JP2002260504A - Triple action pressure switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a triple action pressure switch where initial cost of parts can be brought down while maintaining the same actuating condition without changing the shape, construction or the specifications to a large extent. SOLUTION: In the triple action pressure switch constituted by a housing 1, a switch case 2, a diaphragm 22, a first inverting plate 3, a first sliding receiving member 4 with a hollow hole 27, a second inverting plate 5, a second sliding receiving member 6 with a central axis hole 28 and a central projection 25, a third inverting plate 7 engaged to an inner wall step 26 of the switch case, a first actuating rod 23, a second actuating rod 24, a first electric switch part SW1 consisting of a moving contact point 15 engaged to the bottom edge of the first actuating rod and a fixed contact point 24 brought into contact with or separated from it and a second electric switch part SW2 consisting of a second moving contact point 10 engaged to the bottom edge of the second actuating rod, a third moving point 11 brought into contact with or separated from the second moving contact point and engaged to a central projecting part, each contact point of the electric switch parts are provided with the diameter Dh in a header part in a range within the range of 3.0 mm>Dh>2.0 mm and with the diameter Dr of an attaching part in a range within the range of 1.5 mm>Dr>1.0 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a function of detecting when an abnormally high pressure or abnormally low pressure occurs in a refrigerant system in a refrigeration / air-conditioning system and opening an electric circuit, and providing the refrigeration system independently of the above. The present invention relates to a three-acting pressure switch having a third function of opening and closing an associated electric circuit. In particular, the third function is used when turning on / off a fan motor of a condenser provided in a refrigeration cycle.

[0002]

2. Description of the Related Art The applicant of the present application has already proposed a three-acting pressure switch having the above-mentioned function (Japanese Patent Publication No. Hei 7-1995).
114094). The configuration and operation of the conventional three-acting pressure switch will be described with reference to FIGS. FIG. 3 is a longitudinal sectional view schematically showing the configuration of a conventional three-operation type pressure switch, and FIG. 4 is a characteristic diagram showing the operating pressure characteristics. The three-operation pressure switch shown in FIG. 3 is shown upside down.

As shown in FIG. 3, a conventional three-operation type pressure switch includes a housing 1, a switch case 2, a diaphragm 22, a first snap disk portion 3, and a first slide receiving member. 4, a second snap disk portion 5, a second slide receiving member 6, a third snap disk portion 7, a second operating rod 24, a first operating rod 23,
The first electric switch unit SW1 and the second electric switch unit SW2 are assembled and configured as shown in the figure.

[0004] The housing 1 is formed of a galvanized mild steel or aluminum alloy, is provided with a passage P coaxially communicating with the refrigeration system, and introduces the pressure of the refrigerant into a pressure receiving chamber in the housing. I do.

The switch case 2 is made of an insulating material such as glass fiber reinforced polybutylene terephthalate resin (PBT), and has an upper cavity B for accommodating functional components of the switch and a partition A through a partition A. And two sets of terminals 12, 13 and 19 (only one is shown) extending downward are divided into a lower cavity C in which a total of four terminals are accommodated in a mutually orthogonal manner.

The upper cavity B of the switch case 2 is combined with the housing 1 and the lower end of the housing 1 is caulked and fixed as shown in the drawing to form a space B for accommodating the pressure switch therein. The outer wall of the lower cavity C is combined with the electrical connector of the refrigeration system.

The diaphragm 22 is formed by using a thin film of, for example, a polyimide resin, and is used when assembling the housing 1 and the switch case 2 with a gasket 2 made of an elastic material.
1 and is hermetically fixed between the housing 1 and the switch case 2. The diaphragm 22 separates the space B from the fluid space communicating with the passage P, prevents refrigerant gas from entering the switch case, and transmits refrigerant pressure to various pressure transmitting members in the switch case. .

The first to third switches used in the three-operation type pressure switch are:
Each of the third snap disk portions is formed in a dish shape having a portion protruding on one surface side and having an inclined portion around the periphery,
When a pressure exceeding a predetermined value is applied from the direction of the protrusion, the protrusion reverses in the opposite direction, and when the pressure falls below a value lower than the predetermined value, the hysteresis reverses to the initial position. It is configured using a so-called inversion plate having characteristics.

