Hydraulic device

Abstract

To provide a hydraulic device capable of sufficiently preventing leakage of pressure oil even when an oil path is a high-pressure circuit, by a check valve mechanism provided on mating surfaces of two components.SOLUTION: In a hydraulic device, a check valve mechanism 100 has a poppet 106 inserted into a poppet hole 156 and a seat part 111 with which an umbrella part 106B can come into contact, and a hole 11A in a main casing 11a and a hole 11B in a head casing 11b are in communication with each other and face each other. The hydraulic device has: a substantially annular O-ring groove 107 provided in the main casing 11a or the head casing 11b radially outward with respect to an opposing part of the hole 11A and the hole 11B with an axial core kA or an axial core kB as reference; an O-ring OR inserted into the O-ring groove 107; and a drain groove 150 provided radially outward with respect to the opposing part and radially inward with respect to the O-ring groove 107, and communicating with a drain port of the main casing 11a or the head casing 11b.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a hydraulic device equipped with a check valve mechanism. [Background technology]

[0002] Patent Document 1 discloses an axial piston double-type hydraulic pump comprising a pair of cylinder blocks, each of which has a plurality of cylinders mounted on a pair of rotating shafts rotatably supported within a casing and each of which has a plurality of cylinders through which pistons reciprocate, and a valve plate disposed between the casing and the end face of each cylinder block and having a pair of suction and discharge ports that communicate with each cylinder when the cylinder block rotates. In this hydraulic pump, the casing is composed of a cylindrical casing body having an abutment surface at one end, and a head casing that abuts against the abutment surface of the casing body and covers one end of the casing body. The abutment surface of the casing body is integrally formed with a stepped ring groove, which consists of a deep inner ring groove facing the inner periphery of the casing body and in which a backup ring is fitted, and a shallow outer ring groove located on the outer periphery of the inner ring groove and in which an O-ring is fitted between the backup ring and the inner ring groove.

[0003] Patent Document 2 discloses a check valve retaining device including a pipe body having an enlarged diameter portion formed by enlarging a portion of a pipe line formed along an axial direction and an opening formed in the peripheral wall of the enlarged diameter portion that opens over at least half of the axial circumference, a check valve unit accommodated in the enlarged diameter portion through the opening, and a slide tube attached to the pipe body and capable of sliding along the side of the pipe body along the axial direction to close the opening. In this check valve retaining device, an annular wall is formed at the end of the enlarged diameter portion of the pipe body, into which an end of the check valve unit, which has an O-ring disposed thereon, is fitted, and an annular spacer is disposed in a gap in the enlarged diameter portion when the check valve unit is fitted and attached to the annular wall. In addition, a pair of O-rings are arranged axially on the side of the pipe body, sandwiching the opening, and the inner surface of the slide tube contacts the pair of O-rings to seal the enlarged diameter portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-330850 [Patent Document 2] Patent No. 4755465 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a check valve mechanism is provided on the mating surface of two parts where pressure oil leakage may occur, if the oil passages are high-pressure circuits, the configurations of Patent Document 1 or Patent Document 2 are insufficient as a leakage prevention measure.

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide a hydraulic device that can sufficiently prevent leakage of pressurized oil even when the oil passage is a high-pressure circuit by using a check valve mechanism provided on the mating surfaces of two parts. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a check valve mechanism provided on a mating surface where the first hydraulic component and the second hydraulic component are connected, the check valve mechanism including a poppet hole provided in the first hole or the second hole, a poppet that is slidably inserted into the poppet hole and has a substantially rod-shaped stem and an umbrella portion, and a valve seat provided in the first hole or the second hole and that can be contacted by the umbrella portion of the poppet that slides within the poppet hole, and the first axis and the second axis are aligned. The hydraulic equipment has a first groove having a substantially annular shape, the first groove being provided radially outward from an opposing portion of the first hole and the second hole with respect to the first axis or the second axis, the first hydraulic component or the second hydraulic component being aligned with the first axis or the second axis, an O-ring inserted into the first groove, and a second groove being provided radially outward from the opposing portion and radially inward from the first groove, the second groove communicating with a drain port of the first hydraulic component or the second hydraulic component. [Effects of the Invention]

