JP2509837Y2 - Three-action pressure switch device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-action pressure switch device for controlling on / off of two switch means at three different pressure values.

[0002]

2. Description of the Related Art A three-action pressure switch device as described above is provided with a first switch means and a condenser provided in an electric circuit for a compressor or an electric circuit for an alarm in an air conditioner for an automobile. It is used to turn on / off the second switch means provided in the electric circuit for the fan motor.

A fan motor for a condenser is a small front-wheel drive vehicle in which the heat exchange capacity of the condenser is apt to be insufficient when the temperature of the refrigerant at the outlet of the evaporator becomes high due to a large limitation in the arrangement of the condenser. Is important for the air conditioning system.

More specifically, when the pressure of the refrigerant in the air conditioner for an automobile rises above the upper limit of an appropriate predetermined range and falls below the lower limit of the above predetermined range, the first
Switch means turns off the electrical circuit for the compressor or turns on the electrical circuit of the alarm. The second switch means turns on the electric circuit for the fan motor of the condenser when the pressure of the refrigerant rises above a predetermined value within the predetermined range.

The structure of the three-action pressure switch device is disclosed, for example, in Japanese Patent Laid-Open No. 64-27137. Here, the internal space of the housing having the pressure fluid introduction passage for introducing the pressure fluid into the internal space serves as a pressure working chamber communicated with the pressure fluid introduction passage by a diaphragm and a switch mechanism storage chamber cut off from the pressure fluid introduction passage. The first and second switch means are separated in a hermetically sealed state, and the first and second switch means are turned on / off in the switch mechanism storage chamber at three different pressure values as described above. The switch means drive mechanism for controlling is stored.

The switch mechanism driving mechanism includes a diaphragm and a first and a second diaphragm in the switch mechanism storing chamber in the internal space.
And two diaphragm members, which are interposed between the switch means of FIG.
Three biasing means having mutually different biasing forces interposed between the respective piston members, and elastic deformation of the biasing means between the two piston members inserted into the piston member far from the diaphragm. Driven by the first actuation rod, the piston member closer to the diaphragm and the first actuation rod, and driven by elastic deformation of the biasing means between the diaphragm and the piston member closer to the diaphragm. Second
And the operating rod of.

When the pressure of the refrigerant in the automobile air conditioner falls below the lower limit of an appropriate predetermined range, the first switch means turns off the electric circuit for the compressor or gives an alarm. The electrical circuit of the fan is turned on, while the second switch means simultaneously turns off the electrical circuit for the fan motor.

When the pressure of the refrigerant rises and reaches the lower limit of an appropriate predetermined range, the biasing means adjacent to the side farther from the diaphragm is compressed by the snap action with respect to the piston member farther from the diaphragm. Upon deformation, the piston member causes the first switching means to be switched to turn on the electrical circuit for the compressor or turn off the electrical circuit of the alarm.

When the pressure of the refrigerant further rises and exceeds a predetermined value within an appropriate predetermined range, the biasing means between the diaphragm and the piston member adjacent to the diaphragm is compressed and deformed by the snap action. Two actuating rods switch the second switch means to turn on the electrical circuit for the fan motor and the first switch means turn on the electrical circuit for the compressor or switch the electrical circuit of the alarm. Keep switched to turn off.

When the pressure of the refrigerant further rises and exceeds the upper limit of an appropriate predetermined range, the biasing means interposed between the two piston members is compressed and deformed by the snap action, and the first operation is performed. By means of the rod, the first switch means is switched to turn off the electric circuit for the compressor or to turn on the electric circuit of the alarm, while at the same time the second switch means keeps the electric circuit for the fan motor. Turned on.

When the pressure of the refrigerant decreases from a value exceeding the upper limit of an appropriate predetermined range, the first switch means and the second switch means are turned on / off in the reverse order to that described above. Control is performed.

In such a conventional three-operation type pressure switch device, the air conditioner for automobiles is often arranged in a place where the environmental temperature changes remarkably, such as in the engine room of the automobile. It is required to endure and operate properly. For this reason, the first and second actuating rods of the switch means driving mechanism are made of ceramics mainly composed of alumina, which has extremely small expansion and contraction values due to the influence of temperature and can obtain precise dimensional accuracy. ing.

