Negative pressure spray coater and method thereof

Abstract

The application discloses a negative pressure type spraying machine and a method thereof, which are used for spraying material liquid. The negative pressure type spraying machine comprises a machine body, a plunger pump, a power supply device and a liquid storage bag. The liquid storage bag comprises a soft bag body for containing the material liquid and a liquid supply interface arranged on the soft bag body. The liquid supply interface of the liquid storage bag is adapted to be communicated with a liquid inlet of the plunger pump. When the plunger pump is in a negative pressure working state, a negative pressure is formed in the plunger pump, the material liquid is negatively pressure-sucked from the liquid storage bag, the soft bag body of the liquid storage bag is deflated due to the negative pressure suction of the material liquid, and when the plunger pump is in a positive pressure working state, a positive pressure is formed in the plunger pump, the positively pressure-sucked material liquid is pressurized, and the pressurized material liquid is sprayed from a liquid outlet of the plunger pump through a high-pressure atomizing nozzle, which helps to improve the spraying quality and the spraying efficiency.

Description

Technical Field

[0001] This invention relates to the field of spraying technology, and in particular to a negative pressure spraying machine and method thereof. Background Technology

[0002] In existing technologies, the spraying of liquid coatings or latex paints typically uses compressed air spraying instead of traditional roller or brush coating processes. However, this method suffers from poor spray quality and low efficiency because the compressed air contains impurities such as water and oil, resulting in spots or bubbles on the sprayed surface. High-pressure airless sprayers have emerged on the market, typically using a booster pump to pressurize the paint, which is then sprayed through very fine nozzles to form a fan-shaped mist. While this type of airless sprayer solves the problems of gas sprayers, the air pressure inside the storage bottle decreases with the use of the liquid, making it difficult to draw the liquid into the pump. Therefore, balancing holes are often added to the storage bottle to allow external air to enter and balance the internal and external air pressure, ensuring that the internal pressure of the storage bottle always equals the external atmospheric pressure. However, these balancing holes are prone to spillage and contamination, and are also easily clogged by liquid, thus losing their pressure-balancing function.

[0003] Furthermore, since the added plunger pump is generally installed above the storage bottle and draws the paint into the pump through a suction tube extending into the bottom of the bottle, on the one hand, the plunger pump requires a large suction force to overcome the weight of the paint itself, which consumes a lot of electrical energy and affects work efficiency; on the other hand, if the spraying angle of the airless sprayer is too large during use, the paint in the storage bottle will accumulate at the bottle opening, exposing the suction tube at the bottom of the bottle to the paint. This prevents the paint in the storage bottle from being continuously drawn into the pump, thus mixing in air and causing the sprayed paint to be intermittent, resulting in poor spraying quality and low spraying efficiency. In other words, due to the limitation of the spraying angle, the existing airless sprayer is only suitable for spraying vertical surfaces such as walls, and not suitable for spraying horizontal surfaces such as ceilings or floors.

[0004] In particular, when the liquid in the reservoir is low, existing airless sprayers can introduce air during the liquid intake process, resulting in intermittent spraying and severely impacting coating quality. To maintain quality, workers often add liquid or replace the reservoir when only a small amount remains, reducing efficiency and increasing costs. Furthermore, viscous liquid tends to adhere to the reservoir's inner wall, hindering its utilization and wasting resources. Additionally, the existing airless sprayer's suction pipe causes significant paint dripping after the reservoir is opened, polluting the work environment. Summary of the Invention

[0005] One advantage of this invention is that it provides a negative pressure spraying machine and method, which can improve spraying quality and increase spraying efficiency.

[0006] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine can use a liquid storage bag to supply liquid so as to perform negative pressure liquid suction and reduce power loss.

[0007] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine can utilize the liquid storage bag to achieve airless liquid supply, so as to avoid air mixing into the liquid and help improve the spraying quality.

[0008] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the soft bag of the liquid storage bag in the negative pressure spraying machine can collapse as the liquid inside the bag is sucked out by negative pressure, so as to avoid air mixing into the liquid and help to achieve uniform spraying of the liquid.

[0009] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof. In one embodiment of the present invention, the negative pressure spraying machine can automatically squeeze the soft bag of the liquid storage bag by using external atmospheric pressure during the spraying process, so that the liquid adhering to the inner wall of the bag gathers near the liquid supply port of the liquid storage bag, which facilitates full utilization of the liquid and avoids waste of resources.

[0010] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine can widen the spraying angle to a certain extent, which facilitates high-quality spraying of various surfaces such as walls, ceilings or base plates, without worrying about the spraying quality being affected by intermittent spraying.

[0011] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the invention, the negative pressure spraying machine can fully draw liquid from the liquid storage bag without using a suction tube, which helps to simplify the structure and reduce costs.

[0012] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine can fully draw liquid from the liquid storage bag without using a suction tube, thereby preventing dripping and contamination of the working environment when adding liquid paint.

[0013] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine can use the weight of the liquid material to assist in the liquid supply, so that the plunger pump only needs a small suction force to complete the material suction, which helps to reduce power consumption.

[0014] Another advantage of the present invention is that it provides a negative pressure spraying machine and method thereof, wherein, in one embodiment of the present invention, the negative pressure spraying machine does not require the use of a liquid storage bag to support the machine body or balance the center of gravity, which helps to make it stand stably by means of the handle whether or not a liquid storage bag is present.

[0015] Another advantage of this invention is that it provides a negative pressure spraying machine and method, wherein, to achieve the aforementioned advantages, complex structures or designs are not required. Therefore, this invention successfully and effectively provides a solution that not only offers a simple negative pressure spraying machine and method, but also increases the practicality and reliability of the negative pressure spraying machine and method.

[0016] To achieve at least one of the above advantages or other advantages and objectives, the present invention provides a negative pressure spraying machine for spraying paint liquid, wherein the negative pressure spraying machine comprises:

[0017] Organism;

[0018] A plunger pump, wherein the plunger pump is disposed in the machine body, and the plunger pump has a negative pressure operating state and a positive pressure operating state;

[0019] A power supply device, wherein the power supply device is disposed in the machine body and is energically connected to the plunger pump for supplying power to the plunger pump to enable the plunger pump to reciprocate between the negative pressure operating state and the positive pressure operating state; and

[0020] A liquid storage bag, wherein the liquid storage bag includes a flexible bag body for containing the liquid and a liquid supply port disposed on the flexible bag body, and the liquid supply port of the liquid storage bag is adapted to communicate with the liquid inlet of the plunger pump, wherein when the plunger pump is in the negative pressure operating state, a negative pressure is formed inside the plunger pump to draw the liquid out from the liquid storage bag, causing the flexible bag body of the liquid storage bag to collapse due to the liquid being drawn out by the negative pressure, and when the plunger pump is in the positive pressure operating state, a positive pressure is formed inside the plunger pump to pressurize the liquid drawn out by the negative pressure, causing the pressurized liquid to flow out from the liquid outlet of the plunger pump.

