JP2000094070A - Mis-chuck detecting device of transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect the mis-chuck even when a work is supported by fingers through the scoop-up effect. SOLUTION: In a mis-chuck detecting device of a transfer device in a forging press having the transfer device, a work (a) is supported from both sides of a pair of fingers b, b and successively transferred to each pressing position. The constant voltage is applied between a pair of fingers b, b, and a relay 20 for detecting the current is connected parallel to a constant voltage circuit. The relay 20 is operated at the voltage of not less than a specified value, but non-operated at the voltage lower than the specified value, and the mis-chuck or the normal chuck of a work of the finger (b) is detected according to the operation/non-operation. Since the relay 20 for detection is connected in parallel, the change in current based on the mis-chuck is large, and thus, the detection accuracy is also high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a mis-chuck of a transfer device in a forging press with a transfer device in which a workpiece is supported on both sides by a pair of fingers and is sequentially shifted to each press position. It is about.

[0002]

2. Description of the Related Art For example, a forging press A with a transfer device will be described with reference to FIGS.
(Q ₁ , Q ₂ …) on each press position P ₁ , P ₂ ,
P ₃ , P ₄ , and P ₅ are determined, and the operation of grasping and separating the workpiece (work) a by the finger b of the beam F that moves up, down, left, right, and back and forth of the transfer device is repeated, so that the work a is moved to the initial position. Press work is performed by sequentially shifting from P ₀ to each of the press positions P ₁ . At this time, the work a is supplied to the initial position P _0, and the finished product (product) is carried out (paid out) from the press position P ₅ .

[0003] By the way, today, this type of forging press A
Along with the increase in speed, there are many conventional techniques for making the transfer device B also precise and high speed, but they focus on improving the transfer device body. However, to increase the precision and speed, it is necessary to improve the peripheral device and the control method together with the improvement of the main body.

[0004] One of the problems for improving the peripheral devices and the like is a mischuck (misgrip) of a transfer device. In other words, when the billet and the product (work a) are automatically transferred to the respective press positions P ₁ ... By the transfer device B, the work a is supported by the pair of fingers b (chuck) or the work a Is picked up and conveyed to the next step (next press position) due to the restriction due to the above shape. However, at this time, the finger b does not pinch (scoop up) the work a, which may cause a so-called mis-chuck. The mischuck may cause fatal damage to the apparatus, and it is required to detect the mischuck reliably.

Conventionally, as this mischuck detecting device,
Some have incorporated a proximity switch into the transfer device. That is, as shown in FIG.
1 enters the beam F and is supported by the support cylinder 33 via the case 32 so as to be movable only in the front-back direction. A spring 34 is interposed between the case 32 and the support shaft 31, and the support shaft 31, that is, the finger b is urged rightward in FIG. Support tube 33 and case 32
Is adjusted by a push screw 35 and a pull screw 36. In the drawing, reference numeral 31a denotes a spline shaft which slides on a spline portion 32a of the case 32 to guide the support shaft 31.

An operating piece 37 is fixed to the rear end of the finger support shaft 31 with a nut 38, and a proximity switch 39 provided on the case 32 faces the operating piece 37. The opposing distance is adjusted by the screwing amount of the screw 39a, and the proximity switch 39 is turned on or off at a required far position of the operating piece 37, and when the finger b retreats by holding (abutting) the work a, thereafter, When the operation piece 37 is separated by a predetermined length due to the retreat, the operation piece 37 is turned off or turned on to detect the clamping of the work a.
That is, even if the beam F performs the clamping operation of the work a,
If the clamping is mistaken, the mistake can be detected without operating the switch 39.

As another mischuck detecting device, as shown in FIG. 9, a video device V for monitoring each process or a transmitter such as an infrared ray detects whether or not the work a has been conveyed to each process. There is something.

Further, Japanese Patent Application Laid-Open No. 8-90109 discloses that a current-carrying rod abuts on a workpiece a being conveyed, and an electric circuit via the rod and the workpiece a is turned on.
In this case, a technique has been disclosed in which the work a is detected, so that the work is determined to be normal.

In any of the above-mentioned mis-chuck devices, when an abnormality is detected, the transfer device B and the forging press A are immediately stopped immediately to protect the device B and the press A.

[0010]

The above-described method using the proximity switch is effective at the time of the operation of pinching the work a since the stroke amount of the finger b is detected as appropriate, but as shown by the chain line in FIG. In the operation of picking up the work a, the same operation is performed regardless of whether or not the work a is picked up, so that the mis-chuck cannot be detected.