[0009] By forming the snap disk portion by using a plurality of reversing plates, it is possible to design the shape to improve the durability and reduce the variation of the operation value. Friction may occur and operation may be unstable. To reduce this friction, operation can be made very stable by applying a lubricant containing a small amount of molybdenum disulfide solid powder to the interface of the stacked snap disks.

First snap disk portion (reversing plate) 3
A plurality of reversing plates are stacked and the periphery thereof is provided on a snap disk receiving portion provided on the upper surface of the first slide receiving member 4 so that the upper surface of the convex portion and the inclined portion abut on the lower surface of the diaphragm 22. It is stored and locked by the outer peripheral wall 4a.

The first snap disk section 3 has a function of sensing the intermediate pressures PM and PM-ΔPM.

The first slide receiving member 4 has an outer peripheral wall 4a forming a snap disk receiving portion on the upper surface, a concentric annular projection 4b on the lower surface, a hollow hole 27 at the center, and a switch on the outer periphery. It slides directly on the inner wall of the case 2. The peripheral portion of the first snap disk portion 3 housed in the snap disk receiving portion is locked by the inner side surface of the outer peripheral wall 4a of the first slide receiving member 4. The first operating rod 23 is disposed through the hollow hole 27. The annular projection 4b is provided with the second snap disk 5
Are arranged so as to contact the upper surface inclined portion.

Second snap disk portion (reversing plate) 5
Is formed using three snap disks, has a hole H in the center, and the annular projection 4b of the first receiving member 4 abuts the inclined portion on the upper surface. Second snap disk unit 5
The hole H provided on the center axis of the first working rod 23 allows the first operating rod 23 to penetrate without interference. Usually, a snap disk having a hole has a drawback that its operation varies greatly and its durability is inferior. The variation in operation can be suppressed by giving a degree of freedom to the shape design. In this case, as described above, the friction between the snap disk contact surfaces can be reduced by baking the lubricant containing molybdenum disulfide solid on the contact surfaces of the snap disks.

The second snap disk 5 is supported by a snap disk receiving portion provided on the upper surface of the second slide receiving member 6, and its peripheral portion is locked on the inner surface of the outer peripheral wall 5a.

The second snap disk unit 5 has a function of detecting the high pressure cutoff pressure PH and PH-ΔPH.

The second slide receiving member 6 has a snap disk receiving portion and an outer peripheral wall 5a around the snap disk receiving portion on the upper surface, and a hole H in the center.
And a central projection 25 protruding from the periphery of the central axis hole 28 on the lower surface.
The snap disk portion 5 is accommodated in the snap disk receiving portion on the upper surface, and its peripheral portion is locked by the inner surface of the outer peripheral wall 5a. The outer periphery of the second slide receiving member 6 slides directly on the inner wall of the switch case 2. The center shaft hole 28 has a larger diameter than the center shaft hole 27 of the first slide receiving member 4, and extends downward through the cylindrical second operating rod 24, which is substantially indistinguishable. ing. The first operating rod 23 penetrates through the second operating rod 24.

A stepped flat portion is provided at the root of the central projection 25, and the central axis hole 30 of the third snap disk portion 7 is combined therewith.

The third snap disk portion 7, like the first snap disk 3 and the second snap disk 5, has a first form convex toward the diaphragm 22 side.
The second slide receiving member 6 has a central shaft hole 30 which is combined with a flat portion provided at the base of the central projection 25, and the force from the fluid pressure is reduced by this combination.
2. Received via the first slide receiving member 4 and the second slide receiving member 6. Third snap disk portion (reversing plate) 7
The inner peripheral portion is combined with the side surface of the central protruding portion 25, and the outer peripheral portion is locked to the inner wall step of the switch case 2.

The third snap disk unit 7 has a function of sensing the low pressure cutoff pressure PL, PL + ΔPL.

By providing a step 26 on the inner wall of the switch case 2, the sliding length of the first sliding receiving member 4 and the second sliding receiving member 6 is limited, and a third snap disk is provided. After being once deformed, the third snap disk 7 is not subjected to excessive force, so that the operation of the third snap disk 7 does not impair its function over time.

