JP4270558B2 - Electric heat caulking joining device - Google Patents

Description

The present invention sets a coated wire and a terminal (hereinafter referred to as a connection terminal) in which a plurality of insulated coated wires (hereinafter referred to as a coated wire) such as a motor, a relay coil, and a solenoid terminal are bundled, and pressurizes between these electrodes to energize them. In order to improve the accuracy of the parts in the joints when the terminal height is crushed to the target part height (hereinafter referred to as model thickness dimension) while heating, The present invention relates to an energizing heat caulking joining apparatus having an enhanced quality control function for always determining a thickness dimension of a joint portion to a target model thickness dimension.

  Conventionally, when connecting an insulation-coated wire having a coating of enameled wire or resin and a connection terminal, or overlapping an insulation-coated wire on a connection terminal or other metal chip, the overlapped joined portion generates resistance heat. When heat caulking is used, or when encasing protrusion caulking members such as magnesium-based alloys and aluminum-based alloys such as automobile engine covers are plastically deformed using resistance heat, and heat caulking is applied. The machine has been used.

In the connection between the insulating coated electric wire having a coating such as enameled wire or resin and the connection terminal, the thickness of the heat caulking portion as well as the sufficient welding force of the joining portion must not vary in size.

Conventionally, an air cylinder or an electric motor has been used as an electrode pressurizing actuator of an energizing heat caulking machine. However, one of the conventional pressurization methods using an air method is, for example, a plurality of electric coatings coated with an insulating film. Bundle the conductors and insert them into the hooks (crimp joints) of the connection terminals. After positioning the hooks in the concave grooves with a crescent-shaped cross section of the lower electrode, lower the upper electrode to bring the curved shape of the tip of the electrode tip By pressing and heating the hook part with the convex part, a depressed concave part is formed in a part of the hook part, and at the same time, a part of the insulation film of the conductive wire in the hook part is dissolved and removed to electrically connect the conductive wire and the hook part. In general, a method of joining is known (Patent Documents 1 and 2).

Conventionally, in an energizing heat caulking machine using an electric motor as an actuator for pressurization, in order to improve terminal size control, at least one electrode is driven by an electric motor, and electrode positioning, electrode displacement and / or heat caulking is performed. When the target position is reached, pressurization and energization are performed until the displacement of the electrode driven by the motor output reaches the preset terminal dimensions during energization caulking. A method of performing quality control of the thickness dimension of the terminal joint by releasing energization and electrode pressurization is known (Patent Documents 3 and 4).

The former air type pressurizing mechanism was considered to have the following problems.
1. The range of application of the method for positioning the hook portion in the concave groove in the lower electrode is limited by the size of the hook portion as in the case of the dedicated machine.
2. In addition, this type of conventional method can make the pressure deformation smooth by making the shape of the depressed recess into a curved surface, but the positioning accuracy is not precise and the dimensional accuracy in the thickness direction of the joint is increased. Not enough consideration has been given to quality control measures.
3. In addition, in the conventional method that has been generally tried, an external displacement sensor is attached and the movement of the electrode is measured, and the amount of caulking actually crushed is compared with the set height of the caulking joint. Although there is a method of monitoring whether there is a value, there is a time lag in the transmission / reception of signals from the sensor, the supply of air, and the movement of the sliding part, and it is not possible to sufficiently cope with the improvement of component accuracy.
4). If the accuracy of the parts is poor, the mechanical performance (tensile strength / repetitive bending strength) of the connection terminal and enameled wire will be reduced, the electrical function (increased resistance) will be reduced, and the mechanical / electrical performance. Various variations such as assembly accuracy in the post-process increase, which leads to various problems such as lowering the motor performance.

