JP2000260550A - Heating pressure contact, jig used therefor, and pressure contact device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform satisfactory pressure contact with no possibility of defective conduction or short-circuiting, while confining the widening of a terminal to an appropriate size and a prescribed connection strength is satisfied. SOLUTION: A heating jig 10 is prepared that is made up by detachably incorporating, in a heating part 1, receiving parts 2 having grooves 3 in their upper surfaces for guiding pressure contact terminals 40. A heating wire 4 is buried just under the grooves 3 and heats the receiving parts 2, while temperature control is performed by means of a thermocouple 5 and a temperature controller 6. The pressure contact terminals 40 are heated to a fixed temperature by disposing them for a short time in the heated grooves 3 in the jig 10. The heating temperature and heating time of the terminals 40 are previously determined by experiments so that the terminals are not widened excessively, when wires 50 are press-fitted therein so as to satisfy a prescribed pressure-contact strength. When the terminals 40 have reached the prescribed temperature, the wires 50 are brought into pressure-contact with the pressure contact terminals 40 by pressure contact blades 11. After the pressure contact is performed, the heating part 1 and the receiving parts 2 of the heating jig 10 are separated rapidly from each other, portions of the receiving parts 2 where the pressure contact terminals 40 are disposed are locally cooled in a forced manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to press-fitting, for example, for press-fitting an electric wire to a terminal mounted on a connector in the manufacture of a wire harness or the like.

[0002]

2. Description of the Related Art As shown in FIG. 3, an electric wire 50 is press-fitted into a slot 41 of a press-connecting terminal 40 of a connector by a tip end face of a press-connecting blade 11 and deformed at that time, as shown in FIG.
In this press-fitting, the resin outer skin 52 of the electric wire 50 is peeled off by the inner wall of the slot 41, and the core wire 51 in the outer skin 52 is The electrical contact between the core wire 51 and the press contact terminal 40 is enabled by contact with the inner wall of the base 41.

As described above, since the electric wire 50 is press-fitted into the slot 41 at the time of pressure welding, both walls of the slot 41 are widened. If the width is too large, the strength of the pressure connection itself is insufficient. In addition, it may cause other defects such as a short circuit. In particular, in recent wire harnesses, where the number of wires handled by one connector is large, the pitch of the wires is small, and the thickness of the cavity wall of the connector is small, the adjacent terminals 4
If the spread of 0 becomes too large, the possibility of a short circuit increases.

In order to prevent the terminal 40 from being excessively spread, the electric wire 50 is conventionally heated before being inserted into the slot 41, and its outer skin 52 is softened so that the inner wall of the slot 41 presses the outer skin 52 of the electric wire 50. It is designed to be easy to work or to bite.

[0005]

However, the electric wire 5
If the outer skin 52 is softened by heating the outer layer 52, the problem that the terminal 40 is excessively spread is solved. However, if the degree of softening is large, the outer skin 52 becomes out of shape, and the inner core wire 51 is removed.
This leads to a new problem of breaking the connection and causing poor conduction.

If the degree of softening of the outer cover 52 is further increased, the outer cover 52 is torn and the core wire 51 is exposed, causing a short circuit. In particular, in the case of a wire harness for an automobile, this problem is remarkable because the outer diameter of the electric wire 50 is small and the outer cover 52 is thin.

Therefore, an object of the present invention is to solve such a problem and to prevent the terminals from spreading to an appropriate size.
An object of the present invention is to perform favorable press-contacting while satisfying a predetermined connection strength and without fear of poor conduction or short-circuit.

[0008]

In order to solve the above-mentioned problems, the present invention is configured to heat the press contact terminal before press-fitting the electric wire into the slot with the press contact blade (heating press welding method). ). Because of this, the inner wall of the slot of the heated insulation displacement terminal has a hot knife shape, and the outer skin of the wire press-fit therein is softened by locally heating only the contact portion with the inner wall of the slot. Therefore, there is no danger that the whole outer skin will be out of shape or a tear will occur at a position other than the pressure contact position.

As a jig for heating the press contact terminal, a jig including a heat conductor provided with a groove for guiding the press contact terminal and a heating means for heating the heat conductor can be manufactured. If a thermocouple sensor is connected to the heat conductor, the thermocouple sensor is connected to a temperature controller, and the temperature controller is connected to the heating means, the temperature change of the heat conductor is detected by the thermocouple sensor. Therefore, based on the temperature change, the degree of heating of the heat conductor, that is, the degree of heating of the terminal can be adjusted by the temperature controller, so that the outer sheath of the electric wire contacting the inner wall of the slot is not heated more than necessary. In addition, there is no fear that the outer skin is excessively softened and the pressure contact strength is impaired.

