Remote pressure control valve and hydraulic system having the same

Abstract

Embodiments of the present invention disclose a remote pressure control valve and a hydraulic system including the remote pressure control valve. The remote pressure control valve includes a valve body and a valve core. The valve body includes: a valve cavity extending axially therein; and a first cavity and a second cavity formed in the valve body on either side of the valve cavity in the axial direction and connected to the valve cavity. The valve core is disposed in the valve cavity of the valve body and has a through hole formed therein, the through hole connecting the first cavity and the second cavity, and the through hole includes a damping orifice. The remote pressure control valve and hydraulic system according to embodiments of the present invention have a more compact structure.

Description

Technical Field

[0001] Embodiments of the present invention relate to a remote pressure control valve and a hydraulic system having the remote pressure control valve. Background Art

[0002] Conventional remote pressure control valves usually form a separate passage in the valve body to set the damping. Summary of the Invention

[0003] An object of embodiments of the present invention is to provide a remote pressure control valve and a hydraulic system having the same, thereby, for example, making the structures of the remote pressure control valve and the hydraulic system more compact.

[0004] An embodiment of the present invention provides a remote pressure control valve, comprising: a valve body, the valve body comprising: a valve cavity extending in an axial direction in the valve body; and a first cavity and a second cavity formed in the valve body on both sides of the axial direction of the valve cavity and connected to the valve cavity; and a valve core, the valve core being arranged in the valve cavity of the valve body, a through hole being formed in the valve core, the through hole connecting the first cavity and the second cavity, and the through hole comprising a damping hole.

[0005] According to an embodiment of the present invention, the remote pressure control valve further includes: a spring, which is arranged in the second chamber of the valve body and is used to push the valve core toward the first chamber of the valve body, wherein the valve body further includes a first working port for inputting fluid, a second working port for outputting control fluid, and a return port for returning fluid to the oil tank, the first working port is connected to the first chamber, and wherein the valve core can be moved to a first position toward the first chamber relative to the valve body under the push of the spring and move to a second position toward the second chamber by utilizing the pressure difference between the first chamber and the second chamber, when the valve core is in the first position, the second working port is connected to the return port, and when the valve core is in the second position, the second working port is connected to the first working port.

[0006] According to an embodiment of the present invention, the remote pressure control valve further comprises: a communication port provided on the valve body, the communication port being in communication with the second chamber and being connected to the pressure control valve, the pressure control valve being configured to open when the pressure exceeds a predetermined pressure.

[0007] According to an embodiment of the present invention, the remote pressure control valve further comprises: a damping element, which is detachably mounted in the through hole of the valve core and includes the damping hole.

[0008] According to an embodiment of the present invention, the valve core also includes: a first annular band on the outer periphery of the valve core adjacent to the first chamber, the first annular band having a first groove; a second annular band on the outer periphery of the valve core adjacent to the second chamber; and a third annular band and a fourth annular band between the first and second annular bands and on the outer periphery of the valve core, the first annular band, the third annular band and the inner wall of the valve chamber of the valve body forming a first working chamber, the first working chamber is connected to the first chamber through the first groove of the first annular band, the second annular band, the fourth annular band and the inner wall of the valve chamber of the valve body forming a second working chamber, the second working chamber is connected to the return port, and the first working chamber is connected to the first working port, and when the valve core is in the first position, the second working port is connected to the second working chamber, and when the valve core is in the second position, the second working port is connected to the first working chamber.

[0009] According to an embodiment of the present invention, in a cross section perpendicular to the axial direction, the first groove of the first annular band has an arcuate shape.

[0010] According to an embodiment of the present invention, the valve core includes a second groove formed on an end surface facing the first cavity, and the first working cavity is communicated with the first cavity through the first groove and the second groove of the first annular band.

[0011] An embodiment of the present invention also provides a hydraulic system, comprising: the above-mentioned remote pressure control valve; a pressure control valve, which is connected to the connecting port of the remote pressure control valve and is used to control the pressure in the second chamber of the remote pressure control valve, and the pressure control valve is configured to open when the pressure exceeds a predetermined pressure; a variable displacement hydraulic pump, the output port of the variable displacement hydraulic pump is connected to the first working port of the remote pressure control valve; and a pump servo system, which is connected to the second working port of the remote pressure control valve and is used to control the flow of the variable displacement hydraulic pump.

