JP4028662B2 - Heat generation detector for wire crimping tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus capable of detecting abnormal heat generation during energization in a crimp tube that holds an inserted electric wire by crimping.
[0002]
[Prior art]
The use of a shape memory alloy for detection of abnormal heat generation due to energization of a crimped portion is known from Japanese Patent No. 270876 (hereinafter referred to as Reference 1) and Japanese Patent Application No. 9-139286 (hereinafter referred to as Reference 2).
Reference 1 is a connecting tube in which electric wires are inserted and crimped from both sides. A shape memory alloy thermal sensor body that changes to a predetermined shape when the connecting tube abnormally generates heat is disposed in the axial direction on the surface of the connecting tube. The central part is fastened to the connecting pipe with a band.
Reference 2 uses the same sensor to detect abnormal heat generation at the branch line connection location, but the inventor stated that the surface layer is not necessarily so even if the inside of the specimen is hot in the specification, and It is pointed out that the end of the branch line drawing direction is particularly hot. It is an indication that question the effect of Reference 1. In view of this point, Reference 2 is characterized in that a sensor hole is formed in the metal fitting between the main line and the branch line.
[0003]
[Problems to be solved by the invention]
The above means cannot be applied to a linear sleeve that simply inserts and crimps an electric wire into a cylindrical body because the shape is completely different. In this case, which part is selected and by what means the sensor is attached has been solved as a new problem.
Moreover, the electrolytic corrosion by the dissimilar metal between a sensor and an electric wire arises.
These are the problems to be solved.
[0004]
[Means for Solving the Problems]
An inner diameter near the open end of the aluminum tube body into which the electric wire is inserted is cut out, and an aluminum collar of a size that can be filled with the cut is inserted here. A strip-shaped sensor is previously attached to the surface of the collar by exposing it to an appropriate length. Crimp the entire wire after inserting it. Since the sensor is sandwiched between the aluminum tube and the aluminum collar and is pressed near the open end of the tube body, the two conditions described in Reference 2 are satisfied, and the sensor reacts accurately to the internal temperature of the sleeve. A urethane resin paint is applied to the front surface of the shape memory alloy strip (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]
【Example】
The drawing will be described with reference to an example of a clasp in which the straight sleeve S and the jumper sleeve J are integrated. A main line E1 is inserted into the straight sleeve S, and a jumper line E2 is inserted into the jumper sleeve J and crimped.
In the case of the straight sleeve S, the stepped large diameter portion 1 is formed by cutting away the inner diameter near the opening end as shown in FIG. The collar 2 has a size that can be inserted and filled into the cut portion, and a part of the outer diameter serves as an axial sensor bonding seat. The sensor 3 is a strip shape memory alloy, and is adhered to the adhesive seat, leaving an exposed portion of an appropriate length. Adhesive is not selected because it is temporarily fixed. After the collar with the sensor is stored in the large diameter portion 1, the electric wire E1 is inserted and crimped. FIG. 5 is a front view of a tension clamp provided with a sensor coated with a resin-based paint. Rain water or the like easily collects in the gap between the sensor and the electric wire. When the aluminum electric wire E and the Ni-Ti sensor 3 are short-circuited by energizing this, the electric wire E corrodes due to a potential difference between different metals. In particular, the sensor mounting base 4 and the surface 5 facing the electric wire are susceptible to electrolytic corrosion. In order to prevent this, a colored urethane paint 6 is applied to the front surface of the sensor, and a tar epoxy paint 7 having excellent weather resistance is applied to the surface 5 facing the mounting base 4 and the electric wire E1. Thereby, the colored urethane paint surface faces outward and can be detected from a distance. In particular, a portion that is easily eroded is coated with a tar epoxy paint and thus does not peel off.
It is obvious that the jumper sleeve J can be used by the same means as described above.
[0006]
【The invention's effect】
Since it is only an operation to cut the inner diameter of the tube body near the open end and insert a collar of a size that can be filled into the cut portion, it is easy to carry out and overheat detection can be performed accurately. Since the resin-based paint is applied to the entire surface of the sensor, electric corrosion can be prevented. Two types of resin-based paints, urethane paint and tar epoxy paint, are used, taking into account the location that is particularly susceptible to electrocorrosion and the visibility of detection, so it has excellent durability and easy state detection.
[Brief description of the drawings]
FIG. 1 is a front view of a retaining metal fitting.
FIG. 2 is a front view near the open end of a linear sleeve.
FIG. 3 is a front view of a collar.
FIG. 4 is a side view of a collar.
FIG. 5 is a front view of a wire crimping tube provided with a resin-based paint sensor.
[Explanation of symbols]
S Straight sleeve J Jumper sleeve E1 Main line E2 Jumper wire 1 Large diameter part 2 Color 3 Shape memory alloy short rod (sensor)
4 Urethane paint 5 Tar epoxy paint

Claims (2)

A collar having an insertion hole for an electric wire at one end, with a stepped large-diameter hole cut off from the inner diameter near the opening end, and a collar with a shape memory alloy strip attached to the surface in the axial direction A heat detection device for a wire crimping tube, wherein the exposed portion of the strip is deformed so as to be detectable at a predetermined high temperature by energization after inserting and crimping the wire. 2. An apparatus for detecting heat generation of a crimped tube according to claim 1, wherein a urethane paint is applied to the front surface of the shape memory alloy strip and a tar epoxy paint is applied to the mounting base and a surface facing the electric wire. .

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