Spring member and shock absorber using spring member

Abstract

To provide spring members and shock absorbers with excellent flexibility in setting damping effect. [Solution] A spring member b is an annular shape having an inner edge 11 and an outer edge 12, and comprising a convex surface f1 on the side of the inner edge 11 that protrudes more than the outer edge 12 along the axis, and a concave surface f2 on the back surface thereof, wherein the surface of the convex surface f1 near the inner edge 11 is a convex inner circumferential surface f11, the surface near the outer edge 12 is a convex outer circumferential surface f12, and the surface of the concave surface f2 near the inner edge 11 is a concave inner circumferential surface f21, and the surface near the outer edge 12 is a concave outer circumferential surface f22. Multiple disc springs 1 are arranged in series with the convex surfaces f1 facing each other and the concave surfaces f2 facing each other, and spacers 2 are placed at least between the convex outer circumferential surfaces f12 and between the concave inner circumferential surfaces f21, so that when the disc springs 1 are unloaded, the opposing convex inner circumferential surfaces f11 and the concave outer circumferential surfaces f22 are spaced apart.

Description

Technical Field

[0001] The present invention relates to a shock absorber using such a spring member, in which a plurality of disc springs each having an inner edge and an outer edge are arranged in series with their convex surfaces and concave surfaces facing each other, and spacers are arranged between the convex outer peripheral surfaces and between the concave inner peripheral surfaces, and a piston that reciprocates inside a cylinder, and further a valve that reciprocates inside the piston, and the spring member is used to adjust the amount of fluid flowing inside the piston by the reciprocating movement of the valve to set a damping force.

Background Art

[0002] Conventionally, as related to such a spring member and a shock absorber, for example, there is one shown in Patent Document 1 (see paragraphs

[0091] to

[0096] and FIG. 1).

[0003] As a piston provided in a conventional shock absorber, there is one provided with a valve biased by various springs. The valve moves under the pressure of the fluid when the piston moves. The fluid pressure changes according to the moving speed of the piston. The moving of the valve is configured to adjust the flow path area of the fluid and change the damper resistance force.

[0004] However, when the moving amount of the valve and the change in the flow path area are closely corresponding, the buffer function changes greatly due to variations in the elastic characteristics of the valve, particularly variations in the characteristics of the spring that presses the valve.

[0005] Therefore, in the device according to Patent Document 1, a piston 5 is provided inside a cylinder 3 filled with fluid, and the piston 5 is provided with a valve 79 that opens and closes a piston flow path 67 by the flow of the fluid. The piston 5 is provided with a piston flow path 67 that allows fluid to flow from a pressure chamber 39 by its own movement.

[0006] The valve 79 is substantially conical in shape, and a piston orifice 89 is formed by its insertion movement into the piston passage 67. The valve 79 is biased by a spring 81 in the direction of insertion into the piston passage 67. Depending on the movement speed of the piston 5, the valve 79 is pulled out of the piston passage 67, and the opening area of ​​the piston orifice 89 changes according to the amount of pulling out.

[0007] Thus, with the conventional shock absorber 1, the relative shape change between the valve 79 and the piston passage 67 during extension is gradual, and even if there is variation in the elastic properties of the spring 81, this variation can be absorbed by setting the shape change between the valve 79 and the piston passage 67, thereby stabilizing the characteristics of the shock absorber 1. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2011-226597 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, in the conventional device described above, although slowing down the change in the opening area of ​​the piston orifice 89 reduces the impact on the fluid flow rate, there is a possibility that the spring characteristics of the spring 81 may vary.

[0010] Spring 81 is composed of multiple disc springs stacked on top of each other, but each is merely in contact with the others. Therefore, the umbrella-shaped disc springs can deform until they become flat, in which case the amount of deformation may be excessive and the intended spring constant may not be achieved. In reality, there is no deformation stroke that would result in a flat shape, but as the amount of elastic deformation increases, differences in the deformation state of individual disc springs may occur. In that case, the spring constant of the combined spring made up of multiple disc springs may not be properly achieved.

[0011] Furthermore, even if the spring 81, which is a collection of springs, exhibits the desired spring constant, the resulting spring constant is constant because the disc springs are simply stacked on top of each other. Therefore, to adjust the opening area of ​​the piston orifice 89, the only way to change the flow rate is to finely adjust the surface shape of the reciprocating valve 79 to change the amount of movement. However, since the deformation of the disc spring and the amount of movement of the valve 79 have a simple linear relationship, the valve 79 moves only a distance corresponding to the pressure acting on the disc spring. In other words, because the spring constant is constant, if the fluid flow rate is to be kept constant, a cylindrical surface must be provided so that the gap does not change according to the movement of the valve 79. In this configuration, not only is the manufacturing of the valve 79 complicated, but inconveniences such as the valve 79 and shock absorber 1 becoming longer also occur.

