CN214309313U

CN214309313U - Ball valve air tightness test machine

Info

Publication number: CN214309313U
Application number: CN202022664099.9U
Authority: CN
Inventors: 姚牧; 熊玲花; 宋敏
Original assignee: Guangdong Forerunner Intelligent Technology Co ltd
Current assignee: Guangdong Forerunner Intelligent Technology Co ltd
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-09-28
Anticipated expiration: 2030-11-17

Abstract

The utility model discloses a ball valve air tightness test machine, including frame, carousel, compress tightly frock and airtight test fixture, the carousel pin joint is in the frame, compresses tightly frock and airtight test fixture and distributes in the carousel periphery, airtight test fixture includes climbing mechanism, linkage pendulum rod, cam and sealed lid, and sealed lid is used for the sealed one end opening that covers the ball valve, and the cam articulates in sealed lid week side, and the cam supports with the ball valve lateral surface and pushes against, and the cam is a plurality of, and around the periphery equipartition of sealed lid, the quantity of linkage pendulum rod is the same with the cam, and the one end of linkage pendulum rod is articulated with the cam, and the linkage pendulum rod other end articulates with the climbing end of climbing mechanism; the pressing tool comprises a bottom pressing mechanism and a top pressing mechanism, the bottom pressing mechanism is fixed on the rotary table and rotates along with the rotary table and is used for pressing the ball valve flange, and the top pressing mechanism is used for pressing the ball valve outlet. The utility model discloses can improve the degree of accuracy of airtight test.

Description

Ball valve air tightness test machine

Technical Field

The utility model relates to a testing arrangement of ball valve, concretely relates to ball valve air tightness test machine.

Background

The ball valve is a valve in which a spherical opening and closing piece rotates around the axis of the ball valve under the driving of a valve rod. It has an inlet and an outlet, both of which are generally provided with connecting threads and are provided with flanges for external fixed abutment. In the quality detection test of the ball valve, the air tightness test is an important link for detecting the quality of the ball valve. In the conventional ball valve airtight detection, pressure cannot be directly applied to the ball valve body part, and the deformation of the ball valve body can be caused, so that the test data are inaccurate. Especially for the lightweight valve body made of plastic, the deformation condition is more serious, so that the test result is less credible.

Since ball valves have an inlet and an outlet, it is necessary to seal both the inlet and the outlet. Conventionally, ball valves are tested by screwing a threaded cap on the inlet or outlet and then testing the opposite side under pressure. However, the operation mode of screwing the screw cap is inefficient, and the sealing effect is poor by the screw thread sealing mode, and the inaccurate test data is easily caused. In addition, the ball valve needs to be sealed under the fixed state of spacing and tests, and conventional ball valve closing device compresses tightly the ball valve fixedly with the mode of manual pressurization such as anchor clamps, however, the clamping part such as the pressure sign indicating number of manual bolt tightening regulation, the pressure that applys to the ball valve will be inhomogeneous at every turn, and operating personnel is difficult to control pressure, and too big pressure also can drag the ball valve body and produce deformation.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model aims to provide a ball valve air tightness test machine can improve the degree of accuracy of air tightness test.

The purpose of the utility model is realized through the following technical scheme:

a ball valve air tightness testing machine comprises a rack, a rotary table, a pressing tool and an air tightness testing tool, wherein the rotary table is pivoted to the rack, the pressing tool and the air tightness testing tool are distributed on the periphery of the rotary table, the air tightness testing tool comprises a jacking mechanism, linkage swing rods, cams and sealing covers, the sealing covers are used for sealing and covering openings at one ends of ball valves, the cams are hinged to the periphery of the sealing covers and abut against the outer side faces of the ball valves, the number of the cams is multiple, the cams are uniformly distributed around the periphery of the sealing covers, the number of the linkage swing rods is the same as that of the cams, one ends of the linkage swing rods are hinged to the cams, and the other ends of the linkage swing rods are hinged to the jacking end of the jacking mechanism; the pressing tool comprises a bottom pressing mechanism and a top pressing mechanism, the bottom pressing mechanism is fixed on the rotary table and rotates along with the rotary table and is used for pressing the ball valve flange, and the top pressing mechanism is used for pressing the ball valve outlet.

