CN114441099B

CN114441099B - Vacuum testing device

Info

Publication number: CN114441099B
Application number: CN202111603893.5A
Authority: CN
Inventors: 张和毅
Original assignee: Shanghai Size Automation Equipment Co ltd
Current assignee: Shanghai Size Automation Equipment Co ltd
Priority date: 2021-12-24
Filing date: 2021-12-24
Publication date: 2024-06-21
Anticipated expiration: 2041-12-24
Also published as: CN114441099A

Abstract

The invention discloses a vacuum testing device which is used for detecting the air tightness of a connecting pipe. The box body is divided into an upper section and a lower section, and openings of the upper section and the lower section can be aligned and assembled in a sealing way. The base is fixedly connected to the lower section. The first drive mechanism includes a first drive shaft that is configured to be movable between an abutment position and a disengaged position. The second drive mechanism includes a second drive shaft that is configured to be movable between a closed position and an open position. When the first driving shaft is in the abutting position in the starting state, the second driving shaft is in the sealing position and presses the top end of the connecting pipe, and the limiting piece is arranged to limit the first driving shaft to be away from the abutting position so as to prevent the first driving shaft from being impacted by the gas at the second opening end to be separated from the base.

Description

Vacuum testing device

Technical Field

The invention relates to the technical field of sealing structures, in particular to a vacuum testing device.

Background

The connecting pipe is used for connecting two pipelines, such as pipelines for connecting natural gas or pipelines for other liquids, the connecting pipe is provided with an internal channel for the circulation of the liquid or the gas, a valve is arranged in the internal channel for opening or closing the internal channel, the most main performance of the connecting pipe is the air tightness of the connecting pipe, and the accuracy of the air tightness detection of the connecting pipe is important.

The air tightness of the connecting pipe is detected by placing the connecting pipe in a vacuum box body, and then inflating the internal channel of the connecting pipe under the condition that a valve is closed, wherein helium or other gases are generally used, and then whether the helium exists in the vacuum box body is detected to detect the air tightness of the connecting pipe. The internal channel of connecting pipe has two openings, and the internal channel is L type, needs install the connecting pipe in the vacuum box to aerify two openings, and prior art sets up the mounting groove in the bottom of vacuum box, is located the mounting groove of vacuum box with an opening of connecting pipe, and the vacuum box mounting groove is equipped with connecting pipe bottom open-ended air vent, and the cylinder is used to the vacuum box upper end to compress tightly the connecting pipe, makes it fixed in vertical direction in order to guarantee at the charging process connecting pipe can not break away from the mounting groove. The other opening is located the lateral part of vacuum chamber, uses the drive shaft to support the lateral part opening of leaning on the connecting pipe, in order to prevent that the connecting pipe from receiving the deviation drive shaft of gas pressure impact and making gas leak in the inflation process, influences the accuracy of test, generally needs great drive force to provide the holding power of lateral part in order to prevent that the drive shaft from receiving the gas impact force and breaking away from the connecting pipe, great drive force needs great cylinder, and the ten minutes consumes the energy, occupies bigger space moreover, still inconvenient start-up.

Disclosure of Invention

The object of the present invention is to provide a solution to the above-mentioned problems of the prior art.

In order to solve the above-described problems, according to one aspect of the present invention, there is provided a vacuum testing apparatus for detecting air tightness of a connection pipe, the vacuum testing apparatus of the present invention including a case, a base, a first driving mechanism, a second driving mechanism, and a stopper. The box body is divided into an upper section and a lower section, wherein the upper section is a rectangular frame with an upward opening, the lower section is a rectangular frame with a downward opening, and the openings of the upper section and the lower section can be aligned and assembled in a sealing way. The base is fixedly connected to the bottom plate of the lower section, the base is provided with a first opening end, used for placing the valve, of the mounting groove, the connecting pipe is placed in the mounting groove of the base, and the first opening end is located at the bottom of the base.

The side wall of the lower section is provided with a first through hole for being matched with a first driving mechanism, the first driving mechanism comprises a first driving shaft, one end of the first driving shaft is located outside the lower section, the other end of the first driving shaft extends into the lower section through the first through hole, the first driving shaft is arranged to be movable between an abutting position and a disengaging position, in the abutting position, the end of the first driving shaft is close to the base, the end of the first driving shaft is enabled to be in sealing blockage with the side wall of the inner channel of the second opening end of the connecting pipe, and in the disengaging position, the first driving shaft is far away from the base.

