Airless spraying machine

Abstract

The utility model discloses an airless spraying machine, which relates to the field of spraying equipment and comprises a shell, and a hopper is fixed on one side of the shell. The plunger pump is arranged in the shell and comprises a shell, a control device, a liquid inlet device, a liquid outlet device, a pressure relief device and a pressure protection device, the control device, the liquid inlet device, the liquid outlet device, the pressure relief device and the pressure protection device are connected to the shell, the liquid inlet device is communicated with a liquid outlet formed in the bottom of the hopper, a liquid outlet cavity is formed in the liquid outlet device and externally connected with a spray gun through a liquid outlet connector, and the control device is used for controlling liquid outlet of the liquid outlet device. One end of the pressure relief device is communicated with the liquid outlet cavity, and the other end of the pressure relief device is communicated with a backflow opening formed in the bottom of the hopper and is controlled by a knob to be opened and closed, so that backflow and pressure relief are achieved; and the motor is arranged in the shell and drives the control device to reciprocate in the shell. According to the plunger pump, feed liquid can enter the plunger pump more easily, so that the requirement of the feed liquid on suction force is reduced, and the purpose of reducing the output power of the motor is achieved.

Description

Technical Field

[0001] The utility model relates to the field of spraying equipment, in particular to an airless spraying machine. Background Art

[0002] An airless sprayer is a type of spraying equipment that uses a plunger pump to pressurize the paint. The high-pressure paint is transported to the spray gun through a high-pressure hose, and the pressure is released through the nozzle to form atomization, thereby forming a dense coating on the wall surface. Since the airless sprayer needs to pressurize the paint to a high pressure (commonly used pressure is 60-300kg / cm2), it usually places high requirements on the suction force of the liquid inlet, which is difficult to achieve with a small-power motor. Therefore, a high-power motor is required, which not only causes energy waste, but also is not conducive to the miniaturization and lightweight of the equipment. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the prior art and to provide an airless sprayer, so that the liquid can enter the plunger pump more easily, so as to reduce the suction requirements for the liquid intake, so as to achieve the purpose of reducing the output power of the motor, which can not only save energy, but also increase the amount of liquid entering the pump body within a certain period of time, and the liquid material can be pressurized quickly, and the liquid material can be pressurized to the pressure required for spraying atomization in a short time, and its working efficiency is greatly improved.

[0004] The purpose of the utility model is achieved through the following technical solutions: This airless sprayer includes:

[0005] a housing having a hopper fixed to one side of the housing;

[0006] A plunger pump is arranged in a housing, the plunger pump comprises a housing and a control device, a liquid inlet device, a liquid outlet device, a pressure relief device and a pressure protection device connected to the housing, the liquid inlet device is connected to a liquid outlet opened at the bottom of the hopper to introduce liquid into the housing, a liquid outlet cavity is arranged in the liquid outlet device, and the liquid outlet cavity is externally connected to a spray gun through a liquid outlet interface, the control device is used to selectively connect the liquid inlet device with the liquid outlet device, so as to control the liquid outlet of the liquid outlet device, the pressure protection device is connected to the liquid outlet cavity, and is used to maintain the hydraulic pressure in the liquid outlet cavity, one end of the pressure relief device is connected to the liquid outlet cavity, and the other end is connected to a reflux port opened at the bottom of the hopper, and the pressure relief device is controlled to open and close by a knob arranged on the housing to achieve reflux and pressure relief; and

[0007] The motor is arranged in the shell and drives the control device to perform reciprocating motion in the shell through the transmission mechanism.

[0008] As a further technical solution, the transmission mechanism includes a gear connected to the end of the motor shaft, an eccentric gear meshing with the gear, and a connecting rod installed on the eccentric gear. The connecting rod is driven by the eccentric gear and reciprocates up and down in the shell. The other end of the connecting rod is detachably connected to the control device.

[0009] As a further technical solution, the control device includes a plunger rod sleeve fixed on the shell, a plunger rod is arranged in a relatively sliding manner in the inner hole of the plunger rod sleeve, one end of the plunger rod is connected and driven by a connecting rod, and the other end of the plunger rod is used to control the on-off of the liquid inlet, the inner cavity of the shell and the liquid outlet cavity; a sealing ring assembly is provided at the end of the plunger rod for tightly fitting the inner wall of the plunger rod sleeve.

