Pressure damping device and elastic member

Abstract

Pressure damping device (1) comprising: a cylinder (11) in which a fluid is accommodated; a rod (21) having a first end and a second end movable in an axial direction of the cylinder (11), the first end being housed in the cylinder (11) and the second end protruding from an opening of the cylinder (11); and a damping force generating unit (100) which generates a damping force by a movement of the rod (21), wherein the damping force generating unit (100) comprises: a flow channel forming portion (30) formed with a flow channel (32) through which the fluid flows in conjunction with the movement of the rod (21); an opening / closing member (52) that opens and closes the flow channel (32) in the flow channel forming portion (30); an annular ring member (53) provided on a side of the opening / closing member (52) opposite to a side thereof facing the flow channel forming portion (30); and a biasing spring (54) provided on a side of the ring valve (53) opposite to a side thereof facing the opening / closing member (52), the biasing spring (54) comprising: a radially extending pressing portion (541) which contacts a side of the ring member (53) opposite to a side thereof facing the opening / closing member (52) and which presses the ring member (53) toward the opening / closing member (52), and a positioning portion (542) extending radially and having a length in a radial direction shorter than a protrusion length of the pressing portion (541) in the radial direction, which contacts an inner periphery of an opening (53N) of the ring member (53) and determines a position of the ring member (53), wherein the flow channel forming portion (30) comprises a first flow channel portion (32) forming a flow of the fluid flowing from one side to the other side in an axial direction, and a second flow channel portion (33) forming a flow of the fluid flowing from the other side to the one side in the axial direction, and wherein the opening / closing member (52) is provided on the other side of the flow channel forming portion (30), and wherein the opening / closing member (52) comprises: - a cover section (522) which opens and closes the other side of the first flow channel section (32) and - an opening portion (521) which opens the other side of the second flow channel portion (33), wherein the positioning portion (542) engages with the opening portion (521) to determine the position of the ring member (53) in the radial direction without completely closing the opening portion (521).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to a pressure damping device and an elastic member. 2. Description of the state of the art

[0002] Pressure damping devices that generate a damping force using a fluid to perform damping are known.For example, JP 2008-248956 A discloses a technique relating to a pressure damping device provided with a valve structure comprising: a valve disc on which an inlet is formed; a flap valve constructed by laminating a plurality of ring flaps and laminated on the valve disc with an inner peripheral side as a fixed end for opening and closing the inlet; and a biasing member having a thick-walled outer periphery, which is disposed between the ring flaps and which transmits an initial deflection to the flap valve, wherein the biasing member comprises a thin-walled small-diameter inner peripheral ring, a thick-walled outer peripheral ring having an inner diameter larger than an outer diameter of the inner peripheral ring, and at least one thin-walled arm connecting the inner peripheral ring and the outer peripheral ring.

[0003] JP H07- 41 095 U shows a valve structure of a hydraulic shock absorber. SUMMARY

[0004] If a ring link formed in a ring shape is provided, the ring link must be positioned. In this case, the ring link can conceivably be connected to another link opposite the ring link, for example. However, there is a risk that the ring link and the other link could become detached from each other, causing the ring link to shift.

[0005] An object of the present invention is to stabilize a position of a ring member used in a pressure damping device.

[0006] To achieve the above-described object, the present invention provides a pressure damping device comprising: a cylinder in which a fluid is accommodated; a rod having one end accommodated in the cylinder on one side (hereinafter also referred to as "one end") and another end protruding from an opening of the cylinder and moving in an axial direction of the cylinder (hereinafter also referred to as "the other end") on the other side; and a damping force generating unit that generates a damping force by a movement of the rod, the damping force generating unit comprising: a flow channel forming portion formed with a flow channel through which the fluid flows in association with the movement of the rod; an opening / closing member that opens and closes the flow channel in the flow channel forming portion;an annular ring member provided on the opening / closing member on a side opposite to a side opposite to the flow channel forming portion; and an elastic member in the form of a biasing spring having a positioning portion extending radially and determining a position of the ring member in a radial direction.

[0007] According to the present configuration, a position of the ring member can be stabilized by the radially extending bias spring.

[0008] Furthermore, to achieve the above-described object, the present invention provides an elastic member in the form of a bias spring which is adapted to be disposed opposite to a ring member used in a compression damping device which generates a damping force in association with a movement of a rod with respect to a cylinder, the bias spring comprising: a ring portion having a through-hole traversing the rod; a plurality of first protrusion portions formed to radially extend from the ring portion; and a second protrusion portion formed to radially extend from the ring portion and having a shorter protrusion length in a radial direction than the first protrusion portions.

[0009] According to the present invention, a position of a ring member used in a pressure evaporation apparatus can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an overall configuration diagram of a hydraulic damping device according to a first embodiment; Fig. 2 is a diagram showing a piston body according to the first embodiment; Fig. 3 is an explanatory view of a compression-side valve group according to the first embodiment; Fig. 4 is an explanatory view of a bias spring according to the first embodiment; Fig. 5A to 5C are diagrams showing an assembled state of the bias spring according to the first embodiment; Fig. 6A and Fig. 6B are diagrams showing an oil flow in a piston portion of the hydraulic damping device according to the first embodiment; Fig. 7 is an overall view of a piston portion according to a first modification; Fig. 8 is an exploded perspective view of a compression-side valve group according to a second modification; Fig. 9A and Fig. 9B are explanatory views of a hydraulic damping device according to a third modification; Fig. 10 is an explanatory view of a hydraulic damping device according to a second embodiment; and Fig. 11 is an overall view of a hydraulic damping device according to a third embodiment. DETAILED DESCRIPTION

[0010] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. < First embodiment >

[0011] Fig. 1 is an overall configuration diagram of a hydraulic damping device 1 according to the first embodiment.

