A positive and negative pressure vacuum testing machine for testing watch seals

Abstract

The utility model relates to a watch seal testing arrangement field, concretely relates to a positive and negative pressure vacuum testing machine for testing watch seal for watch seal test, including base, the base top is detachably installed with glass jar through locking assembly, still be fixed with the positive and negative pressure generating subassembly for controlling the positive and negative pressure of glass jar internal space on the base, place the test subassembly for being used for to watch seal test in the glass jar, the utility model's beneficial effects are: can adopt air as test medium, can measure positive pressure and can measure negative pressure, thereby can very good to watch seal carries out the test, and will not cause damage to watch, even if watch is not sealed, also will not damage watch machine total, character, watch needle and so on spare, suitable for widely using.

Description

Technical Field

[0001] This utility model relates to the field of watch sealing testing devices, specifically to a positive and negative pressure vacuum testing machine for testing watch seals. Background Technology

[0002] Existing devices for testing the sealing of watches are usually vacuum water testing machines, but they can only be used to test with water. If the watch is not sealed, water can easily get in, causing great damage to the internal mechanism, dial, hands, etc. Water can easily damage the mechanism. Even if it does not cause irreparable damage, the mechanism must be cleaned and maintained again, and the dial and hands will be corroded by water. Summary of the Invention

[0003] Therefore, this utility model provides a positive and negative pressure vacuum testing machine for testing the seal of watches, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a positive and negative pressure vacuum testing machine for testing the sealing of watches, which is used for watch sealing testing, includes a base, on the top of the base a glass jar is detachably installed by a locking component, and a positive and negative pressure generating component for controlling the positive and negative pressure of the internal space of the glass jar is also fixed on the base, and a testing component for testing the sealing of watches is placed inside the glass jar.

[0005] Preferably, the locking assembly includes a bottom shell, the bottom of which is fixed to the top of the base, the bottom of the glass jar is threadedly connected to the top of the bottom shell, and uprights are symmetrically and vertically fixed on both sides of the top of the bottom shell. A locking rod is rotatably installed at the top of each upright, and a first locking nut is threaded onto the surface of each locking rod.

[0006] Preferably, the locking assembly further includes a top cover, the bottom of which abuts against the top of the glass jar, and the top cover has symmetrically opened slots on both sides. The two locking levers are respectively located in the two slots, and the bottom of the first locking nut abuts against the top of the top cover.

[0007] Preferably, a pressure relief pipe is fixedly connected to the top of the upper cover, and a pressure relief valve is fixed to the body of the pressure relief pipe.

[0008] Preferably, the positive and negative pressure generating component includes a vertically arranged suction tube that passes through and is fixed to the top of the base. The top end of the suction tube passes through the bottom shell and extends to one side inside the glass jar. A three-way pipe is fixedly connected to the bottom end of the suction tube. A pressure gauge is fixedly connected to the front end of the top of the base. One end of the three-way pipe is fixedly connected to the pressure gauge through a first flexible hose, and the other end of the three-way pipe is fixedly connected to a second flexible hose.

[0009] Preferably, the positive and negative pressure generating assembly further includes a positive and negative pressure switching valve body and a dual-head air pump. The positive and negative pressure switching valve body is longitudinally fixed to the side end of the base, and the dual-head air pump is fixed to the bottom of the inner wall of the base. The positive and negative pressure switching valve body has a cavity, and a first air vent is opened in the middle of the side end of the positive and negative pressure switching valve body. The first air vent is connected to the cavity, and the end of the second hose away from the three-way pipe is fixedly connected to the first air vent.

[0010] Preferably, a second vent is provided on the rear side of the positive and negative pressure switching valve body, the second vent is connected to the cavity, and a third hose is fixedly connected to the second vent, the third hose is fixedly connected to the suction end of the dual-head air pump, and a third vent is provided on the front side of the positive and negative pressure switching valve body, the third vent is connected to the cavity, and a fourth hose is fixedly connected to the third vent, the fourth hose is fixedly connected to the exhaust end of the dual-head air pump.

