JP6323098B2 - Pin insertion device and pin insertion failure determination method - Google Patents

Description

  The present invention relates to a pin insertion device and a pin insertion failure determination method for press-fitting pins into a hollow cylinder fixed to a substrate.

  For example, in an insulated circuit board used for a power semiconductor module, when connecting pins for external connection are arranged on the insulated circuit board, one flange part of a cylindrical connecting element having flange parts at both ends of the insulated circuit board. Is soldered, and the connection pin is press-fitted by a pin insertion device from the other flange side (see, for example, Patent Document 1).

US Patent Application Publication No. 2009/0194884

  By the way, in the conventional example described in Patent Document 1, since the connection pin is press-fitted into the connection element soldered to the insulating circuit board by the pin insertion device, when the connection element is soldered to the insulating circuit board. In addition, when solder adheres to the inside of the connection element, or dust adheres to the inside during the manufacturing process of the connection element, or the positional deviation between the connection pin held by the pin insertion device and the connection element. If this occurs, the fitting of the connection pins by the pin insertion device is hindered, and smooth press-fitting cannot be performed.

  However, it is not possible to determine whether or not the connection of the connection pin by the pin insertion device is obstructed, and if the connection pin is broken, it can be confirmed visually, but the connection pin is bent or connected. If the pin is tilted, it can be visually confirmed if the bend or tilt is large, but if the bend or tilt is small, it is difficult to confirm visually, and the pin insertion state is accurately determined. There is an unsolved problem that it cannot be determined.

  Accordingly, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and a pin insertion device and a pin insertion failure determination method capable of accurately determining whether the pin insertion state by the pin insertion device is good or not. The purpose is to provide.

  In order to achieve the above object, one aspect of a pin insertion device according to the present invention is a pin insertion device for press-fitting a pin into a hollow cylinder fixed to a substrate, the pin holding the pin and the cylinder A pin insertion head that is inserted into the pin insertion head, a vibration sensor that is attached to the pin insertion head and that detects vibration energy in a process in which the pin insertion head inserts the pin into the cylindrical body, and vibration energy detected by the vibration sensor An insertion failure determination unit that determines an insertion failure of the pin into the cylindrical body based on a detection value and a determination threshold. Also, in one aspect of the above-described pin insertion device according to the present invention, the substrate is configured by an insulating circuit board including an insulating substrate and a wiring circuit, and the cylindrical body is connected to the cylindrical portion and the wiring circuit. It is preferable that the pin is made of a conductive metal having a flange portion projecting in the radial direction at the end of the pin.

In one aspect of the above-described pin insertion device according to the present invention, it is preferable that the vibration sensor is composed of any one of a strain sensor, a piezo sensor, and an echo stick emission sensor.
In one aspect of the above-described pin insertion device according to the present invention, the insertion failure determination unit receives a vibration energy detection value detected by the vibration sensor, calculates a root mean square of the vibration energy detection value, and calculates When the root mean square peak value exceeds the determination threshold value, it may be determined that the insertion is defective.
In one aspect of the above-described pin insertion device according to the present invention, the insertion failure determination unit includes a defect information storage unit that stores identification information of the cylinder determined to be an insertion failure and the maximum value of the root mean square. You may decide to be.

  Further, in one aspect of the above-described pin insertion device according to the present invention, a pin insertion control unit that drives the pin insertion head is provided, and when the insertion failure determination unit determines that the insertion is defective, the pin insertion head is lowered. A descent stop signal to be stopped may be transmitted to the pin insertion control unit, and the pin insertion control unit may stop the descent of the pin insertion head when receiving the descent stop signal.

Also, one aspect of the pin insertion failure determination method according to the present invention is a method of detecting vibration energy generated when a conductive pin is press-fitted into a conductive cylinder fixed to an insulated circuit board. And determining whether the conductive pin is inserted into the conductive cylinder based on a vibration energy detection value and a predetermined determination threshold.
The vibration energy is preferably detected by an acoustic emission sensor.

  According to the present invention, when the pin is press-fitted into the cylinder fixed to the substrate, the vibration energy transmitted to the pin insertion head holding the pin is detected to determine whether the pin is inserted or not. Therefore, it is possible to accurately determine the quality of the pin insertion state.

