Satchel type portable spraying machine
The shoulder bag type portable sprayer addresses the issue of excessive pressure by incorporating a reflux and pressure limiting system to regulate paint pressure, preventing damage to the pressure pump and ensuring stable operation.
Patent Information
- Application Number
- CN202420460445.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2024-12-10
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional spray machines have a single pressure-limiting valve that can fail, leading to excessively high delivery pressure, potentially damaging the pressure motor.
A shoulder bag type portable sprayer with a reflux part and pressure limiting part, including a reflux valve seat, reflux valve pipe, and pressure limiting valve tube, to control and regulate paint pressure, preventing excessive pressure and protecting the pressure pump.
The sprayer effectively controls paint pressure by allowing it to reflux back into the storage pot when excessive, thereby preventing damage to the pressure pump and ensuring stable operation.
Smart Images
Figure CN222132267U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of sprayers, for example, to a shoulder bag type portable sprayer. Background Art
[0002] At present, it is a special coating equipment that uses spraying technology. The paint in the sprayer can be stably transported through the stable pressurization of the sprayer. The pressurized paint can be sprayed out through the nozzle for spraying. The traditional sprayer pressurizes the paint through the pressurization motor and limits the pressure through the pressure limiting valve, thereby preventing the pressure of the sprayer from being too high when outputting the paint.
[0003] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:
[0004] However, the traditional spray machine only has one pressure-limiting valve to control the delivery pressure. When the pressure-limiting valve fails, it is easy to cause the delivery pressure to be too high. When the pressure continues to increase, it is easy to cause damage to the pressure motor. Utility Model Content
[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.
[0006] The disclosed embodiment provides a shoulder bag type portable sprayer to solve the problem that the pressure cannot be controlled when the pressure limiting valve of the sprayer fails.
[0007] In some embodiments, the shoulder bag type portable sprayer includes: a shell; a material storage pot is arranged inside the shell, and the upper end of the material storage pot extends out of the upper part of the shell; a pressure pump is connected to the bottom of the material storage pot, and the bottom of the material storage pot is connected to the pressure pump; a material delivery pipe is connected to the pressure pump, for delivering the paint in the pressure pump; a reflux part is connected to the side wall of the material delivery pipe, and the reflux part is connected to the material storage pot; a pressure limiting part is connected to the side wall of the material delivery pipe.
[0008] In some embodiments, the reflux part includes: a reflux valve seat, which is a tubular structure, and the reflux valve seat is connected to the side wall of the feed pipe, and the reflux valve seat is communicated with the feed pipe; a reflux port, which is arranged on the side wall of the reflux valve seat, and the reflux valve seat is communicated with the reflux port; a reflux valve pipe, which extends into the reflux valve seat, and the reflux valve pipe is threadedly connected to the reflux valve seat, and one end of the reflux valve pipe is blocked on the reflux port to control the opening and closing of the reflux port; a reflux pipe is provided on the side wall of the storage pot, and the reflux pipe is connected to the reflux port, and the reflux pipe extends into the interior of the storage pot to recover the liquid refluxed in the reflux port.
[0009] In some embodiments, the reflux valve tube is a tubular structure, a reflux valve rod is slidably provided inside the reflux valve tube, one end of the reflux valve rod is blocked at one end of the reflux valve tube, a reflux spring is sleeved on the other end of the reflux valve rod, the reflux spring pushes the reflux valve rod to be pressed on the end of the reflux valve rod extending into the reflux valve seat, a reflux hole is provided at the end of the reflux valve tube extending into the reflux valve seat, and the reflux hole is connected to the reflux port.
[0010] In some embodiments, a sealing ring is sleeved on the reflux valve stem, the sealing ring is arranged between the reflux hole and the reflux spring, and the sealing ring is in contact with the inner wall of the reflux valve tube.
[0011] In some embodiments, a threaded sleeve is provided at one end of the return valve tube away from the return valve seat, the threaded sleeve is threadedly connected to the return valve tube, and the threaded sleeve is pressed onto the return spring.
[0012] In some embodiments, an adjusting button is provided on the threaded sleeve, and the adjusting button extends out of the housing.
