Durable high-pressure airless spray paint machine

Abstract

An object is to provide a durable high-pressure airless spray painting machine. 【Solution means】It includes a casing (1), a liquid storage container (2), and a plunger pump (3). The plunger pump (3) includes a plunger chamber (4), a liquid inlet chamber (5), a liquid outlet chamber (6), and a pressure relief valve (7). The bottom of the liquid storage container (2) communicates with the liquid inlet chamber (5). A pressure protection device is provided in the plunger chamber (4). The plunger pump (3) is arranged on one side of the liquid storage container (2), lower than the lower end surface of the liquid storage container (2). A piston is provided in the plunger chamber (4). A piston rod (29) is fixedly provided at one end of the piston. The piston rod (29) is reciprocated by a drive mechanism. The drive mechanism includes a relay box (30) connected and fixed to one end of the piston rod (29). The relay box (30) is rotatably connected to a drive handle portion (32). The other end of the drive handle portion (32) is rotatably connected to an eccentric rotation mechanism. This spray painting machine can be used safely.

Description

Technical Field

[0001] The present invention relates to the technical field of spray painting machines, and particularly to a durable high-pressure airless spray painting machine.

Background Art

[0002] An airless spray painting machine is a spray painting device that pressurizes paint with a plunger pump, sends the obtained high-pressure paint to a spray gun through a high-pressure hose, and forms a dense paint film on a wall surface by releasing pressure from a nozzle to atomize the paint. The plunger pump generally uses a reciprocating piston structure to pressurize the paint. In the prior art, a plunger pump, such as the plunger pump in the airless spray painting machine disclosed in Patent Document 1 and a controller for controlling the operation of the plunger pump, are both provided under a paint storage container. When the paint storage container leaks, liquid paint may flow into the plunger pump and the controller, damaging the plunger pump and the controller, and further short-circuiting the controller, posing safety concerns and shortening the lifespan of the high-pressure airless spray painting machine.

[0003] Also, for example, Patent Document 2 discloses a plunger pump of a high-pressure airless spray painting machine. In Patent Document 2, an inclined plate abuts against a balance post and a piston to realize the reciprocating movement of the piston. The inclined plate is inclined and needs to overcome the frictional force between the inclined plate and the balance post every time of the reciprocating movement, which not only accelerates the wear between the inclined plate and the balance post, but also increases the driving resistance of the inclined plate and reduces the efficiency of the plunger pump, thus shortening the lifespan of the high-pressure airless spray painting machine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] Book This invention addresses the challenge of needing to extend the lifespan of conventional high-pressure airless spray painting machines by proposing a durable high-pressure airless spray painting machine. [Means for solving the problem]

[0006] The object of the present invention is achieved by the following technical means: A spray painting machine comprising a casing, a liquid storage container, and a plunger pump, wherein the plunger pump comprises a plunger chamber, a liquid inlet chamber, a liquid outlet chamber, and a pressure relief valve, the bottom of the liquid storage container is in communication with the liquid inlet chamber, a pressure protection device is provided in the plunger chamber, the plunger pump is positioned on one side of the liquid storage container and lower than the lower end surface of the liquid storage container, and a control circuit board for controlling the operation of the plunger pump is provided on the plunger pump. A piston is provided in the plunger chamber, a piston rod is fixed to one end of the piston, the piston rod is reciprocated by a drive mechanism, the drive mechanism comprises a relay box connected and fixed to one end of the piston rod, the relay box is rotatably connected to a drive handle, the other end of the drive handle is rotatably connected to an eccentric rotation mechanism, and at least a pair of balls are provided on both sides of the relay box.

