JPH06320220A - Hydraulic press brake - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a press brake capable of highly accurately adjusting the engagement of upper and lower molds and performing bending work with high accuracy. To achieve the above object, in a hydraulic press brake, a pressure detector 97 for detecting a pressure of a hydraulic cylinder 11 when a work W is bent by a punch 9 and a die 15 is provided. Reference numeral 23 denotes a calculation unit that calculates a theoretical approach value D between the punch 9 and the die 15 based on the shape dimensions of the punch 9, the die 15, the plate thickness T of the work W and the bending angle A, and the pressure detector 97. Of the side plate 5 based on the detected value, the correction amount of the ascending limit setting valve 47 branched and connected to the hydraulic circuit of the hydraulic cylinder 11, the strain amount, and the theoretical approach value D.
Based on the above, a control unit for controlling the corrected rising stop position of the lower apron 13 is provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a press brake.

[0002]

2. Description of the Related Art Conventionally, in order to bend a plate-shaped work at a desired bending angle in a press brake, the work is positioned between a punch and a die, and trial bending is performed many times to obtain a desired angle. As described above, the engagement state between the punch and the die was adjusted.

[0003]

Therefore, conventionally, it took a lot of time and materials to start the actual work, and it was not possible to perform the work efficiently.

Further, in order to establish a desired bending work, there are many parts depending on the skill and feeling of the worker, and it is difficult to reach the actual work in a short time.

[0005]

In view of the above-mentioned conventional problems, the present invention provides a lower apron which is vertically movable with respect to an upper apron fixed to the upper portions of the left and right side plates, and moves the lower apron up and down. When a plate-like work is bent with a punch attached to the upper apron and a die attached to the lower apron, the lower apron corresponding to the bending angle of the work is provided. In a hydraulic press brake provided with a control device for controlling an ascending / descending position, a pressure detector for detecting the pressure of the hydraulic cylinder at the time of bending work of the work by the punch and the die is provided, and the control device is A computing unit for computing a theoretical approach value between the punch and the die based on the punch and die shape dimensions, the work thickness and the bending angle; A calculation unit for calculating the amount of strain of the side plate based on the detected value of the force detector, a correction amount of a rising limit setting valve branched and connected to the hydraulic circuit of the hydraulic cylinder, the amount of strain, and the theoretical approach value D. And a control unit for controlling the corrected rising stop position of the lower apron.

[0006]

With the above construction, the pressure of the hydraulic cylinder during bending of the work is detected by the pressure detector, the strain amount of the side plate is calculated based on the detected value of the pressure detector, and the pressure is provided in the hydraulic circuit. The configuration is such that the ascending stop position of the lower apron is corrected based on the correction amount of the ascending limit setting valve and the above-described distortion amount, and more accurate bending processing can be performed.

[0007]

1 and 2, the press brake 1 has left and right side plates 5 and 5 rising from a bottom plate 3 in a C shape, and both side plates are located above the left and right side plates 5 and 5 (on the left side in FIG. 2). An upper apron 7 connecting the above is fixed, and a punch 9 is attached to the lower end of the upper apron 7.

At the lower position corresponding to the upper apron 7,
A lower apron 13 which is driven by the fluid pressure driving device 11 to move up and down is provided, and a die 15 is attached to the upper end thereof.

The C-shaped left and right side plates 5 and 5 are provided with a gap portion 19 in order to take out the work 17 in the bending line direction (longitudinal direction of the press brake 1) after the work 17 is bent and the work is performed from the front. Workpiece 17 when 17 is inserted
Back gauge device 21 for positioning the bending line of the
Is also provided.

At the left end of FIG. 1 is a control device 23 having a built-in computer.

FIG. 3 shows the control panel 2 of the control device 23.
5, a power switch 27, a mode selection switch 29, a function key 31, a feed speed selection switch 33, a process data setting key 35, etc. are provided.

The function key 31 is a process data setting key 31a for setting parameters required for defining each process (one operation), a process data display key 31b for displaying the contents of the above data setting, and a process data setting key 31b. A process setting key 31c for setting the execution sequence, and an M setting key for setting the auxiliary function parameter of the work set above and an appropriate correction amount such as springback, bending at pressurization, valve opening, etc. 31d is provided.

Further, a work call key 31e for designating a work number to be operated prior to continuous operation and a position / speed display key 31f for displaying the current position and speed of the L-axis / D-axis.
And a PA setting key 31g for setting various parameters on the system, a PU start key 31h for starting the puncher and outputting necessary data to a paper tape, and a self-diagnosis key 31i for displaying alarm contents. .

FIG. 4 shows what can be represented graphically among the various data input to the control panel. The work W (1
The plate thickness of 7) is T, the shoulder groove width of the die 15 is V, the shoulder radius Rd of the die 15, the desired bending angle A with respect to the work W, and the tip radius Rp of the punch 9.

As shown in FIG. 4, in the general press brake 1, the punch 9 and the die 15 approach the work W positioned on the die 15 and placed horizontally, and the punch 9
The bending work is performed at the lower end of the and the shoulders of the groove of the die 15.