[0012] Thus, conventional spring members and shock absorbers have various problems that need to be solved, and there has been a need for spring members and shock absorbers using spring members that have a simple configuration while offering excellent freedom in setting the damping effect. [Means for solving the problem]

[0013] (Feature composition) The characteristic configuration of the spring member according to the present invention is: It is an annular shape having an inner edge and an outer edge, and comprises a convex surface on the side where the inner edge protrudes more than the outer edge along the axis, and a concave surface on its back surface, Of the aforementioned convex surfaces, the surface near the inner edge is designated as the convex inner circumferential surface, and the surface near the outer edge is designated as the convex outer circumferential surface, Multiple disc springs, each having a concave surface with the inner edge near the concave inner circumferential surface and the outer edge near the concave outer circumferential surface, are arranged in series with the convex surfaces facing each other and the concave surfaces facing each other. Spacers are placed at least between the convex outer surfaces and between the concave inner surfaces. When the disc spring is unloaded, the opposing convex inner surfaces and the concave outer surfaces are spaced apart.

[0014] (effect) In this configuration, when each disc spring deforms under compressive force, the compressive force is transmitted to each disc spring via spacers placed between the convex outer surfaces and between the concave inner surfaces. As a result, each disc spring undergoes elastic deformation based on its own spring constant, but once a predetermined deformation occurs, the inner edges of the convex inner surfaces and the outer edges of the concave outer surfaces come into contact with each other. This restricts further deformation of each disc spring, limiting the maximum stress generated in each disc spring. By appropriately setting the dimensions of the spacers and the gaps between the convex and concave inner surfaces of the disc springs, the deformation of the disc springs remains within the elastic region. As a result, the disc springs exhibit the desired spring constant, and a spring member with excellent operational stability can be obtained.

[0015] Furthermore, a configuration in which spacers are placed at least between the convex outer surfaces and between the concave inner surfaces means that spacers may also be placed between the convex inner surfaces and between the concave outer surfaces. For example, it is permissible to use additional spacers to adjust the gap between the convex inner surfaces and the gap between the concave outer surfaces.

[0016] (Feature composition) In the spring member according to the present invention, the spacer comprises an outer edge spacer provided between the convex outer circumferential surfaces and an inner edge spacer provided between the concave inner circumferential surfaces. When multiple disc springs are subjected to a pressing force along the axis, The convex inner surfaces are close together and their respective inner edges are in contact with each other, and the inner pressing portion provided on the inner edge spacer presses on the recessed inner surface at a position spaced apart from the inner edge. It is advantageous if the concave outer surfaces are close together and their respective outer edges are in contact with each other, and the outer pressing portion provided on the outer edge spacer is configured to press on the convex outer surface at a position spaced apart from the outer edge.

[0017] (effect) In this configuration, an outer edge spacer provided between convex outer peripheral surfaces and an inner edge spacer provided between concave inner peripheral surfaces are provided as spacers. When a compressive force acts on a plurality of disc springs, each disc spring, the outer edge spacer, and the inner edge spacer move in the compression direction, and the disc spring elastically deforms. When a compressive force of a predetermined value or more acts, the inner edges that contact the convex inner peripheral surfaces of the separated disc springs and the outer edges that contact the concave outer peripheral surfaces come into contact with each other.

[0018] As in this configuration, by setting an inner peripheral pressing portion on the inner edge spacer and an outer peripheral pressing portion on the outer edge spacer, the compressive force acting on the disc spring further bends and deformsthe disc spring with the inner edge and the outer edge related to the above contact as fulcrums. As a result, the contact area between the convex inner peripheral surfaces and the concave outer peripheral surfaces of the disc spring gradually increases.

[0019] By utilizing such bending deformation on the convex inner peripheral surface by the inner peripheral pressing portion and bending deformation on the concave outer peripheral surface by the outer peripheral pressing portion, the spring constant of the disc spring can be rapidly increased, and further, the degree of change in the spring constant can be adjusted by changing the setting positions of the inner peripheral pressing portion and the outer peripheral pressing portion. Thereby, a spring member with a higher degree of freedom in setting the spring constant can be obtained.

[0020] (Characteristic configuration) In the spring member according to the present invention, it is advantageous that a curved surface on which the inner peripheral pressing portion or the outer peripheral pressing portion is sequentially formed is provided on the inner edge spacer and the outer edge spacer so that the inner peripheral pressing portion approaches the inner edge and the outer peripheral pressing portion approaches the outer edge in accordance with the compressive deformation of the disc spring due to the pressing of the spacer.

[0021] (Effect) By providing a curved surface on which the inner circumferential pressing portion or the outer circumferential pressing portion is sequentially formed with respect to the inner edge spacer and the outer edge spacer, the position where the compressive force is applied to the disc spring moves as the spacer is displaced. That is, as the disc spring is compressed and deformed, the concave outer circumferential surfaces and the convex inner circumferential surfaces gradually approach each other, so the relative angle of the disc spring with respect to the outer edge spacer or the inner edge spacer changes. As the compression deformation of the disc spring increases, the inner circumferential pressing portion approaches the inner edge of the disc spring, and the outer circumferential pressing portion approaches the outer edge of the disc spring. As a result, the moment required for the outer edge spacer or the inner edge spacer to bend and deform the disc spring increases, and the spring constant increases.

[0022] With this configuration, for example, even when the disc spring attempts to displace rapidly, the spring constant of the disc spring increases gradually and the deformation speed of the disc spring is smoothly decelerated. Therefore, a spring member with a smoothly changing damping effect can be obtained.

