Shock absorber and method for calibrating same

p0001The invention relates to a shock absorber with a housing tube, a coaxially arranged therein pressure tube and a piston in the axial direction in the pressure pipe is radially sealed displaceable, wherein a piston rod of the piston is sealed guided through an end face of the housing tube and the piston together with at least the pressure pipe a working space limited, from the fluid due to movement of the piston in the axial direction by at least one a throttle cross-section defining throttle opening under throttling effect in a second working chamber and / or a storage space can be displaced. Furthermore, the invention relates to a method for adjusting a shock absorber having a pressure tube with a piston which is axially displaceable in the pressure tube by an impact on a guided out of the shock absorber piston rod, wherein the pressure tube encloses a first working chamber, from which a fluid by means of the piston can be displaced by at least one a throttle cross-section defining throttle opening under throttling effect in a second working chamber and / or a storage space, and wherein a characteristic of the shock absorber is adjusted via the throttle cross section.

p0002Such shock absorbers which are often referred to as industrial shock absorbers, for example, from the <patcit id="pcit0001" dnum="DE102005013734A1"><text>DE 10 2005 013 734 A1</text></patcit> known. The change in damping constant, ie, the throttle effect of the shock absorber takes place for example in that the pressure tube is rotated relative to the housing tube. Either certain throttle bores can closed in the pressure tube and others are released with a different cross-section, or certain orifices are changed with respect to its throttle cross section, the overlap of the orifices can be varied by spiral ridges in the housing tube in the example. The adjustment is carried out manually, for example by means of a front end emerging from the housing tube knurled wheel or by means of a tube of the housing penetrating screw which is actuated by means of a screwdriver. In a □ □ characteristic of a shock absorber which a displacement of the Ko-ben 1 opposite damping force to the speed of displacement is displayed.

p0003The known industrial shock absorbers are, for example, used in internal transport paths, which are designed as so-called roller conveyors as a stop means for transporting containers. In the transport containers there are for example transport pallets for receiving a workpiece to be machined, which is transported on a pallet from one processing station to the next. A typical case is for example the manufacture or processing of cast-engineered and machined remachined engine blocks, cylinder heads and transmission cases. If a befindliches on a pallet workpiece, which comes from a processing station, to be stopped, for example at a different processing station, the transport pallet runs against the piston rod of the shock absorber industry coupled stopper. With the stop element of the piston is displaced in the pressure pipe in the feed direction against the damping force so far that the kinetic energy of the conveyed □ □ consumed is. The Bewegungsenerg ie the workpiece including the transport pallet is that the displacement of the working fluid through the throttle cross sections, converted to heat energy during the braking process in shock as a result of movement of the piston.

p0004The storage space of the known shock absorber is often filled with a flexible, closed-cell foam which is displaced and compressed by the invading fluid. For relief of the stopper member □ in particular by removing the conveyed material from the stop point □ the foam allows compensation of the additional required when retracting the piston rod volume, the provision is based on a coil spring, which the fluid back into the working area and thus the stop member back in promoted to its original position. Alternatively, it is also known to form the storage chamber substantially over the working area on the other side of the piston as a second working chamber and to effect recovery by active pressurization this second working space.

p0005The generated during operation of the known shock absorber heat leads temporarily increasing warming of the fluid (oil or gas), wherein the operating temperature after a time depending on the mass of the fluid and the heat transfer to the environment over time asymptotically approaches the ambient temperature. Compared to the state at ambient temperature, in which the damping rate □ the ratio of damping force, and speed is set □ in general, the fluid has in the meantime on a lower viscosity. With the viscosity and the resistance to flow through the reactor and thus the damping rate is reduced compared to the set value.

p0006The temperature-dependent variation in the damping rate due in particular at short successive □ □ also identical workpieces a surge in achieved with the known shock absorbers stop points on the conveyor track, which must be taken into account in the interpretation. The reduction of the damping rate of use must also be compensated by safety margins in the design and setting, to prevent damage to the known shock absorber which conveyed workpieces and the conveyors.

p0007It is often in such role-based transport systems the case that workpieces conveyed by different mass, that also need to be stopped. The absorbed by the shock kinetic energy thus differs also. The shock absorber or its throttle characteristic is now generally set once such that the workpiece having the largest mass, reaching the dead center of the piston is reliably prevented, ie adjusted so that the total kinetic energy of pallet and workpiece converted from the shock in heat will. The problem with such an attitude that workpieces with significantly smaller mass than the maximum mass due to the lower kinetic energy (it is a movement with the same speed assumed for all workpieces) earlier access to a standstill. This may cause malfunctions in such transport systems, in particular because not achieve lighter workpieces, due to their very short delay path a certain prescribed standstill position to trigger hereby further handling or processing steps.

