WO2021103578A1 - Pneumatic hydraulic safety system - Google Patents

Abstract

A pneumatic hydraulic safety system, comprising an air storage tank (4), a pressure switch (9), a two-position two-way switching valve (10), a three-position five-way reversing valve (11), a shuttle valve (12), a two-position two-way pneumatic control valve (13), a pneumatic motor (15), a hydraulic pump (18), an oil tank (27), a pneumatic control hydraulic valve (22), and a hydraulic cylinder (25.1, 25.2). By means of coordination of the three-position five-way reversing valve (11), the shuttle valve (12), the two-position two-way pneumatic control valve (13), and the pneumatic control hydraulic valve (22), the pneumatic motor (15) is in a stop or start state, and thus expansion or contraction of the hydraulic cylinder (25.1, 25.2) is enabled according to requirements, so that safe operation can be ensured, noise is reduced, the problem of energy waste is solved, and good practicability is achieved because expansion and contraction of the hydraulic cylinder can be switched according to requirements.

Description

Pneumatic hydraulic safety system

Cross-references to related applications

This application claims the priority of the Chinese patent application filed on November 27, 2019, the application number is 201911178216.6 and the title is "Pneumatic Hydraulic Safety System", the entire content of which is incorporated herein by reference.

Technical field

The present disclosure belongs to the technical field of hydraulic control, and in particular relates to a pneumatic hydraulic safety system.

Background technique

In the operation of railway engineering vehicles, hydraulic cylinders are a relatively practical and mature operating mechanism. The expansion and contraction of the hydraulic cylinder is realized by the movement of the hydraulic oil in the rod cavity and the rodless cavity. The hydraulic oil delivered to the rod cavity and rodless cavity of the hydraulic cylinder is realized by pumping hydraulic oil from the oil tank through a hydraulic pump, and the hydraulic pump is driven by an air motor. In the prior art, if the control system is not used, and the compressed air is directly connected to the air motor, the hydraulic pump driven by the air motor will always be in working state, and the expansion and contraction of the hydraulic oil cylinder will always be in working state, which causes a waste of noise and energy. The problem is that the expansion and contraction of the hydraulic cylinder cannot be switched as needed.

Summary of the invention

In view of the above-mentioned shortcomings of the prior art, the present disclosure provides a pneumatic hydraulic safety system to solve the technical problems of noise, energy waste, and inability to perform telescopic switching according to needs caused by the hydraulic cylinder that has been working in the prior art. .

In one aspect of the present disclosure, a pneumatic hydraulic safety system is provided. The system may include: a gas storage tank; a pressure switch and a two-position two-way switch valve, an input end of the pressure switch and the gas storage tank The output end of the two-position two-way switch valve is connected to the output end of the pressure switch, and the P port of the two-position two-way switch valve and the port A of the two-position two-way switch valve can be Switching connection; a three-position five-way pneumatic reversing valve and a shuttle valve, the P port of the three-position five-way pneumatic reversing valve is connected to the A port of the two-position two-way switching valve, the three-position five-way pneumatic reversing valve Port A of the valve _{is connected to port P 2 of} the shuttle valve, port B of the three-position five-way pneumatic reversing valve _{is connected to port P 1 of} the shuttle valve, and port _{P 1 of} the shuttle valve is connected to port P of the shuttle valve. _{The 2} ports are switchably communicated with the A port of the shuttle valve; the two-position two-way air control valve; the control port of the two-position two-way air control valve communicates with the A port of the shuttle valve, the two-position air control The P port of the valve is communicated with the A port of the two-position two-way switch valve, and the P port of the two-position two-way air control valve and the A port of the two-position two-way air control valve can be switchably connected; an air motor, a hydraulic pump And an oil tank, the input port of the air motor is connected to the port A of the two-position air control valve, the output port of the air motor is connected to the control end of the hydraulic pump, and the input port of the hydraulic pump is connected to the control port of the hydraulic pump. The fuel tank is connected; a pneumatic hydraulic valve and a hydraulic cylinder, the pneumatic hydraulic valve is a three-position four-way reversing valve, the pneumatic hydraulic valve has a first control port and a second control port that control its valve position, so The first control port of the pneumatic hydraulic valve is connected to the B port of the three-position five-way pneumatic reversing valve, and the second control port of the pneumatic hydraulic valve is connected to the A port of the three-position five-way pneumatic reversing valve. Port connection, the P port of the pneumatic hydraulic valve is connected with the output port of the hydraulic pump, the A port of the pneumatic hydraulic valve is connected with the rodless cavity of the hydraulic cylinder, and the T of the pneumatic hydraulic valve is connected. The port is in communication with the oil tank, and the port B of the air-controlled hydraulic valve is in communication with the rod cavity of the hydraulic oil cylinder.

In some embodiments, the gas storage tank may be connected to an external air source through an inflation pipeline, and the upper cover of the inflation pipeline is sequentially provided with a first air ball valve, an air filter, and an air check valve. An air ball valve, an air filter, and an air check valve are sequentially arranged in the direction from the external air source to the air storage tank.

In some embodiments, an air safety valve may be provided on the housing of the air storage tank, and a drain valve is provided at the bottom of the housing of the air storage tank.

In some embodiments, a second air ball valve may be provided between the input end of the pressure switch and the output end of the gas tank.

In some embodiments, the system may further include a first exhaust ball valve, the input end of the first exhaust ball valve is connected to the output end of the pressure switch, and the output end of the first exhaust ball valve is connected to the output end of the pressure switch. The port A of the two-position two-way switch valve is connected.

In other embodiments, the system may further include a second exhaust ball valve and a third exhaust ball valve. The input end of the second exhaust ball valve is connected to the A port of the two-position two-way switch valve. The output end of the second exhaust ball valve is connected to the port P of the two-position two-way air control valve; the input end of the third exhaust ball valve is connected to the port A of the two-position switch valve, and the first The output end of the three exhaust ball valve is connected with the P port of the three-position five-way pneumatic reversing valve.

In some embodiments, the system may further include a first gas source treatment device and a second gas source treatment device. The first gas source treatment device is disposed at the output end of the second exhaust ball valve and the two gas source treatment devices. Between the P port of the two-position two-way air control valve, the second air source processing device is arranged between the output end of the third exhaust ball valve and the P port of the three-position five-way pneumatic reversing valve.

