JP2001219222A - Method and system for measuring machanical parameter in press brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently detect the machanical parameters with excellent accuracy. SOLUTION: In measuring the machanical parameters to calculate the mechanical deflection at each machine location in order to give the correction value during the bending, the deflection that a reference point S of measurement preset at each machine location of a press brake 1 is moved when the bending load is applied is measured by a laser length measuring device 21. The deflection at each bending load is measured by changing the bending load. The relationship between the bending load and the deflection σ at each machine location can be efficiently obtained as the machanical parameter with excellent accuracy based on the measured data, and during the bending, the deflection at each machine location can be obtained from the above relationship, and corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a system for measuring mechanical parameters in a bending machine.

[0002]

2. Description of the Related Art Conventionally, for example, a press brake 101 as a bending machine has a pair of left and right side plates 103 (side frames) as shown in FIG. An upper table 105 is fixedly provided, and a lower table 107 is provided on a lower front surface of the side plate 103 so as to be able to move up and down by a hydraulic cylinder 109. A die (not shown) is attached to the upper end of the lower table 107 via a die attachment member (not shown), and a punch (not shown) facing the die has an intermediate plate 111 at the lower end of the upper table 105. It is attached through.

When the work is bent by the cooperation of the punch and the die using the press brake 101,
Upper part of press brake 101, lower table 105, 1
07, the side plate 103, and a machine part such as a mold including a punch and a die. In order to calculate the amount of deflection, a relational expression between the pressing force and the amount of deflection is experimentally obtained, and the relational expression is input to the NC device. Then, for example, the correction of the D value (stroke amount) is performed based on the relational expression between the pressing force and the deflection amount.

The mechanical parameters for calculating the above-mentioned deflection amount include a deflection characteristic (σ
1) The relationship between the pressing force and the amount of deflection in the opening characteristics (σ2) of the hydraulic valve spool used in the hydraulic press brake 101, the bending characteristics (σ3) of the left and right side plates 103, and the bending characteristics (σ4) of the mold. A relational expression is determined. These deflection amounts are obtained in advance as an empirical formula for calculating a correction value during bending.

The deflection (σ 3) of the left and right side plates 103 will be described as an example. As shown in FIG. 17, a pressing table 113 is provided between an intermediate plate 111 and a lower table 107.
Is installed, the lower table 107 is raised, and the pressing table 1 is
13 is pressurized. The deflection (σ3) of the left and right side plates 103 at the pressing force F at this time is measured by the dial gauge 117 via the gauge support base 115 with respect to the floor. By changing the pressing force F, the pressing force F, the deflection (σ3) of the left and right side plates 103 and the relational expression (y = ax) are obtained as shown in FIG.

[0006] The above relational expression is input to the NC device, and is an empirical expression for obtaining the deflection (σ3) of the left and right side plates 103 during bending, and the D value (stroke amount) is corrected. Deflection characteristics (σ1) of other longitudinal tables,
The opening characteristic (σ2) of the hydraulic valve spool used in the hydraulic press brake 101 and the bending characteristic (σ
4) is also measured by the dial gauge 117 in the same manner as the deflection characteristic (σ3) of the left and right side plates 103 described above.

[0007]

However, as described above, since there are many measurement points in order to obtain mechanical parameters,
The scale measurement of the dial gauge 117 is troublesome, and there is a measurement error, so that there are many problems and the efficiency is not efficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method and a system for measuring mechanical parameters in a bending machine capable of calculating (detecting) mechanical parameters efficiently and accurately. Is to provide.

[0009]

According to a first aspect of the present invention, there is provided a method for measuring mechanical parameters in a press brake, comprising: an upper table provided with a punch; and a lower table provided with a die. In a press brake in which one side is reciprocated to bend a work abutted against a back gauge, before bending the work, a bending load is applied between the upper table and the lower table via a pressure table. Press, the length measurement sensor is moved, the displacement of the measurement reference point is measured at a plurality of longitudinal positions of one of the upper and lower tables, and the load measurement increment value set in advance for the bending load The displacement of each of the measurement reference points when pressurized with the added bending load is measured, and the measured bending load and the displacement are used. Calculated deflection diagram of the table,
The obtained deflection diagram is stored in a control device as machine parameter values.

Therefore, the bending characteristics in the longitudinal direction of one of the upper and lower tables when the bending load of the bending process is applied can be obtained by measuring the mechanical parameters efficiently and accurately by the length measuring sensor. Can be Since the amount of deflection of the table at the time of actual bending is obtained based on the deflection characteristics, the correction of the D value (stroke amount) and the crowning amount is performed efficiently and accurately.

