JPS61135440A - Mis-grip detector - Google Patents

Abstract

PURPOSE:To simplify a detector and to permit the exchange thereof by connecting mis-grip detecting switches in series to each of clampers provided successively to feed bars, connecting resistors having different resistance values in parallel to each of the switches and detecting the mis-grip from the overall current value. CONSTITUTION:Materials are distributed by means of the clampers 3a1-3a4, 3b1-3b4 of parallel feed bars 3a, 3b to equal-interval lower dies 21-24 on a bed 1 and are worked. The materials are thereafter successively transferred. The mis-grip detecting switches SW1-SW4 are connected in series to each of the clampers and the resistors R1-R4 having the different resistance values are connected in parallel to each of the switches. The overall analog current value thereof is converted to a digital value by an A/D converter 6 and the grip miss is detected by a level shaper 8. The connecting points are simplified to two pints o the feed bars 3a, 3b and the exchange of the feed bars 3a, 3b is made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a misgrip detection device used in a feed bar in a transfer press device.

[Conventional technology]

Transfer press equipment has traditionally been used as a device that performs multi-stroke pressing while transporting materials between a number of presses arranged in a straight line.In nuclide transfer press equipment, materials are transported sequentially between presses. A feed bar and its attached devices are used for this purpose.

FIG. 3 is a perspective view showing the outline of the transfer press device, in which lower molds 21, 22, 23 are placed at equal intervals on the bed l.
・24 are arranged in one row, and the materials are lower molds 21, 22, and 2.
It is subjected to multi-stroke press working while being conveyed on 3.24.

In order to convey the material between the lower molds, feed bars 3a and 3b are installed along the material conveying direction, and the feed bars 3a and 3b have clampers 3al, 3a2 and 3b arranged at equal intervals from the lower mold. 3a3・3a4・3bl・3b2
・3b3 and 3b4 are placed. In addition, feed bar 3a
- The device for driving 3b is omitted in the drawing.

To explain its basic operation, first, with the material placed on each lower mold, the crank of the press is turned to 1.
While rotating, the feed bar 3a is moved as shown in Fig. 4: clamp (arrow a) - lift (arrow b) - advance (arrow C) - down (arrow d) - unclamp (arrow e). )−
If the material is moved in the order of return (arrow f), the material on a certain lower die will be conveyed onto the lower die adjacent to the right, and will be sequentially subjected to multi-stroke press working.

Regarding the feed bar 3b, the clamping and unclamping operations are simply in the opposite direction to that of the feed bar 3a.
Needless to say, the other operations are similar to those of the feed bar 33.

By the way, in the material conveyance process in such a feed bar device, the clamper must normally clamp the material reliably from the lift process through the advance process to the completion of the down process. If the material falls out, it may cause damage to the mold or other serious secondary disasters.

Since it is not possible to predict in advance which clamper of the feed bars 3a and 3b a material falling accident will occur, it is necessary to install a sensor for detecting misgrip, such as a proximity sensor or a microswitch, for each clamper. Conventionally, the misgrip detection sensors arranged for each clamper were each connected to a control device through an independent line.

[Problem that the invention seeks to solve]

Therefore, in conventional feed bar devices, the number of wires required to connect the sensor for detecting misgrip to the control device is large.Especially when replacing the feed bar, it is necessary to connect the wires for each sensor, resulting in a large amount of wiring. The hassle and possibility of incorrect wiring could not be ignored.

[Means for solving the problem and its operation] The present invention has been made to solve such problems, and it is possible to replace the feed bar while arranging a sensor for detecting misgrip for each clamper. An object of the present invention is to provide a novel misgrip detection device that can be wired at only two locations.

In summary, the misgrip detection device of the present invention connects in series misgrip detection switches provided for each clamper connected to a feed bar, and a resistor for each misgrip detection switch. Resistors with different values are connected in parallel, and the combined resistance of the circuit system as a whole is different for each on/off pattern for each switch for detecting misgrip. This allows you to know if something has occurred.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 is a circuit diagram of a misgrip detection device according to an embodiment of the present invention, and this embodiment shows an example in which there are four clampers.

In the figure, SWt, SW2, SW3, and SW4 are misgrip detection switches provided in each clamper, and each misgrip detection switch SW1, SW2, SW3, and SW4 is connected to a constant voltage source 4 through a voltage dividing resistor 5. are connected in series, and each misgrip detection switch SWI - SW2
・Resistance R1 with different resistance value for each SW3 and SW4.
R2, R3, and R4 are connected in parallel.

