JPH07211207A - Pressure switch - Google Patents

Abstract

PURPOSE:To provide a pressure switch which is easy to handle and to assemble and is provided with a surge absorbing element. CONSTITUTION:An electric switch 3 which can be opened or shut freely and a switch driving mechanism 5 which changes the position by receiving pressure of a fluid and opens or shuts the electric switch 3 are put in housings 1, 2. Regarding the pressure switch, a surge absorbing element 15 to absorb the surge generated at the time of the opening of the electric switch 3 is built in the housings 1, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure switch that receives the pressure of a fluid and operates an electric switch according to the increase or decrease of the pressure.

Such a pressure switch is mounted, for example, on the high pressure side of a refrigeration cycle of a vehicle air conditioner,
It is used to turn off the electrical contacts connected to the compressor when the high-pressure side pressure of the refrigeration cycle circuit rises or falls abnormally.

[0003]

2. Description of the Related Art In such a pressure switch, a surge occurs due to a back electromotive force when the electric switch is opened,
Sparks burn the switch contacts.

Therefore, in order to absorb the surge, a surge absorbing element such as a resistor, a capacitor or a varistor is used.
It is desirable to connect in parallel to the electrical switch. Therefore, conventionally, the terminal of the surge absorbing element provided outside the pressure switch is connected to the terminal to which the electric switch is attached by soldering.

[0005]

However, outside the housing of the pressure switch, which is treated as one unit,
It is very inconvenient to place only the surge absorbing element, and since soldering is required only for connecting the surge absorbing element, it takes time to assemble for that and the manufacturing cost is high. It becomes a thing.

Therefore, an object of the present invention is to provide a pressure switch with a surge absorbing element which is easy to handle and easy to assemble.

[0007]

To achieve the above object, the pressure switch of the present invention comprises an electric switch which can be opened and closed, and a switch drive mechanism which is displaced by receiving the pressure of fluid to open and close the electric switch. In a pressure switch in which the electric switch is arranged in the housing, a surge absorbing element for absorbing a surge generated when the electric switch is opened is incorporated in the housing.

The two terminals of the surge absorbing element may be fixed to the terminals of the electric switch in the housing by spot welding. In that case, the housing is the first housing accommodating the electric switch. , The second housing that houses the switch drive mechanism is connected to form the spot welding at the two locations.
In both cases, the spot electrode may be pressed against the terminal of the surge absorbing element in the first housing from the side of the connecting opening of the first housing with respect to the second housing.

[0009]

The surge generated when the electric switch is opened is absorbed by the surge absorbing element built in the housing.

[0010]

Embodiments will be described with reference to the drawings. FIG. 1 shows a pressure switch. This pressure switch includes a first housing 1 in which electrical components such as first and second electric switches 3 and 4 are incorporated, and an electric switch 3 that receives fluid pressure.
It is covered by a second housing 2 in which a reversing plate mechanism 5 (switch drive mechanism) for driving the motor 4 is incorporated.
Both housings 1 and 2 are molded with a plastic material and are connected to each other at an intermediate portion.

Reference numeral 6 denotes a pressure receiving chamber case having a fluid pressure introducing port 6a formed therein, which is fixed to the second housing 2 by caulking the end portion. Reference numeral 7 denotes an outer edge portion of the diaphragm 51 which is brought into close contact with the upper end surface of the second housing 2 and the pressure receiving chamber case 6.
It is an O-ring for sealing the gap between.

Inside the first housing 1, first and second electric switches 3 and 4 are mounted. Both the electric switches 3 and 4 have movable contacts 3c and 4c attached to the fixed contacts 3a and 4a and the leaf springs 3b and 4b.
In the natural state, the first electric switch 3 is set to be closed, and the second electric switch 4 is set to be opened.

The fixed contacts 3a, 4a and the leaf springs 3b, 4b are respectively connected to the connection terminals 11, 12, 13,
It is fixed to the base end of 14. Each connection terminal 11-14
Are insert-molded integrally with the first housing 1 independently of each other.

On the lower end side of the first housing 1, a connector 10 for connecting to a connector of an external circuit such as another device is integrally formed, in which each connection terminal 1 is formed.
The tips of 1 to 14 project.

The reversing plate mechanism 5 incorporated in the second housing 2 has a diaphragm 51 which is displaced by the pressure in the fluid pressure inlet 6a, and an umbrella-shaped first member which reverses when a pressing force is applied to the peripheral portion. The first, second and third inversion disks 52,
53, 54 are provided, and the respective inverted disks 52, 53,
First and second support wheels 55 and 56 are arranged between 54.

Then, the rod 57 which abuts the lower surface of the first reversing disk 52 pushes the leaf spring 4b of the second electric switch 4 and is stepped by the lower surfaces of the second and third reversing disks 53, 54. The cylindrical sliding cylinder 58 is the first
The electric switch 3 is arranged so as to press the leaf spring 3b.

Further, as shown in FIG. 1, a hole into which the sliding cylinder 58 is slidably fitted is formed in the center of the bottom portion of the second housing 2, and the periphery thereof forms a bottom surface 2a without loss. is doing.