[0021] According to one embodiment of this application, the soft bag body of the liquid storage bag is made of a flexible material.

[0022] According to one embodiment of this application, the soft bag body of the liquid storage bag is formed by heat sealing two pieces of plastic film.

[0023] According to one embodiment of this application, the liquid storage bag is detachably installed on the machine body, and the liquid supply port of the liquid storage bag is directly connected to the liquid inlet of the plunger pump.

[0024] According to one embodiment of this application, the liquid storage bag further includes a bag opening and a bag cap disposed on the soft bag body, wherein the bag cap is detachably sealed to the bag opening.

[0025] According to one embodiment of this application, the liquid storage bag further includes a locking member disposed on the soft bag body, and the body includes a mating member that matches the locking member, wherein the locking member of the liquid storage bag is locked to the mating member of the body.

[0026] According to one embodiment of this application, the reservoir bag is located above the plunger pump.

[0027] According to one embodiment of this application, the liquid supply port of the liquid storage bag is located at the lower part of the soft bag body, and the liquid inlet of the plunger pump is located at the upper part of the plunger pump body.

[0028] According to one embodiment of this application, the negative pressure spraying machine further includes a liquid inlet pipe, wherein one end of the liquid inlet pipe is connected to the liquid supply port of the liquid storage bag, and the other end of the liquid inlet pipe is connected to the liquid inlet of the plunger pump.

[0029] According to one embodiment of this application, the body includes a housing, a handle extending downward from the housing, and a switch assembly disposed on the handle, wherein the plunger pump is disposed within the housing, and the liquid storage bag is mounted on the housing, wherein the power supply device is disposed on the handle, and the switch assembly is controllably connected to the plunger pump for manually controlling the opening and closing of the plunger pump.

[0030] According to one embodiment of this application, the body further includes a pressure relief assembly for relieving pressure on the plunger pump.

[0031] According to one embodiment of this application, the pressure relief assembly includes a pressure relief valve disposed at the pressure relief port of the plunger pump and a pressure relief channel for connecting the return port of the liquid storage bag and the pressure relief port of the plunger pump, wherein the pressure relief valve of the pressure relief assembly is used to open or block the pressure relief port of the plunger pump.

[0032] According to one embodiment of this application, the pressure relief assembly further includes a pressure relief valve trigger for controlling the opening and closing of the pressure relief valve, wherein the pressure relief valve trigger is movably disposed in the housing, and the pressure relief valve trigger is driven to move to a first position, a second position, and a third position, wherein when the pressure relief valve trigger is moved to the first position, the pressure relief valve trigger controls the pressure relief valve to block the pressure relief port of the plunger pump; when the pressure relief valve trigger is moved to the second position, the pressure relief valve trigger controls the pressure relief valve to open the pressure relief port of the plunger pump; and when the pressure relief valve trigger is moved to the third position, the pressure relief valve trigger, while controlling the pressure relief valve to open the pressure relief port of the plunger pump, simultaneously actuates the switching assembly to start the plunger pump.

[0033] According to one embodiment of this application, the plunger pump includes a motor energically connected to the power supply device, a pump body disposed in the machine body, a plunger rod movably disposed in the pump body, and a transmission mechanism tractably connected to the motor and the plunger rod.

[0034] According to one embodiment of this application, the negative pressure spraying machine further includes a nozzle assembly, wherein the nozzle assembly is correspondingly disposed at the liquid outlet of the plunger pump for dispersing the liquid flowing out of the liquid outlet of the plunger pump into a mist.

[0035] According to one embodiment of this application, the negative pressure spraying machine further includes a lighting device, wherein the lighting device is disposed on the machine body for emitting illumination light to illuminate the spraying area.

[0036] According to one embodiment of this application, the negative pressure spraying machine further includes an energy storage component, wherein the energy storage component is correspondingly disposed at the outlet of the plunger pump, and the energy storage component has an energy storage state and an energy release state, wherein when the plunger pump is in the positive pressure operating state, the energy storage component is in the energy storage state, such that a portion of the liquid flowing out from the outlet of the plunger pump is accumulated in the energy storage component, and another portion is sprayed out; when the plunger pump is in the negative pressure operating state, the energy storage component is in the energy release state, such that the liquid accumulated in the energy storage component is released and sprayed out.

[0037] According to one embodiment of this application, the energy storage component is a polyurethane tube or an expansion tube.

[0038] According to another aspect of the present invention, the present invention also provides an airless liquid supply method for a negative pressure sprayer, comprising the steps of:

[0039] When the plunger pump of the negative pressure sprayer is in negative pressure operation, liquid is drawn from the soft bag of the liquid storage bag into the pump body of the plunger pump under negative pressure; and

[0040] Under the action of external atmospheric pressure, the soft bag is squeezed and collapses as the liquid is drawn out by negative pressure, so that the air pressure inside and outside the storage bag is kept in balance.

[0041] According to another aspect of the present invention, the present invention also provides a negative pressure spraying method, comprising the steps of:

[0042] Start the plunger pump of the negative pressure sprayer to switch the plunger pump back and forth between negative pressure and positive pressure working states;

[0043] When the plunger pump is in the negative pressure operating state, liquid is negatively drawn from the soft bag of the liquid storage bag of the negative pressure sprayer into the pump body of the plunger pump, causing the soft bag to deflate as the liquid is drawn out under negative pressure; and

[0044] When the plunger pump is in the positive pressure working state, the liquid that is drawn out by the negative pressure is pressurized and sprayed out from the outlet of the plunger pump.

[0045] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings.

[0046] These and other objects, features and advantages of the present invention will be fully realized through the following detailed description, drawings and claims. Attached Figure Description

[0047] Figure 1 This is a front view schematic diagram of a negative pressure spraying machine according to an embodiment of the present invention.

[0048] Figure 2 An exploded schematic diagram of the negative pressure spraying machine according to the above embodiment of the present invention is shown.

[0049] Figure 3 A bottom view schematic diagram of the liquid storage bag in the negative pressure sprayer according to the above embodiment of the present invention is shown.

[0050] Figure 4 A partial cross-sectional schematic diagram of the liquid storage bag according to the above embodiment of the present invention is shown.

[0051] Figure 5 and Figure 6 A schematic diagram of the negative pressure spraying machine according to the above embodiment of the present invention is shown.

[0052] Figure 7 A schematic diagram is shown of the plunger pump in the negative pressure working state of the negative pressure spraying machine according to the above embodiment of the present invention.