In the heating and pressure welding method, preferably, after the wire is press-fitted into the slot, the pressure-welded portion may be forcibly cooled by, for example, a spot cooler or a Peltier element. After that, the crimping terminal and the wire at the press-fitting position are cooled immediately, and the outer skin of the wire is solidified as it is and the state is maintained as it is, so that the strength of the crimping is further enhanced, and the portion of the outer skin other than the crimping position Unnecessary heat reception is further suppressed, and generation of tears and collapse of the inner core wire are reliably prevented.

In this case, the heat conductor is formed by a receiving portion having the groove and a heating portion for transmitting heat to the receiving portion, the heating portion is connected to the heating portion, and the receiving portion is It can be configured to be removable from the heating unit,
By doing so, to cool the press contact part, immediately after heating, remove the receiving part from the heating part and cool only the receiving part. Is efficiently performed, and the heating unit is not affected by the cooling, so that heat for heating the next terminal can be kept, and the heat is not wasted.

Preferably, the portion of the receiving portion directly below the bottom surface of the groove is formed of a material having a lower thermal conductivity than other portions, so that the bottom portion of the terminal to which heat is transmitted from the bottom surface of the groove. Rather, heat is transmitted preferentially to the side of the terminal where heat is transmitted from the side surface of the groove, that is, to the side of the slot wall, so that the entire receiving portion is formed of one material and the thermal conductivity is uniform. As compared to the case where the pressure contact is made, there is less risk of occurrence of a tear or exfoliation of the core wire at a portion other than the slot portion of the outer skin when pressed.

As a material for forming the receiving portion, for example, aluminum is used for a main portion other than immediately below the bottom surface of the groove, and iron is used for a portion immediately below the bottom surface of the groove. Therefore, this configuration satisfies the above-described effect of preferentially heating the slot wall, and the portion immediately below the bottom surface of the groove is a portion to which the pressing force of the pressing blade is applied, so that the hardness of the iron is Thus, it is possible to withstand the pressing force of the pressing blade.

If the above-mentioned heating jig is provided in the pressure welding device, a pressure welding device capable of performing pressure welding having the advantage of the above-mentioned heating pressure welding method is obtained.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the terminal is heated before the pressure welding as described above.
A heating jig 10 as shown in FIG. 1 was produced. This jig 1
Reference numeral 0 denotes a rectangular heating section 1 and a rectangular receiving section 2 which is removably incorporated into one corner of the heating section 1.

The receiving portion 2 has a plurality of (four in the figure) grooves 3 having a width and a height (depth) of the substantially press-contact terminal 40 from the front surface in the figure to the back from the rectangular upper surface. A terminal 40 is provided in the groove 3 for heating. In this embodiment, the heat transfer in the receiving portion 2 is efficiently performed by forming the heat receiving portion 2 from aluminum having a high thermal conductivity. However, the portions 3a immediately below the bottom surfaces of the respective grooves 3 (portions indicated by a mottled pattern in the figure). Is formed of iron. By making only the portion 3a made of iron, it becomes possible to withstand the pressing force of the press-contact blade, and in this case, the bottom of the terminal 40 is heated through the iron, and the side of the terminal 40, that is, the slot wall is formed. Some parts are heated through aluminum, which has a higher thermal conductivity than iron, so that heat is transmitted preferentially to the inner wall of the slot from the bottom of the terminal 40, and all of the receiving portions 2 are made of one material having a higher thermal conductivity. As compared with the case of forming with the slot, unnecessary heating of the outer skin 52 other than the portion in contact with the inner wall of the slot is suppressed. Can be performed. Further, the use of aluminum not only has the advantage of good heating efficiency, but also is lightweight, so that the receiving portion 2 formed mainly of the same has the advantage that the attachment / detachment operation to the heating portion 1 can be performed smoothly. is there.

On the other hand, the heating section 1 is formed entirely of iron, and when the receiving section 2 is assembled, the receiving section 2
The heating wire 4 is buried just below the bottom surface of. The heating wire 4 extends outward, and its end is connected to an external temperature controller 6 and sequencer 7. The heating section 1 is provided with a thermocouple sensor 5, and an output terminal thereof is connected to the temperature controller 6.

The configuration of the heating jig 10 of this embodiment for heating the press contact terminal 40 has been described above. Next, the usage of the heating jig 10 will be described.

