Durable High-Pressure Airless Spray Coating 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 more 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, for example, 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 motion 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 it reciprocates, not only accelerating the wear between the inclined plate and the balance post, but also increasing the driving resistance of the inclined plate and reducing 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

Summary of the Invention

Problems to be Solved by the Invention

[0005] It is necessary to improve the lifespan of high-pressure airless spray painting machines in the prior art. The present invention proposes a durable high-pressure airless spray painting machine for the problem of the need to extend the lifespan of high-pressure airless spray painting machines in the prior art.

Means for Solving the Problems

[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. The plunger pump includes a plunger chamber, a liquid inlet chamber, a liquid outlet chamber, and a pressure relief valve. The bottom of the liquid storage container communicates with the liquid inlet chamber. A pressure protection device is provided in the plunger chamber. The plunger pump is arranged on one side of the liquid storage container, 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 fixedly provided at one end of the piston. The piston rod is reciprocated by a drive mechanism. The drive mechanism includes a relay box connected and fixed to one end of the piston rod. The relay box is rotatably connected to a drive handle portion. The other end of the drive handle portion is rotatably connected to an eccentric rotation mechanism. 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 surface of the liquid storage container, even if there is a defect in the seal at the bottom of the liquid storage container and 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. Balls are symmetrically arranged on both sides of the relay box of the present invention to limit the linear reciprocating motion of the relay box. When the relay box reciprocates and contacts the balls, the linear passage of the relay box contacts the balls, causing the balls to rotate, thereby greatly reducing the frictional force between the relay box and the balls, improving the driving efficiency of the plunger pump, reducing the wear between components, extending the service life of the components of the balls and the relay box, and making the present invention more durable. Moreover, due to the rolling guiding action of the balls, it is not necessary to position the relay box between the balls on both sides. Even if there is a certain deviation, the balls can easily guide the relay box without increasing the frictional force of the linear reciprocating motion of the relay box, thereby increasing the assembly tolerance and making the installation more convenient.

[0008] Preferably, a liquid outlet is provided at the bottom of the liquid storage container, and the liquid inflow chamber and the liquid outlet are communicated through a communication chamber.

[0009] Preferably, a filter screen is provided at the liquid outlet, a reduced-diameter chamber with a smaller diameter than the liquid inflow chamber is provided between the liquid inflow chamber and the plunger chamber, a liquid inflow ball valve is provided in the reduced-diameter chamber, and an annular stop ring with an inner diameter smaller than the diameter of the liquid inflow ball valve is provided around the end of the reduced-diameter chamber facing the liquid inflow chamber; a propping rod is provided against the filter screen, one end of the propping rod extends to the front end of the liquid inflow ball valve in the reduced-diameter chamber, and the end of the propping rod further extends into the reduced-diameter chamber to be able to push open the liquid inflow ball valve. When the spray painting machine is not used for a long time, the liquid inflow ball valve adheres in the reduced-diameter chamber to block the reduced-diameter chamber, and by applying an external force to push the propping rod, the propping rod can push open the liquid inflow ball valve.

[0010] Preferably, a filter screen is provided at the liquid outlet, a reduced-diameter chamber smaller in diameter than the liquid inlet chamber is provided between the liquid inlet chamber and the plunger chamber, a liquid inlet ball valve is provided in the reduced-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 reduced-diameter chamber facing the liquid inlet chamber; a abutting rod is provided on the filter screen, one end of the abutting rod extends to the retaining ring and abuts against the liquid inlet ball valve, and the end of the abutting rod further extends into the reduced-diameter chamber to be able to push open the liquid inlet ball valve. One end of the abutting rod abuts against the liquid inlet ball valve. When the liquid inlet ball valve closes the reduced-diameter chamber, in addition to manually pushing open the liquid inlet ball valve, as the piston of the plunger pump reciprocates, when the liquid inlet ball valve reciprocates in the reduced-diameter chamber, every time the liquid inlet ball valve returns to the position of the end of the abutting rod, it hits the abutting rod, generating vibration on the filter screen. During the operation of the spray painting machine, due to the continuous vibration of the filter screen, large paint particles that cannot pass through the filter screen and adhere to the filter screen are shaken off, preventing the reduction of the paint pumping capacity of the plunger pump due to the clogging of the filter screen during long-term operation. The filter screen is located at the bottom of the liquid storage container. The vibration of the filter screen vibrates the paint in the liquid storage container, delays the solidification time of the paint, and can keep the paint particles in a small particle state. The spray gun connected to the liquid outlet chamber of the plunger pump is less likely to be clogged at the outlet by the paint even during use, further improving the durability of the entire spray painting machine.

