SU1532174A1 - System for controlling hydraulic pneumatic hammer - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to mechanical engineering, namely to control systems for hydropneumatic hammers. The purpose of the invention is to increase efficiency and reliability. On the rod end of the power cylinder there is a spring accumulator with a check valve and a throttle installed on its pressure line. With the help of an automatic control device, the optimum pressure in the pneumatic receiver is established, as well as the stroke and braking stroke of the woman. The design allows you to increase the speed of movement of the women and reduce the dynamic loads during braking. 1 hp f-ly, 2 ill.

Description

The invention relates to mechanical engineering, namely to hydropneumatic hammer control systems.

The purpose of the invention is to increase K11D and reliability by increasing the speed of movement of the woman and reducing dynamic loads.

FIG. 1 is a circuit diagram of control i in FIG. 2 - the dependence of the pressure (P) in the receiver on the stroke (S) of the woman.

The control system comprises an upper position sensor 1, which interacts with the woman 2, the output of which is connected to the electromagnet of the pneumatic distributor 3, which connects the receiver 4 through the reduction gear 5 to the pneumatic source 6 of pressure. The hydraulic pressure source 7 is connected via pressure 8 and drain 9 valves to the rod end 10 of the power cylinder 11. Switching valves 8 and 9 is performed by electro-hydraulic distributors r-ni 12 and 13. Spring battery 14 is connected through parallel-installed throttle 15 and non-return valve 16 with a cavity 10 of cylinder 11. A receiver 4 is fitted with a pressure sensor 17 of an automatic control device, the output of which is connected to one of the inputs of the pressure calculating unit 18 at the end of the acceleration downward stroke, by the input of the differential block 19 ntsirovani pressure, one of the inputs of block 20 eapo D nani reversal pressure, one of the inputs

SP

00 tC

four

The pressure comparison unit 21 at the acceleration upstream inlet and one of the inputs of the pressure comparison unit 22 during the acceleration downward. The other input of the pressure comparison unit 22 at the acceleration downward direction is associated with the output of the pressure calculation unit 18 during the acceleration downward, and the output with one of the inputs of the trigger 23 of the drain valve, the other input of which is connected to the Start button, and the output from an electromagnet of the distributor 13. The output of the pressure differentiation unit 19 is connected to one of the inputs of the trigger control 2A of the pressure valve, the input of the impact energy task unit 25 and the other input of the reverse pressure storage unit 20, the third input of which is connected to the output of the pressure task unit 26 The reverse is on the first strike, and the fourth entry is with the Start Cycle button. The output of the pressure storage unit 20 of the reverse is connected to another input of the pressure calculation unit 18 at the end of the acceleration downward stroke, and the output of the impact energy task unit 25 is connected to the third input of the pressure calculation unit 18 at the end of the acceleration stroke downward and the input 27 calculating the pressure at the end of the acceleration upward stroke, the output of which is connected to another input of the pressure comparison unit 21 during the acceleration upwards. The output of the pressure comparison unit 21 during the acceleration upward is connected to another input of the trigger valve control 2A of the pressure valve, the output of which is connected to the solenoid 12 of the distributor 12 which is hydraulically connected to the pressure valve 8.

The control system works in the following way.

At the beginning of the punching cycle, the electromagnets of the distributors 12 and 13 are turned off, the drain 9 and the pressure valve 8 are closed. Baba 2 is in the extreme upper position, which corresponds to the minimum volume of the receiver - V. The signal from sensor 1 turns on the solenoid of the distributor 3, while the output of the gearbox 5 is connected to the receiver 4 through the open valve 3 and the nominal pressure P is set in it. The signal of the beginning of the cycle in the block 20 for storing the pressure of the reverse from the output of the block 26 for setting the pressure of the reverse on the first impact sets the initial value of the pressure of the reverse on the first impact

Q n 5 5

0

0

which is set based on the initial height of the workpiece and the height of the dies; In block 18, calculating the pressure at the end of the acceleration downward in accordance with the dependence (H c and the value of the actual pressure in the receiver, the energy setpoint of the first impact T coming from the setting unit 25 impact energy, and the pressure value of the reverse P ,, coming from the pressure memory unit 20, P, you need to set the code for which you need to close the drain valve 9 to finish the raegon down and provide the desired impact energy.

The dependence P ii f (T, P,, P,) follows from the joint solution for P of equation (1) of the energy balance of work and equation (2) of the adiabatic process in the receiver

. () V, -S, -ci-S, S ,,

, “Re 5 .F); (one)

. p, p, o (u -; gr 2)

 P - 1 f 1

where S is the coordinate of the start of the acceleration DOWN}

S, j is the coordinate of the raegon end of the stroke

S, j is the coordinate of the downward stroke end) I SIT braking;

8, „- woman’s move DOWN)

S, p - the course of acceleration down-,

S is the maximum stroke of a woman;

10 nominal pressure in the receiver at the extreme upper position of the woman}

Р ,, - pressure at the beginning of the raegon stroke down

P ,, j - pressure in the receiver at the end of the acceleration down;

P, j - pressure in the receiver at the time of the reverse)

 11 back pressure in the rod plane during the acceleration downward;

11 counterpressure in the rod cavity during braking;

V - constant component of receiver volume

F is the area of the rod end of the power cylinder}

K - adiabatic index / IP - friction force J

1 area of the piston of the power cylinder.

The pressure P is set from the condition

ensure the operation of a thin rod and is adjusted by means of the throttles 15.

The impact cycle starts when the signal is received. Starting up to the input of the trigger 23, which is set to one state and turns on the valve 13, the drain valve 9 is activated, opening the liquid outlet from the rod cavity 10 to the drain tank. Waba 2 accelerates downward under the action of gas in the receiver. The measured value of pressure P in receiver X from the output of sensor 17 is fed to the input of block 22 when it coincides with the code coming from the output of block 18 to another input of the unit, 22 comparison, at its output a signal is generated which goes to the corresponding trigger input 23 and resets it to the zero state. In this case, the electromagnet of the distributor 13 is turned off and the drain valve 9 closes.

The damping of the hydraulic shock when closing the drain valve is provided by the throttle 15, through which fluid from the rod end 10 flows into the accumulator 14.

The moment of reversal is determined by differentiating the pressure in the receiver over time using block 19, the input of which receives a variable pressure value from sensor 17. When at the time of reverse the pressure in reverse 4 reaches its minimum, the derivative becomes zero and at the output of the block a signal is generated that fixes the moment of the reverse, which is transmitted to the input of block 25 and to the corresponding inputs of block 20 and pressure valve trigger 24. In this case, the output energy of the next strike appears at the output of the block 25, the reverse pressure block 20 is entered from the output of the sensor 17, and the trigger 24 is set to one state. The signal from the output of the trigger 24 turns on the solenoid of the distributor 12, while the pressure valve 8 opens and connects the high pressure fluid source to the rod cavity 10, with the result that the baba 2 accelerates upwards. At the same time, the code from the output of sensor 17 goes to the input of block 21 during acceleration. To another input of block 21, a code comes from output of block 27. The pressure at the end of the acceleration upward stroke is determined by the energy setpoint

20

25

5 5,

0 35 40 45 5p gs 1746

It is calculated from the condition of the minimum height of the woman’s height, taking into account the braking stroke when moving upwards by inertia, but sufficient to provide the specified energy of the next stroke. When the codes coincide at the inputs of the block 21, a signal is generated at its output, which arrives at the corresponding input of the trigger 24. At the same time, the solenoid of the distributor 12 turns off and closes the pressure valve 8. The fluid pressure in the rod cavity drops and through the return valve 16 from the battery 14 fluid is flowing. Until the stroke is completed. This prevents the formation of an empty cavity and water hammer, and Baba 2 rises to the calculated height.

The economic effect of the implementation is achieved by increasing efficiency and reliability.

Claims (2)

Invention Formula one . A hydraulic hammer control system containing a hydraulic pressure source connected through drain and pressure valves to the piston cavity of the power cylinder, a piston cavity connected through a receiver to a pneumatic pressure source, and a rod through an electro-hydraulic distributor for switching drain and pressure valves with a source of high pressure working fluid and a battery, as well as a device for automatic control and a sensor for the upper position of the head, from This is because, in order to increase the electrical safety gauge and reliability by increasing the speed of movement of the head and reducing dynamic loads, it is fitted in parallel to the main line connecting the battery with the rod end of the power cylinder, throttle and non-return valve, the battery is spring-loaded and the device for automatic control is designed as a pressure sensor, pressure calculation blocks at the end of the acceleration run up and down, a pressure comparison unit during the acceleration up and down, an energy task block Ars, block differentiation pressure blo1sa reversal pressure tasks at the first impact, reversal pressure storage unit and flush and pressure valve triggers, the output spring of the spring accumulator is connected to the rod end of the power cylinder, the pressure sensor is installed on the receiver, the pressure comparison unit at the acceleration downward stage is connected by its input to the output the pressure calculating unit at the end of the acceleration downward stroke and the output to the inlet of the trigger of the drain valve; the pressure calculating unit at the end of the acceleration stroke upwards is connected by its input to the pressure comparison units During acceleration and downward pressure differentiation, comparing the pressure in the course of acceleration downwards, and output - with the trigger pressure klapa On, the reverse pressure memory unit is connected by its input to the pressure task unit at the first impact and output - by the pressure calculation unit at the end of the acceleration run down, and the output of the pressure sensor is connected to the inputs of the pressure calculation units during the acceleration downward process, the pressure is stored during the acceleration down and the pressure differentiation unit. 2. The system according to claim 1, characterized in that between the pneumatic pressure source and the receiver, a reducer and a pneumatic distributor are installed in series, the electromagnet of which is electrically connected to the upper position sensor | dzig.g