JPH0355248B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling cutting operations in a hydraulic shearing machine.

Hydraulic shearing machines are widely used in the field of sheet metal processing as cutting machines for plate materials because the stroke length and number of strokes can be easily controlled.

In conventional hydraulic shearing machines, in order to achieve good cuts and cut surface roughness, adjustments are made to the clearance between the upper and lower blades and the rake angle. In other words, there are limits to the conventional adjustment methods in cutting with few fractured surfaces, or in other words, achieving good surface viscosity.

In view of the current state of cutting in hydraulic shearing machines as described above, the present invention can realize cutting with an even better cutting surface, and improves the cutting ability of conventional machines even if the drive source output is small. This was developed for the purpose of providing a control method for a hydraulic shearing machine that enables cutting of materials that exceed the The upper blade is characterized in that the upper blade is caused to perform a vibratory stroke operation in the stroke direction by vibratingly supplying and discharging pressure liquid to a hydraulic cylinder that causes the upper blade to perform a stroke operation.

Next, embodiments of the present invention will be described with reference to the drawings.

1 is a hydraulic cylinder that serves as a driving source for cutting work in a hydraulic shearing machine;
The piston 1a is a piston rod. Note that two hydraulic cylinders 1 are provided on the left and right sides of the upper blade 3, which will be described later, and there is also a plunger type cylinder type, but the present invention is applied to the above two cylinders. It is.

2 is an upper blade mounting plate continuous to the tip of the rod 1b, 3 is an upper blade attached to the mounting plate with a shear angle that can be changed as appropriate, and 4 is a slide guide for the upper blade mounting plate 2. , 5 is attached to the upper part of the front end of a lower blade stand 6 which is disposed below the upper blade 3 so as to be movable back and forth in order to adjust the clearance with the upper blade.
The material W to be cut is placed on the lower blade stand 6 and positioned between the upper and lower blades 3 and 5, and the upper blade 3 is lowered by the operation of the hydraulic cylinder 1. and the lower blade 5 below.

Incidentally, during cutting, the material W is fixed on the lower blade stand 6 by a plate holder (not shown). In the figure, 7 is a switching valve provided in the pressure oil circuit of the cylinder 1, 8 is an oil pump, 8a is its drive motor, 9 is piping, 9
a is a regulating valve, 10 is an oil reservoir, and 1 to 10 above constitute a cutting section and its drive system in a conventionally known hydraulic shearing machine.

Therefore, in the conventional hydraulic shearing machine,
Upper and lower blades 3 and 5 depending on the thickness and quality of the material W.
The machine controls the hydraulic cylinder's clearance and rake angle, as well as the number of strokes and stroke length of the hydraulic cylinder depending on the content of the cutting work.
If the cutting conditions are not properly set, it goes without saying that it will not be possible to cut with a good cut surface, and even if the cutting is performed under conditions that are considered appropriate, the condition of the cut surface, especially the surface accuracy, may remain dissatisfied. It was very hot.

In view of the current state of materials produced by hydraulic shearing machines as described above, the present invention is capable of realizing cutting with a better cut surface than conventional cutting even if the set cutting conditions are inappropriate. Of course, if the cutting conditions are appropriate, the pressure oil in the hydraulic cylinder, which is the driving source for the cutting operation, is supplied and discharged in a vibrating state so that a better cut surface can be obtained. In particular, the upper blade is caused to perform an oscillating stroke operation in the stroke direction of the upper blade during the cutting operation.

Therefore, in the present invention, the vibratory stroke operation of the hydraulic cylinder 1 is controlled by an example of a control system as shown in the figure.

Reference numeral 11 designates a servo valve inserted into the piping 9 in communication with the pressure oil supply/discharge port 1c on the lower chamber side of the cylinder 1, and partitions one valve chamber 11a into two chambers, front and rear, in the flow direction of pressure oil. , two or more valves with different diameters in the partition, five valves 11b to 11 in this embodiment.
f, and each valve is provided with its opening/closing actuators 11g to 11k.

The servo valve 11 may be provided on the pressure oil supply/discharge port 1d side of the upper chamber of the cylinder 1. Further, it is preferable that the valve chamber 8a is formed integrally with the cylinder 1.

When the valves 11b to 11f with different diameters are opened and closed individually or in combination as described above, the piston 1a moves downward under the action of a constant pressure oil supplied from the oil pump 8. By arbitrarily controlling the amount of oil discharged from the lower chamber side of the cylinder, the lowering speed can be freely controlled.

12 is each valve 11b in the servo valve 11.
This is a setting section that can arbitrarily set the opening/closing degree of 11f according to the downward stroke position of the upper blade 3 and the stroke speed at that position.In open loop control, the setting position signal SP and the setting speed signal SS are used.
In the processing section 13, the drive actuator 11g
~11k is converted into a control signal for the drive control unit 14, and controls the operation of the piston 1a of the cylinder 1.

A position detector 15 detects the current stroke position of the upper blade 3, that is, the piston 1a, using, for example, 100 pulse signals per 1 mm, and is provided in association with the upper blade mounting plate 2 here.

