JPH0732843U - Pressure switch device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a small gas pressure detection pressure switch device that reliably operates even with slight changes in pressure, and that is reliable and reliable. A switch is composed of a support arm piece 17 fixed to a terminal 20 of a casing, and a reversing spring 16 fixed to the support arm piece 17 by caulking. The reversing spring 16 is a base piece that comes in contact with and separates from a fixed contact 18. 16a is provided with an M-shaped arm piece 16b. The support arm piece 17 includes the casing 10.
Curved along the inner surface. As a result, even with a small casing 10, the support arm piece 17 can be made long and the spring constant thereof can be made small, and the reversing spring 16 can be reversed / returned by a slight pressure change. The reversing spring 16, the support arm piece 17, and the plate piece 21 are caulked and fixed at one end 21a, and the protrusion 21b at the other end is slidably fitted on the reversing spring 16 and the support arm piece 17. As a result, the reversing spring 16 and the support arm piece 17 are regulated and operated at two points, and their actions become accurate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pressure switch device for detecting gas pressure, and more particularly to a small pressure switch device that can operate accurately with a slight pressure.

[0002]

[Prior art]

 Conventionally, a leaf type has been used as this type of pressure switch device. First, as shown in FIGS. 5 to 7, the switch contact is composed of a movable contact piece 1 and a fixed contact piece 2, and is normally The two contact pieces 1 and 2 are brought into contact with each other by the spring property of the spring 3 or the movable contact piece 1, and the plunger 4 moved by a pressure receiving element such as a diaphragm switches the contact pieces 1 and 2 into contact with each other to switch the contact. (See Japanese Utility Model Laid-Open No. 63-101435, Japanese Patent Laid-Open No. 63-160125, etc.).

Further, as shown in FIG. 8, a movable contact piece 1 is provided with an urging spring 5, and the urging spring 5 imparts a spring property to the movable contact piece 1 (actual opening 62- 163835).

Further, as shown in FIG. 9, the switch is fixed to a reversing spring 6 with which the plunger 4 contacts, a support arm piece 7 that supports the reversing spring 6, and a casing with which the reversing spring 6 contacts and separates. The reversing spring 6 has a pair of arm pieces 6b and 6b at both ends of a base piece 6a which comes into contact with and separates from the fixed contact 2, and the both arm pieces 6b and 6b are forwardly arranged, respectively. It is assumed that they are extended in parallel, and when they have been extended a required length, they are inverted inward and extended in parallel toward the base piece 6a, and the support arm piece 7 is fixed to a shaft 8 fixed to the casing (US See Japanese Patent No. 4032734).

In this switch device, when the arm piece 6b and the support arm piece 7 are pushed down by the plunger 4, the base piece 6a instantly moves to the opposite side of the arm piece 6b and the support arm piece 7, as shown by the chain line in the figure. It shifts, that is, instantly reverses and separates from the fixed contact 2. For this reason, the switch is so-called “break” and has excellent characteristics.

[0006]

[Problems to be solved by the device]

 In the switch device shown in FIG. 5 to FIG. 8, the change in the pressure contact force (contact pressure) between the movable contact piece 1 and the fixed contact piece (contact point) 2 based on the pressing or releasing of the plunger 4 is slow. There is a problem that the "cut" between both contact pieces 1 and 2 is bad. Further, since the contact pieces 1 and 2 have the same contact and separation positions, if a foreign substance is interposed between them, the contact surface will be roughened, and problems such as contact pressure and conductivity deterioration will occur.

Further, in order to obtain a sufficient contact pressure, the distance between the fulcrum of the movable contact piece 1 and the contact portion must be lengthened, and the movable contact piece 1 becomes long. This results in an increase in the size of the casing C and cannot meet the demand for downsizing. Further, since the one in FIG. 8 has a large number of parts, the machining and assembling work is complicated, and the machining and assembling accuracy has a great influence on the operating characteristics of the switch, and the actual characteristics are not obtained. .

Although the one shown in FIG. 9 has a good “cut” as described above, in order to make the “cut” smooth and reliable even with a slight pressure change, the support arm piece 7 should be long. However, the degree of flexure may be increased (the spring constant may be decreased) so that the arm pieces 6b and 6b can be displaced by a small load change and the base piece 6a can be inverted (snapped). However, since the length of the support arm piece 7 becomes longer, the casing that accommodates the support arm piece also becomes larger, and the demand for downsizing cannot be met.

By the way, since the support arm piece 7 overlaps along the arm pieces 6b and 6b, if the spring constant of the support arm piece 7 becomes smaller, the arm pieces 6b and 6b also easily bend. It is also conceivable to make the material of the support arm piece 7 easily bendable, but this does not stabilize the support of the reversing spring 6.

