CN112652503A

CN112652503A - Differential pressure switch

Info

Publication number: CN112652503A
Application number: CN201910956905.9A
Authority: CN
Inventors: 侯耀淞
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-10
Filing date: 2019-10-10
Publication date: 2021-04-13
Anticipated expiration: 2039-10-10
Also published as: CN112652503B

Abstract

A differential pressure switch comprises a base, a switch unit, a cover, a bottom plate, a linkage unit and a flexible anti-leakage sheet. The base comprises a first containing space, a first opening, a second containing space, a second opening, a first groove, a second groove, a third groove and a low-pressure channel. The switch unit comprises a shell, a microswitch and a pressing sheet. The bottom plate includes a recess and a high pressure channel. The linkage unit includes an adjustment set, a pressing member, a spring and a linkage plate. When the monitored medium pressure is abnormal, the flexible leakage-proof sheet can move towards the direction of the base plate to enable the linkage sheet to move towards the direction of the base plate, and at the moment, the pressing piece can also move towards the direction of the base plate and enable the adjusting group to swing to trip off the microswitch, so that the monitored medium can be immediately stopped to be conveyed and a worker can immediately overhaul, and therefore the occurrence of an industrial safety accident can be effectively prevented.

Description

Differential pressure switch

Technical Field

The present invention relates to a switch, and more particularly, to a differential pressure switch that monitors abnormality of a high-pressure medium to operate the switch.

Background

The pressure difference switch is a necessary link for production or transportation in the industrial industry, and the change of the pressure difference value between the low-pressure medium and the high-pressure medium is an important parameter for production or transportation in the industrial industry, and the change of the pressure difference value can be used for controlling the production quality and the production efficiency of products and preventing industrial safety accidents.

Among them, the pressure difference switch for monitoring the medium such as flammable gas, flammable liquid, explosive gas or explosive liquid has a very high sensitivity requirement, and the medium such as flammable gas, flammable liquid, explosive gas or explosive liquid is considered to be more important. Because of the slight error in the medium such as flammable gas, flammable liquid, explosive gas or explosive liquid, it is possible to generate great safety accident.

However, the existing differential pressure switch has a complex structure, so that the linkage reaction of the structure is slow when the high-pressure medium is abnormal, and the differential pressure switch cannot be immediately operated, so that the risk of occurrence of an industrial safety accident is increased. Therefore, it is necessary to provide a technical means with a simple structure and high sensitivity.

Disclosure of Invention

The invention aims to provide a differential pressure switch, which enables a linkage unit to act and touch a micro switch through a simple structure when high and low pressure media are abnormal, and further enables the micro switch to act.

In accordance with the above objectives, the present invention provides a pressure difference switch, which includes a base, a switch unit, a cover, a bottom plate, a linkage unit, and a flexible anti-leakage sheet.

The seat body comprises a first accommodating space arranged in one end, a first opening arranged at one end and communicated with the first accommodating space, a second accommodating space arranged in the other end, a second opening arranged at the other end and communicated with the second accommodating space, a first groove arranged in the second accommodating space, a second groove arranged in the second accommodating space and adjacent to the first groove, a third groove arranged in the second accommodating space and adjacent to the first groove and the second groove, and a low-pressure channel; one side of the third groove is communicated with the first accommodating space, one low-pressure channel opening of the low-pressure channel is arranged on the outer periphery of one end adjacent to the second opening, the other low-pressure channel opening of the low-pressure channel is arranged on one side of the wall end of the second accommodating space, and the low-pressure channel is communicated with the second accommodating space.

The switch unit is accommodated in the first accommodating space and arranged on one side of the third groove, and comprises a shell with an inner space, a microswitch accommodated in the shell, and a pressing sheet accommodated and pivoted at the bottom end of the shell and close to the microswitch. Wherein, this casing includes a pair of lamellar body that extends and set up at this third recess both sides wall body in bottom both sides orientation respectively, and this micro-gap switch stretches this casing bottom and sets up between this pair of lamellar body.