The top of the upper section is provided with a second through hole for being matched with a second driving mechanism, the second driving mechanism comprises a second driving shaft, one end of the second driving shaft is located outside the upper section, the other end of the second driving shaft extends into the upper section through the second through hole, the second driving shaft is arranged to be movable between a closed position and a release position, the end of the second driving shaft located in the lower section is close to the base, and the end of the second driving shaft located in the lower section is far away from the base.

When the testing device is in a starting state, the first driving shaft is in the propping position for sealing the second opening end of the connecting pipe and inflating the internal channel from the second opening end, the second driving shaft is in the sealing position and compresses the top end of the connecting pipe to prevent the connecting pipe from being impacted by the gas of the first inflation port and separating from the base, and the limiting piece is arranged to limit the first driving shaft to be away from the propping position to prevent the first driving shaft from being impacted by the gas of the second opening end and separating from the base, so that the connecting pipe is prevented from being detected inaccurately due to leakage of the gas between the first driving shaft and the first opening end in the detection process. According to the invention, the first driving shaft is limited to be far away from the base through the limiting piece, so that the first driving device can ensure the accuracy of testing by using a smaller air cylinder, and the waste of energy and space of the testing device can be reduced.

In one embodiment, one end of the first driving shaft positioned in the lower section is provided with a protruding part extending towards the top of the lower section;

The limiting piece is a U-shaped rod and comprises a first limiting rod, a second limiting rod and a connecting rod, the connecting rod is provided with a connecting hole and sleeved on the second driving shaft, and the first limiting rod and the second limiting rod are connected to two ends of the connecting rod and extend towards the lower section of the box body;

when the testing device is in a starting state, the end part, far away from the connecting rod, of the first limiting rod abuts against one side, far away from the base, of the protruding part, and the second limiting rod abuts against one side, far away from the first driving shaft, of the base.

In one embodiment, the base further comprises a stopper located on a side of the base opposite the first drive shaft;

When the testing device is in the starting state, the second limiting rod abuts against one side, far away from the first driving shaft, of the limiting block.

In one embodiment, a first guide surface is arranged at the end part of the first limiting rod, which is far away from the connecting rod, and the first guide surface is arranged at one side of the first limiting rod, which is close to the second limiting rod, and gradually deviates from the second limiting rod along the direction from the first limiting rod to the end part;

The end part of the second limiting rod, which is far away from the connecting rod, is provided with a second guide surface, and the second guide surface is arranged on one side of the second limiting rod, which is close to the first limiting rod, and gradually deviates from the first limiting rod along the second limiting rod to the end part;

And a third guide surface is arranged on one side, far away from the first driving shaft, of the limiting block, and the third guide surface gradually approaches the first driving shaft from the limiting block to the top.

In one embodiment, the second driving mechanism further comprises a pressing piece connected to the second driving shaft and located below the limiting piece;

The diameter of the connecting hole is larger than that of the second driving shaft so that the second guide surface of the second limiting rod moves along the third guide surface of the limiting block.

In one embodiment, an air inlet pipe is arranged in the first driving shaft, one end of the air inlet pipe is positioned at the end part of the first driving shaft positioned in the lower section of the box body, and the other end of the air inlet pipe is communicated with an air source outside the box body.

In one embodiment, the end of the first driving shaft positioned in the box body is also provided with a sealing device;

In the activated state, the sealing means is arranged such that the end periphery of the first drive shaft sealingly engages the inner channel side wall of the second open end.

In one embodiment, a channel is provided in the first drive shaft;

the sealing device comprises:

A third drive shaft slidably mounted within the passageway, one end of the third drive shaft extending beyond the end of the first drive shaft within the housing and being provided with a circumferentially extending flange defining the end of the first drive shaft within the housing as a sealed end, the outer diameter of the flange being the same as the outer diameter of the sealed end; and

A sealing ring having elasticity and connected to the sealing end and located between the sealing end and the flange;

The third drive shaft is operable away from the base and such that the flange presses the seal ring against the sealing end such that the seal ring protrudes from the flange periphery and sealingly engages the interior channel.

In one embodiment, the second drive shaft is slidably coupled to the upper section;

The second driving mechanism further includes:

the pressing plate is connected to the second driving shaft and is positioned above the upper section, and a through hole penetrating through the thickness of the pressing plate is formed in the pressing plate;

The connecting column is connected to the top of the upper section at one end, the other end of the connecting column is positioned in the through hole and extends to the top of the pressing plate, the diameter of the connecting column is smaller than that of the through hole, a stop piece is arranged at one end of the connecting column positioned at the top of the pressing plate, and the diameter of the stop piece is larger than that of the connecting hole;

And the spring is sleeved on the connecting column and is positioned between the pressing plate and the upper section.

