A powder paint supply device for powder paint spraying

Abstract

The utility model discloses a kind of powder coating powder feeding devices for spraying, belong to powder coating spraying equipment technical field.The powder feeding device includes cover, powder cylinder and powder pump frame set in cover, powder pump and powder suction pipe are equipped on powder pump frame.Powder pump frame lower fixed with central support, central support lower end is equipped with centralizing sleeve, powder suction pipe is worn in centralizing sleeve and is fixedly cooperated with centralizing sleeve, second constraint point is formed in the lower portion of powder suction pipe to shorten cantilever length, reduce swing amplitude.Cover bottom is equipped with the cleaning air pipe corresponding to powder suction pipe one to one, cleaning air pipe is connected with gas source.The device solves the technical problem that powder suction pipe in prior art swing amplitude is large due to overhanging too long, cannot be accurately centered and inserted into cleaning air pipe, with the characteristics of high centering precision, high cleaning efficiency, long service life, widely used in powder coating field.

Description

Technical Field

[0001] This utility model relates to the technical field of powder coating spraying equipment, and in particular to a powder supply device for powder coating spraying. Background Technology

[0002] Powder coating is a coating process in which powder coating is delivered to the spray gun via a powder supply device. Under electrostatic action, the powder is uniformly adsorbed onto the surface of the workpiece, and then cured by high-temperature baking. The powder supply device is the core equipment in the powder coating system, and its function is to draw the powder coating from the powder cylinder and deliver it to the spray gun in the form of a powder-air mixture.

[0003] In the powder supply system, one end of the suction pipe is connected to the powder pump, and the other end extends into the powder cylinder to draw powder. The powder pump frame is vertically mounted inside the housing of the powder supply system, and the powder pump is fixedly installed on the powder pump frame. The suction pipe moves up and down with the powder pump frame to adapt to changes in the powder level inside the powder cylinder. When it is necessary to change the powder color or perform maintenance on the powder supply system, residual powder in the suction pipe and subsequent pipelines must be thoroughly cleaned to prevent mixing of different colored powders and affecting the coating quality.

[0004] Existing technologies include solutions for backflushing and cleaning the powder suction pipe using a cleaning air pipe. For example, Chinese Patent CN203002520U discloses a bottom-opening, sealed powder supply center without exhaust fan, which includes an outer cover, a powder cylinder housed within the outer cover, and a powder pump assembly connected to the powder cylinder. The powder pump assembly is mounted on the outer cover via a lifting device. During cleaning, the powder pump assembly moves downward, and the powder suction pipe is inserted into the cleaning nozzle assembly. High-pressure gas is used to backflush and clean the powder suction pipe and subsequent pipelines. Furthermore, Chinese Patent CN203578066U discloses a rapid color-changing powder supply center with automatic powder tank cleaning, which includes a shell, a powder tank, a powder suction device, and a powder cleaning device. The powder cleaning device is installed inside the shell and located below the powder tank, used to clean the powder suction device when the powder supply center needs to change colors. Chinese patent CN206064663U discloses an external powder suction tube powder supply unit with a rapid cleaning function, and also relates to the cleaning technology of the powder supply unit.

[0005] However, the aforementioned prior art has at least the following shortcomings:

[0006] The suction pipe is a slender tube (its length can reach several hundred millimeters) with a relatively thin wall. It extends a considerable distance downwards from the powder pump frame into the powder cylinder. During the raising and lowering of the powder pump frame, the lower end of the suction pipe inevitably sways because the deflection at the end of the cantilever beam is proportional to the cube of the extension length. This swaying is further amplified by inertial forces, especially during the acceleration and deceleration phases of the powder pump frame. Furthermore, the suction pipe may experience slight bending deformation after prolonged use, and the powder pump frame may accumulate positioning errors after multiple raising and lowering operations. These factors all contribute to the inability of the lower end of the suction pipe to accurately align with the inlet of the cleaning device. The inner diameter of the air jet / cleaning nozzle is only slightly larger than the outer diameter of the suction pipe (to ensure effective airflow into the suction pipe), requiring high alignment accuracy. If the lower end of the suction pipe collides with the inlet of the cleaning device, it will not only affect cleaning efficiency but may also damage the suction pipe or the cleaning device. Utility Model Content

[0007] To overcome the shortcomings of the prior art, the present invention adopts the following technical solution:

[0008] A powder supply device for powder coating spraying includes an outer cover, a powder cylinder disposed within the outer cover, and a powder pump frame, wherein the powder pump frame is equipped with a powder pump and a powder suction pipe communicating with the powder pump; characterized in that it further includes:

[0009] A straightening bracket is fixedly installed below the powder pump frame. The lower end of the straightening bracket is provided with a straightening sleeve, and the powder suction pipe passes through the straightening sleeve and the two are fixedly engaged.