The cover body is connected with the cover and arranged at the first opening. The bottom plate connecting cover is arranged at the second opening, and the bottom plate comprises a concave part arranged at one end and a high-pressure channel. The concave part comprises a chamber, one high-pressure channel port of the high-pressure channel is arranged on the outer periphery of the bottom plate, the other high-pressure channel port of the high-pressure channel is arranged at the bottom end of the chamber, and the high-pressure channel is communicated with the chamber.

The linkage unit comprises an adjusting group accommodated in the first groove, a pressing piece accommodated in the third groove and arranged on one side of the other end of the pressing piece, a spring accommodated in the first groove and connected with one end of a wall body at one end of the first groove, and a linkage piece connected with the other end of the spring and one end of the pressing piece.

The flexible anti-leakage sheet is arranged between the concave part of the bottom plate and the second opening of the base body. The linkage plate comprises a pin joint part which is arranged at one end and is accommodated in the second groove, one side of the other end of the linkage plate is connected with the other end of the spring, the other side of the other end of the linkage plate is connected with one end of the pressing piece, the pressing plate can rotate at the bottom end of the shell and is arranged between the microswitch and the pressing piece, the linkage plate is touched through the pressing plate, the pressing piece is moved to touch the pressing plate, and the pressing plate swings up and down to touch the microswitch.

Further, the seat body comprises an external thread section arranged on the outer periphery of the first opening; wherein, the cover body comprises an internal thread section which is arranged at one end and is in threaded connection with the external thread section of the seat body.

Furthermore, the rubber sealing device also comprises a rubber sealing piece, and the external thread section is provided with an annular groove which is arranged at the inner side and is used for accommodating the rubber sealing piece.

Furthermore, the seat body comprises a first ring groove arranged around the outer side of the second opening; wherein, the bottom plate is provided with a second ring groove which is arranged around the outer side of the concave part and corresponds to the first ring groove; wherein, the outer ring of the flexible anti-leakage sheet is provided with a sealing convex part to be accommodated and fixed between the first ring groove and the second ring groove.

Furthermore, the flexible anti-leakage sheet is further provided with a pressure contact sheet which is connected with one side of the flexible anti-leakage sheet and is close to one side of the second opening, the flexible anti-leakage sheet is made of rubber, two corresponding convex grains are arranged on one side of the flexible anti-leakage sheet, a reinforcing convex body corresponding to the convex grains and a plurality of reinforcing convex strips are respectively arranged on the other side of the flexible anti-leakage sheet, the reinforcing convex strips are distributed in a radial shape, the reinforcing convex strips are respectively connected with the reinforcing convex bodies correspondingly, the pressure contact sheet is provided with a convex circle which is arranged on one side and protrudes towards the second accommodating space, and two holes which are respectively used for correspondingly sleeving the convex grains are arranged on the near the outer periphery of the pressure contact sheet, so that the flexible anti-leakage sheet is connected with the pressure contact sheet.

Furthermore, the base comprises a fixing part which is accommodated in the first accommodating space and is connected with the switch unit and the wall body of the first accommodating space.

Furthermore, the pivoting portion includes a pair of protruding pieces disposed on two sides and extending outward, and a rotating shaft penetrating and pivotally connecting the pair of protruding pieces, wherein the pair of protruding pieces are respectively provided with a shaft hole for the rotating shaft to penetrate and pivotally connect, a placing groove is disposed in the second groove, the pair of protruding pieces are respectively disposed at two ends of the placing groove, and the outer periphery between the two ends of the rotating shaft is fixedly connected in the placing groove.

Furthermore, one end of the pressing sheet is provided with a pivot for the pressing sheet to penetrate through and be pivoted on the two ends of the pair of sheet bodies so as to rotate on the pivot.

