Hydraulic switch control system

Abstract

A hydraulic switch control system comprises an active first cartridge valve provided with a first oil port, a second oil port and an active control port, and the first oil port and the second oil port are connected with the upstream section and the downstream section of a main oil way respectively; the passive second cartridge valve is provided with a first port, a second port and a control port, the first port is connected with the oil tank, and the second port is connected to the active control port of the first cartridge valve; and the pilot oil source is configured to output pilot oil pressure to the active control port of the first cartridge valve and the control port of the second cartridge valve. A first oil cavity, a second oil cavity and a third oil cavity are formed in the first cartridge valve, the first oil port is connected with the first oil cavity, the active control port is connected with the second oil cavity, and the first oil cavity is connected with the third oil cavity through a throttling channel in a valve element of the first cartridge valve. The hydraulic switch control system is higher in safety.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydraulic switch control system, in particular to a hydraulic switch control system with quick closing and self-locking functions. BACKGROUND

[0002] In a large flow hydraulic system, large diameter cartridge valves are widely used; some of the applications require large diameter cartridge valves to achieve quick closing and locking functions, such as the control of press slider, the control of die casting machine injection system, linear active wave compensation system, etc. One prior art uses a passive logic main valve and an accumulator pilot oil circuit to achieve it, in which the quick closing is achieved by the accumulator active oil supply mode. In this prior art, when the accumulator bladder is damaged or the pilot oil source loses pressure, the quick closing and locking functions will completely fail, which may cause safety accidents. CONTENT OF THE INVENTION

[0003] One object of the present application is to provide a hydraulic switch control system which can solve the above-mentioned problems of the prior art.

[0004] To this end, the present application provides, in one aspect thereof, a hydraulic switch control system, comprising:

[0005] an active first cartridge valve having a first port, a second port and an active control port, the first port and the second port being connected to an upstream section and a downstream section of a main oil circuit respectively;

[0006] a passive second cartridge valve having a first port, a second port and a control port, the first port being connected to an oil tank, the second port being connected to the active control port of the first cartridge valve; and

[0007] a pilot oil source configured to output a pilot oil pressure to the active control port of the first cartridge valve and the control port of the second cartridge valve;

[0008] wherein a first oil cavity, a second oil cavity and a third oil cavity are formed in the first cartridge valve, the first port is connected to the first oil cavity, the active control port is connected to the second oil cavity, and the first oil cavity and the third oil cavity are connected through a throttling passage in a spool of the first cartridge valve.

[0009] In one embodiment, the first oil cavity, the second oil cavity and the third oil cavity define a first action area, a second action area and a third action area on the spool of the first cartridge valve respectively, wherein the oil pressure on the first action area and the second action area generates an action force on the spool of the first cartridge valve tending to open the first cartridge valve, and the oil pressure on the third action area generates an action force on the spool of the first cartridge valve tending to close the first cartridge valve.

[0010] In one embodiment, the third acting area is greater than the first acting area and greater than the second acting area, the first acting area is formed on the front end face of the spool of the first cartridge valve, the second acting area is formed on the front surface of the rear flange of the spool, and the third acting area is formed on the rear surface of the rear flange of the spool.

[0011] In one embodiment, the third acting area is equal to the sum of the first acting area and the second acting area.

[0012] In one embodiment, the pilot oil source is connected to the control port of the second cartridge valve through an oil inlet throttle valve and an electromagnetic reversing valve; and the pilot oil source is connected to the main control port of the first cartridge valve through the oil inlet throttle valve, the electromagnetic reversing valve, a one-way valve and a first switch valve in sequence.

[0013] In one embodiment, the working oil port of the electromagnetic reversing valve is connected to the control port of the second cartridge valve and the oil inlet port of the one-way valve, the oil inlet port of the electromagnetic reversing valve is connected to the pilot oil source, the oil return port is connected to the oil tank, and the electromagnetic reversing valve has a first valve position in which the working oil port is communicated with the oil return port and a second valve position in which the working oil port is communicated with the oil inlet port.