[0013] In some embodiments, a guide nozzle is provided at the end of the reflux pipe in the material storage pot, the guide nozzle is perpendicular to the side wall of the material storage pot, and the opening of the guide nozzle is arranged toward the side of the material storage pot.
[0014] In some embodiments, the pressure limiting part includes: a pressure limiting valve seat, which is a tubular structure and is connected to the side wall of the feed pipe; a pressure limiting valve tube is inserted into the pressure limiting valve seat, and the pressure limiting valve tube and the pressure limiting valve seat are threadedly connected; a micro switch is arranged at one end of the pressure limiting valve tube away from the pressure limiting valve seat, and the pressure limiting valve tube controls the opening and closing of the micro switch.
[0015] In some embodiments, the pressure-limiting valve tube is a tubular structure, and a pressure-limiting valve needle is slidably provided in the pressure-limiting valve tube, one end of the pressure-limiting valve needle is in close contact with the inner wall of the pressure-limiting valve tube, and the pressure-limiting valve needle is slidably set in the pressure-limiting valve tube, and a pressure-limiting spring is sleeved on the pressure-limiting valve needle, and the pressure-limiting spring pushes the pressure-limiting valve needle to press against the pressure-limiting valve seat, and the other end of the pressure-limiting valve needle extends out of the pressure-limiting valve tube and contacts the micro switch.
[0016] In some embodiments, a pot cover is provided on the upper portion of the material storage pot, a vent hole is provided on the pot cover, and a one-way valve is provided on the vent hole to prevent the paint from discharging from the material storage pot.
[0017] The shoulder bag portable sprayer provided in the embodiment of the present disclosure can achieve the following technical effects:
[0018] The pressure in the feed pipe can be controlled by the reflux part. When the paint pressure in the feed pipe is too high, the reflux port of the reflux part can be opened, so that the paint in the feed pipe can flow back into the material storage pot through the reflux port. In addition, the reflux part can prevent the pressure in the feed pipe from being too high when a failure of the pressure limiting part occurs.
[0019] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:
[0021] Figure 1 It is a structural schematic diagram of a shoulder bag type portable sprayer provided in an embodiment of the present disclosure;
[0022] Figure 2 This is a schematic diagram of the internal structure of a shoulder bag type portable sprayer provided in an embodiment of the present disclosure;
[0023] Figure 3 is a schematic diagram of the structure of a pressure pump provided in an embodiment of the present disclosure;
[0024] Figure 4 It is a schematic diagram of the structure of a material storage pot provided by an embodiment of the present disclosure;
[0025] Figure 5 It is a schematic diagram of the pot cover structure provided by the embodiment of the present disclosure;
[0026] Figure 6 It is a schematic diagram of the structure of a reflux valve pipe provided by an embodiment of the present disclosure;
[0027] Figure 7It is a schematic diagram of the limit valve stem structure provided in an embodiment of the present disclosure.
[0028] Reference numerals:
[0029] 100, shell; 101, storage pot; 102, reflux pipe; 103, guide nozzle; 104, pot cover; 105, vent; 106, one-way valve; 200, pressure pump; 201, feed pipe; 300, reflux valve seat; 301, reflux port; 302, reflux valve pipe; 303, reflux valve stem; 304, reflux spring; 305, reflux hole; 306, sealing ring; 307, threaded sleeve; 308, adjusting button; 400, pressure-limiting valve seat; 401, pressure-limiting valve pipe; 402, micro switch; 403, pressure-limiting valve needle; 404, pressure-limiting spring. DETAILED DESCRIPTION
[0030] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.
[0031] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.
[0032] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.
[0033] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.
[0034] Unless otherwise stated, the term "plurality" means two or more.
[0035] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.
[0036] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.
[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.
[0038] Combination Figure 1-7 As shown, a shoulder bag type portable sprayer provided by an embodiment of the present disclosure includes: a shell 100; a material storage pot 101, which is arranged inside the shell 100, and the upper end of the material storage pot 101 extends out of the upper part of the shell 100; a pressure pump 200, connected to the bottom of the material storage pot 101, and the bottom of the material storage pot 101 is communicated with the pressure pump 200; a feed pipe 201, connected to the pressure pump 200, for conveying the paint in the pressure pump 200; a reflux part, connected to the side wall of the feed pipe 201, and the reflux part is connected to the material storage pot 101; a pressure limiting part, connected to the side wall of the feed pipe 201.
