JP2526358Y2 - pressure switch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure switch used for detecting a pressure in a pipe for detecting an abnormality in a gas pipe.

[0002]

2. Description of the Related Art For example, there is a pressure sensor that detects, when a gas leaks from a gas pipe, by a change in pressure in the gas pipe. The pressure sensor is generally provided with a pressure switch that operates at a predetermined pressure and generates an electric signal.

[0003] As this kind of pressure switch, there is a pressure switch in which a movable contact plate having a movable contact is switched by using a toggle mechanism. Such a pressure switch is disclosed in Japanese Patent Publication No. 53-7595.

This pressure switch is specifically shown in FIG.
And has a leaf spring 2 and a movable contact plate 3 which are integrally formed. A toggle spring 5 is interposed between the leaf spring (movable lever) 2 and the movable contact plate 3 so that the common contact 3a of the movable contact plate 3 performs a snap action.

The integrally formed portion of the leaf spring 2 and the movable contact plate 3 is fixed to an upper case 6 with bolts 7. Also,
The upper case 6 has an NC (Normary Close) contact 8 and a NO (Normar) contact opposed to each other with the common contact 3a interposed therebetween.
y Open) contact 9 is provided.

The leaf spring 2 is disposed between the upper end wall of the upper case 6 and the center of the upper surface of the leaf spring 2 so that the common contact 3a contacts the NC contact 8 in a normal state.
A main spring 10 for urging the main body downward is provided.

Further, the upper case 6 and the upper case
Between lower case 11 attached to the lower part of case 6
The periphery of the diaphragm 12 that covers the inner wall of the lower case 11 is sandwiched. And, this lower case 11
A pressure introduction hole 14 is provided in the center of the lower wall. That is, when the pressure in the pipe is introduced from the pressure introducing hole 14, the diaphragm 12 is displaced upward.

A leaf spring pressing member 17 for transmitting the displacement of the diaphragm 12 to the leaf spring 2 and causing a snap action on the movable contact plate 3 is provided on the upper surface of the diaphragm 12 via a diaphragm plate 15. Is provided. The leaf spring pressing member 17 is provided so as to face the main spring 10 with the leaf spring 2 interposed therebetween.

Next, the operation and function of the pressure switch 1 will be described. As shown in FIG. 6A, when the pressure introduced from the pressure introduction hole 14 is equal to or lower than a predetermined pressure, the common contact 3a is in contact with the NC contact 8. When the pressure introduced from the pressure introduction hole 14 becomes equal to or higher than a predetermined pressure, the leaf spring pressing member 17 displaces the leaf spring 2 upward, as shown in FIG. 6B. As a result, the movable contact plate 3 performs a snap action, and the common contact 3a is switched to the NO contact 9.
As a result, the pressure switch 1 can detect an increase in the pressure in the gas pipe.

[0010]

As described above, the pressure switch 1 drives the central portion of the leaf spring 2 up and down, and snaps the common contact 3a provided at the tip of the movable contact plate 3. Switching by action. For this purpose, it is necessary to fix one end (connection portion) of the common contact plate 3 and the leaf spring 2 to the upper case 6 with bolts 7 or the like so as not to move.

Due to such a configuration, the conventional pressure switch 1 requires a lot of trouble and a large number of parts to assemble the pressure switch 1 by assembling the common contact plate 3 and the leaf spring 2 and the like. Was. The present invention has been made in view of such circumstances, and has as its object to provide a pressure switch with good assemblability and a small number of parts.

[0012]

SUMMARY OF THE INVENTION The present invention provides a case having a pressure introducing hole and an NC contact provided in the case.
And provided in the case so as to face the NC contact.
NO contact, provided between the NO contact and the NC contact
The common contact and the pressure introduction hole into the case.
Diaphragm that is elastically displaced by the introduced pressure
And snap action due to the displacement of this diaphragm
Cause the common contact to be separated from the NC contact
A toggle leaf spring for contacting the NO contact.
In addition, the toggle leaf spring includes a frame body portion and a frame body portion.
And a pair of protruding pieces provided at the inner edge portion facing each other,
The protruding piece is engaged with a support piece fixedly provided in the case.
It is characterized by being supported together .

