SHOCK ABSORPTION DEVICE AND SUSPENSION DEVICE

Abstract

A shock-absorbing device 2 comprises: an annular elastic element 110, a sealing element 120 located on a side opposite the first piston unit with respect to the elastic element 110 in the axial direction of the rod and designed to contact an inner circumferential surface of a sleeve 17, and a restraint element 150 designed to restrict axial movement of the elastic element 110 and the sealing element 120. The sealing element 120 comprises: a cylindrical base section 130 and a projection 140 that projects annularly from an outer circumference of a surface 131 opposite the elastic element 110 and is designed to contact an outer circumference of the elastic element 110.The base section 130 has recesses 132 formed inwards of the projection 140 and recessed from the opposite surface 131 towards a side opposite the elastic element 110. The projection 140 has a groove 141 which extends circumferentially in at least part of it, the groove 141 being designed to provide communication between the inside and outside of the projection 140.

Description

Technical field

[0001] The present invention relates to a shock absorption device and a suspension device. Technical background

[0002] A vibration damper disclosed in patent literature 1 is designed, for example, as follows. In particular, a first piston is attached to a piston rod that is axially movable within a cylinder. A second piston is attached to the piston rod. Depending on the stroke, the second piston enters a pressure cylinder with a pressure chamber. The second piston has a throttle opening through which a damping medium flows. At the center of the bottom of the pressure cylinder is a pressure relief valve with a pin axially penetrating the bottom, the pressure relief valve being designed to open in the flow direction from the pressure cylinder to the base valve body. The pressure relief valve has a spherical valve and a spring designed to exert a force on the valve to close the flow path. List of citations from patent literature

[0003] Patent literature 1: DE102019206510A Summary of the invention: Technical problem

[0004] The pressure relief valve disclosed in patent literature 1 opens in response to the internal pressure reaching a predetermined level during a compression stroke, in which the piston rod moves into the cylinder. This causes the damping medium to flow out of the pressure cylinder, preventing the pressure inside the cylinder from becoming too high. Because the pressure relief valve is located at the bottom of the pressure cylinder, it is not suitable for use in retraction strokes, in which the piston rod moves out of the cylinder. If the valve is to be used for retraction strokes, the vertical orientation of the cylinder must be reversed. In such cases, an additional hole would be required at the bottom of the cylinder to allow the piston rod to pass through.To ensure proper functioning of the pressure relief valve, an airtight sealing process must be implemented to create an airtight seal between the hole and the piston rod. Furthermore, the pressure relief valve must be positioned offset from the piston rod to prevent interference.

[0005] One object of the present invention is to provide a shock absorption device and the like, thereby providing good flexibility of the layout and also enabling flexible adjustment of the damping force characteristics by preventing an excessive pressure increase within the cylinder during exit operations. Solution to the problem

[0006] In view of the foregoing problem, one aspect of the present invention provides for a shock-absorbing device. The shock-absorbing device comprises: a rod designed such that a portion of it can be inserted into a cylinder; a first piston unit designed to be attached to the rod and to divide a space within the cylinder; a cylindrical jacket arranged within the cylinder closer to the rod than the first piston unit; and a second piston unit designed to be attached coaxially with the first piston unit to the rod, to enter the jacket, and to form a high-pressure chamber within a space inside the jacket, the pressure in the high-pressure chamber being higher than in a space closer to the first piston unit.The second piston unit comprises: an annular elastic element, a sealing element located on one side opposite the first piston unit with respect to the elastic element in the axial direction of the rod, the sealing element being designed to contact an inner circumferential surface of the sleeve, and a restraint element designed to restrict the movement of the elastic element and the sealing element in the axial direction. The sealing element comprises: a base section with a cylindrical shape and a projection extending annularly from an outer circumference of an opposite surface of the base section to the elastic element, the opposite surface facing the elastic element and the projection being designed to contact an outer circumference of the elastic element.The base section has a recess formed inwards of the projection, the recess being recessed from the opposite surface to a side opposite the elastic element. The projection has a groove that extends circumferentially at least in part of it, the groove being designed to provide communication between the inside and outside of the projection. Advantageous effects of the invention

[0007] The present invention can provide a shock absorption device and the like, which offer good flexibility of layout and also allow flexible adjustment of the damping force characteristics by preventing an excessive pressure increase within the cylinder during exit operations. Brief description of the drawings

[0008] They show: Fig. 1 an exemplary schematic configuration of a suspension device, Fig. 2 an exemplary enlarged view of Part II in Fig. 1, Fig. 3 an exemplary view of a sealing element from the first side in axial direction, Fig. 4 an exemplary cross-section of a second piston unit during an exit stroke, wherein the amount of the projection of a rod from a cylinder unit increases, Fig. 5 an exemplary enlarged view of Part V in Fig. 4, Fig. 6 an exemplary cross-section of the second piston unit during an exit stroke, Fig. 7 an exemplary cross-section of the second piston unit during a compression stroke, wherein the rod projection decreases, Fig. 8 an exemplary schematic configuration of a second piston unit according to a second embodiment, Fig. 9 an exemplary state of the second piston unit during a compression stroke, wherein the amount of the rod projection decreases, Fig. 10 an exemplary schematic configuration of a second piston unit according to a third embodiment, Fig. 11 an exemplary axial view of an elastic element according to the third embodiment, Fig. 12 an exemplary schematic configuration of a shock-absorbing device according to a fourth embodiment and Fig. 13 an exemplary cross-section of a third piston unit during a compression stroke. Description of embodiments

[0009] Embodiments of the present invention are described in detail below with reference to the accompanying drawings. <Erste Ausführungsform>

[0010] Fig. Figure 1 shows an exemplary schematic configuration of a suspension device 1.