Furthermore, the base comprises a through hole which is arranged at the periphery of the second opening and is opposite to the first groove; the adjusting set comprises a screw fastener, a moving piece and a fixed elastic piece, wherein the screw fastener comprises a screw rod which is accommodated in the first groove and is provided with an outer screw connection section, a top wall which is arranged in the through hole of the seat body and rotates, and a groove part which is arranged between the outer screw connection section of the screw rod and the top wall, and the outer side surface of the through hole of the top wall is provided with a groove or a cross groove for a linear screwdriver or a cross screwdriver to rotate the top wall; wherein, the moving member comprises an inner screw section which is arranged inside and is used for the outer screw section of the screw rod to be screwed, the outer periphery of the moving member is provided with a ring groove for one end of the spring to be annularly fixed, and a convex block which is arranged on the periphery of one end and is protruded; the fixed elastic sheet is provided with an opening which is sleeved and positioned towards the groove part, the fixed elastic sheet is arranged in the through hole and positioned on one side surface of the first groove to position the screw fastener, and the moving member moves on the outer screw joint section through the inner screw joint section by rotating the top wall to adjust the tightness of the spring.

Furthermore, a vertical lug extends from one side of the other end of the linkage plate, an upper through hole and a lower through hole which are vertically corresponding are arranged on the vertical surface of one side of the vertical lug, so that the other end of the spring is in a hook shape and penetrates through the upper through hole and penetrates through the lower through hole for positioning, and at least one screw hole is arranged on the other side of the other end of the linkage plate for the pressing piece to be screwed.

The invention is characterized in that:

1. the linkage unit is simple in structure, not only are each component in the linkage unit close, but also are close to the micro switch, so that the effect of high sensitivity can be achieved, when the monitored medium is abnormal, the linkage unit can act immediately and trip off the micro switch, the monitored medium can stop conveying immediately and a worker can overhaul immediately, and the occurrence of an industrial safety accident can be effectively prevented.

2. The low pressure medium gets into this second accommodation space via this low pressure passageway, and high pressure medium gets into this appearance room via this high pressure passageway, and it is unusual to represent monitored medium when the pressure of low pressure medium is greater than the pressure of high pressure medium promptly, and this flexible leak protection piece will move towards the direction of this bottom plate and make this pressure contact piece jump off and can not press the pulling to this interlock piece, and this interlock piece also can move towards the direction of this bottom plate and drive this pressure movable part and move towards the direction of this bottom plate this moment, should press the swing of piece to jump off this micro-gap switch by this moment, lets monitored medium can stop conveying immediately, lets the staff can restore immediately.

Drawings

FIG. 1 is an exploded perspective view of the differential pressure switch of the present invention.

Fig. 2 is an exploded perspective view of the interlocking unit in the differential pressure switch of the present invention.

FIG. 3 is an exploded perspective view of the differential pressure switch of the present invention from another angle.

Fig. 4 is a perspective assembly view of the differential pressure switch of the present invention.

FIG. 5 is a perspective assembly view of the differential pressure switch of the present invention from another angle.

FIG. 6 is a perspective bottom view of the differential pressure switch of the present invention.

Fig. 7 is a bottom view of the configuration of the interlocking unit in the differential pressure switch of the present invention.

FIG. 8 is a schematic sectional view of the differential pressure switch according to the present invention.

FIG. 9 is a schematic sectional view of the differential pressure switch of the present invention.

FIG. 10 is a cross-sectional view of another angle of the differential pressure switch of the present invention.

Reference numerals:

