JP2000231855A - Switch for detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switch for detection capable of detecting the loosening of a screw or a nut. SOLUTION: This switch is equipped with a screw 1 for fixing a surface panel 3 to an installation casing 4 and a hexagon nut 11 threadedly engaging with the screw 1. A movable contact piece 6 and a fixed contact piece 9, having contact parts to be closed by fastening the screw 1, are disposed opposite to each other so that they can open when the threaded engagement is loosened. and a terminal part 10 led out from the fixed contact piece 9 detects whether the screw 1 is in a fastened or loosened state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch for detecting looseness of a screw or the like which is attached to a device requiring security and confidentiality.

[0002]

2. Description of the Related Art Conventionally, a detection switch such as a micro switch or a push button switch is attached to a door or a main body in order to secure work safety in repairing equipment, and a power supply is detected by detecting opening of the equipment door and the like. Use a device that shuts off the device, attaches the device to prevent the device from being opened during operation to ensure the safety of the device, and uses a key switch to prevent theft or prohibit opening the device to ensure confidentiality. In some cases.

[0003]

However, in any case, the mounting position of the switch is clear, and if there is little knowledge about the equipment, it is extremely easy to make such a conventional detection switch in the non-detection state. Even if the key switch is provided with a high level of security, it can be easily operated once the device is disassembled. In recent years, there have been reports of bolts being removed from power transmission equipment and accidents in which vehicle bolts that should never be loosened are loosened due to vibration. Conventional detection switches require such high reliability. There is no detection means suitable for the intended use, and the present invention has been invented to solve the above problems.

[0004]

The present invention comprises a screw member for fastening and fixing an equipment housing with a head provided on a screw, and a nut member screwed to the screw member. The back surface of the equipment housing and the nut member are provided. At least a pair of contacts, which are closed by being clamped and clamped therebetween, are arranged in the vicinity of the screw member so as to face each other so as to be opened with a loosely threaded relationship, and a wiring member is derived from the contact. . In addition, a plunger having a movable contact on a bottom surface inside the switch body, at least a pair of fixed contacts that are opened and closed by a pressing operation of the movable contact is disposed below the movable contact, and an insulating member is provided above the movable contact. And a female screw portion is formed in the upper part of the switch body in the operation axis direction, and a screw member is screwed to the female screw portion above the plunger. Further, the screw member is constituted by a special screw. Further, at least one of the opposed contacts is formed by a contact member whose contact resistance value changes according to the contact pressure.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The detection switch of the present invention can protect a repair worker from a high-voltage portion or a high-temperature portion when used as a tightening screw for fixing a housing of an apparatus. In addition, it is possible to detect the loosening of the screw which should not be loosened, and to prevent an accident from occurring by connecting a monitoring device or a recording medium. Further, the present invention can be applied as a switch for preventing forgetting to tighten the housing screw and for setting a device which is rarely used.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present embodiment will be described below in detail with reference to the drawings. FIG. 1 shows a first example of a detection switch according to the present invention.
FIG. 2 is a front sectional view showing the embodiment, FIG. 2 is a bottom view thereof, and FIG. 3 is an exploded perspective view thereof. FIG. 4 is an external view of the housing 5 as viewed from below, and FIG. 5 is a view showing a pair of fixed contact pieces 9 which are insert-molded in the housing 5.
FIG. 6 shows the movable contact piece 6 and the hexagon nut 11.
FIG.

In these figures, a pair of fixed contact pieces 9 made of a conductive member are opposed to a hexagonal column-shaped housing 5 made of an insulating member by insert molding. Are formed so as to constitute the contact portions facing each other. A groove 12 for incorporating the movable contact piece 6 is formed in the hexagon nut 11, and the movable contact piece 6 in which a pair of beam portions 8 formed by folding back is suspended left and right is shown in FIG.
In the groove portion 12 in the state shown in FIG.

FIG. 1 shows a use state in which a front panel is fixed to an equipment housing by screws 1. In a state where the screw 1 is tightened, the hexagon nut 11 abuts on the upper surface of the housing 5, so that the protrusion 7 formed at the upper end of the beam portion 8 of the movable contact piece 6 is strongly pushed down by the housing 5. Thereby, the beam portion 8 is pushed and bent outward and comes into contact with the fixed contact piece 9, and acts so as to maintain an electrically conductive state between the terminal portions 10 of the fixed contact piece 9 disposed opposite to each other.

