JPH0262904A - Angle detecting device for press work - Google Patents

Abstract

PURPOSE:To detect an angle without detaching a work by employing an image parallel scan system which uses one line sensor. CONSTITUTION:The device has a base 10, lighting equipment fitted to the base 10, a lens 20 fitted to the base 10, and one line sensor 74 which is positioned behind the lens 20 and moved in parallel crossing a work light image entering the lens 20. The work is irradiated by the lighting equipment and the light image of the work is projected on a photoelectric sensor 74. Then the detection signal of the sensor is inputted to a counter control circuit and converted into a digital signal. Then the counter circuit counts the distance (b) from XS to XT in terms of the number of pulses and also the distance (c) between XT and XR, i.e. a low-level part of the sensor 74 irradiated with the light image of the work in terms of the number of pulses. Then the counted values (b) and (c) are inputted to an arithmetic circuit to perform specific arithmetic and the angle of the work is displayed digitally on a display device. Consequently, the angle can be detected without detaching the work.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention optically projects the end face of a V-shaped bent portion of a target workpiece, and arranges a photoelectric sensor for photoelectric detection on the image plane to determine the pressing angle of the target workpiece. The present invention relates to an angle detection device for press work that measures the angle of the press work.

When using a press brake receiver, a workpiece 4 made of a metal plate is placed on a mold on a table 2, and the workpiece 4 is pressurized by a pressure table to set the angle of the workpiece 4 as shown in FIG.
The angle of the workpiece 4 changes slightly depending on the pressure of the pressure table 6. In the press brake, once the workpiece 4 is removed from the base 2, it cannot be pressed again.

In addition, the workpiece 4 located between the stand 2 and the pressure table 6 is placed on the stand 2.
6 is in the way and the angle cannot be measured with a measuring device6. Therefore, conventionally, after pressing the workpiece 4, it is removed from the stands 2 and 6, and a separately provided measuring tool is used to measure the pressing angle of the workpiece. If the angle is larger than a predetermined value, the pressure of the pressurizing table 6 against the workpiece 4 is readjusted in the direction of increasing it.

In this case, until the workpiece 4 is set at a predetermined angle.

Many defective products are produced. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an angle detection device that can detect the angle of the press work without removing it from between the press table and the support table.

The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

In FIGS. 2 to 4, 10 is a base.

A mounting plate 12 is erected on this.

An arm is fixed to the base 10, and a lighting fixture 1 is attached to the arm.
4 is attached so that the angle can be adjusted. Said installation @12
A tubular holder 16 is fixed to the holder 16, and a cylinder 18 is rotatably fitted into the holder 16. The cylinder 18 is fixed to the holder 16 with screws. An internal cylinder 20 is slidably fitted into the cylinder 18, and a casing 22 is fixed to the front end of the cylinder 20. Casing 22
A guide 24 is fitted and fixed in the opening of the guide 24.
A threaded portion formed on the outer diameter of the holder that holds the lens 26 is screwed into a threaded portion formed on the inner diameter of the holder.

Reference numeral 28 denotes a screw fixed to the guide 24, on which a bevel gear 30 is rotatably supported, a filter holder 32 is fixed to the bevel gear 30, and colored filters 34 and 36 are vertically disposed on this screw. . Filter 34 is colored green, and filter 36 is colored red. 38 is a shaft body rotatably supported by the mounting plate 12, a rope pulley 40 is fixed to one end of the shaft body, and a pipe 42 is fixed to the other end of the shaft body.
is fixed. Reference numeral 44 denotes a cylindrical body that is slidably fitted onto the inner circumferential surface of the pipe 42. One end of a shaft 46 is fixed to this cylindrical body, and the other end of the shaft 46 is rotatably supported by the casing 22. A long groove is formed in the pipe 42 along its longitudinal direction, and the cylindrical body 4 is inserted into the long groove.
A bottle fixed to 4 is slidably arranged.

An intermediate portion of the shaft body 46 is rotatably supported by a bracket 48 fixed to the casing 22. The shaft body 4
A bevel gear 50 is fixed to 6, and the bevel gear 50 meshes with the bevel gear 30. 52 is a pulse motor fixed to the mounting plate 12, and an endless rope is passed between the rope pulley fixed to the output shaft of this pulse motor and the rope pulley 40. 54 is a holder fixed to the internal cylinder 20, and a heat insulating filter 56 is fixed to this. 58 is a tube rotatably supported on the mounting plate 12, and a shaft 60 is rotatably disposed on this tube, a lever 62 is fixed to one end of the shaft 60, and a lever 62 is fixed to the other end.
A member 64 is fixed. A screen 66 made of a glass plate for checking focus is fixed to the member 64.

A lever 67 is fixed to one end of the tube body 58, and a lever 67 is fixed to the other end.
A glass screen 68 for checking focus is fixed via a member. Reference numerals 70 and 72 designate sensor holding members whose upper ends are rotatably supported by shafts 74a and 76a on the mounting plate 12. Photoelectric sensors 74, 76, 78, 80 are attached to the sensor holding members 70, 72.