The resistance values for each resistor R1, R2, R3, and R4 are as follows (
It is defined by formula-1).

Rn=RI X2n″1(Ω) (Formula-1
) In this embodiment, an example is shown in which there are four clampers, so if the resistance value of resistor R1 is 1Ω, each resistor R2・R
The resistance values of 3 and R4 are shown in Table 1 below.

In Table 1 and FIG. 1, when the voltage across the voltage dividing resistor 5 is detected, the voltage is the same as the resistor 5 and the resistors R1 and R2 connected in parallel to each misgrip detection switch SWI, SW2, SW3, and SW4.・It will be determined by the voltage division ratio with the combined resistance of R3 and R4.

Therefore, for example, if the electromotive force of the voltage source 4 is 32V, the resistance value of the resistor 5 is 1Ω, and the resistance value of the copper wire can be ignored, each misgrip detection switch SWl, SW2, SW
3.Resistance R1~ corresponding to the ON/OFF pattern of SW4
The combined resistance up to R4 and the terminal voltage of resistance 5 are the values shown in Table 2 below, and each misgrip detection switch SWI
- The terminal level of the resistor 5 changes in accordance with the on/off pattern of SW2, SW3, and SW4.

In the table below, 0 indicates an off state and 1 indicates an on state.

Table 2 In this embodiment, as mentioned above, the resistance values of the resistors R1, R2, R3, and R4 connected in parallel for each of the misgrip detection switches swi-SW2, SW3, and SW4 are set in a double series. As shown in Table 2, the terminal levels of the resistor 5 are all different for each on/off pattern of the misgrip detection switches SWI, SW2, SW3, and SW4. Therefore,
If the terminal level of the resistor 5 is converted into a digital pattern by the analog-to-digital converter 6 and applied to a control device (not shown), each misgrip detection switch 5w1-sW2/SW
3. You can know in what combination SW4 is turned on and off.

By the way, as mentioned above, the terminal level of resistor 5 is analog -
If converted into a digital pattern by the digital converter 6, basically each misgrip detection switch SWI/SW2
・It is possible to know in what combination SW3 and SW4 are turned on and off, but in reality each misgrip detection switch SWI, SW2, SW3, SW4
The terminal level of the resistor 5 may deviate slightly from the level shown in Table 2 depending on the contact resistance of the , the resistance of the conductor 7, etc. This leaves the possibility that the control device will make an incorrect decision.

Therefore, in this embodiment, the output pattern of the analog-to-digital converter 6 is applied to the level shaper a8, and after being level-shaped by the level shaper 8, it is applied to the WA control device.

The level shaper 8 is composed of an EP-ROM, and each address has a misgrip detection switch 5WI-3W2, SW3, S.
A pattern corresponding one-to-one to the on/off pattern of W4 is stored. and analog-to-digital conversion F3
6 is the misgrip detection switch SWI, SW2, SW3
- Since the terminal level of the resistor 5 determined in accordance with the on/off pattern of SW4 is converted into a digital pattern with multi-stage dark values, the output pattern of the analog-to-digital conversion 's6 is used as an address in the level shaper 8. When the stored pattern is read out, the level shaper 8 outputs a pattern that corresponds one-to-one to the on/off patterns of the misgrip detection switches SWI, SW2, SW3, and SW4.

Therefore, in the following, the terminal level of resistor 5 and the analog -
The relationship between the output pattern of the digital converter 6 and the output pattern of the level shaper 8 will be explained in more detail.

In this embodiment, the misgrip detection switch SWI/SW2
- Since SW3 and SW4 show four examples, there are 24 on/off patterns of the misgrip detection switches SWI, SW2, SW3, and SW4, that is, 16 patterns.
The pattern stored in the level shaper 8 is determined by turning on/off the misgrip detection switches SW1, SW2, SW3, and SW4.
Since there is a one-to-one correspondence with the off pattern, it is necessary to prepare 16 types of 4-bit patterns in the level shaper 8.

Therefore, it is necessary to prepare at least 166 storage areas with 4 bits per address in the level shaping machine 8, but if you simply prepare a storage area of 166 addresses, the analog
Since the digital converter 6 converts the terminal level of the resistor 5 into 16 types of digital patterns with 15 dark values, the misgrip detection switches SWI, SW2, SW3
- When the terminal level of the resistor 5 fluctuates around the above-mentioned dark value due to fluctuations in the contact resistance of the SW 4, fluctuations in the power supply voltage, etc., the analog-to-digital converter 6 generates adjacent patterns, and the level shaper 8 Subsequent devices may commit recreational actions.

