JPH0563280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a die height adjusting device for a press machine.

[Prior Art] Die height adjustment employed in crank presses and the like is usually performed by rotating a connecting screw, which is a slide adjustment rod attached to the tip of a connecting rod, in the forward or reverse direction.

The die height adjustment device used for this purpose includes a drive mechanism consisting of a drive source, a plurality of worm wheels, and a wormshaft, and is usually attached to the wormshaft that is directly connected to the drive source, and detects the amount of rotation of the wormshaft. , and a positioning device using a rotary encoder or the like, which calculates the amount of rotation of the connecting screw, that is, the amount of vertical movement of the slide, from the detection results.

Then, in advance, divide the total travel distance to reach the planned die height point by the distance corresponding to one pulse of the roller re-encoder, etc., set the corresponding count value, and set the corresponding count value until it matches the count value. A method is adopted in which the die height point is adjusted to a desired point by continuously sliding the die height point.

Incidentally, in an actual system, a signal similar to a pulse signal obtained from a rotary echoder or the like may be input to a counter. Therefore, conventionally, a filter or the like has been installed to prevent such false signals from being input to the counter.

[Problems to be Solved by the Invention] However, the removal of false signals by the above-mentioned filter or the like cannot be completely achieved. For this reason, the counter counts not only regular pulse signals but also false signals, resulting in a drawback that the correct die height point cannot be reached.

The present invention enables accurate die height adjustment by detecting the presence of a false signal and correcting it, and also detects and corrects the false signal even if the rotational speed of the rotary encoder changes. It is an object of the present invention to provide a die height adjustment device for a press machine equipped with a positioning device that can perform the following steps.

[Means for Solving the Problems] In a first aspect of the die height adjustment device for a press machine of the present invention, a worm shaft is directly connected to a positioning drive source, and a slide adjustment rod is connected to the adjustment rod. A drive mechanism having a worm shaft that meshes with a worm wheel that directly reciprocates up and down, and a positioning device that uses a rotary encoder that is disposed to mesh with one of the worm shafts of the drive mechanism. In the die height adjustment device for a press machine, the positioning device includes a disk having slits provided at equal intervals along the circumference, a predetermined number of unique widths and a large number of equal width slits; A light-emitting element and a light-receiving element that transmit and receive light through the slit of the plate, and a CPU that identifies the slit of the specific width based on the pattern of light received by the light-receiving element.
and when the slit position of the singular width calculated by counting the pulses and the slit position of the singular width specified by the CPU means are different, the pulse count value is calculated by the CPU means. and means for correcting the position of the slit having the specific width specified by the method.

In the second aspect of the die height adjustment device for a press machine of the present invention, instead of the positioning device in the first aspect, slits are provided at equal intervals along the circumference, and have a predetermined number of specific widths. and a shield having a disc having a large number of equal width slits, a light emitting element and a light receiving element that transmit and receive light through the slits of the disc, and a small hole provided between the light receiving element and the disc. a first Schmitt circuit which receives the output voltage of the light receiving element as an input and is operated at a predetermined first trigger voltage; a second Schmitt circuit that is activated;
Based on the difference in trigger voltages in the first and second Schmitt circuits, the time required for one side of the slit in the disc to pass through the small hole in the shield plate is calculated, and the time required for one side of the slit in the disc to pass through the small hole in the shield plate is calculated. From the ratio of the time required to pass through the small hole of the shielding plate,
CPU means for identifying a slit with a singular width among the slits of the disc, a slit position of the singular width calculated by counting pulses, and a slit position of the singular width specified by the CPU means are different; If the pulse count value is
and means for correcting the position of the slit having a specific width specified by the CPU means.