[0014] In one embodiment, the control end electromagnet of the electromagnetic reversing valve is connected to a signal amplifier for applying a valve position switching control current to the electromagnetic reversing valve.

[0015] In one embodiment, the electromagnetic reversing valve is a high-frequency response proportional valve.

[0016] In one embodiment, the first switch valve has two oil ports, one of which is connected to the main control port of the first cartridge valve and the other of which is connected to the oil outlet port of the one-way valve; the first switch valve is communicated between the two oil ports at a first valve position; and the first switch valve disconnects the communication between the pilot oil source and the main control port of the first cartridge valve at a second valve position.

[0017] In one embodiment, the hydraulic switch control system further comprises a second switch valve, the second switch valve has two oil ports, one of which is connected to the main control port of the first cartridge valve through a oil discharge throttle valve and the other of which is connected to the oil tank; the second switch valve is communicated between the two oil ports at a first valve position; and the second switch valve cuts off the communication between the main control port of the first cartridge valve and the oil tank at a second valve position.

[0018] According to the hydraulic switch control system of the present application, the fast closing is realized by the active oil discharge mode, and the safety is higher. In addition, in the closed state, the main valve is kept in the self-locking state by the main oil way oil pressure, and the safety is higher. BRIEF DESCRIPTION OF DRAWINGS

[0019] The foregoing and other aspects of the present application will be more fully understood and appreciated by reference to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 is a diagram of an exemplary configuration of the hydraulic switching control system of the present application;

[0021] Figure 2 Figure 3 is a diagram of two operating states of the hydraulic switching control system shown in Figure 1

[0022] Figure 4 is a diagram of a modified configuration of the hydraulic switching control system of the present application. DETAILED DESCRIPTION

[0023] The present application relates generally to a hydraulic switching control system for controlling the hydraulic oil transmission of a hydraulic system, and a feasible configuration of the hydraulic switching control system is shown in Figure 1 .

[0024] As shown in Figure 1 , the hydraulic switching control system contains the following main elements: a main active logic cartridge valve (first cartridge valve) 1, a passive logic cartridge valve (second cartridge valve) 2, a two-position four-way quick electromagnetic valve (reversing valve) 3, a two-position two-way electromagnetic valve (first switching valve) 4, a check valve 5, a two-position two-way electromagnetic valve (second switching valve) 6, an oil inlet throttling valve 7, an oil discharge throttling valve 8, a pilot oil source 9, and a signal amplifier 10.

[0025] ​​The spool valve 1 constitutes a main switch valve of a hydraulic switch control system, and has a first oil port A1 and a second oil port B1, and a main control port Z. The spool of the spool valve 1 has a cylindrical body and a flange at the rear end of the cylindrical body, and the diameter of the flange is larger than that of the cylindrical body. The front end face of the cylindrical body and the valve housing of the spool valve 1 define a first oil cavity with a circular action area S1, the outer periphery of the cylindrical body and the valve housing define a second oil cavity (main control cavity) with an annular action area S2, and the rear end face of the flange and the valve housing define a third oil cavity with a circular action area S3. The first oil port A1 is connected to the first oil cavity, the main control port Z is connected to the second oil cavity, and the first oil cavity and the third oil cavity are connected through a throttling passage with a throttling hole 11. The action area S3 is larger than each of the action area S1 and the action area S2. For example, the sum of the action area S1 and the action area S2 is equal to the action area S3. The oil pressure applied to the action area S1 and the action area S2 generates an action force on the spool of the spool valve 1 tending to open the spool valve 1 (i.e. to open the oil passage between the first oil port A1 and the second oil port B1), and the oil pressure applied to the action area S3 generates an action force on the spool of the spool valve 1 tending to close the spool valve 1 (i.e. to close the oil passage between the first oil port A1 and the second oil port B1). The upstream section 12 and the downstream section 13 of the main oil passage are connected to the first oil port A1 and the second oil port B1, respectively.

[0026] The spool valve 2 has a first port A2 and a second port B2, and a control port X. The first port A2 is connected to an oil tank. The second port B2 is connected to the main control port Z of the spool valve 1. The spool valve 2 is kept disconnected between the first port A2 and the second port B2 by the action force of a spring acting on the spool thereof in the normal state. When the pressure at the second port B2 generates an action force on the spool greater than the sum of the action force of the pressure at the control port X on the spool and the spring force, the first port A2 and the second port B2 are connected.

[0027] The solenoid valve 3 has two valve positions and four oil ports, and a control end solenoid connected to a signal amplifier 10 for applying a control current to the control end solenoid to control the valve position of the solenoid valve 3. The four oil ports are an oil inlet port, an oil return port, a first working oil port and a second working oil port. The oil inlet port is connected to a pilot oil source 9 through an oil inlet throttling valve 7, the oil return port is connected to an oil tank, the first working oil port is blocked, and the second working oil port is connected to the control port X of the spool valve 2. In the first valve position of the solenoid valve 3 in the normal state, the oil inlet port and the first working oil port of the solenoid valve 3 are connected, and the oil return port and the second working oil port are connected. When the control current from the signal amplifier 10 is applied to the control end solenoid of the solenoid valve 3, the solenoid valve 3 is switched to the second valve position, so that the oil inlet port and the second working oil port are connected, and the oil return port and the first working oil port are connected. The valve position of the solenoid valve 3 can also be manually switched. The reset spring of the solenoid valve is a high-stiffness spring, so that rapid switching from the second valve position to the first valve position can be achieved.

[0028] The electromagnetic valve 4 is a two-position two-way valve, having two valve positions and two oil ports. The two oil ports are a first oil port and a second oil port. The first oil port is connected to the active control port Z of the cartridge valve 1, and the second oil port is connected to the control port X of the cartridge valve 2 via the one-way valve 5. The one-way valve 5 is oriented to allow hydraulic oil to flow only from the first oil port to the second oil port of the electromagnetic valve 4, and to prohibit reverse flow. In the first valve position of the electromagnetic valve 4 in normal state, the first oil port is in communication with the second oil port. When the control end electromagnet of the electromagnetic valve 4 is energized, the electromagnetic valve 4 switches to the second valve position, in which the first oil port is in one-way communication with the second oil port, i.e. the built-in one-way valve of the electromagnetic valve 4 allows hydraulic oil to flow from the first oil port to the second oil port, and prohibits hydraulic oil to flow from the second oil port to the first oil port.

[0029] The electromagnetic valve 6 is a two-position two-way valve, having two valve positions and two oil ports. The two oil ports are a first oil port and a second oil port. The first oil port is connected to the oil tank, and the second oil port is connected to the active control port Z of the cartridge valve 1 via the one-way valve 8, i.e. to the first oil port of the electromagnetic valve 4. The one-way valve 8 is oriented to allow hydraulic oil to flow only from the first oil port to the second oil port of the electromagnetic valve 6, and to prohibit reverse flow. In the first valve position of the electromagnetic valve 6 in normal state, the first oil port is in communication with the second oil port. When the control end electromagnet of the electromagnetic valve 6 is energized, the electromagnetic valve 6 switches to the second valve position, in which the first oil port is in one-way communication with the second oil port, i.e. the built-in one-way valve of the electromagnetic valve 6 allows hydraulic oil to flow from the first oil port to the second oil port, and prohibits hydraulic oil to flow from the second oil port to the first oil port.