[0013]

In this pressure switch, a toggle leaf spring for switching contacts by a snap action can be attached with one touch, and a diaphragm can be assembled to the toggle leaf spring in a stacked manner.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. In addition, the conventional example is quoted suitably. Reference numeral 20 in FIG. 1 denotes a case, which is an upper case 2.
0a and the lower case 20b.
On the bottom wall of the lower case 20b, as shown in FIG. 2, a first terminal 22, a second terminal 23 (a support piece of the present invention),
A third terminal 24 is attached. Three terminals 22 to
Reference numerals 24 are arranged substantially parallel to each other, and are respectively connected to first to third output terminals (not shown) provided on the lower surface (outer surface) of the lower case.

The distal end of the first terminal 22 and the distal end of the third terminal 24 extend to the portion of the lower case 20b indicated by A in the figure, and overlap vertically. The two distal ends are opposed to each other in the up-down direction, and the NC contacts 25, NO
It constitutes a contact 26 (shown in FIG. 1).

On the other hand, the second terminal 23 (supporting piece)
As shown in FIGS. 3A to 3D, the second terminal 23 is bent at an intermediate portion, and the second terminal 23 is formed with a projecting portion 27 that rises obliquely. The protrusion 27 is located substantially at the center of the lower case 20b. The width of the projection 23 is lower case 2
It extends from the base portion 28 fixed to 0b. In the present embodiment, the inclination angle α of the projection 27 is 45
Less than degrees.

A rectangular cutout 29 is formed at the center of the tip of the projection 27 in the width direction. Further, the projection 27 has a first engagement groove 30 and two second engagement grooves 31, 31.
Are formed. The first engagement groove 30 is formed on the outer surface 32 of the projection 27 and extends in the width direction of the projection 27 with the center of the notch 29 as the center. The second engagement grooves 31 are formed on the inner surface 33 of the projection 27 and extend from both edges of the projection 27 toward the center. Further, the cross-sectional shape of each of the engagement grooves 30, 31 is V-shaped.

Reference numeral 34 in FIG. 1 indicates a toggle leaf spring. As shown in FIGS. 4 (a) to 4 (c), the toggle leaf spring 34 is formed of a single plate having appropriate elasticity .
Frame-shaped peripheral member 35 as a part ,
It has first and second projecting pieces 36 and 37 as projecting pieces protruding from inner surfaces facing each other. One end 34a in the longitudinal direction of the peripheral member 35 serves as a common contact,
The other end 34b is formed in a convex shape and is bent upward.

The first and second protruding pieces 36 and 37 are separated through an M-shaped modified hole 38 and extend from both ends in the longitudinal direction of the peripheral member 35 toward the center. First protruding piece 3
The tip of 6 is formed in a convex shape, and the first engaging projection 39 is located at the center in the width direction.

The second projecting piece 37 is bent with respect to the peripheral member 35. Further, the distal end of the second protruding piece 37 is notched symmetrically, and second engaging projections 40, 40 are formed on both ends of the distal end.

The toggle leaf spring 34 is combined with the second terminal 23 from above and attached to the lower case 20b. That is, the protrusion 27 of the second terminal 23 protrudes from between the both protrusions 36, 37 of the toggle leaf spring 34.
Further, one end 34a of the toggle leaf spring 34 is connected to the NC contact 25.
And the NO contact 26.

The first projecting piece 36 has the engaging projecting portion 39 inserted into the cutout portion 29 of the second terminal 23 and engages with the second terminal 23 while elastically bending. Furthermore, the first
Both sides of the base end of the engaging projection 39 are locked in the first engaging groove 30 of the second terminal 23. Further, the second protruding pieces 37 are elastically deformed while the second protruding pieces 40, 4.
0 is locked in the second engagement grooves 31 of the second terminal 23. The toggle leaf spring 34 is connected to the second terminal 23.
Supported by

The degree of curvature of the first and second projections 36 and 37 is set so that the toggle leaf spring 34 can perform a desired snap action. Further, the protruding pieces 36 and 37 may be curved at the time of assembly, or may be appropriately curved in advance.

A holding hole 42 for holding a spring 41 is provided in the lower case 20b on the other end 34b side of the toggle leaf spring 34. As shown in FIG. , The spring 41 is inserted.

