CN211314502U

CN211314502U - Novel double-speed exhaust valve and intake valve with unloading function

Info

Publication number: CN211314502U
Application number: CN201922452820.5U
Authority: CN
Inventors: 蓝志鹏; 尹必军; 黄杨洋; 李佑虹
Original assignee: Guangdong Biaoding Technology Corp
Current assignee: Guangdong Biaoding Technology Corp
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-08-21
Anticipated expiration: 2029-12-31

Abstract

The utility model relates to an air compressor machine technical field especially relates to a novel double-speed formula discharge valve and take admission valve of uninstallation function. Comprises a valve body and a valve core piston; the valve body is provided with an air inlet, an air outlet and a pneumatic control valve port; an exhaust hole and a bypass small hole are communicated between the air inlet and the air outlet; the valve core piston is movably arranged in the valve body, the upper end of the valve core piston is abutted against and covered on the exhaust hole, and the lower end of the valve core piston is elastically connected with the valve body through an elastic piece; the pneumatic control valve port is communicated with the middle position of a valve core piston in the valve body and is in driving connection with the valve core piston in the vertical direction, and the valve core piston realizes the conduction and the closing of the exhaust hole by controlling the pressure of the pneumatic control valve port. According to the embodiment, double-speed exhaust can be realized, the exhaust speed and the foam amount in the oil air chamber can be guaranteed while the problem that oil consumption is large due to the fact that the air compressor is quickly emptied to the air compressor is solved, no-load starting of the air compressor is realized, the maintenance cost of the air compressor is effectively reduced, and the market competitiveness of products is enhanced.

Description

Novel double-speed exhaust valve and intake valve with unloading function

Technical Field

The utility model relates to an air compressor machine technical field especially relates to a novel double-speed formula discharge valve and take admission valve of uninstallation function.

Background

An air compressor is a device for compressing gas, which is one of the essential devices in motor vehicles. And in order to ensure the safety and reliability of the use of the air compressor, the air compressor can not be started under pressure, therefore, the air compressor needs to discharge the gas inside through the exhaust valve quickly when being stopped so as to ensure that the air compressor can be started without load when being started next time.

Present air compressor machine discharge valve exhaust is comparatively slow, and also some discharge valves adopt pneumatic control case piston to open, switches on and carry out quick exhaust, can be quick with the evacuation of air compressor machine in to zero, nevertheless in the exhaust process, can produce a large amount of foams and towards oil and gas separator at the lubricating oil of air compressor machine when exhausting to cause the inside jam of oil and gas separator, and increased air compressor machine oil consumption, cause the air compressor machine to damage or shorten the life of air compressor machine.

SUMMERY OF THE UTILITY MODEL

The utility model discloses an overcome among the above-mentioned prior art technical problem that the exhaust is slow or the exhaust is quick but has serious drawback, provide a novel two-speed formula discharge valve and take admission valve of uninstallation function.

In order to solve the technical problem, the technical scheme of the utility model as follows:

a novel double-speed exhaust valve comprises a valve body and a valve core piston; the valve body is provided with an air inlet, an air outlet and a pneumatic control valve port; an exhaust hole and a bypass small hole are communicated between the air inlet and the air outlet; the valve core piston is movably arranged in the valve body, the upper end of the valve core piston is abutted against and covered on the exhaust hole, and the lower end of the valve core piston is elastically connected with the valve body through an elastic piece; the pneumatic control valve port is communicated with the middle position of a valve core piston in the valve body and is in driving connection with the valve core piston in the vertical direction, and the valve core piston realizes the conduction and the closing of the exhaust hole by controlling the pressure of the pneumatic control valve port.

Furthermore, a closed pushing cavity is formed in the valve body at the joint of the valve core piston and the pneumatic control valve port; the valve core piston is provided with a pushing part at the pushing cavity and close to one side of the elastic part, and the pneumatic control valve port is connected with the pushing cavity and drives the valve core piston to move towards the lower end direction through the pushing part.

Furthermore, a chamfer angle is arranged at the corner of the top end of the pushing part of the valve core piston connected with the pneumatic control valve port.

Furthermore, the air inlet, the air outlet and the pneumatic control valve port are sequentially arranged in the valve body from top to bottom.

Furthermore, the upper end of the elastic element is connected with one end of the valve core piston corresponding to the exhaust hole cover, and the lower end of the elastic element is elastically connected with the valve body.

