CN111775075A

CN111775075A - Differential pressure type pneumatic clamp

Info

Publication number: CN111775075A
Application number: CN202010698771.8A
Authority: CN
Inventors: 喻荣山; 常勇
Original assignee: Foshan Beyond Laser Technology Co Ltd
Current assignee: Foshan Beyond Laser Technology Co Ltd
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2020-10-16

Abstract

The invention discloses a differential pressure type pneumatic clamp, and relates to the field of pneumatic clamps. This scheme includes the pincers body, first clamping jaw, second clamping jaw, rack and pinion transmission subassembly drives first clamping jaw, second clamping jaw and removes or carry on the back mutually in opposite directions, still includes the pneumatic telescoping cylinder of differential pressure formula, the cylinder body of the pneumatic telescoping cylinder of differential pressure formula with the pincers body is fixed, the output with first clamping jaw is connected or the second clamping jaw is connected, the moving direction of output with first clamping jaw or the moving direction of second clamping jaw is parallel. This pneumatic telescoping cylinder of differential pressure formula can output not equidimension power to pneumatic clamp can output not equidimension clamping-force, consequently, can use different clamp force to the holder of treating of different rigidity to carry out the centre gripping, reduces because of the too big situation emergence that causes the clamp shrivelled or cause unable clamp tightly because of the clamping-force undersize of clamping-force that causes of clamping-force, improves the stability and the reliability of centre gripping, and the suitability is strong.

Description

Differential pressure type pneumatic clamp

Technical Field

The invention relates to the field of pneumatic clamps, in particular to a differential pressure type pneumatic clamp.

Background

In the field of machining, there are various kinds of clamping tools, of which a pneumatic clamp is one.

In the field of laser cutting, chucks and manipulators are common clamping tools, and for example, in the existing published patent, chinese patent application with application number "201910864876.3" discloses a "manipulator", which comprises an upper clamp 5.9 and a lower clamp 5.8, wherein the upper clamp 5.9 and the lower clamp 5.8 both comprise a clamping block and a clamping rack, the upper clamp 5.9 and the lower clamp 5.8 are arranged oppositely, a clamping motor drives a clamping gear to rotate, and then the clamping gear drives the clamping rack to move, so that the upper clamp and the lower clamp are driven to move oppositely or move back to back.

Although the mode of driving the clamping jaws to move by the motor is simple in structure and convenient to control, the clamping force is uncontrollable, the clamping force provided by the clamping members to be clamped with different sizes and rigidity is constant, and the clamping force cannot be adjusted according to the condition of the clamping members to be clamped, so that the clamping members to be clamped are possibly shriveled for the clamping members to be clamped with lower rigidity, and the clamping force possibly provided by the clamping members to be clamped with higher weight and size is insufficient, so that the clamping is unstable or even falls off in the transferring or machining process to cause machining safety accidents.

Therefore, in view of the problems in the prior art, it is desirable to provide a clamping device capable of outputting different clamping forces to meet the requirements of the actual production process.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a differential pressure type pneumatic clamp, which comprises a differential pressure type pneumatic telescopic cylinder, can output clamping forces with different sizes, is suitable for clamping working conditions of pieces to be clamped with different rigidities, and has the advantages of reliable and stable clamping and wide applicability.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a differential pressure type pneumatic clamp comprises a clamp body, a first clamping jaw, a second clamping jaw, a gear rack transmission assembly and a differential pressure type pneumatic telescopic cylinder, wherein the gear rack transmission assembly drives the first clamping jaw and the second clamping jaw to move in opposite directions or move back to back; a primary sliding cavity is arranged in the cylinder body, a secondary sliding cavity is arranged in the primary telescopic rod, primary vent holes are formed in the primary sliding cavity on two sides of a piston of the primary telescopic rod in pairs, and secondary vent holes are formed in the secondary sliding cavity on two sides of the piston of the secondary telescopic rod in pairs;

one end of the secondary telescopic rod is an output end;

the cylinder body with the pincers body is fixed, the output with first clamping jaw is connected or the second clamping jaw is connected, the moving direction of output with first clamping jaw or the moving direction of second clamping jaw is parallel.

Through the arrangement, the differential pressure type telescopic cylinder is adopted, the primary vent holes are arranged in pairs at two sides of the piston of the primary telescopic rod, so that the air pressure introduced into the primary vent holes at two sides of the piston of the primary telescopic rod can be changed, and the position of the primary telescopic rod and the output force of the primary telescopic rod can be adjusted; similarly, the secondary vent holes are arranged in pairs on two sides of the piston of the secondary telescopic rod, the air pressure introduced into the secondary vent holes on two sides of the piston of the secondary telescopic rod can be changed, so that the position of the secondary telescopic rod and the output force of the secondary telescopic rod can be adjusted, the secondary telescopic rod can move independently, the secondary telescopic rod as the final output power can move independently, the output is adjustable and smaller, when larger force needs to be output, the primary telescopic rod is driven to drive the secondary telescopic rod to move, so that different forces are output, the secondary telescopic rod drives the first clamping jaw (or the second clamping jaw) to move, the gear rack transmission assembly drives the second clamping jaw (or the first clamping jaw) to move, and as the output force of the differential pressure type pneumatic telescopic cylinder is adjustable, the clamping force between the upper clamping jaw and the lower clamping jaw is adjustable, so that workpieces with different rigidities can be stabilized, Reliable clamping and wide applicability.

Preferably, the primary vent hole comprises a first vent hole and a second vent hole, and the first vent hole and the second vent hole are both arranged on the cylinder body and are respectively located on two sides of the first plug body;

the secondary vent hole comprises a third vent hole and a fourth vent hole, the third vent hole is formed in the first-stage telescopic rod, the fourth vent hole is formed in the secondary telescopic rod, and the third vent hole and the fourth vent hole are located on two sides of the second plug body respectively.

Through the arrangement, the third through hole is arranged on the first-stage telescopic rod, and the fourth through hole is arranged on the secondary telescopic rod, so that the size of the first-stage telescopic rod is favorably reduced, and the size of the whole pneumatic telescopic cylinder is further reduced; in addition, the processing difficulty is favorably reduced, and the production is convenient.

Preferably, one side of the first plug body, which is far away from the output end, is a first pushing surface, one side of the first plug body, which is far towards the output end, is a first retreating surface, the first vent hole is located at one side of the first pushing surface, and the second vent hole is located at one side of the first retreating surface;

the second cock body deviates from one side of output is the second and impels the face, the second cock body court one side of output is the second back face, the third ventilation hole is located one side of second propulsion face, the fourth ventilation hole is located one side of second back face.

