JPS6223009Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is installed on the high pressure side of the refrigeration cycle in a car cooler, and stops the compressor, etc. of the refrigeration cycle when the pressure on the high pressure side of the refrigeration cycle drops or rises abnormally. 2.
Regarding actuated pressure switches.

If the pressure on the high pressure side of the refrigeration cycle rises abnormally, the refrigeration cycle will be in a dangerous state, so the compressor must be stopped. However, when the compressor is stopped, the pressure normally stops increasing and quickly decreases, and the pressure switch is reset and the compressor starts operating again. In this case, if there was no hysteresis between the pressures used to open and close the pressure switch, there was a drawback that the switch would open and close frequently. The present invention eliminates such conventional drawbacks and provides a hysteresis in the opening and closing pressure of the switch at the high-pressure side operating point to prevent the switch from repeatedly opening and closing.

The first embodiment of the present invention will be explained with reference to the drawings.
A diaphragm 5 is housed inside an upper body 1 having a pressure introduction hole 2 at the center, and a lower body 6 having a recess 7 at the center is housed to sandwich the periphery of the diaphragm 5 to form a pressure chamber 3 inside the upper body. is provided, and this lower body 6
The caulked portion 4 provided around the lower part of the upper body 1 is bent and fixed substantially at the upper part of the upper body. An annular external piston 11 having a large diameter opening 10 in the center between the large diameter portion 8 provided above the recess of the lower body and the diaphragm 5.
is housed so that it can be moved up and down. Reference numeral 13 denotes an internal piston made of conductive metal whose upper portion is inserted into the opening 10 of the external piston, and a locking collar 14 provided approximately on the outer periphery of the upper portion is latched onto the lower surface of the external piston. Reference numeral 9 denotes a small hole provided in the center of the bottom of the recess of the lower body, through which a small diameter portion 16 provided at the lower part of the internal piston 13 via a locking step 15 is inserted, and a locking ring is attached to the lower end of the hole that protrudes outside the lower body. Install 17. A spring 20, which forms part of the wiring, is activated between a ring-shaped terminal plate 19 accommodated in the bottom surface of the recess 7 of the lower body and a locking collar 14 provided on the internal piston 13. Terminal board 19
has the configuration shown in FIG. 6, in which a first terminal piece 21 at the lower end protrudes outside a lower housing 25 (to be described later), a lower housing 25 having a cavity 24 inside is attached to the lower part of the lower body 6, and the inner piston The lower end of the small diameter portion 16 of
The first fixed contact 18 of the electrical contact 26 is formed.

Reference numeral 27 denotes a leaf spring whose rear part is curved, and has an inner actuating piece 28 on the inside and an outer actuating piece 29 on the outside, and a first movable contact 28a for low pressure is attached to the upper surface of the tip of the inner actuating piece 28. Further, a second movable contact 29a for high pressure is attached to the lower surface of the tip of the outer operating piece 29.
Engagement recess 2 provided at the tip of the inner operating piece 28 of the leaf spring
8b and an engagement recess 29 provided at the inner end of the outer actuating piece 29
A substantially U-shaped arcuate spring 30 is engaged between the inner and outer actuating pieces 28 and 29 to perform a snap action.

The rear lower surface of the leaf spring 28 is fixed to the bottom surface of the lower housing 25, and the first movable contact 28a is positioned so as to be able to come into contact with and separate from the first fixed contact 18 at the lower end of the internal piston, and the tip of the inner actuating piece 28 rises. A first stopper 32 for regulating the straining is made to protrude from the lower surface of the lower body 6. A second fixed contact 35 that comes into contact with and separates from a second movable contact 29a provided on the lower surface of the outer operating piece 29 of the leaf spring.
The second terminal piece 36 provided on the upper surface is made to protrude to the outside of the lower housing 25. A second stopper 33 is provided on the lower surface of the lower body 6 and is positioned on the same straight line passing through the second fixed contact 35 and the second movable contact 29a to prevent the outer operating piece 29 from rising too much. In the second stopper 33, the inner operating piece 28 of the leaf spring that performs the snap action is reversed, and the second movable contact 29a is
This is to keep the outer actuating piece 29a at a predetermined position when it is OFF.

