Switching valve and hydraulic shock absorber with the switching valve

Abstract

A switching valve (10) comprises a valve seat (54), a valve body (60), a through-flow section (73), and a restrictor (71a). The valve seat (54) has a valve seat surface (54b) formed on a circumferential edge of a valve opening (54a). The valve body (60) is a resin-molded part that moves in one direction along an axis (CL) of the valve seat surface (54b). The valve body (60) has a sealing part (61) with a curved sealing surface (61a) that seals the valve seat surface (54b), and an extension part (62) that extends from the sealing part (61) to a side opposite the sealing surface (61a). A mark (63) created during the injection molding of the valve body (60) remains on the extension part (62). The passage section (73) has an oil passage (73a) which forms part of a flow path (Fp) when the sealing surface (61a) is separated from the valve seat surface (54b).The restricting part (71a) limits the position of the extension part (62) in order to maintain an opening and closing position of the sealing surface (61a) relative to the valve seat surface (54b).

Description

TECHNICAL AREA

[0001] The present invention relates to a technique for improving a switching valve and a hydraulic shock absorber that includes the switching valve. STATE OF THE ART

[0002] Among switching valves, there is a so-called ball switching valve, which uses a spherical valve body that moves in one direction along the axis of a valve seat surface to make contact with and separate from the valve seat surface, thus opening and closing a valve orifice. This type of ball switching valve is frequently used, for example, in a check valve, a relief valve, and a hydraulic shock absorber. This type of ball switching valve is known, for example, from patent literature 1.

[0003] The ball-type switching valve known from patent literature 1 is provided in a hydraulic shock absorber (an electrically controlled damper) and comprises a valve seat with a tapered valve seat surface, a spherical valve body capable of contacting and separating from the valve seat surface, and a helical compression spring that presses the valve body against the valve seat surface. The valve body moves in one direction along an axis of the valve seat surface to open and close the valve orifice. The valve orifice communicates with a flow path through which oil flows. The preload force of the helical compression spring is transmitted to the valve body via the pressure element. When the valve body is pushed by the pushrod and separated from the valve seat surface, the valve orifice of the ball-type switching valve opens and the oil flows through the flow path.The spherical valve body has a high contact surface pressure with the valve seat surface and therefore exhibits good sealing properties. CITATION LIST PATENT LITERATURE

[0004] Patent literature 1: JP2016-176552A (see Fig. 3 and Fig. 4) SUMMARY OF THE INVENTIONAL PROBLEM

[0005] Since the valve body has a spherical shape, the entire spherical surface of the switching valve known from patent literature 1 can serve as a sealing surface. Therefore, the area where the valve body contacts the valve seat is not constant. The valve body can, for example, be formed from a resin molded part to reduce costs. During injection molding of the valve body, a mark (a mold track), such as a parting line or a gate, may be created. Regardless of the area where the valve body contacts the valve seat, it is necessary to polish the mark to avoid impairing the sealing performance of the valve body. If the manufacturing process of the valve body includes a polishing process, this is detrimental in terms of increasing the productivity of the valve body and reducing the manufacturing costs of the switching valve.

[0006] One object of the present invention is to provide a technique that is able to reduce the cost of a switching valve which includes a valve body made from a resin molded part, while ensuring sealing performance. SOLUTION TO THE PROBLEM

[0007] As a result of intensive studies, the present inventors focused on the fact that the sealing surface of the valve body, which is the only part in contact with the valve seat surface, can have a curved surface shape. It was then discovered that the position of the valve body can be limited by forming only the sealing surface of the valve body with a curved surface shape and the other section with a non-curved surface shape, thus making the section where the valve body contacts the valve seat surface constant. The present invention was developed based on this finding.

[0008] The present disclosure provides a switching valve which includes the following: comprising a valve seat, a valve opening designed to communicate with a flow path through which oil flows, and a valve seat surface formed on a circumferential edge of the valve opening; a valve body, which is an element manufactured from a resin molded part and which moves in one direction along an axis of the valve seat surface to come into contact with and separate from the valve seat surface in order to open and close the valve orifice, wherein the valve body comprises: comprising a sealing element comprising a sealing surface in a curved shape that rests against the valve seat surface to seal the valve opening; and an extension part which extends from the sealing part to a side opposite the sealing surface and is formed integrally with the sealing part, wherein a marking created during the injection molding of the valve body remains on the extension part; comprising a passage section, an oil passage designed to form part of the flow path when the sealing surface of the valve body is separated from the valve seat surface; and a restricting part designed to limit the position of the extension part in order to maintain an opening and closing position of the sealing surface relative to the valve seat surface. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0009] According to the present disclosure, it is possible to provide a technique that is able to reduce the cost of the switching valve, which includes the valve body manufactured from a resin molded part, while ensuring sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a cross-sectional view of a switching valve according to Example 1. Fig. 2 is an enlarged view of part 2 in Fig. 1. Fig. Figure 3 is an enlarged view of a valve device located in Fig. 2 is shown. Fig. Figure 4 is an exploded view of the valve assembly, which is located in Fig. 2 is shown. Fig. Figure 5 is an enlarged perspective view of a second valve body located in Fig. 4 is shown. Fig. Figure 6 is a cross-sectional view along a line defined by arrows 6-6 in Fig. 2 is displayed. Fig. 7 is an operating view of the valve device, which is located in Fig. 2 is shown in an open state. Fig. Figure 8 is a cross-sectional side view of a main part of a hydraulic shock absorber, which includes the switching valve that is in Fig. 1 is shown. Fig. Figure 9 is an enlarged view around the switching valve of the hydraulic shock absorber, which is located in Fig. 8 is shown. Fig. Figure 10 is a cross-sectional view of a switching valve according to Example 2. Fig. Figure 11 is an enlarged view of part 11 in Fig. 10. Fig. Figure 12 is an exploded view of a valve device located in Fig. 11 is shown. Fig. 13A is a side view of a second valve body, which is located in Fig. 12 is shown, and Fig. 13B is a view of the second valve body along a line indicated by an arrow 13B in Fig. 13A is displayed. Fig. Figure 14 is an enlarged view showing a relationship between a first valve body, the second valve body, and a helical compression spring located in Fig. 11 are shown. Fig. Figure 15 is a diagram showing a restricted inclination state of the second valve body relative to a second valve seat surface, which is in Fig. 14 is shown. Fig. Figure 16 is an operating view of the valve device, which is located in Fig. 11 is shown in an open state. DESCRIPTION OF EXECUTION FORMS

[0010] One embodiment of the present invention is described below with reference to the accompanying drawings. The embodiment shown in the accompanying drawings is an example of the present invention, and the present invention is not limited to such embodiments. <Beispiel 1>

[0011] A switching valve 10 according to Example 1 and a hydraulic shock absorber 100, which includes the switching valve 10, are described with reference to the Fig. 1 to Fig. 9 described.

[0012] As in Fig. As shown in 1, the switching valve 10 opens and closes a flow path Fp (see arrow Fp in Fig. 1), through which oil flows, and can be provided in various oil devices. The switching valve 10 has a configuration of an automatic valve, in which, for example, a valve device 11 is driven by an actuator 20. However, the switching valve 10 is not limited to the configuration of an automatic valve.

