RU2515779C1 - Hydraulic drive of press moving beam - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: hydraulic drive of a moving beam of a press comprises a power and a kicker hydraulic cylinder, a hydraulic distributor, a filling tank, a pressure hydraulic line connected to a pump-and accumulator-station, a drainage hydraulic line connected to the tank and a decompression unit for the fluid in the power cylinder. The decompression unit consists of a hydraulic motor and an adjustable pump with proportional electric control with their shafts being connected by a coupling. The inlet channel of the hydraulic motor is connected to the working cavity of the power hydraulic cylinder by a controlled valve. The outlet channel is connected to the tank. The inlet pump channel is connected to the filling tank. Its outlet channel is connected to the pressure hydraulic line by a check valve. Electric control unit of the pump is connected to the outlet of the controller included in the press control system. The controller inputs are connected to the outputs of the pressure sensor in the working cavity of the power hydraulic cylinder, those of the position sensor of the pump adjusting unit and of the angular velocity sensor for the rotation of hydraulic machines' shafts.

EFFECT: increased efficiency of a hydraulic drive due to keeping the potential energy accumulated for use in future as a result of elastic deformations of the fluid and steel structures of the press during the working stroke.

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Description

The invention relates to the field of press equipment, and in particular to control devices for hydraulic presses, and can be used to create new and modernize existing hydraulic drives of the movable beam, for example, forging and stamping presses.

Known hydraulic drive of the movable traverse of the press, containing the working and return hydraulic cylinders, control valves for these hydraulic cylinders, a filling tank, a pressure line connected to a pump-storage station, a drain line connected to a tank under atmospheric pressure, and a device for decompressing the working fluid in the working fluid a hydraulic cylinder, consisting of a receiving volumetric hydraulic machine and an output volumetric pneumatic machine with a dividing element installed between their movable links ohm, the input channel receiving hydromachine hydraulically connected to the working cylinder working chamber [1].

In this hydraulic drive, the receiving hydraulic machine is made in the form of a hydraulic cylinder, the working cavity of which is hydraulically connected by means of controlled valves to the working cavity of the working hydraulic cylinder and the filling tank, the output pneumatic machine is made in the form of a pneumatic cylinder with a hermetically sealed gas cavity, and the separation element of the decompression device is made in the form of a mechanical gears with a variable gear ratio (for example, in the form of a copier mounted on a movable link of a receiving hydraulic cylinder with the possibility of adjusting the position along its axis and having a curved working surface for cooperation with the movable member of the output of the air cylinder). In this case, a lower value of the gear ratio of the mechanical transmission, which is the ratio of the moving speeds of the moving parts of the output pneumatic cylinder and the receiving hydraulic cylinder, corresponds to a larger value of the coordinate of the mobile link of the receiving hydraulic cylinder, counted from the position of this link, at which the volume of the working cavity of the receiving hydraulic cylinder is minimal. The variable gear ratio is selected so that for any position of the movable link of the receiving hydraulic cylinder during decompression (at the calculated initial value p of the _calculated pressure in the working hydraulic cylinder of the press at the end of the stroke), we obtain the effective force created by the liquid on this link, exceeding with a small the reserve force required to move the movable link of the pneumatic cylinder in the direction of decreasing the volume of the working cavity of the latter. As a result, in the process of unloading the working hydraulic cylinder from pressure using a decompression device in the output pneumatic cylinder of this device by means of gas, energy is accumulated as a result of the conversion of a part of the potential energy of the working fluid and metal structures (in particular, columns) of the press stored in them by the end of the working stroke of the press due to elastic deformations. The energy of the compressed gas enclosed in the working cavity of the output pneumatic cylinder of the decompression device is then used to perform useful work during the subsequent technological operations of changing the position of the movable crosshead of the press.

