Buffer device and suspension device

Abstract

A damper device (2) is provided with: a rod guide (60); and a seal member (80) that is provided so as to form a contact portion that contacts the rod guide (60) in a position closer to the opening side than the rod guide (60) in the axial direction of the rod, the seal member (80) having a seal lip portion (91) and an outer peripheral seal portion (93) that seals the space between the seal member (80) and the inner surface of the outer cylinder, the rod guide (60) having: an inclined surface (724) that is inclined relative to the rod guide (60); an inclined surface (724) which is provided at the end on the opening side of the outer peripheral section and on which a portion of the outer peripheral seal section (93) inside a portion in contact with the inner surface of the outer cylinder is pressed; and an outer peripheral recess (723) which is recessed from the outer peripheral surface, and which forms an outer peripheral flow path for returning the working fluid to the storage chamber between the rod guide (60) and the inner surface of the outer cylinder, and in which a cutout (931) is formed at a location of the outer peripheral seal section (93) that is pressed against the inclined surface (724). The notch (931) forms a relay flow path through which the working fluid reaching the opening part side through the gap between the sealing lip part (91) and the rod flows to the outer peripheral flow path.

Description

TECHNICAL FIELD

[0001] The present application relates to a damper device and a suspension device. BACKGROUND

[0002] For example, the damper of Patent Literature 1 has a cylinder, an outer tube that is disposed outside the cylinder and covers the cylinder, and a rod guide that closes an open end of the cylinder and an open end of the outer tube and axially supports a rod that is movably inserted into the cylinder. A piston that is linked to a lower end of the rod is slidably inserted below the cylinder, and a rod-side chamber and a piston-side chamber that are filled with working oil are divided by the piston inside the cylinder, and a storage portion that is filled with gas and working oil is formed between the cylinder and the outer tube. A seal member is stacked above the rod guide, and the seal member has an embedded metal piece that is ring plate-shaped, an inner peripheral seal piece that is held to an inner periphery of the embedded metal piece and is in sliding contact with an outer periphery of the rod, and an outer peripheral seal piece that is held to an outer periphery of the embedded metal piece and is in close contact with an outer periphery of the rod guide and the outer tube. A cylindrical sliding bearing is installed to an inner periphery of a guide portion of the rod guide, and the rod is slidably inserted into the sliding bearing. Further, the rod guide has a recess portion that is provided to an inner peripheral side and a communication hole that communicates from the recess portion to a surface of the flange that faces the storage portion, and working oil that has passed between the rod and the sliding bearing is able to be returned to the storage portion via the communication hole.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent No. 6080257 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In the damper of Patent Literature 1, since the communication hole that communicates the recess portion provided to the inner peripheral side and the storage portion is formed by a hole that penetrates a portion of the rod guide, there is room for improvement in terms of simply molding the rod guide. For example, in the case of molding the penetrating hole using a mold, the configuration of the mold becomes complicated and the cost of the mold becomes high. In addition, in the case of molding the penetrating hole by cutting, a cutting process is required.

[0008] An object of the present application is to provide a damper device and the like that can simply manufacture a rod guide.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] A buffer device according to the present application includes an inner cylinder that encloses a working fluid; an outer cylinder that is disposed outside a periphery of the inner cylinder, and forms a storage chamber that stores the working fluid between the outer cylinder and the inner cylinder; a piston portion that divides a space formed inside the inner cylinder; a rod that holds the piston portion at one end portion, and protrudes from an opening portion of the outer cylinder at the other end portion; a rod guide that supports the rod so as to be slidable, and a periphery portion of which contacts an inner surface of the outer cylinder; and a seal member that is disposed so as to form a contact portion that contacts the rod guide at a position of the rod in an axial direction that is closer to the opening portion side than the rod guide, and has a first seal portion that seals between the seal member and the rod, and a second seal portion that seals between the seal member and the inner surface of the outer cylinder, the rod guide has a pressed portion that is provided at an end portion of the periphery portion on the opening portion side, a portion of the second seal portion that contacts the inner surface of the outer cylinder is pressed to the pressed portion, and a periphery recessed portion that is recessed from a periphery surface, and forms a periphery flow path that returns the working fluid to the storage chamber between the rod guide and the inner surface of the outer cylinder, a cutout is formed at a portion of the second seal portion that is pressed to the pressed portion, and the cutout forms a relay flow path that causes the working fluid that reaches the opening portion side through a gap between the first seal portion and the rod to flow to the periphery flow path.

[0011] Here, the rod guide can have a groove that communicates an inner side of the contact portion with an outer side of the contact portion.

[0012] Further, the rod guide can have a plurality of grooves that communicate the inner side of the contact portion with the outer side of the contact portion, and the number of the cutouts can be greater than the number of the grooves.

[0013] Further, either one of the number of the grooves and the number of the cutouts can be even, and the other can be odd.

[0014] Further, four or more of the cutouts can communicate with the plurality of grooves.

[0015] Further, the rod guide can form a circumferential flow path that allows the working fluid to move in a circumferential direction between the rod guide and the seal member, and the circumferential flow path can communicate with the grooves.

[0016] Further, the seal member can have a third seal portion between the first seal portion and the second seal portion, the third seal portion can allow the working fluid to flow from the first seal portion to the second seal portion, and can inhibit the working fluid from flowing from the second seal portion to the first seal portion.

[0017] Also, it can be that the end portion in the axial direction of the second seal portion is not pressed against the rod guide.