[0039] A shoulder bag type portable sprayer provided by the embodiment of the present disclosure is adopted, the shell 100 can facilitate the carrying of the sprayer, and a shoulder strap is also connected to the shell 100, the shoulder strap can facilitate the user to carry the sprayer, the shell 100 can protect the material storage pot 101 and the pressure pump 200, the material storage pot 101 is arranged in the shell 100, and can store paint, the paint in the material storage pot 101 can be pressurized by the pressure pump 200, and then output by the material delivery pipe 201, and then sprayed by the nozzle, a pressure limiting part is arranged on the upper side wall of the material delivery pipe 201, and the pressure limiting part can pressurize the material delivery pipe 201 01 is limited, which can prevent the paint pressure in the feed pipe 201 from being too high, and prevent the pressure pump 200 from being damaged due to excessive pressure. The pressure limiting unit can control the opening of the pressure pump 200 and the paint pressure in the feed pipe 201. A reflux unit is also provided on the feed pipe 201. When the paint pressure in the feed pipe 201 is too high, the reflux unit can release the pressure in the feed pipe 201 to an appropriate pressure, and the released paint can flow back into the storage pot 101 through the reflux unit. The paint flowing back into the storage pot 101 can also prevent the waste of paint.
[0040] Combination Figure 1-7As shown, optionally, the reflux portion includes: a reflux valve seat 300, which is a tubular structure, and the reflux valve seat 300 is connected to the side wall of the feed pipe 201, and the reflux valve seat 300 is connected to the feed pipe 201; a reflux port 301, which is arranged on the side wall of the reflux valve seat 300, and the reflux valve seat 300 is connected to the reflux port 301; a reflux valve pipe 302, which extends into the reflux valve In the seat 300, the reflux valve tube 302 is threadedly connected to the reflux valve seat 300, and one end of the reflux valve tube 302 is blocked on the reflux port 301 to control the opening and closing of the reflux port 301; the side wall of the storage pot 101 is provided with a reflux pipe 102, and the reflux pipe 102 is connected to the reflux port 301, and the reflux pipe 102 extends into the interior of the storage pot 101, and is used to recover the liquid refluxed in the reflux port 301. In this way, the reflux part includes a reflux valve seat 300, a reflux port 301 and a reflux valve pipe 302. The reflux valve seat 300 is a tubular structure, and the reflux valve pipe 302 is a tubular structure. The reflux valve pipe 302 can be connected to the threaded valve seat by threads, which facilitates the disassembly and installation of the reflux valve pipe 302 and the reflux valve seat 300, and facilitates the subsequent cleaning of the reflux valve pipe 302 and the reflux valve seat 300. The reflux port 301 is arranged on the side wall of the reflux valve seat 300, and the reflux port 301 can be blocked by the reflux valve pipe 302. The opening and closing of the reflux port 301 can be controlled by the reflux valve pipe 302. The opening and closing of the reflux port 301 can be controlled by the reflux valve pipe 302. The paint in the feed pipe 201 is depressurized by controlling the opening and closing of the reflux port 301. While depressurizing, the paint can flow out through the reflux port 301, and then be transported back to the storage pot 101 by the reflux pipe 102 on the reflux port 301.
[0041] Combination Figure 1-7As shown, optionally, the reflux valve tube 302 is a tubular structure, and a reflux valve rod 303 is slidably provided inside the reflux valve tube 302, one end of the reflux valve rod 303 is blocked at one end of the reflux valve tube 302, and a reflux spring 304 is sleeved on the other end of the reflux valve rod 303, and the reflux spring 304 pushes the reflux valve rod 303 to be pressed on the end of the reflux valve rod 303 extending into the reflux valve seat 300, and a reflux hole 305 is provided at the end of the reflux valve tube 302 extending into the reflux valve seat 300, and the reflux hole 305 is connected to the reflux port 301. In this way, the reflux valve tube 302 is a tubular structure and can be conveniently installed on the reflux valve seat 300 through threads. A reflux valve rod 303 is arranged in the reflux valve tube 302, and the reflux valve rod 303 can slide in the reflux valve tube 302. One end of the reflux valve rod 303 can be blocked at the end of the reflux valve tube 302 extending into the reflux valve seat 300. A reflux hole 305 is arranged on the side of the end of the reflux valve tube 302 extending into the reflux valve seat 300. The reflux hole 305 is connected to the reflux port 301. The reflux spring 304 can push the reflux valve rod 303 to block one end of the reflux valve tube 302. The paint can be blocked from entering the reflux valve tube 302. When the paint pressure in the feed pipe 201 is too high, the paint pushes the reflux valve stem 303 to separate the reflux valve stem 303 from one end of the reflux valve tube 302. When the pressure drops to a suitable pressure, the reflux valve stem 303 blocks the reflux valve tube 302 again under the push of the reflux spring 304. The paint entering the reflux valve tube 302 enters the reflux port 301 through the reflux hole 305. In this way, the discharged paint can be returned to the storage pot 101, thereby realizing the function of the reflux valve tube 302 in controlling the pressure in the feed pipe 201.
[0042] Combination Figure 1-7 As shown, optionally, a sealing ring 306 is sleeved on the reflux valve stem 303, and the sealing ring 306 is arranged between the reflux hole 305 and the reflux spring 304, and the sealing ring 306 contacts the inner wall of the reflux valve tube 302. In this way, the sealing ring 306 on the reflux valve stem 303 can make the reflux valve stem 303 and the reflux valve stem 303 sealed and prevent the paint from entering the reflux spring 304 in the reflux valve tube 302.
[0043] Combination Figure 1-7As shown, optionally, a threaded sleeve 307 is provided at one end of the return valve tube 302 away from the return valve seat 300, and the threaded sleeve 307 is threadedly connected to the return valve tube 302, and the threaded sleeve 307 is pressed on the return spring 304. In this way, a threaded sleeve 307 is sleeved at one end of the return valve tube 302 away from the return valve seat 300, and the threaded sleeve 307 is threadedly connected to the return valve tube 302, and the threaded sleeve 307 can be pressed on the return spring 304, and the pressing force of the return spring 304 can be adjusted by rotating the threaded sleeve 307. By adjusting the pressing force of the return spring 304, the pressure of the paint in the conveying pipe 201 to push open the return valve stem 303 can be controlled, thereby controlling the pressure of the paint reflux in the conveying pipe.
[0044] Combination Figure 1-7 As shown, optionally, the threaded sleeve 307 is provided with an adjusting button 308, and the adjusting button 308 extends out of the housing 100. In this way, the adjusting button 308 on the threaded sleeve 307 can facilitate the rotation of the threaded sleeve 307, facilitate the pressing force of the threaded sleeve 307 on the return spring 304, and the extension of the adjusting button 308 can facilitate the pressure of the paint return.
[0045] Combination Figure 1-7 As shown, optionally, a guide nozzle 103 is provided at the end of the reflux pipe 102 in the material storage pot 101, and the guide nozzle 103 is perpendicular to the side wall of the material storage pot 101, and the opening of the guide nozzle 103 is arranged toward the side of the material storage pot 101. In this way, the guide nozzle 103 is installed on the reflux pipe 102 in the material storage pot 101, and the guide nozzle 103 is arranged toward the side wall of the material storage pot 101. When the paint flows back to the material storage pot 101 from the reflux pipe 102, the paint is sprayed out by the guide nozzle 103. Since the pressure of the sprayed paint is relatively high, it is easy to spray onto the cover of the material storage pot 101 or directly spray out of the material storage pot 101. By changing the tilt direction of the guide nozzle 103, the paint can be sprayed onto the side wall or bottom of the material storage pot 101, so that the splashing of the paint can be prevented.