[0023] (Characteristic configuration) The spring member according to the present invention can be used in a shock absorber having the following configuration. That is, a cylindrical cylinder having an axis, a cylindrical piston connected to the rod and provided so as to be reciprocally movable along the inner wall of the cylinder, dividing the inside of the cylinder into a first outer chamber and a second outer chamber, inside the piston, a valve sandwiched between a first spring and a second spring, normally held at a reference position along the axis, and partitioning the inside of the piston into a first inner chamber and a second inner chamber, on the piston, a first port communicating the first outer chamber and the first inner chamber, a second port communicating the second outer chamber and the second inner chamber, a first discharge portion formed in a part along the circumferential direction of the piston so as to discharge the fluid in the first inner chamber to the second outer chamber, a second discharge portion formed in a part along the circumferential direction of the piston so as to discharge the fluid in the second inner chamber to the first outer chamber, are provided, on the valve, A first opening that communicates with the first interior chamber, As the valve moves from the reference position towards the second inner chamber, a first window portion is formed that connects the first inner chamber to the first discharge portion. A second opening that communicates with the second interior chamber, A second window is provided which, when the valve moves from the reference position towards the first inner chamber, connects the second inner chamber to the second discharge section. The spring members are arranged as the first spring and the second spring.

[0024] (effect) In this shock absorber configuration, a valve is further provided inside the piston, and the position of the valve changes in accordance with the acceleration of the piston's vertical movement. The fluid flow changes according to this displacement, and the damping force is adjusted. The valve is biased by a pair of springs to return to its neutral position.

[0025] In this configuration, the spring members described above are used as the spring. As a result, for example, when the piston acceleration is large and the compressive deformation of the spring member increases, the spring constant increases in stages, thereby enhancing the damping effect. On the other hand, when the piston acceleration is small and the compressive deformation of the spring member is small, the spring constant is kept low, allowing external shocks to be effectively dissipated. Thus, with this configuration, a shock absorber that exhibits an effective damping effect against acting external forces can be obtained. [Brief explanation of the drawing]

[0026] [Figure 1] Cross-sectional view showing the configuration of the shock absorber according to the first embodiment. [Figure 2] Exploded perspective view showing the configuration of the piston and valve according to the first embodiment. [Figure 3] Cross-sectional view showing the configuration of the piston according to the first embodiment. [Figure 4] An explanatory diagram showing the communication state between the piston and valve according to the first embodiment. [Figure 5] Partial cross-sectional perspective view showing the configuration of the spring member according to the first embodiment. [Figure 6] Explanatory diagram showing the deformation mode of the spring member according to the first embodiment. [Figure 7] Explanatory diagram showing the deformation mode of the spring member according to the second embodiment. [Figure 8] Graph showing the characteristics of the spring member according to the second embodiment. [Figure 9] Graph showing the damping characteristics of the shock absorber according to the second embodiment. [Figure 10] An explanatory diagram showing the detailed structure of the disc spring and spacer according to the third embodiment. [Figure 11] Graph showing the characteristics of the spring member according to the third embodiment. [Figure 12] Explanatory diagram showing the deformation mode of the spring member according to the fourth embodiment. [Figure 13] Graph showing the characteristics of the spring member according to the fourth embodiment. [Figure 14] Cross-sectional view showing the main components of the shock absorber according to the fifth embodiment. [Figure 15] Cross-sectional view showing the main components of the shock absorber according to the sixth embodiment. [Modes for carrying out the invention]

[0027] [First Embodiment] (overview) Figures 1 to 4 show a shock absorber A according to the first embodiment of the present invention. Figure 1 is a cross-sectional structure of shock absorber A, and Figure 2 shows the appearance and structure of the piston P and valve V. Figure 3 is a cross-section of piston P, and Figure 4 illustrates the relative movement of valve V with respect to piston P. This shock absorber A is incorporated into, for example, the suspension of a vehicle and used to dampen vertical vibrations input to the vehicle in accordance with the unevenness of the road surface.

[0028] As shown in Figure 1, the shock absorber A in this embodiment comprises a cylindrical cylinder S having an axis X, and a cylindrical piston P that is supported by a rod Pa and moves back and forth along the inner wall of the cylinder S, dividing the inside of the cylinder S into a first outer chamber R1 and a second outer chamber R2.

[0029] As shown in Figures 1 and 2, a cylindrical valve V is provided inside the piston P. The valve V is reciprocally movable along the axis X and rotatable about the axis X. The valve V is held between two spring members b, a first spring b1 and a second spring b2, and is normally held in a reference position along the axis X. Note that in Figure 2, only the first spring b1 is shown, and the second spring b2, which is located below the piston P, is not shown. The valve V also divides the inside of the piston P into a first chamber r1 and a second chamber r2.

[0030] The piston P is provided with a first port p1 connecting the first outer chamber R1 and the first inner chamber r1, and a second port p2 connecting the second outer chamber R2 and the second inner chamber r2. Multiple first discharge sections p11 are formed at various positions along the circumferential direction of the piston P to discharge the fluid from the first inner chamber r1 to the second outer chamber R2. A first groove m1 is formed on the inner surface of the piston P, which communicates with the first discharge section p11.