[0018] Also, it can be that the shape of the cutout as viewed in the axial direction is quadrangular.

[0019] Also, it can be that the cutout is provided with a protrusion that protrudes from the bottom surface toward the rod guide.

[0020] From another viewpoint, the present application is a suspension device that includes the above-described shock absorber and a spring disposed around the shock absorber.

[0021] Effects of Invention

[0022] According to the present application, a shock absorber or the like that can be easily manufactured can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a view that shows an example of the overall structure of the suspension device of the first embodiment.

[0024] Figure 2 is an enlarged view of the II portion of Figure 1

[0025] Figure 3

[0026] Figure 4 is a view that shows an example of the flow path.

[0027] Figure 5 is a view that shows an example of a modification of the cutout.

[0028] Figure 6 is a view that shows an example of the cross section of the rod guide and the seal member of the second embodiment.

[0029] Figure 7 is a view that shows an example of the overall structure of the rod guide and the seal member of the third embodiment.

[0030] Figure 8 is a view that shows an example of the overall structure of the seal member of the fourth embodiment.

[0031] Figure 9 is a view that shows an example of a view of the rod guide of the fifth embodiment as viewed from the second side and a view of the seal member of the fifth embodiment as viewed from the first side.

[0032] Figure 10 is a view that shows an example of the cross section of the rod guide and the seal member of the fifth embodiment. DETAILED DESCRIPTION​​

[0033] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings.

[0034] <First Embodiment>

[0035] Figure 1 is a view showing an example of the schematic structure of the suspension device 1 of the first embodiment.

[0036] Figure 2 is an enlarged view of the II portion of Figure 1

[0037] Figure 3 is a view showing an example of a perspective view of the rod guide 60 and the seal member 80.

[0038] The suspension device 1 is a suspension for a four-wheeled vehicle such as a passenger car, as shown in Figure 1 , and is provided with a hydraulic shock absorber 2 and a coil spring 3 disposed outside the shock absorber 2. In addition, the suspension device 1 is provided with a lower spring seat 4 that supports an end portion of a first side (lower side in Figure 1 ) of the shaft direction of a rod 20 of the coil spring 3, and an upper spring seat 5 that supports an end portion of a second side (upper side in Figure 1 ) of the shaft direction of the rod 20 of the coil spring 3.

[0039] In addition, the suspension device 1 is provided with a vehicle body side bracket 6 that is attached to the end portion of the second side of the shaft direction of the rod 20, for mounting the suspension device 1 to a vehicle, and a wheel side bracket 7 that is fixed to the end portion of the first side of the shaft direction of the rod 20 of the cylinder portion 10, for mounting the suspension device 1 to a wheel. In addition, the suspension device 1 is provided with a dust cover 8 that covers at least a portion of the cylinder portion 10 and the rod 20.

[0040] Hereinafter, the shaft direction of the rod 20 will be sometimes referred to simply as the "shaft direction". The shaft direction is also the center line direction of the inner cylinder 11 that will be described later. In addition, the first side (lower side in Figure 1 ) of the shaft direction, the second side (upper side in Figure 1 ) of the shaft direction will be sometimes referred to simply as the "first side", the "second side", respectively. In addition, the direction intersecting the shaft direction (for example, the vertical direction) will be referred to as the "radial direction". In the radial direction, the center line side of the inner cylinder 11 will be sometimes referred to simply as the "inner side", and the side away from the center line will be sometimes referred to simply as the "outer side".

[0041] Hereinafter, the shock absorber 2 will be described in detail.

[0042] ​The shock absorber 2 includes a cylinder 10 that contains oil, and a rod 20 whose second end protrudes from the cylinder 10 and whose first end is inserted into the cylinder 10. The shock absorber 2 also includes a piston 30 provided at the first end of the rod 20 and a bottom 40 provided at the first end of the cylinder 10. To mitigate the impact of extension of the rod 20, the shock absorber 2 includes a rebound seat 50 fixed to the rod 20 and a rebound rubber 51, an annular elastic member, disposed on the second side of the rebound seat 50.

[0043] The cylinder unit 10 comprises a thin-walled cylindrical inner cylinder 11, a thin-walled cylindrical outer cylinder 12 disposed outside the inner cylinder 11, and a bottom cover 13 that closes the first end of the outer cylinder 12. The inner cylinder 11 and the outer cylinder 12 are arranged so that the centerline of the cylinders aligns with the axial direction. Furthermore, the cylinder unit 10 forms a reservoir R between the outer circumferential surfaces of the inner cylinder 11 and the outer cylinder 12. The reservoir R is filled with oil on the first side and gas on the second side.

[0044] In addition, the cylinder portion 10 includes: a rod guide 60 that supports the rod 20 so that it can move; a crash cap 15 that is mounted on the end portion of the second side of the outer tube 12; and a sealing component 80 that prevents leakage of oil in the cylinder portion 10 and mixing of foreign matter into the cylinder portion 10.

[0045] The rod guide 60 and the sealing member 80 will be described in detail later.

[0046] The rod 20 is a rod-shaped member extending in the axial direction. The rod 20 holds the piston portion 30 on a first side. The rod 20 is connected to, for example, a vehicle body via a vehicle body-side bracket 6 on a second side.

[0047] The piston portion 30 includes a piston 31 , a valve block 32 for blocking a first end portion of a portion of the plurality of oil passages formed in the piston 31 , and a valve block 33 for blocking a second end portion of the portion of the oil passages formed in the piston 31 .