As shown in FIG. 1, the lower case 20b receives the urging force of the first push bolt 45 for adjusting the distance between the NC contact 25 and the NO contact 26 and the spring 41. A second push bolt 46 to be adjusted is screwed.

As shown in FIG. 2, a circular stopper plate 43 is put on the upper surface of the lower case 20b provided with the toggle leaf spring 34 and the spring 41. The stopper plate 43 has a first insertion hole 43a through which the upper portion of the spring 41 is inserted, and a second projection for projecting the projection of the other end 34b of the toggle leaf spring 34 from the upper surface of the stopper plate 43. And an insertion hole 43b.

The stopper plate 43 regulates a lowering amount of a diaphragm 47 to be described later, and a step formed on the lower surface of the other end portion 34b of the toggle leaf spring 34 (C in the figure).
), And also has a function of pressing down the toggle leaf spring 34 in the downward direction. As a result, the other end 34b of the toggle leaf spring 34 is pressed downward.
5 (a state shown by a solid line in FIG. 5).

Further, as shown in FIG. 2, on the upper surface of the stopper plate 43, there is provided a thin leaf spring 44 comprising a ring-shaped peripheral portion 44a and a circular movable portion 44b provided in the peripheral portion 44a. Can be stacked. The peripheral portion 44a and the movable portion 44b of the thin plate spring 44 are partially connected integrally, and the movable portion 44b is connected to the connection portion 44c.
Is configured to pivot elastically in the vertical direction with the fulcrum as a fulcrum.

Here, the area ratio between the peripheral portion 44a and the movable portion 44b is set to about 2: 1. The area of the movable portion 44b is determined according to the force required to cause the toggle leaf spring 34 to cause a snap action and the pressure introduced into the case 20.

The thin plate spring 44 is attached so that the connection portion 44c corresponds to the portion A. At this time, the lower surface of the portion of the movable portion 44b that is 180 degrees away from the connection portion 44c in the circumferential direction contacts the upper end of the spring 41 and the upper end surface of the other end 34b of the toggle leaf spring 34. It has become.

Further, a thin film diaphragm 47 for driving the movable portion 44b of the thin plate spring 44 is covered on the upper surface of the thin plate spring 44. When the stopper plate 43, the thin plate spring 44, and the diaphragm 47 are laminated, the upper case 20a (FIG. 1) is attached to the lower case 20b. As shown in FIG.
The upper case 20a connects the peripheral portions of the diaphragm 47, the thin plate spring 44, and the stopper plate 43 to the lower case.
The lower case 20b is pressed and pressed against the upper surface of the edge of the case 20b, and is fixed to the lower case 20b. A cylindrical stainless coupling is used to connect the upper case 20a and the lower case 20b.

At the center of the upper case 20a, a pressure introducing hole 49 for introducing the pressure in the gas pipe into the pressure switch 21 is provided. The pressure introduced from the pressure introduction hole 49 presses the diaphragm 47 downward.

When the pressure switch 21 is used, the pressure switch 21 is connected to a connection pipe (not shown) by using a screw portion 50 formed on the upper case 20a. Then, the pressure in the gas pipe is guided to the pressure introducing hole 49 via the connection pipe.

Next, the operation and function of the pressure switch 21 will be described. The pressure introduced into the pressure switch 21 from the pressure introduction hole 49 is equal to the pressure of the diaphragm 47.
Is pressed downward. This allows the thin plate spring 44
The movable portion 44b is pushed downward against the restoring force of the spring 41.

Thus, the other end 34b of the toggle leaf spring 34 is pressed downward as shown by an arrow (a) in FIG. 5 (a), and the one end 34a of the toggle leaf spring 34 is It is pressed against the NC contact 25.

When the pressure in the gas pipe rises above a predetermined pressure, the other end 34b of the toggle leaf spring 34 is further pushed down. At this time, the first protrusion 36 is gradually elastically deformed. When the lowering of the other end 34b reaches a certain level, the one end 34a performs a snap action. And
As shown by a two-dot chain line in FIG. 5, the one end 34a is switched from the NC contact 25 to the NO contact 26, and an increase in the pressure in the gas pipe is detected.