The latter type of pressure mechanism is not sufficient for quality control in the following points. That is, by attaching a encoder or linear sensor and measuring the dimensions by mechanical movement, for example, as shown in the pressurization sequence in FIG. 7, the actual crimped terminal caulking amount is compared with the set predetermined dimension. When the caulking amount reaches a predetermined size, the electric current is cut off and torque is generated in the electric motor until the hold time in the sequence (about 1 cycle to 20 cycles) ends, and the electrode adds the caulking joint. Therefore, the tungsten electrode of the heating element is heated to a high temperature of 300 ° C. to 500 ° C. from the completion of the hold to the opening of the electrode. The amount of accuracy of these parts often changes seasonally (summer, winter, etc.). Also it may be influenced by the temperature difference, in order to increase the part accuracy was left still many problems to be solved.
JP-A-7-256464, JP-A-8-132245, JP-A-11-121136 JP 2002-134246 A

The problem to be solved by the present invention is that, for example, the variation in the dimension of the parts in the thickness direction of the crimped joint portion such as the terminal joint portion due to energization heat caulking between the connection terminal such as the electric motor coil terminal and the enamel wire is eliminated. Therefore, it is possible to easily realize an energizing heat caulking joining device for improving the quality control capable of determining and verifying the accuracy of the target model thickness dimension.

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Then invention of claim 1 of the present invention is to bind the plurality of coating lines, the binding was the Insert a coating line to the connection terminals, the insert to be caulked joint formed pair of positive and negative electrodes In an energizing heat caulking joining apparatus that heats by applying pressure, energizing and heating, melting and removing the insulating coating of the caulking joint, and coupling the coated wire and the terminal, at least one of the electrodes is electrically driven The actuator unit driven by the motor is connected to a controller controlled by a closed loop system according to parameter information such as pressure, heating current, energization time, electrode positioning, and moving speed via the motor amplifier of the electric motor. The controller includes a main control unit, a caulking position calculation control unit, and a heating power source control unit, and the calculation control unit is a digital signal from the main control unit of the controller. The motor amplifier is configured to control the electric motor by a torque current with a target position and a motor speed, and the heating power control unit is heated by a digital signal from the main control unit of the controller via a transformer between the electrodes. It is configured to control a switch of a thermal caulking power source that supplies caulking power, thereby detecting a displacement amount of the electrode by a displacement sensor during an energizing thermal caulking process that couples the coated wire and the terminal. The displacement amount detected by the displacement sensor is set in advance in the main control part of the controller , the β reference value corresponding to the model thickness dimension of the energized heat caulking joint, or the electrode corresponds to a position in the vicinity of the model thickness dimension. uptake and α reference value to the arithmetic unit, a result of the comparison operation by the arithmetic unit, when the displacement reaches the β value or α value, the calculation The heating power control unit is operated by an output signal from the unit to cut off the energized heating current, and the torque limit or torque control of the motor is canceled by the arithmetic control unit, and the model thickness dimension is switched to position control. The present invention provides an energizing heat caulking joining apparatus for determining

  Claim 1 of the present invention is in contrast to the conventional method and apparatus for controlling the positioning of electrodes by controlling energization stop and motor output torque with an external signal from a displacement meter, and one movable electrode is in the process of energizing heat caulking. When the model thickness dimension of the energized heat caulking joint set in advance is reached or when a position near the model thickness dimension is reached, the heating current during energization is cut off and the motor torque limit or torque By switching from control to position control, the dimension in the thickness direction of the joint portion is determined to the model thickness accuracy by suppressing variations in the amount of crushing of the crimped portion regardless of the degree of electrode heat generation temperature or cooling temperature. be able to.

According to claim 1 of the present invention, the target position is compared with the conventional electric pressurization method during the energization heat caulking process by performing feedback control so that the dimension in the thickness direction of the joint portion coincides with the model thickness dimension. After confirming the above, the torque limit or torque control is canceled and the control is switched to the position control, so that it can be surely matched with the model thickness dimension, and the component accuracy can be greatly improved.

