JPH10160434A - Method and device for detecting angle for bending machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for detecting angle for bending machine, by which the angle between two surfaces of a bent work can be detected with high accuracy in a non-contact state. SOLUTION: An angle sensor 3 emits light to an object W to be measured from a light source 9 while the sensor 3 rotates in the normal and reverse directions, and a plurality of optical sensors 11 and 13 symmetrically positioned with respect to the light source receive reflected light from the object W. The light receiving quantities of the sensors 11 and 13 are held synchronously to the rotational angle of the sensor 3 detected by means of a rotational angle detector 33 and a peak position detector 31 detects the peak positions of the received light quantities based on the data about the received light quantities. An angle calculator 35 finds the angle of the object W through calculation based on the rotational angle of the sensor 3 corresponding to the peak positions of the received light quantities of the sensors 11 and 13. Alternatively, the rotating angle detector 3 detects the rotational angle of the sensor 3 when the received light quantities of the sensors 11 and 13 become equal to each other and the angle calculator 33 detects the angle of the object W based on the rotational angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle detecting method for a bending machine and an angle detecting device therefor, and more particularly, to an angle detecting method for a bending machine for measuring a bending angle of a bent work. And its angle detecting device.

[0002]

2. Description of the Related Art Referring to FIG.
The angle detection method for the bending machine for detecting the bending angle 2θ of the workpiece W, which is the workpiece to be measured, which has been bent in cooperation with the die D, is performed by moving the detector 101 up and down.
In general, the bending angle θ is obtained by contacting the tip of the work W with the lower surface of the bent work W, and the bending angle 2θ is obtained by doubling the angle.

[0003] As an angle detecting device 103 for implementing such an angle detecting method, a die base 1 on which a die D is mounted is used.
An elevating device 107 such as a cylinder is provided on the workpiece 05, and the elevating device 107 raises the detector 101 upward in FIG. Detector 1 at this time
For example, a rack 109 that moves up and down integrally with the detector 101, a pinion 111 that meshes with the rack 109, and an encoder 113 connected to the pinion 111 are used to detect the bending angle 2θ. General.

Alternatively, an image of a work bent up by a non-contact type image pickup means is taken, and the image pickup is processed by image processing to detect a bending angle of the work.

[0005]

However, in such a conventional technique, the bending angle of the work W is not directly measured, but the detector 10 which is in contact with the work W is not measured.
Since the bending angle is obtained from the positional relationship between the position of the work W obtained by measuring the position 1 and the position of the die D, there is a problem that it is difficult to detect the angle with high accuracy.

Further, since the detector 101 is brought into contact with the work W to detect the angle, the bent work W is deformed depending on the strength of the contact of the detector 101, and the bending angle changes with time. There is a problem that there is a possibility that this may occur.

Further, when an image processing apparatus is used, since it is a non-contact type, there is no possibility of causing a temporal change due to contact, but there is a problem that the apparatus becomes very expensive.

SUMMARY OF THE INVENTION An object of the present invention is to pay attention to the above-described prior art, and to perform highly accurate angle detection by detecting the angle of the surface of a bent work without contact. It is an object of the present invention to provide an angle detecting method for a bending machine and an angle detecting device thereof.

[0009]

According to a first aspect of the present invention, there is provided an angle detecting method for a folding machine, comprising: a plurality of optical sensors at symmetric positions about a light source; Irradiating detection light from the light source to the object to be measured, and rotating the angle sensor in the forward and reverse directions about the intersection of the detection light and the plane on which the light source and the optical sensor are arranged, The angle of the object to be measured is detected based on the rotation angle of the angle sensor when the amount of light received by the sensor is maximum and the rotation angle of the angle sensor when the amount of light received by the other optical sensor is maximum. To do so.

Therefore, the reflected light, which is reflected by the detection light emitted from the light source of the rotating angle sensor and hits the object to be measured, is received by the optical sensor equidistant from the light source,
The angle of the object to be measured is measured from the angle of the angle sensor at which the amount of received light in each optical sensor reaches a peak. That is, at the intermediate position of the rotation angle of the angle sensor when the amount of received light in each optical sensor equidistant from the light source is at a maximum, the detection light is irradiated perpendicularly to the measurement object, so that the angle of the measurement object is Is detected.