[0013]

However, the elongated first and second actuating rods made of ceramics are easily broken or partly broken when a large impact is applied from the diameter direction. If at least one of the actuating rods is broken or partly damaged, the three-action pressure switch device cannot perform the desired operation, and thus the automobile air conditioner can also perform the desired operation. Disappear. The large impact as described above may be dropped on the floor surface during the packing work for shipping after the three-action pressure switch device is manufactured or during the assembling work for the air conditioner for automobiles, or during the transfer work after packing. It is caused by a large impact on the packaging.

The present invention has been made under the above circumstances, and an object of the present invention is not only capable of withstanding a change in environmental temperature and operating properly, but also elongated first and second actuating rods even when shocked. It is an object of the present invention to provide a three-action pressure switch device capable of performing a desired operation without causing breakage or partial damage of at least one of the two.

[0015]

In order to achieve the above-mentioned object, a three-acting pressure switch device according to the invention is:
A housing having a pressure fluid introduction passage for introducing a pressure fluid into the inner space; a switch provided in the inner space of the housing, the pressure working chamber communicating with the pressure fluid introduction passage, and the switch isolated from the pressure fluid introduction passage A diaphragm that divides into a mechanism storage chamber in a sealed state; a first piston member that is disposed adjacent to the diaphragm in the switch mechanism storage chamber and that moves together with the central portion when the central portion of the diaphragm moves; A second piston member that is adjacent to the first piston member on the side farther from the diaphragm in the chamber and that moves together with the first piston member when the first piston member moves; provided in the switch mechanism storage chamber First urging means for urging both the first and second piston members toward the diaphragm; in the switch mechanism storage chamber A first piston member and a first piston member is interposed between the second piston member Te second
Second urging means for urging in a direction away from the piston member; and a first central part of the diaphragm interposed between the central part of the diaphragm and the first piston member in the switch mechanism storage chamber. Third biasing means for biasing the piston member away from the piston member and generating a biasing force having a strength between the biasing force of the first biasing means and the biasing force of the second biasing means. A first actuation rod that is inserted into the second piston member and that moves relative to the second piston member along the movement direction of the second piston member in response to the deformation of the second biasing means. And; the first actuation rod and the first piston member are inserted through the first actuation rod and the first piston member, and the first actuation rod and the first actuation rod and the first piston member are corresponding to the deformation of the third biasing means. A second actuating rod that moves relative to the direction of movement of the piston member of Adjacent to the second piston member at a side remote from the diaphragm in the switch mechanism storing room in,
Both of the first and second piston members move against the urging force of the first urging means to be pressed by the second piston member to be in one of an on state and an off state, A first switch means that is pressed by a first actuation rod that has moved corresponding to the deformation of the urging means and is turned on or off; and a diaphragm in the switch mechanism storage chamber. First on the far side
Second switch means that is adjacent to the switch means and is pressed by the second actuating rod that has moved corresponding to the deformation of the third biasing means to be in either the on state or the off state. The first operating rod is made of synthetic resin, and the second operating rod is made of ceramics.

[0016]

In the three-action pressure switch device according to the present invention, which is characterized as described above, the impact force applied from the outside is mitigated by the first actuation rod made of synthetic resin and made of ceramics. No breakage or partial damage to the second actuating rod of The second working rod made of ceramics, which is longer than the first working rod, has less expansion and contraction due to the influence of heat and can obtain precise dimensional accuracy. Performs switch operation.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-action pressure switch device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that all the numerical values of pressure appearing in the following description are gauge pressures.

In FIG. 1, reference numeral 10 indicates a housing having an internal space. The housing 10 is made of metal, and has a first housing portion 14 having a pressure fluid introduction path 12 for guiding a pressure fluid (for example, a refrigerant in an air conditioner for an automobile) to the internal space, and the first housing portion 1
The second housing portion 16 is connected to the first housing portion 14 by crimping the open end of the inner space 4.

The second housing portion 16 is not required to be particularly airtight, but since it must be able to prevent the entry of moisture and be an electrically non-conductive material, it is glass fiber reinforced polybutylene in this embodiment. It is made of terephthalate.

The opening of the inner space of the second housing portion 16 on the side of connection with the first housing portion 14 is covered with a diaphragm 18 formed of a polyimide resin film, and the peripheral portion of the diaphragm 18 is an annular sealing member. It is sandwiched via 20 between the inner surface of the open end of the internal space of the second housing portion 16 and the inner surface of the open end of the internal space of the first housing portion 14.