In this embodiment, a commercially available line sensor is used as the photoelectric sensor 74°76.78.80. The line sensor has a large number of minute light detection elements arranged in a straight line.

The sensor is located within a through hole formed in the mounting plate 12. At the bottom of the sensor holding member 70, 72,
Holes 82,84 are provided through the shaft 74 of the holes 82,84.
Index holes 86, which are stepped screw holes, are transparently provided in the mounting plate 12 at a predetermined pitch, positioned on a line of rotation centered on a and 76a. Adjacent to the holes 82, 84, holes 88, 90 are transparently provided in the holding member 70, 72 so as to be located on the alignment line of the index holes 82 for finely adjusting the angle of the member. 92 and 94 are limit switches having a stopper function, and are attached to the casing 22.

Limit switches 92 and 94 are connected to a controller (not shown) that drives the pulse motor 52.

FIG. 6 shows the central processing unit CPU of this apparatus, in which 100 is a pulse oscillator, 102, 104, 106.degree. 108 is a timing control circuit, and generates timing for driving the photoelectric sensor. ,110.112,114,1
16 is a driver.

Converts the timing signal generated by the timing control circuit to a level that can drive the sensor. 118°120.1
22, 124 are amplifier circuits, and photoelectric sensors 74, 7
6. Differentially amplify the output signals from 78 and 80. 126
, 128, 130, and 132 are slice level setting circuits that slice the analog signal at a constant level and convert it into a digital signal. 134 is a counter control circuit, which receives the signal from the oscillator 100 and the sensor 74.
．． The range to be counted is determined by comparing the signals from 76.78.80. A counter circuit 136 counts the pulses output from the counter control circuit 134. 138 is an arithmetic circuit, which calculates the center of the thickness of the workpiece 4 based on the value counted by the counter circuit 136, and at the same time calculates a correction value in the angle setting input circuit 142, and calculates the center of the thickness from the coordinate reference of the center. The purpose is to find the distance between . 140 is a register circuit;
Four types of values obtained by the circuit 138 are stored. A calculation circuit 146 calculates the angle A of the workpiece 4 based on the sensor interval value from the register circuit 140.

150 is a display, and 142 is an angle setting input circuit, which sets the approximate angle of the workpiece 4 and stores correction values at each angle.

Next, the operation of this embodiment will be explained.

First, the base 10 is arranged so that the lens 26 faces the press end surface of the workpiece 4 held between the pressure table 6 of the press brake and the press plate 2. Next, the levers 67 and 62 are rotated. and connect the screen 66.68 to the sensors 74 and 76.7.
8 and 80 to face each other. Next, loosen the screw 160 and
Slide the internal cylinder 20 in its longitudinal direction, set the image reflected on the screen 66°68 to the desired magnification, and then tighten the screw 16.
0 to fix the internal cylinder 20 to the cylinder 18. Next, rotate the holder of the lens 26 to remove the screen 66.
Focus the image of work 4 reflected in 68. When the pressure table 6 and the press brake stand 2 and the workpiece 4 are made of the same material and have the same end surface condition, the end surface of the workpiece 4 is painted red in accordance with the green filter 34. Thereby, the contrast between the end face of the workpiece and other parts can be increased, and the end face of the workpiece and the tables 2 and 6 can be distinguished. If the end surfaces of the tables 2, 6 and the workpiece 4 are different, the optical image of the table 2, 6 and the optical image of the workpiece 4 can be distinguished using a central processing bag [color filter 34. Or, it is not necessary to provide the motor 5.
By driving the bevel gear 50.30 and rotating the bevel gear 50.30, the red filter 36 can be positioned on the optical image of the workpiece. When using the red filter 36.

The end surface of the workpiece is colored green. Depending on the pressing angle of the workpiece 4, the sensor 74.7 on a predetermined optical image of the workpiece 4
6. Determine the angle of rotation of the retaining member 70.72 about the axes 74a, 76a so that the 78.80 is located, and insert the stepped screw 162 through the hole 82. Screw the holding member 70 into the hole 86.
．． 72 is fixed to the mounting plate 12. After setting the fixed angle of the holding member 70 , 72 , the angle value is input into the circuit 142 . This angle value can be configured to be automatically input to the circuit 142 by a signal from a switch or the like provided for each index hole. The circuit 142 creates a coordinate correction value of xS, which will be described later, based on this angle value. The workpiece 4 is irradiated by the proving device 14, and the workpiece 4 is
irradiate the photoelectric sensor 74.76.78.80 with the optical image. At this time, the screens 66 and 68 are connected to the levers 62 and 6.
The measurement switch 164 is rotated to move it above the front proximity position of the sensors 74, 76, 78, 80.
When the button is pressed, the detection signals of the sensors 74, 76, 78, and 80 are input to the counter control circuit 134.