Therefore, from there, the third inverted disk 54
The projection 2b that is provided so as to come into contact with the lower surface of the
It is formed into a perfect ring without any breaks in the middle,
The reversing disk 54 of (4) operates accurately without distortion.

The projection 55a projecting from the lower surface of the first support wheel 55 so as to come into contact with the upper surface of the second reversing disk 53 is also formed in a complete annular shape without interruption. The second inverted disk 53 also operates accurately without distortion.

A surge absorbing element 15 is provided in the first housing 1 in the vicinity of a connecting portion with the second housing 2.
It is connected in parallel with the electric switch 3 of FIG.
Although a resistor is used as the surge absorbing element 15 here, a capacitor, a varistor, or the like may be used depending on the circuit used.

The surge absorbing element 15 is attached in a step immediately before connecting the first and second housings 1 and 2.
2 and 3 show the state of the first housing 1 side immediately before being connected to the second housing 2 during assembly, and the first and second electric switches 3, 4 and all of them are shown. The connection terminals 11 to 14 are assembled in the first housing 1.

The head 13a of the terminal 13 to which the movable contact 3b of the first electric switch 3 is attached and the head 11a of the terminal 11 to which the fixed contact 3b is attached are both the second
Is exposed near the surface in the opening of the first housing 1 connected to the housing 2.

The heads 13a and 11a of the two terminals 13 and 11 are connected to the two terminals 1 of the surge absorbing element 15.
6, 17 are fixed by spot welding from the opening side of the first housing 1 and are electrically connected.
The back side of the portion A shown in FIG. 3 is the spot welded portion.

Therefore, the two terminals 16 and 17 of the surge absorbing element 15 are both spotted on the terminals 16 and 17 from the side of the connecting opening of the first housing 1 to the second housing 2 (from above in FIG. 2). By pressing the electrodes, the terminals 13, 11 of the first electric switch 3
Can be spot welded easily.

After the surge absorbing element 15 is attached in this manner, the lower end of the second housing 2 in which the reversing plate mechanism 5 is assembled and the upper end (opening) of the first housing 1 are fitted together. 1 to the state shown in FIG. 1 and then the fitting portion is heat-welded by, for example, ultrasonic welding to
And the second housings 1 and 2 are mechanically connected and coupled.

4 to 6 schematically show the operation of the above embodiment. When the pressure in the fluid pressure inlet 6a is low and the reversing plate mechanism 5 does not operate (the first and second electric switches 3 and 4 are both open), when the pressure becomes higher than a certain level, the diaphragm 51 Is pushed down a little, the second
As shown in FIG. 4, by the support wheels 56 of the third
The reversing disc 54 is reversed so that the first electrical switch 3 is closed.

When the pressure further rises above a certain level, as shown in FIG. 5, the first reversing disk 52 is reversed and the second reversing disk 52 is reversed.
The electric switch 4 of is also closed. Then, when the pressure further rises above a certain level, as shown in FIG. 6, the second reversing disk 53 is also reversed and the first electric switch 3 is opened. At this time, since the surge absorbing element 15 is connected, no surge occurs.

When the pressure drops, each reversing disk 52,
Each of 53 and 54 re-inverts at a lower pressure value than that at the time of inversion and returns to the original state. In the above embodiment, the surge absorbing element 15 is connected to the first electric switch 3 side, but the second electric switch 4 side or both switches 3 are connected depending on the application.
4, and the present invention can be applied to, for example, a two-action type pressure switch or the like.

[0029]

According to the pressure switch of the present invention, since the surge absorbing element is built in the housing, it is very easy to handle, and the surge absorbing element is attached by spot welding. Moreover, since the spot electrode is pressed against the two terminals of the surge absorbing element from the same direction, the assembling work is very easy and the manufacturing cost is reduced. Have the effect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a pressure switch according to an embodiment.

FIG. 2 is a vertical cross-sectional view of a first housing-side half portion of the pressure switch according to the embodiment.

FIG. 3 is a plan view of a first housing-side half portion of the pressure switch according to the embodiment.

FIG. 4 is a schematic view showing the operation of the embodiment.

FIG. 5 is a schematic view showing the operation of the embodiment.

FIG. 6 is a schematic view showing the operation of the embodiment.

[Explanation of symbols]

 1 1st housing 2 2nd housing 3 1st electric switch 5 Inversion board mechanism (switch drive mechanism) 15 Surge absorption element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kuniharu Baba Inventor, Kuniharu 1211-12, Kabata-cho, Hachioji-shi, Tokyo

Claims (3)

[Claims] 1. A pressure switch in which an electric switch which can be opened and closed and a switch drive mechanism which is displaced by receiving fluid pressure to drive the electric switch to open and close are arranged in a housing, which occurs when the electric switch is opened. A pressure switch characterized in that a surge absorbing element for absorbing a surge is built in the housing. 2. The pressure switch according to claim 1, wherein the two terminals of the surge absorbing element are fixed to the terminals of the electric switch in the housing by spot welding. 3. The housing is formed by connecting a first housing accommodating the electric switch and a second housing accommodating the switch drive mechanism,
3. The spot welding at the two locations is performed by pressing a spot electrode against the terminal of the surge absorbing element in the first housing from the side of the connecting opening of the first housing with respect to the second housing. Pressure switch shown.