The second operating rod 24 has a first shaft at its central axis.
And the upper end thereof abuts against the lower surface of the second snap disk portion 5,
Through the central shaft hole 28 of the slide receiving member 6. The second operating rod 24 transmits a force due to the deformation of the second snap disk 5.

The first operating rod 23 has an upper end in contact with the lower surface of the first snap disk portion 3, the hollow hole 27 of the first slide receiving member 4, and the hollow hole H of the second snap disk portion 5. And the inside of the second operating rod 24. First working rod 2
The switch lever 3 of the first electric switch SW1 extends downward without interfering with the second slide receiving member 6, the second operating rod 24, and the second electric switch SW2.
To transmit power.

The first electric switch section SW1 is composed of a first movable contact 15 provided at a tip end of a first switch lever 18 engaged with a lower end of a first operating rod 23, and a fixed contact which comes into contact with and separates from this. 14 First electric switch section SW1
Is installed at the bottom of the upper cavity B of the switch case 2. The first switch lever 18 has one end fixed to the terminal 13 extending to the lower cavity C of the switch case 2,
The first movable contact 15 is fixed on the upper surface of the other end which is a free end, and has a bias force upward. Terminal 12
One end is fixed to the partition A of the switch case 2 and extends through the partition A to the lower cavity C, and the other end is fixed to the fixed contact 14 facing the first movable contact 15.

The second electric switch section SW2 includes a second movable contact 10 provided on the free end side of a second switch lever 16 which is engaged with a lower end of a second operating rod 24, and a central projection 2
The third movable contact 11 is provided on the free end side of the third switch lever 17 engaged with the lower end of the third movable contact 5 and comes into contact with and separates from the second movable contact 10.

The second electric switch section SW2 is disposed above the first electric switch section SW1. The second switch lever 16 is connected to a second
One end is fixed to the fixed end 9 of the pair of terminals 19,
The second movable contact 10 is fixed to the other end which is a free end.
The third switch lever 17 has one end fixed to the fixed end 8 of the second pair of terminals 19 penetrating the partition wall A of the housing 2 and the third movable contact 11 fixed to the other end that is a free end. You. The second switch lever 16 is disposed substantially parallel to the third switch lever 17 and below the third switch lever 17. The second movable contact 10 and the third
Are mounted on the switch lever so that the movable contacts 11 face each other.

A second pair of terminals 19 extends through the partition wall A of the switch lever into the lower cavity C, and
Are arranged so as to intersect the pair of terminals 12 and 13 at right angles. Therefore, only one terminal 19 is shown in the drawing.

The first snap disk portion 3 has a stable shape in the shape of a truncated cone having an upward projection as shown in the figure below the pressure PM, but receives a fluid pressure higher than the pressure PM on the upper surface thereof through the diaphragm 22. Then, the state shifts to the second mode in which the central shaft portion is displaced downward by the snap action. This displacement pushes the first operating rod 23 downward and pushes the first switch lever 18 of the first electric switch unit SW1 to electrically open the fixed contact 14 and the first movable contact 15.

First snap disk portion (reversing plate) 3
Returns to the original form from the second form when the fluid pressure recovers to PM- △ PM, and as a result, the first switch lever 18 of the first electric switch unit SW1 via the first operating rod 23. The power that was pressing is gone. As a result, the reverse operation is performed when the PM is reached, and the fixed contact 14 and the first movable contact 15 of the first electric switch unit SW1 are electrically closed.

When the fluid pressure rises and reaches a certain value PH, the second snap disk portion 5 is displaced by the snap operation so that the central shaft portion is displaced downward from the first stable configuration having an upward convexity shown in the figure. Move to form 2. This movement is transmitted by the second actuation rod 24 to the second switch lever 16 of the second electric switch SW2.

The second operating rod 24 is provided so that the second snap disk 5 can perform the second
When it is deformed into the form, the movement is transmitted to the central portion of the second switch lever 16 of the second electric switch, and the second movable contact 10 is pushed downward against the upward biasing force of the switch lever. .

The peripheral portion of the third snap disk portion 7
It is housed in a receiving portion provided on the inner wall of the switch case. When the fluid pressure is lower than PL + △ PL, the configuration shown in the figure is taken, but when the fluid pressure reaches PL + △ PL, a transition is made to a second configuration in which the center is displaced downward with a snap action.

