JPH09164428A - Method and device for detecting work state in bend-working device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically input work length and offset value to a NC device, etc., by measuring them in process. SOLUTION: Each of pressure at respective pressure measuring points P1 to P5 set at plural places in the longitudinal direction of a bend-working device table is detected by a pressure detecting means, thereby preparing pressure distribution data. The ratio of a pressure value to the maximum value in the pressure distribution data is calculated, and the area in having the ratio of a prescribed value or more is detected, thereby judging that a work exists in this area. Length in the longitudinal direction of the table in this area is defined as work length (LR-LL), the distance between the center position (LR+LL)/2 in the longitudinal direction of the table in the area and the center position C is the longitudinal direction of the table of the bend-working device is operated, thereby calculating an offset value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting a work condition in a bending machine, and more particularly, detecting a length (width dimension) and an offset amount of a work set in a bending machine such as a press brake. The present invention relates to a method and apparatus for detecting a work situation.

[0002]

2. Description of the Related Art In a bending machine such as a press brake, an NC machine is required to automatically calculate a depth in a bending angle input mode and the like. Offset amount etc. As a matter of course, if these values are not input according to actual values, the correct depth is not calculated and the required bending accuracy cannot be obtained.

Conventionally, NC such as work length and offset amount
Data input to the device is performed manually by an operator.

[0004]

Conventionally, since the data such as the work length and the offset amount is manually input by the operator, the number of manually input data in the bending angle input mode of the NC device is increased, and the work is also increased. Since it is necessary to measure and calculate the length and the offset amount in advance, there is a problem that setup takes time.

Further, since it is a manual input, there is no guarantee that the work length and the offset amount will be input as they actually are, including an input error, which may prevent the required bending work.

The present invention has been made by paying attention to the above-mentioned problems, and it is possible to measure the work length and the offset amount in-process and automatically input these data to an NC device or the like. It is an object of the present invention to provide a work situation detecting method and device in a bending apparatus that shortens setup time and enables accurate bending.

[0007]

In order to achieve the above object, a method invention according to a first aspect of the present invention is a method for applying a pressing force at each pressing force measuring point set at a plurality of positions in a longitudinal direction of a table of a bending apparatus. Detected by the pressing force detecting means, create pressing force distribution data from the pressing force detection value of each pressing force measurement point by the pressing force detecting means, and calculate the ratio of the pressing force value to the maximum value in this pressing force distribution data. Then, an area in which the ratio is equal to or greater than a predetermined value is detected, and it is determined that a work is present in this area.

A method invention according to claim 2 is the method according to claim 1.
In the method for detecting the work state in the bending apparatus described in (1), the length of the region in the table longitudinal direction is used as the work length.

A method invention according to claim 3 is the method according to claim 1.
Alternatively, in the work situation detecting method in the bending apparatus described in 2, the offset amount is calculated by calculating the difference between the center position of the region in the table longitudinal direction and the center position of the bending apparatus in the table longitudinal direction. Is.

A method invention according to claim 4 is the method according to claim 1.
In the work situation detecting method in the bending apparatus according to any one of 3 to 3, the pressing force is detected by the pressing force detecting means in the initial stage of bending before the plastic deformation of the work.

In order to achieve the above object, the apparatus invention according to a fifth aspect of the invention is to detect a plurality of pressing forces at each of the pressing force measuring points set at a plurality of positions in the longitudinal direction of the table of the bending apparatus. Means, pressure force distribution data creating means for generating pressure force distribution data from pressure force detection values at each pressure force measuring point by the pressure force detecting means, and pressure force distribution data created by the pressure force distribution data generating means And a work existing area detecting means for calculating a ratio of the pressing force value to the maximum value in the above area to detect an area in which the ratio is a predetermined value or more, and determining that a work exists in this area. It is a thing.

Further, the invention of the apparatus according to the sixth aspect is the fifth aspect.
In the work situation detecting device in the bending apparatus, the work existence region detecting means includes a work length calculating unit that sets a length of the region in the table longitudinal direction as a work length.

The invention according to a seventh aspect of the invention is a fifth aspect of the invention.
Alternatively, in the work situation detecting device in the bending apparatus described in 2, the work existing area detecting means calculates a difference between a central position of the area in the table longitudinal direction and a central position of the bending apparatus in the table longitudinal direction. It includes an offset amount calculation unit that calculates the offset amount.