pressure difference switch 1

Base body 2

The first accommodating space 20

First opening 21

The second accommodating space 22

Second opening 23

First groove 24

Second groove 25

Placing groove 250

Third groove 26

Low voltage channel 27

One of the low pressure passage ports 270

Another low pressure passage port 271

External threaded section 28

Ring groove 280

First ring groove 290

Through hole 291

Switch unit 3

Housing 30

Sheet 300

Microswitch 31

Pressing sheet 32

Pivot 321

Cover 4

Internal thread segment 40

Base plate 5

Recess 50

The compartment 500

High-voltage channel 51

One of the high pressure passage ports 510

Another high pressure passage port 511

Second ring groove 52

Linkage unit 6

Adjustment group 60

Screw 600

External screw connection section 601

Top wall 602

Groove 603

Fixed spring 604

Opening 605

Moving part 61

Inner threaded segment 610

Bump 611

Annular groove 612

Pressing piece 62

Spring 63

One end 631

The other end 632

Linkage plate 64

Pivoting part 640

Screw hole 6400

Tab 641

Shaft hole 6411

Rotating shaft 642

Vertical tab 643

Facade 644

Upper perforation 645

Lower perforation 646

Rubber seal 7

Fixing part 8

Flexible leak-proof sheet 9

Sealing projection 90

Convex particles 91

Reinforcing projection 92

Reinforcing convex strip 921

Pressure contact piece 93

Convex circle 930

Hole 931

Detailed description of the preferred embodiments

Referring to fig. 1 to 3 and fig. 4 to 9, a differential pressure switch 1 according to the present invention includes a base 2, a switch unit 3, a cover 4, a bottom plate 5, a linkage unit 6, and a flexible anti-leakage sheet 9. Wherein,

the seat body 2 comprises a first receiving space 20 formed inside one end, a first opening 21 formed at one end and communicating with the first receiving space 20, a second receiving space 22 formed inside the other end, a second opening 23 formed at the other end and communicating with the second receiving space 22, a first groove 24 formed in the second receiving space 22, a second groove 25 formed in the second receiving space 22 and adjacent to the first groove 24, a third groove 26 formed in the second receiving space 22 and adjacent to the first groove 24 and the second groove 25, a low pressure channel 27 formed around the outer periphery of the seat body 2 and adjacent to the bottom end, and an external thread section 28 formed around the outer periphery of the first opening 21, and a fixing member 8 accommodated in the first accommodating space 20 and connecting the switch unit 3 and the wall body of the first accommodating space 20.

More specifically, the housing 2 has a first ring groove 290 disposed around the outer side of the second opening 23, and a through hole 291 disposed around the outer side of the second opening 23 and opposite to the first groove 24. A placing groove 250 is provided in the second groove 25 of the base body 2. One side of the third groove 26 is communicated with the first receiving space 20, one low pressure passage opening 270 of the low pressure passage 27 is disposed on the outer periphery of one end adjacent to the second opening 23, the other low pressure passage opening 271 of the low pressure passage 27 is disposed on one side of the wall end of the second receiving space 22, and the low pressure passage 27 is communicated with the second receiving space 22.

The switch unit 3 is accommodated in the first accommodating space 20 and disposed at one side of the third groove 26, and the switch unit 3 includes a housing 30 having an inner space, a micro switch 31 accommodated in the housing 30, and a pressing piece 32 accommodated at a bottom end of the housing 30 and close to the micro switch 31. The casing 30 includes a pair of sheet members 300 extending toward the third groove 26 at two sides of the bottom end thereof and disposed on two side walls of the third groove 26, the micro switch 31 extends through the bottom of the casing 30 and is disposed between the pair of sheet members 300, the pressing member 32 is disposed between the pair of sheet members 300 and is close to the micro switch 31, one end of the pressing member 32 is provided with a pivot 321 extending and pivoted on two ends of the pair of sheet members 300, so that the pressing member 32 can rotate on the pivot 321, and the pressing member 32 provides the micro switch 31 with a contact or swinging jumping state.

The cover 4 is connected to the first opening 21 of the base 2, and the cover 4 includes an internal thread 40 formed at one end and screwed with the external thread 28.

The bottom plate 5 is connected to the second opening 23 of the base 2, and the bottom plate 5 includes a recess 50 and a high-pressure channel 51. The recess 50 includes a chamber 500, one high-pressure port 510 of the high-pressure channel 51 is disposed on the outer periphery of the bottom plate 5, and the other high-pressure port 511 of the high-pressure channel 51 is disposed at the bottom end of the chamber 500, so that the high-pressure channel 51 is communicated with the chamber 500, and the bottom plate 5 has a second annular groove 52 disposed on the outer periphery of the recess 50 and corresponding to the first annular groove 290.