Claim 1 of the present invention corresponds to the amount of displacement of the electrode during the energizing heat caulking process and the β reference value corresponding to the preset model thickness dimension of the energizing heat caulking joint or a position near the model thickness dimension. As a result of comparison with the α reference value, the heating current that is energized is cut off and the torque limit or torque control of the motor is released, and then the sequence control is performed by switching to the position control. Compared to the electric pressurization sequence that is mechanically visually observed by the meter, the measurement target position can be actually determined by the motor position control, so the thickness dimension of the crimped joint can be accurately monitored, and a constant model thickness Quality accuracy can be determined in the length dimension. Therefore, it is possible to shorten the energization time by reaching the model thickness dimension h by increasing the heating energization time and the heating current by increasing the accuracy of monitoring, and it is possible to improve productivity by shortening the tact time. There is an advantage that an energizing heat caulking joining device can be manufactured easily and inexpensively.

For example, as shown in the examples of FIGS. 1A, 1B and 1C, a copper-plated connection terminal W1 having a tube-like joint portion such as an electric motor coil terminal and an enameled wire (lead) Bonding with a quality target of the height dimension of the outer diameter of the joint to be crimped W3 by electric heat caulking with the insulated wire W2 such as wire), that is, the thickness dimension H of the joint before caulking. The present invention realizes an energizing heat caulking joining device that is extremely useful in quality control and can obtain a model thickness dimension h of a part and a joint thickness after caulking that is always constant.

FIG. 1 is an embodiment of the present invention and shows a caulking process of an apparatus for carrying out an energizing heat caulking joining method. FIG. 2 is an electric block diagram showing a control configuration of the apparatus of the present invention. FIG. 3 is a sequence showing a control operation for carrying out the energizing heat caulking joining method of the present invention. FIG. 4 is a front view showing the initial pressurizing position of the positive and negative electrodes used in the apparatus of the present invention. FIG. 5 is a plan view of FIG. FIG. 6 is a front view showing the energized heat caulking position by the apparatus of the present invention.

An energizing heat caulking machine 1 shown in the figure is an example used for carrying out the joining method by energizing heat caulking of the present invention. The energizing heat caulking machine 1 shown in the figure is a commonly known stationary energizing heat caulking machine, or a servo spot C type gun or servo spot X type gun which is omitted in the figure but mounted on an automatic device such as a robot or manipulator. is not.

1 and 2, an energizing heat caulking machine 1 according to the present invention has a pair of positive and negative electrodes 2 and 3 as a part of main components, and one of the electrodes 2 is a movable side electrode. N is driven by an actuator unit 5 constituted by a system that converts the rotational motion of the electric motor 4 (servo motor) into linear motion. The electric motor of this actuator unit 5 is controlled by the controller 6 in a closed loop system, and all the other parameters necessary for the welding force, welding current, energizing time, electrode positioning, moving speed, and energizing heat caulking are all described above. Recorded and set in the main control section 7 of the controller 6. One electrode 2 is controlled synchronously by the torque current of the electric motor 4 and the pulse signal from the encoder 8 so that the caulking joint can be clamped between the other fixed side electrode facing the main controller 7. The configuration is reproduced.

The energizing heat caulking machine of the present invention includes a motor amplifier 9 that drives one or two axes of the actuator unit 5, a heating power controller 10 and a contactor 11 that controls an electronic switch of a heat caulking power source of the heat caulking machine, A plurality of crimped joints are fixed in position, a plurality of coated wires W2 wound around a stator of each crimped joint are bundled, and the bundled coated wires are inserted into the connection terminals W1. A work jig (not shown) for supporting W3 at a predetermined position is provided.
In this case, the shape of the connection terminal is a tube terminal having an outer diameter of 10 mm and an inner diameter of 6.0 mm and a length of 10 mm. The thickness of the covered wire was 1 mm, and a caulking joint formed by inserting 20 wires into the terminal tube was tried in the experiment.