[0012] The remote pressure control valve and the hydraulic system according to the embodiments of the present invention have more compact structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a schematic cross-sectional view of a remote pressure control valve with a valve core in a first position according to an embodiment of the present invention:

[0014] Figure 2 yes Figure 1 A simplified schematic diagram of a remote pressure control valve with the valve core shown in a first position;

[0015] Figure 3 1 is a schematic cross-sectional view of a remote pressure control valve with a valve core in a second position according to an embodiment of the present invention:

[0016] Figure 4 yes Figure 3 A simplified schematic diagram of a remote pressure control valve with the valve core in a second position is shown;

[0017] Figure 5 is a schematic perspective view of a valve core of a remote pressure control valve according to an embodiment of the present invention; and

[0018] Figure 6 is a simplified diagram of a hydraulic system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] See also Figure 1 and Figure 3 A remote pressure control valve 100 according to an embodiment of the present invention includes a valve body 10 and a valve core 20. The valve body 10 includes a valve cavity 11 extending axially therein, and a first cavity 101 and a second cavity 102 formed in the valve body 10 on either side of the valve cavity 11 in the axial direction and communicating with the valve cavity 11. The valve core 20 is disposed in the valve cavity 11 of the valve body 10 and has a through hole 21 formed therein, connecting the first cavity 101 and the second cavity 102. The through hole 21 includes a damping orifice 210.

[0020] See also Figure 1 and Figure 3 The remote pressure control valve 100 according to an embodiment of the present invention further includes a spring 30, which is disposed in the second chamber 102 of the valve body 10 and is used to push the valve core 20 toward the first chamber 101 of the valve body 10. The valve body 10 further includes a first working port A for inputting fluid, a second working port B for outputting control fluid, and a return port T for returning fluid to the tank. The first working port A is in communication with the first chamber 101. The valve core 20 can move relative to the valve body 10 toward the first chamber 101 under the urging of the spring 30 to a first position ( Figure 1 The first chamber 101 and the second chamber 102 are moved to the second position ( Figure 3 When the valve core 20 is in the first position, the second working port B is connected to the return port T, and when the valve core 20 is in the second position, the second working port B is connected to the first working port A.

[0021] See also Figures 1 to 4 The remote pressure control valve 100 according to an embodiment of the present invention further includes a communication port X provided on the valve body 10. The communication port X communicates with the second chamber 102 and is connected to the pressure control valve 2. The pressure control valve 2 is configured to open when the pressure exceeds a predetermined pressure. The pressure control valve 2 may be a relief valve.

[0022] See also Figures 1 to 4 The remote pressure control valve 100 according to the embodiment of the present invention further includes a damping element 3, which is detachably mounted in the through hole 21 of the valve core 20 and includes the damping hole 210. Alternatively, the damping hole 210 may be formed by the through hole 21 including a portion with a smaller diameter.

[0023] See also Figure 1 、 Figure 3 、 Figure 5 The valve core 20 further includes: a first annular band 201 on the outer circumference of the valve core 20, adjacent to the first chamber 101, having a first groove 2011; a second annular band 202 on the outer circumference of the valve core 20, adjacent to the second chamber 102; and a third annular band 203 and a fourth annular band 204 on the outer circumference of the valve core 20, located between the first and second annular bands 201, 202. The first and third annular bands 201, 203, and the inner wall 110 of the valve chamber 11 of the valve body 10 form a first working chamber 41, which communicates with the first chamber 101 via the first groove 2011 of the first annular band 201. The second and fourth annular bands 202 and the inner wall 110 of the valve chamber 11 of the valve body 10 form a second working chamber 42. The second working chamber 42 communicates with the return port T, while the first working chamber 41 communicates with the first working port A. When the valve core 20 is in Figure 1 In the case of the first position shown, the second working port B is connected to the second working chamber 42 and then to the return port T, while the second working port B is disconnected from the first working chamber 41 and the first working port A. Figure 3 In the second position shown, the second working port B is connected to the first working chamber 41 and further connected to the first working port A, while the second working port B is disconnected from the second working chamber 42 and the return port T.

[0024] According to an embodiment of the present invention, Figure 5 As shown, in a cross section perpendicular to the axial direction, the first groove 2011 of the first annular band 201 has an arcuate shape. Alternatively, the first groove 2011 of the first annular band 201 can have other shapes as long as the first working chamber 41 can be connected to the first chamber 101.

[0025] According to an embodiment of the present invention, Figure 5As shown, the valve core 20 includes a second groove 2012 formed on the end surface facing the first chamber 101. The first working chamber 41 is connected to the first chamber 101 through the first groove 2011 and the second groove 2012 of the first annular band 201. The second groove 2012 can have a semicircular cross section or other suitable cross section.

[0026] See also Figures 1 to 4 The remote pressure control valve 100 according to the embodiment of the present invention further includes a spring 30, which is disposed in the second chamber 102. The spring 30 may be one spring or two springs.

[0027] See also Figures 1 to 4 and Figure 6 According to an embodiment of the present invention, the hydraulic system includes: a remote pressure control valve 100, a pressure control valve 2, a variable displacement hydraulic pump 5 and a pump servo system 6. The pressure control valve 2 is connected to the communication port X of the remote pressure control valve 100, and is used to control the pressure in the second chamber 102 of the remote pressure control valve 100. The pressure control valve 2 is configured to open when the pressure exceeds a predetermined pressure. The pressure control valve 2 may be a relief valve. The output port of the variable displacement hydraulic pump 5 is connected to the first working port A of the remote pressure control valve 100. The pump servo system 6 is connected to the second working port B of the remote pressure control valve 100, and is used to control the displacement of the variable displacement hydraulic pump 5. In addition, the hydraulic system also includes a motor 7 and a load 8. The pump servo system 6 includes a pump servo hydraulic cylinder 61. The variable displacement hydraulic pump 5 may be a plunger pump.

[0028] During system operation, see Figure 1 、 Figure 2 、 Figure 5 and Figure 6The outlet pressure oil of the variable-displacement hydraulic pump 5 flows through the first working port A in the valve body 10 to the first working chamber 41. From the first working chamber 41, it passes through the first groove 2011 of the valve spool 20 to the first chamber 101, where it acts on the left end face of the valve spool 20. Simultaneously, this portion of hydraulic oil flows from the first chamber 101 through the through hole 21 of the valve spool 20, including the damping orifice 210, to the second chamber 102 of the valve spool 20. The second chamber 102 is connected to the communication port X. The force acting on the right end face of the valve spool 20 is composed of the spring force generated by the compression of the spring 30 and the hydraulic pressure generated by the hydraulic oil in the communication port X in the second chamber 102. The pressure of the hydraulic oil in the second chamber 102 is determined by the pressure control valve 2, such as a relief valve, connected to the communication port X. In other words, during operation, the pressure difference between the outlet pressure of the variable-displacement hydraulic pump 5 and the hydraulic pressure in the second chamber 102 generates a rightward force on the valve spool 20, which balances the spring force generated by the compression of the spring 30. During operation, when the pressure control valve 2 does not open until the set pressure is reached, the oil fills the second chamber 102 and stops flowing. The oil pressures on the left and right ends of the valve core 20 are equal. At this time, the valve core 20 is in Figure 1 In the first position shown, the first working chamber 41 is disconnected from the second working port B, the second working port B is connected to the oil tank through the second working chamber 42, and the variable displacement hydraulic pump 5 is in a large displacement state. When the outlet pressure of the variable displacement hydraulic pump 5 increases to be greater than the set pressure of the pressure control valve 2, the pressure control valve 2 begins to overflow to maintain the pressure in the second chamber 102 unchanged. Since the outlet pressure oil of the variable displacement hydraulic pump 5 passes through the first working port A in the valve body 10 to the first working chamber 41, it passes from the first working chamber 41 through the first groove 2011 of the valve core 20 to the first chamber 101 and acts on the left end face of the valve core 20. At the same time, this part of the hydraulic oil passes from the first chamber 101 through the through hole 21 of the valve core 20 including the damping hole 210 to the second chamber 102 of the valve core 20. Due to the damping effect of the damping hole 210, the pressure drops. Therefore, the pressure of the hydraulic oil in the second chamber 102 is less than the pressure of the hydraulic oil in the first chamber 101, thereby generating a pressure difference at both ends of the valve core 20 to form a rightward force to push the valve core 20 to move to the right. Figure 3 In the second position shown, the second working port B is disconnected from the second working chamber 42, while the first working chamber 41 is connected to the second working port B. Hydraulic oil enters the first working chamber 41 from the first working port A, and from the first working chamber 41 through the second working port B into the pump servo hydraulic cylinder 61 of the pump servo system 6, pushing the swash plate of the variable displacement hydraulic pump 5 toward the smaller displacement direction, thereby reducing the displacement of the variable displacement hydraulic pump 5 and thereby reducing the outlet pressure of the variable displacement hydraulic pump 5 until it returns to a balanced state. Therefore, by adjusting the set pressure of the pressure control valve 2, the variable displacement hydraulic pump 5 can be operated at different pressure setting values, achieving remote pressure control.

