DE416638C - Hydraulic control device - Google Patents

Description

In Fig. Ι of the drawing, A denotes a cylinder in which, on the other hand, sealed, two pistons K, K ' , which form a differential piston and sit on top of one another on a common piston rod 5, are arranged displaceably, the upper piston K, being larger than the lower K. '. In the vertical position shown, the cylinder is at a certain depth below the water level

ίο in a container filled with water, so that the outer end faces F, F 'of both pistons are exposed to an externally acting fluid pressure at the same time. The piston area of the large upper piston K. is 25 cm in diameter

F - ~ 490 sqcm,

that of the lower piston Kf at 20 cm in diameter

",

F ' -: - ~ 314 sq cm.

The. The distance between the outer end faces of the two pistons is | 100 cm. It can be seen that the pressure on both pistons is the same at a certain depth X j of the end face of the upper piston. This depth results from

FX = F ' (X + 1) = F' X + F ' perm = - ^ A-

p

With the values given above for F and F ' ,

X --- - ³ '- ■ * - - ³ ' 4
490-314 176

m,

d. H. when the upper face of the upper piston is 1.8 m below the surface of the water the pressure on both pistons is the same. '

If the cylinder A is now 50 cm j higher, the specific pressure of the water column on the upper piston is 0.18 - 0.05 = 0.13 atm. and on the lower piston o.13 - | - 0.1 = 0.23 atm. and the total pressure on the upper piston F * 0.13 = 490 * 0.13 i = 63.70 kg and on the lower piston; F " 0.23 = 314-0.23 = 72.22 kg. ;

If, on the other hand, the cylinder is 50 cm deeper than 1.8 m, the specific pressure of the water column on the upper piston is 0.18 -j- 0.05 = 0.23 atm. and on the lower piston 0.23 -j- 0.10 = 0.33 atm. and the total pressure on the * upper piston F -0.23 = 490 x 0.23 = 112.70 kg and on the lower piston F 'x 0.33 = 314 x 0.33 = 103.62 kg.

From this comparison it can be seen that when the above the large piston standing water column is less than i, Sm, the pressure on the small piston is greater than the one on the large flask, and vice versa, if the column of water above the large flask is greater than 1.8 m the Pressure on the large piston is greater than that on the small piston.

These changing pressure conditions are greater, the greater the height fluctuations the columns of liquid are. It is of course immaterial whether the cylinder is moves up and down in the water or the level of the water above the cylinder rises and lowers. As a result of the pressure difference between the two pistons, in one case one Movement of the pistons upwards automatically, in the other case it moves downwards executed. This movement of the pistons can be used for work, for example for controlling of gate valves, valves and the like., Can be made usable.

Fig. 2 of the drawing shows the applicability of the device for controlling the gate valve in the water supply for water turbines.

The direction of flow of the water in the feed pipe R leading to the turbine is indicated by the directions of the arrows.

1 represents the gate valve. In the vertical cylinder 3 is the differential piston 2 with the upper large surface F and the lower small surface F '. The piston and slide are firmly connected by a Z rod. 10 is an adjustable cock (shown in longitudinal section in Fig. 2a) with the arm 11 for the action of a regulator. When the tap 10 is in a certain position, the water flows out of the tube JR. through the connecting pipes 7, 6, 4 into the cylinder 3 and, when cylinder 3 is completely full, rises in the riser line 8. At the marked height NN is the surface of the water, similar to the numerical example given at the beginning, 8 m above the upper piston surface F. Since in this case the pressure on the piston surfaces F and F 'is the same, the piston will turn into a Adjust the central position. It should be switched on here that the weight of the piston and the weight of the slide 1 must be balanced by appropriate choice of the dimensions of the piston. When the piston is in the middle position, the slide 1 is also in the position that corresponds to the normal output of the turbine.

should be. When the piston is in the middle position, the cock ι ο is so that only the tubes 4, 6 and 8 are in communication with the cylinder 3.

Now z. B. back the number of revolutions of the turbine, so if the turbine requires a larger flow of water, a connection of the pipes 4, 6, 7, 8 is established again by turning the tap 10 by means of the regulator. The water column in the pipe 8 thus continues to rise, and at the same time, by gradually increasing the pressure on the calving surface F, the piston is pressed down and the slide 1 in the supply pipe R is opened more. If the water rises up to 2 m above the line NN, the pressure to open the slide would increase as follows: Pressure on the upper piston surface F ■ ρ = 490 (o, 2 -j- 0.18) - 490 · 0.38 = - 186 kg, pressure on the lower cylinder surface F ' · j / = 314 (0.2 -J- 0.283 = 314-0.48 = -150 kg.
So there would already be 186 to 150-36kg available. Since you do not need to exceed a maximum pressure on the slide, but the water in the pipe 8 would continue to rise in accordance with the pressure in the pipe R , the line '8' is discharged downwards through the overflow 8 ', where at 13 the pressurized water flows off until the turbine has reached its normal output again.

If, on the other hand, the number of revolutions of the turbine increases, the opposite rotation of the cock 10 simultaneously causes the pipes 4, 6, 8, 9 to be connected the piston area F ' exceeds that on the piston area F and the slide ι is closed more and more. The maximum pressure to be achieved in the case of the example for closing the slide would be reached when the water over the upper piston surface F has completely drained off. Since the piston is in the upper end position in this case, only the water pressure of the piston surface distance of ι m presses on the small piston, ie

F '- ο, ι - 314 ο, ι = 31.4 kg.

5 is a container which, if the water in the tubes 7, 8 and 9 should have run off, adds the necessary water for the volume that is released under the surface F ' when the piston goes up.

Through the tube 12, what may have penetrated the collars of the piston Drain the water.

Claims (3)

P ATENT claim E: 1. Hydraulic control device with one with the larger driving area according to above and with the smaller driving surface pointing downwards, movable up and down Differential piston, the two driving surfaces of which in its movement in both Directions are simultaneously under the action of the pressure fluid, characterized in that the upward movement of the differential piston by reducing and moving it down at the same time by simultaneously increasing the liquid pressures associated with both driving surfaces is effected, the liquid pressure head belonging to the larger propulsion area down to zero, on the other hand the liquid pressure head belonging to the smaller motive surface can only be reduced to a height corresponding to the distance between the driving surfaces. 2. Control device according to claim 1 for controlling the gate valve in the water supply for water turbines, characterized by a riser pipe (8) with overflow (8) corresponding to the pressure of the differential piston (2) required for adjusting the gate valve (i) and corresponding to the water supply ( 8 ') connected by a tap (10) or the like either to the differential piston cylinder (3) and the water supply (R) for the turbine or only to the differential piston cylinder or to the differential piston cylinder and a drain line (9, 13) can be brought. 3. Control device according to claim 1 for setting the diving depth of sea mines, in which the buoyancy is regulated by changing the filling of an air chamber with variable capacity, characterized in that the differential piston of two on the mine body (a) arranged one above the other, in the middle by a Rod (d) consists of flexible plates (b, c) of different sizes connected to one another and exposed to water pressure on opposite sides, of which the larger (b) is at the top and the smaller (r) is at the bottom, and by means of the rod (d ) controls the air flow. 1 sheet of drawings. cprinted in the RnicusDmckerei.