[0030] The operation of the hydraulic switch control system will be described below. Figure 1 The initial state of the system in which the electromagnetic valves 3, 4, 6 are all de-energized and are in the respective first valve positions. At this time, the active control port Z of the cartridge valve 1 is communicated with the oil tank via the electromagnetic valve 6, i.e. the second oil chamber of the cartridge valve 1 has a pressure of zero. The oil pressure of the upstream section 12 of the main oil circuit is transmitted to the first oil chamber via the first oil port Al, and then to the third oil chamber via the throttling passage having the throttling orifice 11, and the pressures of the first oil chamber and the third oil chamber are equal. Since the action area S3 of the third oil chamber is larger than the action area S1 of the first oil chamber, the valve core of the cartridge valve 1 is subjected to a larger oil pressure in the closing direction, and the first oil port Al and the second oil port Bl are closed, and the upstream section 12 and the downstream section 13 of the main oil circuit are disconnected, and the closing state can be self-locked by the oil pressure in the upstream section 12 of the main oil circuit continuously transmitted to the first oil chamber via the first oil port Al, and then to the third oil chamber. At this time, the first port A2 of the cartridge valve 2 is communicated with the oil tank, the second port B2 is communicated with the oil tank via the electromagnetic valve 6, the control port X is communicated with the oil tank via the electromagnetic valve 3, and there is no pressure in the oil chambers of the cartridge valve 2, so the first port A2 and the second port B2 of the cartridge valve 2 are closed.

[0031] From Figures 1 to 2System slow opening process. From Figure 1 System initial state, solenoid 3, 6 are energized to switch to their respective second valve position, solenoid 4 is de-energized to maintain its first valve position, as shown in Figure 2 Pilot oil from pilot oil source 9 enters control port X of spool valve 2 through restrictor 7 and solenoid 3, and also enters second port B2 of spool valve 2 through check valve 5 and solenoid 4. The corresponding oil pressure acting area of control port X of spool valve 2 is larger than that of second port B2, thus maintaining the oil passage between first port A2 and second port B2 of spool valve 2 closed. Meanwhile, pilot oil enters the second oil chamber (pilot control chamber) of spool valve 1 through check valve 5 and solenoid 4 from the active control port Z of spool valve 1, and the spool of spool valve 1 moves under the force of the second oil chamber to open the oil passage between first oil port Al and second oil port Bl, thus connecting upstream section 12 and downstream section 13 of main oil passage. It is noted that solenoid 6 in second valve position cuts off the connection between active control port Z of spool valve 1 and oil tank due to its one-way flow property between the two oil ports, thus maintaining the oil pressure in the second oil chamber of spool valve 1. Restrictor 7 slows down the supply of pilot oil to the active control port Z of spool valve 1, i.e. the opening of spool valve 1. The slow opening speed of spool valve 1 can be adjusted by the flow area of restrictor 7.

[0032] System slow closing process. From Figures 2 to 3 Solenoid 3 is maintained in energized state thus maintaining its second valve position, solenoid 4 is energized to switch to its second valve position, solenoid 6 is de-energized to switch to its first valve position. The one-way flow property between the two oil ports of solenoid 4 in second valve position, combined with the one-way flow property of check valve 5 (opposite to the flow direction allowed by solenoid 4), practically cuts off the flow of hydraulic oil through solenoid 4. Pilot oil from pilot oil source 9 enters control port X of spool valve 2 through restrictor 7 and solenoid 3, thus maintaining the oil passage between first port A2 and second port B2 of spool valve 2 closed. On the other hand, solenoid 4 in second valve position cuts off the supply of pilot oil to the second oil chamber of spool valve 1. The pilot oil in the second oil chamber of spool valve 1 is discharged to oil tank through restrictor 8 and solenoid 6. Since the acting area S3 of third oil chamber is larger than that of first oil chamber SI, the oil pressure of upstream section 12 of main oil passage forces the spool of spool valve 1 to move slowly and eventually close the oil passage between first oil port Al and second oil port Bl, disconnecting the connection between upstream section 12 and downstream section 13 of main oil passage. Restrictor 8 slows down the closing speed of spool valve 1. The slow closing speed of spool valve 1 can be adjusted by the flow area of restrictor 8.