The heating jig 10 is disposed immediately below a pressing machine (not shown) (only the pressing blade 11 is schematically shown). When heating the press contact terminal 40, only the terminal 40 is provided in the groove 3 of the heating unit 1 of the heating jig 10. Terminal 40
Is not always arranged in all the grooves 3, but the number and positions of the grooves 3 in which the terminals 40 are arranged depend on the specifications of the press-contact blades 11 of the press-connecting machine. For example, in the illustrated jig 10, four grooves 3 are formed. However, in the case of a specification in which four pressing blades 11 of a pressing machine simultaneously press-connect, the terminals 40 are provided in all four grooves 3. A specification in which the press-contact blade 11 of the press-connecting machine is provided with only the blade corresponding to the groove 3 of three numbers, for example, of the numbers given to the jig 10 in the drawing. In this case, the press contact terminals 40 are provided only in the three grooves 3 of the number, and the groove 3 of the number is not used. The figure shows a state immediately after one terminal 40 is inserted into the groove 3 and the electric wire 50 is pressed.

The heating jig 10 is already heated before the terminals 40 are provided, and its temperature is controlled by the thermocouple 5 described above.
And the temperature controller 6. Then, after the terminals 40 are arranged in the grooves 3 of the heated jig 10 and a predetermined time has elapsed, the terminals 40 are brought to a predetermined temperature. The predetermined heating temperature of the terminal 40 is a temperature at which the terminal 40 does not spread too much when the electric wire 50 is press-fitted and satisfies a predetermined press-contact strength, and is determined together with other conditions by a preliminary experiment. Keep it. Other conditions are electric wire 5
For example, the material (particularly hardness) and dimensional shape (outer diameter and thickness) of the outer skin 52, the material and the dimensional shape of the terminal 40 (the width of the slot, the thickness of the terminal 40), and the like. The terminal 40 is connected to the heating jig 10.
The time required to reach a predetermined temperature after disposing in the groove 3 is also determined by experiments.

Thus, when the temperature of the terminal 40 reaches a predetermined temperature, the press contact blade 11 is lowered to press the electric wire 50 against the press contact terminal 40. Heating operation and pressing blade 1 up to this point
1 is controlled by the sequencer 7.

When the pressing is completed, as shown in FIG. 2, the heating unit 1 and the receiving unit 2 of the heating jig 10 are quickly separated from each other,
The spot cooler 8 locally cools the receiving portion 2 where the press contact terminal 40 is disposed. This is because if the heating is continued, the heat spreads to an extra portion other than the press-contact position of the outer sheath 52 of the electric wire 50, and the outer sheath 52 may be excessively softened and torn, and the core wire may be exposed. Because there is, to prevent it.

When forced cooling, the outer skin 52 of the electric wire 50 is solidified as it is, and that state is maintained as it is.
The pressure contact strength is ensured, unnecessary heat reception at the portion of the outer skin 52 other than the pressure contact position is prevented, and the occurrence of the above-mentioned tears and the collapse of the inner core wire can be reliably prevented. The forced cooling can be performed by a Peltier element other than the spot cooler 8 used in this embodiment.

In this embodiment, since the receiving part 2 and the heating part 1 are separable, the receiving part 2 is heated by the heating part 1 at the time of cooling the press contact part, that is, cooling the receiving part 2. Since the heat is not transmitted, the cooling is efficiently performed, and the heating unit 1 is not affected by the cooling, so that the heat for heating the next terminal 40 can be kept.
No heat is wasted.

As described above, by heating the press contact terminal 40, only the contact portion of the wire 50 to be pressed into contact with the inner wall of the slot of the outer sheath 52 is softened, and the terminal 40 is prevented from spreading too much. Good press contact with a predetermined connection strength can be performed.

In the next step, the wire 50 to which the press contact terminals 40 are press-connected is mounted in the cavity of the connector in the next step, and the cover is covered to complete the wire harness.

If the heating jig 10 as in this embodiment is provided in the pressure welding device, a pressure welding device capable of performing pressure welding with the advantage of the heating pressure welding method of the present invention is obtained.

[0028]

As described above, according to the present invention, the press-connecting terminal is heated before the wire is press-fitted into the slot, so that the outer skin of the wire pressed into the slot inner wall is in contact with the slot inner wall. Since only the contact portion is locally heated and softened, the terminal can be press-fitted with a predetermined press-contact strength without causing the terminal to spread too much.