Therefore, in this embodiment, the number of dark values in the analog-to-digital converter 6 is increased, and the terminal level of the resistor 5 is subdivided by, for example, four times so that it can be output as 64 digital patterns. 8 storage area is also prepared for 64 4-bit addresses, and the same pattern is stored in the storage area for 4 consecutive addresses.

Incidentally, Table 3, Parts 1 to 4, lists the relationship between the subdivided terminal levels of the resistor 5, the output pattern of the analog-to-digital converter 6, and the output pattern of the level shaping a8. How to read Table 3 for all switches 5
The case where WI-SW4 is off will be explained.

When all switches SW, ~SW4 are off, resistor R1
The combined resistance of ~R4 is theoretically 15Ω, and the terminal level of the resistor 5 is theoretically 2■, but in reality, the terminal level of the resistor 5 is around 2■ due to fluctuations in the power supply and the resistance of the conductor.

Then, when the terminal level of the resistor 5 is 1.94 V or less, the analog-to-digital converter 6 converts the pattern 1111113 to 1.94 V to 1.9 V.
When the voltage is 7V, the pattern [111110] is connected to the resistor 5.
The terminal level is 1.97 V to 2.00 V (7)
When the pattern is (111101), when the terminal level of resistor 5 is 2.00V to 2.03V (7), the pattern is (111101).
1100) are generated respectively, and the above patterns are given to the level shaper 8 as read addresses, and a pattern (0000) is prepared for all addresses specified by any of the above patterns in the level shaper 8. do. Therefore, the terminal level of resistor 5 is 1
．． Level shaper 8 when in the range of 94V to 2.03V
One of the above addresses is specified, and the pattern (0000) is read out.

Table 3 Part 1 Table 3 Part 2 Table 3 Part 3 Table 3 Part 4 Next, the operation of this embodiment will be explained with reference to the above items.

First, while the crank of the press makes one revolution, the feeders 3a and 3b perform clamp-lift-advance-down-
The transport process is performed in the order of unclamping and return. The material on one lower mold is sequentially conveyed onto the lower mold adjacent to the cloth,
Multi-stroke press processing is performed.

As long as the material conveyance process is progressing smoothly, all the misgrid/knob detection switches SW1, SW2, SW3, and 5W are activated during the above-mentioned clamping process and unclamping process.
=4 is in the on state, and as shown in Table 2, the resistors R1~
The combined resistance of the resistor R4 is OΩ. Therefore, since the power supply voltage is directly applied between the terminals of the resistor 5, the level between the terminals of the resistor 5 becomes around 32V, and the misgrip detection switch S
Even if some contact resistance occurs in W1, SW2, SW3, and SW4, or even if the power supply voltage drops slightly, the level between the terminals of the resistor 5 will normally be at least 25V or higher.

As shown in Table 3, Part 4, when the level between the terminals of the resistor 5 is 18.29V or more, the analog-to-digital converter 6 outputs (000011), (000010), and
A digital pattern of (000001) or (000000) is generated, and this digital pattern is given to the level shaper 8 as a read address. As is clear from Table 3 Part 4, the level shaper 8 has the above [000011) and (000
010) ・[000001] ・(00000
Regardless of which of the patterns 0) is given as a readout trace, a pattern 1111 is generated and given to a control device (not shown).

Since the output cover turn of the level shaper 8 corresponds one-to-one to the on/off pattern of the misgrip detection switches SWI, SW2, SW3, and SW4, the control device allows all clampers to operate correctly without dropping the material. I learned that it was activated by lightning.

For example, let us now assume that the clampers 3a2 and 3b2 drop the material during the conveyance process.

When the clampers 3a2 and 3b2 drop the material during the conveyance process, only the misgrip detection switch SW2 is turned off, so the combined resistance of the resistors R1 to R4 becomes around 2Ω. Therefore, approximately 1/1/2 of the power supply voltage is applied between the terminals of the resistor 5.
3 is added, so the level between the terminals of resistor 5 is 10.67
It becomes around V, and the misgrip detection switch 5WI-3W
3. Even if some contact resistance occurs in SW4 or the power supply voltage drops slightly, the level between the terminals of resistor 5 will normally fall within the range of about 9.2V to 10.67V.

As shown in Table 3 Part 4, the level between the terminals of resistor 5 is 8
．． If it falls within the range of 53V to 11.64V, analog-to-digital conversion a6 is (001011)/(001
010) ・ (001001) ・ (0010
00) is generated, and this digital pattern is given to the level shaper 8 as a read address.

