JPH0117784Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is installed in the high-pressure side refrigerant passage of an automobile cooling system, and when the pressure on the high-pressure side of the refrigeration cycle drops abnormally, one electric switch is closed to shut down the compressor. This invention relates to a two-operation type pressure switch consisting of a switch for stopping the switch and a switch that can arbitrarily determine the pressure for switching the electrical contact to open or close under normal pressure conditions on the high pressure side.

Conventionally, this type of switch has had the following background.

If the refrigerant in the refrigeration cycle leaks and a refrigerant shortage occurs, the compressor may be destroyed.In order to stop the compressor and prevent it from being destroyed if the pressure drops, a low pressure switch that is activated by low pressure is installed. It was necessary.

When the high pressure side pressure is normal, the condensing capacity of the condenser may be controlled in order to keep the high pressure side pressure within the normal range depending on the size of the refrigeration load, etc. To do this, when the high-pressure side pressure exceeds a predetermined pressure, the electrical contacts are closed to increase the condensing capacity.
When the pressure drops to a different pressure lower than the above pressure, a mechanism is required to open the contacts and reduce the condensing capacity, and thus a pressure switch is required that has an operating difference in the pressure at which the contacts open and close.

The above switches are all installed in the refrigerant passage on the high pressure side of the refrigeration cycle, and the present invention aims to have the above two functions at the same time. In a pressure switch that has a pressure receiving chamber communicating with a pressure introduction port on the upper surface of a diaphragm whose peripheral edge is sandwiched between the diaphragm and the diaphragm, a small-diameter second housing is provided below the first housing chamber provided at the upper part of the lower body via a locking step. a spring storage chamber is provided at the bottom of the second storage chamber;
A reversible disk with a snap function is housed in the first housing chamber so as to be movable up and down and has a hole in the center. A holder provided so as to intersect the first space and the second space is placed, the upper surface of the holder is brought into contact with the lower surface of the piston, the lower end is made to protrude outside the lower body, and the holder is connected to one of the paired first terminals. The first fixed contact provided and the other first
A first electrical switching section, which is attached to a terminal and includes a first movable contact provided at the tip of a first leaf spring having a hole in the center, is housed in the first space, and the first leaf spring is connected to the lower surface of the piston. A second fixed contact provided on one of the pair of second terminals with the lower end protruding outside the lower body, and a second fixed contact provided on the tip of the second leaf spring attached to the other second terminal. A second electrical switching section comprising a movable contact is accommodated in the second space,
It is characterized in that the second leaf spring and the reversing disc are engaged with each other by a rod inserted through a hole in the piston and the first leaf spring.

An embodiment of the present invention will be described with reference to the drawings. The peripheral part of the diaphragm 4 and the packing 5 are airtightly sandwiched between an upper body 2 having a pressure introduction port 1 and a lower body 3 made of an insulating material. and a lower body, and a pressure receiving chamber 6 communicating with the pressure introduction port 1 is formed in the upper body 2 above the diaphragm.

A small-diameter second storage chamber 9 is formed in the lower body 3 via a locking step 8 formed continuously at the lower part of the large-diameter first storage chamber 7 provided in the upper part. A pair of second terminals 25, 26 and a pair of first terminals 34, 35 are installed around the bottom of the chamber by penetrating through them at 90 degree intervals with their lower ends projecting to the outside.

A spring concave chamber 10 having a slightly small diameter is formed in the center of the bottom surface of the second storage chamber 9, and a small hole 11 communicating with the outside is provided at the bottom of the concave portion. Reference numeral 13 denotes a piston housed in the first housing chamber 7 so as to be able to move up and down, and includes a recessed part 15 formed in an upright part 14 provided on the periphery of the upper surface.
A vertical hole 16 is formed in the center of the piston 1.
An annular protrusion 17 is formed around the hole 16 on the lower surface of the hole 3 .

Reference numeral 18 denotes an inverting disc housed in the upright part 14. Normally, the central part bulges upward, and when a force greater than the second set pressure P2 is applied upward, it instantly inverts downward, and the pressure changes to the third setting pressure P2. When the pressure becomes lower than the set pressure P3, the pressure returns upward.