In one embodiment, an air inlet hole is formed in the base, and one end of the air inlet hole is positioned in the mounting groove of the base and aligned with the first opening; the other end is communicated with the air source.

According to the invention, the first driving shaft is limited by the limiting piece, so that the specification of the air cylinder is reduced, and the accuracy of the test of the connecting pipe can be ensured.

Drawings

FIG. 1 is a cross-sectional view of a vacuum testing apparatus according to one embodiment of the present invention.

Fig. 2 is a partial enlarged view of the region a in fig. 1.

Fig. 3 is a schematic view of a connection tube according to an embodiment of the present invention.

Fig. 4 and 5 are schematic views of the lower section of the housing and the first drive mechanism according to an embodiment of the present invention.

Fig. 6 and 7 are schematic views of a vacuum testing apparatus according to an embodiment of the present invention.

Reference numerals: 100. a vacuum test device; 1. a case; 11. a lower section; 111. a first through hole; 12. an upper section; 121. a second through hole; 2. a base; 21. a mounting groove; 22. a limiting block; 221. a third guide surface; 23. an air inlet hole; 3. a first driving mechanism; 31. a first drive shaft; 311. a boss; 32. an air inlet pipe; 33. a sealing device; 331. a third drive shaft; 332. a seal ring; 333. a flange; 334. a third cylinder; 335. a driving block; 34. a channel; 35. sealing the end; 36. a first cylinder; 312. a first portion; 313. a second portion; 314. a chamber;

4. A second driving mechanism; 41. a second drive shaft; 42. a pressing member; 43. a pressing plate; 44. a connecting column; 45. a spring; 46. an electric cylinder; 6. a limiting piece; 61. a first stop lever; 611. a first guide surface; 62. a second limit rod; 621. a second guide surface; 63. a connecting rod; 631. a connection hole; 5. a support frame; 51. a protective shell; 200. a connecting pipe; 201. a first open end; 202. a second open end; 203. an internal passage;

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that the objects, features and advantages of the present invention will be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the invention, but rather are merely illustrative of the true spirit of the invention.

In the following description, for the purposes of explanation of various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that an embodiment may be practiced without one or more of the specific details. In other instances, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In the following description, for the purposes of clarity of presentation of the structure and manner of operation of the present invention, the description will be made with the aid of directional terms, but such terms as "forward," "rearward," "left," "right," "outward," "inner," "outward," "inward," "upper," "lower," etc. are to be construed as convenience, and are not to be limiting.

The present invention relates to a vacuum testing apparatus 100, which vacuum testing apparatus 100 is used to detect the air tightness of a connection pipe 200. The connection pipe 200 is mainly used to connect pipes in various devices, such as pipes for transferring fuel gas in a fuel gas device. The air tightness of the connection tube 200 is important because the accuracy of detecting the air tightness of the connection tube 200 is important. The connection pipe 200 generally has an internal passage 203 for the flow of liquid or gas, a valve is provided in the internal passage 203 for opening or closing the internal passage 203, one end of the internal passage 203 is a first open end 201, the other end is a second open end 202, and the first open end 201 and the second open end 202 are disposed at an angle. In the embodiment shown in fig. 1,2 and 3, the internal channel 203 is L-shaped, and the first open end 201 and the second open end 202 are connected to two pipes, respectively. The connection pipe 200 is generally detected in the vacuum test device 100, the connection pipe 200 is placed in a vacuum box of the vacuum test device 100, helium is filled into the first opening end 201 and the second opening end 202, and whether the helium exists in the box body 1 is detected to judge the air tightness of the connection pipe 200.

The vacuum test device 100 of the present invention includes a case 1, a base 2, a first driving mechanism 3, a second driving mechanism 4, and a stopper 6. The box 1 is divided into an upper section 12 and a lower section 11, the upper section 12 is downward in opening, the lower section 11 is downward in opening, and the openings of the upper section 12 and the lower section 11 can be aligned with each other for sealing assembly. As shown in fig. 1, the top surface of the lower section 11 is provided with a sealing ring, and the sealing ring is circumferentially arranged along the top surface. After the upper section 12 is covered on the lower section 11, the sealing ring is compressed so that the upper section 12 and the lower section 11 of the box body 1 are connected in a sealing state. And the side part of the box body 1 is also provided with a vacuumizing pipeline so as to facilitate the box body 1 to be vacuumized. The base 2 is fixedly connected to the bottom plate of the lower section 11, the base 2 is provided with a first opening end 201 for placing a valve, the connecting pipe 200 is placed in the mounting groove 21 of the base 2, and the first opening end 201 is positioned at the bottom of the base 2. It will be appreciated that the mounting slots 21 may be provided in any suitable manner as desired, as long as they can be used to house an object to be monitored under vacuum.