[0012] In the following description, a longitudinal direction of the Fig. 1 is referred to as an "axial direction". In addition, a bottom side of the hydraulic damping device 1 in the axial direction is referred to as "one side" in the following description, and a top side of the hydraulic damping device 1 in the axial direction is referred to as "another side". Furthermore, a direction of the Fig. 1, from left to right, is referred to as “radial direction”, a side of a central axis is referred to as “inside”, and a side extending from the central axis is referred to as “outside”. [Configuration of hydraulic damping device 1]

[0013] First, a configuration of the hydraulic damping device 1 according to the first embodiment will be described.

[0014] As in Fig. 1, the hydraulic damping device 1 according to the first embodiment includes a first cylinder 11 and a second cylinder 12 in which oil is accommodated, a piston rod 21, a part of which enters the first cylinder 11 and is movable in the axial direction, a piston portion 100 fixed to the piston rod 21 and moving on an inner side of the first cylinder 11, and a lower valve portion 60 provided in a lower portion of one side of the first cylinder 11. [Configurations of the first cylinder 11 and the second cylinder 12]

[0015] As in Fig. 1, the hydraulic damping device 1 has a so-called double-pipe structure in which the first cylinder 11 and the second cylinder 12 are provided sequentially from the inside to the outside in the radial direction.

[0016] One end (lower portion) on one side of the first cylinder 11 is blocked by the lower valve portion 60. Furthermore, one end on one side of the second cylinder 12 is blocked by a lower cover 13. On the other hand, ends (upper portions) on the other side of the first cylinder 11 and the second cylinder 12 are blocked by a rod guide 14, an oil seal 15, and a cap 16 so as to allow the piston rod 21 to pass through. Furthermore, a reservoir chamber R, which is a space having a cylindrical shape, is formed between the first cylinder 11 and the second cylinder 12. Oil is accommodated in the reservoir chamber R, and at the same time, gas on the other side of the reservoir chamber R is sealed. [Configuration of piston rod 21]

[0017] The piston rod 21 is configured such that a portion on one side enters the first cylinder 11, a remaining portion on the other side is exposed outside the first cylinder 11, and the piston rod 21 is movable in the axial direction. Furthermore, the piston rod 21 is provided with the piston portion 100 at one of its ends on one side. Furthermore, the piston rod 21 and the piston portion 100 move integrally in the axial direction. Furthermore, the piston portion 100 is configured to be movable in the axial direction along an inner peripheral surface of the cylinder. [Configuration of piston section 100]

[0018] The piston portion 100 includes a piston body 30 in which a plurality of oil passages (described below) are formed, which lead into the piston body 30 in the axial direction, an extension-side valve group 40 provided on one side of the piston body 30, a compression-side valve group 50 provided on the other side of the piston body 30, an extension-side valve plug 110 provided on one side of the extension-side valve group 40, and a compression-side valve plug 120 provided on the other side of the compression-side valve group 50.

[0019] In addition, the piston portion 100 divides an inside space of the first cylinder 11 into a first oil chamber Y1, which is a space on one side (a lower side in Fig. 1) in the axial direction, and a second oil chamber Y2, which is a space on the other side (an upper side in Fig. 1) in the axial direction. [Configuration of the lower valve section 60]

[0020] The lower valve portion 60 includes a valve body 61 having a plurality of compression-side lower oil passages 611 leading into the lower valve portion 60 in an axial direction, and a plurality of rebound-side lower oil passages 612 leading into the lower valve portion 60 in an axial direction, on the outer side of the compression-side lower oil passages 611 in the radial direction, a compression-side lower valve 621 provided on one side of the valve body 61, and an rebound-side lower valve 622 provided on the other side of the valve body 61. Furthermore, the rebound-side lower valve 622 includes an oil hole 622R at a location corresponding to the compression-side lower oil passages 611 in the radial direction.

[0021] Furthermore, the lower valve portion 60 is formed at one end and separates the first oil chamber Y1 and the reservoir chamber R from each other.

[0022] Next, the piston portion 100 (the piston body 30, the extension-side valve group 40, and the compression-side valve group 50) will be described in detail.

[0023] Fig. Fig. 2 is a sectional view showing the piston body 30 according to the first embodiment.

[0024] Fig. 3 is an explanatory view of the compression-side valve group 50 according to the first embodiment.

[0025] As in Fig. 1 and Fig. 2, the hydraulic damping device 1 (a pressure damping device) includes the first cylinder 11 (a cylinder) in which oil (a fluid) is accommodated, the piston rod 21 (a rod) of which one end on one side is accommodated in the first cylinder 11 and one end on the other side protrudes from an opening of the first cylinder 11 and which moves in the axial direction of the first cylinder 11, and the piston portion 100 (a damping force generating unit) that generates a damping force by a movement of the piston rod 21.Furthermore, the piston portion 100 includes the piston body 30 (a flow passage forming portion) in which a compression-side oil passage 32 (a flow passage) is formed, through which oil flows in association with a movement of the piston rod 21, a base valve 52 (an opening / closing member) that opens and closes the compression-side oil passage 32 of the piston body 30, an annular ring valve 53 (one form of a ring member) provided on the base valve 52 on a side opposite to a side opposite to the piston body 30, and a bias spring 54 (a protruding member) that extends radially and has a positioning portion 542 (a positioning portion) that determines a position of the ring valve 53 in the radial direction. The respective components are described in detail below. [Configuration of the piston body 30]

[0026] As in Fig. 2, the piston body 30 includes a through hole 31 extending in the axial direction, the compression-side oil passage 32 formed in the axial direction in the piston body 30, an extension-side oil passage 33 formed in the axial direction in the piston body 30, and a piston ring 34 provided on the outside in the radial direction.

[0027] The through hole 31 is a roughly cylindrical hole. Furthermore, a fastening portion 21a of one side of the piston rod 21 is inserted into the through hole 31.

