JPS606057B2 - pressure switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure switch that detects fluid pressure and performs an opening/closing operation.

As automobile air conditioning systems have advanced, there are now more opportunities for air conditioner compressors to be driven even outside of the summer season.

Therefore, the risk of damaging the combrezzar by continuing to use it without sufficient lining has increased. For this reason, in a car cooler compressor, if there is a shortage of cold soot and the pressure on the suction side of the compressor decreases, it is necessary to stop the operation of the compressor. In this case, a pressure switch is required that detects the refrigerant pressure in the medium flow path and deenergizes the electromagnetic clutch at a predetermined pressure to stop the compressor. In a cold soot closed circuit for a car cooler in which a capacitor 1, a evaporator tank 2, an expansion valve 3, an evaporator 4, and a compressor 5 are sequentially connected as shown in FIG. A pressure switch 6 is provided to detect the pressure of cold soot in the conduit and open/close the switch to open/close the electromagnetic clutch of the compressor 5. In a closed refrigerant circuit for a car cooler, a certain pressure, e.g.
．． When the suction side pressure exceeds 5k9/average, compressor 5
In order to protect and effectively utilize the compressor, it is important to start driving the compressor, and then stop driving the compressor when the suction side pressure drops below a certain pressure, for example, 0.4 m/m. preferable.

That is, when it is detected that the suction side pressure has exceeded a certain pressure, for example 2.5 kg/, the contact is closed and the clutch of the combustor 5 is turned on to lower the suction side pressure to a certain low pressure, for example 0.
A hysteresis switch is required that opens and closes at different pressures so that it detects that the pressure has fallen below 4k9/min and opens the contact to switch the compressor clutch. An object of the present invention is to provide a pressure switch that can meet such demands.

A pressure switch according to the present invention that achieves this object will be explained with reference to an embodiment shown in the drawings. In Fig. 1, the casing 7
A sliding member 8 is slidably housed in.

A gap between the sliding member 8 and the casing 7 is sealed by a packing 9. The operating member 1 is located inside the sliding member 8.
0 is slidably mounted.

A gasket 11 seals between the inner surface of the sliding member 8 and the outer surface of the actuating member 10 . At one end of the sliding member 8, there is a lid body 16 having an opening part 13 communicating with the working chamber 12 of the casing 7, and a valve seat 15 on which a valve body 14 for opening and closing the gate part 13 is seated. It is screwed or integrally formed in a sealed state.

On the opposite side of the bog member 8, a spring seat village 18 is integrally molded or removably fixed to the sliding member.

The casing 7 is formed into a cylindrical shape with one end closed and the casing 7 open, and a mounting part 19 is formed at the closed end to be attached to the conduit of the cold soot closed circuit by screwing or the like. A detection channel 20 that fits into the working chamber 12 of
is formed.

A supporting portion 22 for the protrusion 21 of the valve body 14 is formed at the closed end of the casing 7 . Instead of being formed integrally with the valve body 14, the protruding rod 21 may be formed integrally with the valve body portion 22 and formed separately from the valve body 14. At the open end of the casing 7, a copying holder 23 is provided which is fixed to the casing 7 by screwing, caulking, or other fixing method. Spring presser 2
3 and the sliding member 8, and a second spring 25 is installed between the spring seat member 18 of the swamp member 8 and the operating member 10.

The first spring 24 is a spring whose number is smaller than that of the second spring 25. A valve spring 26 is installed between the actuating member 10 and the valve body 14. Cap 27 on casing 7
is installed.

Two terminals 28 and 29 are fixed to the cap 27,
The other end of the movable plate 31 having the contact point 30 at one end is the cap 2.
It is supported by 7. The flexible plate 31 is electrically connected to one terminal 28 and the conductive plate 32. The cap is preferably made of an insulating material. The reversible plate 31 is held by a turnover spring 33 in either a closed position where the contact 30 is seated on the contact 29a of the other terminal 29 or an open position where the contact 30 is separated from the contact 29a.

In the movable plate 31', one end of the actuating rod 34 is fixed in an insulated state.

The actuating rod 34 passes through the spring retainer 23 and the spring seat village 18 and is attached to the actuating member. It is also possible to mold the actuating rod 34 and the actuating member 10 in one piece.

The actuating rod 34 is connected to the turnover spring 3 in the open position of the contact 30.
3 is pressed against the actuating member 10. As the actuating member 10 moves, the actuating rod 34 pushes the flexible plate 31 against the force of the turnover spring 33, so that the flexible plate 31 moves to the closed position and is held in the closed position by the turnover spring 33. Instead of the structure in which the contact point 30 is provided on the flexible plate with one end as a fulcrum, a terminal plate that is reciprocated by the actuating lever 34 is used, and both ends of the terminal plate are in contact with both terminals 28 and 29, thereby forming an electric circuit. It is also possible to have a structure in which the terminal board is closed and the electrical circuit is opened by moving both ends of the terminal board away from both terminals 28 and 29.

The operation will be explained below.

As shown in FIG. 1, the contact 30 is in the open position when the floating member 8, that is, the lid 16 is in contact with the closed end of the casing and the valve body 14 is separated from the valve seat 15.

