JPH0819900A - Load detection/meeting device for press machine - Google Patents

Abstract

PURPOSE:To provide a load detection/meeting device for press machine capable of detecting machine abnormality of a ram, etc., and setting optimum punching force. CONSTITUTION:The device is provided with a load detection means 28 to detect a load applied to a punching tool 13. The load detection device consists of a strain gage, load cell, etc., and is provided in a drive transmitting system 22 between a drive source 21 of press drive device 20 and a punching tool 13 or it can be provided to each punching tool 13. An abnormality decision means 29 to compare a detected value of the load detection means 28 to a setting value is provided, when the detected value exceeds the setting value, a decision signal of machine abnormality is outputted. A setting means 30, which sets an optimum punching force and pulling out force to an output control device 45 of press drive device 22, is provided. The means 30 sets the optimum punching force based on the detected value of load detection device 28 at machine installation and trial run at start in the every morning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press machine such as a punch press for diagnosing a mechanical abnormality of a press drive device.
The present invention relates to a load detection and coping device for a press machine that performs prediction and setting of an optimum punching force.

[0002]

2. Description of the Related Art A punch press has a ram which is vertically moved by a mechanical or hydraulic punch driving device, and punches with a punch tool connected to a lower end of the ram. Further, the punching force by the punch driving device is set to a predetermined value obtained in advance by calculation or the like.

[0003]

In the drive transmission system including the ram, generally, there are some weak points such as a groove for engaging a punch tool and a pin for connecting to a pitman arm of a crank mechanism. is there. In the case of a ram having a two-stage connection structure, the connection between the rams is also a weak point in terms of strength. Therefore, if overload occurs during punching or during punching of the punch tool after punching, a member such as a ram that constitutes a drive transmission system may have mechanical abnormality such as damage at the insufficient strength portion as described above. . In particular, when the punching speed is increased, the above-mentioned problem of breakage easily occurs.
Further, the punching force of the punch driving device is desired to be set to an optimum value in order to eliminate wasteful power consumption and to improve processing quality and processing efficiency. It is difficult to uniformly set the optimum punching force at the design stage due to differences in temperature conditions, operating environment, etc.

An object of the present invention is to provide a load detection / coping device for a press machine capable of predicting a mechanical abnormality in a punch drive system. Another object of the present invention is to facilitate setting of the optimum punching force and the optimum pulling force. Still another object of the present invention is to enable prediction of machine abnormality, detection of the optimum punching force, the punching force for setting the optimum pulling force, and the pulling force with a simple configuration.

[0005]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. The load detection / coping device of this press machine is applied to a press machine that punches a plate material (W) by a punch tool (13) driven forward and backward by a press drive device (20). In this press machine, a load detection means (28) for detecting a load acting on the punch tool (13) and a detection value of the load detection means (28) are compared with a set value, and a machine abnormality occurs when the set value is exceeded. And an abnormality determination means (29) for outputting the determination signal of.
In the above-mentioned configuration, a setting for setting the optimum punching force and / or pulling force for the output control device (45) of the drive source (21) of the press drive device (20) from the detection value of the load detection means (28) Means (30) may be provided. The load detection means (28) includes a press drive device (2
It may be provided in the drive transmission system (22) between the drive source (21) of 0) and the punch tool (13).

[0006]

According to the load detecting / measuring device having this structure, the load acting on the punch tool (13) is detected by the load detecting means (2) at each punching process or at a predetermined punching process.
8) detected. The load may be detected by detecting both the load acting in the punching direction and the load acting in the pulling direction, or by detecting only one of them. The detected value of the load thus detected is compared with the set value by the abnormality judging means (29), and if the detected value exceeds the set value, a mechanical abnormality judgment signal is output. A mechanical abnormality can be predicted from this determination signal. When the setting means (30) is provided, it is possible to set the optimum punching force and pulling force for actual processing from the detection value of the load detecting means (28) at the time of trial punching or the like, and the press driving device can be optimally punched. You can drive with power or pull-out force. When the load detecting means (28) is provided in the drive transmission system (22) of the press drive device (20), it is not necessary to provide the load detecting means for each punch tool (13), and the cost can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a perspective view of a turret type punch press which is a press machine equipped with this load detection / handling device. The frame 1 is composed of a lower frame 2, an upper frame 3 and a column portion 4, and a fixed table 5 is arranged at the center of the lower frame 2. Slide tables 6 are arranged on both sides of the fixed table 5, and the slide tables 6 are driven forward and backward (Y-axis direction) along with a carriage 8 along a rail 7 on the upper surface of the lower frame 2. A cross slide (not shown) that moves left and right (X-axis direction) is arranged on the carriage 8, and a plurality of work holders 9 that hold the plate material W are attached to the cross slide. In the upper frame 3 and the lower frame 4,
The upper turret 10 and the lower turret 11 are rotatably supported, and are rotationally driven in synchronization by an indexing drive mechanism (not shown).