Through the arrangement, the secondary telescopic rod and the primary telescopic rod can move independently, when only small output force is needed, only the secondary telescopic rod can be driven to move, or the air pressure difference is formed between two sides of a piston of the secondary telescopic rod, and small force is output; when large output force needs to be output, the primary telescopic rod is adopted to push the secondary telescopic rod to move, and large output force is obtained, so that the use requirement of large output force is met.

Preferably, be connected with first breather pipe, second breather pipe, third breather pipe, fourth breather pipe on first breather pipe, second breather pipe, third breather pipe and the fourth breather pipe respectively, first breather pipe second breather pipe is connected on first switching solenoid valve, first switching solenoid valve and first intake-tube connection, the second breather pipe still is connected with first back pressure valve and first discharge valve, the third breather pipe fourth breather pipe is connected on second switching solenoid valve, second switching solenoid valve and second intake-tube connection, the third breather pipe still is connected with second back pressure valve and second discharge valve.

Through the arrangement, the first air inlet pipe is ventilated to serve as driving air pressure of the first-stage telescopic rod, the first air vent pipe or the second air vent pipe is ventilated through the first switching electromagnetic valve, back pressure can be adjusted through the first back pressure valve, so that the output force of the first-stage telescopic rod is adjusted, and when the first-stage telescopic rod needs to be driven to move forwards, the first exhaust valve is opened to exhaust air;

and the second air inlet pipe is ventilated to serve as the driving air pressure of the secondary telescopic rod, the third air inlet pipe or the fourth air inlet pipe is ventilated through the second switching electromagnetic valve, the back pressure can be adjusted through the second back pressure valve, so that the output force of the secondary telescopic rod is adjusted, and when the secondary telescopic rod needs to be driven to contract, the second exhaust valve is opened through the second switching electromagnetic valve to exhaust.

As preferred, be connected with first breather pipe, second breather pipe, third breather pipe, fourth breather pipe on first breather pipe, second breather pipe, third breather pipe and the fourth breather pipe respectively, first breather pipe second breather pipe is connected on first switching solenoid valve, first switching solenoid valve and first intake-tube connection, first breather pipe still is connected with first back pressure valve and first discharge valve, the third breather pipe fourth breather pipe is connected on second switching solenoid valve, second switching solenoid valve and second intake-tube connection, the fourth breather pipe still is connected with second back pressure valve and second discharge valve.

Through the arrangement, the arrangement mode is suitable for the situation that the clamping jaw is driven to realize clamping action when the output end extends out, the first air inlet pipe is ventilated to serve as the driving air pressure of the first-stage telescopic rod, the first air vent pipe or the second air vent pipe is switched to be ventilated through the first switch electromagnetic valve, the back pressure can be adjusted through the first back pressure valve, so that the output force of the first-stage telescopic rod is adjusted, and when the first-stage telescopic rod needs to be driven to retract, the first exhaust valve can be opened to exhaust;

and the second air inlet pipe is ventilated to serve as the driving air pressure of the secondary telescopic rod, the third air inlet pipe or the fourth air inlet pipe is switched to be ventilated through the second switching electromagnetic valve, the back pressure can be adjusted through the second back pressure valve, so that the output force of the secondary telescopic rod is adjusted, and when the secondary telescopic rod needs to be driven to move forwards, the second exhaust valve is opened to exhaust.

Preferably, the first air inlet pipe and the second air inlet pipe are respectively provided with a first pressure reducing valve and a second pressure reducing valve, and the first pressure reducing valve and the second pressure reducing valve are respectively connected with a first air gauge and a second air gauge.

Through setting up like this, adjust the atmospheric pressure of exporting to first intake pipe, second intake pipe respectively through first relief pressure valve, second relief pressure valve, set up first barometer and second barometer, be convenient for adjust corresponding atmospheric pressure value.

Preferably, the air inlet ends of the first back pressure valve and the second back pressure valve are respectively connected with a third barometer and a fourth barometer.

Through setting up like this, set up third barometer and fourth barometer, can observe the backpressure value after first backpressure valve and the adjustment of second backpressure valve directly perceivedly, be convenient for adjust the output of telescoping cylinder, and then the clamping-force of adjustment clamp.

Preferably, the gear rack transmission assembly comprises a driving gear and two driving racks, the two driving racks are respectively located on two sides of the driving gear, the driving gear is rotatably arranged on the clamp body, the two driving racks are respectively fixed to the first clamping jaw and the second clamping jaw, and the output end of the gear rack is connected with the second clamping jaw.

Through setting up like this, the output drives the second clamping jaw and removes, and is connected with the drive rack on the second clamping jaw, drives drive gear through this drive rack and rotates, and then drives another drive rack that is located the drive gear opposite side and remove, reaches to make first clamping jaw remove in opposite directions towards the second clamping jaw or deviate from the second clamping jaw back of the body and remove.

Preferably, the clamp body is further provided with a moving guide rail, the moving guide rail is arranged along the moving direction of the first clamping jaw and the second clamping jaw, the first clamping jaw and the second clamping jaw are respectively connected with a sliding block, and the sliding block slides along the moving guide rail.

Through setting up like this, set up the slider and slide along moving guide rail, make the removal of first clamping jaw and second clamping jaw more smooth and easy, stable.

Preferably, the first clamping jaw and the second clamping jaw are both provided with clamping cushion blocks, and the clamping cushion blocks are respectively positioned on the opposite surfaces of the first clamping jaw and the second clamping jaw.

Through setting up like this, set up the centre gripping cushion on first clamping jaw and second clamping jaw, when the holder is treated in the centre gripping, the contact of centre gripping cushion buffering and treating the holder reduces the possibility of treating the holder damage.

Compared with the prior art, the invention has the beneficial technical effects that:

the utility model provides a differential pressure formula pneumatic clamp, including the pneumatic telescoping cylinder of output power adjustable differential pressure formula, the pneumatic telescoping cylinder of this differential pressure formula can export the not power of equidimension, thereby pneumatic clamp can export the not clamping-force of equidimension, consequently, can use different clamp force to the holder of treating of different rigidity to carry out the centre gripping, reduce because of the too big clamp force that causes the clamp shrivelled or cause the unable circumstances of pressing from both sides tightly to take place because of the clamping-force undersize, improve the stability and the reliability of centre gripping, the suitability is strong.