[0013] First, the actuator 20 is described. The actuator 20 is preferably provided by an electromagnetic solenoid that includes an actuating rod 21. The actuator 20 can optionally be referred to as the "electromagnetic solenoid 20". The electromagnetic solenoid 20 is a proportional solenoid in which the current supplied to an excitation coil 22 is proportional to the travel distance (the advance and retraction amount) of a piston 23. Furthermore, the electromagnetic solenoid 20 moves the piston 23 forward by exciting the excitation coil 22. The actuating rod 21 can move forward and backward together with the piston 23 in one direction along a center line CL of the actuating rod 21.In this way, since the electromagnetic solenoid 20 has the form of a proportional solenoid, the degree of opening of the valve device 11 can be adjusted according to the feed distance of the piston 23 and the actuating rod 21.

[0014] The excitation coil 22 and the piston 23 are housed in a tubular actuator housing 24. One end of the actuator housing 24 is closed by a cover 25. The actuating rod 21 extends through the cover 25.

[0015] The valve device 11 is provided at an end section of the actuator housing 24 via an amplifier mechanism 30. The amplifier mechanism 30 is located on one side opposite the electromagnetic solenoid 20 with respect to the cover 25. The amplifier mechanism 30 can achieve a large pressure force (output) with a small pressure force (input) from the actuating rod 21 by utilizing torque compensation.

[0016] The amplifier mechanism 30 includes, for example, a first pressure element 31, a second pressure element 32, and an elastic, plate-shaped element 33 arranged between these pressure elements 31 and 32. The first pressure element 31, the second pressure element 32, and the plate-shaped element 33 are arranged on the centerline CL of the actuating rod 21. The pressure force of the actuating rod 21, which depresses the first pressure element 31, is amplified by the plate-shaped element 33 and transmitted to the second pressure element 32. The second pressure element 32 integrally includes a pressure section 34 at its distal end (the lower end section). The pressure section 34 functions as a valve stem. The amplifier mechanism 30 is housed in a casing section 35, which is attached to an end section of the actuator housing 24.The housing section 35 is provided by a flat, plate-shaped first support element 36 that overlaps the cover 25, and a cup-shaped second support element 37 that overlaps the first support element 36.

[0017] The valve device 11 is detachably attached to the lower end of the amplifier mechanism 30. In particular, as shown in Fig. As shown in Figure 2, the valve device 11 has a configuration of a so-called pilot switching valve, which includes a valve housing 40 and a first valve body 50 and a second valve body 60, which are housed in the valve housing 40. Hereinafter, the switching valve 10 may optionally be referred to as the "pilot switching valve 10".

[0018] The valve housing 40 comprises a flat, plate-shaped first housing section 41, a cylindrical second housing section 42, and a cylindrical third housing section 43 with a base. Any two or all of these housing sections 41 to 43 can be integrated.

[0019] The first housing section 41 can be attached to the lower end of the second support element 37 (see Fig. 1) be fitted. A guide chamber 44, which directs the oil flowing from the valve assembly 11 to the outside, is formed between the first housing section 41 and the second support element 37. As in Fig. As shown in Figure 3, the first housing section 41 includes a first valve seat 41a on the centerline CL of the actuating rod 21. The first valve seat 41a has a first valve opening 41b which is capable of accommodating a flow path Fp (see Figure 3). Fig. 1) to communicate, through which the oil flows, and a first valve seat surface 41c, which is formed on the circumferential edge of the first valve opening 41b.

[0020] As in Fig. As shown in Figure 3, the second housing section 42 has a first oil inlet 42a which can be fitted into an end surface 41d (a surface 41d on the side opposite the amplifier mechanism 30) of the first housing section 41 and extends radially inwards and outwards.

[0021] As in Fig. As shown in Figure 2, the third housing section 43 can press the second housing section 42 against one end surface 41d of the first housing section 41. The third housing section 43 includes a cylindrical section 43a that surrounds an outer circumferential surface 42b of the second housing section 42, and a flat, plate-shaped base plate 43b that is integral with the base of the cylindrical section 43a. The base plate 43b of the third housing section 43 has at least one second oil inlet 43c (an opening 43c) that extends inwards and outwards, and a connecting groove 43d that communicates with the second oil inlet 43c. The second oil inlet 43c is located on the centerline CL of the actuating rod 21. The connecting groove 43d is formed on a base surface 43e of the base plate 43b and communicates with an outer circumferential surface 43f of the third housing section 43.

[0022] As in Fig. 3 and Fig. As shown in Figure 4, the first valve body 50 can open and close the first valve opening 41b by moving in one direction along a centerline CL (an axis CL of the first valve seat surface 41c) of the actuating rod 21 to make contact with and separate from the first valve seat surface 41c. The first valve body 50 is guided slidingly along the axis CL of the first valve seat surface 41c by an inner circumferential surface 42c of the second housing section 42. Furthermore, the first valve body 50 is a cylindrical element with a base, open towards the side of the base plate 43b of the third housing section 43, and includes a first cylindrical section 51, which is slidably fitted to the inner circumferential surface 42c of the second housing section 42, and a flat, plate-shaped first base plate 52 (also referred to as the first upper plate 52), which is integrally formed on the base of the first cylindrical section 51.

[0023] A base surface 52a of the first base plate 52 of the first valve body 50 is a flat surface orthogonal to the center line CL of the actuating rod 21 and has an annular first sealing surface 53 at the edge section. The first sealing surface 53 is a flat surface orthogonal to the center line CL of the actuating rod 21 and is flush with, convex to, or concave to the base surface 52a. The first valve body 50 is, for example, a resin molded part.

[0024] The combined structure of the first valve seat surface 41c of the first housing section 41 and a first sealing element 52a of the first valve body 50 forms a first valve 12. The first valve 12 functions as a main valve of the pilot switching valve 10 (the switching valve 10) and opens and closes by the first sealing element 52a coming into contact with and separating from the first valve seat surface 41c. The first valve 12 may optionally be referred to as the "main valve 12".

[0025] An inner bottom surface 52b (a bottom surface 52b on the inside) of the first bottom plate 52 of the first valve body 50 is a flat surface orthogonal to the centerline CL of the actuating rod 21 and includes a second valve seat 54 on the centerline CL of the actuating rod 21. The second valve seat 54 has a second valve opening 54a capable of communicating with the flow path Fp through which the oil flows, and a second valve seat surface 54b formed at the circumferential edge of the second valve opening 54a. The second valve opening 54a is located on the centerline CL of the actuating rod 21 and extends through the first bottom plate 52. The second valve seat surface 54b is, for example, a tapered surface or an arcuate surface that tapers from the inner bottom surface 52b of the first bottom plate 52 to the second valve opening 54a.