Preferably, the ball valve air tightness testing machine further comprises a rotating device used for rotating the ball valve handle, the rotating device comprises a telescopic cylinder, a rotating motor and a rotating shaft, the telescopic cylinder is fixed on the frame, a body of the rotating motor is fixed on a piston rod of the telescopic cylinder, an output shaft of the rotating motor is in butt joint with one end of the rotating shaft, and the other end of the rotating shaft is used for inserting the ball valve handle.

Preferably, locking openings are formed in the outer side of the sealing cover, and correspond to the cams in a one-to-one position; the outer edge of the locking opening is provided with a hinge seat, one end of the linkage swing rod is hinged with the tail end of the cam, and the head end of the cam is arranged in the locking opening and is hinged with the hinge seat.

Preferably, a sealing plug is fixed in the sealing cover, and the sealing plug is sealed with the ball valve through a radial sealing element; the sealing plug extends from the inside of the sealing cover towards the opening of the sealing cover.

Preferably, the jacking mechanism is a first air cylinder, a cylinder body of the first air cylinder is fixed at the top of the sealing cover, and a piston rod of the first air cylinder is hinged with the other end of the linkage swing rod; the ball valve air tightness testing machine further comprises a fixing frame, a fixing plate, a support and a second air cylinder, wherein a cylinder body of the second air cylinder is fixed on the support, a piston rod of the second air cylinder is fixed on the fixing plate, and the fixing frame of the sealing cover is in flexible connection.

Preferably, the bottom pressing mechanism comprises a bottom plate, a first linear power mechanism, a second linear power mechanism, a first pressing mechanism, a second pressing mechanism and at least two bases which are arranged at intervals, the bases are fixed on the bottom plate and used for limiting one end of the ball valve to be opened, and the first linear power mechanism is arranged between every two adjacent bases; the first pressing mechanism is arranged on the inner sides of the two bases and comprises a linkage rod and a pressing rod, one end of the linkage rod is hinged to one end of the pressing rod, the other end of the linkage rod is hinged to the output end of the first linear power mechanism, the middle of the pressing rod is hinged to the bottom plate, the other end of the pressing rod is used for pressing the flange on the inner side of the ball valve, the second linear power mechanism is arranged on the outer side of the two bases and is in transmission connection with the second pressing mechanism, and the second pressing mechanism is used for pressing the flange on the outer side of the ball valve.

Preferably, a support is fixed on the bottom plate, the middle part of the pressure rod is hinged to the support, and the linkage rod and the pressure rod are contracted in the support when the first linear power mechanism is contracted.

Preferably, the second pressing mechanism comprises a transmission rod and a pressing plate, one end of the pressing plate is hinged to the bottom plate, the other end of the pressing plate is provided with at least two pressing heads used for pressing the flange on the outer side of the ball valve, the output end of the second linear power mechanism is hinged to one end of the transmission rod, and the other end of the transmission rod is hinged to the middle of the pressing plate.

Preferably, the ball valve air tightness testing machine further comprises a buffer cushion, an inserting column protrudes from the buffer cushion, and the buffer cushion is respectively inserted into the pressure head and the other end of the pressure rod through the inserting column.

Preferably, the base is provided with a stepped inner cavity, a joint is arranged on the stepped inner cavity, the top end of the joint is used for being in threaded connection with an opening at one end of the ball valve, and the bottom end of the joint is supported in the stepped inner cavity.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model discloses a rotation of carousel, can drive the ball valve to different station correspondence and carry out the sealed of ball valve entry and export, reach high-efficient automatic good airtight test effect, in particular, through climbing mechanism, the linkage pendulum rod is driven in the linkage drives cam rotary motion, in order to form the cam clamping space that draws close each other on sealed covering, thereby sealed to ball valve one end opening (export) has been realized fast and fast, and, because the cam is in the periphery equipartition of sealed covering, make the ball valve atress more balanced, the deflection is less, it is less to the accuracy influence of test data, thereby realize accurate, quick ball valve airtight test; moreover, through top hold-down mechanism and bottom hold-down mechanism, can effectively compress tightly ball valve bottom flange to stabilize spacing ball valve, reduce external factor influence, further promote the accuracy of airtight test.

