross-sectional view of a rear shock unit equipped with a suspension device according to one embodiment. Figure 2 This is a diagram showing a rear cushion unit mounted on a suspension straddle-type vehicle. Implementation Method

[0010] The present invention will be described based on the embodiments shown in the drawings. Figure 1 and Figure 2 As shown, in one embodiment, the suspension device S is integrated with a shock absorber body D, and together with the shock absorber body D, constitutes a rear shock absorber unit RCU. The suspension device S is interposed between the vehicle body F and the rear wheel W of a suspension straddle-type vehicle M, such as a motorcycle, to elastically support the vehicle body F. Furthermore, in this embodiment, the suspension device S is described using an example in which the suspension device S is applied to the rear shock absorber unit RCU and interposed between the vehicle body F and the rear wheel W of the suspension straddle-type vehicle M. However, the suspension device S may also be used in vehicles other than suspension straddle-type vehicles M, either together with the shock absorber body D or independently of the shock absorber body D.

[0011] Hereinafter, the suspension device S and the respective parts of the rear shock absorber unit RCU equipped with the suspension device S will be described in detail. Figure 1 As shown, the buffer body D in the rear buffer unit RCU comprises: a cylinder 1; a cylindrical rod 2, which is inserted into the cylinder 1 so as to be axially movable; a piston 3, which is connected to the rod 2 and is inserted into the cylinder 1 so as to be axially movable and divides the cylinder 1 into an extension side chamber R1 and a compression side chamber R2; a housing 4, which covers the outer periphery of the cylinder 1 and forms an annular gap between the housing 4 and the cylinder 1; a cover 5, which is mounted on the housing 4. Figure 1 The outer periphery of the upper and middle end and the closed cylinder 1 Figure 1 and a liquid storage tank 6, held in the cover 5.

[0012] The cylinder 1 includes a flange 1a provided on Figure 1 The upper end periphery of the housing 4 abuts against the upper end; the flange 1b is provided at Figure 1and a hole 1c, provided above the flange 1b and near the flange 1b and communicating with the inside and outside of the cylinder 1.

[0013] The piston 3 is inserted into the cylinder 1 so as to be axially movable, and is divided into an extension side chamber R1 and a compression side chamber R2 filled with hydraulic oil. The piston 3 is mounted on the outer periphery of the front end of the annular rod 2 which is inserted into the cylinder 1 so as to be axially movable, and has an extension side port 3a and a compression side port 3b which communicate with the extension side chamber R1 and the compression side chamber R2. Figure 1 The upper and middle ends of the pistons are provided with an annular extension-side leaf valve 13 which opens and closes the extension-side port 3a. Figure 1 An annular compression-side leaf valve 14 is stacked at the lower middle end, opening and closing the compression-side port 3b. The inner circumferences of the expansion-side leaf valve 13 and the compression-side leaf valve 14 are fixed to the outer circumference of the rod 2. By bending their outer circumferences, they open the corresponding expansion-side port 3a and compression-side port 3b, respectively, and apply resistance to the flow of hydraulic oil passing through.

[0014] Next, the outer shell 4 covers the outer periphery of the cylinder 1 so that Figure 1 The upper middle end contacts the lower end of the flange 1a on the upper side of the cylinder 1, and together with the cylinder 1, an annular gap is formed between the flanges 1a and 1b on the outer periphery of the cylinder 1. In addition, a hole 4a is provided near the upper end of the housing 4, which communicates with the inside and outside of the housing 4 and communicates with the annular gap. In addition, a hole 4a is provided near the upper end of the housing 4. Figure 1 A threaded portion 4b is formed on the outer periphery of the lower middle portion.

[0015] Furthermore, in the housing 4 Figure 1 An annular guide 7 is attached to the inner circumference of the lower and middle ends. The rod 2 is inserted into the guide 7, allowing axial movement within the cylinder 1. Furthermore, an annular bushing 8 is attached to the inner circumference of the guide 7, which slides against the outer circumference of the rod 2 to guide its axial movement, and a sealing ring 9 is attached to the outer circumference of the rod 2. Furthermore, a sealing ring 10 is attached to the outer circumference of the guide 7, in close contact with the inner circumference of the housing 4. Thus, the sealing ring 9 seals between the rod 2 and the guide 7, and the sealing ring 10 seals between the guide 7 and the housing 4, thereby hermetically sealing the interiors of the cylinder 1 and the housing 4.

[0016] In addition, at the rod 2 Figure 1 The lower end is provided with a bracket 20 that can be connected to the swing arm SA that holds the rear wheel W in the suspension straddle type vehicle M, and the outer periphery of the rod 2 and the opposite end of the shell are provided. Figure 1A ring-shaped cushion 21 is attached to the lower end of the housing 4. On the other hand, a ring-shaped cushion stopper 22 is attached to the inner periphery of the lower end of the housing 4. Thus, when the rod 2 approaches the housing 4 in the axial direction and the bumper main body D is contracted to the vicinity of the end of stroke on the contraction side, the cushion 21 and the cushion stopper 22 abut and are compressed to generate a repulsive force, thereby preventing the bumper main body D from being further contracted.

[0017] The cap 5 is a top cylinder having a cylindrical portion 5a and a bottom portion 5b, and the cylindrical portion 5a is screwed and fixed to the threaded portion 4b of the housing 4. When the cap 5 is screwed and fixed to the housing 4 in this manner, the flange 1a of the cylinder 1 is sandwiched by the housing 4 and the bottom portion 5b of the cap 5, and the cylinder 1 is fixed to the housing 4 and the cap 5. The cylindrical portion 5a is provided with a stepped portion 5al on the outer periphery on the lower end side. Figure 1 The outer periphery on the lower end side is smaller in diameter than the upper end, and the stepped portion 5al is provided on the outer periphery.