[0026] The first valve body 50 includes a small-diameter section 55 with a smaller diameter than the outer circumferential surface 50a on a section of the outer circumferential surface 50a that faces the first oil inlet 42a of the second housing section 42. An outer circumferential surface 50a of the first valve body 50 and an outer circumferential surface 55a of the small-diameter section 55 connect to a stepped surface 56. A chamber 57 is formed between the small-diameter section 55 and the inner circumferential surface 42c of the second housing section 42. The chamber 57 acts as a hydraulic chamber upstream of the first valve 12. The hydraulic pressure acting on the stepped surface 56 is converted into a force that pushes the first valve body 50 along the centerline CL in a direction away from the first valve seat 41a.

[0027] As in the Fig. 3 and Fig. As shown in Figure 4, the second valve body 60 is a resin molded part and preferably consists of a flexible resin and particularly preferably of a urethane resin (polyurethane) or nitrile rubber (NBR). The second valve body 60 moves in one direction along the center line CL (the axis CL of the second valve seat surface 54b) of the actuating rod 21 to come into contact with and separate from the second valve seat surface 54b, and can open and close the second valve opening 54a.

[0028] With reference also to Fig. In the second valve body 60, the integrally formed product comprises a second sealing part 61 with a second sealing surface 61a and an extension part 62 that extends from the second sealing part 61 to the side opposite the second sealing surface 61a. The second sealing surface 61a (the sealing area 61a) has a curved surface shape. The second sealing surface 61a is able to bear against the second valve seat surface 54b to seal the second valve opening 54a. The second sealing part 61, for example, has a hemispherical shape. The extension part 62 adjoins a bottom section 61b (a boundary 61b) of the second sealing part 61 and is formed as a columnar section with a diameter corresponding to the diameter Bd of the bottom section 61b. The base surface 62a of the extension part 62 is a flat surface orthogonal to the axis CL of the second valve seat surface 54b.

[0029] During the injection molding of the second valve body 60, a mark 63 (a mold track 63), such as a parting line or a gate, can form in the second valve body 60. In Example 1, the section where the mark 63 can form is preset in the extension part 62 of the second valve body 60, which does not require a sealing function. The mark 63 formed during the injection molding of the second valve body 60 remains on the extension part 62 without being removed.

[0030] As in Fig. As shown in Figure 3, the combined structure of the second valve seat surface 54b and the second sealing part 61 of the second valve body 60 forms a second valve 13. The second valve 13 functions as a pilot valve for the pilot switching valve 10 (the switching valve 10) and opens and closes by the second sealing part 61 coming into contact with and separating from the second valve seat surface 54b. The second valve 13 may optionally be referred to as the "pilot valve 13".

[0031] As in Fig. 3 and Fig. As shown in Figure 4, the second valve 13 includes a second retaining element 70 that holds the extension part 62. By fitting into the inner circumferential surface 51a of the first cylindrical section 51 of the first valve body 50, the second retaining element 70 is held slidably by the inner circumferential surface 51a. That is, the position of the second retaining element 70 is held by the first cylindrical section 51, and the second retaining element 70 is movable along the centerline CL (the axis CL of the second valve seat surface 54b) of the actuating rod 21. The first valve body 50 may optionally be referred to as the "first retaining element 50".

[0032] The second retaining element 70 has a recessed retaining bore 71 (a first recess 71) in an end surface 70a, which faces the inner bottom surface 52b of the first base plate 52 of the first valve body 50. An inner circumferential surface 71a, forming the second retaining bore 71, has a circular shape into which the column-shaped extension part 62 can be fitted. A bottom surface 71b of the retaining bore 71 is a flat surface orthogonal to the axis CL of the second valve seat surface 54b. The extension part 62 is fitted into the retaining bore 71 without a gap and is held, for example, by an interference fit. Therefore, the inner circumferential surface 71a, forming the retaining bore 71, limits the position of the extension part 62 in order to maintain the opening and closing position of the second sealing surface 61a relative to the second valve seat surface 54b.The base surface 62a of the extension part 62 preferably comes into contact with the base surface 71b of the retaining bore 71. The inner circumferential surface 71a of the retaining bore 71 can optionally be referred to as the "restricting part 71a". That is, the restricting part 71a is formed on the second retaining element 70. The second retaining element 70 is, for example, made of a resin molded part.

[0033] The columnar shape of the extension part 62 can be cylindrical. Forming the extension part 62 in a cylindrical shape makes it easier to fit the extension part 62 into the retaining bore 71.

[0034] The combined structure of the second valve body 60 and the second retaining element 70, which holds the position of the second valve body 60, forms a single valve body unit 81. That is, it can be considered that the valve body of the second valve 13 is provided by the entire valve body unit 81.

[0035] The second retaining element 70 is biased by a preload element 82 towards the base surface 52a of the first base plate 52 of the first valve body 50. The preload element 82 is provided, for example, by a helical compression spring. The preload element 82 may optionally be referred to as a "helical compression spring 82". The helical compression spring 82 is arranged between the base plate 43b of the third housing section 43 and the second retaining element 70. For example, the second retaining element 70 is provided with a spring receiving recess 72 (a second recess 72) that receives an end section 82a of the helical compression spring 82 on an end surface 70b (the other end surface 70b) opposite a section 71 (a retaining bore 71) that holds the extension part 62.The position of one end section 82a of the helical compression spring 82 relative to the second retaining element 70 is defined by fitting one end section 82a into the spring retaining recess 72. The bottom surface 72a of the spring retaining recess 72 is pre-tensioned by the helical compression spring 82 in a direction in which the second sealing surface 61a of the second valve body 60 rests against the second valve seat surface 54b.

[0036] With reference also to Fig. 6 The second valve 13 further comprises a passage section 73 formed at the second retaining element 70. The passage section 73 can form part of the flow path Fp (see arrow Fp in Fig. 1) form, through which the oil flows when the second valve 13 is open, that is, when the second sealing surface 61a of the second valve body 60 is separated from the second valve seat surface 54b. The passage section 73 includes at least one (preferably a plurality of) oil passages 73a formed on the outer circumferential surface 70c of the second retaining element 70. The oil passage 73a is provided, for example, by a groove formed on the outer circumferential surface 70b of the second retaining element 70, and the oil passage 73a extends in the axial direction CL of the second valve seat surface 54b. The groove-shaped oil passage 73a is closed by the inner circumferential surface 51a of the first cylindrical section 51 of the first valve body 50. Therefore, the oil can flow through the oil passage 73a.

[0037] As in the Fig. 3 and Fig. As shown in Figure 4, a section 74 of the outer circumferential surface 70c of the second retaining element 70, corresponding to the retaining bore 71 (the section 71 that holds the extension part 62), has a small diameter. A small-diameter chamber 75 is formed radially outside the small-diameter section 74. The chamber 75 forms a flow path for the oil flowing between the oil passage 73a and the second valve seat 54. The chamber 75 may optionally be referred to as the "oil flow path 75". In other words, the oil flow path 75 between the oil passage 73a and the second valve seat 54 is formed around the entire circumference by at least one section of the outer circumferential surface 70c of the second retaining element 70. This section holds the extension part 62.

[0038] As can be seen from the preceding description, the second valve 13 has an elongated shape, including the hemispherical second sealing part 61 and the column-shaped extension part 62. Furthermore, the extension part 62 is held by the second retaining element 70. Therefore, the length of the valve body assembly 81, formed by the combination of the second valve body 60 and the second retaining element 70 in the axial direction CL, is greater than that of a spherical valve body in the prior art.