It is a figure which shows the insulated circuit board equipped with the connection cylinder which can apply this invention, Comprising: Fig.1 (a) is a top view, FIG.1 (b) is a side view. It is a figure which shows the connection cylinder fixed to the insulated circuit board, Comprising: Fig.1 (a) is sectional drawing, FIG.2 (b) is a top view. It is a perspective view which shows schematic structure of the pin insertion apparatus which shows one Embodiment of this invention. It is sectional drawing which shows an acoustic emission sensor. It is a block diagram which shows a pin insertion defect determination part. It is a figure which shows the detection signal waveform of an acoustic emission sensor. It is sectional drawing which shows a pin insertion state. It is sectional drawing which shows a pin insertion defect state. It is sectional drawing which shows the poor soldering state of an electroconductive cylinder. It is a wave form diagram which shows the RMS signal at the time of pin insertion defect generation | occurrence | production. It is explanatory drawing which shows the relationship between the defect state of an electroconductive conductor, and a detection signal peak value.

Hereinafter, a pin insertion device according to the present invention will be described with reference to the drawings.
First, the conductive connecting cylinder 1 to which the present invention can be applied and the conductive connecting pin 2 press-fitted into the connecting cylinder 1 will be described.
The connection cylinder 1 is made of copper, for example. As shown in FIG. 2, the connecting cylinder 1 is composed of a hollow cylindrical portion 1a and radially extending flange portions 1b and 1c formed at both ends of the cylindrical portion 1a. The flange portions 1b and 1c are formed with notches 1d on the outer peripheral side for allowing solder to flow in and out. As shown in FIGS. 1 (a) and 1 (b), the connecting cylinder 1 has one flange portion 1c that insulates the cylindrical portion 1a on the wiring circuit 4 formed on the insulating circuit substrate 3. It is fixed by soldering using solder 5 so as to be perpendicular to the upper surface of the substrate 3.

As shown in FIGS. 1 (b), 2 (a) and 2 (b), the connection pin 2 is formed by cutting a linear body made of a copper wire having a square cross section into a predetermined length. The length of the diagonal line of the cross section is formed in a prismatic shape longer than the inner diameter of the cylindrical portion 1 a of the connection conductor 1, and is sufficiently longer than the length of the connection cylinder 1.
Then, by the pin insertion device 11 shown in FIG. 3, the connection pin 2 is inserted into the connection cylinder 1 fixed to the insulating circuit board 3 from above and fitted into the cylindrical portion 1 a of the connection cylinder 1. .

As shown in FIG. 3, in the pin insertion device 11, an insulating circuit board XY table 13 is arranged on a base 12, and this XY table 13 horizontally places the insulating circuit board 3 arranged on the XY table 13. Can be moved in the direction .
A support portion 15 is disposed behind the XY table 13 on the base 12. The support portion 15 is provided with a vertical movement mechanism 16 that supports the pin insertion head 14 arranged to face the insulating circuit board 3 so as to be movable in the vertical direction. A reel 17 around which a linear body 18 is wound is rotatably supported on the back side of the support portion 15, and the linear body 18 is pinned via a guide member 19 disposed on the front side of the support portion 15. It is supplied to the insertion head 14.
The pin insertion head 14 includes a clamp portion 20 that holds the linear body 18 and an advance / retreat mechanism 20c. The clamp part 20 has a pair of divided clamp halves 20a and 20b. One clamp half 20a is fixed to the pin insertion head 14, and the other clamp half 20b is movably supported by an advance / retreat mechanism 20c.
The advancing / retracting mechanism 20c moves the clamp half 20b to clamp the linear body 18 (connection pin 2) with the clamp half 20a and the clamp half 20b, and the linear body 18 (connection pin 2). ) To release the grip.

Furthermore, although not shown in the figure, a cutter member that cuts the linear body 18 into a predetermined length to form the connection pin 2 is disposed in the pin insertion head 14, and the linear body 18 is connected to the connecting cylinder 1 by this cutter member. Cut each time it is inserted. The linear body 18 may be cut into a predetermined length to make the linear body 18 into the connection pin 2 and then inserted into the connection cylinder 1.
An acoustic emission sensor (hereinafter simply referred to as an AE sensor) 25 is disposed on the clamp half 20a of the clamp unit 20, and detects vibration energy generated when the connection pin 2 is fitted to the connection cylinder 1. Used as a vibration sensor.