[0010] As a further technical solution, a connecting block is installed on the connecting rod through a pin, and the connecting block is matched with the plunger rod in a slot-type manner.

[0011] As a further technical solution, the liquid inlet device includes a liquid inlet valve sleeve threadedly connected to the shell, a liquid inlet valve seat resting between the liquid inlet valve sleeve and the shell, a liquid inlet valve ball cooperating with the liquid inlet valve seat, a liquid inlet sealing ring for sealing the shell and the liquid inlet valve seat, and a liquid inlet spring pressed against the liquid inlet valve ball. The liquid inlet valve sleeve is provided with a liquid inlet port, which is connected to the liquid outlet through a liquid inlet pipe to achieve liquid inlet.

[0012] As a further technical solution, the liquid outlet device includes a liquid outlet valve sleeve threadedly connected to the shell, a liquid outlet valve seat resting between the liquid outlet valve sleeve and the shell, a liquid outlet valve ball cooperating with the liquid outlet valve seat, a liquid outlet sealing ring for sealing the shell and the liquid outlet valve sleeve, and a liquid outlet spring pressed against the liquid outlet valve ball. The liquid outlet interface is opened on the liquid outlet valve sleeve and is connected to the spray gun through a high-pressure hose.

[0013] As a further technical solution, the pressure relief device includes a pressure relief nut threadedly connected to the shell, a pressure relief valve seat installed in the shell, a pressure relief valve stem slidably arranged in the shell, a pressure relief valve ball arranged on the pressure relief valve stem for cooperating with the pressure relief valve seat, and a pressure relief sealing ring installed on the outer wall of the pressure relief valve stem and slidingly sealed with the inner wall of the shell; a pressure relief spring is supported on the outer wall of the pressure relief valve stem, and the other end of the pressure relief spring is pressed on the gasket, which is installed between the pressure relief nut and the shell; an inner serrated locking washer cooperating with the end face of the pressure relief nut is arranged at one end of the pressure relief valve stem away from the pressure relief valve seat; a knob extending out of the outer shell is provided at the tail end of the pressure relief valve stem, the pressure relief valve seat is provided with an inner hole connected to the liquid outlet cavity, the valve cavity formed between the pressure relief valve seat and the pressure relief valve stem is connected to the pressure relief exhaust port opened on the shell, and the pressure relief exhaust port is connected to the reflux port through a reflux pipe to realize pressure relief, exhaust and paint reflux.

[0014] As a further technical solution, the pressure protection device includes a pressure valve sleeve threadedly connected to the shell, a pressure protection valve seat arranged in the shell and connected to the liquid outlet chamber, a pressure protection valve stem sliding relative to the pressure protection valve seat, and a pressure regulating spring with one end against the pressure valve sleeve and the other end against the outer wall of the pressure protection valve stem. The pressure protection valve stem penetrates the pressure valve sleeve and touches the micro switch. The pressure protection valve stem extends into the outer wall of one end of the pressure protection valve seat and is sleeved with a gasket and a sealing ring to achieve sliding sealing. A hexagon socket screw is installed on the micro switch, and the micro switch is used to electrically connect the control motor.

[0015] As a further technical solution, the plunger pump is arranged on the side or both sides of the hopper, and a handle, a power switch and a power plug are arranged on the outer shell.

[0016] The beneficial effects of the utility model are:

[0017] 1. The plunger rod driven by the motor makes reciprocating motion, thereby controlling the connection between the liquid inlet device and the liquid outlet device of the plunger pump, making it easier for the liquid to enter the plunger pump and reducing the suction requirements for the liquid inlet. A small-power motor can be used to reduce energy consumption.

[0018] 2. The plunger pump is equipped with a pressure protection device, which can increase the amount of liquid entering the pump body within a certain period of time, and the liquid material is pressurized quickly. In a short time, the liquid material can be pressurized to the pressure required for spray atomization, and its working efficiency is greatly improved;

[0019] 3. At the same time, the plunger pump is also equipped with a pressure relief device, which can quickly relieve pressure and is safe and reliable to use. After pressure relief, the liquid material flows back to the hopper without causing waste;

[0020] 4. The liquid inlet valve, liquid outlet valve and pressure relief valve are all equipped with valve balls, which act as one-way valves to ensure that the liquid does not flow in the reverse direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional structural schematic diagram of the utility model.

[0022] Figure 2 It is a schematic diagram of the main structure of the utility model.

