JPH0325866Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shearing machine, and more specifically, the present invention relates to a shearing machine, and more specifically, the invention presses a board against a table before shearing the board using a lower blade fixed to the table and an upper blade fixed to a ram. This invention relates to a plate holding device for a fixed shearing machine.

The plate holder in a shearing machine is generally made of a hydraulic cylinder, and the pressure of hydraulic oil required to press and fix the plate material is set in advance.
In this way, a large amount of hydraulic oil at a preset high pressure flows into the hydraulic cylinder and presses and fixes the plate material, so in the past, the plate holding device operates vigorously and hits the plate material, causing noise. It was the cause of

The present invention was devised in view of the above-mentioned conventional problems, and its first purpose is to provide a plate holding device that can quietly press and fix a plate.

A second object is to provide a plate holding device that can firmly press and fix a plate when shearing the plate.

In order to achieve the above objectives, in the present invention, a plurality of pressure control valves are connected to the oil line connecting the plate holding device and the fluid pressure device, and by controlling these pressure control valves, initially low pressure is Hydraulic oil acts on the plate holding device, and then high-pressure hydraulic oil acts on it.

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

Referring to FIG. 1, 1 generally indicates a shearing machine, and a lower blade 7 is attached to a table 5 horizontally attached to a frame 3. The ram 9 supported by the frame 3 so as to be able to move up and down is equipped with an upper blade 11 which cooperates with the lower blade 7 to shear the plate material W. An upper end 10 of a greatly curved connecting arm 13 is pivotally connected to the ram 9, and the lower end 12 of this connecting arm 13 is rotated by a motor 17 via a speed reduction device 15 such as a gearbox. It is fitted onto an eccentric shaft 19. Therefore, as the eccentric shaft 19 rotates, the ram 9 is moved up and down, and the plate material W is sheared by the lower blade 7 and the upper blade 11.

A plate holding device 21 is attached to the upper front surface of the frame 3 to press and fix the plate material W to the table 5 before the plate material W is sheared by the lower blade 7 and the upper blade 11. As shown in FIG. 2, the plate holding device 21 is composed of a fluid pressure actuated device such as a plurality of single-acting hydraulic cylinders 25 each having a return spring 23 therein, and includes a lower end portion of a reciprocating piston rod 27. It also includes a pressing pad 29 for pressing the plate material W. The hydraulic cylinder 25 is connected to a suitable fluid pressure generating device 31 via an oil passage.

The fluid pressure generating device 31 is composed of, for example, a plunger pump, and a plunger 35 that is slidably fitted into a frame 33 is always pushed in a direction by an internal bullet mechanism 37 such as a coil spring. energized. A cam follower 39 is rotatably attached to the protruding end of the plunger 35, and the cam follower 39 is in rotatable contact with a cam 41 of an appropriate shape attached to the eccentric shaft 19. Therefore, the fluid pressure generating device 31 is operated in conjunction with the vertical movement of the ram 9.

The inside of the frame 33 is divided into a large-capacity first chamber 43a whose pressure increases when the plunger 35 moves in, a small-capacity second chamber 43b, and a third chamber 43c whose pressure rises when the plunger 35 moves forward. The first chamber 43a is connected to the hydraulic cylinder 25 of the plate holding device 21 via a first oil passage 45. A relief valve is disposed in a first branch passage 47 branched from the first oil passage 45 as a pressure control valve 49 that can freely set the pressure in the first oil passage 45 to an arbitrary pressure. The second chamber 43b is connected to the hydraulic cylinder 25 via a second oil passage 51, and a second branch passage 5 branched from the second oil passage 51.
3 is provided with a relief valve as a second pressure control valve 55. The set pressure of this second pressure control valve 55 is set higher than the set pressure of the first pressure control valve 49.
, the pressure in the first oil passage 45 resists the return spring 23 in the hydraulic cylinder 25 and the piston rod 2
7 can be lowered, and the pressure pad 29 is set to be in a communicating state immediately before it comes into contact with the plate material W.

The third chamber 43c has a pilot oil passage 5 for operating a pilot-operated check valve 53 disposed at the connection between the first oil passage 45 and the second oil passage 51.
5 is connected to the pilot oil passage 55, and a relief valve 57 whose set pressure is relatively low is branch-connected to the pilot oil passage 55. In addition, the reference numeral 59 shown in the figure is the tank T.
This is a check valve that opens only when suctioning oil from the oil passage into the oil passage.

In the above configuration, when the eccentric shaft 19 is rotationally driven to shear the plate material W placed on the table 5, the cam 41 fixed to the eccentric shaft 19 is rotated integrally, and the fluid pressure generating device 31 is rotated. Since the plunger 35 is pushed forward against the ammunition 37,
The pressure in the first chamber 42a and the second chamber 43b increases,
The third chamber 43c becomes negative pressure, and the check valve 59
Oil is sucked in from tank T through. The pressure oil in the first chamber 43a and the second chamber 43b flows through the first oil path 4.
5. The oil is supplied to the hydraulic cylinder 25 of the plate holding device 21 via the second oil passage 51. Therefore, the plate material W is pressed and fixed to the table 5 before being sheared by the lower blade 7 and the upper blade 11.

When the plate material W is press-fixed to the table 5 as described above, a larger amount of hydraulic oil is supplied to the hydraulic cylinder 25 from the first chamber 43a than from the second chamber 43b. As hydraulic oil is supplied to the hydraulic cylinder 25 and the piston rod 27 and pressing pad 29 are lowered, the return spring 23 is gradually compressed, so that the hydraulic cylinder 25 and the first,
The pressure within the second oil passages 45, 51 gradually increases. Then, just before the hydraulic pad 29 comes into contact with the plate material W, the internal pressure in the first oil passage 45 and the like increases relatively, so the first pressure control valve 49 is opened and the pressure inside the first oil passage 45 increases. A portion of the hydraulic oil will be discharged to tank T. Therefore, the amount of hydraulic oil flowing into the hydraulic cylinder 25 decreases, and the downward speed of the piston rod 27 and the pressing pad 29 decreases.

As described above, since the pressing pad 29 contacts the plate material W after the descending speed of the pressing pad 29 and the like is reduced, the noise generated during contact is reduced. After the pressing pad 29 comes into contact with the plate W, the hydraulic oil in the second chamber 43b of the fluid pressure generating device 31 is supplied to the hydraulic cylinder 25 of the plate holding device 21, and the pressure inside the hydraulic cylinder 25 is maintained at a high pressure set by the second pressure control valve 55;
This is to firmly press and fix the plate material W.

When the ram 9 starts to rise as the eccentric shaft 19 rotates after shearing the plate material W, the plunger 35 in the fluid pressure generating device is gradually moved to protrude by the action of the bullet 37. When the plunger 35 is operated to project, the pressure in the third chamber 43c is increased and acts on the check valve 53, so that the check valve 53 is brought into communication, and the hydraulic fluid in the hydraulic cylinder 25 in the plate holding device 21 is Due to the action of the return spring 23, the first
The water will flow back into the chamber 43a and the second chamber 43b. In addition, if there is insufficient hydraulic oil, please check the check valve 59.
The suction is taken from the tank T via the tank T.

As can be understood from the above description of the embodiments, the gist of the present invention is as stated in the claims for utility model registration.As is clear from the description, the fluid pressure generating device consists of a plunger pump in which a plunger is slidably fitted into a frame, and inside the frame are a large-capacity first chamber whose pressure increases when the plunger moves in, a small-capacity second chamber, and a negative pressure chamber. It is divided into a third chamber, an oil passage connected to the first chamber, an oil passage connected to the second chamber and a hydraulic cylinder that presses and fixes the plate material, and an oil passage connected to the first chamber side. The connection is via a pilot-operated check valve that prevents oil from entering. A pilot oil passage for operating the check valve is connected to the third chamber. Furthermore, pressure control valves set at low pressure and high pressure are connected to the first chamber and the second chamber, respectively.

Therefore, in the present invention, a large amount of low-pressure hydraulic oil in the first chamber is discharged to the hydraulic cylinder during the initial stage of plate holding, and when the plate is pressed and fixed by the hydraulic cylinder, high pressure is discharged from the second chamber. Hydraulic oil is supplied to the hydraulic cylinder, and the plate material can be firmly pressed and fixed without making noise.

In particular, in this invention, a large-capacity first
The first chamber side and the second chamber side are connected via a pilot-operated check valve, and the pilot oil passage is connected to the third chamber. Since the plunger pump is connected to a chamber, low-pressure large discharge and high-pressure small discharge can be obtained simultaneously by the operation of one plunger, and the structure of the plunger pump is extremely simple. Further, the high pressure in the second chamber does not flow into the low pressure first chamber, and the plate material can be securely pressed and fixed. Furthermore, when the plate presser is released, the plunger is operated to project and the third chamber becomes high pressure, the check valve is automatically opened, and the oil in the hydraulic cylinder is returned to the first and second chambers. The tank capacity can be relatively small, and the size can be reduced.

Note that the present invention is not limited to the above-described embodiments, but can be implemented in other embodiments by making appropriate changes.

[Brief explanation of the drawing]

FIG. 1 is a side view of the shearing machine, and FIG. 2 is an explanatory diagram of the operating circuit of the plate holding device. Explanation of the symbols representing the main parts of the drawing, 1... Shearing machine, 5... Table, 7... Lower blade, 9... Ram, 11
...Upper blade, 21...Plate holding device, 31...Fluid pressure generation device, 49, 55...Pressure control valve.

Claims (1)

[Scope of utility model registration request] The plate holding device presses and fixes the plate material W on the table 5 before shearing the plate material W using a lower blade 7 attached to a table 5 and an upper blade 11 attached to a vertically movable ram 9 in a shearing machine. The plunger 35 slidably fitted into the frame 33 of the fluid pressure generating device 31 is biased in the projecting direction, and the projecting end of the plunger 35 is connected to an eccentric shaft 19 for vertically moving the ram 9. The inside of the frame body 33 is divided into a large capacity first chamber 43a whose pressure increases when the plunger 35 enters and a small capacity second chamber 43.
b and a third chamber 43c which has a negative pressure, and an oil passage 45 connected to the first chamber 43a and a second chamber 43c.
An oil passage 51 connected to the chamber 43b is connected via a pilot-operated check valve 53 that prevents oil from flowing into the first chamber 43a, and the check valve 53 is operated. A pilot oil passage 55 is provided connected to the third chamber 43c,
A shearing device characterized in that a first pressure control valve 49 set at a low pressure is connected to the first chamber 43a, and a second pressure control valve 55 set at a high pressure is connected to the second chamber 43b. A plate holding device in a machine.