The upper turret 10 is a punch tool 13 (FIG. 1).
A plurality of punch holder holes 12 into which the punch tools are inserted are arranged on the circumference, and the lower turret 11 is formed by similarly arranging a plurality of die tools 14 corresponding to the punch tools 13 on the circumference. The punch tool 13 and the die tool 14 are obtained by installing the punch 15 and the die 17 in the punch holder 16 and the die holder 18, respectively.

Each punch tool 13 is indexed to the punch position P as the upper turret 10 rotates, so that the ram 19
Is connected to the lower end of. That is, the T-shaped connecting portion G, which is the head of the punch tool 13, engages with the groove portion of the connecting portion F formed at the lower end of the ram 19. The ram 19 is supported on the upper frame 3 by a guide member 41 so as to be vertically movable, and is vertically driven by a crank type press drive device 20. The press drive device 20 transmits the rotation of the motor 21 as a drive source to the flywheel 24 by the belt 23, and the drive is transmitted from the flywheel 24 to the ram 19 via the clutch brake 26, the crankshaft 25, and the pitman arm 27. It is a thing. The pitman arm 27 is connected to the ram 19 by a pin 27a. The crankshaft 25, the pitman arm 27, the ram 19, and the like form a drive transmission system 22 between the motor 21 and the punch tool 13.

A strain gauge 28, which is a load detecting means for the punch tool 13, is attached to the side surface of the pitman arm 27. The strain gauge 28 detects the punching force and the pulling force generated as a dynamic load on the punch tool 13 during the punch operation from the strain of the pitman arm 27.
Resistor 28a attached to pitman arm 27
And a bridge box 28b containing a bridge circuit including the resistor 28a. The detection value obtained from the bridge box 28b is input to the abnormality determination means 29 and the punching force setting means 30 via the amplifier 43. The amplifier 43 calibrates the target load measurement value such as the maximum load value accurately according to the predicted dynamic strain waveform during processing. The strain gauge 28
Instead of being provided on the pitman arm 27, may be provided on the ram 19, as shown by the chain line in FIG.

The abnormality determining means 29 compares the detected value of the strain gauge 28 with a predetermined set value, and when the detected value exceeds the set value, it outputs, for example, an alarm or NC device 3 as a machine abnormality determination signal.
It outputs an emergency stop command to 1). The NC device 31 is a device that controls the entire machine. The comparison of the detected value of the strain gauge 28 by the abnormality determining means 29 is performed at a predetermined timing during punching and pulling out in each punching operation according to the stroke position of the ram 19 obtained from the ram position detector 44. It is set. The set value for the punching force of the abnormality determination means 29 and the set value for the pulling force are set separately. In addition,
Since the pull-out force is generally about 5 to 15% of the punching force, the strain gauge 28 is set to double the strain sensitivity when measuring the pull-out force by the 2-gauge method. Instead of the 2-gauge method, the 4-gauge method may be set so that the strain sensitivity at the time of measuring the pull-out force is increased four times to perform the measurement. The setting means 30 is means for setting the optimum punching force and the optimum pulling force in the output control device of the drive source so that the punching operation is performed by the press driving device 20 with the set punching force and pulling force. In the embodiment, the power supply value is set in the output control device 45 including the power supply circuit for the motor 21. The setting means 30 can set the punching force and the pulling force in both the manual mode and the automatic mode by switching the input mode. Also,
When the automatic mode is set, the setting means 30 is provided with an optimum force calculation means for performing a predetermined calculation from the detected value obtained from the strain detector 28 to set the optimum punching force and pulling force. The setting means 30 may set only one of the optimum punching force and the optimum pulling force.

