JPH0449743Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sensor that detects tension, and particularly to a sensor that is connected to a stretched wire, detects the tension acting on the wire, and generates a signal. It is.

[Prior art]

A tension detection type sensor consisting of a wire and a tension detector connected to one end of the wire as described above is used, for example, as a warning device for detecting an intruder.

For example, referring to FIG. 2, if you want to monitor the top of a fence, install a tension detector 11 on one of the pillars 10 of the fence, and connect a predetermined length (usually 10~20m) wire 1
2 on the top of the fence, and the other end is attached to the other support 1.
Fixed to 0.

In this way, if someone climbs over the fence and invades, they will touch the wire 12 and apply tension to the wire 12. As a result, the tension detector 11
Since the sensor outputs a detection signal, it is possible to warn against intruders by issuing an alarm using this detection signal.

The tension detector 11 may be of any type as long as it detects when the wire 12 is pulled and outputs a signal; for example, tension detectors such as those shown in FIGS. 3a and 3b are known. ing.

In the case of FIG. 3a, a movable element 11 made of, for example, a magnet is fixedly connected to the end of the wire 12.
1 and to give a predetermined tension to the wire 12,
A spring 112 that biases the movable element 111 in the opposite direction to the wire, and a detection element 113 made of, for example, a reed switch fixedly arranged in the vicinity of the movable element 111 are housed in a case 114, and the case 114 is used as a support. It is installed by fixing to 10.

When wire 12 is pulled, magnet 111
moves, thereby operating the reed switch 113, so that a detection signal is output to its output lead wire 115.

What is shown in FIG. 3b is an insulating case 114.
A pair of metal members 11 provided inside and insulated from each other.
6 and the metal ball 1 placed on the metal member 116
It consists of 17. The upper surfaces of the pair of metal members 116 are curved downward and are at their lowest point at the space between them. Therefore, normally, the ball 117 is located astride both metal members 116, and if the case 114 is tilted, the metal ball 117 will roll toward one of the metal members. In this detector, respective metal members 116 are fixedly connected to wires 12 and 12' made up of two conductive wires, and a case 114 is supported by a column so as to be rotatable within a vertical plane. wire 12,1
If a voltage is applied between 2', normally both conducting wires 12, 12' will connect to the metal member 116 and the ball 11.
7, current flows through both conductor wires, but when one conductor is pulled and the case is tilted, the ball 117 rolls, breaking the connection between both metal members 116 and causing both conductors 12,12 The current flowing through ′ is interrupted. Thus, it is possible to detect that tension is applied to the wires 12, 12'. This detector has the advantage that it can be used both as a signal line and a wire.

Now, returning to FIG. 2, since the wire 112 stretched over the fence has a length, it needs to be supported at several locations to prevent it from loosening. For this reason, the wire 12 is usually supported by attaching a support 13 having a hole 131 through which the wire 12 passes, as shown in FIG. 4, to each pillar 10 of the fence.

[Problems with conventional technology]

The above-mentioned alarm devices are mainly used outdoors, and the detectors and wires are not always in operation and are usually left stationary for long periods of time. For this reason, in cold regions or during the winter, there is a risk that the device may become covered with rain, snow, or sea spray near the coast, freeze, and become inoperable when needed.

In the case of a detector as shown in FIG. 3a, the movable element 11
1, wire 12, and case 114 are frozen, tension cannot be detected. In addition, for the type b in Figure 3,
If the rotating support part of the case 114 freezes, detection becomes impossible. Furthermore, no matter which type of detector is used, if the wire support 13 and the wire described in FIGS. 2 and 4 freeze, detection becomes impossible.

[Purpose of invention]

In view of the above problems, it is an object of the present invention to provide a tension detection type sensor equipped with an anti-icing device suitable for use in environments that are prone to freezing.

[Structure of the idea]

The present invention provides a tension detection type sensor comprising a wire stretched in the air and a tension detector connected to one end of the wire to detect the tension acting on the wire and generate an output signal. This is a tension detection type sensor characterized in that a traction device is provided at the end of the wire for applying tension to the wire when necessary.

〔Example〕

Embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a wire 12 having one end connected to the tension detector 11 shown in FIG. 3a is connected to a traction device 14 at the other end and stretched.

The traction device 14 includes a solenoid 142 fixedly disposed within a case 141 and a plunger 143 of the solenoid 142. Plunger 143 is connected to spring 1 so that it protrudes from the solenoid when solenoid 142 is not energized.
It is energized by 44. The other end of the wire 12 is connected to the protruding end of the plunger 143. A lead wire of the solenoid 142 is connected to a power source (not shown) via a switch 15.

Now, with the solenoid 142 not energized in the state shown in Figure 1a, operate the switch 15 to
2, the magnetic attraction force of the solenoid causes the plunger 14 to move as shown in FIG. 1b.
3 resists the spring 144 and the solenoid 14
drawn into 2. As a result, the wire 12 is pulled and the movable element 111 of the detector 11 also moves.

Therefore, when there is a risk that the wires and the detector 111 may freeze during winter, it is possible to prevent them from freezing by turning on the switch 15 and moving the plunger and wire movable element at appropriate time intervals. can.

Since the wire is moved, the wire support (first
Even when using the method shown in FIG. 13), freezing of the support and the wire is prevented.

Note that in an environment where the freezing time is short and repeated operations of the switch 15 are troublesome, a program timer that is turned on at predetermined time intervals can be used instead of the switch 15.

Moreover, if the traction device 14 is operated, the detector 1
A detection signal is output from 1. For example, if it is inconvenient for the warning device to generate an alarm, a switch linked to the switch 15 or a timer used in its place can be provided to block the output of the detector 11 only when the traction device 14 is activated. All you have to do is do it.

In the above embodiment, the tension detector 11 shown in FIG. 3a is used, but it can be similarly applied to the tension detector 11 in FIG. 3b or other detectors. should be obvious.

[Effect of idea]

According to the present invention, the wire and the detector can be moved by temporarily operating the traction device when necessary, which has the advantage of preventing the movable parts from freezing. Furthermore, there is an additional effect that the sensor can be tested by operating the traction device even when there is no risk of freezing, such as during the summer.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, in which FIG. 1A shows the state before operation, and FIG. 1B shows the state after operation. Figure 2 is a diagram showing a general arrangement example of a warning device using a tension detection type sensor, Figure 3a,
b is a diagram showing a different example of a tension detector, and FIG. 4 is a diagram showing an example of a support used in FIG. 2. 11...Tension detector, 12...Wire, 14...
…Traction device.

Claims (1)

[Scope of utility model registration request] A tension detection type sensor having a wire stretched in the air and a tension detector connected to one end of the wire to detect the tension acting on the wire and generate a detection signal, the sensor being connected to the other end of the wire. a traction device for applying tension to the wire; and a timer for generating a traction instruction signal every first predetermined period of time for a second predetermined period of time that is shorter than the first period of time. and the traction device comprises:
In response to the traction instruction signal, applying tension to the wire while receiving the traction instruction signal, and preventing the tension detector from generating the detection signal while receiving the traction instruction signal. A tension detection type sensor that is characterized by