Pneumatic motor for coating machine

Abstract

The utility model discloses a pneumatic motor for a spraying machine, which comprises an air cylinder, an air inlet chamber, a large piston and a reversing piston, and the air cylinder is divided into an upper air chamber and a lower air chamber by the large piston; the air inlet chamber is provided with an air inlet allowing compressed air to enter, the reversing piston can be driven to slide, and the upper air chamber and the lower air chamber are alternately communicated with the air inlet chamber along with sliding circulation of the reversing piston so as to drive the large piston to slide. A guide column of the anti-dead-point assembly is provided with an anti-dead-point protrusion, and an anti-dead-point steel ball abuts against the surface of the guide column; the utility model discloses a pneumatic motor for a coating machine, which is characterized in that a reversing piston anti-dead-point assembly of the motor can effectively prevent a reversing piston from entering a neutral dead point in the operation process, the operation is smoother, and the noise is lower; the inner and outer nested silencing components can effectively prevent icing; the large piston controls the pilot valve to exhaust so as to realize continuous reversing of the reversing piston, so that the whole air inlet and exhaust are highly coupled, and the operation is smoother.

Description

Technical Field

[0001] The utility model belongs to the technical field of spraying equipment and relates to a pneumatic motor used for a spraying machine. Background Art

[0002] Pneumatic motors used in sprayers are an indispensable power source for spraying equipment and are widely used in spraying production. Engineers have made unremitting efforts to achieve continuous reciprocating motion of the pneumatic motor piston rod and instantaneous and smooth reversal, and to minimize spray fluctuations during reciprocating motion.

[0003] The existing reversing mechanism of the pneumatic motor used in the sprayer has a complex structure, low precision, high noise, easy icing, poor exhaust and easy dead point, short endurance and poor working reliability. In particular, it is very easy to cause mid-position deadlock during reversing, resulting in unsuccessful reversing of the pneumatic motor.

[0004] Therefore, in order to solve the above problems, a pneumatic motor with an exhaust reversing mechanism without a neutral dead point is needed, which can effectively reduce noise, exhaust smoothly without dead points, prevent icing, have a long endurance time, and have high overall reliability. Utility Model Content

[0005] In view of this, the utility model provides a pneumatic motor for a sprayer, the reversing piston anti-dead point assembly of the motor can effectively prevent the reversing piston from entering the middle dead point during operation, and the operation is smoother and the noise is lower; the silencer assembly embedded inside and outside can effectively prevent icing; the large piston controls the pilot valve for exhaust to achieve continuous reversing of the reversing piston, so that the entire intake and exhaust are highly coupled and the operation is smoother.

[0006] The utility model discloses a pneumatic motor for a spraying machine, comprising a cylinder, an air intake chamber, a large piston and a reversing piston, wherein the large piston is slidably mounted on the cylinder and divides the cylinder into an upper air chamber and a lower air chamber; the air intake chamber is provided with an air inlet for compressed air to enter, the reversing piston can be driven to slide, and the upper air chamber and the lower air chamber are alternately connected to the air intake chamber with the sliding cycle of the reversing piston, so that the compressed air circulates alternately into the upper air chamber and the lower air chamber and drives the large piston to slide;

[0007] It also includes an anti-dead point assembly, which includes a guide column, an anti-dead point steel ball and an elastic member. The guide column is movably installed on the axial end face of the reversing piston, and the guide column extends radially outward to form an anti-dead point protrusion. The anti-dead point steel ball is installed on the inner wall surface of the intake chamber through the elastic member, and the anti-dead point steel ball is pressed against the surface of the guide column under the action of the elastic force of the elastic member.

[0008] Furthermore, the anti-dead point protrusion is composed of a supporting surface with a curved structure and two inclined guide surfaces, and the supporting surface is connected to the surface of the guide column through the two guide surfaces; the anti-dead point steel ball is arranged corresponding to the position of the anti-dead point protrusion when the reversing piston slides to the middle position.