[0010] A cleaning air tube is located at the bottom of the outer cover. The cleaning air tube corresponds one-to-one with the powder suction tube, and the cleaning air tube is connected to an air source.

[0011] Furthermore, the distance between the straightening sleeve and the lower end of the powder suction tube is 1 / 3 to 1 / 2 of the length of the portion of the powder suction tube extending out of the powder pump frame.

[0012] Furthermore, the cleaning air tube is a fitting with an integrated normally closed mechanical trigger valve, and its air inlet end is connected to the air source and kept under pressure; when the lower end of the powder suction tube is inserted into the cleaning air tube, the mechanical trigger valve is triggered to open.

[0013] Furthermore, the inlet end of the cleaning tube is provided with an elastic guide ring, the inner hole of which is tapered with a larger upper diameter and a smaller lower diameter, and its minimum inner diameter is larger than the outer diameter of the powder suction tube.

[0014] Furthermore, the elastic guide ring is made of polyurethane rubber or fluororubber, and the semi-cone angle of the tapered structure of the elastic guide ring is 30° to 45°.

[0015] Furthermore, a guide post is provided inside the outer cover, and a guide sleeve is fitted on the guide post. A lifting cylinder is fixedly installed on the top of the outer cover, and the piston rod of the lifting cylinder is connected to the guide sleeve or the powder pump frame.

[0016] Furthermore, the lifting cylinder is fixedly installed on the top outer side of the outer cover, and the piston rod of the lifting cylinder passes through the top of the outer cover and is connected to the guide sleeve or the powder pump frame.

[0017] Furthermore, the powder pump is equipped with a downwardly extending powder probe, and the detection end of the powder probe is located between the straightening sleeve and the lower end of the powder suction pipe; the powder probe is connected to the lifting cylinder via an external control system.

[0018] Furthermore, the powder pump frame has two symmetrically arranged mounting rods, and each mounting rod is provided with at least one powder extraction assembly consisting of the powder pump and the powder suction pipe.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. By installing a straightening bracket and a straightening sleeve below the powder pump frame, the powder suction pipe passes through the straightening sleeve and is fixedly fitted to it, forming a second radial constraint point at the lower part of the powder suction pipe. The upper end of the powder suction pipe is already fixed and constrained by the powder pump frame, and the straightening sleeve forms a second constraint point at the lower part of the powder suction pipe, effectively shortening the free overhang length of the lower end of the powder suction pipe. This significantly reduces the swing amplitude of the lower end of the powder suction pipe during lifting and lowering, ensuring the alignment accuracy between the powder suction pipe and the cleaning air pipe, avoiding collision damage caused by alignment deviation, and improving the reliability and service life of the device.

[0021] 2. By setting the centering sleeve at 1 / 3 to 1 / 2 of the suspended section of the powder suction tube, the free suspended length of the lower end of the powder suction tube can be effectively shortened, ensuring centering accuracy. At the same time, it can prevent the centering sleeve from being too close to the lower end of the powder suction tube, which would affect the stroke of the powder suction tube when it is inserted into the cleaning air tube. The best balance is achieved between ensuring centering effect and ensuring smooth operation.

[0022] 3. The cleaning air pipe adopts a fitting with an integrated normally closed mechanical trigger valve. Its air inlet end is connected to the air source and kept under pressure. Under natural conditions, it remains closed, avoiding gas leakage when the air source is continuously supplying air and saving energy. When the powder suction tube is inserted into the cleaning air pipe, it is automatically opened by mechanical trigger, realizing automatic on / off control of the air circuit. There is no need for solenoid valves and complex electrical control systems. It has a simple structure, high reliability, and fast response speed.

[0023] 4. By installing an elastic guide ring at the inlet end of the cleaning air tube, the inner hole of the guide ring is tapered, wider at the top and narrower at the bottom. Utilizing the combined effect of the tapered slope and elastic deformation, it provides final guidance and correction as the suction tube is about to enter the cleaning air tube. Even after long-term use, if there are adverse conditions such as positioning deviations of the powder pump frame or slight bending of the suction tube, it can still reliably guide the suction tube into the cleaning air tube. The elastic guide ring is made of polyurethane rubber or fluororubber, which has good elasticity and wear resistance, and can absorb impact energy, preventing damage to the suction tube or cleaning air tube. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the present invention after the powder cartridge is removed;

[0026] Figure 3 This is a structural schematic diagram of another state of the present invention;

[0027] Figure 4 This is a schematic diagram of the assembly structure of the powder pump frame in this utility model;

[0028] Figure 5 for Figure 4 The left view;

[0029] Figure 6 This is a partial schematic diagram of the assembly structure of the powder suction tube and the cleaning air tube in this utility model.

