AU2020389892B2

AU2020389892B2 - Pneumatic hydraulic safety system

Info

Publication number: AU2020389892B2
Application number: AU2020389892A
Authority: AU
Inventors: Yan He; Qingping LEI; Feng Shi; Wei SUI; Chuqiang Tang; Zhiwen Tu; Lina Wang
Original assignee: CRRC Yangtze Co Ltd
Current assignee: CRRC Yangtze Co Ltd
Priority date: 2019-11-27
Filing date: 2020-07-14
Publication date: 2023-05-25
Anticipated expiration: 2040-07-14
Also published as: WO2021103578A1; CN110925254A; CN110925254B; AU2020389892A1

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-REFERENCE OF RELATED ART

[0001] The disclosure claims priority to a Chinese Patent Application No. 201911178216.6, filed on November 27, 2019 and entitled "Pneumatic Hydraulic Safety System", the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

[0002] The disclosure relates to the technical field of hydraulic control, and more particularly to a pneumatic hydraulic safety system.

BACKGROUND OF THE INVENTION

[0003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0004] In railway engineering vehicles, a hydraulic cylinder is a relatively useful and mature operation mechanism. The extension and retraction of the hydraulic cylinder is achieved through movement of the hydraulic oil in rod chamber and rod-less chamber of the hydraulic cylinder. The hydraulic oil is delivered to the rod chamber and rod-less chamber of the hydraulic cylinder by pumping hydraulic oil from an oil tank by a hydraulic pump, and the hydraulic pump is driven by an air motor. In the existing technology, if a control system is not adopted and the compressed air is directly connected into the air motor, the air motor will drive the hydraulic pump to continuously work, so the extension and retraction of the hydraulic cylinder will be operated all the way, causing problems of noise and energy wasting, and it is not possible to switch the extension and retraction of the hydraulic cylinder as needed.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to overcome or substantially ameliorate one or more of the disadvantages of prior art, or at least to provide a useful alternative. It is an object of the present invention in at least one embodiment to provide a pneumatic hydraulic safety system to solve the technical problems in the existing solution, such as noise, energy wasting caused by the hydraulic cylinder working in a non-stop state, and the problems that the extension and retraction of a hydraulic cylinder cannot be switched according to needs.

[0006] According to one aspect of the present disclosure, there is provided a pneumatic hydraulic safety system, comprising: an air storage tank, a pressure switch and a two-position two-way switching valve, an input end of the pressure switch is connected to an output end of the air storage tank, and a P port of the two-position two-way switching valve is connected to an output end of the pressure switch, and the P port of the two-position two-way switching valve and an A port of the two-position two-way switching valve is switchably connected; a three-position five-way pneumatic directional valve and a shuttle valve, a P port of the three-position five-way pneumatic directional valve is connected to the A port of the two-position two-way switching valve, and an A port of the three-position five-way pneumatic directional valve is communicated to a P 2 port of the shuttle valve, and a B port of the three-position five-way pneumatic directional valve is communicated to a Pi port of the shuttle valve, and the Pi port and P2 port of the shuttle valve are switchably communicated to an A port of the shuttle valve; a two-position two-way pneumatic control valve; a control port of the two-position two-way pneumatic control valve is communicated to the A port of the shuttle valve, and a P port of the two-position two-way pneumatic control valve is communicated to the A port of the two-position two-way switching valve, and the P port of the two-position two way pneumatic control valve and an A port of the two-position two-way pneumatic control valve are switchably connected; an air motor, a hydraulic pump and an oil tank, an input port of the air motor is connected to the A port of the two-position two-way pneumatic control valve, and an output port of the air motor is communicated to a control end of the hydraulic pump, and an input port of the hydraulic pump is connected to the oil tank; a pneumatic control hydraulic valve and a hydraulic cylinder and a hydraulic cylinder, the pneumatic control hydraulic valve is a three-position four-way directional valve, and the pneumatic control hydraulic valve has a first control air port and a second control air port that control a valve position of the pneumatic control hydraulic valve, and the first control air port of the pneumatic control hydraulic valve is connected to the B port of the three position five-way pneumatic directional valve, and the second control air port of the pneumatic control hydraulic valve is connected to the A port of the three-position five-way pneumatic directional valve, and a P port of the pneumatic control hydraulic valve is connected to the output port of the hydraulic pump, and an A port of the pneumatic control hydraulic valve is communicated to a rod-less chamber of the hydraulic cylinder, and a T port of the pneumatic control hydraulic valve is communicated to the oil tank, and a B port of the pneumatic control hydraulic valve is communicated to a rod chamber of the hydraulic cylinder; wherein the system further includes a manual oil pump and a three-position five-way hydraulic directional valve; a Pi port of the three position five-way hydraulic directional valve is communicated to the A port of the pneumatic control hydraulic valve, and a T port of the three-position five-way hydraulic directional valve is communicated to the B port of the pneumatic control hydraulic valve, and a P 2 port of the three position five-way hydraulic directional valve is communicated to an one-way valve, and an A port of the three-position five-way hydraulic directional valve is communicated to the rod-less chambers of the hydraulic cylinder and the hydraulic cylinder, and a B port of the three-position five-way hydraulic directional valve is communicated to a rod chamber between the hydraulic cylinder and the hydraulic cylinder; and the manual oil pump is disposed between a P 2 port of the three-position five-way hydraulic directional valve and the oil tank.

[0007] In some embodiments, the air storage tank may be connected to an external air source through an air charging pipeline, and an upper cover of the gas charging pipeline is sequentially provided with a first air ball valve, an air filter and an air check valve; the first air ball valve, the air filter and the air check valve are sequentially disposed in a direction from the external air source to the air storage tank.

[0008] In some embodiments, an air safety valve may be provided on a housing of the air storage tank, and a drain valve is provided at the bottom of the housing of the air storage tank.

[0009] 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 air storage tank.

[0010] In some embodiments, the system may further include a first exhaust ball valve, an input end of the first exhaust ball valve is connected to the output end of the pressure switch, and an output end of the first exhaust ball valve is connected to the A port of the two-position two-way switching valve.