[0011] In the angle detecting method for a bending machine according to the second aspect of the present invention, a detection light is emitted from the light source of the angle sensor having at least a pair of optical sensors at symmetric positions about the light source, The angle sensor is rotated in the normal and reverse directions around the intersection of the plane where the light source and the optical sensor are arranged and the detection light, and from the reference position when the amount of light received by the pair of optical sensors is equal. The angle of the object to be measured is detected based on the rotation angle of the angle sensor.

[0012] Accordingly, the detection light emitted from the light source of the rotating angle sensor is reflected by the object to be measured, and the reflected light is received by a pair of optical sensors equidistant from the light source. The angle of the object to be measured is measured from the rotation angle of the angle sensor when the amounts are equal. That is, when the amounts of light received by the optical sensors equidistant from the light source are equal, the angle of the object to be measured is detected because the detection light is emitted from the light source to the object to be measured perpendicularly.

According to a third aspect of the present invention, there is provided an angle detecting device for a bending machine, wherein a plurality of optical sensors for receiving reflected light from the object to be measured are provided at symmetrical positions around a light source which emits detection light to the object to be measured. An angle sensor that is rotatable in forward and reverse directions around an intersection of the detection light with a plane on which the light source and the optical sensor are disposed and detects a rotation angle of the angle sensor with respect to a predetermined reference position A rotation angle detector, a peak position detector for detecting a peak of the reflected light received by the optical sensor, and detection by the rotation angle detector to correspond to the peak detected by the peak position detector And an angle calculator for calculating the angle of the object to be measured based on the rotation angle of the angle sensor.

Therefore, while the angle sensor is rotated in the forward and reverse directions, the detection light is emitted from the light source to the object to be measured, and a plurality of optical sensors provided at symmetrical positions with respect to the light source emit reflected light from the object to be measured. Is received. The received light amount at this time is held in synchronization with the rotation angle of the angle sensor detected by the rotation angle detector, and the peak position detector determines the peak position of the received light amount based on the data of the received light amount. To detect. The angle calculator detects the rotation angle of the angle sensor corresponding to the peak position of each optical sensor by a rotation angle detector, and calculates and obtains the angle of the measured object based on the rotation angle.

According to a fourth aspect of the present invention, at least one pair of optical sensors for receiving reflected light from the object at a symmetric position about a light source that emits detection light to the object. And an angle sensor rotatable in forward and reverse directions around an intersection of the detection light with a plane on which the light source and the optical sensor are arranged, and a rotation angle of the angle sensor with respect to a predetermined reference position. A rotation angle detector, and an object to be measured based on the rotation angle of the angle sensor detected by the rotation angle detector when the amount of the reflected light received by the pair of optical sensors is equal. And an angle calculator for calculating the angle of (i).

Accordingly, while the angle sensor is rotated in the forward and reverse directions, the detection light is emitted from the light source to the object to be measured, and at least a pair of optical sensors provided at symmetric positions with respect to the light source reflect light from the object to be measured. Receives light. A rotation angle detector detects a rotation angle of the angle sensor when the light reception amounts of the pair of optical sensors are equal, and an angle calculator detects an angle of the measured object based on the rotation angle.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Since a processing machine such as a press brake to which the angle detecting method for a bending machine and the angle detecting device according to the present invention are applied is generally used, a detailed description thereof will be omitted.

FIG. 3 shows a sensor head 3 as an angle sensor in the angle detecting device 1 for a bending machine according to the present invention.
It is shown. In FIG. 3, a sensor head 3 is provided on a die base 5 on which a die D for performing a bending process on a workpiece W to be measured in cooperation with a punch P is mounted. The sensor head 3 is rotatably provided around a rotation axis RC (see FIG. 6) parallel to the longitudinal direction of the die D and the punch P, that is, the bending line, by a rotation driving device (not shown). Further, it is provided so as to be movable in a bending line direction (a direction orthogonal to the paper surface in FIG. 3) by a moving device (not shown).

Referring to FIGS. 4A and 4B, a projector as a light source for emitting a laser beam BM as detection light in a direction orthogonal to the front surface 7 is provided at the center of the front surface 7 of the sensor head 3. 9 are provided. In addition, the sensor head 3
A first light receiver 11 and a second light receiver 13, which are optical sensors, are provided on the front surface 7 at equal distances with the light projector 9 interposed therebetween.

Referring also to FIG. 6, the rotation axis RC is above the laser beam BM emitted from the projector 9 and is orthogonal to the laser beam BM. 9. This line coincides with a straight line included in a plane including the first light receiver 11 and the second light receiver 13. Therefore, the sensor head 3 is configured to rotate about such a rotation axis RC by a driving device (not shown).