The inner space of the first housing portion 14 and the second
The internal space of the housing portion 16 constitutes the internal space of the housing 10, and the diaphragm 18 partitions the two internal spaces in a sealed state. The internal space of the first housing portion 14 communicating with the pressure fluid introduction passage 12 constitutes a pressure working chamber 22, and the second housing portion 16 of the second housing portion 16 is shut off from the pressure working chamber 22 by the diaphragm 18. The internal space constitutes the switch mechanism storage chamber 24.

The second housing remote from the first housing portion 14
A recess 26 is formed in the end surface of the housing portion 16 of the first housing portion 14. The recess 26 is formed in the pressure fluid introducing passage 12 and the pressure working chamber 22 of the first housing portion 14 and the switch mechanism storage chamber of the second housing portion 16. 24 and 24 are arranged in a line along the longitudinal centerline of the housing 10.

The recess 26 in the second housing part 16
Two pairs of terminal members 30 and 32 are inserted in a partition wall 28 between the switch mechanism storage chamber 24 and the switch mechanism storage chamber 24, and both ends of each of the terminal members 30 and 32 are projected into the recess 26 and the switch mechanism storage chamber 24 (note that the both ends are projected). Since FIG. 1 is a longitudinal sectional view, only one of the pair of terminal members 32 is shown in FIG. 1).

The base end portion of the other pair of terminal members 30 in the switch mechanism storage chamber 24 is at the switch mechanism storage chamber 24.
It is arranged such that the inward protruding height from the partition wall 28 is lower than the base end portions of the pair of terminal members 32 in the inside.

One base end portion of the other pair of terminal members 30 is bent on the inner surface of the partition wall 28, and the other base end portion of the other pair of terminal member 30 is inside the partition wall 28. The partition wall 2 is spaced at a predetermined distance inward from the surface.
8 is bent along the inner surface.

One end of a first elastic switch piece 34 formed of a material having conductivity and elasticity is fixed to the base end portion of one terminal member 30, and the first elastic switch piece 34 is fixed. The other end further extends inward from the inner surface of the partition wall 28, is bent along the inner surface of the partition wall 28, and is adjacent to the upper end of the inwardly extending end of the other terminal member 30.

A contact 36 is fixed to the other end (inward extending end) of the first elastic switch piece 34, and the first elastic switch piece 34 is attached to the inner extending end of the other terminal member 30.
Contact 38 with which the contact 36 at the inward extending end of the
Has been fixed.

The first elastic switch piece 34 and the other terminal member 30 combined in this way are
The inwardly extending end of the above constitutes a second switch means 39 for performing a predetermined operation described later.

One base end portion of one pair of terminal members 32 is bent along the inner surface of the partition wall 28 inwardly of the base end portion of the other pair of terminal members 30. The direction extension end 40 is the switch mechanism storage chamber 2
4 is located in the vicinity of the inner peripheral surface. A support piece 42 bent toward the partition wall 28 is formed at the inward extending end 40, and the support piece 42 has a support recess on a support step 44 formed on the inner peripheral surface of the switch mechanism storage chamber 24. It is inserted and supported in the center.

Also fixed to the inward extending end 40 is one end of a second elastic switch piece 46 extending inward of the second switch means 39 and along the inner surface of the partition wall 28. . The second elastic switch piece 46 is also made of a material having conductivity and elasticity, and the second elastic switch piece 4
At the other end of 6, the bottom surface of the switch mechanism storage chamber 24 (that is,
The contact 48 is fixed to the side opposite to the inner surface of the partition wall 28.

The other base end portion of the one pair of terminal members 32 is also bent along the inner surface of the partition wall 28 inwardly of the base end portion of the other pair of terminal members 30. The inner extending end 50 is adjacent to the inner side of the inner extending end 40 of the one terminal member 32 described above. The inward extension end 50 is also formed with a support piece bent toward the partition wall 28, and this support piece is also formed on the support step 44 formed on the inner peripheral surface of the switch mechanism storage chamber 24. It is inserted and supported in the center.

One end of a third elastic switch piece 52, which extends inward of the second elastic switch piece 46 and extends along the inner surface of the partition wall 28, is fixed to the inward extending end 50. . The third elastic switch piece 52 is also made of a material having electrical conductivity and elasticity, and the third elastic switch piece 52
A contact 54 is fixed to the other end of the switch mechanism storage chamber 24 at the bottom surface (that is, the inner surface of the partition wall 28) side. In this embodiment, in the state of FIG. 1, the second elastic switch piece 46 is
The contact 48 at the other end and the contact 54 at the other end of the third elastic switch piece 52 are separated from each other by a predetermined distance.