[0011] In some embodiments, the system may further include a second exhaust ball valve and a third exhaust gas ball valve, an input end of the second exhaust ball valve is connected to the A port of the two-position two-way switching valve, and an output end of the second exhaust ball valve is connected to the P port of the two-position two-way pneumatic control valve; an input end of the third exhaust gas ball valve is connected to the A port of the two-position two-way switching valve, and an output end of the third exhaust ball valve is connected to the P port of the three-position five way pneumatic directional valve.

[0012] In some embodiments, the system may further include a first air source processing device and a second air source processing device, the first air source processing device is disposed between the output end of the second exhaust ball valve and the P port of the two-position two-way pneumatic control valve, and the second air source processing device is disposed between the output end of the third exhaust ball valve and the P port of the three-positionfive-way pneumatic directional valve.

[0013] 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 two-way pneumatic control valve; 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 disposed between the output port of the hydraulic pump and the P port of the pneumatic control hydraulic valve, and the third filter is disposed between the T port of the pneumatic control hydraulic valve and the oil tank.

[0014] In some embodiments, the system may further include an overflow valve, a P port of the overflow valve is communicated to the P port of the pneumatic control hydraulic valve, and a T port of the overflow valve is communicated to the oil tank.

[0015] In some embodiments, a one-way valve is disposed between an input port of the manual oil pump and the oil tank; and the one-way valve is disposed between the P 2 port of the three-position five-way hydraulic directional valve and an output port of the manual oil pump.

[0016] In some embodiments, the hydraulic cylinder may be two hydraulic cylinders parallelly connected.

[0017] In some embodiments, the hydraulic cylinder may be a plurality of hydraulic cylinders parallelly connected.

[0018] In some embodiments, the hydraulic cylinder may be a single hydraulic cylinder.

[0019] The beneficial effects of the disclosure include:

[0020] 1, the pneumatic hydraulic safety system according to some embodiments of the disclosure, the compressed air flowing from the air storage tank first passes through a pressure switch and a two-position two-way switching valve. The pressure switch can detect the pressure of the compressed air output from the air storage tank; when the pressure is lower than a lowest start pressure of the system, the pressure switch does not output an electrical signal, and the two-position two-way switching valve is normally closed and the air path is cut off. At the moment, no compressed air is passing through the two-position two-way switching valve, and each subsequent pneumatic element is not activated, so that the problem caused by low pressure of the compressed air may be effectively avoided; when the pressure is higher than the lowest start pressure of the system, the pressure switch outputs an electrical signal to switch the two-position two-way switching valve on, the air path is unblocked, and the system can work normally.

[0021] 2, the compressed air passing through the two-position two-way switching valve is divided into a first portion and a second portion. The compressed air of the first portion will pass through a three-position five-way pneumatic directional valve; when the three-position five-way pneumatic directional valve is in a middle position, the P port of the three-position five-way pneumatic directional valve is disconnected with the A port and B port of the three-position five-way pneumatic directional valve; the shuttle valve has no input and output; the two-position two-way pneumatic control valve is in an OFF state, and the compressed air cannot enter the input port of the air motor; the air motor is in a stopping state; the pneumatic control hydraulic valve is in the middle position and its P port is closed and its A port and B port are communicated to its T port; and the hydraulic cylinder has no action; when the three-position five-way pneumatic directional valve is in the left position, the P port of the three-position five-way pneumatic directional valve is communicated to its A port; the B port of the three-position five-way pneumatic directional valve has no output; the compressed air opens the P 2 port of the shuttle valve and is delivered from the A port of the shuttle valve to the control port of the two-position two-way pneumatic control valve to make the two position two-way pneumatic control valve switch from an OFF state to an ON state. After the compressed air of the second portion is passed through the two-position two-way pneumatic control valve, it enters the input port of the air motor so that the air motor is activated to drive the hydraulic pump to rotate; the hydraulic pump outputs hydraulic oil to the P port of the pneumatic control hydraulic valve; at the same time, the compressed air passing through the first portion of the three position five-way pneumatic directional valve will enter the second control air port of the pneumatic control hydraulic valve to pneumatically switch the pneumatic control hydraulic valve to a right position so that the P port and A port of the pneumatic control hydraulic valve are communicated and its T port is communicated to its B port and the hydraulic oil output from the hydraulic pump sequentially passes through the P port and A port of the pneumatic control hydraulic valve and enters the rod-less chamber of the hydraulic cylinder; the rod chamber of the hydraulic cylinder is sequentially communicated to the B port and T port of the pneumatic control hydraulic valve, the output end of the hydraulic cylinder extended outwards, and the hydraulic oil of the rod chamber of the hydraulic cylinder flows into the oil tank; when the three-position five-way pneumatic directional valve is in a right position, the P and the B port of the three-position five-way pneumatic directional valve are communicated, and the A port of the three-position five-way pneumatic directional valve has no output; the compressed air opens the Pi 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, so that the two-position two-way pneumatic control valve is switched from an OFF state to an ON state; after the compressed air of the second portion is passed through the two-position two-way pneumatic control valve, it enters the input port of the air motor so that the air motor is activated to drive the hydraulic pump to rotate, and the hydraulic pump outputs hydraulic oil to the P port of the pneumatic control hydraulic valve; at the same time, the compressed air of the first portion passing through the three-position five-way pneumatic directional valve will enter the first control air port of the pneumatic control hydraulic valve to pneumatically switch the pneumatic control hydraulic valve to the left position, so that the P port and B port of the pneumatic control hydraulic valve are communicated and its T port is communicated to its A port, and the hydraulic oil output from the hydraulic pump sequentially enters the P port and B port of the pneumatic control hydraulic valve, and enters the rod chamber of the hydraulic cylinder; the rod-less chamber of the hydraulic cylinder are sequentially communicated with the A port and T port of the pneumatic control hydraulic valve; the hydraulic oil of the rod-less chamber of the hydraulic cylinder flows into the oil tank and the output end of the hydraulic cylinder is retracted.

[0022] In summary, the pneumatic hydraulic safety system according to some embodiments of the disclosure, the air motor is stopped and started by cooperation of a three-position five-way pneumatic directional valve, a shuttle valve, a two-position two-way pneumatic control valve, and a pneumatic control hydraulic valve, so that the extension and retraction of the hydraulic cylinder can be started as needed, thereby resolving the problem of noise and energy wasting, and the extension and retraction of the hydraulic cylinder can be switched as needed, thus it has good practicability.

