JPH0321845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a shape inspection device that inspects the shape of an object to be inspected and determines that the object is defective if deformation of the object is detected to be more than a predetermined ratio. It is something.

``Prior Art'' Shape inspection devices have been used in manufacturing sites that continuously inspect the shape of an object to be inspected and determine a defect when a deviation of the shape of the object from a reference tolerance is detected.

Conventionally, this type of shape inspection device transports the specimen at a constant speed, detects the green side positions of the specimen at both ends in the transport direction to obtain a time-series signal, and detects the specimen based on changes in this time-series signal. This is to inspect the shape of the specimen.

FIG. 8 shows the configuration of this type of shape inspection apparatus, in which a subject 11 is transported at a constant speed in the direction indicated by arrow X in the figure by a feeding device 12 using, for example, a cylinder. For example, contacts made as chain-like parts by press working are used as objects of inspection with this type of shape inspection apparatus. The contacts in this case have a shape in which a plurality of contacts 14-1, 14-2, etc. are integrally arranged in the same direction with respect to the band-shaped carrier 13, as shown in FIG. The object is a shaped contact.

The carrier 13 is provided with equally spaced pilot holes 16-1, 16-2, etc., which are formed during press working, and are positioned at right angles in the same direction to the carrier 13 by these pilot holes. Contacts 14-1, 14-2, . . . are arranged parallel to each other at equal intervals.

Since the contacts and carriers are separated and used in an intermediate process in manufacturing the connector, the connecting portion E is weak in strength. Therefore, during various secondary processing steps, this portion may be deformed and bent, and in the deformed state it may not be possible to insert it into the fixed insulator. This type of shape inspection device is used to detect such a deformed state.

At a predetermined position on the carrier 13 of each contact, a projector 17 is placed between points P ₁ and P ₂ on both edges of the undeformed contact in the transport direction.
-1, 17-2 and light receivers 18-1, 18-2 are respectively provided. Light receiver 18-1, 18-2
The output terminal of is connected to the input terminal of the measuring circuit 19. As the carrier 13 moves _at a constant speed in the direction of the arrow
The time point at which the state of receiving the projected light from 1 is changed to the state of blocking light is detected, and, for example, a photoelectric switch of the measuring circuit 19 is turned on. At the receiver 18-2, the point P ₂
The time point at which the projected light from the projector 17-2 changes from the blocking state to the receiving state is detected, and the measurement circuit 19
The photoelectric switch is turned off. Points P ₁ and P ₂ are selected as points at which the contact is most likely to deform, depending on the shape of the contact and the details of the secondary processing process.

In this way, the measuring circuit 19 obtains a time-series signal corresponding to the width of the contact in the transfer direction at a predetermined position, for example, by turning on and off a photoelectric switch.
When the contact deforms, the photoelectric switch turns on,
Since the time of OFF switching deviates from P ₁ and P ₂ and the time-series signal changes, the deformation of the contact is detected by taking this state of change.

Further, a shape inspection apparatus has also been proposed in which a predetermined position of the subject is photographed with a camera and deformation of the subject is detected based on the video signal.

``Problems to be Solved by the Invention'' As mentioned above, in the method of obtaining time-series signals and inspecting the deformation of the object based on this, it is necessary as a prerequisite that the transport speed of the carrier is constant. If the transport speed of the carrier changes, this will be mistaken for contact deformation, making it impossible to obtain accurate measurement results. Therefore, when a shape inspection device is incorporated into an on-site manufacturing process, certain transfer conditions are required and the conditions become strict.

Furthermore, in the method of inspecting the deformation of a subject based on camera photography, it is necessary to turn on a strobe light to take a picture in order to obtain a still image of the subject being transported. Therefore, the structure of the device becomes complicated due to the provision of a strobe light shielding mechanism, and the manufacturing cost also increases significantly.

The shape inspection device of the present invention solves the drawbacks of the various conventionally used inspection devices of this type described above, and is capable of quickly performing highly accurate deformation inspection without depending on the transport speed of the specimen. The present invention provides a shape inspection device.

``Structure of the Invention'' The object whose shape is to be inspected according to the present invention has pilot holes arranged in a strip-shaped carrier in its longitudinal direction, and is positioned by the pilot holes so as to protrude to the same side of the carrier 3. The specimen is formed and arranged. This carrier is transported in the longitudinal direction, and the shape of the object is inspected while being transported.