Next, a control system of the angle detecting device 1 for a bending machine will be described with reference to FIG. First light receiver 11
And the second light receiver 13 are connected to a light receiver changeover switch 19 via preamplifiers 15 and 17, respectively. The light receiver changeover switch 19 selects a light reception signal from the first light receiver 11 or the second light receiver 13. Is done. The selected light receiving signal is passed by the band-pass filter 21 only to a signal having a frequency of a predetermined width, amplified by the amplifier 23, and input to the synchronous reading circuit 25.

In the synchronous reading circuit 25, the received light data is stored in the first received light data memory 27 or the second received light data memory 29 in synchronization with the emission of the laser beam BM from the light projector 9, and the received light data is The peak position detector 31 detects the peak of the received light signal on the basis of this, and the rotation angle detector 33 calculates the rotation angle of the sensor head 3, and the angle calculator 35 calculates the bending angle of the workpiece W. .

That is, when receiving the signal indicating that the bending process is completed, the measurement control unit 37 issues a light receiver selection signal to the light receiver changeover switch 19 to select the first light receiver 11 or the second light receiver 13. , The sensor head 3 by a predetermined rotation angle
One-step drive is performed by rotating
A one-step drive completion signal is issued to the synchronous reading circuit 25 to synchronize the received light data with the rotation angle of the sensor head 3. The synchronization of the synchronization reading circuit 25 is synchronization with the modulation signal of the modulator 39. If the modulation is performed by a sine wave, the peak of the sine wave is read in synchronization.

Next, with reference to FIGS. 4 and 5, the principle of detecting the bending angle 2 · θ of the work W will be described.

Referring to FIG. 4A, the sensor head 3
Is rotated to a position where the rotation angle becomes θ ₁ as shown in the figure, the amount of laser light BM applied from the light projector 9 to the surface of the work W is reflected and received by the first light receiver 11. Is maximized. Referring to FIG. 4B, when the sensor head 3 is similarly rotated to a position where the rotation angle becomes θ ₂ , the amount of the laser beam BM received by the second light receiver 13 becomes maximum. FIGS. 4A and 4B show the case where the reference angle is 0 degree (that is, horizontal).

FIG. 5 shows a change in the amount of received light with respect to the rotation angle of the sensor head 3 at this time. In general, the inclination angle of the sensor head 3 is equal to the reference angle θ (the example shown in FIG. 4). Is the case of θ = 0 degree), whereas the amount of light received by the first light receiver 11 becomes maximum at θ _{1 in} the counterclockwise direction,
The amount of light received by the second photodetector 13 when the ₂ theta to hour hand direction with respect to the inclination angle of the reference angle theta of the sensor head 3 it can be seen that the maximum.

The first light receiver 11 and the second light receiver 13 are
As described above, the sensor head 3 is provided at an equal distance from the light projector 9, so that the rotation of the sensor head 3 from the horizontal position (that is, θ = 0) when the amount of light received by the first light receiver 11 is maximum in FIG. The angle θ ₁ and the rotation angle θ ₂ of the sensor head 3 from the horizontal position when the amount of light received by the second light receiver 13 is maximum.
In the intermediate position between the above, the laser beam BM is projected perpendicularly to the bent workpiece W. Thus, the angle θ of the bent workpiece W is θ = (θ ₁ +
θ ₂ ) / 2. Here, in θ ₁ and θ ₂ , for example, the hour hand direction is assumed to be positive, and the counter hour hand direction is assumed to be negative.

Next, referring to FIG. 2 and FIG. 1 and FIG. 6, a procedure of a method of obtaining the bending angle of the work W using the above-described angle detecting device 1 will be described.

First, when the angle detecting operation is started (step SS), the sensor head 3 is moved to a measurement position in parallel with the bending line by a moving device (not shown) during bending (step S1). The sensor head 3 is rotated about the rotation axis RC by θ-α (see FIG. 6) with respect to the target bending angle 2 · θ to prepare for the angle detection operation (step S2).
Here, when setting the target bending angle θ, the springback amount is taken into consideration, and the setting is made so that the workpiece W can be surely inserted between θ ± α.