[00231 Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly explain the technical solutions in the disclosure, the accompanying drawings used in the embodiments will be briefly introduced in the following. Obviously the accompanying drawings in the following description are merely some embodiments of the disclosure. For those skilled in the art, it is also possible to obtain other drawings according to these drawings without paying creative labor.

[0025] FIG. 1 is a schematic diagram showing a hydraulic arrangement of a pneumatic hydraulic safety system in accordance with an embodiment of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Next, the technical solutions in the embodiments of the disclosure will be clearly and completely described with reference to the drawings in the embodiments of the disclosure. Apparently, the described embodiments are merely part of the embodiments of the disclosure, rather than all embodiments. Based on the embodiments in the disclosure, all other embodiments obtained by one of ordinary skill in the art without making creative work all fall within the scope of the disclosure.

[0027] FIG. 1 is a diagram showing a hydraulic arrangement of a pneumatic hydraulic safety system in accordance with an embodiment of the disclosure. Referring to FIG. 1, the system comprises an air storage tank 4, a pressure switch 9, a two-position two-way switching valve 10, a three-position five-way pneumatic directional valve 11, a shuttle valve 12, a two-position two-way pneumatic control valve 13, a pneumatic control hydraulic pressure valve 22, an air motor 15, a hydraulic pump 18 and an oil tank 27.

[0028] The air storage tank 4 of the embodiment of the disclosure can be used to store a certain amount of compressed air to ensure continuous gas supply. Referring to FIG. 1, the air storage tank 4 of the embodiment of the disclosure can be connected to an external air source through an air charging pipeline and an upper cover of the gas charging 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 check valve 3 are sequentially disposed in the direction from the external air source to the air storage tank 4.

[0029] The external air source of the embodiment of the disclosure is a blanket term, and the specific form may be diverse, such as an air compressor, a compressed air duct, and the like. The output pressure of the external air source is usually from 0.1 MPa to 1.2 MPa of compressed air.

[0030] In an embodiment of the 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 an OFF state, the external air source is disconnected from the pneumatic hydraulic system, and the compressed air of the external air source cannot enter the pneumatic hydraulic system. When the first air ball valve 1.1 is in an ON state, the compressed air of the external air source enters the pneumatic hydraulic system. In addition, the first air ball valve 1.1 is also a safety control measure. Under the non-operating condition of the system, the air ball valve 1.1 is turned off to avoid accident start of the system, also prevent energy waste caused by pipeline leakage that can not be found and handled in time when no one is working.

[0031] In an embodiment of the disclosure, the air filter 2 can be used to filter compressed air entering a pneumatic hydraulic system from an external air source to exclude impurities such as dust in the compressed air.

[0032] In an embodiment of the disclosure, the air check valve 3 can be an one-way pass element, which only allows the compressed air of the external air source to enter the air storage tank 4, but do not allow the compressed air in the air storage tank 4 to flow to the external air source. When the pressure of the external air source descends due to an influence of various factors, it prevents the compressed air in the air storage tank 4 from flowing back to the external air source to interfere with the external air source due to the pressure of the compressed air in the air storage tank 4 being higher than the external air source.

[0033] Referring to FIG. 1, in an embodiment of the disclosure, an air safety valve 5 may be provided on a 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. The effect of the air safety valve 5 is to ensure that the highest pressure of the compressed air in the air storage tank 4 is within a normal range, excluding excessive pressure, preventing the damage of the air storage tank 4 due to high pressure of the compressed air, thereby reducing the pulsation of air flow input from the external air source and stabilizing the pressure of the air flow output.

[0034] In the disclosure, the pressure of compressed air in the air storage tank 4 can be 0.05-0.2 MPa higher than the highest operating pressure of a subsequent air source processing device, which is used for compensating a loss of pressure in a pneumatic pipeline between the air storage tank 4 and the air source processing device 8. The drain valve 6 is located at the lowest position of the bottom of the air storage tank 4, and is used to discharge the water and dust in the air storage tank 4.

[0035] In an embodiment of the disclosure, it is mainly to input compressed air to the pneumatic hydraulic system through an external air source. When the external air source is unexpectedly interrupted, the compressed air in the air storage tank can be used in emergency treatment to ensure normal operation of the system.

[0036] Referring to FIG. 1, in an embodiment of the disclosure, an input end of the pressure switch 9 is connected to an output end of the air storage tank 4. A P port of the two-position two-way switching valve 10 is connected to an output end of the pressure switch 9. The P port of the two position two-way switching valve 10 and an A port of the two-position two-way switching valve 10 can be switchably connected.

[0037] In an embodiment of the disclosure, the pressure switch 9 and the two-position two-way switching valve 10 cooperate to be used at the output end of the air storage tank 4. The pneumatic hydraulic system is composed of a variety of pneumatic elements, and the lowest starting pressure of each pneumatic element is different. For example, the lowest starting pressure of the pneumatic control hydraulic valve 22 is lower than the lowest starting pressure of the air motor 15. When the pressure of the compressed air is too low, each pneumatic element cannot work properly. In order to solve such problems, an embodiment of the disclosure adopts a combination of the pressure switch 9 and the two-position two-way switching valve 10. The principle of operation is: that the two-position two-way switching valve 10 is normally closed; the air path is usually cut off; the pressure switch 9 is used to control the air path on and off. The pressure of the compressed air output from the air storage tank 4 is detected by the pressure switch 9. When the pressure is lower than the lowest starting pressure of the system, the pressure switch 9 does not output an electrical signal, and the two-position two-way switching valve 10 is still normally closed and the air path is cut off. At the moment, no compressed air is passing through the two-position two-way switching valve 10. Because no compressed air is input into the subsequent pneumatic elements, all pneumatic elements are not activated, which can effectively avoid the problems such as stagnation and damage of the pneumatic elements, due to the fact that the pressure of the compressed air is too low, although the pneumatic elements can barely work, but it cannot work normally. When the pressure is higher than the lowest starting pressure of the system, the pressure switch 9 outputs an electrical signal to switch the two-position two-way switching valve 10 into an ON state, so the air path is unblocked, and the system can work normally.