The operation of the above configuration will be described. The strain gauge 28 detects the strain of the pitman arm 27 that occurs during punching and pulling out of the punch tool 13 for each punching operation, and the detected value is monitored by the abnormality determining means 29. The abnormality determining means 29 compares the detected values of the strain gauge 28 detected during punching and pulling with the set value for the punching force and the set value for the pulling force, respectively, and when the detected value exceeds the set value, a mechanical abnormality is detected. For example, an alarm signal is output as the determination signal. This alarm can predict a mechanical abnormality of the punch press. As a result, for example, it can be predicted that the pin 27a connecting the pitman arm 27 and the ram 19 and the connecting portions G and F between the ram 19 and the punch tool 3 are likely to be damaged. In addition, the tool life of the punch tool 3 can be easily managed. Further, since the strain gauge 28 is provided in the drive transmission system 22 of the punch driving device 20, it is possible to detect the load in the punching direction and the load in the pulling direction with high speed response and high accuracy, and moreover, to detect the load in each punch tool 13. It is not necessary to provide any means, only one strain gauge 28 is required, and the cost can be minimized. The term "one" as used herein means one set, and two strain gauges are used in the 2-gauge method and four strain gauges are used in the 4-gauge method.

The setting means 30 is set with predetermined punching force and pulling force obtained from the measured value of the strain gauge 28 when the plate material is trially punched. The punching force and the like by the trial punching are set, for example, at the time of factory installation after shipment of the punch press or at the start of operation every morning. In this case,
Since the punching force and the pulling force are set based on the measured value of the strain gauge 28, the optimum punching force and pulling force can be set. By setting in this way, the punch drive device 20 is operated with the optimum punching force and the optimum pulling force, waste of power is saved, and improvement of processing quality and production efficiency can be expected. It should be noted that the optimum punching force and the optimum pulling force may be set in the setting means 30 based on the detected value of the strain gauge 28 at the time of normal working, not limited to the trial hitting.

FIG. 3 shows a second embodiment. In this example, the drive transmission system 22 of the press drive device 20 includes a pitman arm 37, a connecting rod 38, a first ram 39A, and a second ram 3.
It is applied to a punch press including 9B. The first ram 39A is rotatable with respect to the upper frame 3, and the second ram 39B is attached to the groove-shaped connecting portion D provided at the eccentric position at the lower end.
The connecting portion E composed of the T-shaped head is engaged. Thereby, a plurality of second rams 39B (only one is shown) can be selected and connected to the first ram 39A. The strain gauge 28, which is a load detecting means, includes a connecting rod 38 that connects the pitman arm 37 and the first ram 39A.
It is attached to the side of the first ram 39A and the second ram 3
The strain gauge 28 may be attached to 9B. Other configurations are the same as those in the example of FIG.

In this structure, since the drive transmission system 22 is connected with a large number of members, a large number of weak points are formed. However, as described above, the strain gauge 28 prevents damage to these points. This can be done based on the alarm from the abnormality determination means 29 by the load detection of. That is, the Pitman arm 37
And connecting portions A and B of the connecting rod 38 with pins, and connecting portions C of the connecting rod 38 and the first ram 39A with pins,
Connecting portions D and E of the first ram 39A and the second ram 39B, the second
It is possible to predict damage at the connecting portions G and F between the ram 39B and the punch holder 16 by the above abnormality determination.

FIG. 4 is a vertical sectional view showing the punch tool 13 in the third embodiment. In this embodiment, a load cell 40 as a load detecting means is interposed between the lower surface of the punch holder 16 and the upper surface of the punch 15 in the punch tool 13. The detection value of the load cell 40 is taken out from a contactless connector 46 such as a photocoupler provided in the punch holder 16 via a cord 47, and an abnormality determination in the example of FIG. 1 via a calibration amplifier (not shown). It is connected to the means 29 and the punching force setting means 30 (FIG. 1). The abnormality determining means 29 and the setting means 30 are those for the calibration described with reference to FIG. The configurations of other parts are the same as those in the example of FIG. Also in the case of this configuration, similarly to each of the above-described embodiments, it is possible to predict a mechanical abnormality and set an optimum punching force. In each of the above-described examples, both the punching force and the pulling force are measured to determine the abnormality, but the measurement and the abnormality determination are performed only on one of the punching force and the pulling force. You may do it.