The signal from sensor 74 will now be explained. sensor 7
4 is converted by circuit 126 into the digital signal shown in FIG. 9C. A low level portion C of the digital signal in FIG. , XT
The distance C between and XR is counted by the number of pulses. This count value C is input to the arithmetic circuit 138, where:
b+(c/2)=d is calculated. Based on the above d value and the angle correction value of the circuit 142, the arithmetic circuit 138 calculates
Based on the coordinate values, the X coordinate value xi of the center point P1 of the optical image of the workpiece 4 is calculated. By the same operation as above, the arithmetic circuit 138 calculates P2. P3. The X coordinate value of point P4 is calculated and these values are stored in register 140. The arithmetic circuit 146 uses the above-mentioned X1, x2 and the sensor 74.
Based on the distance l between 76, first calculate X=lx21-1xll, and thereby, 5inC1=X/J! is calculated, and C1=Sin-"X/Jl is calculated.

P3 for the Y coordinate axis using the same principle as above. Angle C2 of the line segment passing through P4 is calculated. The angle A of the workpiece 4, which is the sum of C1 and 02, is digitally displayed on the display 150. The operator can obtain the desired pressing force of the pressurizing table 6 by increasing the pressurizing force of the pressurizing table 6 until the workpiece 4 reaches a predetermined angle while looking at the above display. This pressing force, ie, the amount of approach of the pressurizing table 6 to the table 2, is stored in a storage device. When measuring the angle of the workpiece 4, the pressure table 6 is moved slightly away from the table 2 to release the pressure on the workpiece 4. This is because the workpiece 4 has a tendency to return to its angle slightly when the pressure from the pressure table 6 is released, and this return needs to be taken into account. As shown in FIG. 8, a half mirror H is placed between the sensor D and the lens L, a screen S is placed above the half mirror H, and the midpoint between the half mirror H and the sensor 0 If the distance a and the distance between the screen S and the midpoint of the half mirror H are set to be the same, the image on the sensor D can be viewed with the screen S, which is sold separately. In the figure, F is a colored filter and G is a heat insulating filter. In this embodiment, as shown in FIG.
Although a semi-fixed method using four 6.78 and 80° wires is used, the method is not particularly limited to this method. For example, as shown in FIG. 11, an image parallel scanning method using 170.2 line sensors may be adopted.

In this method, the angle of the workpiece is measured by moving one sensor 170 on the left and right sides up and down. By arranging the sensor 170 diagonally and moving it at a pitch of about 1/3 of the sensor length, the entire press area of the optical image of the workpiece can be covered. Further, FIG. 12 shows an image parallel scanning method using one line sensor 172. FIG. 13 shows an image rotation scanning method using one line sensor 174. If the sensor 172 is tilted to use a rotational scanning method, it can be rotated at a pitch of 15 to 18 degrees to cover the entire press area of the workpiece light image. FIG. 14 shows an image rotation scanning method using 176.2 single-element sensors. This method is a single-element version of the method shown in Fig. 13 above, and requires a fine scan pitch, but since the reading time for a single element is short, the overall sub-constant time is also more advantageous than the method shown in Fig. 12 above. Become. Figure 15 shows 178.4 to 8 single element sensors.
This shows a semi-fixed system using individual units.

Although the method shown in Fig. 10 is made into a single element, the workpiece light image 1
Since it is not possible to cover the entire area of 80, this is the cheapest method in which manual settings are made each time according to a regular sample depending on the target work. In this method.

Since it is only possible to detect whether the press angle of the workpiece matches the sample angle, the operator must watch the display and press the press table until the workpiece angle matches the sample angle. Bring it closer to the table.

Since the present invention employs an image parallel scanning method using one line sensor, it has the advantage that the brace angle of the workpiece can be detected with a small number of line sensors.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the press brake, Figure 2 is a plan view, Figure 3 is a sectional view taken along line A-A, Figure 4 is a rear view, Figure 5 is a schematic diagram, and Figure 6 is a block circuit diagram. , Fig. 7 is an explanatory drawing, Fig. 8 is an explanatory drawing, Fig. 9 is an explanatory drawing, Fig. 10 is an explanatory drawing, Fig. 11 is an explanatory drawing, Fig. 12 is an explanatory drawing, Fig. 13 is an explanatory drawing, FIG. 14 is an explanatory diagram, and FIG. 15 is an explanatory diagram. 2...Receiver is stand, 4...Workpiece, 6...Pressure stand, 1
0... Base, 12... Mounting plate, 14... Lighting equipment, 16... Holder, 18... Cylindrical body, 20... Lens, 34. 36... Filter, 66 ...Screen, 68...Screen, 70.72...Sensor holding member, 74,76.78°80...Photoelectric sensor.

Claims (1)

[Claims] 1. Base 10 and lighting fixture 14 attached to base 10
, a lens 20 attached to the base 10, and the lens 2
One line sensor 172 is located behind the lens 20 and is moved in parallel in a direction across the workpiece light image entering the lens 20, and the angle of the workpiece light image is determined based on the scan output signal of the line sensor 172. An angle detection device for press work comprising a processing device that generates a signal and a display device that displays the angle signal.