JPH0329861Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a three-action pressure switch installed in a refrigerant passage on the high pressure side of an automobile cooling system.

``Prior art'' A switch that opens an electrical contact to stop a compressor when the pressure on the high pressure side of a refrigerant passage in a refrigeration cycle drops or rises abnormally, and a switch that stops the compressor when the pressure on the high pressure side is under normal conditions. For example, there is a pressure switch having a switch that can arbitrarily determine the pressure for switching the electrical contact between open and close.
There is a number. That is, in this type of switch, as shown in FIG. 8, the electric switch 2 for high voltage and low voltage is connected to the lower body 3.
The structure is such that the reversing disc 4 for high pressure is then installed, and then the electric switch 1 for medium voltage is installed, but in both cases, the reversing disc rotates in the same direction, resulting in a long operating stroke. There were flaws.

Furthermore, there is a conventional reversible disc in which a hole is drilled in the center and the rod passes through it, but if a hole is drilled in the center of the reversible disc, a problem arises in the strength of this reversible disc, making it difficult to use as a component. The drawback was that it lacked durability.

``Problems to be solved by the invention'' Conventionally, the stroke of the rod was configured to operate only downward, which resulted in a long operating stroke and an increase in the size of the housing. The purpose is to set the operating directions in different directions to increase the durability of the reversing disk, and to shorten the operating stroke to ensure reliable operation.

"Means for Solving the Problems" The configuration of the present invention is that a diaphragm is airtightly fixed between an upper body and a lower body having a pressure inlet to form a pressure receiving chamber in the upper body, and a pressure receiving chamber is formed in the lower body. In a pressure switch having first and second electric opening/closing parts, a first reversing disk which is reversed downward by pressure is attached to the upper surface, and the first electric opening/closing part is installed in an insertion hole provided at the center of the piston. A first rod to be operated is accommodated in a vertically movable manner, and a second piston having a second inverting disk mounted on the upper part which is inverted upward by pressure is housed in a lower body in a vertically movable manner, and the second inverting disk The peripheral edge of the rod is hooked to a holding piece provided at the bottom of the first piston, and a second rod for operating the second electric opening/closing portion can be moved up and down into the insertion hole provided at the center of the second piston. A third piston, which is urged upward by an externally adjustable spring, is locked below the second piston, and the second electric opening/closing part is inserted into the notch provided in the third piston. It is characterized by being accommodated.

``Operation'' The operating directions of the reversing discs are set to be opposite to each other, simplifying the configuration of the electrical switching section, and making the parts smaller and lighter, making the whole system more compact.

"Embodiment" An embodiment of the present invention will be described with reference to the drawings. A lower body 13 is fitted below an upper body 12 having a pressure introduction port 11 at the upper part, and a flexible diaphragm 14 is provided between the two. The peripheral edge of the diaphragm 14 is tightly fixed together with a seal packing 15, and a pressure receiving chamber 16 communicating with the pressure introduction port 11 is provided above the diaphragm 14. The inner wall of the lower body 13 is provided with a locking step portion 17 and a locking portion 18 sequentially from above, and furthermore, a somewhat large diameter cavity 19 is provided in the lower body, and a screw hole 20 is provided in the center of the bottom surface of the lower body. is provided.

21 is a first chamber housed in the vacant room 19 so as to be movable up and down.
The piston is a piston that descends downward until it is locked with the locking stepped portion 17, and a dish-shaped recess 23 is formed inside an annular convex portion 22 provided concentrically on the upper surface approximately at the periphery. A stepped insertion hole 24 is provided in the center of the first piston to accommodate a first rod 26 (to be described later) so as to be able to move up and down. 1 rod 26
is housed in a vertically movable manner to prevent the first rod from falling downward. Further, below the first piston 21, a plurality of leg pieces 27 are provided, and at the lower end of the leg pieces 27 there is a second reversing disk 29, which will be described later.
An engaging piece 28 is formed to engage the peripheral edge of the
Further, in the annular convex portion 22, there is a first inverted upwardly.
An inversion disk 30 is housed therein. 31 and 32 are first terminals whose lower ends protrude outside the lower body 13;
The upper end portions are bent toward the center of the lower body, and one of the bent pieces is provided with the first fixed contact 33, and the other bent piece is provided with the fixed contact 33 at the tip.
The base of a leaf spring 35 having a first movable contact 34 in contact with is fixed, and the lower end of the first rod 26 is brought into contact with the intermediate portion of this leaf spring.

Reference numeral 37 denotes a second disk-shaped piston that is housed vertically movably between the bending piece provided at the upper part of the first and second terminals and the hook part 18 in the lower body. A protrusion 38 is provided, and a second rod 41 having an engaging collar 40 on the outer periphery is housed in a stepped insertion hole 39 provided at the center of the second piston to prevent it from falling out of the insertion hole. ing. Reference numeral 29 denotes a second reversing disk having a downwardly concave shape, and is placed on the upper surface of the second piston.

45 is a notch 44 formed in a diameter shape at the center of the upper surface.
A third piston having upper parts on both sides abuts the lower surface of the second piston 37, and a spring 46 is elastically disposed between the lower surface of the third piston and a spring holder 43 housed in the inner bottom of the lower body. The strength of the spring 46 can be adjusted from outside the lower body by means of an adjustment screw 48 screwed into a screw hole 47 at the bottom of the lower body. Incidentally, once the third piston 45 is engaged with the bent pieces of the third and fourth terminals, it cannot rise any further.