[0018] Further, the cap 5 is provided with a bracket 5c that can be coupled to the vehicle body F of the suspension straddle-type vehicle M on the upper end of the bottom portion 5b, and a reservoir tank holding portion 5d that holds the reservoir tank 6 is provided on the lateral side on the upper end side of the cylindrical portion 5a. Figure 1 The reservoir tank holding portion 5d holds the reservoir tank 6.

[0019] The reservoir tank 6 held in the reservoir tank holding portion 5d is divided into an oil chamber O filled with hydraulic oil and a gas chamber G filled with gas by a free piston 6a housed in the interior so as to be axially movable. Further, the oil chamber O is communicated with the compression-side chamber R2 through a passage 11 formed in the reservoir tank holding portion 5d from the bottom portion 5b of the cap 5, and is communicated with the extension-side chamber Rl through a passage 12 formed in the reservoir tank holding portion 5d from the cylindrical portion 5a of the cap 5, the hole 4a of the housing 4, the ring-shaped gap, and the hole 1c of the cylinder 1. In addition, in the reservoir tank 6, a flexible bag or bellows or the like can be provided instead of the free piston 6a to divide the oil chamber O and the gas chamber G.

[0020] Further, the cap 5 is provided with a bracket 5c that can be coupled to the vehicle body F of the suspension straddle-type vehicle M on the upper end of the bottom portion 5b, and a reservoir tank holding portion 5d that holds the reservoir tank 6 is provided on the lateral side on the upper end side of the cylindrical portion 5a.

[0021] The bumper main body D is configured in the above-described manner, and if the extension operation is performed in the state where the switch valve 17 is closed, the piston 3 is moved to the extension side, and the extension-side chamber Rl is expanded. Thus, the hydraulic oil in the extension-side chamber Rl is supplied to the extension-side leaf valve 13 through the passage 12, the hole 4a of the housing 4, the ring-shaped gap, and the hole 1c of the cylinder 1, and the extension-side leaf valve 13 is opened. Further, the hydraulic oil in the extension-side chamber Rl is supplied to the extension-side soft valve 15 through the passage 12, and the extension-side soft valve 15 is opened. Figure 1The hydraulic oil in the elongation-side chamber Rl which is reduced in size by moving upward, moves to the enlarged compression-side chamber R2 through the elongation-side port 3a and the elongation-side vane valve 13. Since the switching valve 17 is closed and the hydraulic oil in the elongation-side chamber Rl cannot pass through the passage 12, the total flow rate of the hydraulic oil from the elongation-side chamber Rl toward the compression-side chamber R2 flows through the elongation-side vane valve 13. Therefore, the damper main body D generates a hard damping force which hinders the elongation action only through the elongation-side vane valve 13. At the time of the elongation action of the damper main body D, the rod member 2 is withdrawn from the cylinder 1, and the volume amount of the hydraulic oil in the cylinder 1 which is withdrawn from the cylinder 1 is insufficient, and the insufficient amount of the hydraulic oil is supplied from the reservoir 6 to the cylinder 1 through the passage 11, and the volume compensation of the rod member 2 is performed.

[0022] On the other hand, if the damper main body D performs the contraction action in the state where the switching valve 17 is closed, since the piston 3 moves downward Figure 1 The hydraulic oil in the compression-side chamber R2 which is reduced in size by moving upward, moves to the enlarged elongation-side chamber Rl through the compression-side port 3b and the compression-side vane valve 14. Since the switching valve 17 is closed and the hydraulic oil in the compression-side chamber R2 cannot pass through the passage 12, the total flow rate of the hydraulic oil from the compression-side chamber R2 toward the elongation-side chamber Rl flows through the compression-side vane valve 14. Therefore, the damper main body D generates a hard damping force which hinders the contraction action only through the compression-side vane valve 14. At the time of the contraction action of the damper main body D, the rod member 2 intrudes into the cylinder 1, and the volume amount of the hydraulic oil in the cylinder 1 which intrudes into the cylinder 1 is excessive, and the excessive amount of the hydraulic oil is discharged from the cylinder 1 to the reservoir 6 through the passage 11, and the volume compensation of the rod member 2 is performed.

[0023] If the damper main body D performs the elongation action in the state where the switching valve 17 is opened, since the piston 3 moves upward Figure 1 The hydraulic oil in the elongation-side chamber Rl which is reduced in size by moving upward, moves to the enlarged compression-side chamber R2 not only through the elongation-side port 3a but also through the elongation-side soft valve 15 of the passage 12. Since the resistance which the elongation-side soft valve 15 applies to the flow of the hydraulic oil is smaller than the resistance which the elongation-side vane valve 13 applies to the flow of the hydraulic oil, the hydraulic oil preferentially passes through the elongation-side soft valve 15. Therefore, the damper main body D generates a soft damping force which hinders the elongation action mainly through the elongation-side soft valve 15.

[0024] On the other hand, if the damper main body D performs the contraction action in the state where the switching valve 17 is opened, since the piston 3 moves downward Figure 1The hydraulic oil in the contraction-side chamber R2, which shrinks as it moves upward and mid-center, flows not only through the contraction-side port 3b and the contraction-side leaf valve 14 but also through the contraction-side soft valve 16 of the passage 12 toward the enlarged extension-side chamber R1. Because the flow resistance of the hydraulic oil applied by the contraction-side soft valve 16 is lower than that applied by the contraction-side leaf valve 14, the hydraulic oil preferentially flows through the contraction-side soft valve 16. Consequently, the damper body D primarily generates a soft damping force, which counteracts contraction, through the contraction-side soft valve 16.

