Directional valve

Abstract

The present invention discloses a reversing valve, including a valve body and a valve stem. The valve stem is arranged in the valve body and divides an upper chamber and a lower air chamber for collecting air in the valve body. An air bag is arranged in the upper chamber. The valve body is provided with a first upper air nozzle connected to the air bag. The valve body is provided with a first lower air nozzle and a second lower air nozzle connected to the lower air chamber. A sealing plug is connected to the lower part of the valve stem and moves synchronously with the valve stem. An air bag and a lower air chamber are arranged in the reversing valve, and the size of the air bag and the lower air chamber is adjusted by the vertical movement of the valve stem, so as to control the sealing plug to open or close the first lower air nozzle. The control is performed by using gas pressure as a power source, and the valve has the advantages of simple structure, light weight and low manufacturing cost. Moreover, the functional component for adjusting the docking of the first upper air nozzle, the first lower air nozzle and the second lower air nozzle can be applied to different control valve bodies, and has powerful functions.

Description

Technical Field

[0001] The invention relates to a reversing valve, in particular to a pneumatically controlled reversing valve, and belongs to the field of pneumatic operation of sanitary products. Background Art

[0002] Directional valves are used in water control systems in the field of plumbing and sanitary ware to control the on / off and reversing of waterways. Most reversing valves use electromagnetic structures to control the on / off action, that is, electromagnetic reversing valves, which use a large number of electromagnetic components and have a complex structure. Although they have strong performance, such as being able to control different waterways at the same time, they are expensive and prone to failure. They also have high requirements for waterproof performance when used in the field of plumbing. (The main solenoid valve requires electricity, either batteries need to be replaced regularly, or alternating current brings safety hazards and is not energy-saving or environmentally friendly.) Some reversing valves also use a mechanical valve core structure to open and cut off the waterway by rotating or moving the valve core. Although this structure is not as complex as the solenoid valve, its performance is also weak. It can often only control the on / off of a single waterway (there is no way to achieve flexible connection), and there is still room for improvement in the structure. The problems of heavy weight and high cost have not been effectively solved. Summary of the invention

[0003] The present invention provides a reversing valve which can be used to control different waterways and has a simple structure, light weight and low manufacturing cost. The technical solution adopted by the present invention to solve its technical problem is:

[0004] The reversing valve comprises a valve body and a valve stem, wherein the valve stem is arranged in the valve body and divides an upper chamber and a lower air chamber for collecting air into the valve body, the valve stem can slide vertically to increase or decrease the upper chamber and the lower chamber, an air bag is arranged in the upper chamber, the bottom of the air bag is supported on the valve stem, a first upper air nozzle connected to the air bag is arranged on the valve body, a first lower air nozzle and a second lower air nozzle connected to the lower air chamber are arranged on the valve body, and the valve body also comprises a sealing plug for opening or closing the first lower air nozzle, the sealing plug is connected to the lower part of the valve stem and moves synchronously with the valve stem, the area of ​​the air bag vertically pressing on the valve stem is larger than the area of ​​the lower air chamber vertically pressing on the valve stem, so that when the air pressure in the air bag and the lower air chamber increases to a set value, the valve stem moves downward due to the driving of the gas pressure difference and drives the sealing plug to close the first lower air nozzle.

[0005] The reversing valve comprises a valve body and a valve stem, wherein the valve stem is arranged in the valve body and divides the upper and lower air chambers for collecting air into the valve body, the valve stem can slide vertically to increase or decrease the upper and lower air chambers, the valve body is provided with a first upper air nozzle and a second upper air nozzle connected to the upper air chamber, the valve body is provided with a first lower air nozzle connected to the lower air chamber, and also comprises a sealing plug for opening or closing the first lower air nozzle, the sealing plug is connected to the lower part of the valve stem and moves synchronously with the valve stem, the area of ​​the upper air chamber vertically pressing on the valve stem is larger than the area of ​​the lower air chamber vertically pressing on the valve stem, so that when the air pressure in the upper and lower air chambers increases to a set value, the valve stem moves downward due to the drive of the gas pressure difference and drives the sealing plug to close the first lower air nozzle.

