RU1779426C - Device for producing long-measure articles on horizontal hydraulic press - Google Patents

Abstract

Usage: the production of simple profiles by pressing. The device comprises a container, a die, a press die with a drive and a device for controlling the speed of the press product in the form of a drive drum for winding the extruded product and a mechanism for synchronizing the exit speed of the extruded product and the peripheral speed of the drum. The latter is made in the form of a hydraulic cylinder, a hydraulic motor, a generator, an engine with an output reducer and an electric pulse forming unit. The hydraulic cylinder rod is mechanically connected to the press ram of the press. The working cavity of the hydraulic cylinder is hydraulically connected to the hydraulic motor with the possibility of returning the spent fluid to the working cavity. The output shaft of the hydraulic motor is rigidly connected to the generator, the latter being electrically connected to the input of the electric pulse forming unit, the output of which is connected to the engine. The motor through the output gear is rigidly connected to the drum. 1 ill. Yo

Description

The invention relates to the production of simple sections by pressing on horizontal hydraulic presses and can be used in those conditions where the matching of the flow rate of the metal and the speed of auxiliary mechanisms, for example a winder, is required. The device may be useful, for example, in high-speed pressing of small section products from easily deformable non-ferrous metals and alloys.

A known method for maintaining a constant extrusion speed of metal profiles is that. what. in order to determine the actual value of the pressing speed is controlled

moving speed of the towing device. The signal obtained as a result of the measurement, characterizing the actual value of the pressing speed, is supplied to the oil flow control unit used to drive the plunger of the press.

The disadvantage of this method is that the speed of the main process (pressing) is predetermined by the speed of the auxiliary equipment (pulling device), which must be matched with the rate of metal outflow: the latter, in turn, depends on the speed of pressing. In addition, speed metering and synchronization are only possible at low flow rates and at relative VI VI

Yu

Yu

Os

a relatively short length of the press product, not exceeding the full stroke length of the pulling device. For hot pressing of long products of small cross section with a high flow rate, this method is also unacceptable due to the high likelihood of plastic elongation of the hot press product.

A hydraulic pressing control system is also known, which comprises a punch position sensor and a pressure sensor for the working fluid in the cylinder. Thanks to the system, the pressing stops immediately after the punch passes the predetermined end position. According to the same principle, a device for decreasing the final speed of the extrusion press rod operates.

A common disadvantage of these devices is that their control systems do not work during the entire pressing process, but actually serve to control its final phase, due to the characteristics of the extrusion process.

A device for determining the rate of exit of a press product from a press is selected as a prototype. The device comprises a container, a die, a stamp (punch) with a drive, and a motion sensor for the stamp. The initial value for determining the exit speed of the press product is a constant dependence of the speed of movement of the punch associated with this speed. The measurement of the speed of movement of the punch is made by counting the pulses generated during a certain time by the sensor of its movement. The ratio of the exit speed of the press product to the speed of movement of the punch is determined by comparing once the specific distance traveled by the press product with the corresponding movement of the punch.

The disadvantage of this device is that the registration of the speed of the punch is carried out on an indirect basis - by the number of pulses generated over a certain time by the sensor, not directly related to the rate of outflow of material. At the same time, the accuracy of maintaining the speed of expiration of the press product is not very high due to the very principle of determining the speed of movement of the press product by recording the speed of movement of the punch. It is known that the expiration rate of a product exceeds the punch speed by a factor of A (I is the extrusion ratio when pressed). Obvious that greatness

10

fifteen

twenty

25

thirty

on the movement of the punch during pressing, compared with the length of the press product is small (it is approximately equal to the length of the workpiece), and its measurement with the accuracy required in the known device is difficult in practice. Therefore, the error in determining the pressing speed or the path traveled by the punch increases when determining the flow rate of the prototype, directly proportional to the value of the extrusion during pressing. The drawing coefficients during pressing are quite large and reach, as is well known, tens and hundreds of units.

Example. According to the condition of the constant volume during the pressing process

. whence it follows that

Vi fo

Vo Fi where Vi is the expiration rate of the press product;

Vo is the pressing speed;

FI is the cross-sectional area of the press product;

Fo is the cross-sectional area of the inner sleeve of the container (cross-sectional area of the ingot after being pressed).