[0031] Similarly, a second discharge section p21 is formed at multiple positions along the circumferential direction of the piston P to discharge the fluid from the second inner chamber r2 to the first outer chamber R1, and a second groove m2 is formed on the inner surface of the piston P that communicates with the second discharge section p21.

[0032] As shown in Figure 2, the valve V is provided with a first opening v1 that communicates with the first inner chamber r1, and a first window w1 that, when the valve V moves from its reference position to the side of the second inner chamber r2, connects the first inner chamber r1 to the first groove m1 and the first discharge section p11.

[0033] Furthermore, the valve V is provided with a second opening v2 that communicates with the second inner chamber r2, and a second window w2 that, when the valve V moves from its reference position towards the first inner chamber r1, connects the second inner chamber r2 to the second groove m2 and the second discharge section p21.

[0034] (Examples of piston and valve operation) In this embodiment, the piston P and valve V operate as follows, for example, when the shock absorber A extends as the vehicle's wheel passes over an uneven surface.

[0035] When the wheel enters the recess, the cylinder S is displaced downward, reducing the volume of the first outer chamber R1 and increasing the pressure. As a result, the hydraulic oil in the first outer chamber R1 enters the first inner chamber r1 through the first port p1, passes through the first opening v1, and enters the interior of the valve V. This hydraulic oil presses against the bottom surface of the valve V, causing the valve V to descend relative to the piston P.

[0036] Before the valve V descends, it is held in a reference position inside the piston P by the first spring b1 and the second spring b2. As shown in Figures 3 and 4, in this position, the first window portion w1 and the second window portion w2 formed on the side surface of the valve V do not face the first groove portion m1 and the second groove portion m2, but rather face the inner surface of the piston P. Therefore, when in the reference position, the operating oil does not flow inside the piston P.

[0037] Until the first window portion w1 communicates with the first discharge portion p11, the valve V descends inside the piston P against the biasing force of the second spring b2. As a result, the total volume of the first outer chamber R1 above the partition portion p3 on the outer surface of the piston P, and the first inner chamber r1 inside the piston P which communicates with it via the first port p1, gradually increases as the valve V descends. In this state, the pressure of the working oil gradually increases, and the damping function of the shock absorber A is exerted.

[0038] As the valve V descends further, the first window portion w1 communicates with the first discharge portion p11, and this communication portion acts as an orifice, allowing the hydraulic oil from the first inner chamber r1 to flow out to the second outer chamber R2 via the first discharge portion p11. In Figure 4, the symbol w1' represents the state where the entire first window portion w1 faces the first groove portion m1. When the first window portion w1 begins to communicate with the first groove portion m1, the hydraulic oil can flow, making the operation of the piston P easier and resulting in a damping effect.

[0039] The longer the travel distance of valve V until the first window section w1 and the first discharge section p11 are in communication, the more the operating speed of piston P from the reference position is suppressed, and the timing of the damping effect is delayed. The shock absorber A is set to what is known as a hard setting.

[0040] With the shapes of the first window portion w1 and the first groove portion m1 in this configuration, when the valve V descends, the relationship between the descending distance of the first window portion w1 and the increase in the opening area is linear.

[0041] (First spring and second spring) For the first opening v1 and first window portion w1 provided in the valve V to function properly, the valve V needs to be appropriately displaced inside the piston P according to the vehicle's driving conditions, for example. For this purpose, the spring constants of the first spring b1 and the second spring b2 (both made of the same spring member b) are important. In this embodiment, the first spring b1 and the second spring b2 are made up of multiple disc springs 1 so that they exhibit appropriate spring constants.

[0042] Figure 5 shows the configuration of spring member b. Here, the disc spring 1 is an annular shape having an inner edge 11 and an outer edge 12, and has a convex surface f1 on the side where the inner edge 11 protrudes more than the outer edge 12 along the axis X, and a concave surface f2 on its back surface. Of the convex surface f1, the surface near the inner edge 11 is designated as the convex inner circumferential surface f11, and the surface near the outer edge 12 is designated as the convex outer circumferential surface f12. Of the concave surface f2, the surface near the inner edge 11 is designated as the concave inner circumferential surface f21, and the surface near the outer edge 12 is designated as the concave outer circumferential surface f22. Multiple of these disc springs 1 are arranged in series with the convex surfaces f1 facing each other and the concave surfaces f2 facing each other, and spacers 2 are placed at least between the convex outer circumferential surfaces f12 and between the concave inner circumferential surfaces f21.

[0043] As shown in Figure 6(a), when the disc spring 1 is unloaded, gaps are formed between the opposing convex inner surfaces f11 and the concave outer surfaces f22. This dimension allows each disc spring 1 to avoid interference with other disc springs 1 and sets the stroke of the first spring b1 or the second spring b2 when it undergoes elastic deformation independently.

[0044] In this configuration, when each disc spring 1 deforms under compressive force, the compressive force is transmitted to each disc spring 1 via the outer edge spacers 22 positioned between the convex outer surfaces f12 and the inner edge spacers 21 positioned between the concave inner surfaces f21. As a result, the disc spring 1 elastically deforms based on its own spring constant, and when a predetermined deformation occurs, the inner edges 11 related to the convex inner surface f11 and the outer edges 12 related to the concave outer surface f22 come into contact with each other (Figure 6(b)). This contact point between the disc springs 1 is referred to as the first contact point t1.

