A PVC glue spraying system

Abstract

This utility model discloses a PVC glue spraying system, relating to the technical field of glue spraying systems. The PVC glue spraying system includes: a movable frame with a glue bucket positioning component on its top surface for placing glue buckets; a feeding mechanism including a feeding pump with a pressure valve at its lower end and a pneumatic motor at its upper end; a pressure regulating mechanism including a pressure stabilizing valve with an adjustable glue flow chamber inside, one end of which is connected to an inlet pipe connected to the outlet of the feeding pump, and the other end connected to an outlet pipe connected to a spraying component; and an accumulator connected to the inlet pipe. This PVC glue spraying system solves the technical problems of existing PVC glue spraying systems, which cannot accurately control the glue dispensing precision of the spraying component and have poor dispensing stability, making it difficult to achieve efficient and stable glue spraying.

Description

Technical Field

[0001] This utility model relates to the technical field of adhesive spraying systems, and in particular to a PVC adhesive spraying system. Background Technology

[0002] PVC spraying involves atomizing and spraying paint onto a workpiece to provide a protective, decorative, or functional PVC coating, meeting various needs such as corrosion resistance, decoration, and insulation. It is an indispensable and crucial step in modern manufacturing. Currently, this coating process is applied to multiple stages of automobile production.

[0003] However, existing PVC adhesive spraying systems cannot precisely control the adhesive dispensing accuracy of the spraying components, and the dispensing stability is poor, making it difficult to achieve efficient and stable adhesive spraying. Therefore, a PVC adhesive spraying system designed to solve the above problems is proposed. Utility Model Content

[0004] The purpose of this invention is to provide a PVC glue spraying system that solves the technical problems of existing PVC glue spraying systems, which cannot accurately control the glue dispensing precision and have poor dispensing stability, making it difficult to achieve efficient and stable glue spraying.

[0005] To achieve the above objectives, this utility model provides a PVC glue spraying system, including: a movable frame, wherein the top surface of the movable frame is provided with a glue bucket positioning component for placing glue buckets;

[0006] A feeding mechanism is located above the movable frame plate. The feeding mechanism includes a feeding pump, the lower end of which is connected to a pressure plate, and the upper end of which is connected to a pneumatic motor. The pneumatic motor can be driven to move downward so that the pressure plate presses down on the glue in the glue bucket.

[0007] The pressure regulating mechanism includes:

[0008] A pressure regulating valve has an internal fluid chamber for adjusting the glue flow rate. One end of the fluid chamber is connected to the glue inlet pipe, which is connected to the outlet of the feed pump. The other end of the fluid chamber is connected to the glue outlet pipe, which is connected to the spraying assembly.

[0009] An accumulator is connected to the glue inlet pipe, and the accumulator is used to adjust the pressure of the glue in the glue inlet pipe according to the pressure of the glue in the glue outlet pipe.

[0010] Preferably, the top surface of the movable frame is provided with a lifting mechanism, which includes two symmetrically arranged lifting cylinders, the output ends of the two lifting cylinders being respectively connected to the two ends of the crossbeam, and the crossbeam being connected to the pneumatic motor.

[0011] Preferably, the glue bucket positioning assembly includes a positioning groove disposed on the top surface of the movable frame plate, and a plurality of positioning frames are symmetrically arranged on both sides of the positioning groove.

[0012] Preferably, the top surface of the positioning frame is provided with an oblong hole, the extension direction of which is consistent with the radial direction of the glue bucket, and the locking bolt passes through the oblong hole to thread-connect the movable frame plate.

[0013] Preferably, a filter is installed at one end of the glue inlet pipe that connects to the outlet of the feed pump.

[0014] Preferably, a first pressure relief device is provided at one end of the glue outlet pipe connected to the outlet of the feed pump, and the first pressure relief device is located at the outlet end of the filter.

[0015] Preferably, the first pressure relief device is provided with a control valve for controlling the opening and closing of the internal passage of the first pressure relief device.

[0016] Preferably, a shut-off ball valve for controlling the opening and closing of the dispensing pipeline is provided in the dispensing pipeline.