[0011] Preferably, a positive and negative pressure switching valve rod runs longitudinally through the cavity, and rubber plugs are symmetrically fixed on the front and back surfaces of the positive and negative pressure switching valve rod. The rubber plugs abut against the inner surface of the cavity. When the internal pressure of the glass jar is controlled to be negative, the first vent and the second vent are located between the two rubber plugs. When the internal pressure of the glass jar is controlled to be positive, the first vent and the third vent are located between the two rubber plugs.

[0012] Preferably, the test assembly includes a test base, the bottom of which is placed on top of the bottom shell. The test base is located inside the glass jar. An end plate is longitudinally fixed to the front top of the test base. A rear clamping plate is elastically installed on the rear top of the end plate. A front clamping plate is provided on the front top of the end plate. A second locking nut is threaded to the bottom of the side end of the front clamping plate. A waist-shaped hole is longitudinally opened on the end plate. The second locking nut passes through the waist-shaped hole and its end abuts against the surface of the end plate. The watch is clamped and fixed between the front clamping plate and the rear clamping plate.

[0013] Preferably, a column is vertically fixed to the rear top of the test stand, a connecting plate is vertically fixed to the top front end of the column, a manual fine-tuning slide is vertically fixed to the front end of the connecting plate, a lifting block is fixed to the manual fine-tuning slide, a digital display electronic dial indicator is fixed to the front end of the lifting block, and the bottom end of the pin of the digital display electronic dial indicator is attached to the watch surface.

[0014] The beneficial effects of this utility model are: by using the base, locking component, glass jar, positive and negative pressure generating component and testing component together, air can be used as the testing medium, which can measure both positive and negative pressure, thus effectively testing the watch's seal without damaging the watch. Even if the watch is not sealed, it will not damage the watch movement, dial, hands and other parts, making it suitable for widespread use. Attached Figure Description

[0015] Figure 1 A structural cross-sectional view provided for this utility model; Figure 2 A side view of the structure of the test component provided by this utility model; Figure 3 The usage effect diagram of the test component provided by this utility model; Figure 4 The structural front view provided for this utility model; Figure 5 A three-dimensional structural view of the bottom shell provided by this utility model; Figure 6 A three-dimensional structural view of the upright provided for this utility model; Figure 7 A three-dimensional view of the locking rod provided by this utility model; Figure 8 A three-dimensional structural view of the top cover provided for this utility model; Figure 9 A three-dimensional structural view of the top cover provided for this utility model; Figure 10 A three-dimensional structural view of the positive and negative pressure switching valve body provided by this utility model; Figure 11 A three-dimensional structural view of the positive and negative pressure switching valve body provided by this utility model; Figure 12 A three-dimensional view of the positive and negative pressure switching valve stem provided by this utility model; Figure 13 A schematic diagram showing the position of the positive / negative pressure switching valve stem when controlling the negative pressure inside the glass jar, provided by this utility model; Figure 14 This is a schematic diagram showing the position of the positive and negative pressure switching valve stem when controlling the positive pressure inside the glass jar, as provided by this utility model.

[0016] In the diagram: 1. Base; 2. Bottom shell; 3. Upright pole; 4. Locking rod; 5. First locking nut; 6. Glass jar; 7. Top cover; 8. Opening slot; 9. Pressure relief pipe; 10. Pressure relief valve; 11. Suction pipe; 12. T-connector; 13. Pressure gauge; 14. First hose; 15. Second hose; 16. Positive / negative pressure switching valve body; 17. Dual-head air pump; 18. Cavity; 19. First vent; 20. Second vent; 21. Third vent. 21. Hose; 22. Third vent; 23. Fourth hose; 24. Positive / negative pressure switching valve stem; 25. Rubber plug; 26. Test seat; 27. End plate; 28. Rear clamp plate; 29. ​​Front clamp plate; 30. Second locking nut; 31. Waist-shaped hole; 32. Column; 33. Connecting plate; 34. Manual fine-tuning slide; 35. Lifting block; 36. Digital display electronic dial indicator; 37. Pin; 38. Watch; 39. Adjusting screw; 40. Indicator slot. Detailed Implementation