The linking unit 6 includes an adjusting set 60 received in the first groove 24, a pressing member 62 received in the third groove 26 and disposed at one side of the other end of the pressing sheet 32, a spring 63 received in the first groove 24 and having one end connected to one end wall of the first groove 24, and a linking sheet 64 connecting the other end of the spring 63 and one end of the pressing member 62. Wherein the pressing piece 32 is disposed between the microswitch 31 and the pressing piece 62.

Referring to fig. 1 to 3 and fig. 7 to 10, the adjusting set 60 includes a screw 600, a moving member 61, and a fixed spring 604. The screw 600 includes a screw received in the first groove 24 and having an outer screw section 601, a top wall 602 disposed in the through hole 291 of the base 2, and a groove 603 disposed between the outer screw section 601 and the top wall 602 of the screw, wherein the top wall 602 can rotate in the through hole 291, and the top wall 602 has a groove or a cross groove on the outer side of the through hole 291, so that a horizontal screwdriver or a cross screwdriver can rotate the top wall 602, and can drive the moving member 61 to move forward or backward to adjust the tightness of the spring 63. The fixed elastic piece 604 has an opening 605, so that the opening 605 of the fixed elastic piece 604 is inserted into the groove 603 and positioned around the groove 603, and the fixed elastic piece 604 is disposed in the through hole 291 and located at a side of the first groove 24 to position the fastener 600.

The outer circumference of the moving member 61 is connected to one end 631 of the spring 63, and the other end 632 of the spring 63 is formed in a hook shape to be connected to the interlocking piece 64. The moving member 61 includes an inner threaded section 610 inside and a protruding block 611 disposed around an end of the moving member 61, and a ring groove 612 is disposed around an end 631 of the spring 63. The inner screw section 610 is used for the outer screw section 601 of the screw 600 to screw, and the moving member 61 is moved on the outer screw section 601 through the inner screw section 610 by rotating the top wall 602 to adjust the tightness of the spring 63 (as shown in fig. 10).

Due to the arrangement of the protrusion 611, when the top wall 602 is rotated by a screw driver with a straight shape or a cross-shaped screw driver, the moving member 61 can move on the outer screw connecting section 601 of the screw 600 through the inner screw connecting section 610, so as to adjust the tightness of the spring 63 and the rotating range of the pivot portion 640 of the linking plate 64, thereby adjusting the sensitivity of the pressure difference.

The linking plate 64 includes a pivot portion 640 disposed at one end and received in the second groove 25, a vertical protruding piece 643 extends from one side of the other end of the linking plate 64, and an upper through hole 645 and a lower through hole 646 corresponding to each other in the vertical direction 644 on one side of the vertical protruding piece 643 are disposed on a vertical surface 644 of the other side of the vertical protruding piece 643, so that the other end 632 of the spring 63 is hooked to the upper through hole 645 and passes through the lower through hole 646, the other end 632 of the spring 63 is hooked on the vertical surface 644 on one side of the vertical protruding piece 643 for positioning, the other end of the linking plate 64 is connected to one end of the pressing member 62, and at least one screw hole 6400 is disposed on the other end of the linking plate 64 for screwing the pressing member 62. The pivoting portion 640 includes a pair of protruding pieces 641 extending outward and located at two sides, and a rotating shaft 642 extending through and pivoting the pair of protruding pieces 641, wherein the pair of protruding pieces 641 are respectively provided with a shaft hole 6411 for the rotating shaft 642 to extend through and pivot in the shaft hole 6411. The pair of protruding pieces 641 are respectively disposed at two ends of the placing groove 250 of the second groove 25, and the outer periphery between two ends of the rotating shaft 642 is fixedly connected in the placing groove 250.

Referring to fig. 1 to fig. 3 in addition to fig. 8, the flexible anti-leakage sheet 9 is disposed between the recess 50 of the bottom plate 5 and the second opening 23 of the base 2, wherein the flexible anti-leakage sheet 9 is made of rubber. In the embodiment of the present invention, the flexible anti-leakage sheet 9 further has a pressure contact plate 93 connected to one side of the flexible anti-leakage sheet 9 and close to one side of the second opening 23, and the connection manner between the flexible anti-leakage sheet 9 and the pressure contact plate 93, wherein the outer ring of the flexible anti-leakage sheet 9 is provided with a sealing protrusion 90 to be accommodated and fixed between the first annular groove 290 and the second annular groove 52, and one side of the flexible anti-leakage sheet 9 is provided with two corresponding protruding grains 91, and the other side of the flexible anti-leakage sheet 9 is respectively provided with a reinforcing protrusion 92 corresponding to the protruding grains 91 and a plurality of reinforcing protrusions 921, wherein the reinforcing protrusions 921 are radially distributed, and wherein the corresponding reinforcing protrusions 921 are respectively connected to the reinforcing protrusion 92 to increase the strength of the flexible anti-leakage sheet 9. The pressure contact plate 93 has a convex round 930 disposed at one side and protruding toward the second receiving space 22, and two holes 931 are disposed near the outer periphery of the pressure contact plate 93 for the convex particles 91 to correspondingly socket, and the holes 931 are used to respectively embed and fix the convex particles 91 at one side of the flexible anti-leakage plate 9, so that the flexible anti-leakage plate 9 is connected with the pressure contact plate 93. When the flexible anti-leakage plate 9 is connected to the pressure contact plate 93 and disposed in front of the concave portion 50 of the bottom plate 5 and the second opening 23 of the base body 2, the protruding particles 91 on one side of the flexible anti-leakage plate 9 can evade contact with the linking plate 64, so as to prevent the protruding particles 91 from obstructing the movement of the linking plate 64.

Specifically, please refer to fig. 8 and fig. 9, in combination with fig. 1 to fig. 7.

In practice, a high-pressure pipeline is connected to one of the high-pressure ports 510 of the high-pressure passage 51 located at the outer side, so that the high-pressure medium enters the accommodating chamber 500 through the other high-pressure port 510 of the high-pressure passage 51. Then, a low pressure line is connected to one of the low pressure passage ports 270 of the low pressure passage 27 located at the outer side, so that the low pressure medium enters the second accommodating space 22 through the other low pressure passage port 271 of the low pressure passage 27.

Referring to fig. 8, when the pressure of the low-pressure medium in the second receiving space 22 is lower than the pressure of the high-pressure medium in the receiving chamber 500, the flexible leakage-proof sheet 9 moves toward the micro-switch 31, so that the convex circle 930 above the pressing contact sheet 93 touches the linkage sheet 64, the linkage sheet 64 then moves toward the micro-switch 31, the pressing piece 62 moves toward the pressing sheet 32 and touches the pressing sheet 32, and at this time, the pressing sheet 32 swings to touch the micro-switch 31, so that the micro-switch 31 normally operates.

Referring to fig. 9, when the pressure of the low-pressure medium is greater than the pressure of the high-pressure medium, it indicates that the monitored medium is abnormal, the flexible leakage-proof sheet 9 will move toward the bottom plate 5, so that the pressing sheet 93 will jump away and will not press the interlocking sheet 64, at this time, the interlocking sheet 64 will also move toward the bottom plate 5 to drive the pressing piece 62 to move toward the bottom plate 5, at which time the pressing sheet 32 swings to jump away the microswitch 31, so that the monitored medium can stop conveying immediately, and the staff can repair immediately.

Furthermore, because the structure of the linkage unit 6 is simple, not only every component in the linkage unit 6 is close, but also the linkage unit 6 is close to the microswitch 31, thereby obtaining the effect of higher sensitivity, when the monitored medium is abnormal, the linkage unit 6 can immediately act and jump off the microswitch 31, the monitored medium can immediately stop conveying and the staff can immediately overhaul, thereby effectively preventing the occurrence of industrial safety accidents.

In an embodiment, referring to fig. 1 and fig. 3, a rubber sealing member 7 is further included, the external thread section 28 of the seat body 2 is provided with an annular groove 280 at an inner side for accommodating the rubber sealing member 7, so that the cover body 4 is covered above the seat body 2, and the cover body 4 and the seat body 2 are more tightly arranged.

The invention is characterized in that:

1. the linkage unit 6 is simple in structure, each component in the linkage unit 6 is close, the linkage unit 6 is close to the micro switch 31, and therefore the effect of high sensitivity can be achieved.

2. When the pressure of the low-pressure medium is greater than that of the high-pressure medium, which indicates that the monitored medium is abnormal, the flexible leakage-proof sheet 9 moves towards the bottom plate 5, so that the pressure contact sheet 93 jumps and cannot press the linkage sheet 64, at this time, the linkage sheet 64 also moves towards the bottom plate 5 to drive the pressure moving piece 62 to move towards the bottom plate 5, and then the pressure sheet 32 swings to jump off the microswitch 31, so that the monitored medium can be immediately stopped being conveyed, and a worker can immediately repair the monitored medium.

Claims

1. A differential pressure switch, comprising:

a seat body, the seat body including a first containing space arranged inside one end, a first opening arranged at one end and communicated with the first containing space, a second containing space arranged inside the other end, a second opening arranged at the other end and communicated with the second containing space, a first groove arranged in the second containing space, a second groove arranged in the second containing space and adjacent to the first groove, a third groove arranged in the second containing space and adjacent to the first groove and the second groove, and a low-pressure channel; one side of the third groove is communicated with the first accommodating space, one low-pressure channel opening of the low-pressure channel is arranged on the outer periphery of one end adjacent to the second opening, the other low-pressure channel opening of the low-pressure channel is arranged on one side of the wall end of the second accommodating space, and the low-pressure channel is communicated with the second accommodating space;

the switch unit is accommodated in the first accommodating space and arranged on one side of the third groove, and comprises a shell with an inner space, a microswitch accommodated in the shell and a pressing sheet accommodated and pivoted at the bottom end of the shell and close to the microswitch; the casing comprises a pair of sheet bodies which extend towards the third groove at two sides of the bottom end respectively and are arranged on wall bodies at two sides of the third groove, and the microswitch penetrates through the bottom of the casing and is arranged between the pair of sheet bodies;

the cover body is connected with the cover and arranged at the first opening;

a bottom plate, the bottom plate is connected with the second opening in a covering mode and comprises a concave portion arranged at one end and a high-pressure channel; the concave part comprises a containing chamber, one high-pressure channel port of the high-pressure channel is arranged on the outer periphery of the bottom plate, the other high-pressure channel port of the high-pressure channel is arranged at the bottom end of the containing chamber, and the high-pressure channel is communicated with the containing chamber;

a linkage unit, which comprises an adjusting group contained in the first groove, a pressing piece contained in the third groove and arranged at one side of the other end of the pressing piece, a spring contained in the first groove and with one end connected with the wall body at one end of the first groove, and a linkage piece connected with the other end of the spring and one end of the pressing piece; and

a flexible anti-leakage sheet arranged between the concave part of the bottom plate and the second opening of the seat body; the linkage plate comprises a pin joint part which is arranged at one end and is accommodated in the second groove, one side of the other end of the linkage plate is connected with the other end of the spring, the other side of the other end of the linkage plate is connected with one end of the pressing piece, the pressing plate can rotate at the bottom end of the shell and is arranged between the microswitch and the pressing piece, the linkage plate is touched through the pressing plate, the pressing piece is moved to touch the pressing plate, and the pressing plate swings up and down to touch the microswitch.

2. A differential pressure switch as claimed in claim 1, wherein the seat comprises an externally threaded section disposed around an outer periphery of the first opening; wherein, the cover body comprises an internal thread section which is arranged at one end and is in threaded connection with the external thread section of the seat body.

3. A differential pressure switch as claimed in claim 2 further comprising a rubber seal, the male threaded section having an annular groove disposed on an inner side for receiving the rubber seal.

4. A differential pressure switch as recited in claim 1, wherein the housing comprises a first annular groove disposed around an outer side of the second opening; wherein, the bottom plate is provided with a second ring groove which is arranged around the outer side of the concave part and corresponds to the first ring groove; wherein, the outer ring of the flexible anti-leakage sheet is provided with a sealing convex part to be accommodated and fixed between the first ring groove and the second ring groove.

5. A pressure differential switch as claimed in claim 1, wherein the flexible anti-leaking plate further comprises a pressure contact plate connected to one side of the flexible anti-leaking plate and adjacent to one side of the second opening, the flexible anti-leaking plate is made of rubber, and two corresponding protruding particles are disposed on one side of the flexible anti-leaking plate, the other side of the flexible anti-leaking plate is respectively provided with a reinforcing protrusion corresponding to the protruding particles and a plurality of reinforcing protruding strips, the reinforcing protruding strips are radially distributed, and wherein the corresponding reinforcing protruding strips are respectively connected to the reinforcing protrusions, the pressure contact plate has a protruding circle disposed on one side and protruding toward the second receiving space, and two holes are disposed near the outer periphery of the pressure contact plate for the corresponding engaging of the protruding particles, so that the flexible anti-leaking plate is connected to the pressure contact plate.

6. A differential pressure switch as claimed in claim 1, wherein the housing comprises a fixing member received in the first receiving space and connecting the switch unit and the wall of the first receiving space.

7. A differential pressure switch as claimed in claim 1, wherein the pivotal portion comprises a pair of protruding pieces disposed at two sides and extending outward, and a rotating shaft passing through and pivotally connecting the pair of protruding pieces, wherein the pair of protruding pieces are respectively provided with a shaft hole for passing through and pivotally connecting the rotating shaft, a placement groove is disposed in the second groove, the pair of protruding pieces are respectively disposed at two ends of the placement groove, and the outer periphery between the two ends of the rotating shaft is connected and fixed in the placement groove.

8. A differential pressure switch as claimed in claim 1, wherein one end of the pressing plate is provided with a pivot for the pressing plate to extend through and pivot on the two ends of the pair of plates for the pressing plate to rotate on the pivot.

9. A differential pressure switch as recited in claim 1, wherein the seat comprises a through hole disposed around the outer periphery of the second opening and opposite to the first recess; the adjusting set comprises a screw fastener, a moving piece and a fixed elastic piece, wherein the screw fastener comprises a screw rod which is accommodated in the first groove and is provided with an outer screw connection section, a top wall which is arranged in the through hole of the seat body and rotates, and a groove part which is arranged between the outer screw connection section of the screw rod and the top wall, and the outer side surface of the through hole of the top wall is provided with a groove or a cross groove for a linear screwdriver or a cross screwdriver to rotate the top wall; wherein, the moving member comprises an inner screw section which is arranged inside and is used for the outer screw section of the screw rod to be screwed, the outer periphery of the moving member is provided with a ring groove for one end of the spring to be annularly fixed, and a convex block which is arranged on the periphery of one end and is protruded; the fixed elastic sheet is provided with an opening which is sleeved and positioned towards the groove part, the fixed elastic sheet is arranged in the through hole and positioned on one side surface of the first groove to position the screw fastener, and the moving member moves on the outer screw joint section through the inner screw joint section by rotating the top wall to adjust the tightness of the spring.

10. A differential pressure switch as claimed in claim 1, wherein a vertical protruding piece extends from one side of the other end of the linking plate, and an upper through hole and a lower through hole are formed in the vertical surface of one side of the vertical protruding piece, which are vertically corresponding to each other, so that the other end of the spring is bent and penetrates through the upper through hole and penetrates through the lower through hole for positioning, and at least one screw hole is formed in the other side of the other end of the linking plate for screwing the pressing member.