Furthermore, the elastic part is a spring, and a sealing ring and a guide ring are further arranged on the circumferential direction of the valve core piston.

Furthermore, the diameter of the bypass small hole is 0.3-0.8 mm.

Furthermore, the air pressure corresponding to the elastic force critical value of the elastic member is 200 to 300 kPa.

Furthermore, the upper end of the valve core piston is provided with a sealing sheet, and the valve core piston is abutted against and covered at the bottom of the exhaust hole through the sealing sheet.

The utility model also provides an air inlet valve with unloading function, which comprises an air inlet valve, a compressor head, an oil-gas separator and the novel double-speed exhaust valve; the air inlet end of the compressor head is connected with the air inlet valve port of the air inlet valve, and the air outlet end of the compressor head is connected with the downstream air outlet end through the oil-gas separator; the oil-gas separator is in driving connection with the check valve plate through an electromagnetic valve so as to be in switch control connection with the air inlet valve port; the air inlet of the dual-speed exhaust valve is connected with the air outlet port of the oil-gas separator, the air outlet of the dual-speed exhaust valve is connected with the emptying pipe of the air inlet valve, and the pneumatic control valve port is communicated with the air inlet end of the compressor head.

The utility model discloses two-speed formula discharge valve is through setting up the elastic component between case piston and valve body, through the quick carminative displacement of elastic component control discharge valve, guarantees that the air compressor machine can directly not be with the direct evacuation of inside gas, but reserves certain gas and slowly discharges through the bypass aperture to the speed is too fast when having solved the exhaust of air compressor machine final stage, produces a large amount of foams in the oil gas chamber easily, thereby causes the oil and gas separator of air compressor machine to block up, the oil consumption is high and the problem that the loss is short-lived fast. Additionally, the utility model discloses take admission valve of uninstallation function to exhaust through discharge valve, the non return valve plate of admission valve can fast close and lead to the automatic exhaust of opening of discharge valve after the air compressor machine shuts down, it is effective fast to exhaust, self-closing exhaust when uninstallation and loading, it is sensitive to close the action, can be when solving the quick exhaust of air compressor machine and cause the loss scheduling problem to the air compressor machine easily, guarantee carminative speed, guarantee the carminative reliability and practicality of air compressor machine, the preparation time that the air compressor machine starts next time has been shortened, effectively reduce the maintenance cost of air compressor machine, strengthen the market competition of product.

Drawings

Fig. 1 is a sectional view of a dual-speed exhaust valve according to an embodiment of the present invention.

Fig. 2 is an internal structure view of the dual-speed exhaust valve according to the embodiment of the present invention.

Fig. 3 is a structural diagram of an intake valve with an unloading function according to an embodiment of the present invention.

Wherein: the device comprises an exhaust valve 1, an air inlet valve 2, a compressor head 3, an oil-gas separator 4, an electromagnetic valve 5, a check valve plate 6, a vent pipe 7, an unloading vent channel 8, a valve body 11, a valve core piston 12, an elastic piece 13, a sealing ring 14, a guide ring 15, an air inlet 111, an air outlet 112, a pneumatic control valve port 113, an exhaust hole 114 and a bypass small hole 115.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Examples

The embodiment provides a novel dual-speed exhaust valve, referring to fig. 1-2, including a valve body 11 and a valve core piston 12, the valve body 11 is provided with an air inlet 111, an air outlet 112 and a pneumatic control valve port 113, specifically, the air inlet 111, the air outlet 112 and the pneumatic control valve port 113 are sequentially arranged on the valve body 11 from top to bottom. An exhaust hole 114 and a bypass small hole 115 are arranged between the air inlet 111 and the air outlet 112 in a communicating manner, and air in the air compressor can penetrate through the exhaust hole 114 through the air inlet 111 and be rapidly exhausted from the air outlet 112 to the outside, and meanwhile, the air can be slowly exhausted through the bypass small hole 115. The valve core piston 12 is movably arranged in the valve body 11, the valve core piston 12 and the valve body 11 are attached, the upper end of the valve core piston 12 is abutted to cover the exhaust hole 114, and the lower end of the valve core piston is elastically connected with the valve body 11 through the elastic piece 13. More specifically, the size of the lower end of the valve core piston 12 is larger than that of the exhaust hole 114, and the connecting end of the valve core piston 12 is attached to and covered with the exhaust hole 114, so that the gas inlet 111 and the gas outlet 112 are blocked to conduct and discharge gas through the exhaust hole 114.