The side wall of the lower section 11 is provided with a first through hole 111 for cooperation with the first driving mechanism 3. Specifically, the first drive mechanism 3 includes a first drive shaft 31, one end of the first drive shaft 31 is located outside the lower section 11, and the other end extends into the lower section 11 via a first through hole 111, and the first drive shaft 31 is hermetically slidable along the through hole and is provided to be movable between an abutment position and a release position. In the rest position, the end of the first drive shaft 31 is close to the base 2 and causes the end of the first drive shaft 31 to sealingly block the side wall of the internal passage 203 of the second open end 202 of the connection tube 200. In the disengaged position, the first drive shaft 31 is remote from the base 2.

The top of the upper section 12 is provided with a second through hole 121 for cooperation with the second drive mechanism 4. Specifically, the second driving mechanism 4 includes a second driving shaft 41, one end of the second driving shaft 41 is located outside the upper section 12, and the other end extends into the upper section 12 via a second through hole 121. The second drive shaft 41 is arranged to be movable between a closed position, in which the end of the second drive shaft 41 located in the lower section 11 is close to the base 2, and a disengaged position, in which the end of the second drive shaft 41 located in the lower section 11 is remote from the base 2.

In the activated state of the testing device, the first driving shaft 31 is in the abutting position for sealing the second open end 202 of the connection tube 200 and inflating the internal passage 203 from the second open end 202, and the second driving shaft 41 is in the sealing position and compresses the top end of the connection tube 200 to prevent the connection tube 200 from being impacted by the high pressure gas in the first inflation port to be separated from the base 2. The stopper 6 is provided to restrict the first driving shaft 31 from moving away from the abutment position to prevent the first driving shaft 31 from being impacted by the gas of the second open end 202 from being separated from the base 2, and to prevent inaccuracy of the detection caused by leakage of the gas between the first driving shaft 31 and the first open end 201 during the detection of the connection pipe 200. According to the invention, the first driving shaft 31 is limited to be far away from the base 2 through the limiting piece 6, so that the first driving device can ensure the accuracy of testing by using a smaller air cylinder, and the waste of energy and space of the testing device can be reduced.

The base 2 is provided in the floor of the lower section 11 with the mounting slot 21 opening upwardly and shaped to match the first open end 201 of the connecting tube 200. The connection tube 200 is placed in the mounting groove 21, specifically the first open end 201 of the connection tube 200 is located in the mounting groove 21. The base 2 is provided with an air inlet hole 23, as shown in fig. 1, one end of the air inlet hole 23 is positioned at the bottom of the mounting groove 21 of the base 2 and aligned with the first opening, and the other end extends from the bottom of the base 2 to the bottom of the bottom plate of the box 1 and is communicated with an external air source, and the base 2 and the bottom plate are also in sealing connection so as to prevent air from leaking when entering from the bottom plate through the air inlet hole 23. During detection, gas from the gas source may be introduced into the internal passageway 203 through the gas inlet. Further, a sealing ring 332 is further disposed at a position where the bottom of the mounting groove 21 contacts the first open end 201, and the sealing ring 332 is disposed along the circumferential direction of the first open end 201 to ensure sealing connection between the bottom of the mounting groove 21 and the first open end 201, so as to prevent gas from flowing out through the bottom of the mounting groove 21 during detection to affect the accuracy of detection.

Further, the base 2 further comprises a limiting block 22. As shown in fig. 4 and 5, the stopper 22 is located on the opposite side of the base 2 from the first drive shaft 31. Specifically, the base 2 includes a base body and a stopper 22. The mounting groove 21 is formed by inwards sinking from the top of the base body, the limiting block 22 is connected to the top of the base body, and one side of the limiting block 22 is close to the mounting groove 21. When the connecting pipe 200 is installed in the installation groove 21, one side of the connecting pipe 200 away from the first driving shaft 31 abuts against the limiting block 22. When the first driving shaft 31 abuts against the second opening end 202 of the connection tube 200 during detection, the stopper 22 can prevent the connection tube 200 from being deviated from the mounting groove 21 of the base 2 due to the impact force of the gas in the second driving shaft 41.