[0017] Preferably, a piston seat is provided in the middle of the fluid chamber, the piston seat is used to separate the upper end and the lower end of the fluid chamber, and a feed hole is provided at the axial position of the piston seat to connect the upper end and the lower end of the fluid chamber. The bottom of the fluid chamber is connected to a piston member by a support spring. The piston member is located at one end of the feed hole and can be driven to reciprocate along the axial direction of the piston seat to adjust the gap between the piston seat and the piston member.

[0018] Preferably, a diaphragm is provided at the upper end of the pressure regulating valve, and the upper part of the diaphragm and the pressure regulating valve are combined to form a sealed cavity. An air inlet is provided at the top of the pressure regulating valve, the air inlet is connected to the sealed cavity, and the air inlet is connected to a proportional pressure valve through an air inlet pipe. A movable column is provided on the bottom surface of the diaphragm, the movable column is slidably disposed at the upper end of the fluid chamber, and a ejector pin is connected to the bottom of the movable column, the ejector pin being located directly above the piston.

[0019] Compared with the above-mentioned background technology, the PVC glue spraying system provided by this utility model has the following beneficial effects: the feeding mechanism transports the glue in the glue bucket to the glue inlet pipe, and the glue inlet pipe further transports the glue to the fluid chamber in the pressure regulating valve. By adjusting the glue flow rate in the fluid chamber, the pressure of the glue in the glue outlet pipe can be precisely controlled to ensure the glue dispensing accuracy of the spraying component, improve the glue dispensing stability of the spraying component, and thus achieve efficient and stable glue spraying work; moreover, the accumulator can adjust the pressure of the glue in the feeding pipe according to the pressure of the glue in the glue outlet pipe, offset the pressure change of the glue in the glue outlet pipe, stabilize the pressure of the glue in the glue outlet pipe, and further ensure the glue dispensing accuracy of the spraying component. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a three-dimensional structural diagram of the PVC adhesive spraying system provided in the embodiment of this utility model;

[0022] Figure 2 This is an exploded view of the PVC adhesive spraying system provided in an embodiment of the present invention.

[0023] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0024] Figure 4 A three-dimensional structural diagram of the adjustment mechanism provided in an embodiment of this utility model;

[0025] Figure 5 This is a cross-sectional schematic diagram of the pressure regulating valve provided in an embodiment of the present invention.

[0026] Specifically, 1-Moving frame; 2-Pressure regulator; 201-Glue inlet; 202-Glue outlet; 3-Fluid chamber; 4-Piston seat; 5-Support spring; 6-Piston component; 7-Glue inlet pipe; 8-Feed hole; 9-Accumulator; 10-Moving column; 11-Annular groove; 12-Glue outlet pipe; 13-Reset spring; 14-Ejector pin; 15-Diaphragm; 16-Sealed cavity; 17-Air inlet; 18-Proportional pressure valve; 19-Assembly block; 20-Lower diaphragm; 21-... - Pressure sensor; 22 - Second pressure relief device; 23 - Second control valve; 24 - Shut-off ball valve; 25 - Feed pump; 26 - Discharge port; 27 - Pressure plate; 28 - Pneumatic motor; 2801 - Support rod; 29 - Positioning groove; 30 - Positioning frame; 3001 - Waist-shaped hole; 3002 - Locking bolt; 31 - Spraying assembly; 32 - Lifting cylinder; 3201 - Crossbeam; 33 - Filter; 34 - First pressure relief device; 35 - First control valve; 36 - Control cabinet. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 and Figure 2 As shown, in order to achieve the above objectives, this utility model provides a PVC glue spraying system, including: a movable frame 1, a feeding mechanism and a pressure regulating mechanism. The movable frame 1 is equipped with several casters on the ground to facilitate the transfer of the entire PVC glue spraying system and make it more convenient to use. The top surface of the movable frame 1 is equipped with a glue bucket positioning component for placing glue buckets. The glue bucket positioning component is mainly used to position the glue buckets.

[0030] A feeding mechanism is installed above the movable shelf 1. The feeding mechanism includes a feeding pump 25. Optionally, the feeding pump 25 is a 55-gallon pressure plate pump 27, equipped with a low liquid level alarm device. When the remaining glue in the glue bucket is less than 5%, the low liquid level alarm device will sound an alarm to prompt the staff to replace the glue bucket in time. The lower end of the feeding pump 25 is connected to the pressure plate 27, and the upper end of the feeding pump 25 is connected to a pneumatic motor 28 through a ventilation pipe. The pneumatic motor 28 is used to provide power to the feeding pump 25. It should be noted that the pneumatic motor 28 is connected to the feeding pump 25 through multiple support rods 2801. By driving the pneumatic motor 28 to move downward, the pressure plate 27 can press down the glue in the glue bucket. At the same time, the feeding pump 25 works to transport the glue in the glue bucket to the glue inlet pipe 7.

[0031] The pressure regulating mechanism includes a pressure regulating valve 2. The pressure regulating valve 2 has a fluid chamber 3 inside which the glue flow rate can be adjusted. One end of the fluid chamber 3 is connected to the glue inlet pipe 7, and the other end of the fluid chamber 3 is connected to the glue outlet pipe 12. The glue outlet pipe 12 is connected to the spraying assembly 31. The glue in the glue bucket is transported to the glue inlet pipe 7 by the feeding mechanism. The glue inlet pipe 7 further transports the glue to the fluid chamber 3 in the pressure regulating valve 2. By adjusting the glue flow rate in the fluid chamber 3, the pressure of the glue in the glue outlet pipe 12 can be precisely controlled to ensure the glue dispensing accuracy of the spraying assembly 31, improve the glue dispensing stability of the spraying assembly 31, and thus achieve efficient and stable glue spraying.

[0032] Accumulator 9 is connected to glue inlet line 7. Accumulator 9 is used to adjust the pressure of glue in glue inlet line 7 according to the pressure of glue in glue outlet line 12. Accumulator 9 can store excess glue in glue in glue inlet line 7 and can also release stored glue into glue inlet line 7. Specifically, when the pressure of glue output from fluid chamber 3 increases, accumulator 9 stores excess glue in glue inlet line 7; when the gap between piston seat 4 and piston 6 decreases, accumulator 9 releases stored glue to offset the pressure change of glue in glue outlet line 12, stabilize the pressure of glue in glue outlet line 12, and further ensure the glue dispensing accuracy of spraying assembly 31.

[0033] In some embodiments of this utility model, a lifting mechanism is provided on the top surface of the movable frame 1. The lifting mechanism includes two symmetrically arranged lifting cylinders 32, which are vertically arranged. The output ends of the two lifting cylinders 32 are respectively connected to the two ends of the crossbeam 3201. The crossbeam 3201 is connected to a pneumatic motor 28. By controlling the synchronous extension and retraction of the two lifting cylinders 32, the crossbeam 3201 is driven to move up and down, thereby driving the pneumatic motor 28, the glue supply pump, and the pressure plate 27 located at the lower end of the glue supply pump to move up and down synchronously. When the two lifting cylinders 32 are controlled to retract synchronously, driving the crossbeam 3201 to move downward, the crossbeam 3201 drives the pneumatic motor 28, the glue supply pump, and the pressure plate 27 located at the lower end of the glue supply pump to move downward synchronously, causing the pressure plate 27 to press down the glue in the glue bucket. At the same time, it works in conjunction with the feed pump 25 to transport the glue in the glue bucket to the glue inlet pipe 7.

[0034] like Figure 2 As shown, in some embodiments of this utility model, the glue bucket positioning assembly includes a positioning groove 29 disposed on the top surface of the movable frame plate 1. When replacing a new glue bucket, the positioning groove 29 can initially position the glue bucket. In addition, several positioning frames 30 are symmetrically arranged on both sides of the positioning groove 29. By moving the positioning frames 30, each positioning frame 30 abuts against the outer wall of the glue bucket to ensure that the glue bucket can be stably fixed on the movable frame plate 1, so that the pressure plate 27 and the glue bucket can be precisely matched, ensuring the stability of the entire PVC glue spraying system during operation.

[0035] like Figure 3 As shown, it should be noted that the top surface of the positioning frame 30 is provided with an oblong hole 3001. The extension direction of the oblong hole 3001 is consistent with the radial direction of the glue bucket. That is, when the glue bucket is placed in the positioning groove 29, the positioning frame 30 can abut against or move away from the outer wall of the glue bucket along the radial direction of the glue bucket. After each positioning frame 30 abuts against the outer wall of the glue bucket, the moving frame plate 1 is threaded through the threaded connection oblong hole 3001 by the locking bolt 3002, thereby locking the positioning frame 30 on the moving frame plate 1 and making the glue bucket stably fixed on the moving frame plate 1.