[0038] Referring to FIG. 1, in the embodiment of the 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 storage tank 4. The second air ball valve 1.2 is located at an output port of the air storage tank 4 to control the connection of the air storage tank 4 and the subsequent pneumatic hydraulic system. When the second air ball valve 1.2 is in an Off state, the air storage tank 4 is disconnected from the subsequent pneumatic hydraulic system and the compressed air in the air storage tank 4 cannot be output. When the second air ball valve 1.2 is in an ON state, the compressed air in the air storage tank 4 freely enters the subsequent pneumatic hydraulic system. The second air ball valve 1.2 is also a safety control measures. Under a non-operating condition of the system, the second air ball valve 1.2 is cut off to avoid that the compressed air in the air storage tank 4 starts the subsequent pneumatic hydraulic system inadvertently; also, it can also avoid energy waste caused by a leakage in the subsequent pneumatic hydraulic system that cannot be discovered and dealt with timely.

[0039] Referring to FIG. 1, an embodiment of the disclosure may further include a first exhaust ball valve 7.1. An input end of the first exhaust ball valve 7.1 is connected to the output end of the pressure switch 9, and an output end of the first exhaust ball valve 7.1 is connected to the A port of the two-position two-way switching valve 10. That is, the first exhaust ball valve 7.1 and the two position two-way switching valve 10 are arranged in parallel and is in a close state normally, so that the first exhaust ball valve 7.1 is opened to work when the two-position two-way valve 10 has an accidental fault and cannot be opened.

[0040] Referring to FIG. 1, in an embodiment of the disclosure, a P port of the three-position five way pneumatic directional valve 11 is connected to the A port of the two-position two-way switching valve 10; an A port of the three-position five-way pneumatic directional valve 11 is communicated to a P2 port of the shuttle valve 12; a B port of the three-position five-way pneumatic directional valve 11 is communicated to a Pi port of the shuttle valve 12; and the Pi port and the P 2 port of the shuttle valve 12 are switchably communicated to an A port of the shuttle valve 12.

[0041] In some embodiments, the pneumatic control hydraulic valve 22 may be a three-position four-way directional valve having a first control air port and a second control air port for controlling a valve position of the pneumatic control hydraulic valve 22. The first control air port of the pneumatic control hydraulic valve 22 is connected to the B port of the three-position five-way pneumatic directional valve 11, and the second control air port of the pneumatic control hydraulic valve 22 is connected to the A port of the three-positionfive-way pneumatic directional valve 11.

[0042] In an embodiment of the disclosure, the three-position five-way pneumatic directional valve 11 can be a middle-sealing type, which may be a manual directional valve. Of course, the three position five-way pneumatic directional valve 11 may also be an electromagnetic directional valve. This is not limited in the embodiments of the disclosure. Two output ends of the three-position five way pneumatic directional valve 11 are respectively connected to a switching interface for manipulating the pneumatic control valve 22 so as to manipulate the directional change of the pneumatic control hydraulic valve 22; and the shuttle valve 12 is connected in parallel with the pneumatic control hydraulic valve 22, and two output ends of the three-position five-way pneumatic directional valve 11 are also connected to two input ports of the shuttle valve 12 so as to control the ON-OFF of the shuttle valve 12.

[0043] Referring to FIG. 1, in an embodiment of the disclosure, air flow input port of the two position two-way pneumatic control valve 13 is communicated to the A port of the shuttle valve 12; a P port of the two-position two-way pneumatic control valve 13 is communicated to the A port of the two-position two-way switching valve 10; and the P port of the two-position two-way pneumatic control valve 13 and an A port of the two-position two-way pneumatic control valve 13 can be switchably connected.

[0044] In some implementation of the of the disclosure, referring to FIG. 1, the embodiments of the disclosure may further include a second exhaust ball valve 7.2, a third exhaust gas valve 7.3, a first air source processing device 8.1 and a second air source processing device. 8.2. An input end of the second exhaust ball valve 7.2 is connected to the A port of the two-position two-way switching valve , and an output end of the second exhaust ball valve 7.2 is connected to the P port of the two position two-way pneumatic control valve 13; an input end of the third exhaust ball valve 7.3 is connected to the A port of the two-position two-way switching valve 10, and an output end of the third exhaust ball valve 7.3 is connected to the P port of the three-position five-way pneumatic directional valve 11. Furthermore, the first air source processing device 8.1 is disposed between the output end of the second exhaust ball valve 7.2 and the P port of the two-position two-way pneumatic control valve 13, and the second air source processing device 8.2 is disposed between the output end of the third exhaust ball valve 7.3 and the P port of the three-position five-way pneumatic directional valve 11.

[0045] In an embodiment of the disclosure, the second exhaust ball valve 7.2 and the third exhaust ball valve 7.3 are both normally opened, and the second exhaust ball valve 7.2 and/or the third exhaust ball valve 7.3 can be closed only when a leakage occurs in the pipeline of the subsequent pneumatic elements. In this way, it can be convenient for troubleshooting, and energy wasting can be avoided.

[0046] In an embodiment of the disclosure, the first air source processing device 8.1 and the second air source processing device 8.2 have functions of decompression, water separating filtration, oil mist, etc., for processing compressed air input to the subsequent pneumatic elements so as to improve the purity of the compressed air.

[0047] Referring to FIG. 1, in an embodiment of the disclosure, an input port of the air motor 15 is connected to the A port of the two-position two-way pneumatic control valve 13; an output port of the air motor 15 is communicated to a control end of the hydraulic pump 18; and an input port of the hydraulic pump 18 is connected to the oil tank 27.

[0048] In an embodiment of the disclosure, the two-position two-way pneumatic control valve 13 can be used to control the start and stop of the air motor. The valve is in a normally closed state, and the air motor 15 cannot be started arbitrarily. When the three-position five-way pneumatic directional valve 11 is in a middle position, the output end of the three-position five-way pneumatic directional valve 11 has no compressed air outputting, and no compressed air enters or exits the shuttle valve 12, and the two-position two-way pneumatic control valve 13 remains in an OFF state. When the three-position five-way pneumatic directional valve 11 is switched to any non-middle position, there is compressed air output from the output end of the three-position five-way pneumatic directional valve 11, and there is compressed air entering and exiting the shuttle valve 12, and the two-position two-way pneumatic control valve 13 is switched into an unblocked state, so the compressed air can enter the input port of the air motor 15, and the air motor 15 is started.