[0028] The compression-side oil passage 32 includes a compression-side first oil passage inlet 321 opening to the first oil chamber Y1 on one side and a compression-side second oil passage inlet 322 opening to the second oil chamber Y2 on the other side. Furthermore, in the present embodiment, the compression-side oil passage 32 forms a path for oil flowing from the first oil chamber Y1 to the second chamber Y2 during the compression stroke (described below). Furthermore, in the present embodiment, the compression-side oil passage 32 is provided at a plurality of locations (eight locations in the present embodiment) at approximately equal intervals in a circumferential direction of the piston body 30.

[0029] The rebound-side oil passage 33 includes a rebound-side first oil passage inlet 331 opening to the first oil chamber Y1 on one side and a rebound-side second oil passage inlet 332 opening to the second oil chamber Y2 on the other side. Furthermore, the rebound-side oil passage 33 forms a path for oil flowing from the second oil chamber Y2 to the first oil chamber Y1 during a rebound stroke (described below). Furthermore, in the present embodiment, the rebound-side oil passage 33 is provided at a plurality of locations (eight locations in the present embodiment) at approximately equal intervals in a circumferential direction of the piston body 30.

[0030] The piston ring 34 is provided on an outer periphery of the piston body 30. Furthermore, the piston ring 34 is provided to be in sliding contact with an inner peripheral surface of the first cylinder 11. Furthermore, the piston ring 34 reduces frictional resistance with the first cylinder 11. (Rebound side valve group 40)

[0031] As in Fig. 2, the rebound-side valve group 40 includes a rebound-side slit valve 41 having a passage 41S on an outer periphery thereof, a plurality of rebound-side damping valves 42 provided on one side of the rebound-side slit valve 41, a rebound-side first valve seat 43 provided on one side of the plurality of rebound-side damping valves 42, and a rebound-side second valve seat 44 provided on one side of the rebound-side first valve seat 43. Moreover, the rebound-side first valve seat 43 and the rebound-side second valve seat 44 act as deflection fulcrums when the rebound-side damping valves 42 deform. (Compression-side valve group 50)

[0032] As in Fig. 2 and Fig. 3, the compression-side valve group 50 includes a compression-side slit valve 51, the base valve 52 provided on the other side of the compression-side slit valve 51, the ring valve 53 provided on the other side of the base valve 52, the bias spring 54 provided on the other side of the ring valve 53, a compression-side first valve seat 55 provided on the other side of the bias spring 54, and a compression-side second valve seat 56 provided on the other side of the compression-side first valve seat 55.

[0033] As in Fig. 3, the compression-side slit valve 51 is a disc-shaped metallic member having a through hole 51H for passing the fixing portion 21a on one side (see Fig. 2) of the piston rod 21. In addition, the compression-side slit valve 51 includes an oil hole 511 and a cover portion 512.

[0034] The oil hole 511 is formed at multiple locations (three locations in the present embodiment) in a circumferential direction of the compression-side slit valve 51. The piston body 30 according to the first embodiment includes the compression-side oil passages 32 (first flow passage portions) that form an oil flow from the first oil chamber Y1 to the second oil chamber Y2, and the rebound-side oil passages 33 (second flow passage portions) that form an oil flow from the second oil chamber Y2 to the first oil chamber Y1. Moreover, the oil holes 511 are respectively formed at positions opposite to the rebound-side second oil passage inlets 332 of the rebound-side oil passages 33 (see Fig. 2). In other words, the oil holes 511 (opened portions) always open the rebound-side second oil passage inlets 332 (the other side of the rebound-side oil passages 33).

[0035] On the other hand, the cover portion 512 is a portion formed in an annular shape on the outer side of the oil holes 511 in the radial direction of the jounce-side slit valve 51. Moreover, the cover portion 512 is formed at a position opposite the jounce-side second oil passage inlets 322 of the jounce-side oil passages 32. Furthermore, the cover portion 512 opens and closes the jounce-side second oil passage inlets 322 according to an oil flow at the jounce-side second oil passage inlets 322.

[0036] Furthermore, the compression-side slit valve 51 includes a passage 51S on an outer periphery of the compression-side slit valve 51. The passage 51S is formed in a notched shape in a part of the cover portion 512. Furthermore, the passage 51S is formed to oppose the compression-side second oil passage inlets 322 of the compression-side oil passages 32 (see Fig. 2).

[0037] The base valve 52 is a disc-shaped metallic member having a through hole 52H for passing the one-side fixing portion 21a (see Fig. 2) of the piston rod 21. In addition, the base valve 52 includes an oil hole 521 and a cover portion 522.

[0038] Furthermore, the oil hole 521 is formed at a plurality of locations (three locations in the present embodiment) in a circumferential direction of the base valve 52. Furthermore, the oil holes 521 are each formed at positions opposite to the rebound-side second oil passage inlets 332 of the rebound-side oil passages 33 (see Fig. 2). In other words, the oil holes 521 always open the extension-side second oil passage inlets 332, with the oil holes 511 of the compression-side slit valve 51 positioned therebetween.

[0039] On the other hand, the cover portion 522 is a portion formed in an annular shape on the outer side of the oil holes 521 in the radial direction of the base valve 52. Moreover, the cover portion 522 is formed at a position opposite the compression-side second oil passage inlets 322 of the compression-side oil passages 32. Furthermore, the cover portion 522, together with the compression-side slit valve 51, opens and closes the compression-side second oil passage inlets 322 according to an oil flow at the compression-side second oil passage inlets 322.

[0040] The ring valve 53 is a metallic member formed in a ring shape and including an opening 53N on the inner side in the radial direction. An outer diameter of the ring valve 53 is approximately equal to an outer diameter of the base valve 52. Moreover, an inner diameter of the ring valve 53 is made larger than an outer side edge in the radial direction of the oil holes 521 of the base valve 52. In other words, the ring valve 53 is configured so as not to block the oil holes 521 of the base valve 52.

