JPS59176611A - Angle detector for press work - Google Patents

Abstract

PURPOSE:To detect the angle of a work without detaching the work from a pressure nor receiving table by forming an optical image of the work by illumination light on a photoelectric sensor through a lens, heat insulating filter, etc, and generating a work angle signal. CONSTITUTION:The work 4 in process of machining such as bending by the pressure and receiving tables of a press is lighted by a luminaire 14 provided to the arm of the base of the press so that the angle is adjusted freely. Then, a light image of the work 4 is formed on screens 66 and 68 through the lens, a color filter 34, heat insulating filter 56, etc., and detected by photoelectric line sensors 74 and 76, and 78 and 80. Their detected values are A/D-converted and processed by a CPU together with the angle of rotation of the luminaire 14 for arithmetic value correction to calculate two straight lines successively to the coordinate position of the center point of the light image of the work 4 and also decide on the angle of intersection of those straight lines corresponding to the work angle, thereby displaying them on a display device 150. Therefore, the angle of the work being machined is detected without being detached from the pressure table nor receiving table.

Description

Detailed Description of the Invention The present invention optically projects the end face of the V-shaped bent part of the target workpiece, and installs a photoelectric sensor for photoelectric detection on the image plane to determine the press 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.

The press brake receiver is used when a workpiece 4 made of a metal plate is placed on a mold on a table 2, and the workpiece 4 is pressed by a pressure table 6 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 a press brake, the workpiece 4 is placed once, and the support is placed on the stand 2.
If you remove it, you will not be able to press it again. Further, the angle of the workpiece 4 located between the support table 2 and the pressure table 6 cannot be measured with a measuring tool because the tables 2 and 6 get in the way. Therefore, conventionally, after the workpiece 4 is pressed, it is removed from the tables 2 and 6, and the press angle of the workpiece is measured using a separately provided measuring tool, and when the angle is larger than a predetermined value, Readjust to increase the pressure on the workpiece 4. In this case, a large number of defective products will be produced before the workpiece 4 is set at a predetermined angle. 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, IO is a base, and 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. The mounting plate 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.

28 is 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 the colored filter 3 is fixed to this screw.
4.36 is installed vertically. Filter 34 is colored green, and filter 36 is colored red. A shaft 38 is rotatably supported by the mounting plate 12, and a rope pulley 40 is fixed to one end of the shaft, and a pipe 42 is fixed to the other end. 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 44 is inserted into the long groove.
The pins fixed to are arranged so that they can slide freely. An intermediate portion of the shaft body 46 is rotatably supported by a bracket 48 fixed to the casing 22. The shaft body 46
A bevel gear 50 is fixed to the bevel gear 50, 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, on which a shaft 60 is rotatably arranged, a lever 62 is fixed to one end of the shaft 60, and a member 64 is fixed to the other end. 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 tubular body 58, and a glass screen 68 for checking focus is fixed to the other end via a member. 70.72 is a sensor holding member, the upper end of which is rotatably attached to the mounting plate 12 with shafts 740J76. supported. A photoelectric sensor 74, 76, 78, 80 is attached to the sensor holding member 70, 72.

As the photoelectric sensors 74, 76, 78, and 80, commercially available line sensors are used in this embodiment. 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. A hole 82.84 is transparently provided in the lower part of the sensor holding member 70.72, and the shaft 7 of the hole 82.84
Index holes 86, which are stepped screw holes, are transparently provided in the mounting plate 12 at a predetermined pitch, located on the rotation line centered on the 4th and 76th lines. 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. 92.94 is a limit switch with a stopper function.

It is 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, and 102, 104, 106, and 108 are timing control circuits, which generate timing for driving the photoelectric sensor. 110, 112, 114, 11
6 is a driver, which converts the timing signal generated by the timing control circuit to a level that can drive the sensor. Amplifier circuits 118, 120, 122, and 124 differentially amplify output signals from the photoelectric sensors 74, 76, 78, and 80. Slice level setting circuits 126, 128, 130, and 132 slice the analog signal at a constant level and convert it into a digital signal. 13
4 is a counter control circuit, and an oscillator 100
The range to be counted is determined by comparing the signals from the sensors 74, 76, 78, and 80. 136 is a counter circuit, and the counter control circuit 13
Count the pulses output from 4. 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, which stores four types of values obtained by the circuit 138 described above. 146 calculates the angle A of the workpiece 4 based on the sensor interval value. 150 is a display, 142
An angle setting input circuit 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 sandwiched between the pressure table 6 of the press brake and the press plate 2. Next, rotate the lever 67.62 to move the screen 66.68 to the sensor 74, 76°7.
8. Place it opposite to 80. 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 2o to the cylinder 18.