[0017] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0018] Please refer to the appendix. Figures 1-14 The present invention provides a positive and negative pressure vacuum tester for testing the seal of a watch, for testing the seal of watch 38. It includes a base 1, a glass jar 6 is detachably installed on the top of the base 1 by a locking component, and a positive and negative pressure generating component for controlling the positive and negative pressure inside the glass jar 6 is also fixed on the base 1. The glass jar 6 contains a test component for testing the seal of watch 38. The locking assembly includes a bottom shell 2, the bottom of which is fixed to the top of the base 1. The bottom of the glass jar 6 is threadedly connected to the top of the bottom shell 2. Vertical rods 3 are symmetrically and vertically fixed on both sides of the top of the bottom shell 2. Locking rods 4 are rotatably installed on the top of each rod 3. First locking nuts 5 are threadedly connected to the surface of each locking rod 4. The locking assembly also includes a top cover 7, the bottom of which abuts against the top of the glass jar 6. Opening slots 8 are symmetrically opened on both sides of the top cover 7. Two locking rods 4 are located in the two opening slots 8 respectively. The bottom of each first locking nut 5 abuts against the top of the top cover 7. A pressure relief pipe 9 is fixedly connected to the top of the top cover 7. A pressure relief valve 10 is fixedly installed on the body of the pressure relief pipe 9. Specifically, the operator can control whether the top cover 7 is locked by rotating the first locking nut 5 in both directions to control the up and down movement of the first locking nut 5 on the locking rod 4. The locking rod 4 can rotate, which makes it convenient to disassemble and assemble the top cover 7 and the glass jar 6. The positive and negative pressure generating component includes a vertically arranged suction tube 11, which is inserted through and fixed to the top of the base 1. The top end of the suction tube 11 penetrates the bottom shell 2 and extends to one side of the inside of the glass jar 6. A three-way tube 12 is fixedly connected to the bottom end of the suction tube 11. A pressure gauge 13 is fixedly fixed to the front end of the top of the base 1. One end of the three-way tube 12 is fixedly connected to the pressure gauge 13 through a first flexible tube 14, and the other end of the three-way tube 12 is fixedly connected to a second flexible tube 15. It should be noted that the pressure gauge 13 is preferably set as a YN6OZ-axial shock-resistant pressure gauge. Specifically, when positive and negative pressure is controlled inside the glass jar 6 through the suction tube 11, the positive and negative pressure values ​​inside the glass jar 6 can be monitored in real time through the pressure gauge 13. The positive and negative pressure generating assembly also includes a positive and negative pressure switching valve body 16 and a dual-head air pump 17. The positive and negative pressure switching valve body 16 is longitudinally fixed to the side of the base 1, and the dual-head air pump 17 is fixed to the bottom of the inner wall of the base 1. It should be noted that the dual-head air pump 17 is a technology known to those skilled in the art and is widely available on the market. Moreover, the dual-head air pump 17 is electrically connected to the external 220V mains power through a control switch (not shown in the figure). The positive and negative pressure switching valve body 16 has a cavity 18 inside, and a first vent 19 is opened in the middle of the side end of the positive and negative pressure switching valve body 16. The first vent 19 is connected to the cavity 18. The end of the second hose 15 away from the three-way pipe 12 is fixedly connected to the first vent 19. A second vent 20 is opened on the rear side of the side end of the positive and negative pressure switching valve body 16. The second vent 20 is connected to the cavity 18. A third hose 21 is fixedly connected to the second vent 20. The third hose 21 is connected to the dual-head air pump 17. The intake end is fixedly connected. A third vent 22 is opened on the front side of the positive and negative pressure switching valve body 16. The third vent 22 is connected to the cavity 18. A fourth hose 23 is fixedly connected to the third vent 22. The fourth hose 23 is fixedly connected to the exhaust end of the double-headed air pump 17. A positive and negative pressure switching valve rod 24 runs longitudinally through the cavity 18. Rubber plugs 25 are symmetrically fixed on the front and back of the surface of the positive and negative pressure switching valve rod 24. The rubber plugs 25 abut against the inner surface of the cavity 18. When the internal negative pressure of the glass jar 6 is controlled, the first vent 19 and the second vent 20 are located between the two rubber plugs 25. When the internal positive pressure of the glass jar 6 is controlled, the first vent 19 and the third vent 22 are located between the two rubber plugs 25. Specifically, when the internal negative pressure of the glass jar 6 is controlled, the operator pushes the positive and negative pressure switching valve rod 24 to the position where the first vent 19 and the second vent 20 are located between the two rubber plugs 25 (e.g., Figure 13 (As shown), then start the dual-head air pump 17. At this time, the suction end of the dual-head air pump 17 draws in air, which is then extracted from the inside of the glass jar 6 through the third hose 21, the second vent 20, the cavity 18 space between the two rubber stoppers 25, the first vent 19, the second hose 15, the three-way pipe 12, and the suction pipe 11. At the