[0039] On the other hand, the second valve body 60 and the second retaining element 70 are fitted and housed within the first valve body 50, which has a cylindrical shape with a base. The base surface 52a (the outer surface 52a) of the first base plate 52 of the first valve body 50 incorporates the first sealing element 52a of the first valve body 50 of the first valve 12. The inner base surface 52b (the inner surface 52b) of the first base plate 52 of the first valve body 50 incorporates the second valve seat 54 of the second valve 13. One of the features of the switching valve 10 is that the first base plate 52, which has a flat plate shape, incorporates both the first sealing element 52a and the second valve seat 54 on its front and back surfaces. The first valve 12 and the second valve 13 are arranged on both sides of the flat, plate-shaped first base plate 52 to position the first base plate 52 between them.Therefore, the switching valve 10 (the pilot switching valve 10), which includes both the first valve 12 and the second valve 13, can be reduced in size.

[0040] Next, the opening and closing process of the switching valve 10 will be described with reference to the Fig. 2 and Fig. 7 described.

[0041] In the switching valve 10 in which in Fig. In the state shown in Figure 2, the pressure section 34 is separated from the second valve body 60. Therefore, due to the preload force of the helical compression spring 82, the second sealing surface 61a of the second valve body 60 comes into contact with the second valve seat surface 54b and is closed, and the first sealing surface 53 of the first valve body 50 comes into contact with the first valve seat surface 41c and is closed. The first valve 12 and the second valve 13 are closed.

[0042] Then, when the pressure section 34 is lowered to press the second sealing part 61 of the second valve body 60, the pressure force is transferred from the extension part 62 of the second valve body 60 to the bottom surface 71b (see Fig. 3) the retaining bore 71 of the second retaining element 70. Therefore, as in Fig. As shown in Figure 7, the second valve body 60 and the second retaining element 70 are displaced in one direction away from the second valve seat surface 54b against the preload force of the helical compression spring 82. As a result, since the second sealing surface 61a of the second valve body 60 is separated from the second valve seat surface 54b, the second valve 13 is in an open state. The oil flowing from the second oil inlet 43c of the third housing section 43 (the valve housing 40) into the third housing section 43 flows through the oil passage 73a of the second retaining element 70 and the oil passage flow path 75 and flows out of the valve housing 40 through the gap between the second sealing surface 61a and the second valve seat surface 54b.

[0043] In a state where the second valve 13 is open, the first valve body 50 does not absorb the preload force of the helical compression spring 82. Therefore, due to the pressure difference of the oil between the upstream and downstream sides of the second valve 13, the first sealing surface 53 of the first valve body 50 is separated from the first valve seat surface 41c, and thus the first valve 12 is in an open state. As a result, the flow rate of the flow path Fp through which the oil flows can be increased.

[0044] Then, when the second pressure element 32 rises, the pressure section 34 separates from the second sealing part 61 of the second valve body 60. As a result, the preload force of the helical compression spring 82 returns the first valve 12 and the second valve 13 to their original closed state, which is in Fig. 2 is shown.

[0045] Next, an example of the use of the switching valve 10 will be given with reference to the Fig. 8 and Fig. 9 described. The switching valve 10 can be provided in various oil devices, for example, the hydraulic shock absorber 100. The hydraulic shock absorber 100 forms the main section of a front fork mounted on the front section of a straddle-seat vehicle, such as a two-wheeled or three-wheeled vehicle. The hydraulic shock absorber 100 includes a vehicle-body-side tube 101 and an axle-side tube 102 of a telescopic type, provided on the vehicle-body side and wheel-side, respectively, and a helical compression spring (not shown) that preloads the tubes 101 and 102 in a direction in which the tubes 101 and 102 are separated from each other. The space surrounded by the tubes 101 and 102 is filled with oil.

[0046] The lower end section of the axle-side tube 102 includes an axle-side bracket 103. The lower section of the axle-side tube 102 includes a bladder 104 and the switching valve 10. The bladder 104 can temporarily store excess oil in the axle-side tube 102.

[0047] The switching valve 10 can open and close the flow path Fp of the oil flowing between the shaft-side tube 102 and the bladder 104. The lower section of the shaft-side tube 102 has a valve mounting bore 105 with a base. As shown in Fig. As shown in Figure 1, the switching valve 10 can be attached to the axle-side pipe 102 (see Figure 1). Fig. 8) is attached by inserting it into the valve mounting bore 105 and screwing the actuator housing 24 to an inner circumferential surface 105a of the valve mounting bore 105. The bottom surface 43b (see Fig. 2) of the third housing section 43 is pressed against a bottom surface 105b of the valve mounting bore 105, so that the valve housing 40 is fixed between the actuator housing 24 and the bottom surface 105b of the valve mounting bore 105. <Beispiel 2>

[0048] A switching valve 200 according to example 2 is described with reference to the Fig. 10 to Fig. 16 described.

[0049] Fig. Figure 10 is a cross-sectional view showing the switching valve 200 according to Example 2, and corresponds to Fig. 1, which shows the switching valve 10 according to example 1 described above. Fig. Figure 11 is a cross-sectional view showing a valve device 211 according to Example 2, and corresponds to Fig. 2, which shows the valve device 11 according to Example 1 described above.

[0050] The switching valve 200 according to example 2, which is in the Fig. 10 and Fig. The one shown in Figure 11 differs from the switching valve 10 according to Example 1, which is shown in the Fig. 1 and Fig. As shown in Figure 2, the following embodiment is modified. First, the valve assembly 11 is changed to a valve assembly 211. Second, the third housing section 43 is changed to a third housing section 243, and the third housing section 243 also serves as the second housing section 42 according to Example 1. Third, the first valve body 50 is changed to a first valve body 250, and the first valve body 250 also serves as the second retaining element 70 according to Example 1. Fourth, the second valve body 60 is changed to a second valve body 260. Fifth, the preloading element 82 is changed to a preloading element 282. Other basic embodiments are the same as those of the switching valve 10 according to Example 1. Components common to the switching valve 10 according to Example 1 are designated by the same reference numerals, and their detailed description is omitted.

[0051] The switching valve 200 is described in detail below according to example 2.

[0052] As in Fig. As shown in Figure 10, the switching valve 200 has the configuration of an automatic valve, in which, for example, the valve assembly 211 is driven by the actuator 20. However, the switching valve 200 is not limited to the configuration of an automatic valve. The valve assembly 211 is detachably attached to the lower end of the amplifier mechanism 30.

[0053] In particular, as in Fig. As shown in Figure 11, the valve device 211 has a configuration of a so-called pilot switching valve, which includes a valve housing 240 and a first valve 212 and a second valve 213, which are housed in a valve housing 240. Hereinafter, the switching valve 200 may optionally be referred to as the "pilot switching valve 200".

[0054] The first valve 212 is provided by a combination of the first valve seat surface 41c of the first housing section 41 and the first sealing part 52a of the first valve body 250. The first valve 212 functions as a main valve of the pilot switching valve 200 (the switching valve 200) and opens and closes by the first sealing part 52a coming into contact with and separating from the first valve seat surface 41c. The first valve 212 may optionally be referred to as the "main valve 212".