[0053] Figure 8 A schematic diagram is shown of the plunger pump in the positive pressure working state of the negative pressure sprayer according to the above embodiment of the present invention.

[0054] Figure 9 A schematic diagram of the state of the pressure relief assembly in the negative pressure spraying machine according to the above embodiment of the present invention is shown.

[0055] Figure 10 A first example of an energy storage component in a negative pressure sprayer according to the above embodiments of the present invention is shown.

[0056] Figure 11 A second example of an energy storage component in the negative pressure sprayer according to the above embodiments of the present invention is shown.

[0057] Figure 12 A modified embodiment of the negative pressure spraying machine according to the above-described embodiment of the present invention is shown.

[0058] Figure 13 This is a schematic flowchart of an airless liquid supply method for a negative pressure sprayer according to an embodiment of the present invention.

[0059] Figure 14 This is a schematic flowchart of a negative pressure spraying method according to an embodiment of the present invention. Detailed Implementation

[0060] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0061] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0062] In this invention, the term "a" in the claims and specification should be understood as "one or more," that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple. Unless explicitly indicated in the disclosure of this invention that the number of the element is only one, the term "a" should not be construed as unique or single, and the term "a" should not be construed as a limitation on the quantity.

[0063] In the description of this invention, it should be understood that terms such as "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, terms such as "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through a medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] Application Overview

[0066] As described in the background section, in existing technologies, the spraying of liquid coatings or latex paints typically uses compressed air spraying instead of traditional roller or brush coating processes. However, this method suffers from poor spraying quality and low efficiency because the compressed air contains impurities such as water and oil, resulting in spots or bubbles on the sprayed surface. Currently, high-pressure airless sprayers are available on the market. These typically use a booster pump to pressurize the paint, which is then sprayed through very fine nozzles on the sprayer, forming a fan-shaped mist. While this type of airless sprayer solves the problems associated with gas sprayers, the air pressure in the storage bottle decreases as the liquid is used, making it difficult for the liquid to be drawn into the pump. Furthermore, to facilitate the suction of the liquid material into the pump, a balance hole must be made in the storage bottle. This allows external air to enter the storage bottle while the liquid is being suctioned out, balancing the air pressure inside and outside the bottle. Existing sprayers all employ air-exchange feeding, but this method easily introduces air during liquid suction, especially when the liquid level in the storage bottle is low or the spray angle is too large, causing intermittent spraying and severely affecting the spraying quality. Therefore, to solve this technical problem, this application provides a negative pressure sprayer and method that enables airless liquid supply, preventing air from being introduced during negative pressure suction, thus improving spraying quality and increasing spraying efficiency.

[0067] Specifically, the technical concept of this application breaks away from the traditional use of rigid storage bottles for material supply and spraying. Instead, it creatively conceives of using a storage bag to achieve airless liquid supply. In other words, the storage bag in the continuous spraying machine of this application collapses due to its soft bag body being sucked out by the negative pressure of the liquid inside the bag. During the entire liquid supply process, external air will not and cannot enter the bag, completely avoiding the mixing of air into the liquid when it is sucked out by negative pressure, preventing intermittent spraying, and helping to improve spraying quality and increase spraying efficiency.

[0068] Based on this, this application provides a negative pressure spraying machine suitable for spraying liquid coatings, comprising: a machine body; a plunger pump, wherein the plunger pump is disposed in the machine body and has a negative pressure state and a positive pressure state; a power supply device, wherein the power supply device is disposed in the machine body and is used to provide electrical energy to the plunger pump, causing the plunger pump to operate to reciprocate between the negative pressure state and the positive pressure state; and a liquid storage bag, wherein the liquid storage bag includes a flexible bag body for containing the liquid coating and a... A liquid supply port is provided in the soft bag body, and the liquid supply port of the liquid storage bag is adapted to communicate with the liquid inlet of the plunger pump. When the plunger pump is in the negative pressure state, the plunger pump is used to draw out the liquid from the liquid storage bag under negative pressure, so that the soft bag body of the liquid storage bag collapses due to the liquid being drawn out under negative pressure. When the plunger pump is in the positive pressure state, the plunger pump is used to pressurize the liquid drawn out under negative pressure, so that the pressurized liquid is ejected through the liquid outlet of the plunger pump.

[0069] illustrative examples

[0070] Referring to the accompanying drawings of this invention Figures 1 to 11 An embodiment of the present invention provides a negative pressure spraying machine 1 suitable for spraying paint liquid, wherein the negative pressure spraying machine 1 may include a machine body 10, a plunger pump 20, a power supply device 30, and a liquid storage bag 40. The plunger pump 20 is disposed on the machine body 10 and has a negative pressure operating state 2001 and a positive pressure operating state 2002. The power supply device 30 is disposed on the machine body 10 and is electrically connected to the plunger pump 20 for supplying power to the plunger pump 20 so that the plunger pump 20 reciprocates between the negative pressure operating state 2001 and the positive pressure operating state 2002. The liquid storage bag 40 includes a soft bag body 41 for containing the liquid and a liquid supply port 42 disposed on the soft bag body 41, and the liquid supply port 42 of the liquid storage bag 40 is adapted to communicate with the liquid inlet 201 of the plunger pump 20. Thus, when the plunger pump 20 is in the negative pressure working state 2001, a negative pressure is formed inside the plunger pump 20, so that while the liquid is being drawn out from the liquid storage bag 40 under negative pressure, the soft bag body 41 of the liquid storage bag 40 will collapse due to the liquid being drawn out under negative pressure; while when the plunger pump 20 is in the positive pressure state, a positive pressure is formed inside the plunger pump 20, so that the liquid being drawn out under negative pressure is pressurized, and the pressurized liquid flows out through the liquid outlet 202 of the plunger pump 20.

[0071] It is worth noting that, such as Figures 3 to 6 As shown, the flexible bag body 41 of the liquid storage bag 40 can be made of a flexible material to ensure that while the liquid stored in the liquid storage bag 40 is being drawn out by the plunger pump 20 under negative pressure, the flexible bag body 41 of the liquid storage bag 40 will deform and deflate under the action of external atmospheric pressure. In this way, without the need for external air to enter the liquid storage bag 40, the liquid storage bag 40 can maintain the pressure balance inside and outside the bag. This not only does not hinder the plunger pump 20 from drawing out the liquid from the liquid storage bag 40 under negative pressure, but also completely prevents air from mixing into the liquid drawn out under negative pressure, thus preventing intermittent spraying.

[0072] Furthermore, since the sprayed liquid is usually highly viscous, a large amount of liquid often adheres to the inner wall of existing storage bottles and cannot be sucked out for use, resulting in significant waste and difficulty in cleaning. While the inner wall of the liquid storage bag 40 in the negative pressure sprayer 1 of this application also has liquid adhering to it, as the liquid is sucked out by negative pressure, the external atmospheric pressure acts on the outer wall of the liquid storage bag 40, squeezing the soft bag body 41 until it collapses. This causes the liquid adhering to the inner wall of the liquid storage bag 40 to be squeezed by the soft bag body 41 and gather towards the liquid supply port 42, facilitating full utilization of the liquid and avoiding waste.

[0073] Specifically, according to the above embodiments of this application, such as Figure 3 and Figure 4 As shown, the flexible bag body 41 of the liquid storage bag 40 can be, but is not limited to, formed by heat-sealing two pieces of plastic film, which has a simple manufacturing process and low manufacturing cost. Thus, when not filled with liquid, the flexible bag body 41 of the liquid storage bag 40 is sheet-like, making it easy to carry; however, when filled with liquid, the flexible bag body 41 of the liquid storage bag 40 expands to store a larger amount of liquid; subsequently, during the negative pressure extraction of liquid, the flexible bag body 41 of the liquid storage bag 40 deflates to maintain pressure balance inside and outside the bag while preventing air from entering, until the liquid is completely extracted and the bag becomes sheet-like again. It is understood that the flexible material used to prepare the flexible bag body 41 can be, but is not limited to, polymeric materials such as resin or fiber, composite materials, or other materials that can be made into films; this application will not elaborate further on this.

[0074] More specifically, such as Figure 5 and Figure 6 As shown, the liquid storage bag 40 is disposed on the body 10, and the liquid supply interface 42 of the liquid storage bag 40 is directly connected to the liquid inlet 201 of the plunger pump 20, so as to supply airless liquid to the plunger pump 20 through the liquid storage bag 40.

[0075] In one example of this application, such as Figure 2 As shown, the liquid storage bag 40 is detachably installed on the machine body 10, and the liquid supply interface 42 of the liquid storage bag 40 is detachably connected to the liquid supply port 201 of the plunger pump 20, so as to disassemble and install the liquid storage bag 40. This facilitates the replacement of the liquid storage bag 40 containing different liquids as needed, and expands the application scenarios of the negative pressure spraying machine 1, such as spraying waterproofing or paint, etc.

[0076] Preferably, such as Figure 4As shown, the liquid storage bag 40 further includes a bag opening 43 and a bag cap 44 disposed on the flexible bag body 41, wherein the bag cap 44 is adapted to be detachably sealed to the bag opening 43 so that new liquid can be filled into the flexible bag body 41 through the bag opening 43 without disassembling the liquid storage bag 40, facilitating the reuse of the liquid storage bag 40 and saving resources. Of course, in other examples of this application, even if the liquid storage bag 40 is not detachable from the machine body 10, different liquids can still be replaced through the bag opening 43 so that the negative pressure spraying machine 1 can adapt to different application scenarios. It is understood that the bag cap 44 may be, but is not limited to, screwed to the bag opening 43 of the liquid storage bag 40.

[0077] More preferably, such as Figure 2 and Figure 3 As shown, the liquid storage bag 40 further includes a locking member 45 disposed on the soft bag body 41, and the body 10 includes a mating member 11 that matches the locking member 45, wherein the locking member 45 of the liquid storage bag 40 is locked to the mating member 11 of the body 10 to detachably install the liquid storage bag 40 onto the body 10.

[0078] Most preferably, the liquid storage bag 40 is positioned above the plunger pump 20, allowing the liquid in the storage bag 40 to flow towards the plunger pump 20 under its own weight. This helps the plunger pump 20 draw liquid out from the storage bag 40 under negative pressure, reducing the resistance to negative pressure suction and improving the liquid supply efficiency. It is understood that in other examples of this application, the storage bag 40 may also be located to the side or even below the plunger pump 20, eliminating the need for a suction tube inserted into the storage bag 40 to achieve negative pressure suction by the plunger pump 20.

[0079] For example, such as Figure 4 and Figure 5 As shown, the liquid supply port 42 of the liquid storage bag 40 is located at the lower part of the soft bag body 41, and the liquid inlet 201 of the plunger pump 20 is located at the upper part of the pump body of the plunger pump 20. In this way, when the liquid supply port 42 of the liquid storage bag 40 is connected to the liquid inlet 201 of the plunger pump 20, the liquid storage bag 40 is above the plunger pump 20, which facilitates the negative pressure suction of the plunger pump 20 by the weight of the liquid itself.

[0080] Furthermore, the locking member 45 of the liquid storage bag 40 may include a rear fastener 451 and a front locking member 452 disposed on the soft bag body 41, and the rear fastener 451 of the liquid storage bag 40 is adapted to fasten to the mating member 11 located at the rear of the machine body 10, and the front locking member 452 of the liquid storage bag 40 is adapted to lock to the mating member 11 located at the front of the machine body 10, so as to stably install the liquid storage bag 40 on the machine body 10. It is understood that the front and back are defined in this application by the spraying direction of the negative pressure sprayer 1, that is, the negative pressure sprayer 1 sprays from back to front, that is, the liquid outlet 202 of the plunger pump 20 faces forward.

[0081] It is worth noting that in existing airless sprayers, the storage bottle is usually located below the plunger pump, and the storage bottle, in conjunction with the handle, supports the entire machine body, allowing the existing airless sprayer to stand upright. However, existing airless sprayers cannot stand upright after the storage bottle is removed. Therefore, when changing the storage bottle or adding new liquid, the existing airless sprayer must lie flat, easily contaminating the nozzles and severely affecting subsequent spraying quality. In contrast, the liquid storage bag 40 of this application is installed above the machine body 10, ensuring that the center of gravity of the machine body 10 does not shift significantly before and after removing the liquid storage bag 40. Therefore, the negative pressure sprayer 1 can stand stably using the handle of the machine body 10 before and after removing the liquid storage bag 40, preventing the nozzles of the negative pressure sprayer 1 from contacting the ground and becoming contaminated.

[0082] For example, such as Figure 5 and Figure 6 As shown, the body 10 of the negative pressure sprayer 1 may include a housing 12 with the mating part 11, a handle 13 extending downward from the housing 12, and a switch assembly 14 disposed on the handle 13. The plunger pump 20 is disposed within the housing 12, and the liquid storage bag 40 is mounted on the housing 12. The power supply device 30 is disposed on the handle 13, and the switch assembly 14 is controllably connected to the plunger pump 20 for manually controlling the opening and closing of the plunger pump 20. This allows the user to manually trigger the switch assembly 14 to control the operation of the plunger pump 20 while holding the handle 13, facilitating one-handed operation of the negative pressure sprayer 1. For example, the negative pressure sprayer 1 may be pistol-shaped to function as a spray gun, allowing for one-handed spraying operations.