The press contact terminal can be heated by a heat conductor provided with a groove for guiding the press contact terminal and a heating jig formed by a heating means for heating the heat conductor. A thermocouple sensor is connected to the heat conductor. When the thermocouple sensor is connected to a temperature controller and the temperature controller is connected to the heat conductor, the degree of heating based on the temperature change of the heat conductor detected by the thermocouple sensor, that is, Since the degree of heating of the terminals can be adjusted by the temperature controller, the outer sheath of the electric wire contacting the inner wall of the slot is not heated more than necessary, and there is no possibility that the outer sheath is excessively softened and the press-contact strength is impaired.

After press-fitting the electric wire into the slot,
If the press-contact portion is forcibly cooled, after press-fitting, the press-contact terminal and the wire at the press-fitting position are immediately cooled, and the outer sheath of the wire is solidified as it is and the state is maintained as it is, so that the press-fit strength is reduced. The securing is further enhanced, and unnecessary heat reception at the outer skin portion other than the press-contact position is further suppressed, and the generation of tears and the collapse of the inner core wire are reliably prevented.

Further, the heat conductor portion of the heating jig is
A receiving portion having the groove and a heating portion for transmitting heat to the receiving portion are formed, the heating means is connected to the heating portion, and the receiving portion is detachable from the heating portion. Then, if the receiving portion is removed from the heating portion to cool the pressure contact portion, that is, the receiving portion, if the receiving portion is removed, the cooling of the heating portion is efficiently performed without transferring the heat of the heating portion to the receiving portion. Because it is not affected by the cooling, the heat for heating the next terminal can be kept as it is,
No heat is wasted.

Furthermore, if the portion of the receiving portion directly below the bottom surface of the groove is made of a material having a lower thermal conductivity than the other portion, the side wall portion having the slot wall is closer to the bottom portion of the terminal. Since the heat is transmitted preferentially, only the portion of the electric wire sheath that comes into contact with the inner wall of the slot is efficiently heated, and the degree of heating of the other portions is suppressed, so that the occurrence of tears and stripping of the core wire is suppressed. For example, the main portion other than immediately below the bottom of the groove may be formed of aluminum, and the portion immediately below the bottom of the groove may be formed of iron. In this case, the heating of the slot wall is preferentially performed. In addition to fulfilling the function, the portion immediately below the bottom surface of the groove is a portion that receives the pressing force of the press contact blade. Therefore, by forming the portion therefrom with iron, durability against the pressing force can be imparted.

If the above-mentioned heating jig is provided in the pressure welding device, a pressure welding device capable of performing pressure welding having the advantage of the heating pressure welding method of the present invention is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment.

FIG. 2 is a perspective view showing a use mode of the embodiment.

FIG. 3 is a perspective view showing pressure welding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating part 2 Receiving part 3 Groove 4 Heating wire 5 Thermocouple sensor 6 Temperature controller 7 Sequencer 8 Spot cooler 10 Heating jig 11 Pressure contact blade 40 Pressure contact terminal 41 Slot 50 Electric wire 51 Core wire 52 Outer sheath

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryosuke Shioda 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi Harness Research Institute F-term (reference) 5E051 JA03 JB03

Claims (9)

[Claims] 1. A pressure welding method for press-fitting an electric wire into a slot of a press-connecting terminal and connecting the wire, wherein the press-connecting terminal is heated before press-fitting the electric wire into the slot. 2. A temperature change when the pressure contact terminal is heated is detected by a thermocouple sensor, and based on the temperature change,
The heating pressure welding method according to claim 1, wherein the degree of heating is adjusted by a temperature controller. 3. After press-fitting the wire into the slot,
The heating and pressure welding method according to claim 1 or 2, wherein the pressure contact portion is forcibly cooled. 4. A jig for heating the press contact terminal when performing the heat press contact according to claim 1, wherein the heat conductor has a groove for guiding the press contact terminal. And a heating means for heating the heating jig. 5. The heat conductor comprises a receiving portion having the groove, and a heating portion for transmitting heat to the receiving portion, wherein the heating means is connected to the heating portion, and the receiving portion is connected to the heating portion. The heating jig according to claim 4, wherein the heating jig is detachable from the unit. 6. The heating jig according to claim 5, wherein a portion of the receiving portion directly below the bottom surface of the groove is formed of a material having a lower thermal conductivity than other portions. 7. The heating jig according to claim 6, wherein iron is used as a material of a portion immediately below a bottom surface of the groove, and aluminum is used as a material of the other portion. 8. A thermocouple sensor is connected to the heat conductor, the thermocouple sensor is connected to a temperature controller, and the temperature controller is connected to the heating means, and based on a temperature change of the heat conductor, The heating jig according to any one of claims 4 to 7, wherein the degree of heating is adjustable. 9. A heating press apparatus comprising the heating jig according to claim 4. Description: