JPH0963658A - Connection structure of lead wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely get connection structure which has enough strength with simple work by forming a conductor bent at the tip of the conductor of a cable, and abutting the end of the lead wire of a circuit element against this bend such that it crosses this, and spot-welding them. SOLUTION: The insulating cover at the tip of the cable 3 where an insulating cover is applied is removed to expose the conductor 4 of a single core, and the end of this exposed part is bent at a proper angle to form a conductor bend 7. Each lead wire 2 of a circuit element is placed at this bend 7 such that it crosses this in point contact condition, and a current is let flow, holding one electrode each of positive and negative, and Joule's heat is generated with the contact resistance between the lead wire 2 and the conductor 4, and they are fused and welded together by spot welding. Hereby, a welded part 8 having enough strength can be obtained surely and stably with a simple work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead wire connection structure for connecting a circuit element for detecting temperature and humidity to a conductor of an electric wire by welding.

[0002]

2. Description of the Related Art Conventionally, in air-conditioning equipment, a detection element has been inserted as a circuit element for detecting temperature and humidity in an air-conditioning pipe, duct or tank, and the air-conditioning system is based on the detection output from this detection element. Drive control of an air conditioner is performed in order to optimally control temperature and humidity.

In order to take out the detection output from such a detection element to the outside, a conductor of an electric wire for taking out the detection output to the outside is usually connected to the lead wire of the detection element.

In this connection work, the electric wire is exposed to the outside to expose the tip portion of the conductor as a core wire by removing the insulating coating, and the lead wire is soldered or brazed to the tip portion, or a part thereof. These are connected by melting and attaching them together, or by passing the conductor end and the lead wire end through a connector called a sleeve and then crimping the connector.

FIG. 10 shows such a conventional lead wire connection structure. Reference numeral 1 denotes a circuit element as a temperature detecting element, which has two lead wires 2 and each of these lead wires 2 is used for an external circuit or the like. The ends of the conductors 4 of each electric wire 3 to be connected are soldered or brazed with solder or silver solder 5.

Further, in FIG. 11, both the lead wire 2 and the conductor 4 of the electric wire 3 similar to the above are inserted into each one connector (sleeve) 6 made of an aluminum material having an insertion hole.
The figure shows that the lead wire 2 and the conductor 4 are electrically and mechanically coupled in the connector 6 by crushing the connector from the outside.

[0007]

However, in the lead wire connection structure in which the lead wire 2 is soldered or brazed to the conductor 4 of the electric wire 3, in addition to the brazing material such as solder or silver solder 5, In addition to the need for flux such as pine and varnish, the processing temperature is high, laborious work such as stacking the lead wire 2 on the conductor 4 and soldering is required, and automation of the connection process is difficult because the connection time is long. There was a problem.

Particularly, when the circuit element as the above-mentioned detecting element is small or the diameter of the lead wire 2 is as small as 0.5 mm or less, the manual connection work inevitably occupies a large proportion and the work efficiency is high. However, there was a problem in that not only the quality deteriorated, but also the finish, shape and size of the connection part varied.

On the other hand, when the lead wire 2 and the conductor are connected using the connector 6, the lead wire 2 of the circuit element is
In many cases, since it is a thin single-core conductor, if it is simply crimped by passing it through the connector 6 together with the conductor 4 of the electric wire 3, the electrical contact may be unreliable depending on the degree of crimping, and a large When mechanically pulled, the connector 6 may be detached from the connector 6, and therefore, there is a problem that the lead wire 2 and the conductor 4 need to be brazed on the connector 6 after crimping. .

If the above-mentioned crimping force is excessive, a large tensile stress acts on the base portion of the lead wire 2 and the strength of this base portion deteriorates. In addition, since the connector 6 is used, the cross-sectional shape of the connection portion is Therefore, there is a problem in that the lead wires 2 are adjacent to each other and the distance between adjacent lead wires 2 is close to each other, which makes the insulation process difficult.

On the other hand, instead of the above soldering and brazing,
Although spot welding, which is advantageous in terms of easiness of connection work and automation, can be performed, the diameter of the lead wire 2 is less than 0.
5 mm or less, or the distance between each lead wire 2 is several meters
If the conductor 4 connected to the lead wire 2 has a diameter of 1 mm or less with a circular cross section, the lead wire 2 stacked on the conductor 4 will not be seated well,
Since positioning is also difficult, there is a problem that it is difficult to weld both of them in a stable state.

The present invention has been made in order to solve the above-mentioned problems, and the lead wire end of the circuit element can be easily worked with respect to the conductor end of the electric wire while ensuring sufficient strength. The purpose is to obtain a connecting structure of connectable lead wires.