[0045] As a result, each disc spring 1 is restricted from further deformation, and the maximum stress generated in each disc spring 1 is limited. By appropriately setting the dimensions of the outer edge spacer 22 and the inner edge spacer 21, and the gap dimensions between the convex outer surface f12 and the concave inner surface f21 of the disc spring 1, the deformation of the disc spring 1 remains within the elastic region. As a result, the disc spring 1 exhibits the desired spring constant, and a spring member b with excellent operational stability can be obtained.

[0046] Furthermore, in a configuration in which spacers 2 are placed at least between convex outer surfaces f12 and between concave inner surfaces f21, additional spacers 2 may be placed between convex inner surfaces f11 and between concave outer surfaces f22. For example, additional spacers 2 may be used as appropriate to adjust the gap between convex inner surfaces f11 and the gap between concave outer surfaces f22.

[0047] The specific operation of the disc spring 1 is as follows: When the valve V moves relative to another within the piston P, and a compressive force is applied to, for example, the first spring b1, the disc springs 1 constituting the first spring b1 undergo elastic deformation while exhibiting a predetermined spring constant. As the displacement of the valve V progresses further, the amount of elastic deformation reaches the desired amount, and as shown in Figure 6(b), the inner edges 11 and outer edges 12 come into contact with each other without the spacer 2 interposed between them. In this state, each disc spring 1 can no longer undergo elastic deformation in the same way as before.

[0048] In other words, for each disc spring 1, the maximum travel distance of the inner edge 11 and outer edge 12 is kept within a predetermined range so that elastic deformation is achieved within a healthy range, and a spring member b that exhibits a stable spring constant can be obtained. As a result, a shock absorber A with excellent operational stability can be obtained.

[0049] Furthermore, the spring constant can be arbitrarily set by changing the thickness and material of the disc spring 1, as well as the total number of springs arranged in series. For example, if the thickness and material of the disc spring 1 are selected to make it more difficult to deform, the spring constant will increase. Also, by increasing the number of springs arranged in series, the overall spring constant of the first spring b1 and the second spring b2 will decrease. For example, the combined spring constant k when n disc springs 1, each with different spring constants k1 to kn, are arranged in series can be calculated using the following formula. 1 / k = 1 / k1 + 1 / k2 + ... + 1 / kn Equation (a)

[0050] In this embodiment, umbrella-shaped disc springs 1 were used as the first spring b1 and second spring b2, which are the same spring member b. However, flat springs that are naturally flat and annular may also be used. Even in this case, after elastic deformation, the inner edges 11 or outer edges 12 on the side without the spacer 2 will come into contact with each other, producing the same effect as described above.

[0051] [Second Embodiment] In this embodiment, the first spring b1 and the second spring b2 can be further elastically compressed after reaching the state shown in Figure 6(b) by modifying the shape of the spacer 2. Therefore, Figure 7 shows the detailed structure of such a disc spring 1 and spacer 2.

[0052] Figures 7(a) to 7(c) show the deformation patterns when, for example, the first spring b1 of the two springs b1 and b2 is subjected to compression. Note that Figure 7 also shows a cross-sectional view on one radial side with respect to the axis X. Figure 7(a) shows the state in which each disc spring 1 can undergo elastic deformation independently. This deformation mode is referred to as the first mode.

[0053] Figure 7(b) shows the state in which the disc springs 1 are further compressed and are in contact with each other at their inner edges 11 and outer edges 12, respectively. The black circles (●) in the figure indicate the contact points between the disc springs 1 (first contact point t1) and the contact points between the disc springs 1 and the spacer 2 (second contact point t2). The first contact point t1 is the position where the disc springs 1 come into contact with each other, and the second contact point t2 is the position where the spacer 2 makes annular line contact with the disc spring 1. When forming the second contact point t2, the portion formed on the inner edge spacer 21 is called the inner circumferential pressing portion t21, and the portion formed on the outer edge spacer 22 is called the outer circumferential pressing portion t22.

[0054] As shown in the enlarged view on the right side of Figure 7(b), for example, at the outer edge 12, the disc springs 1 come into contact with each other at the first contact portion t1 of the outer edge 12. On the other hand, the contact with the spacer 2 is at the second contact portion t2, which is slightly offset inward from the first contact portion t1. The meaning of "inward" here is that the disc spring 1 is a conical and annular plate member having an inner edge 11 and an outer edge 12, and when an annular central position Xc is set at a position equidistant from the inner edge 11 and the outer edge 12 of the plate member, it means the side closer to the central position Xc with respect to the first contact portion t1.

[0055] By pressing the second contact portion t2, which is located at a distance L1 inward from the first contact portion t1, the spacer 2 can further press the disc spring 1, causing the end of the disc spring 1 to elastically deform. Incidentally, the first contact portion t1 is not necessarily formed at the corner of the end face 12a of the outer edge 12, but may also be formed at a position spaced at a distance L2 from the end face 12a, as shown in the enlarged view of Figure 7(b). With this configuration, the first contact portion t1 is reliably formed near the edge of the disc spring 1. To achieve this, for example, the inner edge 11 or outer edge 12 of the disc spring 1 can be chamfered.