[0055] The second valve 213 is formed by a combination of the second valve seat surface 54b and the second sealing part 61 (see Fig. 12) of the second valve body 260. The second valve 213 functions as a pilot valve for the pilot switching valve 200 (the switching valve 200) and opens and closes by the second sealing part 61 coming into contact with and separating from the second valve seat surface 54b. The second valve 213 may optionally be referred to as the "pilot valve 213".

[0056] As in Fig. 11 and Fig. As shown in Figure 12, the valve housing 240 comprises a flat, plate-shaped first housing section 41 and a cylindrical third housing section 243 with a base. These housing sections 41 and 243 can be integrated.

[0057] The third housing section 243 also serves as the cylindrical second housing section 42 (see Fig. 2) according to Example 1. The third housing section 243 can be fitted to one end face 41d of the first housing section 41 and has the first oil inlet 42a, which extends radially inwards and outwards. Other embodiments of the third housing section 243 are the same as those of the third housing section 43 according to Example 1.

[0058] The first valve body 250 is guided slidably along the axis CL of the first valve seat surface 41c by an inner circumferential surface 43g of the cylindrical section 43a of the third housing section 243. The first valve body 250 also serves as the second retaining element 70 according to Example 1. The first valve body 250 may optionally be referred to as the "retaining element 250". Other embodiments of the first valve body 250 are the same as those of the first valve body 50 according to Example 1.

[0059] The first valve body 250 is a cylindrical element with a base, open towards the side of the base plate 43b of the third housing section 243, and has an interior 251 surrounded by the inner circumferential surface 51a of the first cylindrical section 51 and the first base plate 52. The interior 251 can accommodate at least a portion of the second valve body 260 and the preload element 282. The interior 251 may optionally be referred to as the "housing recess 251".

[0060] By fitting into the inner circumferential surface 51a of the first cylindrical section 51 of the first valve body 250, the second valve body 260 is held slidably by the inner circumferential surface 51a. As shown in the Fig. 13A and Fig. As shown in Figure 13B, the second valve body 260 is a resin molded part and preferably consists of a flexible resin and particularly preferably of a urethane resin (polyurethane) or nitrile rubber (NBR). The second valve body 260 is an integrally molded product comprising the second sealing part 61 with the second sealing surface 61a, a large-diameter section 262 extending from the second sealing part 61 to a side opposite the second sealing surface 61a, and a small-diameter section 263 extending from the large-diameter section 262 to a further opposite side. The second sealing part 61, the large-diameter section 262, and the small-diameter section 263 are located on the axis CL of the second valve seat surface 54b (see Figure 13B). Fig. 11).

[0061] Since the second sealing part 61 has the same design and function as the second sealing part 61 (see Fig. 5) according to example 1 described above, its description is omitted.

[0062] The large-diameter section 262 has a tapered shape (including a substantially tapered shape) whose diameter increases from the bottom section 61b (the boundary 61b) of the second sealing part 61 to the side opposite the second sealing surface 61a. A tapered surface 262a (an outer surface 262a) of the large-diameter section 262 preferably extends along a tangent Tn to the second sealing surface 61a with a curved surface shape. A surface 262b of the large-diameter section 262 on a side opposite the bottom section 61b of the sealing part 61 is referred to as the "bottom surface 262b of the large-diameter section 262". A surface 262c of the large-diameter section 262 on a part with the largest diameter Cd is referred to as the "outer circumferential surface 262c of the large-diameter section 262".

[0063] The size of the diameter Cd of the outer circumferential surface 262c of the large-diameter section 262 is preferably set within a range capable of meeting the following two conditions. The first condition is that the outer circumferential surface 262c of the large-diameter section 262 is, relative to the inner circumferential surface 51a of the first cylindrical section 51 of the first valve body 250, which is located in Fig. As shown in Figure 11, it is smooth sliding. The second condition is that the offset amount of the large-diameter section 262 in the radial direction relative to the axis CL of the second valve seat surface 54b, which is shown in Figure 11, is smooth sliding. Fig. As shown in 11, it can be minimized.

[0064] The small-diameter section 263 extends from the base surface 262b of the large-diameter section 262 to a side opposite the base section 61b of the sealing part 61. The small-diameter section 263 has a columnar shape with a smaller diameter than the outer circumferential surface 262c of the large-diameter section 262.

[0065] The overall shape of the second valve body 260 is a so-called "mushroom shape". A section 264 of the second valve body 260 other than the sealing part 61 may optionally be designated as the "extension part 264". The extension part 264 corresponds to the extension part 62 described above according to Example 1. The extension part 264 has the large-diameter section 262 (the first extension part 262) in a tapered shape and the small-diameter section 263 (the second extension part 263) in a columnar shape.

[0066] During the injection molding of the second valve body 260, a mark 265 (a mold track 265), such as a parting line or a gate, can form in the second valve body 260. In Example 2, the section where the mark 265 can form is preset in the extension section 264 of the second valve body 260, which does not require a sealing function. The mark 265 formed during the injection molding of the second valve body 260 remains on the extension section 264 without being removed. For example, the section where the mark 265 can form is set on the outer circumferential surface 262c of the large-diameter section 262.

[0067] With reference also to Fig. 14 is a through-pass section 273 formed at the large-diameter section 262 of the second valve body 260. The through-pass section 273 can form part of the flow path Fp (see the arrow Fp in Fig. 10) form, through which the oil flows when the second valve 13 is open, that is, when the second sealing surface 61a of the second valve body 260 is separated from the second valve seat surface 54b. The through-passage section 273 has the outer circumferential surface 262c of the large-diameter section 262, is formed at the tapered surface 262a (of the outer surface 262a), and the through-passage section 273 extends in the axial direction CL of the second valve seat surface 54b. The through-passage section 273 has the outer circumferential surface 262c of the large-diameter section 262 and includes at least one (preferably a plurality of) oil passages 273a formed at the tapered surface 262a. The oil passage 273a, for example, includes the outer circumferential surface 262c of the large diameter section 262 and is provided by a flat surface or a groove formed on the tapered surface 262a.Therefore, the oil can flow through oil passage 273a.

[0068] As in Fig. As shown in Figure 14, the base surface 262b of the large-diameter section 262 of the second valve body 260 is pre-tensioned by the pre-tensioning element 282 in a direction in which the second sealing surface 61a bears against the second valve seat surface 54b. The second pre-tensioning element 282 is provided, for example, by a helical compression spring. The pre-tensioning element 282 may optionally be referred to as a "helical compression spring 282". The helical compression spring 282 is located between the base plate 43b (see Figure 14). Fig. 11) of the third housing section 43 and the bottom surface 262b of the large-diameter section 262. The position of the helical compression spring 282 relative to the first valve body 250 is defined by fitting the helical compression spring 282 into the housing recess 251.