However, if the working stroke of the press ends when the pressure in the working hydraulic cylinder is not sufficient at the current gear ratio of the mechanical transmission of the decompression device to move the movable link of the receiving hydraulic cylinder in the direction corresponding to the increase in the volume of the working cavity of this hydraulic cylinder, then the decompression device does not work in this situation. In this case, the potential energy accumulated due to elastic deformations of the liquid and the metal structures of the press during the working stroke is converted into thermal energy (and ultimately is lost, dissipating into the environment) during the release of liquid from the working hydraulic cylinder through the filling and drain valve. Moreover, such unloading of the working hydraulic cylinder from pressure can be accompanied by undesirable transient processes (water hammer) in the filling and draining press hydraulic line.

With a low value of p _calc . Adopted in the design of the mechanical transmission, and the actual values of p _fact.n , the pressure in the working hydraulic cylinder at the end of the stroke, exceeding the value of p _calc. , The potential energy accumulated during the stroke (due to elastic deformation fluid and metal structures of the press), the more lost, the greater the difference (p _fact.n - p _calc . _n ).

In addition, using the mechanical transmission of the decompression device, energy is converted twice during operation of the hydraulic drive in question (first, the potential energy accumulated due to elastic deformations of the liquid and metal structures of the press during the working stroke is converted to compressed gas energy, and then the compressed gas energy is converted into mechanical energy liquid), which is accompanied by additional energy losses, reducing the energy efficiency of the hydraulic press as a whole.

Significant effort is transmitted through the mechanical transmission of the decompression device during its operation, which (to ensure the required reliability and durability of the specified transmission with a variable gear ratio) predetermines high requirements for its design and execution, increasing the cost of the decompression device.

In the hydraulic drive in question, the output pneumatic cylinder of the decompression device is actually a pneumatic accumulator and is a high-risk device for maintenance personnel. The need to use such a pneumatic accumulator as a part of a decompression device is not unconditional, given that the hydraulic press is powered by a high-pressure fluid from a pump-accumulator station, which includes a pneumohydraulic accumulator.

Thus, the design of the known hydraulic drive of the movable crosshead of the press has a number of disadvantages, the main of which is that in some situations it does not provide the accumulation of potential energy accumulated due to elastic deformation of the liquid and the metal structure of the press during the working stroke, for subsequent execution due to the aforementioned energy of useful work or allows you to do this is not effective enough.

Closest to the claimed technical solution is the hydraulic drive of the press traverse adopted as a prototype, comprising a working and return hydraulic cylinders, control valves for controlling these hydraulic cylinders, a filling tank, a pressure hydraulic line connected to a pump-storage station, a drain hydraulic line connected to a tank located under atmospheric pressure, and a device for decompression of a working fluid in a working hydraulic cylinder, consisting of a receiving and output volumetric hydraulic machine with lennym between their functioning movable separating element, wherein the input channel receiving hydraulic machine is hydraulically connected to the working chamber of the working cylinder, and the outlet duct of the hydraulic output decompression device through a check valve connected to a pressure line [2].

In the specified hydraulic actuator, the receiving and output hydraulic machines are made in the form of hydraulic cylinders, while the working cavity of the receiving hydraulic cylinder is hydraulically connected by means of controlled valves to the working cavity of the working hydraulic cylinder and with a drain hydraulic line, and the working cavity of the output hydraulic cylinder is connected to the pressure hydraulic valve and by means of another return valves with a filling tank. The separating element of the decompression device is made in the form of a clinch-hinge mechanism with a variable gear ratio, selected so that during unloading of the working hydraulic cylinder from pressure (during decompression), the effective force created by the liquid on the movable link of the receiving hydraulic cylinder exceeds the force required for a small margin while moving the movable link of the output hydraulic cylinder in the direction of decreasing the volume of the working cavity of the latter and displacing the working fluid from the output the first hydraulic cylinder through a respective non-return valve in the pressure line of the press (and further to the pump-accumulator station battery).