In the method and apparatus for detecting a work condition according to the present invention, the principle of detecting the work existence area differs in the longitudinal direction of the table between the area where the work exists and the area where the work does not exist due to the bending reaction force on the table. Is based on that.

As a result, in the work situation detecting method and apparatus according to the present invention, the pressing force at each pressing force measuring point set at a plurality of positions in the longitudinal direction of the table is detected by the pressing force detecting means during the bending process. The pressing force detection data at each measuring point of the pressing force detected by the pressing force detecting means is used to create pressing force distribution data in the longitudinal direction of the table by the pressing force distribution data creating means, and the pressing force value with respect to the highest value in the pressing force distribution data Is calculated by the work presence area detection means, a region in which the ratio of the pressing force is equal to or greater than a predetermined value is detected, and it is determined that a work is present in this region.

The length in the longitudinal direction of the table in this region can be regarded as the work length, and the difference between the central position in the longitudinal direction of the table in that region and the central position in the longitudinal direction of the bending machine is calculated. The offset amount is calculated.

Further, the pressure detection by the pressure detection means is
Since it is performed in the initial stage of bending before the plastic deformation of the work, it is possible to substantially prevent the deflection amount component of the mechanical system from being included in the pressing force detection.

In the work state detecting method and apparatus according to the present invention, the pressing force measuring point is set for each intermediate plate on which the upper die is mounted on the upper table, and the pressing force detecting means may be mounted on each intermediate plate. it can. Examples of the pressing force detecting means include a piezo load sensor and an electric resistance type strain sensor.

Further, in the work state detecting method and apparatus according to the present invention, the upper die used, that is, the punch die, may be an integral body or a divided die, and in any case, the same applies, It is possible to detect the work length and the offset amount.

The pressure distribution data creating means, the work existence area detecting means including the offset amount calculating section and the work length calculating section in the work situation detecting apparatus according to the present invention can be embodied as software by a computer.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a bending apparatus to which the work situation detecting apparatus according to the present invention is applied. This folding device is a press brake of the lower table rising type,
The lower movable table 1 includes a lower movable table 1, left and right side plates 3, an upper fixed table 5 fixed to the side plates 3, and a table drive device 7 such as a hydraulic cylinder device that moves the lower movable table 1 up and down. Die holder 9 on top of
The lower die (die die) 11 is attached by the above, the upper die (punch die) 15 is attached by the plurality of intermediate plates 13 to the lower edge portion of the upper fixed table 5, and the lower portion is moved by the table drive device 7. When the table 5 is driven upward, the lower die 11 and the upper die 15 sandwich the work piece between the upper and lower parts to perform bending work. In addition, the bending device includes an NC device 1
7 is connected.

Pressurization force measurement points are set at a plurality of positions in the longitudinal direction of the table (left-right direction in FIG. 1). In this embodiment, the pressurizing force measurement points are set at equal intervals in the table longitudinal direction for each intermediate plate 13, and a piezoelectric force sensor or a pressurizing force sensor 19 such as an electric resistance type strain sensor 19 is provided on each intermediate plate 13. Two are provided.

In this case, the pressing force measurement points set for each of the intermediate plates 13, that is, the pressing force detection values of the five pressing force measurement points P1 to P5 in the illustrated example, are applied to each of the five intermediate plates 13. Since the two sensors 19 are provided, it is the average value of the pressure detection values of the two pressure sensors 19.

The pressing force detection values of the pressing force measurement points P1 to P5 detected by the pressing force sensor 19 are input to a data processing device 21 such as a microcomputer. The data processing device 21 executes a program to create pressure distribution data 23 in the table longitudinal direction from pressure detection values of the pressure measurement points P1 to P5 detected by the pressure sensor 19. And a ratio of the pressing force value to the maximum value in the pressing force distribution data created by the pressing force distribution data creating unit 23 is calculated, and a region where the ratio is a predetermined value (about 90%) or more is detected, and this region is detected. A work existence area detection unit 25 that determines that a work exists in (hereinafter, this area is referred to as a work existence area) is implemented by software.

Further, the work existence area detection unit 25 has a work length calculation unit 27 for setting the length of the work existence area in the longitudinal direction of the table as a work length, a center position of the work existence area in the longitudinal direction of the table, and the bending apparatus. An offset amount calculation unit 29 that calculates the offset amount by calculating the difference from the center position in the table longitudinal direction is included.