Drawings

FIG. 1 is a schematic structural view of a differential pressure type pneumatic telescoping cylinder in embodiment 1 of the present invention;

FIG. 2 is a schematic view of the inside of a differential pressure type pneumatic telescoping cylinder in embodiment 1 of the present invention;

fig. 3 is a schematic view of the air path connection of the differential pressure type pneumatic telescopic cylinder in embodiment 1 of the present invention;

FIG. 4 is a schematic view of the inside of a differential pressure type pneumatic telescoping cylinder in embodiment 2 of the present invention;

FIG. 5 is a schematic view showing the overall structure of the differential pressure type pneumatic clamp in embodiment 3 of the present invention;

FIG. 6 is a front view of the differential pressure type pneumatic clamp in embodiment 3 of the invention;

FIG. 7 is a rear view of the differential pressure type pneumatic clamp in embodiment 3 of the invention;

FIG. 8 is a schematic view of a first ventilation state and force analysis of a differential pressure type pneumatic telescopic cylinder in working condition one according to embodiment 4 of the present invention;

FIG. 9 is a schematic view of a second ventilation state and force analysis of the differential pressure type pneumatic telescopic cylinder in the working condition one according to the embodiment 4 of the present invention;

fig. 10 is a schematic view of analysis of the ventilation state and the stress of the differential pressure type pneumatic telescopic cylinder in the second working condition according to the embodiment 4 of the present invention;

fig. 11 is a schematic view of a first ventilation state and a force analysis of a differential pressure type pneumatic telescopic cylinder in a third working condition according to embodiment 4 of the present invention;

fig. 12 is a schematic view of a second ventilation state and a force analysis of the differential pressure type pneumatic telescopic cylinder in the third operating mode according to embodiment 4 of the present invention;

fig. 13 is a schematic view of a third ventilation state and a force analysis of the differential pressure type pneumatic telescopic cylinder in the third operating mode in embodiment 4 of the present invention;

fig. 14 is a schematic view of the air path connection of the differential pressure type pneumatic telescoping cylinder in embodiment 6 of the present invention.

Wherein, the technical characteristics that each reference numeral refers to are as follows:

1. a differential pressure type pneumatic telescopic cylinder; 101. a cylinder body; 1011. a primary slide cavity; 102. a piston; 1021. a first plug body; 10211. a first pusher surface; 10212. a first receding surface; 1022. a second plug body; 10221. a second pusher surface; 10222. a second receding surface; 103. a piston rod; 1031. a first-stage telescopic rod; 10311. a secondary slide cavity; 1032. a secondary telescopic rod; 10321, an output end; 103211, a connecting nut; 2. a primary vent; 201. a first vent hole; 2011. a first vent pipe; 202. a second vent hole; 2021. a second vent pipe; 20211. a one-way valve; 3. a secondary vent; 301. a third vent hole; 3011. a third vent pipe; 302. a fourth vent hole; 3021. a fourth air vent pipe; 4. a first on-off solenoid valve; 5. a first intake pipe; 501. a first pressure reducing valve; 5011. a first barometer; 6. a first back pressure valve; 601. a third barometer; 7. a first exhaust valve; 8. a second on-off solenoid valve; 9. a second intake pipe; 901. a second pressure reducing valve; 9011. a second barometer; 10. a second back pressure valve; 1001. a fourth barometer; 11. a second exhaust valve; 12. differential pressure type pneumatic clamp; 1201. A clamp body; 1202. a first jaw; 1203. a second jaw; 12031. a connecting plate; 120311, a connecting card slot; 1204. a rack and pinion drive assembly; 12041. a drive gear; 12042. a drive rack; 13. a moving guide rail; 1301. a slider; 14. And clamping the cushion block.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.

Example 1

Referring to fig. 1 to 3, the present embodiment discloses a differential pressure type pneumatic telescopic cylinder 1, including a cylinder body 101, a piston 102 and a piston rod 103 connected to the piston 102, the piston rod 103 is provided with at least two, each piston rod 103 is connected to a piston 102, a first-stage sliding chamber 1011 is provided in the cylinder body 101, the piston rod 103 includes a first-stage telescopic rod 1031 and a plurality of secondary telescopic rods 1032, the piston 102 of the first-stage telescopic rod 1031 slides in the first-stage sliding chamber 1011, the first-stage telescopic rod 1031 and the plurality of secondary telescopic rods 1032 are provided with secondary sliding chambers 10311, the first-stage telescopic rod 1031 and the plurality of secondary telescopic rods 1032 are sequentially arranged in a nested manner, and the piston 102 of the secondary telescopic rods 1032;

the primary slide chamber 1011 is provided with primary vent holes 2 in pairs on both sides of the piston 102 of the primary telescopic bar 1031, and the secondary slide chamber 10311 is provided with secondary vent holes 3 in pairs on both sides of the piston 102 of the secondary telescopic bar 1032.

Referring to fig. 1 to 3, in the present embodiment, two piston rods 103 are provided, including a primary telescopic rod 1031 and a secondary telescopic rod 1032, in other embodiments, more than three piston rods 103 may be provided, including a telescopic rod and a plurality of secondary telescopic rods 1032;

in this embodiment, two pistons 102 are provided, including a first plug body 1021 and a second plug body 1022, wherein the first plug body 1021 is connected to the first telescopic rod 1031, and the second plug body 1022 is connected to the second telescopic rod 1032;

referring to fig. 2 to 3, the primary vent hole 2 includes a first vent hole 201 and a second vent hole 202, the first vent hole 201 and the second vent hole 202 are both disposed on the cylinder 101 and respectively located at two sides of the first plug 1021, and the first vent hole 201 and the second vent hole 202 are located at two ends of the cylinder 101 along the length direction;

referring to fig. 2 to 3, in the present embodiment, the secondary vent hole 3 includes a third vent hole 301 and a fourth vent hole 302, the third vent hole 301 is disposed on the first telescopic rod 1031, the fourth vent hole 302 is disposed on the secondary telescopic rod 1032, and the third vent hole 301 and the fourth vent hole 302 are respectively located at two sides of the second plug body 1022.

Referring to fig. 2 to 3, an output end 10321 is disposed at one end of the secondary expansion link 1032, a first pushing surface 10211 is disposed at a side of the first plug 1021 facing the output end 10321, a first retreating surface 10212 is disposed at a side of the first plug 1021 facing the output end 10321, the first air vent 201 is disposed at a side of the first pushing surface 10211, and the second air vent 202 is disposed at a side of the first retreating surface 10212;

the second plug body 1022 is provided with a second advanced surface 10221 at a side facing away from the output end 10321, a second retreated surface 10222 at a side facing the output end 10321, the third vent hole 301 is provided at a side of the second advanced surface 10221, and the fourth vent hole 302 is provided at a side of the second retreated surface 10222.