By this operation, the second slide receiving member 6 slides downward, and the central projection 25 thereof also moves downward.
This movement is transmitted to the third switch lever 17 of the second electric switch unit SW2, and the second electric switch unit SW2
Is closed. Once the fluid pressure reaches the high normal pressure and then drops again to the low abnormal pressure PL, the third snap disk returns to its original shape, thereby pushing the second slide receiving member 6 upward. Therefore, the central projection 25 does not lose the force exerted on the second electric switch SW2, and the second electric switch SW2 is opened.

The operation of the three-operation type pressure switch having such a configuration will be described with reference to FIG. Fluid pressure PL +
When ΔPL is applied to the diaphragm 22, the first snap disk portion 3, the first slide receiving member 4, the second snap disk portion 5, the second slide receiving member 6, and the third snap disk portion A load acts on 7. This load causes the third
Snap disk 7 snaps toward the electric switch, the second slide receiving member 6 moves toward the electric switch, and the central projection 25 of the second slide receiving member 6 The third switch lever 17 of the switch section SW2 is pushed down to bring the third movable contact 11 into contact with the second movable contact 10, thereby closing the second electric switch section SW2.

At this time, the lower surface near the outer periphery of the second slide receiving member 6 is supported by the step 26 provided inside the switch case 2, and does not move further toward the electric switch.

Further, when the fluid pressure increases and reaches the pressure PM, the first snap disk unit 3 snaps to the switch unit side, and the first operating rod 23 moves to the first electric switch unit SW1 side. , The first switch lever 18 of the first electric switch unit SW1 is pushed down, and the first movable contact 1
5 is separated from the fixed contact 14, and the first electric switch unit SW1 is opened.

When the fluid pressure further increases to the pressure PH, the first
Slide receiving member 4 moves to the electric switch side, and the annular projection 4b of the first sliding receiving member 4 causes the second snap disk portion 5 to snap to the electric switch side. Pushes down the second switch lever 16 of the second electric switch SW2, pulls the second movable contact 10 away from the third movable contact 11, and activates the second electric switch SW2 to open.

When the fluid pressure decreases from PH to PH-.DELTA.PH, the second snap disk portion 5 returns, the pushing force of the second operating rod 24 decreases, and the second switch lever 16 exerts its own restoring force. As a result, the second movable contact 10 comes into contact with the third movable contact 11 and the second electric switch unit SW2 is closed.

Further, when the fluid pressure decreases to PM-ΔPM, the first snap disk portion 3 returns from the second configuration, the pressing force of the first operating rod 23 is released, and the first switch lever 18 is released. Is restored by its restoring force,
The first movable contact 15 is pressed against the fixed contact 14, and the first electric switch unit SW1 shifts to the closed state.

Further, when the fluid pressure drops to PL,
The third snap disk portion 7 returns from the second configuration, the pressing force of the central protrusion 25 of the second slide receiving member 6 is released, and the third movable lever 3 is restored by the restoring force of the third switch lever 17. The contact 11 is separated from the second movable contact 10, and the second electric switch unit SW2 shifts to the open state.

In this case, the numerical values of the set pressure numbers are all gauge pressures, PH: 2.65 Mpa, PH- △ PH: 2.
15 Mpa, PL + △ PL: 250 Kpa, PL: 21
0 Kpa, PM: 1.47 Mpa, PM-ΔPM: 1.
08 MPa.

In this manner, the three-operation type pressure switches can be operated three-way with hysteresis characteristics.

The switch of such a three-operation type pressure switch is a switch for operating a relay, and only a minute current flows through the contact.

Since such a three-operation type pressure switch is used for an air conditioner or the like mounted on a vehicle, it is an extremely demanding component for cost reduction.

The contacts of the switch portion of the conventional three-acting pressure switch have a rivet shape including a header portion that contacts the opposing contacts and a mounting portion that fixes the contacts to the switch lever or terminal. It consists of. First movable contact 10: header portion diameter Dh; 3.0 mm,
Mounting part diameter Dr; 1.5 mm. Second movable contact 11: header portion diameter Dh; 3.0 mm,
Mounting part diameter Dr; 1.5 mm. Fixed contact 14: header part diameter Dh; 3.0 mm, mounting part diameter Dr; 1.5 mm. Third movable contact 15: header portion diameter Dh; 3.0 mm,
Mounting part diameter Dr; 1.5 mm.