Reference numeral 20 denotes a holder housed in the second storage chamber 9 so as to be able to move up and down.
The space portions 22 are formed to cross each other, and the upper end of the holder 20 is always locked to the lower surface of the piston 13.
A spring 23 is provided between the lower surface of the holder 20 and the bottom surface of the recessed chamber 10 to urge the holder upward.

Reference numerals 25 and 26 designate a pair of first terminals, the lower ends of which protrude outside the lower body 3, and the upper parts bent inward to form bent pieces, one of which has a first fixed contact 27.
to fix. Reference numeral 28 denotes a first leaf spring whose base part is fixed to another first terminal 26 and bent from the middle.A first movable contact 29 that comes into contact with and separates from the first fixed contact 27 is attached to the lower surface of the tip, and the first fixed contact 28 The contact 27 and the first movable contact 29 form a first electrical switching section 30 .

A hole 32 is formed in the center of the first leaf spring 28, through which the rod 31 inserted into the hole 16 of the piston is inserted, and the first leaf spring 28 is always elastically upwardly pushed to the convex portion 17 of the piston 13. The first electrical switching section 30 is opened by contacting the lower surface of the electrical switch. The first terminals 25 and 26 each having a bent piece forming the first electrical opening/closing part 30 and the first leaf spring 28 are accommodated in the first space 21 of the holder 20.

34 and 35 are shifted by 90 degrees so as to intersect with the first terminals 25 and 26, and their lower ends protrude outside the lower body 3, and their upper parts are formed higher than the first terminals and are bent inward, respectively. The second terminal has a second fixed contact 36 attached to the bent piece of one of the second terminals 34, and a second movable contact 37 attached to the tip to make contact with and separate from the second fixed contact 36. Leaf spring 3
8 is bent and fixed to the other second terminal 35. One second terminal 34 has the second fixed contact 36, and the other second terminal has the second movable contact 37.
A second plate spring 38 is provided on the upper surface of the holder 20.
It is housed in the space 22, and the second fixed contact 36 and the second movable contact 37 form a second electrical switching section 40.

The second leaf spring 38 has an upward elastic force, and the second leaf spring 38 has an upward elastic force.
The bent pieces provided on the tops of the terminals 34 and 35 are attached to the holder 20 which is urged upward by a spring 23.
It has the function of hanging. Also piston 13
The upper end of the rod 31, which is passed through the through hole 16 and the hole 32 of the first leaf spring 28, is engaged with the lower surface of the reversing disk 18, and the lower end is engaged with the upper surface of the second leaf spring 38.

Next, to explain the operation of this embodiment, the pressure P (Kg/cm ² ) entering the pressure receiving chamber 6 from the pressure introduction port 1
is the force multiplied by the effective pressure receiving area S (cm ² ) formed by the piston 13, the lower body 3, and the diaphragm 4.
F1 (Kg) is transmitted downward via diaphragm 4.

On the other hand, the force F2 (Kg) of the spring 23 pushes the piston 13 upward via the holder 20 which is movable up and down within the lower body 3. As a result, when P×S=F1<F2, the piston moves upward, and when P×S=F1>F2, the piston moves downward, and the value of P that makes F1=F2 is the first set pressure P1. Become. In Figure 2, the pressure P entering the pressure receiving chamber 6 is the first.
This shows a state in which the pressure is lower than the set pressure P1, and since both the piston 13 and the holder 20 are stationary, the first electric opening/closing part 30 is open, and as shown in FIG. 3, the second electric opening/closing part 40 is also open. In this case, the second leaf spring 3
8 has a stronger elastic force than the rod 31's own weight.