According to a second aspect of the present invention, there is provided a method for measuring mechanical parameters in a press brake, comprising: moving one of an upper table on which a punch is mounted and a lower table on which a die is mounted by reciprocating by a hydraulic drive unit; In a press brake for performing a bending process on a workpiece abutted against a workpiece, before performing a bending process on the workpiece, a pressurizing table is used to press the upper table and the lower table with a bending load via a pressing table. To measure the displacement of the measurement reference point indicating the opening of the hydraulic valve that supplies the hydraulic pressure to the hydraulic drive device, and increments the bending load by a preset load measurement increment and adds this The displacement of the measurement reference point when pressurized by the bending load is measured, and the measured bending load and the displacement are used to calculate the opening-displacement line of the hydraulic valve. Look, the the obtained opening - is characterized in that the allowed to store the machine parameters values to the control device the displacement diagram.

Therefore, the opening characteristics of the hydraulic valve when the bending load of the bending process is applied can be obtained by measuring the mechanical parameters efficiently and accurately by the length measuring sensor. Based on the opening characteristics of the hydraulic valve, the opening of the hydraulic valve is corrected efficiently and accurately during actual bending.

According to a third aspect of the present invention, there is provided a method for measuring mechanical parameters in a press brake, wherein one of an upper table on which a punch is mounted and a lower table on which a die is mounted are reciprocally moved with respect to the left and right side plates. In a press brake for performing a bending process on a workpiece abutted against a workpiece, before performing a bending process on the workpiece, a pressurizing table is used to press the upper table and the lower table with a bending load via a pressing table. Is moved to measure the displacement of the measurement reference point at an arbitrary position on the left and right side plates, and when the pressurization is performed by adding the increment of the preset load measurement to the bending load and applying the added bending load. The displacement of the measurement reference point is measured, and the spring constants of the left and right side plates are obtained based on the measured bending load and the displacement. It is characterized in that the allowed to store the machine parameters values.

Therefore, the deflection characteristics of the left and right side plates when the bending load of the bending process is applied can be obtained by measuring the mechanical parameters efficiently and accurately by the length measuring sensor. Since the amount of deflection of the left and right side plates during actual bending is obtained based on the deflection characteristics of the left and right side plates, the correction of the D value (stroke amount) and the crowning amount is performed efficiently and accurately.

According to a fourth aspect of the present invention, there is provided a method for measuring mechanical parameters in a press brake, wherein one of an upper table on which a punch is mounted and a lower table on which a die is mounted are reciprocated to abut against a back gauge. In a press brake for bending a work, before bending the work, press the bending load between the punch and the die via a pressing table, and move the length measurement sensor to move the punch and the die. When the displacement of the measurement reference point is measured at a plurality of positions in the longitudinal direction of one of the molds, and the bending load is added to the bending load by an increment of a preset load measurement, and pressurized by the added bending load. The displacement of each of the measurement reference points is measured, and a deflection diagram of the mold is obtained based on the measured bending load and displacement, and the obtained deflection diagram is used as a control device. It is characterized in that the allowed to store the machine parameters values.

Therefore, when the bending load of the bending process is applied, the bending characteristics of one of the dies of the punch and the die are
It can be obtained by efficiently and accurately measuring a mechanical parameter with a length measuring sensor. Since the amount of deflection of the mold during actual bending is determined based on the deflection characteristics,
Correction of the D value (stroke amount) and the crowning amount is performed efficiently and accurately.

According to a fifth aspect of the present invention, there is provided a press brake mechanical parameter measuring method according to any one of the first to fourth aspects, wherein the length measuring sensor is connected to a back gauge. It is characterized by being attached.

Accordingly, since the length measuring sensor can be easily attached to the back gauge, the upper and lower tables, hydraulic valves, left and right side plates, punches and dies, etc. can be moved by moving the back gauge forward, backward, up and down and left and right. The displacement of the measurement reference point of the machine part can be measured efficiently and accurately.