[0036] In some embodiments of this utility model, a filter 33 is provided at one end of the glue inlet pipe 7 connected to the outlet 26 of the feed pump 25. The filter 33 can filter and purify the glue to ensure that the glue entering the feed pipe and the spraying assembly 31 is free of impurities, thereby extending the service life of the overall PVC glue spraying system.

[0037] In some embodiments of this utility model, a first pressure relief device 34 is provided at one end of the glue inlet pipe 7 connected to the outlet 26 of the feed pump 25. The first pressure relief device 34 is located at the outlet end of the filter 33. The glue inlet pipe 7 and the fluid chamber 3 are quickly discharged through the first pressure relief device 34 to ensure that the glue inlet pipe 7 and the fluid chamber 3 are always kept clean. In addition, a second pressure relief device 22 is provided on the glue outlet pipe 12. After the glue application is stopped, the glue in the glue outlet pipe 12 and the fluid chamber 3 are quickly discharged through the second pressure relief device 22 to ensure that the glue outlet pipe 12 and the fluid chamber 3 are always kept clean.

[0038] Optionally, a first control valve 35 is provided on the first pressure relief device 34 to flexibly control the opening and closing of the first pressure relief device 34, and a second control valve 23 is provided on the second pressure relief device 22 to flexibly control the opening and closing of the second pressure relief device 22; at the same time, a shut-off ball valve 24 is provided in the glue dispensing pipeline 12 to flexibly control the opening and closing of the glue dispensing pipeline 12.

[0039] like Figure 4 and Figure 5 As shown, in some embodiments of this utility model, a piston seat 4 is provided in the middle of the fluid chamber 3, separating the upper end and the lower end of the fluid chamber 3. Further, a feed hole 8 is provided at the axial position of the piston seat 4, connecting the upper end and the lower end of the fluid chamber 3. Simultaneously, a piston 6 is provided at the bottom of the fluid chamber 3. The piston 6 is generally spherical; preferably, it is a steel ball. The lower part of the piston 6 is connected to the bottom of the fluid chamber 3 via a support spring 5, the extension and retraction direction of which is consistent with the axial direction of the piston seat 4.

[0040] It should be noted that the pressure regulating valve 2 is provided with an inlet 201 and an outlet 202. The inlet 201 is connected to the inlet pipe 7, and the outlet 202 is connected to the outlet pipe 12. That is, the inlet 201 connects the inlet pipe 7 and the fluid chamber 3, and the outlet 202 connects the outlet pipe 12 and the fluid chamber 3.

[0041] It should be further explained that the piston 6 is located at one end of the feed hole 8. By controlling the reciprocating movement of the piston 6 along the axis of the piston seat 4, the gap between the piston seat 4 and the piston 6 can be adjusted to precisely control the amount of glue passing through the fluid chamber 3. This allows for precise adjustment of the glue pressure in the glue dispensing pipe 12 to ensure the glue dispensing accuracy of the spraying assembly 31.

[0042] In some embodiments of this utility model, a diaphragm 15 is provided at the upper end of the pressure regulating valve 2, a movable column 10 is provided on the bottom surface of the diaphragm 15, and a movable column 10 is slidably provided at the upper end of the fluid chamber 3. The axis of the movable column 10 is aligned with the axis of the piston seat 4. A pin 14 is connected to the bottom of the movable column 10. The pin 14 is located directly above the piston 6. The movable column 10 can be driven to reciprocate along the axis of the piston seat 4, so that the pin 14 holds or moves away from the top of the piston 6. When the control drive moving column 10 moves downward along the axis of the piston seat 4, the ejector pin 14 presses against the top of the piston 6, causing the piston 6 to gradually move away from the lower end of the piston seat 4, increasing the gap between the piston seat 4 and the piston 6. At this time, the support spring 5 is compressed and has elastic potential energy. When the control drive moving column 10 moves upward along the axis of the piston seat 4, the ejector pin 14 leaves the top of the piston 6, and the support spring 5 extends back to its initial length, causing the top of the piston 6 to gradually approach the lower end of the piston seat 4, decreasing the gap between the piston seat 4 and the piston 6.