[0048] The piston 31 contacts the inner circumferential surface of the inner tube 11 via a sealing member provided on its outer circumferential surface, dividing the oil-sealed space in the inner tube 11 into a first oil chamber Y1 on a first side of the piston 31 and a second oil chamber Y2 on a second side of the piston 31 .

[0049] like Figure 4 As shown, the bottom portion 40 includes a valve body 41 having a plurality of oil passages extending therethrough in the axial direction, a valve 42 provided on a first side of the valve body 41 , and a valve 43 provided on a second side of the valve body 41 .

[0050] The valve body 41 of the bottom portion 40 partitions the first oil chamber Y1 and the reservoir chamber R. As shown in FIG.

[0051] [Rod guide 60]

[0052] The rod guide 60 has a thin-walled cylindrical guide 61 disposed on the inner side and a guide housing 70 that holds the guide 61 on the inner side.

[0053] The inner diameter of the guide 61 is set to be slightly larger than the outer diameter of the rod 20 inserted into the inner side. For example, the inner diameter of the guide 61 is 0.1 mm to 1 mm larger than the outer diameter of the rod 20. The guide 61 is formed of a material having superior wear resistance to the guide housing 70 because the inner peripheral surface is in contact with the outer peripheral surface of the rod 20.

[0054] The guide housing 70 has a cylindrical inner side cylindrical portion 71 disposed on the inner side and a cylindrical outer side cylindrical portion 72 disposed on the outer side of the inner side cylindrical portion 71. The inner side cylindrical portion 71 and the outer side cylindrical portion 72 are integrally formed in a manner that the outer peripheral surface of the portion of the second side of the inner side cylindrical portion 71 is joined to the inner peripheral surface of the portion of the first side of the outer side cylindrical portion 72.

[0055] The guide 61 is fitted on the inner side of the inner side cylindrical portion 71. The outer diameter of the inner side cylindrical portion 71 is formed to be equal to the inner diameter of the inner cylinder 11. Further, the inner side cylindrical portion 71 is disposed on the inner side of the inner cylinder 11 in a state that the outer peripheral surface is in contact with the inner peripheral surface of the inner cylinder 11.

[0056] The outer diameter of the outer side cylindrical portion 72 is formed to be equal to the inner diameter of the end portion of the second side of the outer cylinder 12. Further, the outer side cylindrical portion 72 is disposed between the rod 20 and the outer cylinder 12 in a state that the outer peripheral surface is in contact with the inner peripheral surface of the outer cylinder 12 on the second side of the inner cylinder 11.

[0057] The outer side cylindrical portion 72 has an inner side recessed portion 721 formed on the inner side of the end portion of the second side, recessed from a second side end surface 720 that is an end surface of the second side, an outer side recessed portion 722 formed on the outer side of the end portion of the second side, recessed from the second side end surface 720, and an outer peripheral recessed portion 723 recessed from the outer peripheral surface.

[0058] The second side opening portion of the inner side recessed portion 721 is chamfered.

[0059] The outer side recessed portion 722 is recessed in a substantially cylindrical shape, and has an inclined surface 724 formed so that the outer diameter of the end portion of the second side of the outer side cylindrical portion 72 gradually decreases toward the second side. In addition, the outer side recessed portion 722 has a parallel surface 725 extending toward the second side from the end portion of the second side of the inclined surface 724, which is substantially parallel to the axial direction, and a perpendicular surface 726 extending toward the outer side from the end portion of the first side of the inclined surface 724, which is perpendicular to the axial direction.

[0060] The outer peripheral recess 723 is formed by molding a portion of the outer peripheral surface of the outer cylindrical portion 72 into a plane parallel to the axial direction. The outer peripheral recess 723 is recessed in the entire region in the axial direction. The outer side recess 722 communicates with the storage chamber R formed in the first side of the outer cylindrical portion 72 through the outer peripheral recess 723. The outer peripheral recess 723 is formed with a plurality of (for example, four) at equal intervals in the circumferential direction. Furthermore, the shape of the outer peripheral recess 723 is not limited as long as the outer side recess 722 communicates with the storage chamber R. For example, the outer peripheral recess 723 can also be recessed in a concave shape from the outer peripheral surface. In addition, the number of the outer peripheral recess 723 can also be one.

[0061] In addition, a groove 727 recessed from the second side end surface 720 and communicating the inner side recess 721 with the outer side recess 722 is formed at the end portion of the second side of the outer cylindrical portion 72. The groove 727 is formed in a straight line shape extending in the radial direction. In addition, the groove 727 is formed with a plurality of at equal intervals in the circumferential direction. For example, the groove 727 is formed in the same number as the outer peripheral recess 723, and is formed so that the circumferential position becomes the same position as the outer peripheral recess 723.

[0062] The size in the circumferential direction of the groove 727 can be exemplified as 1 / 15 to 1 / 25 of the size in the circumferential direction of the second side end surface 720.

[0063] The guide member housing 70 configured as described above can be exemplified as being molded from a metal such as steel, a non-metallic material such as polytetrafluoroethylene.

[0064] [Sealing member 80]

[0065] The sealing member 80 has a ring 81 molded from a metal such as steel in a circular ring shape, and an elastic portion 90 molded from a material having a low modulus of elasticity such as synthetic rubber. The sealing member 80 is molded by, for example, sintering bonding the elastic portion 90 on the ring 81, and the ring 81 holds the elastic portion 90.

