JPS6119868Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a pressure circuit of a shearing machine, and particularly relates to a pressure regulating device for adjusting the plate pressing force in relation to the ram driving force.

Generally, in a hydraulic shearing machine, the plate material is held by the plate holding force F _H from the plate holding cylinder, and the workpiece is cut by the ram driving force F _B from the ram driving cylinder. The plate holding force and the ram driving force had to maintain a certain ratio.

However, in the conventional hydraulic circuit, as shown in the graph of Fig. 1, when the ram driving force F _B increases beyond a certain point, the plate holding force F _H reaches a certain value and does not increase any further. It was hot. Therefore, when the plate material becomes thicker and the cutting resistance of the plate material increases, the ram driving force F _B increases, but the plate holding force F _H
did not increase, and as a result, there was a problem that the plate material could not be sufficiently pressed down and fixed.

In addition, for large forging machines, etc., a movable upper blade is installed at the center of one large-diameter hydraulic ram, and one or two blades are installed at the eccentric part.
Some machines have a hydraulic plunger installed vertically through it, leading the upper blade downwards, and acting as a plate holder between it and the fixed lower blade holder, but this type has only the plate holder independently. I had the inconvenience of not being able to activate it.

Among the above-mentioned inconvenient conventional devices, an example that belongs to the former category is disclosed in Japanese Patent Publication No. 10046/1986, which is a device that presses a plate by switching between two types of pressing force, high and low. Publication No. 46-35099 discloses an example of the latter.

This device was devised in view of the above problems, and its purpose is to reduce the plate holding force F.
By increasing _H at a constant ratio to the ram driving force F _B , it is possible to securely hold the plate material, and even before the shearing operation begins, only the plate holding device can be activated to cut long cuts using multiple plate pressers. To provide an efficient plate presser pressure adjustment device that can fix a plate material on a work table over a period of time.

To achieve this purpose, this invention
An oil passage 27 leading from the ram drive cylinders 15 and 17 that drive the plate holder 1 to the plate holder cylinder 37 that drives the plate holder 7, and the pressure is adjusted so that the plate holding force increases or decreases in proportion to the increase or decrease in the ram driving force. A cylinder 29 is provided.

Hereinafter, one embodiment of this invention will be described in detail using the drawings.

FIG. 2 is a schematic explanatory diagram of a shearing machine, in which a plate material 1 is placed on a work table 5 having a lower blade 3 at its edge, and is fixedly held by a plate holder 7. Then, the plate material 1 is attached to the lower blade 3.
The upper blade 9, which cuts in cooperation with the upper blade 9, is provided on a vertically movable ram 11.

FIG. 3 is a hydraulic circuit diagram showing one embodiment of this invention. The ram 11 has arms 13a, 13
The compression side pressure chamber 15b of the drive cylinder 15 and the expansion side pressure chamber 17a of the drive cylinder 17 are connected to the pistons 19a and 19b of the left and right drive cylinders 15 and 17 through the oil passage 19. tied together. A first solenoid valve 23 with 4 ports and 3 positions is disposed in the path of an oil passage 21 connecting the extension side pressure chamber 15a of the cylinder 15 and the hydraulic pump P.
Motor M sucks up oil from tank port T and sends it out.

Then, the compression side pressure chamber 17 of the cylinder 17
b and the solenoid valve 23 are connected by an oil passage 25, and the oil passage 25 and the oil passage 2
1 is branched and connected by an oil passage 27. In the path of the oil passage 27, a pressure adjustment cylinder 29 with the piston rod on the oil passage 21 side, a second solenoid valve 31 with 3 ports and 2 positions, and a check valve 33 are arranged. An oil passage 35 branches off from the oil passage 27 between the solenoid valve 29 and the solenoid valve 31, and a plurality of plate holding cylinders 37 are arranged in parallel in the oil passage 35.

Further, a relief valve 39 is branched and connected to the oil passage 21 . In the oil passage 25, an accumulator 4 is provided between the contraction side pressure chamber 17b of the cylinder 17 and the branch oil passage 27.
1 is branch-connected. Similarly, a pressure regulating valve 43 is disposed between the branch oil passage 27 and the solenoid valve 23 in the oil passage 25, and a check valve is provided between the pressure regulation valve 43 and the branch oil passage 27. A valve 45 is provided.

Next, the operation of the embodiment with the above configuration will be explained.

As shown in FIG. 3, the pressure of the pump P is set to P
_P , the pressure of the accumulator 41 is P _ACC , and the plate presser pressure of the plate presser cylinder is P _H ,
When holding the plate material 1 by the plate presser 7 and cutting the plate material by the ram 11, the solenoid valve 28 is energized and the switching valve 23a is energized, and the solenoid valve 31 is energized and switched. Valve 3
Switch to 1b. Then, first, the hydraulic oil at the pressure P _ACC stored in the accumulator 41 passes through the oil passages 25 and 27, the check valve 33, the solenoid valve 31, and the oil passage 35 to the plate holding cylinder. 37 into the extension side pressure chamber 37a, the plate presser 7 is moved downward, and the plate material 1 is held. At the same time, P _P < P _H = P _ACC
Since the relationship holds true, the hydraulic oil from the accumulator 41 passes through the oil passages 25, 27, the check valve 33, and the solenoid valve 31, and is discharged into the compression side pressure chamber _A1 of the adjustment cylinder 29, and The piston 28 of the adjusting cylinder 29 is pressed against the piston rod.

In the above explanation, the plate material 1 is held by the plate holder 7 and the plate material is cut by the ram 11.
3 without switching the solenoid valve 31 or even when the hydraulic pump P is stopped.
It is clear that it is possible to operate the plate presser 27 independently at any time simply by switching.

Next, the hydraulic oil from the pump P driven by the operation of the motor M passes through the oil passage 21 and the solenoid valve 23 to the drive cylinder 15.
The piston 19a of the drive cylinder 15 is pushed downward. At the same time, the contraction side pressure chamber 1 of the drive cylinder 15 is caused by the movement of the piston 19a.
The hydraulic oil sent out from 5b is discharged into the extension side pressure chamber 17a of the drive cylinder 17, the piston 19b of the drive cylinder 17 is also pushed down, and the movement of both pistons 19a, 19b causes the ram 11 to move downward. Moving.

Next, when the ram 11 moves downward and begins to cut the plate material 1 held by the plate holder 7, the pressure _P from the pump P increases, and the oil passage 21 cylinder 15, and 1
The pressure of the hydraulic oil sent to ram 7 also increases, and the pressure of the hydraulic oil sent to ram 1 increases.
1, that is, the cutting force F _B increases.
When the pressure P _P rises, the hydraulic oil from the pump P passes through the oil passage 21, the solenoid valve 23, and the oil passage 27, and is also discharged to the contraction side pressure chamber _A2 of the adjustment cylinder 29. , the piston 28 of said adjusting cylinder 29 is moved to the opposite side of the piston rod. When the piston 28 is moved to the opposite side of the piston rod, hydraulic oil is sent out from the extension side pressure chamber _A1 , and the hydraulic oil passes through the oil passages 27 and 35 to the extension side of the plate holding cylinder 87. It is discharged into the pressure chamber 37a, and the plate holding force _FH of the plate presser 7 becomes stronger. and,
The piston 28 of the adjustment cylinder 29 continues to move until the pressure P _P of the pump P and the plate presser pressure P _H reach a certain relationship (P _H =A ₂ /A ₁ P _P ). That is, as shown in the _graph of _FIG .
As the cutting force F _B increases, the plate presser 7
The plate holding force F _H also increases. Therefore, even if the cutting force F _B of the ram 11 increases, such _as when cutting a thick plate or when the upper blade 9, lower blade 3, etc. Since the plate holding force F _H of the plate holder 7 also increases, the plate holder 7 can hold the plate 1 reliably.

Furthermore, when the piston 19b of the driving cylinder 17 is moved downward in order to move the ram 11 downward as described above when cutting the plate material 1, the compression side pressure chamber 17b of the driving cylinder 17 is moved downward.
The hydraulic oil sent out from the pump is stored in the accumulator 41 through the oil passage 25.