[0007] In the above technical means, since both the plunger pump and the control circuit board are located on the side of the liquid storage container, even if there is a malfunction in the seal at the bottom of the liquid storage container and liquid leaks out, the operation of the plunger pump and the control circuit board will not be affected, ensuring the safety of the plunger pump. Balls are symmetrically arranged on both sides of the relay box of the present invention to restrict the linear reciprocating motion of the relay box. When the relay box reciprocates and contacts the balls, the linear passage of the relay box causes it to contact the balls and rotate, significantly reducing the frictional force between the relay box and the balls, improving the driving efficiency of the plunger pump, reducing wear between components, extending the service life of the balls and the components of the relay box, and making the present invention more durable. Furthermore, due to the rolling guidance action of the balls, it is not necessary to position the relay box between the balls on both sides, and even if there is some misalignment, the relay box can be easily guided by the balls without increasing the frictional force of the linear reciprocating motion of the relay box, thus increasing the tolerance for assembly and making installation more convenient.

[0008] Preferably, a liquid outlet is provided at the bottom of the liquid storage container, and the liquid inlet chamber and the liquid outlet are connected via a communication chamber.

[0009] Preferably, a filter screen is provided at the liquid outlet, a smaller diameter chamber is provided between the liquid inlet chamber and the plunger chamber, a liquid inlet ball valve is provided inside the smaller diameter chamber, and an annular retaining ring having an inner diameter smaller than the diameter of the liquid inlet ball valve is provided around the end of the smaller diameter chamber facing the liquid inlet chamber; a stopper rod is provided on the filter screen, one end of the stopper rod extends to the front end of the liquid inlet ball valve in the smaller diameter chamber, and the other end of the stopper rod extends further into the smaller diameter chamber to push open the liquid inlet ball valve. If the spray painting machine is not used for a long period of time, the liquid inlet ball valve may become stuck inside the smaller diameter chamber and block it, and an external force pushing the stopper rod will cause the stopper rod to push open the liquid inlet ball valve.

[0010] Preferably, a filter screen is provided at the liquid outlet, a smaller diameter chamber is provided between the liquid inlet chamber and the plunger chamber, a liquid inlet ball valve is provided in the smaller diameter chamber, and an annular retaining ring having an inner diameter smaller than the diameter of the liquid inlet ball valve is provided around the end of the smaller diameter chamber facing the liquid inlet chamber; a stopper rod is provided on the filter screen, one end of the stopper rod extends to the retaining ring and abuts against the liquid inlet ball valve, and the other end of the stopper rod further extends into the smaller diameter chamber and can push open the liquid inlet ball valve. One end of the stopper rod abuts against the liquid inlet ball valve. In addition to manually pushing open the liquid inlet ball valve when it blocks the different-diameter chamber, the plunger pump's piston reciprocates the liquid inlet ball valve. As the liquid inlet ball valve moves back and forth within the different-diameter chamber, it strikes the stopper rod each time it returns to its end position, generating vibrations in the filter mesh. This continuous vibration of the filter mesh during spray painting operation shakes off large paint particles that cannot pass through the filter mesh and adhere to it, preventing a decrease in the plunger pump's paint pumping capacity due to clogging of the filter mesh during prolonged operation. The filter mesh is located at the bottom of the liquid storage container. The vibration of the filter mesh vibrates the paint inside the liquid storage container, delaying the paint's solidification time and keeping the paint particles in a small particle state. This makes the spray gun connected to the plunger pump's liquid outlet chamber less likely to clog with paint even during use, further improving the overall durability of the spray painting machine.

[0011] Preferably, a concave step is provided around the liquid outlet, the filter mesh is attached to the step by interference fit, and two grooves having a depth greater than the depth of the step are provided symmetrically on the step. By providing grooves, the contact surface between the step and the circumference of the filter mesh is reduced, the filter mesh above the grooves becomes more easily deformed by external forces, and the force required to push the stopper rod is reduced.

[0012] Preferably, a contact post is provided in the plunger chamber, with one end of the contact post slightly extending into the differential chamber, and a first compression spring is provided between the contact post and the liquid inlet ball valve. By providing the first compression spring, in the absence of external force, the liquid inlet ball valve is brought into contact with the retaining ring, blocking the passage between the retaining ring and the differential chamber. When the plunger pump is in operation, the liquid inlet ball valve moves toward the plunger chamber due to the lifting action of the plunger pump, and as the liquid inlet ball valve moves away from the retaining ring, the passage between the retaining ring and the differential chamber opens, allowing paint to enter the plunger chamber and flow into the liquid outlet chamber of the plunger pump, where the paint can be sprayed to the outside.