[0046] Combination Figure 1-7As shown, optionally, the pressure limiting part includes: a pressure limiting valve seat 400, which is a tubular structure, and the pressure limiting valve seat 400 is connected to the side wall of the feeding pipe 201; a pressure limiting valve tube 401, which is inserted into the pressure limiting valve seat 400, and the pressure limiting valve tube 401 and the pressure limiting valve seat 400 are threadedly connected; a micro switch 402, which is arranged at one end of the pressure limiting valve tube 401 away from the pressure limiting valve seat 400, and the pressure limiting valve tube 401 controls the opening and closing of the micro switch 402. In this way, the pressure limiting part includes a pressure limiting valve seat 400, a pressure limiting valve tube 401 and a micro switch 402. The pressure limiting valve seat 400 is connected to the feed pipe 201. The pressure limiting valve seat 400 and the pressure limiting valve tube 401 are both tubular structures, so that the pressure limiting valve tube 401 can be conveniently connected to the pressure limiting valve seat 400 by threads. The other end of the pressure limiting valve tube 401 is provided with a micro switch 402. When the pressure in the feed pipe 201 is too high, the paint pushes the pressure limiting valve tube 401 to move, and the pressure limiting valve tube 401 presses on the micro switch 402 to close the switch. Closing the micro switch 402 will turn off the pressure pump 200 and stop pressurizing the feed pipe 201, thereby ensuring the pressure stability in the feed pipe 201.
[0047] Combination Figure 1-7 As shown, optionally, the pressure-limiting valve tube 401 is a tubular structure, and a pressure-limiting valve needle 403 is slidably provided in the pressure-limiting valve tube 401, one end of the pressure-limiting valve needle 403 is in close contact with the inner wall of the pressure-limiting valve tube 401, and the pressure-limiting valve needle 403 is slidably set in the pressure-limiting valve tube 401, and a pressure-limiting spring 404 is sleeved on the pressure-limiting valve needle 403, and the pressure-limiting spring 404 pushes the pressure-limiting valve needle 403 to press against the pressure-limiting valve seat 400, and the other end of the pressure-limiting valve needle 403 extends out of the pressure-limiting valve tube 401 and contacts the micro switch 402. In this way, the limit valve tube is a tubular structure that can be easily connected to the pressure limiting valve seat 400. A pressure limiting valve needle 403 is slidably provided in the pressure limiting valve tube 401. One end of the pressure limiting valve needle 403 is tightly connected to the inner wall of the pressure limiting valve tube 401. The pressure limiting spring 404 is pressed on the pressure limiting valve needle 403, so that the pressure limiting valve needle 403 is pressed on the pressure limiting valve seat 400. When the paint pressure in the feed pipe 201 is too high, the paint in the feed pipe 201 can push the pressure limiting valve needle 403 to move, and the other end of the pressure limiting valve needle 403 presses on the micro switch 402 to close the micro switch 402. In this way, the pressure pump 200 can be turned off to prevent the pressure in the feed pipe 201 from being too high.
[0048] Combination Figure 1-7As shown, optionally, a pot cover 104 is provided on the upper part of the material storage pot 101, and a vent hole 105 is provided on the pot cover 104, and a one-way valve 106 is provided on the vent hole 105 to prevent the paint from being discharged from the material storage pot 101. In this way, the pot cover 104 on the material storage pot 101 can prevent the paint in the material storage pot 101 from overflowing, and the vent hole 105 on the pot cover 104 allows air to enter, which can prevent the pressure pump 200 from extracting paint and causing the air pressure in the material storage pot 101 to decrease, and the one-way valve 106 at the bottom of the vent hole 105 can prevent the paint from flowing out of the vent hole 105.
[0049] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims
1. A shoulder bag type portable sprayer, characterized in that: include: Housing (100); A material storage pot (101) is arranged inside the shell (100), and the upper end of the material storage pot (101) extends out of the upper part of the shell (100); A pressure pump (200) is connected to the bottom of the material storage pot (101), and the bottom of the material storage pot (101) is in communication with the pressure pump (200); A material delivery pipe (201), connected to the pressure pump (200), and used for delivering the paint in the pressure pump (200); A reflux portion connected to the side wall of the material delivery pipe (201), and the reflux portion is in communication with the material storage pot (101); The pressure limiting part is connected to the side wall of the material conveying pipe (201).