[0069] The helical compression spring 282 preferably has a "conical helical compression spring" configuration, in which one side of the end section 282a, which abuts the base surface 262b of the large-diameter section 262, is tapered (the coil diameter is reduced). This is because the small-diameter section 263 of the second valve body 260 can be fitted into the coil of the helical compression spring 282 with substantially no gap. As a result, the coil center of the end section 282a of the helical compression spring 282 can be substantially aligned with the center (axis CL) of the second valve body 260. The end section 282a of the helical compression spring 282 can uniformly preload the base surface 262b of the large-diameter section 262.

[0070] The helical compression spring 282 limits the position of the second valve body 260 within a range in which the opening and closing position of the second sealing surface 61a relative to the second valve seat surface 54b is maintained. For example, as in Fig. As shown in Figure 15, where the center line QL of the second sealing surface 61a is inclined relative to the axis CL of the second valve seat surface 54b, the bottom surface 262b of the large-diameter section 262 and the small-diameter section 263 are also inclined together with the second sealing surface 61a. At this point, one end section 282a of the helical compression spring 282, which is pressed through the small-diameter section 263, repulses in a direction Rb in which the small-diameter section 263 is returned to the original axis CL.

[0071] Furthermore, the inclination of the base surface 262b of the large-diameter section 262 causes a preload to act on one end section 282a of the helical compression spring 282. At this point, reaction forces P1 and P2 (preload forces P1 and P2) acting from one end section 282a on the base surface 262b of the large-diameter section 262 are preloaded. In the base surface 262b, the first reaction force P2, acting in the direction of deep compression of one end section 282a, is greater than the first reaction force P1, acting in the direction away from one end section 282a. Due to the difference between the reaction forces P1 and P2, a moment in the direction Rb of returning the centerline QL of the second sealing surface 61a to the axis CL of the second valve seat surface 54b is generated in the second valve body 260.

[0072] In this way, the position of the second valve body 260 can be limited by the base surface 262b of the large-diameter section 262, the small-diameter section 263, and the helical compression spring 282. The small-diameter section 263 and the helical compression spring 282 can optionally be referred to as the "limiting part 263, 282".

[0073] As in Fig. As shown in Figure 14, the first valve body 250 (the retaining element 250) directly holds the second valve body 260. The helical compression spring 282 directly pre-tensions the second valve body 260. Therefore, the second retaining element 70 is in accordance with Example 1 described above, which is shown in Figure 1. Fig. Figure 3 is unnecessary. Accordingly, the number of components of the switching valve 200 can be reduced, and the size of the switching valve 200 can be reduced.

[0074] Next, the opening and closing process of the switching valve 200 will be described with reference to the Fig. 11, Fig. 14 and Fig. 16 described.

[0075] In the switching valve 200 in which in the Fig. 11 and Fig. In the state shown in Figure 14, the pressure section 34 is separated from the second valve body 260. Therefore, due to the preload force of the helical compression spring 282, the second sealing surface 61a of the second valve body 260 comes into contact with the second valve seat surface 54b and is closed, and the first sealing surface 53 of the first valve body 250 comes into contact with the first valve seat surface 41c and is closed. The first valve 212 and the second valve 213 are closed.

[0076] Subsequently, when the pressure section 34 is lowered to press the second sealing part 61 of the second valve body 260, the second valve body 260 is displaced in one direction away from the second valve seat surface 54b against the preload force of the helical compression spring 282. As a result, as shown in Fig. Figure 16 shows that the second sealing surface 61a of the second valve body 260 is separated from the second valve seat surface 54b, and the second valve 213 is in an open state. The oil flowing from the second oil inlet 43c of the third housing section 243 (the valve housing 240) into the third housing section 243 flows through the oil passage flow path 273 and flows out of the valve housing 240 through the gap between the second sealing surface 61a and the second valve seat surface 54b.

[0077] As in Fig. As shown in Figure 16, the first valve body 250, in a state where the second valve 213 is open, does not accept the preload force of the helical compression spring 282. Therefore, due to the pressure difference of the oil between the upstream and downstream sides of the second valve 213, the first sealing surface 53 of the first valve body 250 is separated from the first valve seat surface 41c, and thus the first valve 212 is in an open state. As a result, the flow rate of the flow path Fp, through which the oil flows, can be increased.

[0078] Then, when the second pressure element 32 rises, the pressure section 34 separates from the second valve body 260. As a result, the first valve 212 and the second valve 213 return to their original closed state by the preload force of the helical compression spring 282, which is in Fig. 11 is shown.

[0079] The operation and effect of the switching valve 200 according to Example 2 are the same as those of the switching valve 10 according to Example 1, which is described above. Similar to Example 1, the switching valve 200 according to Example 2 can be provided in various oil devices, for example, the hydraulic shock absorber 100 (see Fig. 8 and Fig. 9).

[0080] The switching valve 10, 200 and the hydraulic shock absorber 100 including the switching valve 10, 200 described above are summarized as follows.

[0081] It will be directed to the Fig. 1, Fig. 2, Fig. 10 and Fig. 11. Reference is made to this example. According to the present example, a switching valve 10, 200 first comprises a valve seat 54 (a second valve seat 54) having a valve opening 54a (a second valve opening 54a) capable of communicating with a flow path Fp through which the oil flows, and a valve seat surface 54b (a second valve seat surface 54b) formed on a circumferential edge of the valve opening 54a. Furthermore, the switching valve 10, 200 comprises an element 60, 260 made of a resin molded part, which moves in one direction along an axis CL of the valve seat surface 54b to come into contact with and separate from the valve seat surface 54b in order to open and close the valve opening 54a, that is, a valve body 60, 260 (a second valve body 60, 260).The valve body 60, 260 includes a sealing part 61 (a second sealing part 61) having a sealing surface 61a (a second sealing surface 61a) in a curved shape which is able to bear against the valve seat surface 54b in order to seal the valve opening 54a, as well as an extension part 62, 264 (see . Fig. 3 and Fig. 13A), which extends from the sealing part 61 to a side opposite the sealing surface 61a and is formed integrally with the sealing part 61. A marking 63, 265 created during the injection molding of the valve body 60, 260 (see Fig. 3 and Fig. 13A) remains on the extension part 62, 264. Furthermore, the switching valve 10, 200 includes a passage section 73, 273, which is capable of forming part of the flow path Fp when the sealing surface 61a of the valve body 60, 260 is separated from the valve seat surface 54b. The switching valve 10, 200 also includes a restricting part 71a, 263, 282, which is configured to restrict a position of the extension part 62, 264 in order to maintain an open and closed position of the sealing surface 61a relative to the valve seat surface 54b.

[0082] In this way, the valve body 60, 260, manufactured from a resin molded part, includes the sealing part 61 with the sealing surface 61a in a curved surface shape and the extension part 62, 264, which is formed integrally with the sealing part 61 to extend from the sealing part 61 to the side opposite the sealing surface 61a. A section of the marking 63, 265, such as a parting line or a gate, which may occur during the injection molding of the valve body 60, 260, is located in the extension part 62, 264. Since the extension part 62, 264 is a section that does not bear against the valve seat surface 54b, the sealing property is not required. Furthermore, the position of the extension part 62, 264 is restricted by the limiting part 71a, 263, 282.Even if the marking 63, 265 remains on the extension part 62, 264, the sealing properties of the sealing surface 61a for the valve seat surface 54b are not affected. Since it is not necessary to remove the marking 63, 265 from the extension part 62, 264, the manufacturing costs of the valve body 60, 260 can be reduced accordingly. In this way, it is possible to reduce the cost of the switching valve 10, 200, which includes the valve body 60, 260 manufactured from a resin molded part, while simultaneously ensuring sealing performance.