[0011] The suspension device 1 is a shock absorber used in four-wheeled vehicles of the type of passenger car and features, as shown in Fig. Figure 1 shows a shock-absorbing device 2 and a coil spring 3 arranged outside the shock-absorbing device 2. The suspension device 1 further comprises a lower spring seat 4 and an upper spring seat 5. The lower spring seat 4 supports one end of the coil spring 3 on the first side (underside). Fig. 1) in the axial direction of a rod 20 (described below), and the upper spring seat 5 supports the other end of the coil spring 3 on the second side (top side in Fig. 1) in the axial direction.

[0012] The suspension device 1 comprises a vehicle body-side mounting bracket 6 and a wheel-side mounting bracket 7. The vehicle body-side mounting bracket 6 is attached to a secondary end of the rod 20 in the axial direction for mounting the suspension device 1 to the vehicle, and the wheel-side mounting bracket 7 is attached to a primary end of a cylinder unit 10 (described below) in the axial direction of the rod 20 for mounting the suspension device 1 to a wheel. The suspension device 1 further comprises a dust cover 8 for covering at least parts of the cylinder unit 10 and the rod 20.

[0013] The axial direction of the rod 20 can below simply be referred to as the “axial direction”. The axial direction also corresponds to the centerline direction of a cylinder 11 (described below). The first side in the axial direction (the bottom side in Fig. 1) and the second side in axial direction (the top side in Fig. 1) can simply be referred to as the "first side" and "second side," respectively. The direction that intersects the axial direction (e.g., the vertical direction) is called the "radial direction." In the radial direction, the side closer to the center line of cylinder 11 can simply be called the "inside," and the side farther from the center line can be called the "outside."

[0014] The shock-absorbing device 2 will now be described in detail.

[0015] The shock absorber 2 comprises a cylinder unit 10 for receiving oil and a rod 20, the latter having its far end projecting from the cylinder unit 10 and its far end being slidably inserted into the cylinder unit 10. The shock absorber 2 further comprises a first piston unit 30 located at the far end of the rod 20 and a bottom valve 40 located at the far end of the cylinder unit 10. The shock absorber 2 further comprises a second piston unit 100 located on the far side relative to the first piston unit 30. [Cylinder unit 10]

[0016] The cylinder unit 10 comprises a cylinder 11 for receiving oil, an outer cylinder body 12 located outside the cylinder 11, and a bottom cover 13 for closing the first end of the outer cylinder body 12. The cylinder 11 and the outer cylinder body 12 are arranged such that the centerline direction of these cylinders coincides with the axial direction. The cylinder unit 10 has a reservoir chamber R formed between the outer circumferential surface of the cylinder 11 and the inner circumferential surface of the outer cylinder body 12. Oil, which is an example of the fluid, is filled into the outer cylinder body 12.

[0017] The cylinder unit 10 further comprises a rod guide unit 14 for movably holding the rod 20, a stop cap 15 attached to the far end of the outer cylinder body 12, and an oil seal 16 to prevent oil from leaking out of the cylinder unit 10 and foreign substances from entering the cylinder unit 10. The cylinder unit 10 also comprises a jacket 17 located at the far end of the cylinder 11. The jacket 17 has a cylindrical shape and is chamfered at its far end, such that its inner diameter gradually increases towards the far end. By providing the jacket 17 with such a cylindrical shape and by dispensing with a pressure control valve, as disclosed in patent literature 1, it becomes unnecessary to provide a hole for the passage of the rod 20 and to perform an airtight sealing process, thereby improving the flexibility of the layout.For example, the jacket 17 can be connected to the cylinder 11 by welding or gluing. [Bar 20]

[0018] The rod 20 is a solid or hollow rod-shaped element and has a columnar or cylindrical rod section 21. The rod 20 also has a lower mounting section 22 at its lower end for attaching the first piston unit 30 and an upper mounting section 23 at its upper end for attaching the vehicle body-side mounting bracket 6. External threads are formed at the ends of the lower and upper mounting sections 22, 23.

[0019] The rod section 21 has a first groove 211 (see Fig. 2) and a second groove 212 (see Fig. 2) which are formed at predetermined positions on the rod section 21 and are each recessed over the entire circumference relative to the outer circumferential surface of the rod section 21. The first groove 211 has a triangular cross-section along a plane parallel to the axial direction, while the second groove 212 has a semicircular cross-section along a plane parallel to the axial direction. [First piston unit 30]

[0020] The first piston unit 30 comprises a first piston 31, a valve group 32 for closing the first-side ends of some of several oil passages formed in the first piston 31, and a valve group 33 for closing the second-side ends of some of these oil passages formed in the first piston 31.

[0021] The first piston 31 contacts the inner circumferential surface of the cylinder 11 by means of an element provided on the outer circumferential surface of the first piston 31 in order to seal a gap between the outer circumferential surface of the first piston 31 and the inner circumferential surface of the cylinder 11, thereby dividing the oil-filled space inside the cylinder 11 into a first oil chamber Y1 on the first side of the first piston 31 and a second oil chamber Y2 on the second side of the first piston 31. [Bottom valve 40]

[0022] The bottom valve 40 has a valve body 41 with several oil passages extending axially through it, a valve 42 provided on the first side of the valve body 41, and a valve 43 provided on the second side of the valve body 41.