[0009] Furthermore, it also includes an upper intermediate air chamber and a lower intermediate air chamber arranged along the sliding direction of the reversing piston, and an exhaust port arranged between the upper intermediate air chamber and the lower intermediate air chamber; the upper intermediate air chamber is connected with the upper air chamber, and the lower intermediate air chamber is connected with the lower air chamber; the upper intermediate air chamber is provided with an upper connecting port, and the lower intermediate air chamber is provided with a lower connecting port; the upper intermediate air chamber is connected to the air intake chamber through the upper connecting port, and the lower intermediate air chamber is connected to the air intake chamber through the lower connecting port; the reversing piston is movably mounted with a reversing slider, and the exhaust port is connected with the upper connecting port or the lower connecting port through the reversing slider to discharge the gas in the upper air chamber or the lower air chamber.

[0010] Furthermore, it also includes a pilot valve, the reversing piston axially divides the intake chamber into an upper ventilation chamber, an intake chamber and a lower ventilation chamber from top to bottom in sequence, the pilot valve includes a valve body and a valve core, the valve body is provided with a valve chamber and an exhaust channel that are interconnected, and the valve core is installed in the valve chamber in a driven single-degree-of-freedom movable manner to control the connection and disconnection of the valve chamber and the exhaust channel.

[0011] Further, the pilot valve is provided with two, namely a lower pilot valve communicated with the upper ventilation chamber and an upper pilot valve communicated with the lower ventilation chamber; the upper ventilation chamber is communicated with the valve chamber of the lower pilot valve, and the valve core of the lower pilot valve can be driven to move so that the upper ventilation chamber is communicated with the exhaust passage of the lower pilot valve through the valve chamber of the lower pilot valve; the lower ventilation chamber is communicated with the valve chamber of the upper pilot valve, and the valve core of the upper pilot valve can be driven to move so that the lower ventilation chamber is communicated with the exhaust passage of the upper pilot valve through the valve chamber of the upper pilot valve;

[0012] Furthermore, the upper pilot valve and the lower pilot valve are both installed on the cylinder, the valve core of the upper pilot valve extends into the upper air chamber along the sliding direction of the large piston, and the valve core of the lower pilot valve extends into the lower air chamber along the sliding direction of the large piston, and the large piston can be driven to slide back and forth in a single degree of freedom to drive the valve core of the upper pilot valve or the valve core of the lower pilot valve to move.

[0013] Furthermore, it also includes a silencer assembly, which includes a silencer outer cylinder, a silencer inner cylinder and a silencer end cover, the silencer inner cylinder is connected to the exhaust port through the silencer end cover, the radial wall surface of the silencer inner cylinder is provided with a plurality of silencer holes, and the bottom of the silencer inner cylinder is provided with an exhaust inner port; the silencer outer cylinder is installed on the silencer end cover and is outer-mounted on the silencer inner cylinder, the bottom of the silencer outer cylinder is provided with an exhaust outer port, and the inner wall surface of the silencer outer cylinder is covered with silencer cotton.

[0014] Furthermore, it also includes a reset rod, one end of which is located in the lower ventilation chamber, and the other end extends to the outside of the air intake chamber along the sliding direction of the reversing piston. The reset rod can be driven to move with a single degree of freedom, and the moving direction of the reset rod is the same as the sliding direction of the reversing piston.

[0015] Furthermore, the reversing slider is provided with a reversing channel with an arc-shaped cross-section, and the exhaust port is connected with the upper connecting port or the lower connecting port through the reversing channel; the reversing piston is provided with a connecting channel, and the connecting channel connects the upper ventilation chamber, the air intake chamber and the lower ventilation chamber.

[0016] Furthermore, a plurality of exhaust channels are provided, and the plurality of exhaust channels are evenly distributed along the circumference of the valve body.

[0017] Beneficial effects of the utility model:

[0018] The utility model discloses a pneumatic motor for a sprayer, wherein the anti-dead point assembly of the reversing piston of the motor can effectively prevent the reversing piston from entering the middle dead point during operation, so that the operation is smoother and the noise is lower; the silencer assembly embedded inside and outside can effectively prevent icing; the large piston controls the pilot valve to exhaust air to realize the continuous reversal of the reversing piston, so that the entire intake and exhaust are highly coupled and the operation is smoother.