[0033] System slow closing process. From Figures 2 to 1This describes the process of the system rapidly closing from the open state. Solenoid valves 3, 4, and 6 simultaneously lose power and switch to their respective second valve positions. Solenoid valve 3 closes rapidly under the action of a high-stiffness return spring. The pressure oil at the control port X of cartridge valve 2 is rapidly depressurized via solenoid valve 3. The oil pressure in the second port B2 of cartridge valve 2, which is connected to the active control port Z of cartridge valve 1, is released, causing the valve core of cartridge valve 2 to rise and open the oil passage between the first port A2 and the second port B2. This allows the pressure oil in the second oil chamber of cartridge valve 1 to be rapidly depressurized via cartridge valve 2. Due to the difference in the effective area S3 of the third oil chamber of cartridge valve 1 compared to the effective area S1 of the first oil chamber, the valve core of cartridge valve 1 rapidly closes the oil passage between the first oil port A1 and the second oil port B1 under the pressure of the upstream section 12 of the main oil line and self-locks, disconnecting the upstream section 12 and downstream section 13 of the main oil line.

[0034] Based on the principles of this application, those skilled in the art can make various adaptive modifications to the structure of the hydraulic switch control system described above.

[0035] For example, in Figure 4 In the modified version shown, solenoid valve 3 uses a high-frequency response proportional valve to achieve rapid switching, replacing... Figures 1-3 The solenoid valve 3 and amplifier 10 are shown in the diagram. Figure 4 In the modified version shown, the high-frequency response proportional valve type solenoid valve 3 has three valve positions and four ports. The four ports are an inlet port, a return port, a first working port, and a second working port. The inlet port is connected to the pilot oil source 9 via an inlet throttle valve 7, the return port is connected to the oil tank, the first working port is cut off, and the second working port is connected to the control port X of the cartridge valve 2. In the first valve position of the solenoid valve 3, the inlet port is connected to the first working port, and the return port is connected to the second working port. In the second valve position of the solenoid valve 3, the inlet port is connected to the second working port, and the return port is connected to the first working port. In the third valve position of the solenoid valve 3, the four ports are throttled and connected. The high-frequency response proportional valve can use electromagnetic force to drive the valve core to achieve precise movement, thereby changing the valve position and flow area.

[0036] For example, when solenoid valves 4 and 6 are in their respective second valve positions, they can be configured to cut off the connection between their first and second oil ports.

[0037] It should be noted that, in this field, for various cartridge valves and other hydraulic valves, as long as their specific functions are specified, those skilled in the art can design specific structures or even use commercially available products. Therefore, this application does not describe the specific structures of the various valves used in the hydraulic switch control system, and those skilled in the art can use various suitable structures to achieve the corresponding functions of each valve.

[0038] The hydraulic switch control system according to the present application can realize quick closing of the main oil path. The quick closing is realized by a positive oil discharging mode controlled by the electromagnetic reversing valve (electromagnetic valve 3), and is safer. When the system is in a closed state, the cartridge valve 1 as the main switch valve is kept in a self-locking state by the main oil path oil pressure, and is safer.

[0039] In addition, the prior art can only realize slow opening and quick closing of the main valve, and cannot realize slow closing action. In comparison, the hydraulic switch control system according to the present application has a slow closing function, and can prolong the service life of the main switch valve and reduce operation noise and impact in non-emergency situations or when the slow closing function is required.

[0040] Although the present application is described herein with reference to specific exemplary embodiments, the scope of the present application is not limited to the details shown. Various modifications can be made to these details without departing from the essential principles of the present application.