[0025] In this way, the damper body D can switch between soft and hard damping forces during extension and contraction by opening and closing the on-off valve 17. The specific structure of the damper body D is merely an example and is not limited to the aforementioned structure as long as it can generate damping forces during extension and contraction. Therefore, the damper body D can, for example, have a structure with a fluid reservoir between the housing 4 and the cylinder 1, or a single-rod structure in which the cylinder 1 is eliminated and the inner circumference of the housing 4 is in sliding contact with the piston 3.

[0026] Next, the suspension device S comprises: a suspension spring 30; a movable spring bracket 31 supporting one end of the suspension spring 30; Figure 1 The movable spring bracket 31 is mounted on the upper middle end and can move in the extension and contraction direction of the suspension spring 30; the shell 32 is installed on the outer periphery of the cover 5 to allow the movable spring bracket 31 to move in the extension and contraction direction of the suspension spring 30, and forms a pressure chamber P for containing liquid between the movable spring bracket 31 and the movable spring bracket 31; the stopper 33 prevents the movable spring bracket 31 from moving further toward the suspension spring side when the movable spring bracket 31 moves toward the suspension spring side relative to the shell 32 to make the pressure chamber P maximum; and the elastic pressurizing mechanism 34 can pressurize the pressure chamber P through elastic force and can adjust the elastic force.

[0027] The suspension spring 30 is a coil spring with one end Figure 1 The upper end is supported by a movable spring bracket 31 and serves as the other end. Figure 1 The lower end is mounted on the rod 2 provided on the buffer body D. Figure 1 The bracket 20 is supported by the fixed spring bracket 25 at the lower middle end. The suspension spring 30 is compressed between the movable spring bracket 31 and the fixed spring bracket 25, constantly urging the shock absorber body D in the extension direction. Furthermore, when the rear shock absorber unit RCU is installed between the vehicle body F and the rear wheels W of the suspension straddle-type vehicle M, the suspension spring 30 slightly contracts under the weight of the vehicle body F, elastically supporting the vehicle body F. Therefore, if vibrations input from the road surface cause the shock absorber body D to expand or contract while the suspension straddle-type vehicle M is traveling, the suspension spring 30 also expands or contracts along with the shock absorber body D.

[0028] The movable spring bracket 31 is cylindrical and includes a large diameter portion 31a having a larger inner and outer diameter on the side of the suspension spring, a small diameter portion 31b having a smaller inner and outer diameter than the large diameter portion 31a on the side opposite to the suspension spring, and a flange-shaped pressure-receiving portion 31c connecting the large diameter portion 31a and the small diameter portion 31b. In addition, the inner diameter of the small diameter portion 31b, which is the smallest inner diameter of the movable spring bracket 31, is larger than the outer diameter of the small diameter portion at the lower end of the cylindrical portion 5a of the housing 4 and the cover 5. This allows the movable spring bracket 31 to move in the direction of expansion and contraction of the suspension spring 30 without interfering with the housing 4 and the cover 5. Figure 1 5. Alternatively, the inner periphery of the small-diameter portion 31b may be brought into sliding contact with the outer periphery of the small-diameter portion of the cylindrical portion 5a of the cover 5. Furthermore, in the movable spring support 31 of this embodiment, the outer diameter of the pressure-receiving portion 31c is larger than that of the large-diameter portion 31a. Furthermore, a seal ring 31d is mounted within an annular groove (not shown) formed on the outer periphery of the pressure-receiving portion 31c of the movable spring support 31.

[0029] In addition, the large diameter portion 31a of the movable spring bracket 31 Figure 1 The middle and lower end of the suspension spring 30 Figure 1 The seat ring 35 is installed between the middle and upper ends. The seat ring 35 includes: a fitting portion 35a, which fits with the inner periphery of the suspension spring 30; a flange-shaped seat portion 35b, which is provided on the inner periphery of the fitting portion 35a. Figure 1 The outer periphery of the upper end is connected to the suspension spring 30 Figure 1 The upper and middle ends of the suspension springs 30 abut against each other; and the annular positioning portion 35c bends from the outer circumference of the seat portion 35b toward the larger diameter portion, movably fitting within the outer circumference of the larger diameter portion 31a. When the seat ring 35 has the seat portion 35b laminated to the end of the larger diameter portion 31a, it allows circumferential rotation relative to the movable spring holder 31, and prevents the positioning portion 35c from becoming radially dislodged from the movable spring holder 31 by facing the outer circumference of the larger diameter portion 31a. Since the suspension spring 30 is a coil spring, its end exhibits slight circumferential rotation as it expands and contracts. However, by laminating the seat ring 35 circumferentially rotatable relative to the movable spring holder 31, this rotation of the suspension spring 30 is prevented from being transmitted to the movable spring holder 31. The movable spring holder 31 includes a seal ring 31d, which forms a pressure chamber P with the housing 32. Since the seal ring 35 is relatively resistant to circumferential rotation, this arrangement prevents rotation of the movable spring holder 31 and protects the seal ring 31d from deterioration. Furthermore, the seat ring 35 may be omitted if not required, and the end portion of the suspension spring 30 may directly contact the end portion of the movable spring support 31 .

[0030] The housing 32 includes an annular base portion 32a that contacts the step portion 5a1 on the outer periphery of the cover 5, and a base portion 32a extending from the base portion 32a. Figure 1The lower end of the housing 32 is provided with an annular socket 32b. If the housing 32 is attached to the lid 5 in a state where the outer periphery of the cylindrical portion 5a of the lid 5 is in contact with the step portion 5al, an annular gap into which the small-diameter portion 31b of the movable spring support 31 can be inserted is formed between the cylindrical portion 5a of the lid 5, and an annular space into which the pressure receiving portion 31c and the large-diameter portion 31a of the movable spring support 31 can be inserted is formed in the socket 32b. In this way, the housing 32 and the movable spring support 31 are attached to the case 4 via the lid 5. Alternatively, the housing 32 and the movable spring support 31 can be attached to the case 4 via the lid 5 and other components that are attached to the case 4, or can be directly attached to the case 4.