[0019] The utility model can effectively reduce noise as a whole, has smooth exhaust without dead spots, is anti-icing, has a long cruising time, and is highly reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the working structure of the large piston of the utility model;

[0021] Figure 2 This is a schematic diagram of the working structure of the reversing piston of the utility model;

[0022] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0023] Figure 4 for Figure 2 A local enlarged schematic diagram of point B in the middle. DETAILED DESCRIPTION

[0024] It should be noted that in the description of this specification, the terms "upper", "lower", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In the drawings of this embodiment, the arrows indicate the flow direction of the gas medium.

[0025] As shown in the figure, the utility model discloses a pneumatic motor for a sprayer, comprising a cylinder 1, an air intake chamber, a large piston 2 and a reversing piston 3, wherein the large piston 2 is slidably mounted on the cylinder 1 and divides the cylinder 1 into an upper air chamber 5 and a lower air chamber 6; the air intake chamber is provided with an air inlet 4 for compressed air to enter, the reversing piston 3 can be driven to slide, and the upper air chamber 5 and the lower air chamber 6 are alternately connected to the air intake chamber with the sliding cycle of the reversing piston 3, so that the compressed air circulates alternately into the upper air chamber 5 and the lower air chamber 6 and drives the large piston 2 to slide. In this embodiment, it also includes an upper intermediate air chamber 9 and a lower intermediate air chamber 10 arranged along the sliding direction of the reversing piston 3, and an exhaust port 11 arranged between the upper intermediate air chamber 9 and the lower intermediate air chamber 10; the upper intermediate air chamber 9 is connected with the upper air chamber 5, and the lower intermediate air chamber 10 is connected with the lower air chamber 6; the upper intermediate air chamber 9 is provided with an upper connecting port 29, and the lower intermediate air chamber 10 is provided with a lower connecting port 30; the upper intermediate air chamber 9 is connected to the air intake chamber through the upper connecting port 29, and the lower intermediate air chamber 10 is connected to the air intake chamber through the lower connecting port 30; the reversing piston 3 is movably installed with a reversing slider 33, and the exhaust port 11 is connected with the upper connecting port 29 or the lower connecting port 30 through the reversing slider 33 to discharge the gas in the upper air chamber 5 or the lower air chamber 6. In this embodiment, the upper air chamber 5 is connected to the upper intermediate air chamber 9 through the upper air passage 7, and the lower air chamber 6 is connected to the lower intermediate air chamber 10 through the lower air passage 8. The sliding direction of the reversing piston 3 is the same as that of the large piston 2. The sliding of the reversing piston 3 in the air intake chamber has an upper limit position and a lower limit position. When in the upper limit position, the reversing slider 33 connects the upper connecting port 29 with the exhaust port 11. At this time, only the lower connecting port 30 is connected to the air intake chamber. The compressed air enters the air intake chamber from the air intake port 4, and then enters the lower air chamber 6 through the lower connecting port 30, the lower intermediate air chamber 10 and the lower air passage 8 in turn, so that the large active The plug 2 is pushed by the compressed air to slide from bottom to top and compress the upper air chamber 5. The gas in the upper air chamber 5 passes through the upper airway 7, the upper intermediate air chamber 9 and the reversing slider 33 in the upper air chamber 5 in sequence, and is discharged to the atmosphere through the exhaust port 11; when the large piston 2 slides upward to abut against the top surface of the cylinder 1 in the figure, the reversing piston 3 slides from the upper limit position to the lower limit position. At this time, the reversing slider 33 connects the lower connecting port 30 with the exhaust port 11, and the upper connecting port 29 is connected to the air intake chamber, and the medium flow direction of the compressed air is opposite to that when the reversing piston 3 is in the upper limit position, which will not be repeated here. When the large piston 2 slides to the lower side of the cylinder 1, the reversing piston 3 slides to the upper limit position again, and this cycle is repeated to realize the pneumatic drive of the large piston 2. The upper limit position and the lower limit position here are two limit positions in the sliding stroke of the reversing piston 3, which can be understood by technicians in this technical field and will not be repeated here.In this embodiment, the large piston 2 is composed of a piston body and a piston rod. The piston body is slidably arranged in the cylinder 1 and can be pushed by compressed air to slide. The piston rod is installed on the piston body and extends outside the cylinder 1 to output power.