In this invention, a subject detection signal generating means is provided, and the subject detection signal generating means generates a subject detection signal having a pulse width corresponding to the direction of movement of the subject at a predetermined position. Further, a pilot signal generating means is provided, and the pilot signal generating means generates a pilot signal corresponding to the presence or absence of a pilot hole in the transport direction of the carrier. In this invention, the duration of the object detection signal or the pilot signal is counted by the first counter, and the duration of the deviation between the pilot signal and the object detection signal is counted by the second counter. The calculation means calculates the ratio of the count value of the first counter to the count value of the first counter.

When the ratio obtained by this calculation means exceeds a predetermined value, this is detected and a defect determination signal is issued from the determination means.

Therefore, since the deformation is always determined as a ratio based on the duration of the object detection signal or the pilot signal, the deformation rate of the object can be detected with high precision.

``Example'' The present invention will be described in detail below based on an example using the drawings.

In the embodiment, a contact as shown in FIG. 5 will be described as a subject. That is, pilot holes 16- are provided in the longitudinal direction of the belt-shaped carrier 13.
1, 16-2... are arranged at equal intervals, and contacts 14-1, 14-2... as test objects are mutually arranged on the same side of the carrier 13 at the center position of the carrier area where these pilot holes are not present. They are arranged in parallel and protruding. In FIG. 5, contacts 14-2, 14-4 and 14-6 are each deformed at their connecting portions E. In FIG.

The carrier 13 is transported in the longitudinal direction, and a test object detection signal generating means generates a test object detection signal having a pulse width corresponding to the width in the transport direction at a predetermined position of the contacts 14-1, 14-2, etc., which are transported accordingly. will be provided.

That is, a light projector and a light receiving sensor are arranged to sandwich the contact, and a first change from light receiving to light blocking and a second change from light blocking to light receiving at the side edge portion in the transfer direction at a predetermined position of a contact with a normal shape without deformation are performed. The change is detected by the light receiving sensor 21. The output of the light receiving sensor 21 is given to an amplifier 22, and the output signal of the amplifier 22 is used as the object detection signal _A1 .
This object detection signal _A1 is a signal whose logical value becomes "1" when the light-receiving sensor 21 is in a light-shielded state, and its pulse width corresponds to the width of a predetermined position in the transport direction of the object.

In this case, the predetermined position is set on the straight line MM in FIG. Therefore, for a subject as shown in FIG. 5, a subject detection signal as shown in FIG. 6B is obtained.

Pilot hole signal generating means is provided for generating a pilot signal corresponding to the presence or absence of a pilot hole in the carrier transport direction.

That is, in FIG. 5, the pilot holes 16-1, 1
A light projector and a light receiving sensor are arranged with the carrier 13 in between so as to be located on the straight line NN connecting the centers of 6-2..., and the output of the light receiving sensor 23 is sent to an amplifier 24.
given to. The output signal of the amplifier 24 is set as a pilot signal _A2 whose logical value becomes "1" when the light receiving sensor 23 is in a light-shielded state. The pulse width of the pilot signal _A2 corresponds to the length of the portion of the straight line NN in FIG. 5 where no pilot hole exists.

Therefore, for the subject shown in FIG. 5, FIG.
A pilot signal _A2 as shown in is obtained. A first counter is provided for counting the duration of the object detection signal or pilot signal.

In the embodiment, the first counter is configured to count the duration of the object detection signal. As shown in FIG. 1, the output terminal of the amplifier 22 is applied to the enable terminal _te of a first counter 25, and the output terminal of a clock generator 26 is connected to the clock terminal _tc of the first counter 25. Ru. The output of the first counter 25 is given to the CPU 27 as an input signal.

Therefore, when the light-receiving sensor 21 detects the width of the object at a predetermined position of the contact, that is, the width in the transport direction of the object on the straight line MM in _FIG . The clock of the clock generator 26 is output to the first counter 2 between
5, and the counted value is input to the CPU 27.

A second counter is provided for counting the duration of the deviation between the pilot signal and the subject detection signal.

The output terminal of the amplifier 24 is connected to one input terminal of an AND circuit 29 via an inverter 28.
An amplifier 22 is connected to the other input terminal of the AND circuit 29.
output terminal is connected. The output terminal of the AND circuit 29 is connected to the enable terminal _te of a second counter 30, and the output terminal of the clock generator 26 is connected to the clock terminal _tc of the second counter 30.