The work length data calculated by the work length calculation unit 27 and the offset amount data calculated by the offset amount calculation unit 29 are automatically input to the NC device 17 by communication.

Next, a method of detecting the work length and the offset amount will be described in detail with reference to FIGS.

FIG. 2A shows a work arrangement state in which the work W is offset to the left. At the initial stage of bending of the work W, the pressing force at each pressing force measurement point P1 to P5 is set to each intermediate plate. It is detected by the pressing force sensor 19 of 13.

The initial stage of bending for detecting the applied pressure is a stage before the plastic deformation of the work W is performed,
The pressing force is detected by the sensor output value in the elastic deformation region shown in FIG. 3 or at the pressure peak point (yield point). As a result, the pressing force is detected at a stage where the bending of the mechanical system is small, and it is possible to substantially prevent the bending amount component of the mechanical system from entering the pressing force detection.

The pressing force detection value (sensor output) by the pressing force sensor 19 of each intermediate plate 13 is used as the pressing force distribution data creating section 2.
3 is input to the pressure force distribution data creating unit 23, and the pressure force detection points P1 to P5 detected by the pressure force sensor 19 are applied to the pressure force measurement point P1 as shown in FIG. Create pressure distribution data for each P5.

Next, the work existence area detecting unit 25 calculates the ratio of the pressing force value to the maximum value (the maximum pressing force detection value) in the pressing force distribution data created by the pressing force distribution data creating unit 23, A region whose ratio is equal to or higher than the threshold value S% is detected.

In the example of FIG. 2 (b), since the pressure detection value at the pressure measurement point P2 is the highest value, the pressure detection value at this pressure measurement point P2 is set to 100% and the other pressure measurement points are set. The ratio of the pressing force detection values at P1, P3, P4, and P5 is calculated, and from this, the pressing force ratio distribution in the form of a line graph of the pressing force ratios continuous in the longitudinal direction of the table as shown in FIG. 2C. Create the data.

Next, a region having a threshold value S% or more, for example, 93% or more, is extracted as a work existing region in the above-mentioned pressure force ratio distribution data. As shown in FIG. 2D, this region extraction can be performed by calculating the intersection of the polygonal line based on the pressing force ratio distribution data in the polygonal line graph and the horizontal line indicating the threshold value 93%.

Normally, this intersection appears in two places on the left and right, as shown in FIG.
As shown in (e), the work length is calculated by performing a calculation (LR-LL) for subtracting the table longitudinal coordinate value LL of the left intersection from the table longitudinal coordinate value LR of the right intersection. In other words, the length of the work existing region in the longitudinal direction of the table is calculated as the work length.

Further, the center position in the table longitudinal direction of the work existing area, which is 1/2 of the sum of the coordinate value LR in the table longitudinal direction of the intersection point on the right side and the coordinate value LL in the table longitudinal direction of the left side intersection point, is calculated. And the known center position (machine center position) C in the longitudinal direction of the folding device to calculate the offset amount. The calculation formula of this offset amount is C- (LR + LL) / 2.

The punching die used in the method and apparatus for detecting the work condition according to the present invention may be either a unitary piece or a divided die. In either case, the work length and the offset amount should be detected equally. Is possible. FIG.
4 (a) to 4 (d) show sensor output examples when the punch die is an integrated body, and FIGS. 4 (e) to 4 (h) show sensor output examples when the punch die is a split die. There is. FIG.
From (a) to (h), in the case of the one-piece punch, the bending pressure is dispersed in the longitudinal direction of the table, so the output level is lower than in the case of the split type, but the distribution of the sensor output in the bending range. It can be seen that the pattern (polygonal line shape) is substantially similar.

Therefore, the work length and the offset amount can be detected by the above-described method regardless of whether the punching die is an integral die or a split die.

FIGS. 5A to 5F show the relationship between the pressing force detection pattern and the threshold value S%. FIG.
From (f), the threshold S% is 93 regardless of bending conditions.
It can be seen that the values may be approximately the same at about 94%.

As shown in FIG. 6 (a),
When the above-mentioned intersection points do not exist because the pressing force ratios are all above the predetermined value, the work length becomes the entire sensor output range, and as shown in FIG. 6B, the intersection points are the work end position. It may appear at a position offset to the outside and the bending length may become longer than the actual work length, but this does not pose a practical problem.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to this, and various embodiments may be made within the scope of the present invention. The possibilities will be clear to the skilled person.