However, such a choice of the gear ratio is possible only for the case of a certain calculated initial value p _{calc. Of the} working fluid pressure in the working hydraulic cylinder of the press at the end of the working stroke of the movable crosshead. If the actual value p _{fact.n of the} indicated pressure is greater than the calculated one, then the potential energy accumulated during the working stroke (due to elastic deformation of the liquid and the metal structure of the press) is lost to a greater extent, the greater the difference (p _fact.n - p _{calculation. m} ). If, on the contrary, during the operation of the press, p _fact.n turns out to be less than p _calculated , then the decompression device does not work due to the insufficient pressure of the liquid to move the movable link of the receiving hydraulic cylinder. In the latter case, the potential energy accumulated due to elastic deformations of the liquid and the metal structures of the press during the working stroke is converted into thermal energy (and ultimately is lost, dissipating into the environment) during the release of liquid from the working hydraulic cylinder through the filling and drain valve. In addition, such a release of compressed liquid from the working hydraulic cylinder may be accompanied by undesirable transients (water hammer) in the filling and draining press hydraulic line.

The complete loss in some situations of the potential energy accumulated due to elastic deformations of the liquid and the metal structures of the press during the working stroke, or insufficiently complete accumulation (conservation) of this energy for subsequent commission due to its useful work are the main disadvantages of the known hydraulic drive.

Another drawback of the hydraulic drive under consideration is the presence of a mechanical transmission (in the form of a clinch-hinge mechanism) with a variable gear ratio in the design of the decompression device of the working hydraulic cylinder. Firstly, a significant force is transferred from this high pressure cylinder during this process of unloading the working hydraulic cylinder, which makes it an element of unreliability, and secondly, the conversion of potential energy accumulated due to elastic deformations of the liquid and the metal structure of the press during the working stroke using the device decompression is accompanied by additional energy losses in the mechanical transmission, which reduces the energy efficiency of the hydraulic press as a whole.

The technical problem solved by the invention is to increase the energy efficiency (efficiency) of the hydraulic drive of the press by preserving for future use the potential energy accumulated due to elastic deformation of the liquid and the metal structure of the press during the working stroke, with its minimal losses and regardless of the pressure in the working hydraulic cylinder at the end of the working stroke of the movable beam.

To solve the problem in the known hydraulic drive of the movable traverse of the press, containing the working and return hydraulic cylinders, control valves for these hydraulic cylinders, a filling tank, a pressure hydraulic line connected to a pump-storage station, a drain hydraulic line connected to a tank under atmospheric pressure, and a device decompression of the working fluid in the working hydraulic cylinder, consisting of the inlet and outlet volumetric hydraulic machines installed between their movable links, divide an element, the input channel of the receiving hydraulic machine is hydraulically connected to the working cavity of the working hydraulic cylinder, and the output channel of the output hydraulic machine of the decompression device is connected to the pressure hydraulic line by means of a check valve, according to the invention, a hydraulic motor is used as the receiving hydraulic machine, the output channel of which is hydraulically connected to the drain hydraulic line, as the output hydraulic machine, a pump is used, the input channel of which is hydraulically connected to the filling tank, and a separation element The vent is made in the form of a coupling between the shafts of the hydraulic motor and the pump, while one of these hydraulic machines is adjustable with electric proportional control and its electrical control unit is connected to the output of the controller press included in the control system, the corresponding inputs of which are connected to the outputs of the pressure sensor in the working the cavity of the working hydraulic cylinder, the position sensor of the regulatory body of an adjustable hydraulic machine and the sensor of the angular velocity of rotation of the shafts of the hydraulic machines.

The set of features of the proposed hydraulic drive, consisting in the fact that a hydraulic motor is used as a receiving hydraulic machine, the output channel of which is hydraulically connected to a drain hydraulic line, a pump is used as an output hydraulic machine, the input channel of which is hydraulically connected to the filling tank, and the separation element is made in the form of a connecting couplings between the shafts of the hydraulic motor and the pump, while one of these hydraulic machines is made adjustable with electric proportional control and its electric the tric control unit is connected to the output of the controller press included in the control system, the corresponding inputs of which are connected to the outputs of the pressure sensor in the working cavity of the working hydraulic cylinder, the position sensor of the regulating body of the adjustable hydraulic machine and the sensor of the angular velocity of the shaft of the hydraulic machines, allows you to save potential energy for later use accumulated due to elastic deformations of the liquid and metal structures of the press during the working stroke, with its mini cial loss and is a function of pressure values in the hydraulic cylinder of the working end of the working stroke of the moving crosshead.