Therefore, the second counter 30 receives the object detection signal.
When the logical value of _A1 is "1" and the logical value of pilot signal _A2 is "0", the clocks of the clock generator 26 are counted, and the counted value is input to the CPU 27,
The duration of the deviation between the pilot signal _A2 and the subject detection signal _A1 is counted.

For a test object such as that shown in FIG. 5, the signal shown in FIG.
clocks are counted by a second counter 30.
Also, the output terminals of amplifiers 22 and 24 are connected to
The output terminal of the AND circuit 31 is connected to the input terminal of the flip-flop 32, and the output terminal of the flip-flop 32 is connected to the input terminal of the AND circuit 31.
It is input to the CPU 27.

Therefore, the logical values of the object detection signal _A1 and the pilot signal _A2 from the flip-flop 32 are "1".
In this case, a signal with logical value “1” is issued and the CPU
27.

The output terminal of the amplifier 22 is connected to the input terminal of a flip-flop 34 via an inverter 33;
The output of flip-flop 34 is input to CPU 27. Therefore, the logic value of the output signal of the flip-flop 34 becomes "1" in response to the fall of the subject detection signal _A1 , and this signal is input to the CPU 27.

The output terminal of the amplifier 24 is connected to the input terminal of a flip-flop 36 via an inverter 35;
The output of flip-flop 36 is input to CPU 27. Therefore, the logic value of the output signal of the flip-flop 36 becomes "1" in response to the fall of the pilot signal _A2 , and this signal is input to the CPU 27.

A common reset signal is connected to each reset terminal t _R of the first counter 25, second counter 30 and flip-flop 34 of the clock generator 26 so that a reset signal from the CPU 27 is supplied. A common reset signal line is connected to the reset terminals _tR of the flip-flops 34 and 36 so that a reset signal from the CPU 27 is supplied thereto.

The relative positional relationships in each case of the pilot signal _A2 and the subject detection signal _A1 whose mutual positional relationship is to be determined in this invention are shown in FIGS. 4A to 4I. In the embodiment, the pilot signal A ₂ shown in FIG.
On the other hand, when the object detection signal _A1 is in the states B, E, and F, it is assumed that the object is not deformed. A
If the object detection signal _A1 has a relative positional relationship of C, H, and I with respect to the pilot signal _A2 shown in FIG.

If the subject detection signal A ₁ has the relative positional relationship D and G with respect to the pilot signal A ₂ shown in A, then the pilot signal A ₂ and the subject detection signal A for the duration T of the subject detection signal A ₁ It is determined whether the deformation of the subject is within the allowable range based on the ratio of the durations t ₁ and t ₂ of the deviation portion from ₁ .

If the transport speed of the specimen is V, then the specimen detection signal is
The width of A ₁ is given by VT, and the width of the deviation portion between pilot signal A ₂ and object detection signal A ₁ is given by Vt, where its duration is t. If the allowable deformation constant of the object is n and the allowable deformation condition is Vt/VT<n, then t<nT is obtained, and the allowable deformation condition does not depend on the transport speed V of the object.

Figures 7 A to C show the pilot signal A ₂ and the object detection signal when the object is transferred while being accelerated.
The waveforms of the input signals of _A1 and the second counter 30 are shown respectively. In this case, the signal obtained based on the deformation of the object is no longer uniquely proportional to the extent of the deformation. However, even in such a case, the present invention determines the permissible range of deformation of the object based on t<nT, so that the shape of the object can be inspected regardless of the transport speed of the object.

A case will be described in which the pilot signal _A2 and the subject detection signal _A1 are in a relative positional relationship as shown in A and B in FIG. 4.

The first counter 25 starts counting from time τ ₃ and counts the time T up to τ ₄ . At the fall of the object detection signal _A1 at time _τ4 , the logic value of the output signal of the flip-flop 34 becomes "1". The logic value “1” of the output signal of the flip-flop 34 is
When the CPU 27 takes in the data, the CPU 27 executes the interrupt processing shown in FIG.

In the first step 1, the CPU 27 reads the output of the second counter 30 and the output of the first counter 25, but the count value of the second counter 30 is zero in this case, and the output of the first counter 25 is It is T. In the second step (2) the clock generator 2
6. First counter 25 and flip-flop 3
4 is reset. In the third step (3), it is determined whether the duration t of the shifted portion is t=0. In this case, since t=0, no defect determination output is obtained.