The AE sensor 25 detects an AE (acoustic emission) wave. The AE wave is emitted by a phenomenon in which elastic energy stored therein is emitted as a sound wave (elastic wave, AE wave) when the material is deformed or broken. This AE wave mainly has a high frequency component of several tens of kHz to several MHz which is a frequency in the ultrasonic region.
Here, as shown in FIG. 4, the AE sensor 25 is formed of an aluminum or stainless steel box-shaped shield case 26 with one surface opened, and an insulator such as alumina covering the open end surface of the shield case 26. A wave receiving plate 27 and a piezoelectric (PZT) element 29 mounted on the inner surface side of the shield case 26 of the wave receiving plate 27 via a silver vapor deposition film 28 are disposed. The external output line 31 is connected to the same silver vapor deposition film 30 formed on the opposite side, and the external output line 31 is connected to the connector 32.

  The signal wiring extended from the connector 32 of the AE sensor 25 is connected to the insertion failure determination unit 40 as shown in FIG. As shown in FIG. 5, the insertion failure determination unit 40 converts the analog signal preprocessing circuit 33 to which the AE signal of the AE sensor 25 is input and the analog signal output from the analog signal preprocessing circuit 33 into a digital signal. An A / D conversion circuit 34 for conversion and a determination unit 35 for analyzing the converted digital signal are provided. The analog signal preprocessing circuit 33 includes an AE preamplifier 33a that amplifies the AE signal output from the AE sensor 25, and a bandpass filter 33b that extracts an AE wave frequency component from the amplified signal amplified by the AE preamplifier 33a. Has been.

The determination unit 35 includes a signal processing circuit 35a, a pin insertion quality determination circuit 35b, a defect information storage unit 35c, and a display unit 35d .
The signal processing circuit 35a receives the amplified AE wave digital signal input from the A / D conversion circuit 34, and the pin insertion pass / fail judgment circuit 35b of the RMS signal obtained by performing root mean square (RMS) processing on the AE wave digital signal. Output to.

The pin insertion pass / fail determination circuit 35b compares the RMS signal output from the signal processing circuit 35a with a predetermined determination threshold value to determine whether the pin insertion state is good or not, and the RMS signal is less than the pin insertion failure determination threshold value. Sometimes it is determined that the pin insertion state is good, and when the RMS signal exceeds the pin insertion failure determination threshold, it is determined that the pin insertion state is bad. Then, in the pin insertion pass / fail determination circuit 35b, when the determination result is a pin insertion failure, the maximum value of the RMS signal and the identification information of the connection cylinder currently inserted with the pin are paired and stored in the failure information storage unit 35c. In addition, these are displayed on the display unit 35d. At the same time, when the pin insertion pass / fail determination circuit 35b determines that the pin insertion is defective, that is, when the value of the RMS signal exceeds the determination threshold, a descent stop signal for stopping the descent of the pin insertion head 14 is generated. , To the pin insertion control unit 36. And pin insertion control part 36 will stop descent of pin insertion head 14, if a descent stop signal is received .
The pin insertion control unit 36 receives a stroke detection signal from a stroke sensor 37 that detects a downward stroke of the pin insertion head 14. The pin insertion controller 36 controls the XY table 13 to move the insulating circuit board so as to move the insulating circuit board so that the connecting cylinder 1 is positioned directly below the linear body 18 clamped by the pin insertion head 14. The control is driven, and the vertical movement mechanism 16 and the advance / retreat mechanism 20c are driven to perform the vertical movement of the pin insertion head 14 and the pin insertion control for gripping and releasing the linear body 18.

Next, the operation of the above embodiment will be described.
First, as shown in FIG. 3, the insulating circuit board 3 to which the connecting cylinder 1 is soldered is placed and fixed on the XY table 13 of the pin insertion device 11. In the pin insertion device 11, the linear body 18 wound around the reel 17 is supplied to the pin insertion head 14 via the guide member 19. The front end of the linear body 18 is gripped by the clamp halves 20a and 20b so as to protrude a predetermined length so as not to contact the connecting cylinder 1. Insulated circuit board When the pin insertion device 11 starts operating in this state, the center of the cylindrical portion 1a of the connecting cylinder 1 into which the linear body 18 (connection pin 2) is first inserted is gripped by the clamp portion 20. The XY table 13 is controlled so that it is positioned directly below the tip of the linear body 18 that is positioned. At this time, the connection cylinder 1 is accurately positioned by capturing a planar image of the connection cylinder 1 with an imaging device (not shown) arranged in the pin insertion head 14.

