Negative pressure detection device

Abstract

The utility model relates to the field of leakage detection of plastic products, in particular to a negative pressure detection device. Comprising a bottom plate and a connecting base, a lower die is installed on the upper surface of the bottom plate, a workpiece body is attached to the inner wall of the lower die, an air cylinder is installed on the upper surface of the connecting base, a sealing pressing plate is installed at the output end of the air cylinder, the size of the sealing pressing plate is larger than that of the lower die, and a control switch is installed on the upper surface of the connecting base. A first vacuum meter is installed on the upper surface of the connecting seat, a second vacuum meter is installed on the upper surface of the connecting seat, a vacuum detection transmission pipe is installed on one side of the first vacuum meter, a vacuum transmission pipe is installed on one side of the second vacuum meter, and a compressed air inlet is formed in the upper surface of the connecting seat. The negative pressure detection device provided by the utility model has the advantages that the product performance can be detected and judged in advance, and compared with the prior art that the leakage condition of a workpiece body cannot be detected, the qualification rate is obviously improved.

Description

Technical Field

[0001] The utility model relates to the field of plastic product leakage detection, in particular to a negative pressure detection device. Background Art

[0002] During the production process of plastic products, a negative pressure detection device is needed to detect the sealing performance of plastic products.

[0003] The utility model with announcement number CN209841310U discloses a negative pressure detection device, and the key points of its technical solution are: it includes an exhaust mechanism, a connecting mechanism and a pressure gauge, the connecting mechanism includes two oppositely arranged ends, one end of the connecting mechanism is connected to the exhaust mechanism, and the other end is used to connect to the object to be detected, the pressure gauge is connected to the connecting mechanism, and is used to detect the internal air pressure of the connecting mechanism.

[0004] In response to the above-mentioned relevant contents, the inventor believes that the following technical defects exist: the negative pressure detection device in the prior art cannot detect the sealing performance of the product in advance, which may easily lead to unqualified products after welding and inability to rework, which will in turn cause the entire product to be scrapped, resulting in a huge waste of parts and product costs. Utility Model Content

[0005] The utility model aims to solve the shortcomings in the prior art and proposes a negative pressure detection device.

[0006] In order to solve the above technical problems, the utility model provides a negative pressure detection device, including: a base plate and a connecting seat, a lower mold is installed on the upper surface of the base plate, the inner wall of the lower mold is fitted with a workpiece body, a cylinder is installed on the upper surface of the connecting seat, a sealing pressure plate is installed on the output end of the cylinder, the size of the sealing pressure plate is larger than the size of the lower mold, and a control switch is installed on the upper surface of the connecting seat.

[0007] Preferably, a first vacuum gauge is installed on the upper surface of the connecting seat, a second vacuum gauge is installed on the upper surface of the connecting seat, a vacuum detection transmission tube is installed on one side of the first vacuum gauge, a vacuum transmission tube is installed on one side of the second vacuum gauge, a compressed air inlet is provided on the upper surface of the connecting seat, and a vacuum source is provided on the upper surface of the connecting seat.

[0008] Preferably, two guide sleeves are fixedly connected to the surface of the sealing pressure plate, and guide pillars are slidably connected to the inner walls of the guide sleeves, and two ends of the guide pillars are fixedly connected to the bottom plate and the connecting seat respectively.

[0009] Preferably, a sealing pad is glued to the lower surface of the sealing pressure plate by means of glue.

[0010] Preferably, a plurality of fixing screws are threadedly penetrated through the surface of the sealing rubber gasket, and the fixing screws are threadedly connected to the sealing pressure plate.

[0011] Preferably, a pre-inspection solenoid valve sealing housing is installed on the upper surface of the lower mold.

[0012] Preferably, a compression spring is arranged inside the sealing shell of the pre-check solenoid valve.