[0041] The bias spring 54 is a disc-shaped metallic member having a through hole 54H for passing through the fixing portion 21a on one side (see Fig. 2) of the piston rod 21. Furthermore, the biasing spring 54 is an elastic member having an elastic force. Further, the biasing spring 54 includes a ring portion 540 provided on the inner side in the radial direction and in which the through hole 54H is formed, a plurality of pressing portions 541 (five in the present embodiment) formed on the outer side in the radial direction with respect to the ring portion 540, and a plurality of positioning portions 542 (five in the present embodiment) formed on the outer side in the radial direction with respect to the ring portion 540.

[0042] Furthermore, the preload spring 54 will be described below with reference to Fig. 4 to 5C are described in detail.

[0043] The jounce-side first valve seat 55 is an annular metallic member having a through hole 55H for passing the fixing portion 21a on one side of the piston rod 21. An outer diameter of the jounce-side first valve seat 55 is smaller than the jounce-side slit valve 51 and the base valve 52. Moreover, in the present embodiment, the jounce-side first valve seat 55 forms a space when the jounce-side slit valve 51 and the base valve 52 deform, and simultaneously acts as a deflection fulcrum when the jounce-side slit valve 51 and the base valve 52 deform.

[0044] The jounce-side second valve seat 56 is an annular metallic member having a through hole 56H for passing the fixing portion 21a on one side of the piston rod 21. An outer diameter of the jounce-side second valve seat 56 is smaller than the jounce-side first valve seat 55. Moreover, in the present embodiment, the jounce-side second valve seat 56 forms a space when the jounce-side first valve seat 55, the jounce-side slit valve 51, and the base valve 52 deform, and simultaneously acts as a deflection fulcrum when the jounce-side first valve seat 55, the jounce-side slit valve 51, and the base valve 52 deform. (Extension-side valve plug 110, compression-side valve plug 120)

[0045] As in Fig. 2, the piston rod 21 passes through a central part of the rebound-side valve plug 110, and the rebound-side valve plug 110 is formed smaller than the rebound-side damping valve 42 and prevents deformation of the rebound-side damping valve 42 to one side beyond the rebound-side valve plug 110.

[0046] The piston rod 21 passes through a central part of the compression-side valve plug 120, and the compression-side valve plug 120 is formed with an outer diameter approximately equal to those of the compression-side slit valve 51 and the base valve 52, and prevents the compression-side slit valve 51 and the base valve 52 from deforming further to one side than the compression-side valve plug 120. Furthermore, the compression-side valve plug 120 includes a plurality of oil passages 122. In the present embodiment, the oil passages 122 are provided at positions opposite to the rebound-side second oil passage inlets 332 of the rebound-side oil passages 33. - Preload spring 54 -

[0047] Fig. 4 is an explanatory view of the bias spring 54 according to the first embodiment.

[0048] Fig. 5A to 5C are diagrams showing an assembled state of the bias spring 54 according to the first embodiment.

[0049] As in Fig. 4, an outer diameter of the ring portion 540 is formed smaller than an inner diameter of the ring valve 53. Furthermore, in the present embodiment, the outer diameter of the ring portion 540 is formed to be located further inside in the radial direction than the oil holes 521 of the base valve 52.

[0050] As in Fig. 4, the pressing portions 541 are formed to protrude toward the outside in the radial direction. In other words, the pressing portions 541 are formed to extend radially. Moreover, in the present embodiment, the plurality of pressing portions 541 are arranged at approximately equal intervals in the circumferential direction. Further, an outline of each of the pressing portions 541 is formed in an approximately rectangular shape. In other words, the pressing portions 541 are formed with approximately equal widths in the radial direction. Furthermore, the ends 541P of the pressing portions 541 are formed in approximately straight lines.

[0051] In addition, the ends 541P of the respective pressing portions 541, as shown in Fig. 5A and Fig. 5B, positioned further to the outside than the opening 53N of the ring valve 53. Thus, in a state where the biasing spring 54 is assembled, the plurality of pressing portions 541 are positioned so that the pressing portions 541 overlap with the ring valve 53 on the other side of the ring valve 53. Furthermore, the biasing spring 54, as shown in Fig. 5B, is inserted between the base valve 52 and the compression-side first valve seat 55 in the annular portion 540 on the inner side in the radial direction. Thus, the bias spring 54 urges the annular valve 53 toward one side by means of the plurality of urging portions 541.

[0052] Specifically, the biasing spring 54 is pressed by the ring portion 540 against the base valve 52, which is positioned on one side of the ring portion 540 as described above. Meanwhile, the end 541P side of the pressing portions 541 is engaged by the ring valve 53, which protrudes further to the other side than the base valve 52. As a result, in a deflection state, the pressing portions 541 come into contact with the ring valve 53. Thus, the biasing spring 54 applies, by means of an elastic force (restoring force) of the pressing portions 541, a force (load) that presses the base valve 52 against the piston body 30 via the ring valve 53, even in a state before the base valve 52 is deformed, as described below.

[0053] Furthermore, although the present embodiment employs a configuration in which five pressing portions 541 are provided, the number of pressing portions 541 is not limited to this example. The pressing portions 541 only need to press the ring valve 53 to one side, and for example, two or more pressing portions 541 may preferably be provided.

[0054] As in Fig. 4, the positioning portions 542 are formed to protrude toward the outside in the radial direction. In other words, the positioning portions 542 are formed to extend radially. Moreover, in the present embodiment, the plurality of positioning portions 542 are arranged at approximately equal intervals in the circumferential direction. Furthermore, the positioning portions 542 are each arranged between two adjacent pressing portions 541. In other words, the pressing portions 541 and the positioning portions 542 are alternately arranged in the circumferential direction in the present embodiment.

[0055] Furthermore, in the present embodiment, the positioning portions 542 are formed approximately in a tapered shape with a width decreasing toward the outside in the radial direction. The ends 542P of the positioning portions 542 (outer side ends) are formed approximately in a semicircular shape.