[0026] In this embodiment, an anti-dead point assembly is also included, and the anti-dead point assembly includes a guide column 26, an anti-dead point steel ball 22 and an elastic member. The guide column 26 is movably mounted on the axial end surface of the reversing piston 3, and the guide column 26 extends radially outward to form an anti-dead point protrusion 28. The anti-dead point steel ball 22 is mounted on the inner wall surface of the intake chamber through the elastic member, and the anti-dead point steel ball 22 is held against the surface of the guide column 26 under the elastic force of the elastic member. In this embodiment, the anti-dead point steel ball 22 is arranged corresponding to the position of the anti-dead point protrusion 28 when the reversing piston 3 slides to the middle position. As shown in the figure, the axial cross-section of the anti-dead point protrusion 28 in this embodiment is an arc-shaped supporting surface plus two inclined guide surfaces, and the supporting surface is naturally transitioned to the surface of the guide column 26 through the guide surface; the elastic member is a spring, which is installed on the inner wall surface of the intake chamber through a spring seat. The elastic member supports the anti-dead point steel ball 22 on the surface of the guide column 26, so that when the reversing piston 3 slides, the guide column 26 and the anti-dead point steel ball 22 will move relative to each other. When the reversing piston 3 slides to the middle dead point (that is, when it is in the middle position, the reversing slider 33 will close the upper connecting port 29 and the lower connecting port 30 at the same time, and the reversing piston 3 and the large piston 2 will stop sliding), the anti-dead point steel ball 22 is supported on the anti-dead point protrusion 28. At this time, the two aforementioned are tangent, and the elastic force will force the anti-dead point steel ball 22 to squeeze the anti-dead point protrusion 28, thereby causing the two to produce relative displacement, and the reversing piston 3 will leave the middle dead point area and can continue to slide. The anti-dead point steel ball 22 is set to the position of the anti-dead point protrusion 28 when the reversing piston 3 slides to the middle position. This means that when the reversing piston 3 slides to the middle position, the anti-dead point steel ball 22 is set to the position of the anti-dead point protrusion 28 at that position.

[0027] In this embodiment, a pilot valve is also included. The reversing piston 3 axially divides the air intake chamber into an upper air exchange chamber, an air intake chamber and a lower air exchange chamber 34 from top to bottom. The pilot valve includes a valve body 20 and a valve core 27. The valve body 20 is provided with a valve chamber and an exhaust channel 19 that are interconnected. The valve core 27 is installed in the valve chamber in a driven single-degree-of-freedom movable manner to control the connection and disconnection of the valve chamber and the exhaust channel 19. In this embodiment, there are multiple exhaust channels 19, and the multiple exhaust channels 19 are evenly distributed along the circumference of the valve body 20, so that the exhaust and ventilation are faster. As shown in the figure, in this embodiment, the anti-dead point assembly is arranged as a whole in the upper air exchange chamber, the air inlet 4 is arranged in the air intake chamber, and the autonomous reversing of the reversing piston 3 is achieved by air pressure difference. In this embodiment, there are two pilot valves, namely a lower pilot valve 31 connected to the upper ventilation chamber and an upper pilot valve 32 connected to the lower ventilation chamber 34; the upper ventilation chamber is connected to the valve chamber of the lower pilot valve 31 through the channel 24 of the lower pilot valve 31, and the valve core 27 of the lower pilot valve 31 can be driven to move so that the upper ventilation chamber is connected to the exhaust channel 19 of the lower pilot valve 31 through the valve chamber of the lower pilot valve 31; the lower ventilation chamber 34 is connected to the valve chamber of the upper pilot valve 32 through the channel 21 of the upper pilot valve 32, and the valve core 27 of the upper pilot valve 32 can be driven to move so that the lower ventilation chamber 34 is connected to the exhaust channel 19 of the upper pilot valve 32 through the valve chamber of the upper pilot valve 32; when the lower pilot valve 31 The valve core 27 of the valve core 27 is driven to move, so that the upper air exchange chamber is connected to the exhaust channel 19 of the lower pilot valve 31, and the upper air exchange chamber is also connected to the atmosphere, the pressure drops, and the pressure in the intake chamber remains unchanged, so the reversing piston 3 will move upward to the upper limit position, when the valve core 27 of the valve core 27 of the upper pilot valve 32 is driven to move, so that the lower air exchange chamber 34 is connected to the exhaust channel 19 of the upper pilot valve 32, the lower air exchange chamber 34 is also connected to the atmosphere, the pressure drops, and the pressure in the intake chamber remains unchanged, so the reversing piston 3 will move downward to the lower limit position, and the upper pilot valve 32 and the lower pilot valve 31 are opened alternately in this way, thereby realizing the reciprocating sliding of the reversing piston 3, and also realizing the change of the flow direction of the compressed air, so that the pneumatic motor continues to work. At the same time, in this embodiment, the valve core 27 of the pilot valve is composed of a valve stem and a sealing head, the valve stem is responsible for transmission, and the sealing head controls the communication between the valve cavity and the exhaust passage 19. A spring is arranged on the top of the valve core 27, so that the valve core 27 is closed under normal conditions, that is, the valve cavity and the exhaust passage 19 are disconnected, and it will only open when pushed by the large piston 2. The drawings of this embodiment take the upper pilot valve 32 as an example, the upper pilot valve 32 and the lower pilot valve 31 have the same structure and function, but are arranged in different positions, which can be understood by those skilled in the art and will not be repeated here.

[0028] In this embodiment, the upper pilot valve 32 and the lower pilot valve 31 are both installed on the cylinder 1, the valve core 27 of the upper pilot valve 32 extends into the upper air chamber 5 along the sliding direction of the large piston 2, and the valve core 27 of the lower pilot valve 31 extends into the lower air chamber 6 along the sliding direction of the large piston 2, and the large piston 2 can be driven to slide back and forth in a single degree of freedom to drive the valve core 27 of the upper pilot valve 32 or the valve core 27 of the lower pilot valve 31 to move. That is, as the large piston 2 continues to move, the large piston 2 alternately pushes open the valve core 27 of the upper pilot valve 32 and the valve core 27 of the lower pilot valve 31, so that the upper air exchange chamber and the lower air exchange chamber 34 are alternately connected to the outside atmosphere, and the sliding of the large piston 2 and the sliding of the reversing piston 3 are highly coupled, so that the operation of the entire pneumatic motor is smoother. In this embodiment, the reversing piston 3 is provided with a connecting channel 23, and the connecting channel 23 connects the upper ventilation chamber, the air intake chamber and the lower ventilation chamber 34, ensuring that the pressure of each chamber can be balanced during the sliding and reversing process of the reversing piston 3, thereby ensuring the smooth reversing sliding. The connecting channel 23 in this embodiment is divided into two segments, which are arranged at the two ends of the axial direction of the reversing piston, and connect the upper ventilation chamber and the air intake chamber as well as the lower ventilation chamber and the air intake chamber respectively.

[0029] In this embodiment, a silencer assembly is also included, which includes a silencer outer cylinder 13, a silencer inner cylinder 14 and a silencer end cap 12. The silencer inner cylinder 14 is connected to the exhaust port 11 through the silencer end cap 12. The radial wall of the silencer inner cylinder 14 is provided with a plurality of silencer holes 16. The bottom of the silencer inner cylinder 14 is provided with an exhaust inner port 17. The silencer outer cylinder 13 is installed on the silencer end cap 12 and is covered on the silencer inner cylinder 14. The bottom of the silencer outer cylinder 13 is provided with an exhaust outer port 18. The inner wall of the silencer outer cylinder 13 is covered with silencer cotton 15. As shown in the figure, the silencer assembly in this embodiment is a silencer structure in which the inner and outer cylinders are mutually nested. The exhaust gas first enters the silencer inner cylinder 14, and then is discharged from the silencer hole 16 to the silencer outer cylinder 13. After multiple reflections and silences on the silencer cotton 15, it is discharged through the exhaust outer port 18. Since compressed air is discharged, ice may form during the exhaust process. Therefore, an exhaust inner port 17 is provided at the bottom of the exhaust inner tube so that water mist and ice crystals in the exhaust of high-pressure air can be discharged directly along a straight line through the exhaust inner port 17 without staying in the entire exhaust assembly. The exhaust is smooth and the noise is effectively reduced.