Thus, the pressure within the pressure chamber 3 acting on the external piston 11 is applied to the locking collar 14 of the internal piston 13,
The force pushing the spring 20 downward is the sum of the pressure acting on the inner piston 13, and the sum of the pressures is determined by the outer diameter of the outer piston 11.

Assuming that the first set pressure is _P1 , the load of the spring 20 is _F1 , and the effective pressure-receiving area determined by the outer diameter of the external piston 11 is A, there is the following relationship between them.

P ₁ =F ₁ /AKg/cm ² G (F ₁ ...Kg) (A ... cm ² ) When the pressure P in the pressure chamber 3 is smaller than P ₁ , the internal piston 13 is pushed up by the spring 20, When the first fixed contact 18 at the lower end of the internal piston moves upward and the inner actuating piece 28 of the leaf spring 27 contacts the first stopper 32, it cannot rise any further, and only the first fixed contact 18 is held by the locking ring 17. and continues to rise until it is locked with the outer end of the small hole in the lower body,
The first movable contact 28a is separated from the first fixed contact 18, and the first electric contact 20 is turned off (FIG. 1).

When the pressure P in the pressure chamber 3 becomes greater than _P1 , the spring 20 is compressed and the internal piston 13 descends, the first fixed contact 18 contacts the first movable contact 28a, and the lower surface of the external piston 11 Once it is locked to the bottom of the large diameter chamber 8 of the lower body, it cannot be lowered any further, and the force that compresses the spring 20 thereafter acts only on the upper part of the internal piston 13. When the inner actuating piece 28 descends to the position where the inner piston 13 moves downward and the leaf spring 27 that performs the snap action is reversed, the outer actuating piece 29 is reversed upward by the leaf spring 30 and is locked to the second stopper 33. However, the second movable contact 29a separates from the second fixed contact 33, and the second electric contact 31 is turned off. When the pressure inside the pressure chamber 3 increases further, the locking step 15 of the internal piston 13 locks on the bottom surface of the lower body 6,
The inner operating piece 28 cannot be moved downward any further, and the first fixed contact 18 and the first movable contact 26a come into contact to turn the first electric contact 26 ON (FIG. 3).

When the pressure inside the pressure chamber 3 decreases, the inner piston 13 is raised by the spring 20, and the inner actuating piece 2 moves up to the position where the outer actuating piece 29 of the leaf spring returns downward.
8 is moved upward, the outer operating piece 28 is reversed downward, and the second movable contact 29a contacts the second fixed contact 35 to turn on the second electric contact 31. In this case, since the first electrical contact 26 is also ON, the electrical circuit of the switch is in a energized state (FIG. 2).

The snap action leaf spring is reversed and the second
The inner actuating piece 28 is located at the position where the electrical contact 31 turns OFF.
The load of the spring 20 until it reaches is _F2 , the time at which it returns is _F3 , and the effective pressure-receiving area of the internal piston determined by the outer diameter of the head of the internal piston is B, then the second electric contact 31 is The second set pressure P ₂ that turns off is P ₂ =F ₂ /B.

The difference (i.e., hysteresis) ΔP between the pressure at which the second electrical contact 31 is turned on and the pressure at which it is turned off is ΔP=(F ₂ −F ₃ )/B.

The hysteresis ΔP is F ₃ if the position of the second stopper 33 is changed because the position of the inner actuating piece 28 where the leaf spring 27 snaps back changes depending on the position of the second stopper 33. Since ΔP can be changed, ΔP can also be made adjustable. That is, the second embodiment shown in FIG. 13 shows this, in which an adjustment screw 38 that is adjustable from the outside has the function of determining the inverted position of the leaf spring.

The third embodiment will be described with reference to FIGS. 8 to 12. A substantially U-shaped notch is provided in a leaf spring 40 whose rear portion is curved to form an inner actuating piece 41 and an outer actuating piece 42. L-shaped claw pieces 43 having the function of pulling up the outer actuating piece 42 are formed on substantially both sides of the tip, and a movable contact 44 is provided on the lower surface of the tip of the outer actuating piece 42, and the tip of the inner actuating piece 41 An arcuate spring 45 having the same shape as the arcuate spring shown in FIG. 5 is engaged between the inner end of the outer operating piece 42 and the inner end of the outer actuating piece 42 to perform a snap action. That is, due to the pressure received by the diaphragm, the internal piston and the external piston, which move up and down, are pushed up by the spring 48, which is elastically activated between the bottom surface of the recess 47 of the lower body 46, and the small diameter part 49 provided at the lower part of the internal piston is pushed up. It projects into the lower working chamber 51 from an opening 50 provided in the lower body. Reference numerals 52 and 53 denote terminal pieces that protrude outside the lower housing 54, and the rear part of the leaf spring 40 is attached to the upper part of one of the terminal pieces 52, and is in contact with the movable contact 44 provided on the lower surface of the outer operating piece 42 of the leaf spring. The fixed contact 55 to be released is attached to the top of the other terminal piece 53. Note that the configurations of the inner and outer pistons are the same as those in the first embodiment, and will therefore be omitted.