To carry out decompression with conservation of energy at any current value of pressure p _rc in the working cavity of the working hydraulic cylinder of the press after the completion of the working stroke, it is necessary that the current value of M _{gm of} torque on the motor shaft be not less than the value of M _{n of the} torque that you want to create on pump shaft at the same time t in order to ensure the rotation of the shafts of both of these hydraulic machines with a certain angular velocity ω, that is, the condition must be met:

$$M_{gm}\ge M_{n}PR\mathrm{and}t=idem,\left(\mathrm{one}\right)$$

Where $$M_{gm}=\left(R_{R.c}-R_{\mathrm{from}l}\right)q_{gm}{\eta }_{gm}/\left(2\pi \right);\left(2\right)$$

$$M_n=\left(R_{P\mathrm{and}t}-R_{b.n}\right)q_n/\left(2\pi {\eta }_n\right);\left(3\right)$$

q _gm , η _gm - current values, respectively, of the working volume and hydromechanical coefficient of performance (COP) of the hydraulic motor;

q _n , η _n - current values, respectively, of the working volume and hydromechanical efficiency of the pump;

p _pit is the pressure in the pressure head hydraulic line;

r _b.n - pressure in the filling tank;

p _cl - the pressure in the discharge line _(cl p <p _BN).

According to the expressions (1), (2) and (3) in the process of decompression and energy conversion, the following relation between the values of the working volumes of the hydraulic motor and the pump should be maintained by changing the working volume of that of these hydraulic machines, which is adjustable:

$$q_n\le \left(R_{R.c}-R_{\mathrm{from}l}\right)q_{gm}{\eta }_{gm}{\eta }_n/\left(R_{P\mathrm{and}t}-R_{b.n}\right).\left(\mathrm{four}\right)$$

Since the current value of the pressure _r.c. in the working hydraulic cylinder of the press is controlled using a pressure sensor, the output signal of which is supplied to the corresponding input of the controller, then the controller, based on relation (4), calculates the time necessary at the given moment for decompression of the limit value of the working the volume of the adjustable hydraulic machine (at which the said ratio has the form of equality) and based on the dependence of the working volume of this hydraulic machine on the position (coordinate) z of its reg of the incumbent authority, the required value of the coordinate z _t

In order for the regulatory body of the adjustable machine to take a position with the coordinate z _t , it is necessary to apply an electric signal U of the form

$$U=U_t+k_{\mathrm{about}\mathrm{from}.m}\left(z_t-z_f\right)+k_{\mathrm{and}nt.m}{\displaystyle \underset{0}{\overset{t}{\int }}\left(z_t-z_f\right)}dt,\left(5\right)$$

where U _t is the electric signal necessary to set the regulating body of the adjustable hydraulic machine in the position with the coordinate z _t in accordance with the experimental data in some test situation;

z _f - the current actual value of the coordinate of the regulatory body of the adjustable hydraulic machine, controlled using the appropriate position sensor, the output signal of which is fed to the corresponding input of the controller;

k _os.m , k _int.m - gain factors;

t is time.

However, setting the regulating body of an adjustable hydraulic machine in a position with a coordinate z _t does not guarantee the desired course of the decompression process, since the calculation of z _{t is} performed using relation (4) for some average statistical efficiency values η _um , η _n , which change during operation of the hydraulic machines in quite wide limits.

In this regard, the control electric signal U _control , supplied from the controller output to the electric control unit of the adjustable hydraulic machine, in the process of decompression is formed taking into account the given ω _s and the actual ω _f current values of the angular velocity ω of rotation of the motor and pump shafts (using negative feedback angular velocity):

$$U_{\mathrm{at}PR}=U_t+k_{\mathrm{about}\mathrm{from}.m}\left(z_t-z_f\right)+k_{\mathrm{and}nt.m}{\displaystyle \underset{0}{\overset{t}{\int }}\left(z_t-z_f\right)}dt+k_{\mathrm{about}\mathrm{from}}\left({\omega }_s-{\omega }_f\right)+k_{\mathrm{and}nt}{\displaystyle \underset{0}{\overset{t}{\int }}\left({\omega }_s-{\omega }_f\right)}dt,\left(6\right)$$

where k _OS , k _int - gain.