Further, according to the present invention, by spot welding,
An object of the present invention is to obtain a lead wire connection structure in which the lead wire end of a circuit element can be easily positioned with respect to the conductor end of an electric wire, and these lead wire and conductor can be reliably connected in the positioned state.

Further, according to the present invention, the lead wire end of the circuit element can be easily positioned with respect to the conductor end of the electric wire by projection welding, and the lead wire and the conductor can be surely connected in the positioned state. The purpose is to obtain a connection structure of.

Further, according to the present invention, it is possible to surely prevent adjacent lead wires of a circuit element from coming into contact with each other or coming close to each other, and to obtain a lead wire connection structure capable of preventing a short circuit accident of the circuit element. To aim.

[0016]

According to a first aspect of the present invention, there is provided a lead wire connecting structure, wherein a conductor bent portion formed at a tip portion of a conductor of an electric wire and a conductor bent portion intersecting the conductor bent portion. A lead wire end portion of a circuit element in contact is provided, and the conductor bent portion and the lead wire end portion are spot-welded at the contact portion.

According to a second aspect of the present invention, there is provided a lead wire connecting structure in which a conductor flat portion is formed at a tip end portion of a conductor of an electric wire, and a lead wire end portion of a circuit element brought into contact with the conductor flat portion. And the conductor flat portion and the lead wire end portion are spot-welded at the contact portion.

According to a third aspect of the present invention, there is provided a lead wire connecting structure in which a linear projection portion projecting from a tip of a conductor of an electric wire and a circuit element which is in contact with the linear projection portion in a crossing manner. And a lead wire end portion, and the linear projection portion and the lead wire end portion are spot-welded at the contact portion.

According to a fourth aspect of the present invention, there is provided a lead wire connecting structure in which a connecting portion between a plurality of conductors of the electric wire and respective lead wires connected thereto is displaced in a longitudinal direction of the lead wire. .

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. In FIG. 1, reference numeral 1 denotes a circuit element as a temperature detecting detection element, which has two single-core lead wires 2.

Reference numeral 3 denotes an electric wire coated with an insulating coating, and the insulating coating is removed from the tip end of the electric wire to expose a single-core conductor 4 as a core wire. In addition, the exposed conductor 4 is bent at an appropriate angle (for example, 90 degrees) at the end to form a conductor bent portion 7.

Then, each lead wire 2 of the circuit element 1
Is placed so as to intersect the conductor bent portion 7 of the conductor 4 in a point contact state, and these are sandwiched by one positive electrode and one negative electrode, and a current is caused to flow between the lead wire and the conductor 4. Joule heat is generated by contact resistance, and these are melt-bonded by spot welding. Here, 8 indicates the welded portion by the spot welding.

In this embodiment, since the end of the lead wire 2 is placed at the point of contact with the conductor bent portion 7 of the conductor 4 during welding, their mutual positioning and sitting are good, and their position is good. The mutual contact resistance in can be stabilized.

As a result, the quality of spot welding when the lead wire 2 and the conductor 4 are deformed by the pressure applied by each welding electrode during welding can be improved.

In this embodiment, the two lead wires 2 are shown to have the same length as shown in FIG. 1, but one lead wire 2 is connected to the other lead wire as shown in FIG. By making it longer or shorter than the wire, it becomes possible to make the welded portion 8 on the one conductor bent portion 7 side face the vicinity of the insulating coating of the electric wire 3 on the other conductor bent portion 7 side.

By doing so, it is not necessary to subject each lead wire 2 to an insulation treatment with a heat shrinkable tube or the like, and the number of parts for insulation and the number of work steps can be reduced. The bending process for providing the conductor bent portion 7 is easy, and if the bending process and the working conductor bending process are performed at the same time when the insulating coating is removed, the number of working steps does not increase.

Further, by embedding the circuit element 1, the lead wire 2, the welded portion 8 and the vicinity of the tip end of the electric wire 3 having the insulating coating in the resin mold portion 9, these are electrically and thermally externally supplied. Insulation protected.

FIG. 3 shows another embodiment of the present invention.
Instead of bending the conductor 4 end of the electric wire 3 as shown in FIG. 1, the conductor flat part 1 is formed by pressing the conductor 4 end.
0 is formed, the lead wire 2 end of the circuit element 1 is placed on the conductor flat portion 10, and spot welding is performed. Here, 8 is the welded portion.

In this embodiment, since the lead wire 2 is in linear contact with the conductor flat portion 10, the spot welding state is somewhat instable, but the end of the lead wire 2 is positioned and seated with respect to the conductor 4. In addition, the conductor 4 end of the conductor 4 can be easily pressed, and the shape of the welded portion can be kept small.
It is possible to realize the connection to, and it becomes highly practical.