Further, a third guiding surface 221 is disposed on a side of the limiting block 22 away from the first driving shaft 31, the third guiding surface 221 gradually approaches the first driving shaft 31 along the limiting block 22 to the top, and the third guiding surface 221 is configured to cooperate with the second limiting rod 62 of the limiting member 6 to limit the first driving shaft 31 away from the base 2, which will be described in detail below.

The first drive mechanism 3 further comprises an external first cylinder 36, as shown in fig. 4 and 5. The first cylinder 36 is located outside the housing 1 and is connected to the first drive shaft 31, the first cylinder 36 being able to push the first drive shaft 31 between an abutment position and a distant position. It will be appreciated that the abutment position may be adjusted as required when testing different connection pipes 200 to ensure that the end of the first drive shaft 31 at the inner end of the housing 1 seals against the open end of the connection pipe 200 in the abutment position. As shown in fig. 1, 4 and 5, the first cylinder 36 of the present invention is very small due to the stopper 6, and the stability of the first driving shaft 31 against the second open end 202 of the connection pipe 200 during testing can be ensured.

The first driving shaft 31 is slidably passed through the first through hole 111, and the first driving shaft 31 is gradually thickened from the outside of the case 1 to the inside of the case 1 and is provided with a passage 34 inside. As shown in fig. 1, the first drive shaft 31 is divided into two parts, a first part 312 and a second part 313, respectively. The first portion 312 inside the housing 1 has a larger radial dimension and the second portion 313 outside the housing 1 has a smaller radial dimension to fit the first cylinder 36 mounted outside the housing 1. The two parts are a first part and a second part, and the first part and the second part are hermetically connected, and in order to maintain the stability of the first driving shaft 31 moving in the horizontal direction, a sealing tube is provided on the side wall outside the lower section 11. As shown in fig. 1,4 and 5, a sealing tube is sealingly connected to the sidewall of the lower section 11, and the first driving shaft 31 is sealingly slidable along the sealing tube, and the sealing tube supports the first driving shaft 31 to be slidable in a horizontal direction. A bracket is also provided in the base 2 to support the first drive shaft 31, the first drive shaft 31 being movable in the abutting position and the distant position in the horizontal direction through the bracket. The end of the first driving shaft 31 located in the lower section 11 is provided with a protruding portion 311 extending towards the top of the lower section 11, which protruding portion 311 cooperates with the first stop lever 61 of the stop member 6 to limit the distance of the first driving shaft 31 from the base 2, as will be described in more detail below.

Further, the first driving shaft 31 is provided with an air inlet pipe 32, one end of the air inlet pipe 32 is positioned at the end of the first driving shaft 31 positioned in the lower section 11 of the box body 1, and the other end is communicated with an air source outside the box body 1. Specifically, as shown in fig. 1, the air inlet pipe 32 is an elongated pipe at a section of the lower section 11, one end of the air inlet pipe 32 is located at an end of the first driving shaft 31 near the base 2, and the other end of the air inlet pipe is located in a first portion 312 of the first driving shaft 31, the radial dimension of the other end of the air inlet pipe is gradually increased, and the air inlet pipe 32 is conveyed from an external air source through a channel 34 of a second portion 313 of the first driving shaft 31, and then conveyed to a second opening end 202 of the connecting pipe 200 through the air inlet pipe 32 to detect the air tightness of the connecting pipe 200.