On both sides of the lower tip of the inner actuating piece 41, there is an outer actuating piece 4.
Since claw pieces 43, 43 for pulling up 2 are provided,
When the pressure in the pressure chamber is lower than the first set pressure, in the first embodiment, the first fixed contact 18 of the internal piston and the first movable contact 28a of the internal actuating piece 28 are separated and the first
The electric contact 26 is opened, but in the second embodiment, the electric contact between the inner piston and the inner actuating piece is eliminated, and the outer actuating piece 42 is forcibly pulled up by the claw piece 43 to open the movable contact 44 to the fixed contact 55. Pull away from the OFF
(Figure 10).

When the pressure is between the first set pressure and the second set pressure, the internal piston is depressed and the electrical contact 56 is closed, and the movable contact 44 and the fixed contact 55 are ON.
(Fig. 11). Further, when the pressure is equal to or higher than the second set pressure, the inner piston is pushed down to the lower part, and as a result, the tip of the outer actuating piece 42 is reversed and pushed up by the arcuate spring 45, and the fixed contact 55 and the movable contact 44 The electrical contact 56 is separated from the
It turns OFF. Furthermore, when the pressure decreases and the internal piston is pushed up by the elastic force of the spring 48,
The inner actuating piece 41 rises due to its elasticity, and then the claw pieces 43, 43 provided below both sides of the tip of the inner actuating piece engage the outer actuating piece 42 and pull it up, thereby separating the movable contact 44 from the fixed contact 55. (10th
figure).

In this example, there is only one electrical contact, so
Its configuration can be further simplified.

As described above, in the present invention, the inner and outer pistons can create two types of pressure with only one spring, that is, the pressures acting on both the outer piston and the inner piston and the head of the inner piston without affecting each other. Furthermore, one or more electrical contacts consisting of an inner actuating piece and an outer actuating piece of the leaf spring that performs the snap action are interposed in the electric circuit, and at least one electric contact is connected to the snap action that the leaf spring has. By providing a hysteresis in the opening and closing operations of the switch, the switch does not repeat opening and closing operations in a short period of time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
Figures 2 and 3 are sectional views showing each operating state, Figure 4 is a perspective view of the leaf spring, Figure 5 is a perspective view of the leaf spring, Figure 6 is a perspective view of the terminal piece, and Figure 7 is the perspective view of the leaf spring. 2
8 to 12 show a partially cutaway front view of the embodiment, FIG. 8 is a sectional view of the main part, FIG. 9 is a perspective view of the leaf spring, 11,1
2 is a side view showing the operating state of the internal piston and the leaf spring, and FIG. 13 is an explanatory view showing the open/closed state of the electrical contacts. DESCRIPTION OF SYMBOLS 1... Upper body, 5... Diaphragm, 6... Lower body, 11... External piston, 13... Internal piston, 20... Spring, 27... Leaf spring, 2
8... Inner operating piece, 29... Outer operating piece, 30... Arc-shaped spring.

Claims (1)

[Scope of utility model registration request] The periphery of the diaphragm is sandwiched between an upper body and a lower body that have pressure introduction holes, and an external piston and an internal piston that move up and down separately are placed below the diaphragm in the main body, which has a pressure chamber inside the upper body. It consists of an internal piston that is concentrically assembled and springs from below with a spring, and a leaf spring that has a snap action function by engaging an arcuate spring between the inner actuating piece and the outer actuating piece. The inner actuating piece engages the lower end of the inner piston, and an electric contact is provided between the movable contact and the fixed contact provided on the outer actuating piece and has an electric contact that has a response difference in opening/closing pressure on the high pressure side. Pressure switch.