[0006] Compared with the background technology, this technical solution has the following advantages:

[0007] An air bag (or upper air chamber) and a lower air chamber are arranged in the reversing valve, and the size of the air bag (or upper air chamber) and the lower air chamber is adjusted by the vertical movement of the valve stem, thereby controlling the sealing plug to open or close the first lower air nozzle, and using gas pressure as a power source for control, which has the advantages of simple structure, light weight and low manufacturing cost. Moreover, (the existing pneumatic operation of sanitary ware products remains at single pneumatic start, and linkage is not achieved) the functional components for adjusting the docking of the first upper air nozzle, the first lower air nozzle, and the second lower air nozzle, in conjunction with the switching opening or closing of the first lower air nozzle, can be applied to different control valve bodies, and the function is powerful.

[0008] For example, after a second upper air nozzle connected to the airbag is simultaneously provided on the valve body, the first upper air nozzle is connected to the inflating device, and the second upper air nozzle is connected to the second lower air nozzle and connected to the air-controlled needle valve, the switch of the air-controlled needle valve can be controlled;

[0009] For another example, after a second upper air nozzle connected to the airbag is simultaneously provided on the valve body, the first upper air nozzle is connected to the inflating device, the second upper air nozzle is connected to the second lower air nozzle and both are connected to the air-controlled needle valve, and the first lower air nozzle is connected to the pressure relief valve, so that the delayed closing of the air-controlled needle valve can be controlled;

[0010] For another example, after the third lower air nozzle connected to the lower air chamber is provided on the valve body, the first upper air nozzle is connected to the second lower air nozzle and both are connected to the drain valve and the pressure relief valve, and at the same time, the first lower air nozzle is connected to the water inlet valve, and the third lower air nozzle is connected to the air pumping device, so that the water inlet valve can be controlled to firstly let water in, and then the drain valve starts to delay drainage, and after the drainage is completed, the water inlet valve finally stops letting water in;

[0011] For another example, after a second upper air nozzle connected to the air bag is simultaneously provided on the valve body, the first upper air nozzle is connected to the inflating device, and after the second upper air nozzle and the second lower air nozzle are connected, they are both connected to the drain valve, and at the same time, the first lower air nozzle is connected to the pressure relief valve and the water inlet valve, so that the drain valve can be controlled to be started first to drain water, and the water inlet valve can be started with a delay to inlet water;

[0012] For another example, after a second upper air nozzle connected to the airbag is simultaneously provided on the valve body, the first upper air nozzle is connected to the inflation device, and after the second upper air nozzle and the second lower air nozzle are connected, they are both connected to the drain valve and the water inlet valve, and at the same time the first lower air nozzle is connected to the pressure relief valve. In this way, the drain valve and the water inlet valve can be controlled to start at the same time, and the opening time of the water inlet valve can be advanced, which is applied to occasions with special requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0014] Figure 1 A three-dimensional exploded schematic diagram of a first embodiment of a reversing valve of the present invention is shown.

[0015] Figure 2 Draws Figure 1 A three-dimensional schematic diagram of the reversing valve shown.

[0016] Figure 3 Draws Figure 1 A schematic cross-sectional view of the reversing valve is shown.

[0017] Figure 4 Draws Figure 1 The connection diagram of the reversing valve shown is used in the first control system.

[0018] Figure 5 Draws Figure 1 The shown diagram is a connection diagram of the directional control valve used in the second control system.

[0019] Figure 6 Draws Figure 1 The connection diagram of the reversing valve used in the third control system is shown.

[0020] Figure 7 Draws Figure 1 The connection diagram of the reversing valve shown is used in the fourth control system.

[0021] Figure 8 Draws Figure 1 The connection diagram of the reversing valve shown is used in the fifth control system.

[0022] Fig. 9 A cross-sectional schematic diagram of a second embodiment of a reversing valve of the present invention is depicted. DETAILED DESCRIPTION