[0083] Specifically, the switching assembly 14 of the body 10 includes a main switch 141 disposed in the circuit between the plunger pump 20 and the power supply device 30 and a switch trigger 142 movably disposed on the handle 13, wherein the switch trigger 142 is activated to trigger the opening and closing of the main switch 141, so that the circuit between the plunger pump 20 and the power supply device 30 is closed or opened, so that the plunger pump 20 starts or stops working.

[0084] More specifically, the power supply device 30 may include, but is not limited to, a battery pack 31 mounted on the handle 13, wherein the battery pack 31 is electrically connected to the plunger pump 20 to provide power to the plunger pump 20. Of course, in other examples of this application, the power supply device 30 may be implemented as a power plug or power socket for electrically connecting to an external power source, thereby connecting the external power source and the plunger pump 20 and providing power to the plunger pump 20.

[0085] Preferably, such as Figure 2 and Figure 5 As shown, the battery pack 31 of the power supply device 30 is detachably mounted on the handle 13 so that when the battery pack 31 is mounted on the handle 13, the battery pack 13 can be electrically connected to the plunger pump 20, and when the battery pack 31 is removed from the handle 13, it is convenient to charge the battery pack 31 or replace it with a new battery pack.

[0086] According to the above embodiments of this application, as Figures 5 to 8 As shown, the plunger pump 20 may include a motor 21 that is electrically connected to the power supply device 30, a pump body 22 disposed in the body 10, a plunger rod 23 that is movably disposed in the pump body 22, and a transmission mechanism 24 that transmittably connects the motor 21 and the plunger rod 23. Thus, when the power supply device 30 provides electrical energy to the motor 21, the motor 21 operates to drive the plunger rod 23 to reciprocate within the pump body 22 via the transmission mechanism 24. When the plunger rod 23 is driven to move backward, the plunger pump 20 is in the negative pressure operating state 2001, creating a negative pressure within the pump body 22 to draw liquid out from the storage bag 40 through the inlet 201. When the plunger rod 23 is driven to move forward, the plunger pump 20 is in the positive pressure operating state 2002, creating a positive pressure within the pump body 22 to pressurize the liquid within the pump body 22, allowing the pressurized liquid to be ejected from the outlet 202.

[0087] For example, the transmission mechanism 24 of the plunger pump 20 may include, but is not limited to, a transmission gear, wherein the transmission gear meshes with the output shaft gear of the motor 21, and the conventional gear is connected to the plunger rod 23 so that when the motor 21 is working, the transmission gear is driven to drive the plunger rod 23 to reciprocate within the pump body 22.

[0088] In addition, such as Figure 7 and Figure 8 As shown, the plunger pump 20 may further include an inlet valve assembly 25 disposed at the inlet 201 and an outlet valve assembly 26 disposed at the outlet 202. When the plunger pump 20 is in the negative pressure operating state 2001, the outlet valve assembly 26 is used to block the outlet 202 to create a negative pressure environment within the pump body 22 of the plunger pump 20, and the inlet valve assembly 25 is used to open the inlet 201 to open the flow channel between the storage bag 40 and the plunger pump 20, allowing the storage bag 40 to... The liquid material in the container is drawn out by the negative pressure of the plunger pump 20 and flows into the pump body 22 from the inlet 201. When the plunger pump 20 is in the positive pressure working state 2002, the inlet valve assembly 25 is used to block the inlet 201 to create a positive pressure environment in the pump body 22 of the plunger pump 20, so that the liquid material drawn out by the negative pressure is pressurized in the pump body 22, and the outlet valve assembly 26 is used to open the outlet 202, so that the pressurized liquid material is sprayed out from the outlet 202 for spraying operation.

[0089] It is understood that the inlet valve assembly 25 and the outlet valve assembly 26 of the plunger pump 20 may, but are not limited to, include a one-way valve consisting of a valve ball and a spring, wherein the inlet valve assembly 25 allows liquid to flow from outside the pump into the pump, but prevents liquid from flowing from inside the pump out of the pump; while the outlet valve assembly 26 allows liquid to flow from inside the pump out of the pump, but prevents liquid from flowing from outside the pump into the pump.

[0090] According to the above embodiments of this application, as Figure 2 and Figure 5 As shown, the negative pressure sprayer 1 may further include a nozzle assembly 50, wherein the nozzle assembly 50 is correspondingly disposed at the liquid outlet 202 of the plunger pump 20, for dispersing the liquid flowing from the liquid outlet 202 of the plunger pump 20 into a mist for uniform spraying. It is understood that the nozzle assembly 50 may be detachably mounted to the housing 12 of the machine body 10, or the nozzle assembly 50 may be integrally formed into the housing 12 of the machine body 10, as long as it corresponds to the liquid outlet 202 of the plunger pump 20; this application will not elaborate further on this.

[0091] Specifically, the nozzle assembly 50 may include a nozzle head 51 and a nozzle valve 52, wherein the nozzle valve 52 is correspondingly mounted to the pump body 22 of the plunger pump 20 to correspond to the liquid outlet 202 of the plunger pump 20, and the nozzle head 51 is detachably mounted to the nozzle valve 52 to open or close the spraying channel of the nozzle head 51 through the nozzle valve 52. It is understood that the nozzle assembly 50 may, but is not limited to, be implemented as a high-pressure atomizing nozzle.

[0092] According to the above embodiments of this application, as Figure 2 and Figure 5 As shown, the body 10 of the negative pressure spraying machine 1 may further include a pressure relief assembly 15, wherein the pressure relief assembly 15 is used to relieve pressure on the plunger pump 20, preventing the plunger pump 20 from maintaining high pressure when not in operation, which helps to extend the service life of the plunger pump 20.

[0093] Specifically, the pressure relief assembly 15 includes a pressure relief valve 151 disposed at the pressure relief port 203 of the plunger pump 20, for opening or blocking the pressure relief port 203 of the plunger pump 20. When the pressure relief valve 151 is controlled to block the pressure relief port 203 of the plunger pump 20, the negative pressure sprayer 1 can perform spraying operations normally. When the pressure relief valve 151 is controlled to open the pressure relief port 203 of the plunger pump 20, the plunger pump 20 will be depressurized through the pressure relief port 203. Although the negative pressure sprayer 1 cannot perform normal spraying operations at this time, the high pressure inside the plunger pump 20 can be released so that the plunger pump 20 can be maintained or repaired in the future. Specifically, when the pressure relief valve 151 is controlled to open the pressure relief port 203 of the plunger pump 20, even if the plunger pump 20 is still operating, the pressurized liquid will not flow out from the outlet port 202 of the plunger pump 20, but will flow out from the pressure relief port 203 of the plunger pump 20, making normal spraying impossible, but cleaning can be performed.