[0023] The valve body 41 of the bottom valve 40 provides a partition between the first oil chamber Y1 and the reservoir chamber R. [Second piston unit 100]

[0024] Fig. Figure 2 is an example enlarged view of Part II in Fig. 1.

[0025] Fig. Figure 3 shows an exemplary view of a sealing element 120 from the first side in the axial direction.

[0026] The second piston unit 100 has an annular elastic element 110 and a sealing element 120, which is located on the side opposite the first piston unit 30 (i.e., on the second side) with respect to the elastic element 110 in the axial direction of the rod 20 and can contact the inner circumferential surface of the sleeve 17. The second piston unit 100 further has a restraint element 150 for restricting the axial movement of the elastic element 110 and the sealing element 120, and a clamp 180 for restricting the axial movement of the restraint element 150. The clamp 180 has a circular cross-section and is C-shaped when viewed in the axial direction. (Elastic element 110)

[0027] The elastic element 110 is, for example, a ring-shaped metal plate. The elastic element 110 has an inner diameter that is at least as large as the diameter of the outer circumferential surface of the rod section 21 of the rod 20, and an outer diameter that is smaller than the diameter of the inner circumferential surface of the shell 17. (Sealing element 120)

[0028] The sealing element 120 is, for example, a cylindrical element made of metal or resin. In particular, the sealing element 120 has a cylindrical base section 130 and a projection 140 that extends annularly from the outer circumference of an opposite surface 131 of the base section 130, which faces the elastic element 110, towards the elastic element 110 (i.e., towards the first side).

[0029] The inner diameter of the base section 130 is larger than the diameter of the outer circumferential surface of the rod section 21 of the rod 20, and its outer diameter is equal to the diameter of the inner circumferential surface of the shell 17. The base section 130 has several (ten in the Fig. 3 shown example) recesses 132 which are formed along the circumferential direction at positions located inside the projection 140, wherein the recesses 132 are sunk from the opposite surface 131 to the side opposite the elastic element 110 (i.e. to the second side).

[0030] The projection 140 has a rectangular cross-section along a plane parallel to the axial direction, with the radial direction corresponding to the longitudinal direction of the rectangle and the axial direction corresponding to the transverse direction of the rectangle. However, the inner circumferential surface of the projection 140 can be an inclined surface whose inner diameter increases towards the first side. This is because such an inclined surface allows for a smooth flow of oil along the inclined surface.

[0031] The projection 140 has a groove 141 extending radially, thus providing communication between sections inside and outside the projection 140. The groove 141 is formed, for example, at a position where it does not overlap the recesses 132 in the circumferential direction. In the Fig. In the example shown in Figure 3, a single groove 141 is formed; however, the number of grooves 141 is not limited to one, and there can be multiple grooves 141. The total cross-sectional area of ​​the one or more grooves 141 along a plane perpendicular to the axial direction is, however, smaller than the total cross-sectional area of ​​the multiple recesses 132. (Restriction element 150)

[0032] The restraint element 150 comprises a first element 160 and a second element 170, which are arranged in an axial direction. The restraint element 150 can be made of, for example, metal or resin.

[0033] The first element 160 has a cylindrical section 161 and a section 162 projecting from the lower end of the cylindrical section 161 to the inside.

[0034] The inner diameter of the cylindrical section 161 is at least as large as the diameter of the outer circumferential surface of the rod section 21 of the rod 20. The outer diameter of the cylindrical section 161 is smaller than the diameter of the inner circumferential surface of the shell 17 and larger than the inner diameters of the elastic element 110 and the sealing element 120.

[0035] The projecting section 162 extends from the lower end of the cylindrical section 161 over its entire circumference in an axially inclined direction. The distal end of the projecting section 162 fits into the first groove 211 of the rod section 21, thereby holding the first element 160 against the rod 20 so that it does not move relative to it.

[0036] The second element 170 has a first cylindrical section 171 and a second cylindrical section 172, which is provided on the second side of the first cylindrical section 171. The first and second cylindrical sections 171, 172 have the same inner diameter, which is at least as large as the diameter of the outer circumferential surface of the rod section 21. The second cylindrical section 172 has a larger outer diameter than the first cylindrical section 171. The outer diameter of the first cylindrical section 171 is smaller than the inner diameter of the sealing element 120. The outer diameter of the second cylindrical section 172 is smaller than the diameter of the inner circumferential surface of the sleeve 17 and larger than the inner diameter of the sealing element 120.

[0037] The restraint element 150 according to the present embodiment is attached to the rod 20, with the inner circumference of the elastic element 110 sandwiched between the first element 160 and the second element 170. Because the projecting section 162 of the first element 160 fits onto the first groove 211 of the rod section 21, the first element 160 is held on the rod 20 in such a way that it does not move relative to it, and the movement of the second element 170 to the second side is restricted by the clamp 180. Thus, the inner circumference of the elastic element 110 serves as the fixed end, while its outer circumference serves as the free end. (Functions of the second piston unit 100)

[0038] Fig. Figure 4 shows an exemplary cross-section of the second piston unit 100 during an exit stroke, with the amount of the projection (which may sometimes be referred to below as the ‘projection amount’) of the rod 20 from the cylinder unit 10 increasing.

[0039] Fig. Figure 5 is an example enlarged view of Part V in Fig. 4.

[0040] Fig. Figure 6 shows an exemplary cross-section of the second piston unit 100 during an exit stroke.