In some embodiments, the system may further include a throttle valve, a first filter, a second filter, a hydraulic pressure gauge, and a third filter. The throttle valve is disposed between the input port of the air motor and the A port of the two-position gas control valve, and the first filter is disposed between the input port of the hydraulic pump and the oil tank The second filter and the hydraulic pressure gauge are sequentially arranged between the output port of the hydraulic pump and the P port of the pneumatic hydraulic valve, and the third filter is arranged on the pneumatic hydraulic valve Between the T port and the fuel tank.

In some embodiments, the system may further include an overflow valve, the P port of the overflow valve is in communication with the P port of the pneumatic hydraulic valve, and the T port of the overflow valve is in communication with the oil tank.

In some embodiments, the system may further include a manual hydraulic pump and three five-way valve; P ₁ port communicating said three five-hydraulic control valve and said air port A hydraulic valve, the three five-port T of the hydraulic valve and hydraulic valve port B of the air communication control, the three five-P ₂ of the hydraulic valve port and the one-way valve in communication, the three Port A of the five-position hydraulic reversing valve communicates with the rodless cavity of the hydraulic cylinder, and port B of the three-position five-way hydraulic reversing valve communicates with the rod cavity between the hydraulic cylinder; the manual _{The oil pump is arranged between the P 2} port of the three-position five-way hydraulic reversing valve and the oil tank, and a one-way valve is arranged between the input port of the manual oil pump and the oil tank; the three-position five-way valve _{A check valve is arranged between the P 2} port of the hydraulic reversing valve and the output port of the manual oil pump.

In some embodiments, the hydraulic cylinders may be two hydraulic cylinders connected in parallel.

In some embodiments, the hydraulic cylinders may be several hydraulic cylinders with more parallel connections.

In some embodiments, the hydraulic cylinder may be a hydraulic cylinder.

The beneficial effects of the present disclosure are:

1. According to a pneumatic hydraulic safety system according to some embodiments of the present disclosure, the compressed air flowing from the air storage tank first passes through a pressure switch and a two-position two-way switch valve. The pressure switch can detect the pressure of the compressed air output from the air storage tank. When the pressure is lower than the minimum starting pressure of the system, the pressure switch does not output an electrical signal, and the two-position two-way switch valve is normally closed and disconnects the air circuit. At this time, when the uncompressed air passes through the two-position two-way switch valve, the subsequent pneumatic components will not start, which can effectively avoid the problems caused by the low compressed air pressure; when the pressure is higher than the minimum starting pressure of the system, the pressure switch The output electric signal converts the two-position two-way switch valve to open, the air path is unblocked, and the system can work normally.

2. The compressed air passing through the two-position two-way switch valve (10) is divided into the first part and the second part. The first part of the compressed air will pass through the three-position five-way pneumatic directional valve (11); when the three-position five-way pneumatic directional valve is in the neutral position, the P port of the three-position five-way pneumatic directional valve (11) is equal to three The A and B ports of the five-position pneumatic reversing valve (11) are disconnected, the shuttle valve (12) has no input and output, and the two-position two-way pneumatic control valve is in the off state, and the compressed air cannot enter the input port of the air motor. The air motor is in a stopped state, the air-controlled hydraulic valve is in the neutral position, its P port is closed, its A port, B port and T port are connected, and the hydraulic cylinder has no action; when the three-position five-way pneumatic reversing valve is in the left position, The P port of the three-position five-way pneumatic reversing valve is connected to the port A, and the B port of the three-position five-way pneumatic reversing valve has no output. The compressed air opens the P ₂ port of the shuttle valve and delivers it from the A port of the shuttle valve to the two The control port of the two-position two-way air control valve makes the two-position two-way air control valve switch from off to on. After the second part of compressed air passes through the two-position two-way air control valve, it enters the input port of the air motor. The air motor starts and drives the hydraulic pump to rotate. The hydraulic pump outputs hydraulic oil to the P port of the air control hydraulic valve. The compressed air of the first part of the five-way pneumatic reversing valve will enter the second control port of the pneumatic hydraulic valve. Pneumatically, the pneumatic hydraulic valve will be switched to the right position, so that the P port and A port of the pneumatic hydraulic valve are connected. , T port and B port are connected, the hydraulic oil output by the hydraulic pump passes through the P port and A port of the pneumatic hydraulic valve in turn, and enters the rodless cavity of the hydraulic cylinder, and the rod cavity of the hydraulic cylinder is in turn with the pneumatic hydraulic valve The B port and T port of the hydraulic cylinder are connected, the output end of the hydraulic cylinder is extended, and the hydraulic oil with the rod cavity of the hydraulic cylinder flows into the oil tank; when the three-position five-way pneumatic reversing valve is in the right position, the three-position five-way pneumatic reversal The P port of the valve is connected with the B port, the A port of the three-position five-way pneumatic reversing valve has no output. The compressed air opens the P ₁ port of the shuttle valve and is delivered from the A port of the shuttle valve to the two-position two-way pneumatic control valve. The two-position two-way air control valve is switched from off to on. After the second part of the compressed air passes through the two-position two-way air control valve, it enters the input port of the air motor, the air motor starts, and drives the hydraulic pump to rotate, and the hydraulic pump outputs The hydraulic oil reaches the P port of the pneumatic hydraulic valve. At the same time, the compressed air passing through the first part of the three-position five-way pneumatic reversing valve will enter the first control port of the pneumatic hydraulic valve, and pneumatically change the pneumatic hydraulic valve to In the left position, the P port and B port of the pneumatic hydraulic valve are connected, and the T port is connected with the A port. The hydraulic oil output by the hydraulic pump passes through the P and B ports of the pneumatic hydraulic valve in turn, and enters the hydraulic cylinder. Rod cavity, the rodless cavity of the hydraulic cylinder is in turn connected with the A and T ports of the air-controlled hydraulic valve. The hydraulic oil in the rodless cavity of the hydraulic cylinder flows into the oil tank, and the output end of the hydraulic cylinder retracts.

In summary, according to the pneumatic hydraulic safety system of some embodiments of the present disclosure, through the cooperation of the three-position five-way pneumatic reversing valve, the shuttle valve, the two-position two-way pneumatic control valve, and the pneumatic hydraulic valve, the pneumatic motor can be It is in the stopped and started state, so that the expansion and contraction of the hydraulic cylinder can be started as required, thereby reducing the problems of noise and energy waste, and the expansion and contraction of the hydraulic cylinder can be switched as needed, which has good practicability.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some implementations of the present disclosure. For example, for those of ordinary skill in the art, without creative work, other drawings can be obtained from these drawings.