[0045]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned demands, and maintains completely the same operating conditions without significantly changing the shape, structure and specifications of a conventional three-acting pressure switch. It is an object of the present invention to provide a three-acting pressure switch that uses less raw materials for components.

[0046]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by reducing the size of the contacts forming the switch section in a three-operation type pressure switch.

That is, the present invention provides a housing having a passage for introducing a fluid pressure, a switch case combined with the housing, a diaphragm airtightly fixed between the housing and the switch case, and an upper surface formed on a lower surface of the diaphragm. A first inverting plate abutting on the first inverting plate and a peripheral portion of the first inverting plate are locked on an upper surface, have an annular projection on the lower surface, have a hollow hole in the center, and have an outer periphery directly on the inner wall of the switch case. A first sliding receiving member that slides, a second reversing plate having an upper surface in contact with the annular protrusion and having a hole in the center, and a peripheral portion of the second reversing plate locked on the upper surface. A second central part having a central axis hole concentric with the hole and a central projection projecting from the periphery of the central axis hole on the lower surface, and having an outer periphery directly sliding on an inner wall part of the switch case; And the sliding receiving member A third reversing plate having an inner peripheral portion engaged with a side surface of the central protruding portion and an outer peripheral portion locked to an inner wall step of the switch case, and an upper end abutting on a lower surface of the second reversing plate; A second operating rod penetrating the center shaft hole of the second slide receiving member, and an upper end abutting against the lower surface of the first reversing plate, and penetrating through the hollow hole, the hole and the inside of the second operating rod. A first operating rod, a first electric switch portion including a first movable contact engaging with a lower end of the first operating rod, and a fixed contact coming and going from the first movable contact; and the second operating rod. A second movable contact engaged with the lower end of the second movable contact, and a third movable contact engaged with the central protrusion and separated from the second movable contact.
In the three-operation type pressure switch comprising the electric switch part, the diameter of the contact of the electric switch part is smaller than 3.0 mm and larger than 2.0 mm, and the diameter Dr of the mounting part is 1.5 mm. The size was less than 1.0 mm.

[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a three-acting pressure switch according to the present invention will be described. The configuration and operation of the pressure switch itself are the same as those of the conventional three-operation pressure switch shown in FIG. 3 except for the following differences.

That is, in the three-acting pressure switch according to the present invention, the shape of the contact forming the electric switch is such that the diameter Dh of the header portion is less than 3.0 mm and exceeds 2.0 mm, and the diameter of the mounting portion is It is different from the structure of the conventional three-acting pressure switch in that Dr is set to a range of less than 1.5 mm and more than 1.0 mm.

The shape of the contact portion of the three-acting pressure switch according to the present invention will be described with reference to FIGS. Figure 1
FIGS. 4A and 4B are diagrams for explaining the shapes of a fixed contact 14 and a first movable contact 15 of the first switch section SW1. FIG. 4A shows a conventional contact shape, and FIG. 4B shows a contact shape according to the present invention. FIGS. 2A and 2B are diagrams illustrating the shapes of the second movable contact 10 and the third movable contact 11 of the second switch unit SW2, and FIG.
Shows a conventional contact shape, and (b) shows a contact shape according to the present invention.

The size of the contact of the three-acting pressure switch according to the present invention will be described with reference to an enlarged view. Each contact has a header diameter Dh of less than 3.0 mm and 2.0 mm.
mm, and the diameter Dr of the mounting portion was less than 1.5 mm and more than 1.0 mm. The reason why the diameter Dh of the header portion is smaller than 3.0 mm and larger than 2.0 mm is determined in consideration of the reduction of the raw material and the current value, and when the diameter Dh of the header portion is smaller than 3.0 mm. If so, the raw material can be reduced, and when it exceeds 2.0 mm, the current for driving the relay can be passed without any problem, and it can function sufficiently as a contact. On the other hand, the diameter D of the mounting portion
The reason why R is less than 1.5 mm and exceeds 1.0 mm is determined in consideration of the reduction of the raw material, the strength of the mounting portion, and the workability of the contact, and the diameter Dh of the mounting portion is 1.5 mm. If it is less than this, the raw materials can be reduced,
When it exceeds 1.0 mm, the rivet can be attached to the switch lever without lowering the strength of the rivet and without deteriorating workability.