[0041] During an exit stroke, in which the amount of the projection of the rod 20 from the cylinder unit 10 increases, the movement of the second piston unit 100 from a position on the first side with respect to the shell 17 (in Fig. (State 2 shown) to the second side, that the sealing element 120 enters the jacket 17 and comes into contact with the inner circumferential surface of the jacket 17. This leads to the formation of a high-pressure chamber within the space in the jacket 17, the high-pressure chamber being at a higher pressure than a space located within the second chamber Y2 closer to the first piston unit 30 than to the sealing element 120 (i.e., on the first side with respect to the sealing element 120). Hereinafter, the space located within the jacket 17 on the first side with respect to the sealing element 120 can be referred to as the “third chamber Y3”, and the space located within the jacket 17 on the second side with respect to the sealing element 120 can be referred to as the “fourth chamber Y4”. The fourth chamber Y4 corresponds to the high-pressure chamber described above.

[0042] When the pressure in the fourth chamber Y4 increases and the force acting on the second-sided end surface 133 of the sealing element 120 becomes greater than the force acting on the first-sided sections of the sealing element 120 and the elastic element 110, the sealing element 120 deforms the outer circumference of the elastic element 110. This causes the opposite surface 131 of the sealing element 120 to come into contact with the elastic element 110, as shown in the Fig. 4 and Fig. 5 shown, whereby the elastic element 110 is sandwiched between the sealing element 120 and the cylindrical section 161 of the first element 160.

[0043] In the Fig. 4 and Fig. In the state shown in Figure 5, some of the oil in the fourth chamber Y4 flows through the recesses 132 of the sealing element 120 into a fifth chamber Y5, which is a space surrounded by the opposite surface 131 of the sealing element 120, the inner circumferential surface of the projection 140, and the elastic element 110. Then, as shown in Figure 5, some of the oil flows into the fifth chamber Y5. Fig. Figure 5 shows that some of the oil in the fifth chamber Y5 flows out through the groove 141 formed in the projection 140 of the sealing element 120 to the third chamber Y3. In this way, a damping force is generated as oil flows out over the groove 141 to the third chamber Y3. The groove 141 acts as an opening that allows the oil to flow from the fourth chamber Y4 to the third chamber Y3.

[0044] If the pressure in the fifth chamber Y5 in the Fig. 4 and Fig. As the temperature in the state shown in Figure 5 continues to rise, the outer circumference of the elastic element 110 deforms further, causing it to move away from the projection 140, as shown in Figure 5. Fig. 6 shown. This causes oil to flow from the fifth chamber Y5 to the third chamber Y3. In the Fig. In the state shown in Figure 6, a damping force is generated when oil flows from the fourth chamber Y4 through the recesses 132 of the sealing element 120 to the third chamber Y3. Even if the jacket 17 is designed as a cylindrical body, the second piston unit 100 accordingly fulfills both the requirements shown in the Fig. 4 and Fig. The opening function shown in section 5, as well as the one in [section / document], are shown. Fig. The 6 shown blow-off valve function provides both layout flexibility and damping properties.

[0045] To ensure that the elastic element 110 separates from the projection 140 after the sealing element 120 has deformed the outer circumference of the elastic element 110 and the pressure in the fourth chamber Y4 has increased by a predetermined value above that in the third chamber Y3, the flow path areas of the recesses 132 and the groove 141 (i.e., the cross-sectional areas along a plane perpendicular to the axial direction) are defined as follows. Specifically, the total flow path area formed by the groove 141 and the elastic element 110 when the opposite surface 131 and the projection 140 come into contact with the elastic element 110 is smaller than the total flow path area formed by the recesses 132 and the elastic element 110.

[0046] Fig. Figure 7 shows an exemplary cross-section of the second piston unit 100 during a compression stroke, in which the projection of the rod 20 decreases.

[0047] As in Fig. As shown in Figure 7, during a compression stroke, in which the projection of the rod 20 from the cylinder unit 10 decreases, the sealing element 120 moves to the second side and abuts the second cylindrical section 172 when the force acting on the first-sided section of the sealing element 120 becomes greater than that acting on the second-sided end face 133 of the sealing element 120. The movement of the sealing element 120 to the first side with respect to the shell 17 allows oil to flow around the outside of the sealing element 120, thus equalizing the pressure within the spaces on the first and second sides of the sealing element 120.

[0048] As described above, the shock-absorbing device 2 comprises the following: the rod 20, part of which is inserted into the cylinder 11; the first piston unit 30, which is attached to the rod 20 and divides the space within the cylinder 11; and the cylindrical shell 17, which is located within the cylinder 11 and, with respect to the first piston unit 30, closer to the rod 20 (i.e., on the second side). The shock-absorbing device 2 further comprises the second piston unit 100, which is attached to the rod 20 coaxially with the first piston unit 30 and can enter the shell 17 to form the fourth chamber Y4, for example, the high-pressure chamber, within the space inside the shell 17, the pressure in the fourth chamber Y4 being higher than that in the space closer to the first piston unit.The second piston unit 100 comprises the following: the annular elastic element 110, the sealing element 120, which is located on the opposite side of the first piston unit 30 in the axial direction of the rod 20 relative to the elastic element 110 and can contact the inner circumferential surface of the sleeve 17, and the restricting element 150, which restricts the axial movement of the elastic element 110 and the sealing element 120. The sealing element 120 comprises the following: the base section 130 with a cylindrical shape and the projection 140, which projects annularly from the outer circumference of the opposite surface 131 of the base section 130, which faces the elastic element 110, towards the elastic element 110 and can contact the outer circumference of the elastic element 110.The base section 130 has recesses 132 formed inwards of the projection 140, the recesses 132 being sunken from the opposite surface 131 towards the side opposite the elastic element 110. The projection 140 has a groove 141 formed circumferentially in at least one section thereof, the groove 141 providing communication between the inside and outside of the projection 140.