Referring to fig. 1 to 3, a first vent 201, a second vent 202, a third vent 301, and a fourth vent 302 are respectively connected to a first vent 2011, a second vent 2021, a third vent 3011, and a fourth vent 3021, the first vent 2011, and the second vent 2021 are connected to a first on-off solenoid valve 4, the first on-off solenoid valve 4 is connected to a first intake pipe 5, the second vent 2021 is further connected to a first back pressure valve 6 and a first exhaust valve 7, the third vent 3011, and the fourth vent 3021 are connected to a second on-off solenoid valve 8, the second on-off solenoid valve 8 is connected to a second intake pipe 9, and the third vent 3011 is further connected to a second back pressure valve 10 and a second exhaust valve 11.

Specifically, the first switching solenoid valve 4 and the second switching solenoid valve 8 are two-position five-way solenoid valves, the first backpressure valve 6 and the second backpressure valve 10 are adjustable pressure release valves, the first exhaust valve 7 and the second exhaust valve 11 are two-position two-way solenoid valves, and the solenoid valves can be selected from the solenoid valves of "haddock" in the market at present.

Referring to fig. 3, the first intake pipe 5 and the second intake pipe 9 are respectively provided with a first pressure reducing valve 501 and a second pressure reducing valve 901, the first pressure reducing valve 501 and the second pressure reducing valve 901 are respectively connected with a first barometer 5011 and a second barometer 9011, and the intake ends of the first backpressure valve 6 and the second backpressure valve 10 are respectively connected with a third barometer 601 and a fourth barometer 1001.

Referring to fig. 3, the second vent pipe 2021 and the third vent pipe 3011 are further respectively connected to a check valve 20211, the check valve 20211 is disposed at one end of the second vent pipe 2021 connected to the first on-off electromagnetic valve 4, and one end of the third vent pipe 3011 connected to the second on-off electromagnetic valve 8.

Example 2

Referring to fig. 4, the present embodiment discloses another differential pressure type pneumatic telescoping cylinder 1, and based on embodiment 1, the present embodiment is different from embodiment 2 in that:

in this embodiment, the third vent hole 301 and the fourth vent hole 302 are both disposed on the first-stage telescopic rod 1031, and the third vent hole 301 and the fourth vent hole 302 are respectively located at two sides of the second plug body 1022.

The primary telescopic bar 1031 has a larger dimension in the radial direction than in embodiment 1.

Example 3

Referring to fig. 5 to 7, the present embodiment discloses a differential pressure type pneumatic clamp 12, including the differential pressure type pneumatic telescopic cylinder 1 of the above embodiments, further including a clamp body 1201, a first clamping jaw 1202, a second clamping jaw 1203, and a gear and rack transmission assembly 1204, where the gear and rack transmission assembly 1204 drives the first clamping jaw 1202 and the second clamping jaw 1203 to move toward or away from each other, a cylinder body 101 of the differential pressure type pneumatic telescopic cylinder 1 is fixed to the clamp body 1201, an output end 10321 of the differential pressure type pneumatic telescopic cylinder is connected to the first clamping jaw 1202 or the second clamping jaw 1203, and a moving direction of the output end 10321 is parallel to a moving direction of the first clamping jaw 1202 or the second clamping jaw 1203.

Referring to fig. 6, in the present embodiment, the gear-rack transmission assembly 1204 includes a driving gear 12041 and a driving rack 12042, the driving gear 12041 is rotatably disposed on the forceps body 1201, two driving racks 12042 are disposed on two sides of the driving gear 12041, respectively, when the driving gear 12041 rotates in one direction, the driving gears 12041 on two sides move in opposite directions, the two driving racks 12042 are respectively fixed to the first clamping jaw 1202 and the second clamping jaw 1203, and the output end 10321 is connected to the second clamping jaw 1203.

Referring to fig. 7, a connecting plate 12031 is fixedly connected to the second clamping jaw 1203, a connecting slot 120311 is formed in the connecting plate 12031, a connecting external thread (not shown) is formed on the output end 10321, two connecting nuts 103211 are connected to the output end 10321 through threads, a maximum gear of the connecting nut 103211 is larger than the width of the connecting slot 120311, the output end 10321 is inserted into the connecting slot 120311, and the two connecting nuts 103211 are respectively abutted against two sides of the connecting plate 12031 to fix the connecting plate 12031 and the output end 10321.

The forceps body 1201 is further provided with a moving guide rail 13, the moving guide rail 13 is arranged along the moving direction of the first clamping jaw 1202 and the second clamping jaw 1203, the first clamping jaw 1202 and the second clamping jaw 1203 are respectively connected with a sliding block 1301, and the sliding block 1301 slides along the moving guide rail 13, so that the first clamping jaw 1202 and the second clamping jaw 1203 can slide oppositely or reversely along the moving guide rail 13.

The first clamping jaw 1202 and the second clamping jaw 1203 are both provided with clamping cushion blocks 14, the clamping cushion blocks 14 may be rubber or silica gel, or may be blocks made of other flexible materials, and the clamping cushion blocks 14 are respectively located on the opposite surfaces of the first clamping jaw 1202 and the second clamping jaw 1203.

Example 4

The embodiment discloses a workpiece clamping method, which is used for clamping a workpiece by using the differential pressure type pneumatic clamp of the embodiment and comprises the following steps:

s1: measuring the cross section dimension D of the clamping position of the to-be-clamped piece and the wall thickness B of the to-be-clamped piece; d is the maximum size of the cross section of the to-be-clamped piece, if the cross section of the to-be-clamped piece is a regular figure, such as a circle, D is the maximum outer diameter of the to-be-clamped piece, if the cross section of the to-be-clamped piece is a rectangle, D is the diagonal length of the to-be-clamped piece, and if the cross section of the to-be-clamped piece is an ellipse, D is the major axis of the ellipse;

s2: when D is less than 60mm and B is more than 1mm, firstly ventilating a primary vent hole 2 on one side of a first plug body 1021, enabling the first plug body 1021 on a primary telescopic rod 1031 to be in abutting joint with the inner wall of any side of a primary sliding cavity 1011, referring to fig. 8 and 9, and then ventilating a secondary vent hole 3 on one side of a second plug body 1022, enabling a secondary telescopic rod 1032 to move along the secondary sliding cavity 10311, driving an output end 10321 to drive a first clamping jaw 1202 or a second clamping jaw 1203 to move, and under the transmission action of a gear rack transmission assembly 1204, enabling the first clamping jaw 1202 and the second clamping jaw 1203 to move oppositely, so as to clamp a workpiece to be clamped;

