SE430183B - SERVO CYLINDER WITH THROUGH Piston Rod - Google Patents

Description

10_ 15 20 25 50 55 aoo fi ëoø-4 The invention is described in more detail with reference to the accompanying figure. The cylinder 1 is built up of a tube 2 with ends 5 and 4 which are axially fixed in the tube 2 with locking rings 5, 6, 7 and 8 and sealing rings 9 and 10 seal between the ends 5 and 4 and the tube 2. The piston rod 11 passes completely through the tube 2 and thus passes through the ends 5 and 4. In these there are seals 12 and 15 which seal against the piston rod 11. The piston 14 is connected to the piston rod 11 and divides the cylinder in two. chambers 15 and 16, and a seal 17 seals between the piston 14 and the tube 2. On. on either side of the piston 14, the piston rod 11 is formed with two enlarged portions 17 and 18, respectively, which form stop means which limit the movement of the piston 14 upon contact with the ends 5 and 4. There are two in the piston rod. urborr- mgee- gzo een 21. nenee aeeee fnmee a wall 22 with an opening 25.: puben- rrlngenrufinnes a valve slide 24 with an operating rod 25, which at its outer end threads and has a stop sleeve. 26 with which the movement of the valve slide 24 to the right is limited. The valve slide 24 is formed at its inner end with a pin 27 which passes through the wall 22. A locking ring 28 on. the part projecting into the bore 21 restricts the movement of the slide 24 to the left. Between the slide 24 and the wall 22 there is a spring 19 which seeks to move the slide 24 to the left to the boundary position determined by the wall 22 and the locking ring 28. In the cylinder space 16 there is a spring 29 which seeks to move the piston 14 to the left to the boundary position determined of the piston rod portion 17 and the end 5. In the tubular. The piston rod 11 is on. on either side of the piston 14 radial openings 50 and 51. Via its openings 50 and 51 and the annular channel 52 formed between the slide 24 and the bore 20 ', the cylinder spaces 15 and 16 communicate more closely when the veins 24 do not: ae: 1 the figure vieeae made. In the piston 14 there may be an atial channel 55 which guarantees a certain overflow of pressure medium when the valve slide completely shuts off the communication via the piston rod 11. The servo cylinder 1 is part of a closed hydraulic system with a pump 54 which via the line 55 is on. the pressure side communicates with the cylinder space 15 and on. the suction side with the container 56 via the line 57. The cylinder space 16 is connected via the line 58 to, for example, other servo equipment or directly to the container 36.2 The servo cylinder operates in the following manner. At the position of the valve slide 24 in the piston rod 11 shown in the figure, pressure medium with very small pressure loss circulates through the inclined circuit consisting of the cylinder 1, the line 58, the container 56, the line 57, the pump 54 and the line 55. when the slide 24 is displaced to the right the opening 50 is partially or completely closed, whereby the flow resistance increases and pressure release is obtained in the space 15 so. that a right-acting actuating force is obtained, which displaces the piston to the right. With the absolute position of the valve slide 24 unchanged, the opening 50 is exposed to its equilibrium

Claims (4)

eoo14oo-4 is obtained between the piston force and the counter force from one of the members of the piston tongs 11. Emulsion movement is obtained which is close. equal. the absolute displacement of the sheath 24. Further displacement of the sheath 24 means a further piston movement until the maximum pressure in the space 15 is obtained. This. maximum pressure and thus maximum operating force can be limited by means of the top nut 26 by limiting the throttle at the opening 50. The stop nut 26 limits the movement of the slide 24 relative to the piston rod 11. The servo cylinder according to the invention has proved to be very useful as a brake cylinder in, for example, fork trucks. PATENT REQUIREMENTS Servo cylinder (1) containing a continuous piston rod (11) with a keiv (14) nen nppaeien eynnaenn (1) 1 a hair dryer and an enane nen (15, 16), 1: anneteeknea ast-ev, a keivenången (11) to find out a single bit (20) and with radial openings (50, 51) on. tender sides of the piston (14), the wine opening (50, 51) enables connection neuen memory-found (15, 16) via the bore (20) in the piston rod (11) and overflow of a pressure medium between these spaces (15, 16), arranged in the bore an axially displaced one (24) with a petiole (40) in a ninane cross-section other than the bore (20) so that an axial channel (52) is formed, that the slide (24) is actuated by a spring (19) net a gnäneiäne where a fr: connection nellen ae bean eynnaen- rummen (15, 16) is via. the partial openings (50, 51) and the channel (52) together with the slide (24) when displaced from the boundary layer determined by the spring (19) cause a throttling of one of the radial ones. the opening yarn (50, 51) and thus the flow between the two cylinder runes (15, 16) so. that a pressure difference and a maximum force are obtained. Servocylizades according to claim 1, characterized in that the piston (4) is actuated in one of them. direction of a spring (29) towards a position to be determined) by a stop (2, 17). 3. 5. Servo cylinder according to petentlmav 1, characterized in that the slide valve (24) is actuated in one of them. direction of movement of a spring (19) towards a limit position determined by a stop (22, 28). Servo cylinder according to claim 5, characterized in that the cylinder is provided with an adjustable stop device (26) with which the movement of the slide valve (24) can be restricted in the direction which causes restriction of the flow nenen eyltnaerne bath (15, 16).