An elongated through hole 56 is formed in the middle of the second elastic switch piece 46 in the longitudinal direction thereof, and an elongated through hole 56 is also formed in the intermediate portion of the third elastic switch piece 52 in the longitudinal direction thereof. The hole 58 is formed concentrically with the through hole 56 of the second elastic switch piece 46. The diameter of the latter through hole 58 is larger than the diameter of the former through hole 56.

The second and third elastic switch pieces 46 and 52 arranged and constructed as described above constitute the first switch means 60 which cooperates with each other to perform a predetermined operation described later. ing.

In the switch mechanism housing chamber 24 of the second housing portion 16, the first switch means 60 and the diaphragm 1 are provided.
A switch means drive mechanism for selectively turning on / off the first switch means 60 and the second switch means 39 at three different predetermined pressure values is housed between the switch 8 and the switch 8. There is.

The switch means driving mechanism is the diaphragm 1
8 adjacent to the first piston member 62, the diaphragm 1
Second piston member 64 adjacent to the first piston member 62 on the side remote from 8, first biasing means 66 adjacent to the second piston member 64 on the side remote from diaphragm 18, first Second biasing means 68 interposed between the piston member 62 and the second piston member 64, and a third biasing means 70 interposed between the diaphragm 18 and the first piston member 62, The second piston member 64 is inserted into the second urging means 68 and the second switch means 60.
The first actuation rod 7 extending between the elastic switch piece 46 and
2, and the first piston member 62 and the first actuation rod 7
The second urging means 70 inserted into the second urging means 70 and extending between the third urging means 70 and the first elastic switch piece 34 of the second switch means 39.
Of the actuating rod 74, and these various components are arranged concentrically with respect to the diaphragm 18 and the housing 10.

Next, the structure of the switch means driving mechanism will be described in more detail. Arranged adjacent to the diaphragm 18 in the switch mechanism storage chamber 24 is a third urging means 70, and in this embodiment, the third urging means 70 is two.
It is composed of a number of snap disks. The two snap disks are overlapped with each other with a lubricant containing solid powder of molybdenum disulfide interposed therebetween in order to improve the sliding between them. In the state of FIG.
Is in a convex state toward the diaphragm 18.

The peripheral edge of the third biasing means 70 is defined by the peripheral edge of the biasing means receiving recess 76 concentrically arranged with respect to the diaphragm 18 on the diaphragm side surface of the first piston member 62 adjacent to the diaphragm 18. It is supported.

The second urging means 68 interposed between the first piston member 62 and the second piston member 64 is composed of three snap disks in this embodiment. The three snap disks are overlapped with each other with a lubricant containing solid powder of molybdenum disulfide interposed therebetween in order to improve the sliding between them, and in the state of FIG. It is in a state of being convex toward the first piston member 62.

The peripheral edge of the second biasing means 68 is supported by the peripheral edge of a biasing means receiving recess 78 that is concentrically arranged with respect to the diaphragm 18 on the diaphragm side surface of the second piston member 64. On the surface of the first piston member 62 remote from the diaphragm 18, a plurality of support projections 80 arranged in an annular shape concentric with the diaphragm 18 abut on the surface of the second biasing means 68 on the diaphragm side. Touching.

The first biasing means 66 adjacent to the second piston member 64 on the side farther from the diaphragm 18 is constituted by one snap disk in this embodiment, and in the state of FIG. The urging means 66 is in a convex state toward the second piston member 64.

The peripheral edge of the first biasing means 66 is formed on the inner peripheral surface of the switch mechanism storage chamber 24 of the second housing portion 16 between the first switch means 60 and the second piston member 64. It is supported by a notch at the inner peripheral end of the substantially annular stepped portion 82, and movement of the first switch means 60 in the direction is blocked.

A through hole 8 is formed in the center of the first biasing means 66.
4 is formed, and the first switch means 60 is formed from the center of the surface of the second piston member 64 on the first biasing means side.
The switch means operating protrusion 86 projecting toward is inserted. The protruding end of the switch means operating protrusion 86 is separated from the third elastic switch piece 52 of the first switch means 60 by a predetermined distance, and the diameter of the switch means operating protrusion 86 is the middle portion of the third elastic switch piece 52. It is larger than the diameter of the through hole 58.