According to a sixth aspect of the present invention, there is provided a mechanical parameter measuring system for a bending machine, wherein one of an upper table on which a punch is mounted and a lower table on which a die is mounted are moved back and forth with respect to the left and right side plates. In a press brake that bends a workpiece abutted against a gauge, a press table is provided between the upper table and the lower table when pressurized with a bending load. Measurement reference points at a plurality of positions in the direction, a measurement reference point indicating the opening of a hydraulic valve that supplies hydraulic pressure to a hydraulic drive device for reciprocating one of the upper and lower tables, and an arbitrary position on the left and right side plates. Of the measurement reference points of each machine part, which comprises a measurement reference point and measurement reference points at a plurality of positions in the longitudinal direction of one of the dies of the punch and the die. A bending measuring sensor for measuring the displacement of a measurement reference point of at least one machine part is provided so as to be movable and positionable with respect to the displacement position of the measurement reference point, and the bending load is added to the bending load by an increment of a preset load measurement. A control device having a memory for storing, as a machine parameter, measurement data of each machine part obtained by measuring the displacement of the measurement reference point when pressurized by a load by the length measurement sensor, is provided. It is assumed that.

Therefore, when the bending load of the bending process is applied, the bending characteristics in the longitudinal direction of one of the upper and lower tables, the opening characteristics of the hydraulic valves, the bending characteristics of the left and right side plates, and one of the punch and the die. The deflection characteristics of the mold can be obtained by measuring the mechanical parameters efficiently and accurately with a length measuring sensor.

The amount of deflection of the one of the upper and lower tables obtained during the actual bending process is determined based on the deflection characteristics of one of the upper and lower tables, and the actual amount of deflection is determined based on the opening characteristics of the hydraulic valve. The degree of opening of the hydraulic valve during bending is determined, and the amount of deflection of the left and right side plates during actual bending is determined based on the deflection characteristics of the left and right plates, based on the deflection characteristics of one of the punch and die dies. Since the amount of deflection of the mold at the time of actual bending is obtained,
The correction of the value (stroke amount), the crowning amount, and the opening of the hydraulic valve is performed efficiently and accurately.

According to a seventh aspect of the present invention, there is provided the bending machine according to the sixth aspect, wherein the length measuring sensor is attached to a back gauge. It is a feature.

Therefore, since the length measuring sensor can be easily attached to the back gauge, the back gauge can be moved back and forth, up and down, and left and right directions so that the upper and lower tables, hydraulic valves, left and right side plates, punches and dies, etc. The displacement of the measurement reference point of the machine part can be measured efficiently and accurately.

According to an eighth aspect of the present invention, there is provided a mechanical parameter measuring system for a bending machine according to the sixth aspect, wherein the length measuring sensor is rotatable to change a measuring direction. It is characterized by being provided.

Therefore, the measuring direction can be changed by turning the length measuring sensor, so that the displacement of the measuring reference point of each machine part such as the upper and lower tables, the hydraulic valves, the left and right side plates, the punch and the die, etc. can be efficiently controlled. Good and accurate measurement is possible.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for measuring mechanical parameters and a system for measuring mechanical parameters in a bending machine according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a press brake 1 as a bending machine. Here, since the press brake 1 is already known, the detailed description is omitted and only the outline is described.

The press brake 1 has a pair of left and right side plates 3, and a lower table 5 is fixedly provided on the lower front surface (the right side surface in FIG. 1) of the side plates 3. An upper table 7 is provided on the front surface so as to be vertically movable by a hydraulic cylinder 9. A die D is mounted on the upper end of the lower table 5 via a die holder 11, and a punch P facing the die D is mounted on a lower end of the upper table 7 via a punch holder 13.

Referring back to FIG. 1 and FIG. 2, a back gauge device 15 is provided behind the die D (left side in FIG. 1) to abut a workpiece W to be bent to determine a bending position. .

In the back gauge device 15, a pair of left and right L-axis members L (in the direction perpendicular to the paper surface in FIG. 1; in the Y-axis direction)
L and LR are provided in the front-rear direction (left-right direction in FIG. 1; X-axis direction), and the left and right L-axis members LL and LR are provided.
In between, for example a stretch 17 as a lateral support member
Has been passed. The stretch 17 is provided on the left and right L-axis members LL and LR so as to be movable and positioned in the front-rear direction by an L-axis moving mechanism (not shown).

The stretch 17 is provided with a pair of abutments 19 for abutting the work W so as to be freely adjustable in the horizontal direction and movable in the vertical direction. For example, a non-contact laser displacement meter as a length measuring sensor is built in the butting 19 as a diffusion type laser measuring device 21, and the laser measuring device 21 is supported so as not to protrude from the butting surface 23. I have.

As shown in FIG. 3, it is desirable that the laser length measuring device 21 be provided on the abutment 19 so as to be freely rotatable so that the measuring direction of the laser beam can be freely changed. This makes it easy to measure at an arbitrary position even if the machine part to be measured (described in detail later) is, for example, the side surface in the width direction of the left and right side plate 3 like the left and right side plate 3.