50 and 51 are the first and second terminals 31 and 3
The third and fourth terminals are shifted by 90 degrees from the second terminal, and their lower ends protrude outside, and their upper ends are bent at different levels, and the second fixed contact 52 is attached to the upper end of one of the third terminals 50. The base end of a leaf spring 54, which has a second movable contact 53 at its tip that comes into contact with and separates from the second fixed contact 52, is attached to the upper end of the fourth terminal.

Next, to explain the operation of this embodiment, when external pressure enters the pressure receiving chamber 16 from the pressure introduction port 11 in the normal state shown in FIG. acts downwardly on the first piston 21 through the second reversing disk 29
is transmitted to the second piston 37 via. The lower surface of the second piston 37 is engaged with a third piston 45, and the third piston 45 is pushed up by a spring 46.

Next, when the pressure within the pressure receiving chamber 16 reaches _P1 , the first and second pistons 21, 37 descend until the second piston 37 is latched to the latching portion 18, and
The second rod 41 is restricted from moving upward by a second reversing disk 42, and the second rod 41 pushes down the leaf spring 54, which is composed of a second fixed contact 52 and a second movable contact 53. Turn on the second electric switch B. In this case, the first and second
The reversing disks 30 and 29 are not yet reversing, and the first electrical switching section A is OFF.

Next, when the pressure inside the pressure receiving chamber 16 reaches _P2 , the first reversing disk 30 reverses downward and instantly pushes the first rod 26 downward, as shown in FIG. leaf spring 3 at the bottom end of
5 to turn on the first electric switch A.
In this case, the second electrical switching section B remains ON.

Furthermore, when the pressure inside the pressure receiving chamber 16 increases and reaches P ₄ , the second reversing disk 29 has its peripheral edge attached to the engaging piece 28 provided at the lower part of the first piston 21, as shown in FIG. The lower surface of the substantially peripheral edge of the second reversing disk is connected to the annular protrusion 3 of the second piston.
8, the second reversing disk 29 is instantaneously reversed upward, and as a result, the downward pressing force of the second rod 41 is released, and the leaf spring 54 is lifted upward by its own elastic force and turns off the second electric switch B. In this case, the first inversion disk 30
remains inverted downward, so the first electrical switching section A remains ON. In addition, the first electrical switching section A
is set to turn off when the pressure drops to _P3 , which is smaller than pressure _P2 and larger than _P1 , and
The second electric switching section B is configured to turn ON when the pressure _P5 is smaller than the pressure _P4 and larger than the pressure _P2 .

In this way, pressure control is performed by combining two reversing disks and leaf springs that operate in different reversing directions according to pressure changes.

"Effects of the invention" The invention as described above has the following effects.

The first and second rods that turn on the first and second electrical switching parts are short and do not fall out of their respective insertion holes, so they are easy to assemble.
Moreover, the operating stroke of the rod can be made smaller, the overall component structure can be simplified, and the rod can be made smaller and lighter.

By reversing the operating directions of the reversing discs, the operating timing is made clear, and
Each has excellent responsiveness.

Even after the entire assembly is assembled, the operating timing of the second electrical switching section can be easily adjusted by operating the adjustment screw.

Since the first and second reversing discs operate instantaneously, chattering can be prevented, thereby increasing the durability of the contacts of the opening/closing part.

Since the reversing discs are combined so that they act in opposite directions, and there is no need to drill holes in the reversing discs, it is relatively easy to set the pressure on the reversing discs, and the parts are highly durable. It has advantages.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an exploded perspective view of the whole, Fig. 2 is a side sectional view, and Fig.
Figures 4, 5, and 6 are longitudinal sectional views shifted by 90 degrees to show each operating state, Figure 7 is an explanatory diagram showing the operating states of the first and second electrical switching parts, and Figure 8 is a conventional longitudinal sectional view. It is. 11...Pressure inlet, 12...Upper body, 13...
... lower body, 14 ... diaphragm, 21 ... first
Piston, 26...first rod, 30...first reversing disk, 37...second piston, 44...third piston, A...first electric switching section, B...second electrical switching section.

Claims (1)

[Scope of utility model registration request] In a pressure switch, a diaphragm is airtightly fixed between an upper body and a lower body having a pressure introduction port to form a pressure receiving chamber in the upper body, and first and second electrical switching parts are provided in the lower body, A first reversing disk that is reversed downward by pressure is installed on the top surface, and a first rod for operating the first electric opening/closing part is movably housed in the insertion hole provided in the center of the piston, and the first rod is movable upward by pressure. A second piston with a second reversing disk mounted on the upper part thereof is housed in the lower body so as to be movable up and down, and the peripheral edge of the second reversing disk is attached to a holding piece provided at the lower part of the first piston. A second rod for operating the second electric opening/closing part is housed in an insertion hole provided at the center of the second piston so as to be movable up and down, and a rod below the second piston is provided with a rod that can be adjusted from the outside. A three-acting pressure switch comprising a third piston that is springed upwardly by a spring, and the second electrical opening/closing part is accommodated in a notch provided in the third piston.