Next, if the pressure P entering the pressure receiving chamber 6 is higher than the first set pressure P1 and lower than the second set pressure P2, the pressure P causes the spring 23 to stop until the piston 13 is locked in the locking step 8. It is compressed to push down the holder 20 and piston 13. In this state, the lower surface of the piston 13 or the protrusion 17
The leaf spring 28 is pressed down, the first movable contact 29 and the first fixed contact 27 are connected, and the first electrical switching section 30 is connected.
is closed (Figure 4). In this case, the inverted disk 18
The second plate spring 38 has not yet reversed downward, and the lower end of the rod 31 is locked by the lowered piston 13.
is slightly lowered, but the second electrical switching section 40 is open (FIG. 5).

Next, when the pressure P entering the pressure receiving chamber 6 becomes higher than the second set pressure P2, the reversing disk 18 is reversed downward and pushes the rod 31 downward. The second leaf spring 38 to which the lower end of the rod 31 is engaged is pushed down, and the second movable contact 37 and the second fixed contact 36 are connected to close the second electrical switching section 40 (seventh
figure). In this case, the first electrical switching section 30 remains closed (FIG. 6).

Then, the pressure P in the pressure receiving chamber 6 becomes the third set pressure P.
When it becomes smaller than 3, the reversing disk 18 returns upward, and the second electric switch section 40 opens. In this case, when the pressure inside the pressure receiving chamber 6 is higher than the first set pressure P1, the first electrical switching section 30 remains closed, but when the pressure inside the pressure receiving chamber 6 becomes lower than the first set pressure P1, the first electrical switching section 30 is something that becomes open.

The present invention has the following effects.

A spring for repelling the piston from below via a holder is housed in a spring housing chamber,
Since the first and second electrical opening/closing parts are accommodated and fixed within the space provided on the upper surface of the holder, pressure fluctuation and durability can be improved.

By utilizing the hysteresis that exists between the reversal and return of the reversal disk, chattering of the switch can be prevented and the durability of the contact can be increased.

Since the first and second electrical switching sections are independent, the pressure of each electrical switching section can be easily adjusted after the terminal is attached to the lower body.

Since the second and third set pressures utilize the reversing operation of the reversing disk, they have the advantage that the switch can be changed instantaneously.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is an exploded perspective view of the entire structure with the upper body omitted;
Figures 3, 4, 5, 6, and 7 are cross-sectional views showing each operating state, and Figure 8 is an explanatory view showing the relationship between the first and second electric switching sections and each set pressure. 1...Pressure introduction port, 2...Upper body, 3...Lower body, 4...Diaphragm, 13...Piston, 1
8... Inversion disk, 20... Holder, 21... First space, 22... Second space, 23... Spring, 25, 26, 34, 35... Terminal, 30...
...first electrical switching section, 40... second electrical switching section.

Claims (1)

[Scope of utility model registration request] In a pressure switch that has a pressure receiving chamber communicating with a pressure introduction port on the upper surface of a diaphragm whose periphery is sandwiched between an upper body and a lower body, a locking stage is provided below a first storage chamber provided at the upper part of the lower body. A second housing chamber with a small diameter is provided through the spring housing chamber, and a spring housing chamber is formed on the bottom of the second housing chamber, and a spring housing is housed in the first housing chamber so as to be movable up and down, and a snap is attached to the top surface of the piston having a hole in the center. A functional reversing disk is housed in a manner that protrudes upward, and a holder having a first space and a second space intersecting each other on the top surface is placed on top of the spring housed in the spring housing chamber. A first fixed contact provided on one of a pair of first terminals with its upper surface abutting the lower surface of the piston and its lower end protruding outside the lower body, and a first fixed contact attached to the other first terminal and having a hole in the center. A first electrical switching section consisting of a first movable contact provided at the tip of a leaf spring is accommodated in the first space so that the first leaf spring is always in contact with the lower surface of the piston, and the lower end thereof also protrudes outside the lower body. a second fixed contact provided on one of the second terminals of the pair;
A second electrical switching section consisting of a second movable contact provided at the tip of a second leaf spring attached to the other second terminal is housed in the second space, and inserted through the holes of the piston and the first leaf spring. A two-action pressure switch that locks a second leaf spring and a reversing disk with a rod.