Fig. 1 is a schematic diagram of the hydraulic arrangement of a pneumatic hydraulic safety system according to an embodiment of the present disclosure.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all implementations. example. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

Fig. 1 is a schematic diagram of the hydraulic arrangement of a pneumatic hydraulic safety system according to an embodiment of the disclosure. With reference to Figure 1, the system includes a gas storage tank 4, a pressure switch 9, a two-position two-way switch valve 10, a three-position five-way pneumatic reversing valve 11, a shuttle valve 12, a two-position two-way pneumatic control valve 13, and a pneumatic hydraulic Valve 22, air motor 15, hydraulic pump 18 and oil tank 27.

The gas storage tank 4 of the embodiment of the present disclosure may be used to store a certain amount of compressed air to ensure continuous air supply. With reference to Figure 1, the gas storage tank 4 of the embodiment of the present disclosure can be connected to an external air source through an inflation pipeline. The upper cover of the inflation pipeline is sequentially provided with a first air ball valve 1.1, an air filter 2 and an air check valve 3 . The first air ball valve 1.1, the air filter 2 and the air one-way valve 3 are arranged in sequence in the direction from the external air source to the air storage tank 4.

The external air source in the embodiments of the present disclosure is a general term, and the specific form may be various, such as an air compressor, a compressed air pipeline, and so on. The output pressure of the external air source is usually 0.1MPa～1.2MPa compressed air.

In the embodiment of the present disclosure, the first air ball valve 1.1 can be used to control the connection between the external air source and the pneumatic hydraulic system. When the first air ball valve 1.1 is in the open position, the external air source is disconnected from the pneumatic hydraulic system, and the compressed air from the external air source cannot enter the pneumatic hydraulic system; when the first air ball valve 1.1 is in the open position, the compressed air from the external air source Enter the pneumatic hydraulic system. In addition, the first air ball valve 1.1 is also a safety control measure. When the system is not working, close the air ball valve 1.1 to avoid accidental startup of the system and prevent pipeline leaks that cannot be discovered and handled in time when unmanned operations. Cause energy waste.

In the embodiment of the present disclosure, the air filter 2 can be used to filter the compressed air that enters the pneumatic hydraulic system from an external air source, and remove impurities such as dust in the compressed air.

In the embodiment of the present disclosure, the air check valve 3 may be a one-way passing element, which only allows compressed air from an external air source to enter the air storage tank 4, and does not allow the compressed air in the air storage tank 4 to flow back into the external air. source. When the pressure of the external air source drops due to various factors, it is prevented that the compressed air in the air storage tank 4 has a higher pressure than the external air source and flows back into the external air source and interferes with the external air source.

With reference to FIG. 1, in the embodiment of the present disclosure, an air safety valve 5 may be provided on the housing of the air storage tank 4, and a drain valve 6 may be provided at the bottom of the housing of the air storage tank 4. Among them, the function of the air safety valve 5 is to ensure that the maximum pressure of the compressed air in the air storage tank 4 is within the normal range, eliminate excessive pressure, and prevent the air storage tank 4 from being damaged due to the excessively high pressure of the compressed air, so as to reduce Minimize the pulsation of the input air flow from the external air source to stabilize the output air pressure.

In the present disclosure, the pressure of the compressed air in the gas storage tank 4 may be higher than the maximum working pressure of the subsequent gas source treatment device by about 0.05 to 0.2 MPa, which is used to compensate for the pressure between the gas storage tank 4 and the gas source treatment device 8. The pressure loss of the pneumatic pipeline; and the drain valve 6 is at the lowest position at the bottom of the gas storage tank 4, and its function is to remove the accumulated water and dust in the gas storage tank 4.

In the embodiments of the present disclosure, compressed air is mainly input to the pneumatic hydraulic system through an external air source. When the external air source is unexpectedly interrupted, the compressed air stored in the air tank can be used for emergency treatment to ensure the normal operation of the system.

With reference to Figure 1, in the embodiment of the present disclosure, the input end of the pressure switch 9 is connected to the output end of the gas tank 4, the P port of the two-position two-way switch valve 10 is connected to the output end of the pressure switch 9, and the two-position two-way switch valve is connected to the output port of the pressure switch 9. The P port of the two-way on-off valve 10 and the A port of the two-position two-way on-off valve 10 are switchably connected.

In the embodiment of the present disclosure, the pressure switch 9 and the two-position two-way switch valve 10 are used together at the output end of the gas storage tank 4. The pneumatic hydraulic system is composed of a variety of pneumatic components, and the minimum starting pressure of each pneumatic component is different. For example, the minimum starting pressure of the pneumatic hydraulic valve 22 is lower than the minimum starting pressure of the air motor 15. When the pressure of compressed air is too low, all pneumatic components cannot work normally. In order to solve such problems, the embodiment of the present disclosure adopts a combination of a pressure switch 9 and a two-position two-way switch valve 10. Its principle of action is: the two-position two-way switch valve 10 is normally closed, and the gas circuit is usually disconnected. The pressure switch 9 is used to control its on and off. The pressure of the compressed air output from the output end of the air storage tank 4 is detected by the pressure switch 9. When the pressure is lower than the minimum starting pressure of the system, the pressure switch 9 does not output an electrical signal, and the two-position two-way switch valve 10 is still normally closed , Disconnect the air circuit. At this time, no compressed air passes through the two-position two-way switch valve 10. Because no compressed air is input to the subsequent pneumatic components, all pneumatic components will not start, which can effectively avoid the low pressure of the compressed air. Although the pneumatic components can barely move, they cannot work normally, causing problems such as jamming and damage. When the pressure is higher than the minimum starting pressure of the system, the pressure switch 9 outputs an electrical signal to convert the two-position two-way switch valve 10 into a vent, the air path is unblocked, and the system can work normally.