FIG. 4 shows another embodiment of the present invention.
In this case, the conductor 4 end of each electric wire 3 is formed into a conductor flat portion 10 by press working, and at the same time, the conductor flat portion 10 is provided with a linear protrusion 11.

Then, the linear projections 11 are overlapped with each other so that the ends of the lead wires 2 of the circuit element 1 cross each other, and are brought into point contact with each other. The lead wire 2 and the conductor 4 are connected at the welded portion 8 by sandwiching each electrode and performing spot welding.

In this embodiment, since the lead wire 2 is in point contact with the linear protrusion 11 of the conductor 4 at the portion where the projection welding is to be performed, the welding current can be concentrated at this position, and the usual welding current can be concentrated. The joint strength can be increased as compared with spot welding. Also, the finished size of the welded part can be small.

That is, in projection welding, an electric current is caused to flow while pressing the lead wire 2 onto the upper surface of the linear projection 11, and the Joule heat generated at this time causes a part of the projection to be melted to form the lead wire 2. The linear projection 11 is slightly inserted into the linear projection 11, and
By welding a part of the wire 1 so as to surround the lead wire, mutual welding is possible. As a result, the bonding strength becomes extremely high.

Further, since the lead wire 2 is placed so as to intersect the linear protrusion portion 11, the lead wire 2 sits well on the linear protrusion portion 11, and mutual positioning is easy. Can be done reliably.

In particular, since the linear projection 11 is formed by press working, a slight spring property is generated when pressure is applied by the electrode during spot welding, and the lead wire on the linear projection 11 is spot-welded. It can prevent slipping and slipping from time to time.

The linear projection 11 can be easily formed by press working, and this does not seriously impair the workability.

In the above embodiment, the case where the two lead wires 2 have the same length as shown in FIG. 4 has been described. However, as shown in FIG. 5, one lead wire 2 is connected to the other lead wire 2. By making the length of the lead wire 2 longer or shorter than that of the lead wire 2, the welded portion 8 on the side of the one linear protrusion 11 can be made to face the vicinity of the insulation coating of the electric wire 3 on the side of the other linear protrusion 11.

By doing so, it is not necessary to re-insulate the heat-shrinkable tube or the like to insulate the connection between the lead wires 2 and the number of parts for insulation and the number of work steps are reduced. be able to. In this case as well, by embedding the connecting portion together with the circuit element 1 in the resin mold portion 9, the overall waterproof, moistureproof and insulating effects can be obtained together.

FIG. 6 shows still another embodiment of the present invention. This is a connection structure implemented to cancel an error due to a temperature change of the conductor resistance when the circuit element 1 is a detection element such as a resistance temperature detector.

In this embodiment, as shown in FIG.
A conductor 13 of another separately prepared electric wire 12 is spot-welded to the end of the conductor 4 of one electric wire 3 for outputting a detection signal among the electric wires 3 of the book.

Here, the tip of the conductor 13 is bent to form a conductor bent portion 14, and the conductor bent portion 14 is superposed on the conductor 4 and spot-welded at the welding portion 15. The conductor 4 in the welded portion 15 may be flat.

Further, one of the connecting portions of the conductor 4 and the lead wire 2 is covered with a heat-shrinkable tube 16 for insulation so that contact with the vicinity of the other connecting portion can be avoided.

In FIG. 6, the conductor 4 of one of the two electric wires 3 is spot-welded with the conductor 13 of the other electric wire 12 prepared separately, but as shown in FIG. In addition, the conductor 18 of the other electric wire 17 may be spot-welded to the end of the conductor 4 of the other electric wire 3 which remains.

Here, the tip portion of the conductor 18 is bent to form a conductor bent portion 19, and the conductor bent portion 19 is superposed on the conductor 4 and spot-welded at the welding portion 20.

Further, in this embodiment, the two lead wires 2 have different lengths from each other, and one connecting portion of the lead wire 2 faces the insulating coating of the electric wire 3 connected to the other lead wire. Then, the whole of these is molded with resin 9
Covered by

As described above, even in the case of using an electric wire of four-wire connection, it is possible to suppress the influence of the error due to the temperature change of the conductor resistance of the resistance temperature detector or the like, and improve the temperature measurement accuracy. .

FIG. 8 shows a temperature detecting circuit using the circuit element 1 as the resistance temperature detector shown in FIG.
T is the resistance of the resistance temperature detector, and r is the conductor resistance of each of the electric wires 3 and 12.

Further, r1 and r2 are resistors for voltage detection, and r
V is a resistor for balancing circuit resistance, C is a comparator for detecting a potential change across the resistor RT, and PW is a constant voltage source for applying a power supply voltage across the resistor RT.

In this temperature detection circuit, the power supply voltage is applied from the constant voltage source PW to the resistance RT of the circuit element 1 as the resistance temperature detector via the conductor resistance r.