same time, the pressure gauge 13 monitors the negative pressure value inside the glass jar 6 in real time. Then, the air discharged from the exhaust end of the dual-head air pump 17 is discharged into the cavity 18 through the fourth hose 23 and the third vent 22, and then discharged to the outside from the cavity 18. When the positive pressure inside the glass jar 6 is controlled, the operator pushes the positive and negative pressure switching valve rod 24 to the position where the first vent 19 and the third vent 22 are located between the two rubber stoppers 25 (as shown). Figure 14(As shown), then start the dual-head air pump 17. At this time, the suction end of the dual-head air pump 17 draws in air, which is connected to the cavity 18 through the third hose 21 and the second vent 20, thereby drawing air from the outside. Then, the air discharged from the exhaust end of the dual-head air pump 17 is discharged into the glass jar 6 through the fourth hose 23, the third vent 22, the space of the cavity 18 between the two rubber stoppers 25, the first vent 19, the second hose 15, the three-way pipe 12 and the suction pipe 11. At the same time, the pressure gauge monitors the positive pressure value in the glass jar 6 in real time, so that the positive and negative pressure can be switched easily. It should be noted that the positive and negative pressure switching valve stem 24 is symmetrically provided with indicator grooves 40 on the front and rear sides. Under the action of the indicator grooves 40, the operator can easily push the positive and negative pressure switching valve stem 24 to the appropriate position to achieve the function of precise positive and negative pressure switching. The test assembly includes a test base 26, which is placed on top of the bottom shell 2 and located inside the glass jar 6. An end plate 27 is longitudinally fixed to the front top of the test base 26, and a rear clamping plate 28 is elastically installed on the rear top of the end plate 27. The rear clamping plate 28 is secured by a spring. A front clamping plate 29 is provided on the front top of the end plate 27, and a second locking nut 30 is threaded to the bottom of the side end of the front clamping plate 29. A slotted hole 31 is longitudinally formed on the end plate 27, through which the second locking nut 30 passes, and its end abuts against the surface of the end plate 27. 38 is clamped and fixed between the front clamping plate 29 and the rear clamping plate 28. Specifically, since the upper cover 7 is easy to disassemble, it is convenient to take out and put in the test seat 26, that is, to take out and put in the watch 38. The operator can place the watch 38 dial between the front clamping plate 29 and the rear clamping plate 28, and then control the front clamping plate 29 to move back and forth by tightening and loosening the second locking nut 30, so that the watch 38 dial can be clamped and fixed. The operation is simple and convenient. The rear clamping plate 28 is installed elastically by a spring and can move back and forth, so it can be used for dials of different sizes, so that dials of different sizes can be adjusted to the appropriate center position. A column 32 is vertically fixed to the rear top of the test base 26. A connecting plate 33 is vertically fixed to the top front end of the column 32. A manual fine-tuning slide 34 is vertically fixed to the front end of the connecting plate 33. It should be noted that the manual fine-tuning slide 34 is preferably set to the LWFX25-L model, which has a built-in locking structure to prevent the slide from loosening. This is a technology known to those skilled in the art and is widely sold on the market. A lifting block 35 is fixed on the manual fine-tuning slide 34. A digital display electronic micrometer 36 is fixed to the front end of the lifting block 35. It should be noted that the digital display electronic micrometer 36 is a technology known to those skilled in the art and is widely sold on the market. The bottom end of the pin 37 of the digital display electronic micrometer 36 is attached to the surface of the watch 38. Specifically, when the glass jar 6 is evacuated to a negative pressure, a pressure difference is formed between the glass jar 6 and the watch 38, which has one atmosphere of pressure. If the watch 38 does not leak air... When the watch face and the back cover of the watch 38 are not sealed, the reading of the digital micrometer 36 will change. Conversely, if the glass jar 6 is not sealed, the pressure inside will decrease when it is under negative pressure, and the air inside the watch 38 will be drawn out. The pressure inside the glass jar 6 will be the same as the pressure inside the watch 38, and the reading of the digital micrometer 36 will not change. Similarly, when the glass jar 6 is filled with positive pressure, if the watch 38 is sealed, the pressure inside the glass jar 6 will be greater than the pressure inside the watch 38, and the face and back of the watch 38 will be dented (deformed), and the reading of the digital micrometer 36 will change. Conversely, if the watch 38 is not sealed, when the glass jar 6 is filled with positive pressure, the gas inside the glass jar 6 will also enter the watch 38, so that the pressure inside the watch 38 will be the same as the pressure inside the glass jar 6, and the reading of the digital micrometer 36 will not change. It should be noted that a threaded hole is vertically opened at the middle of the top of the test base 26. The threaded hole passes through and is threadedly connected to an adjusting screw 39. The top of the adjusting screw 39 abuts against the bottom of the dial of the watch 38 to support the dial of the watch 38 to better abut against the bottom of the pin 37.