1, in the embodiment of the present disclosure, a second air ball valve 1.2 is provided between the input end of the pressure switch 9 and the output end of the air tank 4, and the second air ball valve 1.2 is located at the output port of the air tank 4 , Used to control the connection between the gas storage tank 4 and the subsequent pneumatic hydraulic system. When the second air ball valve 1.2 is in the open position, the air tank 4 is disconnected from the subsequent pneumatic hydraulic system, and the compressed air in the air tank 4 cannot be output; when the second air ball valve 1.2 is in the open position, the air tank 4 is in the open position. The compressed air enters the subsequent pneumatic hydraulic system freely. The second air ball valve 1.2 is also a safety control measure. When the system is not working, close the air ball valve 1.1 to prevent the compressed air in the air tank 4 from accidentally starting the subsequent pneumatic hydraulic system, and prevent the subsequent pneumatic hydraulic system from appearing Leaks cannot be discovered and dealt with in time, resulting in waste of energy.

With reference to FIG. 1, the embodiment of the present disclosure may further include a first exhaust ball valve 7.1. The input end of the first exhaust ball valve 7.1 is connected to the output end of the pressure switch 9, and the output end of the first exhaust ball valve 7.1 is connected to the A port of the two-position two-way switch valve 10. That is, the first exhaust ball valve 7.1 and the two-position two-way switch valve 10 are arranged in parallel and are in a normally closed state, and are used to open the first exhaust ball valve 7.1 when the two-position two-way switch valve 10 fails to open due to an unexpected failure. Work on it.

1, in the embodiment of the present disclosure, the P port of the three-position five-way pneumatic reversing valve 11 is connected to the A port of the two-position two-way switching valve 10, and the three-position five-way pneumatic reversing valve 11 is connected to the port A _{The P 2} port of the shuttle valve 12 is connected, the B port of the three-position five-way pneumatic reversing valve 11 _{is connected with the P 1} port of the shuttle valve 12, and the P ₁ and P ₂ ports of the shuttle valve 12 are switchably connected with the shuttle valve 12 Port A is connected.

In some embodiments, the pneumatic hydraulic valve 22 may be a three-position four-way reversing valve, which has a first control port and a second control port for controlling its valve position, and the first control port and three control ports of the pneumatic hydraulic valve 22 The B port of the five-position pneumatic reversing valve 11 is connected, and the second control port of the pneumatic hydraulic valve 22 is connected to the A port of the three-position five-way pneumatic reversing valve 11.

In the embodiment of the present disclosure, the three-position five-way pneumatic reversing valve 11 may be a center-sealed type, which may be a manual reversing valve, of course, it may also be an electromagnetic reversing valve. No restrictions. The two output ends of the three-position five-way pneumatic reversing valve 11 are respectively connected to the reversing interfaces of the pneumatic control hydraulic valve 22, which are used to manipulate the reversing of the pneumatic control hydraulic valve 22, and the shuttle valve 12 is connected in parallel with the pneumatic control hydraulic valve 22 , The two output ends of the three-position five-way pneumatic reversing valve 11 are also connected with the two inlets of the shuttle valve 12 to control the on and off of the shuttle valve 12.

With reference to Figure 1, in the embodiment of the present disclosure, the airflow inlet of the two-position two-way air control valve 13 communicates with the A port of the shuttle valve 12, and the P port of the two-position two-way air control valve 13 and the two-way switch valve 10 The port A is connected, and the port P of the two-position two-way air control valve 13 and the port A of the two-position two-way air control valve 13 can be switched and connected.

In other embodiments, with reference to FIG. 1, the embodiments of the present disclosure may further include a second exhaust ball valve 7.2, a third exhaust ball valve 7.3, a first gas source treatment device 8.1, and a second gas source treatment device 8.2. The input end of the second exhaust ball valve 7.2 is connected to the port A of the two-position two-way switch valve 10, and the output end of the second exhaust ball valve 7.2 is connected to the port P of the two-position two-way air control valve 13; the third exhaust ball valve 7.3 The input end of is connected to the port A of the two-position two-way switch valve 10, and the output end of the third exhaust ball valve 7.3 is connected to the port P of the three-position five-way pneumatic reversing valve 11. In addition, the first air source treatment device 8.1 is arranged between the output end of the second exhaust ball valve 7.2 and the P port of the two-position two-way air control valve 13, and the second air source treatment device 8.2 is arranged on the third exhaust ball valve 7.3 Between the output end and the P port of the three-position five-way pneumatic reversing valve 11.

In the embodiment of the present disclosure, the second exhaust ball valve 7.2 and the third exhaust ball valve 7.3 are both normally open. Only when the pipeline leading to the subsequent pneumatic components leaks, the second exhaust ball valve 7.2 and the third exhaust ball valve can be closed. / Or the third exhaust ball valve 7.3, which is convenient for troubleshooting and avoids energy waste.

In the embodiments of the present disclosure, the functions of the first air source treatment device 8.1 and the second air source treatment device 8.2 are pressure reduction, water separation filtration, oil mist, etc., to process the compressed air input to the subsequent pneumatic components, Improve the purity of compressed air.

1, in the embodiment of the present disclosure, the input port of the air motor 15 is connected to the port A of the two-position two-way air control valve 13, and the output port of the air motor 15 is connected to the control end of the hydraulic pump 18, and the hydraulic pump 18 The input port is connected to the fuel tank 27.

In the embodiment of the present disclosure, the two-position two-way air control valve 13 can be used to control the start and stop of the air motor. When the valve is in a normally closed state, the air motor 15 cannot be started randomly. When the three-position five-way pneumatic reversing valve 11 is in the neutral position, there is no compressed air output at the output end, and the shuttle valve 12 has no compressed air in and out, and the two-position two-way pneumatic control valve 13 still maintains a cut-off state. When the three-position five-way pneumatic reversing valve 11 is switched to any non-neutral position, the output end has compressed air output, and the shuttle valve 12 has compressed air in and out. The two-position two-way pneumatic control valve 13 is converted to a smooth state, and the compressed air can be Enter the input port of the air motor 15, and the air motor 15 starts.

In the embodiment of the present disclosure, the air motor 15 may be an actuator that converts the compression energy of compressed air into continuously rotating mechanical energy. The hydraulic pump 18 may be an energy conversion device that converts continuously rotating mechanical energy into hydraulic energy. In the present disclosure, the air motor 15 and the hydraulic pump 18 can be used in combination. The air motor is used to rotate and drive the hydraulic pump to rotate. The hydraulic pump outputs hydraulic oil with a certain pressure and flow rate to realize the compression energy of the compressed air and the compression energy of the hydraulic oil. The conversion, that is, the conversion between pneumatic and hydraulic.

