JPH11254042A - Emergency stopping method in press brake and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of a machine by applying an emergency stop to the machine in the case of judging what an abnormal state develops, based on the difference between a pinching point in the calculation and the actual pinching point during working. SOLUTION: Various information of machine information, die information, work information, etc., is inputted into an abutting position calculating means 20B as a signal S1 and the pinching point P is calculated and inputted into an emergency stopping means 20A as a signal S2. An abutting position detecting means 20C inputs a detected signal S5 from a pressure sensor 22 and the actual pinching point P' is detected and inputted into the emergency stopping means 20A as a signal S3. The emergency stopping means 20A calculates the difference between the pinching point P in the calculation and the actual pinching point P'. Then, in the case of being |P-P'|>=β (prescribed value), this difference is regarded as the abnormal state, and the stopping signal S4 is transmitted to a driving table control means 23 and a lower table 1 is stopped to stop the machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency stop method and apparatus for a press brake, and more particularly to a press brake for emergency stop of a machine before abnormal pressure rises when a mold origin is set incorrectly. And an emergency stop method therefor.

[0002]

2. Description of the Related Art Conventionally, in press brakes,
As is well known, a mold origin may be set in advance before machining.

The setting of the mold origin is performed as follows.

That is, in FIG. 4A, for example, in a lift press brake, a die 51 is attached to a lower table 50 which moves up and down by a cylinder 53, and the die 51
The workpiece is bent in cooperation with the punch 52.

In such a lift press brake, first, before work, the die 51 and the punch 52 are brought into direct contact with each other by raising the lower table 50 by a distance g without inserting a work.

Then, the cylinder 53 of the lower table 50
The position of the mold when the pressure sensor 54 incorporated in the mold detects a predetermined pressure is defined as the mold origin 0 (the right figure in FIG. 4A).

After the mold origin is set in this way, as shown in FIG. 4B, the work W is placed on the die 51 and the lower table 50 is raised to process the work W. I do.

In this case, the bending angle θ of the work W can be arbitrarily controlled by changing the D value (the right diagram in FIG. 4B), which is the distance between the tip of the punch 52 and the die 51.

The above-described setting of the mold origin (FIG. 4) is an operation that must be performed when the punch 52, the die 51, and the like are replaced in the press brake.

[0010]

However, in the past, there has been a case where the user forgets to set the mold origin or mistakenly sets the origin position, which has been one of the causes of the accident.

In order to solve this problem, an emergency stop pressure system has conventionally been adopted.

In this emergency stop pressure method, an emergency stop pressure is automatically calculated for each process based on mold pressure data and bending length, and when a pressure higher than the calculated emergency stop pressure is generated, a mechanical Emergency stop.

However, in the conventional method, an abnormal pressure rises before an emergency stop is applied to the machine.

For this reason, when an emergency stop is applied, the pressure applied to the machine has already risen to the capacity tonnage,
Machine or mold is damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide an emergency stop before an abnormal pressure rises in a press brake where the mold origin is set incorrectly, thereby preventing the machine from being stopped early and preventing damage. .

[0016]

In order to solve the above-mentioned problems, the present invention provides a step (1) for inputting various information such as machine information, mold information and work information as shown in FIGS. Based on the above various information, a step (2) of calculating a position P at which the workpiece W contacts the mold, a step (3) of processing the workpiece W, and a position at which the workpiece W contacts the mold 4 during the processing. Step (4) for detecting P ′, an abnormal situation is determined based on the calculated contact position P calculated in step (2) and the actual contact position P ′ detected in step (4). An emergency stop method (FIG. 2) for a press brake, comprising: a step (5) of judging whether or not an emergency is determined, and a step (6) of emergencyly stopping the machine in the case of an abnormal situation. Machine information, mold information,
Input means 21 for inputting various information such as work information; contact position calculating means 20B for calculating a position P at which the work W and the mold 4 are in contact with each other based on various information from the input means 21; , A contact position detecting means 20C for detecting a position P 'at which the workpiece W contacts the mold 4 based on an increase in pressure detected by the pressure detecting unit 22, and the contact position. Based on the difference between the calculated contact position P calculated by the calculation means 20B and the actual contact position P 'detected by the contact position detection means 20C, an emergency stop means 20A for emergency stopping the machine is provided. The technical means of the emergency stop device in the press brake characterized by having is provided.

Therefore, according to the configuration of the present invention, the work W
At the moment when the abutment with the mold, it is determined whether or not it is regarded as an abnormal situation (step 107 in FIG. 3). If it is considered as an abnormal situation (YES), an emergency stop is performed (step 107). FIG.
Step 108).

For this reason, if the mold origin is set incorrectly, the machine can be stopped earlier than before before the abnormal pressure rises, thereby preventing damage to the machine.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings according to embodiments. FIG. 1 is a view showing an embodiment of the present invention, wherein reference numeral 20 is an NC, 21 is an input unit, 22 is a pressure sensor, 23 is a drive table control unit, and 24 is a display unit.