Drawings

Fig. 1 is a schematic structural view of the ball valve airtightness testing machine of the present invention;

fig. 2 is a schematic view of the air tightness testing tool of the present invention;

fig. 3 is a cross-sectional view of the jacking mechanism, the sealing cover, the sealing plug, the cam and the ball valve of the present invention;

fig. 4 is a cross-sectional view of the bottom pressing mechanism of the present invention (showing the first pressing mechanism and the second pressing mechanism in pressing and opening states);

fig. 5 is a schematic structural diagram of the bottom pressing mechanism of the present invention.

In the figure: 100. a frame; 200. a turntable; 300. pressing the tool; 301. a top hold down mechanism; 302. a bottom hold down mechanism; 400. an air tightness testing tool; 500. a rotating device; 501. A telescopic cylinder; 502. rotating the motor; 503. a rotating shaft; 600. a ball valve; 601. a handle; 41. a jacking mechanism; 42. linking a swing rod; 43. a cam; 44. a sealing cover; 441. a locking port; 442. a hinged seat; 46. a sealing plug; 47. a fixed mount; 48. a fixing plate; 49. a support; 410. a second cylinder; 31. a base plate; 32. a first linear power mechanism; 321. a linkage rod; 322. a pressure lever; 33. a second linear power mechanism; 331. a transmission rod; 332. pressing a plate; 3321. a pressure head; 34. a first hold-down mechanism; 35. a second hold-down mechanism; 36. a base; 38. A support; 39. a cushion pad; 310. inserting a column; 311. a stepped inner cavity; 312. and (4) a joint.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are presented herein only to illustrate and explain the present invention, and not to limit the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The ball valve air-tightness testing machine shown in fig. 1-3 comprises a rack 100, a turntable 200, a pressing tool 300 and an air-tightness testing tool 400, wherein the turntable 200 is pivoted to the rack 100, the pressing tool 300 and the air-tightness testing tool 400 are distributed on the periphery of the turntable 200, the air-tightness testing tool 400 comprises a jacking mechanism 41, linkage swing rods 42, a plurality of cams 43 and sealing covers 44, each sealing cover 44 is used for sealing and covering an opening (outlet) at one end of each ball valve 600, each cam 43 is hinged to the periphery of each sealing cover 44, each cam 43 abuts against the outer side face of each ball valve 600, the cams 43 are uniformly distributed around the periphery of each sealing cover, the linkage swing rods 42 are the same in number as the cams 43, one end of each linkage swing rod 42 is hinged to the cam 43, and the other end of each linkage swing rod 42 is hinged to the jacking end of the jacking mechanism 41; the pressing tool 300 comprises a bottom pressing mechanism 302 and a top pressing mechanism 301, the bottom pressing mechanism 302 is fixed on the turntable 200 and rotates along with the turntable 200 and is used for pressing the flange of the ball valve 600, and the top pressing mechanism 301 is used for pressing the outlet of the ball valve 600.

The rotary table 200 can be driven to rotate by a motor and a corresponding transmission assembly, the ball valve 600 can be driven to different stations to correspondingly seal the inlet and the outlet of the ball valve 600 by the rotation of the rotary table 200, and a high-efficiency and automatic good airtight test effect is achieved, particularly, the jacking mechanism 41 is used for driving the linkage swing rod 42 to drive the cam 43 to rotate in a linkage manner so as to form a clamping space of the cam 43 close to each other on the sealing cover 44, so that the opening (outlet) at one end of the ball valve 600 is quickly sealed, and the cam 43 is uniformly distributed on the periphery of the sealing cover 44, so that the ball valve 600 is more balanced in stress, smaller in deformation, and smaller in influence on the accuracy of test data, and accurate and quick airtight test of the ball valve 600 is achieved; moreover, through top hold-down mechanism 301 and bottom hold-down mechanism 302, can effectively compress tightly ball valve 600 bottom flange to stabilize spacing ball valve 600, reduce the influence of external factors, further promote the accuracy of airtight test. The sealing cover 44 may be made of a soft material such as silica gel, which has little damage to the ball valve 600. The jacking end of the jacking mechanism 41 stretches and retracts, and can drive the cams 43 to move towards the closing and clamping direction and the dispersed loosening direction. The top hold-down mechanism 301 may pre-position the outlet of the ball valve 600 by means of a gland.