[0049] In an embodiment of the disclosure, the air motor 15 may be an actuating element that converts the compression energy of the compressed air into continuous rotating mechanical energy. The hydraulic pump 18 may be an energy conversion device that converts a continuous rotating mechanical energy into a hydraulic energy. In an embodiment of the disclosure, the air motor 15 and the hydraulic pump 18 can be used in combination, adopting the rotation of the air motor to drive the hydraulic pump to be rotated, and the hydraulic pump outputs a hydraulic oil having a certain pressure and flow rate, thereby realizing the conversion between the compression energy of the compressed air and the compression energy of the hydraulic oil, i.e., the conversion between pneumatic operation and hydraulic operation.

[0050] Referring to FIG. 1, in an embodiment of the disclosure, a P port of the pneumatic control hydraulic valve 22 is connected to an output port of the hydraulic pump 18; an A port of the pneumatic control hydraulic valve 22 is communicated to a rod-less chamber of the hydraulic cylinder 25.1; a T port of the pneumatic control hydraulic valve 22 is communicated to the oil tank 27; and a B port of the pneumatic control hydraulic valve 22 is communicated to a rod chamber of the hydraulic cylinder 25.2.

[0051] The pneumatic control hydraulic valve 22 of the embodiment of the disclosure may be a hydraulic direction control valve to change direction pneumatically. It can be an M-type three position four-way directional valve, which switches a hydraulic oil path by changing a spool position of the pneumatic control hydraulic valve 22 so as to realize extension and retraction of an extendable end of the hydraulic cylinder.

[0052] Referring to FIG. 1, an embodiment of the 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 disposed between the input port of the air motor 15 and the A port of the two-position two-way pneumatic control valve 13, and the first filter 16 is disposed between an input port of hydraulic pump 18 and the oil tank 27; the second filter 19 and the hydraulic pressure gauge 21 are sequentially disposed between the output port of the hydraulic pump 18 and the P port of the pneumatic control hydraulic valve 22, and the third filter 17 is disposed between the T port of the pneumatic control hydraulic valve 22 and the oil tank 27.

[0053] In an embodiment of the disclosure, the throttle valve 14 can be located at a front end of the input port of the air motor 15 to adjust an air intake amount of the air motor 15 and reduce the fluctuation of the compressed air entering the air motor, maintaining the air intake amount and the pressure of the air motor within a predetermined range to ensure the quality of the air motor in continuous operation.

[0054] In the embodiment of the disclosure, each filter can be used to filter impurities in the oil to control the impurities in the oil to be within a range ensuring a normal operation of the hydraulic system. The embodiment of the disclosure provides three types of hydraulic filters: the first filter 16, which can be located ahead of the input port of the hydraulic pump 18 to ensure a normal operation of the hydraulic pump 18; the second filter 19, which can be located behind the output port of the hydraulic pump 18 for further fine filtration to ensure a normal operation of hydraulic elements such as a hydraulic valve; and the third filter 17, which can be located at an end of an oil return pipeline for filtration of hydraulic oil returning back to the oil tank through the oil return pipeline after the hydraulic operation of the hydraulic elements such as a hydraulic cylinder, a hydraulic valve.

[0055] The hydraulic pressure gauge 21 of the embodiment of the disclosure can be used to observe the operation pressure of the hydraulic system.

[0056] Referring to FIG. 1, an embodiment of the disclosure may further include an overflow valve 23. A P port of the overflow valve 23 is communicated to the P port of the pneumatic control hydraulic valve 22, and a T port of the overflow valve 23 is communicated to the third filter 17. The overflow valve 23 is a hydraulic pressure control valve, which maintains the pressure of a controlled hydraulic system stable by opening the port of the valve for overflow, so as to realize pressure stabilization, pressure regulation, or pressure limitation, and control the highest working pressure of the hydraulic system and play a role of overload protection of the system. In some embodiments, the hydraulic oil discharged from the hydraulic pump 18 enters the P port of the pneumatic control hydraulic valve 22 and the P port of the overflow valve 23 after passing through the second filter 19, and the overflow valve 23 is normally closed. When the pressure of the hydraulic oil is smaller than a set pressure of the overflow valve 23, the overflow valve 23 maintains a normally closed state, and the hydraulic oil all enters the P port of the pneumatic control hydraulic valve 22. When the pressure of the hydraulic oil is not smaller than the set pressure of the overflow valve 23, the overflow valve 23 is in an open state, so that a portion of the hydraulic oil above the set pressure is returned from the P port via the T port of the overflow valve 23 back to the oil tank, ensuring that the pressure of the hydraulic oil entering the P port of the pneumatic control hydraulic valve 22 is within a secure range, so as to ensure a safe operation of the hydraulic system.

[0057] Referring to FIG. 1, an embodiment of the disclosure can also include a manual oil pump 20 and a three-position five-way hydraulic directional valve 24. A P port of the three-position five-way hydraulic directional valve 24 is communicated to the A port of the pneumatic control hydraulic valve 22; a T port of the three-position five-way hydraulic directional valve 24 is communicated to the B port of the pneumatic control hydraulic valve 22; the T port of the three-position five-way hydraulic directional valve 24 is communicated to the oil tank 27; an A port of the three-position five-way hydraulic directional valve 24 is communicated to the rod-less chamber of the hydraulic cylinder 25.1; a B port of the three-position five-way hydraulic directional valve 24 is communicated to the rod chamber of the hydraulic cylinder 25.2; the manual oil pump 20 can be disposed between a P 2 port of the three-position five-way hydraulic directional valve 24 and the oil tank 27, and an one-way valve 26.1 is provided between an input port of the manual oil pump 20 and the oil tank 27. An one-way valve 26.2 is disposed between the P 2 port of the three-position five-way hydraulic directional valve 24 and an output port of the manual oil pump 20.

[0058] In an embodiment of the disclosure, the manual oil pump 20 can be used to realize hydraulic cylinder recovery when an external air source or a pneumatic pipeline has an accidental failure in the operation. The three-position five-way hydraulic directional valve 24 can be a middle-discharge type, which can be manually controlled or electromagnetically controlled, which controls the hydraulic oil output from the hydraulic pump 18 and the hydraulic oil output from the manual oil pump 20 respectively. When the three-position five-way pneumatic directional valve 24 is manually moved to a middle position, the manual oil pump 20 is turned off from the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2, and an output pipeline of the hydraulic pump 18 is communicated to the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2. When the three-position five-way pneumatic directional valve 24 is manually moved to a left or right position, the manual oil pump 20 is turned on to communicate to the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2, and the output pipeline of the hydraulic pump 18 is turned off from the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2.