Further, the method of monitoring the work a with the video apparatus V is an expensive apparatus and has a problem economically.
The same applies to the method of detecting whether or not the work a has been conveyed to each step by an infrared transmitter.

The technique described in the above-mentioned publication may be effective when transfer-transferring at normal temperature (cold working) as in sheet metal press working. However, in hot forging, the work is performed at a high temperature (around 1100 ° C.). Therefore, the life of the rod is short due to the configuration in which the tip of the rod is in contact with the outer surface of the work a. Further, since an oxide film is adhered to the outer surface of the work a, stable energization cannot be performed.
The mold Q is cooled, and the mold release agent containing the carbon powder is applied so that the mold Q and the work a are easily separated. This also hinders stable detection.

Further, the energization of the electric circuit through the work a
Conventional detection means for detecting non-energization is connected in series to the electric circuit, and the detection means is connected to a relay R shown in FIG.
In the case of y, the detection operation becomes unstable. That is, for example, the applied voltage: DC 24 V, the resistance of the relay Ry: 64
Assuming that the resistance of the workpiece a between the pair of fingers b and b is 3.35 Ω and the resistance of the mis-chuck (non-chuck) is 78 Ω, the current flowing through the relay Ry is 36. 89 mA, when mis-chucked: 33.06 mA, no significant difference. The reason why the resistance does not become で も even at the time of the mis-chuck is because the presence of the release agent (mold lubricant) or the like allows the pair of fingers b, b to conduct not less than a little in the scooping operation. The mold lubricant is electrolyzed to enhance its conductivity. For this reason, the resistance at the time of mis-chucking becomes small, the current flowing through the relay Ry becomes close to that at the time of normal chucking, and the relay Ry may not operate.

An object of the present invention is to make it possible to accurately detect a mis-chuck even when the work a is supported by the finger b while the work a is being supported.

[0015]

In order to solve the above-mentioned problems, the present invention applies a constant voltage between the above-mentioned pair of fingers, and connects a current detecting means to the constant voltage circuit in parallel. A mis-chuck of the work of the finger is detected based on a current fluctuation of the detecting means.

When the current detecting means is connected in parallel, the current change of the current detecting means due to the resistance change between the fingers is large (see the embodiment). For this reason, even if the insulation is reduced by the electrolysis of the mold lubricant, the current change due to the resistance change is large, and the detection accuracy of the current detection means is also improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is as follows.
In a forging press with a transfer device that supports the workpiece from both sides with a pair of fingers and sequentially shifts to each press position, in the mis-chuck detection device of the transfer device, a constant voltage is applied between the pair of fingers. Apply
A current detection relay is connected in parallel to the constant voltage circuit, and the relay operates at a certain voltage or higher and is inoperable at a certain voltage lower than the certain voltage and below a certain voltage. A configuration for detecting a mis-chuck and a normal chuck of a finger work may be employed.

In a transfer apparatus having a plurality of pairs of fingers, a sensor detects whether or not the work has been sent to the first support position of the transfer apparatus, and based on the detection signal, the work is fed. , Continuous, one step, or discontinuous, and the stored value is sequentially converted to the stored value of the next support position for each transfer cycle of the transfer device, and each stored value is In addition, a configuration is adopted in which a mischuck detection signal at each clamping position is compared, and if they do not match, it is determined to be a mischuck.

According to this configuration, a mis-chuck between each pair of fingers can be detected regardless of the manner in which the work is fed into the transfer device.

The above embodiments are advantageous in that the forging press is a hot forging press and the fingers support the workpiece by a rake operation. This is because the influence of the mold lubricant can be reduced.

When a constant voltage is applied between the pair of fingers, it is preferable that one of the fingers is grounded. Normally, however, the pair of fingers is used for a pair of beams moving up, down, left, right, and back and forth of the transfer device. It is preferable that one finger is attached to one beam in an insulated state, and the other finger is attached to the other beam in a conductive state and grounded.
In this case, the beam can be made of an insulating resin such as FRP to reduce the weight, and the ground can be separately grounded with a lead wire or the like. One beam may be made of FRP and the other beam may be made of metal.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, a forging press A of a transfer apparatus B of this embodiment has five upper and lower dies P _{1 to} P ₅ ,
Q _{1 to} Q ₅ are provided, and the operation of scooping up and supporting the work a by the finger b of the beam F that moves up and down, left and right and back and forth of the transfer device B (see FIG. 8A) and the operation of retreating and separating are repeated. , not shown initial position fed by the workpiece feeding device workpieces a of (the first support position) P _0, and one after the other to shift between each mold _{P 1, Q 1 ...... P 5} , Q 5, press Processing. Below, the upper mold P ₁ ~P
The descending position of ₅ is defined as a press (process) position, and P _{1 to} P ₅
Indicated by