In the vicinity of the press brake 1, for example, an NC device as a control device that controls the front-rear position of the above-described stretch 17 and receives a signal from a laser length measuring device 21 provided on the abutment 19. 25 are provided. Accordingly, the abutment 19 can be moved and positioned in the Z-axis direction (vertical direction in FIG. 1) and the Y-axis direction (left-right direction in FIG. 2).
1 can also be moved and positioned in the Z-axis direction and the Y-axis direction. Alternatively, a moving mechanism that supports the laser length measuring device 21 further movably in the Z-axis and Y-axis directions with respect to the abutment 19 may be provided.

According to the above configuration, the interval between the pair of abutments 19 is set on the stretch 17 in accordance with the bending width of the work W (the width in the direction perpendicular to the paper surface in FIG. 1), and the projection is formed in accordance with the bending position. The pad 19 is set at a desired position. The workpiece W is placed on the die D and is positioned against the abutment surface 23 of the abutment 19, and the upper table 7 and the punch P are lowered by the control of the NC device 25. The work W is bent by the cooperation of.

When the above bending is performed, the lower part of the press brake 1, the upper tables 5, 7 and the right and left side plates 3
In addition, bending occurs in each machine part such as a mold including the punch P and the die D. In order to calculate this deflection amount, a relational expression between the bending load and the deflection amount is experimentally obtained, and this relational expression is input to the NC device 25.

The mechanical parameters for calculating the above-mentioned deflection amount include the deflection characteristics (σ
1) Bending load F (pressing force) in the opening characteristics (σ2) of the hydraulic valve spool used in the hydraulic press brake 1, the bending characteristics (σ3) of the left and right side plates 3, and the bending characteristics (σ4) of the mold. And the relationship between the deflection amounts σ1, σ2, σ3, and σ4 are obtained. These deflection amounts are obtained in advance as an empirical formula for calculating a correction value during bending. For example, the D value (stroke amount) is corrected based on the above-described relational expression between the bending load and the amount of deflection.

In the embodiment of the present invention, the aforementioned laser length measuring device 21 is used to measure the above mechanical parameters. A measurement reference point S is provided in advance at each mechanical part of the press brake 1 to be measured, and the amount of movement when the measurement reference point S moves due to a bending load is measured by the laser length measuring device 21. Therefore, the laser length measuring device 21 is not always attached to the back gauge device 15, and as shown in FIG. 12, depending on the deflection characteristics to be measured, as shown in FIG. 27.

Next, the configuration of the NC unit 25 will be described with reference to FIG. The NC device 25 has a CPU 29 which is a central processing unit. The CPU 29 has an input device 31 such as a keyboard for inputting various data and machining programs, and a CPU 29 for displaying various data. A display device 33 such as a CRT is connected.

The CPU 29 stores various input data and machining programs, and calculates the movement amount (deflection amount) of the measurement reference point S due to pressurization obtained from the calculation result by the calculation unit described later, and Memory 35 for storing the bending load at the time as a data table of machine parameters.
And the X axis of the measurement reference point S using the measured distance from the butting 19 to the measurement reference point S of the punch P or the die D;
Calculation for calculating the Y-axis and Z-axis coordinates or calculating the amount of deflection predicted at the time of bending based on the empirical formula of the mechanical parameters in the memory 35 when bending the workpiece W to calculate the correction value. An operation unit 37 as a means is connected. Further, the laser length measuring device 21 is also connected to the CPU 29.

Further, the CPU 29 includes the above-described arithmetic unit 37.
And a command unit 41 for giving commands to driving devices such as a hydraulic cylinder 9 for setting a D value, for example, based on the correction amount at the time of bending calculated by the above, and a crowning cylinder 39 for correcting deflection of the lower table 5. ing.

With reference to FIG. 5, a method for measuring mechanical parameters will be described.

Referring to FIG. 6 to FIG. 9, when obtaining the relational expression between the deflection (σ1) of the longitudinal table and the bending load F (pressing force), the punch holder 13 attached to the upper table 7 is used. A pressing table 43 is provided between the lower surface and the upper surface of the lower table 5, and the upper table 7 is lowered by driving the hydraulic cylinder 9 to press the pressing table 43. At this time, as shown by the two-dot chain line in FIG. 7, the upper table 7 bends so as to curve upward, while the lower table 5 bends so as to curve downward.