As is clear from Table 3 Part 4, the level shaper 8 has the above (001011), (001010),
No matter which of the patterns (001001) and (OO1000) is given as a read address,
A pattern (1101) is generated and given to a control device (not shown).

Since the output cover turn of the level shaper 8 corresponds one-to-one to the on/off pattern of the misgrip detection switches 5WI-3W2, SW3, and SW4, the control device allows the clampers 3a2 and 3b2 to raise and lower the material during the conveyance process. For example, the clamper that has dropped the material is displayed on an operation panel (not shown).

Next, FIG. 2 is a circuit diagram showing another embodiment of the present invention, and parts similar to those in the embodiment in FIG. 1 are given the same reference numerals as in FIG. To explain the difference, in the embodiment shown in FIG. 2, a series circuit of misgrip detection switches SW1-SW2, SW3, and SW4 is connected to a constant current source 9 of, for example, IA.

Therefore, in the circuit shown in FIG. 2, the voltage generated by the constant current source 9 is
Since it is determined in accordance with the on/off pattern of SW3 and SW4, the voltage generated by the constant current source 9 can be converted from analog to digital in the same way as in the embodiment shown in FIG. 56 to convert it into a digital pattern, and convert it to an analog-to-digital converter 6.
If the output pattern is shaped by the level shaper 8, the level shaper 8 will detect the misgrip detection switches SWI and SW.
A pattern corresponding one-to-one to the on/off pattern of SW3 and SW4 is output.

Then, if the output pattern of the level shaper 8 is given to a control device (not shown), the misgrip detection switch SWI
・You can know the on/off pattern of SW2, SW3, and SW4.

In addition, Table 4 shows the misgrip detection switches SWI and SW2.
・SW3/SW4 on/off pattern and resistors R1 to R
Table 4 shows the relationship between the theoretical combined resistance of 4 and the theoretical generated voltage of constant current source 9.

In the embodiment shown in Table 4 and FIG. 2, the resistances R1 to R4 are
The combined resistance varies slightly around the values shown in Table 4, and the power supply voltage of the constant current source 9 also changes slightly around the values shown in Table 4.

Therefore, in the embodiment shown in FIG. 2, for example, 63 threshold values are prepared in the analog-to-digital converter 6 as in the embodiment shown in FIG. 1, and the power supply voltage of the constant current source 9 is output as 64 digital patterns. In addition, if you prepare the storage area for the level shaper 8 for 64 4-bit addresses and prepare the same pattern for the storage area for 4 consecutive addresses, a slight error will occur in the power supply current. Level shaper 8
Misgrip detection switch/nochi SWI/SW2/S
It becomes possible to output a pattern corresponding to the on/off pattern of the W-SW4 on a one-to-l basis.

In the above example, the level shaper 8 is provided with a storage area for 4 bits and 64 addresses, but the pattern generator a8 is provided with a storage area for 4 bits and 16 addresses, and the analog-digital The upper four bits of the output pattern of the converter 6 may be given to the level shaper 8 as a read address.

Further, in the above example, the number of misgrip detection switches is four, but it goes without saying that the number of misgrip detection switches is determined according to the number of clampers. It goes without saying that the detection accuracy improves as the darkness value in .

〔Effect of the invention〕

As explained above, according to the present invention, each misgrip detection switch is connected in series to the power supply, and a resistor with a double resistance value is connected in parallel for each misgrip detection switch. By observing the combined resistance, it is possible to detect in which clamper the misgrip has occurred. Therefore, even when replacing the feed bar, only two wiring locations are required, which reduces wiring effort and significantly reduces the possibility of incorrect wiring.

Furthermore, according to the present invention, a pattern corresponding one-to-one with the on/off pattern of the misgrip detection switch is output, so that a predetermined on/off pattern is periodically output like so-called toothless operation. Even in the case of repeated operation, if this periodically repeated on/off pattern is stored in advance, the above-mentioned tooth extraction operation can be handled as is.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are circuit diagrams showing embodiments of the present invention, respectively;
FIG. 3 is a perspective view showing the principle of the transfer device, and FIG. 4 is a diagram showing the running order of the feed bar in the device shown in FIG. SWl/SW2/SW3/SW4...Misgrip detection switch

Claims (1)

[Claims] The misgrip detection switches provided for each clamper connected to the feed bar are connected in series, and resistors with different resistance values are connected in parallel for each of the misgrip detection switches. A misgrip detection device characterized in that a clamper in which a misgrip occurs is detected by a combined resistance.