When the pressure in the gas pipe decreases,
The other end 34 b of the toggle leaf spring 34 is connected to the peripheral member 3.
It is raised by the restoring force of 5. At this time, the first protrusion 36
Restores elasticity. When the other end 34b rises to a certain extent, the one end 34a again causes a snap action, and switches to the NC contact 25.

The pressure switch 21 is adjusted by changing the amount of screwing of the first and second push bolts 45 and 46 and by increasing the restoring force of the spring 41 or the NC and NO contacts 25. , 26 is adjusted.

In such a pressure switch 21, the toggle leaf spring 34 is different from the prior art in that the second terminal 2
3 supported. The first protrusion 36 and the second protrusion 37 of the toggle leaf spring 34 are locked to the second terminal 23. Then, the other end 34b of the toggle leaf spring 34 is pressed, and the two protruding pieces 36 and 37 are bent, so that the one end 34a of the toggle leaf spring 34 performs a snap action.
Further, the toggle leaf spring 34 restricts the upward movement of the other end 34b so that the common contact of the one end 34a is N
The C contact 25 can be closed.

As a result, it is not necessary to fix one end to the case 6 with bolts 7 or the like as in the conventional example, and this toggle leaf spring 34 can be set in a one-touch manner in a plug-in manner. Work is facilitated and the number of parts is reduced.

According to such a configuration, the components such as the diaphragm can be assembled in a stacked manner, so that the assemblability is improved. Further, the first projection 39 formed on the first projection 36 of the toggle leaf spring 34 engages with the notch 29 of the second terminal, so that the notch 29 serves as a guide, and the toggle leaf spring 34 is provided. Can be positioned only by locking the second terminal 23 to the second terminal 23. Therefore, for example, assembling is easier than when a positioning hole having a predetermined size is used for positioning.

The pressure switch 21 of the present invention is not limited to the above-described embodiment, but can be variously modified without changing the gist of the present invention. For example, in the above embodiment, both the NC contact 25 and the NO contact 26 are provided as terminals, but either one of them may be a contact as a stopper.

In the above embodiment, the diaphragm 47
The above-mentioned toggle leaf spring 34
The other end 34b of the thin plate spring 44 is driven by using a diaphragm made of a thin metal plate.
May not be required.

In the above embodiment, the lower case 2
Although the spring 41 is provided at 0b, the spring 41 is not provided when the elastic restoring force of the toggle leaf spring 34 is sufficiently strong, or when the pressure in the gas pipe for operating the pressure switch 21 is small. Is also good. In this case, the restoring force of the toggle leaf spring 34 is sufficient.

[0045]

As described above, the pressure switch of the present invention engages with the support piece and is supported by the support piece, and also causes a snap action by being pressed by the diaphragm to switch the NC and NO contacts. Is a pressure switch having a toggle leaf spring for performing the following.

According to such a structure, the toggle leaf spring does not need to be fixed to the case, and can be attached to the case with one touch, so that the assembling property is good and the number of parts is small, and the diaphragm is not required. And the like can be assembled in a stacked manner, which has the effect of improving the assemblability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the assembly.

FIGS. 3A to 3D are views showing a second terminal from four directions.

FIGS. 4A to 4C are three views showing a configuration of a toggle leaf spring.

FIG. 5 is an explanatory view showing the operation of a toggle leaf spring.

6A and 6B are longitudinal sectional views showing a conventional example.

[Explanation of symbols]

20 case, 21 pressure switch, 23 second terminal (supporting piece), 25 NC contact, 26 NO contact, 34
Toggle leaf spring, 34a ... One end (common contact), 34b ...
The other end, 36: a first protruding piece (engaging piece), 37: a second protruding piece (engaging piece), 47: diaphragm, 49: pressure introducing hole.

Claims (1)

(57) [Scope of request for utility model registration] 1. A a case having a pressure introduction hole, the cable
NC contact provided in the
NO contact provided in the case, and this NO contact
A common contact provided between the contact and the NC contact;
Elastic by pressure introduced into the case from the introduction hole
And the displacement of the diaphragm
Causing a more snap action and connecting the common contact to the
And is separated from the NC contact will be and a toggle <br/> Le plate spring to abut on the NO contact, said toggle plate spring frame
Part and a pair provided at opposed inner edges of the frame part.
And these projections are fixed in the case.
A pressure switch, wherein the pressure switch is supported by being engaged with a regularly provided support piece .