The deflection (σ1) of the longitudinal table under the bending load F is measured by a laser length measuring device 21 attached to the back gauge device 15 as shown in FIG. For example, a measurement reference point S is provided on the back surface of the upper table 7, and a distance L1 from the measurement reference point S is determined. While maintaining this distance L1, the laser length measuring device 21
It is moved in the axial direction, and the position of the measurement reference point S ′ at the time of pressurization is searched for and detected. Therefore, assuming that the Z-axis coordinate of the measurement reference point S before pressurization is Z and the Z-axis coordinate of the measurement reference point S ′ during pressurization is Z ′, the deflection σ at this position in the Y-axis direction is
1 becomes | Z−Z ′ |.

When the bending load F increases, the deflection σ1
Will also increase. Therefore, as shown in FIG. 7, the measurement reference points S ₁ , S ₂ , S ₃ ,... Sn located at the upper part at a plurality of positions along the bending line (longitudinal direction) of the upper table 7.
Is provided in advance, the table deflection amount σ1 in the longitudinal direction at each bending load F when the bending load F is changed is detected. The measurement reference points of the lower table 5 are the same as those of the upper table 7, and are measurement reference points located at a plurality of lower positions on the bending line (longitudinal direction) of the lower table 5, and therefore, the description of the lower table 5 is omitted. I do.

Referring to FIG. 5, the maximum bending load to be measured is defined as Fmax, and the preset increment of the load measurement is Δ
Assuming that F, the bending load F is increased by an increment ΔF, and each time, for example, a deflection σ1i as a displacement at a plurality of measurement reference points S ₁ , S ₂ , S ₃ ,. Steps S1 to S5 in FIG. 5 are repeated until the upper limit bending load Fmax is reached. As a result, the deflection diagrams of the lower and upper tables 5 and 7 are obtained and stored as machine parameters in the memory 35 (steps S6 and S10).

At the time of actual bending, a command is given from the command unit 41 to the crowning cylinder 39 based on the above-described deflection diagrams of the lower and upper tables 5 and 7, and crowning correction is given to the lower table 5. For example,
When the pressure PC is applied to the crowning cylinder 39 as shown in FIG. 7, the lower table 5 bends so as to curve upward as shown by the dotted line, and the lower table 5 and the upper table 7 Correction is performed so that the interval becomes uniform.

The above-mentioned crowning correction is performed by referring to FIGS.
PC _1, PC ₂ is pressure PC as shown in, ... P
... PCn, the correction value of the lower table 5 also changes to σ1 ₁ , σ1 ₂ ,.

Referring to FIG. 10 and FIG. 11, a description will be given of how to determine the opening degree characteristic (σ2) of the hydraulic valve spool used in the hydraulic press brake 1.

The drive system of the left and right hydraulic cylinders 9 is configured such that the pressure oil is adjusted, for example, from a mechanical valve 45 to a lower limit valve 47 (in the case of a hydraulic press brake in which the lower table moves up and down, it becomes an upper limit valve). The spool 5 that opens and closes the lower limit valve 47 has a bolt 5
1 is protruded.

When the upper table 7 is lowered and a dog (not shown) attached to the upper table 7 hits a member that interlocks the spool 49, the spool 49 is lowered, the lower limit valve 47 is opened, and the hydraulic pressure is reduced. It is configured to stop at the point of equilibrium. This lower limit valve 4
The opening degree 7 (the distance in the vertical direction) causes an error in the transition distance between the left and right dies, and therefore needs to be corrected.

As shown in FIG. 6 described above, a pressing table 43 is provided between the lower surface of the punch holder 13 and the upper surface of the lower table 5, and pressure is applied so that the transition distance becomes a certain set value.
Until the transition distance reaches the set value, the lower limit valve 47 remains closed, but when the set value is reached, the spool 49 descends by a certain limit and stops. The distance that has fallen during this time is an error σ2 due to the opening characteristic of the lower limit valve 47.
2 is measured by the laser length measuring device 21.

The method of measuring with the laser length measuring device 21 is the same as the case of the above-described deflection (σ1) of the longitudinal direction table, and as shown in FIG. is the distance L ₂ between the measurement reference point S is determined, laser measurement device 21 while maintaining the distance L ₂
Is moved in the Z-axis direction, and the position of the measurement reference point S ′ at the tip of the bolt 51 at the time of pressurization is detected and detected. For example, the opening characteristic error σ2 as the displacement of the measurement reference point S is measured.

By changing the set value of the above-mentioned transition distance several times, that is, as in the case of the above-described bending (σ1) of the longitudinal table, the upper limit bending load Fma
Steps S1 to S5 are repeatedly performed in FIG. 5 until x is reached. As a result, a relational expression between the bending load F and the error σ2 due to the opening characteristic of the lower limit valve 47 is obtained. It is stored as a parameter (step S7 and step S10).