in this embodiment, when clamping a workpiece, referring to fig. 3 and 8, first, the first switching solenoid valve 4 is set to "0" position, the first exhaust valve 7 is closed, the second vent pipe 2021 is vented, air is introduced into the first stage sliding chamber 1011 through the second vent hole 202, the first stage telescopic rod 1031 is retracted until the first plug 1021 and the inner wall of the first stage sliding chamber 1011 on the side away from the output end 10321 are held in abutment, then, the second switching solenoid valve 8 is set to "0" position, air is introduced into the fourth vent pipe 3021, and the second exhaust valve 11 is opened, so that the second stage telescopic rod 1032 is retracted, assuming: the effective stressed area of the first plug body 1021 is S1, the effective stressed area of the second plug body 1022 is S2, the air pressure introduced into the second vent pipe 2021 is P1, the air pressure introduced into the third vent pipe 3011 is P2, and since the second exhaust valve 11 is opened, no back pressure exists in the third vent pipe 3011, or the back pressure value is 0, under this condition, the stress conditions of the primary telescopic rod 1031 and the secondary telescopic rod 1032 are analyzed as follows: introducing air pressure P1 into the primary sliding cavity 1011, and generating an acting force F1 to the first plug body 1021, namely P1S 1; to secondary slide chamber 10311The air pressure P2 is introduced into the secondary stopper body 1022, so that the acting force F2 to the secondary stopper body 1022 is P2S 2, and the acting force F3 to the primary telescopic rod 1031 is P2S 2; therefore, the resultant force F received by the first stage extension bar 1031_{In 1. sup.}F1-F3; because the first clamping jaw 1202 and the second clamping jaw 1203 are vertically installed, the force applied to the secondary expansion link 1032 further includes the self gravity G1 and the sum G2 of the gravity of the second clamping jaw 1203, the connecting plate and the connecting nut, and the resultant force F applied to the secondary expansion link 1032_{In combination with 2}F2-G1-G2, and F_{In 1. sup.}>0，F_{In combination with 2}>0。

By F_{In combination with 2}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the transmission action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 are close to each other, so that a workpiece to be clamped is clamped;

when D is less than 60mm and B is greater than 1mm, referring to fig. 3 and 9, the first switching solenoid valve 4 may be set to "1" position, so as to supply air to the first vent pipe 2011, open the first exhaust valve 7, and move the first telescopic rod 1031 forward until the first plug 1021 and the inner wall of the first sliding chamber 1011 on the side of the output end 10321 are kept in abutment, and then, the second switching solenoid valve 8 is set to "0" position, so as to supply air to the fourth vent pipe 3021, and open the second exhaust valve 11, so as to move the second telescopic rod 1032 backward, assuming that: the air pressure introduced into the first vent pipe 2011 is P1, the air pressure introduced into the fourth vent pipe 3021 is P2, and since the first exhaust valve 7 and the second exhaust valve 11 are both opened, no back pressure is present in the first vent pipe 2011 and the third vent pipe 3011, or the back pressure value is 0,

under this condition, the stress condition of the primary telescopic rod 1031 and the secondary telescopic rod 1032 is analyzed as follows: air pressure P1 is introduced into the primary sliding cavity 1011, and an acting force F1 generated on the second plug body 1022 is P1S 1; the air pressure P2 is introduced into the secondary slide chamber 10311, the acting force F2 generated to the second plug body 1022 is P2S 2, and the acting force F3 generated to the primary telescopic rod 1031 is P2S 2; therefore, the resultant force F received by the first stage extension bar 1031_{In 1. sup.}F1+ F3; because the first clamping jaw 1202 and the second clamping jaw 1203 are vertically installed, the force applied to the secondary telescopic rod 1032 further includes the self-gravity G1 and the weight of the second clamping jaw 1203, the connecting plate and the connecting nutThe sum of forces G2, the resultant force F experienced by the secondary frame 1032_{In combination with 2}F2-G1-G2, and F_{In 1. sup.}>0，F_{In combination with 2}>0, for the same reason, depend on F_{In combination with 2}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the driving action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 approach to each other, so that a workpiece to be clamped is clamped.

When D is larger than or equal to 60mm and B is larger than 2mm, firstly ventilating a secondary vent hole 3 positioned on one side of a second plug body 1022, enabling the second plug body 1022 on a secondary expansion link 1032 to be in butt joint with the inner wall of one side of a secondary sliding cavity 10311, enabling the resultant force direction of the secondary vent hole 3 applied to the second plug body 1022 to be opposite to the direction in which an output end 10321 needs to move, then ventilating a primary vent hole 2, enabling a primary expansion link 1031 to move along a primary sliding cavity 1011, enabling the primary expansion link 1031 to overcome the resultant force of air pressure introduced into the secondary vent hole 3 to apply to the second plug body 1022 and drive the secondary expansion link 1032 to move, enabling the output end 10321 to drive a first clamping jaw 1202 or a second clamping jaw 1203 to move, and enabling the first clamping jaw 1202 and the second clamping jaw 1203 to move oppositely under the transmission action of a gear-rack transmission assembly;

in this embodiment, referring to fig. 3 and 10, since the secondary expansion link 1032 retracts to enable the first clamping jaw 1202 and the second clamping jaw 1203 to approach each other to achieve clamping, first, the second switching electromagnetic valve 8 is in the "1" position, air is supplied to the third air connecting pipe 3011, the second exhaust valve 11 is closed, the secondary expansion link 1032 advances, the second plug body 1022 is abutted to the inner wall of the secondary sliding chamber 10311 on the side of the output end 10321, the first switching electromagnetic valve 4 is in the "0" position, the first exhaust valve 7 is closed, air is supplied to the second air connecting pipe 2021, and the primary expansion link 1031 retracts, assuming: the effective force-bearing area of the first plug body 1021 is S1, the effective force-bearing area of the second plug body 1022 is S2, the air pressure introduced into the second vent pipe 2021 is P1, the air pressure introduced into the third vent pipe 3011 is P2, since the first on-off solenoid valve 4 is at "0" position and the second on-off solenoid valve 8 is at "1" position, the first vent pipe 2011 and the fourth vent pipe 3021 are communicated with the outside, therefore, no back pressure exists in the first vent pipe 2011 and the fourth vent pipe 3021, or the back pressure value is 0,under this condition, the stress condition of the primary telescopic rod 1031 and the secondary telescopic rod 1032 is analyzed as follows: introducing air pressure P1 into the primary sliding cavity 1011, and generating an acting force F1 to the first plug body 1021, namely P1S 1; the air pressure P2 is introduced into the secondary slide chamber 10311, the acting force F2 generated to the second plug body 1022 is P2S 2, and the acting force F3 generated to the primary telescopic rod 1031 is P2S 2; because the first clamping jaw 1202 and the second clamping jaw 1203 are vertically installed, the force applied to the secondary expansion link 1032 further includes the self gravity G1 and the sum G2 of the gravity of the second clamping jaw 1203, the connecting plate and the connecting nut, and therefore, the resultant force F applied to the secondary expansion link 1032_{In combination with 2}F2+ G1+ G2, F of the primary extension bar 1031_{In 1. sup.}After the secondary expansion link 1032 abuts against the inner wall of the primary sliding cavity 1011, the primary expansion link 1031 drives the secondary expansion link 1032 to move back together, and at the moment, the resultant force of the primary expansion link 1031 and the secondary expansion link 1032 is F_{3 in a word}＝F_{In 1. sup.}-F_{In combination with 2}＝F1+F3-(F2+G1+G2)＝F1-G1-G2，F_{3 in a word}>0, by F_{3 in a word}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the driving action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 approach to each other, so that a workpiece to be clamped is clamped.