Another embodiment of the three-operation type pressure switch to which the present invention is applied will be described with reference to FIGS. In this embodiment, the structure of the first electric switch unit SW1 is configured to be closed when the fluid pressure exceeds the pressure PM and to be opened when the pressure decreases to the pressure PM−ΔPM. The contact 14 is provided at a point farther from the first snap disk portion 3 than the first movable contact 15. Other configurations are the same as those of the embodiment shown in FIG. Each of the contacts 10, 11, 14, 15 can be the same as the embodiment shown in FIG.

[0053]

According to the present invention, a three-acting pressure switch that performs substantially the same operation as a conventional three-acting pressure switch is provided.
It is possible to reduce the size of the contact and reduce the manufacturing cost without making a significant change in the shape of the components.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view illustrating a contact structure of a three-operation type pressure switch.

FIG. 2 is a partially enlarged view illustrating another structure of the contact of the three-operation type pressure switch.

FIG. 3 is a longitudinal sectional view illustrating the structure of a three-operation type pressure switch.

FIG. 4 is a diagram illustrating operating pressure characteristics of a three-operation type pressure switch.

FIG. 5 is a longitudinal sectional view illustrating another embodiment of a three-operation type pressure switch.

FIG. 6 is a view for explaining the operating pressure characteristics of the three-operation pressure switch shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Switch case 3 1st snap disk 4 1st slide receiving member 5 2nd snap disk 6 2nd slide receiving member 7 3rd snap disk 8 Fixed end 9 Fixed end 10 2nd movable Contact 11 Third movable contact 12 Terminal 13 Terminal 14 Fixed contact 15 First movable contact 16 First switch lever of second electric switch unit 17 Second switch lever of second electric switch unit 18 First Switch lever of electric switch section 19 Terminal 21 Gasket 22 Diaphragm 23 First operating rod 24 Second operating rod 25 Central projection 26 Step

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G051 AA03 AA27 AB01 AC07 5G056 DB04 DD01 DD32 DE01 DE07 DE16 DE17 DE20 DE21 DE28 DE32 DG07

Claims (1)

[Claims] 1. A housing having a passage for introducing a fluid pressure, a switch case combined with the housing,
A diaphragm hermetically fixed between the housing and the switch case, a first reversing plate having an upper surface abutting on a lower surface of the diaphragm, and a peripheral portion of the first reversing plate locked at the upper surface, and a ring on the lower surface A first sliding receiving member having a projection and having a hollow hole at the center, the outer periphery of which slides directly on the inner wall of the switch case; and an upper surface abutting on the annular projection, and a hole is formed in the center. A second reversing plate having the second reversing plate and a peripheral portion of the second reversing plate locked at an upper surface, having a central axis hole concentric with the hole at a central portion, and projecting from a periphery of the central axis hole at a lower surface. A second slide receiving member having a central projection, the outer periphery of which slides directly on the inner wall of the switch case; and an inner periphery on the side surface of the central projection, the outer periphery being an inner wall of the switch case. A third reversing plate locked to the step, In contact with the lower surface of the reversing plate, the second
A second operating rod penetrating through the central shaft hole of the sliding receiving member, and an upper end abutting on the lower surface of the first reversing plate, and penetrating through the hollow hole, the hole and the inside of the second operating rod. A first electric switch portion including a first operating rod, a first movable contact engaged with a lower end of the first operating rod, and a fixed contact which comes into contact with and separates from the first movable contact; A three-acting pressure comprising a second movable contact engaged with the lower end, and a second electric switch comprising a third movable contact which comes into contact with and separates from the second movable contact and engages with the central projection. In the switch, the contact point of the electric switch part is such that the diameter Dh of the header part is 3.0 mm> D.
h> 2.0 mm, diameter Dr of the mounting portion is 1.5 mm> Dr
3. A three-acting pressure switch characterized by a range of> 1.0 mm.