JPH08164500A - Distributed pressure application type press - Google Patents

Abstract

PURPOSE: To provide a distributed pressure application type press capable of uniform pressurizing as a whole by using a hydraulic cylinder to individuallly drive and control a machine requiring a large pressure such as a press machine, a press brake or an extruder. CONSTITUTION: In a pressure applying device such as a press brake where a cylinder is a pressure source, at least both end parts are turnably fitted to a beam member 1 or a plate member supported by an appropriate supporting member, and one end side of three or more sets of hydraulic cylinders C1 -Cn are turnably fitted. The other end side of the hydraulic cylinders C1 -Cn are turnably fitted to a pressure transmitting member such as a ram 3 or a table 5, and the pressure or the displacement on the hydraulic cylinders C1 -Cn is individually driven and controlled so that the stress may be nearly uniformly distributed as a whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine that requires a large pressing force, such as a press machine, a press brake or an extrusion molding machine, by dispersing the pressing force.
The present invention relates to a dispersion pressure type press device capable of performing uniform pressure as a whole.

[0002]

2. Description of the Related Art Pressing machines conventionally used for press working such as bending and drawing of metal plates mainly utilize hydraulic pressure in order to obtain a strong pressing force. In most pressurizing devices such as a press machine using a liquid as a pressure medium, a single hydraulic cylinder obtains a pressing force.

In a press machine, a press brake, or a machine requiring a large pressing force such as an extrusion molding machine, the larger the size of the mold, its holder, ram, frame, etc. Bending becomes a problem in maintaining processing accuracy.

Therefore, various proposals have heretofore been made so as not to cause the above-mentioned bending, but most of them are intended to increase the rigidity of the structure itself, so that a machine having a rigid structure is mainly used. Had occupied.

However, since a machine having a rigid structure inevitably becomes large in size and also increases in weight, the larger the machine becomes, the larger the structure becomes and the more difficult it is to carry the finished product. Therefore, the foundation work at the installation site becomes large-scale, and in some cases, after the installation work is completed, the building is constructed, which may require a huge amount of construction cost.

As described above, most of the conventional machines use a single hydraulic cylinder to generate a pressing force, but the mold is spread in two dimensions. That is, the mold has a flat shape, and it is necessary to uniformly press the entire surface. For that purpose, the concentrated stress generated by one cylinder must be evenly distributed over the entire surface of the mold. Therefore, as shown in FIG. 15, the concentrated stress generated by pushing out the rod of one cylinder is dispersed in the ram to uniformly press the entire surface of the die. The rigid structure led to an increase in the size and weight of the machine. In press brake, there is a technique to operate two cylinders synchronously, but this also distributes the concentrated stress applied to the right and left two points of the ram to the ram.
Therefore, the ram has a rigid structure.

On the other hand, in a plate bending machine in which two cylinders such as a press brake are used to form a pressing force in a one-dimensional, that is, linearly arranged die, a ram is formed in a rigid structure. However, it is known that the bending angle of the material to be processed is sagging when the upper frame or the table of the plate bending machine is bent by the reaction force of the bending process.

Further, in a plate bending machine such as a press brake, wear may occur at a local portion of the die such as a central portion of the die due to long-term use of the die, and the bending angle of the portion may be weakened. It is known that when bending is performed to correct this angle, on the contrary, there is a problem that the bending ends tend to be excessively bent, which makes it difficult to obtain a satisfactory bent product.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and in a machine that requires a large pressing force such as a press machine, a press brake or an extrusion molding machine, three or more liquids are used. It is an object of the present invention to provide a distributed pressure type press device capable of performing uniform pressurization as a whole by driving and controlling these individually using a pressure cylinder to disperse the applied pressure. is there.

Further, according to the present invention, it is possible to perform plate bending so as to easily correct the drooping, without equipping the member on the side opposite to the pressurizing side of the press brake with a device for preventing the drooling. It is an object of the present invention to provide a dispersion-pressing type press device.

Further, according to the present invention, the insufficient bending angle or the excessive bending angle, which is mainly caused by the wear of the die, is artificially applied to the ram or table of the upper die or the lower die. The bending state is locally corrected by causing the bending to occur, the workability of the bending work accompanied by such correction is improved, and the correction value of the bending correction is stored in the NC data. As a result, it is possible to improve the reproducibility of the processing accompanied by such correction, and realize a highly accurate bending processing. Providing is one of the challenges.

[0012]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving each of the problems described above. The structure of a distributed press type press device is a press brake using a cylinder as a press source. In the pressurizing device, at least both ends of the beam member or plate member supported by a suitable fulcrum member,
Three or more hydraulic cylinders are attached so that one end side of them can be turned.
The other end of the hydraulic cylinder is rotatably attached to a pressing force transmitting member such as a ram or a table, and the pressing force or displacement of the hydraulic cylinders is adjusted so that the stress can be dispersed almost uniformly as a whole. The drive control of the hydraulic cylinder can be performed by the following modes.

A measurer attached to a pressing force transmitting member such as a ram, a displacement sensor attached to the tip ends of the rods of the left and right linear actuators via a guide bar, and a displacement detected by the displacement sensor. A control valve, such as a servo valve or a proportional control valve, which operates by a signal proportional to the quantity, can control the oil flow direction and flow rate.

A measurer attached to a pressing force transmitting member such as a ram, a displacement sensor attached to the tip ends of the rods of the left and right linear actuators via a guide bar, and each cylinder were connected. It is carried out by a bidirectional variable displacement hydraulic pump and a servo motor which directly controls the drive of the pump by a feedback signal from a displacement sensor.

A linear scale whose one end is fixed and which measures the absolute position of a pressing force transmission member such as a ram, and a servo valve which operates by the signal, which is a signal measured by the linear scale, is used as a feedback signal. Alternatively, a control valve such as a proportional control valve capable of controlling the flow direction and flow rate of oil is used.