[Operation] In the first aspect of the present invention, die height adjustment by movement of the slide is controlled in the positioning device as follows. That is, in the positioning device, light emitted from the light receiving element is received by the light receiving element through slits provided at equal intervals along the circumference of the disk. The slit consists of a predetermined number of singular width slits and a large number of equal width slits, and the interrupt section consists of a singular width interrupt section on both sides adjacent to the singular width slit and a large number of equal width interrupt sections. As a result, at constant speed, the light emitted from the light-emitting element is observed by the light-receiving element with a light-receiving time proportional to the width of each slit, and the intersection part is observed with a non-light-receiving time proportional to the width of each slit. That is, the large interrupt portion, the small slit portion, and the large interrupt portion are detected successively in this order, thereby identifying the unique width slit. Then, by correcting the number of pulses when detecting this unique width slit to a predetermined value, it is possible to accurately adjust the die height.

In the second aspect of the invention, die height adjustment is controlled as follows. That is, in the positioning device, light emitted from the light emitting element passes through slits provided at equal intervals along the circumference of the disk and small holes in the shielding plate, and is received by the light receiving element. The output from the light receiving element is sent to two Schmitt circuits with different trigger voltages. The outputs of the two Schmidt circuits are sent to the CPU means,
Calculate the time required for one side of the slit in the disc to pass through the small hole in the shield plate. The CPU means further identifies a slit of a specific width among the slits in the disk from the ratio of this and the time required for the slit in the disk to pass through the small hole in the shielding plate. and,
By performing the same correction process as above, it is possible to accurately adjust the die height.

[Example] Hereinafter, a die height adjusting device for a press machine according to the present invention will be described with reference to the drawings.

FIG. 1 shows the arrangement of the crankshaft, connecting rod, connecting screw, slide, etc., and FIGS. 2 and 3 show the die height adjusting device and its main parts according to this embodiment.

Reference numeral 1 denotes a slide on which the upper mold is attached, which is connected to the crankshaft 4 via a connecting screw 2 and a connecting rod 3, and is guided by a gib (not shown) attached to the press machine frame. It is possible to reciprocate up and down. Pressing is then carried out by moving the slide 1 close to and away from a lower die attached to a bolster (not shown) fixed to the lower part of the press machine frame.

10 is a worm shaft directly connected to a positioning drive source; 11 is a worm wheel; and 12 is a worm shaft having a worm 12a formed on the front end side and meshing with the worm wheel 13. The worm wheel 13 is interlocked with the connecting screw 2 and is arranged to be able to move the connecting screw 2 directly up and down.

A rotary encoder 20 is detachably attached to the front end of the wormshaft 12, and constitutes a positioning device.

As shown in FIG. 3, the rotary encoder 20 includes a disc 21 rotatably locked to a rotating shaft 22 disposed on a wormshaft 12 via gears 15 and 16, and a disc 21 fixed to a gear box 17. It consists of a photodetector 23 made up of a light emitting element and a light receiving element attached to a stay 24. Note that 25 is a digital display type die height meter.

As shown in FIG. 4b, the disk 21 has slits 21b, 21d, 21f, . have. The width of each slit is the same except for the slit 21d. Therefore, the slit 21d is replaced with a slit of a specific width, and the other slits 21b, 21
f... is called a slit of equal width. Also, 21
21c and 21e are referred to as an interrupt portion with a specific width, and the other interrupt portions 21a, 21g, . . . are referred to as an interrupt portion with a constant width. A light emitting element 231 and a light receiving element 232 are installed with the disk 21 in between. Light emitted from the light emitting element 231 passes through each slit of the disc 21 and is received by the light receiving element 232.

In Fig. 4c, when the disk 21 rotates at a constant speed, the slits 21b, 21d, 21f, . It is observed as a non-light receiving time proportional to the width of the area. That is, the large interrupt portion, the small slit portion, and the large interrupt portion are detected successively in this order, thereby making it possible to accurately identify the slit 21d having a specific width.

By the way, when the disc 21 is rotating at an accelerated rate or when it is rotating at a decelerated rate, each slit has a different light receiving time depending on the speed at that time. It is not possible to specify the slit 21d having a specific width. Therefore, when the speed changes, it is necessary to detect a slit with a specific width using a method different from that used when the speed is constant.