The end of the first drive shaft 31 located within the housing 1 is further provided with sealing means 33, the sealing means 33 being arranged such that, in the activated state, the outer periphery of the end of the first drive shaft 31 sealingly engages the side wall of the internal channel 203 of the second open end 202. The sealing means 33 may be a sealing ring 332 provided at the outer periphery of the inner end portion of the first driving shaft 31 in the case 1, the end portion of the first driving shaft 31 is abutted into the inner passage 203 of the second open end 202 of the connection pipe 200 by applying pressure, and the sealing ring 332 is pressed to seal the first driving shaft 31 and the inner passage 203 of the connection pipe 200. In the embodiment shown in fig. 1,4 and 5, the sealing means 33 comprises a third drive shaft 331 and a sealing ring 332, the third drive shaft 331 being slidably mounted in the channel 34 of the first portion 312 of the first drive shaft 31, and one end of the third drive shaft 331 extending beyond the end of the first drive shaft 31 located in the housing 1 and being provided with a circumferentially extending flange 333 defining the end of said first drive shaft 31 located in the housing 1 as a sealing end 35, the outer diameter of the flange 333 being the same as the outer diameter of the sealing end 35. The seal 332 is resilient and is connected to the sealing end 35 and is located between the sealing end 35 and the flange 333. The third drive shaft 331 is operable to be remote from the base 2 and such that the flange 333 presses the seal ring 332 against the sealing end 35 such that the seal ring 332 protrudes beyond the periphery of the flange 333 and sealingly engages the internal passageway 203. As shown in fig. 2, a chamber 314 is provided in the first portion 312 of the first driving shaft 31, two ends of the chamber 314 are communicated with the channel 34 of the first portion 312, and the diameter of the chamber 314 is larger than that of the channel 34. The sealing device 33 further comprises a driving block 335 located in the chamber 314 and a third cylinder 334 communicating with the chamber 314, the length of the driving block 335 in the horizontal direction being smaller than the length of the chamber 314 in the horizontal direction to ensure that the driving block 335 can move in the horizontal direction, and the diameter of the chamber 314 and the driving block 335 being larger than the diameter of the channel 34 to ensure that the moving position of the driving block 335 does not exceed the chamber 314, and to ensure that the flange 333 can compress the sealing ring 332 to deform to a required extent. The side of the drive block 335 and the chamber 314 are in sealing engagement to prevent gas leakage. The end of the driving block 335 near the base 2 is connected to the third driving shaft 331. The third cylinder 334 is mounted to the outside of the first drive shaft 31 and can vent to the side of the chamber 314 near the base 2. When testing, after the first driving shaft 31 is in the abutting position, the flange 333 and the sealing end 35 of the third driving shaft 331 are both located in the internal channel 203 at the second opening end 202 of the connecting tube 200, the third chamber 314 is ventilated, the driving block 335 drives the third driving shaft 331 to be far away from the base 2 and compress the sealing ring 332, and the sealing ring 332 is deformed after being compressed and protrudes out of the periphery of the flange 333 and presses the internal channel 203 of the connecting tube 200, so as to form a sealing effect.

The vacuum testing apparatus 100 further comprises a support 5, and the support 5 is located outside the case 1 for supporting the second driving mechanism 4.

The second drive mechanism 4 further comprises an electric cylinder 46. As shown in fig. 1, 6 and 7, the second driving shaft 41 is slidably connected to the supporting frame 5, and the second driving shaft 41 extends in the vertical direction and is movable in the vertical direction. An electric cylinder 46 is located at the top of the support frame 5 and is connected to the top end of the second drive shaft 41 to drive the movement of the second drive shaft 41.

The second driving mechanism 4 further comprises a pressing member 42, the pressing member 42 is fixedly connected to one end of the second driving shaft 41 close to the base 2, the shape of the bottom of the pressing member 42 matches the shape of the top of the connecting pipe 200, and the second driving shaft 41 is in a sealing position so that the pressing member 42 can press the top of the connecting pipe 200 to ensure the stability of the connecting pipe 200 along the vertical direction.

The second drive shaft 41 is slidably connected to the upper section 12 and the sealing engagement between the second drive shaft 41 and the upper section 12 prevents air from entering the housing 1 and affecting the test.

The second drive mechanism 4 further includes a platen 43, a connecting post 44, and a spring 45. The pressing plate 43 is connected to the second driving shaft 41 and is located above the upper section 12, and as shown in fig. 1, 6 and 7, the pressing plate 43 is provided with a plurality of through holes penetrating the thickness thereof. The connecting column 44 is plural and has one end connected to the top of the upper section 12, the other end is located in the through hole and extends to above the pressing plate 43, the diameter of the connecting column 44 is smaller than that of the through hole, so that the pressing plate 43 can move along the connecting column 44, one end of the connecting column 44 located at the top of the pressing plate 43 is provided with a stopper, the diameter of the stopper is larger than that of the connecting hole 631, and the pressing plate 43 can move along the connecting column 44 without being separated from the connecting column 44. The spring 45 is sleeved on the connecting post 44 and is positioned between the pressing plate 43 and the upper section 12. During testing, the second driving shaft 41 drives the compressing element 42, the upper section 12 of the box 1 and the pressing plate 43 to move downwards to a certain position, the position is defined as an adjusting position, at this time, the upper section 12 of the box 1 is covered to the lower section 11 and is not completely compressed, the compressing element 42 is positioned at the top of the connecting pipe 200 and is not completely compressed at the top of the connecting pipe 200, a certain distance is reserved between the pressing plate 43 and the upper section 12, and as the cooperation between the compressing element 42 and the connecting pipe 200 needs to be ensured, the speed of the second driving shaft 41 moving downwards to the sealing position can be slow, so that the compressing element 42 compresses the top of the connecting pipe 200 after being finely adjusted by grinding in the moving downwards process, and at this time, the pressing plate 43 approaches the upper section 12 and presses the upper section 12 to be tightly matched with the lower section 11 by the spring 45. It will be appreciated that in other embodiments, there may be no pressure plate and the second drive mechanism 4 may directly drive the upper section 12 and the hold down member 42 directly down to the sealing position.

The limiting member 6 is a U-shaped rod and comprises a first limiting rod 61, a second limiting rod 62 and a connecting rod 63. As shown in fig. 1, the connecting rod 63 is provided with a connecting hole 631 and is sleeved on the second driving shaft 41, and the first limiting rod 61 and the second limiting rod 62 are connected to two ends of the connecting rod 63 and extend towards the lower section 11 of the box 1. In the embodiment shown in fig. 6 and 7, the first limiting rods 61 are two and can respectively abut against two ends of the protruding portion 311, and the second limiting rods 62 are plate-shaped. It will be appreciated that in other embodiments, the second stop bar 62 may be rod-shaped. When the testing device is in the starting state, the first driving shaft 31 is located at the abutting position, the second driving shaft 41 drives the limiting piece 6 to move downwards and be located at the sealing position, at this time, the end part of the first limiting rod 61, which is far away from the connecting rod 63, abuts against one side of the protruding part 311, which is far away from the base 2, and the second limiting rod 62 abuts against one side of the base 2, which is far away from the first driving shaft 31. Specifically, the second stopper rod 62 abuts against a side of the stopper 22 remote from the first drive shaft 31. When the test is started, the first driving shaft 31 is inflated towards the second opening end 202 of the connecting pipe 200 and then subjected to the reverse pushing force of the gas, namely, the pushing force towards the direction away from the base 2, the protruding part 311 abuts against the first limiting rod 61 of the limiting piece 6 and is limited by the first limiting rod 61, the first limiting rod 61 is stressed by the pushing force which can apply force to the second limiting rod 62 to enable the second limiting rod 62 to have the pushing force towards the direction close to the base 2, the second limiting rod 62 is limited by the limiting block 22, namely, the limiting block 22 and the protruding part 311 respectively limit the first driving shaft 31 to be away from the base 2, so that the first driving shaft 31 can be stably located at the abutting position, and the tightness of the test is ensured.

Further, the end of the first stopper rod 61 remote from the connecting rod 63 is provided with a first guide surface 611. The first guiding surface 611 is disposed on one side of the first limiting rod 61 near the second limiting rod 62, and gradually deviates from the second limiting rod 62 along the first limiting rod 61 to the end. In the process of moving the second driving shaft 41 downward close to the base 2 along the vertical direction, the bottom of the first guiding surface 611 contacts one side of the protruding portion 311 away from the base 2, and slides to the bottom of the protruding portion 311 along with the downward movement of the second driving shaft 41, and the first guiding surface 611 can enable the first limiting rod 61 to slide to the bottom of the protruding portion 311 more smoothly.

The end of the second stop lever 62 remote from the connecting rod 63 is provided with a second guide surface 621. The second guide surface 621 is disposed on a side of the second stop lever 62 near the first stop lever 61, and gradually deviates from the first stop lever 61 along the second stop lever 62 to the end. During the downward movement of the second driving shaft 41, the second guide surface 621 of the second stopper rod 62 slides along the third guide surface 221 of the stopper 22. The third guiding surface 221 provides guiding function for the second guiding surface 621 during the downward movement, so that the second guiding surface 621 moves down along the third guiding surface 221 to the side of the limiting block 22 during the downward movement.