[0030] In the diagram: 1. Outer cover; 2. Powder cylinder; 3. Powder pump frame; 31. Mounting rod; 4. Powder pump; 5. Suction pipe; 6. Straightening bracket; 61. Straightening sleeve; 7. Cleaning air pipe; 8. Elastic guide ring; 9. Guide column; 91. Guide sleeve; 10. Lifting cylinder; 11. Powder probe. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings. It should be noted that the specific embodiments described below are only for explaining the present invention and do not constitute a limitation on the scope of protection of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0032] In the description of this utility model, the terms "upper," "lower," "top," "bottom," "inner," "outer," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model 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, they should not be construed as limitations on this utility model. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connect," "fix," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a signal connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] Furthermore, unless otherwise explicitly specified and limited, "located on" another element means that the element may be located inside, on the surface, or above the other element, and the two elements may be in direct contact or indirect contact through an intermediate element. "Multiple" refers to two or more.

[0035] Please refer to the instruction manual appendix. Figure 1-6 The present invention provides the following technical solution:

[0036] Example 1, as Figure 1-6 As shown, a powder supply device for powder coating spraying includes an outer cover 1, a powder cylinder 2, and a powder pump frame 3. The outer cover 1 has a box-like structure with a cavity inside. The powder cylinder 2 is disposed within the cavity of the outer cover 1 to hold the powder coating. Furthermore, the bottom surface of the cavity of the outer cover 1 has a limiting structure (not separately labeled in the figure) to restrict the position of the powder cylinder 2. The upper end of the powder cylinder 2 is open. The powder pump frame 3 is disposed above the powder cylinder 2 and can move up and down relative to the outer cover 1.

[0037] Furthermore, a guide post 9 is provided inside the outer cover 1. The guide post 9 is a vertically arranged columnar structure, with its lower end fixedly connected to the bottom wall of the outer cover 1 and its upper end fixedly connected to the top wall of the outer cover 1. The outer wall of the guide post 9 is a smooth cylindrical surface, used to guide the lifting and lowering movement of the powder pump frame 3. A guide sleeve 91 is fitted onto the guide post 9. The guide sleeve 91 is a cylindrical structure, with its inner wall slidingly fitted to the outer wall of the guide post 9. The guide sleeve 91 can slide up and down along the axial direction of the guide post 9. The powder pump frame 3 is fixedly connected to the guide sleeve 91. When the guide sleeve 91 slides along the guide post 9, the powder pump frame 3 rises and falls synchronously with the guide sleeve 91.

[0038] In a preferred embodiment, there are two guide posts 9 and two guide sleeves 91, with the two guide posts 9 symmetrically arranged on both sides of the inner side of the outer cover 1. The two guide sleeves 91 are respectively fitted onto the corresponding guide posts 9. Both ends of the powder pump frame 3 are fixedly connected to the two guide sleeves 91. This arrangement ensures that the powder pump frame 3 remains horizontal during lifting and lowering, avoiding tilting caused by unilateral guidance, and further improving the alignment accuracy between the powder suction pipe 5 and the cleaning air pipe 7.

[0039] A lifting cylinder 10 is fixedly installed on the top of the outer cover 1. The cylinder body of the lifting cylinder 10 is fixedly installed on the outer side of the top wall of the outer cover 1, and the piston rod of the lifting cylinder 10 passes through the top wall of the outer cover 1 and extends into the interior of the outer cover 1. The lower end of the piston rod of the lifting cylinder 10 is connected to the guide sleeve 91 or directly connected to the powder pump frame 3. When the piston rod of the lifting cylinder 10 extends, it pushes the guide sleeve 91 and the powder pump frame 3 to move downward along the guide column 9; when the piston rod of the lifting cylinder 10 retracts, it pulls the guide sleeve 91 and the powder pump frame 3 to move upward along the guide column 9. By controlling the extension and retraction of the lifting cylinder 10, the powder pump frame 3 can be raised and lowered, thereby driving the powder suction pipe 5 to insert or withdraw from the cleaning air pipe 7.