[0031] The inner diameter of the base portion 32a is set to a diameter that allows the small-diameter portion 31b of the movable spring support 31 to be in sliding contact therewith, and is fixed to the lid 5 in a state where the step portion 5al of the lid 5 is in contact therewith. Further, a seal ring 32c that is in sliding contact with the outer periphery of the small-diameter portion 31b of the movable spring support 31 is attached to an annular groove (not shown) provided on the inner periphery of the base portion 32a. The pressure receiving portion 31c of the movable spring support 31 is slidably inserted into the socket 32b, and the socket 32b and the pressure receiving portion 31c are sealed by a seal ring 31d on the outer periphery of the pressure receiving portion 31c. Further, after the movable spring support 31 is inserted into the housing 32, the outer periphery of the pressure receiving portion 31c is in sliding contact with the inner periphery of the socket 32b, and the outer periphery of the small-diameter portion 31b is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the Figure 1 Further, the pressure receiving portion 31c of the movable spring support 31 is in sliding contact with the inner periphery of the socket 32b, and the small-diameter portion 31b of the movable spring support 31 is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the Figure 1 Further, the pressure receiving portion 31c of the movable spring support 31 is in sliding contact with the inner periphery of the socket 32b, and the small-diameter portion 31b of the movable spring support 31 is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the Figure 1 Further, the pressure receiving portion 31c of the movable spring support 31 is in sliding contact with the inner periphery of the socket 32b, and the small-diameter portion 31b of the movable spring support 31 is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the Figure 1 Further, the pressure receiving portion 31c of the movable spring support 31 is in sliding contact with the inner periphery of the socket 32b, and the small-diameter portion 31b of the movable spring support 31 is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the Figure 1 Further, the pressure receiving portion 31c of the movable spring support 31 is in sliding contact with the inner periphery of the socket 32b, and the small-diameter portion 31b of the movable spring support 31 is in sliding contact with the inner periphery of the base portion 32a, so the movable spring support 31 is guided by the housing 32 and can move in the up-and-down direction of the

[0032] Further, when the movable spring support 31 is inserted into the housing 32, an annular gap surrounded by the small-diameter portion 31b and the pressure receiving portion 31c of the movable spring support 31 and the base portion 32a and the socket 32b of the housing 32 is formed between the housing 32 and the movable spring support 31, and a pressure chamber P that accommodates a liquid is formed. Further, the liquid accommodated in the pressure chamber P is hydraulic oil in the suspension device S of the present embodiment, but can be a liquid other than hydraulic oil. Since the pressure chamber P is sealed by the seal rings 31d and 32c between the movable spring support 31 and the housing 32, the liquid in the pressure chamber P is prevented from leaking outside the pressure chamber P.

[0033] Furthermore, the pressure in the pressure chamber P acts on the pressure receiving portion 31c of the movable spring support 31. Figure 1 The upper middle end of the movable spring bracket 31 is formed by the pressure receiving portion 31c. Figure 1 The force is the value obtained by multiplying the area of ​​the upper end facing the pressure chamber P by the pressure in the pressure chamber P. Figure 1 Apply force to the suspension spring side at the lower center.

[0034] Furthermore, a stopper 33 is mounted on the outer periphery of the socket 32b of the housing 32. The stopper 33 comprises: a cylindrical portion 33a having a threaded portion on the inner periphery and being screwed and fixed to the outer periphery of the socket 32b; and an annular stopper portion 33b extending radially from the inner periphery of the cylindrical portion 33a. The inner diameter of the stopper portion 33b is larger than the outer diameter of the large diameter portion 31a of the movable spring support 31 and smaller than the inner diameter of the socket 32b. When the stopper 33 is mounted on the socket 32b of the housing 32, the inner periphery of the stopper portion 33b is aligned with the outer diameter of the pressure receiving portion 31c of the movable spring support 31. Figure 1 Furthermore, when the movable spring bracket 31 moves to the maximum extent relative to the housing 32 toward the suspension spring, the stopper portion 33b of the stopper 33 abuts against the lower end outer periphery of the pressure receiving portion 31c of the movable spring bracket 31, and the movable spring bracket 31 cannot move from the housing 32 toward the suspension spring. Figure 1 The suspension spring side of the lower center portion is further displaced. Thus, when the movable spring support 31 moves toward the suspension spring relative to the housing 32, maximizing the pressure chamber P, the stopper 33 prevents further movement of the movable spring support 31 toward the suspension spring. Consequently, the movable spring support 31 can move from a position where the pressure chamber P is minimized, where the pressure-receiving portion 31c contacts the base 32a of the housing 32, to a position where the pressure chamber P is maximized, where the pressure-receiving portion 31c contacts the stopper portion 33b of the stopper 33.

[0035] As described above, the movable spring support 31 includes the large-diameter portion 31a, the small-diameter portion 31b, and the pressure-receiving portion 31c. The housing 32 includes the base 32a that is in sliding contact with the outer periphery of the small-diameter portion 31b, and the socket 32b that is suspended from the base 32a and into which the pressure-receiving portion 31c is slidably inserted. Therefore, the sliding surfaces of both the housing 32 and the movable spring support 31 that moves in and out of the housing 32 are not exposed to the outside of the suspension device S. Therefore, according to the suspension device S including the movable spring support 31 and the housing 32 configured as described above, the sliding surfaces of both the movable spring support 31 and the housing 32 can be protected, and leakage of liquid from the pressure chamber P can be prevented. In addition, the inner peripheral surface of the stopper portion 33b of the stopper 33 faces the outer peripheral surface of the large-diameter portion 31a of the movable spring support 31, and not only functions as a stopper to restrict the movement of the movable spring support 31, but also covers the housing 32. Figure 1The movable spring support 31 is installed to the outer periphery of the case 32 as long as it can form the pressure chamber P between the case 32 and the movable spring support 31 and move in the extension and contraction direction of the suspension spring 30 with respect to the case 32.