[0066] The ring 81 is in a circular ring shape, has an inner diameter larger than the outer diameter of the rod 20, and has an outer diameter slightly smaller than the inner diameter of the end portion of the second side of the outer cylinder 12. For example, the outer diameter of the ring 81 is 0.5 mm to 3 mm smaller than the inner diameter of the end portion of the second side of the outer cylinder 12.

[0067] The elastic portion 90 has a seal lip portion 91 provided at a position closer to the first side than the ring 81, has a wedge-like cross-sectional shape, and is pressed by a ring-shaped spring to adhere to the entire circumference of the outer peripheral surface of the rod 20. In addition, the elastic portion 90 has a dust lip 92 provided at a position closer to the second side than the ring 81, and suppresses the intrusion of dust from the outside by adhering to the entire circumference of the outer peripheral surface of the rod 20. The seal lip portion 91 and the dust lip 92 are integrally molded in a manner of being joined at a position closer to the inside than the ring 81.

[0068] Further, the elastic portion 90 has an outer peripheral seal portion 93 protruding from the outer peripheral portion of the ring 81 to the first side over the entire circumference. The outer peripheral seal portion 93 is cylindrical and has an outer diameter larger than that of the ring 81 before the seal member 80 is assembled in the outer cylinder 12. The inner diameter of the outer peripheral seal portion 93 is equal to or larger than the diameter of the end portion of the first side of the inclined surface 724 and is smaller than the outer diameter of the ring 81. The outer peripheral seal portion 93 is positioned at the position of the outer side recessed portion 722 of the guide housing 70 of the insertion rod guide 60 and is in contact with the inner peripheral surface of the outer cylinder 12, thereby suppressing leakage of oil from the gap between the outer peripheral surface of the guide housing 70 and the inner peripheral surface of the outer cylinder 12.

[0069] In the outer peripheral seal portion 93, a plurality of (for example, eight) notches 931 recessed from the inner peripheral surface to the outer side are formed at equal intervals in the circumferential direction. When viewed in the axial direction, the notches 931 are in the shape of a circular arc with the bottoms 932 as the top. Further, the notches 931 are formed such that the bottoms 932 gradually become positioned on the outer side as they go from the second side toward the first side, and the cross-sectional area of the notches 931 when cut by a surface perpendicular to the axial direction gradually becomes larger as they go from the second side toward the first side.

[0070] The size of the circumferential direction of the notches 931 can be exemplified as 1 / 60 to 1 / 100 of the size of the circumferential direction of the outer peripheral seal portion 93.

[0071] Further, the elastic portion 90 has a central seal portion 94 protruding from the inner peripheral portion of the ring 81 to the first side and the outer side in a direction inclined with respect to the axial direction. The central seal portion 94 is in contact with the inner side recessed portion 721 of the outer side cylindrical portion 72 of the guide housing 70, thereby suppressing the oil and gas filled in the reservoir chamber R from going to the inner side via the flow path 75 (refer to Figure 4 ) and the like. The central seal portion 94 and the seal lip portion 91 are integrally formed in a manner combined at a portion on the first side of the ring 81.

[0072] Further, the elastic portion 90 has a connecting portion 95 connecting the outer peripheral seal portion 93 and the central seal portion 94 on the first side of the ring 81. The connecting portion 95 is formed over the entire circumference. The connecting portion 95 protrudes, for example, 1 mm to 5 mm from the first side end surface 811 of the ring 81.

[0073] In the seal member 80 of the present embodiment, the first side end surface 811 of the ring 81 is covered with the seal lip portion 91, the central seal portion 94, the connecting portion 95, and the outer peripheral seal portion 93. On the other hand, the portion on the inner side of the second side end surface 812 of the ring 81 is covered with the dust lip 92, and the portion on the outer side is not covered with the elastic portion 90 and is exposed.

[0074] In assembling the damper 2, after the rod guide 60 is inserted into the outer cylinder 12, the seal member 80 is inserted into the outer cylinder 12 until the elastic portion 90 of the first side end face 811 of the ring 81 contacts the second side end face 720 of the guide housing 70. Then, the seal member 80 is held to the outer cylinder 12 by performing so-called roll pressing that bends the end portion of the second side of the outer cylinder 12 inward. That is, by bringing the connecting portion 95 of the elastic portion 90 into contact with the second side end face 720 of the outer side cylindrical portion 72 of the guide housing 70, and bringing the outer peripheral portion of the second side end face 812 of the ring 81 into contact with the outer cylinder 12 that is bent inward, the axial movement of the seal member 80 is restricted. In this way, the seal member 80 is disposed to the opening portion of the second side of the outer cylinder 12, and plugs the opening portion.

[0075] Also, in the state where the rod guide 60 and the seal member 80 are assembled, the tip portion of the central seal portion 94 of the seal member 80 contacts the inner side recessed portion 721 of the guide housing 70. In addition, the outer peripheral face 934 of the outer peripheral seal portion 93 of the seal member 80 contacts the inner peripheral face of the outer cylinder 12, and the inner peripheral face 935 contacts the inclined face 724 of the guide housing 70. However, the tip portion 933 of the outer peripheral seal portion 93 of the seal member 80 does not contact the vertical face 726 of the guide housing 70, and a gap is formed between the tip portion 933 and the vertical face 726.

[0076] Figure 2 is a view that shows an example of the flow path 75.

