DE1251157B - Device for controlling the liquid supply from the cylinder of a liquid motor - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int CL:

Number:
File number:
Registration date:
Display day:

FlSb

German class: 60-30

1251157
C 256721 a / 60
December 6, 1961
September 28, 1967

Gives way away q on

The invention relates to a device for controlling the discharge of liquid from the cylinder of a liquid motor through a tapered outlet channel, with an in one end wall of the cylinder arranged valve piston, the opposite surfaces of which the Fluid pressures on opposite sides of the taper are exposed to part of the piston a control valve in the channel behind the taper forms, and a spring the piston in the open valve position presses.

In such previously known devices for controlling the discharge of liquid from the cylinder of a liquid motor, the throttle cross-section is changed.

The invention is based on the object of such a device, the operation and the To improve adjustability.

This is achieved in that the spring can be adjusted with an adjusting screw in order to adjust the ge ao to regulate the speed of the liquid outlet. · ■ '.' ..

In an advantageous further embodiment of the invention, the adjusting screw is used to adjust the spring load accessible from outside the cylinder.

The resulting technical progress consists in the fact that a simple operation option when installed directly in one Servomotor cylinder is reached. Another advantage of the subject matter of the invention over the previously known. Embodiments in which an adjustment of the throttle cross-section is carried out exists in that there is practically no influence from external loads and gravitational forces, acting on the piston, as well as hydraulic pressure fluctuations acting on the piston or by changes in the back pressure in the return line between the cylinder and The forces occurring in the control valve are not noticeable in a disadvantageous manner. V

The invention is explained below, for example, with reference to the drawing. she shows a vertical view in section through a working cylinder, wherein the control mechanism according to the invention is arranged in the end wall of the cylinder.

In the drawing there is shown a piston 61 reciprocating in a cylinder 59, the cylinder is closed by means of an end wall 60. By the piston 61; the end wall 60 and the cy- so linder wall a pressure chamber 63 is formed.

The end wall 60 has an inlet outlet 64.

Device for controlling the discharge of liquid from the cylinder a? Liquid motor

Applicant:

The Cessna Aircraft Company, Wichita, Kan. (V. St A.)

Represent

Dipl.-Ing. W. Meissner and Dipl.-Ing. H. Tischer, Patent Attorneys, Berlin 33, Herbertstr. 22nd Named as the inventor Marvin Clifford Darling, Burrton, Kan. (V. St A.) Claimed priority: V. St ν. America january 12, 1961 (82189)

The inlet-outlet has an opening 4 with a reduced or otherwise tapered diameter which opens into the chamber 63 and in connecting lines 5, 6 and 7, as well as with a Inlet outlet 8 is in communication. The end wall 60 also has a transverse bore 65 with the chamber 63 via the line 15 is in communication. The transverse bore 65 is divided into one Pressure chamber 16, a bore 66, in common parts of the connecting lines S, 6 and 7 and in a chamber 18. The opposite ends of the transverse bore 65 are closed by end screws 67 and 68 closed, which carry limit stops 24 and 19, respectively, to the movement of a valve piston 9 limit in both directions. The end screw 68 carries a spring seat 69 which is in the The end screw is screwed in and can therefore be rotated in any direction to increase the force which is transmitted against the head 70 of the valve piston 9 by means of a spiral spring 17. A bypass conduit 12 is provided at one end with inlet outlet 64 and at the other end with the cylinder chamber 63 in communication. A shut-off valve 13 in one end of the line 12 prevents however, allows the liquid to flow from the chamber 63 into the inlet outlet 64 an opposite flow. A short line 14 connects the shunt line 12 with the chamber 18, whereby the head 70 of the valve piston 9 is subjected to the pressure that is in the

709649 / M2-

Claims (5)