[0013] Preferably, the stopper rod comprises a first portion perpendicular to the filter screen and a second portion parallel to the liquid inlet chamber, the first and second portions being connected and fixed, with an inclined surface provided at the connection between the first and second portions; a slope is provided within the communication chamber, the slope is located at the lower end of the inclined surface of the stopper rod, and the inclination ratio of the slope is the same as that of the inclined surface. The slope restricts the inclined surface from sliding only along the slope, pushing and moving the liquid inlet ball valve so that the first portion moves downward while moving horizontally toward the second portion, allowing the second portion to move horizontally.

[0014] Preferably, the first portion extends from the lower end of the filter screen to the upper end of the filter screen. The first portion extends to the upper end of the filter screen, and when it is necessary to manually push the stopper rod, it is convenient to do so. This eliminates the need to push the filter screen to apply pressure to the stopper rod, allowing the center of the filter screen to deform the most, thus saving effort.

[0015] Preferably, the filter mesh is arched slightly upward from the periphery towards the center. After the center of the filter mesh is moved downward by the downward movement of the first portion of the stopper rod, such a structure of the filter mesh becomes even more advantageous for the rebound of the filter mesh.

[0016] Preferably, the pressure protection device includes a pressure detection chamber connected to the inside of the plunger chamber, a pressure detection rod that moves up and down within the pressure detection chamber in response to pressure changes in the plunger chamber, a microswitch provided outside the pressure detection chamber, and a toggle lever that drives the operation of the microswitch on the pressure detection rod. When the operating pressure of the plunger pump reaches a set value, the motor that drives the operation of the plunger pump stops, and when the operating pressure of the plunger pump falls below the set value, the motor operates to pressurize, keeping the equipment in a safe state at all times. Because the microswitch is located outside the pressure detection chamber, wear or leakage inside the pressure detection chamber does not affect the microswitch, improving the durability of the pressure protection device.

[0017] Preferably, an adjustment screw is provided at the end of the pressure detection chamber opposite to the plunger chamber, with one end of the adjustment screw deeply inserted into the pressure detection chamber, and a second compression spring is provided between the adjustment screw and the pressure detection rod. By screwing the adjustment screw into and out of the pressure detection chamber, the pressure value of the second compression spring between the pressure detection chamber and the pressure detection rod is adjusted, thereby adjusting the pressure at which the pressure detection rod strikes the plunger pump, and the pressure change inside the plunger pump is detected by the displacement of the pressure detection rod.

[0018] Preferably, the eccentric rotation mechanism includes a circular gear plate, a drive post provided on one side of the gear plate, the center of the drive post being eccentric with respect to the center of the gear plate, a bearing provided inside the drive post, a mounting post provided at the center of the bearing passing through the center of the gear plate, both ends of the mounting post being attached to the pump body of the plunger pump, a circular through hole provided at the end of the drive handle opposite to the piston rod, the diameter of the through hole being larger than the diameter of the drive post, and the drive handle being fitted onto the drive post through the through hole. The rotation of the gear plate rotates the drive post, the diameter of the drive post is smaller than the diameter of the through hole of the drive handle fitted onto the drive post, and when the drive post performs eccentric circular motion, the drive handle is made to reciprocate. [Effects of the Invention]