FIG. 7 shows a state in which the screw 1 is loosened from FIG. 1. Even if the abutting relationship between the projection 7 and the housing 5 is slightly loose, the contact between the fixed contact piece 9 and the movable contact piece 6 is immediately opened. Therefore, the looseness of the screw 1 can be easily detected by the interruption between the terminal portions 10. FIG. 8 shows a configuration example in which a standard hexagon nut 31 having no groove on the opposite side is used, and various applications are possible for the butting shape of the beam portion 28 and its method.

FIG. 9 is a partial cross-sectional view showing the usage of the first embodiment of the detection switch of the present invention. In the detection switch of the present invention thus constructed, the screws are slightly loosened. Since it is possible to detect the loose state, it is possible to obtain extremely high security that the loosening of the screw is detected before the screw is lost and a serious state is caused.

Further, since it is completely unknown from the front panel side that the loosening of the screw is detected, it can be used as a place where confidentiality is required or as an alarm switch for theft prevention.

FIG. 10 is a front sectional view showing a second embodiment of the detection switch of the present invention, and FIG. 11 is an exploded perspective view thereof. In this embodiment, a contact piece 46 integrally formed with a terminal portion 50 is provided in a donut-shaped housing 45 formed of an insulating member, and a spring is provided at the center of the housing 45 so as to be concentric with the contact piece 46. With the washer 42 included, the hexagonal nut 51 and the equipment housing 44 are opposed to each other so as to be vertically sandwiched therebetween.

When the screw 41 is loosened, the spring switch pushes and spreads the contact piece 46, which has come into contact with the contact piece 46, in such a direction as to separate the contact piece 46, thereby releasing electrical conduction. Switches can be configured.

FIG. 12 is a front sectional view showing a third embodiment of the detection switch according to the present invention. A bolt 61 is used as a screw, and FIG. 13 is a partially enlarged view showing a state where the bolt 61 is loosened. In this embodiment, the housing 6
A female thread 71 is screwed into the thread 5, and a plunger 73 formed of an elastic member is disposed vertically below the thread. As a movable contact piece, a curved disk-shaped movable contact piece 66, a fixed contact 69 and a common contact 67 corresponding to a lower part of the movable contact piece 66 are provided on a base 68 formed of an insulating member, and are fixed. A terminal portion 70 formed integrally with the contact 69 and the common contact 67 is led down from the base 68. In addition, the movable contact piece 66 is sealed in the base 68 by the waterproof film 72 to maintain waterproofness.

The base 68 is firmly swaged to the lower end of the housing 65 to withstand the tightening of the hexagon bolt. However, since the plunger 73 is an elastic member, it absorbs dimensional errors in the stroke direction. 68
The structure is such that strong breaking strength is not added between them.
In this embodiment, the wiring method of the terminal section 70 is performed by the connector 74, but the connecting method of the electric wire is not limited.

FIG. 14 shows a use method in which the detection switch of the present invention is not fixed to the equipment housing but is independent as the detection switch. Although the method of use is not particularly limited, in this embodiment, the movable contact piece 86 is pushed down by turning of the driver, and as a hidden switch or setting switch, the frequency of use is extremely low, but the contact reliability and the security are high. Can be used in places where sex is required.

In order to further enhance security, it is possible to use a special screw 101 as a screw as shown in FIG. 15 so that the screw can be operated only by a special tool.

FIG. 16 is an external view showing another embodiment of the detection switch of the present invention. In this embodiment, the opposite contact 1
Ring-shaped switch body 112 with 11 normally open up and down
Is pinched by a screw or a nut to close the normally open contact and detect loosening of the screw.

In the above-described embodiment, the contact portion is formed of a hard metal member for detecting the presence or absence of opening and closing. However, at least one of the opposed contacts has an elasticity in which the contact resistance value changes according to the contact pressure. By forming the contact member, the tightening torque value of the screw and the nut can be estimated, and a more detailed detection system can be constructed. In addition to the screws and bolts, similar detection can be performed for deterioration or destruction of a permanently fixed structure such as a rivet.

[0020]