In addition, the pneumatic control valve port 113 is disposed at the middle position of the valve core piston 12 in the valve body 11 in a conductive manner, and is in driving connection with the valve core piston 12, specifically, the pneumatic control valve drives the valve core piston 12 to move toward the lower end direction thereof, i.e., the direction of the elastic element 13, by forming high pressure at the valve core piston 12, so as to open the covering connection between the valve core piston 12 and the exhaust hole 114, so that the valve core piston 12 can complete the conduction and the closing of the exhaust hole 114 through the pneumatic control valve port 113, i.e., the opening and the closing of the rapid exhaust of the air inlet 111 and the air outlet 112 through. Specifically, the middle position of the spool piston 12 refers to a portion between the upper end and the lower end of the spool piston 12. It is worth to be noted that the air inlet 111 is connected with the output end of the oil-gas separator 4 of the air compressor, the air outlet 112 is in conduction connection with the blow-down pipe 7 of the air compressor, and the pneumatic control valve port 113 is connected with the air inlet end of the compressor head 3 of the air compressor, so that the exhaust valve 1 drives the valve core piston 12 according to the pressure of the air inlet end of the compressor head 3 of the air compressor, and the quick exhaust of the air compressor is started and closed.

In some embodiments, the valve body 11 forms a closed pushing cavity at the joint of the valve core piston 12 and the pneumatic control valve port 113, the lower end of the valve core piston 12 is provided with a pushing portion, the pushing portion is disposed below the pushing cavity, specifically, two sides of the pushing portion are tightly attached to the valve body 11, so as to ensure the closing of the pushing cavity. The pneumatic control valve port 113 is connected to the push cavity, and a high pressure is formed in the push cavity by the air pressure adjusting device, so that the valve core piston 12 is pushed toward the elastic member 13 by the push portion, thereby opening and connecting the exhaust hole 114. It should be noted that the diameter of the side surface of the lower end of the spool piston 12 is larger than the diameter of the side surface of the upper end of the spool piston 12, and the protruding portion at the connection between the upper end and the lower end forms a pushing portion, so that the spool piston 12 is pushed downward by the pushing portion, thereby opening the exhaust hole 114.

Specifically, the specific working steps and working principle of the exhaust valve 1 in this embodiment are that, when the air compressor is in operation, that is, when the air compressor is in the loading mode, the check valve plate 6 of the intake valve 2 moves downward to open the valve port, so that the pneumatic control valve port 113 is in a negative pressure state, at this time, the valve core piston 12 is connected with the exhaust hole 114 in a covering manner, the gas in the oil separator is not discharged through the exhaust valve 1 or can be discharged only through the bypass small hole 115 in a slow and trace manner, and the slow and trace discharge of the gas is an acceptable discharge deviation of the air. When the air compressor operates in the unloading mode, the pneumatic control valve port 113 is in a negative pressure state, the exhaust hole 114 is also in a closed state, and only the bypass small hole 115 and the unloading emptying channel 8 have slow trace gas discharge. When the air compressor is stopped, the check valve plate 6 of the air inlet valve 2 moves upwards to close the valve port, the pneumatic control valve port 113 is at positive pressure, the valve core piston 12 overcomes the elasticity of the elastic part 13 to move towards the lower end direction under the action of pressure, the exhaust hole 114 is opened, the air inlet 111 is communicated with the air outlet 112, and air in the air compressor is rapidly exhausted.