When D is more than or equal to 60mm and B is less than or equal to 2mm or when D is less than 60mm and B is less than or equal to 1mm, firstly ventilating a primary vent hole 2 on one side of a first plug body 1021, enabling the first plug body 1021 on a primary telescopic rod 1031 to be in abutting contact with the inner wall of any one side of a primary sliding cavity 1011, then ventilating secondary vent holes 3 on two sides of a second plug body 1022, or only ventilating the secondary vent holes 3 on one side of the second plug body 1022, enabling the secondary vent holes 3 on the other side to maintain back pressure, enabling pressure difference to be formed on two sides of the second plug body 1022, driving a secondary telescopic rod 1032 to move along the secondary sliding cavity 1022 through the pressure difference, driving an output end 10321 to drive a first clamping jaw 1202 or a second clamping jaw 1203 to move, and driving the first clamping jaw 1202 and the second clamping jaw 1203 to move oppositely under the transmission action of a gear rack transmission component 1204.

Referring to fig. 3 and 11, in the present embodiment, first, the first switching solenoid valve 4 is set to "0", the first exhaust valve 7 is closed,air is admitted into the second vent pipe 2021, so that the first-stage telescopic rod 1031 retracts to be in butt joint with the inner wall of one side of the first-stage slide chamber 1011 away from the output end 10321, then the second switching electromagnetic valve 8 is enabled to be in a position of '0', air is admitted into the fourth vent pipe 3021, the second exhaust valve 11 is closed, and the back pressure value in the third vent pipe 3011 can be adjusted through the second back pressure valve 10, assuming that: the air pressure introduced into the second air pipe 2021 is P1, the air pressure introduced into the fourth air pipe 3021 is P2, and since the first on-off solenoid valve 4 is at the "0" position, the first air pipe 2011 is communicated with the outside, so that no back pressure or a back pressure value in the first air pipe 2011 is 0, and the pressure set by the second back pressure valve 10 is P3, under this working condition, the stress conditions of the primary telescopic rod 1031 and the secondary telescopic rod 1032 are analyzed as follows: introducing air pressure P1 into the primary sliding cavity 1011, and generating an acting force F1 to the first plug body 1021, namely P1S 1; the air pressure P2 is introduced into the secondary slide chamber 10311, so that the acting force F2 ═ P2 ═ S2 generated on the second plug body 1022 and the acting force F5 ═ P2 ═ S2 generated on the first plug body 1021; because the back pressure P3 exists in the third air vent 3011, the force F6 applied by the back pressure P3 to the primary telescopic rod 1031 is P3S 2, and the force F3 applied to the second plug body 1022 is P3S 2; the force on the secondary expansion link 1032 further includes the self-gravity G1 and the sum G2 of the gravity of the second clamping jaw 1203, the connecting plate and the connecting nut, so that the primary expansion link 1031 receives F_{In 1. sup.}＝F1+F6-F5，F_{In 1. sup.}>0; resultant force F experienced by secondary expansion link 1032_{In combination with 2}F2-F3- (G1-G2), dependent on F_{In combination with 2}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the transmission action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 are close to each other, so that a workpiece to be clamped is clamped;

under the working condition, pressure difference P2-P3 is formed at two sides of the second plug body 1022, the pressure difference overcomes moving resistance G1+ G2 to provide driving force for contraction of the secondary telescopic rod 1032, and due to the existence of back pressure P3, the air pressure value borne by the second plug body 1022 is reduced, so that the clamping force is finally reduced, and the clamping device is suitable for clamping a workpiece to be clamped with poor rigidity.

When D is more than or equal to 60mm and B is less than or equal to 2mm or when D is less than 60mm and B is less than or equal to 1mm, refer to FIG. 3 and FIG. 12, the first switching electromagnetic valve 4 is enabled to be at the position of '1', the air is supplied to the first vent pipe 2011, the first exhaust valve 7 is opened, the first-stage telescopic rod 1031 moves forwards, and the first-stage telescopic rod 1031 is kept in abutting joint with the inner wall of the first-stage sliding cavity 1011 on one side close to the output end 10321; then, the second on-off solenoid valve 8 is set to "0" position, air is supplied to the fourth exhaust pipe 3021, the second exhaust valve 11 is closed, and the back pressure value in the third exhaust pipe 3011 can be adjusted by the second back pressure valve 10, assuming that: the air pressure introduced into the first vent pipe 2011 is P1, the air pressure introduced into the fourth vent pipe 3021 is P2, and since the first exhaust valve 7 is opened, there is no back pressure in the second vent pipe 2021, or the back pressure value is 0, and the pressure set by the second back pressure valve 10 is P3, under this condition, the stress conditions of the primary telescopic rod 1031 and the secondary telescopic rod 1032 are analyzed as follows: introducing air pressure P1 into the primary sliding cavity 1011, and generating an acting force F1 to the first plug body 1021, namely P1S 1; the air pressure P2 is introduced into the secondary slide chamber 10311, so that the acting force F2 ═ P2 ═ S2 generated on the second plug body 1022 and the acting force F3 ═ P2 ═ S2 generated on the first plug body 1021; because the back pressure P3 exists in the third air vent 3011, the force F5 applied by the back pressure P3 to the primary telescopic rod 1031 is P3S 2, and the force F4 applied to the second plug body 1022 is P3S 2; the force on the secondary expansion link 1032 further includes the self-gravity G1 and the sum G2 of the gravity of the second clamping jaw 1203, the connecting plate and the connecting nut, so that the primary expansion link 1031 receives F_{In 1. sup.}＝F1+F3-F5，F_{In 1. sup.}>0; resultant force F experienced by secondary expansion link 1032_{In combination with 2}F2-F4- (G1-G2), dependent on F_{In combination with 2}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the transmission action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 are close to each other, so that a workpiece to be clamped is clamped;

similarly, under this condition, a pressure difference P2-P3 is formed between two sides of the second plug body 1022, the pressure difference overcomes the moving resistance G1+ G2 to provide driving force for the contraction of the secondary expansion link 1032, and due to the existence of the back pressure P3, the air pressure value borne by the second plug body 1022 is reduced, so that the clamping force is finally reduced, and the clamping device is suitable for clamping a workpiece to be clamped with poor rigidity.

