JP4131528B2 - Heat generation detection device for tension clamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat generation detection device capable of detecting the occurrence of abnormal heat generation in a dovetail-type electric wire retaining clamp.
[0002]
[Prior art]
When an abnormal heat generation occurs in an aluminum tube into which an electric wire has been inserted and pressure-bonded, the wire is often cut inside, and an early countermeasure is required. Japanese Patent Application No. 9-139286 discloses an example in which a shape memory alloy is used to detect the occurrence of this abnormal heat generation. This reference relates to a branch line fitting, but first points out the following. Even if the inside of the aluminum tube becomes abnormally hot, the surface is not necessarily hot, and the distribution of heat generation inside becomes particularly high near the opening of the wire insertion hole.
[0003]
[Problems to be solved by the invention]
In the above reference, a sensor hole is formed in the middle of the main line and the branch line on the branch line take-out side of the aluminum pipe body based on this indication, and a shape memory alloy strip sensor is inserted therein.
Since this disclosed example is extremely effective, an attempt was made to use a sensor made of the same alloy for a retaining clamp. In this case, however, a space for piercing the sensor insertion hole as in the case of a branch line fitting is provided on the end face. I can't get it. Moreover, the electrolytic corrosion by the dissimilar metal between a sensor and electric wires arises.
This is a problem that needs to be solved.
[0004]
[Means for Solving the Problems]
A strip-shaped sensor made of shape memory alloy is prepared. In the vicinity of the wire outlet end of the tension clamp, an axial notch that can be filled at the end of the sensor is made, and the filling is temporarily fixed with a sensor and an adhesive, and then crimped and integrated with the insertion wire. Abnormality can be detected reliably because the tip of the sensor is located at the highest temperature due to heat generation. A urethane resin resin paint is applied to the front surface of the shape memory alloy strip-shaped sensor, and a tar epoxy paint is applied to the sensor mounting base and the surface facing the electric wire to prevent electrolytic corrosion.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The drawings are described. One end of the retaining clamp 1 is a retaining portion 1a, and the other end is an insertion groove portion 1b of the electric wire E. The groove 1b is a dovetail groove, and a lid 2 is provided. Separately, a shape memory alloy strip sensor 3 is prepared, and a notch capable of filling the end portion of the sensor is provided near the inner surface outer end of the groove portion 1b. The cut is temporarily fixed at the sensor end, and the other part of the sensor is projected.
The electric wire E is fitted into the groove portion 1b from the side, and is crimped after the lid 2 is inserted. Since the sensor 3 is surrounded by an aluminum material and pressed in the vicinity of the end of the groove, that is, at the maximum temperature portion as shown in FIG. 3, it is surely exposed to the internal high temperature. Although the sensor 3 bends thereby, the relative angle phase of each member is adjusted so that the sensor 3 can be easily detected from a remote position.
FIG. 4 is a front view of a tension clamp provided with a sensor coated with a resin-based paint. When rainwater or the like accumulates in the gap between the sensor and the electric wire, it is energized to short-circuit between the aluminum electric wire E and the Ni-Ti sensor 3, and galvanic corrosion occurs due to a potential difference between different metals. . In particular, the sensor mounting base 4 and the surface 5 facing the electric wire E are easily eroded. In order to prevent this, a colored urethane paint 6 is applied to the front surface of the shape memory alloy short rod-shaped sensor 3, and a tar epoxy paint 7 having excellent weather resistance is applied to the mounting base 4 and the surface 5 facing the electric wire E. Thereby, the colored urethane paint surface faces outward and can be detected from a distance. In particular, the tar-epoxy paint is applied to the portion that is easily eroded, so the paint does not peel off easily.
[0006]
【The invention's effect】
In the dovetail type retention clamp, the strip sensor is inserted into the notch on the inner surface of the clamp tip and crimped and integrated with the insertion wire, so that the sensor reacts reliably to the internal high temperature and makes it possible to detect the high temperature. Since resin-based paint is applied to the sensor, electric corrosion can be prevented. A colored urethane paint is applied to the sensor confirmation surface, and a highly weather-resistant tar epoxy paint is applied to the sensor base and the electric wire facing surface, which are particularly susceptible to electrical corrosion, so that the detection confirmation visibility and durability are excellent.
[Brief description of the drawings]
FIG. 1 is a front view of a retaining clamp.
FIG. 2 is a plan view of the same.
FIG. 3 is a cross-sectional view of a wire insertion groove.
FIG. 4 is a front view of a tension clamp provided with a sensor coated with a resin-based paint.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tension clamp 1a Tension part 1b Groove part 2 Lid 3 Sensor 4 Sensor mounting base 5 Sensor facing surface 6 Urethane paint 7 Tar epoxy paint E Electric wire

Claims (1)

One end of a shape memory alloy strip-shaped sensor provided with a rectangular cut in the axial direction on the inner surface near the open end of the dovetail groove part, in a retention clamp that has a handle at one end and the other end is a dovetail-type wire crimping part. The other end of the sensor is extended in the axial direction along the surface of the inserted electric wire, and one end of the sensor is placed near the surface of the electric wire in the electric wire crimping portion that is compression-connected integrally with the electric wire. When the sensor reaches a predetermined high temperature due to compression, the extension part of the sensor is set so that it can detectably deform, and tar epoxy paint is applied to the opposing surface of the one end side mounting base and the extension part of the sensor. An apparatus for detecting heat generation of a tension clamp, characterized in that urethane coloring paint is applied to a surface opposite to the facing surface .

Images