  In the energizing heat caulking machine 1, the contactor 11 is interposed in the main circuit of the power source and the transformer 12, and when energizing heat caulking is performed, the energizing signal is received from the main control unit 7 to operate the electronic switch, And the magnitude of the heating current flowing between the pair of electrodes 2 and 3 through the secondary conductor of the energizing heat caulking machine and the energizing time are directly controlled.

In the movable side electrode 2 and the fixed side electrode 3 of the thermal caulking machine 1, a chip (not shown) made of pure tungsten, copper tungsten or the like is inserted at the tip of each electrode. This tungsten-based metal chip has a high electric resistance value and a high melting point. In addition, a sintered metal obtained by sintering carbide, molybdenum, copper, or silver can also be used.

The position of the movable electrode 2 is detected by an encoder pulse built in the electric motor 4. In this case, the chip origin setting is performed with the position where the torque current flows as a result of air pressure being applied to the stationary electrode 3 from the fully open origin position of the movable electrode 2 as a base point (zero).
The setting of the reference value in the caulking process of FIGS. 1A, 1B, and 1C will be described. The thickness H of the caulking joint is obtained by back calculation from the chip origin position. Assuming 10 mm, the electrode movement is decelerated immediately before the movable electrode 2 reaches 10 mm in the H dimension, and the positioning of the soft landing is detected by the encoder pulse. If the quality target model thickness dimension h is 4.0 mm, a target value corresponding to 4.0 mm is detected from the encoder pulse as the β reference value. Further, in the case of the α reference value, the caulking amount is obtained by back-calculating the position a little before the model thickness dimension h, for example, a distance of about 0.1 to 1.0 mm before the α target value. Thus, the β reference value corresponding to the model thickness dimension h of the product or the α reference value taken before the model thickness dimension h is set in the caulking position calculation control unit 13 of the controller. Whether or not the stroke displacement amount of the electrode 2 is a β value or an α value of a model thickness dimension set in advance is determined by the calculation unit of the caulking position calculation control unit 13 from the number of pulses output from the encoder 8 every moment. read.
Even when correcting the displacement between the electrodes due to wear of the tip, the origin of the tip is defined as the base point (zero) at the position where the fixed side electrode 3 is air-pressed from the fully open origin position of the movable side electrode 2 and the torque current flows. Do the set.

In the control configuration diagram of FIG. 2, the main control unit 7 includes the target position (the β reference value or the α reference value) of the caulking sequence and the pressurizing force, the heating current value, the energizing time, and other energizing heat caulking. The necessary patterns and parameters are set, and commands are issued according to those parameters. The caulking position calculation control unit 13 receives the commanded caulking position of the reference value and the torque current stop position command, and commands torque control such as the target position and motor speed of the electric motor 4 to the motor amplifier 9. The model thickness dimension is detected from the pulse signal from the encoder 8, and when the target value is reached, the heating power supply controller is turned off and the torque limit or torque control is turned off to switch the position control to the model thickness position. Commands the motor amplifier 9.

Next, the operation of the present invention will be described with reference to FIGS.
First, before conducting heat and caulking, insert a reference material between the movable side electrode 2 and the fixed side electrode 3 or between the electrodes 2 and 3 and clamp them without inserting a workpiece between the electrodes 2 and 3 by an automatic device. The encoder 8 detects the origin and zero base of the electrode from the amount of electrode movement on the movable side at the time of the stop, and stores the data in the controller 6.

The controller 6 of the energizing heat caulking machine teaches parameter information on the sequence such as the electrode speed and electrode positioning as well as various operations such as the pressure pattern, current pattern and energizing pattern necessary for the energizing heat caulking of the actuator unit 5. .

  Coated wire joining terminals that are the targets of energizing heat caulking are fixed to a plurality of motor set positions provided in advance on the work jig.

Next, in response to a command from the main control unit 7 of the controller 6, the caulking position calculation control unit 13 commands the motor amplifier 9 to control the torque current such as the target position and the motor speed, and operates the electric motor 4 of the actuator unit 5. The electrode 2 descends toward the fixed-side electrode 3.