[0023] Please refer to Figures 1 to 3 The reversing valve includes a valve body 10, a valve stem 20, and a sealing plug 30. The valve stem 20 is arranged in the valve body 10 and divides the valve body into an upper chamber 11 and a lower air chamber 12 for collecting and storing air. The valve stem 20 can slide vertically to increase or decrease the upper chamber 11 and the lower air chamber 12. An air bag 40 is arranged in the upper chamber 11. The bottom of the air bag 40 is supported on the valve stem 20. The air bag 40 is also used to collect and store air. The valve body 10 is provided with a first upper air nozzle 13 and a second upper air nozzle 14 that are connected to the air bag 40 (the second upper air nozzle 14 is not necessary, for example, in Figure 6 In the control system shown in the figure, if the pressure-stabilizing valve is not provided, the second upper air nozzle may not be provided. The valve body is provided with a first lower air nozzle 15 and a second lower air nozzle 16 which are connected to the lower air chamber 12. The sealing plug is used to open or close the first lower air nozzle 15, and the sealing plug 30 is connected to the lower part of the valve stem 20 and moves synchronously with the valve stem. The area of ​​the valve stem 20 vertically pressed by the airbag 40 is larger than the area of ​​the valve stem 20 vertically pressed by the lower air chamber 12, that is, the area of ​​the bottom surface of the airbag in contact with the valve stem is larger than the area of ​​the top surface of the lower air chamber in contact with the valve stem, so that when the air pressure in the airbag 40 and the lower air chamber 12 increases to a set value, the valve stem 20 moves downward due to the drive of the gas pressure difference and drives the sealing plug 30 to close the first lower air nozzle 15. It can be understood that if the airbag 40 and the lower air chamber 12 are connected to the atmosphere, the pressure difference between the upper and lower sides of the valve stem 20 is very small, and the sealing plug 30 is not sufficient to seal the first lower air nozzle 15. The gap between the sealing plug 30 and the first lower air nozzle 15 can pass gas, so the first lower air nozzle 15 is in an open state under normal atmospheric conditions.

[0024] Preferably, a spring 50 is further included, the spring 50 is stretched between the valve body 10 and the valve stem 20 and applies a vertical upward elastic force to the valve stem 20. When the airbag 40 and the lower air chamber 12 are connected to the outside atmosphere, the elastic force of the spring 50 slightly lifts the sealing plug 30 to open the first lower air nozzle 15. In this way, the lower air nozzle 15 can be easily opened and closed by slightly pressurizing the lower air chamber 12, and the switching of the reversing valve becomes more sensitive.

[0025] Preferably, the upper part of the valve stem 20 is a tube structure with an opening on the top surface and covers the airbag 40, and the lower part is a tube structure with an opening on the bottom surface, and the cross-sectional area of ​​the upper part is larger than the cross-sectional area of ​​the lower part, so as to ensure that the force-bearing area corresponding to the valve stem 20 and the airbag 40 is larger than the force-bearing area corresponding to the lower air chamber 12. A sealing ring 60 is provided between the outer wall of the lower part and the inner wall of the valve body 10, and the lower part and the valve body enclose the lower air chamber 12.

[0026] Preferably, the valve body 10 includes a valve sleeve 17 and an upper cover 18, the first lower air nozzle 15 and the second lower air nozzle 16 are arranged at the lower part of the valve sleeve 17, the upper cover 18 covers the top opening of the valve sleeve 17, and the first upper air nozzle 13 and the second upper air nozzle 14 are arranged on the upper cover 18. An air hole is arranged on the side wall of the valve sleeve 17, and the air hole is located between the sealing ring 60 and the upper end surface of the valve stem 20. In this way, during the vertical movement of the valve stem, the air in the interval between the top surface of the valve stem 20 and the sealing ring 60 can be easily discharged or replenished through the air hole and communicated with the atmosphere, so that the movement of the valve stem 20 will not be affected by air resistance, the air pressure of the air bag and the lower air chamber is stable, and the reversing valve is more sensitive.

[0027] Preferably, the valve body 10 is provided with a third lower air nozzle 19 (such as Figure 6 The third lower air nozzle 19 is reserved to further increase the functionality of the reversing valve, as illustrated below.

[0028] Also refer to Figure 4 , when the third lower air nozzle 19 of the reversing valve is closed or not provided, the first upper air nozzle 13 is connected to the air pumping device 200, the second upper air nozzle 14 is connected to the second lower air nozzle and is connected to the air-controlled needle valve 300. When the air pumping device 200 is inflated, the airbag 40 and the lower air chamber 12 are pressurized at the same time, and the pressures are equal. Therefore, the sealing plug 30 moves downward to close the first lower air nozzle 15, and the air-controlled needle valve 300 is opened under the drive of the increased air pressure to achieve pressure relief and drainage, which can be water out of a faucet or a urinal. When the exhaust device 200 returns air, the pressures of the airbag 40 and the lower air chamber 12 drop at the same time, and the air-controlled needle valve 300 is closed again. The structure and working principle of the air-controlled needle valve 300 are prior art and will not be introduced in detail.