[0008] According to the present invention, the check valve mechanism provided on the mating surfaces of the two components can sufficiently prevent leakage of pressure oil even when the oil passage is a high-pressure circuit. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing the overall structure of a variable displacement hydraulic pump to which a check valve mechanism according to one embodiment of the present invention is applied. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view taken along the line BB in FIG. [Figure 4] FIG. 4 is a hydraulic circuit diagram showing the main parts of a hydraulic drive system for a construction machine, including the hydraulic pump shown in FIGS. 1 to 3. [Figure 5] FIG. 4 is an enlarged view of a main part in FIG. 3. [Figure 6] 6 is a cross-sectional view taken along the CC line in FIG. 5. [Figure 7] FIG. 3 is an enlarged cross-sectional view showing a check valve mechanism according to a first comparative example. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing a check valve mechanism according to a second comparative example. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing a modified example in which a poppet hole is provided in the head casing. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] <Variable displacement hydraulic pump> A variable displacement hydraulic pump to which the check valve mechanism of this embodiment is applied will be described with reference to Figures 1, 2, and 3. Figure 1 is a cross-sectional view showing the overall structure of the variable displacement hydraulic pump, Figure 2 is a cross-sectional view taken along line AA in Figure 1, and Figure 3 is a cross-sectional view taken along line BB in Figure 1.

[0012] 1 to 3, a hydraulic pump 10 has a casing 11, a cylinder block 12, a plurality of pistons 13, a tilting mechanism 14, and a tilting actuator 15. Note that, although the present embodiment illustrates an example in which the present invention is applied to a bent-axis hydraulic pump 10, the present invention can also be applied to hydraulic pumps other than bent-axis types.

[0013] The casing 11 is the main body of the hydraulic pump and includes a main casing 11a and a head casing 11b. The main casing 11a is a cylindrical member that houses the cylinder block 12 and the rotating shaft 16. The tip of the rotating shaft 16 (the right end in Figures 1, 2, and 3) protrudes from the casing 11 and is connected to the output shaft of the prime mover (engine or electric motor) of the construction machine on which the hydraulic pump 10 is mounted. A circular drive disk 16a is integrally formed at the base end (the left end in Figures 1, 2, and 3) of the rotating shaft 16. The rotating shaft 16 is inserted into the main casing 11a from an opening on one side (the right side in Figures 1, 2, and 3) and is rotatably supported relative to the main casing 11a via bearings 16b and 16c, with the drive disk 16a facing the cylinder block 12. The head casing 11b closes the opening on the other side (the left side in FIGS. 1, 2, and 3) of the main casing 11a.

[0014] The cylinder block 12 is housed inside the main casing 11a and is connected to the drive disk 16a via a center shaft 17, rotating together with the rotary shaft 16. A plurality of cylinder chambers 12a are formed in the cylinder block 12 in the axial direction. These cylinder chambers 12a are arranged in a ring shape around the rotational center line of the cylinder block 12. A piston 13 is inserted inside each cylinder chamber 12a so that it can slide back and forth. A connecting rod 13a is attached to the base end (the right end in Figures 1, 2, and 3) of each piston 13. The tip of each connecting rod 13a is a joint ball 13b, and each piston 13 is connected to the drive disk 16a via the joint ball 13b so that it can swing freely.

[0015] The tilt mechanism 14 adjusts the stroke amount (pump capacity) of the piston 13 relative to the cylinder chamber 12a and includes a valve plate 14a with a cylindrical lens-shaped sliding surface 14b. A center shaft 17 and a swing pin 18 are inserted into the center of the valve plate 14a from both sides. The center shaft 17 passes through the rotation center of the cylinder block 12 and is connected to the drive disk 16a. The center shaft 17 and the cylinder block 12 rotate together. The opposing surfaces of the valve plate 14a and the cylinder block 12 form a rotational sliding surface, and the cylinder block 12 rotates and slides relative to the valve plate 14a around the center shaft 17. The tip of the center shaft 17 (the right end in Figures 1, 2, and 3) forms a joint ball 17a, and the center shaft 17 is connected to the drive disk 16a via this joint ball 17a so that it can swing freely.