A through hole 88 is formed concentrically with the diaphragm 18 in the center of the second piston member 64, and a cylindrical first operating rod 72 is inserted into the through hole 88. , The first actuating rod 72 is the second piston member 64.
With respect to the first switch means 6, it is slidable along the moving direction of the central portion of the diaphragm 18 and extends from the second biasing means 68 toward the first switch means 60.
It is inserted into the through hole 58 in the middle portion of the third elastic switch piece 52 of No. 0 and is separated from the second elastic switch piece 46 by a predetermined distance. The diameter of the first actuation rod 72 is larger than the diameter of the through hole 56 in the middle portion of the second elastic switch piece 46.

In this embodiment, the first actuation rod 72 is made of synthetic resin (for example, polyphenine sulfide containing 40% glass fiber). A through hole 90 having a diameter smaller than the outer diameter of the first actuating rod 72 and larger than the inner diameter of the first actuating rod 72 is formed in the central portion of the second actuating rod 72. Is formed concentrically with respect to the first actuation rod 72, and a through hole 92 having an inner diameter equal to the inner diameter of the first actuation rod 72 is also formed concentrically with respect to the first actuation rod 72 in the central portion of the first piston member 62. Has been done.

A second actuating rod 74 is inserted in the inner hole of the first actuating rod 72, and the second actuating rod 74 is a through hole of the second biasing means 68 in the direction toward the diaphragm 18. Through the through hole 92 of the first piston member 62
Has reached the third urging means 70, and in the direction away from the diaphragm 18, it has been inserted into the through hole 56 in the intermediate portion of the second elastic switch piece 46 of the first switch means 60, and 1 of the switch means 39 of 1
Is separated from the elastic switch piece 34 by a predetermined distance.

The second actuating rod 74 is slidably supported by the inner hole of the first actuating rod 72 and the through hole 92 of the first piston member 62 along the moving direction of the central portion of the diaphragm 18.

In this embodiment, the second operating rod 74 is made of alumina ceramics. Next, the operation of the three-action pressure switch device of one embodiment of the present invention constructed as described above will be described.

In the three-action pressure switch device according to one embodiment of the present invention, the pressure fluid introduction passage 12 of the first housing portion 14 of the housing 10 is used, for example, in the refrigerant passage of a refrigeration system (not shown) of an automobile air conditioner. To the compressed fluid passageway between the evaporator and the condenser, and at the outwardly projecting ends of the two pairs of terminal members 30, 32 are recesses 26 in the second housing portion 12 of the housing 10. It is electrically connected to a socket member (not shown) inserted in. Here, the pair of terminal members 32 for the first switch means 60 are electrically connected to the electric circuit of the refrigeration system (not shown), for example, the electric circuit of the compressor or the electric circuit of the alarm device, and the second switch means 39. A pair of terminal members 30 for the above are connected to an electric circuit of a fan motor for the condenser (not shown) of the refrigeration system (not shown).

In the initial state of FIG. 1, the first switch means 60 is in the off state, and the electric circuit of the corresponding compressor is turned off or the electric circuit of the alarm device is turned on. Also, the second switch means 39 is in the on state and the electric circuit of the fan motor for the corresponding condenser is in the off state.

When the pressure of the refrigerant in the refrigerant passage increases from the initial state of FIG. 1 to reach 250 kPa, the pressure of the refrigerant introduced into the pressure working chamber 22 of the first housing portion 14 is changed to the diaphragm 18 and the third. The first biasing means 66 transmitted through the biasing means 18, the first piston member 62, the second biasing means 68, and the second piston member 64 to the diaphragm 18 as shown in FIG. As shown in FIG. 2A, the convex shape is compressed and deformed so as to be convex in the direction away from the diaphragm 18.

Such compressive deformation of the first urging means 66 causes a third urging force interposed between the first urging means 66 and the diaphragm 18 as shown in FIG. Means 1
8, the first piston member 62, the second biasing means 68, and the second piston member 64 are moved by a predetermined distance in the direction toward the first switch means 60.

By this movement, the switch means operating projection 86 of the second piston member 64 presses the corresponding third elastic switch piece 52 of the first switch means 60, and the free end of the third elastic switch piece 52 is pushed. The contact 54 is brought into contact with the contact 48 at the free end of the second elastic switch piece 46 of the corresponding first switch means 60.

Then, the electric circuit of the electric circuit of the compressor corresponding to the first switch means 60 is turned on, or the electric circuit of the alarm device is turned off. Diaphragm 1
8, the third urging means 18, the first piston member 62 and the second urging means 68 together with the movement of the second piston member 64 as described above is caused by the movement of the second piston farther from the diaphragm 18. The peripheral portion of the side surface of the member 64 comes into contact with the stepped portion 82 in the second housing portion 16 to be stopped.