[0056] The elastic deformation that follows the state shown in Figure 7(b) continues until the spacers 2 come into contact with each other or until the disc springs 1 come into contact with each other in the range from the end face 12a of the outer edge 12 to the second contact point t2, as shown in Figure 7(c). This deformation mode is referred to as the second mode. Furthermore, the spring constant of the disc springs 1, as defined by this elastic deformation, increases as the distance L1 decreases, requiring a greater force to bend the disc springs 1.

[0057] Figure 8 shows the relationship between the displacement of spring member b in Figure 7 and the load. Each point in Figure 8 corresponds to the state shown in Figure 7. Three regions are defined here.

[0058] From the origin point a to point b, this is the region where all the disc springs 1 deform in a first mode, separated from each other. The disc springs 1 are supported by the second contact portion t2 near the inner edge 11 and outer edge 12, and their spring constants are smallest.

[0059] From point b to point c, this is the second mode region where, after all the disc springs 1 have come into contact at the first contact point t1, bending deformation is applied at the second contact point t2 near the inner edge 11 and outer edge 12 of the disc springs 1. Beyond point b, the degree of increase in load relative to the displacement of the disc springs 1 clearly increases.

[0060] Point c represents the state where the inner edge 11 and outer edge 12 of the disc spring 1 are in contact over a distance L1 (Figure 7(c)). From this point onward, there is no further compression deformation of the disc spring 1, and the first spring b1 and the second spring b2 become similar in structure to rigid bodies, with only the load increasing in response to the compressive force.

[0061] Figure 9 shows an example of the damping characteristics of a shock absorber A in which a valve V, sandwiched between the first spring b1 and the second spring b2 as described above, is mounted inside a piston P. The horizontal axis represents the movement speed of the piston P, and the vertical axis represents the damping force of the shock absorber A.

[0062] The valve V and piston P are configured such that the communication area between the first discharge portion p11 on the piston P and the first window portion w1 on the valve V changes according to the relative distance traveled between the piston P and the valve V, and the communication area between the two decreases as the distance traveled by the valve V increases. Two examples with different degrees of reduction in the communication area are then provided.

[0063] Characteristic 1 in Figure 9 represents the case where the reduction in the communication area is small when the valve V moves. In this case, the dashed line represents the characteristics before the displacement of the valve V, and the solid line represents the characteristics after the displacement. Even when the valve V is displaced, the change in the amount of fluid flowing through the first chamber r1 and the second chamber r2 of the piston P is small. Therefore, the piston P can move more easily at a constant speed, and the damping effect of the shock absorber A is reduced.

[0064] On the other hand, characteristic 2 in Figure 9 represents the case where the reduction in the communication area is large when the valve V moves. The dashed line represents the characteristics before the displacement of the valve V, and the solid line represents the characteristics after the displacement. In this case, the amount of fluid flowing through the first chamber r1 and the second chamber r2 decreases significantly as the displacement of the valve V increases. Consequently, the movement of the piston P encounters resistance, and the damping effect of the shock absorber A increases.

[0065] Furthermore, in the case of characteristic 2, the damping effect changes according to the deformation of the first spring b1 and the second spring b2, and points b and c appear in Figure 9, corresponding to the appearance of points b and c in Figure 8.

[0066] As described above, by providing a first contact portion t1 and a second contact portion t2 on the disc spring 1 that constitutes the first spring b1 and the second spring b2, the spring constants of the first spring b1 and the second spring b2 can be increased in multiple modes. As a result, the movement speed of the piston P relative to the cylinder S is well controlled, and a shock absorber A with a large range of damping effect can be obtained.

[0067] Although not shown in the diagram, the spring constants of the first spring b1 and the second spring b2 can be further adjusted by changing the distance L1 between the first contact point t1 and the second contact point t2, for example. This setting can be adjusted by changing the shape of the spacer 2 that contacts each individual disc spring 1. Two types of spacers 2 are used for the inner edge spacer 21 and outer edge spacer 22 used for the first spring b1, each with a different distance L1.

[0068] More specifically, for spacers 2 that face each other to sandwich two disc springs 1, the second contact portions t2 of each spacer that sandwich the two disc springs 1 are configured to face each other at the same position. However, the distance L1 of the inner circumferential pressing portion t21 formed on the inner edge spacer 21 to press the inner edges 11 together and the distance L1 of the outer circumferential pressing portion t22 formed on the outer edge spacer 22 to press the outer edges 12 together are set to different values.

[0069] With this configuration, the number of contact modes between the disc springs 1 in the second mode that occur during the compression process of the first spring b1 increases. By arbitrarily designing the compression characteristics of the first spring b1 and the second spring b2 in this way, a shock absorber A that is highly adaptable to various conditions can be obtained.