The value of ω _s is set using the controller, and the value of ω _{f is} controlled using the angular velocity sensor, the output signal of which is fed to the corresponding input of the controller.

As a result, the decompression process with conservation of energy occurs regardless of the pressure in the working hydraulic cylinder at the end of the working stroke of the movable beam. Moreover, due to the use of negative feedback on the angular speed of rotation of the shafts of the hydraulic motor and pump, this process proceeds at a given angular speed of rotation of the shafts of the hydraulic machines, which allows you to adjust the intensity and duration of decompression. Energy losses in this case are minimal and are determined mainly only by the perfection of the standard hydraulic machines used (hydraulic motor and pump).

The invention is illustrated by the drawing, which shows a schematic hydraulic diagram of the hydraulic drive of the movable beam of the press.

The hydraulic drive of the movable crosshead of the press contains a working hydraulic cylinder 1, return hydraulic cylinders 2, 3, control valves 4, 5 controlling workers 1 and return 2, 3 hydraulic cylinders, a filling tank 6, a pressure hydraulic line 7 connected to a pump-storage station 8, a drain hydraulic line 9 connected to the tank 10 under atmospheric pressure, and a decompression device 11.

The plungers of the hydraulic cylinders 1, 2, 3 are connected to the movable traverse 12 of the press.

The composition of the control valve 4 includes pressure 13 and filling and drain valves 14. The working cavity of the hydraulic cylinder 1 is connected by means of a pressure valve 13 with a pressure hydraulic line 7 of the press, and by means of a filling and drain valve 14 with a filling and drain hydraulic line 15 of the press, which in turn is connected to the filling tank 6.

The composition of the valve 5 includes pressure 16 and drain valves 17. The working cavity of the return hydraulic cylinders 2, 3 are interconnected by means of a pressure valve 16 with a pressure hydraulic line 7 of the press, and by means of a drain valve 17 with a filling and drain hydraulic line 15.

All of the above valves have individual electro-hydraulic control. In the drawing, all valves are shown in a state where their flow area is closed.

The decompression device 11 consists of a volumetric hydraulic motor 18 and a pump 19, the shafts of which are interconnected by means of a coupling 20.

The drawing shows as an example the case when the hydraulic motor 18 is made unregulated, and the pump 19 is adjustable with proportional electrical control. An embodiment of the decompression device is possible when the pump is unregulated and the hydraulic motor is adjustable with proportional electrical control.

The inlet channel of the hydraulic motor 18 is hydraulically connected via a controlled valve 21 to the working cavity of the working hydraulic cylinder 1, and its output channel is connected to a drain hydraulic line 9.

The inlet channel of the pump 19 is connected to the filling and draining hydraulic line 15 of the press, which in turn is connected to the filling tank 6, and the outlet channel of the pump through the check valve 22 is connected to the pressure line 7.

The electrical control unit of the pump 19 is connected to the output of the controller 23 press included in the control system, the inputs of which are connected to the outputs of the pressure sensor 24 in the working cavity of the working hydraulic cylinder 1, the position sensor 25 of the regulatory body of the pump 19 (inclined unit or inclined disk in the case of using axial a piston pump; a movable stator in the case of using a radial piston or vane pump) and a sensor 26 of the angular velocity of rotation of the shafts of the hydraulic machines.

The hydraulic drive of the movable crosshead of the press operates as follows.

In the initial stopped position of the movable crosshead 12 of the press, the flow-through section of the fill-drain valve 14 is open, and the flow-through sections of the pressure valves 13, 16 and the drain valve 17 of the control valves 4, 5 are closed. The pressure in the working cavity of the working hydraulic cylinder 1 is determined by the pressure of the liquid in the filling tank 6.