I 251 connecting line 5 is present. The valve piston 9 is provided with an end part 23 which has a notch 21 cut into the edge 20 of this end part. As soon as the piston 61 moves in the direction of the S end wall 60 of the cylinder, either due to a load acting on the distal end of the piston rod 32 or due to a fluid pressure acting on the surface 45 of the piston, the pressure contained in the chamber 63 becomes Liquid squeezed out through openings 4 and 8. The valve piston 9 is normally held against its stop 24 by the spring 17, which normally leaves the connecting line 6 completely open and free. The liquid flow through the opening 4 of reduced diameter leads to a pressure build-up in the chamber 63 when the flow rate is sufficient, and a pressure difference arises between the chamber and the connecting line 5. The opposite ends of the valve piston 9 are thus subjected to these different pressures. As soon as this pressure difference becomes sufficiently large, the force acting on the left end of the valve piston 9 through the line 15 overcomes the spring force of the as spring 17, which acts on the opposite end of the valve piston, and this moves in the drawing according to the right. A limitation of the flow through the connecting line 6 begins practically immediately and increases progressively as the valve piston continues to move. As soon as the edge 20 of the valve piston 9 enters the connecting line 6, the control edge 22 interacts with the edge 20 of the valve piston in order to allow all of the liquid flowing out of the chamber 63 to only pass through the notch 21. This decreases in size when the valve piston 9 is moved to the right and increases in size when the valve piston 9 is moved to the left. Since the flow of liquid is limited by means of the valve piston 9, the pressure in the connecting line 5, line 12 and in the chamber 18 increases. This increase in pressure leads to a reduction in the pressure difference between the chamber 16 and the chamber 18, so that the spring 17 can move the valve piston 9 to the left. This floating action of the valve piston prevents the pressure difference between the chambers 63 and 18 from increasing above a predetermined value which is determined by the compression force exerted by the spring 17, the spring in turn being adjustable in its force by adjusting the spring seat 69. The speed at which the piston 61 can move is limited by the rate at which the liquid flows through the inlet outlet 64. There is also provided a cushioning stop which can be moved by and with the piston as it approaches the end wall 60 so as to further progressively limit the flow of fluid from the cylinder chamber 63 to the outside through the inlet outlet 64. It consists of a tapered measuring pin 62 which is carried by the piston 61 in a position aligned with the longitudinal axis of the opening 4. With continued movement of the piston in the direction of the end wall 60, the pin 62 enters the opening 4, as a result of which the size of this opening is progressively reduced. Since the valve piston 9 limits the pressure difference between the chambers 63 and 18 to a practically constant value at this point in time, the amount of liquid that can flow through the opening 4 depends on the possible flow area after the pin 62 has entered this opening. The progressive reduction of the flow area through the opening 4 by means of the measuring pin 62 leads to a rapid retardation of the movement of the piston 61 until the flow from the chamber 63 and the speed of the piston have reached a minimum value that is determined by the flow area through the opening 4 is determined after the pin 62 has fully entered this opening. The cylinder part 71 of the pin 62 advantageously has practically the same diameter as the inside diameter of the opening 4, so that the part 71 entering the opening interrupts the entire flow of liquid from the chamber 63. As soon as this flow is interrupted, the piston has been resiliently stopped, the pressure is equalized, and the valve piston 9 is again brought into a position against its stop 24 by means of the spring 17. In order to move the piston in the opposite direction, pressure fluid is introduced through the opening 8 into the inlet outlet 64. The liquid is passed through the line 12 past the shut-off valve 13 in order to set the movement of the piston 61 in motion. As a result of this movement, the measuring pin 62 is quickly moved out of the opening 4, so that the liquid can enter the chamber 63 directly through this opening. The measuring pin 62 and its arrangement are not the subject of the invention. The valve piston 9 together with the spring 17, the stops and connecting lines can also be provided in the end wall lying on the piston rod side, the inlet-outlet 64 having to be arranged off-center. Patent claims: 1. Device for controlling the discharge of liquid from the cylinder of a liquid motor through a tapered one Outlet channel, with a valve piston arranged in an end wall of the cylinder, its opposite surfaces reflect the liquid pressures on opposite sides of the Are exposed to taper, with part of the piston a control valve in the channel behind the Taper forms, and a spring presses the piston into the open valve position, characterized in that that the spring (17) can be adjusted with an adjusting screw (68 or 75) so as to increase the speed of the liquid outlet to regulate. 2. Apparatus according to claim 1, characterized in that the adjusting screw for the purpose Adjusting the spring load is accessible from outside the cylinder. Considered publications:
German Patent No. 1,039,844;
Swiss Patent No. 270 652;
Automatic magazine, 1960, p. 134, fig. 7. 1 sheet of drawings 709 649/242 9.67 © Bundesdrockerei Berlin