Referring to FIG. 12, when calculating the relational expression between the deflection (σ3) of the left and right side plates 3 and the bending load F (force), the distance between the lower surface of the punch holder 13 and the upper surface of the lower table 5 is determined. The press table 43 is installed, and the upper table 7 is lowered to press the press table 43. At this time, 2 in FIG.
As shown by the dotted line, the left and right side plates 3 bend upward.

The deflection (.sigma.3) of the left and right side plates 3 under the bending load F is measured by a laser length measuring device 21 mounted on a length measuring device support base 27 so as to be movable and adjustable in the X-axis direction and the Z-axis direction. The method of measuring with the laser length measuring device 21 is the same as in the case of the deflection (σ1) of the longitudinal table described above, and the distance L between the laser length measuring device 21 and the measurement reference point S provided at the upper end of the side plate 3 is measured. ₃ is determined, the distance L ₃ laser measurement device 21 while maintaining the is detected by looking for the position of being moved in the Z-axis direction measurement reference point S of pressurized ', the right and left side plates 3 measurement reference point S For example, a deflection σ3 is measured as the displacement of.

The deflection of the longitudinal table (σ)
As in the case of 1), steps S1 to S5 are repeatedly performed in FIG. 5 until the upper limit bending load Fmax is reached. As a result, as shown in FIG. (Y) with the deflection (σ3)
= Ax) is obtained and stored as machine parameters in the memory 35 (steps S8 and S10).

As another example, as shown in FIG. 14, the measurement reference point S is provided at an arbitrary position on the left and right side plates 3, and the measurement reference point S is attached to the back gauge device 15. Even when the measurement is performed by the length measuring device 21, the relational expression (y = ax) between the bending load F and the deflection (σ3) of the left and right side plates 3 is obtained as in the above-described embodiment.

Referring to FIG. 15, the deflection of the mold (σ
When obtaining the relational expression between 4) and the bending load F (pressing force), the press table 43 is installed between the punch P attached to the punch holder 13 and the lower table 5, and the upper table 7 is lowered. Then, the press table 43 is pressurized. At this time,
Punch P is deflected in the aforementioned longitudinal table (σ1)
In this case, the upper table 7 bends in the same manner as the upper table 7, so that the punch P is bent σ4 as shown by a two-dot chain line in FIG. In the case of the die D, it bends downward similarly to the lower table 5 in FIG.

Deflection of mold at bending load F (σ4)
Is measured by a laser measuring device 21 attached to the back gauge device 15. The method of measuring with the laser length measuring device 21 is based on the deflection (σ) of the longitudinal table described above.
1) is the same as in the case of, is the distance L ₄ is determined between the measurement reference point S provided e.g. punch P of the laser length measuring machine 21 and the mold, laser measurement device while maintaining the distance L ₄ 21 is moved in the Z-axis direction, the position of the measurement reference point S 'of the punch P at the time of pressurization is searched for and detected, and the deflection σ4 as the displacement of the measurement reference point S of the punch P is measured. The method of measuring the deflection of the die D is the same as that of the punch P described above, and thus the description is omitted.

The deflection of the longitudinal table (σ
As in the case of 1), the steps S1 to S5 are repeated in FIG. 5 until the upper limit bending load Fmax is reached. As a result, as shown in FIG. Equation (y = a ') with deflection (σ4)
x) is obtained and stored as machine parameters in the memory 35 (steps S9 and S10).

As described above, the respective relational expressions between the bending load F and the deflections σ1, σ2, σ3, σ4 are calculated as the mechanical parameters for obtaining the amount of deflection of each machine part during bending. The calculation (detection) is performed well and accurately, and the D value (stroke amount), the crowning amount, and the opening of the hydraulic valve spool are automatically corrected.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. In this embodiment, a diffusion type laser length measuring device is used as a laser length measuring device, but a reflection type laser length measuring device may be used.

[0063]

As will be understood from the above description of the embodiments of the present invention, according to the first aspect of the present invention, one of the upper table and the lower table when the bending load of the bending process is applied. The deflection characteristics in the longitudinal direction of the table can be obtained by measuring the mechanical parameters efficiently and accurately with a length measuring sensor. As a result, the deflection amount of the table at the time of actual bending is obtained based on the deflection characteristics, so that the D value (stroke amount) and the crowning amount can be corrected efficiently and accurately.

According to the second aspect of the present invention, the opening characteristics of the hydraulic valve when the bending load of the bending process is applied can be obtained as a mechanical parameter by efficiently and accurately measuring with a length measuring sensor. Can be. As a result, the opening of the hydraulic valve can be corrected efficiently and accurately based on the opening characteristics of the hydraulic valve during actual bending.