[0029] Also refer to Figure 5, when the third lower air nozzle 19 of the reversing valve is closed or not provided, the first upper air nozzle 13 is connected to the inflating device 200, the second upper air nozzle 14 is connected to the second lower air nozzle 16 and connected to the pressure regulating valve 400 (the pressure regulating valve can be omitted) and the air control needle valve 300, and the first lower air nozzle 15 is connected to the pressure relief valve 500, and a one-way valve 600 is provided at the outlet position of the second upper air nozzle 14 to prevent air from flowing into the airbag 40 from the second upper air nozzle 14. When the inflating device 200 is inflated, the airbag 40, the lower air chamber 12, and the pressure regulating valve 400 are pressurized at the same time, the sealing plug 30 closes the first lower air nozzle 15, and the air control needle valve 300 is opened under the drive of the increased air pressure to achieve pressure relief and drainage. When the exhaust device 200 returns air, the pressure of the airbag 40 drops, and the air pressure in the lower air chamber 12 drives the valve stem 20 to move upward to open the first lower air nozzle 15. The air in the air-controlled needle valve 300 and the pressure-stabilizing valve 400 flows back to the lower air chamber 12, and then exhausts from the pressure relief valve 500. After the gas is exhausted, the air-controlled needle valve 300 is closed again to stop the water, thereby achieving the delayed closing of the air-controlled needle valve 300, that is, controlling the length of time for drainage. This structure can simplify the air pipeline and simplify the structure of the drainage system. The structures of the pressure-stabilizing valve 400 and the pressure relief valve 500 are also prior art and will not be described in detail.

[0030] Also refer to Figure 6When the reversing valve is provided with the third lower air nozzle 19, the second upper air nozzle 14 is connected to the pressure regulating valve 400 (the second upper air nozzle and the pressure regulating valve can be omitted), and after the first upper air nozzle 13 is connected to the second lower air nozzle 16, they are both connected to the drain valve 700 and the pressure relief valve 500, and a one-way valve 600 is provided at the outlet position of the second lower air nozzle 16 to prevent air from flowing back into the lower air chamber, the first lower air nozzle 15 is connected to the water inlet valve 800, and the third lower air nozzle 19 is connected to the inflation device 200. When the air-inflating device 200 inflates, the pressure in the lower air chamber 12 increases instantaneously and opens the first lower air nozzle 15, and at the same time, air enters the starting airbag of the water inlet valve 800 and drives the water inlet valve 800 to open and let in water (after the air enters the starting airbag, it presses the connecting rod on the float downward, thereby opening the back pressure switch of the water inlet valve). The air-inflating device 200 continues to inflate, and the pressure-stabilizing valve 400, the airbag 40, and the drain valve 700 are pressurized at the same time. After that, the airbag of the drain valve 700 reaches the set pressure, and the drain valve starts to open to drain water (the drain valve airbag expands and lifts the pull rod to open the water outlet), and after the airbag 40 is pressurized, it drives the valve stem 20 to move downward to close the first lower air nozzle 16, and the water inlet valve 800 continues to let in water. The air pumping device 200 stops pumping, and the air in the pressure regulating valve 400, the air bag 40, and the drain valve 700 is gradually exhausted by the pressure relief valve 500. When it drops to the set value, the drain valve 700 closes the drain, and the water inlet valve 800 starts the gas pressure in the air bag to drive the sealing plug 30 to move upward to open the first lower air nozzle 15, and then the pressure relief valve 500 exhausts the air. After the water inlet valve 800 starts the air bag to exhaust the air, the sealing plug 30 closes the first lower air nozzle 15 again, and the water inlet valve 800 stops the water intake by the rise of the float. The system controls the start of the water inlet valve 800 and the start of the drain valve 700 at the same time, and the water inlet valve 800 first realizes the water intake, and then the drain valve 700 starts to drain. After the drainage is completed, the water inlet valve 800 is driven by its own float to stop the water, so it can be applied to low-pressure water tanks, relying on the water intake of the water inlet valve 800 to enhance the flushing force.