[0019] Compared with the prior art, the present invention has the following advantageous effects. Since both the plunger pump and the control circuit board of the present invention are located on the side of the liquid storage container, even if there is a problem with the seal at the bottom of the liquid storage container and the liquid leaks out, it will not affect the operation of the plunger pump and the control circuit board, ensuring the safety of the plunger pump. By providing the abutting rod, when the liquid inlet ball valve closes the different-diameter chamber, the abutting rod can be pushed by an external force, and the abutting rod can push open the liquid inlet ball valve. The balls provided on both sides of the relay box limit the relay box to move linearly back and forth only between the two balls. When the relay box moves back and forth and contacts the balls, hand by rotating the balls, the frictional force between the relay box and the balls is greatly reduced, the driving efficiency of the plunger pump is improved, the service life of the components of the balls and the relay box is extended, and the present invention becomes more durable.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic configuration diagram of the present invention. [Figure 2] It is a partial cross-sectional view of the present invention. [Figure 3] It is a schematic configuration diagram when the abutting rod acts on the liquid inlet ball valve. [Figure 4] It is a schematic diagram showing the mechanism of the plunger pump. [Figure 5] It is an exploded perspective view of the plunger pump. [Figure 6] It is an exploded perspective view of the pressure protection device. [Figure 7] It is a schematic configuration diagram of the eccentric rotation mechanism.

Embodiments for Carrying out the Invention

[0021] The present invention will be further described below with reference to the embodiments shown in the attached drawings.

[0022] (First Embodiment) As shown in Figure 1, the spray painting machine comprises a casing 1, a liquid storage container 2, and a plunger pump 3. The plunger pump 3 includes a plunger chamber 4, a liquid inlet chamber 5, a liquid outlet chamber 6, and a pressure relief valve 7. The bottom of the liquid storage container 2 is connected to the liquid inlet chamber 5, a pressure protection device is provided in the plunger chamber 4, and the plunger pump 3 is positioned on one side of the liquid storage container 2, lower than the lower end surface of the liquid storage container 2. A control circuit board 8 for controlling the operation of the plunger pump 3 is provided on the plunger pump 3. Since both the plunger pump 3 and the control circuit board 8 are located on the side of the liquid storage container 2, even if there is a malfunction in the seal at the bottom of the liquid storage container 2 and liquid leaks out, it does not affect the operation of the plunger pump 3 and the control circuit board 8, thus ensuring the safety of the plunger pump 3.

[0023] As shown in Figures 2 and 3, a liquid outlet 9 is provided at the bottom of the liquid storage container 2, and the liquid inlet chamber 5 and the liquid outlet 9 are connected via a communication chamber 20. A concave step 10 is provided around the liquid outlet 9, and the filter mesh 12 is attached to the step 10 by interference fit, forming a slightly upward arch shape from the periphery towards the center. Two grooves 11, deeper than the depth of the step 10, are symmetrically provided in the step 10. A filter screen 12 is provided at the liquid outlet 9, a smaller diameter chamber 15 is provided between the liquid inlet chamber 5 and the plunger chamber 4, a liquid inlet ball valve 17 is provided inside the smaller diameter chamber 15, an annular retaining ring 16 having an inner diameter smaller than the diameter of the liquid inlet ball valve 17 is provided around the end of the smaller diameter chamber 15 facing the liquid inlet chamber 5, a contact post 18 is provided inside the plunger chamber 4, one end of the contact post 18 extends slightly into the smaller diameter chamber 15, and a first compression spring 19 is provided between the contact post 18 and the liquid inlet ball valve 17. A stopper rod is provided on the filter screen 12, one end of the stopper rod extends to the front end of the liquid inlet ball valve 17 in the smaller diameter chamber 15, and the other end of the stopper rod extends further into the smaller diameter chamber 15 to push open the liquid inlet ball valve 17. If the spray painting machine is not used for a long period of time, the liquid inlet ball valve 17 may become stuck inside the differential-diameter chamber 15, blocking the chamber 15. By applying external force to the stopper rod, the stopper rod can push open the liquid inlet ball valve 17.

[0024] The stopper rod described above comprises a first portion 13 perpendicular to the filter screen 12 and a second portion 14 parallel to the liquid inlet chamber 5. The first portion 13 extends from the lower end to the upper end of the filter screen 12 and is located in the center of the filter screen 12. The first portion 13 and the second portion 14 are connected and fixed, and an inclined surface 21 is provided at the connection between the first portion 13 and the second portion 14; a slope 2222 is provided in the communication chamber 20, the slope 2222 is located at the lower end of the inclined surface 21 of the stopper rod, and the inclination ratio of the slope 2222 is the same as that of the inclined surface 21. The slope 2222 restricts the inclined surface 21 from sliding only along the slope 2222, so that the first portion 13 moves downward while moving horizontally toward the second portion 14, allowing the second portion 14 to move horizontally and push and move the liquid inlet ball valve 17.