FIG. 5 is a configuration diagram of a positioning device used in another embodiment of the die height adjusting device according to the present invention, and is configured to be able to detect a unique width slit not only at constant speed but also when speed changes. be.

In the figure, the disk 21, the light emitting element 231, and the light receiving element 232 have the same configuration as that shown in FIG. 4a.

In this embodiment, the disc 21 and the light receiving element 23 are
2, a shielding plate 27 having a small hole 27a is provided. 6A to 6I show the relative positions of the two when an arbitrary slit passes through the small hole 27a of the shielding plate 27, and FIG. 6J shows the output of the light receiving element 232 at that time. . Figure 6j
The symbols a to i inside correspond to the positions in FIG. 6 a to i.

The output of the light receiving element 232 is transmitted to a first Schmitt circuit 28 operated at a predetermined first trigger voltage;
a second Schmitt circuit 29 which is operated with a second trigger voltage different from the first trigger voltage. The output of the Schmitt circuit 28 is
It is sent via the NOT circuit 30 to the AND circuit 32 along with the output of the Schmitt circuit 29. Also,
The output of the Schmitt circuit 29 is transmitted together with the output of the Schmitt circuit 28 via the NOT circuit 31.
It is sent to the AND circuit 33.

For example, the trigger voltage of the Schmitt circuit 28 is
3/4V _DD at rise and 1/4V _DD at rise, while
The trigger voltage of the Schmitt circuit 29 is set to 2/
When set to 3V _DD and 1/3V _DD at fall, the outputs of the light receiving element 232, first Schmitt circuit 28, second Schmitt circuit 29, first AND circuit 32, and second AND circuit 33 are the seventh
It will look like Figures a to e.

In Fig. 7d, the H section indicated by C ₁ represents the time from 2/3V _DD to reach 3/4V _DD at the time of rise, while in Fig. 4e, the H section indicated by D ₁
The part represents the time from 1/3V _DD to 1/4V _DD at the time of falling. These times correspond to 1/12 of the time required for FIG. 6 f to i and a to d, respectively. That is, it corresponds to 1/12 of the time required for one side of the slit of the disk 21 to pass through the small hole 27a of the shielding plate 27.

On the other hand, as shown in FIG. 7b, the time (A ₁ to A ₂ ) required for the slit of the disk 21 to pass through the small hole 27a of the shielding plate 27 is measured.
This time is divided by the arithmetic mean of the pulse widths designated D ₁ in FIG. 7e and C ₁ in FIG. 7d. Similarly, the time (A ₂ to _{A 3} ) required for the intersection part of the disk 21 to pass through the small hole 27a of the shielding plate 27 is calculated by the pulse width represented by C ₁ in FIG. 7d and the pulse width shown in FIG. divided by the arithmetic mean of the pulse widths, expressed as _D2 .

These values indicate that as the rotational speed of the disc 21 becomes faster (slower), the time required for the slit of the disc 21 to pass through the small hole 27a of the shielding plate 27 (A ₁ to _{A 2} )
becomes shorter (longer), and correspondingly, the pulse widths C ₁ , D ₁ , and D ₂ also become shorter (longer). It can be used to identify.

The positioning device of this embodiment also uses the arithmetic mean of the pulse widths C ₁ and D ₁ at the time of rising and falling, and is therefore effective even when the disk 21 moves with uniform acceleration.

As shown in FIGS. 6a to 6i and 6j, after determining the output of the light receiving element when an arbitrary slit passes through the small hole of the shielding plate, if the configuration of the present invention is used, the disc 21 slits 21b, 21d, 21
f... and the interface parts 21a, 21 therebetween
It is also possible to estimate the absolute lengths of c, 21e....

In this way, the slit 21d of the disc 21 having a specific width can be specified by the positioning device using the rotary encoder configured as described above.

Next, a method of detecting when the counter counts false signals using the above-described positioning device using the rotary encoder will be described.

Counting error detection method by identifying singular width slits.

First, the method for detecting whether or not the counter has counted a false signal is as follows.