Next, rotate the holder of the lens 26 so that 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.

In addition, if the end surface condition of the workpiece 4 is different from that of the workpiece 2 and 6,
, 6 and the optical image of the workpiece 4 can be distinguished by the internal circuit of the central processing unit CPU, the colored filter 34. Alternatively, 36 may not be provided. Note that the red filter 36 can be positioned on the optical image of the work by driving the motor 50 and rotating the bevel gear 50.30.

When using the red filter 36, the end face of the workpiece is colored green. Depending on the press angle of the workpiece 4, a sensor 74, 76°78.80
The shafts 74 (L, 7
6. Determine the rotation angle about the stepped screw 162
is screwed into the desired index hole 86 through hole 82.84 or hole 88.90 to secure the retaining member 70.72 to the mounting drawer 2. 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 an XS coordinate correction value, which will be described later, based on this angle value. The workpiece 4 is illuminated by the lighting fixture 14, and the optical image of the workpiece 4 is illuminated onto the photoelectric sensors 74, 76, 78, 80. At this time, the screen 66, 68 is moved above the front proximity position of the sensors 74, 76, 78, 80 by rotating the levers 62, 67, and when the measurement switch 164 is pressed,
Detection signals from each sensor 74, 76, 78, 80 are input to the counter control circuit 134. The signal from sensor 74 will now be explained. The signal of sensor 74 is converted by circuit 126 into a digital signal as shown in FIG. 9C. A low-level portion C of the digital signal in FIG. 9C shows a portion where the optical image of the workpiece 4 hits the sensor 74. The counter circuit 136 counts the distance C between XS and XT by the number of pulses, and counts the distance C between XT and XR by the number of pulses. This count value and C is input to the arithmetic circuit 138, where b+(c/
2)=d is calculated. The arithmetic circuit 138 calculates the above d value and
Based on the X coordinate value of XS based on the angle correction value of the circuit 142, the X coordinate value x1 of the center point PL 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 calculation circuit 146 first calculates X =lX2+-IX11 based on the distance between xi, x2 and the sensor 74.76,
As a result, S in C1=X/L is calculated, and C
1=SlnX/JJ is calculated.

Using the same principle as above, the angle C2 of the line segment passing through the points P3 and P4 with respect to the Y coordinate axis is calculated. The angle A of the workpiece 4, which is the sum of C1 and C2, is digitally displayed on the display 150. The operation lid can increase the pressing force of the pressurizing table 6 while observing the above display until the workpiece 4 reaches a predetermined angle, thereby obtaining the desired pressurizing force of the pressurizing table 6. 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 consideration. 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. 10, line sensors 74, 76, 78,
Although a semi-fixed method using 80.4 wires is adopted, the method is not particularly limited to this method. For example, as shown in FIG. 11, an image parallel scanning method using 1.70.2 line sensors may be adopted. In this method, the angle of the workpiece is measured while 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. Also, the first
Figure 2 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 Figure 13 above, and requires a finer scan pitch, but since the reading time for a single element is shorter, the overall measurement time is also more advantageous than the method shown in Figure 12 above. Become. FIG. 15 shows a semi-fixed system using 178.4 to 8 single-element sensors. Although the system shown in FIG. 10 is made into a single element, since the entire area of the workpiece light image 180 cannot be covered, this is the cheapest method in which manual setting is performed each time according to the target workpiece, in accordance with a regular sample. With this method, it is only possible to detect whether the press angle of the workpiece matches the sample angle, so the operator presses the workpiece while watching the display until the workpiece angle matches the sample angle. Place the stand close to the stand.

Since the present invention is configured as described above, it has the advantage of being able to detect the pressing angle of the workpiece by the press brake.

[Brief explanation of drawings]

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...The receiver is the stand, 4...The workpiece, 6...The pressure stand. 10...Base, 12...Mounting plate, 14...
Lighting equipment, 16... Holding body, 18... Cylindrical body, 2
0...Lens, 34.36...Filter, 66
...Screen, 68...Screen, 70.
72...Sensor holding member, 74,76°78.8
0...Photoelectric sensor, 86... Index hole.

Claims (1)

[Claims] 1. A base, a lighting fixture attached to the base, a lens attached to the base, and a photoelectric sensor located behind the lens and placed on a workpiece light image that enters the lens. a heat insulating filter disposed between the lens and the photoelectric sensor; a processing device that creates an angle signal of a workpiece optical image based on the output signal of the photoelectric sensor; and a display that displays the angle signal. Angle detection device for press work consisting of.