[0049] It is desirable for the shock absorber 2 to generate a high damping force during an extension stroke. For example, such a high damping force helps to suppress the lifting of the inside wheel during cornering, which in turn reduces body roll and contributes to improved ride comfort. In the shock absorber 2, the second piston unit 100 forms a high-pressure chamber (i.e., the fourth chamber Y4) within the casing 17 during an extension stroke, thereby providing a higher damping force than, for example, in a configuration that does not have the second piston unit 100.

[0050] On the other hand, excessive damping force during a rebound stroke can lead to a stiff ride, which could conversely worsen ride comfort. When the second piston unit 100 in the shock absorber 2 forms a high-pressure chamber within the casing 17 during a rebound stroke, the groove 141 acts as an opening, allowing oil to flow from the fourth chamber Y4 to the third chamber Y3. This configuration can prevent the damping force from becoming too high.

[0051] Additionally, the shock-absorbing device 2 allows the damping force to be adjusted by changing the flow path surfaces of the groove 141 and the recesses 132, thus enabling flexible adjustment of the damping force characteristics. Furthermore, the second piston unit 100 consists of the elastic element 110, the sealing element 120, and the restraint element 150. This configuration enables the shock-absorbing device 2 to provide the effects described above cost-effectively.

[0052] According to the first embodiment, the restraint element 150 comprises the first element 160 and the second element 170, which are arranged in the axial direction, and the elastic element 110 is sandwiched between the first element 160 and the second element 170. This configuration can prevent the axial movement of the elastic element 110, thereby enabling a rapid transition from a compression stroke to a recovery stroke or vice versa.

[0053] However, the elastic element 110 does not necessarily have to be arranged in a sandwich-like manner between the first element 160 and the second element 170. For example, the inner diameter of the elastic element 110 can be smaller than that of the sealing element 120 and larger than that of the first cylindrical section 171 of the second element 170 to allow the elastic element 110 to move between the first element 160 and the sealing element 120. <Zweite Ausführungsform>

[0054] Fig. Figure 8 shows an exemplary schematic configuration of a second piston unit 200 according to a second embodiment.

[0055] One difference between the second piston unit 200 according to the second embodiment and the second piston unit 100 according to the first embodiment concerns a sealing element 220, which corresponds to the sealing element 120. The difference compared to the first embodiment is described below. The same reference numerals are used to identify the identical elements between the first and second embodiments, and detailed descriptions thereof are omitted.

[0056] The sealing element 220 differs from the sealing element 120 in that the sealing element 220 is symmetrical with respect to a plane perpendicular to the axial direction. In particular, the sealing element 220 has a base section 230, which corresponds to the base section 130 according to the first embodiment, the projection 140, and another projection 240, which extends annularly from the outer circumference of a two-sided end surface 233 of the base section 230 to the second side.

[0057] The projection 240 is symmetrical to the projection 140 with respect to a plane perpendicular to the axial direction. The projection 240 has a groove 241 extending radially, thus providing communication between the inside and outside of the projection 240.

[0058] The base section 230 differs from the base section 130 according to the first embodiment in that the base section 230 has several (for example, ten) recesses 232 formed along the circumferential direction inwards of the projection 240, wherein the recesses 232 are recessed from the end surface 233 towards the first side. The recesses 232 are symmetrical with respect to a plane perpendicular to the axial direction. The base section 230 is also symmetrical with respect to a plane perpendicular to the axial direction.

[0059] The second piston unit 200 according to the second embodiment provides the same effects as those provided by the second piston unit 100 according to the first embodiment described above. In addition, the second piston unit 200 has a sealing element 220 with a shape symmetrical with respect to a plane perpendicular to the axial direction. This allows the sealing element 220 to be mounted regardless of its orientation. This facilitates the assembly of the second piston unit 200.

[0060] Fig. Figure 9 shows an exemplary state of the second piston unit 200 during a compression stroke, in which the projection of the rod 20 decreases.

[0061] Even when the sealing element 220 is located inside the shell 17 during the compression stroke, oil flows from the third chamber Y3 through the recesses 232 of the sealing element 220 to the fourth chamber Y4, while the end face 233 of the sealing element 220 is in contact with the second cylindrical section 172. This enables a smooth transition from an exit stroke to the compression stroke. <Dritte Ausführungsform>

[0062] Fig. Figure 10 shows an exemplary schematic configuration of a second piston unit 300 according to a third embodiment.

[0063] Fig. Figure 11 shows an exemplary axial view of an elastic element 310 according to the third embodiment.

[0064] Differences between the second piston unit 300 according to the third embodiment and the second piston unit 100 according to the first embodiment relate to an elastic element 310 and a restraint element 350, which correspond to the elastic element 110 and the restraint element 150, respectively. The differences compared to the first embodiment are described below. The same reference numerals are used to identify the corresponding elements between the first and third embodiments, and detailed descriptions thereof are omitted.