The diaphragm 18, the third biasing means 18, the first piston member 6 together with the second piston member 64.
The first and second actuating rods 72 and 74 also move in the direction toward the partition wall 28 of the second housing portion 16 by simultaneously moving the second and second biasing means 68, but The actuating rod 72 and the second actuating rod 74 approach the corresponding second elastic switch piece 52 of the first switch means 60 and the first elastic switch piece 34 of the second switch means 39, respectively. There is no need to press to turn off each of the first switch means 60 and the second switch means 39.

That is, the electric circuit of the compressor or the electric circuit of the alarm device corresponding to the first switch means 60 can maintain the ON state or the OFF state as described above, and the condensation circuit corresponding to the second switch means 39. The electrical circuit of the fan motor for the appliance remains in the off state, similar to the initial state shown in FIG.

When the pressure of the refrigerant in the refrigerant passage drops from 250 kPa to 210 kPa, the first urging means 66 is projected by the elastic force of the first urging means 66 in the direction away from the diaphragm 18 as shown in FIG. As shown in FIG. 1, the original shape returns to a convex shape toward the diaphragm 18.

Due to the elastic force of the first urging means 66 and the elastic force of the third elastic switch piece 52 of the first switch means 60, the second piston member 64 causes the diaphragm 1 to move.
8, the third urging means 18, the first piston member 62 and the second urging means 68 are returned to the initial position shown in FIG. 1, and the corresponding first switch by the switch means operating protrusion 86 is returned. The pressing of the third elastic switch piece 52 of the means 60 is released.

Then, the first switch means 60 is turned off, the electric circuit of the compressor corresponding to the first switch means 60 is turned off, or the electric circuit of the alarm device is turned on. .

When the pressure of the refrigerant in the refrigerant passage further rises from 250 kPa and reaches 1.47 MPa, the third urging means 70 is provided in addition to the first urging means 66 as shown in FIG. 2), it is elastically deformed from the convex shape toward the diaphragm 18 to the substantially flat convex shape as shown in FIG. This deformation of the third biasing means 70 causes the second actuating rod 7 in the direction towards the partition 28 of the second housing part 16.
4 further movement, the second actuating bar 74 causes the first elastic switch piece 3 of the corresponding second switch means 39 to move.
4 is pressed to change the second switch means 39 from the ON state to the OFF state.

As a result, the electric circuit of the fan motor for the condenser corresponding to the second switch means 39 changes from the off state to the on state. The pressure of the refrigerant in the refrigerant passage is 1.
When it descends from 47 MPa and reaches 1.08 MPa,
The third urging means 70 is elastically applied to the third urging means 70 as shown in FIG.
As shown in FIG. 2, the flat shape returns to the convex shape toward the diaphragm 18 as shown in FIG. As the shape of the third urging means 70 is restored, the second operating rod 74
Follows the shape recovery of the third urging means 70 by the elastic force of the first elastic switch piece 34 of the corresponding second switch means 39, and as shown in FIG. No longer pressing the first elastic switch piece 34 of the second
The switch means 39 is changed from the off state to the on state.

As a result, the electric circuit of the fan motor for the condenser corresponding to the second switch means 39 changes from the on state to the off state. The pressure of the refrigerant in the refrigerant passage is 1.
When the pressure further rises from 47 MPa and reaches 2.65 MPa, the second urging means 68 in addition to the first urging means 66 and the third urging means 70, this time, the second urging means 68 is shown in FIGS. As shown in (B) and FIG. 2 (B), it is elastically deformed from the convex shape toward the diaphragm 18 to the substantially flat convex shape as shown in FIG. 2 (C). This deformation of the second biasing means 68 causes the first actuation rod 7 in the direction towards the partition 28 of the second housing part 16.
2 further movement, the first actuating rod 72 causes the second elastic switch piece 4 of the corresponding first switch means 60 to move.
6 is pressed to change the second switch means 39 from the ON state to the OFF state.

As a result, the electric circuit of the compressor or the electric circuit of the alarm device corresponding to the first switch means 60 changes from the on state to the off state or from the off state to the on state.