At this moment, the valve core piston 12 is stressed by downward thrust generated by pushing the cavity, upward elastic force of the elastic piece 13 and downward pressure of the exhaust hole 114, when gas in the air compressor is discharged to a certain degree, the elastic force of the elastic piece 13 is greater than the thrust for pushing the cavity and the pressure of the exhaust hole 114, the elastic piece 13 pushes the valve core piston 12 upward, so that the exhaust hole 114 is closed, residual compressed gas in the air compressor is ensured not to be directly exhausted through the exhaust hole 114, but is slowly exhausted through the bypass small hole 115, the air compressor is ensured not to exhaust too fast, a large amount of foam generated in an oil-gas chamber of the air compressor is effectively prevented, and the problems of blocking of the oil-gas separator, high oil consumption, high loss and the like are avoided. Specifically, the amount of gas left during the rapid exhaust of the air compressor depends on the elastic force value of the elastic member 13. Specifically, the air pressure corresponding to the critical value of the elasticity of the elastic part 13 is 200-300 kpa, namely, the air pressure is reset when 200-300 kpa remains in the air compressor, so that the problems of blockage of an oil-gas separator of the air compressor, high oil consumption and short service life caused by high loss can be solved, and meanwhile, the emptying speed of the air compressor after shutdown is ensured. When the elasticity of elastic component 13 enables the gas in the air compressor machine to remain 200~300kpa, exhaust hole 114 closes, and gas in the air compressor machine can be discharged completely in slow in-process through bypass aperture 115 this moment to realize the no load when the air compressor machine starts next time and start. Preferably, the elastic force of the elastic member 13 has a critical value of 300 kpa.

The benefit of this structure lies in, this structure is through setting up elastic component 13 between case piston 12 and valve body 11, through the quick carminative displacement of elastic component 13 control discharge valve 1, guarantee that the air compressor machine can directly not be with the direct evacuation of inside gas to zero, but reserve certain gas and slowly discharge through bypass aperture 115, thereby speed is too fast when having solved the exhaust of air compressor machine final stage, produce a large amount of foams in the oil gas chamber easily, thereby cause the jam of air compressor machine oil-gas separator, the oil consumption is high and the problem that the loss is short-lived soon. The structure is quick and effective, can ensure the exhaust speed while solving the problems that the air compressor is easy to exhaust and causes large oil consumption and the like, ensures the reliability and rapidity of the air compressor exhaust, and realizes the no-load starting of the air compressor.

In some embodiments, a chamfer is provided at a top end corner of the pushing portion of the spool piston 12 connected to the pneumatic control valve port 113, and the gas in the pneumatic control valve port 113 can enter into the pushing cavity more smoothly through the chamfer, so that the spool piston 12 is pushed toward the elastic member 13 more quickly and effectively.

In some embodiments, the air inlet 111, the air outlet 112 and the pneumatic control valve port 113 are sequentially arranged in the valve body 11 from top to bottom, so as to effectively increase the exhaust speed of the exhaust valve 1. The upper end of the elastic member 13 is connected to the lower end of the valve body piston 12, and the lower end of the elastic member 13 is elastically connected to the valve body 11. Specifically, the elastic member 13 is a spring. When the air compressor works, namely negative pressure is generated in the pneumatic control valve port 113, the valve core piston 12 is jacked by the spring to be attached and covered with the exhaust hole 114, so that the exhaust hole 114 is closed; when the air compressor is stopped, namely the pressure in the pneumatic control valve port 113 is positive, the spring is in a compressed state, the exhaust hole 114 is communicated, the exhaust valve performs rapid exhaust, the spring reset degree is adjusted according to the required residual air pressure, and when 300kpa of air in the air compressor is left, the spring can elastically drive the valve core piston 12 to recover to be connected with the abutting cover of the exhaust hole 114, namely the exhaust hole 114 is closed.

In some embodiments, the bypass small hole 115 is disposed beside the exhaust hole 114, and the diameter of the bypass small hole is 0.3-0.8 mm, so as to ensure proper exhaust and increase the reliability of the air compressor. Specifically, the upper end of the valve core piston 12 is embedded with a sealing sheet, and the valve core piston 12 is abutted against and covered on the exhaust hole 114 through the sealing sheet, so that the conduction of the air inlet 111 and the air outlet 112 through the exhaust hole 114 can be smoothly blocked. The valve core piston 12 is closely attached to the valve body 11, and a sealing ring 14 and a guide ring 15 are arranged between the valve core piston 12 and the valve body 11, so that the smooth movement and the corresponding sealing performance of the valve core piston 12 in the valve body 11 are ensured.

For better operation experience, a specific structure of the novel dual-speed exhaust valve of the present embodiment is provided, specifically, the air inlet 111, the air outlet 112, and the pneumatic control valve port 113 of the exhaust valve 1 are respectively disposed on the valve body 11 from top to bottom, the exhaust hole 114 penetrates through between the air inlet 111 and the air outlet 112 of the valve body 11, the spool piston 12 abuts against the lower portion of the exhaust hole 114 through a spring force, that is, the exhaust hole 114 is disposed on a port on one side of the air outlet 112, the push cavity is disposed on the top of the push portion, and is in conductive connection with the pneumatic control valve port 113, the spool piston 12 is driven to open and close at the exhaust hole 114 through positive and negative pressure of the pneumatic control valve port 113, and quick exhaust between the air inlet 111 and the air. When the gas in the oil-gas separator 4 of the air compressor is exhausted to 300kpa, the valve core piston 12 is driven to reset by the spring elasticity, and at the moment, the residual gas in the air compressor is slowly exhausted through the bypass small hole 115, so that the oil-gas chamber in the air compressor is ensured not to generate a large amount of foam, the problems of blockage, high oil consumption and short service life of the oil-gas separator of the air compressor caused by the foam generated by quick exhaust of the air compressor are solved, the use reliability of the air compressor is ensured, the use cost of a user is reduced, and the market competitiveness of a product.

Fig. 3 shows a structural view of the intake valve with the unloading function of the present embodiment.

As shown in fig. 3, the present embodiment further provides an air intake valve with an unloading function, which includes an air intake valve 2, a compressor head 3, an oil-gas separator 4, and the above-mentioned novel dual-speed exhaust valve, wherein an air intake end of the compressor head 3 is connected to the air intake valve 2, and an air outlet end is connected to a downstream air outlet end through the oil-gas separator 4. Specifically, an inlet valve 2 port of the inlet valve 2 is connected with an external air filter, air enters an air inlet end of the compressor head 3 through the inlet valve 2, low-pressure air is converted into high-pressure air through the compressor head 3 and is output to a downstream air outlet end for air supply. A check valve plate 6 is arranged at the position of the air inlet valve 2, and the oil-gas separator 4 is in driving connection with the check valve plate 6 through an electromagnetic valve 5, so that the connection with the opening and closing of the air inlet valve 2 is realized. An air inlet 111 of the exhaust valve 1 is connected with an air outlet port of the oil-gas separator 4, an air outlet 112 is connected with an emptying pipe 7 of the air inlet valve 2, and a starting control valve port is communicated with an air inlet end of the compressor head 3.

Specifically, the working process of the air intake and exhaust device of the embodiment is that when the air compressor is in unloaded operation, the check valve plate 6 is abutted to cover the air intake valve 2 of the air intake valve 2 through the control of the electromagnetic valve 5, the air intake valve is in a closed state, at this time, no sufficient gas flows into the air intake end of the compressor head 3, only a small amount of air is sucked through the bypass small hole on the check valve plate, compressed and then discharged through the unloading and emptying channel 8 to realize the unloading function, at this time, the pneumatic control valve port 113 of the exhaust valve 1 is in negative pressure, and therefore the exhaust hole 114 is in a closed state. When the air compressor is loaded and operated, the check valve plate 6 moves downwards to open the valve port under the control of the electromagnetic valve 5 and the action of atmospheric pressure, so that the pneumatic control valve port 113 is in a negative pressure state, the valve core piston 12 is covered and connected with the exhaust hole 114, and the valve core piston 114 is in a closed state. When the air compressor machine shuts down, check valve plate 6 passes through the control of solenoid valve 5 and the butt of admission valve 2 mouth, the admission valve is in the closed condition, the compressed air in the compressor aircraft nose 3 is to the inlet end against the current this moment, pneumatic control valve port 113 of discharge valve 1 is in the malleation, thereby exhaust hole 114 is in the open mode, discharge valve 1 exhausts to the gas in the compressor aircraft nose 3, when the gas that discharges in the compressor aircraft nose 3 remains 200~300kpa, exhaust hole 114 resets through elastic component 13 and closes, the surplus gas is discharged slowly through bypass aperture 115, thereby prevent that the quick evacuation of gas in the air compressor machine to zero and lead to producing a large amount of foams in the oil gas and appearing the jam of air compressor machine oil and gas separator, the oil consumption is big, the problem of short-.

For better use experience, the specific structure of the air inlet valve with the unloading function is provided, specifically, the check valve plate 6 is provided with the bypass small hole, the lower part of the check valve plate is provided with the piston, the bottom of the piston is in conduction connection with the output end of the oil-gas separator 4 through the electromagnetic valve 5, and elastic resetting is performed through the reset spring and the check spring. When the air compressor runs and the electromagnetic valve is powered off, the air outlet port of the oil-gas separator 4 is communicated with the bottom of the piston of the check valve plate 6, the piston overcomes the reset spring and the check spring to push the check valve plate 6 upwards under the action of bottom pressure, the port of the air inlet valve 2 is closed, trace gas is sucked in through the bypass small hole of the check valve plate 6, the air compressor exhausts through the bypass small hole 115 of the exhaust valve 1 and the unloading emptying channel 8 of the air inlet valve, and the air compressor enters an unloading mode. When the air compressor runs, after the electromagnetic valve is electrified, the air outlet port of the oil-gas separator 4 and the piston of the check valve plate 6 are in a cut-off state, the piston is reset under the action of the reset spring and the check spring, the check valve plate 6 moves downwards, the air inlet valve 2 is opened, and the air compressor is in a loading mode. It should be noted that the solenoid valve is a normally open solenoid valve.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations to the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A novel double-speed exhaust valve is characterized by comprising a valve body (11) and a valve core piston (12); the valve body (11) is provided with an air inlet (111), an air outlet (112) and a pneumatic control valve port (113); an exhaust hole (114) and a bypass small hole (115) are arranged between the air inlet (111) and the air outlet (112) in a communicated manner; the valve core piston (12) is movably arranged in the valve body (11), the upper end of the valve core piston is abutted against and covered on the exhaust hole (114), and the lower end of the valve core piston is elastically connected with the valve body (11) through an elastic piece (13); the pneumatic control valve port (113) is communicated with and arranged in the middle of the valve core piston (12) in the valve body (11) and is in driving connection with the valve core piston (12) in the vertical direction, and the valve core piston (12) realizes the communication and the closing of the exhaust hole (114) by controlling the pressure of the pneumatic control valve port (113).

2. The new dual-speed exhaust valve according to claim 1, characterized in that the valve body (11) forms a closed pushing cavity at the junction of the spool piston (12) and the pneumatic control valve port (113); the valve core piston (12) is provided with a pushing part at the pushing cavity and on one side close to the elastic part (13), and the pneumatic control valve port (113) is connected with the pushing cavity and drives the valve core piston (12) to move towards the lower end direction through the pushing part.

3. The new dual-speed exhaust valve according to claim 2 wherein the top corner of the poppet piston (12) where the push portion connects to the pneumatic control valve port (113) is chamfered.

4. A new dual-speed exhaust valve according to claim 1, characterized in that said inlet (111), outlet (112) and pneumatic control valve ports (113) are arranged in sequence from top to bottom in the valve body (11).

5. The new dual-speed exhaust valve according to claim 1, characterized in that the upper end of the elastic member (13) is connected to the lower end of the spool piston (12), and the lower end of the elastic member (13) is elastically connected to the valve body (11).

6. The new dual-speed exhaust valve according to claim 1, characterized in that the elastic member (13) is a spring, and the valve core piston (12) is further provided with a sealing ring (14) and a guide ring (15) in the circumferential direction.

7. A new dual speed exhaust valve according to any of claims 1-6 wherein the diameter of the bypass orifice (115) is 0.3-0.8 mm.

8. The new dual-speed exhaust valve according to any of claims 1-6, wherein the critical value of the elastic force of the elastic member (13) corresponds to an air pressure of 200-300 kPa.

9. The novel dual-speed exhaust valve according to any one of claims 1-6, characterized in that the upper end of the valve core piston (12) is provided with a sealing sheet, and the valve core piston (12) is abutted against the bottom of the exhaust hole (114) through the sealing sheet.

10. An air inlet valve with unloading function, which is characterized by comprising an air inlet valve (2), a compressor head (3), an oil-gas separator (4) and a novel double-speed exhaust valve as claimed in any one of claims 1 to 9; the air inlet end of the compressor head (3) is connected with the opening of the air inlet valve (2), and the air outlet end is connected with the downstream air outlet end through the oil-gas separator (4); a check valve plate (6) is arranged at the position of an air inlet valve (2) of the air inlet valve (2), and the oil-gas separator (4) is in driving connection with the check valve plate (6) through an electromagnetic valve (5) and is connected with the air inlet valve (2) in a switching control mode; an air inlet (111) of the exhaust valve (1) is connected with an air outlet port of the oil-gas separator (4), an air outlet (112) is connected with a vent pipe (7) of the air inlet valve (2), and a pneumatic control valve port (113) is in through connection with an air inlet end of the compressor head (3).