When the testing device is used, the ball valve 600 is positioned by the pressing tool 300 firstly by rotating the turntable 200, and then is rotated to the position of the air tightness testing tool 400, so that the outlet and the inlet of the ball valve 600 are sealed by the sealing pressing tool 300 and the air tightness testing tool 400, at the moment, the rotating shaft 503 is rotated, so that the handle 601 of the ball valve 600 is rotated to drive the valve core to rotate, and after the testing gas is introduced from the opening at one end of the ball valve 600 (the testing inlet can be additionally formed), whether the gas leaks from the opening at the other end of the ball valve 600 is tested, and the air tightness test is completed.

As shown in fig. 1, in order to form a more automated air tightness test, the air tightness test machine for a ball valve 600 further comprises a rotating device 500 for rotating a handle 601 of the ball valve 600, wherein the rotating device 500 comprises a telescopic cylinder 501, a rotating motor 502 and a rotating shaft 503, the telescopic cylinder 501 is fixed to the frame 100, a body of the rotating motor 502 is fixed to a piston rod of the telescopic cylinder 501, an output shaft of the rotating motor 502 is in butt joint with one end of the rotating shaft 503, and the other end of the rotating shaft 503 is used for inserting the handle 601 of the ball valve 600. The rotating shaft 503 can be inserted into an installation notch of the handle 601 of the ball valve 600, and the installation notch and the rotating shaft 503 can be just clamped to realize linkage rotation driving.

As shown in fig. 2 to 3, in order to make the cam 43 apply the force to the ball valve 600 more uniformly, the sealing cover 44 is provided at the outer side thereof with locking holes 441, and each locking hole 441 corresponds to the cam 43 in one-to-one position. In order to better fix the cam 43, the outer edge of the locking opening 441 is provided with a hinge seat 442, one end of the link swing rod 42 is hinged with the tail end of the cam 43, and the head end of the cam 43 is inserted into the locking opening 441 and is hinged with the hinge seat 442.

In the sealing cover 44 of the present embodiment, a sealing plug 46 is fixed, and the sealing plug 46 is sealed with the ball valve 600 through a radial sealing element; the sealing plug 46 extends from within the sealing cap 44 in the direction of the opening of the sealing cap 44. The sealing plug 46 is in threaded connection with an opening (outlet) at one end of the ball valve 600, so that a double sealing effect of the ball valve 600 is realized, and the sealing effect is better in combination with the covering of the sealing cover 44. The sealing plug 46 is made of silica gel, and can be directly inserted into an opening (outlet) at one end of the ball valve 600 without rotation, so that the quick installation is facilitated; of course, it may be configured in a manner that requires a rotary tightening. More critically, the plug 46, which may extend into the opening (outlet) at one end of the ball valve 600, fills the volume within the ball valve 600, relatively reducing the amount of gas and venting time required to vent the ball valve 600.

The lifting mechanism 41 of this embodiment is a first cylinder, a cylinder body of the first cylinder is fixed on the top of the sealing cover 44, and a piston rod of the first cylinder is hinged to the other end of the linkage swing rod 42. The linkage swing rod 42 and the cam 43 are driven to move by the jacking acting force of the piston rod of the air cylinder.

The ball valve air tightness testing machine of the embodiment further comprises a fixed frame 47, a fixed plate 48, a bracket 49 and a second air cylinder 410, wherein a cylinder body of the second air cylinder 410 is fixed on the bracket 49, a piston rod of the second air cylinder 410 is fixed on the fixed plate 48, and the sealing cover 44 is flexibly connected with the fixed frame 47. The piston rod of the second cylinder 410 drives the fixing plate 48 to move up and down, and then drives the first cylinder and the sealing cover 44 to move up and down integrally, so as to automatically cover the opening (outlet) at one end of the ball valve 600. More than two sealing covers 44 can be fixed on the fixing plate 48 through the fixing frame 47 to simultaneously cover and seal the plurality of ball valves 600.

As shown in fig. 4 and 5, preferably, the bottom pressing mechanism 302 includes a bottom plate 31, a first linear power mechanism 32, a second linear power mechanism 33, a first pressing mechanism 34, a second pressing mechanism 35, and at least two bases 36 arranged at intervals, the bases 36 are fixed to the bottom plate 31, the bases 36 are used for limiting an opening (inlet) at one end of the ball valve 600, and the first linear power mechanism 32 is arranged between two adjacent bases 36; the first pressing mechanism 34 is respectively arranged on the inner sides of the two bases 36 and comprises a linkage rod 321 and a pressing rod 322, one end of the linkage rod 321 is hinged with one end of the pressing rod 322, the other end of the linkage rod 321 is hinged with the output end of the first linear power mechanism 32, the middle part of the pressing rod 322 is hinged with the bottom plate 31, the other end of the pressing rod 322 is used for pressing the flange on the inner side of the ball valve 600, the second linear power mechanism 33 is respectively arranged on the outer sides of the two bases 36, the second linear power mechanism 33 is in transmission connection with the second pressing mechanism 35, and the second pressing mechanism 35 is used for pressing the flange on the outer side of the ball valve 600.