Preferably, before S1, step S0, S0 is also performed: and manufacturing a clamping sample block of the to-be-clamped piece, and performing test clamping on the clamping sample block through the differential pressure type pneumatic clamp 12.

Example 5

The embodiment of the invention discloses another workpiece clamping method, and based on the embodiment 4, the embodiment is different from the embodiment 4 in that:

in S2, when D is greater than or equal to 60mm and B is less than or equal to 2mm or D is less than 60mm and B is less than or equal to 1mm, the primary vent holes 2 at both sides of the first plug 1021 are all vented, or only the primary vent hole 2 at one side of the first plug 1021 is vented, the primary vent hole 2 at the other side maintains back pressure, so that a first pressure difference is formed at both sides of the first plug 1021, and the secondary vent holes 3 at both sides of the second plug 1022 are all vented, or only the secondary vent hole 3 at one side of the second plug 1022 is vented, and the secondary vent hole 3 at the other side maintains back pressure, so that a second pressure difference is formed at both sides of the second plug 1022, the first pressure difference drives the primary telescopic rod 1031 to move along the primary sliding chamber 1011 in a direction away from the output end 10321, the secondary telescopic rod 1032 is driven to move along the secondary sliding chamber 10311 by the second pressure difference, and after the secondary telescopic rod 1032 and the inner wall of the secondary sliding chamber 10311, the resultant force of the force applied by the first pressure The secondary telescopic rod 1032 is driven to move, the output end 10321 drives the first clamping jaw 1202 or the second clamping jaw 1203 to move, and under the driving action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 move oppositely, so that a workpiece to be clamped is clamped.

Referring to fig. 3 and 13, in the present embodiment, assuming that the second on-off solenoid valve 8 is set to the "0" position, the air is supplied to the fourth breather pipe 3021, the second exhaust valve 11 is closed, the back pressure value in the third breather pipe 3011 is adjusted by the second back pressure valve 10, the air is supplied to the first breather pipe 2011, the first exhaust valve 7 is closed, and the back pressure value in the second breather pipe 2021 is adjusted by the first back pressure valve 6: the air pressure introduced into the first vent pipe 2011 is P1, the air pressure introduced into the fourth vent pipe 3021 is P2, the pressure set by the second backpressure valve 10 is P3, the pressure set by the first backpressure valve 6 is P4, and under the working condition, the first-stage extension pipe is opposite to the first-stage extension pipeThe force conditions of the telescopic bar 1031 and the secondary telescopic bar 1032 are analyzed as follows: p1 and P4 exist in the primary sliding cavity 1011, an acting force F1 ═ P1 ═ S1 generated by P1 on the first plug body 1021, and an acting force F4 ═ P4 ═ S1 generated by P4 on the first plug body 1021; p2 and P3 exist in the secondary slide chamber 10311, the acting force F2 generated by P2 on the second stopper 1022 is P2S 2, and the acting force F5 generated by the primary telescopic rod 1031 is P2S 2; the acting force F3 of P3 on the second stopper 1022 is P3S 2, and the acting force F6 on the first-stage telescopic rod 1031 is P3S 2; the force on the secondary expansion link 1032 further includes the self-gravity G1 and the sum G2 of the gravity of the second clamping jaw 1203, the connecting plate and the connecting nut, so that the primary expansion link 1031 receives F_{In 1. sup.}＝F4+F5-F1-F6，F_{In 1. sup.}>0; after the second plug body 1022 abuts against the inner wall of the secondary slide chamber 10311 on the side far from the output end 10321, the resultant force F borne by the secondary expansion link 1032_{In combination with 2}F2-F3- (F4+ F5-F1-F6) - (G1-G2), by virtue of F_{In combination with 2}The second clamping jaw 1203 is driven to move towards the direction close to the first clamping jaw 1202, and under the transmission action of the gear rack transmission assembly 1204, the first clamping jaw 1202 and the second clamping jaw 1203 are close to each other, so that a workpiece to be clamped is clamped;

under the working condition, a first pressure difference P2-P3 is formed on two sides of the second cock body 1022, a second pressure difference P1-P4 is formed on two sides of the second cock body 1022, and the first pressure difference P2-P3 generates driving force F2-F3 movement resistance F on the secondary telescopic rod 1032_{In 1. sup.}And G1+ G2, which provides driving force for the contraction of the secondary expansion link 1032, and the driving force applied to the second plug body 1022 is further reduced due to the existence of the back pressure P3 and the second pressure difference P1-P4, so as to further reduce the clamping force, and the clamping device is suitable for clamping a workpiece to be clamped with lower rigidity.

The above operation processes of the first telescopic rod 1031 and the second telescopic rod 1032 and the open and close states of the first on-off solenoid valve 4, the second on-off solenoid valve 8, the first exhaust valve 7, the second exhaust valve 11, the first back pressure valve 6 and the second back pressure valve 10 are summarized as follows:

example 6

Referring to fig. 14, the present embodiment discloses another differential pressure type pneumatic telescoping cylinder 1, and based on embodiment 1, the present embodiment is different from embodiment 1 in that:

referring to fig. 14, the first back pressure valve 6 and the first exhaust valve 7 are connected to a first exhaust pipe 2011, and the second back pressure valve 10 and the second exhaust valve 11 are connected to a fourth exhaust pipe 3021.

Referring to fig. 14, the check valve 20211 is disposed on the first vent pipe 2011 and the fourth vent pipe 3021, and the check valve 20211 is located at one end of the first vent pipe 2011 connected to the first on-off solenoid valve 4 and one end of the fourth vent pipe 3021 connected to the second on-off solenoid valve 8.