[0094] More specifically, the pressure relief assembly 15 includes a pressure relief channel 152, wherein the pressure relief channel 152 is connected to the pressure relief port 203 of the plunger pump 20 and the return port 46 of the liquid storage bag 40, so that after the pressure relief port 203 of the plunger pump 20 is opened, the liquid in the plunger pump 20 can return to the liquid storage bag 40 through the pressure relief channel 152 to avoid waste of liquid.

[0095] Preferably, the pressure relief channel 152 extends from the pressure relief port 203 of the plunger pump 20 to the liquid inlet valve assembly 25 of the plunger pump 20, and the return port 46 of the liquid storage bag 40 is adjacent to the liquid supply port 42 of the liquid storage bag 40. Thus, when the liquid storage bag 40 is installed on the machine body 10, the liquid supply port 42 and the return port 46 of the liquid storage bag 40 are respectively connected to the liquid inlet valve assembly 25 of the plunger pump 20 and the pressure relief channel 152 of the pressure relief assembly 15, so that the liquid supply port 42 and the return port 46 of the liquid storage bag 40 are respectively connected to the liquid inlet 201 and the pressure relief port 203 of the plunger pump 20.

[0096] For example, such as Figure 5 and Figure 9 As shown, the pressure relief assembly 15 may further include a pressure relief valve trigger 153 for controlling the opening and closing of the pressure relief valve 151, wherein the pressure relief valve trigger 153 is movably disposed in the housing 12, and the pressure relief valve trigger 153 can be driven to move to a first position 1501 (e.g., position P) and a second position 1502 (e.g., position X), wherein when the pressure relief valve trigger 153 is moved to the first position 1501, the pressure relief valve trigger 153 controls the pressure relief valve 151 to block the pressure relief port 203 of the plunger pump 20, so that the negative pressure sprayer 1 can spray normally; and when the pressure relief valve trigger 153 is moved to the second position 1502, the pressure relief valve trigger 153 controls the pressure relief valve 151 to open the pressure relief port 203 of the plunger pump 20, so that the plunger pump 20 of the negative pressure sprayer 1 can depressurize.

[0097] Preferably, such as Figure 9 As shown, the pressure relief valve trigger 153 can be further driven to move to a third position 1503 (such as position Q), so that while controlling the pressure relief valve 151 to open the pressure relief port 203 of the plunger pump 20, the switch trigger 142 of the switch assembly 14 is activated, causing the main switch 141 to close and start the plunger pump 20, thereby realizing the automatic cleaning process of the negative pressure sprayer 1.

[0098] More preferably, the pressure relief valve trigger 153 is pivotally connected to the housing 12 near the switch assembly 14, wherein when the pressure relief valve trigger 153 is rotated to the third position 1503, the pressure relief valve trigger 153 directly actuates the switch trigger 142 to activate the plunger pump 20. Thus, when the pressure relief valve trigger 153 is in the third position 1503, the pressure relief valve 151 is controlled to open the pressure relief port 203 of the plunger pump 20, and the main switch 141 is triggered to activate the plunger pump 20, thereby initiating the cleaning process. This eliminates the need to continuously hold down the switch trigger during the cleaning process, as is required with existing spray guns.

[0099] It is worth noting that, due to the working principle of the plunger pump 20, when the plunger pump 20 is in the positive pressure working state 2002, the plunger pump 20 pressurizes the liquid so that the pressurized liquid is sprayed out from the outlet 202; while when the plunger pump 20 is in the negative pressure working state 2001, the inlet 201 of the plunger pump 20 opens to perform negative pressure liquid suction, but the outlet 202 of the plunger pump 20 is blocked and will not continue to discharge liquid. That is to say, when the plunger pump 20 is in the negative pressure working state, no liquid will be sprayed out, causing the negative pressure sprayer 1 to spray intermittently. To solve this problem, existing spraying machines typically use multi-cylinder plunger pumps, which stagger the pressurization processes in different cylinders of the plunger pump to perform time-sharing spraying. However, this solution not only requires a more complex structure and increases manufacturing costs, but also requires that the pressurization processes in different cylinders still be spaced out in order to avoid interference between them. This can only shorten the intermittent time of spraying and cannot truly achieve continuous spraying.

[0100] Therefore, as Figure 5 , Figure 10 as well as Figure 11 As shown, in order to achieve truly continuous spraying, the negative pressure spraying machine 1 of this application may further include an energy storage component 60, wherein the energy storage component 60 is correspondingly disposed between the liquid outlet 202 of the plunger pump 20 and the nozzle assembly 50, and the energy storage component 60 has an energy storage state 602 and an energy release state 601. When the plunger pump 20 is in the positive pressure working state 2002 to pressurize the liquid and allow it to flow out from the liquid outlet 202, the energy storage component 60 will be in the energy storage state 602, so that a portion of the pressurized liquid is stored in the energy storage component 60, and another portion of the pressurized liquid will be sprayed out from the nozzle assembly 50. When the plunger pump 20 is in the negative pressure working state 2001, the energy storage component 60 is in the energy release state 601, so that the stored liquid is released and sprayed out from the nozzle assembly 50.

[0101] In other words, when the plunger pump 20 is in the positive pressure working state, the energy storage component 60 accumulates a portion of the liquid material, and the remaining liquid material is sprayed out for spraying operations; while when the plunger pump 20 is in the negative pressure working state 2001, the energy storage component 60 can release the accumulated liquid material, so that the accumulated liquid material can still be sprayed out for spraying operations. In this way, regardless of whether the plunger pump 20 is in the positive pressure working state 2002 or the negative pressure working state 2001, liquid material will be sprayed out, thereby truly achieving the effect of continuous spraying.

[0102] Specifically, such as Figure 10 and Figure 11 As shown, the energy storage component 60 may have a variable volume energy storage chamber 600, and the energy storage chamber 600 is connected to the liquid outlet 202 of the plunger pump 20 and the nozzle assembly 50. When the energy storage component 60 is in the energy storage state 602, the volume of the energy storage chamber 600 increases from small to large to accumulate pressurized liquid, i.e., accumulate pressure potential energy; while when the energy storage component 60 is in the energy release state 601, the volume of the energy storage chamber 600 decreases from large to small to release the accumulated liquid, i.e., release pressure potential energy.