[0025] As shown in Figures 4 to 6, the pressure protection device includes a pressure detection chamber 23 that communicates with the inside of the plunger chamber 4. A pressure detection rod 24 is provided in the pressure detection chamber 23, which moves up and down in response to pressure changes in the plunger chamber 4. An adjustment screw 27 is provided at the end of the pressure detection chamber 23 opposite to the plunger chamber 4, with one end of the adjustment screw 27 deeply inserted into the pressure detection chamber 23, and a second compression spring 28 is provided between the adjustment screw 27 and the pressure detection rod 24. By screwing the adjustment screw 27 into and out of the pressure detection chamber 23, the pressure value of the second compression spring 28 between the pressure detection chamber 23 and the pressure detection rod 24 is adjusted, thereby adjusting the pressure at which the pressure detection rod 24 strikes the plunger pump 3, and the pressure change inside the plunger pump 3 is detected by the displacement of the pressure detection rod 24.

[0026] A microswitch 25 is provided outside the pressure detection chamber 23, and a toggle lever 26 that drives the operation of the microswitch 25 is provided on the pressure detection rod 24. When the operating pressure of the plunger pump 33 reaches a set value, the pressure inside the plunger pump 3 pushes up the pressure detection rod 24, moving the toggle lever 26 on the pressure detection rod 24 towards the microswitch 25, and activating the microswitch 25, which stops the operation of the motor that drives the operation of the plunger pump 3. If the operating pressure of the plunger pump 3 falls below the set value, the motor operates to pressurize, keeping the equipment in a safe state at all times. Because the microswitch 25 is located outside the pressure detection chamber 23, wear or leakage inside the pressure detection chamber 23 does not affect the microswitch 25, improving the durability of the pressure protection device.

[0027] As shown in Figure 7, a piston is provided in the plunger chamber 4, a piston rod 29 is fixed to one end of the piston, the piston rod 29 is reciprocated by a drive mechanism, the drive mechanism includes a relay box 30 connected and fixed to one end of the piston rod 29, the relay box 30 is rotatably connected to a drive handle 32, the other end of the drive handle 32 is rotatably connected to an eccentric rotation mechanism, and two pairs of balls 31 are provided on both sides of the relay box 30. The balls 31, which are symmetrically arranged on both sides of the relay box 30, restrict the relay box 30 to reciprocating linearly only between the balls 31 on both sides, and when the relay box 30 reciprocates and contacts the balls 31, the linear passage of the relay box 30 contacts the balls 31 and causes the balls 31 to rotate, thereby significantly reducing the frictional force between the relay box 30 and the balls 31, improving the driving efficiency of the plunger pump 3, and extending the lifespan of the components of the balls 31 and the relay box 30, thus enabling a longer lifespan in the present invention.

[0028] The above eccentric rotation mechanism includes a circular gear plate 33, a drive post 34 provided on one side of the gear plate 33, the center of the circle of the drive post 34 being eccentric with respect to the center of the circle of the gear plate 33, a bearing 35 provided inside the drive post 34, a mounting post 36 passing through the center of the circle of the gear plate 33 provided at the center of the bearing 35, a circular through hole 37 provided at the end of the drive handle 32 opposite to the piston rod 29, a needle bearing 38 provided inside the through hole 37, and the drive handle 32 is fitted onto the drive post 34 via the needle bearing 38. The rotation of the gear plate 33 rotates the drive post 34, and the eccentric circular motion of the drive post 34 causes the through hole 37 of the drive handle 32 to roll eccentrically, causing the other end of the drive handle 32 to reciprocate linearly under the constraint of the relay box 30.