At time τ ₂ , pilot signal A ₂ falls,
The logic value of the output signal of flip-flop 36 becomes "1". When the CPU 27 takes in the logic value "1" of the output signal of the flip-flop 36, the CPU
27 executes the interrupt processing shown in FIG.

In the first step (1), the CPU 27 reads the output signal of the flip-flop 32. Next, in the second step (2), it is determined whether the logical value of the output signal of the flip-flop 34 read is "1". In this case, the logic value of the output signal of the flip-flop 32 is "1" at the time T between times τ ₃ and τ ₄ within the duration of the pilot signal, and the process moves to the fourth step, where the failure judgment output is I can't get it. In this case, flip-flops 32 and 36 are reset in a fourth step.

The object detection signal is located at the positions shown by E and F in Figure 4.
Even when A ₁ is obtained, a similar determination is made in this embodiment, and no defective determination output is obtained.

The operation when the object detection signal _A1 is obtained at the position shown in FIG. 4C will be described.

The first counter 25 counts the clocks of the clock generator 26 during the time T ₁ ≈T from time τ ₅ to τ ₆ . In this case, the interrupt process shown in FIG. 2 is executed at time τ ₆ , but since t=0 in the third step, no defect determination output is obtained. Also, at time τ ₂ , the logical value of the output of the flip-flop 36 becomes "1", and when this is taken into the CPU 27, the interrupt shown in FIG. 3 is performed.

In the first step of the interrupt processing shown in FIG. 3, the output of flip-flop 32 is read and the second
The logical value is determined in step . In this case, since the logic value of the output signal of the flip-flop 32 is "0" within the duration of the pilot signal, a defect determination output is obtained in the third step.

The case where the object detection signal _A1 is obtained at the position shown in FIG. 4D will be explained.

At time τ ₈ , the CPU 27 outputs the object detection signal A ₁
When the falling edge of is detected, the interrupt process shown in FIG. 2 is executed, and in the first step (1), t and T ₂ ≈T are read. In the second step (2), the clock generator 26, first counter 25 and flip-flop 34 are reset.

Next, in the third step (3), it is confirmed that t ₁ ≠ 0, so the process proceeds to the fourth step (4), where it is determined whether T < nt. It will be done. In this case, if T<nt, it indicates that the deformation of the object is within the allowable deformation range, so
Defective judgment output cannot be obtained. On the other hand, if it is confirmed that Tnt is present and the deformation of the object exceeds the allowable range, a defect determination output is obtained in the fifth step (5).

At time τ ₂ , the fall of the pilot signal A ₂ causes the logic value of the output signal of the flip-flop 36 to be “1”.
When this is confirmed, the CPU 27 takes it in and performs the interrupt processing shown in FIG. 3. In the first step, the output signal of the flip-flop 32 is read, and in the second step (2), it is determined whether the logic value of the output signal of the flip-flop 32 is "1". In this case, since the logic value of the output signal of the flip-flop 32 is "1" during the duration of the pilot signal, no defect determination output is obtained.

The case where the object detection signal _A1 is obtained at the position G in FIG. 4 will be explained.

At time τ ₂ , the fall of the pilot signal A ₂ causes the logic value of the output signal of the flip-flop 36 to be “1”.
When the CPU 27 detects the
Execute the interrupt processing shown in the figure. In a first step (1), the output signal of flip-flop 32 is read. In this case, the logic value of the output signal of flip-flop 32 is "1", and no defect determination signal is sent out.

In this case, the output signal of the flip-flop 34 becomes "1" at time τ ₁₁ , which is taken into the CPU 27, and the interrupt processing shown in FIG. 2 is executed. The following is the same as the case already described for the case where the object detection signal _A1 is obtained at the position shown in FIG. 4D,
A determination is made that T<nt, and if the deformation of the object exceeds the allowable deformation range, a defect determination output is obtained.

When the object detection signal _A1 is obtained at the position shown in FIG. _4H , the interrupt shown in FIG. Re, 2nd
Since it is determined in step (2) that the logical value is "0", a defect determination output is issued in fourth step (4).

When the fall of the object detection signal _A1 is detected by the output signal of the flip-flop 34 at time _τ13 , the interrupt shown in FIG. 2 is executed, but since t=0 in the third step, no defect judgment output is obtained. do not have.

In this invention, the execution of the interrupt shown in FIG. 3 is given priority over the execution of the interrupt shown in FIG.
It is also possible to adopt a configuration in which execution of the interrupt in FIG. 2 is omitted when a defect determination output is obtained in the interrupt in FIG. 3.