[0070] [Third Embodiment] Figure 10 shows a configuration in which the contact state of the spacer 2 with respect to the outer edge 12 of the disc spring 1 is changed according to the degree of compression of the disc spring 1. Specifically, in a cross-section of the disc spring 1 and spacer 2 with respect to the axis X, the setting positions of the inner circumferential pressing portion t21 and the outer circumferential pressing portion t22 with respect to the disc spring 1 are configured on a curved surface 23.

[0071] In this configuration, as shown in Figures 10(a) to 10(c), the disc spring 1 undergoes elastic deformation in response to the pressing displacement of the spacer 2, and the outer peripheral pressing portion t22 of the spacer 2 moves closer to the first contact portion t1 of the disc spring 1. The shorter the distance L1 between the second contact portion t2 and the first contact portion t1, which are identified by the outer peripheral pressing portion t22, the greater the force required to elastically deform the disc spring 1.

[0072] As the position of the second contact point t2 shifts, the bends in the characteristic curve, such as points b and c shown in Figure 8, are eliminated, and the characteristic curve changes continuously like a quadratic curve, as shown in Figure 11. Points a to c in Figure 11 correspond to the states shown in Figure 10. The dashed line in the figure is shown for comparison and is the same curve as in Figure 8.

[0073] Furthermore, even in this configuration, some bending characteristics remain at point b, where the deformation mode of the disc spring 1 changes from the first mode to the second mode. With this configuration, for example, even when the piston P attempts to displace rapidly, the piston P is gradually decelerated, and the damping effect of the shock absorber A increases smoothly. Therefore, a shock absorber A that reproduces a good ride comfort can be obtained regardless of the degree of unevenness of the road surface.

[0074] [Fourth Embodiment] As shown in Figure 12, a region can be provided in a part of the disc spring 1 that constitutes the spring member b, where identical disc springs 1 are stacked on top of each other. For example, in addition to the basic region where one disc spring 1 is arranged opposite each other as in the above embodiment, a stacked region can be provided where a parallel spring 1A, which is constructed by stacking three disc springs 1, is arranged opposite each other.

[0075] In this case, the spring constant of the overlapping region becomes larger than the spring constant of the basic region. For example, the combined spring constant k of n disc springs 1, each with different spring constants k1 to kn, arranged in parallel can be calculated using the following formula. k = k1 + k2 + ... + kn Equation (b)

[0076] Therefore, the spring constant of spring member b in this configuration can be determined by first calculating the spring constants of each parallel spring, and then using these spring constants along with the spring constant of single spring 1B to obtain formula (i). With this configuration, the change in the spring constant during compression of the first spring b1, etc., is as shown in Figure 13.

[0077] Points a to e in Figure 13 correspond to the states shown in Figure 12. Point b in Figure 13 is the state where the single springs 1B, which constitute the disc spring 1 of the basic region, come into contact sequentially, until all of the single springs 1B are in contact. When the first spring b1, etc., is further compressed, the parallel springs 1A with large spring constants that constitute the overlapping region come into contact sequentially, and point c is the state where all of the parallel springs 1A are in contact. When the first spring b1, etc., is further compressed, the single springs 1B that constitute the basic region, which are in contact with each other, undergo elastic deformation in the second mode, and point d is the state where the possible elastic deformation has been completed. Next, point e is the state where the elastic deformation in the second mode has been completed for the parallel springs 1A of the overlapping region. After that, the first spring b1, etc., become a single rigid body, and the first spring b1 does not undergo compressive deformation, only the load increases.

[0078] In this way, by changing the stacking state of the disc spring 1, the relationship between the displacement of the valve V and the load required for that displacement can be divided into multiple regions. Therefore, the degree of freedom in setting the spring constant related to the first spring b1, etc., is increased, and a shock absorber A that can meet various requirements can be provided.

[0079] [Fifth Embodiment] As shown in Figure 14, an actuator a and an operating rod a1 for rotating the valve V are provided inside the piston P, and the communication area between the first window portion w1 and the first discharge portion p11, and the communication area between the second window portion w2 and the second discharge portion p21 are limited to a part in the circumferential direction. By changing the rotational phase of the first window portion w1 provided on the valve V, the communication area between, for example, the first window portion w1 and the first discharge portion p11 when the valve V moves can be adjusted along the circumferential direction, thereby allowing for more detailed setting of the damping effect of the shock absorber A.

[0080] Vehicles equipped with the shock absorber A are fitted with acceleration sensors, etc., and the rotational phase of the valve V is controlled based on acceleration information obtained while the vehicle is in motion. The rotational phase of the valve V is controlled according to the road surface irregularities, such as when there are large bumps and the jolt is large, or when the road surface irregularities are small and the vehicle vibrates in small increments, and the area of ​​communication between the first window portion w1 of the valve V and the first discharge portion p11 of the piston P during the vertical movement of the valve V is adjusted.

[0081] When the communication area is large and the fluid flow rate is set high, the up-and-down movement of the piston P relative to the cylinder S becomes easier, and the damping effect can be set to be soft. On the other hand, when the communication area is small and the fluid flow rate is set low, the up-and-down movement of the cylinder S becomes more difficult, and the damping effect can be set to be hard.

[0082] As in this configuration, if it is possible to set the movement characteristics of the piston P in addition to setting the spring constant of the valve V, a shock absorber A with even greater freedom in setting the damping characteristics can be obtained.