According to the third aspect of the present invention, the deflection characteristics of the left and right side plates when the bending load of the bending process is applied can be obtained by measuring the mechanical parameters efficiently and accurately by the length measuring sensor. it can. As a result, the amount of deflection of the left and right side plates during actual bending can be obtained based on the deflection characteristics of the left and right side plates, so that the D value (stroke amount) and the crowning amount can be corrected efficiently and accurately.

According to the fourth aspect of the present invention, the bending characteristic of one of the dies of the punch and the die when the bending load of the bending process is applied is efficiently and accurately detected as a mechanical parameter by the length measuring sensor. It can be obtained by measuring. As a result, the amount of deflection of the mold at the time of actual bending is obtained based on the deflection characteristics, so that the D value (stroke amount) and the crowning amount can be corrected efficiently and accurately.

According to the fifth aspect of the present invention, since the length measuring sensor can be easily attached to the back gauge, the upper and lower tables, the hydraulic valve, The displacement of the measurement reference point of each machine part such as the left and right plates, punches and dies can be measured efficiently and accurately.

According to the sixth aspect of the present invention, when the bending load of the bending process is applied, the bending characteristics in the longitudinal direction of one of the upper and lower tables, the opening characteristics of the hydraulic valve, and the bending of the left and right side plates. The characteristics and the bending characteristics of one of the dies of the punch and the die can be obtained by measuring the mechanical parameters efficiently and accurately with a length measuring sensor.

As a result, the amount of deflection of the one of the upper and lower tables obtained in the actual bending process can be obtained based on the obtained bending characteristics in the longitudinal direction, and the opening of the hydraulic valve can be determined. The degree of opening of the hydraulic valve during actual bending can be determined based on the characteristics, and the amount of deflection of the left and right side plates during actual bending can be determined based on the deflection characteristics of the left and right side plates. Since the amount of deflection of the mold at the time of actual bending can be obtained based on the deflection characteristics of one mold, correction of the D value (stroke amount), the crowning amount, and the opening of the hydraulic valve can be performed efficiently and. It can be performed with high accuracy.

According to the seventh aspect of the present invention, since the length measuring sensor can be easily attached to the back gauge, the upper and lower tables, the hydraulic valve, The displacement of the measurement reference point of each machine part such as the left and right plates, punches and dies can be measured efficiently and accurately.

According to the eighth aspect of the present invention, since the measuring direction can be changed by turning the length measuring sensor, the mechanical parts such as the upper and lower tables, the hydraulic valves, the left and right side plates, the punch and die dies, etc. The displacement of the measurement reference point can be measured efficiently and accurately.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a press brake as a bending machine used in an embodiment of the present invention.

FIG. 2 is a plan view taken along line II-II in FIG.

FIG. 3 is a perspective view showing a laser length measuring device provided for abutment of a press brake according to the embodiment of the present invention.

FIG. 4 is a block diagram of a control device.

FIG. 5 is a flowchart of a mechanical parameter measuring method.

FIG. 6 is a state explanatory diagram when measuring the deflection (σ1) of the longitudinal direction table.

FIG. 7 is an overall right side view of FIG. 6;

FIG. 8 is an explanatory diagram of a state when a crowning correction is given to a lower table.

FIG. 9 is a table deflection diagram in the longitudinal direction when a crowning pressure is applied to the lower table.

FIG. 10 is a state explanatory diagram when measuring an opening degree characteristic (σ2) of a hydraulic valve spool used for a hydraulic press brake.

11 is a partially enlarged detailed view showing the inside of the lower limit valve of FIG. 10;

FIG. 12 is a state explanatory view when measuring the deflection (σ3) of the left and right side plates.

FIG. 13 is a diagram illustrating bending loads and deflections of left and right side plates.

FIG. 14 is a state explanatory view showing another embodiment when measuring the deflection (σ3) of the left and right side plates.

FIG. 15 is an explanatory diagram of a state when measuring the deflection (σ4) of the mold.

FIG. 16 is a diagram illustrating a bending load and a deflection of a mold.

FIG. 17 shows a conventional example, in which the deflection of the left and right side plates (σ
It is a state explanatory view at the time of measuring 3).