[0077] With the rod guide 60 and the seal member 80 configured as above, a flow path 75 is formed that returns oil that has reached the second side of the inner side cylindrical portion 71 of the guide housing 70 through the gap between the rod 20 and the guide 61 to the reservoir chamber R. The flow path 75 is constituted by the gap between the rod guide 60 and the seal member 80, and the gap between the rod guide 60 and the outer cylinder 12. The flow path 75 has a first flow path 751 constituted by the groove 727 of the outer side cylindrical portion 72 and the seal member 80, and a second flow path 752 constituted by the gap between the parallel face 725 of the outer side cylindrical portion 72 and the outer peripheral seal portion 93. In addition, the flow path 75 has a third flow path 753 constituted by the inclined face 724 and the cutout 931 formed in the outer peripheral seal portion 93, a fourth flow path 754 constituted by the tip portion 933 of the outer peripheral seal portion 93 and the vertical face 726, and a fifth flow path 755 constituted by the outer side recessed portion 723 and the outer cylinder 12.

[0078] The first flow path 751 is a flow path that moves in the radial direction from the inner recess 721. The second flow path 752 is a flow path that moves in the circumferential direction between the parallel face 725 of the guide housing 70 and the seal member 80. The third flow path 753 is a flow path that moves in a direction inclined with respect to the axial direction between the inclined face 724 of the guide housing 70 and the seal member 80. The fourth flow path 754 is a flow path that moves in the circumferential direction between the perpendicular face 726 of the guide housing 70 and the seal member 80 and the outer tube 12. The fifth flow path 755 is a flow path that moves in the axial direction between the outer peripheral recess 723 of the guide housing 70 and the outer tube 12.

[0079] Further, when the rod guide 60 and the seal member 80 are assembled, in a case where the circumferential positions of the groove 727 and the outer peripheral recess 723 of the guide housing 70 coincide with the circumferential positions of the cutout 931 of the outer peripheral seal portion 93 formed in the seal member 80, the oil, after moving in the first flow path 751, sometimes does not move in the circumferential direction in the second flow path 752 and flows into the third flow path 753. In addition, after moving in the third flow path 753, sometimes does not move in the circumferential direction in the fourth flow path 754 and flows into the fifth flow path 755.

[0080] As described above, the damper device 2 is provided with: the inner tube 11 that encloses oil that is an example of a working fluid; the outer tube 12 that is provided outside the outer periphery of the inner tube 11, and that forms a reservoir chamber R that stores oil between the outer tube 12 and the inner tube 11; and the piston portion 30 that divides a space formed inside the inner tube 11. In addition, the damper device 2 is provided with: the rod 20 that holds the piston portion 30 at an end portion that is an example of a first side, and that protrudes from an opening portion of the outer tube 12 at an end portion that is an example of a second side; and the rod guide 60 that supports the rod 20 so as to be slidable, and that contacts an inner surface of the outer tube 12 with an outer peripheral portion. In addition, the damper device 2 is provided with the seal member 80 that is provided so as to form a contact portion 100 that contacts the rod guide 60 at a position that is closer to the opening portion in the axial direction of the rod 20 than the rod guide 60, and that has: a seal lip portion 91 that is an example of a first seal portion that seals between the seal member 80 and the rod 20; and an outer peripheral seal portion 93 that is an example of a second seal portion that seals between the seal member 80 and the inner surface of the outer tube 12. The contact portion 100 is constituted by a second side end face 720 of the outer side cylindrical portion 72 of the rod guide 60 and a connection portion 95 of the elastic portion 90 of the seal member 80 (refer to FIG. 6). Figure 5). Also, the rod guide 60 has an inclined surface 724 as an example of a pressed portion, which is provided at an end portion of the opening portion side of the outer peripheral portion, and a portion (e.g., an inner peripheral surface 935) of the outer peripheral seal portion 93 on the inner side of a portion (e.g., an outer peripheral surface 934) that contacts the inner surface of the outer cylinder 12 is pressed against the inclined surface 724. In addition, the rod guide 60 has an outer peripheral recessed portion 723 that is recessed from the outer peripheral surface, and a fifth flow path 755 as an example of an outer peripheral flow path that returns oil to the reservoir chamber R is formed between the rod guide 60 and the inner surface of the outer cylinder 12. Also, the inner peripheral surface 935 of the outer peripheral seal portion 93 that is pressed against the inclined surface 724 is formed with a cutout 931 that forms a third flow path 753 as an example of a relay flow path that causes oil that has reached the opening portion side through the gap between the seal lip portion 91 and the rod 20 to flow to the fifth flow path 755.

[0081] In the damper device 2 configured as described above, a flow path 75 that returns working oil that has reached the second side of the inner cylindrical portion 71 of the guide housing 70 through the gap between the rod 20 and the guide 61 to the reservoir chamber R is formed using the gap between the rod guide 60 and the seal member 80. Also, in the guide housing 70 of the rod guide 60, a communication path that communicates the inner recessed portion 721 with the reservoir chamber R is not formed by a hole that penetrates the guide housing 70 in the axial direction, for example. Therefore, the guide housing 70 can be easily molded. That is, for example, in the case of molding a hole that penetrates in the axial direction using a mold, at least either one of a first side mold and a second side mold that are divided in the axial direction needs a protrusion for molding the penetrating hole. Or, in the case of molding a hole that penetrates in the axial direction by cutting, a process of cutting needs to be performed. In contrast, in the guide housing 70, the communication path that communicates the inner recessed portion 721 with the reservoir chamber R is not formed by a hole that penetrates the inside of the guide housing 70, and therefore the guide housing 70 can be easily molded.

[0082] In addition, the rod guide 60 has the inclined surface 724 against which the inner peripheral surface 935 of the outer peripheral seal portion 93 is pressed, and therefore the outer peripheral seal portion 93 is difficult to deform inwardly, and therefore the contact pressure between the outer peripheral surface 934 of the outer peripheral seal portion 93 and the inner peripheral surface of the outer cylinder 12 is high. Thus, leakage of oil from the gap between the outer peripheral seal portion 93 and the inner peripheral surface of the outer cylinder 12 is suppressed.

[0083] Here, the rod guide 60 is formed with the groove 727 that communicates the inner side and the outer side of the contact portion 100. Thus, the flow path 75 can be formed using the gap between the rod guide 60 and the seal member 80.

[0084] Further, the rod guide 60 is formed with a plurality of grooves 727 that communicate the inner side and the outer side of the contact portion 100, and the number of the cutouts 931 is larger than the number of the grooves 727. Thereby, it is possible to make the oil that passed through the grooves 727 quickly return to the reservoir chamber R.

[0085] Further, the rod guide 60 forms a second flow path 752 that is an example of a circumferential flow path through which the oil moves in the circumferential direction between the sealing member 80, and the second flow path 752 communicates with the grooves 727. Thereby, even if the circumferential position of the grooves 727 does not coincide with the circumferential position of the cutouts 931, it is possible to make the oil that passed through the grooves 727 return to the reservoir chamber R.

[0086] Further, the end portion 933 of the outer peripheral sealing portion 93 in the axial direction is not pressed against the rod guide 60. Thereby, a gap is formed between the end portion 933 and the rod guide 60, and therefore even if the circumferential position of the cutouts 931 does not coincide with the circumferential position of the outer peripheral recessed portion 723 of the guide housing 70, it is possible to make the oil that passed through the grooves 727 return to the reservoir chamber R.

[0087] Further, the sealing member 80 has a central sealing portion 94 that is an example of a third sealing portion between the sealing lip portion 91 and the outer peripheral sealing portion 93, the central sealing portion 94 allows the oil to flow from the sealing lip portion 91 to the outer peripheral sealing portion 93, and suppresses the oil from flowing from the outer peripheral sealing portion 93 to the sealing lip portion 91. Thereby, it is possible to suppress the oil from flowing into the inner cylinder 11 from the reservoir chamber R through the gap between the rod guide 60 and the sealing member 80.

[0088] (Modified example of the cutout 931)

[0089] The shape of the cutout 931 formed in the outer peripheral sealing portion 93 when cut by a surface perpendicular to the axial direction is a circular arc shape with the bottom portion 932 as the top, but is not particularly limited to this shape.

[0090] Figure 6 is a drawing that shows an example of a modified example of the cutout 931.

[0091] The shape of the cutout 931 when cut by a surface perpendicular to the axial direction can also be a quadrangle. The connection portion 936 where the both end portions of the circumferential direction of the cutout 931 are connected to the inner peripheral surface 935 is a substantially right angle, and thereby even if the inner peripheral surface 935 is pressed against the inclined surface 724 of the guide housing 70, the cutout 931 is difficult to be flattened, and therefore the third flow path 753 is formed with high accuracy.

[0092] Furthermore, a protrusion 938 that protrudes inward from the bottom surface 937 may be provided at the circumferential center of the cutout 931. Even if the cutout 931 is rectangular when cut along a plane perpendicular to the axial direction and has a large circumferential size, the cutout 931 is less likely to be crushed by pressing the protrusion 938 against the inclined surface 724 of the guide housing 70. As a result, the third flow path 753 is formed with high precision.

[0093] <Second embodiment>

[0094] Figure 6 This is a diagram showing an example of a cross section of the rod guide 260 and the seal member 280 according to the second embodiment.

[0095] The rod guide 260 of the second embodiment differs from the rod guide 60 of the first embodiment in a guide housing 270 corresponding to the guide housing 70. Furthermore, the seal member 280 of the second embodiment differs from the seal member 80 of the first embodiment in an elastic portion 290 corresponding to the elastic portion 90. The differences from the first embodiment will be described below. Identical parts in the first and second embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0096] Here, in the first embodiment, depending on the position of the sealing member 80 relative to the guide housing 70 , there may not be a portion where the circumferential position of the groove 727 of the outer cylindrical portion 72 coincides with the circumferential position of the notch 931 of the outer peripheral seal portion 93 .

[0097] In contrast, the guide housing 270 and the sealing member 280 of the second embodiment are configured so that the circumferential positions of the grooves 727 of the outer cylindrical portion 72 constituting the first flow path 751 and the circumferential positions of the cutouts 931 of the outer peripheral sealing portion 93 always coincide with each other at four or more locations.

[0098] That is, the guide housing 270 differs from the guide housing 70 of the first embodiment in that seven grooves 727 are formed at equal intervals in the circumferential direction. In addition, the sealing component 280 differs from the sealing component 80 of the first embodiment in that twelve cutouts 931 are formed at equal intervals in the circumferential direction. Therefore, there must be at least four locations where the circumferential positions of the grooves 727 coincide with the circumferential positions of the cutouts 931. Figure 6 FIG. 7 shows a configuration in which there are five locations (circles in the figure) where the circumferential positions of the grooves 727 coincide with the circumferential positions of the cutouts 931 .

[0099] According to the rod guide 260 and the sealing member 280 of the second embodiment configured as described above, the oil that has moved to the second side through the gap between the rod 20 and the guide 61 can be quickly returned to the reservoir chamber R.

[0100] Further, in the example shown, seven grooves 727 are formed in the guide housing 270, and twelve notches 931 are formed in the seal member 280, but the numbers are not particularly limited to these. Either the number of grooves 727 or the number of notches 931 can be even, and the other can be odd. Thus, the circumferential positions of the grooves 727 and the circumferential positions of the notches 931 easily coincide. However, it is preferable that the number of notches 931 be greater than the number of grooves 727. This is because the oil that has moved to the second side through the gap between the rod 20 and the guide 61 can be quickly returned to the reservoir chamber R. Figure 7

[0101] <Third Embodiment>

[0102] Figure 8 is a perspective view showing an example of the outline structure of the rod guide 360 and the seal member 380 of the third embodiment.

[0103] The rod guide 360 of the third embodiment differs from the rod guide 60 of the first embodiment in the guide housing 370 corresponding to the guide housing 70. Also, the seal member 380 of the third embodiment differs from the seal member 80 of the first embodiment in the elastic portion 390 corresponding to the elastic portion 90. Hereinafter, the points different from the first embodiment will be described. In the first and third embodiments, the same reference numerals are used for the same parts, and detailed description thereof will be omitted.

[0104] In the guide housing 370 and the elastic portion 390 of the third embodiment, the circumferential positions of the grooves 727 of the outer cylindrical portion 72 constituting the first flow path 751 and the circumferential positions of the notches 931 of the outer peripheral seal portion 93 are made to coincide with high precision.

[0105] That is, in the guide housing 370, the fitting recess 371 recessed from the parallel face 725, the inclined face 724, and the vertical face 726 is formed between the groove 727 and the outer peripheral recess 723. The size of the circumferential direction of the fitting recess 371 is greater than the size of the circumferential direction of the groove 727 and is smaller than the size of the circumferential direction of the outer peripheral recess 723.

[0106] Also, in the elastic portion 390, the protruding portions 394 protruding inward from the inner peripheral face 935 are provided at both end portions in the circumferential direction of the notches 931 of the outer peripheral seal portion 393 corresponding to the outer peripheral seal portion 93. The size of the circumferential direction between the protruding portions 394 provided at both end portions in the circumferential direction of the notches 931 is smaller than the size of the circumferential direction of the fitting recess 371 of the guide housing 370.

[0107] ​Further, when the seal member 380 is arranged at the second side of the rod guide 360, the protrusions 394 provided at both circumferential end portions of the cutout 931 are fitted into the fitting recesses 371 of the guide housing 370. Thus, the circumferential position of the grooves 727 of the outer cylindrical portion 72 constituting the first flow path 751 coincides with the circumferential position of the cutout 931 of the outer peripheral seal portion 393 with high precision. As a result, the oil that has passed through the grooves 727 can be caused to quickly return to the reservoir chamber R via the cutout 931 and the outer peripheral recess 723 without moving in the circumferential direction.

[0108] Further, in the guide housing 370 and the elastic portion 390 of the third embodiment, the circumferential position of the grooves 727 coincides with the circumferential position of the cutout 931 with high precision, and thus the cutout 931 can also be formed in the same number as the grooves 727. Further, the number of the grooves 727 and the cutout 931 can also be less than that in the first embodiment. For example, the number of the grooves 727 and the cutout 931 can each be two.

[0109] <Fourth Embodiment>

[0110] Figure 9 FIG. 4 is a view showing an example of the schematic structure of a seal member 480 according to the fourth embodiment.

[0111] The seal member 480 of the fourth embodiment differs from the seal member 80 of the first embodiment in a ring 481 corresponding to the ring 81 and an elastic portion 490 corresponding to the elastic portion 90. Hereinafter, the points different from the first embodiment will be described. In the first and fourth embodiments, the same reference numerals are used for the same parts, and detailed description thereof will be omitted.

[0112] The ring 481 differs from the ring 81 of the first embodiment in that the first side end surface 811 is configured to be in contact with the second side end surface 720 of the guide housing 70. That is, a plurality of (for example, eight) recesses 482 recessed toward the second side from the first side end surface 811 are formed at the circumferential direction central portion of the ring 481 at equal intervals in the circumferential direction.

[0113] The elastic portion 490 differs from the elastic portion 90 of the first embodiment in a connection portion 495 corresponding to the connection portion 95 connecting the outer peripheral seal portion 93 and the central seal portion 94. The connection portion 495 is provided only at the portions where the recesses 482 are formed on the ring 481, and connects the outer peripheral seal portion 93 and the central seal portion 94 only at the portions where the recesses 482 are formed.

[0114] That is, in the seal member 480 of the fourth embodiment, the first side end surface 811 of which the recess 482 is not formed is not covered with the elastic portion 490 and is exposed. Also, in a state where the rod guide 60 and the seal member 480 are assembled, the first side end surface 811 is in contact with the second side end surface 720 of the guide housing 70. Thereby, it is possible to suppress a decrease in the axial holding force of the end portion of the second side of the outer cylinder 12 that is bent inwardly due to the elastic body interposed between the ring 481 of the seal member 480 and the guide housing 70.

[0115] < Fifth Embodiment >

[0116] Figure 10 is a drawing that shows an example of a perspective view of the rod guide 560 of the fifth embodiment viewed from the second side and a perspective view of the seal member 580 of the fifth embodiment viewed from the first side.

[0117] ​ is a drawing that shows an example of a cross section of the rod guide 560 and the seal member 580 of the fifth embodiment.