[0043] It should be noted that the upper part of the diaphragm 15 and the mounting housing combine to form a sealed cavity 16. An air inlet 17 is provided on the top of the mounting housing, which is connected to the sealed cavity 16 and a proportional pressure valve 18. Gas is supplied to the proportional pressure valve 18 from the front triplet. The proportional pressure valve inputs gas into the sealed cavity 16 through the air inlet pipe. Under the action of gas pressure, the bottom surface of the diaphragm 15 moves towards the piston seat 4, thereby precisely controlling the downward movement of the moving column 10. When the proportional pressure valve stops supplying gas to the sealed cavity 16, the bottom surface of the diaphragm 15 moves away from the piston seat 4 under the action of gas pressure, thereby precisely controlling the upward movement of the moving column 10.

[0044] In some embodiments of this utility model, an assembly block 19 is provided at the first end of the fluid chamber 3, and an assembly hole is provided at the axial position of the assembly block 19. The axis of the assembly hole is consistent with the axis of the moving column 10. The assembly hole is slidably connected to the moving column 10. By slidingly engaging the assembly hole with the moving column 10, the movement path of the moving column 10 can be effectively controlled, thereby improving the fitting accuracy between the ejector pin 14 and the piston 6, effectively ensuring precise control of the gap between the piston seat 4 and the piston 6, and thus precisely controlling the amount of glue passing through the fluid chamber 3, ensuring the glue dispensing accuracy of the spraying assembly 31.

[0045] Optionally, a lower diaphragm 20 is provided on the bottom surface of the assembly block 19. The lower diaphragm 20 can seal the top of the fluid chamber 3 to prevent the glue in the fluid chamber 3 from entering above, so as to ensure that the moving column 10 and the assembly block 19 are always stably engaged.

[0046] In some embodiments of this utility model, an annular groove 11 is provided at the bottom of the moving column 10. The annular groove 11 is coaxially arranged on the outer circumferential side of the moving column 10. A return spring 13 is coaxially arranged on the outer circumferential side of the moving column 10. The upper end of the return spring 13 is connected to the end face of the annular groove 11, and the lower end of the return spring 13 is connected to the top surface of the assembly block 19. When the pressure proportional valve inputs gas into the sealed cavity 16 through the air inlet pipe, and the bottom surface of the diaphragm 15 moves towards the piston seat 4 under the action of gas pressure, the moving column 10 descends, and the return spring 13 is compressed to have elastic potential energy. When the pressure proportional valve stops supplying gas to the sealed cavity 16, and the bottom surface of the diaphragm 15 moves away from the piston seat 4 under the action of gas pressure, the return spring 13 extends and returns to its initial state, causing the moving column 10 to rise rapidly.

[0047] In some embodiments of this utility model, a control cabinet 36 is also provided. The control cabinet 36 is equipped with a control system. The control system is connected to the proportional pressure valve 18, the accumulator 9, the shut-off ball valve 24, and the pressure sensor 21. The control system can set the pressure value when the glue is output from the fluid chamber 3, thereby controlling the pressure of the proportional pressure valve 18 supplying air to the pressure regulating valve 2, changing the pressure adjustment range of the pressure regulating valve 2, that is, the gap between the piston seat 4 and the piston 6, thereby adjusting the pressure when the glue is output from the fluid chamber 3. The whole process is automatically controlled without manual intervention, saving manpower.

[0048] In some embodiments of this invention, a pressure sensor 21 is provided at the glue outlet 202 position, which can detect the pressure of the glue when it is output from the fluid chamber 3. Optionally, based on the detected pressure of the glue when it is output from the fluid chamber 3, the pressure supplied by the proportional pressure valve 18 is controlled, and the gap between the piston seat 4 and the piston 6 in the pressure regulating valve 2 is flexibly controlled, so that the pressure of the glue when it is output from the fluid chamber 3 is always kept stable.

[0049] The working principle of this utility model is as follows: the proportional pressure valve 18 inputs gas into the sealed cavity 16 through the air inlet pipe. Under the action of gas pressure, the bottom surface of the diaphragm 15 moves towards the piston seat 4. The moving column 10 descends and pushes the ejector pin 14 to hold the top of the piston 6. The piston 6 gradually moves away from the lower end of the piston seat 4 until the gap between the piston seat 4 and the piston 6 is adjusted to a suitable value. The feeding mechanism delivers the glue in the glue bucket to the glue inlet pipe 7. The glue inlet pipe 7 delivers the glue to the fluid chamber 3 in the pressure regulating valve 2. The glue in the fluid chamber 3 is further delivered to the spraying assembly 31 through the glue outlet pipe 12. The glue is then stably sprayed out by the spraying assembly 31.