  When the positioning of the connecting cylinder 1 is completed, the vertical movement mechanism 16 is actuated to lower the pin insertion head 14 as shown in FIG. The linear body 18 (connection pin 2) clamped by the clamp part 20 is inserted into the cylindrical part 1a of the connection cylinder 1 fixed to the insulating circuit board 3. At this time, since the length of the diagonal line of the cross section of the connection pin 2 is longer than the inner diameter of the cylindrical portion 1 a of the connection cylinder 1, the linear body 18 (connection pin 2) is press-fitted into the connection cylinder 1.

  When the linear body 18 (connection pin 2) is press-fitted, the AE sensor 25 measures the vibration of the linear body 18 (connection pin 2) via the clamp portion 20, and an AE signal is output from the AE sensor 25. The The AE signal is amplified by the AE preamplifier 33a, and the analog signal in the ultrasonic region shown in FIG. 6A is extracted by the band pass filter 33b. The analog signal is converted into a digital signal by the A / D conversion circuit 34 and input to the signal processing circuit 35 a of the determination unit 35.

  In the signal processing circuit 35a, the digital signal is subjected to root mean square processing to be converted into an RMS signal shown in FIG. The pin insertion pass / fail determination circuit 35b compares the value of the RMS signal with a determination threshold, and determines that the pin insertion state is good when the RMS signal is equal to or less than the determination threshold. When the good state of this pin insertion state continues and the tip of the linear body 18 that becomes the connection pin 2 is press-fitted into the connection cylinder 1 to a predetermined position, the stroke sensor 37 shown in FIG. This ON signal is supplied to the pin insertion control unit 36. Next, when the pin insertion control unit 36 receives the ON signal of the stroke sensor 37, the pin insertion control unit 36 releases the grip of the conductive connection pin 2 by the clamp unit 20. When the vertical movement mechanism 16 is actuated to raise the pin insertion head 14 and rise to a predetermined position, the linear body 18 is gripped again by the clamp portion 20. At this time, the clamp unit 20 grips a part of the linear body 18 that is a predetermined length above the planned cutting part. Next, the pin insertion control unit 36 operates a cutter unit (not shown) to cut the linear body 18 to form the connection pin 2.

  The above operation is repeated to press-fit the linear bodies 18 (connection pins 2) into all the connection cylinders 1 on the insulating circuit board 3. Then, the insulated circuit board 3 that has been completed is taken out from the XY table 13, a new insulated circuit board 3 is set on the XY table 13, and the above-described pin insertion operation is executed. By the way, the connecting cylinder 1 is soldered to the insulating circuit board 3 by the solder 5 applied on the wiring circuit 4 of the insulating circuit board 3, so that the cylindrical portion 1a of the connecting cylinder 1 is subjected to soldering processing. As shown in FIGS. 9A to 9C, a soldering defect that causes solder to adhere may occur on the inner peripheral surface.

  That is, as shown in FIG. 9 (a), a specific example of this soldering failure is that the solder 5 is soldered to the upper end of the inner peripheral surface of the cylindrical portion 1a when the connecting cylinder 1 is soldered to the insulating circuit board 3. 9B, when the solder 5 rises to the middle of the inner peripheral surface of the cylindrical portion 1a, as shown in FIG. 9C, or as shown in FIG. It may adhere to a part of the inner peripheral surface of 1a. Thus, when poor soldering occurs on the inner peripheral surface of the cylindrical portion 1a of the connection cylinder 1, the connection pin 2 of the connection cylinder 1 is press-fitted until the tip reaches the solder adhesion portion. As shown in FIG. 10, the level of the RMS signal output from the signal processing circuit 35a fluctuates below the determination threshold value Sth. For this reason, the pin insertion pass / fail judgment circuit 35b determines that the pin insertion is normal, and press-fitting of the linear body 18 to be the connection pin 2 into the connection cylinder 1 is continued.