2. A shoulder bag type portable sprayer according to claim 1, characterized in that: The reflux portion comprises: A reflux valve seat (300), the reflux valve seat (300) being a tubular structure, and the reflux valve seat (300) being connected to a side wall of the material conveying pipe (201), and the reflux valve seat and the material conveying pipe (201) being in communication; A reflux port (301) is arranged on a side wall of the reflux valve seat (300), and the reflux valve seat (300) is in communication with the reflux port (301); A reflux valve tube (302) extends into the reflux valve seat (300), the reflux valve tube (302) and the reflux valve seat (300) are threadedly connected, and one end of the reflux valve tube (302) is blocked on the reflux port (301) to control the opening and closing of the reflux port (301); The side wall of the material storage pot (101) is provided with a reflux pipe (102), the reflux pipe (102) is connected to the reflux port (301), and the reflux pipe (102) extends into the interior of the material storage pot (101) and is used to recover the liquid refluxed in the reflux port (301).
3. A shoulder bag type portable sprayer according to claim 2, characterized in that: The return valve tube (302) is a tubular structure. A return valve rod (303) is slidably arranged inside the return valve tube (302). One end of the return valve rod (303) is blocked at one end of the return valve tube (302). A return spring (304) is sleeved on the other end of the return valve rod (303). The return spring (304) pushes the return valve rod (303) to be pressed against one end of the return valve rod (303) extending into the return valve seat (300). A return hole (305) is arranged at one end of the return valve tube (302) extending into the return valve seat (300). The return hole (305) is communicated with the return port (301).
4. A shoulder bag type portable sprayer according to claim 3, characterized in that: The return valve stem (303) is sleeved with a sealing ring (306), the sealing ring (306) is arranged between the return hole (305) and the return spring (304), and the sealing ring (306) is in contact with the inner wall of the return valve tube (302).
5. A shoulder bag type portable sprayer according to claim 4, characterized in that: A threaded sleeve (307) is provided at one end of the return valve tube (302) away from the return valve seat (300), the threaded sleeve (307) is threadedly connected to the return valve tube (302), and the threaded sleeve (307) is pressed onto the return spring (304).
6. A shoulder bag type portable sprayer according to claim 5, characterized in that: The threaded sleeve (307) is provided with an adjusting button (308), and the adjusting button (308) extends out of the housing (100).
7. A shoulder bag type portable sprayer according to claim 2, characterized in that: A flow guide nozzle (103) is provided at the end of the return pipe (102) in the material storage pot (101); the flow guide nozzle (103) is perpendicular to the side wall of the material storage pot (101); and the opening of the flow guide nozzle (103) is arranged toward the side of the material storage pot (101).
8. A shoulder bag type portable sprayer according to claim 1, characterized in that: The pressure limiting unit comprises: A pressure-limiting valve seat (400), wherein the pressure-limiting valve seat (400) is a tubular structure, and the pressure-limiting valve seat (400) is connected to the side wall of the material conveying pipe (201); A pressure-limiting valve tube (401) is inserted into the pressure-limiting valve seat (400), and the pressure-limiting valve tube (401) and the pressure-limiting valve seat (400) are threadedly connected; The micro switch (402) is arranged at one end of the pressure limiting valve tube (401) away from the pressure limiting valve seat (400), and the pressure limiting valve tube (401) controls the opening and closing of the micro switch (402).
9. A shoulder bag type portable sprayer according to claim 8, characterized in that: The pressure-limiting valve tube (401) is a tubular structure, and a pressure-limiting valve needle (403) is slidably arranged inside the pressure-limiting valve tube (401), one end of the pressure-limiting valve needle (403) is in close contact with the inner wall of the pressure-limiting valve tube (401), and the pressure-limiting valve needle (403) is slidably arranged inside the pressure-limiting valve tube (401), and a pressure-limiting spring (404) is sleeved on the pressure-limiting valve needle (403), and the pressure-limiting spring (404) pushes the pressure-limiting valve needle (403) to press against the pressure-limiting valve seat (400), and the other end of the pressure-limiting valve needle (403) extends out of the pressure-limiting valve tube (401) and contacts the micro switch (402).
10. The shoulder bag type portable sprayer according to claim 1, characterized in that: The upper part of the material storage pot (101) is provided with a pot cover (104), the pot cover (104) is provided with a vent hole (105), and the vent hole (105) is provided with a one-way valve (106) for preventing the paint from being discharged from the material storage pot (101).