[0083] It will be on Fig. 2. Secondly, the switching valve 10, according to the first aspect, preferably includes a retaining element 70 (a second retaining element 70) configured to hold the extension part 62. The passage section 73 and the restricting part 71a are formed on the retaining element 70.

[0084] By holding the extension part 62 of the valve body 60 in place with the retaining element 70, the position of the sealing surface 61a of the valve body 60 relative to the valve seat surface 54b is stabilized. Therefore, the sealing properties of the switching valve 10 can be reliably maintained. Furthermore, since the passage section 73 with the oil passage 73a and the restrictor 71a are integrated into the retaining element 70, separate passage sections and restrictors are not required. The size of the switching valve 10 can be reduced.

[0085] It will be directed to the Fig. 2 and Fig. 7. Thirdly, in the switching valve 10 according to the first and second aspects, the passage section 73 is preferably provided by the oil passage 73a, which is formed on an outer circumferential surface 70c of the retaining element 70 (of the second retaining element 70), and the passage section 73 extends in the axial direction CL of the valve seat surface 54b.

[0086] The center of the retaining element 70 has a section 71 (a retaining bore 71) that holds the extension part 62 of the valve body 60 (of the second valve body 60). On the other hand, the outer circumferential surface 70c of the retaining element 70 is not restricted. Since the oil passage 73a is formed on the outer circumferential surface 70c of the retaining element 70, a large cross-sectional area of ​​the oil passage 73a can be ensured.

[0087] It will be directed to the Fig. 2 and Fig. 7. Fourthly, in the switching valve 10, according to the third aspect, an oil flow path 75 is formed between the oil passage 73a and the valve seat 54 (the second valve seat 54), preferably over an entire circumference around at least a section of the outer circumferential surface 70c of the retaining element 70. The section holds the extension part 62.

[0088] In the outer circumferential surface 70c of the retaining element 70, the oil flow path 75 with a relatively large cross-sectional area can be provided near the valve seat 54. When the switching valve 10 is open, the oil can flow from the oil passage 73a to the flow path Fp through the oil flow path 75, a space between the sealing surface 61a and the valve seat surface 54b of the valve body 60, and the valve opening 54a. By ensuring a large cross-sectional area of ​​the oil flow path 75, the flow resistance of the oil can be reduced, and the oil can flow more smoothly.

[0089] It will be directed to the Fig. 2 and Fig. 4. Fifthly, in the switching valve 10 according to the second to fourth aspects, the retaining element 70 is preferably provided with a spring receiving recess 72 which receives an end section 82a of a helical compression spring 82 on an end surface 70b opposite a section 71 (a retaining bore 71) which holds the extension part 62. A bottom surface 72a of the spring receiving recess 72 is pre-tensioned by the helical compression spring 82 in a direction in which the sealing surface 61a of the valve body 60 bears against the valve seat surface 54b.

[0090] The helical compression spring 82 indirectly pre-tensions the valve body 60 via the retaining element 70. Although the extension part 62 is held by the retaining element 70, the helical compression spring 82 can therefore stably pre-tension the valve body 60 in a direction in which the sealing surface 61a rests against the valve seat surface 54b.

[0091] It will be on Fig. 5. Sixthly, in the switching valve 10 according to the first to fifth aspects, the sealing part 61 preferably has a hemispherical shape. The extension part 62 connects to a bottom section 61b (a boundary 61b) of the sealing part 61 and is designed as a column-shaped section with the same diameter as the diameter Bd of the bottom section 61b.

[0092] The valve body 60 is an integrally formed product consisting of the hemispherical sealing part 61 and the column-shaped extension part 62 and is designed in a so-called spherical shape. Therefore, the valve body 60, in which the position of the extension part 62 is restricted by the limiting part 71a, can have a fairly simple design.

[0093] It will be directed to the Fig. 2 and Fig. 5. Seventhly, in the switching valve 10 according to the second to sixth aspects, the valve body 60 (the second valve body 60) is preferably a resin molded part made of a flexible resin. The retaining element 70 (the second retaining element 70) has a retaining bore 71 which holds the extension part 62. The extension part 62 is held in the retaining bore 71 by an interference fit. Urethane resin (polyurethane), nitrile rubber (NBR) or the like can be applied as the flexible resin.

[0094] The valve body 60 is made of urethane resin. Even if the marking 63 on the extension part 62 remains, the extension part 62 can be easily press-fitted into the retaining bore 71 of the retaining element 70, thus simplifying the retaining design. The valve body 60 can then be easily mounted onto the retaining element 70.

[0095] It will be directed to the Fig. 10 and Fig. 14 Reference is made to this. Eighth, in the switching valve 200 according to the first aspect, the extension part 264 preferably includes a tapered large-diameter section 262 (a first extension part 262) with a diameter that increases from the bottom section 61b (the boundary 61b) of the sealing part 61 (of the second sealing part 61) to a side opposite the sealing surface 61a. The through-pass section 273 is formed on an outer circumferential surface 262c of the large-diameter section 262, and the through-pass section 273 extends in the axial direction CL of the valve seat surface 54b. The switching valve 200 includes a retaining element 250 (a first valve body 250) which is configured to hold an outer circumferential surface 262c of the extension part 264 on a part with the largest outer diameter of the large-diameter section 262.

[0096] The retaining element 250 holds the outer circumferential surface 262c of the section with the largest outer diameter of the large-diameter section 262, which has a diameter that increases from the bottom section 61b of the sealing part 61. That is, the retaining element 250 can hold a section of the valve body 260 with a larger diameter than the sealing part 61. Therefore, the retaining element 250 can hold the valve body 260 stably.

[0097] Furthermore, the passage section 273 is formed on the outer circumferential surface 262c of the large-diameter section 262. Therefore, the sealing properties of the sealing part 61 can be ensured without forming the passage section 273 in the retaining element 250. The size of the retaining element 250 can be reduced.

[0098] It will be on Fig. Reference is made to paragraph 14. Ninthly, in the switching valve 200 according to the eighth aspect, the extension part 264 preferably includes a column-shaped small-diameter section 263 (a second extension part 263) which extends from a base surface 262b of the large-diameter section 262 to a side opposite the base surface 61b of the sealing part 61 and has a smaller diameter than the base surface 262b of the large-diameter section 262. The base surface 262b of the large-diameter section 262 is biased by a helical compression spring 282 in a direction in which the sealing surface 61a of the valve body 260 bears against the valve seat surface 54b. The small-diameter section 263 is fitted into a coil of the helical compression spring 282. The limiting part 263, 282 includes the small-diameter section 263 and the helical compression spring 282.