[0050] In summary, the feeding mechanism delivers the glue from the glue bucket to the glue inlet pipe 7, which then delivers the glue to the fluid chamber 3 in the pressure regulating valve 2. By adjusting the glue flow rate in the fluid chamber 3, the pressure of the glue in the glue outlet pipe 12 can be precisely controlled to ensure the glue dispensing accuracy of the spraying component, improve the glue dispensing stability of the spraying component 31, and thus achieve efficient and stable glue spraying.

[0051] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0052] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A PVC adhesive spraying system, characterized in that, include: A movable shelf, the top surface of which is provided with a glue bucket positioning assembly for placing glue buckets; A feeding mechanism is located above the movable frame plate. The feeding mechanism includes a feeding pump, the lower end of which is connected to a pressure plate, and the upper end of which is connected to a pneumatic motor. The pneumatic motor can be driven to move downward so that the pressure plate presses down on the glue in the glue bucket. The pressure regulating mechanism includes: A pressure regulating valve has an internal fluid chamber for adjusting the glue flow rate. One end of the fluid chamber is connected to the glue inlet pipe, which is connected to the outlet of the feed pump. The other end of the fluid chamber is connected to the glue outlet pipe, which is connected to the spraying assembly. An accumulator is connected to the glue inlet pipe, and the accumulator is used to adjust the pressure of the glue in the glue inlet pipe according to the pressure of the glue in the glue outlet pipe.

2. The PVC glue spraying system according to claim 1, wherein, The top surface of the movable frame is provided with a lifting mechanism, which includes two symmetrically arranged lifting cylinders. The output ends of the two lifting cylinders are respectively connected to the two ends of the crossbeam, and the crossbeam is connected to the pneumatic motor.

3. The PVC glue spraying system of claim 1, wherein, The glue bucket positioning assembly includes a positioning groove disposed on the top surface of the movable frame plate, and several positioning frames are symmetrically arranged on both sides of the positioning groove.

4. The PVC glue spraying system of claim 3, wherein, The top surface of the positioning frame is provided with an oblong hole, the extension direction of which is consistent with the radial direction of the rubber bucket, and the locking bolt passes through the oblong hole to thread the movable frame plate.

5. The PVC glue spraying system of claim 1, wherein, A filter is installed at one end of the glue inlet pipe that connects to the outlet of the feed pump.

6. The PVC glue spraying system of claim 5, wherein, A first pressure relief device is provided at one end of the glue outlet pipeline connected to the outlet of the feed pump, and the first pressure relief device is located at the outlet end of the filter.

7. The PVC glue spraying system of claim 6, wherein, The first pressure relief device is equipped with a control valve for controlling the opening and closing of the internal passage of the first pressure relief device.

8. The PVC glue spraying system of claim 1, wherein, The dispensing pipeline is equipped with a shut-off ball valve for controlling the opening and closing of the dispensing pipeline.

9. A PVC glue spraying system according to any one of claims 1-8, characterized in that, A piston seat is provided in the middle of the fluid chamber, which separates the upper end and the lower end of the fluid chamber. A feed hole is provided at the axial position of the piston seat, connecting the upper end and the lower end of the fluid chamber. The bottom of the fluid chamber is connected to a piston member by a support spring. The piston member is located at one end of the feed hole and can be driven to reciprocate along the axial direction of the piston seat to adjust the gap between the piston seat and the piston member.

10. The PVC glue spraying system of claim 9, wherein, The pressure regulating valve has a diaphragm at its upper end, and the diaphragm and the pressure regulating valve together form a sealed cavity. The pressure regulating valve has an air inlet at its top, which is connected to the sealed cavity and connected to a proportional pressure valve via an air inlet pipe. The bottom surface of the diaphragm has a movable column, which is slidably disposed at the upper end of the fluid chamber. The bottom of the movable column is connected to a ejector pin, which is located directly above the piston.

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