1, in the embodiment of the present disclosure, the P port of the pneumatic hydraulic valve 22 is connected with the output port of the hydraulic pump 18, and the A port of the pneumatic hydraulic valve 22 is connected with the rodless cavity of the hydraulic cylinder 25.1. The T port of the valve 22 is in communication with the oil tank 27, and the B port of the pneumatic hydraulic valve 22 is in communication with the rod cavity of the hydraulic cylinder 25.2.

The air-controlled hydraulic valve 22 in the embodiment of the present disclosure may be a hydraulic directional control valve, and the reversing method adopts pneumatic. It may be an M-type three-position four-way reversing valve. By changing the position of the spool of the air-controlled hydraulic valve 22, Realize the switching of the hydraulic oil circuit, and then realize the expansion and contraction of the telescopic end of the hydraulic oil cylinder.

With reference to Fig. 1, the embodiment of the present disclosure may further include a throttle valve 14, a first filter 16, a second filter 19, a hydraulic pressure gauge 21, and a third filter 17. The throttle valve 14 is provided between the input port of the air motor 15 and the A port of the two-position two-way air control valve 13, the first filter 16 is provided between the input port of the hydraulic pump 18 and the oil tank 27, and the second filter 19 And the hydraulic pressure gauge 21 is sequentially arranged between the output port of the hydraulic pump 18 and the P port of the pneumatic hydraulic valve 22, and the third filter 17 is arranged between the T port of the pneumatic hydraulic valve 22 and the oil tank 27.

In the embodiment of the present disclosure, the throttle valve 14 may be located at the front end of the input port of the air motor 15 to adjust the air intake volume of the air motor 15 and reduce the fluctuation of the compressed air entering the air motor, so as to maintain the air motor's intake. The air volume and pressure are within the predetermined range to ensure the continuous working quality of the air motor.

In the embodiments of the present disclosure, the function of each filter may be to filter impurities mixed in the oil, and control the impurities in the oil within a range that can ensure the normal operation of the hydraulic system. The embodiment of the present disclosure provides three types of hydraulic filters: the first filter 16 may be located before the input port of the hydraulic pump 18 to ensure the normal operation of the hydraulic pump 18; the second filter 19 may be located at the hydraulic pump 18 After the output port, it is used for further fine filtering to ensure the normal operation of hydraulic components such as hydraulic valves; the third filter 17 can be located at the end of the oil return line to filter through hydraulic cylinders, hydraulic valves and other hydraulic components, and then return The oil pipe returns the hydraulic oil to the oil tank.

The hydraulic pressure gauge 21 of the embodiment of the present disclosure may be used to observe the working pressure of the hydraulic system.

1, the embodiment of the present disclosure may further include an overflow valve 23, the P port of the overflow valve 23 is in communication with the P port of the pneumatic hydraulic valve 22, and the T port of the overflow valve 23 is in communication with the third filter 17 , Overflow valve 23 is a hydraulic pressure control valve. Through the opening and overflow of the valve port, the pressure of the controlled system can be maintained constant, so as to realize the function of stabilizing, regulating or limiting the pressure, and control the maximum working pressure of the hydraulic system. The overload protection function is specifically: after the hydraulic oil discharged from the hydraulic pump 18 passes through the second filter 19, it enters the P port of the pneumatic hydraulic valve 22 and the P port of the overflow valve 23, and the overflow valve is in a normally closed state. When the hydraulic oil pressure is less than the setting pressure of the overflow valve 23, the overflow valve 23 remains normally closed, and all hydraulic oil enters the P port of the pneumatic hydraulic valve 22; when the hydraulic oil pressure is not less than the setting pressure of the overflow valve 23 Under pressure, the overflow valve 23 is in an open state, so that part of the hydraulic oil higher than the set pressure is returned to the tank from port P to port T through the overflow valve to ensure that the pressure of the hydraulic oil entering the P port of the pneumatic hydraulic valve 22 is all In the safe range, ensure the safe operation of the hydraulic system.

1, the embodiment of the present disclosure may also include a manual oil pump 20 and a three-position five-way hydraulic reversing valve 24. The P port of the three-position five-way hydraulic reversing valve 24 and the A port of the pneumatic hydraulic valve 22 are connected, and the three positions The T port of the five-way hydraulic reversing valve 24 is connected with the B port of the pneumatic hydraulic valve 22, the T port of the three-position five-way hydraulic reversing valve 24 is connected with the oil tank 27, and the A port of the three-position five-way hydraulic reversing valve 24 is connected with The rodless cavity of the hydraulic cylinder 25.1 is connected, and the B port of the three-position five-way hydraulic reversing valve 24 is connected with the rod cavity of the hydraulic cylinder 25.2; the manual oil pump 20 can be set at the P ₂ port of the three-position five-way hydraulic reversing valve 24 Between the oil tank 27 and the input port of the manual oil pump 20 and the oil tank 27, a one-way valve 26.1 is provided. A one-way valve 26.2. is provided between the P2 port of the three-position five-way hydraulic reversing valve 24 and the output port of the manual oil pump 20.

In the embodiment of the present disclosure, the function of the manual oil pump 20 can be to complete operations such as recovery of the hydraulic cylinder when an unexpected failure occurs in the external air source or the pneumatic pipeline during the operation. The three-position five-way hydraulic reversing valve 24 may be a middle-discharge type, manual control or electromagnetic control, which controls the hydraulic oil output by the hydraulic pump 18 and the hydraulic oil output by the manual oil pump 20, respectively. When the three-position five-way pneumatic reversing valve 24 is manually moved to the neutral position, the manual oil pump 20 is shut off with the hydraulic cylinders 25.1 and 25.2, and the output pipeline of the hydraulic pump 18 is connected with the hydraulic cylinders 25.1 and 25.2. When the three-position five-way pneumatic reversing valve 24 is manually moved to the left or right position, the manual oil pump 20 is connected to the hydraulic cylinders 25.1 and 25.2, and the output pipeline of the hydraulic pump 18 and the hydraulic cylinders 25.1 and 25.2 are shut off.

In some embodiments, the one-way valve installed at the input end of the manual oil pump 20 in the embodiment of the present disclosure can be used to prevent the hydraulic oil in the manual oil pump 20 from returning to the oil tank 27. The one-way valve installed at the output end of the manual oil pump 20 can be used to prevent the hydraulic oil in the hydraulic pump pipeline from returning to the manual oil pump 20, which can keep the manual oil pump 20 working normally and prevent the unfiltered hydraulic oil from flowing in tank.

In some embodiments, in the embodiments of the present disclosure, in the default state, each reversing valve is automatically in the neutral position when there is no operation.

In some embodiments, in the drawings of the present disclosure, the upper cavity of the hydraulic cylinder is a rodless cavity, and the lower cavity of the hydraulic cylinder is a rod cavity.

In some embodiments, in the pneumatic hydraulic valve 22 and the three-position five-way hydraulic reversing valve, the A port can be connected to the rodless cavity, and the P port can be connected to the A port. The rod cavity can be used to enter oil, the T port can be connected to the B port, the rod cavity is used to discharge oil to the oil return tank, and the hydraulic cylinder extends; the B port can be connected to the rod cavity, and the P ports are both It can be connected to port B, the rod cavity is used for oil intake, the T port can be communicated with port A, the rodless cavity is used for oil output to the oil return tank, and the hydraulic cylinder is retracted.

In some embodiments, the A port of the three-position five-way pneumatic reversing valve 11 is connected to the P ₂ port of the shuttle valve 12 and the second control port of the pneumatic hydraulic valve 22; the three-position five-way pneumatic reversing valve Port B of 11 is connected to port P _{1 of} shuttle valve 12 and the first control port of air-controlled hydraulic valve 22.

In some embodiments, when the three-position five-way hydraulic reversing valve (24) is in the neutral position, the hydraulic pump (18) drives the hydraulic cylinder, the manual oil pump (20) is disconnected from the hydraulic cylinder, and the pneumatic hydraulic valve (22) controls The hydraulic cylinder is telescopic.

In some embodiments, when the three-position five-way hydraulic reversing valve 24 is in the left or right position, the manual oil pump 20 drives a hydraulic cylinder, and the hydraulic pump 18 is disconnected from the hydraulic cylinder. The three-position five-way hydraulic reversing valve 24 controls the expansion and contraction of the hydraulic cylinder. At this time, the air-controlled hydraulic valve 22 must be in the neutral position.

The working principle of the embodiments of the present disclosure is:

1. Connect an external air source: the compressed air from the external air source is inflated into the air tank 4 through the first air ball valve 1.1, the air filter 2, the air check valve 3.

2. The compressed air flowing out of the air storage tank 4 passes through the second air ball valve 1.2, the pressure switch 9 and the two-position two-way switch valve 10, and then is divided into the first part and the second part. The first part of the compressed air enters the air control pipeline. The second part of the compressed air enters the pneumatic line. In the air control pipeline, compressed air passes through the third exhaust ball valve 7.3 and the second air source processing device 8.2, and enters the input end of the three-position five-way pneumatic reversing valve 11; in the pneumatic pipeline, the compressed air passes through the second The exhaust ball valve 7.2, the first air source treatment device 8.1, enter the input end of the two-position two-way air control valve 13.

3. Switch the three-position five-way pneumatic reversing valve 11 in the neutral position, the P port of the three-position five-way pneumatic reversing valve 11 is disconnected from the A and B ports of the three-position five-way pneumatic reversing valve 11, the shuttle valve 12 No input and output, the two-position two-way air control valve 13 is in the off state, compressed air cannot enter the input port of the air motor 15, the air motor 15 is in a stopped state, the air control hydraulic valve 22 is in the neutral position, and its P port is closed , Its A port, B port and T port are connected, and the hydraulic cylinders 25.1 and 25.2 have no action.

4. Switching the three-position five-way pneumatic reversing valve 11 is in the left position, the P port of the three-position five-way pneumatic reversing valve 11 is connected to the A port, and the three-position five-way pneumatic reversing valve 11 has no output and compressed air. Open the P1 port of the shuttle valve 12, and deliver it from the A port of the shuttle valve 12 to the two-position two-way air control valve 13, so that the two-position two-way air control valve 13 is switched from off to on, and the second part of the compressed air passes through After the two-position two-way air control valve 13 enters the input port of the air motor 15, the air motor 15 starts and drives the hydraulic pump 18 to rotate, the hydraulic pump 18 outputs hydraulic oil, and the hydraulic oil output by the hydraulic pump 18 is the second filter 19, The relief valve 23 enters the P port of the pneumatic hydraulic valve 22. At the same time, the compressed air passing through the first part of the three-position five-way pneumatic reversing valve 11 will enter the first control port of the pneumatic hydraulic valve 22, and the pneumatic will The control hydraulic valve 22 is switched to the right position, so that the P port and A port of the pneumatic hydraulic valve 22 are connected, and the T port is connected with the B port. The hydraulic oil output by the hydraulic pump 18 sequentially passes through the P port and the P port of the pneumatic hydraulic valve 22. A port, and enters the rodless cavity of the hydraulic cylinder 25.1. The rodless cavity of the hydraulic cylinder 25.2 is in turn connected to the B and T ports of the pneumatic hydraulic valve 22. The output end of the hydraulic cylinder 18 retracts, and the hydraulic cylinder 25.2 has the rodless cavity. The hydraulic oil in the rod cavity flows into the oil tank 17 through the first filter 17, and the output ends of the hydraulic oil cylinders 5.1 and 25.2.

5. Switch the three-position five-way pneumatic reversing valve 11 in the right position, the P port of the three-position five-way pneumatic reversing valve 11 is connected to the B port, and the three-position five-way pneumatic reversing valve 11 has no output and compressed air. P ₁ is opened shuttle valve port 12, and port a is delivered from the shuttle valve 12 to the two two vent valves 13 control the two valves 13 of two pneumatic control is converted into the on state is turned off, the second portion of the compressed air After passing through the two-position two-way air control valve 13, it enters the input port of the air motor 15, the air motor 15 is started, and drives the hydraulic pump 18 to rotate, the hydraulic pump 18 outputs hydraulic oil in turn, the second filter 19, the overflow valve 23, and then enters the air Control the P port of the hydraulic valve 22. At the same time, the compressed air passing through the first part of the three-position five-way pneumatic reversing valve 11 will enter the second control port of the pneumatic hydraulic valve 22, and pneumatically switch the pneumatic hydraulic valve 22 to the left position to make the pneumatic hydraulic valve The P port and the B port of 22 are connected, the T port is connected with the A port, the hydraulic oil output by the hydraulic pump 18 sequentially passes through the P and B ports of the pneumatic hydraulic valve 22, and enters the rod cavity of the hydraulic cylinder 25.2. The rod cavity of the oil cylinder 25.1 is sequentially connected to the A port and T port of the air-controlled hydraulic valve 22, the output end of the hydraulic oil cylinder is retracted, and the hydraulic oil in the rod cavity 25.1 of the hydraulic oil cylinder flows into the oil tank 27.