When the bending is completed (step S3),
The measurement controller 37 outputs the first light receiver selection signal to the light receiver switch 19 to select the first light receiver 11 (step S4). The sensor head 3 at the [theta]-[alpha] position, which is the measurement start angle, is rotated one step at a predetermined angle in the hour hand direction by a rotation driving device (not shown) (step S5). At this time, the synchronous reading circuit 2
5 sends a one-step drive completion signal to the sensor head 3
The amount of light received by the first light receiver 11 is measured in synchronization with the rotation of the first light receiver 11, and the data is stored in the first light reception data memory 27 (step S6).

Step 5 and subsequent steps are repeated until the rotation angle of the sensor head 3 reaches θ + α. When the rotation angle of the sensor head 3 reaches θ + α (step S7), the measurement control unit 37 sends a second light receiver selection signal to the light receiver switch 19. The output is performed to select the second light receiver 13 (step S8). Here, the value of α is set according to the distance between the light projector 9 and the first and second light receivers 11 and 13 and the distance between the sensor head 3 and the work W to be measured, and is set to, for example, about 10 degrees. .

The sensor head 3, which has been rotated to the θ + α position for measurement by the first photodetector 11, is rotated one step at a predetermined angle in the counterclockwise direction by the rotation driving device (step S9). At this time, a one-step drive completion signal is issued from the measurement control unit 37 to the synchronous reading circuit 25,
The amount of light received by the second light receiver 13 is measured in synchronization with the rotation of the sensor head 3, and the data is stored in the second light reception data memory 29 (step S10).

Steps 9 and subsequent steps are repeated until the rotation angle of the sensor head 3 reaches θ-α. When the rotation angle reaches θ-α (step S11), the first light reception data memory 2
7, the peak position detector 3
1 detects the peak position of the amount of light received by the first light receiver 11 (step S12). Similarly, the peak position of the amount of light received by the second light receiver is detected from the data string stored in the second light reception data memory 29 (step S13).

The angle θ ₁ of the sensor head 3 corresponding to the peak position of the first light receiver 11 and the sensor head 3 corresponding to the peak position of the second light receiver 13 thus obtained.
From the angle θ ₂ , the angle calculator 35 calculates the bending angle θ of the workpiece W (step S14), and completes the angle detection operation (step SE).

From the above results, since the sensor head 3 is a non-contact type angle sensor, there is no possibility that the work W is deformed by applying an external force as in the related art, and the adjustment state of the sensor itself changes with time. Since there is no fear, the workability is good.

Further, since an expensive apparatus such as an image processing apparatus is not required, the entire apparatus can be configured at low cost.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. That is, in the above-described embodiment, the sensor head 3 is provided on the die base 5 so as to be movable and rotatable in the bending line direction. However, the sensor head 3 may be attached to the press brake bed so as to be movable up and down and back and forth. is there. Thereby, it is possible to cope with the measurement of the bending angle in a wider range.

[0038]

As described above, in the angle detecting method for a bending machine according to the first aspect of the present invention, the detection light emitted from the light source of the rotating angle sensor hits the object to be measured and reflects the reflected light. The angle sensor receives light with an optical sensor equidistant from the light source, and measures the angle of the measured object from the angle of the angle sensor at which the amount of light received by each optical sensor reaches a peak. That is, since the angle is detected by the non-contact type angle sensor, there is no possibility that the work is deformed by applying an external force as in the conventional case, and the adjustment state of the sensor itself is not subject to change with time, so that the accuracy is high. Can be detected. Further, since an expensive device such as an image processing device is not required, the entire device can be configured at low cost.

In the angle detecting method for a bending machine according to the second aspect of the present invention, the detection light emitted from the light source of the rotating angle sensor is reflected by the object to be measured, and the reflected light is reflected by the angle sensor from the light source. Light is received by a pair of optical sensors at a distance, and the angle of the object to be measured is measured from the rotation angle of the angle sensor when the amount of light received by each optical sensor becomes equal. That is, since the angle is detected by the non-contact type angle sensor, there is no possibility that the work W is deformed by applying an external force unlike the related art, and the adjustment state of the sensor itself does not change with time. Accurate angle detection can be performed. Further, since an expensive device such as an image processing device is not required, the entire device can be configured at low cost.