[0040] The powder pump frame 3 has two symmetrically arranged mounting rods 31. Both mounting rods 31 are elongated structures, located on the left and right sides of the powder pump frame 3 respectively. Each mounting rod 31 is equipped with at least one powder suction assembly. The powder suction assembly consists of a powder pump 4 and a powder suction pipe 5. That is, at least one powder pump 4 is mounted on each mounting rod 31, and each powder pump 4 is connected to a corresponding powder suction pipe 5. The powder suction assemblies on the two mounting rods 31 are arranged symmetrically.

[0041] In actual spray coating production lines, the workpieces to be coated are typically moved along the spray coating channel by a conveyor, with spray guns installed on both the left and right sides of the workpiece. A powder extraction assembly located on the left mounting rod 31 of the powder pump frame 3 is connected to the spray gun on the left side of the workpiece via a pipeline, supplying powder to the left spray gun; similarly, a powder extraction assembly located on the right mounting rod 31 of the powder pump frame 3 is connected to the spray gun on the right side of the workpiece via a pipeline, supplying powder to the right spray gun. By symmetrically arranging the powder extraction assemblies on the two mounting rods 31, symmetrical powder supply to the spray guns on both sides of the workpiece is achieved, ensuring consistent coating thickness on both sides of the workpiece and improving coating quality.

[0042] The number of powder extraction components on each mounting rod 31 can be flexibly configured according to the actual production capacity requirements and the number of spray guns in the painting production line. For example, when the painting line requires multiple spray guns to operate simultaneously, two, three or more sets of powder extraction components can be set on each mounting rod 31 to meet the needs of simultaneous powder supply to multiple guns.

[0043] The powder pump frame 3 is equipped with a powder pump 4 and a powder suction pipe 5. The powder pump 4 is fixedly installed on the upper surface of the powder pump frame 3. The upper end of the powder suction pipe 5 is connected to the powder inlet of the powder pump 4. The powder suction pipe 5 extends downward through the powder pump frame 3 and into the interior of the powder cylinder 2. The lower end of the powder suction pipe 5 extends into the powder coating contained in the powder cylinder 2. The air inlet of the powder pump 4 is connected to an air supply source (not shown in the figure) through a pipeline, and the discharge port of the powder pump 4 is connected to the spray gun (not shown in the figure) through a pipeline. During powder supply, the air supply source supplies air to the powder pump 4, which generates negative pressure, drawing the powder coating in the powder cylinder 2 into the powder pump 4 through the powder suction pipe 5. The powder pump 4 then delivers the powder coating to the spray gun through the discharge port, thus realizing the spraying operation.

[0044] Furthermore, the powder pump frame 3 is also equipped with a powder probe 11. The powder probe 11 is fixedly installed on the powder pump frame 3, and the powder probe 11 extends downward into the interior of the powder cylinder 2. Specifically, the height of the detection end of the powder probe 11 is higher than the height of the lower end of the powder suction pipe 5. The powder probe 11 is used to detect the level of powder coating material in the powder cylinder 2. The powder probe 11 is connected to the lifting cylinder 10 via an external control system (not shown in the figure). The external control system is a programmable logic controller (PLC) or a microcontroller control circuit. Its signal input terminal is electrically connected to the powder probe 11, and its control signal output terminal is electrically connected to the solenoid valve that controls the action of the lifting cylinder 10. When the powder probe 11 detects a low level signal, the signal is transmitted to the external control system, which then sends a control command to the solenoid valve to control the lifting cylinder 10 to drive the powder pump frame 3 to descend, so that the lower end of the powder suction pipe 5 descends synchronously with the powder pump frame 3 to a position closer to the bottom of the powder cylinder 2, so as to ensure that the powder suction pipe 5 can always suck up powder coating material. As the spraying operation proceeds, the powder coating in the powder cylinder 2 is gradually consumed and the material level continues to drop. Under the control of the powder probe 11 and the external control system, the powder pump frame 3 gradually descends, ensuring that the lower end of the powder suction pipe 5 is always kept in an effective powder suction position below the powder liquid surface, thus ensuring the continuity and stability of powder supply.