[0059] In some embodiments, an one-way valve mounted at the input end of the manual oil pump 20, which can be used to prevent the hydraulic oil in the manual oil pump 20 from back-flow to the oil tank 27. An one-way valve mounted at the output end of the manual oil pump 20, which can be used to prevent the hydraulic oil in the pipeline of the hydraulic pump from back-flow to the manual oil pump 20.It can not only maintain a normal operation of the manual oil pump 20, but also prevent non-filtrated hydraulic oil from flowing into the oil tank.

[0060] In some implementations of the embodiment of the disclosure, in a default state, each directional valve is located automatically in a middle position.

[0061] In some embodiments, in the drawings of the disclosure, an upper chamber of the hydraulic cylinder is a rod-less chamber, and a lower chamber of the hydraulic cylinder is a rod chamber.

[0062] In some embodiments, in the pneumatic control hydraulic valve 22 and the three-position five-way hydraulic-directional valve, each A port may be communicated to the rod-less chamber, and each P port may be communicated with A port. The rod-less chamber can be used for oil inflow and T port may be communicated with B port. Each rod chamber is used to discharge oil to an oil return box, and the hydraulic cylinder is extended. Each B port may be communicated to a rod chamber, and each P port may be communicated to B port. The rod chamber is used for oil inflow. T port may be communicated to A port, and the rod-less chamber is used for discharging oil to the oil return box, and the hydraulic cylinder is retracted.

[0063] In some embodiments, the A port of the three-position five-way pneumatic directional valve 11 is connected to the P 2 port of the shuttle valve 12 and the second control air port of the pneumatic control hydraulic valve 22; the B port of the three-position five-way pneumatic directional valve 11 is connected to the Pi port of the shuttle valve 12 and the first control air port of the pneumatic control hydraulic valve 22.

[0064] In some embodiments, when the three-position five-way hydraulic pressure directional valve 24 is in a middle position, the hydraulic pump 18 drives the hydraulic cylinder, and the manual oil pump 20 is disconnected from the hydraulic cylinder, and the pneumatic control hydraulic valve 22 controls the hydraulic cylinder to extend or retract.

[0065] In some embodiments, when the three-position five-way directional valve 24 is in a left or right position, the manual oil pump 20 drives the hydraulic cylinder, and the hydraulic pump 18 is disconnected from the hydraulic cylinder, and the three-position five-way hydraulic directional valve 24 controls the hydraulic cylinder to extend or retract, at which moment the pneumatic control hydraulic valve 22 should be in a middle position.

[0066] The operation principle of the embodiments of the disclosure is:

[0067] 1. Connecting an external air source: the compressed air from the external air source is charged to the air storage tank 4 through the first air ball valve 1.1, the air filter 2 and the air check valve 3.

[0068] 2, The compressed air flowing from the air storage tank 4 is divided into a first portion and a second portion after passing through the second air ball valve 1.2, the pressure switch 9 and the two position two-way switching valve 10. The first portion of the compressed air enters the pneumatic control pipeline, and the second portion of the compressed air enters the pneumatic operation pipeline. In the pneumatic control pipeline, the compressed air passes through the third exhaust ball valve 7.3, the second air source processing device 8.2 and enters into the input end of the three position five-way pneumatic directional valve 11. In the pneumatic operation pipeline, the compressed air passes through the second exhaust ball valve 7.2, the first air source processing device 8.1 and enters into the input end of the two-position two-way pneumatic control valve 13.

[0069] 3, The three-position five-way pneumatic directional valve 11 is switched to the middle position, and each P port of the three-position five-way pneumatic directional valve 11 is cut off from the A port and B port of the three-position five-way pneumatic directional valve 11. The shuttle valve 12 has no input and output. The two-position two-way pneumatic control valve 13 is in a closed state. The compressed air cannot enter the input port of the air motor 15, and the air motor 15 is in a stopped state. The pneumatic control hydraulic valve 22 is in a middle position and its P port is turned off and its A port and B port are communicated to T port, and the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 have no operation.

[0070] 4, The three-position five-way pneumatic directional valve 11is in a left position, and the P port of the three-position five-way pneumatic directional valve 11 is connected to its A port, and the B port of the three-position five-way pneumatic directional valve 11 has no output. The compressed air opens the Pi port of the shuttle valve 12, and is delivered from the A port of the shuttle valve 12 to the two-position two-way pneumatic control valve 13, so that the two-position two-way pneumatic control valve 13 is switched to an ON state from an off state. The second portion of the compressed air passes through the two-position two-way pneumatic control valve 13 and then 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. The hydraulic oil output from the hydraulic pump 18 sequentially passes through the second filter 19, the overflow valve 23 and enters the P port of the pneumatic control hydraulic valve 22. At the same time, the first portion of the compressed air passing through the three-position five-way pneumatic directional valve 11 will enter the first control air port of the pneumatic control hydraulic valve 22 and pneumatically switch the pneumatic control hydraulic valve 22 into the right position, so that the P port of the pneumatic control hydraulic valve 22 is communicated to its A port and its T port is communicated to its B port. The hydraulic oil output from the hydraulic pump 18 sequentially passes through the P port and A port of the pneumatic control hydraulic valve 22 and enters the rod-less chamber of the hydraulic cylinder 25.1. The rod-less chamber of the hydraulic cylinder 25.2 is sequentially communicated to the B port and T port of the pneumatic control hydraulic valve 22. The output end of the hydraulic cylinder 18 is retracted. The hydraulic oil of the rod chamber of the hydraulic cylinder 25.2 flows into the oil tank 17 through the first filter 17. The output ends of the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 are extended outwardly.

[0071] 5. The three-position five-way pneumatic directional valve 11 is switched to the right position; the P port of the three-position five-way pneumatic directional valve 11 is communicated to its B port; the A port of the three-position five-way pneumatic directional valve 11 has no output; the compressed air opens the Pi port of the shuttle valve 12, and is delivered from the A port of the shuttle valve 12 to the two-position two-way pneumatic control valve 13, so that the two-position two-way pneumatic control valve 13 is switched to an ON state from an off state; the second portion of the compressed air passes through the two-position two-way pneumatic control valve 13 and 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 oil output from the hydraulic pump 18 sequentially passes through the second filter 19 and the overflow valve 23 to enter the P port of the pneumatic control hydraulic valve 22. At the same time, the first portion of the compressed air passing through the three-position five-way pneumatic directional valve 11 will enter the second control air port of the pneumatic control hydraulic valve 22 and pneumatically switch the pneumatic control hydraulic valve 22 to the left position, so that the P port of the pneumatic control hydraulic valve 22 is communicated to its B port and its T port is communicated to its A port; the hydraulic oil output from the hydraulic pump 18 sequentially passes through the P port and B port of the pneumatic control hydraulic valve 22 and enters the rod chamber of the hydraulic cylinder 25.2; the rod chamber of the hydraulic cylinder 25.1 is sequentially communicated to the A port and T port of the pneumatic control hydraulic valve 22 ; the output end of the hydraulic cylinder is retracted, and the hydraulic oil of the rod chamber of the hydraulic cylinder 25.1 flows into the oil tank 27.

[0072] 6. The three-position five-way hydraulic directional valve 24 is switched to the middle position, the hydraulic oil path of the hydraulic pump 18 is in communication with the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 to drive the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 to extend or retract; the output end of the manual oil pump 20 is disconnected from the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 and the manual oil pump 20 has no effect on the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2; the three-position five-way hydraulic directional valve 24 is switched to the left position, so the hydraulic oil path of the hydraulic pump 18 is cut off from the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2 and the manual oil pump 20 has no effect on the hydraulic cylinder 25.1 and the hydraulic cylinder 25.2. The output end of the manual oil pump 20 is communicated to the rod-less chamber of the hydraulic cylinder 25.2; the rod chamber of the hydraulic cylinder 25.2 is communicated to an oil return pipeline, and the hydraulic cylinder is extended; the three-position five-way hydraulic directional valve 24 is switched to the right position. The hydraulic oil path of the hydraulic pump 18 is cut off from the hydraulic cylinder, which has no effect on the hydraulic cylinder; the output end of the manual oil pump 20 is communicated to the rod chamber of the hydraulic cylinder 25.1, and the rod-less chamber of the hydraulic cylinder 25.2 is communicated to the oil return pipeline; and the hydraulic cylinder is retracted.

[0073] 7, In order to ensure the cleanness of the hydraulic oil in the oil tank 27 and prevent the non filtrated hydraulic oil from entering the oil tank 27, an one-way valve 26.1 is disposed between the input port of the manual oil pump 20 and the oil tank 27 to prevent the hydraulic oil in the manual oil pump 20 from flowing back to the oil tank 27; and an one-way valve 26.2 is disposed between the P 2 port of the three-position five-way hydraulic directional valve 24 and the output port of the manual oil pump 20 to prevent the hydraulic oil in the pipeline from flowing back to the manual oil pump 20.

[0074] In summary, a pneumatic hydraulic safety system provided by the embodiments of the disclosure can control the air motor to be in a stopped and started state by cooperation of a three position five-way pneumatic directional valve 11, a shuttle valve 12, a two-position two-way pneumatic control valve 13, and a pneumatic control hydraulic valve 2, so that the extension and retraction of the hydraulic cylinder can be activated as needed, thereby reducing the problem of noise and energy wasting. The extension and retraction of the hydraulic cylinder may further be switched as needed to meet a general requirement of the pneumatic hydraulic system for railway engineering vehicles. The pneumatic hydraulic safety system has a good practicality.

[0075] In some implementations, embodiments of the disclosure can detect and limit the highest pressure of the compressed air and the highest pressure of the hydraulic oil, so as to eliminate safety hazards caused by excessive pressure.

[0076] In some implementations, the embodiments of the disclosure can also detect and limit the lowest working pressure of the compressed air, only allowing the control valve to operate and the air motor to rotate in a normal pressure range, so as to eliminate unnecessary energy and time wasting. The pressure of the compressed air is too low, which is usually caused by the leakage of pipeline and pneumatic elements. If failure to start after detection, it can prompt the operator to make maintenance for troubleshooting immediately. In this way, it can guarantee safety operations of equipment and avoid energy and time wasting.

[0077] In some implementations, the embodiments of the disclosure can complete a variety of works by manipulating each ball valve, facilitating independent maintenance of each region, referring to FIG.1. It can also avoid waste of compressed air during non-operation period and save energy and guarantee safety, E.g:

[0078] 1, The start, stop, and direction change of the hydraulic cylinder can be controlled at any time by manipulating the three-position five-way pneumatic directional valve 11: after the hydraulic cylinder is activated to extend or retract by manipulating the three-position five-way pneumatic directional valve 11, when the extension or retraction of the hydraulic cylinder reaches to a needed position, the three-position five-way pneumatic directional valve 11 is returned to the middle position, and the hydraulic cylinder is immediately stopped extending or retracting, so that the amount of the extension or retraction of the hydraulic cylinder can be controlled.

[0079] 2, Controlling the speed of the extension or retraction of the hydraulic cylinder: a handle of the first air ball valve 1.1 or the second air ball valve 1.2 is pulled to change an air-pass area of the air ball valve, so as to control the flow amount of the compressed air entering a subsequent pipeline, causing changes of rotation speed of the air motor 15 and the hydraulic pump 18, and changing the flow rate of the hydraulic oil, thereby realizing the control of the speed of the extension or retraction of the hydraulic cylinder; the handle of the third exhaust ball valve 7.3 is pulled, and the air-pass area of the air ball valve is changed, controlling the flow amount of the compressed air entering the first air source processing device 8.1, thus changing the flow amount of the compressed air entering the air motor 15 and causing changes of the rotation speed of the air motor 15 and the hydraulic pump 18, and changing the flow rate of the hydraulic oil, thereby realizing the control of the speed of the extension or retraction of the hydraulic cylinder; the air-pass area of the throttle valve 14 is adjusted to control the flow amount of the compressed air entering the air motor 15, so as to change the rotation speed of the air motor 15 and the hydraulic pump 18 and thereby change the flow rate of the hydraulic oil, realizing the control of the speed of the extension or retraction of the hydraulic cylinder.