[0099] The helical compression spring 282 directly pre-tensions the base surface 262b of the large-diameter section 262 within the valve body 260. Therefore, the helical compression spring 282 can stably pre-tension the valve body 260 in the direction in which the sealing surface 61a contacts the valve seat surface 54b. Furthermore, the small-diameter section 263, which extends from the base surface 262b of the large-diameter section 262 to the side opposite the base section 61b of the sealing part 61, is fitted into the coil of the helical compression spring 282. Therefore, the limiting element 263, 282, which is designed to limit the position of the valve body 260 by means of the small-diameter section 263 and the helical compression spring 282, can have a simple design.

[0100] It will be on Fig.8 Reference is made to. Tenthly, the switching valve 10, 200, which is described in the first to ninth aspects, is preferably provided in the hydraulic shock absorber 100.

[0101] Since the hydraulic shock absorber 100 is equipped with the switching valve 10, 200, which is equipped with the valve body 60, 260 made from a resin molded part in order to reduce costs while ensuring sealing performance, it is possible to reduce the cost of the hydraulic shock absorber 100 while ensuring the properties of the hydraulic shock absorber 100 itself.

[0102] The switching valve 10, 200 and the hydraulic shock absorber 100, including the switching valve 10, 200, according to the present invention are not limited to the examples described above, as long as the operation and effect of the present invention are demonstrated. For example, the switching valve 10, 200 is not limited to the design of an automatic valve and can be a manually operated valve or a check valve. The switching valve 10, 200 is not limited to the pilot-type valve design. The amplifier mechanism 30 may or may not be provided, and the switching valve 10, 200 can be directly actuated by the electromagnetic solenoid 20. Commercial applicability

[0103] The switching valve 10, 200 according to the present invention is preferably applied to a pilot-type valve. The switching valve 10, 200 and the hydraulic shock absorber 100, which incorporates the switching valve 10, 200 according to the present invention, are suitable for mounting on a straddle-seat vehicle. Reference symbol list 10 switching valve 54 Valve seat (second valve seat) 54a Valve opening (second valve opening) 54b Valve seat surface (second valve seat surface) 60 valve bodies (second valve body) 61 Sealing part (second sealing part) 61a Sealing surface (second sealing surface) 61b Bottom section (boundary) of the sealing part 62 Extension part 63 Marking (form track) 70 Holding element (second holding element) 70b End face opposite the section holding the extension part 70c outer circumference Section 71 (retaining hole) for holding the extension part 71a Restriction section 72 Spring mounting recess 72a Base surface of the spring mounting recess 73 Passage section 73a Oil passage 75 Oil flow path 82 helical compression spring 82a an end section of the helical compression spring 100 hydraulic shock absorbers 200 switching valve 250 retaining element (second retaining element, first valve body) 260 valve bodies (second valve body) 262 Large diameter section (first extension part) 262b Floor area of ​​the large diameter section 262c Outer circumferential area of ​​the large diameter section 263 Small diameter section (second extension part, restrictor part) 264 Extension part 265 Marking (Form track) 273 Passage section 282 Screw compression spring (restriction part) Bd Diameter of the bottom section of the sealing part CL axis of the valve seat surface Fp Flow path through which the oil flows QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] JP 2016-176552A

[0004]

Claims

Switching valve (10, 200), comprising: a valve seat (54) having a valve opening (54a) configured to communicate with a flow path (Fp) through which oil flows, and a valve seat surface (54b) formed on a circumferential edge of the valve opening (54a); a valve body (60, 260) being an element made of a resin molded product, which moves in a direction along an axis (CL) of the valve seat surface (54b) to come into contact with and separate from the valve seat surface (54b) in order to open and close the valve opening (54a), wherein the valve body (60, 260) comprises: a sealing part (61) having a sealing surface (61a) in a curved shape which bears against the valve seat surface (54b) to seal the valve opening (54a);and an extension part (62, 264) extending from the sealing part (61) to a side opposite the sealing surface (61a) and formed integrally with the sealing part (61), wherein a mark (63, 265) created during the injection molding of the valve body (60, 260) remains on the extension part (62, 264); a passage section (73, 273) configured to form part of the flow path (Fp) when the sealing surface (61a) of the valve body (60, 260) is separated from the valve seat surface (54b); and a restricting part (71a; 263, 282) designed to restrict a position of the extension part (62, 264) in order to maintain an opening and closing position of the sealing surface (61a) relative to the valve seat surface (54b). Switching valve (10, 200) according to claim 1, further comprising: a retaining element (70) designed to hold the extension part (62), wherein the passage section (73) and the restriction part (71a) are formed on the retaining element (70). Switching valve (10, 200) according to claim 2, wherein the passage section (73) is provided by an oil passage (73a) formed on an outer circumferential surface (70c) of the retaining element (70), and the passage section (73) extends in the axial direction (CL) of the valve seat surface (54b). Switching valve (10, 200) according to claim 3, wherein an oil passage flow path (75) is formed between the oil passage (73a) and the valve seat (54) over an entire circumference around at least a section of the outer circumferential surface (70c) of the retaining element (70), in which the section holds the extension part (62). Switching valve (10, 200) according to claim 2, wherein the retaining element (70) is provided with a spring receiving recess (72) which receives an end section of a helical compression spring (82) on an end surface opposite to a section which holds the extension part (62), and wherein a bottom surface (72a) of the spring receiving recess (72) is pre-tensioned by the helical compression spring (82) in a direction in which the sealing surface (61a) of the valve body abuts the valve seat surface (54b). Switching valve (10, 200) according to claim 1, wherein the sealing part (61) has a hemispherical shape; and wherein the extension part (62) connects to a bottom section (61b) of the sealing part (61) and is designed as a column-shaped section with a diameter (Bd) corresponding to the diameter of the bottom section (61b). Switching valve (10, 200) according to claim 2, wherein the valve body (60) is the resin molded part made from a flexible resin, wherein the retaining element (70) has a retaining bore (71) which holds the extension part (62), wherein the extension part (62) is held in the retaining bore (71) by press fit. Switching valve (200) according to claim 1, wherein the extension part (264) has a tapered large-diameter section (262) with a diameter that increases from the bottom section (61b) of the sealing part (61) to a side opposite the sealing surface (61a), wherein the through-pass section (273) is formed on an outer circumferential surface (262c) of the large-diameter section (262) and the through-pass section (273) extends in the axial direction (CL) of the valve seat surface (54b), and wherein the switching valve (200) further comprises a retaining element (250) configured to hold an outer circumferential surface of the extension part (264) on a part having a largest outer diameter of the large-diameter section (262). Switching valve (10, 200) according to claim 8, wherein the extension part (264) has a column-shaped small diameter section (263) which extends from a bottom surface (262b) of the large diameter section (262) to a side opposite the bottom section (61b) of the sealing part and has a smaller diameter than the bottom surface (262b) of the large diameter section, wherein the bottom surface (262b) of the large diameter section (262) is biased by the helical compression spring (282) in a direction in which the sealing surface (61a) of the valve body abuts the valve seat surface (54b), wherein the small diameter section (263) is fitted into a coil of the helical compression spring (282), and wherein the limiting part is formed from the small diameter section (263) and the helical compression spring (282). Hydraulic shock absorber comprising the switching valve (10, 200) according to claim 1 .

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