Next, when the cutting of the plate material 1 is completed, the solenoid valve 23 is switched to the switching valve 23c, and the solenoid valve 31 is switched to the switching valve 31a. Then, the hydraulic oil from the pump P is
The compression side pressure chamber 17b of the drive cylinder 17 passes through the oil passages 21, 25 and the check valve 45.
The piston 19 of the drive cylinder 17
Move b upward. When the piston 19b moves upward, the hydraulic oil sent out from the extension side pressure chamber 17a of the drive cylinder 17 is discharged into the contraction side pressure chamber 15b of the drive cylinder 15 through the oil passage 19, and 15 piston 19a is also moved upward. The ram 11 is then pushed upwards. Further, the hydraulic oil sent out from the extension side pressure chamber 15a of the drive cylinder 15 is drained to the discharge tank 47 of the solenoid valve 23 through the oil passage 21.

Next, since the plate holder 7 is lifted by the return spring 36 of the plate holder cylinder 37, hydraulic oil is sent out from the extension side pressure chamber 37a of the plate holder cylinder 37, and the hydraulic oil is sent to the discharge tank 49 of the solenoid valve 31. be drained.

Next, after the ram 11 rises, the solenoid valve 23 is switched to the switching valve 23b, and the hydraulic oil from the pump P passes through the oil passages 21 and 25 to compress the accumulator 41 and the drive cylinder 17. It is discharged into the side pressure chamber 17b and holds the ram 11 at the upper limit position. In this case, when the pressure of the hydraulic oil from the pump P increases, the pressure control valve 43 is switched by the pilot pressure, and the hydraulic oil from the pump P is discharged from the discharge tank 5.
Drained to 1. The next cut is then performed by the operations described above.

This device has the configuration described in the claims for utility model registration, so it can cut thick plates and also securely hold the plates even if the upper and lower blades are worn during cutting. If the solenoid valve 23 is in the neutral position,
Even when the hydraulic pump is stopped, the plate holding device can be operated to fix the plate at will.

It should be noted that this invention is not limited to the above-mentioned embodiments, and can be implemented in modes other than the above-mentioned embodiments.

Further, the symbols added for convenience in the claims for utility model registration do not limit the technical scope of this invention.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the relationship between ram driving force F _B and plate holding force F _H in a conventional shearing machine, Fig. 2 is a schematic explanatory diagram of the shearing machine,
FIG. 3 is a hydraulic circuit diagram of an embodiment of this invention, and FIG. 4 is a graph showing the relationship between ram driving force F _B and plate holding force F _H in a shearing machine implementing this invention. Explanation of symbols representing main parts of the drawing, 7...
Plate holder, 11... Ram, 15, 17... Drive cylinder, 27... Oil path, 29... Pressure adjustment cylinder, 37... Plate holder cylinder.

Claims (1)

[Scope of utility model registration request] A pair of left and right hydraulic cylinders 15 and 17 that drive the ram 11 of the shearing machine up and down are connected in series, and pressure oil from the hydraulic pump P is routed through one oil passage 21 through the first electromagnetic switching valve 23. Through the lowering drive side oil chamber 15 of the ram 11 of the left hydraulic cylinder 15
a, and further connects pressure oil from the hydraulic pump P to the upward drive side oil chamber 17b of the ram 11 of the right hydraulic cylinder 17 via the first electromagnetic switching valve 23 and the other oil passage 25. an accumulator 41 is provided branching off in the middle of the other oil passage 25, and a check valve 45 is provided between the accumulator 41 and the first electromagnetic switching valve 23;
The check valve 33 and the second electromagnetic switching valve 31 are located between the oil passages 27 and 35 that connect the oil passage 25 between the accumulator 41 and the check valve 45 and the hydraulic oil chambers 37a of the plural plate holding cylinders 37. are installed in series,
A piston 2 is provided between the oil passage 35 and the oil passage 21.
8 is a pressure regulating device for a plate presser in a shearing machine, characterized in that a pressure regulating cylinder 29 is provided which is slidably movable with its piston rod side facing the oil passage 21 side.