The connection rod 63 is floatably connected to the second driving shaft 41 in the horizontal direction. Specifically, the diameter of the connection hole 631 is slightly larger than that of the second driving shaft 41, the bottom of the connection rod 63 is supported by the pressing member 42, and the top is pressed by the upper section 12 of the casing 1 so that the connection rod 63 does not come off the second driving shaft 41. In the process of moving down the second driving shaft 41, the first limiting rod 61 and the second limiting rod 62 at two ends of the connecting rod 63 need to be respectively matched with the protruding portion 311 and the limiting block 22, and the connecting hole 631 is larger than the diameter of the second driving shaft 41, so that the connecting rod 63 can be fixed in a certain degree along the horizontal direction, and therefore, the position tolerance of the first limiting rod 61 and the second limiting rod 62 in the process of moving down is ensured, and the first limiting rod 61 and the second limiting rod 62 are ensured to respectively and stably move along the protruding portion 311 and the third guiding surface 221 of the second guiding surface 621. During testing, the second driving shaft 41 moves down to the adjusting position, the first guiding surface 611 of the first limiting rod 61 and the second guiding surface 621 of the second limiting rod 62 respectively contact the protruding portion 311 and the third guiding surface 221, the upper section 12 covers the lower section 11, and as the second driving shaft 41 continues to move down slowly, the first guiding surface 611 and the second guiding surface 621 respectively move down along the protruding portion 311 and the third guiding surface 221 gradually until the second driving shaft 41 is located at the sealing position, and the first limiting rod 61 and the second limiting rod 62 respectively stably abut against one side of the protruding portion 311 away from the base 2 and one side of the limiting block 22 away from the base 2.

The support 5 is further provided with a protective shell 51, and as shown in fig. 7, the protective shell 51 is installed outside the box 1 to reduce interference of the outside to the vacuum test device 100.

The invention reduces the specification of the first cylinder 36 and the waste of energy and space by limiting the first driving shaft 31 by the limiting piece 6, and can ensure the test accuracy of the connecting pipe 200 when the first cylinder 36 with smaller specification is used for testing.

While the preferred embodiments of the present application have been described in detail, it will be appreciated that those skilled in the art, upon reading the above teachings, may make various changes and modifications to the application. Such equivalents are also intended to fall within the scope of the application as defined by the following claims.

Claims

1. A vacuum testing apparatus for detecting air tightness of a connection pipe having an internal passage in which a valve is provided, the valve being arranged to open or close the internal passage, one end of the internal passage being a first open end and the other end being a second open end, comprising:

The box body is divided into an upper section and a lower section, the upper section and the lower section can be assembled in a sealing way, a first through hole is formed in the side wall of the lower section, and a second through hole is formed in the top of the upper section;

The base is fixedly connected to the bottom plate of the lower section, and is provided with a mounting groove for placing the first opening end of the valve;

A first drive mechanism including a first drive shaft having one end located outside the lower section and the other end extending into the lower section via the first through hole, the first drive shaft being arranged to be movable between an abutment position in which an end of the first drive shaft is adjacent to the base and such that the end of the first drive shaft sealingly blocks the second open end of the connecting tube, and a disengaged position in which the first drive shaft is remote from the base;

A second drive mechanism including a second drive shaft having one end located outside the upper section and the other end extending into the upper section via the second through-hole, the second drive shaft being arranged to be movable between a closed position in which an end of the second drive shaft located in the lower section is adjacent the base and a disengaged position in which an end of the second drive shaft located in the lower section is remote from the base;

The limiting piece is connected to the second driving shaft and is positioned in the lower section of the box body;

The first drive shaft is in an abutting position and the second drive shaft is in the sealing position when the testing device is in an activated state, and the limiting piece is arranged to limit the first drive shaft to be far away from the abutting position.

2. The vacuum test device of claim 1, wherein an end of the first drive shaft within the lower section is provided with a boss extending toward the top of the lower section;

3. The vacuum testing device of claim 2, wherein the base further comprises a stopper located on a side of the base opposite the first drive shaft;

4. The vacuum testing device according to claim 3, wherein a first guiding surface is arranged at the end of the first limiting rod far away from the connecting rod, the first guiding surface is arranged at one side of the first limiting rod close to the second limiting rod, and gradually deviates from the second limiting rod along the first limiting rod to the end;

5. The vacuum testing device of claim 4, wherein the second drive mechanism further comprises a hold-down member coupled to the second drive shaft and positioned below the stop member;

6. The vacuum testing device of claim 1, wherein an air inlet tube is provided in the first drive shaft, one end of the air inlet tube is positioned at the end of the first drive shaft positioned in the lower section of the box body, and the other end of the air inlet tube is communicated with an air source outside the box body.

7. The vacuum test device of claim 6, wherein the end of the first drive shaft within the housing is further provided with a sealing device;

8. The vacuum testing device of claim 7, wherein a channel is provided in the first drive shaft;

the sealing device comprises:

9. The vacuum testing device of claim 2, wherein the second drive shaft is slidably coupled to the upper section;

The second driving mechanism further includes:

10. The vacuum testing device of claim 6, wherein an air inlet is provided in the base, and one end of the air inlet is positioned in the mounting groove of the base and aligned with the first opening; the other end is communicated with the air source.