A linear scale having one end fixed to measure the absolute position of a pressing force transmission member such as a ram, a bidirectional variable displacement hydraulic pump connected to each cylinder, and a signal measured by the linear scale The feedback signal is used as a feedback signal and is controlled by a servo motor which directly controls the drive of the pump.

A measurer attached to a pressing force transmitting member such as a ram, a displacement sensor attached to the tips of the rods of the left and right linear actuators via a guide bar, and each cylinder were connected. It is carried out by a variable phase bidirectional variable displacement hydraulic pump and a servo motor which directly controls the drive of the pump by a feedback signal from a displacement sensor.

A linear scale having one end fixed to measure the absolute position of a pressing force transmission member such as a ram, a variable phase bidirectional variable displacement hydraulic pump connected to each cylinder, and the measurement of the linear scale This signal is used as a feedback signal, and a servo motor that directly drives and controls the pump by the signal is used.

The hydraulic pump used in each of the above controls may be a bidirectional fixed displacement hydraulic pump instead of the variable displacement hydraulic pump.

On the other hand, the structure of the distributed pressure type press device capable of plate bending with compensating for sagging is as follows: between the upper frame and the upper mold holder or between the table and the lower mold holder. Equipped with 3 or more hydraulic cylinders for pressurization at appropriate intervals, hold the molds in the upper and lower mold holders, insert the plate material between the upper and lower molds, and apply the pressure of the hydraulic cylinders. In a press device that acts on the upper or lower die holder to bend the plate material by the cooperation of the upper and lower dies, at the time of bending, the pressing force of the required cylinder in each hydraulic cylinder is controlled. It is characterized in that the deformation curve on the machine side supporting the upper or lower die at the bottom dead center of the bending process is controlled.

Further, according to the present invention, the constitution of the distributed press type press device capable of plate bending with local correction bending is such that it is integrated between the upper frame and the upper die holder or the lower frame. Between the table and the lower mold holder, equip three or more hydraulic cylinders for pressurizing at an appropriate fixed interval, hold the molds in the upper and lower mold holders, and press the upper and lower mold holders. In a press device in which a plate material is inserted between the molds, the pressing force of the hydraulic cylinder is applied to the upper or lower mold holders, and the plate materials are bent by the cooperation of the upper and lower molds, during bending, Each of the hydraulic cylinders is driven and controlled so that the bottom dead center is locally changed, and the bending angle is locally corrected.

[0022]

In the dispersion press machine of the present invention, at least both ends of the beam member are supported by appropriate fulcrum members so that the upper ends of three or more hydraulic cylinders are rotatably mounted, and the lower ends of the cylinders are fixed. , Rams, etc., are attached so as to be rotatable, and these cylinders are individually driven and controlled so that the stress can be evenly distributed as a whole.
When a plurality of cylinders are simultaneously projected to pressurize the pressing force transmitting member, the beam member bends upward in a bow due to the reaction force, but the stress is evenly distributed over the entire surface of the pressing force transmitting member, and There is no waste. Therefore, when a press brake ram is used as the pressing force transmitting member, an upper die is attached to the ram, and a work is inserted between the ram and the lower die to bend the work, the upper die is used. Since the mold acts on the work with uniform pressure, the work is bent uniformly.

By allowing the bending of the upper beam member in this way, the beam can be made to have a flexible structure, so that the weight of the beam can be inevitably reduced. In addition, since multiple cylinders are individually driven and controlled, the structure becomes complicated, but on the other hand, a small cylinder with low output is sufficient, and a commercially available off-the-shelf product will suffice, so the cost of the device will also be low. .

A distributed press type press device for plate bending having a sagging correction function of the present invention is provided between an upper frame and an upper mold holder or between a table and a lower mold holder. Equipped with three or more hydraulic cylinders for pressurization at appropriate intervals, hold the molds on the upper and lower mold holders, insert a plate material between both molds, and apply the pressure of each hydraulic cylinder. In the above-mentioned press device which is made to act on the upper or lower die holder to bend the plate material by the cooperation of the upper and lower dies, at the time of bending, the pressing force of the required cylinder of each hydraulic cylinder is controlled. , The machine side supporting the upper or lower mold at the bottom dead center of the bending process, for example, by controlling the deformation curve due to the pressing force of the mold holder, so as to correct the sagging, the simple structure Who can be corrected with high accuracy.

Further, the distributed press type press device for plate bending having the local correction function of the present invention locally bends the hydraulic cylinder for pressurizing the upper die holder or the lower die holder during bending. Since the bending angle can be locally corrected by controlling the drive so that the bottom dead center of the work is changed, the bending angle of the work can be locally corrected with high accuracy with a simple structure.

[0026]

Embodiments of the present invention will now be described with reference to the drawings.
1 is a front view of a main part of an example in which the device of the present invention is applied to a press brake, FIG. 2 is a side view of FIG. 1, FIG. 3 is a front view of a guide bar attached state, and FIG. 4 is a view of the device of FIG. FIG. 5 is a system diagram showing an example of cylinder drive control, FIG. 6 is a system diagram showing an example of cylinder drive control, and FIG. 7 is a diagram showing a linear actuator without using a linear actuator. 8 is a side view of an example using a linear scale, FIG. 8 is a system diagram showing an example of drive control of upper and lower mold cylinders, and FIG. 9 is a front view of an example of a plate bending machine to which the present invention is applied. 10 is a system diagram showing another example of drive control of the upper and lower mold cylinders, FIG. 11 is a perspective view showing an arrangement example of cylinders for performing two-dimensional press working to which the present invention is applied, and FIG. FIG. 13 is a partially enlarged view of the case, FIG. 13 is a plan view of an example of a two-dimensional press device, and FIG. 14 is A- of FIG.
FIG. 15 is a front view schematically showing the configuration of a conventional two-dimensional press machine, which is a sectional view taken along the arrow A '.

In FIG. 1, 1 is a beam whose left and right ends are supported by fulcrum members 2 and 2, 2a is a connecting shaft between the fulcrum members 2 and 2 and the beam 1, and C ₁ , C ₂ , ... Hydraulic cylinders (hereinafter referred to as cylinders) mounted by shafts S _{1 to} Sn so that the upper ends of the cylinders ₁ can be swung at intervals, respectively. The lower ends of the cylinders C ₁ , C ₂ , ... It is attached to a ram 3 to which the upper die 4 is attached so as to be pivotable by shafts P _{1 to} Pn. A lower die holder 5 is provided at the upper end of the lower table, and a lower die 6 is attached to the holder 5 so as to face the upper die 4, whereby the distributed pressure type press device of the present invention is mounted. It constitutes an example of a main part. The number of the fulcrum members 2 is not limited to two at each end, and three or more may be provided.

When the press mechanism of FIG. 1 is applied to a press ply, and plate bending is performed by this, the upper and lower dies 4,
A work is inserted between 6 and a plurality of cylinders C ₁ , C ₂ , ...
If Cn is projected at the same time, the movement urges the ram 3 and the upper die 4, and presses the work to perform bending work. At this time, the beam 1 is bent upward as shown in FIG. 4 by the reaction force of the pressurization of the cylinders C ₁ , C ₂ , ... Cn, but the ram 3 and the upper die 4 are evenly distributed over the entire surface. Since the stress is dispersed and applied to, there is no bending.

By allowing the upper beam 1 to bend as described above, the beam 1 can have a flexible structure. In addition, the flexible structure of the beam 1 inevitably reduces the weight of the beam 1. Furthermore, compared with the conventional one using two cylinders on the left and right, a plurality of cylinders C ₁ ~
When Cn is used, the structure becomes complicated, but on the other hand, the cylinders C _{1 to} Cn have a low output and are small in size, and commercial off-the-shelf products can be used sufficiently, which is advantageous in terms of cost reduction.

Next, the control of the protrusion amount and thrust of the plurality of cylinders C _{1 to} Cn will be described. Figure 2 shows the method, 3a is provided horizontally to the mounting portion of the cylinder C ₁ to Cn in ram 3 Measuring - bar - 7,7, as shown in FIG. 3, guide bar -8 linear actuator provided on the left and right - motor, 8 is the linear actuator - rod 7a of motor 7, 7, pivotably to the tip of 7a bodywork has been guide bar -, the cylinder C ₁ is in the guide bar -8 9 Displacement sensor attached to the position corresponding to ~ Cn, 9a is each displacement sensor 9
2, the measurer 3a is in contact with the probe 9a in FIG.

The left and right linear actuators 7,
When 7 is operated synchronously and the guide bar 8 is translated downward from the state shown in the figure, the guide bar 8 descends and the probe 9a of each displacement sensor 9 comes into contact with the major bar 3a and is compressed. A signal proportional to the amount of displacement is output. As shown in FIG. 5, this output is fed back to the adder 10 and the servo valve 12 via the servo amplifier 11 controls the push and pull amounts and thrusts of the cylinders C _{1 to} Cn. ,Cylinder
Lower C ₁ to Cn so as to follow the guide bar 8. As a result, the distance from the guide bar 8 is kept constant. still,
Instead of the servo valve 12 described above, a control valve such as a proportional control valve capable of controlling the flow direction and flow rate of oil may be used.

As described above, in the present invention, as long as the flatness of the guide bar 8 is not impaired, such follow-up control is simultaneously performed for all of the plurality of cylinders C _{1 to} Cn, so that the ram is pressurized. When 3 bends even a little, the cylinder in the position with a large amount of deflection automatically controls the displacement and thrust due to the stroke to correct the deflection of the ram 3, so that the flatness of the ram 3 can be maintained. Of.

In the above example, the probe 9a of the displacement sensor 9 and the measurer 3a are brought into contact with each other to measure the amount of displacement of the probe 9a, but as shown in FIG. Alternatively, the displacement sensor 9 may measure the distance d between the measuring point attached to the guide bar 8 and the measuring point attached to the measurer bar 3a.

The guide bar 8 normally moves in the vertical direction while keeping parallel to the lower die 6, but it is also possible to move it in a tilted state with respect to the lower die 6. For example, the linear actuator 7 on the left side is made to protrude by a predetermined amount more than the protruding amount of the linear actuator 7 on the right side in FIG. That is, if the left side protrusion amount is set to x + α with respect to the right side protrusion amount x, the upper mold 4 is always tilted to the left side by a certain amount and moves up and down in parallel. When the work is processed in such a state, the bending angle on the left side becomes larger than the bending angle on the right side, and so-called taper bending becomes possible.

In FIG. 5, port P is a hydraulic source.
The port T is connected to a high-pressure port of a space unit (not shown), and the port T is connected to a low-pressure port on the tank side. Normally, a plurality of cylinders and the servo valve 12 are connected in parallel to one hydraulic source unit, but a separate hydraulic source unit may be used for each cylinder unit.

Further, although the feedback signal Ef is added to the adder 10 of FIG. 5, the external control signal Ei is also added. Since the external control signal Ei is added to the feedback signal Ef, the feedback signal Ef can be finely adjusted. That is, it means that the distance d can be changed. When mounting the displacement sensor 9 on the guide bar 8 without changing the feedback signal Ei,
The ram 3 and the mold 4 can be mounted by changing the distance d so that the position is along the desired deformation curve.
It is possible to apply pressure while flexibly deforming.

In order to finely adjust the relative position between the guide bar 8 and the ram 3 in FIG. 5, the position of the sensor 9 attached to the guide bar 8 may be mechanically moved, but the external control signal Ei is used.
It is also possible to make an electrical fine adjustment by controlling. Of course, the adder 10 is removed and the feedback signal is
There is no problem even if Ef is directly applied to the servo amplifier 11.

The guide bar 8 is supported by the left and right linear actuators 7, 7 and a plurality of displacement sensors 9 arranged substantially evenly measure the distance d from the major bar 3a. Since only a small force for moving the probe 9a of the sensor 9 acts, the flatness of the sensor 9 will not be impaired if it is designed not to bend under its own weight.

As described above, the displacement sensor 9 may be either a contact type or a non-contact type, but a non-contact type displacement sensor is preferable because no force is required for distance measurement.

In FIG. 6, one bidirectional variable displacement hydraulic pump 13 is connected to each of the cylinders C _{1 to} Cn described above, and the displacement sensor 9 is connected.
Is fed back to the adder 10 and the servo amplifier 11
FIG. 3 is a system diagram of an example of drive control in which the pump 13 is directly driven by a servomotor SM via a motor for implementing the above method. In this case, as many hydraulic pumps 13 as cylinders are required, but since the hydraulic pumps 13 themselves have a function of controlling the discharge direction and discharge amount of the hydraulic oil, as shown in FIG. Hydraulic source
The control valve such as the servo valve 12 or the proportional control valve, which is required when the unit is used, becomes unnecessary. The guide bar 8, the measurer 3a, and the displacement sensor 9 in the mechanism shown in FIG.
The functions and operations such as are exactly the same as those in FIG. Of course, this system also operates exactly the same even if replaced with a servo valve or a servo control by a combination of a proportional control valve and an ordinary hydraulic source unit.

Here, in the system using the control valve, even when the cylinder is stopped, the electric motor of the hydraulic source unit rotates at full power and the produced hydraulic energy is released.
Since it is returned to the tank via the valve, the consumed electric energy is converted into heat energy and raises the temperature of the hydraulic oil in the tank, resulting in wasteful consumption of energy.

However, in another control method of the apparatus of the present invention illustrated in FIG. 6, when the cylinder is stopped, the servo is stopped.
Since the motor SM is also stopped, energy is not wastefully consumed, and therefore, energy efficiency is improved as compared with the control method using the servo valve of FIG.

Further, in FIG. 6, the hydraulic pump 13 is driven by the servo motor SM, but recently, even in the case of an ordinary induction motor, by combining it with an inverter, the servo motor can be driven. Since it is possible to operate as, it is possible to do so.

The gist of the above drive control method is to obtain the relative distance between the guide bar 8 and the ram 3 with the guide bar 8 as a reference line so that the shortened amount of the probe 9a or the distance d is always constant. That is, that is, the servo control is performed so as to maintain the flatness of the upper die 4, and the distance d is finely adjusted to apply the pressure while bending the upper die 4.

However, the method is as shown in FIG.
The linear scale 14 fixed at one end measures the absolute position of the ram 3 and processes the information, and this signal is used as a feedback signal, as shown in FIG.
By operating the control valve through 11 and driving the cylinders C _{1 to} Cn, it is possible to pressurize the upper mold 4 while keeping the upper mold 4 flat and parallel or inclined with the lower mold as in the above. Incidentally, 14a in FIG. 7 is a probe of the linear scale 14. Also in this case, the desired deformation can be performed by adding the numerical value according to the desired deformation curve to the output information of the linear scale 14 by the computer.

The drive control method (1) is a method in which the cylinder is driven and controlled by the servo motor SM and the hydraulic pump 13 which are paired with the cylinder, without using the control valve in the drive control method.

On the other hand, in the drive control method of and, instead of the bidirectional variable displacement hydraulic pump in the drive control method of and, the variable phase type described in the publication of "Hydraulic piston device" of Japanese Patent Publication No. 256883/1990. By using a bidirectional discharge variable displacement hydraulic pump (not shown), the same operational effects as those of the drive control method and can be obtained.

In the pressing apparatus of the present invention described above, the arrangement of three or more cylinders can be applied to the lower die side of the pressing machine. That is, although not shown, the lower frame is formed on a lower beam member whose both ends are supported by fulcrum members, and between the beam member and the lower die holder or its table, on the three cylinders, The lower end portions are respectively rotatable, that is, they are connected to each other via a horizontal shaft oriented in a direction orthogonal to the mold.

FIG. 8 shows the lower mold 6 in the control example of FIG.
The table 5 supporting the above is controlled by being dispersedly supported by a plurality of cylinders C '. That is, the alcove and the holder 5 in which a lower mold 6 so as to face the cylinder C ₁ to Cn are a plurality of cylinders C ₁ 'to Cn' are equipped upwardly. Although not shown, both ends of the holder 5 are tapes.
Both ends are restrained by being locked by a horizontal shaft orthogonal to the length direction of the bull, and are flexibly supported by the action of the cylinders C ₁ ′ to Cn ′.

A bidirectional variable displacement hydraulic pump 13 is connected to each of the upper cylinders C _{1 to} Cn among the upper and lower cylinders facing each other, and one side of each pump 13 is connected to the upper cylinder C ₁ respectively. ~ Cn corresponding lower cylinder
It is also connected to the C ₁ '~Cn'. Here, the signals of the displacement sensors 9 are fed back to the adder 10 and directly drive the pumps 13 by the servo motor SM via the servo amplifier 11. ing. The feedback signal Ef from each displacement sensor 8 is applied to each adder 10.
However, the external control signal Ei is also added. Since the external control signal Ei is added to the feedback signal Ef, the feedback signal Ef can be finely adjusted. This means that the relative distance d between each displacement sensor 9 and the measurer bar 3a can be changed.

Thus, there is a wire between the upper die 4 and the lower die 6.
Insert a click and by driving the cylinder C ₁ to Cn simultaneously imparting pressure to the upper mold 4, follower by the lower die 6 in cooperation with receiving the upward pressure simultaneously - is click is bent However, at this time, when any one of the displacement sensors 9 corresponding to the cylinders C _{1 to} Cn detects the displacement of the distance between the ram 3 of the upper die and the guide bar 8, the signal indicates the corresponding cylinder. It is fed back to the adder 10, and the hydraulic pump 13 is controlled by the servo motor SM via the servo amplifier 11.
Any of the corresponding cylinder C ₁ to Cn, and the is to control drive either of the cylinder C ₁ cylinder C ₁ corresponding to the to Cn 'to Cn'.

That is, when the ram 3 of the upper and lower molds and the holder 5 are in a straight line state, the distance between the ram 3 of the upper mold and the guide bar 8 does not change, but the upper cylinders C _{1 to} Cn. When the ram 3 of the upper die is bent due to the pressurization of
The displacement to each sensor 9 in accordance with the deflection amount corresponding to the position of the C ₁ to Cn is detected, each of the above cylinder C ₁ to Cn on the basis of the detected displacement, the required cylinder C ₁ 'to Cn' By controlling the pressure output of the ram 3, the distance between the ram 3 and the guide bar 8 is corrected to a regular distance, and thereby the bending of the ram 3 on the upper die side is corrected. Here, in the control system of the embodiment described so far, the bidirectional variable displacement hydraulic pump is used as the hydraulic pump, but in the present invention, a bidirectional fixed displacement hydraulic pump is used instead of the variable displacement hydraulic pump. Can be used. This also applies to the control system in the embodiment of the press device described below.

Next, the dispersion pressure type press device described above is
An example applied to a press brake capable of plate bending with a drooping correction function will be described. FIG. 9 shows the front of the press brake. In this FIG. 9, 21 is the upper frame, which is the beam 1 in the press device illustrated in FIG.
Cylinders C _{1 to} Cn are provided between the upper frame 21 and the upper mold holder 3 corresponding to the ram 3 in FIG. 1. A lower table 22 is provided with a lower mold holder 5 on the upper part, and the lower mold is attached to the holder 5. In the press brake of FIG. 9, a work (plate material) is inserted between the upper mold 4 and the lower mold 6, and the cylinders C _{1 to} Cn are simultaneously driven to apply a pressing force to the upper mold 4. Then, the work is bent by the cooperation with the lower die 6, but at this time, the sagging occurs and any one of the displacement sensors 9 corresponding to the cylinders C _{1 to} Cn is moved upward. When the displacement of the distance between the mold holder 3 and the guide bar 8 is detected, as shown in FIG.
Is Dobakku, Sa - - Fi to the adder 10 of the cylinder to which the signal corresponding service via the ball amplifier 11 - Vomo - the by motor SM hydraulic pump 13 is controlled, corresponding cylinder C ₁ ~
It controls the pressure of the required cylinder in Cn.

That is, for example, when the upper and lower mold holders 3 and 5 are both in a straight line state, the distance between the upper mold holder 3 and the guide bar 8 does not change, but the cylinders C _{1 to} Cn.
The upper frame of the press brake 1 due to the reaction force of the pressing force of
Alternatively, when the table ₅ bends and sagging occurs in the bending angle of the work, displacement is detected by each displacement sensor 9 according to the amount of bending corresponding to the position of each cylinder C ₁ -Cn. Between the upper mold 3 and the guide bar 8 by controlling the pressing force of the cylinders C _{1 to} Cn based on the detected displacement amount and controlling the deformation curve due to the pressing force of the upper mold holder 3. Is corrected to a regular distance to correct the drooping that occurs at the bending angle of the work.

In the above embodiment, the cylinders C ₁ to
Although Cn is provided between the upper frame 1 and the upper mold holder 3, the present invention is not limited to this. That is, even if it is provided between the table 5 and the lower die holder, the same effect as above can be obtained. In addition, the dispersion pressurizing mechanism is shown in FIG.
Alternatively, even if the structure illustrated in FIG. 8 is adopted, the same effect as the above can be obtained. Further, in the above embodiment, the method of feedback controlling the protruding amount of the piston rod by the displacement detected by the measurer 3a or the linear scale 14 has been described.
It is also possible to insert a pressure gauge into the pressure (pushing side) pipe and feed back the pressure detected by this pressure gauge to control it. Further, the displacement and the pressure may be detected at the same time, and the protruding amount of the rod and the pressure of the cylinder may be controlled by both feedback signals.

On the other hand, an example in which the above-mentioned distributed pressure type press device is applied to a press brake having a local bending correction function will be described. Thus, in the press brake of FIG. 9, each cylinder C ₁ to apply a pressure to the upper mold holder 3
As illustrated in FIG. 6, the variable displacement hydraulic pumps 13, which are NC controlled, are connected to Cn. Then, each pump 13 is driven by each servo amplifier 11 which operates by the NC control signal Ei input to each pump 13 in consideration of the signal Ef fed back to each adder 10 from each sensor 9. controlled is - Vomo - because motor SM is connected as a drive source, each cylinder C ₁ to Cn described above, individually its stroke - is the click state is controlled. This is Measuring the detected member and the sensor 9 corresponding to each cylinder C ₁ to Cn of the - based on the change of the individual relative distance between the bar -3a, it can be controlled individual cylinders C ₁ to Cn Means

Therefore, a wire is provided between the upper die 4 and the lower die 6.
When a cylinder (not shown) is inserted and the cylinders C _{1 to} Cn are simultaneously driven to apply a pressing force to the upper mold 4, the work is bent by cooperation with the lower mold 6. At this time, if the center of the mold is worn and the bending angle of that part becomes weak, or if the bottom dead center is lowered to make the sweet bending angle a predetermined bending angle, both ends of the bending are The phenomenon that it bends too much occurs. In such a case, each cylinder described above
Among the displacement sensors 9 corresponding to C _{1 to} Cn, _{one of the} sensors 9 corresponding to the under-bent portion and the over-bent portion detects a change in the distance between the upper die holder 3 and the guide bar 8. Therefore, the signal is fed to the adder 10 of the corresponding cylinder.
It is driven back and is sent to the servo motor via the servo amplifier 11.
The hydraulic pump 13 is controlled by SM and the corresponding cylinder
It is designed to control the bottom dead center of C _{1 to} Cn.

That is, when the upper and lower mold holders 3 and 5 are in a linear state, the distance between the upper mold holder 3 and the guide bar 8 does not change, but local wear occurs in the lower mold. Therefore, when the phenomenon of excessive bending occurs at both ends of the bend,
Bending occurs in the holder 3 or the lower die holder 5 (table) corresponding to the positions of the cylinders C _{1 to} Cn, and the displacement is detected by each displacement sensor 9 in accordance with the amount of the bending, so it is detected. The distance between the upper die 3 and the guide bar 8 is controlled by controlling the pressure applied to each of the cylinders C _{1 to} Cn based on the displacement amount and controlling the pressurization curve of the upper die holder 3. In this case, the bottom of the mold is corrected so that the bottom dead center is lower due to a slight bending angle correction, and the bottom dead center is slightly higher on both outsides of the mold so that the bending angle is not excessive. The bottom dead center is changed, and the bending angle is locally corrected.

Further, since the stroke motion of each of the cylinders C _{1 to} Cn is NC controlled, the correction value of the bottom dead center is stored in this NC data to perform the machining with the above correction. The reproducibility can be improved, the workability is improved, and highly accurate bending can be performed together with the above-mentioned cylinder drive control.

In the above embodiment, the cylinders C ₁ to
Although Cn is provided between the upper frame 1 and the upper mold holder 3, the present invention is not limited to this. That is, even if it is provided between the lower mold holder 5 and the table, the same effect as above can be obtained. Moreover, even if the mechanism illustrated in FIG. 5 or FIG. 8 is adopted as the dispersion pressurizing mechanism, the same effect as the above can be obtained.

In the example in which the dispersion pressurizing mechanism according to the present invention described above is applied to the press brake, the downward cylinders C _{1 to} Cn and the upward cylinders C ₁ ′ to Cn ′ illustrated in FIG. 8 are used.
The case of a pressurized by cooperation of, pressurizing port of the cylinder C ₁ to Cn - has been described bets as a method of pressurizing the same hydraulic connected in parallel to the cylinder C ₁ 'to Cn', further advances in the present invention Then, as illustrated in FIG. 10, the upper and lower cylinders C _{1 to} Cn
To have independent control functions separately for C ₁ '~Cn',
It is also possible to control the protruding amount and thrust of each cylinder rod. By doing so, the flatness of the ram 3 on the upper die 4 side and the table or the holder 5 on the lower die side can be freely obtained, or the ram 3 on the lower die side can be freely bent. It will be possible. Therefore, it is possible to uniformly press the work by the dispersion stress and to freely change the pressing force at any place. In FIG. 10, the same reference numerals (including dashes) as in the previous embodiment refer to the same functional members. 5a
Is a measurer provided on the holder 5.

The above is a description of the one-dimensional bending process in which the present invention is applied to a press brake. However, the present invention provides a plurality of cylinders as shown in FIGS. 11 and 12, for example. The same cylinder drive control method as described above can be applied to the two-dimensional press working.

12 and 13 are planer upper molds (punch).
And a lower die (die) is installed between the flat plate-shaped ram 31 and the table 51, and press working is performed by the cooperation of the ram 31 and the table 51. This will be described below with reference to the drawing and the sectional view taken along the line AA 'in FIG. A guide plate 31b is provided on the plate-shaped ram 31 to guide the plurality of cylinders C _U.

In the plan view of FIG. 13, a guide plate 31b, a linear actuator 71, and a plurality of cylinders C _U arranged in 3 columns and 5 rows are shown. In FIG. 14, twelve cylinders C _U are mounted on the mounting plate 21 downward at substantially equal intervals, while on the floor F, twelve upward hydraulic cylinders C _L are the downward cylinders. It is arranged corresponding to the position of C _U.

The rod of the downward cylinder C _U presses the ram 31 mounted so as to be rotatable and compresses the molds 41 and 61. Its pressure Te - is table 51 and via the upward cylinder C _L received by the floor F. Two left and right linear actuators
The rotor 71 is fixed to a place where it is not easily affected by the distortion of the main body frame at the time of pressurization, and its rod 71a is connected to the guide plate 31b to move the guide plate 31b up and down. Here, two linear actuators 71 are shown on the left and right, but they support four points, two on the right and two on the left, or one on the left.
It may be operated as a three-point support of two units, the right and the right. In short, it is necessary that the guide plate 31b is supported so as not to cause an unintended movement or inclination while moving up and down. Although the rod 71a of the linear actuator 71 and the guide plate 31b are fixed in the figure, they may be mounted so as to be rotatable.

A measurer 31a is individually attached to the rod of each cylinder C _U , and a displacement sensor 9 is attached to the tip thereof, and a distance (distance) d between the measurer 31a and the guide plate 31b. Is constantly being measured. The displacement sensor 9 may be a contact type such as a differential transformer or a linear scale,
A non-contact type such as an optical sensor may be of any type and structure as long as the distance d can be accurately measured.

By doing so, even if the cylinder C _U mounting plate 21 is bent by the reaction force of the mold 41 dispersedly pressed by the individual cylinders C _U , as long as the guide plates 31b are flat, Since the cylinder C _U operates following the movement of the guide plate 31b, the flatness of the ram 31 can be maintained. According to the experiment, the flatness of the ram could be reduced to 1/100 mm or less.

When the lower die 61 is pressed by the upper die 41,
Due to uneven material, uneven thickness, and asymmetrical shape of the work, simply applying uniform dispersive stress to the pressing surfaces of the molds 41 and 61 may cause deterioration of the quality of the pressed product. In the conventional press machine, the flatness of the die is forcibly maintained even if the dispersion stress is uneven due to the rigidity of the die, the ram and the table.

In the present invention, when the individual cylinders C _U cooperate to apply pressure so as to maintain the flatness of the ram, the pressure applied to the individual cylinders C _U causes the above-mentioned uneven dispersion stress. There is an advantage of corresponding change automatically. That is, when the cylinder is operated by controlling the stroke position, the internal pressure of the cylinder changes according to the reaction force of the load.

In this embodiment, the follow-up control system using the guide plate 31b and the measurer 31a is used. However, as described in the example of pressurizing the one-dimensional press, the number of linear actuators corresponding to each cylinder is used. -Although the unit 71 is installed in a place where it is not easily distorted during pressurization of the main unit, its output is fed back to control the protrusion of the rod of each hydraulic cylinder so that the flatness of the ram is maintained. , The same effect can be obtained.

In FIG. 14, the tip of the rod of the hydraulic cylinder C _U and the ram 31 are fitted to each other with a spherical concave-convex surface. However, a connecting mechanism that can rotate so that the ram does not fall when the ram rises may be used. Further, in the present invention, the upward hydraulic cylinder C _L has the same piston diameter as the downward cylinder C _U, and the opposing cylinders are paired and connected as shown in FIG. You can also Normally, the
Since Bull 51 is fixed to the press apparatus body, stroke only the cylinder C _L compensates for the deflection amount of the floor of the pressurization -
It will be good with Ku. Therefore, the upward cylinder C _L is very stroke - in time with those short click. In this case, the cylinder C _L need only be inserted between the fixed table 51 and the floor F so that it does not move. Of course, if the rigidity of the floor surface F is sufficiently obtained, the upward cylinder C _L may be omitted.

[0072]

The present invention is as described above, and a pressing force transmitting member such as a ram in a press brake is attached to the lower portion of three or more cylinders attached to a beam member or the like, and these cylinders are assembled as a whole. Since the driving force is controlled individually so that the stress can be evenly distributed, the stress is evenly distributed over the entire surface of the pressing force transmitting member, which enables uniform press working, and is applied to the press brake. In this case, highly accurate bending can be realized.

In particular, since the beam member is allowed to bend, it can have a flexible structure.
That is, the weight of the frame can be reduced.
Further, since the structure is complicated because each cylinder is individually driven and controlled, each cylinder can be a low-power, small-sized off-the-shelf product, so the overall cost of the device is significantly higher than that of the conventional rigid structure. It becomes possible to reduce.

Therefore, when the present invention is applied to a machine that requires a large pressing force such as a press machine, a press brake, or an extrusion molding machine, uniform pressing can be performed as a whole, and a processed product can be obtained. The quality of can be improved.

Further, in a plate bending machine such as a press brake, conventionally, the ram is driven by one or two hydraulic cylinders, and a pressing force is applied to the upper die to cooperate with the lower die. Since the bending process was performed, the upper mold holder was bent, and this bending caused a sag in the bending angle of the work. However, in the present invention, the upper frame and the upper mold holder are bent. Or a table and a lower die holder with an appropriate fixed interval, three or more hydraulic cylinders for pressurization are equipped, and the upper and lower die holders hold the die, and the upper and lower die holders are held. A plate material is inserted between them, the pressing force of each hydraulic cylinder is applied to the upper or lower mold holder, and the plate material is bent by the cooperation of the upper and lower molds.
By controlling the pressurizing force of the required cylinder in each of the hydraulic cylinders, the machine side supporting the upper or lower die at the bending bottom dead center, for example, the deformation curve of the die holder due to the pressurizing force, By controlling to be parallel below,
Since the droop is corrected, it is possible to correct the droop with high precision with a simple structure, and it is possible to obtain a bent product with high precision. Also, the hydraulic cylinder used has a low output. Since it is sufficient, it is possible to reduce the cost of the plate bending machine as a whole.

Further, in the conventional plate bending machine, the ram is driven by one or two hydraulic cylinders, the pressing force is applied to the long upper die, and the bending is performed in cooperation with the lower die. As a result, the mold may be locally worn by a long-term use and the bending angle may become unfavorable.If the bent angle is corrected, excessive bending may occur at both ends of the bending, which is troublesome to prevent. Although work was required, the plate bending machine to which the present invention is applied has an appropriate fixed interval between the upper frame and the upper mold holder or between the table and the lower mold holder. Equipped with three or more pressurizing hydraulic cylinders, hold the molds in the upper and lower mold holders, insert the plate material between the upper and lower molds, and apply the pressure of the hydraulic cylinders to the upper or lower mold holders. By acting, bending the plate material by the cooperation of the upper and lower molds In addition, since each hydraulic cylinder is simultaneously driven and individually controlled during bending, it is possible to locally control the bottom dead center corresponding to each cylinder in the mold length direction of the upper mold. Therefore, it is possible to locally correct the bending, so that not only the workability of the bending work accompanied by the angle correction is improved but also the bending precision is improved, and a highly accurate bent product can be obtained and used. As the hydraulic cylinders with low output are sufficient,
The cost of the plate bending machine as a whole can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of a main part of an example in which the device of the present invention is applied to a press brake.

FIG. 2 is a side view of FIG.

FIG. 3 is a front view of a mounted state of the guide bar.

FIG. 4 is a front view showing the bending of the beam when pressure is applied by the device of FIG.

FIG. 5 is a system diagram showing an example of cylinder drive control.

FIG. 6 is a system diagram showing an example of cylinder drive control.

FIG. 7 is a side view of an example in which a linear scale is used without using a linear actuator.

FIG. 8 is a system diagram showing an example of drive control of upper and lower mold cylinders.

FIG. 9 is a front view of an example of a plate bending machine to which the present invention is applied.

FIG. 10 is a system diagram showing another example of drive control of the upper and lower mold cylinders.

FIG. 11 is a perspective view showing an arrangement example of cylinders that perform two-dimensional press processing to which the present invention is applied.

FIG. 12 is a partially enlarged view of FIG. 11.

FIG. 13 is a plan view of an example of a two-dimensional press device.

14 is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 15 is a front view schematically showing the configuration of a conventional two-dimensional pressing device.

[Explanation of symbols]

 1 beam 2 fulcrum member 3,31 ram 3a measurer 4 upper mold 7,71 linear actuator 8 guide bar 9 displacement sensor 10 adder 11 servo amplifier 12 servo valve 13 bidirectional variable displacement hydraulic pressure Pump 14 Linear scale SM Servo motor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B30B 15/16 C 15/26

Claims (13)

[Claims] 1. A pressurizing device such as a press brake using a cylinder as a pressurizing source, in which at least both ends are supported by beam members or plate members supported by appropriate fulcrum members, and three or more hydraulic cylinders are provided. One end side of the hydraulic cylinder is rotatably attached, and the other end side of the hydraulic cylinder is rotatably attached to a pressing force transmission member such as a ram or a table so that the hydraulic cylinders have a substantially uniform stress as a whole. A dispersion pressure type press device characterized in that the pressurizing force or displacement thereof is individually driven and controlled so that they can be dispersed. 2. A drive control of a hydraulic cylinder is performed by a measurer bar attached to a pressing force transmitting member such as a ram or a table.
Alternatively, a measure plate, a displacement sensor attached to the ends of at least two left and right linear actuator rods through a guide bar or a measure plate, and a displacement amount detected by the displacement sensor 2. The distributed press machine according to claim 1, which is carried out by a control valve such as a servo valve or a proportional control valve which is operated by the signal which can control the flow direction and flow rate of oil. 3. A drive control of a hydraulic cylinder is performed by a measurer bar attached to a pressing force transmitting member such as a ram or a table.
Alternatively, a main plate, a displacement sensor attached to the ends of at least two rods of the left and right linear actuators via a guide bar or a main plate, and a bidirectional variable connected to each cylinder Capacity hydraulic pump, or
2. The distributed pressurizing press apparatus according to claim 1, wherein the bidirectional fixed displacement hydraulic pump and a servomotor which directly drives and controls the pump by a feedback signal from a displacement sensor are used. 4. The drive control of the hydraulic cylinder includes a linear scale having one end fixed to measure an absolute position of a pressing force transmitting member such as a ram or a table, and a signal measured by the linear scale. 2. The distributed pressurizing press apparatus according to claim 1, wherein the depressurizing signal is used as a feedback signal and a control valve such as a servo valve or a proportional control valve that can control the flow direction and flow rate of oil is operated. 5. A hydraulic cylinder drive control is a linear scale having one end fixed to measure the absolute position of a pressing force transmitting member such as a ram or a table, and a bidirectional variable connected to each cylinder. A displacement hydraulic pump or a bidirectional fixed displacement hydraulic pump, and a signal measured by the linear scale is used as a feedback signal, and a servomotor for directly driving and controlling the pump by the signal is used. Item 1
Dispersion pressurizing type press machine. 6. The drive control of the hydraulic cylinder is performed by a measurer bar attached to a pressing force transmitting member such as a ram or a table.
, A displacement sensor attached to the tips of the rods of the left and right linear actuators via a guide bar, a variable phase bidirectional variable displacement hydraulic pump connected to each cylinder, and a displacement sensor fed back. 2. The distributed press machine according to claim 1, wherein the distributed press machine is directly controlled by a servomotor which drives the pump. 7. A hydraulic cylinder drive control is a linear scale, one end of which is fixed to measure an absolute position of a pressing force transmission member such as a ram or a table, and a variable phase type connected to each cylinder. 2. The dispersion according to claim 1, wherein a bidirectional variable displacement hydraulic pump and a signal measured by the linear scale are used as feedback signals, and a servomotor for directly driving and controlling the pumps by the signals is used. Pressure type press machine. 8. An appropriate fixed space 3 is provided between the upper frame and the upper mold holder or between the table and the lower mold holder.
Equipped with a hydraulic cylinder for pressurization above the base, hold the mold in the upper and lower mold holders, insert the plate material between the upper and lower molds, and apply the pressure of the hydraulic cylinder to the upper or lower mold holder. In the press device according to any one of claims 2 to 7, which is actuated to bend the plate material by the cooperation of the upper and lower dies, the pressurizing force of a required cylinder in each of the hydraulic cylinders is controlled during the bending process. In addition, the dispersion press machine is characterized in that the deformation curve on the machine side supporting the upper or lower mold at the bending bottom dead center is controlled. 9. The bending generated in the upper frame or the table is calculated according to the bending condition, and the angular error or the flatness error generated by the bending is corrected by controlling the pressing force of the hydraulic cylinder. 9. The dispersion press machine according to claim 8, wherein the drooping is corrected. 10. Three or more units are provided at appropriate fixed intervals between the upper frame and the upper mold holder, or between the table integrated with the lower frame and the lower mold holder. Equipped with a hydraulic cylinder for pressurization, hold the mold in the upper and lower mold holders,
The plate member is inserted between the upper and lower molds, and the pressing force of the hydraulic cylinder is exerted on the upper or lower mold holder to bend the plate member by the cooperation of the upper and lower molds.
In any one of the press devices of No. 7, in the bending process, each of the hydraulic cylinders is drive-controlled so as to locally change the bottom dead center so that the bending angle or the flatness is locally corrected. Dispersion pressurizing type press device. 11. The upper frame or the table is formed of a material having low rigidity and easily bending, so that an arbitrary bending is generated in the upper frame in a pressurizing state by a hydraulic cylinder and a bending angle. 11. The dispersion press machine according to claim 10, wherein the flatness is locally corrected. 12. The NC control of each hydraulic cylinder, the NC
12. The distributed press machine according to claim 11, wherein the bottom dead center is locally changed by data to locally correct the bending angle or flatness. 13. The distributed pressing machine according to claim 12, wherein a correction value is stored in the NC data to enhance the reproducibility of the bending process accompanied by the correction.