[0011] Preferably, a concave stepped portion is provided around the liquid outlet, the filter screen is attached to the stepped portion by an interference fit, and two grooves having a depth deeper than the depth of the stepped portion are symmetrically provided on the stepped portion. By providing the grooves, the contact surface between the stepped portion and the circumference of the filter screen is reduced, and the filter screen above the grooves is more likely to be deformed when subjected to an external force, making it more labor-saving when pushing the abutting rod.

[0012] Preferably, an abutting post is provided in the plunger chamber, one end of the abutting post extends slightly into the stepped chamber, and a first compression spring is provided between the abutting post and the liquid inlet ball valve. By providing the first compression spring, when there is no external force, the liquid inlet ball valve is abutted against the stop ring, the passage between the stop ring and the stepped chamber is blocked, and during the operation of the plunger pump, the liquid inlet ball valve is subjected to the lifting force of the plunger pump and moves toward the plunger chamber. When the liquid inlet ball valve moves away from the stop ring, the passage between the stop ring and the stepped chamber opens, the paint enters the plunger chamber, flows into the liquid outlet chamber of the plunger pump, and the paint can be sprayed to the outside.

[0013] Preferably, the abutting rod includes a first portion perpendicular to the filter screen and a second portion parallel to the liquid inlet chamber. The first portion and the second portion are connected and fixed, and an inclined surface is provided at the connecting portion between the first portion and the second portion; a slope is provided in the communicating chamber, the slope is located at the lower end of the inclined surface of the abutting rod, and the slope rate of the slope is the same as the slope rate of the inclined surface. The slope restricts the inclined surface from sliding only along the slope, enables the first portion to move horizontally toward the second portion while moving downward, and enables the second portion to move horizontally, so as to push and move the liquid inlet ball valve.

[0014] Preferably, the first portion passes from the lower end to the upper end of the filter screen. If it is necessary to manually push the abutting rod when the first portion passes to the upper end of the filter screen, it is convenient to push, there is no need to push the filter screen to apply pressure to the abutting rod, the center of the filter screen is most deformed, and labor can be saved.

[0015] Preferably, the filter screen is slightly upwardly arched from the periphery toward the center. After the center of the filter screen is moved downward by the downward movement of the first portion of the abutting rod, such a structure of the filter screen is more advantageous for the rebound of the filter screen.

[0016] Preferably, the pressure protection device includes a pressure detection chamber communicated with the inside of the plunger chamber. A pressure detection rod is provided in the pressure detection chamber to move up and down in the pressure detection chamber according to the pressure change in the plunger chamber. A microswitch is provided outside the pressure detection chamber, and a toggle lever for driving the operation of the microswitch is provided on the pressure detection rod. When the operating pressure of the plunger pump reaches the set value, the operation of the motor driving the operation of the plunger pump stops. When the operating pressure of the plunger pump is less than the set value, the motor operates to pressurize, keeping the equipment in a safe state at all times. Since the microswitch is outside the pressure detection chamber, wear and leakage in the pressure detection chamber do 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. One end of the adjustment screw extends deeply 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 can be adjusted, thereby adjusting the pressure at which the pressure detection rod abuts against the plunger pump, and detecting the pressure change in the plunger pump due to the displacement of the pressure detection rod.

[0018] Preferably, the eccentric rotation mechanism includes a circular gear plate. A drive post is provided on one side of the gear plate. The center of the circle of the drive post is eccentric with respect to the center of the circle of the gear plate. A bearing is provided in the drive post, and a mounting post passing through the center of the circle of the gear plate is provided at the center of the bearing. Both ends of the mounting post are respectively attached to the pump body of the plunger pump. A circular through hole is provided at the end of the drive handle opposite to the piston rod. The diameter of the through hole is larger than the diameter of the drive post, and the drive handle is fitted into the drive post through the through hole. When the gear plate rotates, the drive post rotates. The diameter of the drive post is smaller than the diameter of the through hole of the drive handle fitted into the drive post. When the drive post performs an eccentric circular motion, the drive handle is reciprocated.

Advantages 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 linearly reciprocate only between the two balls on both sides. When the relay box reciprocates and contacts the balls, the linear passage of the relay box contacts the balls and rotates the balls, greatly reducing the frictional force between the relay box and the balls, improving the driving efficiency of the plunger pump, extending the service life of the components of the balls and the relay box, and making the present invention more durable.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0021] Hereinafter, the present invention will be further described with reference to the embodiments shown in the accompanying drawings.

[0022] (First Embodiment) As shown in FIG. 1, a spray painting machine 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 inflow chamber 5, a liquid outflow chamber 6, and a pressure relief valve 7. The bottom of the liquid storage container 2 communicates with the liquid inflow chamber 5. A pressure protection device is provided in the plunger chamber 4. The plunger pump 3 is disposed on one side of the liquid storage container 2, lower than the lower end surface of the liquid storage container 2, and 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 surface of the liquid storage container 2, even if there is a problem with the seal at the bottom of the liquid storage container 2 and the liquid leaks out, it will not affect the operation of the plunger pump 3 and the control circuit board 8, ensuring the safety of the plunger pump 3.

[0023] As shown in FIGS. 2 and 3, a liquid outlet 9 is provided at the bottom of the liquid storage container 2, and the liquid inflow chamber 5 and the liquid outlet 9 are communicated via a communication chamber 20. A concave stepped portion 10 is provided around the liquid outlet 9, and the filter net 12 is attached to the stepped portion 10 by interference fit and has a slightly upward arch shape from the periphery toward the center. Two grooves 11 having a depth deeper than the depth of the stepped portion are symmetrically provided in the stepped portion 10. A filter net 12 is provided at the liquid outlet 9, a reduced-diameter chamber 15 having a smaller diameter than the liquid inflow chamber 5 is provided between the liquid inflow chamber 5 and the plunger chamber 4, a liquid inflow ball valve 17 is provided in the reduced-diameter chamber 15, and an annular retaining ring 16 having an inner diameter smaller than the diameter of the liquid inflow ball valve 17 is provided around the end of the reduced-diameter chamber 15 facing the liquid inflow chamber 5. An abutting post 18 is provided in the plunger chamber 4, one end of the abutting post 18 slightly extends into the reduced-diameter chamber 15, and a first compression spring 19 is provided between the abutting post 18 and the liquid inflow ball valve 17. A propping rod is provided on the filter net 12, one end of the propping rod extends to the front end of the liquid inflow ball valve 17 in the reduced-diameter chamber 15, and the end of the propping rod further extends into the reduced-diameter chamber 15 to push open the liquid inflow ball valve 17. When the spray painting machine is not used for a long time, the liquid inflow ball valve 17 is fixed in the reduced-diameter chamber 15 to block the reduced-diameter chamber 15, and by applying an external force to push the propping rod, the propping rod can push open the liquid inflow ball valve 17.

[0024] The above abutting rod includes a first part 13 perpendicular to the filter screen 12 and a second part 14 parallel to the liquid inlet chamber 5. The first part 13 passes from the lower end to the upper end of the filter screen 12 and is located at the center of the filter screen 12. The first part 13 and the second part 14 are connected and fixed, and an inclined surface 21 is provided at the connecting part of the first part 13 and the second part 14; a slope 2222 is provided in the communication chamber 20, and the slope 2222 is located at the lower end of the inclined surface 21 of the abutting rod, and the slope rate of the slope 2222 is the same as that of the inclined surface 21. The slope 2222 restricts the inclined surface 21 to slide only along the slope 2222, enables the first part 13 to move horizontally toward the second part 14 while moving downward, allows the second part 14 to move horizontally, and pushes and moves the liquid inlet ball valve 17.

[0025] As shown in FIGS. 4 to 6, the pressure protection device includes a pressure detection chamber 23 communicated with the inside of the plunger chamber 4. A pressure detection rod 24 is provided in the pressure detection chamber 23 to move up and down in the pressure detection chamber 23 according to the pressure change 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. One end of the adjustment screw 27 deeply enters 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, so as to adjust the pressure at which the pressure detection rod 24 abuts against the plunger pump 3, and detect the pressure change in the plunger pump 3 according to 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 for driving the operation of the microswitch 25 is provided on the pressure detection rod 24. When the operating pressure of the plunger pump 33 reaches the set value, the pressure in the plunger pump 3 pushes up the pressure detection rod 24, moves the toggle lever 26 on the pressure detection rod 24 toward the microswitch 25 side, and activates the microswitch 25, thereby stopping the operation of the motor that drives the operation of the plunger pump 3. When the operating pressure of the plunger pump 3 is less than the set value, the motor operates to pressurize and keep the equipment in a safe state at all times. Since the microswitch 25 is outside the pressure detection chamber 23, even if wear or leakage occurs in the pressure detection chamber 23, it will not affect the microswitch 25, and the durability of the pressure protection device is improved.

[0027] As shown in FIG. 7, 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, and two pairs of balls 31 are provided on both sides of the relay box 30. The balls 31 symmetrically arranged on both sides of the relay box 30 limit the relay box 30 to linearly reciprocate only between the balls 31 on both sides. When the relay box 30 reciprocates and contacts the balls 31, the relay box 30 contacts the balls 31 by linearly passing through, and the balls 31 are rotated, thereby greatly reducing the frictional force between the relay box 30 and the balls 31, improving the driving efficiency of the plunger pump 3, extending the service life of the components of the balls 31 and the relay box 30, and enabling the present invention to achieve a longer service life.

[0028] The above eccentric rotation mechanism includes a circular gear plate 33. A drive post 34 is provided on one side of the gear plate 33. The center of the circle of the drive post 34 is eccentric with respect to the center of the circle of the gear plate 33. A bearing 35 is provided in the drive post 34. An attachment post 36 passing through the center of the circle of the gear plate 33 is provided at the center of the bearing 35. A circular through hole 37 is provided at the end of the drive handle portion 32 on the side opposite to the piston rod 29. A needle bearing 38 is provided in the through hole 37. The drive handle portion 32 is fitted into the drive post 34 via the needle bearing 38. When the gear plate 33 rotates, the drive post 34 is rotated. Due to the eccentric circular motion of the drive post 34, the through hole 37 of the drive handle portion 32 is eccentrically rolled, so that the other end of the drive handle portion 32 makes a linear reciprocating motion under the limitation of the relay box 30.

[0029] (Second Embodiment) The difference between this embodiment and the first embodiment is that One end of the abutting rod extends to the stop ring 16 and abuts against the liquid inlet ball valve 17. The end of the abutting rod further extends into the stepped chamber 15 to be able to push open the liquid inlet ball valve 17. One end of the abutting rod abuts against the liquid inlet ball valve 17. When the liquid inlet ball valve 17 closes the stepped chamber 15, in addition to manually pushing open the liquid inlet ball valve 17, as the piston of the plunger pump 3 reciprocates, when the liquid inlet ball valve 17 reciprocates in the stepped chamber 15, every time the liquid inlet ball valve 17 returns to the position of the end of the abutting rod, it hits the abutting rod, generates vibration on the filter screen 12, and shakes off large paint particles adhering to the filter screen 12 that cannot pass through the filter screen 12 due to the continuous vibration of the filter screen 12 during the operation of the spray painting machine, preventing the reduction of the paint pumping ability of the plunger pump 3 due to the clogging of the filter screen 12 during long-term operation. The filter screen 12 is located at the bottom of the liquid storage container 2. The vibration of the filter screen 12 vibrates the paint in the liquid storage container 2, delays the solidification time of the paint, and can keep the paint particles in a small particle state. The spray gun connected to the liquid outflow chamber 6 of the plunger pump 3 is less likely to be clogged at the outlet by the paint even during use, further improving the durability of the entire spray painting machine.

[0030] The specific embodiments described in this specification are merely illustrative of the spirit of the present invention. Those skilled in the art can make various modifications and supplements to the described specific embodiments or use substitutions with equivalents, but such modifications, supplements, or substitutions with equivalents do not deviate from the spirit of the present invention or exceed the scope limited by the appended claims.

Description of Reference Numerals

[0031] 1 Casing 10 Step portion 11 Groove 12 Filter screen 13 First part 14 Second part 15 Reducing chamber 16 Stop ring 17 Liquid inlet ball valve 18 Contact post 19 First compression spring 2 Liquid storage container 20 Communication chamber 21 Inclined surface 22 Slope 23 Pressure detection chamber 24 Pressure detection rod 25 Microswitch 26 Toggle lever 27 Adjusting screw 28 Second compression spring 29 Piston rod 3 Plunger pump 30 Relay box 31 Ball 32 Driving handle part 33 Gear plate 34 Driving post 35 Bearing 36 Mounting post 37 Through hole 38 Needle bearing 4 Plunger chamber 5 Liquid inlet chamber 6 Liquid outlet chamber 7 Pressure relief valve 8 Control circuit board 9 Liquid outlet

Claims

1. A durable high-pressure airless spray painting machine 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) communicates with the liquid inlet chamber (5), and 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 comprises 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, and at least a pair of rollers (31) are provided on both sides of the relay box (30).

2. 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 communicated via a communication chamber (20). The durable high-pressure airless spray painting machine according to Claim 1.

3. A filter screen (12) is provided at the liquid outlet (9), a reduced-diameter chamber (15) is provided between the liquid inlet chamber (5) and the plunger chamber (4), a liquid inlet ball valve (17) is provided in the reduced-diameter chamber (15), an annular stop ring (16) having an inner diameter smaller than the diameter of the liquid inlet ball valve (17) is provided around the end of the reduced-diameter chamber (15) facing the liquid inlet chamber (5), a abutting rod is provided on the filter screen (12), one end of the abutting rod extends to the front end of the liquid inlet ball valve (17) in the reduced-diameter chamber (15), and the end of the abutting rod further extends into the reduced-diameter chamber (15) to be able to push open the liquid inlet ball valve (17). The durable high-pressure airless spray painting machine according to Claim 2.

4. A filter screen (12) is provided at the liquid outlet (9), a reduced-diameter chamber (15) having a smaller 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 in the reduced-diameter chamber (15), and an annular retaining ring (16) having an inner diameter smaller than the diameter of the liquid inlet ball valve (17) is provided around the circumference of the end of the reduced-diameter chamber (15) facing the liquid inlet chamber (5). A propping rod is provided against the filter screen (12), one end of the propping rod extends to the retaining ring (16) and abuts against the liquid inlet ball valve (17), and the end of the propping rod further extends into the reduced-diameter chamber (15) and can push open the liquid inlet ball valve (17). The high-pressure airless spray painting machine with durability according to claim 2 is characterized in that.

5. A concave stepped portion (10) is provided around the circumference of the liquid outlet (9), the filter screen (12) is attached to the stepped portion (10) by interference fit, and two grooves (11) having a depth deeper than the depth of the stepped portion (10) are symmetrically provided in the stepped portion (10). The high-pressure airless spray painting machine with durability according to claim 3 or 4 is characterized in that.

6. A contact post (18) is provided in the plunger chamber (4), one end of the contact post (18) extends slightly into the reduced-diameter chamber (15), and a first compression spring (19) is provided between the contact post (18) and the liquid inlet ball valve (17). The high-pressure airless spray painting machine with durability according to claim 3 or 4 is characterized in that.

7. The propping rod includes 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, an inclined surface (21) is provided at the connecting portion between the first portion (13) and the second portion (14), a slope (22) is provided in the connecting chamber (20), the slope (22) is located at the lower end of the inclined surface (21) of the propping rod, and the slope rate of the slope (22) is the same as the slope rate of the inclined surface (21). The high-pressure airless spray painting machine with durability according to claim 3 or 4 is characterized in that.

8. The durable high-pressure airless spray painting machine according to claim 7, wherein the first part passes from the lower end to the upper end of the filter screen.

9. The durable high-pressure airless spray painting machine according to claim 7, wherein the filter screen is in a slightly upward arch shape from the periphery toward the center.

10. The pressure protection device includes a pressure detection chamber (23) communicated with the inside of the plunger chamber (4). A pressure detection rod (24) is provided in the pressure detection chamber (23) to move up and down in the pressure detection chamber (23) according to the pressure change in the plunger chamber (4). A micro switch (25) is provided outside the pressure detection chamber (23), and a toggle lever (26) for driving the operation of the micro switch (25) is provided on the pressure detection rod (24). The durable high-pressure airless spray painting machine according to claim 1 is characterized by this.

11. An adjustment screw (27) is provided at an end of the pressure detection chamber (23) opposite to the plunger chamber (4). One end of the adjustment screw (27) deeply enters the pressure detection chamber (23), and a second compression spring (28) is provided between the adjustment screw (27) and the pressure detection rod (24). The durable high-pressure airless spray painting machine according to claim 1 is characterized by this.

12. The eccentric rotation mechanism includes a circular gear plate (33). A drive post (34) is provided on one side of the gear plate (33). The center of the circle of the drive post (34) is eccentric with respect to the center of the circle of the gear plate (33). A bearing (35) is provided in the drive post (34), and a mounting post (36) passing through the center of the circle of the gear plate (33) is provided at the center of the bearing (35). A circular through hole (37) is provided at an end of the drive handle portion (32) opposite to the piston rod (29). A needle bearing (38) is provided in the through hole (37), and the drive handle portion (32) is fitted into the drive post (34) through the needle bearing (38). The durable high-pressure airless spray painting machine according to claim 1 is characterized by this.

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