As shown in FIG. 3, the finger b has the shape of a rake claw, and is bolted to a mounting bracket 10 fixed to the beam F. An epoxy insulating plate 11 is fixed to the mounting surface of the finger b of the beam F to which one of the pair of fingers b is mounted by a bolt 12, as shown in FIG. 13 is connected to the metal beam F. An insulating bush 14 is inserted into the bolt 13, and the mounting bracket 10 is further inserted.
Project into the beam F without touching the beam F. An insulating bush may be interposed between the beam F and the metal fitting 10. A lead wire 15 is screwed to a protruding end of the mounting bracket 10, and the lead wire 15 is connected to a metallic outlet 16 provided on the back surface of the beam F. Therefore, one of the fingers b is connected to the metallic outlet 16 while being insulated from the beam F. In addition,
An insulating agent is applied to the interface between the bolt 13 and the beam F and the insulating plate 11. The other finger b is bolted to the beam F without the interposition of the insulating plate 11. For this reason, this finger b conducts to the beam F. If the beam F to which the one finger b is attached is made of an insulating resin such as FRP, it is not necessary to employ an insulating structure using the epoxy insulating plate 11 or the like.

As shown in FIG. 4, a DC power source E is applied between the pair of fingers b, b, and a resistor R is interposed in the constant voltage circuit. When a is scooped, the current is limited so as not to cause an overcurrent. Further, a detection relay 20 is connected in parallel to the constant voltage circuit between the fingers b, b, and a capacitor 21 is connected to this relay 20 in parallel.
Means that the workpiece a moves during the transport of the workpiece, causing a change in current
Chattering of the relay 20 due to the change is prevented.
The grounding in the figure was performed on the frame of the transfer device.

In the mis-chuck detection circuit shown in FIG. 4, when the work a is not scooped, the resistance R
, The detection relay 20 is energized (operated). When the work a is scooped by the fingers b and b, both ends of the detection relay 20 are short-circuited via the finger b and the work a. If a short circuit occurs, the bias of the detection relay 20 is released (deactivated), and it is detected that the work a has been scooped. The non-operation of the detection relay 20 is taken out as an action signal of the a contact or the b contact of the relay. In this manner, when the detection relay 20 operates, the mis-chuck state is detected, and when the detection relay 20 is not operated, the normal chuck state including the transport state (during transition to the next process) is detected.

The circuit shown in FIG. 4 is arranged between each pair of fingers b, b as shown in FIG. 5, and this circuit is provided with a normality judgment relay 30 for the mis-chuck power source E. When the relay 30 is not operating, the detection device does not operate, and the transfer device and the press A do not operate. In the figure, R _1, R ₂ ...... resistance R, 20 _1, 20 ₂ ...... shows the relay 20.

The operation of the mischuck detecting device having this configuration will be described with reference to FIGS. 6 and 7. Each signal of the work presence signal shift command and the mischuck normal monitoring timing is as follows.
The data is input to the press control sequencer (CPU) every transfer cycle of the transfer device (transport device) B. On the other hand, at the initial position P ₀ , a detection signal indicating whether or not the work a is present at the position P ₀ is input to and stored in the CPU by a sensor such as a photoelectric tube in each feed cycle. Then, every time the transfer apparatus B sends one cycle, the CPU converts the work presence signal of one process into a work presence signal of the next process. For example, a 0ST (0 stage) work signal is converted into a 1ST work presence signal, and a 1ST work presence signal is converted into a 2ST work presence signal.

The converted work presence signal of each ST is compared with a mischuck detection signal output from the circuit of FIG. 4, for example, an open / close signal of an a contact or a b contact by the operation of the relay 20. If they do not match,
Since there is an error in supporting the work a of the corresponding finger b, b, the press machine A is stopped, and the peripheral devices such as the transfer device B and the work supply device are stopped. For example, FIG. 7 is a signal flow chart in the case where only one work a is conveyed.
If the ST grip (chucking) signal is ON, a normal conveyance state is indicated. Conversely, if the 3ST grip signal is not ON at this time, an error signal is generated as a mis-chuck abnormality and the press body stops and peripheral devices are generated. Operation such as stop is performed. Since the last one work transfer of the press working can be regarded as the signal chart shown in FIG. 7, the work delivery is completed when the automatic stop signal is turned on and all the ST work existence signals are turned off. Then, the forging press A and the transfer device B are stopped (operation is completed).

