JPH09225725A - Shearing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shearing machine in which the balance is obtained in a wide thin plate, and a large working force is obtained in a narrow thick plate. SOLUTION: First circuits 39, 41, 43 to connect in series a plurality of hydraulic cylinders 23L, 23R of a shearing machine 57 to shear a work by cooperating an upper blade 7U and a lower cutting blade 7L, and second circuits 39, 45, 43 to connect in parallel the hydraulic cylinders are provided, and a switching valve 47 to selectively connect these to a pump P, and the series circuits or the parallel circuits can be selected by the work. Because the sectional area of head side chambers 49U, 51U of the hydraulic cylinders 23L, 23R is same as that of a rod side chamber 49L, the stroke length of a piston rod becomes equal in the case of the series circuit, and a ram 9 is descended with excellent balance. In the case of the parallel circuit, a large shearing force can be obtained if working is achieved in the vicinity of the central part of the ram 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shearing machine, and more particularly to a shearing machine having an improved hydraulic circuit for shearing a work by a fluid pressure cylinder.

[0002]

2. Description of the Related Art The work of a contractor for shearing a sheet metal material often involves a mixture of shearing of a wide thin plate and shearing of a very thin plate used for fasteners and the like. When purchasing the shirring machine to be used, select the maximum cutting width of the material to be handled, and select the capacity tonnage considering the maximum plate thickness of the material to be processed. The number used the machine corresponding to the narrow slab. Or, since the product price rises significantly in proportion to the cutting width and the capacity tonnage, we had to purchase multiple units for general-purpose production and other production.

Next, a hydraulic circuit of a conventional shearing machine will be described. 2. Description of the Related Art Conventionally, a hydraulic circuit of a shearing machine that shears a sheet metal or the like includes a series circuit and a parallel circuit as a circuit arrangement of a plurality of cylinders for driving a ram.

Shirring machine 1 using a series circuit
4, the table 5 is integrally provided between the left and right side plates 3R and 3L, and the lower blade 7L is in the left-right direction (the left-right direction in FIG. 4) with the blade facing upward on the table 5.
Mounted on

A ram 9 is provided above the table 5 so as to be vertically movable, and the lower blade 7 is provided at the lower end of the ram 9.
An upper blade 7U is attached so as to face L and maintain a predetermined regret angle α. Further, a left hydraulic cylinder 11L and a right hydraulic cylinder 11R are provided downward inside the upper portions of the left and right side plates 3L, 3R. The lower ends of the piston rods 13L and 13R of the hydraulic cylinders 11L and 11R are attached to the ram 9. The head-side chamber 15U of the left hydraulic cylinder 11L is connected to the pump P by an oil pipe 17, and the rod-side chamber 15L is connected to the oil pipe 19.
Is connected to the head side chamber 21U of the right hydraulic cylinder 11R. That is, the left hydraulic cylinder 11L and the right hydraulic cylinder 11R are connected in series to form a series circuit.

Therefore, when the pump P is driven to supply the pressure oil to the head side chamber 15U of the left side hydraulic cylinder 11L, the piston rod 13L is lowered, and the pressure oil of the rod side chamber 15L is correspondingly moved to the head of the right side hydraulic cylinder 11R. Side room 2
The piston rod 13R of the right hydraulic cylinder 11R is lowered by pressure feeding to 1U.

When shearing a wide work W, the rake angle α causes the load to move in the left-right direction with shearing. However, in a series circuit, for example, when the shear load is eccentric to the left, The work W is on the left side of the blade 7U
To the left side hydraulic cylinder 11L, an upward force acts on the left side hydraulic cylinder 11L to reduce the pressure in the rod side chamber 15L, and the pressure in the head side chamber 21U of the right side hydraulic cylinder 11R also decreases accordingly. Since the pressing force of 11R can be automatically balanced, there is an advantage that the force for changing the rake angle α is hard to work.

On the other hand, in the shearing machine 1 using the parallel circuit, as shown in FIG. 5, the head side chamber 15U of the left hydraulic cylinder 11L and the head side chamber 21U of the right hydraulic cylinder 11R are connected to the pump P in parallel. There is.

Therefore, when the pump P is operated, the pressure oil is supplied to the head side chambers 15U and 21U of the left hydraulic cylinder 11L and the right hydraulic cylinder 11R, respectively, and the piston rods 13L and 13R simultaneously descend to lower the ram 9. And perform shearing.

Therefore, when the pump P and the hydraulic cylinders 11L and 11R having the same output and the same size as those in the case of the series circuit described above are used, twice the force is generated as in the case of the series circuit.
This is advantageous when shearing a thick plate work W.

[0011]

However, in the sheet metal working industry, in the shearing machine 1 using a series circuit as shown in FIG. 4, when a narrow and thick work W is sheared at an eccentric position. Although there is an advantage that the pressures of the left and right hydraulic cylinders 11L and 11R are automatically balanced, a large shearing force cannot be generated as compared with the parallel circuit, and the thick work W cannot be sheared regardless of the width.

Further, in the shearing machine 1 using the parallel circuit as shown in FIG. 5, the same force is always generated in the left and right hydraulic cylinders 11L and 11R, so that theoretically double the force is obtained in the case of the series circuit. Although there is an advantage that a thicker material can be sheared, an equal force is exerted from the left and right hydraulic cylinders 11L and 11R against the upward force applied to the eccentric position during shearing, and it is difficult to balance the material. For example, when the shear load is eccentric to the left, the pressing force of the left hydraulic cylinder 11L is received by the work W, but the pressing force of the right hydraulic cylinder 11R is not received, so the rake angle α changes. The shear accuracy may be adversely affected.

It is an object of the present invention to combine the advantages of the conventional series circuit and parallel circuit in order to suppress the increase in cost due to the purchase of a large expensive machine or a plurality of machines. (EN) A shearing machine that can perform narrow plate shearing with a general-purpose production machine that processes a relatively low shear tonnage and that does not reduce processing accuracy.

[0014]

To achieve the above object, a shearing machine of the present invention according to claim 1 is provided with an upper blade and a lower blade facing each other so as to cooperate with each other to shear a workpiece. A shearing machine having a plurality of fluid pressure cylinders for driving a ram having at least one of them, and a pump for driving the plurality of fluid pressure cylinders, wherein the plurality of fluid pressure cylinders are connected in series. Circuit, a second circuit that connects the plurality of fluid pressure cylinders in parallel, and a switching valve that selectively connects one of the first circuit and the second circuit to the pump, and at least a pump It is characterized in that all the head side chambers and the rod side chambers except the rod side chamber of the most downstream fluid pressure cylinder have the same sectional area.

A first circuit for connecting a plurality of fluid pressure cylinders in series and a second circuit for connecting in parallel are provided, and one of the first circuit and the second circuit is selectively connected to the pump. Since the switching valve is provided, a series circuit or a parallel circuit can be selected depending on the work.

Here, at least the head side chamber and the rod side chamber except the rod side chamber of the fluid pressure cylinder located at the most downstream side as viewed from the pump have the same sectional area. The pressure oil discharged by the cylinder is supplied to the head side chamber of the next fluid pressure cylinder, the stroke lengths of the piston rods become equal, and the ram descends in a balanced manner. Further, in the case of the parallel circuit, since the same amount of pressure oil is supplied to all the fluid pressure cylinders, if the machining is performed in the vicinity of the central portion of the ram, the shearing force becomes equal.

Therefore, when shearing a thin thin work piece, the first circuit can be connected to the pump by the switching valve to form a series circuit, so that the shearing position can be changed. The left and right fluid pressure cylinders can be balanced.

On the other hand, when shearing a thick work having a narrow width, the switching valve can connect the second circuit to the pump to form a parallel circuit. Since it is possible to obtain a force twice as large as that when a series circuit is used, it is suitable for processing a thick plate having a narrow width.

Further, in the shearing machine of the present invention according to claim 2, an upper blade and a lower blade are provided in opposition to each other so as to perform shearing of a work in cooperation with each other, and a ram having at least one of them is driven. A shearing machine having a plurality of fluid pressure cylinders and a pump for driving the plurality of fluid pressure cylinders, wherein a fluid pressure cylinder on the most upstream side and a fluid on the most downstream side of the pump among the plurality of fluid pressure cylinders. A second circuit that is connected in parallel with a first circuit that connects a pressure cylinder in series and a first switching valve that connects or disconnects the first circuit and the second circuit to the pump is provided. A second switching valve that selectively connects one of the first circuit and the second circuit to the pump is provided, and at least the head side chamber of the upstream fluid pressure cylinder and Head side chamber and the cross-sectional area of the head side chamber of said downstream side of the fluid pressure cylinder is characterized in that it has the same.

Of the plurality of fluid pressure cylinders driving the ram, a first circuit for connecting the fluid pressure cylinder on the most upstream side and the fluid pressure cylinder on the most downstream side with respect to the pump in series is connected in parallel. Since the two circuits are provided and the first switching valve that connects or disconnects the first circuit and the second circuit to the pump is provided, it is possible to select such that the first and second circuits do not operate. Further, since the second switching valve for selectively connecting one of the first circuit and the second circuit to the pump is provided, the fluid pressure cylinders at the left and right ends are connected in series or in parallel according to the workpiece. Can be selected.

Here, at least the head side chamber and the rod side chamber of the most upstream fluid pressure cylinder and the head side chamber of the most downstream fluid pressure cylinder have the same cross-sectional area. The pressure oil discharged by the fluid pressure cylinder is supplied to the head side chamber of the fluid pressure cylinder on the downstream side, the stroke lengths of the piston rods become equal, and the ram descends in a balanced manner. Further, in the case of the parallel circuit, since the same amount of pressure oil is supplied to the left and right fluid pressure cylinders, if the machining is performed near the center of the ram, the shearing force will be double that in the case of the series circuit.

Therefore, as in the case described above, when shearing a thin thin work piece having a wide width, it is possible to form a series circuit so that balance can be achieved, and a thick work piece having a narrow width can be balanced. Since a parallel circuit can be used when shearing, the double strength can be obtained when shearing in the vicinity of the central part, so a narrow thick plate can be processed. It is suitable for

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the first embodiment of the present invention. In FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals, and overlapping description will be omitted. That is, in FIG. 1, above the ram 9, left and right hydraulic cylinders 23L and 23R as fluid pressure cylinders for driving the ram 9 downward are provided with piston rods 25L and 25R facing downward near both left and right ends of the ram 9. Is provided. The lower end of this piston rod 25 has a ram 9
Mounted on Further, a return spring 27 for constantly biasing the ram 9 upward is attached to the body frame at one end and to the ram 9 at the other end.

Accordingly, the ram 9 is lowered by lowering the piston rods 25L, 25R of the hydraulic cylinders 23L, 23R to shear the work W, and the ram 9 is raised by the action of the return spring 27 after processing. Become.

Next, the hydraulic circuit will be described. The pump P for driving the hydraulic cylinders 23L, 23R is connected to an electromagnetic switching valve (which may be a manual operation switching valve or a mechanical switching valve) 29 as a first switching valve, and this electromagnetic switching valve 29 is a tank T or an oil passage. Main circuit 33 via 31
To be selectively connected to.

Therefore, when the solenoid 35 is turned on, the pump P and the oil passage 31 are connected, and when the solenoid 35 is turned off, the return spring 37 serves to connect the oil passage 31 to the tank T. There is. Here, one solenoid 35 is attached to the first electromagnetic switching valve 29.
Although one having one return spring 37 is used, one having two solenoids may be used instead.

The main circuit 33 includes the left and right hydraulic cylinders 23.
Oil passage 3 as the first circuit connecting L and 23R in series
Oil passages 39, 45, 4 as a second circuit connecting the left and right hydraulic cylinders 23L, 23R in parallel
3 and a second electromagnetic switching valve 47.
That is, the oil passage 31 connected to the first electromagnetic switching valve 29 branches into the oil passage 39 and the oil passage 45, and the oil passage 39 is connected to the head side chamber 49U of the left hydraulic cylinder 23L and the oil passage 4 is formed.
5 is connected to the second electromagnetic switching valve 47. The oil passage 41 connects the rod side chamber 49L of the left hydraulic cylinder 23L and the second electromagnetic switching valve 47. Further, the second electromagnetic switching valve 47 is connected to the head side chamber 51U of the right hydraulic cylinder 23R by the oil passage 43, and is also connected to the tank T. The rod side chamber 51L of the right hydraulic cylinder 23R is opened and connected to the tank T.

Here, except for the rod side chamber 51L of the right hydraulic cylinder 23R which is the most downstream from the pump P,
That is, the head side chamber 49U of the left hydraulic cylinder 23L
The cross-sectional areas of the rod-side chamber 49L and the head-side chamber 51U of the right hydraulic cylinder 23R are all equal.

Therefore, if the solenoid 53 of the second electromagnetic switching valve 47 is turned off while the solenoid 35 of the first electromagnetic switching valve 29 is turned on and the pump P and the oil passage 31 are connected, the return spring 55 of the return spring 55 is turned on. Oil passage 4 due to work
Since the oil passage 41 and the oil passage 43 are connected at the same time when 5 is cut off, the main circuit 33 has the left and right hydraulic cylinders 23L, 23
R is connected in series.

When the solenoid 53 of the second electromagnetic switching valve 47 is turned on, the oil passage 41 is opened to the tank T and at the same time the oil passage 45 and the oil passage 43 are connected, so that the main circuit 33 is left and right. The hydraulic cylinders 23L and 23R are connected in parallel.

A case where the shearing process of the work W is performed by the shearing machine 57 having the hydraulic circuit described above will be described.

When the work W is a wide thin plate, the solenoid 53 of the second electromagnetic switching valve 47 is turned off to form a series circuit, and the first electromagnetic switching valve 29 is turned on to operate the pump P. As a result, the left and right hydraulic cylinders 23
L and 23R operate in series to lower the ram 9, and the upper blade 7
The work W is sheared by the cooperation of the U and the lower blade 7L.

On the other hand, when the work W is a thick plate having a narrow width, the work W is set in the vicinity of the center of the processing area, and the solenoid 53 of the second electromagnetic switching valve 47 is turned on to form a parallel circuit. The electromagnetic switching valve 29 is turned on and the pump P
Activate As a result, the left and right hydraulic cylinders 23L,
23R operates in parallel to lower the ram 9, and the work W is sheared by the cooperation of the upper blade 7U and the lower blade 7L.

As described above, when the work W is a wide thin plate, it is possible to perform the shearing process by selecting the series circuit. Therefore, it is possible to perform high-precision machining while balancing the left and right hydraulic cylinders 23L and 23R. . Further, when the work W is a thick plate having a narrow width, a parallel circuit can be selected, so that a shearing force twice that in the case of a series circuit can be obtained and efficient machining can be performed.

The present invention is not limited to the examples of the above-described embodiments, but can be implemented by appropriately changing it. In the example of the above embodiment, the case where the two hydraulic cylinders 23L and 23R are provided has been described, but the case where three or more hydraulic cylinders are provided can be considered in the same manner.

That is, according to the first aspect, as shown in FIG. 2, a plurality of hydraulic cylinders 59, 59, 59 and a hydraulic circuit 61 are provided. In this case, the electromagnetic switching valve 6
By operating 3, 63 simultaneously, a series circuit or a parallel circuit can be selected. Here, all the head side chambers 67U and the rod side chambers 67L other than the rod side chamber 65L of the most downstream hydraulic cylinder 59 when viewed from the pump P have the same sectional area. In this case, when a parallel circuit is used, a shearing force as many as the number of cylinders is obtained as compared with the case of a series circuit. Further, in FIG. 2, as a specific example in which the above-described head-side chambers have the same cross-sectional area, a piston rod penetrating the center of the cylinder piston is projected both above and below the cylinder.

On the other hand, according to claim 2, even when it has three or more hydraulic cylinders, it relates to only the two hydraulic cylinders at the left and right ends (23L and 23R in FIG. 1), so that it is completely different from the above-mentioned embodiment. It can be treated similarly. Further, the arrangement of the hydraulic cylinders, the direction of the rake angle, etc. do not matter.

FIG. 3 shows an example of the second embodiment. In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals, and overlapping description will be omitted. That is, in FIG. 3, the oil passage 69 connected to the pump P
Is branched and connected to the first and second electromagnetic switching valves 71 and 73. The oil passage 75 connects the first electromagnetic switching valve 71 and the head side chamber 79U of the left hydraulic cylinder 77L, and the oil passage 81 branches from the oil passage 75 and passes through the first and second pilot operation valves 83 and 85 to the left hydraulic pressure. It is connected to the rod side chamber 79L of the cylinder 77L. Further, an oil passage 87 branches between the first and second pilot operated valves 83 and 85,
It is connected to the head side chamber 89U of the right hydraulic cylinder 77R. The oil passage 91 is connected to the second pilot operation valve 8
5 and the left side hydraulic cylinder 77L are branched from the oil passage 81 and connected to the rod side chamber 89L of the right side hydraulic cylinder 77R via the third pilot operation valve 93. An accumulator 95 is provided at an intermediate position of the oil passage 91.

Oil passage 97 from the second electromagnetic switching valve 73
Is connected to the third pilot operated valve 93 and the first pilot operated valve 83. The oil passage 99 connects the second electromagnetic switching valve 73 and the second pilot operation valve 83.

Here, all head side chambers 79U and 89U
The cross-sectional areas of the rod side chambers 79L and 89L are the same.
Further, the pilot operated valves 83, 85, 93 are closed when the pilot pressure is applied, and when the pilot pressure is drained, the springs are pushed by the pressure of the main circuit to open the valves.

Next, the shearing process in the example of the present embodiment will be described.

When the work W is a wide thin plate, first,
By turning off the second electromagnetic switching valve 73, the pilot pressure to the first and third pilot operating valves 83 and 93 is applied to close the valve, and the pilot pressure of the second pilot operating valve 85 is drained. To open the valve. As a result, the left and right hydraulic cylinders 77L and 77R are connected in series. When the first electromagnetic switching valve 71 is turned on in this state, the ram 9 descends and shearing can be performed. When the first electromagnetic switching valve 71 is turned off, the hydraulic cylinders 77L and 77R are driven by the pressure set by the accumulator 95 to raise the ram 9.

On the other hand, when the work W is a thick plate having a narrow width,
First, by turning on the second electromagnetic switching valve 73, the pilot pressure to the first and third pilot operated valves 83 and 93 is drained to open the valve, and the pilot pressure to the second pilot operated valve 85 is set. To close the valve. As a result, the left and right hydraulic cylinders 77L and 77R are connected in parallel. In this state, the first electromagnetic switching valve 71
When is turned on, the ram 9 descends and shearing can be performed. When the first electromagnetic switching valve 71 is turned off, the hydraulic cylinders 77L and 77R are driven by the pressure set by the accumulator 95 to raise the ram 9.

Also in the example of the present embodiment, it is possible to obtain the same effects as in the example of the above-described embodiment.

In the example of this embodiment, the case where two hydraulic cylinders are used has been described. However, similar to the example of the above-mentioned embodiment, the same effect can be obtained by using three or more hydraulic cylinders. Can be obtained.

[0047]

The shirring machine of the invention according to claim 1 has the above-described structure, and includes a first circuit for connecting a plurality of fluid pressure cylinders in series and a second circuit for connecting in parallel. And a switching valve that selectively connects one of the first circuit and the second circuit to the pump is provided, it is possible to select a series circuit or a parallel circuit depending on the work with one shearing machine.

Here, the head side chamber and the rod side chamber of all the fluid pressure cylinders have the same sectional area, or all the head side chambers and the rod side chambers except the rod side chamber of the most fluid pressure cylinder seen from the pump. In the case of a series circuit, the pressure oil discharged by the fluid pressure cylinder on the upstream side is supplied to the head side chamber of the next fluid pressure cylinder, and the stroke length of the piston rod is Equalize and the ram descends in a balanced manner. Further, in the case of the parallel circuit, since the same amount of pressure oil is supplied to all the fluid pressure cylinders, if the machining is performed in the vicinity of the central portion of the ram, the shearing force becomes equal.

Therefore, when shearing a wide thin work piece, the first circuit can be connected to the pump by the switching valve to form a series circuit, so that the shearing position can be changed. The left and right fluid pressure cylinders can be balanced.

On the other hand, when shearing a thick plate work having a narrow width, the second circuit can be connected to a pump by a switching valve to form a parallel circuit. Since it is possible to obtain a force twice as large as that when a series circuit is used, it is suitable for processing a thick plate having a narrow width. Therefore, the processing can be performed without lowering the processing accuracy.

Further, according to the shearing machine of the present invention according to claim 2, among the plurality of fluid pressure cylinders driving the ram, the fluid pressure cylinder on the most upstream side and the fluid pressure cylinder on the most downstream side of the pump. A second circuit connecting in parallel with a first circuit connecting in series, and a first switching valve connecting or disconnecting the first circuit and the second circuit to the pump. The first and second circuits can be chosen to be inactive. Further, since the second switching valve for selectively connecting one of the first circuit and the second circuit to the pump is provided, the fluid pressure cylinders at the left and right ends are connected in series or in parallel according to the workpiece. Can be selected.

Here, since the head side chamber and the rod side chamber of the most upstream side fluid pressure cylinder and the head side chamber of the most downstream side fluid pressure cylinder have the same cross-sectional area, the stroke of the piston rod in the case of a series circuit. The lengths are equal and the ram descends in a balanced manner. Further, in the case of the parallel circuit, since the same amount of pressure oil is supplied to the left and right fluid pressure cylinders, if the machining is performed near the center of the ram, the shearing force will be double that in the case of the series circuit.

Therefore, as in the case described above, when shearing a thin thin work piece having a wide width, it is possible to achieve a balance as a series circuit, and when shearing a thick thick work piece with a narrow width. In the case of the parallel circuit, shearing in the vicinity of the central portion can obtain twice the force as in the case of using the series circuit, and is suitable for processing a thick plate having a narrow width. Therefore, the processing can be performed without lowering the processing accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a hydraulic circuit of a shearing machine according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a case where there are three or more fluid pressure cylinders.

FIG. 3 is a diagram showing an example of a hydraulic circuit of a shearing machine according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a hydraulic circuit in series in a conventional shearing machine.

FIG. 5 is a diagram showing parallel hydraulic circuits in a conventional shearing machine.

[Explanation of symbols]

 7U Upper blade 7L Lower blade 9 Ram 23L, 23R Hydraulic cylinder (fluid pressure cylinder) 39, 41, 43 First circuit 39, 45, 43 Second circuit 47 Electromagnetic switching valve (switching valve) 49U, 51U Head side chamber 49L Rod side chamber 57 Shearing machine W work P pump

Claims (2)

[Claims] 1. A plurality of fluid pressure cylinders for driving a ram provided with an upper blade and a lower blade facing each other so as to cooperate with each other for shearing a work, and a plurality of fluid cylinders. A shearing machine having a pump for driving a pressure cylinder, comprising: a first circuit connecting the plurality of fluid pressure cylinders in series; a second circuit connecting the plurality of fluid pressure cylinders in parallel; A switching valve that selectively connects one of the first circuit and the second circuit to the pump is provided, and at least all the head-side chambers / rod-side chambers except the rod-side chamber of the fluid pressure cylinder located most downstream when viewed from the pump are provided. Shirring machine with the same cross-sectional area. 2. A plurality of fluid pressure cylinders for driving a ram having at least one of the upper blade and the lower blade facing each other so as to cooperate with each other for shearing a work, and the plurality of fluids. A shearing machine having a pump for driving a pressure cylinder, wherein a first fluid pressure cylinder of a plurality of fluid pressure cylinders is connected in series to a fluid pressure cylinder on the most upstream side and a fluid pressure cylinder on the most downstream side of the pump. A second circuit that is connected in parallel with a circuit is provided, and a first switching valve that connects or disconnects the first circuit and the second circuit to the pump is provided, and the first circuit or the second circuit A second switching valve that selectively connects one to the pump is provided, and at least the head side chamber and rod side chamber of the upstream fluid pressure cylinder and the head side chamber of the downstream fluid pressure cylinder are provided. A shirring machine having the same cross-sectional area.