[0016] The valve plate 14a has a sliding surface 14b that slides on an arc-shaped guide surface formed in the head casing 11b, and the cylinder block 12 and valve plate 14a swing back and forth along an arc orbit around a swing centerline that passes through the center of the joint ball 17a. The valve plate 14a also has ports 14c and 14d (see FIG. 1) that intermittently communicate with each cylinder chamber 12a as the cylinder block 12 rotates. The ports 14c and 14d communicate with oil passages 11c and 11d in the head casing 11b regardless of the position of the valve plate 14a. Therefore, when the tilt angle (tilt angle) of the center shaft 17 relative to the rotary shaft 16 changes, the stroke amount (pump capacity) of the piston 13 relative to the cylinder chamber 12a changes, and the amount of hydraulic oil supplied and discharged via the oil passages 11c and 11d also changes.

[0017] The tilt actuator 15 is a sector-type variable displacement mechanism. The tilt mechanism 14 is driven by a servo piston 15b that reciprocates axially inside a cylinder chamber 15a formed in the head casing 11b, causing the valve plate 14a to slide along the guide surface. The interior of the cylinder chamber 15a is separated into two pressure-receiving chambers 15A and 15B by the servo piston 15b. A corresponding pilot port (not shown) is connected to the pressure-receiving chamber 15A, and a corresponding pilot port (not shown) is connected to the pressure-receiving chamber 15B. The pressure-receiving chamber 15A is constantly pressurized via the corresponding pilot port. When the pressure-receiving chamber 15B is pressurized via the corresponding pilot port, the servo piston 15b moves upward in FIG. 2, and when the pressure-receiving chamber 15B is depressurized, the servo piston 15b moves downward in FIG. 2. The valve plate 14a is connected to the servo piston 15b via the swing pin 18, and the tilt is changed by driving the servo piston 15b.

[0018] 3, a check valve mechanism 100 is provided at the mating surface where the main casing 11a and the head casing 11b are connected. Details of this check valve mechanism 100 will be described later. The check valve mechanism 100, the main casing 11a, and the head casing 11b constitute a hydraulic device, with the main casing 11a constituting a first hydraulic component and the head casing 11b constituting a second hydraulic component.

[0019] In the hydraulic pump 10 configured as described above, when the rotating shaft 16 is driven to rotate by the prime mover, the drive disk 16a and the cylinder block 12 rotate, causing each piston 13 to sequentially reciprocate within the cylinder chamber 12a. When the piston 13 is pulled out of the cylinder chamber 12a, hydraulic oil is sucked into the cylinder chamber 12a, for example, from the oil passage 11c via the port 14c. When the piston 13 is pushed into the cylinder chamber 12a, the hydraulic oil inside the cylinder chamber 12a is pressurized and discharged from the port 14d via the oil passage 11d. The intake flow rate and discharge flow rate change depending on the tilt angle.

[0020] <Hydraulic circuit> The hydraulic pump 10 in this embodiment discharges and supplies pressure oil to a hydraulic actuator (hydraulic motor, hydraulic cylinder, etc.) provided in, for example, a construction machine. The tilting angle of this hydraulic pump 10 is adjusted by drive control of the tilting actuator 15 using a regulator 41. A hydraulic circuit diagram showing the main parts of the hydraulic drive system of the construction machine, including this regulator 41 and hydraulic pump 10, is shown in FIG.

[0021] 4, the regulator 41 includes a solenoid 42, spools 43 and 44, a spring 45, a piston chamber 46, and a drain chamber 47. A discharge line PL of an auxiliary pump (pilot pump, not shown) that is mounted on the construction machine separately from the hydraulic pump 10 is connected to input ports 44a and 44b of the regulator 41. The discharge line PL of the auxiliary pump is connected to the input ports 44a and 44b of the regulator 41 as well as to the pressure-receiving chamber 15B of the tilt actuator 15. The regulator 41 is driven by a command signal (excitation current) input to the solenoid 42 from, for example, a controller (not shown).

[0022] In this example, the primary pressure (regulator primary pressure) that controls the servo piston 15b uses the discharge pressure via the conduit 11P in the head casing 11b when the pressure is high, and the pilot pressure via the discharge line PL of the auxiliary pump when the pressure is low. To realize this method, the illustrated hydraulic circuit is provided with two check valve mechanisms for switching pressure, namely, the check valve mechanism 100 that is a main part of this embodiment, and another check valve mechanism 200.

[0023] <Behavior when primary pressure is low> The operating behavior when the primary pressure of the regulator is low is as follows. That is, for example, when the command amount of the command signal to the solenoid 42 increases, the spool 43 moves downward in FIG. 4 against the biasing force of the spring 43a, and the opening ratio of the oil passage connecting the port 44a communicating with the discharge line PL of the auxiliary pump and the piston chamber 46 increases. As a result, the spool 44 moves upward in FIG. 4 against the biasing force of the spring 45. As a result, the opening ratio of the oil passage connecting the pressure receiving chamber 15A of the tilting actuator 15 and the tank (not shown) increases, the servo piston 15b moves upward in FIG. 4, and the tilting angle of the hydraulic pump 10 described above increases. As a result, the pump capacity of the hydraulic pump 10 increases, and the flow rate of pressure oil supplied from the hydraulic pump 10 to the hydraulic actuator increases.

[0024] Conversely, for example, if the command amount of the command signal to the solenoid 42 decreases, the spool 43 moves upward in FIG. 4 due to the biasing force of the spring 43a. This increases the open ratio of the oil passage connecting the piston chamber 46 and the drain chamber 47 (decreases the open ratio of the oil passage connecting the piston chamber 46 and the discharge line PL of the auxiliary pump), and the spool 44 moves downward in FIG. 4 due to the biasing force of the spring 45. This increases the open ratio of the oil passage connecting the pressure receiving chamber 15A of the tilting actuator 15 and the port 44b communicating with the discharge line PL of the auxiliary pump, and the servo piston 15b moves downward in FIG. 4, thereby reducing the tilting angle. This reduces the pump capacity of the hydraulic pump 10, and reduces the flow rate of pressure oil supplied from the hydraulic pump 10 to the actuator.

[0025] <Check valve mechanism> The check valve mechanism 100, which is a main part of this embodiment, will be described in detail with reference to Fig. 3. Fig. 5 is an enlarged view of the main part in Fig. 3, and Fig. 6 is a view taken along the CC cross section in Fig. 5.

[0026] 5 and 6, the check valve mechanism 100 is provided on the mating surface where the main casing 11a and the head casing 11b are connected. A hole 11A (first hole) having an axis kA (first axis) is formed in the main casing 11a, and a hole 11B (second hole) having an axis kB (second axis) is formed in the head casing 11b. The hole 11A and the hole 11B form an oil passage for the pressurized oil discharged from the hydraulic pump 10.

[0027] 5, in this embodiment, the axis kA and the axis kB are aligned, and the hole 11A in the main casing 11a and the hole 11B in the head casing 11b are opposed to and communicate with each other with the axis kA or the axis kB as the reference. The check valve mechanism 100 has a poppet hole 156 provided in the hole 11A, a poppet 106 slidably inserted into the poppet hole 156, and a seat portion 111 (valve seat portion) provided in the hole 11A or the hole 11B.

[0028] The poppet 106 has a generally rod-shaped stem 106A and an umbrella portion 106B, and moves along the axis kA due to the pressure difference in the poppet hole 156. The umbrella portion 106B of the poppet 106 sliding inside the poppet hole 156 comes into contact with the seat portion 111, thereby limiting the movement of the poppet 106. In this example, the seat portion 111 is provided on the edge of the hole 11B.

[0029] In this embodiment, a substantially annular O-ring groove 107 (first groove) is provided in the main casing 11a radially outward from the opposing portion of the hole 11A and the hole 11B relative to the axis kA. An O-ring OR is inserted and disposed in the O-ring groove 107. That is, the O-ring groove 107 is a groove for mounting an O-ring OR for preventing oil leakage on one end face of the main casing 11a.

[0030] Furthermore, a drain groove 150 (second groove) that communicates with the drain port 11D (see Figure 4 above) of the main casing 11a is provided radially outward from the opposing portion and radially inward from the O-ring groove 107 in the main casing 11a.

[0031] In the above configuration, a small amount of high-pressure oil flows out from the poppet hole 156 through the gap between the main casing 11a and the head casing 11b. However, because there is only a small gap between the casings 11a and 11b, the pressure of the pressurized oil between the casings 11a and 11b behaves as shown by P1 to P5 in FIG. 5. That is, pressure P1 at the poppet hole 156 decreases from pressure P1 to pressure P2 to pressure P3 as the pressure moves radially outward from the poppet hole 156, and then suddenly decreases to pressure P4, which is equal to the drain pressure (≈ case internal pressure), in the drain groove 150 communicating with the drain port 11D. As a result, only pressure P5, which is even lower than pressure P4, is applied to the O-ring OR located further radially outward from the drain groove 150.

[0032] It should be noted that the present invention is not limited to the above-described configuration in which an O-ring OR is disposed in the O-ring groove 107. In other words, since it is sufficient to simply have the function of preventing low-pressure oil leakage, a sealing method such as a gasket may be used for the O-ring OR.

[0033] <Effects of the embodiment> In the present embodiment configured as described above, the main casing 11a and the head casing 11b are connected to face each other. Specifically, they are connected so that the axis kA of the hole 11A in the main casing 11a and the axis kB of the hole 11B in the head casing 11b are aligned with each other (i.e., coaxial). In this case, a check valve mechanism 100 is provided at the mating surface between the main casing 11a and the head casing 11b, where leakage of pressure oil may occur. The check valve mechanism 100 is composed of a poppet hole 156, a poppet 106 slidably inserted into the poppet hole 156, and a seat portion 111 with which the head portion 106B of the poppet 106 can come into contact.

[0034] When a pressure oil passage is formed by holes 11A and 11B that share the same axis, pressure oil flows out from the gap between the main casing 11a and the head casing 11b, which are in contact with each other. In this embodiment, pressure oil that flows out from this gap can be reliably prevented from leaking outside the main casing 11a and the head casing 11b. This effect will be described in detail below with reference to two comparative examples in Figures 7 and 8. Parts equivalent to those in the above embodiment are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0035] A first comparative example is shown in Fig. 7. In Fig. 7, in this first comparative example, an O-ring groove 107 for mounting an O-ring OR is provided on one end face of the main casing 11a and is integrally formed radially outside of and communicates with the poppet hole 156. With this configuration, the poppet 106 may bite the O-ring OR at the seat portion 111 during operation, which could damage the O-ring OR, making it less reliable.

[0036] A second comparative example is shown in Fig. 8. In Fig. 8, in this second comparative example, a partition wall 120 is added between the O-ring groove 107 and the poppet hole 156 to address the above-mentioned concerns of the first comparative example 1. In this case, there is no risk of the poppet 106 getting caught in the O-ring OR as in the first embodiment, but the diameter of the O-ring groove 107 is increased by the amount of the partition wall 120 added. As a result, the surface pressure of the O-ring OR increases, making it easier for the gap between the main casing 11a and the head casing 11b to open up, and sufficient leakage prevention cannot be achieved.

[0037] On the other hand, in this embodiment, as described above, pressure oil leaking between the main casing 11a and the head casing 11b is sealed by the O-ring OR inserted in the O-ring groove 107 located radially outward of the opposing portion where the holes 11A and 11B communicate with each other. In this case, the drain groove 150, which communicates with the drain port of the main casing 11a, is provided radially outward of the opposing portion (radially inward of the O-ring OR). Therefore, even if high-pressure pressure oil leaks out, the high pressure can be reduced to the drain pressure by the drain groove 150 (see the behavior of pressure P1 → P2 → P3 → P4 → P5 described above). This prevents the gap between the main casing 11a and the head casing 11b from opening, as in the second comparative example. Furthermore, as a result of the above, only low pressure is applied to the O-ring OR inserted in the O-ring groove 107, and therefore the O-ring OR is not damaged, as in the first comparative example. As a result, this embodiment provides highly reliable and sufficient leakage prevention.

[0038] Although it is necessary to process the drain groove 150 in the main casing 11a, the number of parts constituting the check valve mechanism 100 is reduced, thereby reducing costs. Furthermore, as a result of reducing the number of parts, the check valve mechanism 100 itself can be easily assembled and disassembled. Furthermore, the check valve mechanism 100 as a whole can be made smaller, which saves space during installation, so the above configuration can be applied to narrow places where it would not normally be possible.

[0039] In this embodiment, the above-described configuration is particularly provided in the hydraulic pump 10 that discharges pressure oil, and the holes 11A and 11B form an oil passage for the discharged pressure oil. That is, this embodiment can be applied to a high-pressure circuit to which high-pressure pressure oil discharged from the hydraulic pump 10 is guided as described above, and can sufficiently prevent leakage from the high-pressure circuit with high reliability.

[0040] Furthermore, this embodiment can be particularly applied to a variable displacement hydraulic pump 10. In this case, the pump has a main casing 11a that houses the rotating shaft 16, the cylinder block 12, and the piston 13, and a head casing 11b that houses the servo piston 15b and the cylinder chamber 15a. By providing the check valve mechanism 100 on the mating surface between the main casing 11a and the head casing 11b and configuring them as described above, it is possible to sufficiently prevent leakage even if high-pressure oil flows out of the oil passages of the variable displacement hydraulic pump 10.

[0041] Furthermore, particularly in this embodiment, the check valve mechanism 100 is configured such that the poppet 106 is inserted into the poppet hole 156 of the hole 11A of the main casing 11a, and the head portion of the poppet 106 contacts the seat portion 111 at the edge of the hole 11B of the head casing 11b that faces the main casing 11a. The check valve mechanism 100 configured in this manner can provide sufficient leakage prevention with high reliability even when high-pressure oil leaks out.

[0042] <Modification> The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit and technical concept of the present invention. Such modifications will be described below in order.

[0043] (1) When providing a poppet hole in the head casing This modified example is shown in Figure 9, which corresponds to Figure 5 of the above embodiment. In Figure 9, in this modified example, the poppet hole 156 is provided in the hole 11B of the head casing 11b, and the seat portion 111 is provided at the bottom of the poppet hole 156 provided in the hole 11B.

[0044] The O-ring groove 107 and the drain groove 150 are provided in the main casing 11a, as in the above embodiment. That is, the O-ring groove 107 is provided in the main casing 11a, radially outward from the opposing portion of the hole 11A and the hole 11B with respect to the axis kA. Furthermore, the drain groove 150, which communicates with the drain port 11D of the main casing 11a, is provided in the main casing 11a, radially outward from the opposing portion and radially inward from the O-ring groove 107.

[0045] The O-ring groove 107 and the drain groove 150 may be provided on the head casing 11b side. In this case, the O-ring groove 107 is provided in the main casing 11a radially outward from the opposing portion with respect to the axis kB, and the drain groove 150, which communicates with the drain port 11D of the head casing 11b, is provided radially outward from the opposing portion and radially inward from the O-ring groove 107.

[0046] In this modified example, the check valve mechanism 100 is configured such that a poppet 106 is inserted into a poppet hole 156 in the hole 11B of the head casing 11b, and an umbrella portion 106B of the poppet 106 contacts a seat portion 111 provided at the bottom of the hole 11B of the head casing 11b. According to this modified example, even if high-pressure oil leaks in the check valve mechanism 100 configured in this way, sufficient leakage prevention can be achieved with high reliability, as in the above embodiment. Furthermore, according to this modification, in the head casing 11b, the seat portion 111 of the hole 11B and the poppet hole 156 can be machined simultaneously using the axis kB as a reference, so that their coaxiality can be easily ensured. As a result, the sealing performance of the seat portion 111 can be reliably and satisfactorily ensured.

[0047] (2) When applied to a control valve In the above embodiment and modified example (1), the present invention has been described with reference to an example in which it is applied to the oil passage of the hydraulic pump 10, but the present invention is not limited to this. That is, the configuration of the present invention including the check valve mechanism 100 may be applied to the oil passage of a control valve arranged between a hydraulic source such as a hydraulic pump and a hydraulic actuator (not shown). In this case, the first hole and the second hole described above constitute the oil passage for pressurized oil from the hydraulic source. In this modified example, by applying the present invention to the high-pressure circuit in the control valve provided between the hydraulic power source and the hydraulic actuator, it is possible to sufficiently prevent leakage from the high-pressure circuit with high reliability.

[0048] (3) Other <About the problem to be solved and the effects of the invention> The problems to be solved by the invention and the effects of the invention are not limited to those described above. That is, the present invention may solve problems or achieve effects not described above, or may solve only some of the problems or achieve only some of the effects described above. <About shape, numbers, structure, and time series> Concerning the components illustrated in the embodiments and drawings, the shapes, values, and interrelationships between the structures of multiple components can be arbitrarily modified and improved within the scope of the technical concept of the present invention.

[0049] <equal to> It should be noted that the term "equal" in the above description does not have a strict meaning. In other words, "equal" means "substantially equal," allowing for tolerances and errors in design and manufacturing.

[0050] In addition to the above, the methods according to the above embodiments and modifications may be used in appropriate combination.

[0051] Although not specifically illustrated, the present invention can be implemented with various modifications within the scope of the invention. [Explanation of symbols]

[0052] 10 Hydraulic pump 11A hole (1st hole) 11a Main casing (first hydraulic component) 11B hole 11b Head casing (second hydraulic component) 11D Drain port 12 Cylinder block 13 Piston 15a Cylinder chamber 15b Servo piston 16 Rotation Axis 16a drive disk 17 Center shaft 41 Regulator 100 Check valve mechanism 106 Poppet 106A stem 106B Umbrella section 107 O-ring groove (first groove) 111 Seat portion (valve seat portion) 150 Drain groove (second groove) 156 Poppet hole kA Axis center (1st axis center) kB Axis center (2nd axis center)

Claims

1. a first hydraulic component having a first hole with a first axis; a second hydraulic component having a second hole with a second axis; a check valve mechanism provided on a mating surface where the first hydraulic component and the second hydraulic component are connected, the check valve mechanism includes a poppet hole provided in the first hole or the second hole, a poppet slidably inserted into the poppet hole and including a substantially rod-shaped stem and an umbrella portion, and a valve seat provided in the first hole or the second hole and contactable by the umbrella portion of the poppet sliding within the poppet hole, In a hydraulic device in which the first axis and the second axis are aligned, and the first hole of the first hydraulic component and the second hole of the second hydraulic component are opposed to each other while communicating with each other with respect to the first axis or the second axis, a substantially annular first groove provided in the first hydraulic component or the second hydraulic component radially outward from an opposing portion of the first hole and the second hole with respect to the first axis center or the second axis center; an O-ring inserted into the first groove; a second groove provided radially outward from the opposing portion and radially inward from the first groove, the second groove communicating with a drain port of the first hydraulic component or the second hydraulic component; A hydraulic device comprising:

2. The hydraulic device according to claim 1, It is installed in a hydraulic pump that discharges pressurized oil, The first hole and the second hole form an oil passage for the discharged pressure oil. A hydraulic device characterized by:

3. The hydraulic device according to claim 2, The hydraulic pump a rotating shaft connected to the output shaft of the prime mover and equipped with a drive disc; a cylinder block connected to the drive disk via a center shaft and including a plurality of cylinder chambers; a piston inserted into the cylinder chamber so as to be reciprocally slidable and connected to the drive disk so as to be able to swing freely; a servo piston that changes the inclination angle of the center shaft with respect to the rotation axis to change the stroke amount of the piston; a cylinder chamber in which the servo piston reciprocates; A variable displacement pump having The first hydraulic component is a pump casing that houses the rotating shaft, the cylinder block, and the piston; The second hydraulic component is a head casing that houses the servo piston and the cylinder chamber; A hydraulic device characterized by:

4. The hydraulic device according to claim 1, The control valve is provided between the hydraulic source and the hydraulic actuator, The first hole and the second hole form an oil passage for pressure oil from the hydraulic source. A hydraulic device characterized by:

5. The hydraulic device according to claim 1, The poppet hole is provided in the first hole, the valve seat is provided on an edge of the second hole, The first groove and the second groove are provided in the first hydraulic component. A hydraulic device characterized by:

6. The hydraulic device according to claim 1, The poppet hole is provided in the second hole, the valve seat is provided at the bottom of the poppet hole provided in the second hole, The first groove and the second groove are provided in the first hydraulic component. A hydraulic device characterized by:

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