[0103] It is worth noting that, since the volume of the energy storage chamber 600 of the energy storage component 60 changes under the action of the liquid material, the energy storage component 60 can not only accumulate and release the liquid material at different times, but also balance the pressure of the liquid material, so that the spraying speed of the liquid material remains consistent. In other words, when the plunger pump 20 is in the positive pressure working state 2002, after the pressurized liquid material flows into the energy storage chamber 600 of the energy storage component 600, the volume of the energy storage chamber 600 increases to act as a buffer, so that the spraying speed of the liquid material does not suddenly increase; while when the plunger pump 20 is in the negative pressure working state 2001, the volume of the energy storage chamber 600 decreases to release the liquid material, so that the spraying speed of the liquid material does not suddenly decrease, which helps to achieve continuous and uniform spraying.

[0104] More specifically, the energy storage assembly 60 may include a hollow elastic tube 61, wherein one end of the hollow elastic tube 61 is connected to the liquid outlet valve assembly 25 of the plunger pump 20, and the other end of the hollow elastic tube 61 is connected to the nozzle valve 52 of the nozzle assembly 50, so as to form a variable volume energy storage cavity 600 between the plunger pump 20 and the nozzle assembly 50 through the hollow elastic tube 61. Thus, when the plunger pump 20 is in the positive pressure working state 2002, the pressurized liquid flows out of the outlet 202 of the plunger pump 20 and first enters the hollow elastic tube 61. At this time, the tube wall of the hollow elastic tube 61 undergoes elastic deformation under the pressure of the liquid, thereby increasing the volume of the energy storage cavity 600. This causes a portion of the liquid flowing out from the outlet 202 to accumulate in the energy storage cavity 600, while the other portion of the liquid is sprayed out through the nozzle assembly 50. When the plunger pump 20 is in the negative pressure working state 2001, the tube wall of the hollow elastic tube 61 returns to its original shape under its own elastic force, causing the volume of the energy storage cavity 600 to decrease. This releases the liquid accumulated in the energy storage cavity 600 and sprays it out from the nozzle assembly 50, thereby achieving continuous spraying of the liquid.

[0105] For example, such as Figure 10 As shown, in the first example of this application, the hollow elastic tube 61 is implemented as a polyurethane tube 611. When the plunger pump 20 is in the positive pressure working state 2002, the tube wall of the polyurethane tube 610 is squeezed by the liquid and becomes thinner, so that the volume of the energy storage cavity 600 increases to accumulate the liquid, that is, the energy storage component 60 is in the energy storage state; and when the plunger pump 20 is in the negative pressure working state 2001, the tube wall of the polyurethane tube 610 thickens to return to its original state, so that the volume of the energy storage cavity 600 decreases to release the liquid, that is, the energy storage component 60 is in the energy release state.

[0106] like Figure 11 As shown, in the second example of this application, the hollow elastic tube 61 can also be implemented as an expansion tube 612, wherein when the plunger pump 20 is in the positive pressure working state 2002, the expansion tube 612 is squeezed by the liquid and expands, so that the volume of the energy storage cavity 600 increases to store the liquid, that is, the energy storage component 60 is in the energy storage state; and when the plunger pump 20 is in the negative pressure working state 2001, the expansion tube 612 contracts to return to its original state, so that the volume of the energy storage cavity 600 decreases to release the liquid, that is, the energy storage component 60 is in the energy release state.

[0107] It is worth mentioning that, such as Figure 1 and Figure 2As shown in the above embodiments of this application, the negative pressure spraying machine 1 may further include a lighting device 70, wherein the lighting device 70 is disposed on the machine body 10 for emitting illumination light to illuminate the spraying area, so that the user can observe the spraying area or the spraying effect in a dim or dark environment.

[0108] For example, such as Figure 5 and Figure 6 As shown, the lighting device 70 may include a light source 71 and a lighting switch 72 that are electrically connected to the power supply device 30. The light source 71 is mounted on the front end of the housing 12 and is used to emit illumination light along the spraying direction. The lighting switch 72 is used to turn the light source 71 on or off, allowing the user to control the light source 71 to be lit or extinguished as needed. It is understood that the light source 71 may, but is not limited to, be implemented as an LED lamp.

[0109] It is worth noting that, although the liquid storage bag 40 in the negative pressure sprayer 1 described in the above embodiments is installed on the machine body 10 to be directly connected to the plunger pump 20, so that the negative pressure sprayer 1 has an integrated structure, in other embodiments of this application, the liquid storage bag 40 may not be installed on the machine body 10, so that the negative pressure sprayer 1 has a split structure. In this case, it is only necessary to transport the liquid in the liquid storage bag 40 to the inlet 201 of the plunger pump 20 through the conveying device.

[0110] For example, Appendix Figure 12 A modified embodiment of the negative pressure sprayer 1 according to the above embodiments of this application is shown, wherein the negative pressure sprayer 1 further includes a liquid delivery pipe 80, one end of which is connected to the liquid supply port 42 of the liquid storage bag 40, and the other end of which is connected to the liquid inlet 201 of the plunger pump 20. When the plunger pump 20 is in the negative pressure operating state, the liquid in the liquid storage bag 40 first flows out from the liquid supply port 42 under the action of the pressure difference, then flows through the liquid delivery pipe 80 to the liquid inlet 201 of the plunger pump 20, and finally flows from the liquid inlet 201 of the plunger pump 20 into the pump body 22 of the plunger pump 20. It is understood that in this modified embodiment of the present application, the liquid storage bag 40 does not need to be installed on the machine body 10, which helps to significantly reduce the user's carrying weight and reduce the user's workload.

[0111] It is worth mentioning that, according to another aspect of this application, such as Figure 13 As shown, one embodiment of this application further provides an airless liquid supply method for the above-described negative pressure sprayer 1, which may include the following steps:

[0112] S110: When the plunger pump of the negative pressure sprayer is in negative pressure operation, liquid is negatively drawn from the soft bag of the liquid storage bag of the negative pressure sprayer into the pump body of the plunger pump; and

[0113] S120: Under the action of external atmospheric pressure, the soft bag is squeezed to deflate as the liquid is drawn out by negative pressure, so that the air pressure inside and outside the storage bag is kept in balance.

[0114] Understandably, because the soft bag can deflate as the liquid is drawn out under negative pressure, the air pressure inside and outside the storage bag can be kept balanced without the need for external air to enter. Therefore, the soft bag inside the storage bag can always remain airless, preventing air from mixing into the liquid drawn out under negative pressure, thus achieving the effect of airless liquid supply and helping to improve the spraying quality of the negative pressure sprayer.

[0115] It is worth mentioning that, according to another aspect of this application, such as Figure 14 As shown, one embodiment of this application further provides a negative pressure spraying method, which may include the following steps:

[0116] S210: Start the plunger pump of the negative pressure sprayer so that the plunger pump switches back and forth between negative pressure and positive pressure working states;

[0117] S220: When the plunger pump is in the negative pressure operating state, liquid is negatively drawn from the soft bag of the liquid storage bag of the negative pressure sprayer into the pump body of the plunger pump, causing the soft bag to collapse as the liquid is drawn out under negative pressure; and

[0118] S230: When the plunger pump is in the positive pressure working state, the liquid that is sucked out by the negative pressure is pressurized so that it is ejected from the outlet of the plunger pump.