[0036] The elastic pressure mechanism 34 that adjusts the pressure in the pressure chamber P is provided with a container 37, a movable partition wall 38 that is movably inserted into the container 37 to form a space in the container 37 that communicates with the pressure chamber P through the pipe 36, and an elastic partition wall 39 that divides the space into a gas chamber A filled with gas and a liquid chamber B that communicates with the pressure chamber P.

[0037] The container 37 is cylindrical, and the open portion of one end is closed by a cap 40 that holds the elastic partition wall 39 formed by the air bag. Further, a screw cap 41 that is annular and has a threaded portion in the inner periphery is installed to the other end of the container 37. A screw shaft 42 that protrudes into the container 37 with the front end is screw-fixed to the inner periphery of the screw cap 41. Further, a nut 43 is screw-fixed to the outer periphery of the screw shaft 42, and after the nut 43 is further tightened in a state where it is rotated with respect to the screw shaft 42 to abut against the screw cap 41, the screw shaft 42 is fixed to the screw cap 41 by the screw cap 41 and the nut 43 in a double-nut arrangement that prevents rotation of the screw shaft 42. Further, if the nut 43 is loosened from the state where the screw shaft 42 is fixed to the screw cap 41, rotation of the screw shaft 42 with respect to the screw cap 41 is allowed, and axial movement of the screw shaft 42 with respect to the container 37 is allowed by rotation operation of the screw shaft 42 with respect to the screw cap 41. The screw shaft 42 has a head portion 42a that can be gripped by a tool at the rear end that protrudes out of the container 37, and if it is protruded into the container 37 to the maximum, the head portion 42a contacts the nut 43 that abuts against the screw cap 41 Figure 1 The movable spring support 31 is installed to the outer periphery of the case 32 as long as it can form the pressure chamber P between the case 32 and the movable spring support 31 and move in the extension and contraction direction of the suspension spring 30 with respect to the case 32.

[0038] Further, a movable partition wall 38 axially slidably inserted into the container 37 is attached to the front end of the screw shaft 42. The movable partition wall 38 forms a space in the container 37 which communicates with the pressure chamber P, and is displaced in the container 37 together with the screw shaft 42 by the axial movement of the screw shaft 42 relative to the container 37, thereby changing the volume of the space. In addition, the mechanism for displacing the movable partition wall 38 relative to the container 37 can be a structure other than the feed screw structure composed of the screw shaft 42 and the screw cap 41, and can be appropriately changed in design, but by using the feed screw structure, the movable partition wall 38 can be steplessly displaced relative to the container 37 with a small torque, and the pressure in the pressure chamber P can be steplessly adjusted using the elastic pressure mechanism 34. Further, in order to displace the movable partition wall 38 relative to the container 37, the power of an actuator such as a motor or air pressure can be used. Furthermore, the movable partition wall 38 can be a free piston slidably inserted into the container 37, or can be a movable partition wall such as a metal bellows which can change the volume of the space divided by the movable partition wall 38 in the container 37.

[0039] The space in the container 37 communicates with the pressure chamber P through the pipe 36. Further, an elastic partition wall 39 is housed in the container 37 and in the aforementioned space, and a gas is filled in the elastic partition wall 39. Also, a liquid is filled in the space in the container 37 and outside the elastic partition wall 39. By inserting the movable partition wall 38 into the container 37 in this way, the space in the container 37 divided by the movable partition wall 38 is divided by the elastic partition wall 39 into a gas chamber A filled with the gas and a liquid chamber B filled with the liquid, and the liquid chamber B communicates with the pressure chamber P through the pipe 36. In addition, the liquid filled in the liquid chamber B can be the same liquid as the liquid filled in the pressure chamber P, and can be, for example, hydraulic oil or a diethylene glycol aqueous solution, or other liquid. Further, the elastic partition wall 39 can be a diaphragm plate or a bellows.

[0040] The gas chamber A in the elastic partition wall 39 is filled with a gas in a compressed state, and thus the pressure in the gas chamber A acts on the pressure chamber P through the liquid chamber B. In this way, the elastic pressure mechanism 34 functions as an air spring, and always pressurizes the pressure chamber P with the repulsive force of the gas in the gas chamber A. Also, by the rotational operation of the screw shaft 42 to axially displace the movable partition wall 38 in the container 37, when the volume of the space is reduced, the gas in the gas chamber A is compressed and the repulsive force of the gas becomes greater, and thus the pressure in the pressure chamber P can be increased. Further, conversely, if the movable partition wall 38 is axially displaced into the container 37 by the rotational operation of the screw shaft 42 to increase the volume of the space, the gas chamber A expands and the degree of compression of the gas decreases, and thus the repulsive force of the gas can be reduced and the pressure in the pressure chamber P can be decreased.