Then, the voltage obtained across the resistor RT by the current flowing through the resistor RT is taken into the comparator C via the conductor resistor r, and the current corresponding to the difference voltage is output to the galvanometer or the like. Detects temperature.

FIG. 9 shows a temperature detecting circuit using the circuit element 1 shown in FIG. In this circuit, the constant current source CW and the comparator C are connected in a balanced state to the resistance RT of the resistance temperature detector via the conductor resistances r of the four conductors 4, 13, and 18.

In this temperature detecting circuit, a constant current is supplied from the constant current source CW to the resistance RT of the circuit element 1 through the conductor resistance r, so that a voltage change occurs in the resistance RT according to a temperature change. By inputting this voltage change into the comparator C, the temperature detection signal can be output from the comparator C.

[0053]

As described above, according to the first aspect of the present invention, the conductor bent portion formed at the tip of the conductor of the electric wire and the circuit element which intersects and abuts against the conductor bent portion. The lead wire end portion of the circuit element is configured to be spot-welded to the conductor bent portion and the lead wire end portion at the abutting portion thereof. There is an effect that it is possible to obtain a product that can be reliably connected while obtaining sufficient strength by a simple work.

According to the second aspect of the present invention, there is provided a conductor flat portion formed at the tip of the conductor of the electric wire and a lead wire end portion of the circuit element brought into contact with the conductor flat portion. Since the conductor flat portion and the lead wire end portion are configured to be spot-welded in the portion, the lead wire end of the circuit element can be easily positioned with respect to the conductor end of the electric wire, and the lead wire and the conductor are There is an effect that what can be surely connected in the positioned state is obtained.

According to the third aspect of the present invention, the linear projection portion projecting from the tip of the conductor of the electric wire and the lead wire end portion of the circuit element which intersects and abuts against the linear projection portion. Since the linear projection portion and the lead wire end portion are spot-welded at the abutting portion thereof, the lead wire end of the circuit element is positioned more reliably and more reliably with respect to the conductor of the electric wire. There is an effect that what can be connected with sufficient strength is obtained.

According to the fourth aspect of the invention, the connecting portions between the conductors of the plurality of electric wires and the lead wires connected to these conductors are
Since it is configured to be displaced in the longitudinal direction of the lead wire, it is possible to prevent adjacent lead wires of the circuit element from coming into contact with each other or coming close to each other, and it is possible to prevent the short circuit accident of the circuit element. There is.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing a lead wire connection structure according to an embodiment of the present invention.

FIG. 2 is a plan view showing a modified example of the lead wire connection structure in FIG.

FIG. 3 is a perspective view of essential parts showing a lead wire connection structure according to another embodiment of the present invention.

FIG. 4 is a perspective view of essential parts showing a lead wire connection structure according to another embodiment of the present invention.

5 is a perspective view showing a modified example of the lead wire connection structure in FIG. 4. FIG.

6 is a perspective view showing another modification of the lead wire connection structure in FIG. 4. FIG.

7 is a perspective view showing another modification of the lead wire connection structure in FIG. 4. FIG.

8 is a circuit diagram showing a temperature detection circuit using the circuit element shown in FIG.

9 is a circuit diagram showing a temperature detection circuit using the circuit element shown in FIG.

FIG. 10 is a plan view showing a conventional lead wire connection structure.

FIG. 11 is a plan view showing another conventional connecting structure of lead wires.

[Explanation of symbols]

 1 circuit element 2 lead wire 3 electric wire 4 conductor 7 conductor bent portion 8 welded portion 10 conductor flat portion 11 linear protrusion

Claims (4)

[Claims] 1. A conductor bent portion formed at a tip end portion of a conductor of an electric wire, and a lead wire end portion of a circuit element which is in contact with the conductor bent portion so as to contact the conductor bent portion. A lead wire connection structure characterized in that the conductor bent portion and the lead wire end portion are spot-welded. 2. A conductor flat portion formed on a tip portion of a conductor of an electric wire and a lead wire end portion of a circuit element brought into contact with the conductor flat portion, and the conductor flat portion at the contact portion. A lead wire connection structure, characterized in that the lead wire ends are spot-welded. 3. A wire projection comprising a linear projection protruding from a tip of a conductor of an electric wire, and a lead wire end of a circuit element which is in contact with the linear projection and abuts on the wire. 2. The lead wire connection structure according to claim 1, wherein the linear protrusion and the lead wire end are spot-welded. 4. The conductor according to claim 1, wherein the connecting portions between the conductors of the plurality of electric wires and the respective lead wires connected to these conductors are displaced in the longitudinal direction of the lead wires. The lead wire connection structure according to item 1.