As a press brake to which the present invention is applied, for example, there is a lift press brake (lower view in FIG. 1). The lift press brake has a lower table 1 which is vertically moved by a cylinder 8. A die 3 is attached to the lower table 1.

The lift press brake shown in FIG.
Side plates 7 are provided on both sides thereof, and an upper table 6 is fixed to the side plates 7, and a punch 4 is attached to the upper table 6.

With this configuration, the lift press brake is configured to bend the work W by cooperation of the punch 4 and the die 3, as is well known.

The emergency stop device shown in the upper diagram of FIG. 1 is connected to the lift press brake. The emergency stop device includes an input means 21, an NC 20, a pressure sensor 22, a drive table control means 23, It is constituted by display means 24.

The input means 3 is a keypad or the like for inputting various information. The various information includes, for example, machine information, mold information, and work information.

The mechanical information includes the tonnage capacity of the press brake and the open height a (FIG. 2).

The die information includes die holder height b (FIG. 2), die height c, punch height d, punch holder height e, and the like.

Further, as work information, the plate thickness t of the work W (FIG. 2), bending length, tensile strength, bending angle θ (FIG. 4)
(B)).

The NC 20 includes a contact position calculating means 20.
B, contact position detection means 20C, and emergency stop means 20A
It consists of.

The contact position calculating means 20B calculates a position P (FIG. 2) at which the work W and the die are in contact with each other based on various information input from the input means 21.

That is, in the lift press brake,
More specifically, as shown in FIG. 2, the die 3 is attached to the lower table 1 via a die holder 2, and the punch 4 is attached to an upper table 6 via a punch holder 5.

In such an ascending press brake, the work W is previously placed on the die 3 and the lower table 1 is raised before the work, and the work W on the die 3 is brought into contact with the punch 4 before the work.

In FIG. 2, the open height a is a lower dead center Q of the lower table 1 and a lower end position R of the upper table 6.
And is constant depending on the machine.

The die holder height b is the die holder 2
, Die height c is the height of the die 3, t is the thickness of the work W, punch height d is the height of the punch 4, and punch holder height e is the height of the punch holder 5.

Accordingly, when the lower table 1 moves upward, the moving distance f of the lower table 1 from the bottom dead center Q when the workpiece W comes into contact with the punch 4 is expressed by the following equation.

F = a− (b + c + t + d + e) By calculating the moving distance f of the lower table 1 by this formula, the position P ( FIG. 2) is the contact position P between the workpiece W and the mold, that is, the calculated pinching point P (Step 102 in FIG. 3).

The contact position detecting means 20C detects a position P 'at which the workpiece W contacts the mold 4 based on an increase in pressure detected by a pressure detecting means 22 described later during machining.

That is, the cylinder 8 of the lift press brake
Is provided with a pressure sensor 22 as pressure detecting means.

When the lower table 1 is raised during the processing and the workpiece W comes into contact with the punch 4, the pressure sensor 22
And the pressure increases as the work W is pushed into the punch 4.

The contact position detecting means 20C includes the pressure sensor 2
The rise is detected by inputting the pressure detected in step 2 (FIG. 1).

Then, the contact position detecting means 20C detects when the pressure has risen to a certain value (step 105 in FIG. 3).
YES) Position P ′ with respect to bottom dead center Q of lower table 1
Is detected as the contact position P 'between the workpiece W and the mold 4, that is, the actual pinching point P' (Step 106 in FIG. 3).

The emergency stop means 20A stops the machine on the basis of the difference between the contact position P calculated by the contact position calculation means 20B and the contact position P 'detected by the contact position detection means 20C. Let it.

That is, as described above, the emergency stop means 20
A is the calculated pinching point P calculated by the contact position calculating means 20B and the contact position detecting means 2
Actual pinching point P 'detected by OC
Is determined, and it is determined whether or not the difference is equal to or greater than a predetermined value (parameter) (step 107 in FIG. 3). If the difference is equal to or greater than the predetermined value (YE in step 107 in FIG. 3).
S), an emergency stop is applied (step 108 in FIG. 3).

For example, a calculation pinching point P
And the difference between the actual pinching point P ′ and | P−
If a predetermined value is β and | P−P ′ | ≧ β... Holds, it is considered that an abnormal situation has occurred, and the emergency stop means 20A performs an emergency stop. multiply.

The drive table control means 23 controls a servo shaft such as the cylinder 8 of the lower table 1 which is a drive table which moves up and down in this embodiment.

For example, if the above inequality is satisfied and the emergency stop means 20A is regarded as having an abnormal situation, the drive table control means 23 sets the emergency stop means 20
The lower table 1 is stopped based on the stop signal S4 from FIG.