[0045] The bottom of the outer cover 1 is also equipped with a cleaning air pipe 7. The cleaning air pipe 7 is fixedly installed on the bottom wall of the outer cover 1, and the axis of the cleaning air pipe 7 is set in the vertical direction. The cleaning air pipe 7 corresponds one-to-one with the powder suction pipe 5, that is, a cleaning air pipe 7 is set below each powder suction pipe 5. The upper opening of the cleaning air pipe 7 (i.e., the inlet end of the cleaning air pipe 7) is set upward, and the upper opening of the cleaning air pipe 7 is vertically aligned with the lower end of the powder suction pipe 5. The lower end of the cleaning air pipe 7 is connected to an air source (not shown in the figure) through a pipeline. This air source is used to introduce compressed gas into the cleaning air pipe 7 so as to backflush and clean the powder suction pipe 5 and subsequent pipelines in the cleaning mode.

[0046] A straightening bracket 6 is fixedly installed below the powder pump frame 3. The upper end of the straightening bracket 6 is fixedly connected to the powder pump frame 3, and the lower end of the straightening bracket 6 extends vertically downward and into the interior of the powder cylinder 2. A straightening sleeve 61 is provided at the lower end of the straightening bracket 6. The straightening sleeve 61 is a hollow sleeve structure with its axis set in the vertical direction. The powder suction pipe 5 passes through the straightening sleeve 61, and the powder suction pipe 5 and the straightening sleeve 61 are fixedly fitted. The fixed fit means that the outer wall of the powder suction pipe 5 and the inner wall of the straightening sleeve 61 are fixedly connected by interference fit or bonding, and there is no relative movement between the two. When the powder pump frame 3 is raised and lowered, the powder suction pipe 5 is raised and lowered synchronously with the powder pump frame 3, and the straightening bracket 6 and the straightening sleeve 61 are also raised and lowered synchronously with the powder pump frame 3. The lower end of the powder suction pipe 5 always extends a certain distance beyond the lower end of the straightening sleeve 61 to ensure that the powder suction pipe 5 can normally suck up the powder coating in the powder cylinder 2. The straightening sleeve 61 forms a radial constraint point at the lower part of the powder suction pipe 5, which effectively shortens the cantilever length of the lower end of the powder suction pipe 5, thereby significantly reducing the swing amplitude of the lower end of the powder suction pipe 5 during the lifting process and ensuring the alignment accuracy between the powder suction pipe 5 and the cleaning air pipe 7.

[0047] As a preferred embodiment, the centering sleeve 61 is disposed in the lower middle part of the powder suction pipe 5 and located above the detection end of the powder probe 11. Specifically, if the length of the cantilever section of the powder suction pipe 5 extending out of the lower surface of the powder pump frame 3 is defined as L, then the distance between the centering sleeve 61 and the lower end of the powder suction pipe 5 is 1 / 3 to 1 / 2 of the cantilever length L. In other words, the centering sleeve 61 is disposed in the lower middle position of the cantilever section of the powder suction pipe 5. Experimental verification shows that when the centering sleeve 61 is disposed in this position, it can effectively shorten the cantilever length of the lower end of the powder suction pipe 5, ensure centering accuracy, and prevent the centering sleeve 61 from contacting the powder coating contained in the powder cylinder 2. If the position of the centering sleeve 61 is higher than 1 / 2 of the length of the powder suction pipe 5 (i.e., the centering sleeve 61 is close to the powder pump frame 3), the cantilever length at the lower end of the powder suction pipe 5 will still be too long, the swing amplitude will still be large, and the centering effect will be poor. If the position of the centering sleeve 61 is lower than 1 / 3 of the length of the powder suction pipe 5 (i.e., the centering sleeve 61 is too close to the lower end of the powder suction pipe 5), the centering sleeve 61 may come into contact with the powder coating contained in the powder cylinder 2. Therefore, setting the centering sleeve 61 at 1 / 3 to 1 / 2 of the cantilever section of the powder suction pipe 5 is the preferred choice to achieve a balance between ensuring the centering effect and preventing the centering sleeve 61 from coming into contact with the powder coating contained in the powder cylinder 2.

[0048] As a further preferred embodiment, the outer contour dimensions of both the straightening bracket 6 and the straightening sleeve 61 are smaller than the inner diameter of the powder cylinder 2. Furthermore, throughout the entire lifting stroke of the powder pump frame 3, the straightening sleeve 61 remains inside the powder cylinder 2, and a gap is maintained between the outer wall of the straightening sleeve 61 and the inner wall of the powder cylinder 2, ensuring they do not contact each other. This arrangement fully utilizes the internal space of the powder cylinder 2 to constrain and straighten the powder suction pipe 5 throughout its entire lifting stroke, while simultaneously preventing the straightening sleeve 61 from colliding with or interfering with the powder cylinder 2 during lifting, thus ensuring the reliability and safety of the device's operation.

[0049] When it is necessary to clean the powder suction pipe 5, powder pump 4, and spray gun pipeline, the external control system controls the lifting cylinder 10 to drive the powder pump frame 3 to descend to the lowest working position, so that the lower end of the powder suction pipe 5 is inserted into the cleaning air pipe 7, and then the air source is started for backflushing cleaning. After cleaning is completed, the external control system controls the lifting cylinder 10 to drive the powder pump frame 3 to rise to the highest working position, so that the powder suction pipe 5 is withdrawn from the cleaning air pipe 7, and the powder pump frame 3 and powder suction pipe 5 are kept in the standby position, waiting for the next powder supply operation.

[0050] Through the linkage control of the powder probe 11 and the lifting cylinder 10, the automatic adjustment of the position of the powder suction pipe 5 and the automatic switching of the cleaning mode are realized during the powder supply process, which improves the automation level of the device and reduces manual intervention.

[0051] During cleaning, first remove (or move) the powder cylinder 2 from the outer cover 1, exposing the cleaning air pipe 7 located at the bottom of the outer cover 1. Then, activate the lifting cylinder 10 to drive the powder pump frame 3 downwards. The powder pump frame 3 drives the powder suction pipe 5, the straightening bracket 6, and the straightening sleeve 61 to move downwards simultaneously. When the powder pump frame 3 descends to the working position, the lower end of the powder suction pipe 5 is inserted into the cleaning air pipe 7. Because the straightening sleeve 61 provides effective radial constraint to the lower part of the powder suction pipe 5, the swing amplitude of the lower end of the powder suction pipe 5 during descent is significantly suppressed, thus ensuring accurate insertion into the cleaning air pipe 7 and avoiding collision damage caused by alignment deviation. Subsequently, activate the air source, and compressed gas enters the powder suction pipe 5 through the cleaning air pipe 7 to backflush and clean the residual powder in the powder suction pipe 5, powder pump 4, and spray gun pipeline. After cleaning, turn off the air source, start the lifting cylinder 10 to drive the powder pump frame 3 to rise and reset, the powder suction pipe 5 will exit from the cleaning air pipe 7, and then put the powder cylinder 2 back into the outer cover 1, and the normal powder supply operation can continue.

[0052] Example 2, as Figure 1-3 As shown, a powder supply device for powder coating spraying, based on Embodiment 1, this embodiment further describes in detail the connection relationship between the cleaning air pipe 7 and the air source.

[0053] The cleaning air pipe 7 is located at the bottom of the outer cover 1, with its upper opening facing upwards and vertically aligned with the lower end of the powder suction pipe 5. The lower end of the cleaning air pipe 7 is connected to an air source via an air supply line. This air source is used to introduce compressed gas into the cleaning air pipe 7 to perform backflushing cleaning of the powder suction pipe 5 and subsequent pipes in cleaning mode.

[0054] The inner diameter of the upper opening of the cleaning air pipe 7 is larger than the outer diameter of the powder suction pipe 5. During cleaning, the lower end of the powder suction pipe 5 is inserted into the upper opening of the cleaning air pipe 7, forming a clearance fit between them. When the gas from the air source enters the powder suction pipe 5 through the cleaning air pipe 7, due to the small gap between the powder suction pipe 5 and the cleaning air pipe 7, most of the gas enters the powder suction pipe 5, backflushing and cleaning the residual powder in the powder suction pipe 5, powder pump 4, and spray gun pipeline. A small amount of gas escapes from the gap between the outer wall of the powder suction pipe 5 and the inner wall of the cleaning air pipe 7, but this does not affect the cleaning effect.

[0055] In one possible implementation, a solenoid valve is provided between the cleaning air pipe 7 and the air source. This solenoid valve is electrically connected to the controller. In cleaning mode, the external control system controls the solenoid valve to open, and the gas from the air source enters the powder suction pipe 5 through the solenoid valve and the cleaning air pipe 7; after cleaning is completed, the controller controls the solenoid valve to close. This scheme facilitates automated control and timing management.

[0056] In another possible implementation, the cleaning air tube 7 is a fitting with an integrated normally closed mechanical trigger valve, and the cleaning air tube 7 is directly connected to the air source. This normally closed mechanical trigger valve remains closed in its natural state due to elastic restoring force. When the lower end of the suction tube 5 is inserted into the inlet of the cleaning air tube 7, the lower end of the suction tube 5 pushes the trigger component inside the cleaning air tube 7, overcoming the elastic restoring force and opening the valve structure inside the cleaning air tube 7. When the suction tube 5 is withdrawn from the cleaning air tube 7, the cleaning air tube 7 automatically returns to the closed state. Specifically, the cleaning air tube 7 includes a tube body and a valve core and elastic element disposed within the tube body. The elastic element is preferably a compression spring, with one end abutting against the inner wall of the tube body and the other end abutting against the valve core, so that the valve core closes the airflow passage of the tube body in its natural state (normally closed state). When the lower end of the suction pipe 5 is inserted into the cleaning air pipe 7, the end of the suction pipe 5 pushes the valve core downward, compressing the elastic element, thereby opening the airflow channel and allowing gas to enter the suction pipe 5 for backflushing cleaning. When the suction pipe 5 is withdrawn, the valve core moves upward under the restoring force of the elastic element, re-closing the airflow channel. This type of fitting, which integrates a normally closed mechanical trigger valve, has been widely used in the field of pneumatic control. Its specific structure and working principle are well-known technologies in this field and will not be described in detail here.

[0057] Preferably, the air source continuously supplies air to the air inlet of the cleaning air pipe 7, keeping the air inlet of the cleaning air pipe 7 under pressure at all times. When the powder suction pipe 5 is inserted into the cleaning air pipe 7 and its opening is triggered, the gas can respond instantly and enter the interior of the powder suction pipe 5 without waiting for the air source to start or the valve to open, thereby improving cleaning efficiency and shortening the cleaning cycle.

[0058] Example 3, as Figure 6 As shown, a powder supply device for powder coating spraying, based on Embodiment 1 or Embodiment 2, further includes an elastic guide ring 8 at the inlet end of the cleaning air pipe 7. The elastic guide ring 8 is fixedly installed at the upper inlet of the cleaning air pipe 7. The elastic guide ring 8 is made of an elastic material, preferably polyurethane rubber or fluororubber. Both polyurethane rubber and fluororubber have good elasticity and wear resistance, maintaining structural integrity even under repeated impacts from the end of the powder suction pipe 5 without scratching the outer wall of the suction pipe 5. Fluororubber, in particular, has excellent chemical corrosion resistance, adapting to various chemical components that may be present in the powder coating.

[0059] The inner diameter of the elastic guide ring 8 is a truncated cone shape, wider at the top and narrower at the bottom. Specifically, the inner diameter of the elastic guide ring 8 gradually decreases from its upper inlet to its lower outlet. The inner diameter at the upper inlet of the elastic guide ring 8 is larger than the outer diameter of the powder suction tube 5. Preferably, this maximum inner diameter is 6mm to 10mm larger than the outer diameter of the powder suction tube 5 to form a larger inlet opening, facilitating the entry of the lower end of the powder suction tube 5. The inner diameter at the lower outlet of the elastic guide ring 8 is slightly larger than the outer diameter of the powder suction tube 5. Preferably, this minimum inner diameter is 0.5mm to 1.0mm larger than the outer diameter of the powder suction tube 5 to ensure that the powder suction tube 5 can smoothly pass through the elastic guide ring 8 and enter the cleaning gas tube 7, while minimizing the leakage of cleaning gas.

[0060] The semi-cone angle of the conical structure of the elastic guide ring 8 is 30° to 45°. The semi-cone angle refers to the angle between the generatrix of the conical hole and the vertical axis. When the semi-cone angle is within this range, it can provide sufficient guide slope length to ensure the guiding effect, without causing excessive radial resistance at the end of the powder suction tube 5 when entering due to an excessively large cone angle. If the semi-cone angle is less than 30°, the conical hole is too thin and long, and the axial dimension is too large, which is not conducive to the compact design of the device; if the semi-cone angle is greater than 45°, the conical hole is too steep, the guiding effect is poor, and the end of the powder suction tube 5 is prone to getting stuck at the inlet.

[0061] The working principle of the elastic guide ring 8 is as follows: When the powder pump frame 3 descends and the lower end of the powder suction pipe 5 approaches the inlet end of the cleaning air pipe 7, even if there is a certain radial deviation between the lower end of the powder suction pipe 5 and the axis of the cleaning air pipe 7 (for example, deviation caused by installation errors, slight bending of the powder suction pipe 5 after long-term use, or vibration during the lifting process), the lower end of the powder suction pipe 5 first contacts the conical inclined surface at the upper inlet of the elastic guide ring 8. Guided by the conical inclined surface, the lower end of the powder suction pipe 5 slides along the conical surface towards the center. At the same time, the elastic material of the elastic guide ring 8 undergoes adaptive elastic deformation when squeezed by the powder suction pipe 5, further absorbing the radial deviation and reducing the impact force. Finally, the lower end of the powder suction pipe 5 accurately enters the interior of the cleaning air pipe 7 under the combined guidance of the conical inclined surface and elastic deformation, completing the insertion action.