6. Switch the second three-position five-way hydraulic reversing valve 24 to the neutral position, the hydraulic oil circuit output by the hydraulic pump 18 is connected with the hydraulic cylinders 25.1 and 25.2, driving the hydraulic cylinders 25.1 and 25.2 to expand and contract, and the output end of the manual oil pump 20 With the hydraulic cylinders 25.1 and 25.2 turned off, the manual oil pump 20 has no effect on the hydraulic cylinders 25.1 and 25.2; switch the second three-position five-way hydraulic reversing valve 24 to the left position, the hydraulic oil circuit output by the hydraulic pump 18 and the hydraulic cylinder 25.1 and 25.1 25.2 Shut-off has no effect on the hydraulic cylinders 25.1 and 25.2. The output end of the manual oil pump 20 is connected to the rodless cavity of the hydraulic cylinder 25.2, and the rod cavity of the hydraulic cylinder 25.2 is connected to the oil return line, and the hydraulic cylinder extends; switching The second three-position five-way hydraulic reversing valve 24 to the right position, the hydraulic oil circuit and the hydraulic cylinder output by the hydraulic pump 18 are shut off, which has no effect on the hydraulic cylinder. The output end of the manual oil pump 20 is connected to the rod cavity of the hydraulic cylinder 25.1 Open, the rodless cavity of the hydraulic cylinder 25.2 is connected to the oil return line, and the hydraulic cylinder retracts.

7. In order to ensure the cleanliness of the hydraulic oil in the oil tank 27 and prevent unfiltered hydraulic oil from entering the oil tank 27, a check valve 26.1 is provided between the input port of the manual oil pump 20 and the oil tank 27 to prevent the manual oil pump The hydraulic oil in 20 enters the oil tank 27 in reverse flow; _{a check valve 26.2 is set between the P 2} port of the three-position five-way hydraulic reversing valve 24 and the output port of the manual oil pump 20 to prevent the hydraulic oil in the pipeline Reverse flow enters the manual oil pump 20.

In summary, the pneumatic-hydraulic safety system provided by the embodiments of the present disclosure is implemented by the three-position five-way pneumatic reversing valve 11, the shuttle valve 12, the two-position two-way pneumatic control valve 13, and the pneumatic hydraulic valve 2. With the cooperation, the air motor can be stopped and started, so that the expansion and contraction of the hydraulic cylinder can be started as required, which can reduce the problems of noise and energy waste, and the expansion and contraction of the hydraulic cylinder can be switched according to the needs, which can meet the requirements of railway engineering. The general requirements of vehicles for pneumatic and hydraulic systems. It has good practicability.

In some embodiments, the embodiments of the present disclosure can detect and limit the maximum pressure of compressed air and the maximum pressure of hydraulic oil, and eliminate potential safety hazards caused by excessive pressure.

In some embodiments, the embodiments of the present disclosure can also detect and limit the minimum working pressure of compressed air, and only allow control valve action and air motor rotation within the normal pressure range, eliminating unnecessary energy and time waste. The low pressure of compressed air is usually caused by the leakage of pipelines and pneumatic components. After detection, the failure to start can prompt the operator to repair and troubleshoot immediately. This not only ensures the safe operation of the equipment, but also avoids waste of energy and time.

In some embodiments, the embodiments of the present disclosure can facilitate various operations by manipulating each ball valve to facilitate independent overhaul of each area; it can also avoid wasting compressed air during non-operations; save energy and ensure safety, for example:

1. By manipulating the three-position five-way pneumatic reversing valve 11, the hydraulic cylinder can be started, closed, and reversed at any time: after manipulating the three-position five-way pneumatic reversing valve 11 to open or retract the hydraulic cylinder, when the hydraulic cylinder is When the amount of expansion and contraction reaches the required position, the first three-dimensional five-way reversing valve 11 is returned to the neutral position, the hydraulic oil immediately stops extending or contracting, and the expansion and contraction of the hydraulic cylinder can be controlled.

2. Control the expansion speed of the hydraulic cylinder: move the handle of the first air ball valve 1.1 or the second air ball valve 1.2, change the air passage area of the air ball valve, and control the compressed air flow into the subsequent pipelines, causing the air motor 15 and the hydraulic pump 18 The change in the speed of the hydraulic oil changes the flow of hydraulic oil to control the expansion speed of the hydraulic cylinder; move the handle of the third exhaust ball valve 7.3 to change the air passage area of the air ball valve to control the compressed air flow into the first air source processing device 8.1, The compressed air flow into the air motor 15 is changed, which causes the rotation speed of the air motor 15 and the hydraulic pump 18 to change, and the hydraulic oil flow is changed to realize the control of the expansion speed of the hydraulic cylinder; the air passage area of the throttle valve 14 is adjusted to control the inlet air flow. The compressed air flow rate of the motor 15 changes the speed of the air motor 15 and the hydraulic pump 18, and changes the hydraulic oil flow rate to control the expansion and contraction speed of the hydraulic cylinder.

The above-mentioned embodiments are preferred implementations of the present disclosure, which are only used to facilitate the description of the present disclosure, and are not intended to limit the present disclosure in any form. Anyone with ordinary knowledge in the technical field, within the scope of the technical features mentioned in the present disclosure, uses the technical content disclosed in the present disclosure to make partial changes or modifications of equivalent embodiments, and does not depart from The technical features of the present disclosure still fall within the scope of the technical features of the present disclosure.