The pressure of the refrigerant in the refrigerant passage is 2.65 MPa.
When the second urging means 68 descends from 2.15 MPa and reaches 2.15 MPa, the second urging means 68 is changed from the flat shape as shown in FIG. 2 (C) to the diaphragm 1 as shown in FIG. 2 (B) by its own elastic force.
It returns to a convex shape toward 8. With the return of the shape of the second urging means 68, the first actuation rod 72 is moved by the elastic force of the second elastic switch piece 46 of the corresponding first switch means 60 to the third urging means 70. Following the shape recovery,
As shown in FIG. 2A, the second switch means 60 has a second
The elastic switch piece 46 is no longer pressed and the first switch means 60 is changed from the off state to the on state.

As a result, the electric circuit of the compressor or the electric circuit of the alarm device corresponding to the first switch means 60 changes from the off state to the on state or from the on state to the off state.

The first in the three-action pressure switch device of the above-described embodiment corresponding to the change of the pressure of the refrigerant in the refrigerant passage.
And the operating characteristics of the second switch means 60, 39 are schematically shown in FIG.

In FIG. 2D, P _L is 2.10k.
Pa, P _L + ΔP _L is 250 kPa, P _M
-ΔP _M is 1.08MPa, P _M is 1.47MP
a, P _H −ΔP _H is 2.15 MPa, and P _H is 2.65 MPa.

P _L + ΔP _L means that the first switch means 60 is first turned on (ie the electric circuit of the corresponding compressor is turned on, or while the pressure of the refrigerant is increasing). (The electric circuit of the alarm device is turned off)
The pressure value of the refrigerant at the time is shown, and P _L and P _H are in charge of the first
The first switch means 60 is turned off after the switch means 60 is turned on (ie, the electric circuit of the corresponding compressor is turned off or the electric circuit of the alarm device is turned on). ), The lower and upper limits of the pressure value of the refrigerant are shown, and P _H- ΔP _H is P where the pressure of the refrigerant is the upper limit value.
The first switch means 60 is turned on again after the first switch means 60 is turned off at a level higher than _H (that is, the electric circuit of the corresponding compressor is turned on, or
Or the pressure value of the refrigerant when the electric circuit of the alarm device is turned off).

That is, the first switch means 60 once reaches P _L + ΔP _L while the pressure of the refrigerant is rising and is turned on (that is,
If the electric circuit of the corresponding compressor is turned on or the electric circuit of the alarm device is turned off), the lower limit and upper limit of the refrigerant pressure are set at P _L and P _H. It is turned off (that is, the electric circuit of the corresponding compressor is turned off or the electric circuit of the alarm device is turned on) only when it falls or rises outside the predetermined range.

In FIG. 2D, P _M is 1.
47 MPa, and P _M −ΔP _M is 1.08 MP
a. P _M is such that the second switch means 39 is first turned off while the refrigerant pressure is increasing (ie,
It shows the pressure value of the refrigerant when the electric circuit of the fan motor for the corresponding condenser is in the ON state), and P _M −Δ
P _M and the second switch means 39 is turned on again after the switch means 39 one担第2 is turned off (i.e., the electric circuit of the fan motor for the corresponding condenser is off) The pressure value of the refrigerant at the time is shown.

That is, the second switch means 39 once reaches P _M while the pressure of the refrigerant is rising and is turned off (that is, the electric circuit of the fan motor for the corresponding condenser is turned on). If so, it is turned on (that is, the electric circuit of the fan motor for the corresponding condenser is turned off) only when the pressure of the refrigerant drops to P _M −ΔP _M.

As described above in detail, the first actuation rod 72 is made of alumina ceramics and the second actuation rod 74 is made of synthetic resin. And a three-acting pressure switch device in which both the first and second actuating rods are made of alumina ceramics, and both the first and second actuating rods are made of steatite ceramics. The following Table 1 shows the results of the impact resistance test of the three-action pressure switch device.

In this impact resistance test, ten of each of the above-mentioned three types of three-action pressure switch devices were dropped from a height of 80 cm and a height of 2 m onto a flat concrete floor surface.

[0074]

[Table 1]

From the results of the impact resistance test, it is understood that the impact resistance reliability of the three-action pressure switch device according to the embodiment of the present invention is far superior. In addition, in the above-mentioned three-action pressure switch device of one embodiment of the present invention, the first to third
Of the first and second switch means 60, 39 by appropriately changing the respective urging forces of the urging means 66, 68, 70 and the structures of the first and second switch means 60, 39. The value of the pressure at which each of them turns on and off can be changed appropriately.