[0056] As in Fig. 5 A and Fig. 5C, the outer side ends 542P in the radial direction are formed to approximately correspond to an inner diameter of the opening 53N of the ring valve 53. In other words, a protrusion length of the positioning portions 542 in the radial direction is formed shorter than a protrusion length of the pressing portions 541 in the radial direction. Thus, the ends 542P of the positioning portions 542 come into contact with an inner periphery of the opening 53N of the ring valve 53. In addition, as in Fig. 5C, a thickness W1 of the positioning portions 542 according to the present embodiment is formed larger than a thickness W2 of the ring valve 53.

[0057] Thus, the plurality of positioning sections 542, as shown in Fig. 5 A and Fig. 5C, in a state where the biasing spring 54 is assembled, it is positioned to be located on approximately the same plane as the ring valve 53. Specifically, the positioning portions 542 are arranged at approximately the same height positions as the ring valve 53 on the other side of the base valve 52. In this case, a position, in the radial direction, of the biasing spring 54 itself is determined by the piston rod 21 on the inside. Thus, the biasing spring 54 determines a position of the ring valve 53 in the radial direction with the plurality of positioning portions 542.

[0058] In addition, the pressing portions 541 and the positioning portions 542 leave the oil holes 521 open as a whole, as shown in Fig. 4, although the pressing portions 541 and the positioning portions 542, which are formed to extend radially, partially overlap the oil holes 521 of the base valve 52. Furthermore, the biasing spring 54 allows a continuous flow of oil through the oil holes 521 of the base valve 52.

[0059] Furthermore, although the present embodiment employs a configuration in which five positioning portions 542 are provided, the number of positioning portions 542 is not limited to this example. The positioning portions 542 only need to position the ring valve 53 in the radial direction, and, for example, three or more positioning portions 542 may preferably be provided.

[0060] In addition, the thickness W1 of the positioning portions 542 in the Fig. 5C may correspond to the thickness W2 of the ring valve 53 or may be less than the thickness W2 of the ring valve 53.

[0061] Furthermore, a small gap may be provided between the positioning portions 542 and the inner diameter (the opening 53N) of the ring valve 53. [Operations of the hydraulic damping device 1]

[0062] Next, operations of the hydraulic damping device 1 according to the first embodiment will be described.

[0063] Fig. 6A and Fig. 6B are diagrams showing an oil flow in the piston portion 100 of the hydraulic damping device 1 according to the first embodiment. In particular, Fig. 6A an oil flow during a rebound stroke, and Fig. Figure 6B shows oil flow during a compression stroke. (During the rebound stroke)

[0064] During a rebound stroke of the hydraulic damping device 1, the piston rod 21 moves with respect to the first cylinder 11 to the other side in the axial direction (an upper side in Fig. 6A). With the movement of the piston rod 21, oil in the second oil chamber Y2 is compressed and negative pressure is generated in the first oil chamber Y1.

[0065] At this point, in a case where a moving speed of the piston rod 21 is at a speed called very low, the oil in the second oil chamber Y2 flows through the oil passage 122 of the compression-side valve plug 120, the oil holes 521 of the base valve 52, and the oil holes 511 of the compression-side slit valve 51, and into the rebound-side oil passages 33 of the piston body 30. Moreover, the oil that has flowed into the rebound-side oil passages 33 flows from the rebound-side first oil passage inlets 331 through the passage 41S of the rebound-side slit valve 41 and out to the first oil chamber Y1 (in Fig. 6A (arrow shown with a dashed line).

[0066] In addition, when the moving speed of the piston rod 21 is relatively high, the oil in the second oil chamber Y2 equally flows into the rebound-side oil passages 33 of the piston body 30. Further, the oil that has flowed into the rebound-side oil passages 33 flows out to the first oil chamber Y1 while opening the rebound-side damping valve 42, which closes the rebound-side first oil passage inlets 331 (in Fig. 6A (arrow shown with a solid line).

[0067] Furthermore, the oil in the reservoir chamber R opens, as in Fig. 1, the rebound side lower valve 622, which closes the rebound side lower oil passage 612 of the valve body 61, and flows into the first oil chamber Y1. (During the compression stroke)

[0068] During a compression stroke of the hydraulic damping device 1, the piston rod 21 moves with respect to the first cylinder 11 to one side in the axial direction (a lower side in Fig. 6B). The piston portion 100 fixed to the piston rod 21 compresses oil in the first oil chamber Y1 and causes an increase in pressure in the first oil chamber Y1.

[0069] At this point, when a moving speed of the piston rod 21 is at a speed called very low, the oil in the first oil chamber flows into the compression-side oil passages 32 of the piston body 30. Moreover, the oil that has flowed into the compression-side oil passages 32 flows from the compression-side second oil passage inlets 322 through the passage 51S of the compression-side slit valve 51 and out to the second oil chamber Y2 (in Fig. 6B (arrow shown with a dashed line).

[0070] In addition, when the moving speed of the piston rod 21 is relatively high, the oil that has flowed into the compression-side oil passages 32 flows out to the second oil chamber Y2 while opening the base valve 52, which closes the compression-side second oil passage inlets 322 (in Fig. 6B (arrow shown with a solid line).

[0071] Furthermore, the oil flows in the first oil chamber Y1, as in Fig. 1, in the lower valve portion 60 through the oil hole 622R of the extension-side lower valve 622 and into the compression-side lower oil passage 611. Further, the oil in the compression-side lower oil passage 611 opens the compression-side lower valve 621, which closes the compression-side lower oil passage 611, and flows from the first oil chamber Y1 into the reservoir chamber R.

[0072] Moreover, in the first embodiment, the base valve 52 deforms during a compression stroke, and when subsequently transitioning to a rebound stroke, the bias spring 54 instantly shifts the base valve 52 to one side, and the base valve 52 blocks the compression-side oil passages 32. Accordingly, the hydraulic damping device 1 according to the first embodiment can instantly provide for switching the hydraulic damping device 1 from a compression stroke to a rebound stroke and switching to the next compression stroke.

[0073] Furthermore, in the present embodiment, the bias spring 54 determines a position of the ring valve 53 in the radial direction. Accordingly, the position of the ring valve 53 in the radial direction is stably fixed even if the use of the hydraulic damping device 1 extends over a long period of time. < First modification >

[0074] Fig. 7 is an overall view of the piston portion 100 according to a first modification.