  However, as shown in FIG. 8, when the tip of the linear body 18 serving as the connection pin 2 reaches the solder adhesion portion, the press-fitting of the connection pin 2 is obstructed. Therefore, as shown in FIG. The maximum value of the signal is a large RMS signal that exceeds the determination threshold value Sth. Therefore, a defect detection signal is output from the pin insertion pass / fail determination circuit 35 b to the pin insertion control unit 36. Thereby, the descent of the pin insertion head 14 of the pin insertion device 11 is stopped. Then, the maximum value of the RMS signal exceeding the determination threshold value Sth and the unique identification information of the connection cylinder 1 currently press-fitted with the linear body 18 are stored in the defect information storage unit 35c. Then, these pieces of information are displayed on the display unit 35d.

As described above, since the press-fitting is stopped before the linear body 18 press-fitted into the connection cylinder 1 is bent or broken greatly, the damage to the pin insertion device 11 and the influence on the insulating circuit board 3 are affected. Giving can be surely prevented.
Then, by removing the insulated circuit board 3 from which the insertion of the connection pins 2 has been stopped from the XY table 13 and setting a new insulated circuit board 3 on the XY table 13, the pin insertion process is continued again.

For the insulated circuit board 3 in which the pin insertion failure has occurred, the failure information is stored in the failure information storage unit 35c together with the unique identification information of the connection cylinder 1, in the failure information storage unit 35c, and in the display device 35d. Since it is displayed, it is possible to identify the connection cylinder 1 in which the soldering failure has occurred and confirm the soldering failure state.
As described above, with respect to the insulating circuit board 3 having the connection cylinder 1 in which the soldering failure state has occurred, the corresponding connection cylinder 1 is removed, and a new conductive cylinder 1 is manually soldered, and thereafter For example, the pin insertion process can be completed by press-fitting the connection pin 2 into the remaining conductive cylinder 1 with a manual pin insertion machine.

At this time, although not shown, the AE sensor 25 is also attached to the clamp portion of the manual pin insertion machine, and the analog signal preprocessing circuit 33, the A / D conversion circuit 34, and the determination portion 35 are connected to the connector 32 of the AE sensor 25. Accordingly, it is possible to determine a pin insertion failure similarly to the above-described pin insertion device 11.
In the above embodiment, since the AE sensor 25 is applied as the vibration sensor, the responsiveness to detect the pin insertion failure is fast, and the quality determination of the pin insertion state can be performed quickly.

Even when the pin insertion is good, the pin insertion state can be evaluated by storing the maximum value of the RMS signal when the connection pin is inserted into each connection cylinder 1.
Incidentally, when an X-ray image of the quality of the connection cylinder 1 is compared with the peak value of the RMS signal in a state where the connection pin 2 is press-fitted into the corresponding connection cylinder 1, the result shown in FIG. 11 is obtained. Obtained. That is, in connection cylinders 1A to 1C with a large amount of solder on the inner peripheral surface, the peak value of the RMS signal exceeds the determination threshold value Sth, and connection cylinders 1D to 1F with a small amount of solder on the inner peripheral surface are present. It was confirmed that the maximum value of the RMS signal was sufficiently smaller than the determination threshold value Sth. Therefore, it is possible to accurately determine whether the pin insertion state is good or not based on the maximum value of the RMS signal.

In addition, in the said embodiment, although the case where the linear body 18 was cut | disconnected and the connection pin 2 was formed with the pin insertion apparatus 11 was demonstrated, it is not limited to this, The connection pin 2 cut | disconnected beforehand is used. A vibration feeder or the like to be held may be installed to supply the connection pins 2 to the clamp unit 20 one by one.
In addition, the cross-sectional shape of the connecting cylinder 1 and the cross-sectional shape of the connecting pin 2 are not limited to a cylindrical shape and a rectangular shape. Any shape can be used as long as the connecting pin 2 can be press-fitted into the connecting cylinder 1, such as a circular cross section, a cylindrical portion of the connecting cylinder 1 and a triangular cross section of the connecting pin 2. Can be a combination.

  Moreover, in the said embodiment, although the insulated circuit board 3 side of the pin insertion apparatus 11 was XY-moved and the pin insertion head 14 moved to the up-down direction, the pin insertion head 14 was moved XY and the insulated circuit board was demonstrated. The three sides may be fixed, or both may be moved in the XY direction, one may be moved in the X direction, and the other may be moved in the Y direction.