If, for example, the diameter of the pressed ingot is mm, and the diameter of the matrix point is mm, then

fo

Fi

d |

ti

200 202

 100

Thus, the error in the definition

the expiration rate of the press during registration of the speed of movement of the punch in the known device, according to the considered example, is increased 100 times;

this leads to a significant mismatch of the speed of the press product with the speed of the auxiliary equipment and the resulting negative consequences. When winding a pressed long product, this mismatch either creates a loop of excess metal, which causes poor-quality winding and sharply reduces the level of safety in this area, or

leads to a significant tension of the reeling profile, accompanied by unacceptable violations of the geometry of its cross section, the formation of localized deformation sections, and in

A number of cases - leading to cliffs. At the same time, the productivity of the equipment decreases and the quality of the products deteriorates.

In practice, pressing is often carried out with even more significant do / di ratios, therefore, errors

will increase even more and the consequences will become more severe. In addition, the comparison of the velocity parameters of the expiration of the material and the movement of the punch according to the prototype is performed once, and not during the entire pressing process, which can ensure the normal operation of the equipment only if the pressure of the working fluid of the press hydraulic system is constant. However, under the conditions of a workshop-wide centralized hydraulic system, the pressure of which can vary stepwise depending on fluctuations in fluid flow rate for various ways of turning on the workshop equipment, it is desirable to monitor the change in the speed of movement of the punch and the matching speeds of the auxiliary devices during the entire pressing process.

The aim of the invention is to improve product quality and productivity by synchronizing the speed of metal flow from the matrix point and the speed of the working bodies of auxiliary mechanisms, for example, a winder.

This goal is achieved in that, in contrast to the prototype, the speed control device of the press product is made in the form of a drive drum for winding the extruded product and a mechanism for synchronizing the output speed of the extruded product and the peripheral speed of the drum, made in the form of a hydraulic cylinder, hydraulic motor, generator, engine with the output gearbox, as well as the electric pulse forming unit, while the hydraulic cylinder rod is mechanically connected to the press stamp of the press, the working cavity of the hydraulic cylinder It is connected directly to the hydraulic motor with the possibility of returning the spent liquid to the working cavity, the output shaft of the hydraulic motor is rigidly connected to the generator, the latter is electrically connected to the input of the electric pulse forming unit, the output of which is connected to the motor, which is rigidly connected to the drum through the output gearbox.

The invention is described in more detail below. The expiration rate of the extruded product and its oscillations in the device of the invention are recorded by using a high-pressure head of fluid flowing from a copying hydraulic cylinder installed parallel to the working hydraulic cylinder, with the help of which the basic pressing process is simulated, in particular its speed mode. For this, the stem of the copying hydraulic cylinder is mechanically connected to the ram, as a result of which the rod completely repeats the movements of the ram. Thus, any fluctuations in the speed of the plunger of the working hydraulic cylinder (and, accordingly, the expiration rate of the extruded product) cause proportional fluctuations in the parameters of the jet of fluid flowing through the output channel of the copying hydraulic cylinder. These parameters can be converted into an electric signal using any of the known methods, for example, recording the number of revolutions of a hydraulic motor operating from a stream of fluid flowing out of a copying hydraulic cylinder, for example, using an electric current generator driven by a hydraulic motor, and a speed graph will be obtained at the generator terminals pressing process in varying

0 parameters of electric current. The electric signal is processed in an amplifier or thyristor converter, it is fed to an electric drive of auxiliary mechanisms, for example, a winder, and thereby ensure that the change in the winding speed corresponds to any fluctuations in the pressing speed.

Thus, in the absence of means and capabilities of directly measuring the expiration rate of the press product, information on changes in the expiration rate using the proposed device is carried out in parallel and simultaneous copying

5 of the basic pressing process, which is fully simulated on a fluid medium, allowing for the accounting of fluctuations in the velocity of the flow by available methods.

A patent search carried out in the art did not find technical solutions having similar features with the claimed: in none of the known technical solutions the expiration rate

5, the press products do not synchronize with the speed of the auxiliary equipment by using any methods and devices that copy the pressing process and affect the high-speed mode by changing the parameters of the electric current. Based on this, it can be concluded that the proposed device for producing long products on a horizontal hydraulic press satisfies a criterion of significant differences.

The proposed device for producing long products with synchronization of the winding speed with the expiration rate can be used on a hydraulic press practically any

designs. As an example of a specific implementation, its use on a horizontal hydraulic press with a force of 15 MN, producing a coil blank with a diameter of 5.8 - 16 mm by hot pressing, is considered. The temperature of the workpiece (ingot with a diameter of 165 mm) is 710-790 ° C, the diameter of the inner sleeve of the container is 170-172 mm. Pressed alloys: LS59-1, LS58-2, LS63-3, L63, i.e. mostly lead brass. The drawing ratio reaches 860, the metal outflow speed is up to 20 m / s, the length of the resulting press article is up to 200 m. Before continuing the consideration of the example, it makes sense to state the following information.

The term copying hydraulic cylinder (hereinafter - KG) strictly theoretically means a hydraulic cylinder, which in its geometric parameters (volume, inner diameter, length) fully corresponds to the internal cavity of the working container of the hydraulic press, while the working volume of the KG must correspond to the volume of the ingot or billet, compressible.

In this case, with equal sections of the output channel of the KG and the dot of the matrix, the rate of expiration of the metal from the container and the liquid from the KG will be equal. Volumetric flow rates, however, will be equal even at different exit cross sections.

From the foregoing, it follows that in order to obtain information on changes in the rate of outflow of metal with a view to its further use, the task is to measure the volumetric rate of outflow of liquid through the outlet channel.

The solution to this problem is carried out using a hydraulic motor, which, passing through the liquid flowing out from the CH, develops a rotation speed corresponding to the volumetric rate of fluid outflow. Any change in the rate of its expiration entails a corresponding, almost inertialess, change in the speed of rotation of the motor shaft.

For the convenience of taking readings on the number of revolutions of the hydraulic motor shaft, the rate of fluid (metal) outflow and its changes, a tachogenerator is installed on the hydraulic motor shaft. The voltage at the terminals of the tachogenerator, depending on the revolutions of the hydraulic motor shaft, at any moment of time will reflect the rate of outflow of liquid and metal, as well as its changes in time, recorded by a voltmeter. The voltage fluctuations at the terminals of the tachogenerator can be simultaneously used as a control signal to coordinate the rotation speeds of the winders, applying it to the thyristor control of the drive.

The drive of the winding devices under the influence of voltage fluctuations of the tachogenerator will accelerate or decelerate the revolutions of the coiler, according to their speed

fluid flow, thereby providing synchronous winding of the product.

These are general aspects of using the inventive device for adjusting and adjusting the rotation speed of the winders to the metal flow rate when pressing on a hydraulic press. The main advantage of the technical solution lies in the fact that the regulation is carried out by changing the direct main parameter - the volume of the flowing metal (liquid) per unit time, while all known devices and methods are based on controlling the speed of change

various indirect parameters that do not fully reflect the expiration process itself, which reduces their accuracy and sensitivity.

According to an embodiment of a specific embodiment of the method, its application to a horizontal hydraulic press with a force of 15 MN, pressing a long coarse billet, is considered. A copying hydraulic cylinder with a volume of 10 ... 12 dm3 with a piston diameter equal to the inner diameter of the working sleeve of the container 170 mm is fixed on the rear cross member of the press.

Considering that the pressing time (stroke) lasts 10 ... 12 s, the volumetric flow rate of the liquid will be approximately 1 liter per second.

At this rate of fluid outflow, the hydraulic motor can develop a power of 3 ... 4

kW accordingly, the voltage on the tachogenerator will be several hundred volts, which is obviously redundant, as enough voltage to control the speed of the winding drive

several tens of millivolts.

In addition, it is undesirable to expend the efforts of the movable cross member on additional extrusion of liquid from the CG. In order to avoid unjustified loss of power of the press, applying the scaling principle, we proportionally reduce the volume of CG to the level of 1 ... 1.2 dm. Then the power of the hydraulic motor can be reduced to 0.2 ... 0.5 kW, which will provide a voltage of

terminals of the serial tachogenerator at the level of several tens of volts.

In this case, the absolute value of the outgoing control signal is not a parameter limiting the use of the device.

The magnitude of the control signal can be obtained in any required size, varying the volume of the CG and using various types of serial hydraulic motors and tachogenerators, while the dimensions of these devices compared to the size of the press are negligible. Thus, for example, a 0.6 kW hydraulic motor with a rotation speed in the range of 10 ... 2500 rpm and a flow rate of up to 8 dm3 / s has a length of 200 mm and a mass of 4.5 kg. Considering that the dimensions of the tachogenerator are even smaller, these devices for the implementation of the necessary parameters form a device weighing about 5 kg. Ultimately, the control device can be brought to the level of a typical device suitable for installation on any hydraulic press with the appropriate setting.

The drawing shows a diagram illustrating one of the possible variants of a specific implementation of the device.

The device comprises a plunger 1 with a press stamp 2 and a press washer 3 with the possibility of their impact on the workpiece 4 located in the container 5. The forming tool is a matrix 6 for receiving a press product 7, which, after winding in the form of a bay 8, is placed on coiler 9. A copying hydraulic cylinder 10 is fixedly mounted on the press frame or on the floor of the workshop. The hydraulic cylinder 10 is equipped with a piston 11 and a rod 12 having a rigid connection with the plunger 1 through the bracket 13 with the adjusting nuts 14 and 15. The hydraulic cylinder 10 has an output channel 16.

The device also includes a valve 17, a pipe 18, a hydraulic motor 19 connected to an electric current generator 20, a signal processing and amplification unit 22, a winder electric drive 24, a filling tank 25 and a check valve 26.

An electric signal 21 carrying information about the flow rate and an electric pulse 23. are shown in FIG. arrows.

The device operates as follows.

The pressing process begins with the inclusion of the working pressure, under the influence of which the plunger 1 of the press by means of the stamp 2 and the press washer 3 acts on the workpiece 4 located in the confined space of the container 5. Under

the action of the plunger 1, the workpiece material begins to be pressed out through the matrix point b in the form of a press product 7 of a predetermined shape, which is wound into a bay 8 by a winder 9 at the output of the press. rod 12, which has a rigid connection with the plunger 1 through the bracket 13, comes into operation earlier than the main pressing process begins - to accelerate the winder to operating speed, for which the idle value of the bracket 13 is set to 5 nuts 14 and 15 in accordance with the length of the idle stroke of the plunger 1. Through the bracket 13 and the nut 15, the plunger 1 of the press acts on the piston 11 with the rod 12, moving them forward at the same linear speed as the press washer 3. Liquid, located in the hydraulic cylinder 10, is displaced through the outlet channel 16. opening the valve 17, through the pipe 18 enters the hydraulic motor 19 connected to the generator 20 of electric current, and after working out merges into the filling tank 25. The volume displaced from the hydraulic cylinder 10 into a unit fluid time depends on ck growth in the movement of the piston 11 (ra plunzhe0 1) and determines, in turn, the speed of rotation of the turbine motor 19 and the armature of the generator 20. The current produced by the generator will have at any given time characteristics (current,

5 voltage) corresponding to the number of revolutions. Thus, the values of the electric current parameters at the terminals of the generator 20 will correspond to the level of the rate of fluid outflow from the copying hydraulic cylinder 10, and therefore, the rate of outflow of the press article 7 in the parallel main pressing process. The electric signal 21, which carries information about the level of flow rate 5 of the press article 7, is fed to the processing and amplification unit 22, from where it is supplied as an electric control pulse 23 to the electric drive 24, which drives the winder 9 at a speed corresponding to the expiration rate press products 7. Filling of the copying hydraulic cylinder 10 with spent liquid occurs during the reverse stroke of the plunger 1 from the filling tank 25 through the return

5 valve 26.

Claims (1)

SUMMARY OF THE INVENTION A device for producing long products on a horizontal hydraulic press, comprising a container, a die, a press die with a drive, and a device for controlling the speed of the press product, characterized in that. that, in order to improve product quality and productivity, the device for controlling the speed of the press product is made in the form of a drive drum for winding the extruded product and a mechanism for synchronizing the output speed of the extruded product and the peripheral speed of the drum, made in the form of a hydraulic cylinder, hydraulic motor, generator, motor with output gearbox, as well as block form0 electric pulses, while the hydraulic cylinder rod is mechanically connected to the press stamp of the press, the working cavity of the hydraulic cylinder is hydraulically connected to the hydraulic motor with the possibility of returning the spent fluid to the working cavity, the output shaft of the hydraulic motor is rigidly connected to the generator, the last is electrically connected to the input of the block forming electrical pulses, the output of which is connected to the motor, which is rigidly connected to the drum through the output gearbox.