[0019] In summary, this positive and negative pressure vacuum testing machine can use air as the testing medium, and can measure both positive and negative pressure. Therefore, it can effectively test the seal of watches without damaging them. Even if the watch is not sealed, it will not damage the watch movement, dial, hands, or other parts.

[0020] The usage process of this utility model is as follows: When in use, the operator places the dial of the watch 38 to be tested between the front clamp plate 29 and the rear clamp plate 28, and then controls the front clamp plate 29 to move back and forth by tightening and loosening the second locking nut 30, so that the surface of the watch 38 can be clamped and fixed. Then, the bottom end of the pin 37 of the digital display electronic micrometer 36 is controlled to be attached to the surface of the watch 38 by manually adjusting the slide 34. Then, the test seat 26 is placed into the glass jar 6 and the top cover 7 is covered. Then, the locking levers 4 on both sides are rotated into the opening slot 8, and the first locking nut 5 is rotated to press down and lock the top cover 7. Then, the positive and negative pressure inside the glass jar 6 are controlled one after another. When controlling the negative pressure inside the glass jar 6, the operator pushes the positive / negative pressure switching valve rod 24 to the position where the first vent 19 and the second vent 20 are located between the two rubber stoppers 25 (e.g., Figure 13 (As shown), then start the dual-head air pump 17. At this time, the suction end of the dual-head air pump 17 draws in air, which is then extracted from the glass jar 6 through the third hose 21, the second vent 20, the cavity 18 space between the two rubber stoppers 25, the first vent 19, the second hose 15, the three-way pipe 12, and the suction pipe 11. At the same time, the pressure gauge 13 monitors the negative pressure value inside the glass jar 6 in real time. Then, the air discharged from the exhaust end of the dual-head air pump 17 is discharged into the cavity 18 through the fourth hose 23 and the third vent 22, and then from the cavity... When the glass jar 6 is under negative pressure, it creates a pressure difference with the watch 38, which is 1 atmosphere. If the watch 38 does not leak, the face glass and the back cover of the watch will bulge outward (deform), and the reading of the digital micrometer 36 will change. Conversely, if it is not sealed, the pressure inside the glass jar 6 will decrease when it is under negative pressure, and the air inside the watch 38 will also be drawn out. The pressure inside the glass jar 6 will be the same as the pressure inside the watch 38, and the value of the digital micrometer 36 will not change. When controlling the positive pressure inside the glass jar 6, the operator pushes the positive / negative pressure switching valve rod 24 to the position where the first vent 19 and the third vent 22 are located between the two rubber stoppers 25 (e.g., Figure 14(As shown), then the dual-head air pump 17 is started. At this time, the suction end of the dual-head air pump 17 draws in air, which is connected to the cavity 18 through the third hose 21 and the second vent 20, thereby drawing air from the outside. Then, the air discharged from the exhaust end of the dual-head air pump 17 is discharged into the glass jar 6 through the fourth hose 23, the third vent 22, the space between the two rubber stoppers 25 in the cavity 18, the first vent 19, the second hose 15, the three-way pipe 12 and the suction pipe 11. At the same time, the pressure gauge monitors the pressure inside the glass jar 6 in real time. When the glass jar 6 is filled with positive pressure, if the watch 38 is sealed, the pressure inside the glass jar 6 will be greater than the pressure inside the watch 38. The face and bottom of the watch 38 will be dented (deformed), and the value of the digital micrometer 36 will change. Conversely, if the watch 38 is not sealed, when the glass jar 6 is filled with positive pressure, the gas inside the glass jar 6 will also enter the watch 38, so that the pressure inside the watch 38 is the same as the pressure inside the glass jar 6, and the value of the digital micrometer 36 will not change. After the test, the operator opens the pressure relief valve 10 to balance the air pressure inside the glass jar 6, then removes the top cover 7, takes out the test base 26, and then removes the watch 38.