FIG. 18 is a diagram illustrating a bending load and deflection of right and left side plates according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 press brake (bending machine) 5 lower table 7 upper table 15 back gauge device 19 butting 21 laser length measuring device (length measuring sensor) 25 NC device (control device) 27 length measuring device support base 35 memory 37 arithmetic unit 39 Crowning cylinder 41 Command unit 47 Lower limit valve (hydraulic valve)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E063 AA01 BA07 FA02 FA03 FA04 FA05 GA04 JA03 JA07 LA03 LA04 LA07 LA12 LA17 LA19

Claims (8)

[Claims] 1. A press brake for reciprocating one of an upper table on which a punch is mounted and a lower table on which a die is mounted to bend a work abutted against a back gauge. Before performing, press the bending table between the upper table and the lower table with a bending load, and move the length measuring sensor to move the upper and lower tables at a plurality of longitudinal positions of one of the lower tables. The displacement of the measurement reference point is measured, and the displacement of each of the measurement reference points when pressurized with the added bending load is added to the bending load by adding an increment value of a preset load measurement, Based on the measured bending load and displacement, a deflection diagram of the table is obtained, and the obtained deflection diagram is stored as a mechanical parameter value in a control device. Machine parameters measuring method in a press brake to symptoms. 2. A press brake in which one of an upper table on which a punch is mounted and a lower table on which a die is mounted is reciprocated by a hydraulic driving device to bend a work abutted against a back gauge. Before bending the workpiece, pressurize with a bending load between the upper table and the lower table via a pressure table, move the length measuring sensor and supply the hydraulic pressure to the hydraulic drive. The displacement of the measurement reference point indicating the degree of opening of the valve is measured, and an increment value of a preset load measurement is added to the bending load, and the measurement reference point when pressurized with the added bending load is added. The displacement is measured, and the opening-displacement diagram of the hydraulic valve is obtained from the measured bending load and displacement, and the obtained opening-displacement diagram is used as a mechanical parameter value by the control device. Machine parameters measuring method in a press brake, characterized in that allowed to store. 3. A press brake in which one of an upper table on which a punch is mounted and a lower table on which a die is mounted is reciprocated with respect to left and right side plates to bend a workpiece abutted against a back gauge. Before bending the work, press the bending table between the upper table and the lower table with a bending load, and move the length measuring sensor to measure the reference point at any position on the left and right side plates. The displacement of the measurement reference point when pressurized by the added bending load was measured by adding the increment of the preset load measurement to the bending load, and the measured displacement was measured. The press brake is characterized in that the spring constants of the left and right side plates are obtained from the bending load and the displacement, and the obtained spring constants are stored as mechanical parameter values in a control device. Machine parameters measuring how. 4. A press brake in which one of an upper table on which a punch is mounted and a lower table on which a die is mounted is reciprocated to bend a work abutted against a back gauge. Before performing the test, press the bend between the punch and the die with a bending load via a pressurizing table, move the length measurement sensor, and measure the measurement standard at multiple positions in the longitudinal direction of one die of the punch and the die. The displacement of each point is measured, and the displacement of each of the measurement reference points when pressurized by the added bending load is measured by adding an increment value of a preset load measurement to the bending load. A bending diagram of the mold is obtained from the obtained bending load and displacement, and the obtained bending diagram is stored in a control device as a mechanical parameter value. Machine parameters measuring how. 5. The method for measuring mechanical parameters of a press brake according to claim 1, wherein said length measuring sensor is attached to a back gauge. 6. A press brake in which one of an upper table on which a punch is mounted and a lower table on which a die is mounted is reciprocated with respect to left and right side plates to bend a work abutted against a back gauge. A pressurizing table is provided between the upper table and the lower table when pressurizing with a bending load, and measurement reference points at a plurality of longitudinal positions of one of the upper and lower tables, and A measurement reference point indicating the degree of opening of a hydraulic valve that supplies hydraulic pressure to a hydraulic drive device that reciprocates one of them, a measurement reference point at an arbitrary position on the left and right side plates, and the length of one of the dies for punch and die Measurement reference points at a plurality of positions in the direction, and a length measurement sensor for measuring a displacement of a measurement reference point of at least one of the machine parts among the measurement reference points of each of the machine parts. The displacement of the measurement reference point is provided by the length measurement sensor when it is pressurized with a bending load obtained by adding an increment value of a preset load measurement to the bending load. A machine parameter measurement system for a press brake, comprising a control device including a memory for storing measurement data of each machine part obtained by measurement as machine parameters. 7. The system according to claim 6, wherein the length measurement sensor is attached to a back gauge. 8. The sensor according to claim 6, wherein the length measuring sensor is pivotably provided to change a measuring direction.
3. A system for measuring mechanical parameters of a press brake according to claim 1.