In the angle detecting device for a bending machine according to the third aspect of the present invention, the light source irradiates the object to be measured with the detection light while rotating the angle sensor in the forward and reverse directions. The plurality of optical sensors receive reflected light from the object to be measured. The received light amount at this time is held in synchronization with the rotation angle of the angle sensor detected by the rotation angle detector, and the peak position detector determines the peak position of the received light amount based on the data of the received light amount. Since the angle detector detects and calculates the angle of the measured object based on the rotation angle of the angle sensor corresponding to the peak position in each optical sensor,
Unlike the related art, there is no possibility that the sensor is deformed by directly or indirectly contacting the work W, and the adjustment state of the sensor itself is not likely to change with time, so that highly accurate angle detection can be performed. Further, since an expensive device such as an image processing device is not required, the entire device can be configured at low cost.

In the angle detecting device for a bending machine according to the fourth aspect of the present invention, detection light is emitted from the light source to the object to be measured while rotating the angle sensor in the forward and reverse directions. In addition, at least one pair of optical sensors receives the reflected light from the object to be measured, and the turning angle detector detects the turning angle of the angle sensor when the amount of light received by the pair of optical sensors becomes equal. Since the angle calculator detects the angle of the object to be measured based on the rotation angle, there is no risk of deformation by directly or indirectly coming into contact with the work W unlike the related art, and the adjustment state of the sensor itself changes with time. Since there is no possibility of receiving the angle, highly accurate angle detection can be performed. Further, since an expensive device such as an image processing device is not required, the entire device can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an angle detection device for a bending machine according to the present invention.

FIG. 2 is a flowchart showing a procedure of an angle detecting method for a bending machine according to the present invention.

FIG. 3 is a side view showing the structure and operation of the sensor head.

FIGS. 4A and 4B are explanatory diagrams showing the movement of inspection light in a sensor head.

FIG. 5 is a graph showing a change in the amount of light received by the light receiver with respect to the rotation angle of the sensor head.

FIG. 6 is an explanatory diagram showing the operation of the sensor head in the angle detection operation.

FIG. 7 is an explanatory view showing a conventional angle detecting method for a bending machine and its angle detecting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 angle detector 9 light emitter (light source) 3 sensor head (angle sensor) 11 first light receiver (optical sensor) 13 second light receiver (optical sensor) 31 peak position detector 33 rotation angle detector 35 angle calculator W Work (measurement object)

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[Procedure amendment]

[Submission date] February 5, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (4)

[Claims] 1. An angle sensor having a plurality of optical sensors at symmetrical positions around a light source, the detection light is emitted from the light source to an object to be measured, and the angle sensor is provided with the light source and an optical sensor. It is rotated in the forward and reverse directions about the intersection of the plane and the detection light, and the rotation angle of the angle sensor when the amount of light received by one optical sensor is maximized and the amount of light received by the other optical sensor is maximized Detecting the angle of the object to be measured based on the rotation angle of the angle sensor when
A method for detecting an angle for a bending machine. 2. An angle sensor having at least a pair of optical sensors at a symmetric position with respect to a light source as a center irradiates detection light from the light source to an object to be measured, and the angle sensor is provided with the light source and an optical sensor. The measured light based on the rotation angle of the angle sensor from the reference position when the amount of light received by the pair of optical sensors becomes equal, about the intersection of the plane and the detection light. An angle detecting method for a bending machine, comprising detecting an angle of an object. 3. A plane on which a plurality of optical sensors for receiving reflected light from the object to be measured are provided at symmetric positions about a light source that emits detection light to the object to be measured, and the light source and the optical sensors are arranged. An angle sensor rotatable in forward and reverse directions around an intersection of the detection light and the detection light, a rotation angle detector for detecting a rotation angle of the angle sensor with respect to a predetermined reference position, and light received by the optical sensor. A peak position detector for detecting a peak of the reflected light, and a measured position based on a rotation angle of the angle sensor detected by the rotation angle detector to correspond to the peak detected by the peak position detector. An angle detector, comprising: an angle calculator that calculates an angle of an object. 4. At least a pair of optical sensors for receiving reflected light from the object to be measured are provided at symmetric positions about a light source that emits detection light to the object to be measured, and the light source and the optical sensors are arranged. An angle sensor rotatable in forward and reverse directions about an intersection of a plane and the detection light, a rotation angle detector for detecting a rotation angle of the angle sensor with respect to a predetermined reference position, and the pair of optical elements An angle calculator that calculates the angle of the object to be measured based on the rotation angle of the angle sensor detected by the rotation angle detector when the amount of the reflected light received by the sensor is equal. An angle detecting device, comprising: