RU145394U1 - ADAPTIVE HYDRAULIC PRESS MANAGEMENT SYSTEM - Google Patents

Abstract

An adaptive hydraulic press control system for separating plate and profile products, containing means for measuring the parameters of the slide of the press and a two-stage hydraulic amplifier fed from the press-accumulator press station, the first stage of which is formed by constant chokes and multidirectional nozzles with a damper located between them, which are connected along the bridge scheme, and the second cascade is made in the form of a four-line throttling valve spool type th in diagonal bridge ensuring regulation slider press speed, characterized in that the first stage hydraulic amplifier, the flap which is made spring-inertia type, secured to the slide presses with vertical arrangement of its sensitivity axis and to ensure the performance of the function of the measuring transducer of the linear acceleration of the slide movement of the press.

Description

The utility model relates to forge-and-press equipment, in particular, to presses with a hydraulic drive for separation (cutting, cutting, punching, etc.) of plate and profile steel in the cold state.

A control system for a hydraulic press with a shock absorber is known, in which the nominal force on the slider is determined by pre-setting the safety valve for a given pressure, and the speed of movement of the slider is determined by adjusting the throttle or adjustable pump for a given flow rate supplied to the press cylinder or withdrawn from it into the tank . During operation, the settings of the control devices are not changed [1].

During the operation of this press, the force in the process of deformation of the material to be separated gradually increases to the maximum value, after which, when working with brittle materials, a sharp decrease in force occurs, and when plastic materials are separated, first a smooth decrease, and then a sharp drop in force. The change in force is due to the resistance to deformation of the material to be separated, and a sharp decrease in force corresponds to the moment of separation of the part from the workpiece.

A sharp decrease in the deformation force occurs in a very short period of time, and the potential energy stored in the structural elements of the press in the form of elastic deformation during the period of increase in effort is almost instantly spent on accelerated movement of the press slider and oncoming movement of the bed and table. In this case, alternating dynamic loads arise, affecting all structural elements of the press and its drive, and causing machine vibration and noise. Vibrations adversely affect the operation of the structural elements of the press and its drive, as well as the cutting edges of the separation dies, and may even cause them to break.

The hydraulic shock compensator available in the control system does not eliminate alternating dynamic loads on the components and parts of the press, but only slightly reduces their level.

A hydraulic press control system is also known, in which to reduce the level of dynamic loads in the process of material separation, a special hydraulic accumulator is used, which is not part of the pumping station [2]

The use of a pneumohydraulic accumulator does not eliminate alternating dynamic loads on the components and parts of the press, but only slightly reduces their level and prolongs the oscillatory process in time with its gradual attenuation. In addition, the operation of such a system is not regulated.

The closest technical solution adopted for the prototype is a hydraulic press control system containing means for measuring the parameters of the slide and a two-stage hydraulic amplifier, the first cascade of which is formed by constant throttles and multidirectional nozzles with a damper located between them, connected by a bridge circuit, and the second cascade is made in the form of a four-line throttling valve of the spool type, included in the diagonal of the bridge and regulating the crawl speed and as well a pumping-station battery providing power press cylinders and hydraulic amplifier [3].

This press control system cannot provide a significant reduction in the level of dynamic loads in the process of material separation and has a complex structure. The use of a large number of heterogeneous elements of the control system necessitates the transmission, amplification and repeated conversion of signals from one type of energy to another, which leads to inevitable errors and reduces the achieved control effect.

The task to which the claimed utility model is directed is to reduce the level of dynamic loads in the process of separation of the material in the press and simplify the design of the control system.

The solution to this problem is achieved by the fact that the first cascade of the hydraulic amplifier, the damper of which is spring-loaded inertia, is mounted on the slider of the press with a vertical location of its sensitivity axis and ensuring that it functions as a measuring transducer of linear acceleration of the slider of the press.

The use of liquid energy at the same time for the operation of the control system and the drive of the press slide allows you to abandon the electromechanical control of the valve and significantly reduce the number of elements that make up the control system. This significantly improves the dynamic characteristics of the hydraulic drive and simplifies the design of the press control system.

Comparison of the claimed device with the prototype shows that there is a presence of new parts and functional connections between them.

New details: the first stage of the hydraulic amplifier, the damper of which is spring-loaded inertia, is mounted on the slider of the press with a vertical position of its sensitivity axis and ensuring that it functions as a measuring transducer of linear acceleration of the slider of the press.

New functional relationships: the position of the spring-loaded inertial damper between the nozzles is determined by the action of inertia, which is proportional to the acceleration of the press slide, which ensures the adaptation of the control system and the press drive to changing working conditions, including at the time of separation of the material. The signal at the output of the measuring transducer is directly used to control the throttling valve of the spool type, whose operation reduces the level of dynamic loads acting on the structural elements of the press and its drive during the separation of the material.

The presence of new elements and functional relationships can reduce the level of dynamic loads in the process of separation of the material on the press, abandon the electromechanical control of the valve, significantly reduce the number of elements that make up the control system, and thereby simplify its design.

Figure 1 shows a schematic diagram of a hydraulic press for the separation of plate and profile hire with an adaptive control system.

Press 1 contains a slider 2 and a tool block 3.

The hydraulic drive of the press includes a main working cylinder 4, the body of which is connected with a slider and a tool unit, and the piston with the rod is stationary; clamping cylinders 5 and 6, which during the separation of the material by means of wedges 7 and 8 hold the workpiece 9 and the detachable part 10 in the tool block. Cylinders are powered from the pumping station with pump 11, safety valve 12, valves 13 and 14.

The distributor 13 provides the initial position in the cycle of the press and the reverse of the clamping cylinders 5 and 6, and the distributor 14 reciprocating motion of the slider 2.

The adaptive control system of the press includes a two-stage hydraulic amplifier 15.

The first amplifier stage is formed by multidirectional nozzles 16 with a spring-loaded inertial damper located between them and constant chokes 17 and 18, which are connected by a bridge circuit and are fed from the pump station through a pressure reducing valve 19. This amplifier stage is mounted on a press slider with a vertical location of its sensitivity axis and is a linear acceleration measuring transducer.

The second stage of the amplifier is made in the form of a four-line throttling valve 20 of the spool type, included in the diagonal of the bridge.

A pneumohydraulic accumulator 21 is included in the upper cavity of the cylinder 4 of the slider.

Adaptive hydraulic press control system operates as follows.

In the process of separating the part 10 from the workpiece 9, the speed of the slider 2 of the press is determined by setting the deformation of the centering springs of the spool of the throttle distributor 20. The accelerated movement of the slider causes a corresponding displacement of the nozzles relative to the inertia damper, pressure changes in the inter-throttle chambers of the first amplifier stage (linear acceleration transducer) and under the ends of the spool of the throttling valve 20. The resulting control action leads to the displacement of the spool and changes the flow rate of fluid supplied to the cylinder 4 and discharged from it. As a result, the acceleration will be eliminated and the set speed of the slider will be restored.

At the time of separation of the material, the slider 2 abruptly, with great acceleration, falls down and with it the cylinder body 4 and the housing of the measuring transducer 16. The liquid pressure in the upper cavity of the cylinder 4 increases stepwise, and decreases in the lower cavity.

The inertia flap lags behind the movement of the housing of the measuring transducer, which leads to a significant change in pressure in the inter-throttle chambers and under the ends of the spool of the throttle valve 20. The spool moves to the left and at the same time increases the drainage of liquid from the upper cavity and its supply to the lower cavity of the cylinder 4, which leads to a rapid stabilize the pressure in the cylinder cavities and reduce the level of dynamic loads on the components and parts of the press.

Simultaneously with the operation of the control system, pressure peaks are extinguished by the pneumohydraulic accumulator 21 included in the upper cavity of the cylinder 4.

Reducing the level of dynamic loads in the process of separation of material in the cold state leads to a decrease in the loads on the press elements and its foundation, to increase the tool life, simplify the design and reduce the cost of the foundation, increase the life of the press and increase the reliability of its work, improve the working conditions of staff.

Sources of information taken into account

1. Zhivov, L.I. Press-forging equipment: a textbook for high schools / Zhivov L.I., Ovchinnikov A.G., Skladchikov E.N. / Ed. L.I. Zhivova. - M.: Publishing House of MSTU. N.E. Bauman, 2006 .-- P.216.

2. Copyright certificate No. 778953, Cl. B23D 23/00, 06/19/1978.

3. Pavlov, A.A. The use of servo-hydraulic drive in the press for cutting plate / A.A. Pavlov, Yu.M. Tityakov, I.I. Silantyev // Hydraulic drive of new forging and pressing machines. - Voronezh: ENIKMASH, 1983. - P.25-38 (prototype).

Claims (1)

An adaptive hydraulic press control system for separating plate and profile products, containing means for measuring the parameters of the slide of the press and a two-stage hydraulic amplifier fed from the press-accumulator press station, the first stage of which is formed by constant chokes and multidirectional nozzles with a damper located between them, which are connected along the bridge scheme, and the second cascade is made in the form of a four-line throttling valve spool type, included th in diagonal bridge ensuring regulation slider press speed, characterized in that the first stage hydraulic amplifier, the flap which is made spring-inertia type, secured to the slide presses with vertical arrangement of its sensitivity axis and to ensure the performance of the function of the measuring transducer of the linear acceleration of the slide movement of the press.