[0075] Next, the piston portion 100 according to the first modification will be described. Furthermore, in the first modification, components similar to those of the first embodiment are assigned the same numerals, and a detailed description of these components will be omitted.

[0076] As in Fig. 7, the hydraulic damping device 1 according to the first modification includes a rebound-side valve group 70 instead of the rebound-side valve group 40 according to the first embodiment. (Rebound-side valve group 70)

[0077] The rebound-side valve group 70 includes a base valve 72, a ring valve 73 provided on one side of the base valve 72, a bias spring 74 provided on one side of the ring valve 73, a rebound-side first valve seat 43 provided on one side of the bias spring 74, and a rebound-side second valve seat 44 provided on one side of the rebound-side first valve seat 43.

[0078] Basic configurations of the base valve 72, the ring valve 73, and the bias spring 74 according to the first modification are similar to those of the base valve 52, the ring valve 53, and the bias spring 54 according to the first embodiment.

[0079] The base valve 72 is a disc-shaped metallic member having a through hole 72H for passing the fixing portion 21a on one side (see Fig. 2) of the piston rod 21. Furthermore, the base valve 72 includes an oil hole 721. The oil hole 721 is formed at a position opposite to the rebound-side oil passages 33 and is smaller than a width (a flow passage cross-sectional area) of the rebound-side oil passages 33.

[0080] The ring valve 73 includes an opening 73N. The opening 73N is formed such that the oil hole 721 is not blocked.

[0081] The bias spring 74 includes a plurality of radially extending urging portions 741 and a plurality of radially extending positioning portions 742. Furthermore, the bias spring 74 urges the base valve 72 with the urging portions 741 via the ring valve 73 to one side of the piston body 30. Furthermore, the bias spring 74 determines a position of the ring valve 73 in the radial direction by means of the positioning portions 742.

[0082] With the piston portion 100 according to the first modification configured as described above, a damping force is generated by the compression-side valve group 50 during a compression stroke. Furthermore, a damping force is generated by the rebound-side valve group 70 during a rebound stroke. Specifically, the oil hole 721 of the base valve 72 is provided in the base valve 72 at a position opposite to the rebound-side oil passages 33. Thus, oil that has flowed into the rebound-side oil passages 33 flows through the oil hole 721 of the base valve 72. However, upon attempting to flow oil in an amount equal to or exceeding an amount permitted through the oil hole 721, the base valve 72 deforms and opens the rebound-side oil passages 33.In this way, the oil hole 721 provided on the base valve 72 with the piston portion 100 according to the first modification imparts its characteristics to the generated damping force.

[0083] Furthermore, in the first modification, the bias spring 74 adjusts the ease of opening of the base valve 72 when the urging portion 741 causes deformation of the base valve 72 to open the rebound-side oil passages 33. In other words, the urging portion 741 of the bias spring 74 adjusts a damping force (a so-called damping force rise time) in an initial phase during a rebound stroke. Furthermore, the bias spring 74 determines a position of the ring valve 73 in the radial direction with the positioning portion 742.

[0084] Furthermore, for example, the plurality of pressing portions 741 in the bias spring 74 according to the first modification may each have different shapes. Similarly, for example, the plurality of pressing portions 741 in the bias spring 74 according to the first modification may each have different widths. Accordingly, for example, when the bias spring 74 causes deformation of the base valve 72 due to oil, the generated damping force is imparted its characteristics by transmitting the change in the base valve 72 in the circumferential direction. <Zweite Modifikation>

[0085] Fig. 8 is an exploded perspective view of a compression-side valve group 350 according to a second modification.

[0086] Next, the piston portion 100 according to the second modification will be described. Furthermore, in the second modification, components similar to those of the first embodiment are assigned the same numerals, and a detailed description of these components will be omitted.

[0087] As in Fig. 8, the hydraulic damping device 1 according to the second modification includes a ring valve 83 instead of the ring valve 53 according to the first embodiment, and includes a second bias spring 81 and a positioning ring 82 instead of the bias spring 54 according to the first embodiment.

[0088] The ring valve 83 is a metallic member including an opening 83N. The opening 83N is formed so that the oil holes 521 of the base valve 52 are not blocked. Moreover, a thickness of the ring valve 83 is formed larger than a thickness at the overlap of the second bias spring 81 and the positioning ring 82.

[0089] The second bias spring 81 is a disc-shaped metallic member having a through hole 81H for passing through the fixing portion 21a on one side (see Fig. 2) of the piston rod 21. Furthermore, the second biasing spring 81 includes a plurality of (five in the second modification) radially extending pressing portions 811. Furthermore, the second biasing spring 81 presses the annular valve 83 toward the base valve 52 with the pressing portions 811.

[0090] The positioning ring 82 is a disc-shaped metallic member having a through hole 82H for passing the fixing portion 21a on one side (see Fig. 2) of the piston rod 21. Furthermore, the positioning ring 82 includes a plurality of (five in the second modification) radially extending positioning portions 821. Furthermore, the positioning ring 82 determines a position of the ring valve 83 in the radial direction with the positioning portions 821. <Dritte Modifikation>

[0091] Fig. 9A and Fig. 9B are explanatory views of the piston portion 100 according to a third modification.

[0092] Next, the piston portion 100 according to the third modification will be described. Furthermore, in the third modification, components similar to those of the first embodiment are assigned the same numerals, and a detailed description of these components will be omitted.

[0093] A third bias spring 84 according to the third modification includes a ring portion 540 and a pressing positioning portion 841 formed on the outside of the ring portion 540 in the radial direction.

[0094] The push-positioning portion 841 is formed to protrude in the radial direction. In other words, the push-positioning portion 841 is formed to extend radially. Furthermore, a plurality of (five in the present example) push-positioning portions 841 are provided at approximately equal intervals in the circumferential direction. Furthermore, a total length of the push-positioning portions 841 is formed longer than the opening 53N of the ring valve 53.