[0119] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A negative pressure sprayer for spraying paint liquid, characterized in that, The negative pressure spraying machine includes: Organism; A plunger pump, wherein the plunger pump is disposed in the machine body, and the plunger pump has a negative pressure operating state and a positive pressure operating state; A power supply device, wherein the power supply device is disposed in the machine body and is electrically connected to the plunger pump for supplying power to the plunger pump to enable the plunger pump to switch back and forth between the negative pressure operating state and the positive pressure operating state; and a liquid storage bag, wherein the liquid storage bag includes a soft bag body for containing the liquid and a liquid supply port disposed in the soft bag body, and the liquid supply port of the liquid storage bag is adapted to communicate with the liquid inlet of the plunger pump, wherein when the plunger pump is in the negative pressure operating state, a negative pressure is formed inside the plunger pump to draw the liquid out from the liquid storage bag, causing the soft bag body of the liquid storage bag to collapse due to the liquid being drawn out by the negative pressure, and when the plunger pump is in the positive pressure operating state, a positive pressure is formed inside the plunger pump to pressurize the liquid drawn out by the negative pressure, causing the pressurized liquid to flow out from the liquid outlet of the plunger pump; An energy storage component is provided, wherein the energy storage component is correspondingly disposed at the outlet of the plunger pump, and the energy storage component has an energy storage state and an energy release state, wherein when the plunger pump is in the positive pressure operating state, the energy storage component is in the energy storage state, such that a portion of the liquid flowing out from the outlet of the plunger pump is accumulated in the energy storage component, and another portion is ejected; when the plunger pump is in the negative pressure operating state, the energy storage component is in the energy release state, such that the liquid accumulated in the energy storage component is released and ejected.

2. The negative pressure spraying machine as described in claim 1, wherein, The soft bag body of the liquid storage bag is made of a flexible material.

3. The negative pressure spraying machine as described in claim 2, wherein, The soft bag body of the liquid storage bag is made of two pieces of plastic film heat-sealed together.

4. The negative pressure spraying machine as described in claim 1, wherein, The liquid storage bag is detachably installed on the machine body, and the liquid supply port of the liquid storage bag is directly connected to the liquid inlet of the plunger pump.

5. The negative pressure spraying machine as described in claim 4, wherein, The liquid storage bag further includes a bag opening and a bag cap disposed on the soft bag body, wherein the bag cap is removably sealed to the bag opening.

6. The negative pressure spraying machine as described in claim 4, wherein, The liquid storage bag further includes a locking member disposed on the soft bag body, and the machine body includes a mating member that matches the locking member, wherein the locking member of the liquid storage bag is locked to the mating member of the machine body.

7. The negative pressure spraying machine as described in any one of claims 1 to 6, wherein, The reservoir bag is located above the plunger pump.

8. The negative pressure spraying machine as described in claim 7, wherein, The liquid supply port of the storage bag is located at the lower part of the soft bag body, and the liquid inlet of the plunger pump is located at the upper part of the plunger pump body.

9. The negative pressure spraying machine according to any one of claims 1 to 6, further comprising a liquid delivery pipe, wherein one end of the liquid delivery pipe is connected to the liquid supply port of the liquid storage bag, and the other end of the liquid delivery pipe is connected to the liquid inlet of the plunger pump.

10. The negative pressure spraying machine as described in any one of claims 1 to 6, wherein, The machine body includes a housing, a handle extending downward from the housing, and a switch assembly disposed on the handle, wherein the plunger pump is disposed within the housing, and the liquid storage bag is mounted on the housing, wherein the power supply device is disposed on the handle, and the switch assembly is controllably connected to the plunger pump for manually controlling the opening and closing of the plunger pump.

11. The negative pressure spraying machine as described in claim 10, wherein, The body further includes a pressure relief assembly for relieving pressure on the plunger pump.

12. The negative pressure spraying machine as described in claim 11, wherein, The pressure relief assembly includes a pressure relief valve disposed at the pressure relief port of the plunger pump and a pressure relief channel for connecting the return port of the liquid storage bag and the pressure relief port of the plunger pump, wherein the pressure relief valve of the pressure relief assembly is used to open or block the pressure relief port of the plunger pump.

13. The negative pressure spraying machine as described in claim 12, wherein, The pressure relief assembly further includes a pressure relief valve trigger for controlling the opening and closing of the pressure relief valve, wherein the pressure relief valve trigger is movably disposed in the housing, and the pressure relief valve trigger is driven to move to a first position, a second position, and a third position, wherein when the pressure relief valve trigger is moved to the first position, the pressure relief valve trigger controls the pressure relief valve to block the pressure relief port of the plunger pump; When the pressure relief valve trigger is moved to the second position, the pressure relief valve trigger controls the pressure relief valve to open the pressure relief port of the plunger pump; When the pressure relief valve trigger is moved to the third position, the pressure relief valve trigger, while controlling the pressure relief valve to open the pressure relief port of the plunger pump, simultaneously activates the switching assembly to start the plunger pump.

14. The negative pressure spraying machine as described in any one of claims 1 to 6, wherein, The plunger pump includes a motor energically connected to the power supply device, a pump body disposed in the machine body, a plunger rod movably disposed in the pump body, and a transmission mechanism tractably connected to the motor and the plunger rod.

15. The negative pressure spraying machine as claimed in any one of claims 1 to 6, further comprising a nozzle assembly, wherein the nozzle assembly is correspondingly disposed at the outlet of the plunger pump for dispersing the liquid flowing from the outlet of the plunger pump into a mist.

16. The negative pressure spraying machine as claimed in any one of claims 1 to 6, further comprising a lighting device, wherein the lighting device is disposed on the machine body for emitting illumination light to illuminate the spraying area.

17. The negative pressure spraying machine as described in claim 1, wherein, The energy storage component is a polyurethane tube or an expansion tube.

18. A negative pressure spraying method based on any one of the negative pressure spraying machines according to claims 1-6, characterized in that, Including the following steps: Start the plunger pump of the negative pressure sprayer to switch the plunger pump back and forth between negative pressure and positive pressure working states; When the plunger pump is in the negative pressure working state, the liquid is negatively drawn from the soft bag of the liquid storage bag of the negative pressure sprayer into the pump body of the plunger pump, so that the soft bag collapses as the liquid is drawn out under negative pressure; and when the plunger pump is in the positive pressure working state, the liquid drawn out under negative pressure is pressurized to be sprayed out from the outlet of the plunger pump.

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