[0083] [Sixth Embodiment] As shown in Figure 15, the spring member b of this embodiment can also be used in a shock absorber A having a conventional configuration. The shock absorber A comprises a cylindrical cylinder S having an axis X, and a cylindrical piston P connected to a rod Pa and provided to be reciprocally movable along the inner wall of the cylinder S, dividing the inside of the cylinder S into a first outer chamber R1 and a second outer chamber R2.

[0084] Within the cylinder S, a first spring b1 and a second spring b2 are positioned on either side of the piston P. A predetermined gap is maintained between the piston P and the first spring b1, and between the piston P and the second spring b2, so that these spring members b do not function when the piston P moves back and forth a small distance from the reference position. As a result, when vibrations are small, it functions as a normal shock absorber A. On the other hand, when the displacement of the piston P is large and the acceleration is greater than a predetermined value, the damping effect is changed by activating either the first spring b1 or the second spring b2.

[0085] With this configuration, even a standard type shock absorber A can achieve the desired spring constant, and a shock absorber A can be obtained that can appropriately change the damping force in response to the applied external force. [Industrial applicability]

[0086] The spring member and shock absorber using the spring member of the present invention can be widely used in devices in which a spring-biased valve reciprocates inside a piston, and the damping force can be set by adjusting the flow rate of the working oil circulating inside the piston. [Explanation of symbols]

[0087] 1. Disc spring 11 Common-law marriage 12 Outer edge 2 Spacers 21 Inner edge spacer 22 Outer edge spacer 23 Curved surface A Shock absorber b1 First spring b2 Second spring f1 convex f11 Convex inner circumferential surface f12 Convex outer surface f2 concave f21 Concave inner circumferential surface f22 concave outer surface L1 Distance between the first contact point and the second contact point P Piston p1 1st port p11 1st discharge section p2 2nd port p21 2nd discharge section R1 1st outer room R2 2nd outer room r1 1st interior room r2 2nd interior room S Cylinder t1 1st contact part t2 2nd contact part t21 Inner circumference pressing part t22 Outer circumference pressing part V-valve v1 1st aperture v2 2nd aperture w1 First Window Section w2 Second Window Section X-axis center

Claims

1. It is an annular shape having an inner edge and an outer edge, and comprises a convex surface on the side where the inner edge protrudes more than the outer edge along the axis, and a concave surface on its back surface, Of the aforementioned convex surfaces, the surface near the inner edge is designated as the convex inner circumferential surface, and the surface near the outer edge is designated as the convex outer circumferential surface, Multiple disc springs, each having a concave surface with the inner edge near the concave inner circumferential surface and the outer edge near the concave outer circumferential surface, are arranged in series with the convex surfaces facing each other and the concave surfaces facing each other. Spacers are placed at least between the convex outer surfaces and between the concave inner surfaces. A spring member in which, when the disc spring is unloaded, the opposing convex inner surfaces and the concave outer surfaces are spaced apart.

2. The spacer comprises an outer edge spacer provided between the convex outer surfaces and an inner edge spacer provided between the concave inner surfaces. When multiple disc springs are subjected to a pressing force along the axis, The convex inner surfaces are close together and their respective inner edges are in contact with each other, and the inner pressing portion provided on the inner edge spacer presses on the recessed inner surface at a position spaced apart from the inner edge. The spring member according to claim 1, wherein the concave outer surfaces are close together and their respective outer edges are in contact with each other, and the outer pressing portion provided on the outer edge spacer is configured to press on the convex outer surface at a position spaced apart from the outer edge.

3. The spring member according to claim 2, wherein the inner edge spacer and the outer edge spacer are provided with curved surfaces on which the inner circumferential pressing portion and the outer circumferential pressing portion are sequentially formed, such that in response to the compression deformation of the disc spring due to the pressing of the spacer, the inner circumferential pressing portion approaches the inner edge and the outer circumferential pressing portion approaches the outer edge.

4. A cylindrical cylinder having an axis, A cylindrical piston is connected to a rod and is provided to be reciprocally movable along the inner wall of the cylinder, dividing the inside of the cylinder into a first outer chamber and a second outer chamber, The piston is equipped with a valve, which is held between a first spring and a second spring inside the piston and normally maintained at a reference position along the axis, and which divides the inside of the piston into a first chamber and a second chamber. The piston has, A first port connecting the first outer chamber and the first inner chamber, A second port connecting the second outer chamber and the second inner chamber, A first discharge section is formed on a part of the piston along its circumferential direction to discharge the fluid in the first inner chamber to the second outer chamber, A second discharge portion is provided, which is formed on a part of the piston along the circumferential direction to discharge the fluid in the second inner chamber to the first outer chamber. The aforementioned valve includes: A first opening that communicates with the first interior chamber, As the valve moves from the reference position towards the second inner chamber, a first window portion is formed that connects the first inner chamber to the first discharge portion. A second opening that communicates with the second interior chamber, A second window is provided which, when the valve moves from the reference position towards the first inner chamber, connects the second inner chamber to the second discharge section. A shock absorber in which the spring members described in any one of claims 1 to 3 are arranged as the first spring and the second spring.

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