[0118] The rod guide 560 of the fifth embodiment differs from the rod guide 60 of the first embodiment in the guide housing 570 that corresponds to the guide housing 70. Also, the seal member 580 of the fifth embodiment differs from the seal member 80 of the first embodiment in the elastic portion 590 that corresponds to the elastic portion 90. Hereinafter, points that differ from the first embodiment are described. In the first embodiment and the fifth embodiment, the same reference numerals are used for the same parts, and detailed description thereof is omitted.

[0119] The guide housing 570 differs from the guide housing 70 of the first embodiment in that the groove 727 is not formed.

[0120] The elastic portion 590 differs from the elastic portion 90 of the first embodiment in the connecting portion 595 that corresponds to the connecting portion 95. The connecting portion 595 is formed with the recess 596 that is recessed from the first side end surface at a position where the cutout 931 is formed on the outer peripheral seal portion 93. The recess 596 is formed so as to be continuous with the cutout 931.

[0121] In the guide housing 570 and the elastic portion 590 of the fifth embodiment, in a state where the first side end surface of the connecting portion 595 of the elastic portion 590 is in contact with the second side end surface 720 of the outer side cylindrical portion 72 of the guide housing 70, oil that reaches the second side of the inner side cylindrical portion 71 of the guide housing 570 through the gap between the rod 20 and the guide 61 flows into the cutout 931 through the recess 596 of the connecting portion 595 and returns to the reservoir chamber R. That is, the first flow path 751 is constituted by the recess 596 of the connecting portion 595.

[0122] According to the rod guide 560 and the seal member 580 of the fifth embodiment, since the groove 727 does not need to be formed on the guide housing 570, the mold for molding the guide housing 570 can be provided in a simple structure. In addition, the oil that has passed through the recessed portion 596 of the connection portion 595 can be caused to not move in the circumferential direction and to quickly return to the reservoir chamber R via the cutout 931, the outer peripheral recessed portion 723.

[0123] Explanation of Reference Numerals

[0124] 1: suspension device; 2: shock absorbing device; 3: coil spring (example of spring); 10: cylinder portion; 11: inner tube; 12: outer tube; 20: rod; 30: piston portion; 60: rod guide; 75: flow path; 80: seal member; 91: seal lip portion (example of first seal portion); 93: outer peripheral seal portion (example of second seal portion); 94: central seal portion; 95: connection portion; 100: contact portion; 722: outer side recessed portion; 723: outer peripheral recessed portion; 724: inclined surface (example of pressed portion); 726: vertical surface; 727: groove; 751: first flow path; 752: second flow path; 753: third flow path; 754: fourth flow path; 755: fifth flow path; 931: cutout; 933: end portion; 938: protruding portion; R: reservoir chamber.

Claims

1. A damper comprising: an inner cylinder in which a working fluid is enclosed; an outer cylinder provided outside a periphery of the inner cylinder, a storage chamber in which the working fluid is stored being formed between the outer cylinder and the inner cylinder; a piston portion that divides a space formed inside the inner cylinder; a rod that holds the piston portion at one end portion and protrudes from an opening portion of the outer cylinder at the other end portion; a rod guide that supports the rod so as to be slidable and a periphery portion of which contacts an inner surface of the outer cylinder; and a seal member that is provided so as to form a contact portion that contacts the rod guide at a position of the rod that is closer to the opening portion than the rod guide in an axial direction of the rod, and has a first seal portion that seals between the seal member and the rod and a second seal portion that seals between the seal member and the inner surface of the outer cylinder, the rod guide has a pressed portion that is provided at an end portion of the periphery portion on the opening portion side, a portion of the second seal portion that is inside a portion that contacts the inner surface of the outer cylinder is pressed to the pressed portion, and a periphery recessed portion that is recessed from a periphery surface, a periphery flow path that returns the working fluid to the storage chamber is formed between the rod guide and the inner surface of the outer cylinder, a notch is formed at a portion of the second seal portion that is pressed to the pressed portion, the notch forms a relay flow path that causes the working fluid that reaches the opening portion side through a gap between the first seal portion and the rod to flow to the periphery flow path.

2. The damper according to claim 1, wherein a groove that communicates an inside and an outside of the contact portion is formed in the rod guide.

3. The damper according to claim 1, wherein a plurality of grooves that communicate the inside and the outside of the contact portion are formed in the rod guide, and the number of the notches is larger than the number of the grooves.

4. The damper according to claim 3, wherein either one of the number of the grooves and the number of the notches is even and the other is odd.

5. The damper according to claim 4, wherein four or more of the notches communicate with the plurality of grooves.

6. The damper according to claim 2, wherein the rod guide forms a circumferential flow path that allows the working fluid to move in a circumferential direction between the rod guide and the seal member, and the circumferential flow path communicates with the groove.

7. The damper according to claim 1, wherein the seal member has a third seal portion between the first seal portion and the second seal portion, the third seal portion allows the working fluid to flow from the first seal portion to the second seal portion, and suppresses the working fluid from flowing from the second seal portion to the first seal portion.

8. The damper according to claim 1, wherein a tip portion of the seal member in the axial direction is not pressed to the rod guide.

9. The damper according to claim 1, wherein a shape of the notch when viewed in the axial direction is quadrangular.

10. The damper according to claim 9, wherein a protrusion portion that protrudes from a bottom surface toward the rod guide is provided in the notch. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 11. A suspension device comprising: the damping device according to any one of claims 1 to 10; and a spring disposed around the damping device.

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