[0013] Compared with the related art, the negative pressure detection device provided by the utility model has the following beneficial effects:

[0014] The utility model provides a negative pressure detection device. When in use, the electromagnetic valve which has been welded and riveted is first welded to the upper cover of the part, and the electromagnetic valve is placed in the bottom plate imitation groove of the detection device. The sealing pressure plate lifting cylinder control switch is turned on to make the sealing pressure plate contact with the welding surface of the product. The cylinder output pressure presses the surface to be welded to achieve the purpose of vacuum without leakage. Then, a 12V power supply is passed to the electromagnetic valve of the product to observe whether the electromagnetic valve operates normally. After the electromagnetic valve operates normally, a vacuum pump is turned on to vacuumize the product, and the pressure of the second vacuum gauge is observed to reach 0.085 MPa. Then, the vacuum pump switch is turned off, and the pointer of the second vacuum gauge is observed for about 5 seconds. Whether the pressure pointer of the vacuum gauge drops or not. If it can still reach 0.085 MPa after 5 seconds, it means that there is no problem in the sealing of the rubber pad of the moving iron core of the product and the upper cover of the product. Then, the 12V power supply is continued to be passed to the electromagnetic valve of the product. After powering on, a passage is formed between the first vacuum gauge and the second vacuum gauge. When the vacuum pump power is turned off, the pressure pointers of the first vacuum gauge and the second vacuum gauge do not drop, indicating that the product does not leak. Then, the plastic shell of the electromagnetic valve is welded. After welding, remove the sealing shell of the pre-inspection solenoid valve, place the welded product in the bottom plate profiling groove and repeat the above steps. If there is no leakage, it means that the product welding is qualified.

[0015] This solution uses a mold frame structure and a profiling structure to replace plastic parts for pre-testing. By adding pipes and connections between vacuum gauges, the product's sealing performance can be predicted. The leakage of the vacuum gauge of the product can be observed to determine whether the product is qualified. Since the parts are pre-tested for leakage before welding, they can be reworked without welding.

[0016] By setting up the overall structure, product performance can be detected and judged in advance. Compared with the previous process where leakage could not be detected, the pass rate has been significantly improved. The original process could not detect product performance in advance, and unqualified products after welding could not be reworked, resulting in the entire product being scrapped, causing a huge waste of parts and product costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a negative pressure detection device provided by the utility model;

[0018] Figure 2 for Figure 1The left structural diagram shown;

[0019] Figure 3 for Figure 1 Schematic diagram of the local structure shown.

[0020] Numbers in the figure: 1. Base plate; 2. Connecting seat; 3. Sealing pressure plate; 4. First vacuum gauge; 5. Control switch; 6. Second vacuum gauge; 7. Cylinder; 8. Guide column; 9. Guide sleeve; 10. Sealing rubber pad; 11. Fixing screw; 12. Sealing housing of pre-inspection solenoid valve; 13. Compression spring; 14. Vacuum detection transmission tube; 15. Vacuum transmission tube; 16. Compressed air inlet; 17. Vacuum source; 18. Lower die; 19. Workpiece body. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0022] The specific implementation of the present utility model is described in detail below in conjunction with specific embodiments.

[0023] See also Figures 1 to 3 A negative pressure detection device provided by an embodiment of the utility model includes: a base plate 1 and a connecting seat 2, a lower mold 18 is installed on the upper surface of the base plate 1, and a workpiece body 19 is attached to the inner wall of the lower mold 18, a cylinder 7 is installed on the upper surface of the connecting seat 2, and a sealing pressure plate 3 is installed on the output end of the cylinder 7, the size of the sealing pressure plate 3 is larger than the size of the lower mold 18, and a control switch 5 is installed on the upper surface of the connecting seat 2.

[0024] In the embodiments of the present invention, please refer to Figure 1 , Figure 2 and Figure 3 , a first vacuum gauge 4 is installed on the upper surface of the connecting seat 2, a second vacuum gauge 6 is installed on the upper surface of the connecting seat 2, a vacuum detection transmission tube 14 is installed on one side of the first vacuum gauge 4, a vacuum transmission tube 15 is installed on one side of the second vacuum gauge 6, a compressed air inlet 16 is provided on the upper surface of the connecting seat 2, a vacuum source 17 is provided on the upper surface of the connecting seat 2, two guide sleeves 9 are fixedly connected to the surface of the sealing plate 3, a guide column 8 is slidably connected to the inner wall of the guide sleeve 9, and the two ends of the guide column 8 are respectively fixedly connected to the bottom plate 1 and the connecting seat 2, a sealing pad 10 is glued to the lower surface of the sealing plate 3 by means of glue, a plurality of fixing screws 11 are threadedly penetrated on the surface of the sealing pad 10, and the fixing screws 11 are threadedly connected to the sealing plate 3, a pre-inspection solenoid valve sealing shell 12 is installed on the upper surface of the lower mold 18, and a compression spring 13 is provided inside the pre-inspection solenoid valve sealing shell 12;