[0023] Figure 3 It is a schematic diagram of the top structure of the utility model.

[0024] Figure 4 for Figure 3 AA section view.

[0025] Figure 5 It is a schematic diagram of the three-dimensional structure of the utility model after the shell is hidden.

[0026] Figure 6This is a schematic diagram of the main structure of the utility model after the shell is hidden.

[0027] Figure 7 It is a three-dimensional structural schematic diagram of the plunger pump in the utility model.

[0028] Figure 8 This is a schematic diagram of the main structure of the plunger pump in the utility model.

[0029] Fig. 9 for Figure 8 BB cross-sectional view.

[0030] Fig.10 for Figure 8 CC cross-sectional view.

[0031] Description of the accompanying drawings: handle 1, knob 2, liquid outlet interface 3, power switch 4, power plug 5, hopper 6, housing 7, motor 8, gear 9, eccentric gear 10, connecting rod 11, latch 12, plunger rod 13, plunger rod screw sleeve 14, sealing ring assembly 15, liquid outlet 16, liquid inlet 17, liquid inlet valve screw sleeve 18, liquid inlet valve seat 19, housing 20, liquid inlet valve ball 21, liquid inlet spring 22, liquid inlet sealing ring 23, liquid outlet valve seat 24, liquid outlet valve ball 25, liquid outlet spring 26, liquid outlet sealing ring 2 7. Liquid outlet valve sleeve 28, pressure relief valve seat 29, pressure relief valve ball 30, pressure relief valve stem 31, pressure relief sealing ring 32, pressure relief spring 33, gasket 34, pressure relief nut 35, internal serrated lock washer 36, sealing ring 37, gasket 38, pressure protection valve stem 39, pressure regulating spring 40, pressure valve sleeve 41, micro switch 42, hexagon socket screw 43, liquid inlet pipe 44, reflux pipe 45, pressure relief exhaust port 46, spray gun 47, reflux port 48, connecting block 49, liquid outlet cavity 50, pressure protection valve seat 51. DETAILED DESCRIPTION

[0032] The utility model will be described in detail below with reference to the accompanying drawings:

[0033] Example: As attached Figures 1 to 10As shown, the airless sprayer includes a handle 1, a knob 2, a liquid outlet interface 3, a power switch 4, a power plug 5, a hopper 6, a housing 7, a motor 8, a gear 9, an eccentric gear 10, a connecting rod 11, a latch 12, a plunger rod 13, a plunger rod screw sleeve 14, a sealing ring assembly 15, a liquid outlet 16, a liquid inlet 17, a liquid inlet valve screw sleeve 18, a liquid inlet valve seat 19, a housing 20, a liquid inlet valve ball 21, a liquid inlet spring 22, a liquid inlet sealing ring 23, a liquid outlet valve seat 24, a liquid outlet valve ball 25, a liquid outlet spring 26, a liquid outlet seal Sealing ring 27, liquid outlet valve sleeve 28, pressure relief valve seat 29, pressure relief valve ball 30, pressure relief valve stem 31, pressure relief sealing ring 32, pressure relief spring 33, gasket 34, pressure relief nut 35, internal serrated lock washer 36, sealing ring 37, gasket 38, pressure protection valve stem 39, pressure regulating spring 40, pressure valve sleeve 41, micro switch 42, hexagon socket screw 43, liquid inlet pipe 44, reflux pipe 45, pressure relief exhaust port 46, spray gun 47, reflux port 48, connecting block 49, liquid outlet cavity 50 and pressure protection valve seat 51.

[0034] Reference Figure 1 , 2 A hopper 6 is fixed on the right side of the shell 7, a plunger pump is arranged in the shell 7 and is located on the side or left and right sides of the hopper 6, a handle 1 is arranged on the top of the shell 7, and a power switch 4 and a power plug 5 are arranged at the lower part of the shell 7.

[0035] like Figure 4 , 7 As shown in Figure 10, the plunger pump includes a housing 20 and a control device, a liquid inlet device, a liquid outlet device, a pressure relief device and a pressure protection device connected to the housing 20. The motor 8 is arranged in the housing 7 and drives the control device to reciprocate up and down in the housing 20 through the transmission mechanism.