Through the first linear power mechanism 32, the two pressing rods 322 of the first pressing mechanism 34 can be driven to press the ball valves 600 on the two adjacent bases 36, so that the pressing effect of the inner side flanges of the two ball valves 600 can be achieved through one action, the mounting efficiency is high, the stress of the first linear power mechanism 32 is more balanced through the sharing balance of the forces on the two sides, the pressing rods 322 obtain a balanced bending moment, the service life is longer, the two adjacent ball valves 600 are also balanced in stress, and the two adjacent ball valves 600 are not prone to deformation; combine second straight line power unit 33 to drive the effect of second hold-down mechanism 35, make ball valve 600 obtain complete effect of compressing tightly, finally realize ball valve 600's quick, the atress compresses tightly steadily to reduce the deformation that pressure produced ball valve 600, promote the degree of accuracy of airtight test. Wherein, because the pressure lever 322 is hinged to the bottom plate 31, the pressure lever 322 forms a lever mechanism, so that the force transmission of the first linear power mechanism 32 is amplified. Specifically, a support 38 is fixed on the bottom plate 31 of the embodiment, the middle portion of the pressing rod 322 is hinged to the support 38, and when the first linear power mechanism 32 contracts, the linkage rod 321 and the pressing rod 322 contract in the support 38.

The first linear power mechanism 32 and the second linear power mechanism 33 of this embodiment both use cylinders, and the output ends thereof are piston rods of the cylinders. The linkage rod 321 configured in this embodiment is beneficial to increasing the stroke of the piston rod to avoid the too fast compressing speed, and meanwhile, when the linkage rod 321 and the pressure rod 322 are contracted, enough positions can be opened for the ball valve 600 to be taken out.

The second pressing mechanism 35 of this embodiment includes a transmission rod 331 and a pressing plate 332, one end of the pressing plate 332 is hinged to the bottom plate 31, the other end of the pressing plate 332 has at least two pressing heads 3321 for pressing the outer flange of the ball valve 600, the output end of the second linear power mechanism 33 is hinged to one end of the transmission rod 331, and the other end of the transmission rod 331 is hinged to the middle of the pressing plate 332. The pressure plate 332 includes two or more pressure heads 3321, and can be more uniformly pressed against the outer flange of the ball valve 600.

Furthermore, in order to further prevent the pressure from damaging the ball valve 600 or deforming the ball valve 600, the pressing mechanism for the air tightness test of the ball valve 600 further comprises a cushion pad 39, an insertion column 310 protrudes from the cushion pad 39, the cushion pad 39 is respectively inserted into the other ends of the pressure head 3321 and the pressure rod 322 through the insertion column 310, and the arrangement of the insertion column 310 is favorable for the installation of the cushion pad 39.

In order to facilitate the testing and installation of the ball valve 600, the base 36 of the embodiment has a stepped inner cavity 311, a connector 312 is disposed on the stepped inner cavity 311, the top end of the connector 312 is used for being in threaded connection with an opening at one end of the ball valve 600, and the bottom end of the connector 312 is supported in the stepped inner cavity 311.

The embodiments of the present invention are not limited to the above embodiments, and according to the contents of the above embodiments of the present invention, the above preferred embodiments can also make modifications, replacements or combinations in various forms without departing from the basic technical idea of the present invention and without conflict, and the obtained other embodiments all fall within the scope of the present invention.