The number of pulses counted from the start when the slit 21d of the disc 21 with a specific width is detected is:
n is the number of pulses per revolution, m is the number of rotations of the disk 21 from the start, and a is the slit 21 with a specific width from the origin at the start (m=0).
If the number of pulses is up to d, then X=nm+a.

Therefore, at the time when the slit 21d of a singular width is detected, the number of counted pulses It means that something happened. For example, n=50, a=8
Assume that the number of pulses is 0→200→50→300.

FIG. 8 is a diagram showing the state of each movement and the number of pulses of the slit 21d having a specific width to be detected during the movement.

If the number of counted pulses as described in the column ``Number of Pulses with Unique Width Slit Detected'' in FIG. 8 is detected, the counter has not counted a false signal.

By the way, it is assumed that the number of counted pulses X becomes 58, 108, 158, 209, and 259 in the actual movement from 50 to 300. Dividing the number of counting pulses 209 and 259 by the number of pulses per revolution 50,
The remainder is 9 for each. If the counter is not counting false signals, the remainder must be 8. Therefore, in such a case, it means that the electrical circuit such as the CPU that counts the number of pulses has mistakenly counted noise unrelated to the actual amount of slide movement as pulses from the encoder. .

As a result, since the output of the encoder is mechanically fixed with respect to the drive unit, an error in counting the number of pulses directly causes an error in the amount of slide movement. In this example, the final movement amount should be 300 pulses, but in reality,
This means that it has stopped at the pulse number 299.

Next, a correction method will be described when it is detected that the counter has counted a false signal using the positioning device using the rotary encoder configured as described above.

How to correct counting errors.

Assume that the remainder when the count pulse is divided by the number n of pulses per rotation is "b" instead of "a". In that case, the amendments shall be as follows.

() When b>a, b-a<n/2, Let b → a.

() When b>a, b-a>n/2, Let b→n+a.

() When b<a, a-b<n/2, Let b → a.

() When b<a, a-b>n/2, Let b→−n+a.

() When b=a or |b-a|=n/2, No correction.

For example, if n=50, () If a=8 and b=9, correct b=8. In other words, it is assumed that X→X-1.

() If a=8 and b=48, correct it to b=58. In other words, let X→X+10.

() If a=8 and b=7, correct b=8. In other words, X→X+1.

() If a=45 and b=3, correct b=45. In other words, it is assumed that X→X-8.

FIG. 9 is a diagram illustrating the correction methods () to () above.

As is clear from FIG. 9, the above-described correction method attempts to correct the count value at point a, which is the closest to the pulse count value at that time.

In this way, the correction method described above can be applied even when it is detected that the counter has counted a false signal.
The feature is that the pulse count value is corrected while continuing a predetermined movement, rather than by performing a return to the origin.

This allows you to repeat the specified movement from the beginning.
Alternatively, it is possible to avoid drawbacks such as deviation from a predetermined amount of movement during a series of movements up to the return to the origin.

Note that in actual positioning devices, the number of errors in counted values due to electrical noise is at most one per revolution, and if it is sufficiently small compared to n, the above correction method is an extremely effective method. .

Further, in the above correction method, since a correction operation is performed each time a slit with a specific width is detected, it is possible to prevent errors from accumulating and causing a large deviation in the amount of movement.

Next, a method for determining the number of pulses a from the origin at the start to the slit having a singular width will be explained.

How to determine the initial value of the singular width slit.

The first method is to input the number of pulses a from the starting point to the slit 10d of singular width using a numeric keypad or the like and store it in a non-volatile memory. The second method is to rotate the disk 21 multiple times, divide the number of counted pulses x by the number of pulses per rotation n, compare the respective remainders, and if they match, calculate the value. This is a method of storing data in non-volatile memory. This method is effective when the stopping position of the disk 21 at the starting point, and hence the stopping position of the slit 21d having a specific width, cannot be visually observed.