That is, the pressure switch is in an open state. The fluid pressure in the detection flow path 20 increases, and the fluid flowing into the working chamber 12 through the end face of the lid body 16 and the groove 16a formed in the end face of the lid body 16, and acting on the sliding member 8, such as a butterfly, flows into the working chamber 12. When the pressure reaches a predetermined value, that is, the value shown at point a in FIG.
is compressed, and the lid 16 and the sliding member 8 start sliding.
In this case, since the tension of the second spring 25 is still greater than the fluid pressure, the actuating member 10 is pressed against and in contact with the abutting surface 35 of the lid 16, and the actuating member 10 also moves together. This indicates that the actuating rod 34 in contact with the actuating member 101 moves. - After the valve seat 15 of the lid body 16 has moved slightly, it comes into contact with the valve body 14, and the fluid that has flowed into the valve chamber 36 formed inside the lid body 16 is sealed. When the sliding member 8 comes into contact with the supporting surface 37 of the spring presser 23, the point b in FIG. 4 is reached.

In this state, the force of the second spring 25 is greater than the fluid pressure, so the actuating rod 34 and the actuating member 10 are at rest even though the fluid pressure increases. When the fluid pressure reaches a predetermined pressure, or before that, the valve body 14 is pushed up against the valve spring 26, the closing portion 13 is opened, and the fluid acts on the actuating member 10, and at point C in FIG. The actuating member 10 compresses the second spring 25 and moves with the predetermined pressure shown.

At this time, the operating rod 34 is moved. When the actuating rod 34 reaches a predetermined position, the contact 30 instantly moves to the closed position where it is seated on the contact 29a of the terminal 29. For example, the fluid pressure at this time is 2.
If you set it so that it is 4k9/equal, as shown in Figure 5, the contact point 3 will be at a constant pressure, for example, 2.4k9/pressure.
Switch from FF to ON. At this time, the actuating member 10 comes into contact with the stepped portion 38 of the sliding member 8 at the pressure indicated by point d in FIG. 4, and stops in the state shown in FIG. 3. This state is maintained even if the pressure increases. When the pressure decreases, the valve body 14 first contacts the valve seat 15 and closes the closing portion 13, and when the pressure decreases to the point shown in FIG. 4, the sliding member 8 is moved by the force of the first spring 24, and accordingly. Actuation member 10 and actuation rod 34 begin to move.

When it moves slightly, the valve body 14 opens the opening 13 by the action of the thrust rod 21. The pressure in the valve chamber 36 thus decreases and the actuating member 10 begins to move under the action of the spring 25. Sekiguchi section 1
3 opens, the lid body 16 comes into contact with the end face of the casing 7 and stops, and then, when the operating lever reaches a predetermined position, the contact 3 instantly changes from the closed position to the open position due to the action of the turnover spring 33. Move to. The pressure at this time is set, for example, to the above-mentioned 0.4k9/ground. Point e in FIG. 4 corresponds to this pressure. The action of the turnover spring 33 and the second
Under the action of spring 38, actuating shaft 34 and actuating member 10 are instantly returned to the initial position shown in FIG. That is, the pressure switch is set to a predetermined pressure, for example 0.4k9, as shown in FIG.
/ can be used to switch from ON to OFH. The present invention has a simple structure including two springs and a sliding member having different spring constants, two sliding members of the operating member, and a valve for opening and closing the valve chamber between the two sliding members. It is now possible to set the operating pressure for switching from OFF to ON and the operating pressure for cutting from ON to OFF to be different pressures.

The present invention provides a hysteresis switch and makes it possible to effectively protect the combustor.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of the refrigerant circuit of a car cooler, Fig. 2 is a cross-sectional view of the pressure switch according to the present invention in the open state, Fig. 3 is a cross-sectional view of the pressure switch in the closed state, and Fig. 4 is a diagram showing the fluid pressure. FIG. 5 is a diagram showing the relationship between change and movement of the actuating member, and FIG. 5 is a diagram showing the relationship between opening and closing of the switch and pressure. 7... Casing, 8... Sliding member, 10... Working part village, 12... Working chamber, 13... Sekiguchi part, 14...
... Valve body, 15... Valve seat, 20... Detection channel, 21
...Pushing rod, 24...First spring, 25...Second spring, 26
...Valve spring, 28, 29...Terminal, 30...Contact, 31...Movable plate (member), 34...Operation lever. Figure 1 Figure 12 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. Two terminals, a member that moves the contact between a closed position that conducts both terminals and an open position that cuts off the connection between both terminals, an actuation rod that has one end attached to the member, and a connection to the actuation rod. an actuating member, a sliding member that slidably houses the actuating member, and a casing that slidably houses the sliding member;
A first spring installed between the casing and the sliding member acts on the sliding member in the same direction as the first spring acts on the sliding member installed between the sliding member and the operating member. Between the second spring, the valve chamber formed between the sliding member and the surface of the operating member opposite to the second spring action surface, and the operating chamber formed between the sliding member and the casing. a valve body that opens and closes the opening of the valve body; a valve spring installed between the valve body and the operating member; and a valve spring installed between the valve body and the operating member; The spring constant of the first spring is set to be smaller than the spring constant of the second spring, the working chamber of the casing is communicated with the pressure measuring part by a detection flow path, and the contact point is set by the working member. A pressure switch characterized in that the operating pressure of a pressure-reducing fluid that switches a contact from closed to open is set lower than the operating pressure of a pressure-increasing fluid that switches a contact from open to closed.