Further, in the structure shown in FIG. 9, the support arm piece 7 and the reversing spring 6 (arm piece 6b) are fixed by fixing the movable shaft 9 by riveting. In this case, it is necessary to take measures to prevent the reversing spring 6 from rotating with respect to the support arm piece 7. In addition, if multiple small rivets are used to caulk multiple points to prevent rotation, in addition to the small one, it is difficult to machine, and there is a problem in workability as well as in machining accuracy. . If the caulking is inaccurate or insufficient, the action of the reversing spring 6 becomes unstable, resulting in a lack of reliability.

In view of the above points, an object of the present invention is to improve switch characteristics such as “break” and to improve manufacturability and reliability in a snap type without increasing the size.

[0012]

[Means for Solving the Problems]

 In order to solve the above problems, in the above-mentioned snap type conventionally well-known switch device shown in FIG. 9, the support arm piece is fixed to the tip ends of both arm pieces of the reversing spring, and the tip ends thereof are fixed. After that, a structure is adopted in which the base portion is fixed to the casing after bending along the inner extending portion of the arm piece and then along the inner surface of the casing.

In this configuration or in the snap type switch device shown in FIG. 9, the plate piece along the inner extending portion of the arm piece overlaps the inner extending portion of the reversing spring and the supporting arm piece. Of the plate pieces, one end of the plate piece is fixed to the arm piece and the support arm piece together with the both, and a projection in the thickness direction is formed on the other end of the plate piece, and the projection is formed on the support arm piece and the arm piece. It can be configured to be slidably fitted into the inner extending portion of the piece.

It is also possible to provide a stopper on the inner surface of the casing, which faces the fixed contact with the base piece of the reversing spring in between and which abuts on the base piece to prevent the reversal from exceeding a required amount.

It should be noted that both outer extending portions and both inner extending portions of the arm piece may not be parallel to each other, but may be equidistant from the vertical bisector between the base piece and both arm pieces. . This is because if the equidistant distance is maintained, the degree of bending of both the outer and inner extended portions will be balanced (see Figs. 3 and 4).

[0016]

[Action]

 In the pressure switch device according to the present invention configured as described above, the reversing spring is reversed / returned by the pressure receiving element based on the change of the introduced gas pressure into the casing, and the base piece and the fixed contact are contacted / separated. The switching operation is performed.

At this time, since the support arm piece is bent, it can be made longer in a casing of the same size as compared with a straight one. Therefore, the spring constant of the supporting arm piece can be reduced without deteriorating the supporting force of the reversing spring, and the snapping action of the reversing spring can be achieved by a slight change in pressure. Also, a sufficient pressure contact force between the base piece of the reversing spring and the fixed contact can be obtained, and the contact / separation of the base piece slides on the fixed contact as the plunger is pressed or released until the base piece separates. Therefore, the contacts are self-cleaned by the wiping action.

In the case where the plate piece is provided, when the reversing spring acts, the support arm piece and the reversing spring operate while maintaining the required relationship by using the projection of the plate piece as a guide. That is, it is positioned and operated at two points, the fixed point and the sliding point.

The stopper restricts the reversing operation of the reversing spring more than necessary. For this reason, the reversing spring is less likely to be damaged, and it is possible to obtain an accurate action over a long period of time and also increase durability.

[0020]

【Example】

 This embodiment relates to gas pressure detection, and as shown in FIG. 1, the casing 10 comprises an outer member 10a, an inner member 10b and a bottom member 10c. Each of the members 10a, 10b, 10c is a molded product of a transparent synthetic resin, and the mutual connection is made by various well-known means such as screwing or adhesion. If it is transparent, the inside of the casing 10 can be viewed, which is convenient for practical use.

A metal diaphragm 11 of a pressure receiving element is stretched on the outer surface of the inner member 10b inside the outer member 10a, and the gas pressure from the gas pipe is applied to the diaphragm 11 through the gas introduction hole 12. A plunger 13 slidably passing through the inner member 10b is in contact with the diaphragm 11.

A pressure switch is formed in the inner member 10 b, and as shown in FIGS. 1 and 3, the switch is composed of a reversing spring 16, a support arm piece 17, a fixed contact 18, and a spring 19.

As shown in FIG. 3, the reversing spring 16 has a pair of arm pieces 16b and 16b at both ends of a base piece 16a that contacts and separates from the fixed contact 18, and the both arm pieces 16b and 16b are connected to the front side. Each of them is extended in parallel (outer extending portion 16c), and after extending a required length, it is turned inward and is extended in parallel toward the base piece 16a (inward extending portion 16d). is there.

The support arm piece 17 is made of a conductive spring material, and its tip overlaps with the tip of the arm piece 16b, reaches the inner surface of the casing (inner member 10b) along the inner extending portion 16d, and then bends. The base portion 17a is curved along the inner surface and reaches the base portion 17a. The base portion 17a is fitted into the terminal 20 and is supported by caulking. The terminal 20 is led out of the casing 10 together with the fixed contact 18.

A plate piece 21 is applied to an overlapping portion of the arm piece inside extension portion 16d of the reversing spring 16 and the support arm piece 17, and a projection 21a at one end of the plate piece 21 is provided at the arm piece inside extension portion 16d. Also, it is fitted and crimped at the tip of the support arm piece 17, and by this crimping, the three members 16d, 17, and 21 are integrally fixed. Further, the protrusion 21b at the other end of the plate piece 21 is slidably fitted to the arm piece inner extending portion 16d and the support arm piece 17 apart from the caulking portion, and the reversing spring 16 described later is caulked. When the inversion return operation is performed by using the female portion as a fulcrum, the protrusion 21b serves as a guide to bring the inwardly extending portion 16d of the arm piece into contact with and separate from the support arm piece 17. That is, the caulked portion and the guide portion are positioned and come into contact with and separated from each other. The reversing spring 16 is in a normal state in which the base piece 16a of FIG. 1 is located above the arm piece inner extending portion 16d.

The spring 19 is housed in the hole of the bottom member 10 c and is prevented from coming off by a screw 25. A seat 22 is applied to the upper end of the spring 19, and a support rod 22a of the seat 22 penetrates the bottom member 10c and then abuts on the plate piece 21 to be further thinned to an inner extending portion 16d and a support arm piece. 17 is fitted into the plunger 13 through the tip portion (see FIG. 3B). The operating pressure of the pressure switch is adjusted by the screwing amount of the screw 25.

The casing 10 is made of a material whose coefficient of linear expansion is similar to that of the diaphragm 11, so that the changes in the two 10, 11 due to environmental changes are approximated. It should be stable at all times. For example, a PBT (polybutylene terephthalate) resin or an ABS resin filled with 15 to 30% by weight of glass fiber is used. This results in a coefficient of linear expansion of approximately 2.3 × 10 ^-5 deg-cm.

This embodiment is configured as described above, and the reversing spring 16, the support arm piece 17, and the plunger 13 are urged upward in FIG. 1 by the spring 19, and a required gas pressure is applied. If it is in the normal state, that is, in the normal state, the diaphragm 11 bulges downward and the plunger 13 descends against the spring 19, so that the reversing spring 16 is not heavily loaded. Therefore, as shown in FIG. 2A, the inversion spring 16 is close to a normal state, the base piece 16a is in contact with the stopper 23, and the support arm piece 17 is in contact with the stopper 24.

From this normal state, when the gas pressure decreases due to gas leakage, the diaphragm 11 bulges upward as shown by the chain line in FIG. 1, and the spring 19 pushes up the middle of the plate piece 21 and If the outer extension portion 16c and the inner extension portion 16d of the reversing spring 6 shown by the chain line exceed the same level state, the base piece 16a is inverted as shown by the solid line in FIG. To do. The switching is led out as an electric signal through the terminal 20 and the contact point 18, and the electric signal closes the on-off valve of the gas pipe and gives a warning by blinking a lamp, ringing an alarm, or the like.

When the gas pressure becomes normal, the diaphragm 11 returns as shown by the solid line, and as the plunger 13 descends, the reversing spring 16 goes from the solid line state of FIG. 2 (b) to the chain line state of FIG. 2 (a). Invert like the solid line. The reversing operation is restricted by the stopper 23 on the inner surface of the casing (inner member 10b). The amount of protrusion of the stoppers 23 and 24 is appropriately set in consideration of the reversing operation and the switching operation of the reversing spring 16.

[0031] In this embodiment, when reversing 8.45mm spring 16 in the left and right length of the FIG. 1, other manufactured ones dimensional ratio of its figure was attached to the gas pipe of the existing, 20～70MmH ₂ Due to the change in the O gas pressure, the switching action of the reversing spring 16 was performed smoothly and reliably. It is considered that this is because the supporting arm piece 17 is bent so that the supporting arm piece 17 is sufficiently bent even with a slight pressure change.

In the embodiment, the inner and outer extending portions 16c, 16c and 16d, 16d of the arm piece 16b are parallel to each other, but they are, for example, as shown in FIGS. 4 (a) and 4 (b). In addition, even if it is opened to the outside or fitted to the inside, it is only necessary to keep an equal distance to the vertical bisector c between the arm pieces of the base piece 16a.

Further, even in the conventional example shown in FIG. 9, that is, in the case where the support arm piece 7 is not bent, the plate piece 21 is separately placed on the arm piece 6a and the support arm piece 7 to form the protrusions 21a and 21b. If it is caulked or fitted, it is the present invention.

[0034]

EFFECTS OF THE INVENTION The present invention is configured as described above, and the supporting arm piece is lengthened so that the spring constant can be reduced without destabilizing the support of the reversing spring. The smoothing and switching can be performed even by urging even with a slight pressure change.

Further, the plate piece and the projection thereof do not cause a change in the positional relationship between the support arm piece and the reversing spring, and the switching action is performed. Since the plate pieces are attached by caulking and fitting, the processing and work are easy, and automatic assembly is possible, and the cost can be low.

Furthermore, the stopper makes the switching action accurate over the long term.

[Brief description of drawings]

FIG. 1 is a cutaway front view of an embodiment.

2 (a) and 2 (b) are explanatory views of the operation of the embodiment.

FIG. 3A is a perspective view of a switch portion of the same embodiment,
(B) is a cutaway front view of the same main part

4 (a) and 4 (b) are partial perspective views of switch portions of other embodiments.

FIG. 5 is a schematic diagram of a conventional example.

FIG. 6 is a schematic diagram of a conventional example.

FIG. 7 is a cut front view of a conventional example.

FIG. 8 is a cut front view of a conventional example.

FIG. 9 is a perspective view of a switch portion of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Casing 11 Pressure receiving element (diaphragm) 12 Gas introduction hole 13 Plunger 16 Inversion spring 16a Base piece 16b Arm piece 16c Arm piece outside extension part 16d Arm piece inside extension part 17 Support arm piece 17a Support arm piece base part 18 Fixed contact 19 spring 20 terminal 21 plate piece 21a, 21b plate piece projection 22 seat 23, 24 stopper 25 screw

Claims (4)

[Scope of utility model registration request] 1. A pressure switch device in which a switch for opening and closing a contact by displacement of a pressure receiving element is provided in a casing, the switch being a reversing spring of a movable contact receiving the displacement of the pressure receiving element, and the reversing spring in a casing. A supporting arm piece for supporting and a contact fixed to the casing where the reversing spring contacts and separates, and the reversing spring has a pair of arm pieces at both ends of a base piece that contacts and separates the fixed contact, Extend both arms forward, keeping an equal distance to the vertical bisector between the base and both arms, turn them inward when the required length has been extended, and turn them toward the base. The supporting arm pieces are fixed to the tip ends of both arm pieces of the reversing spring at their tips, and extend along the inner extending portion of the arm pieces. Later the casing Bent along the surface, the pressure switch device characterized by its base, which are fixed to the casing. 2. A pressure switch device in which a switch for opening and closing a contact by a displacement of a pressure receiving element is provided in a casing, wherein the switch is a reversing spring of a movable contact which receives the displacement of the pressure receiving element, and the reversing spring in a casing. A supporting arm piece for supporting and a contact fixed to the casing where the reversing spring contacts and separates, and the reversing spring has a pair of arm pieces at both ends of a base piece that contacts and separates the fixed contact, Extend both arms forward, keeping an equal distance to the vertical bisectors between the base and both arms, and flip them inward when the required length has been extended, and then turn them toward the base. Each of them is extended at an equal distance to the equal line, and the plate piece along the inner extending portion of the arm piece is overlapped with the overlapping portion of the arm piece inner extending portion and the supporting arm piece of the reversing spring, One of the plate pieces The end is fixed to the arm piece and the support arm piece together with the fixing of the both, and a protrusion in the thickness direction is formed on the other end of the plate piece, and the protrusion is formed on the inner extending portion of the support arm piece and the arm piece. A pressure switch device, which is slidably fitted in the pressure switch device. 3. A plate piece along an inner extending portion of the arm piece is overlapped with an overlapping portion of the arm piece inner extending portion of the reversing spring and a supporting arm piece, and one end of the plate piece is attached to the arm piece and the arm piece. It is fixed to the support arm piece together with the above fixation of both,
2. The pressure switch device according to claim 1, wherein a protrusion in the thickness direction is formed at the other end of the plate piece, and the protrusion is slidably fitted in the support arm piece and the inner extending portion of the arm piece. . 4. A stopper is provided on the inner surface of the casing so as to face the fixed contact with the base piece of the reversing spring in between, and the base piece comes into contact with the fixed contact to prevent the reversal from exceeding a required amount. Item 5. A pressure switch device according to any one of items 1 to 3.