More specifically, the tip rounded portion Rp of the punch 9 is
Since the bending work is performed at three points on both shoulder radius portions Rd of the die 15, it is a so-called air bend type bending work in which there is no plane rigid body in contact with the lower surface of the work W.

Therefore, the engagement state between the lower end of the punch 9 and the die 15, in other words, the lower end of the radius Rp at the tip end of the punch 9 is moved to a distance from the position where it abuts against the V groove bottom of the die 15. For example, whether or not it can be bent at a desired bending angle can be geometrically calculated by mathematical calculation.

Referring to FIG. 4, in order to bend the work W to the angle A as described above, the distance from the position where the tip of the punch 9 contacts the bottom of the V groove to D (hereinafter referred to as theoretical approach distance). It indicates that they should be brought closer.

When the bottom angle of the V groove of the die 15 is θ, the angle of A cannot be bent smaller than the angle of θ, and the portion adjacent to the rounded end of the punch 9 is bent. Since it is clear that it is not allowed to contact the upper surface of the work W, the punch 9 is not shown in FIG. 4 in this sense.

Next, FIG. 5 will be described.

FIG. 5 shows a control mechanism for controlling the raising / lowering operation of the lower apron 13. The lever 39 is engageable with and disengageable from a locking piece 37 provided at the center of the lower apron 13 in the longitudinal direction.
Is provided.

The lever 39 is swingable around a shaft 45 provided in a part of a rotatable movable member 43 via a shaft 41 fixed to a frame (not shown) provided on the back side of the lower apron 13. .

Further, a frame (not shown) is provided with an ascending limit setting valve 47 of the lower apron 13, and its spool 49 is fixed to the frame.
It is engaged with one end of the lever 39 via 1.

The rotating member 43 is connected to one end of a feed screw 57 via a pin 53 and a link 55, and the feed screw 57 is rotatably supported by a case 59 fixed to a frame.

An internal gear 61 is provided at the other end of the feed screw 57, and a clutch gear 63 is provided for approaching and engaging with the internal gear 61 on the spline shaft and disengaging from the internal gear 61. .

A manual handle 65 is attached to the other end of the clutch gear 63, and the shift lever 6 for moving the clutch gear 63 along the above-mentioned spline shaft.
7 is provided.

The internal gear 6 attached to the feed screw 57
1, a belt 75 is wound around a gear 73 attached to a shaft 71 of a detector 69 such as an encoder provided in a part of the corresponding case 59.

The detector 69 has a gear 77.
Shaft 85 of clutch 83 via belt 79 and gear 81
Is further connected, and the output shaft 89 of the electric motor 87 attached to the case 59 and the clutch 83 are also axially connected.

A tacho-generator 91 for detecting the rotational speed of the electric motor 87 is connected to the other end of the shaft of the electric motor 87.

Next, FIG. 6 is a part of a fluid pressure driving device 11 for vertically moving the lower apron 7 and a fluid pressure piping diagram relating to the ascent limit setting valve 47, which is a pump device connected to an electric motor. 93, an oil tank 95 and a pressure detector 97 for raising the lower apron 13 are shown.

Although not shown, the pressure detector 97 is wired so as to transmit the detected pressure value to the control device 23.

In the above structure, the locking piece 3 provided on the lower apron 13 is controlled by appropriately controlling the electric motor 87.
It is possible to control the position where 7 contacts the lever 39 and the lever 39 presses the spool 49 of the ascent limit setting valve 47, in other words, the position at which the upper apron 13 stops rising.

By the way, in the hydraulic press brake of the type in which the lower apron 13 moves up and down, the pressure in the hydraulic cylinder 11 for moving the lower apron 13 up and down, the weight of the lower apron 13 and the bending load of the work are: The balance is such that the rise of the lower apron 13 is stopped. The pressure of the hydraulic cylinder 11 is controlled by the opening degree of the rising limit setting valve 47. Therefore, since the pushing amount of the spool 49 in the upper limit setting valve 47 varies depending on the magnitude of the load during bending of the work, the rising stop position of the lower apron 13 also varies. Therefore, by detecting the pressure, the opening degree of the upper limit setting valve 47 can be known, and the pushing amount of the spool 49 can be controlled.
Therefore, by correcting the pushing amount of the spool 49,
The lower apron 13 can be lifted and stopped at an accurate position and is controlled by a computer.

The correction value of the ascent limit setting valve 47 may be obtained experimentally from the relationship between the opening degree of the valve 47 and the pressure of the hydraulic cylinder 11, and may be made into a data table or may be used as a preliminary experiment. It is also possible to calculate by calculating an equation or the like.

An example of carrying out the present invention with the press brake 1 having the control device 23 having the above-described computer built therein will be described below in order.