During this time, the amount of electrode movement is detected by receiving an encoder pulse from the electric motor 4. The speed of the movable electrode 2 set in the main control unit 7 can operate fast up to the height H before the electrode tip is in contact with the crimped joint W3, so that the movable electrode 2 is crimped. At the moment of contact with the portion W3, the speed is reduced and substantially contacts with the joint portion W3 by a soft touch. The joint W3 is sandwiched between the fixed side electrode 3 and pressurized (see FIGS. 1A and 3).

Thereafter, a torque current for obtaining a high pressurization force of, for example, 4 kN to 10 kN is generated between the fixed electrode 3 and the movable electrode 2 as the pressurizing force, and the crimped joint W3 between 5 and 15 cycles. Is mechanically crushed. The switch of the contactor 11 is operated in response to an energization start command from the heating current control unit 10 in accordance with a setting command from the main control unit 7. In this case, a heating current of about 10 kA to 20 kA flows from the transformer 12 during, for example, 50 to 200 cycles according to the setting data of the main control unit 7 (see FIGS. 2 and 3).

Thus, when a heating current is supplied to the movable electrode 2 and the fixed electrode 3, the electrode surface in contact with the crimped joint is accelerated and this heat is transmitted to the connection terminal and the coated wire for insulation. The coating can be thermally destroyed to melt and press-contact the insulation of the coating wire (see FIG. 1C).

The caulking amount is detected by the encoder pulse of the motor from the electrode displacement, and the caulking amount gradually progresses and these data are monitored at each hitting point sequentially, and whether or not the target reference value has been reached is calculated by a calculation unit. Is done. When the calculation result does not reach the reference value, feedback control is performed on the difference, and correction control such as continuing or increasing or decreasing the pressure and / or heating current until the target α reference value or β reference value is reached. Done.

The present invention unilaterally does not pressurize to a caulking position set to a target value by torque control, but during the thermal caulking process, the joint portion is crushed by the pressure of the movable electrode 2 and the electric motor When the detected value detects the β reference value or α reference value of the target position from the pulse signal from the encoder 4, the contactor 11 performs heating between the electrodes in response to a command from the caulking position calculation control unit 13 to the heating power supply control unit 10. At the same time as the current is stopped, torque limit or torque control is turned off by a command from the caulking position calculation control unit 13, and the motor amplifier 9 is commanded to switch the position control to the β reference value of the model thickness dimension or an α reference value in the vicinity thereof. The point is clearly different from the conventional method (see FIGS. 1B, 1C, 2 and 3).

Thus, when the torque current and the heating current are interrupted almost simultaneously, the energized heat caulking joint is held between the electrodes until the hold time (for example, 0.5 to 20 cycle range) is completed. During this time, the electric motor torque is maintained at the reference position in the state of holding torque, and the thickness of the crimped joint is kept constant. In other words, the present invention eliminates the torque limit or torque control at a predetermined position during energization caulking and shifts to position control, so that the model thickness of the joint is not affected by changes in the heating temperature and / or cooling temperature of the tungsten electrode. The tolerance of the dimension h can be determined to a value corresponding to the accuracy of motor encoder disassembly (for example, 1/100 or less) (see FIGS. 1C and 3).

After completion of the heat caulking, one cycle of the heat caulking is completed when the electric motor 4 of the actuator unit 5 rotates in reverse according to a command from the main control unit 7 and the movable electrode 2 is fully stroked to the origin. Next, the manipulator moves the actuator unit 5 from the work jig and stops at a predetermined position, and a new work is taken in and out, and the heat caulking cycle is repeated in the same manner.

The electrode operation and the manipulator operation of the actuator unit 5 move in synchronization. The amount of chip consumption is measured by blanking the positive and negative electrodes 2 and 3 once every arbitrary number (10 times) according to the amount of wear, and the base point is reset as described above.