[0062] The elastic guide ring 8 and the straightening sleeve 61 work together to ensure the alignment accuracy between the suction pipe 5 and the cleaning air pipe 7. The straightening sleeve 61 forms a radial constraint at the lower part of the suction pipe 5, controlling the swing amplitude of the lower end of the suction pipe 5 within a small range; the elastic guide ring 8 provides final guidance and correction when the suction pipe 5 is about to enter the cleaning air pipe 7, compensating for any slight radial deviation that may still exist after the constraint of the straightening sleeve 61. The synergistic effect of the two ensures that even after long-term use, if there are adverse conditions such as mounting bracket positioning deviation or slight bending of the suction pipe, the suction pipe 5 can still be reliably inserted into the cleaning air pipe 7.

[0063] Structures, components, and connection methods not described in detail in this utility model are all prior art known to those skilled in the art unless otherwise specified. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent features of the claims within this utility model.

Claims

1. A powder supply device for powder coating spraying, comprising an outer cover (1), a powder cylinder (2) disposed within the outer cover (1), and a powder pump frame (3), wherein the powder pump frame (3) is provided with a powder pump (4) and a powder suction pipe (5) communicating with the powder pump (4); characterized in that, Also includes: A straightening bracket (6) is fixedly installed below the powder pump frame (3). The lower end of the straightening bracket (6) is provided with a straightening sleeve (61). The powder suction pipe (5) passes through the straightening sleeve (61) and the two are fixedly matched. A cleaning air pipe (7) is set at the bottom of the outer cover (1). The cleaning air pipe (7) corresponds one-to-one with the powder suction pipe (5). The cleaning air pipe (7) is connected to an air source.

2. The powder supply device for powder coating spraying according to claim 1, characterized in that, The distance between the straightening sleeve (61) and the lower end of the powder suction pipe (5) is 1 / 3 to 1 / 2 of the length of the part of the powder suction pipe (5) that extends out of the powder pump frame (3).

3. The powder supply device for powder coating spraying according to claim 1, characterized in that, The cleaning air pipe (7) is a pipe fitting with a normally closed mechanical trigger valve integrated. Its air inlet end is connected to the air source and is kept under pressure. When the lower end of the powder suction pipe (5) is inserted into the cleaning air pipe (7), the mechanical trigger valve is triggered to open.

4. The powder supply device for powder coating spraying according to claim 1, characterized in that, The inlet end of the cleaning tube (7) is provided with an elastic guide ring (8). The inner hole of the elastic guide ring (8) is a cone shape with a larger upper diameter and a smaller lower diameter. Its minimum inner diameter is larger than the outer diameter of the powder suction tube (5).

5. The powder supply device for powder coating spraying according to claim 4, characterized in that, The elastic guide ring (8) is made of polyurethane rubber or fluororubber, and the semi-cone angle of the tapered structure of the elastic guide ring (8) is 30° to 45°.

6. The powder supply device for powder coating spraying according to claim 1, characterized in that, The outer cover (1) is provided with a guide post (9), and a guide sleeve (91) is fitted on the guide post (9). A lifting cylinder (10) is fixedly installed on the top of the outer cover (1). The piston rod of the lifting cylinder (10) is connected to the guide sleeve (91) or the powder pump frame (3).

7. The powder supply device for powder coating spraying according to claim 6, characterized in that, The lifting cylinder (10) is fixedly installed on the top outer side of the outer cover (1). The piston rod of the lifting cylinder (10) passes through the top of the outer cover (1) and is connected to the guide sleeve (91) or the powder pump frame (3).

8. The powder supply device for powder coating spraying according to claim 6, characterized in that, The powder pump frame (3) is provided with a downwardly extending powder probe (11), and the detection end of the powder probe (11) is located between the lower end of the straightening sleeve (61) and the powder suction pipe (5); the powder probe (11) is connected to the lifting cylinder (10) via an external control system.

9. The powder supply device for powder coating spraying according to claim 1, characterized in that, The powder pump frame (3) has two symmetrically arranged mounting rods (31), and each mounting rod (31) is provided with at least one powder suction assembly consisting of the powder pump (4) and the powder suction pipe (5).

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