The valve 21 is mainly designed to disconnect the decompression device 11 from the working hydraulic cylinder 1 during repair work and during the operation of the press can be used in two ways, namely: 1) its bore can be constantly open; 2) the valve cross-section is opened only for decompression, and the rest of the time is closed.

If the bore of the valve 21 is constantly open, then at all periods of time, except when decompression is performed, the regulating body of the pump 19 is set to the position at which the pump displacement is maximum by the signal from the controller 23. In this case, the maximum working volume of the pump should exclude the fulfillment of the relation (4) with p _rc = p _pit so that the shafts of the hydraulic motor 18 and pump 19 do not rotate during the working stroke of the movable beam.

If the flow area of the valve 21 is closed after the decompression is completed, then until the start of the next working stroke of the movable beam 12, the position of the regulating body of the pump 19 does not change, that is, remains the same as at the time the decompression was completed.

To move the movable crosshead 12 in the direction of the workpiece to be deformed (the workpiece is not shown in the drawing), the passage section of the drain valve 17 of the return hydraulic cylinders 2, 3 is opened. Before the workpiece begins to deform, the movement of the crosshead 12 (idle) occurs under the action of a pressure force acting on the crosshead from the side of the working hydraulic cylinder 1, in the case of horizontal presses and additionally the gravity of the movable crosshead 12 and moving parts with it in the case of vertical presses. In this case, the working fluid in the working cavity of the working hydraulic cylinder 1 enters through the valve 14 through the filling and draining hydraulic line 15 from the filling tank 6, and is displaced from the working cavities of the return hydraulic cylinders 2, 3 through the draining valve 17 into the filling and draining hydraulic line 15.

To stop the movable crosshead 12 when it is idling, it is enough to close the bore of the drain valve 17 of the control valve 5 of the return hydraulic cylinders 2, 3.

After the entry of the tool mounted on the movable traverse 12 of the press (the tool is not shown in the drawing), the workpiece moves into contact with the workpiece and the deformation of the latter begins.

To carry out the working stroke, the passage section of the filling and drain valve 14 of the working hydraulic cylinder 1 is closed and then the passage section of its pressure valve 13 is opened by the amount necessary to effect the deformation of the workpiece with a given traverse speed 12. During the working stroke, the working cavity of the working hydraulic cylinder 1 the fluid enters through the valve 13 from the pressure line 7.

If the orifice of the valve 21 is closed, then during the working stroke, as the pressure in the working cavity of the working hydraulic cylinder 1 increases, the position of the regulatory body of the pump 19 is changed due to the supply of a control electric signal to its electrical control unit from the controller 23, which changes in accordance with the dependence (5 ) As a result, by the end of the stroke, the regulating body of the pump 19 occupies a position close to optimal for the start of decompression.

At the end of the working stroke, the liquid in the working cavity of the working hydraulic cylinder 1 has a large potential energy due to the elastic deformation of the liquid itself and the metal parts of the press.

After the end of the stroke, the bore of the pressure valve 13 is closed, and the bore of the drain valve 17 is closed. If the bore of the valve 21 has been closed, it opens. On the electrical control unit of the adjustable pump 19 from the output of the controller 23, based on the signals from the sensors 24, 25, 26, a control electric signal is supplied, changing in accordance with the dependence (6).

In this case, the liquid from the cavity of the working hydraulic cylinder 1, due to its expansion and reduction of stresses in the metal parts of the press, enters the inlet channel of the hydraulic motor 18 and creates a torque on its shaft, under the action of which the hydraulic shaft together with the pump shaft 19 connected to it via the coupling 20 comes into rotation with a given angular velocity, which is accompanied by a pump 19 supplying working fluid from a filling tank 6 through a return valve 22 into a pressure head hydraulic line 7 of the press (and then into the accumulator pump-accumulator the secondary station 8).