[0065] The restraint element 350 comprises the first element 160 and the second element 370, which corresponds to the second element 170. The second element 370 differs from the second element 170 according to the first embodiment in that the second element 370 has a recess 373 at its first end over its entire circumference, which is recessed relative to the outer circumferential surface of the second element 370. The axial size of the recess 373 is at least as large as the thickness of the elastic element 310. The second element 370 is arranged such that its first end surface can contact the second end surface of the first element 160. In other words, unlike in the second piston unit 100 according to the first embodiment, the elastic element 310 is not sandwiched between the first element 160 and the second element 370.

[0066] The elastic element 310 differs from the elastic element 110 according to the first embodiment in that the elastic element 310 has several (eight in the circumferential direction) Fig. (as shown in the example in Figure 11) has projecting sections 311, each extending from the inner circumferential end of the elastic element 310 to the center. The projecting sections 311 can, for example, be formed at equal intervals in the circumferential direction. The radius of a virtual circle defined by the distal ends of the multiple projecting sections 311 is at most as large as the diameter of a section of an outer circumferential surface 374 of the second element 370, where the recess 373 is formed. The elastic element 310 is attached to the restraint element 350 by the multiple projecting sections 311 engaging in the outer circumferential surface 374.

[0067] The second piston unit 300 according to the third embodiment also provides the same effects as those provided by the second piston unit 100 according to the first embodiment described above. In addition, the elastic element 310 of the second piston unit 300 has the projecting sections 311, which engage in the outer circumferential surface 374 of the restraint element 350 to fasten the elastic element 310 to the restraint element 350. This configuration allows the elastic element 310 and the restraint element 350 to be integrated before the second piston unit 300 is assembled. This facilitates the assembly of the second piston unit 300. <Vierte Ausführungsform>

[0068] Fig. Figure 12 shows an exemplary schematic configuration of a shock-absorbing device 400 according to a fourth embodiment.

[0069] The shock-absorbing device 400 according to a fourth embodiment differs from the shock-absorbing device 2 according to the first embodiment in that the shock-absorbing device 400 comprises a cylinder unit 410, corresponding to the cylinder unit 10, and a third piston unit 500, which prevents the pressure within the cylinder 11 from becoming too high during a compression stroke. The differences compared to the first embodiment are described below. The same reference numerals are used to identify the identical elements between the first and fourth embodiments, and detailed descriptions thereof are omitted.

[0070] The cylinder unit 410 differs from the cylinder unit 10 in that the cylinder unit 410 further comprises a second jacket 420 at the first end of the cylinder 11. The second jacket 420 is designed in the form of a cylinder with a closed end and has a cylindrical section 421 and a closing section 422, which closes a first-sided opening of the cylindrical section 421. The second jacket 420 further comprises several leg sections 423, which are provided on the first side with respect to the closing section 422.

[0071] The cylindrical section 421 can accommodate the third piston unit 500 and forms a space between the cylindrical section 421 and the cylinder 11.

[0072] Each leg section 423 extends radially and to the first side from an outer part of the closing section 422. Viewed axially, the portion of each leg section 423 extending to the first side has an arc shape. Several (for example, three) leg sections 423 are provided at equal intervals in the circumferential direction.

[0073] The second jacket 420 is attached to the first end of the inside of the cylinder 11 by connecting the leg sections 423 to the cylinder 11, for example by welding or gluing. The leg sections 423 are positioned outside the valve 43, and the closing section 422 is positioned on the second side with respect to the bottom valve 40. The wall thickness of each section of the second jacket 420 can be kept to a minimum because the second jacket 420 only needs to accommodate the third piston unit 500.

[0074] The third piston unit 500 has an annular elastic element 510 and a sealing element 520, which is arranged axially on the side opposite the first piston unit 30 (i.e., on the first side) with respect to the elastic element 510 and can contact the inner circumferential surface of the cylindrical section 421 of the second shell 420. The third piston unit 500 further has a first restraint element 550 for restricting the axial movement of the elastic element 510 and the sealing element 520. The third piston unit 500 further has an annular second restraint element 590 for restricting the axial movement of the first piston unit 30. (Elastic element 510)

[0075] The elastic element 510 is, for example, a ring-shaped metal plate. The elastic element 510 has an inner diameter that is at least as large as the diameter of the outer circumferential surface of the lower attachment section 22 of the rod 20, and an outer diameter that is smaller than the diameter of the inner circumferential surface of the cylindrical section 421 of the second shell 420. (Sealing element 520)

[0076] The sealing element 520 is, for example, a cylindrical element made of metal or resin. In particular, the sealing element 520 has a cylindrical base section 530 and a projection 540 that extends annularly from the outer circumference of an opposite surface 531 of the base section 530, which faces the elastic element 510, towards the elastic element 510 (i.e., towards the second side).

[0077] The base section 530 has an outer diameter that is essentially equal to the diameter of the inner circumferential surface of the cylindrical section 421 of the second shell 420. The base section 530 has several (for example, ten) recesses 532 formed along the circumferential direction inwards of the projection 540, which are recessed from the opposite surface 531 towards the side opposite the elastic element 510 (i.e., towards the first side).

[0078] The projection 540 has a rectangular cross-section along a plane parallel to the axial direction, with the radial direction corresponding to the longitudinal direction of the rectangle and the axial direction corresponding to the transverse direction of the rectangle. However, the inner circumferential surface of the projection 540 can be an inclined surface whose inner diameter increases towards the second side. This is because such an inclined surface allows for a smooth flow of oil along the inclined surface.

[0079] The projection 540 has a groove 541 extending radially, thus providing communication between sections inside and outside the projection 540. The groove 541 is formed, for example, at a position where it does not overlap the recesses 532 in the circumferential direction. Either a single groove 541 or multiple grooves 541 may be formed. However, the total cross-sectional area of ​​the one or more grooves 541 along a plane perpendicular to the axial direction is smaller than the total cross-sectional area of ​​the multiple recesses 532. (First restriction element 550)

[0080] The first restraint element 550 comprises a first element 560 and a second element 570, which are arranged in the axial direction. The first restraint element 550 can, for example, be made of metal or resin.

[0081] The first element 560 has a cylindrical section 561 and a section 562 projecting from the upper end of the cylindrical section 561 to the inside.

[0082] The inner diameter of the cylindrical section 561 is at least as large as the diameter of the outer circumferential surface of the lower mounting section 22 of the rod 20. The cylindrical section 561 has an outer diameter that is smaller than the outer diameter of the elastic element 510 and larger than the inner diameters of the elastic element 510 and the sealing element 520.

[0083] The projecting section 562 extends from the upper end of the cylindrical section 561 over its entire circumference in an axially inclined direction. The distal end of the projecting section 562 fits into the first groove 211 of the lower mounting section 22, thereby holding the first element 560 against the rod 20 so that it does not move relative to it.

[0084] The second element 570 is ring-shaped. The inner diameter of the second element 570 is at least as large as the diameter of the outer circumferential surface of the lower mounting section 22. The outer diameter of the second element 570 is smaller than the diameter of the inner circumferential surface of the cylindrical section 421 of the second shell 420. The second element 570 is prevented from moving to the second side, for example, by pressing or a similar method. As shown in Fig. As shown in Figure 12, the movement of the second element 570 to the second side can also be restricted by a clamp 580 which is fitted into a second groove 222 formed on the outer circumferential surface of the lower mounting section 22. (Functions of the third piston unit 500)

[0085] Fig. Figure 13 shows an exemplary cross-section of the third piston unit 500 during a compression stroke.

[0086] During a compression stroke, the movement of the third piston unit 500 from a position on the second side in relation to the second jacket 420 (the one in Fig. (as shown in Figure 12) to the first side, the sealing element 520 enters the second shell 420 and comes into contact with the inner circumferential surface of the cylindrical section 421 of the second shell 420. This leads to the formation of a high-pressure chamber within the space inside the cylindrical section 421, the high-pressure chamber being at a higher pressure than a space located inside the first chamber Y1 and closer to the first piston unit 30 than to the sealing element 520 (i.e., on the second side with respect to the sealing element 520). Hereinafter, the space located inside the cylindrical section 421 and on the second side with respect to the sealing element 520 can be referred to as the “seventh chamber Y7”, and the space located inside the cylindrical section 421 and on the first side with respect to the sealing element 520 can be referred to as the “eighth chamber Y8”.The eighth chamber Y8 corresponds to the high-pressure chamber described above.

[0087] When the pressure in the eighth chamber Y8 increases and the force acting on the first-sided end face 533 of the sealing element 520 becomes greater than that acting on the second-sided sections of the sealing element 520 and the elastic element 510, the sealing element 520 deforms the outer circumference of the elastic element 510. This causes the opposite surface 531 of the sealing element 520 to come into contact with the elastic element 510, as shown in Fig. 13 shows that the elastic element 510 is sandwiched between the sealing element 520 and the cylindrical section 561 of the first element 560.

[0088] In the Fig. In the state shown in Figure 13, a portion of the oil in the eighth chamber Y8 flows through the recesses 532 of the sealing element 520 into a space enclosed by the opposite surface 531 of the sealing element 520, the inner circumferential surface of the projection 540, and the elastic element 510. This oil then flows through the groove 541 formed in the projection 540 of the sealing element 520 to the seventh chamber Y7. In this way, a damping force is generated as the oil flows through the groove 541 to the seventh chamber Y7. The groove 541 acts as a throttle, allowing the oil to flow from the eighth chamber Y8 to the seventh chamber Y7.

[0089] When the pressure in the space surrounded by the opposite surface 531 of the sealing element 520, the inner circumferential surface of the projection 540 and the elastic element 510 in Fig. As the condition shown in Figure 13 continues to increase, the outer circumference of the elastic element 510 deforms further, causing it to separate from the projection 540. This allows oil to flow into the seventh chamber Y7, generating a damping force. Accordingly, the third piston unit 500, with its second jacket 420 designed to have a minimal wall thickness, also fulfills the requirements shown in Figure 13. Fig. The throttle function shown in Figure 13, as well as the blow-off valve function, provides both layout flexibility and damping properties.

[0090] To ensure that the elastic element 510 separates from the projection 540 after the sealing element 520 has deformed the outer circumference of the elastic element 510 and the pressure in the eighth chamber Y8 has increased by a predetermined value above that in the seventh chamber Y7, the flow path areas of the recesses 532 and the groove 541 (i.e., the cross-sectional areas along a plane perpendicular to the axial direction) are defined as follows. Specifically, the total flow path area formed by the groove 541 and the elastic element 510 when the opposite surface 531 and the projection 540 come into contact with the elastic element 510 is smaller than the total flow path area formed by the recesses 532 and the elastic element 510.

[0091] On the other hand, during an extension stroke, when the force acting on the second-sided section of the sealing element 520 becomes greater than the force acting on the first-sided end face 533 of the sealing element 520, the sealing element 520 moves towards the first side and abuts the second element 570. The movement of the sealing element 520 towards the second side with respect to the cylindrical section 421 of the second shell 420 allows oil to flow around the outside of the sealing element 520, thus equalizing the pressure within the spaces on the first and second sides with respect to the sealing element 520.