[0017]

The load detecting and coping device for a press machine according to the present invention compares the detected value of the load detecting means for detecting the load acting on the punch tool with the set value and exceeds the set value. In this case, an abnormality determination means for outputting a machine abnormality determination signal is provided, so it is possible to easily predict a machine abnormality by the determination signal output from the abnormality determination means and to prevent machine damage due to excessive punching force or excessive pulling force. Can be prevented. According to the invention of claim 2, since the setting means for setting the optimum punching force and / or the pulling-out force from the detection value of the load detecting means is provided, the actual value is detected from the detection value of the load detecting means at the time of trial punching or the like. The optimum punching force and pulling force can be easily set, and the setting can be automated. According to the invention of claim 3, since the load detecting means is provided in the drive transmission system between the drive source of the press drive device and the punch tool, it is not necessary to provide the load detecting means for each punch tool, and the cost is reduced. it can.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a block diagram of a load detecting / measuring device according to a first embodiment of the present invention and a cross section of a press machine.

FIG. 2 is a perspective view of a punch press equipped with the same load detection / handling device.

FIG. 3 is an explanatory diagram showing a block diagram of a load detection / coping device according to a second embodiment and a cross section of a press machine.

FIG. 4 is a vertical cross-sectional view of a punch tool equipped with load detecting means of a load detecting / measuring device according to a third embodiment.

[Explanation of symbols]

13 ... Punch tool, 20 ... Press drive device, 21 ... Motor (drive source), 22 ... Drive transmission system, 28 ... Strain gauge (load detection means), 29 ... Abnormality determination means, 30 ... Setting means,
40 ... Load cell (load detection means)

[Procedure amendment]

[Submission date] June 13, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. The load detection / coping device of this press machine is applied to a press machine that punches a plate material (W) by a punch tool (13) driven forward and backward by a press drive device (20). In this press machine, a load detection means (28) for detecting a load acting on the punch tool (13) and a detection value of the load detection means (28) are compared with a set value, and a machine abnormality occurs when the set value is exceeded. And an abnormality determination means (29) for outputting the determination signal of.
It also acts on the punch tool (13) in the press machine.
The press drive device (2) based on the load detection means (28) for detecting the applied load and the detection value of the load detection means (28).
Setting means (30) for setting the optimum punching force and / or pulling force may be provided for the output control device (45) of the drive source (21) of 0). The load detection means (2
8) is a drive source (21) of the press drive device (20)
It may be provided in the drive transmission system (22) between the punch tool (13) and the punch tool (13).

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017]

The load detecting and coping device for a press machine according to the present invention compares the detected value of the load detecting means for detecting the load acting on the punch tool with the set value and exceeds the set value. In this case, an abnormality determination means for outputting a machine abnormality determination signal is provided, so it is possible to easily predict a machine abnormality by the determination signal output from the abnormality determination means and to prevent machine damage due to excessive punching force or excessive pulling force. Can be prevented. The invention of claim 2 acts on a punch tool.
From the detection value of the load detection means for detecting the load to be detected, and the detection value of the load detection means at the time of trial punching, since the setting means for setting the optimum punching force and / or the pulling force is provided from the detection value of the load detection means, The optimum punching force and / or pulling force for actual machining can be easily set, and the setting can be automated. According to the invention of claim 3, since the load detecting means is provided in the drive transmission system between the drive source of the press drive device and the punch tool, it is not necessary to provide the load detecting means for each punch tool, and the cost is reduced. it can.

Claims (3)

[Claims] 1. A press machine for punching a plate material by a punch tool driven forward and backward by a press drive device,
A press provided with load detecting means for detecting a load generated in the punch tool, and abnormality determining means for comparing a detection value of the load detecting means with a set value and outputting a machine abnormality determination signal when the value exceeds the set value. Machine load detection and coping device. 2. The press machine according to claim 1, further comprising setting means for setting an optimum punching force and / or a pulling force for an output control device of a drive source of the press drive device from the detection value of the load detection means. Load detection and coping device. 3. The load detection / coping device for a press machine according to claim 1, wherein the load detection means is provided in a drive transmission system between a drive source of the press drive device and a punch tool.