JPH0711550B2 - Crimping defective terminal detection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for detecting a crimping defective terminal when a crimping terminal is attached to an electric wire terminal.

[Prior Art] To attach a crimp terminal to the end of an electric wire, the wire barrel of the crimp terminal is crimped to the core wire of the electric wire terminal, and the insulation barrel is crimped to the insulating resin coating portion of the electric wire terminal. Among the many crimp terminals, there may occur terminals such as a crimp failure of the core wire portion and a crimp failure of the resin coating portion.

In such a crimp terminal, a large number of terminals provided with a wire barrel, an insulation barrel and a contact terminal portion are connected by a carrier to form a terminal row, and the terminals are cut from the carrier by a crimping device, as shown in FIG. 3A. The wire barrel 21 of the crimp terminal 20 is crimped to the core wire W1 of the electric wire terminal w, and the insulation barrel 22 is crimped to the insulating resin coating portion W0.

The crimp terminal 20 thus attached to the wire end is in a state as shown in FIG. 3A when it is normally crimped, but in the case of improper attachment, as shown in B of the same figure, the core wire W1 of the wire end is Part of the wire barrel 21 protrudes from the wire barrel 21, or the wire barrel 21 is not crimped to the core wire W1 but is crimped to the end of the insulating resin coating W2 as shown in Fig. C. Or the tip of the core wire W1 fell below the wire barrel 21 as shown in FIG. 6D, and the insulation barrel 22 was crimped to the wire W1 without being crimped to the end of the insulating resin coating W2. It becomes the state of "core wire sag."

As a method of detecting a crimping defect of the crimping terminal attached to the wire end as described above, the applicant of the present invention detects the crimping force of the wire barrel and the insulation barrel with a load sensor and determines the detection signal as a waveform pattern. It is put in the strain amplifier of the circuit, the A / D converter is level-triggered by the trigger signal of the comparator and the detection signal is sampled.The detection signal waveform is plotted along the horizontal axis and the crimping force along the vertical axis. As shown in FIG. 4, the reference signal waveform m, which is the detection signal waveform in a normal crimping state, is compared with the time variation pattern of the detection signal waveform n. We have developed a terminal crimping defect detection method for crimped terminal wires of Japanese Patent Application No. 62-114423, which is designed to detect whether or not the crimping is normal and detect abnormal crimping terminals.

[Problems to be Solved by the Invention] As described above, when sampling the detection signal of the load sensor, the sampling start point is determined based on the signal level from the load sensor. Due to the noise, as shown in FIG. 5, the detected signal waveform n deviates from the reference signal waveform m in the normal pressure-bonding state, and therefore there is a problem that an accurate determination cannot be made. As a countermeasure against this, it is conceivable to filter with a strain amplifier or raise the trigger level, but with this, the amplitude signal is blunted, and if there is a difference in initial behavior, that part of the signal cannot be obtained.

Therefore, the present invention provides a crimping defective terminal detecting method which is not affected by noise when the waveform pattern of the defective crimping terminal is compared with the waveform pattern of the normal crimping terminal as described above.

[Means for Solving Problems] In order to solve the above problems, the present invention detects a crimping force with a load sensor when crimping a crimping terminal to an electric wire end by a pressing mechanism, and detects the detection signal. In the method of detecting a crimping defective terminal by comparing the waveform pattern with the reference signal waveform pattern of the normal crimping force in the waveform pattern judging circuit, the crimping operation start time is detected by the output signal of the sensor that detects the start of the crimping operation of the press mechanism. The waveform pattern determination circuit is triggered after a predetermined time from the detection of, to take in the detection signal of the load sensor to the waveform pattern determination circuit.

[Operation] The load sensor detects a load equal to the crimping force generated in the pressing blade type when crimping the terminal to the wire end by the terminal crimping device.

The waveform pattern determination circuit stores a crimping force reference signal waveform pattern in a normal crimping state in its memory, and compares the crimping force detection signal waveform pattern with this reference signal waveform pattern to obtain both waveforms. If the crimping force is abnormal, the abnormal signal is output.

The sensor that detects the start of the crimping operation of the press mechanism detects the operation start time point of the ram, toggle, link, etc. of the press mechanism, and the output signal is the above-mentioned waveform after a certain time from the detection of this operation start time point. Trigger the pattern decision circuit.

As a result, the waveform pattern determination circuit takes in the detection signal of the load sensor that detects the terminal crimping force after a certain time from the start of the crimping operation of the press mechanism, and the terminal crimping is stably performed without being affected by noise. It becomes possible to determine the state.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a terminal crimping device used in the method of the present invention, where 1 is a press frame, 2 is an applicator, 3 is a crimping terminal pressing blade type attached to the lower end of the applicator 2, and 4 is a pressing blade. A terminal crimping table under the mold 3 and a tray 41 for discharging the terminal end of the electric wire with the terminal to which the crimping terminal is attached.

Reference numeral 5 is a toggle device for moving the applicator 2 and the pressing blade die 3 up and down. The upper link 51, the lower link 52 and the toggle 53 are pivotally supported at a pivot point 54, and the other end of the toggle 53 is a rotary wheel 55.
The upper link 51 is pivotally connected to the fixed portion 57.
And the other end of the lower link 52 is pivotally supported on the ram 6 at a pivot 59.
The lower end of the ram 6 is connected to the upper end of the applicator 2.

Reference numeral 7 denotes a terminal feeding lever, which pivotally supports 71 at its end, and the arm 72 moves up and down together with the applicator 2 so that the terminal feeding lever 7 swings left and right by a groove 73 into which the arm tip is fitted. , The tip of the rod 74 at the lower end moves left and right, and the terminals 20 in the terminal row 23 are sequentially fed onto the terminal crimping table 4 one by one.

When the terminal crimping operation is started by the toggle device 5,
The ram 6 and the applicator 2 move up and down, and the terminal feeding lever 7
Feeds the terminals 20 of the terminal row 23 onto the terminal crimping table 4, and the pressing blade die 3 at the lower end of the applicator 2 is lowered onto the terminals 20.
Disconnect the terminal 20 from the terminal row 23 and press the terminal 20 to
While crimping the wire barrel to the core wire of the electric wire terminal, crimp the insulation barrel to the insulating resin coating portion and attach the crimp terminal to the electric wire terminal portion.

As described above, the toggle device 5, the ram 6, and the applicator 2
The pressing blade die 3 constitutes a pressing mechanism that presses the terminal 20 and crimps it to the end portion of the electric wire.

When the pressing blade die 3 crimps the crimp terminal 20 on the terminal crimping base 4 to the end of the electric wire, a distortion due to a reaction force equal to the crimping force is generated in the pressing blade die 3.

Therefore, if the load of the strain generated in the pressing blade mold 3 at the time of crimping the terminal is detected, the crimping force is detected. Therefore, the load sensor 8 for detecting the crimping force is attached to the pressing blade die 3 to detect the crimping force.

The load sensor 8 for detecting the crimping force is a pressure sensor 8 including a pressure sensor such as a load cell using a strain resistance element.
1, 1 and 82 are attached to the front surface of the pressing blade mold 3, pressure sensors 83 and 84 are attached to the back surface, and these pressure sensors are assembled into a bridge as shown in the second illustration.

The crimping force detection signal output from the bridge of the load sensor 8 is input to the strain amplifier 91 of the crimping force detection signal waveform pattern determination circuit 9, which is then fed to the A / D converter 92 and the memory 9
3.Process the CPU94 to sample the detection signal, and compare this detection signal waveform pattern with the crimping force detection signal waveform pattern in the normal crimping state stored in the memory 93 to crimp the crimp terminal to be detected. It is determined whether the state is normal or abnormal, and if it is abnormal, an abnormality determination signal is output.

The output abnormality determination signal is input to an abnormality detection / informing device such as an alarm lamp or a terminal crimping device to notify the occurrence of a defective product, and counts the type of defective condition and discharges the defective product.

In this way, the detection signal waveform pattern of the crimping state detection target terminal and the detection signal waveform pattern of the normal crimping state are compared and judged, and both waveform patterns are as shown in FIG.
Since the detection signal waveform n deviates from the normal reference signal waveform m, a crimping operation start detection sensor 10 for detecting the start point of the terminal crimping operation by the pressing mechanism is installed in order to prevent this.

The start time of the operation of crimping the crimp terminals 20 one by one to each electric wire end by the press mechanism is the start time of the operation member of the press mechanism in each stroke in which the toggle mechanism 5 reciprocates the press mechanism. Therefore, the crimping operation start detection sensor 10 is installed close to the operating member of the press mechanism.

In the illustrated example, a proximity sensor is used as the pressure-bonding operation start detection sensor 10, and its sensor head is made to face and approach the upper end portion of the ram 6, which is the operating member of the press mechanism, and the press frame 1 is pressed.
When the ram 6 starts to descend to perform the operation of crimping the crimp terminal 20 to the wire end, the sensor 10 detects the start time of the descending operation to detect the start time of the terminal crimping operation. To do.

The output point of this crimping operation start detection sensor 10 is the sensor amplifier.
The output of the amplifier 11 is input to the A / D converter 92 of the waveform pattern determination circuit 9 for the crimping force detection signal.

The crimping operation start detection sensor 10 of this terminal detects the A / D
When input to the converter 92, the A / D converter 92 starts sampling of the crimping force detection signal output from the bridge of the load sensor 8 at the time of crimping the terminal, after a certain time from the input point of the detection signal. .

The waveform pattern of this detection signal is compared with the waveform pattern of the normal crimping force as described above to determine whether the crimping state of the crimp terminal to be detected is normal or abnormal. Since the detection signal of the crimping state of the crimping terminal of the detection target is output after a certain time after the start of the crimping operation of the detection target terminal is detected, it is stable within this time and therefore the signal of the load sensor The detection signal waveform n does not deviate from the reference signal waveform m in the normal pressure-bonding state due to noise on the line as shown in FIG. 5, and an accurate comparison judgment can be made.

Although the proximity sensor is used as the pressure-bonding operation start detection sensor in the above-described embodiment, a normal limit switch can be used, and the installation location thereof is instead of the proximity of the ram of the press mechanism as described above. , The toggle or the link may be installed so as to detect the operation start time.

[Effects of the Invention] As described above, the present invention detects a defective crimp terminal by comparing the waveform pattern of the detection signal of the crimping force with the normal reference signal waveform pattern when crimping the wire end with the crimping device, Since the waveform pattern determination circuit is triggered to capture the crimping force detection signal after a fixed time from the start of the crimping operation, the crimping state of the terminal can be stably determined without being affected by noise. Is.

[Brief description of drawings]

FIG. 1 is a front view of one embodiment of an apparatus for carrying out the method of the present invention, FIG. 2 is a waveform pattern determination circuit diagram, and FIGS.
C and D are diagrams showing a terminal crimping state, and FIGS. 4 and 5 are diagrams showing waveform patterns. 2, 3, 5, 6 ,: Press mechanism 8: Load sensor 9: Waveform pattern determination circuit 10: Crimp operation start detection sensor 20: Crimp terminal

Claims (1)

[Claims] 1. A crimping force is detected by a load sensor when crimping a crimping terminal to a wire end by a pressing mechanism, and a waveform pattern of this crimping force detection signal is used as a reference signal waveform pattern of a normal crimping force in a waveform pattern determination circuit. In the method of detecting a crimping defective terminal by contrast, the crimping defectiveness is characterized in that the waveform pattern determination circuit is triggered by an output signal of the crimping operation start detection sensor after a predetermined time from the start of the crimping operation of the pressing mechanism. Pin detection method.