In the above-described embodiment, the longer second actuating rod 74 is made of ceramics and the shorter first actuating rod 72 is made of synthetic resin. This is because by using a synthetic resin having a large coefficient of thermal expansion for the first actuation rod 72 having a short length, fluctuations in dimensional accuracy due to thermal expansion can be reduced as much as possible.

[0077]

As described above in detail, according to the three-action pressure switch device of the present invention, not only can it withstand the environmental temperature change and operate properly, but also the first synthetic resin pressure switch can be used even if it receives an impact. The second operating rod, which is longer than the operating rod and the first operating rod and is made of ceramics, can perform a desired operation without being broken or partly damaged.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a three-action pressure switch device according to an embodiment of the present invention in an initial state.

2 (A) is a graph showing a case where the pressure of the refrigerant of the vehicle air conditioner introduced into the pressure working chamber of the housing reaches the lower limit of a predetermined pressure range in the three-action pressure switch device in the initial state of FIG. 1. It is a longitudinal cross-sectional view showing a state, (B) is FIG.
FIG. 6 is a vertical cross-sectional view showing a state when the pressure of the refrigerant of the vehicle air conditioner introduced into the pressure working chamber of the housing in the three-action pressure switch device of FIG. 3 reaches a predetermined value within a predetermined pressure range, FIG. 3C is a vertical cross-sectional view showing a state when the pressure of the refrigerant of the vehicle air conditioner introduced into the pressure working chamber of the housing in the three-action pressure switch device of FIG. 1 reaches the upper limit of a predetermined pressure range. , (D) are diagrams schematically showing operating characteristics of the first and second switch means in the three-action pressure switch device of FIG. 1 corresponding to changes in the pressure of the refrigerant.

[Explanation of symbols]

10 ... Housing, 12 ... Pressure fluid introduction passage, 18 ... Diaphragm, 22 ... Pressure actuation chamber, 24 ... Switch mechanism storage chamber, 39 ... Second switch means, 60 ... First switch means, 62 ... First piston Member, 64 ... second piston member, 66 ... first biasing means, 68 ... second biasing means, 70 ... third biasing means, 72 ... first actuation rod, 74
… Second actuation rod.

Claims (1)

(57) [Scope of utility model registration request] 1. A housing having a pressure fluid introducing passage for introducing a pressure fluid into the internal space; a pressure working chamber and a pressure fluid introducing passage which are provided in the internal space of the housing and communicate with the pressure fluid introducing passage. A diaphragm that divides in a sealed state from the switch mechanism storage chamber that is cut off from the;
A first piston member disposed in the switch mechanism storage chamber adjacent to the diaphragm and moving together with the central portion when the central portion of the diaphragm moves; a first piston on a side farther from the diaphragm in the switch mechanism storage chamber A second piston member that is adjacent to the member and that moves together with the first piston member when the first piston member moves; both the first and second piston members provided in the switch mechanism storage chamber facing the diaphragm First urging means for urging; intervening between the first piston member and the second piston member in the switch mechanism storage chamber to move the first piston member away from the second piston member. Second urging means for urging; a die interposed between the central portion of the diaphragm and the first piston member in the switch mechanism storage chamber. The central portion of the flam is urged in a direction away from the first piston member, and an urging force having a strength between the urging force of the first urging means and the urging force of the second urging means is applied. A third urging means to be generated; inserted into the second piston member, and relative to the second piston member along the moving direction of the second piston member in response to the deformation of the second urging means. A first actuating rod that moves; a first actuating rod and a first piston member, and a first actuating rod and a first piston member that are inserted through the first actuating rod and the first piston member, corresponding to the deformation of the third biasing means. A first actuating rod and a second actuating rod that moves relatively along the direction of movement of the first piston member; a second actuating rod adjacent to the second piston member on the side farther from the diaphragm in the switch mechanism storage chamber, Both the first and second piston members move against the biasing force of the first biasing means. By Rukoto the second
Is turned on or off by the piston member of No. 1 and is turned on by the first actuation rod that has moved corresponding to the deformation of the second urging means. A first switch means that is in a state; and a second switch means that is adjacent to the first switch means on the side farther from the diaphragm in the switch mechanism storage chamber and that moves in response to the deformation of the third biasing means. Second switch means that is pressed by the actuation rod to be turned on or off, and the first actuation rod is made of synthetic resin, and the second actuation rod is made of ceramics. A three-action pressure switch device characterized by being formed.