[0031] Also refer to Figure 7, when the third lower air nozzle 19 of the reversing valve is closed or not provided, the first upper air nozzle 13 is connected to the air pumping device 200, and the second upper air nozzle 14 and the second lower air nozzle 16 are connected to the pressure regulating valve 400 (the pressure regulating valve can be omitted) and the drain valve 700, and a one-way valve 600 is provided at the outlet of the second upper air nozzle 14 to prevent air from flowing back into the air bag 40, and the first lower air nozzle 15 is connected to the pressure relief valve 500 and the water inlet valve 800. When the air pumping device 200 is inflated, the sealing plug 30 closes the first lower air nozzle 15, and the air bag 40, the lower air chamber 12, the pressure regulating valve 400, and the drain valve 700 are pressurized at the same time. When the set pressure is reached, the drain valve 700 is activated to drain water (the drain valve air bag expands and the pull rod is lifted to open the water outlet). After the air is returned to the air pump 200, the pressure in the airbag 40 drops, and the gas pressure in the lower air chamber 12 drives the valve stem 20 to move upward to open the first lower air nozzle 15. The gas in the pressure regulating valve 400 and the drain valve 700 enters the pressure relief valve 500 and the water inlet valve 800, and the kinetic energy of the gas is used to break the limit of the float of the water inlet valve 800 (for example, the float is hooked by a hook, and after the hook is broken, the float falls and opens the back pressure switch of the water inlet valve), and the water inlet valve 800 is started to let water in. After the gas is gradually released, the drain valve 700 stops water again. The system also controls the water inlet valve 800 and the drain valve 700 at the same time, and starts the drain valve 700 first, which can prevent the water flow from impacting the drain valve 700 after the water inlet valve 800 is opened, causing the drain valve 700 to work unstably.

[0032] Also refer to Figure 8When the third lower air nozzle 19 of the reversing valve is closed or the third lower air nozzle is not set, the first upper air nozzle 13 is connected to the inflation device 200, and the second upper air nozzle 14 and the second lower air nozzle 16 are connected to the pressure regulating valve 400, the drain valve 700 and the water inlet valve 800, and a one-way valve 600 is set at the outlet position of the second upper air nozzle 14 to prevent air from flowing back into the airbag 40, and the first lower air nozzle 15 is connected to the pressure relief valve 500. When the inflating device 200 inflates, the sealing plug 30 closes the first lower air nozzle 15, and the airbag 40, the lower air chamber 12, the pressure regulating valve 400, the drain valve 700, and the water inlet valve 800 are pressurized at the same time. When the set pressure is reached, the drain valve 700 is activated (the airbag of the drain valve expands and lifts the pull rod to open the water outlet), and the water inlet valve 800 is activated (after the air enters the starting airbag, the connecting rod on the float is pressed downward, thereby opening the back pressure switch of the water inlet valve). That is, the water inlet valve 800 is opened before the liquid level drops, and the opening time of the water inlet valve 800 is advanced. After the inflating device 200 returns air, the pressure of the airbag 40 drops, and the gas pressure of the lower air chamber 12 drives the valve stem 20 to move upward to open the first lower air nozzle 15, and the gas of the pressure regulating valve 400, the drain valve 700, and the water inlet valve 800 enter the pressure relief valve 500 for delayed exhaust. After the gas is gradually released, the drain valve 700 stops water again, and the water inlet valve 800 is closed after the liquid level rises to the set height. The system controls the water inlet valve 800 and the drain valve 700 at the same time, and advances the opening time of the water inlet valve 800. It can be applied to low-pressure water tanks and rely on the water inlet of the water inlet valve 800 to improve the flushing force.

[0033] Please refer to Fig. 9 The second embodiment of the reversing valve of the present invention is different from the first embodiment in that the valve stem 20 directly divides the upper air chamber 70 and the lower air chamber 12 for collecting air in the valve body 10, and the upper air chamber 70 and the lower air chamber 12 increase or decrease as the valve stem 20 slides vertically. (In specific implementation, a V-shaped sealing ring can be provided at the connection between the valve sleeve 17 and the upper cover 18, so as to ensure the sealing of the upper air chamber.) The upper air chamber 70 replaces the airbag in the first embodiment, and therefore, the first upper air nozzle 13 and the second upper air nozzle 14 (the second upper air nozzle can also be omitted) are connected to the upper air chamber 70. The area of ​​the upper air chamber 70 vertically pressing on the valve stem 20 is larger than the area of ​​the lower air chamber 12 vertically pressing on the valve stem 20, so that when the air pressures in the upper and lower air chambers are equal, the valve stem moves downward due to the driving force of the gas pressure difference and drives the sealing plug to close the first lower air nozzle 15. The structure of the second embodiment can replace the structure of the first embodiment and be applied in Figure 4-8 In the control system, the corresponding control functions can also be realized.