[0080] The embodiments described above are preferred embodiments of the disclosure, which are used only to facilitate the description of the disclosure, rather than limiting the disclosure in any way. Any equivalent embodiments obtained by those of ordinary skill in the art by modifying or varying the embodiments partially based on the content disclosed in the disclosure without departing from the technical features of the disclosure are still within the scope of the disclosure.

Claims

1. A pneumatic hydraulic safety system, comprising: an air storage tank, a pressure switch and a two-position two-way switching valve, an input end of the pressure switch is connected to an output end of the air storage tank, and a P port of the two-position two-way switching valve is connected to an output end of the pressure switch, and the P port of the two position two-way switching valve and an A port of the two-position two-way switching valve is switchably connected; a three-position five-way pneumatic directional valve and a shuttle valve, a P port of the three position five-way pneumatic directional valve is connected to the A port of the two-position two way switching valve, and an A port of the three-position five-way pneumatic directional valve is communicated to a P 2 port of the shuttle valve, and a B port of the three-position five-way pneumatic directional valve is communicated to a Pi port of the shuttle valve, and the Pi port and P 2 port of the shuttle valve are switchably communicated to an A port of the shuttle valve; a two-position two-way pneumatic control valve; a control port of the two-position two-way pneumatic control valve is communicated to the A port of the shuttle valve, and a P port of the two position two-way pneumatic control valve is communicated to the A port of the two-position two way switching valve, and the P port of the two-position two-way pneumatic control valve and an A port of the two-position two-way pneumatic control valve are switchably connected; an air motor, a hydraulic pump and an oil tank, an input port of the air motor is connected to the A port of the two-position two-way pneumatic control valve, and an output port of the air motor is communicated to a control end of the hydraulic pump, and an input port of the hydraulic pump is connected to the oil tank; a pneumatic control hydraulic valve and a hydraulic cylinder and a hydraulic cylinder, the pneumatic control hydraulic valve is a three-position four-way directional valve, and the pneumatic control hydraulic valve has a first control air port and a second control air port that control a valve position of the pneumatic control hydraulic valve, and the first control air port of the pneumatic control hydraulic valve is connected to the B port of the three-position five-way pneumatic directional valve, and the second control air port of the pneumatic control hydraulic valve is connected to the A port of the three-position five-way pneumatic directional valve, and a P port of the pneumatic control hydraulic valve is connected to the output port of the hydraulic pump, and an A port of the pneumatic control hydraulic valve is communicated to a rod-less chamber of the hydraulic cylinder, and a T port of the pneumatic control hydraulic valve is communicated to the oil tank, and a B port of the pneumatic control hydraulic valve is communicated to a rod chamber of the hydraulic cylinder; wherein the system further includes a manual oil pump and a three-position five-way hydraulic directional valve; a Pi port of the three-position five-way hydraulic directional valve is communicated to the A port of the pneumatic control hydraulic valve, and a T port of the three position five-way hydraulic directional valve is communicated to the B port of the pneumatic control hydraulic valve, and a P 2 port of the three-position five-way hydraulic directional valve is communicated to an one-way valve, and an A port of the three-position five-way hydraulic directional valve is communicated to the rod-less chambers of the hydraulic cylinder and the hydraulic cylinder, and a B port of the three-position five-way hydraulic directional valve is communicated to a rod chamber between the hydraulic cylinder and the hydraulic cylinder; and the manual oil pump is disposed between a P 2 port of the three-positionfive-way hydraulic directional valve and the oil tank.

2. The pneumatic hydraulic safety system as claimed in claim 1, wherein the air storage tank is connected to an external air source through an air charging pipeline, and an upper cover of the gas charging pipeline is sequentially provided with a first air ball valve, an air filter and an air check valve; the first air ball valve, the air filter and the air check valve are sequentially disposed in a direction from the external air source to the air storage tank.

3. The pneumatic hydraulic safety system as claimed in claim 1 or 2, wherein an air safety valve is provided on a housing of the air storage tank, and a drain valve is provided at the bottom of the housing of the air storage tank.

4. The pneumatic hydraulic safety system as claimed in any one of the preceding claims, wherein a second air ball valve is provided between the input end of the pressure switch and the output end of the air storage tank.

5. The pneumatic hydraulic safety system as claimed in any one of the preceding claims, wherein the system further includes a first exhaust ball valve, an input end of the first exhaust ball valve is connected to the output end of the pressure switch, and an output end of thefirst exhaust ball valve is connected to the A port of the two-position two-way switching valve.

6. The pneumatic hydraulic safety system as claimed in claim 1 or 5, wherein the system further includes a second exhaust ball valve and a third exhaust gas ball valve, an input end of the second exhaust ball valve is connected to the A port of the two-position two-way switching valve, and an output end of the second exhaust ball valve is connected to the P port of the two-position two-way pneumatic control valve; an input end of the third exhaust gas ball valve is connected to the A port of the two-position two-way switching valve, and an output end of the third exhaust ball valve is connected to the P port of the three-position five-way pneumatic directional valve.

7. The pneumatic hydraulic safety system as claimed in claim 6, wherein the system further includes a first air source processing device and a second air source processing device, the first air source processing device is disposed between the output end of the second exhaust ball valve and the P port of the two-position two-way pneumatic control valve, and the second air source processing device is disposed between the output end of the third exhaust ball valve and the P port of the three position five-way pneumatic directional valve.

8. The pneumatic hydraulic safety system as claimed in any one of the preceding claims, wherein the system further includes a throttle valve, a first filter, a second filter, a hydraulic pressure gauge and a third filter; the throttle valve (14) is disposed between the input port of the air motor and the A port of the two-position two-way pneumatic control valve; 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 disposed between the output port of the hydraulic pump and the P port of the pneumatic control hydraulic valve, and the third filter is disposed between the T port of the pneumatic control hydraulic valve and the oil tank.

9. The pneumatic hydraulic safety system as claimed in any one of the preceding claims, wherein the system further includes an overflow valve, a P port of the overflow valve is communicated to the P port of the pneumatic control hydraulic valve, and a T port of the overflow valve is communicated to the oil tank.

10. The pneumatic hydraulic safety system as claimed in any one of the preceding claims, wherein a one-way valve is disposed between an input port of the manual oil pump and the oil tank; and the one-way valve is disposed between the P2 port of the three-position five-way hydraulic directional valve and an output port of the manual oil pump.