Claims (10)

A pneumatic hydraulic safety system, including: Gas storage tank (4); The pressure switch (9) and the two-position two-way switch valve (10); the input end of the pressure switch (9) is connected to the output end of the gas tank (4), and the two-position two-way switch valve (10) The P port of) is connected to the output end of the pressure switch (9), and the P port of the two-position two-way switch valve (10) and the A port of the two-position two-way switch valve (10) are switchably connected; The three-position five-way pneumatic reversing valve (11) and the shuttle valve (12), the P port of the three-position five-way pneumatic reversing valve (11) is connected to the A port of the two-position two-way switching valve (10) the three five-pneumatic valve (11) and the port a of the shuttle valve (12) communicating the port P _2, the pneumatic three five-way valve (11) and the port B The P ₁ port of the shuttle valve (12) is connected, and the P ₁ port and the P ₂ port of the shuttle valve (12) are switchably connected with the A port of the shuttle valve (12); Two-position two-way pneumatic control valve (13); the control port of the two-position two-way pneumatic control valve (13) communicates with the A port of the shuttle valve (12), and the P of the two-position two-way pneumatic control valve (13) Port is connected with port A of the two-position two-way switch valve (10), port P of the two-position two-way valve (13) and port A of the two-position valve (13) can be switchably connected ； The air motor (15), the hydraulic pump (18) and the oil tank (27); the input port of the air motor (15) is connected to the A port of the two-position two-way air control valve (13), and the air motor (15) The output port of) is connected with the control end of the hydraulic pump (18), and the input port of the hydraulic pump (18) is connected with the oil tank (27); Air-controlled hydraulic valve (22) and hydraulic cylinders (25.1) and (25.2), said air-controlled hydraulic valve (22) is a three-position four-way reversing valve, and said air-controlled hydraulic valve (22) has control over its valve position The first control port and the second control port of the pneumatic control hydraulic valve (22) are connected to the B port of the three-position five-way pneumatic reversing valve (11), and the pneumatic control hydraulic valve The second control port of (22) is connected to the port A of the three-position five-way pneumatic reversing valve (11), the port P of the pneumatic hydraulic valve (22) and the output port of the hydraulic pump (18) Connected, the A port of the pneumatic hydraulic valve (22) is in communication with the rodless chamber of the hydraulic cylinder (25.1), and the T port of the pneumatic hydraulic valve (22) is in communication with the oil tank (27), so The B port of the pneumatic hydraulic valve (22) is communicated with the rod cavity of the hydraulic cylinder (25.2). The pneumatic-hydraulic safety system according to claim 1, wherein the gas storage tank (4) is connected to an external air source through an inflation pipeline, and the upper cover of the inflation pipeline is sequentially provided with a first air ball valve (1.1) , The air filter (2) and the air check valve (3), the first air ball valve (1.1), the air filter (2) and the air check valve (3) are directed from the outside air source to the The directions of the gas storage tanks (4) are arranged in sequence. The pneumatic-hydraulic safety system according to claim 1, wherein an air safety valve (5) is provided on the shell of the air storage tank (4), and a drain is provided at the bottom of the shell of the air storage tank (4). Valve (6). The pneumatic hydraulic safety system according to claim 1, wherein a second air ball valve (1.2) is provided between the input end of the pressure switch (9) and the output end of the air storage tank (4). The pneumatic hydraulic safety system according to claim 1, further comprising a first exhaust ball valve (7.1), the input end of the first exhaust ball valve (7.1) and the output end of the pressure switch (9) are connected, so The output end of the first exhaust ball valve (7.1) is connected to the A port of the two-position two-way switch valve (10). The pneumatic hydraulic safety system according to claim 1 or 5, further comprising a second exhaust ball valve (7.2) and a third exhaust ball valve (7.3), the input end of the second exhaust ball valve (7.2) and the The A port of the two-position two-way switch valve (10) is connected, and the output end of the second exhaust ball valve (7.2) is connected to the P port of the two-position two-way air control valve (13); the third exhaust The input end of the ball valve (7.3) is connected to the port A of the two-position two-way switch valve (10), and the output end of the third exhaust ball valve (7.3) is connected to the three-position five-way pneumatic reversing valve (11). ) P port connection. The pneumatic hydraulic safety system according to claim 6, further comprising a first air source processing device (8.1) and a second air source processing device (8.2), and the first air source processing device (8.1) is arranged on the first air source processing device (8.1). Between the output end of the two exhaust ball valve (7.2) and the P port of the two-position two-way air control valve (13), the second air source processing device (8.2) is arranged on the third exhaust ball valve (7.3 Between the output end of) and the P port of the three-position five-way pneumatic reversing valve (11). The pneumatic hydraulic safety system according to claim 1, further comprising a throttle valve (14), a first filter (16), a second filter (19), a hydraulic pressure gauge (21), and a third filter (17) ); The throttle valve (14) is set between the input port of the air motor (15) and the A port of the two-position two-way air control valve (13), and the first filter (16) is set Between the input port of the hydraulic pump (18) and the oil tank (27), the second filter (19) and the hydraulic pressure gauge (21) are sequentially arranged on the hydraulic pump (18) Between the output port and the P port of the pneumatic hydraulic valve (22), the third filter (17) is arranged between the T port of the pneumatic hydraulic valve (22) and the oil tank (27) . The pneumatic hydraulic safety system according to claim 1, further comprising an overflow valve (23), the P port of the overflow valve (23) and the P port of the pneumatic hydraulic valve (22) are connected, and the overflow The T port of the flow valve (23) is in communication with the oil tank (17). Hydraulic safety system according to claim 1, further comprising a manual pump (20) and three five-way hydraulic valve (24); said three five-way hydraulic valve (24) P ₁ of the port and The A port of the pneumatic hydraulic valve (22) is connected, the T port of the three-position five-way hydraulic reversing valve (24) is connected with the B port of the pneumatic hydraulic valve (22), the three-position five-way The P ₂ port of the two-way hydraulic reversing valve (24) communicates with the one-way valve (26.2), and the A port of the three-position five-way hydraulic reversing valve (24) is connected to the hydraulic cylinders (25.1) and (25.2). ) Is in communication with the rodless cavity, and the B port of the three-position five-way hydraulic reversing valve (24) is in communication with the rod cavity between the hydraulic cylinders (25.1) and (25.2); _{The manual oil pump (20) is arranged between the P 2} port of the three-position five-way hydraulic reversing valve (24) and the oil tank (27), and the input port of the manual oil pump (20) and the oil tank (27) is provided with a one-way valve (26.1); a one-way valve (26.1) is provided between the P ₂ port of the three-position five-way hydraulic reversing valve (24) and the output port of the manual oil pump (20) Valve (26.2).

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