[0029] Comparison of the work signal present and misses the chuck signals of each ST, press working, fed continuously, jump one step, or the like discontinuities, corresponding to feeding of the workpiece a to either the initial position P ₀ The detected mischuck can be detected.

Incidentally, a constant voltage power supply E: DC 24 V, R
_{(R 1, R 2 ......)} : 30Ω, detection relay 20 (2
0 ₁ , 20 ₂ …)): 648Ω, ON coil voltage: 80% (19.2 V) or more of rated voltage, OFF
Coil voltage: 10% (2.4V) or less of the rated voltage,
Resistance when unclamping (mis-grip, mis-chuck) between fingers b, b: 78Ω, Resistance when clamping:
When the resistance is set to 3.35Ω, the detection relay 20 flows 26 mA at the time of unclamping and 3.7 mA at the time of clamping,
The former coil voltage is 16.7 V, and the latter coil voltage is 2.4
V, which reliably exceeded the voltage at the time of the ON / OFF operation of the relay 20, and could operate normally.

[0031]

As described above, according to the present invention, a mis-chuck is detected by a detection circuit connected in parallel to a pair of fingers, and the detection accuracy is high.

[Brief description of the drawings]

FIG. 1 is a schematic partially cut plan view of an embodiment.

FIG. 2 is a schematic partially cut front view of the embodiment.

FIG. 3 is an enlarged sectional view of a finger portion of the embodiment.

FIG. 4 is a circuit diagram of a mischuck detection circuit according to the embodiment.

FIG. 5 is a circuit diagram of a mischuck detection circuit of the embodiment.

FIG. 6 is a diagram of a mischuck detection system of the embodiment.

FIG. 7 is a timing chart of a mischuck detection signal of the embodiment.

8A and 8B show a conventional mischuck detecting mechanism, wherein FIG. 8A is a cut front view, and FIG.

FIG. 9 is a schematic diagram of a conventional mischuck detection mechanism.

FIG. 10 is a circuit diagram of a conventional mischuck detection circuit.

[Explanation of symbols]

A forging press machine B transfer device E constant voltage source R, R _1, R ₂ ...... resistance P ₀ the initial position P ₁ to P ₅ press position a workpiece (work) b fingers 20, 20 _1, 20 ₂ ...... Detection relay 21 Capacitor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B30B 15/00 B30B 15/00 B (72) Inventor Toyoichi Shimotsu 1-12-19 Kitahorie, Nishi-ku, Osaka-shi No. F-term in Kurimoto Iron Works, Ltd. (reference) 4E087 FA03 GA01 4E088 HA04 HA05 4E090 FA02 FA06

Claims (5)

[Claims] 1. A pair of fingers b, and supports the workpiece a from both sides in b, the transfer device forging press machine A with B to shift in sequence to each press position P ₁ to P _5, the transfer device B, a constant voltage is applied between the pair of fingers b, b, a current detecting means is connected in parallel to the constant voltage circuit, and the finger is detected based on a current fluctuation of the current detecting means. b, workpiece a of b
A mis-chuck detection device of a transfer device for detecting a mis-chuck of a transfer device. 2. The relay according to claim 1, wherein said current detecting means is a relay which operates at a certain voltage or higher and is inactive at a certain voltage lower than said certain voltage. 2. The mis-chuck detecting device for a transfer device according to claim 1, wherein the mis-chuck and the normal chuck of the workpiece a of the finger b are detected. 3. The first support position P of the transfer device B
_The sensor detects whether or not the workpiece a has been sent to ₀ , and based on the detection signal, stores whether the feeding of the workpiece a is continuous, skips one step, or is discontinuous. The stored values are sequentially converted into the stored values of the next support positions P ₁ ... Every transfer cycle of the transfer apparatus B,
And their respective stored value, the transfer apparatus according to claim 1 or 2, characterized in that so as to determine a miss chuck if they do not match by comparing the miss chuck detection signal at each support position P ₀ to P ₅ Mischuck detection device. 4. The forging press according to claim 1, wherein the forging press is a hot forging press, and the support of the workpiece a by the finger b is a rake operation. Mis-chuck detection device of transfer equipment. 5. The pair of fingers b, b are respectively attached to a pair of beams F, F which move up and down, left and right and back and forth of the transfer device B, and one of the fingers b is insulated from one of the beams F. Attached, the other finger b
5. A mis-chuck detecting device for a transfer device according to claim 1, wherein the device is connected to the other beam F in a conductive state and grounded.