Therefore, the total stroke amount of piston 1a is 100
mm, and the number of strokes is 30 times per minute, in order to repeatedly increase or decrease the stroke speed at 5 mm intervals during the downward stroke of the piston 1a using the open loop control system, the servo The setting unit 12 is set to open and close the valves 11b to 11f selected in advance in the valve 11, and each time a pulse signal representing a stroke amount of 5 mm is supplied from the position detection unit 15 to the setting unit 12, the valves 11b to 11f are opened or closed. All you have to do is make it open and close.

In the illustrated embodiment, the control system is configured in a closed loop, which will be explained below.

In the figure, 16 is an appropriate unit time, for example, 1
A pulse oscillator 17 that generates 100 pulse signals per second corresponds the distance pulse signal LP supplied from the position detector 15 to the time pulse signal CP of the oscillator 16, and calculates the current moving speed of the piston 1a in distance pulses/unit. A current moving speed detection unit 18 forms the current moving speed signal LS in the form of a time pulse or a time pulse/unit distance pulse; 18 is the current moving speed signal;
A speed calculation section 19 compares and calculates LS with a planned movement speed signal supplied from the setting section 12, and a speed calculation section 19 supplies a current position signal LP regarding the unit stroke amount and total stroke amount detected by the position detector 15 from the setting section 12. Scheduled position signal SP regarding unit stroke amount and total stroke amount
A position calculation unit that performs a comparison calculation with the upper blade 3 calculates information regarding the stroke speed change points set for the upper blade 3 and the start and end positions of various operating states.
Incidentally, the pulse signal from the position detector 15 is supplied via its processing storage section 15a.

Therefore, the speed calculation section 18 and the position calculation section 1 described above
The calculation result outputted from 9 is supplied to the processing section 13, where it is converted into a control signal for the drive control section 14 to control the control section 14. The drive control unit 14 has its output controlled by the output of the processing unit 13, controls actuators 11g to 11k provided to each valve 11b to 11f of the servo valve 11, and controls the opening/closing operation of each valve 11b to 11f. That's what I do.

By configuring the control system as described above, the upper blade 3 can be caused to perform the following stroke operations.

First, when the stroke length and number of strokes of the upper blade 3 are set separately, a speed is set in the setting section 12 to increase or decrease the stroke speed by an arbitrary unit stroke pitch between the strokes. .

Here, the descending stroke speed of the upper blade 3 is within the maximum speed of each valve 1 in the servo valve 11.
Since it can be finely and arbitrarily realized by adjusting the opening/closing degree of the valves 1b to 11f, the above-mentioned scheduled stroke speed set in the setting section 12 is determined by the pulse signal processed in the form of time/distance or distance/time for each valve 11b. ~
It is determined by the degree of opening or closing of 11f.

Note that the unit of repetition pitch of the speed change here may be either distance or time.

In open loop control, command signals for the speed and speed set in the setting section 12 and the respective stroke speeds are used as control signals for the drive control section 14 in the processing section 13, but in the illustrated closed loop control,
During the stroke operation, each pitch amount and the stroke speed between them are formed into a current position signal and a current speed signal, and these are compared and calculated with the signals representing each of the above scheduled values to correct each of the scheduled values. A control signal for the drive control section 14 is formed in the processing section 13 based on the deviation value.

Note that when the pitch for slowing down or slowing down the stroke speed is formed based on time, the end of the stroke is detected by the signal from the position detector 15.

As a result, when the upper blade 3 operates its stroke, the stroke speed set at the scheduled speed change pitch is increased or decreased, so that the upper blade 3 has a so-called oscillatory stroke in which the speed is gradually fed in the stroke direction. It will be activated.

In hydraulic shearing machines,
When the cutting edge performs a so-called vibrating stroke operation in the minute range described above during cutting, warping or twisting of the cut material is less likely to occur, and cutting can be achieved with good cut surface roughness. Even if the output of the drive source is small, thicker plates can be cut.

The present invention is as described above, and is extremely useful as a control method for a hydraulic shearing machine.

[Brief explanation of drawings]

The figure shows an example of implementing the method of the present invention, and is a block diagram of a control system. 1...Hydraulic cylinder, 2...Upper blade mounting plate, 3...
...Upper blade, 4...Slide guide, 5...Lower blade, 6
...Lower blade stand, 7...Switching valve, 8...Oil pump, 9
... Piping, 11 ... Servo valve, 12 ... Setting section,
13... Processing section, 14... Drive control section, 15...
position detector, 16... oscillator, 17... speed detector, 18... speed calculation section, 19... position calculation section.

Claims (1)

[Claims] 1 In a hydraulic shearing machine, when the upper blade is performing a cutting operation, by supplying and discharging pressure liquid vibratingly to a hydraulic cylinder that causes the upper blade to perform a stroke operation, the upper blade is controlled in the stroke direction. A method for controlling a hydraulic shearing machine, characterized by causing vibrational stroke operation in a hydraulic shearing machine.