[0030] In this embodiment, a reset rod 24 is also included. One end of the reset rod 24 is located in the lower air exchange chamber 34, and the other end extends to the outside of the air intake chamber along the sliding direction of the reversing piston 3. The reset rod 24 can be driven to move with a single degree of freedom, and the moving direction of the reset rod 24 is the same as the sliding direction of the reversing piston 3. Before starting the starter motor, in order to ensure smooth starting, a reset rod 24 for manually resetting the reversing piston 3 is provided. By pushing the reset rod 24, the reset rod 24 pushes the reversing piston 3 to the upper limit position, and then starting the compressed air, it can ensure that the pneumatic motor starts smoothly.

[0031] In this embodiment, the reversing slider 33 is provided with a reversing channel with an arc-shaped cross-section, and the exhaust port 11 is connected with the upper connecting port 29 or the lower connecting port 30 through the reversing channel; as shown in the figure, the reversing channel is an arc-shaped channel, or a hemispherical cavity, and its main purpose is to ensure that the exhaust port 11 is connected with only one of the upper connecting port 29 or the lower connecting port 30 at two extreme positions, so as to ensure the smooth operation of the starter motor.

[0032] In this embodiment, in order to improve the overall sealing performance of the device, a seal is provided at each movable connection position (including the sliding mating surface), and the seal includes but is not limited to a sealing ring, a sliding shaft seal, etc. This is understandable to those skilled in the art and will not be described in detail here. In this embodiment, the seal of the reversing piston and the large piston is a Y-shaped sealing ring 36, and the upper pilot valve and the lower pilot valve are provided with an X-shaped sealing ring 35; taking the reversing piston as an example, the axial ends of the reversing piston are provided with the following seals: Figure 4 The Y-shaped sealing ring 36 shown in the figure has an outer lip position of the Y-shaped sealing ring 36 extending radially outward to form a protrusion to thicken the Y-shaped sealing ring 36, so that during the actual sliding operation of the reversing piston, even if wear occurs, the protrusion will be worn first, and the air tightness of the device will not be affected, thereby improving the overall reliability of the device.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A pneumatic motor for a spraying machine, characterized in that: The invention comprises a cylinder, an air intake chamber, a large piston and a reversing piston, wherein the large piston is slidably mounted on the cylinder and divides the cylinder into an upper air chamber and a lower air chamber; the air intake chamber is provided with an air inlet for compressed air to enter, the reversing piston can be driven to slide, and the upper air chamber and the lower air chamber are alternately connected to the air intake chamber with the sliding cycle of the reversing piston, so that the compressed air circulates alternately into the upper air chamber and the lower air chamber and drives the large piston to slide; It also includes an anti-dead point assembly, which includes a guide column, an anti-dead point steel ball and an elastic member. The guide column is movably installed on the axial end face of the reversing piston, and the guide column extends radially outward to form an anti-dead point protrusion. The anti-dead point steel ball is installed on the inner wall surface of the intake chamber through the elastic member, and the anti-dead point steel ball is pressed against the surface of the guide column under the action of the elastic force of the elastic member.

2. The pneumatic motor for a spraying machine according to claim 1, characterized in that: The anti-dead point protrusion is composed of a supporting surface with a curved structure and two inclined guide surfaces, and the supporting surface is connected to the surface of the guide column through the two guide surfaces; the anti-dead point steel ball is arranged corresponding to the position of the anti-dead point protrusion when the reversing piston slides to the middle position.