The present invention controls the position of the current heat caulking joint until it finally matches the model thickness dimension h by position control that is switched while the torque is released halfway, and reliably detects and holds the normal position. be able to. In the conventional method, the dimensional accuracy of the parts was not stable because the pressure was continuously or empirically applied to the target model thickness by unilateral torque control or air pressure control. As a result, the quality control for improving the accuracy of parts can be improved, the tact time can be shortened and the productivity can be improved.

  In the embodiment of the energizing heat caulking machine of the present invention, the pressure surface (electrode surface in contact with the caulking joint) of the electrode forming a positive and negative pair is shown in a flat shape, but depending on the size and shape of the caulking joint, the electrode An arbitrary shape can be selected according to the hook shape and size of the connection terminal, such as a U-shape, V-shape, curved shape, or convex shape.

The energizing heat caulking joining device of the present invention is heated by using resistance heat generation, and is electrically compressed by hot pressing such as a forging valve in addition to electric riveting which plastically deforms and press-fits a rivet member, a saddle member, etc. It can also be applied to electrical upsetting applications manufactured by processing.

The Example of this invention shows the caulking process of the apparatus for enforcing the energization heat caulking joining method. It is an electric block diagram which shows the control structure of this invention apparatus. It is a sequence which shows the control operation which implements the energization heat caulking joining method of the present invention. It is a front view which shows the initial pressurization position of the electrode which makes the positive / negative pair used for the apparatus of this invention, and respond | corresponds to FIG. 1 (A). FIG. 5 is a plan view corresponding to a fixed-side electrode and a crimped joint in FIG. 4. It is a front view which shows the electric conduction heat crimping position by the apparatus of this invention, and respond | corresponds to FIG.1 (C). It is a sequence which shows the pressurization control operation by the electric motor which implements the conventional energization heat caulking joining method.

Explanation of symbols

1 Current heat caulking machine 2 One electrode (movable electrode)
3 The other electrode (fixed side electrode)
4 Electric motor (servo motor)
5 Actuator unit 6 Controller 7 Main controller 8 Encoder 9 Motor amplifier 10 Heating power controller
11 Contactor 12 Transformer 13 Caulking Position Calculation Control Unit W1 Connection Terminal
W2 Coated wire W3 Caulking joint B Ball screw N Nut

Claims (1)

Bundling a plurality of coated wires, inserting the bundled coated wires into a connection terminal , sandwiching the crimped joint formed by inserting the coated wire with a pair of positive and negative electrodes, heating by pressurizing and energizing In the energizing heat caulking joining apparatus that melts and removes the insulating coating of the caulking joining portion and couples the coating wire and the terminal, the actuator unit that pressurizes and drives at least one of the electrodes by the electric motor is the electric motor. pressure through the motor amplifier, heating current, weld time, electrode positioning, connected to a controller for controlling a closed-loop in accordance with the parameter information such as the moving speed, the controller main control unit, the caulking position calculation control unit and The heating control unit includes a heating power source control unit, and the arithmetic control unit sends a target position to the motor amplifier by a digital signal from the main control unit of the controller. A heat caulking power supply configured to control the electric motor by a torque current with a motor speed, and the heating power supply controller supplies a heat caulking power via a transformer between the electrodes by a digital signal from the main controller of the controller The displacement amount of the electrode is detected by a displacement sensor during the energizing heat caulking process for coupling the coated wire and the terminal, and the displacement amount detected by the displacement sensor is determined. advance said arithmetic unit model thickness β reference value or the electrode corresponding to the size of the energization heat staked portion that is set to the main control unit and a reference value α corresponding to the vicinity of the model the thickness of the controller When the displacement amount reaches the β value or the α value as a result of the comparison calculation by the calculation unit, the heating power supply is output by an output signal from the calculation unit. An energizing heat caulking joining device that operates a control unit to cut off a heating current that is energized, releases torque limitation or torque control of the motor by the arithmetic control unit, and switches to position control to determine the model thickness dimension .

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