[0041] Further, in a case where the moving partition wall 38 intrudes into the container 37 to the maximum so as to minimize the volume of the space, the elastic force of the gas in the gas chamber A is maximized, and the pressure of the pressure chamber P by the elastic pressure mechanism 34 is maximized. In this state, the force received by the movable spring support 31 from the pressure chamber P in the direction of compressing the suspension spring 30 is set to be greater than the force received by the movable spring support 31 from the suspension spring 30 in the direction of pressing the pressure chamber P in a state where the bumper main body D is most compressed and the suspension spring 30 is most contracted. Therefore, in a case where the moving partition wall 38 intrudes into the container 37 to the maximum so as to minimize the volume of the space, the movable spring support 31 does not move upward from the original position under the action of the force received from the suspension spring 30, but is always located at the lowermost position in abutment with the stopper 33 without moving from the original position. Figure 1

[0042] On the other hand, in a case where the moving partition wall 38 retreats to the maximum in the container 37 so as to maximize the volume of the space, the elastic force of the gas in the gas chamber A is minimized, and the pressure of the pressure chamber P by the elastic pressure mechanism 34 is also minimized. In this state, the force received by the movable spring support 31 from the pressure chamber P in the direction of compressing the suspension spring 30 and the force received by the movable spring support 31 from the suspension spring 30 compressed in a state where the vehicle body F of the straddle-type vehicle M carries a prescribed weight in the direction of pressing the pressure chamber P are balanced. The prescribed weight is set to a weight of a degree of the body weight of an occupant in a range of, for example, 50 kg to 80 kg, and the pressure of the gas in the gas chamber A, the pressure receiving area of the pressure chamber P of the movable spring support 31, and the specifications of the suspension spring 30 are set in such a manner that the force received by the movable spring support 31 from the pressure chamber P and the force received by the movable spring support 31 from the suspension spring 30 are balanced in a state where the straddle-type vehicle M carries an occupant.

[0043] In the suspension device S and the rear cushion unit RCU configured in the above-described manner, the elastic pressure mechanism 34 that pressurizes the pressure chamber P with an elastic force is provided, and when the moving partition wall 38 is disposed at a position in the container 37 that minimizes the volume of the space, the pressure of the gas in the gas chamber A is maximized and acts in the pressure chamber P. In this state, as described above, even in a range of the travel of the bumper main body D, the suspension spring 30 is most contracted, and the elastic force of the suspension spring 30 does not exceed the force with which the movable spring support 31 is pressed toward the suspension spring 30 side under the pressure of the pressure chamber P, and the movable spring support 31 does not move from the position where the stopper 33 is maximally withdrawn from the housing 32.

[0044] ​Therefore, if the movable partition wall 38 is provided in this way at a position that minimizes the volume of the space within the container 37, the position of the movable spring bracket 31 does not change, and thus the spring constant of the suspension device S becomes the spring constant of the suspension spring 30 alone that is stretched and contracted with the extension and contraction of the bumper body D, taking the maximum value.

[0045] In contrast, if the movable partition wall 38 is provided at a position that maximizes the volume of the space within the container 37, the pressure of the gas within the gas chamber A is minimized and acts within the pressure chamber P. In this state, as described above, the force with which the suspension spring 30 that is contracted by supporting the vehicle body F of the suspension straddle-type vehicle M loaded with a prescribed weight pushes the movable spring bracket 31 upward and the force with which the movable spring bracket 31 is pushed against the suspension spring 30 side under the pressure of the pressure chamber P are balanced. Moreover, if the suspension spring 30 that is contracted by supporting the vehicle body F of the suspension straddle-type vehicle M loaded with a prescribed weight is further contracted due to vibrations input during travel of the suspension straddle-type vehicle M, the elastic force generated by the suspension spring 30 becomes greater, the force with which the suspension spring 30 pushes the movable spring bracket 31 upward is greater than the force with which the movable spring bracket 31 is pushed against the suspension spring 30 side under the pressure of the pressure chamber P, and thus the movable spring bracket 31 is displaced upward in the direction of arrow Figure 1 Due to the upward displacement of the movable spring bracket 31 in the direction of arrow Figure 1 , the pressure chamber P is reduced, the liquid is discharged from within the pressure chamber P to the container 37, and the volume of the gas chamber A is reduced and the force with which the movable spring bracket 31 is pushed against the suspension spring 30 side under the pressure of the pressure chamber P becomes greater. This upward displacement of the movable spring bracket 31 in the direction of arrow Figure 1 continues until the force with which the suspension spring 30 pushes the movable spring bracket 31 upward and the force with which the movable spring bracket 31 is pushed downward toward the suspension spring 30 side under the pressure of the pressure chamber P are balanced. In addition, even if the bumper body D is contracted, the stroke length is ensured so that the upper end surface of the pressure receiving portion 31c, i.e., the opposing surface 31cl of the movable spring bracket 31 does not come into contact with the base portion 32a of the housing 32 before the bumper pad 21 comes into contact with the bumper stopper 22. Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Figure ​Therefore, if the suspension spring 30, which is contracted by supporting the vehicle body F of the suspension straddle-type vehicle M carrying a prescribed weight, further contracts due to vibration input during travel of the suspension straddle-type vehicle M, the movable spring support 31 also displaces with respect to the housing 32, and thus the vehicle body F becomes a state of being elastically supported by the suspension spring 30 and the elastic pressure mechanism 34 functioning as an air spring in series, and the spring constant of the suspension device S becomes a spring constant obtained by combining the spring constant of the suspension spring 30 and the spring constant of the elastic pressure mechanism 34 functioning as an air spring. In this case, if the spring constant of the suspension spring 30 is set to k1 and the spring constant of the elastic pressure mechanism 34 functioning as an air spring is set to k2, the spring constant K of the suspension device S is K = k1 · k2 / (k1 + k2), which is smaller than the spring constant k1 when only the suspension spring 30 is stretched and contracted.

[0046] On the other hand, if the suspension spring 30, which is contracted by supporting the vehicle body F of the suspension straddle-type vehicle M carrying a prescribed weight, is stretched due to vibration input during travel of the suspension straddle-type vehicle M, the movable spring support 31 does not displace from the position at which the stopper 33 is positioned because the elastic force of the suspension spring 30 becomes small, and thus the spring constant of the suspension device S is equal to the spring constant of the suspension spring 30.

[0047] Thus, in the suspension device S of the present embodiment and the rear cushion unit RCU that applies the suspension device S, by adjusting the pressure of the pressure chamber P using the elastic pressure mechanism 34, it is possible to switch to a state in which only the suspension spring 30 is stretched and contracted, and a state in which not only the suspension spring 30 but also the movable spring support 31 can displace with respect to the housing 32, and it is possible to adjust the spring constant in the suspension device S. In addition, when the movement interval wall 38 is maximally retracted within the container 37 to maximize the volume of the space, the force that the movable spring support 31 receives in the direction in which the compression suspension spring 30 is compressed from the pressure chamber P and the force that the movable spring support 31 receives in the direction in which the suspension spring 30 compressed in a state in which the vehicle body F of the suspension straddle-type vehicle M carries a prescribed weight presses the pressure chamber P are balanced, but the range of the prescribed load is set to be smaller than the maximum load that can be supported by the elastic force generated when the suspension spring 30 is contracted within the stroke range of the damper main body D. If the prescribed load is set within this range, the movable spring support 31 can displace within the stroke range of the damper main body D, and thus it is possible to change the spring constant of the suspension device S. In addition, even if the position of the movement interval wall 38 does not maximize the volume of the space within the container 37, as long as the movable spring support 31 displaces with respect to the housing 32 as the suspension spring 30 is stretched and contracted, it is possible to adjust the degree of contraction of the suspension spring 30 and the degree of reduction of the spring constant when the spring constant of the suspension device S is reduced.

[0048] The suspension device S of the present embodiment has the suspension spring 30 that supports the vehicle body F in the suspension astride vehicle (vehicle) M, the movable spring support 31 that supports one end of the suspension spring 30 and is displaceable in the expansion / contraction direction of the suspension spring 30, the housing 32 that allows the movable spring support 31 to move in the expansion / contraction direction of the suspension spring 30 and forms the pressure chamber P that contains a liquid between the movable spring support 31 and the housing 32, the stopper 33 that stops the movable spring support 31 from further moving toward the suspension spring side when the movable spring support 31 moves toward the suspension spring side with respect to the housing 32 to make the pressure chamber P largest, and the elastic pressure application mechanism 34 that applies pressure to the pressure chamber P by the elastic force and is adjustable.

[0049] In the suspension device S configured in this way, since the elastic pressure application mechanism 34 applies pressure to the pressure chamber P by the elastic force and one end of the suspension spring 30 is supported by the movable spring support 31, the movable spring support 31 can be fixed at the position limited by the stopper 33 by adjusting the pressure of the pressure chamber P applied by the elastic pressure application mechanism 34, and the movable spring support 31 can be displaced with respect to the housing 32 according to the degree of contraction of the suspension spring 30. Also, since the elastic pressure application mechanism 34 applies pressure to the pressure chamber P by the elastic force, when the movable spring support 31 is displaced with respect to the housing 32, the movable spring support 31 functions as a spring together with the suspension spring 30 by the elastic force of the elastic pressure application mechanism 34, so the spring constant in the suspension device S is reduced.

[0050] As described above, according to the suspension device S of the present embodiment, the spring constant as a whole of the suspension device S can be changed by adjusting the elastic force of the elastic pressure application mechanism 34, so the ride in the vehicle can be improved.

[0051] Further, in the suspension device S of the present embodiment, since the liquid is contained in the pressure chamber P and the elastic force of the elastic pressure application mechanism 34 is transmitted to the movable spring support 31 with the liquid as a medium, the seal ring 31d, 32c that seals the inside of the pressure chamber P can be a seal ring with an existing track record for liquids, so the practicality is improved.

[0052] Further, the elastic pressure applying mechanism 34 in the suspension device S of the present embodiment is provided with a container 37, a movable partition wall 38 movably inserted into the container 37 to divide a space in the container 37 that communicates with the pressure chamber P, and a gas and a liquid contained in the container 37. According to the suspension device S configured in this way, the elastic pressure applying mechanism 34 functions as an air spring, adjusts the degree of compression of the gas by displacement of the movable partition wall 38 in the container 37, and can adjust the repulsive force acting on the pressure chamber P. Therefore, according to the suspension device S of the present embodiment, the repulsive force can be adjusted by using a gas, so the elastic pressure applying mechanism 34 can be made small and light, and the mountability to a vehicle can be improved. In addition, the elastic pressure applying mechanism 34 can also cancel the gas chamber A and fill only a liquid in the space divided by the movable partition wall 38 in the container 37, and adjust the pressure acting on the pressure chamber P by adjusting the repulsive force of a coil spring or the like that applies a force to the movable partition wall 38. Further, the elastic pressure applying mechanism 34 can also be configured to be provided with an inner metal bellows that stores a liquid that communicates with the pressure chamber P, a spring or an air spring that applies a force to compress the metal bellows, and an adjustment mechanism that adjusts the repulsive force of the spring or the air spring. The adjustment mechanism can be, for example, a feed screw structure or the like that can displace the end portions of the metal bellows on the opposite sides.

[0053] Further, the elastic pressure applying mechanism 34 of the present embodiment is divided into the gas chamber A and the liquid chamber B by an elastic partition wall 39, and prevents the gas from mixing into the pressure chamber P. In the suspension device S configured in this way, the pressure chamber P is pressurized by the repulsive force of the gas, but a liquid seal ring can be used in the seal rings 31d and 32c that seal the pressure chamber P, and a gas that is difficult to seal can not be sealed. Therefore, according to the suspension device S of the present embodiment, even if the pressure in the pressure chamber P is made high by the repulsive force of the gas, the seal rings 31d and 32c that prevent leakage of the liquid can be used, and the practicality is improved. In addition, if the gas in the container 37 can be prevented from flowing into the pressure chamber P without using the elastic partition wall 39, the elastic partition wall 39 can be omitted, but if the elastic partition wall 39 is used, the advantage that the gas does not intrude into the pressure chamber P does not have to be worried about.

[0054] Further, in the suspension device S of the present embodiment, the elastic pressure mechanism 34 brings the elastic force to a minimum state, and the elastic force generated by the suspension spring 30 that supports the vehicle body F with a prescribed weight and the force applied to the suspension spring 30 when the movement of the movable spring support 31 is restricted by the stopper 33 are balanced. According to the suspension device S configured in this way, when the vehicle body F of the suspension straddle-type vehicle (vehicle) M is loaded with a prescribed weight in the state where the elastic pressure mechanism 34 brings the elastic force to a minimum, the movable spring support 31 also moves into the housing 32 when the suspension spring 30 contracts, and thus the spring constant of the suspension device S can be made smaller than the spring constant of the suspension spring 30. Further, if the prescribed weight is set to the weight of one rider, the spring constant of the suspension device S provided in the suspension straddle-type vehicle M can be changed to be smaller than the spring constant of the suspension spring 30 during vehicle travel, and a comfortable ride feeling for the rider of the suspension straddle-type vehicle M can be achieved.

[0055] Further, the rear cushion unit RCU of the present embodiment includes the cushion main body D having the housing 4 and the rod member 2 that is axially movably inserted into the housing 4 and that can generate a damping force that suppresses the relative movement of the housing 4 and the rod member 2, the suspension device S, and the fixed spring support 25 that is provided to the rod member 2 and that supports the other end of the suspension spring 30, and the housing 32 and the movable spring support 31 are provided to the housing 4. In the rear cushion unit RCU configured in this way, since the suspension device S is provided, the spring constant of the suspension device S can be changed, and thus the ride feeling in the vehicle can be improved, and the suspension device S and the cushion main body D are integrated, and the rear cushion unit RCU can be easily mounted between the vehicle body F and the rear wheel W of the suspension straddle-type vehicle (vehicle) M, and the suspension device S can be easily mounted to the suspension straddle-type vehicle (vehicle) M.

[0056] Further, the rear cushion unit RCU of the present embodiment includes the annular cushion pad 21 that is mounted to the outer periphery of the end of the housing opposite to the rod member 2, and the cushion stopper 22 that is mounted to the housing 4 and that is axially opposed to the cushion pad 21, and the housing 32 does not restrict the movement of the movable spring support 31 to the side opposite to the suspension spring before the cushion pad 21 and the cushion stopper 22 abut when the cushion main body D contracts. According to the rear cushion unit RCU of the present embodiment configured in this way, when the spring constant of the suspension device S is reduced, even if the situation where the cushion pad 21 and the cushion stopper 22 abut when the cushion main body D contracts occurs, the stroke length of the movable spring support 31 with respect to the housing 32 in the direction of the contraction pressure chamber P is sufficiently ensured, and the movable spring support 31 and the housing 32 do not collide before the cushion pad 21 and the cushion stopper 22 abut, and thus the spring constant does not suddenly become high, and the rider of the suspension straddle-type vehicle (vehicle) M does not feel an uncomfortable ride feeling due to the unevenness.

[0057] In addition, the shape and structure of the movable spring support 31 and the housing 32 are examples, and design changes can be appropriately made. For example, in the case where the suspension device S is applied to the damper main body D, the housing 32 can be attached to the outer periphery of the housing 4, and the movable spring support 31 can be in sliding contact with the outer periphery of the housing 4 in addition to the housing 32.

[0058] The preferred embodiments of the present application have been described in detail above, but modifications, variations, and changes can be made without departing from the scope of the application. Symbol Explanation

[0059] 2 Rod 4 Housing 21 Cushion 22 Cushion stopper 25 Fixed spring support 30 Suspension spring 31 Movable spring support 32 Housing 33 Stopper 34 Elastic pressure applying mechanism 37 Container 38 Movement interval wall D Damper main body F Vehicle body M Suspension straddle vehicle (vehicle) P Pressure chamber RCU Rear cushion unit S Suspension device W Rear wheel

Claims

1. A suspension device comprising: Suspension springs, which support the body of a vehicle; a movable spring bracket, supporting one end of the suspension spring and capable of moving in the extension and contraction direction of the suspension spring; a housing, allowing the movable spring support to move in the expansion and contraction direction of the suspension spring and forming a pressure chamber for accommodating liquid between the housing and the movable spring support; a stopper for preventing the movable spring support from further moving toward the suspension spring when the movable spring support moves toward the suspension spring relative to the housing to maximize the pressure chamber; and The elastic pressurizing mechanism can pressurize the pressure chamber through elastic force and can adjust the elastic force.

2. The suspension device according to claim 1, wherein: The elastic pressure mechanism comprises: container; a movable partition wall movably inserted into the container to define a space in the container that communicates with the pressure chamber; and Gas and liquid are contained in the container.

3. The suspension device according to claim 1 , wherein, when the elastic pressure mechanism minimizes the elastic force, a spring force generated by the suspension spring supporting the vehicle body bearing a predetermined weight and a force biasing the suspension spring when movement of the movable spring support is restricted by the stopper are in a balanced state.

4. A rear buffer unit, comprising: A buffer body having a housing and a rod inserted into the housing so as to be axially movable, and capable of generating a damping force for suppressing relative movement between the housing and the rod; The suspension device according to any one of claims 1 to 3; as well as a fixed spring bracket, provided on the rod and supporting the other end of the suspension spring; The housing and the movable spring bracket are mounted on the outer shell.

5. The rear buffer unit according to claim 4, comprising: an annular buffer pad mounted on the outer periphery of the rod member at the opposite side of the outer shell; and a buffer stopper, mounted on the housing and axially opposite to the buffer pad; The housing does not restrict movement of the movable spring bracket toward the side opposite to the suspension spring before the shock absorber body contracts and the shock absorber pad abuts against the shock absorber stopper.

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