First, various data relating to the shape dimensions such as the work plate thickness T, the desired bending angle A, the tip radius Rp of the punch 9, the V groove shoulder width V of the die 15, the die shoulder radius Rd, and the V groove bottom angle θ. , Bending line length, work tensile strength, work elastic characteristics, elastic part of elastic deformation in which the upper apron 7 rises due to bending reaction force due to bending brake structural parts such as left and right sidewall C-shapes, Punch tip R
From the control panel 25, control the elements that generate mechanical distortion, such as the theoretical approach distance error due to the p portion biting into the work W, and the flow resistance in the spool and piping of the fluid pressure drive device 11, including empirical formulas. Input in the device.

Next, as the first step, the punch 9 and the die 15 are brought close to each other until the theoretical approach D is reached.

Since the theoretical approach distance D neglects the distortion and error of the portion related to the pressurization as described above, the work W does not reach the desired bending angle.

During the progress of the first step, the fluid pressure drive device 1
The pressure detector 97 of No. 1 detects the fluid pressure.

According to the experiment, for example, when the work W is bent at 90 degrees, the fluid pressure is 1 from 130 degrees to nearly 90 degrees.
Although it is reduced by about 0%, it is considered that this phenomenon is caused by the distortion of the punch 9 and the die 15 and the distance.

The calculated value of the distortion correction based on the mechanical data previously input is corrected by the detected fluid pressure data to calculate the additional approach distance as the second step.

The actual bending angle of the work W when the punch 9 and the die 15 are brought close to the theoretical approach distance D is detected by detecting the height of the work W at a certain distance from the center of the V groove on the bent surface. Even if the calculation is performed, the above-mentioned correction is possible.

[0043]

As will be understood from the above description of the embodiments, the present invention is basically provided with the lower apron 13 vertically movable with respect to the upper apron 7 fixed to the upper portions of the left and right side plates 5, 5. And a hydraulic cylinder 11 for moving the lower apron 13 up and down, and an upper apron 7
When the plate-shaped work W is bent by the punch 9 attached to the lower apron 13 and the die 15 attached to the lower apron 13, the rising stop position of the lower apron 13 is controlled according to the bending angle of the work W. In the hydraulic press brake including the control device 23, a pressure detector 97 that detects the pressure of the hydraulic cylinder 11 when the work W is bent by the punch 9 and the die 15 is provided. 23 is the punch 9 and the die 15
Of the side wall 5 based on the detection value of the pressure detector 97, and a calculation unit that calculates the theoretical approach value D between the punch 9 and the die 15 based on the shape dimension of the workpiece W, the plate thickness T of the work W, and the bending angle A.
Based on the correction amount of the ascending limit setting valve 47 branched and connected to the hydraulic circuit of the hydraulic cylinder 11, the distortion amount, and the theoretical approach value D, and the correction amount of the lower apron 13 is corrected. And a control unit for controlling the ascending / descending position.

As is apparent from the above configuration, in the present invention, the pressure of the hydraulic cylinder 11 during bending of the work W is detected by the pressure detector 97, and the side plate is detected based on the detected value of the pressure detector 97. According to the present invention, the strain amount of No. 5 is calculated, and the rising stop position of the lower apron 13 is corrected based on the correction amount of the rising limit setting valve 47 provided in the hydraulic circuit and the above-described strain amount. It is possible to perform bending processing with higher accuracy.

[Brief description of drawings]

FIG. 1 is a front view of a press brake as an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a front view of a control panel.

FIG. 4 is a detailed cross-sectional view of a die, a punch, and a work when they are bent.

FIG. 5 is an explanatory diagram of an approach distance setting mechanism.

FIG. 6 is a part of the above hydraulic piping diagram.

[Explanation of symbols]

 1 Press Brake 9 Punch 11 Fluid Pressure Driving Device 15 Die 23 Control Device 27 Locking Piece 47 Ascending Limit Setting Valve 97 Pressure Detector

Claims (1)

[Claims] 1. A hydraulic pressure for vertically moving a lower apron (13) with respect to an upper apron (7) fixed to the upper portions of the left and right side plates (5, 5). A punch (9) equipped with a cylinder (11) and attached to an upper apron (7) and a lower apron (1)
The plate-shaped work (1
When performing the bending process of 7), the work (17) described above is used.
In a hydraulic press brake comprising a control device (23) for controlling the ascending / descending position of the lower apron (13) corresponding to the bending angle of the work (17) formed by the punch (9) and the die (15). )
Is provided with a pressure detector (97) for detecting the pressure of the hydraulic cylinder (11) during the bending process, and the controller (23) controls the shape and dimensions of the punch (9) and the die (15), A calculation unit for calculating a theoretical approach value D between the punch (9) and the die (15) based on the plate thickness (T) and the bending angle (A) of the work (17), and the pressure detector (97). A calculation unit that calculates the strain amount of the side plate (5) based on the detected value, the correction amount of the ascending limit setting valve (47) branch-connected to the hydraulic circuit of the hydraulic cylinder (11), the strain amount, and the theory. The lower apron (13) based on the approach value D
And a control unit that controls the ascending stop position after correction of the hydraulic press brake.