[0092] In the shock-absorbing device 400, the third piston unit 500 forms a high-pressure chamber (i.e., the eighth chamber Y8) within the cylindrical section 421 of the second jacket 420 during a compression stroke, thus providing a higher damping force than, for example, in a configuration lacking the third piston unit 500. When the third piston unit 500 forms a high-pressure chamber within the cylindrical section 421 of the second jacket 420 during a compression stroke, the groove 541 acts as a throttle to allow oil to flow from the eighth chamber Y8 to the seventh chamber Y7. This configuration prevents the damping force from becoming too high.

[0093] In addition, the shock-absorbing device 400 allows the damping force to be adjusted by changing the flow path surfaces of the groove 541 and the recesses 532, thus enabling flexible adjustment of the damping force characteristics. Furthermore, the third piston unit 500 consists of the elastic element 510, the sealing element 520, and the first restraint element 550. This configuration enables the shock-absorbing device 400 to provide the effects described above cost-effectively. Reference symbol list 1 Suspension device 2,400 shock absorption device 3 coil springs 10 cylinder unit 11 cylinders 17 coat 20 bars 30 first piston unit 100, 200, 300 second piston unit 110, 310 elastic element 120, 220 sealing element 130, 230 Base section 131 opposite area 132, 232 recess 140, 240 lead 141, 241 groove 150, 350 restriction element 160 first element 170, 370 second element 311 preceding section 374 external perimeter area 420 second coat (example of the coat) 500 third piston unit (example of the second piston unit) Y1 first chamber Y2 second chamber Y3 third chamber Y4 fourth chamber Y5 fifth chamber QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102019206510A

[0003]

Claims

[1] Shock absorption device comprising: a rod designed so that part of it can be inserted into a cylinder, a first piston unit designed to be attached to the rod and to divide a space within the cylinder, a jacket with a cylindrical shape, which is located inside the cylinder closer to the rod than the first piston unit, and a second piston unit designed to be attached coaxially with the first piston unit on the rod, to enter the jacket and to form a high-pressure chamber within a space inside the jacket, wherein the pressure in the high-pressure chamber is higher than in a space closer to the first piston unit, wherein the second piston unit has the following features: a ring-shaped elastic element, a sealing element located on one side opposite the first piston unit with respect to the elastic element in the axial direction of the rod, wherein the sealing element is designed to be able to contact an inner circumferential surface of the sleeve, and a restrictive element designed to limit the movement of the elastic element and the sealing element in the axial direction, wherein the sealing element has the following features: a base section with a cylindrical shape and a projection that extends in a ring shape from an outer circumference of an opposite surface of the base section to the elastic element, wherein the opposite surface faces the elastic element and the projection is designed to be able to touch an outer circumference of the elastic element, wherein the base section has a recess formed inwards of the projection, wherein the recess is sunken from the opposite surface to a side opposite the elastic element, and the projection has a groove which is formed in the circumferential direction at least in part of it, the groove being designed to provide communication between the inside and outside of the projection. [2] Shock absorption device according to claim 1, wherein the recess and the groove are each formed at at least one point in the sealing element and The total flow path area formed by the groove and the elastic element when the opposite surface and the projection come into contact with the elastic element is smaller than the total flow path area formed by the recess and the elastic element. [3] Shock absorption device according to claim 1, wherein the sealing element is symmetrical with respect to a plane perpendicular to the axial direction. [4] Shock absorption device according to claim 1, wherein the elastic element further comprises a projecting section extending from an inner circumferential end of the elastic element to a center, wherein the projecting section is designed to encompass an outer circumferential surface of the restraint element in order to attach the elastic element to the restraint element. [5] Shock absorption device according to claim 1, wherein the restraint element has a first and a second element that are arranged in the axial direction and The elastic element is arranged in a sandwich-like fashion between the first and second elements. [6] Suspension device comprising: the shock absorption device according to one of claims 1 to 5 and a coil spring that is located outside the shock absorber. [7] Shock-absorbing device comprising: a rod designed so that part of it can be inserted into a cylinder with a closed end, having a bottom and a cylindrical section, a first piston unit designed to be attached to the rod and to divide a space within the cylinder, a jacket in the form of a cylinder with a closed end, located at the bottom and open towards the first piston unit, and a second piston unit designed to be attached coaxially with the first piston unit on the rod, to enter the jacket and to form a high-pressure chamber within a space inside the jacket, wherein the pressure in the high-pressure chamber is higher than in a space closer to the first piston unit, wherein the second piston unit has the following features: a ring-shaped elastic element, a sealing element located on one side opposite the first piston unit with respect to the elastic element in the axial direction of the rod, wherein the sealing element is designed to be able to contact an inner circumferential surface of the sleeve, and a restrictive element designed to limit the movement of the elastic element and the sealing element in the axial direction, wherein the sealing element has the following features: a base section with a cylindrical shape and a projection that extends in a ring shape from an outer circumference of an opposite surface of the base section to the elastic element, wherein the opposite surface faces the elastic element and the projection is designed to be able to touch an outer circumference of the elastic element, wherein the base section has a recess formed inwards of the projection, wherein the recess is sunken from the opposite surface to a side opposite the elastic element, and the projection has a groove which is formed in the circumferential direction at least in part of it, the groove being designed to provide communication between the inside and outside of the projection.

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