As described above, according to the present invention, the following effects can be obtained. (1) A screw member for fixing the equipment housing, and a nut member screwed to the screw member, at least one pair of which is closed by being clamped between the back surface of the equipment housing and the nut member. A contact is arranged in the vicinity of the screw member so as to be opened in a state where the screwing relationship is loosened, and a wiring member is led out from the contact to tighten the screw member and the nut member, and to loosen the screw member. Since it is configured to detect, it is possible to detect an important looseness of the screw, and it is possible to prevent an accident from occurring. (2) A movable contact is provided on the inner bottom surface of the switch body, and at least a pair of fixed contacts that are opened and closed by a pressing operation of the movable contact are disposed below the movable contact, and an insulating member is provided above the movable contact. A plunger is mounted, and a female screw portion is formed in the operation axis direction above the switch main body, and a screw member is screwed to the female screw portion above the plunger, and the turning operation of the screw member is performed. As a result, the movable contact is depressed, so that it can be applied as a setting switch for a device that prevents forgetting to tighten the housing screw and that is used less frequently. (3) Since the screw member has a head and a structure can be supported between the upper surface of the switch body and the lower surface of the head, it is completely detected that the screw is loose from the front panel side. Because it is not known, it can be used as a place where confidentiality is required or as an alarm switch for theft prevention. (4) Since the turning operation of the screw member can be performed by a dedicated tool, a detection switch with higher security can be obtained. (5) Since at least one of the contacts is formed by a contact member whose contact resistance value changes according to the contact pressure, it is possible to estimate the tightening torque value of the screw and the nut, and to construct a more detailed detection system. it can.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of a detection switch of the present invention.

FIG. 2 is a bottom view showing a first embodiment of the detection switch of the present invention.

FIG. 3 is an exploded perspective view showing a first embodiment of the detection switch of the present invention.

FIG. 4 is an external view of the lower surface of the housing of the first embodiment of the detection switch of the present invention.

FIG. 5 is an external view of a fixed contact piece of the detection switch according to the first embodiment of the present invention.

FIG. 6 is a combination diagram of a movable contact piece and a hexagon nut of the first embodiment of the detection switch of the present invention.

FIG. 7 is a front side view showing a first embodiment of the detection switch according to the present invention in a state where screws are loosened.

FIG. 8 is an external view showing a configuration example using a grooveless hexagon nut of the detection switch of the present invention.

FIG. 9 is a partial cross-sectional external view illustrating a use state of the detection switch according to the first embodiment of the present invention.

FIG. 10 is a front sectional view showing a second embodiment of the detection switch of the present invention.

FIG. 11 is an exploded perspective view showing a second embodiment of the detection switch of the present invention.

FIG. 12 is a front sectional view showing a third embodiment of the detection switch of the present invention.

FIG. 13 is a partially enlarged view showing a state where bolts are loosened in a third embodiment of the detection switch of the present invention.

FIG. 14 is a front sectional view showing another method of using the detection switch of the present invention.

FIG. 15 is an external view illustrating an example in which the detection switch of the present invention is configured by a special screw.

FIG. 16 is an external view showing another embodiment of the detection switch of the present invention.

[Explanation of symbols]

 1, 41 Screw 2 Washer 3, 43, 63 Surface panel 4, 44, 64 Equipment housing 5, 45, 65, 85, 105 Housing 6, 26, 66, 86 Movable contact piece 7, 27 Projection 8, 28 Beam Part 9 Fixed contact piece 10, 50, 70, 90 Terminal part 11, 31, 51 Hex nut 12 Groove part 42, 62 Spring washer 46 Contact piece 61 Bolt 67, 87 Common contact 68, 88, 108 Base 69, 89 Fixed contact 71 Female thread part 72 Waterproof film 73 Plunger 74 Connector 82 Set screw 92 O-ring 101 Special screw 111 Contact point 112 Switch body

Claims (6)

[Claims] At least one of a screw member for fixing an equipment housing, and a nut member screwed to the screw member, wherein the nut member is closed by being clamped between the back surface of the equipment housing and the nut member. A pair of contacts are disposed in the vicinity of the screw member so as to face each other so as to be opened in a state where the screw member and the nut member are loosely screwed, and a wiring member is derived from the contacts to form the screw member. And a tightening state and a loose state of the nut member. 2. The method according to claim 1, wherein at least one of the opposed contacts is formed by a contact member having a contact resistance value that changes according to a contact pressure, and detects a tightening torque of the screw member and the nut member. 2. The detection switch according to 1. 3. The switch according to claim 1, wherein said screw member is a rivet. 4. The switch comprises a movable contact and a fixed contact, has a movable contact on the inner bottom surface of the switch body, and has at least a pair of fixed contacts opened and closed by a pressing operation of the movable contact below the movable contact. A plunger made of an insulating member is placed above the movable contact, and a female screw portion is formed in the operation axis direction above the switch body, and a screw member is screwed to the female screw portion above the plunger. A switch for detection, wherein the switch is disposed in such a manner that the movable contact is pressed through the plunger by a turning operation of the screw member. 5. The detection switch according to claim 4, wherein the screw member has a head, and a structure can be supported between an upper surface of the switch body and a lower surface of the head. 6. The detection switch according to claim 4, wherein the screw member can be rotated by a dedicated tool.