This differential pressure pneumatic telescoping cylinder 1 is suitable for situations where the secondary telescoping pole 1032 outputs a clamping force when extended.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The differential pressure type pneumatic clamp comprises a clamp body (1201), a first clamping jaw (1202), a second clamping jaw (1203), a gear and rack transmission assembly (1204), wherein the gear and rack transmission assembly (1204) drives the first clamping jaw (1202) and the second clamping jaw (1203) to move oppositely or back to back, and the differential pressure type pneumatic clamp is characterized by further comprising a differential pressure type pneumatic telescopic cylinder (1), wherein the differential pressure type pneumatic telescopic cylinder (1) comprises a cylinder body (101), a piston (102) and a piston rod (103) connected with the piston (102), the piston rod (103) comprises a primary telescopic rod (1031) and a secondary telescopic rod (1032), and the piston (102) comprises a first plug body (1021) and a second plug body (1022) which are respectively connected with the primary telescopic rod (1031) and the secondary telescopic rod (1032); a primary sliding cavity (1011) is arranged in the cylinder body (101), a secondary sliding cavity (10311) is arranged in the primary telescopic rod (1031), primary vent holes (2) are formed in the primary sliding cavity (1011) on two sides of a piston (102) of the primary telescopic rod (1031) in pairs, and secondary vent holes (3) are formed in the secondary sliding cavity (10311) on two sides of the piston (102) of the secondary telescopic rod (1032) in pairs;

one end of the secondary telescopic rod (1032) is an output end (10321);

the cylinder body (101) is fixed with the clamp body (1201), the output end (10321) is connected with the first clamping jaw (1202) or the second clamping jaw (1203), and the moving direction of the output end (10321) is parallel to the moving direction of the first clamping jaw (1202) or the second clamping jaw (1203).

2. The differential pressure type pneumatic clamp according to claim 1, wherein the primary vent hole (2) comprises a first vent hole (201) and a second vent hole (202), the first vent hole (201) and the second vent hole (202) are both arranged on the cylinder body (101) and are respectively positioned at two sides of the first plug body (1021);

the secondary vent hole (3) comprises a third vent hole (301) and a fourth vent hole (302), the third vent hole (301) is formed in the first-stage telescopic rod (1031), the fourth vent hole (302) is formed in the secondary telescopic rod (1032), and the third vent hole (301) and the fourth vent hole (302) are respectively located on two sides of the second plug body (1022).

3. The differential pressure pneumatic clamp according to claim 2, wherein a side of the first plug body (1021) facing away from the output end (10321) is a first advancing surface (10211), a side of the first plug body (1021) facing the output end (10321) is a first retreating surface (10212), the first vent hole (201) is located on a side of the first advancing surface (10211), and the second vent hole (202) is located on a side of the first retreating surface (10212);

one side of the second cock body (1022) departing from the output end (10321) is a second pushing surface (10221), one side of the second cock body (1022) facing the output end (10321) is a second retreating surface (10222), the third vent hole (301) is located on one side of the second pushing surface (10221), and the fourth vent hole (302) is located on one side of the second retreating surface (10222).

4. The differential pressure type pneumatic clamp as claimed in claim 3, wherein the first vent hole (201), the second vent hole (202), the third vent hole (301) and the fourth vent hole (302) are respectively connected with a first vent pipe (2011), a second vent pipe (2021), a third vent pipe (3011) and a fourth vent pipe (3021), the first vent pipe (2011) and the second vent pipe (2021) are connected with a first on-off solenoid valve (4), the first on-off solenoid valve (4) is connected with a first air inlet pipe (5), the second vent pipe (2021) is further connected with a first back pressure valve (6) and a first exhaust valve (7), the third vent pipe (3011) and the fourth vent pipe (3021) are connected with a second on-off solenoid valve (8), and the second on-off solenoid valve (8) is connected with a second air inlet pipe (9), the third air through pipe (3011) is also connected with a second backpressure valve (10) and a second exhaust valve (11).

5. The differential pressure type pneumatic clamp as claimed in claim 3, wherein the first vent hole (201), the second vent hole (202), the third vent hole (301) and the fourth vent hole (302) are respectively connected with a first vent pipe (2011), a second vent pipe (2021), a third vent pipe (3011) and a fourth vent pipe (3021), the first vent pipe (2011) and the second vent pipe (2021) are connected with a first on-off solenoid valve (4), the first on-off solenoid valve (4) is connected with a first air inlet pipe (5), the first vent pipe (2011) is further connected with a first back pressure valve (6) and a first exhaust valve (7), the third vent pipe (3011) and the fourth vent pipe (3021) are connected with a second on-off solenoid valve (8), and the second on-off solenoid valve (8) is connected with a second air inlet pipe (9), the fourth air pipe (3021) is further connected with a second backpressure valve (10) and a second exhaust valve (11).

6. The differential pressure type pneumatic clamp as claimed in claim 4 or 5, wherein a first pressure reducing valve (501) and a second pressure reducing valve (901) are respectively arranged on the first air inlet pipe (5) and the second air inlet pipe (9), and a first air pressure gauge (5011) and a second air pressure gauge (9011) are respectively connected to the first pressure reducing valve (501) and the second pressure reducing valve (901).

7. The differential pressure pneumatic clamp according to claim 4 or 5, wherein a third barometer (601) and a fourth barometer (1001) are connected to the air inlet ends of the first backpressure valve (6) and the second backpressure valve (10), respectively.

8. The differential pneumatic pliers according to any one of claims 1 to 5, wherein the rack and pinion assembly (1204) comprises two driving gears (12041) and two driving racks (12042), the two driving racks (12042) are respectively located on two sides of the driving gears (12041), the driving gears (12041) are rotatably arranged on the pliers body (1201), the two driving racks (12042) are respectively fixed to the first clamping jaw (1202) and the second clamping jaw (1203), and the output end (10321) is connected to the second clamping jaw (1203).

9. The differential pressure type pneumatic clamp according to any one of claims 1 to 5, wherein a moving guide rail (13) is further arranged on the clamp body (1201), the moving guide rail (13) is arranged along the moving direction of the first clamping jaw (1202) and the second clamping jaw (1203), a sliding block (1301) is respectively connected to the first clamping jaw (1202) and the second clamping jaw (1203), and the sliding block (1301) slides along the moving guide rail (13).

10. The differential pressure pneumatic clamp of claim 9, wherein the first clamping jaw and the second clamping jaw are provided with clamping cushion blocks, and the clamping cushion blocks are respectively positioned on the opposite surfaces of the first clamping jaw and the second clamping jaw.