As described above, according to the present invention, the emergency stop can be performed at the moment when the work W comes into contact with the punch 4, that is, when the pressure detected by the pressure sensor 22 is not high.

Therefore, the emergency stop time is earlier than in the prior art, and the machine is stopped earlier before the abnormal pressure rises, so that damage to the machine can be prevented.

The display means 24 is provided with the emergency stop means 20.
If A is regarded as an abnormal situation, the emergency stop means 20A
Based on the alarm signal S6 (FIG. 1), the operator is notified of an abnormal situation by, for example, blinking red on the screen.

In addition, the display means 24 can display a processing step when the workpiece W is actually processed by the ascending press brake.

The NC 20 controls the entire apparatus shown in FIG. 1 in addition to the above.

Hereinafter, the operation of the present invention having the above configuration will be described.
This will be described with reference to FIG.

First, in step 101 of FIG. 3, when various information is input by the input means 21, the information is input to the contact position calculating means 20B constituting the NC 20 as a signal S1 (FIG. 1). , A calculated pinching point P is calculated by an equation, and the calculated value is calculated as a calculated pinching point signal S2.
(FIG. 1) is input to the emergency stop means 20A.

Next, in step 103, the work W
Is put on the die 3 to start the processing, and in step 104, the lower table 1 is moved.

Then, in step 105, the contact position detecting means 20C detects the detection signal S from the pressure sensor 22.
5 (FIG. 1) to determine whether the pressure has increased. If it is determined that the pressure has increased (Y in step 105).
ES), the process proceeds to the next step, step 106, and if it is determined that it does not rise (NO in step 105), step 1
04, the lower table 1 is moved again, and the above operation is repeated.

If the contact position detecting means 20C determines that the pressure has risen (YES in step 105), in step 106, the position P 'where the workpiece W abuts on the punch 4, ie, the actual pinching The point P 'is detected, and the detected value is input to the emergency stop means 20A as an actual pinching point signal S3 (FIG. 1).

Next, in step 107, the emergency stop means 20A sets the calculated pinching point P
And the difference between the actual pinching point P ′ and the difference | P−P ′ | ≧ β as shown in the equation (YES), the drive table control means 23 sends a stop signal S4
(FIG. 1) is transmitted, and in step 108, the lower table 1 is stopped via the drive table control means 23, and the machine is stopped in an emergency.

In step 107, when | P−P ′ | ≧ β does not hold as in the equation, (N
O) In step 109, the lower table 1 is positioned at the target position.

In the above embodiment, the case where the present invention is applied to a lift press brake has been described in detail. However, the present invention is not limited to this, and the lower table is fixed and the upper table moves up and down. It is needless to say that the present invention is also applied to a descending type press brake which has the same effect.

[0059]

As described above, the difference between the calculated pinching point calculated based on various information and the actual pinching point during machining is used to judge whether or not an abnormal situation is to be considered. When the present invention is configured by a method of performing an emergency stop when deemed to be deemed, and an apparatus for performing the method, an emergency stop can be performed at the moment when the workpiece and the mold come into contact with each other. Therefore, if the mold origin is set incorrectly, the machine can be stopped quickly before the abnormal pressure rises, and the technical effect of preventing damage to the machine is achieved.

[0060]

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 shows a calculated pinching point P according to the invention.
It is a figure which shows (the contact position P in a calculation).

FIG. 3 is a flowchart illustrating the operation of the present invention.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower table 2 Die holder 3 Die 4 Punch 5 Punch holder 6 Upper table 7 Side plate 8 Vertical cylinder 20 NC 20A Emergency stop means 20B Contact position calculation means 20C Contact position detection means 21 Input means 22 Pressure sensor 23 Drive table control means 24 Display means

Claims (2)

[Claims] 1. A step of inputting various information such as machine information, mold information, work information, and the like (1) a step of calculating a position where the work and the mold come into contact based on the various information; Step (3) of processing, Step (4) of detecting a position at which the workpiece and the mold come into contact with each other during processing, and a contact position calculated in Step (2) and a position detected in Step (4). Based on the actual abutment position,
An emergency stop method for a press brake, comprising: a step (5) of determining whether or not an abnormal situation is considered; and a step (6) of emergencyly stopping the machine when the situation is regarded as abnormal. 2. Input means for inputting various information such as machine information, mold information, work information, etc., and a contact position calculation for calculating a position at which a work and a mold abut on the basis of various information from the input means. Means, pressure detecting means for detecting a pressure during processing, contact position detecting means for detecting a position at which a workpiece and a mold come into contact based on an increase in pressure detected by the pressure detecting means, and the contact position Emergency stop means for emergency stopping the machine based on the difference between the calculated contact position calculated by the calculation means and the actual contact position detected by the contact position detection means. Emergency stop device for press brake.