Further, the pin insertion device 11 is not limited to the above configuration, and any configuration can be applied as long as it is a configuration capable of gripping the connection pin and press-fitting into the connection cylinder 1.
Further, the cylindrical body is not limited to the connecting cylindrical body, and any cylindrical body can be applied regardless of the presence or absence of electrical conductivity, and the cylindrical body has a conductive or non-conductive pin. The present invention can be applied when press-fitting.

Further, the vibration sensor is not limited to the AE sensor, and any sensor capable of detecting a pin insertion failure such as a piezo sensor or a strain sensor can be applied.
Furthermore, in the said embodiment, although the case of the solder defect in which the solder adhered to the internal peripheral surface of the connection cylinder 1 was demonstrated, it is not limited to this, A processus | protrusion and a protrusion on the internal peripheral surface of the connection cylinder 1 are demonstrated. It is possible to determine a pin insertion failure such as when an insertion prevention object is attached, the cylindrical portion of the connection cylinder 1 is deformed, or when the connection cylinder 1 is tilted and fixed to the insulating circuit board 3. it can.

DESCRIPTION OF SYMBOLS 1 ... Connection cylinder 1a ... Cylindrical part 1b, 1c ... Flange part 1d ... Notch part 2 ... Connection pin 3 ... Insulation circuit board 4 ... Wiring circuit 5 ... Solder 11 ... Pin insertion apparatus 12 ... Base 13 ... XY table 14 ... Pin insertion head 15 ... support portion 16 ... vertical movement mechanism 17 ... reel 18 ... linear body 19 ... guide member 20 ... clamp portions 20a, 20b ... clamp half body 20c ... advance / retreat mechanism 25 ... acoustic emission (AE) sensor 26 ... Shield case 27 ... wave receiving plates 28, 30 ... silver deposited film 29 ... piezo element 31 ... external output line 32 ... connector 33 ... analog signal preprocessing circuit 33a ... AE preamplifier 33b ... bandpass filter 34 ... AD conversion circuit 35 ... Determining part 35a ... Signal processing circuit 35b ... Pin insertion pass / fail judgment circuit 35c ... Defect information storage part 35d ... Display part 36 ... Pin insertion control part 3 ... stroke sensor 40 ... insertion defect determining unit

Claims (8)

A pin insertion device for press-fitting pins into a hollow cylinder fixed to a substrate,
A pin insertion head for holding the pin and inserting it into the cylinder;
A vibration sensor mounted on the pin insertion head and detecting vibration energy after the pin insertion head starts press-fitting the pin into the cylinder;
Pin insertion device being characterized in that a determining insertion defect determining unit failure insertion by press fitting failure of the pin to said vibration sensor is detected by the vibrational energy detected value and the determination threshold and the tubular body inside based on . The substrate is composed of an insulating circuit substrate including an insulating substrate and a wiring circuit;
The cylindrical body is constituted by a conductive cylindrical body having a cylindrical portion and a flange portion protruding in a radial direction at an end connected to the wiring circuit.
The pin insertion device according to claim 1, wherein the pin is made of a conductive metal.   3. The pin insertion device according to claim 1, wherein the vibration sensor includes one of a strain sensor, a piezo sensor, and an echo stick emission sensor.   When the vibration energy detection value detected by the vibration sensor is input to the poor insertion determination unit, the root mean square of the vibration energy detection value is calculated, and the calculated root mean square peak value exceeds the determination threshold The pin insertion device according to claim 1, wherein the pin insertion device is determined to be defective. 5. The pin insertion according to claim 4, wherein the insertion failure determination unit includes a defect information storage unit that stores identification information of the cylinder determined to be an insertion failure and a maximum value of the root mean square. apparatus. A pin insertion control unit for driving the pin insertion head;
When the insertion failure determination unit determines an insertion failure, the insertion failure determination unit transmits a descent stop signal for stopping the descent of the pin insertion head to the pin insertion control unit,
6. The pin insertion device according to claim 4, wherein the pin insertion control unit stops the lowering of the pin insertion head when receiving the lowering stop signal. 7. Detecting vibration energy generated after starting to press-fit the conductive pin into the conductive cylinder fixed to the insulating circuit board;
Pin insertion failure determination, comprising: determining insertion failure due to a press-fitting failure of the conductive pin to the conductive cylinder based on a detected vibration energy detection value and a predetermined determination threshold value Method.   The pin insertion failure determination method according to claim 7, wherein the vibration energy is detected by an acoustic emission sensor.