[0034] In addition, in order to increase the sealing performance of the upper air chamber 70, an upper sealing ring 80 is provided between the outer wall of the upper part of the valve stem 20 and the inner wall of the valve body 10, and the upper air chamber 70 is directly surrounded by the upper part of the valve stem 20 and the valve body 10. Further, a sealing ring 90 is provided between the upper cover 18 and the inner wall of the valve sleeve 17. In this embodiment, the air hole is located between the upper sealing ring 80 and the lower sealing ring 60, and the lower sealing ring 60 is a sealing ring between the lower part of the valve stem 20 and the inner wall of the valve body 10.

[0035] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A reversing valve, comprising a valve body, characterized in that: The vent valve is then opened and closed by the venting device, and the venting device is used to open and close the venting device, and the venting device is used to close the venting device.

2. The reversing valve according to claim 1, characterized in that: It also includes a spring, which is tensioned between the valve body and the valve stem and applies a vertical upward elastic force to the valve stem. When the airbag and the lower air chamber are connected to the outside atmosphere, the elastic force of the spring pushes up the sealing plug to open the first lower air nozzle.

3. The reversing valve according to claim 1 or 2, characterized in that: The upper part of the valve stem is a tube structure with an opening on the top surface and covers the airbag, and the lower part is a tube structure with an opening on the bottom surface, and the cross-sectional area of ​​the upper part is larger than that of the lower part. A sealing ring is provided between the outer wall of the lower part and the inner wall of the valve body, and the lower part and the valve body form the lower air chamber.

4. The reversing valve according to claim 3, characterized in that: The valve body includes a valve sleeve and an upper cover, a first lower air nozzle and a second lower air nozzle are arranged at the lower part of the valve sleeve, the upper cover covers the top end opening of the valve sleeve, and the first upper air nozzle is arranged on the upper cover; an air hole is provided on the side wall of the valve sleeve, and the air hole is located between the sealing ring and the upper end surface of the valve stem.

5. The reversing valve according to claim 1 or 2, characterized in that: The valve body is provided with a second upper air nozzle communicating with the air bag; the valve body is provided with a third lower air nozzle communicating with the lower air chamber.

6. A reversing valve, comprising a valve body, characterized in that: The closure of the valve body is shaped like a circle, and the closure of the valve body is shaped like a circle. The closure of the valve body is shaped like a circle, and the closure of the valve body is shaped like a circle. The closure of the valve body is shaped like a circle, and the closure of the valve body is shaped like a circle. The closure of the valve body is shaped like a circle, and the closure of the valve body is shaped like a circle.

7. The reversing valve according to claim 6, characterized in that: It also includes a spring, which is tensioned between the valve body and the valve stem and applies a vertical upward elastic force to the valve stem. When the upper air chamber and the lower air chamber are connected to the outside atmosphere, the elastic force of the spring pushes up the sealing plug to open the first lower air nozzle.

8. The reversing valve according to claim 6 or 7, characterized in that: The upper part of the valve stem is a cylindrical structure with an opening on the top surface, an upper sealing ring is provided between the outer wall of the upper part and the inner wall of the valve body, and the upper part and the valve body form the upper air chamber; the lower part is a cylindrical structure with an opening on the bottom surface, a lower sealing ring is provided between the outer wall of the lower part and the inner wall of the valve body, and the lower part and the valve body form the lower air chamber; and the cross-sectional area of ​​the upper part is greater than that of the lower part.

9. The reversing valve according to claim 8, characterized in that: The valve body includes a valve sleeve and an upper cover, a first lower air nozzle and a second lower air nozzle are arranged at the lower part of the valve sleeve, the upper cover covers the top end opening of the valve sleeve, a sealing ring is arranged between the upper cover and the inner wall of the valve sleeve, the first upper air nozzle is arranged on the upper cover, an air hole is arranged on the side wall of the valve sleeve, and the air hole is located between the upper and lower sealing rings.

10. The reversing valve according to claim 6 or 7, characterized in that: The valve body is provided with a second upper air nozzle communicating with the upper air chamber; the valve body is provided with a third lower air nozzle communicating with the lower air chamber.

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