[0029] (Second embodiment) The differences between this embodiment and the first embodiment are as follows: One end of the stopper rod extends to the retaining ring 16 and abuts against the liquid inlet ball valve 17, and the other end of the stopper rod further extends to the different diameter chamber 15 and can push open the liquid inlet ball valve 17. In addition to the fact that one end of the stopper rod abuts against the liquid inlet ball valve 17 and manually pushes open the liquid inlet ball valve 17 when the liquid inlet ball valve 17 blocks the different diameter chamber 15, as the liquid inlet ball valve 17 moves back and forth within the different diameter chamber 15 in conjunction with the reciprocating piston motion of the plunger pump 3, each time the liquid inlet ball valve 17 returns to the position of the end of the stopper rod, it hits the stopper rod, generating vibrations in the filter screen 12. During operation of the spray painter, the continuous vibration of the filter screen 12 shakes off large paint particles that cannot pass through the filter screen 12 and adhere to it, preventing a decrease in the paint pumping capacity of the plunger pump 3 due to clogging of the filter screen 12 during long-term operation. The filter mesh 12 is located at the bottom of the liquid storage container 2. The vibration of the filter mesh 12 vibrates the paint inside the liquid storage container 2, delaying the paint's solidification time and keeping the paint particles in a small particle state. This makes it less likely for the spray gun connected to the liquid outlet chamber 6 of the plunger pump 3 to become clogged with paint even during use, further improving the overall durability of the spray painting machine.

[0030] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art can make various modifications, additions, or substitutions with equivalents to the specific embodiments described herein, but such modifications, additions, or substitutions with equivalents will not depart from the spirit of the invention or exceed the scope limited by the appended claims. [Explanation of symbols]

[0031] 1 Casing 10 Stepped section 11 Groove 12 Filter net 13 Part 1 14 Part 2 15 Different diameter chamber 16 Retaining ring 17. Liquid Inlet Ball Valve 18 Contact Post 19 First compression spring 2. Liquid storage containers 20-way connecting chamber 21 Slope 22 slopes 23 Pressure detection chamber 24 Pressure detection rods 25 microswitches 26 Toggle lever 27 Adjustment screw 28 Second compression spring 29 Piston rod 3. Plunger pump 30 relay boxes 31 Ball 32 Drive handle 33 Gear Plate 34 Drive Post 35 Bearings 36 Mounting Post 37 Through hole 38 Needle Bearings 4. Plunger Room 5 Liquid inlet chamber 6 Liquid outflow chamber 7. Pressure relief valve 8 Control circuit board 9 Liquid outlet

Claims

1. A durable high-pressure airless spray painter comprising a casing (1), a liquid storage container (2), and a plunger pump (3), wherein the plunger pump (3) comprises a plunger chamber (4), a liquid inlet chamber (5), a liquid outlet chamber (6), and a pressure relief valve (7), the bottom of the liquid storage container (2) is in communication with the liquid inlet chamber (5), and a pressure protection device is provided in the plunger chamber (4), wherein the plunger pump (3) is located on one side of the liquid storage container (2), and the liquid storage container (2) A piston is provided in the plunger chamber (4) at a lower end than the lower end surface, a piston rod (29) is fixed to one end of the piston, the piston rod (29) is reciprocated by a drive mechanism, the drive mechanism includes a relay box (30) connected and fixed to one end of the piston rod (29), the relay box (30) is rotatably connected to a drive handle (32), the other end of the drive handle (32) is rotatably connected to an eccentric rotation mechanism, and at least one pair of balls (31) are provided on both sides of the relay box (30), A liquid outlet (9) is provided at the bottom of the liquid storage container (2), and the liquid inlet chamber (5) and the liquid outlet (9) are connected via a communication chamber (20). A filter screen (12) is provided at the liquid outlet (9), a different diameter chamber (15) is provided between the liquid inlet chamber (5) and the plunger chamber (4), a liquid inlet ball valve (17) is provided inside the different diameter chamber (15), an annular retaining ring (16) having an inner diameter smaller than the diameter of the liquid inlet ball valve (17) is provided around the end of the different diameter chamber (15) facing the liquid inlet chamber (5), a stopper rod is provided on the filter screen (12), one end of the stopper rod extends to the front end of the liquid inlet ball valve (17) in the different diameter chamber (15), and the other end of the stopper rod further extends into the different diameter chamber (15) and the liquid A durable high-pressure airless spray painter characterized in that it can push open a body inlet ball valve (17), the stopper rod comprises a first portion (13) perpendicular to the filter screen (12) and a second portion (14) parallel to the liquid inlet chamber (5), the first portion (13) and the second portion (14) are connected and fixed, and an inclined surface (21) is provided at the connection between the first portion (13) and the second portion (14); a slope (22) is provided in the communication chamber (20), the slope (22) is located at the lower end of the inclined surface (21) of the stopper rod, and the inclination ratio of the slope (22) is the same as that of the inclined surface (21).