As the fluid flows from the working hydraulic cylinder 1 through the hydraulic motor 18 to the tank 10, the liquid pressure in the working hydraulic cylinder 1 decreases, which is accompanied by a decrease in the working volume of the pump 19 (and, accordingly, the moment of resistance on its shaft), due to which, despite the decrease in pressure in the working hydraulic cylinder 1 , the decompression process continues while providing a given speed of rotation of the shafts of the hydraulic motor 18 and the pump 19.

The energy of the high-pressure liquid supplied by the pump 19 of the decompression device 11 to the pressurized press hydraulic line 7 is used further to perform useful work during subsequent technological operations of changing the position of the movable beam 12 of the press.

After reducing the pressure in the working hydraulic cylinder 1 to the set minimum value (this pressure is close to the pressure in the filling tank 6), the flow cross-section of the filling and drain valve 14 is opened based on the signal from the pressure sensor 24. As a result, the working cavity of the working hydraulic cylinder 1 is connected to the filling tank 6.

If the control algorithm provides for the closure of the flow area of the valve 21, then it closes. If the bore of the valve 21 is constantly open, then, as noted above, the regulating body of the pump 19 is set to the position at which the pump displacement is maximum by the signal from the controller 23.

To reverse the movable crosshead of the press, the passage section of the pressure valve 16 of the return hydraulic cylinders 2, 3 is opened. During the return stroke, the liquid enters the working cavities of the return hydraulic cylinders 2, 3 through the open passage section of the valve 16 from the pressure hydraulic line 7. At the same time, from the working cavity working hydraulic cylinder 1, the liquid is displaced into the filling tank 6 through an open passage section of the filling and drain valve 14 and the filling and drain hydraulic line 15.

To stop the movable crosshead 12 when performing a reverse stroke, it is enough to close the passage section of the pressure valve 16 of the return hydraulic cylinders.

As follows from the above description of the device and operation, the proposed hydraulic drive of the movable traverse of the press ensures the potential energy accumulated due to elastic deformation of the liquid and the metal structure of the press during the stroke, with minimal losses and regardless of the pressure in the working hydraulic cylinder for later use the end of the working stroke of the movable traverse, which increases the energy efficiency (efficiency) of the hydraulic drive pres sa in general.

In addition, the design of the proposed hydraulic drive allows you to adjust the intensity and duration of the conversion process of the above potential energy.

Literary sources

1. Hydraulic press drive: Patent for invention RU No. 2078640, IPC B21J 9/12, B30B 15/16. Declared 08.08.1995. Published on May 10, 1997.

2. Hydraulic press with the return of elastic energy to the power supply system: Patent for utility model UA No. 10297, MPK V30V 15/16, V30V 1/00. Stated April 11, 2005. Published on November 15th, 2005.

Claims (1)

The hydraulic drive of the movable traverse of the press, made with a control system, containing a working and return hydraulic cylinders, control valves for these hydraulic cylinders, a filling tank, a pressure hydraulic line connected to a pump-storage station, a drain hydraulic line connected to a tank under atmospheric pressure, and a decompression device working fluid in the working hydraulic cylinder, consisting of a receiving and output volumetric hydraulic machines with a separation element installed between their mobile links entent, while the input channel of the receiving volumetric hydraulic machine is hydraulically connected to the working cavity of the working hydraulic cylinder, and the output channel of the output volumetric hydraulic machine is connected via a non-return valve to the pressure hydraulic line, characterized in that a hydraulic motor is used as the receiving hydraulic machine, the output channel of which is hydraulically connected to the drain hydraulic line , a pump is used as the output hydraulic machine, the input channel of which is hydraulically connected to the filling tank, and the separation element is made n in the form of a coupling connecting the shafts of the hydraulic motor and the pump, while one of these hydraulic machines is made adjustable with electric proportional control and has an electrical control unit that is connected to the output of the controller press included in the control system, the corresponding inputs of which are connected to the outputs of the pressure sensor in the working cavity of the working hydraulic cylinder, the position sensor of the regulatory body of an adjustable hydraulic machine and the sensor of the angular speed of rotation of the hydraulic machine shafts.