3. The pneumatic motor for a spraying machine according to claim 1, characterized in that: It also includes an upper intermediate air chamber and a lower intermediate air chamber arranged along the sliding direction of the reversing piston, and an exhaust port arranged between the upper intermediate air chamber and the lower intermediate air chamber; the upper intermediate air chamber is connected with the upper air chamber, and the lower intermediate air chamber is connected with the lower air chamber; the upper intermediate air chamber is provided with an upper connecting port, and the lower intermediate air chamber is provided with a lower connecting port; the upper intermediate air chamber is connected to the air inlet chamber through the upper connecting port, and the lower intermediate air chamber is connected to the air inlet chamber through the lower connecting port; the reversing piston is movably mounted with a reversing slider, and the exhaust port is connected with the upper connecting port or the lower connecting port through the reversing slider to discharge the gas in the upper air chamber or the lower air chamber.

4. The pneumatic motor for a spraying machine according to claim 3, characterized in that: It also includes a pilot valve, the reversing piston axially divides the intake chamber into an upper ventilation chamber, an intake chamber and a lower ventilation chamber from top to bottom, the pilot valve includes a valve body and a valve core, the valve body is provided with a valve chamber and an exhaust channel that are interconnected, and the valve core is installed in the valve chamber in a driven single-degree-of-freedom movable manner to control the connection and disconnection of the valve chamber and the exhaust channel.

5. The pneumatic motor for a spraying machine according to claim 4, characterized in that: The pilot valves are provided with two, namely a lower pilot valve connected to the upper ventilation chamber and an upper pilot valve connected to the lower ventilation chamber; the upper ventilation chamber is connected to the valve chamber of the lower pilot valve, and the valve core of the lower pilot valve can be driven to move so that the upper ventilation chamber is connected to the exhaust channel of the lower pilot valve through the valve chamber of the lower pilot valve; the lower ventilation chamber is connected to the valve chamber of the upper pilot valve, and the valve core of the upper pilot valve can be driven to move so that the lower ventilation chamber is connected to the exhaust channel of the upper pilot valve through the valve chamber of the upper pilot valve.

6. The pneumatic motor for a spraying machine according to claim 5, characterized in that: The upper pilot valve and the lower pilot valve are both installed on the cylinder, the valve core of the upper pilot valve extends into the upper air chamber along the sliding direction of the large piston, and the valve core of the lower pilot valve extends into the lower air chamber along the sliding direction of the large piston. The large piston can be driven to slide back and forth in a single degree of freedom to drive the valve core of the upper pilot valve or the valve core of the lower pilot valve to move.

7. The pneumatic motor for a spraying machine according to claim 6, characterized in that: It also includes a silencer assembly, which includes a silencer outer cylinder, a silencer inner cylinder and a silencer end cover, the silencer inner cylinder is connected to the exhaust port through the silencer end cover, a plurality of silencer holes are distributed on the radial wall surface of the silencer inner cylinder, and an exhaust inner port is provided at the bottom of the silencer inner cylinder; the silencer outer cylinder is installed on the silencer end cover and is externally mounted on the silencer inner cylinder, an exhaust outer port is provided at the bottom of the silencer outer cylinder, and the inner wall surface of the silencer outer cylinder is covered with silencer cotton.

8. The pneumatic motor for a spraying machine according to claim 4, characterized in that: It also includes a reset rod, one end of which is located in the lower ventilation chamber, and the other end extends to the outside of the air intake chamber along the sliding direction of the reversing piston. The reset rod can be driven to move in a single degree of freedom, and the moving direction of the reset rod is the same as the sliding direction of the reversing piston.

9. The pneumatic motor for a spraying machine according to claim 4, characterized in that: The reversing slider is provided with a reversing channel with an arc-shaped cross-section, and the exhaust port is connected with the upper connecting port or the lower connecting port through the reversing channel; the reversing piston is provided with a connecting channel, and the connecting channel connects the upper ventilation chamber, the air intake chamber and the lower ventilation chamber.

10. The pneumatic motor for a spraying machine according to claim 4, characterized in that: A plurality of exhaust passages are provided, and the plurality of exhaust passages are evenly distributed along the circumference of the valve body.

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