[0021] The above description is merely a preferred embodiment of this utility model. Any person skilled in the art can modify this utility model or modify it into an equivalent technical solution using the technical solution described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solution of this utility model are within the scope of protection claimed by this utility model.

Claims

1. A positive and negative pressure vacuum testing machine for testing the seal of a watch (38), comprising a base (1), characterized in that: A glass jar (6) is detachably mounted on the top of the base (1) via a locking assembly. A positive and negative pressure generating assembly for controlling the positive and negative pressure inside the glass jar (6) is also fixed on the base (1). A test assembly for sealing the watch (38) is placed inside the glass jar (6).

2. The positive and negative pressure vacuum testing machine for testing watch seals according to claim 1, characterized in that: The locking assembly includes a bottom shell (2), the bottom of which is fixed to the top of the base (1), the bottom of which is threaded to the top of the bottom shell (2), and uprights (3) are symmetrically and vertically fixed on both sides of the top of the bottom shell (2). Each upright (3) is rotatably mounted with a locking rod (4) at the top of each upright (3), and each locking rod (4) is threaded with a first locking nut (5) on its surface.

3. The positive and negative pressure vacuum testing machine for testing watch seals according to claim 2, characterized in that: The locking assembly also includes a top cover (7), the bottom of which abuts against the top of the glass jar (6), and the top cover (7) has symmetrical opening slots (8) on both sides. The two locking levers (4) are located in the two opening slots (8) respectively, and the bottom of the first locking nut (5) abuts against the top of the top cover (7).

4. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 3, characterized in that: The top of the cover (7) is fixedly connected to a pressure relief pipe (9), and a pressure relief valve (10) is fixed to the body of the pressure relief pipe (9).

5. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 2, characterized in that: The positive and negative pressure generating component includes a vertically arranged suction tube (11), which is inserted through and fixed to the top of the base (1). The top end of the suction tube (11) penetrates the bottom shell (2) and extends to one side inside the glass jar (6). A three-way tube (12) is fixedly connected to the bottom end of the suction tube (11). A pressure gauge (13) is fixedly connected to the front end of the top of the base (1). One end of the three-way tube (12) is fixedly connected to the pressure gauge (13) through a first flexible tube (14), and the other end of the three-way tube (12) is fixedly connected to a second flexible tube (15).

6. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 5, characterized in that: The positive and negative pressure generating assembly also includes a positive and negative pressure switching valve body (16) and a dual-head air pump (17). The positive and negative pressure switching valve body (16) is fixed longitudinally to the side of the base (1). The dual-head air pump (17) is fixed to the bottom of the inner wall of the base (1). A cavity (18) is opened inside the positive and negative pressure switching valve body (16). A first air vent (19) is opened in the middle of the side of the positive and negative pressure switching valve body (16). The first air vent (19) is connected to the cavity (18). The end of the second hose (15) away from the three-way pipe (12) is fixedly connected to the first air vent (19).

7. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 6, characterized in that: The positive and negative pressure switching valve body (16) has a second vent (20) on the rear side of its side end. The second vent (20) is connected to the cavity (18). The second vent (20) is fixedly connected to a third hose (21). The third hose (21) is fixedly connected to the suction end of the dual-head air pump (17). The positive and negative pressure switching valve body (16) has a third vent (22) on the front side of its side end. The third vent (22) is connected to the cavity (18). The third vent (22) is fixedly connected to a fourth hose (23). The fourth hose (23) is fixedly connected to the exhaust end of the dual-head air pump (17).

8. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 7, characterized in that: A positive and negative pressure switching valve rod (24) runs longitudinally through the cavity (18). Rubber plugs (25) are symmetrically fixed on the front and back surfaces of the positive and negative pressure switching valve rod (24). The rubber plugs (25) abut against the inner surface of the cavity (18). When the internal pressure of the glass jar (6) is controlled to be negative, the first vent (19) and the second vent (20) are located between the two rubber plugs (25). When the internal pressure of the glass jar (6) is controlled to be positive, the first vent (19) and the third vent (22) are located between the two rubber plugs (25).

9. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 2, characterized in that: The test assembly includes a test base (26), the bottom of which is placed on top of the bottom shell (2). The test base (26) is located inside the glass jar (6). An end plate (27) is longitudinally fixed on the front side of the top of the test base (26). A rear clamping plate (28) is elastically installed on the rear side of the top of the end plate (27). A front clamping plate (29) is provided on the front side of the top of the end plate (27). A second locking nut (30) is threaded to the bottom of the side end of the front clamping plate (29). A waist-shaped hole (31) is longitudinally opened on the end plate (27). The second locking nut (30) passes through the waist-shaped hole (31). The end of the second locking nut (30) abuts against the surface of the end plate (27). The watch (38) is clamped and fixed between the front clamping plate (29) and the rear clamping plate (28).

10. A positive and negative pressure vacuum testing machine for testing watch seals according to claim 9, characterized in that: A column (32) is vertically fixed to the rear top of the test stand (26). A connecting plate (33) is vertically fixed to the top front end of the column (32). A manual fine-tuning slide (34) is vertically fixed to the front end of the connecting plate (33). A lifting block (35) is fixed on the manual fine-tuning slide (34). A digital display electronic micrometer (36) is fixed to the front end of the lifting block (35). The bottom end of the pin (37) of the digital display electronic micrometer (36) is attached to the surface of the watch (38).

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