2. A durable high-pressure airless spray painter according to claim 1, characterized in that a filter screen (12) is provided at the liquid outlet (9), a different-diameter chamber (15) smaller in diameter than the liquid inlet chamber (5) is provided between the liquid inlet chamber (5) and the plunger chamber (4), a liquid inlet ball valve (17) is provided inside the different-diameter chamber (15), an annular retaining ring (16) having an inner diameter smaller than the diameter of the liquid inlet ball valve (17) is provided around the end of the different-diameter chamber (15) facing the liquid inlet chamber (5), a stopper rod is provided on the filter screen (12), one end of the stopper rod extends to the retaining ring (16) and abuts against the liquid inlet ball valve (17), and the other end of the stopper rod further extends into the different-diameter chamber (15) and can push open the liquid inlet ball valve (17).

3. A durable high-pressure airless spray painter according to claim 1 or 2, characterized in that a concave stepped portion (10) is provided around the liquid outlet (9), the filter mesh (12) is attached to the stepped portion (10) by interference fit, and two grooves (11) having a depth greater than the depth of the stepped portion (10) are symmetrically provided in the stepped portion (10).

4. A durable high-pressure airless spray painting machine according to claim 1 or 2, characterized in that a contact post (18) is provided in the plunger chamber (4), one end of the contact post (18) extends slightly into the different diameter chamber (15), and a first compression spring (19) is provided between the contact post (18) and the liquid inlet ball valve (17).

5. The durable high-pressure airless spray painting machine according to claim 1 or 2, characterized in that the first part extends from the lower end of the filter mesh to the upper end of the filter mesh.

6. The durable high-pressure airless spray painting machine according to claim 5, characterized in that the filter mesh is slightly arched upward from the periphery towards the center.

7. The pressure protection device comprises a pressure detection chamber (23) communicating with the inside of the plunger chamber (4), a pressure detection rod (24) is provided in the pressure detection chamber (23) that moves up and down within the pressure detection chamber (23) in response to pressure changes in the plunger chamber (4), a microswitch (25) is provided outside the pressure detection chamber (23), and a toggle lever (26) is provided on the pressure detection rod (24) that drives the operation of the microswitch (25), characterized in that the durable high-pressure airless spray painting machine according to claim 1.

8. A durable high-pressure airless spray painter according to claim 7, characterized in that an adjustment screw (27) is provided at the end of the pressure detection chamber (23) opposite to the plunger chamber (4), one end of the adjustment screw (27) is deeply inserted into the pressure detection chamber (23), and a second compression spring (28) is provided between the adjustment screw (27) and the pressure detection rod (24).

9. The eccentric rotation mechanism comprises a circular gear plate (33), a drive post (34) provided on one side of the gear plate (33), the center of the circle of the drive post (34) being eccentric with respect to the center of the circle of the gear plate (33), a bearing (35) provided inside the drive post (34), a mounting post (36) passing through the center of the circle of the gear plate (33) provided at the center of the bearing (35), a circular through hole (37) provided at the end of the drive handle (32) opposite to the piston rod (29), a needle bearing (38) provided inside the through hole (37), and the drive handle (32) being fitted onto the drive post (34) via the needle bearing (38), characterized in that the durable high-pressure airless spray painting machine according to claim 1.

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