[0095] Furthermore, the push-positioning portions 841 include a stepped portion 841L. The stepped portion 841L is formed at a position where it contacts the opening 53N (an inner periphery thereof) of the ring valve 53. Moreover, the push-positioning portions 841 determine a position of the ring valve 53 in the radial direction with the stepped portion 841L.

[0096] As described above, the third biasing spring 84 according to the third modification pushes the ring valve 53 as a whole toward the base valve 52 and simultaneously determines the position of the ring valve 53 in the radial direction with the stepped portion 841L. In other words, the third biasing spring 84 according to the third modification is configured so that a single pushing positioning portion 841 simultaneously functions as, for example, the pushing portion 541 and the positioning portion 542 of the biasing spring 54 according to the first embodiment.

[0097] Furthermore, in the third bias spring 84, a stepped portion in contact with an inner periphery of the ring valve 53 may be formed by giving the push positioning portions 841 approximately the same thickness in the radial direction and folding the push positioning portions 841. <Zweite Ausführungsform>

[0098] Fig. 10 is an explanatory view of a hydraulic damping device 1 according to a second embodiment.

[0099] Next, the hydraulic damping device 1 according to the second embodiment will be described. Furthermore, in the second embodiment, components similar to those of the first embodiment are assigned the same numerals, and a detailed description of these components will be omitted.

[0100] First, a principle of the hydraulic damping device 1 according to the second embodiment will be described.

[0101] As in Fig. 1 and Fig. 10, the hydraulic damping device 1 (a pressure damping device) according to the second embodiment includes a first cylinder 11 (a cylinder) in which oil (a fluid) is accommodated, a piston rod 21 (a rod) of which one end on one side is accommodated in the first cylinder 11 and one end on the other side protrudes from an opening of the first cylinder 11 and which moves in the axial direction of the first cylinder 11, and a lower valve portion 260 (a damping force generating unit) that generates a damping force by a movement of the piston rod 21.Furthermore, the lower valve portion 260 includes a valve body 230 (a flow passage forming portion) in which an extension-side lower oil passage 612 (a flow passage) is formed, through which oil flows in association with a movement of the piston rod 21; a base valve 52 (an opening / closing member) that opens and closes the extension-side lower oil passage 612 of the valve body 230; an annular ring valve 53 (one form of a ring member) provided on a side opposite to a side opposite to the valve body 230 of the base valve 52; and a bias spring 54 (a projecting member) that extends radially and has a positioning portion 542 (a positioning portion) that determines a position of the ring valve 53 in the radial direction.

[0102] Even with the hydraulic damping device 1 according to the second embodiment configured as described above, oil circulates between a first oil chamber Y1 and a reservoir chamber R in the lower valve portion 260 in conjunction with movement of a piston portion (not shown). Moreover, even in the second embodiment, the bias spring 54 pushes the ring valve 53 with the pushing portions 541 toward the base valve 52. Specifically, the bias spring 54 transmits force across the ring valve 53 when the base valve 52 attempts to close an oil flow passage and acts to immediately close the base valve 52. Furthermore, the bias spring 54 determines a position of the ring valve 53 in the radial direction with the positioning portion 542. <Dritte Ausführungsform>

[0103] Fig. 11 is an overall view of a hydraulic damping device 1 according to a third embodiment.

[0104] Next, the hydraulic damping device 1 according to the third embodiment will be described. Furthermore, in the third embodiment, components similar to those of the first embodiment are assigned the same numerals, and a detailed description of these components will be omitted.

[0105] First, a principle of the hydraulic damping device 1 according to the third embodiment will be described.

[0106] As in Fig. 11, the hydraulic damping device 1 (a pressure damping device) according to the third embodiment includes a first cylinder 11 (a cylinder) in which oil (a fluid) is accommodated, a piston rod 21 (a rod) of which one end on one side is accommodated in the first cylinder 11 and one end on the other side protrudes from an opening of the first cylinder 11 and which moves in the axial direction of the first cylinder 11, and a lower valve portion 360 (a damping force generating unit) that generates a damping force by a movement of the piston rod 21.Furthermore, the lower valve portion 360 includes a valve body 330 (a flow passage forming portion) in which an extension-side lower oil passage 612 (a flow passage) is formed, through which oil flows in association with a movement of the piston rod 21; a base valve 352 (an opening / closing member) that opens and closes the extension-side lower oil passage 612 of the valve body 330; an annular ring valve 53 (one form of a ring member) provided on a side opposite to a side opposite to the valve body 330 of the base valve 352; and a bias spring 54 (a projecting member) that extends radially and has a positioning portion 542 (a positioning portion) that determines a position of the ring valve 53 in the radial direction.

[0107] As in Fig.As shown in FIG. 11, the hydraulic damping device 1 according to the third embodiment includes a piston portion 91 instead of the piston portion 100 according to the first embodiment, and includes a lower valve portion 360 instead of the lower valve portion 60 according to the first embodiment. Furthermore, the hydraulic damping device 1 according to the third embodiment includes a solenoid valve portion 93 that generates a damping force in association with movement of the piston portion 91 in the axial direction.

[0108] Furthermore, according to the third embodiment, the first cylinder 11 forms a cylinder hole 11H on the other side together with a groove formed on the rod guide 14. A second cylinder 12 is a thin-walled cylindrical member. Moreover, the second cylinder 12 is located on the outside of the first cylinder 11, and a communication passage L constituting an oil path between the first oil chamber Y1 and the second oil chamber Y2 is formed between the second cylinder 12 and the first cylinder 11. A third cylinder 17 is located on the outside of the first cylinder 11, and a reservoir chamber R storing oil is formed between the third cylinder 17 and the second cylinder 12.

[0109] The piston portion 91 is attached to one end of one side of the piston rod 21. Furthermore, with movements of the piston rod 21 on one side and on the other side, the piston portion 91 generates oil flows between the first oil chamber Y1 and the second oil chamber Y2 and between the first oil chamber Y1 and the reservoir chamber R.