Claims

1. The ball valve air tightness testing machine is characterized by comprising a rack, a rotary table, a pressing tool and an air tightness testing tool, wherein the rotary table is pivoted to the rack, the pressing tool and the air tightness testing tool are distributed on the periphery of the rotary table, the air tightness testing tool comprises a jacking mechanism, a linkage swing rod, a cam and a sealing cover, the sealing cover is used for sealing and covering an opening at one end of a ball valve, the cam is hinged to the periphery of the sealing cover and abuts against the outer side surface of the ball valve, the cams are uniformly distributed around the periphery of the sealing cover, the number of the linkage swing rods is the same as that of the cam, one end of each linkage swing rod is hinged to the cam, and the other end of each linkage swing rod is hinged to the jacking end of the jacking mechanism; the pressing tool comprises a bottom pressing mechanism and a top pressing mechanism, the bottom pressing mechanism is fixed on the rotary table and rotates along with the rotary table and is used for pressing the ball valve flange, and the top pressing mechanism is used for pressing the ball valve outlet.

2. The ball valve tightness testing machine according to claim 1, further comprising a rotating device for rotating the ball valve handle, the rotating device comprising a telescopic cylinder, a rotating motor and a rotating shaft, wherein the telescopic cylinder is fixed to the frame, a body of the rotating motor is fixed to a piston rod of the telescopic cylinder, an output shaft of the rotating motor is in butt joint with one end of the rotating shaft, and the other end of the rotating shaft is used for inserting the ball valve handle.

3. The ball valve airtightness testing machine according to claim 1 or 2, wherein locking ports are provided on the outer side of the sealing cover, each locking port corresponding to the cam in one-to-one position; the outer edge of the locking opening is provided with a hinge seat, one end of the linkage swing rod is hinged with the tail end of the cam, and the head end of the cam is arranged in the locking opening and is hinged with the hinge seat.

4. A ball valve airtightness testing machine according to claim 3, wherein a sealing plug is fixed in the sealing cover, the sealing plug sealing with the ball valve through a radial seal, the sealing plug extending from the inside of the sealing cover toward the opening of the sealing cover.

5. The ball valve air tightness testing machine according to claim 4, characterized in that the jacking mechanism is a first cylinder, a cylinder body of the first cylinder is fixed on the top of the sealing cover, and a piston rod of the first cylinder is hinged with the other end of the linkage swing rod; the ball valve air tightness testing machine further comprises a fixing frame, a fixing plate, a support and a second air cylinder, wherein a cylinder body of the second air cylinder is fixed on the support, a piston rod of the second air cylinder is fixed on the fixing plate, and a sealing cover is flexibly connected with the fixing frame.

6. The ball valve tightness testing machine according to claim 5, wherein the bottom pressing mechanism comprises a bottom plate, a first linear power mechanism, a second linear power mechanism, a first pressing mechanism, a second pressing mechanism and at least two bases arranged at intervals, the bases are fixed on the bottom plate and used for limiting an opening at one end of the ball valve, and the first linear power mechanism is arranged between two adjacent bases; the first pressing mechanism is arranged on the inner sides of the two bases and comprises a linkage rod and a pressing rod, one end of the linkage rod is hinged to one end of the pressing rod, the other end of the linkage rod is hinged to the output end of the first linear power mechanism, the middle of the pressing rod is hinged to the bottom plate, the other end of the pressing rod is used for pressing the flange on the inner side of the ball valve, the second linear power mechanism is arranged on the outer side of the two bases and is in transmission connection with the second pressing mechanism, and the second pressing mechanism is used for pressing the flange on the outer side of the ball valve.

7. The ball valve tightness testing machine according to claim 6, wherein a support is fixed on the bottom plate, the middle portion of the pressure lever is hinged to the support, and when the first linear power mechanism contracts, the linkage lever and the pressure lever contract in the support.

8. The ball valve tightness testing machine according to claim 7, wherein the second pressing mechanism includes a transmission rod and a pressing plate, one end of the pressing plate is hinged to the bottom plate, the other end of the pressing plate has at least two pressing heads for pressing the flange at the outer side of the ball valve, the output end of the second linear power mechanism is hinged to one end of the transmission rod, and the other end of the transmission rod is hinged to the middle of the pressing plate.

9. The ball valve tightness testing machine according to claim 8, further comprising a buffer pad, wherein an insertion column protrudes from the buffer pad, and the buffer pad is respectively inserted into the other end of the pressure head and the other end of the pressure rod through the insertion column.

10. The ball valve tightness testing machine according to claim 9, wherein the base has a stepped inner cavity, a connector is disposed on the stepped inner cavity, a top end of the connector is adapted to be threaded with an opening at one end of the ball valve, and a bottom end of the connector is supported in the stepped inner cavity.