[Effects of the Invention] According to the die height adjustment device for a press machine of the present invention, by using a disc having a specific width and specifying the specific width slit, accurate signals can be obtained even when a false signal is input. Since a positioning device that can perform positioning is used, die height adjustment can be performed extremely accurately. Moreover,
The position of the unique width slit can be specified not only when the disc of the positioning device rotates at a constant speed, but also when the speed changes.

[Brief explanation of the drawing]

Fig. 1 is an assembly diagram showing the arrangement relationship of the crankshaft, connecting rod, connecting screw, slide, etc. Fig. 2 is a plan view showing the die height adjustment device according to the present invention, and Fig. 3 is one of the parts. FIG. 4a is a schematic diagram of an embodiment of the positioning device of the present invention, FIG. 4b is a front view of the disc shown in FIG. 4a, and FIG. 4c is a diagram of FIG. Figure 5 showing the signal pattern of the light receiving element shown in a.
The figures are block diagrams of positioning devices used in other embodiments of the die height adjusting device according to the present invention, and FIGS.
i and j respectively represent the relative positions of the two when an arbitrary slit passes through the small hole of the shielding plate, and the output of the light receiving element when an arbitrary slit passes through the small hole of the shielding plate. Figure, Figure 7 a~
e is a diagram showing the outputs of the light receiving element, the first Schmitt circuit, the second Schmitt circuit, the first AND circuit, and the second AND circuit, respectively;
The figure shows the state of each movement and the number of slit pulses with a specific width that should be detected during that time. Figure 9 shows the correction method when it is detected that the counter has counted a false signal. be. 1...Slide, 2...Connecting screw, 3...Connecting rod, 10, 12...
...Wormshaft, 11, 13...Worm wheel, 20...Total encoder, 21...
Disc, 21b, 21d, 21f...slit, 2
1a, 21c, 21e...interrupt section, 23
1... Light emitting element, 232... Light receiving element, 26...
CPU, 27... Shielding plate, 27a... Small hole, 28,
29... Schmitt circuit, 30, 31... NOT
Circuit, 32, 33...AND circuit.

Claims (1)

[Scope of Claims] 1. A drive having a wormshaft that is directly connected to a positioning drive source, and a wormshaft that meshes with a worm wheel that is connected to a slide adjustment rod and directly reciprocates the adjustment rod up and down. A die height adjustment device for a press machine, comprising: a mechanism; and a positioning device using a rotary encoder disposed in mesh with one of the wormshafts of the drive mechanism, wherein the positioning device is arranged such that the positioning device adjusts the die height along the circumference. A disc having a predetermined number of unique width slits and a large number of equal width slits provided at intervals, a light emitting element and a light receiving element that transmit and receive light through the slits of the disc, and the light receiving element. The slit having the specific width is identified by the pattern of light received by the slit.
CPU means, when the slit position of the singular width calculated by counting the pulses and the slit position of the singular width specified by the CPU means are different, the pulse count value is sent to the CPU means. 1. A die height adjustment device for a press machine, comprising means for adjusting the position of the slit having a specific width thus specified. 2. The die height adjusting device for a press machine according to claim 1, wherein instead of the positioning device, slits are provided at equal intervals along the circumference,
a disc having a predetermined number of singular widths and a large number of equal width slits, a light emitting element and a light receiving element that transmit and receive light through the slits in the disc, and a light receiving element and a light receiving element provided between the light receiving element and the disc. A shielding plate having a small hole, a first Schmitt circuit which receives the output voltage of the light receiving element as an input and is activated with a predetermined first trigger voltage; a second actuated with a trigger voltage of 2;
The time required for one side of the slit in the disc to pass through the small hole in the shielding plate is calculated based on the difference in trigger voltage between the Schmitt circuit and the first and second Schmitt circuits. CPU means for identifying a slit with a specific width among the slits in the disc based on the ratio of the time required for the slit in the disc to pass through the small hole in the shielding plate; If the slit position of the singular width is different from the slit position of the singular width specified by the CPU means, the pulse count value is set to the position of the slit of the singular width specified by the CUP means. A die height adjusting device for a press machine, comprising a positioning device having means for correspondingly correcting the die height.