[0110] The lower valve portion 360 shares a basic configuration with the piston portion 100 according to the first embodiment. Furthermore, the lower valve portion 360 is provided at one-side ends of the first cylinder 11 and the second cylinder 12.

[0111] Furthermore, the base valve 352 in the lower valve section 360 is disc-shaped without any oil holes.

[0112] The solenoid valve portion 93 throttles an oil flow that has flowed in via the communication passage L in conjunction with a movement of the piston portion 91. Thereafter, the solenoid valve portion 93 discharges the oil to the reservoir chamber R. Furthermore, the solenoid valve portion 93 is capable of varying an amount of throttling of the oil flow and changing the generated damping force using a solenoid mechanism (not shown).

[0113] With the hydraulic damping device 1 according to the third embodiment configured as described above, oil circulates between the first oil chamber Y1 and the reservoir chamber R in the lower valve portion 360 in conjunction with movement of the piston portion 91. Moreover, even in the third embodiment, the biasing spring 54 pushes the ring valve 53 with the pushing portions 541 toward the base valve 352. Specifically, the biasing spring 54 transmits force via the ring valve 53 when the base valve 352 attempts to close an oil flow passage and acts to immediately close the base valve 352. Furthermore, the biasing spring 54 determines a position of the ring valve 53 in the radial direction with the positioning portion 542.

[0114] Furthermore, although the above-described hydraulic damping device 1 according to the first embodiment (first to third modifications) and the second embodiment has a so-called double-tube structure, the structure of the hydraulic damping device 1 is not limited thereto. For example, the hydraulic damping device 1 according to the first embodiment (first to third modifications) and the second embodiment may have a triple-tube structure.

[0115] Moreover, the lower valve portion 60 according to the first embodiment (first to third modifications) and the piston portion 91 according to the third embodiment are not limited to the structures described in the above embodiments and may have other shapes and configurations as long as damping mechanism functions are provided.

[0116] Furthermore, the structures according to the first to third modifications can be applied to the lower valve portion 260 according to the second embodiment or to the lower valve portion 360 according to the third embodiment.

[0117] Furthermore, for example, although the biasing spring 54 according to the first embodiment is configured to determine a position of the ring valve 53 in the radial direction using the positioning portion 542 contacting the inner periphery of the ring valve 53, this configuration is not limiting. For example, the biasing spring 54 may determine a position of the ring valve 53 in the radial direction while contacting the outer periphery of the ring valve 53. This also applies to the other modifications and embodiments.

[0118] Furthermore, the extension-side slit valve 41 and the compression-side slit valve 51 according to the first embodiment (first to third modifications), the second embodiment, and the third embodiment are not necessary components.

[0119] Moreover, for example, with respect to the pressing portions 541 and the positioning portions 542 of the bias spring 54 according to the first to third embodiments, the pressing portions 741 and the positioning portions 742 of the bias spring 74 according to the first modification, the pressing portions 811 of the second bias spring 81 and the positioning portions 821 of the positioning ring 82 according to the second modification, and the pressing positioning portions 841 of the third bias spring 84 according to the third modification, the shapes, numbers, and intervals between the respective portions are not limited to the contents described above, and other configurations may be employed.

Claims

[1] Pressure damping device (1) comprising: a cylinder (11) in which a fluid is accommodated; a rod (21) having a first end and a second end movable in an axial direction of the cylinder (11), the first end being housed in the cylinder (11) and the second end protruding from an opening of the cylinder (11); and a damping force generating unit (100) which generates a damping force by a movement of the rod (21), wherein the damping force generating unit (100) comprises: a flow channel forming portion (30) formed with a flow channel (32) through which the fluid flows in conjunction with the movement of the rod (21); an opening / closing member (52) that opens and closes the flow channel (32) in the flow channel forming section (30); an annular ring member (53) provided on a side of the opening / closing member (52) opposite to a side thereof facing the flow channel forming portion (30); and a biasing spring (54) provided on a side of the ring valve (53) opposite to a side thereof facing the opening / closing member (52), the biasing spring (54) comprising: a pressing portion (541) extending radially, which contacts a side of the ring member (53) opposite to a side thereof facing the opening / closing member (52), and which presses the ring member (53) toward the opening / closing member (52), and a positioning portion (542) extending radially and having a length in a radial direction shorter than a projection length of the pressing portion (541) in the radial direction, which contacts an inner periphery of an opening (53N) of the ring member (53) and determines a position of the ring member (53), wherein the flow channel forming section (30) comprises a first flow channel section (32) forming a flow of the fluid flowing from one side to the other side in an axial direction, and a second flow channel section (33) forming a flow of the fluid flowing from the other side to the one side in the axial direction, and wherein the opening / closing member (52) is provided on the other side of the flow channel forming portion (30), and wherein the opening / closing member (52) comprises: - a cover section (522) which opens and closes the other side of the first flow channel section (32) and - an opening section (521) which opens the other side of the second flow channel section (33), wherein the positioning portion (542) engages with the opening portion (521) to determine the position of the ring member (53) in the radial direction without completely closing the opening portion (521). [2] A preload spring (54) adapted to be arranged facing a ring member (53) used in a pressure damping device (1) generating a damping force in connection with a movement of a rod (21) relative to a cylinder (11), the preload spring (54) comprising: a ring portion (540) having a through hole (54H) through which the rod (21) can be passed; a plurality of first projection portions (541) formed to extend radially from the ring portion (540); and a second projection portion (542) formed to extend radially from the ring portion (540) and having a shorter projection length in a radial direction than the first projection portions (541), wherein the projection portion is formed such that, in a state facing the ring member (53), a distal end (542P) of the second projection portion (542) contacts an inner circumference of an opening (53N) of the ring member (53) so that a center point of the biasing spring (54) is aligned centrally with a center point of the ring member (53).

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