In the case shown in FIG _. 4, the object detection signal _A1 does not exist within the predetermined period, and the interrupt process shown in _FIG . Since the logical value is "0", it is configured to issue a defective determination signal. In this case, the subject is missing from the carrier.

"Effects of the Invention" In this invention, the duration of the object detection signal and the duration of the difference between the pilot signal and the object detection signal are counted, the ratio of these counted values is calculated, and this calculated value is calculated. If exceeds a predetermined value, a defective judgment is issued for the subject. Therefore, even if the transport speed of the subject changes, no error will occur in the test results.

The configuration of the device is also relatively simple, and the manufacturing cost can be significantly reduced.
When a contact as shown in the figure is used as a test object,
It can also perform high-speed inspections at 50 pieces per second. The defect determination criteria can also be set to a desired value with high precision.

For example, when this invention is applied to a digital cassette that stores signals in multiple channels, one channel is used to record a reference clock signal of a constant width as a reference signal, and the other channels are used to record data. Data can be extracted by recording the signal and comparing the time lengths of the reference clock signal and the data signal. By using such a comparison method, data can be extracted without depending on the rise, fall, or speed fluctuation of the rotating system.

In the explanation of FIG. 4, the deformation of the contact as the object to be examined is within a predetermined limit, and T ₁ ≒ T ₂ ≒
Assuming that T ₃ ≈T, the duration of the object detection signal A ₁ was counted by the first counter 25 and used as a reference for ratio calculation. However, if the deformation of the object is large, the duration of the pilot signal _A2 is determined by the first counter 25.
It can be counted and used as a basis for ratio calculation.

Also, for the object detection signals shown in FIGS. 4E and F, for example, the times t ₃ and t ₄ between the fall of the object detection signal A ₁ and the fall of the pilot signal A ₂ fall within the reference range, respectively. It is possible to confirm that the limit has been exceeded and make a defective judgment. That is, assuming that the reference upper and lower limit values are Tl and Th, Tl<τ ₃ <Th and Tl<τ ₄
It can be configured to output a defective determination signal when <Th is not confirmed. With this configuration, defective determination can be performed with even higher accuracy.

According to this invention, as explained in detail above,
The configuration is relatively simple, and the shape of the object can be inspected with high accuracy without depending on the transport speed of the object.
It is possible to provide a shape inspection device that can significantly reduce manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the shape inspection device of the present invention, FIGS. 2 and 3 are flowcharts showing each step of the interrupt processing of the present invention, and FIG. 4 is a shape inspection device of the present invention. A waveform diagram showing the operation of the device, FIG. 5 is a diagram showing the shape of the object to be inspected by the shape inspection device of the present invention, and FIGS. 6A, B, and C are waveform diagrams obtained at each part of the shape inspection device of the present invention. Figures 7A, B, and C are waveform diagrams of Figure 6A, B, and C obtained when transporting with acceleration;
FIG. 8 is a diagram showing the configuration of a conventionally used shape inspection apparatus, and FIG. 9 is a diagram showing the shape of a main part of an example of a subject. 13: Band-shaped carrier, 16-1, 16-2...:
Pilot hole, 14-1, 14-2...: Contact, 21, 23: Light receiving sensor, 22, 24: Amplifier, 25: First counter, 26: Clock generator, 27: CPU, 28, 33, 35: Inverter, 29, 31: AND circuit, 30: second counter, 32, 34, 36: flip-flop.

Claims (1)

[Claims] 1. Pilot holes are arranged in the longitudinal direction of a strip-shaped carrier, a subject is positioned by these pilot holes and protrudes from the same side of the carrier, and the carrier is transferred in the longitudinal direction, and this transfer In the shape inspection apparatus for inspecting the shape of the object under test, the object detection signal generating means generates an object detection signal having a pulse width corresponding to the width in the transport direction at a predetermined position of the object; a pilot signal generating means for generating a pilot signal corresponding to the presence or absence of the pilot hole in the transport direction; a first counter for counting the duration of the object detection signal or the pilot signal; and a first counter for counting the duration of the object detection signal or the pilot signal; a second counter that counts the duration of the deviation from the detection signal; a calculation means that calculates a ratio of the count value of the second counter to the count value of the first counter; 1. A shape inspection device comprising: determination means for detecting that the ratio exceeds a predetermined value and outputting a defective determination signal.