[0029] The remote pressure control valve and the hydraulic system according to the embodiments of the present invention have a more compact structure and low cost.

[0030] Furthermore, the remote pressure control valve according to an embodiment of the present invention incorporates a flow channel and damping element within the valve core 20, integrating the damping element with the valve core 20. Furthermore, the damping element 3 is replaceable, allowing the damping to be adjusted to accommodate a wide range of operating conditions. For valves with load sensing (LS) functionality, a remote pressure control valve can be constructed by simply replacing the valve core 20 without redesigning the valve body 10.

[0031] although Figure 6 A hydraulic system is shown, but the remote pressure control valve according to the embodiment of the present invention can be applied to any suitable hydraulic system, not limited to Figure 6 The hydraulic system is shown.

Claims

1. A remote pressure control valve, comprising: A valve body, the valve body comprising: a valve cavity extending in an axial direction in the valve body; and a first cavity and a second cavity formed in the valve body on both sides of the valve cavity in the axial direction and communicating with the valve cavity; A valve core is disposed in a valve cavity of a valve body and comprises: a first annular band on an outer periphery of the valve core adjacent to the first cavity, the first annular band having a first groove, a second annular band on an outer periphery of the valve core adjacent to the second cavity; and a third annular band between the first and second annular bands and on an outer periphery of the valve core, the first annular band, the third annular band, and an inner wall of the valve cavity of the valve body forming a first working cavity, the first working cavity being communicated with a first working port of the valve body for inputting fluid, the first working cavity being communicated with the first cavity via the first groove of the first annular band, a through hole being formed in the valve core, the through hole communicating with the first cavity and the second cavity, the through hole comprising a damping hole; and A damping element is detachably mounted in one end of the through hole of the valve core close to the first chamber and includes the damping hole.

2. The remote pressure control valve according to claim 1, further comprising: a spring disposed in the second cavity of the valve body and configured to push the valve core toward the first cavity of the valve body, The valve body further comprises a second working port for outputting the control fluid and a return port for returning the fluid to the oil tank, the first working port is communicated with the first chamber, and The valve core is capable of moving relative to the valve body to a first position toward the first chamber under the push of the spring and moving toward the second chamber to a second position using the pressure difference between the first chamber and the second chamber. When the valve core is in the first position, the second working port is connected to the return port, and when the valve core is in the second position, the second working port is connected to the first working port.

3. The remote pressure control valve according to claim 1 or 2, further comprising: A communication port is provided on the valve body, the communication port being in communication with the second chamber and being adapted to be connected to a pressure control valve, the pressure control valve being configured to open when pressure exceeds a predetermined pressure.

4. The remote pressure control valve according to claim 2, wherein: The valve core further includes: a fourth annular band between the first annular band and the second annular band and on the outer circumference of the valve core, The second annular belt, the fourth annular belt and the inner wall of the valve cavity of the valve body form a second working cavity. The second working chamber is connected to the return port, and When the valve core is in the first position, the second working port is communicated with the second working chamber, and when the valve core is in the second position, the second working port is communicated with the first working chamber.

5. The remote pressure control valve according to claim 4, wherein: In a cross section perpendicular to the axial direction, the first groove of the first annular band has an arcuate shape.

6. The remote pressure control valve according to claim 4, wherein: The valve core includes a second groove formed on an end surface facing the first cavity, and the first working cavity is communicated with the first cavity through the first groove of the first annular band and the second groove.

7. A hydraulic system comprising: The remote pressure control valve according to claim 3; a pressure control valve connected to the communication port of the remote pressure control valve for controlling the pressure in the second chamber of the remote pressure control valve, the pressure control valve being configured to open when the pressure exceeds a predetermined pressure; a variable displacement hydraulic pump, wherein an output port of the variable displacement hydraulic pump is connected to a first working port of the remote pressure control valve; as well as A pump servo system is connected to the second working port of the remote pressure control valve and is used to control the flow of the variable displacement hydraulic pump.

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