[0042]

As can be understood from the above description, according to the method and apparatus for detecting the work condition in the bending apparatus according to the present invention, each pressing force set at a plurality of positions in the table longitudinal direction of the bending apparatus. The pressing force at the measuring point is detected by the pressing force detecting means, pressing force distribution data is created from the pressing force detection value at each pressing force measuring point by the pressing force detecting means, and the pressing force for the maximum value in this pressing force distribution data is created. The ratio of the values is calculated to detect a region where the ratio is a predetermined value or more, the work length is calculated from the length of the region in the table longitudinal direction, and the center position of the region in the table longitudinal direction and the bending device. Since the offset amount is calculated by calculating the difference from the center position of the table in the longitudinal direction of the table, the in-process measurement of the work length and the offset amount becomes possible. It can be automatically input to such devices. As a result, the setup time can be shortened and accurate bending can be performed.

The pressure detection by the pressure detection means is
By performing the bending process in the initial stage before the plastic deformation of the work, it is possible to substantially avoid the bending amount component of the mechanical system from being included in the pressing force detection. Due to this, the work length and the offset amount can be accurately obtained, and more accurate bending can be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a bending apparatus to which a work situation detecting apparatus according to the present invention is applied.

2A to 2E are explanatory views showing a method of detecting a work length and an offset amount according to the present invention.

FIG. 3 is a graph showing a relationship between a bending stroke and a sensor output.

4 (a) to 4 (h) are explanatory views showing examples of sensor outputs when the punch die is an integral body and when the punch die is a divided die.

5A to 5F are explanatory diagrams showing a relationship between a pressing force detection pattern and a threshold value S%.

6A and 6B are explanatory diagrams showing the relationship between a pressing force detection pattern and a threshold value S%.

[Explanation of symbols]

 1 Lower movable table 3 Side plate 5 Upper fixed table 7 Table driving device 9 Die holder 11 Lower mold 15 Upper mold 17 NC device 19 Pressure sensor 21 Data processing device 23 Pressure distribution data generation unit 25 Work existence area detection unit 27 Work Length calculator 29 Offset amount calculator

[Procedure amendment]

[Submission date] February 19, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

[Fig. 2]

Claims (7)

[Claims] 1. A pressurizing force detecting means detects the pressurizing force at each pressurizing force measuring point set at a plurality of positions in the longitudinal direction of the table of the bending apparatus, and the pressurizing force measuring means applies the pressurizing force at each pressurizing force measuring point. Create the pressure distribution data from the detected pressure value, calculate the ratio of the pressure value to the maximum value in this pressure distribution data, detect the area where the ratio is above the specified value, and the work exists in this area. A method for detecting a work state in a bending apparatus, which is characterized in that it is determined that the work is performed. 2. The work condition detecting method in the bending apparatus according to claim 1, wherein the length of the region in the table longitudinal direction is the work length. 3. The offset amount is calculated by calculating the difference between the center position of the region in the table longitudinal direction and the center position of the bending device in the table longitudinal direction. Method for Detecting Work Situation in a Bending Machine of Machinery. 4. The bending apparatus according to claim 1, wherein the pressing force is detected by the pressing force detection means at an initial stage of bending before the plastic deformation of the work. Work status detection method. 5. A plurality of pressurizing force detecting means arranged at a plurality of pressurizing force measuring points set at a plurality of positions in the longitudinal direction of the table of the bending apparatus, and the pressurizing force measuring points by the pressurizing force detecting means. A pressing force distribution data creating unit that creates pressing force distribution data from the pressing force detection value, and a ratio of the pressing force value to the highest value in the pressing force distribution data created by the pressing force distribution data creating unit Is a predetermined value or more, and a work presence area detection means for determining that a work is present in this area, and a work situation detection device in a bending apparatus. . 6. The bending apparatus according to claim 5, wherein the work presence area detection unit includes a work length calculation unit that sets a length of the area in a table longitudinal direction as a work length. Work status detector. 7. The work presence region detection means includes an offset amount calculation unit for calculating an offset amount by calculating a difference between a center position of the region in the table longitudinal direction and a center position of the folding device in the table longitudinal direction. The work condition detection device in the bending device according to claim 5, wherein the work condition detection device includes the work condition detection device.