DE3436679A1 - Hydropneumatic drive device - Google Patents

Abstract

A fully integrated hydropneumatic drive device is constructed with concentric cylinder spaces (10, 12; 14, 16). A freely displaceable annular piston (28) is inserted into the outer cylinder spaces, and a drive piston (18) connected to the piston rod (20) is inserted into the inner working spaces. The outer annular piston can contain a permanent magnet (29) for activating a reed switch (44) for the motion control. The admission of fluid is interchangeable in a simple manner, and the outer piping is dispensed with, since the adjacent sectional spaces can be connected to one another in each case. The reversing valves can be integrated in the cylinder base (32) or cover (30), and a rotary drive connected to the piston rod can be used (Fig. 1). <IMAGE>

Description

The invention relates to a hydropneumatic drive

device with two cylinder chambers connected by controlled flow paths, in each of which a sealingly displaceable piston is used, each piston from one side with a pneumatic, from the other side with one hydraulic pressure medium can be acted upon, and wherein at least one piston with a piston rod leading out of the cylinder chamber is connected.

Such hydronneumatic drive devices (compressed air technology, Sentember 1983, pages 24-28) combine the advantages of compressed air technology (high Working speed due to the rapid availability of energy) with that of the hydraulics (good controllability of the hydraulic flow) and are especially used where rapid actuation with precise switching to slow and controlled propulsion slow advance should be achieved. Either a double or single-acting pneumatic cylinder connected in parallel to a hydraulic cylinder, the connection usually takes place via the piston rods. This is disadvantageous the one-sided loading of the piston rods and the space required by the parallel switched hydraulic cylinder. It is also known to pressure medium converters or Provide pressure intensifiers, which are arranged separately from the actual actuating cylinder are, but a complex and fault-prone piping or tubing require. It was therefore one of the preamble of claim 1 appropriate fully integrated hydropneumatic drive device developed, for example from picture 2 and 5 on page 25 of the magazine compressed air technology, Sentember 1983 known is. A common cylinder with a piston rod can be used here, wherein the cylinder space is divided in the longitudinal direction, and in each case the outer and the inner cylinder sub-spaces are connected to one another. To compensate for the Loss of hydraulic pressure medium is one of the two pistons on the piston rod sprung guided. In this case there is no one-sided loading of the piston rod on by laterally arranged brake cylinder, but there is an enlarged Overall length, and cylinder base and cover must be connected to each other by hoses or Pipes are connected.

The invention is therefore based on the object of an integrated to create hydropneumatic drive device of the type mentioned that is compact and is largely maintenance-free, and in which the outer piping or No tubing is required.

To solve the problem is with a hydronneumatic drive device of the type mentioned provided that the approximately the same cross-sectional areas having cylinder spaces are arranged concentrically around one another, and that the Connection channels in the common cylinder cover or in the common Cylinder base are arranged so that the cylinder cover respectively. -bottom adjacent cylinder sub-spaces can each be filled with the same pressure medium are.

The drive device equipped in this way has separate connections for the pneumatic and hydraulic pressure medium in the cylinder cover or -boden on, the diameter of the outer cylinder is compared to a simple one Cylinders with the same power requirement increased by less than 50%, and the otherwise necessary compensation device for the hydraulic pressure medium, since the ring-shaped outer piston running freely through the action of the pneumatic Pressure medium always remains in the pressure system with the hydraulic pressure medium.

It is sufficient to do this on the wall seals during longer maintenance periods hydraulic pressure medium escaping in a slight pale is refilled. The structure of the drive device according to the invention corresponds to that of a normal one Actuating cylinder. It is up to the user from which side he acts, i.e. the piston rod can push or pull be applied. No connection piping or tubing is necessary, so that the susceptibility to failure is largely eliminated.

If the drive device is further formed that the connecting channels to the outside of the cylinder cover or testicle with the same connection pattern are, so can be appropriate when designing the connection diagrams the Valve connection standards a simple exchange of the pressure medium application sides and any commercially available valve corresponding to the standard image can be used Control can be used.

A particularly advantageous further development is characterized by that an actuating valve which switches the current control elements on the hydraulic connection side is arranged, which is provided with impulse-controlled actuation and which with 2 pressure-actuated control piston is equipped. It's one that way simple reversal, for example, from rapid to creep speed using switching cams the piston rod possible, e.g. mechanically, by pneumatic or hydraulic Servo lines or electrically cause the valve to be reversed. The holding of the reversed valve in the respective actuation state then happens through the pressure medium itself.

The influence in the return, which is mostly continuous in rapid traverse occurs, is usually avoided in such valves so that control pistons are different Areas are provided. However, it can also be a pre-controlled pulse instead Self-pressure controlled one-way flow control valve can be used in the control piston the same size are provided. Due to the special connection of the control piston line any unwanted influence on the return is avoided.

A further reduction in space requirements and increased security against damage and other malfunctions can be achieved by opening the control valves are each integrated in the cylinder base or the cylinder cover.

A particularly advantageous further development is characterized by that at least the outer cylinder wall is made of non-magnetizable material, that a permanent magnet is used in the outer bulb that on the outer cylinder wall at least one Reeiontakt is arranged to be longitudinally displaceable, and that at least that the flow control element or the flow control elements controlling valve or both pressure medium control valves Solenoid valves are.

In this way, a precise change of position can be achieved even with a short piston rod the operating states of the drive device take place. Such an attitude control is reliable, inexpensive and easy to change and adjust. Must with rough Operation and inadequate maintenance are feared that with long operating times If the loss of pressure medium is too high, this can be done via an on the piston rod or a corresponding electrical switching device attached to a moving part with the eedkontakt via a coincidence circuit that is easy to set up on this Way a monitoring of the pressure medium fill level take place. It is special of advantage if the procedure is carried out according to claim 7, since in this way also a Rotation of the outer bulb has no effect on the control device.

As already noted, there is a free choice of the pressure medium connection given, however, there is a particular simplification in that the pneumatic Pressure medium is applied via the cylinder base, since in this way the External connections of the pneumatic pressure medium facing away from the processing side are, especially if the switching device for the hydraulic pressure medium, such as already mentioned, in the cylinder cover is housed.

In this way, the drive device according to the invention can still particularly do so universally usable designed that the piston rod one on both sides is a continuous piston rod, and it is advantageous for special purposes Further development can be achieved in that the piston rod is secured against rotation.

Finally, as a result of the automatic leakage compensation, the drive device can not only as a linear drive, but also as a rotary drive, if it is designed so that the acted upon with hydraulic pressure medium On the side, a hydraulic rotary drive is provided that is non-rotatably connected to the piston rod is through the connecting channel leading away from the adjacent inner cylinder sub-space is fed that the piston is slidably guided on the piston rod, and that the piston rod at its outwardly led end or at both to the outside guided ends is provided with a rotary drive transmission. Also in this In the case of a sliding contact, the equipment proves to be very much advantageous, as this enables monitoring of the fill level of the hydraulic pressure medium can be implemented in the simplest possible way. Hydraulic rotary drives are known which work largely slip-free, so that a precisely positioned rotation is possible is.

The universally applicable hydronneumatic drive device according to of the invention thus proves to be the 3 respectively existing installation conditions in excellent way customizable, it is inexpensive, in general Can be built from standardized parts (cylinder walls, cover, piston rod, etc.) and can also be used for heavy-duty operation with low maintenance requirements.

The invention is illustrated below on the basis of exemplary embodiments Drawing explained in more detail; in this shows: FIG. 1 a hydropneumatic drive device with a pneumatic connection on the cylinder base, FIG. 2 shows one of the embodiment according to FIG 1 corresponding drive device with cover-side pneumatic connection, and FIG 3 shows an embodiment of the drive device as a rotary drive.

In Figure 1 is an embodiment of the hydropneumatic according to the invention Drive device shown in which the pneumatic application of the working piston pushes he follows. With two concentrically arranged, each sealing with a cylinder base 32 and a cylinder cover 30 connected cylinder walls, the outer cylinder wall 52 and the inner cylinder wall 54 are two concentric Z = 71inder spaces, the inner cylinder space 10, 12 and the outer cylinder space 14, 16, formed by an inserted inner piston 18 and an annular outer piston 28 in the respective cover-side inner cylinder space lo or outer cylinder space 14 and divides the bottom inner cylinder space 12 and the outer cylinder space 16 are. The outer piston 28 designed as a rinholben is free inserted displaceably, while the inner piston 18 is screwed to the piston rod 20 and is sealed against it by an annular seal 23. Usual sealing rings 22 ensure the sliding seal of the piston on the inside of the inner Cylinder wall 34. The outer ring piston 28 contains a permanent magnetic ring insert 29 The piston rod 20 is mounted in the cover 30 in the usual way and through Sealing and scraper rings 24, 26 sealed. At the outer end is the piston rod 20 provided with a piston rod thread to which, depending on the intended use, fastening parts can be attached. The pressure medium is supplied in the cylinder cover 30 Via a channel 31 leading to the inner cylinder subchamber 10 and one to the outer one Outer channel 31a leading to the cylinder subspace 14. The inner ones are accordingly Bottom-side cylinder sub-space 12 via a channel 33 and the outer cylinder sub-space 16 accessible via a channel 33a. The connection holes for the two channels 31, 31a in the cylinder cover or

33, 33a in the cylinder base are preferably designed so that they correspond to the VD3S connection standards for valve connections, so that on the simplest Way, every standard pneumatic or hydraulic valve is placed on top can. In the embodiment shown, there is one in the longitudinal direction of the drive device slidable reed contact 44 intended for controlling the hydraulic valve, while on the cylinder base a common one 4/2-way pneumatic valve 46, fed by a source 48 for pneumatic pressure medium, is attached. The hydraulic reversing valve 34, which is placed on the cover side here, serves to that - from the cover-side inner cylinder sub-space 10 to the outer cover-side Cylinder subchamber 14 flowing pressure medium in one position practically unhindered to let flow, while in the other position via a flow control element 36 is guided in order to bring about the slow work advance. This one Pre-pulse controlled intrinsic pressure held throttle check valve 34 is with two pressurized control piston 38 and 40 of the same size provided, which over Control channels 39 and 41 are in communication with the pressure medium flow. How easy can be seen, at the beginning of the expulsion of the piston rod in the direction of the arrow 51 on the side of the control piston 38 the pressure medium flows through practically freely, and the existing pressure reaches this piston via the connecting channel 39. As soon as the magnetic ring 29 in the outer annular piston 28 reaches the reed contact 44, the actuating magnet -42 is applied and the reversing valve 3 is knocked over. That hydraulic pressure medium now flows through the flow control member 36, so that in the to the control piston 40 leading channel 41 is a higher pressure than at the junction of the duct 39 located downstream. The redirected The position of the reversing valve 34 is maintained in this way and the drive device moves the rest of the way at a speed reduced by the flow control element. Will the control valve 46 reversed for the pneumatic pressure medium and thus the cover-side outer cylinder subchamber 16 is pressurized, see above the outer annular piston 19 pushes the pressure medium out of the outer cover-side Cylinder subspace 14 through the channel 31a to the reversing valve 34, so that now A higher pressure builds up in the channel 39, through which the control piston 38 counteracts the force of the control piston 40 of the reversing valve can overturn. True, as soon as the permanent magnet ring 29 comes close to the reed contact 44, another switching pulse through the Actuating magnet 42 exercised, however, because of the increased pressurization of the control piston 38 thereby the reversing valve will not be knocked over, because also at the same time the pressure on the control piston 40 is lower than that on the Control piston 38 is acting pressure. In this way, the control pulse emitted by reed contact 44 has no effect.

Taking into account the previous description, the effect is the opposite also easily understandable in FIG. Here the loading takes place via the cover-side cylinder sub-spaces 101 and 14 ', while the bottom-side sub-spaces 12 'and 16' are filled with hydraulic pressure medium. There are similarly structured Control valves 46 'for the pneumatic pressure medium or as a reversing valve 34' for the hydraulic pressure medium use, and the mode of operation is under consideration the same as the reverse application.

The use of the hydropneumatic according to the invention shown in FIG Drive device as a rotary drive differs from the two linear drive applications in Figure 1 and Figure 2 only in that in the current path of the to the inner bottom Cylinder compartment 12 "leading channel 33" and 33b "a hydraulic rotary drive 56 is inserted, which is connected to the piston rod 60 in a rotationally fixed manner. For acceptance the drive torque is provided by a rotary connection at the end of the piston rod 60 that is led out 62, for example a simple transverse slot, a transversely inserted pin, and the like.

can be. When the piston 58 "passes through the on the cover side in the Cylinder subspace 1o "Pneumatic pressure medium supplied to the cylinder base 32" is driven towards, it displaces hydraulic pressure medium from the inner subspace 12 "in the bottom outer subspace 16" so that the rotary drive 56 in the is driven in one direction and thus takes the piston rod with it. When switching of the pneumatic valve 46 ″, the flow of the hydraulic pressure medium takes place in in the opposite direction and the hydraulic drive rotates accordingly 56 with the piston rod 60 in the opposite direction.

When using a slack-free rotary actuator, the position of the outer piston 28 "with the help of the permanent magnet ring 29" in the same Way, as previously discussed, the reed contact 44 "is applied, so that here too Via a corresponding reversing valve 46 ″, if necessary, a flow control element in the current path of the hydraulic pressure medium can be switched on to different To evoke movement characteristics.

By another reed contact, or if it is not for reversing is used, by the reed contact 44 ″ itself, can be a little complex monitoring of the fill level for the hydraulic pressure medium can be brought about, since the rotary position of the piston rod 60 with the associated position of the outer ring piston 28all is easy to monitor.

This monitoring can also be used as a linear drive Drive devices according to Figures 1 and 2 can be carried out without great effort in such a way that that e.g. via a limit switch or another switching element and a coincidence detector a loss of pressure fluid can be determined at any time.

The embodiments described can be particularly advantageous Way can be provided with further refinements according to the invention. So can several reed contacts used to initiate different control processes will; the current actuator 36 can be adjusted with a fine adjustment (proportional control) be provided to enable precise control of the advance speed, and the reversing valve 46 can be provided with a closed center position; around a movement block, e.g. for set-up purposes or with appropriate control to achieve as accident protection. The control valves 34 and 46 can also be in the cylinder base or cover to be integrated in order to allow particularly favorable spatial conditions. In this way, especially when the pneumatic pressure medium is connected at the bottom a considerable saving in the space required for the drive device on the Machining side can be achieved.

Finally, instead of the reed contacts, with the appropriate design the outer cylinder wall 52 also on capacitive scanning measuring elements Control of the impulse-controlled internal pressure controlled one-way flow control valve 34 can be used.

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Claims (11)

1. Franz Henke Weidachstr. 14, 8922 Peiting 2. Herbert Kainzmeier Alpenstrasse 31, 8925 Altenstadt 3. Klaus Will Lerchenstr. 48, 8920 Schongau Hydropneumatic Drive device claims: 1. Hydropneumatic drive device with two Cylinder chambers connected by controlled flow paths, each with a sealing Slidable piston is used, each piston from one side with a pneumatic, from the other side with a hydraulic pressure medium can be acted upon, and wherein at least one piston with one from the cylinder space outgoing piston rod is connected, thereby g e -k e n n n n z i c h n e t that the cylinder chambers (10, 12; 14, 16) having approximately the same cross-sectional areas concentric are arranged around one another, and that the connecting channels (31,31a; 33,33a) each in the common cylinder cover (30) or in the common Cylinder base (32) are arranged so that the cylinder cover (30) or base (32) adjacent cylinder sub-spaces (10, 14; 12, 16) each with the same pressure medium are fillable. 2. Drive device according to claim 1, characterized in that g e k e n n -z e i c h n e t that the connecting channels (31,31a; 33,33a) on the cylinder cover (30) or bottom (32) are each guided to the outside with the same connection pattern. 3. Drive device according to claim 1 or 2, - thereby g e -k e n It is noted that an actuating valve which switches the flow control valves (36) (34) is arranged on the hydraulic connection side, the pulse-controlled actuation (42) and equipped with a pressure-actuated control piston (38,40). 4. Hvdronneumatic drive device according to claim 3, characterized it is noted that the control piston (38, 40) of the flow control valves switching valve (34) are of the same size. 5. Drive device according to one of the preceding claims, characterized it is noted that the control valves (34; 46) are each in the cylinder base (30) or the cylinder cover (32) are integrated. 6. Drive device according to one of the preceding claims, characterized it is noted that at least the outer cylinder wall (52) does not magnetizable material is that in the outer bulb (28) a permanent magnet (29) is used that on the outer ZYlindervand (52) at least one reed contact (44) is arranged to be longitudinally displaceable, and that at least the flow control element or the valve (34) controlling the flow control elements (36) or both pressure medium control valves (34, 46) are solenoid valves. 7. Drive device according to claim 6, characterized in that g e k e n n -z e i c h n e t that the permanent magnet is an annular permanent magnet (29). 8. Drive device according to one of the preceding claims, characterized it is not indicated that the pneumatic pressure medium is applied via the cylinder base (32) takes place. 9. Drive device according to one of the preceding claims, characterized it is noted that the piston rod (20) is one that is continuous on both sides Piston rod is. 10. Drive device according to one of claims 1 to 9, characterized it is not indicated that the piston rod (s) is (are) secured against rotation. 11. Drive device according to one of claims 1 to 9, characterized it is not noted that at the pressurized with hydraulic pressure medium Side a hydraulic rotary drive (56) connected to the piston rod (60) in a torque-proof manner is provided, which by the adjacent inner cylinder sub-space (12) leading away connecting channel (33) is fed that the piston (58) is slidably guided on the piston rod (60), and that the piston rod (60) at its outwardly led end or at both outwardly led ends is provided with a rotary drive transmission (62).