[0025] The working principle of a negative pressure detection device provided by the utility model is as follows: when in use, first weld and rivet the solenoid valve, weld it to the upper cover of the part, put it in the imitation groove of the bottom plate 1 of the detection device, open the sealing pressing plate 3 lifting cylinder 7 control switch 5, make the sealing pressing plate 3 contact the welding surface of the product, and the cylinder 7 outputs pressure to press the surface to be welded to achieve the purpose of vacuum without leakage, then pass 12V power to the solenoid valve of the product, observe whether the solenoid valve operates normally, after the solenoid valve operates normally, turn on the vacuum pump to vacuum the product, observe whether the pressure of the second vacuum gauge 6 reaches 0.085 MPa, then turn off the vacuum pump switch, observe the pointer of the second vacuum gauge 6 for about 5 seconds, and see if the pressure pointer of the vacuum gauge drops. If it can still reach 0.085 MPa after 5 seconds, it means that there is no problem with the sealing of the rubber pad of the moving iron core of the product and the upper cover of the product, and then continue to pass 12V power to the solenoid valve of the product. After powering on, the first vacuum gauge 4 and the second vacuum gauge 6 form a passage, turn off the vacuum pump power, and the pressure pointers of the first vacuum gauge 4 and the second vacuum gauge 6 do not drop, indicating that the product does not leak, and weld the plastic shell of the solenoid valve. After welding, remove the sealed housing 12 of the pre-inspection solenoid valve, place the welded product in the profiling groove of the bottom plate 1, and repeat the above steps. If there is no leakage, it means that the product welding is qualified.

[0026] This solution uses a mold frame structure and a profiling structure to replace plastic parts for pre-testing. By adding pipes and connections between vacuum gauges, the product's sealing performance can be predicted. The leakage of the vacuum gauge of the product can be observed to determine whether the product is qualified. Since the parts are pre-tested for leakage before welding, they can be reworked without welding.

[0027] By setting up the overall structure, product performance can be detected and judged in advance. Compared with the previous process where leakage could not be detected, the pass rate has been significantly improved. The original process could not detect product performance in advance, and unqualified products after welding could not be reworked, resulting in the entire product being scrapped, causing a huge waste of parts and product costs.

[0028] The circuits and controls involved in the present invention are all prior art and will not be described in detail here.

[0029] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A negative pressure detection device, characterized in that: include: A base plate (1) and a connecting seat (2), wherein a lower die (18) is mounted on the upper surface of the base plate (1), and a workpiece body (19) is fitted to the inner wall of the lower die (18), a cylinder (7) is mounted on the upper surface of the connecting seat (2), a sealing pressure plate (3) is mounted on the output end of the cylinder (7), and the size of the sealing pressure plate (3) is larger than the size of the lower die (18), and a control switch (5) is mounted on the upper surface of the connecting seat (2).

2. A negative pressure detection device according to claim 1, characterized in that: A first vacuum gauge (4) is installed on the upper surface of the connecting seat (2), a second vacuum gauge (6) is installed on the upper surface of the connecting seat (2), a vacuum detection transmission tube (14) is installed on one side of the first vacuum gauge (4), a vacuum transmission tube (15) is installed on one side of the second vacuum gauge (6), a compressed air inlet (16) is provided on the upper surface of the connecting seat (2), and a vacuum source (17) is provided on the upper surface of the connecting seat (2).

3. A negative pressure detection device according to claim 1, characterized in that: Two guide sleeves (9) are fixedly connected to the surface of the sealing pressure plate (3), and the inner wall of the guide sleeve (9) is slidably connected to a guide column (8), and the two ends of the guide column (8) are respectively fixedly connected to the bottom plate (1) and the connecting seat (2).

4. A negative pressure detection device according to claim 1, characterized in that: The lower surface of the sealing pressure plate (3) is glued with a sealing rubber pad (10).

5. A negative pressure detection device according to claim 4, characterized in that: A plurality of fixing screws (11) are threadedly provided on the surface of the sealing rubber pad (10), and the fixing screws (11) are threadedly connected to the sealing pressure plate (3).

6. A negative pressure detection device according to claim 1, characterized in that: A pre-test solenoid valve sealing housing (12) is installed on the upper surface of the lower mold (18).

7. A negative pressure detection device according to claim 6, characterized in that: A compression spring (13) is arranged inside the sealed housing (12) of the pre-check solenoid valve.

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