[0036] Further, such as Figure 4 As shown, the transmission mechanism includes a gear 9 connected to the shaft end of the motor 8, an eccentric gear 10 meshing with the gear 9 and a connecting rod 11 installed on the eccentric gear 10. The connecting rod 11 is driven by the eccentric gear 10 and reciprocates up and down in the housing 20. The other end of the connecting rod 11 is installed with a connecting block 49 through a latch 12. The connecting block 49 is slotted with the plunger rod 13. Figure 4 , 10 As shown, the control device includes a plunger rod screw sleeve 14 fixed on the housing 20, a plunger rod 13 is relatively slidably arranged in the inner hole of the plunger rod screw sleeve 14, one end of the plunger rod 13 is connected and driven by the connecting rod 11, and the other end of the plunger rod 13 is used to control the opening and closing of the liquid inlet 17, the inner cavity of the housing 20 and the liquid outlet cavity 50. A sealing ring assembly 15 is provided at the end of the plunger rod 13, which can closely fit the inner wall of the plunger rod screw sleeve 14. Driven by the transmission mechanism, the control device can connect the liquid inlet device and the liquid outlet device, thereby controlling the liquid outlet device to discharge liquid.

[0037] Reference Figures 4 to 6 , 10, the liquid inlet device is connected with the liquid outlet 16 opened at the bottom of the hopper 6, and can introduce liquid into the housing 20. The liquid inlet device includes a liquid inlet valve sleeve 18 threadedly connected to the housing 20, a liquid inlet valve seat 19 resting between the liquid inlet valve sleeve 18 and the housing 20, a liquid inlet valve ball 21 matched with the liquid inlet valve seat 19, a liquid inlet sealing ring 23 used to seal the housing 20 and the liquid inlet valve seat 19, and a liquid inlet spring 22 supported on the liquid inlet valve ball 21. The liquid inlet valve sleeve 18 is provided with a liquid inlet 17, and the liquid inlet 17 is connected with the liquid outlet 16 through a liquid inlet pipe 44 to achieve liquid inlet.

[0038] like Figure 2 , 4 As shown in 10, a liquid outlet cavity 50 is provided in the liquid outlet device (liquid outlet valve sleeve 28), and the liquid outlet cavity 50 is externally connected to the spray gun 47 through the liquid outlet interface 3. The liquid outlet device includes a liquid outlet valve sleeve 28 threadedly connected to the shell 20, a liquid outlet valve seat 24 resting between the liquid outlet valve sleeve 28 and the shell 20, a liquid outlet valve ball 25 matched with the liquid outlet valve seat 24, a liquid outlet sealing ring 27 for sealing the shell 20 and the liquid outlet valve sleeve 28, and a liquid outlet spring 26 pressed against the liquid outlet valve ball 25. The liquid outlet interface 3 is provided on the liquid outlet valve sleeve 28, and is connected to the spray gun 47 through a high-pressure hose.

[0039] Reference Fig. 9 , 10 The pressure protection device is connected with the liquid outlet chamber 50 and can maintain the hydraulic pressure in the liquid outlet chamber 50. The pressure protection device includes a pressure valve screw sleeve 41 threadedly connected to the housing 20, a pressure protection valve seat 51 arranged in the housing 20 and connected with the liquid outlet chamber 50, a pressure protection valve stem 39 sliding relative to the pressure protection valve seat 51, and a pressure regulating spring 40 with one end against the pressure valve screw sleeve 41 and the other end against the outer wall of the pressure protection valve stem 39. The pressure protection valve stem 39 penetrates the pressure valve screw sleeve 41 and contacts the micro switch 42. The pressure protection valve stem 39 extends into the outer wall of one end of the pressure protection valve seat 51, and a gasket 38 and a sealing ring 37 are sleeved to realize sliding sealing. A hexagon socket screw 43 is installed on the micro switch 42, and the micro switch 42 controls the motor 8 to work through electrical connection.

[0040] like Figures 5 to 9As shown, one end of the pressure relief device is connected to the liquid outlet chamber 50, and the other end is connected to the reflux port 48 opened at the bottom of the hopper 6. The pressure relief device is controlled by the knob 2 set on the shell 7 to open and close, so as to realize reflux and pressure relief. The pressure relief device includes a pressure relief nut 35 threadedly connected to the shell 20, a pressure relief valve seat 29 installed in the shell 20, a pressure relief valve stem 31 slidably set in the shell 20, a pressure relief valve ball 30 set on the pressure relief valve stem 31 to cooperate with the pressure relief valve seat 29, and a pressure relief sealing ring 32 installed on the outer wall of the pressure relief valve stem 31 and slidingly sealed with the inner wall of the shell 20. A pressure relief spring 33 is supported on the outer wall of the pressure relief valve stem 31, and the other end of the pressure relief spring 33 presses on the gasket 34, which is installed on the pressure relief valve stem 31. Between the nut 35 and the shell 20, an inner serrated locking washer 36 that cooperates with the end face of the pressure relief nut 35 is provided at the end of the pressure relief valve stem 31 away from the pressure relief valve seat 29; the tail end of the pressure relief valve stem 31 is provided with a knob 2 that extends out of the outer shell 7, the pressure relief valve seat 29 is provided with an inner hole that is connected to the liquid outlet cavity 50, and the valve cavity formed between the pressure relief valve seat 29 and the pressure relief valve stem 31 is connected to the pressure relief exhaust port 46 opened on the shell 20, and the pressure relief exhaust port 46 is connected to the reflux port 48 through the reflux pipe 45 to achieve pressure relief, exhaust and paint reflux.

[0041] Preferably, the liquid inlet valve, the liquid outlet valve and the pressure relief valve are all provided with valve balls, which can cooperate with the corresponding valve seats to act as a one-way valve to ensure that the liquid does not flow in the reverse direction.

[0042] The working process of the utility model is as follows: when working, add liquid material into the hopper 6, connect the power plug 5 and turn on the power switch 4, the plunger rod 13 is driven by the motor 8 to make up and down reciprocating motion, control the liquid inlet device of the plunger pump to communicate with the liquid outlet device (i.e. the inner cavity of the shell 20 and the liquid outlet cavity 50), the liquid material enters the plunger pump more easily through the liquid inlet pipe 44, and reduces the suction requirement of the liquid inlet. The liquid material enters the spray gun 47 from the liquid outlet interface 3, and the spray gun 47 can be sprayed by pressing it. After the spraying is completed, turn the knob 2, and under the action of the pressure relief device, the liquid material is depressurized and flows back from the reflux pipe 45 to the reflux port 48 of the hopper 6 to avoid waste.

[0043] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and the concept of the utility model should fall within the protection scope of the claims attached to the utility model.

Claims

1. An airless sprayer, characterized in that: include: A housing (7), a hopper (6) being fixed on one side of the housing (7); A plunger pump is arranged in a housing (7), the plunger pump comprising a housing (20) and a control device, a liquid inlet device, a liquid outlet device, a pressure relief device and a pressure protection device connected to the housing (20); the liquid inlet device is connected to a liquid outlet (16) provided at the bottom of the hopper (6) to introduce liquid into the housing (20); a liquid outlet cavity (50) is provided in the liquid outlet device, the liquid outlet cavity (50) is externally connected to a spray gun (47) via a liquid outlet interface (3); the control device is used to selectively connect the liquid inlet device with the liquid outlet device, thereby controlling the liquid outlet of the liquid outlet device; the pressure protection device is connected to the liquid outlet cavity (50) to maintain the hydraulic pressure in the liquid outlet cavity (50); one end of the pressure relief device is connected to the liquid outlet cavity (50), and the other end is connected to a reflux port (48) provided at the bottom of the hopper (6); the pressure relief device is controlled to open and close by a knob (2) provided on the housing (7) to achieve reflux and pressure relief; as well as The motor (8) is arranged in the housing (7) and drives the control device to perform reciprocating motion in the housing (20) through a transmission mechanism.

2. The airless sprayer according to claim 1, characterized in that: The transmission mechanism comprises a gear (9) connected to the shaft end of the motor (8), an eccentric gear (10) meshing with the gear (9) for transmission, and a connecting rod (11) mounted on the eccentric gear (10); the connecting rod (11) is driven by the eccentric gear (10) and performs up and down reciprocating motion in the housing (20); the other end of the connecting rod (11) is detachably connected to the control device.

3. The airless sprayer according to claim 2, characterized in that: The control device comprises a plunger rod screw sleeve (14) fixed on a housing (20), a plunger rod (13) being relatively slidably arranged in the inner hole of the plunger rod screw sleeve (14), one end of the plunger rod (13) being connected and driven by a connecting rod (11), and the other end of the plunger rod (13) being used to control the on-off of a liquid inlet (17), an inner cavity of the housing (20) and a liquid outlet cavity (50); a sealing ring assembly (15) is provided at the end of the plunger rod (13) for tightly fitting with the inner wall of the plunger rod screw sleeve (14).

4. The airless sprayer according to claim 3, characterized in that: A connecting block (49) is installed on the connecting rod (11) via a latch pin (12), and the connecting block (49) is slot-matched with the plunger rod (13).

5. The airless sprayer according to claim 1, characterized in that: The liquid inlet device comprises a liquid inlet valve screw sleeve (18) threadedly connected to a housing (20), a liquid inlet valve seat (19) abutting between the liquid inlet valve screw sleeve (18) and the housing (20), a liquid inlet valve ball (21) matched with the liquid inlet valve seat (19), a liquid inlet sealing ring (23) for sealing the housing (20) and the liquid inlet valve seat (19), and a liquid inlet spring (22) abutting against the liquid inlet valve ball (21); a liquid inlet port (17) is provided on the liquid inlet valve screw sleeve (18), and the liquid inlet port (17) is communicated with the liquid outlet (16) through a liquid inlet pipe (44) to achieve liquid inlet.

6. The airless sprayer according to claim 1, characterized in that: The liquid outlet device comprises a liquid outlet valve screw sleeve (28) threadedly connected to a housing (20), a liquid outlet valve seat (24) abutting between the liquid outlet valve screw sleeve (28) and the housing (20), a liquid outlet valve ball (25) matched with the liquid outlet valve seat (24), a liquid outlet sealing ring (27) for sealing the housing (20) and the liquid outlet valve screw sleeve (28), and a liquid outlet spring (26) abutting against the liquid outlet valve ball (25); the liquid outlet interface (3) is provided on the liquid outlet valve screw sleeve (28) and is connected to a spray gun (47) via a high-pressure hose.

7. The airless sprayer according to claim 1, characterized in that: The pressure relief device comprises a pressure relief nut (35) threadedly connected to the housing (20), a pressure relief valve seat (29) installed in the housing (20), a pressure relief valve stem (31) slidably arranged in the housing (20), a pressure relief valve ball (30) arranged on the pressure relief valve stem (31) for cooperating with the pressure relief valve seat (29), and a pressure relief sealing ring (32) installed on the outer wall of the pressure relief valve stem (31) and slidingly sealing with the inner wall of the housing (20), a pressure relief spring (33) is supported on the outer wall of the pressure relief valve stem (31), the other end of the pressure relief spring (33) is pressed against a gasket (34), and the gasket (34) is installed on the pressure relief valve stem (31). An inner serrated locking washer (36) matched with the end surface of the pressure relief nut (35) is arranged between the nut (35) and the housing (20) at one end of the pressure relief valve stem (31) away from the pressure relief valve seat (29); a knob (2) extending out of the housing (7) is arranged at the rear end of the pressure relief valve stem (31); an inner hole is arranged on the pressure relief valve seat (29) and communicates with the liquid outlet cavity (50); a valve cavity formed between the pressure relief valve seat (29) and the pressure relief valve stem (31) is communicated with a pressure relief exhaust port (46) provided on the housing (20); the pressure relief exhaust port (46) is connected to the reflux port (48) via a reflux pipe (45) to achieve pressure relief, exhaust and paint reflux.

8. The airless sprayer according to claim 1, characterized in that: The pressure protection device comprises a pressure valve screw sleeve (41) threadedly connected to a housing (20), a pressure protection valve seat (51) arranged in the housing (20) and connected to a liquid outlet chamber (50), a pressure protection valve stem (39) sliding relative to the pressure protection valve seat (51), and a pressure regulating spring (40) with one end abutting against the pressure valve screw sleeve (41) and the other end abutting against the outer wall of the pressure protection valve stem (39); the pressure protection valve stem (39) penetrates the pressure valve screw sleeve (41) and contacts with a micro switch (42); a gasket (38) and a sealing ring (37) are sleeved on the outer wall of one end of the pressure protection valve stem (39) extending into the pressure protection valve seat (51) to achieve sliding sealing; a hexagon socket screw (43) is installed on the micro switch (42); and the micro switch (42) is used for electrically connecting to a control motor (8).

9. The airless sprayer according to claim 1, characterized in that: The plunger pump is arranged on the side or both sides of the hopper (6), and the housing (7) is provided with a handle (1), a power switch (4) and a power plug (5).

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