Claims

1. A hydraulic switch control system, characterized in that... include: The active first cartridge valve (1) has a first oil port (A1), a second oil port (B1) and an active control port (Z). The first oil port (A1) and the second oil port (B1) are respectively connected to the upstream section (12) and the downstream section (13) of the main oil circuit. The passive second cartridge valve (2) has a first port (A2), a second port (B2) and a control port (X). The first port (A2) is connected to the oil tank, and the second port (B2) is connected to the active control port (Z) of the first cartridge valve (1). as well as The pilot oil source (9) is configured to output pilot oil pressure to the active control port (Z) of the first cartridge valve (1) and the control port (X) of the second cartridge valve (2); The first cartridge valve (1) forms a first oil chamber, a second oil chamber and a third oil chamber. The first oil port (A1) is connected to the first oil chamber, and the active control port (Z) is connected to the second oil chamber. The first oil chamber and the third oil chamber are connected through a throttling channel in the valve core of the first cartridge valve (1).

2. The hydraulic switch control system as described in claim 1, characterized in that, The first oil chamber, the second oil chamber, and the third oil chamber define a first working area (S1), a second working area (S2), and a third working area (S3) on the valve core of the first cartridge valve (1), respectively. The oil pressure on the first working area (S1) and the second working area (S2) generates a force on the valve core of the first cartridge valve (1) that tends to open the first cartridge valve (1), and the oil pressure on the third working area (S3) generates a force on the valve core of the first cartridge valve (1) that tends to close the first cartridge valve (1).

3. The hydraulic switch control system as described in claim 2, characterized in that, The third working area (S3) is greater than the first working area (S1) and greater than the second working area (S2). The first working area (S1) is formed on the front end face of the valve core of the first cartridge valve (1), the second working area (S2) is formed on the front surface of the rear flange of the valve core, and the third working area (S3) is formed on the rear surface of the rear flange of the valve core.

4. The hydraulic switch control system as described in claim 2, characterized in that, The third action area (S3) is equal to the sum of the first action area (S1) and the second action area (S2).

5. The hydraulic switch control system as described in any one of claims 1-4, characterized in that, The pilot oil source (9) is connected to the control port (X) of the second cartridge valve (2) via the inlet throttle valve (7) and the solenoid directional valve (3); and the pilot oil source (9) is connected to the active control port (Z) of the first cartridge valve (1) via the inlet throttle valve (7), the solenoid directional valve (3), the check valve (5) and the first switching valve (4) in sequence.

6. The hydraulic switch control system as described in claim 5, characterized in that, The working port of the electromagnetic reversing valve (3) is connected to the control port (X) of the second cartridge valve (2) and the inlet of the check valve (5). The inlet of the electromagnetic reversing valve (3) is connected to the pilot oil source (9), and the return port is connected to the oil tank. The electromagnetic reversing valve (3) has a first valve position that connects its working port to the return port and a second valve position that connects its working port to the inlet port.

7. The hydraulic switch control system as described in claim 6, characterized in that, The control terminal electromagnet of the electromagnetic directional valve (3) is connected to the signal amplifier (10) to apply a control current for valve position switching to the electromagnetic directional valve (3).

8. The hydraulic switch control system as described in claim 6, characterized in that, The electromagnetic directional valve (3) is a high-frequency response proportional valve.

9. The hydraulic switch control system as described in claim 6, characterized in that, The first switching valve (4) has two ports, one of which is connected to the active control port (Z) of the first cartridge valve (1) and the other is connected to the outlet of the check valve (5); the first switching valve (4) is connected between the two ports in the first valve position; the first switching valve (4) is disconnected from the pilot oil source (9) and the active control port (Z) of the first cartridge valve (1) in the second valve position.

10. The hydraulic switch control system as described in claim 6, characterized in that, The hydraulic switch control system further includes a second switch valve (6), which has two ports. One port is connected to the active control port (Z) of the first cartridge valve (1) via an oil discharge throttle valve (8), and the other port is connected to the oil tank. When the second switch valve (6) is in the first valve position, the two ports are connected. When the second switch valve (6) is in the second valve position, the connection between the active control port (Z) of the first cartridge valve (1) and the oil tank is cut off.

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