task

p0008The invention is therefore based on the object to so develop a shock absorber with a housing tube, a pressure tube and a piston that workpieces of different mass within a certain distance, the maximum permissible the maximum stroke of the piston, are brought to a standstill, with simultaneously but also in light work pieces to achieve a minimum delay path is to be ensured.

solution

p0009Starting from a shock absorber of the type described above, this object is inventively achieved in that the effective throttle cross section is adjustable by means of a remotely controllable drive means.

p0010The remotely controllable drive device allows a very simple manner to adapt the damping characteristics to different damping tasks, ie for example the stopping of workpieces with different sized mass. Since the effective throttle cross section can be changed according to the invention very simply and quickly with the help of a remote-controlled drive device, the attenuation constant can be matched to the prescribed by the workpiece mass damper object as needed before each stop operation. For example, the attenuation constant can always be adjusted before each braking process so that the workpiece with a certain security against the end stop, ie, comes to a standstill before use of the maximum stroke. Problems with pallets, which are provided with light work pieces, thus result by the shock absorber according to the invention no longer, because a premature stoppage, ie a lack of attainment of a required stop position, no longer occurs.

p0011Typical be that the attenuation constant of the shock absorber is not changed before each damping process, but that, for example, a certain amount of time working long because of identical workpieces with a first effective throttle cross section and that is then changed to workpieces with a different mass, so that then the effective throttle cross-section is adjusted accordingly. But even if a change in the damping constant is only at longer intervals, the shock absorber of the invention is particularly economical because it can be dispensed with a manual setting, whereby staff and time can be saved and operating errors can be avoided.

p0012The remote control of the setting is carried out in particular by means of electrical energy, ie, at the remote controlled actuator is typically an electric motor or other coils anchor device. In principle, however pneumatic or hydraulic drives, or even mechanically acting actuators, such as cables or rods in question.

p0013A particularly simple way to form a compact unit of shock absorber and drive means is that the latter is fixed to the casing tube, in particular its end side. The construction is particularly simple when the longitudinal axis of the shock absorber or the housing tube with the central axis of the drive device, in particular an electric motor aligned. In order to simplify the construction of the shock absorber according to the invention further, the drive means should be arranged on the side opposite the piston rod side of the housing tube. In principle, however, an arrangement on the opposite side where the piston rod exits the housing pipe, is possible. In this case, a sleeve-shaped transmission element of the drive device sealed penetrate the end face of the housing tube in order to effect, for example, a rotation of the pressure tube.

p0014A known shock absorber particularly easy to use embodiment of the invention is that by means of the drive means, the pressure pipe to the casing pipe is relatively rotatable and / or slidable. In this case, an overflow, which allows the overflow of fluid past the piston from the first working space into the second working chamber or the storage space, as a helical groove in the casing pipe or arranged between the pressure tube and the housing tube cap sleeve or as a flat on the outer lateral surface of the pressure tube be formed.

p0015Alternatively, the pressure tube is also provided in a with a gradient extending in the axial direction of the pressure tube slot and coaxial with the pressure tube arranged push-on sleeve to be mounted, which is arranged coaxially in the housing tube, wherein the slot forms an overflow duct, the an overflow of fluid to the piston past allowed from the first working chamber into the second working chamber or the storage space. In order to realize different throttle cross sections, the pressure pipe and the coupling sleeve by means of the drive device are rotatable relative to each other in this case.

p0016In the pressure tube, a plurality may be located by running in the axial direction rows of orifices, wherein the rows are arranged distributed in the circumferential direction on the outer surface of the pressure tube and by the drive means each comprise a series in register with the slot can be brought into the coupling sleeve.

p0017As an alternative to the throttle holes in the pressure pipe, the throttle cross-section or the throttle opening may be located at an end side of the working space, in which case the effective throttle cross-section is changed by a conical or pyramidal or spherical throttle body in the axial direction of the pressure tube with the aid of the drive means is displaced. Preferably, the drive means produces a rotary movement, which can be implemented by means of two thread-like co-operating parts in a movement in the axial direction of the pressure tube.

p0018Thus, the throttle body may be a frontally inserted in the housing pipe plug or be operable by this stopper, wherein the stopper has a throttle point or is actuated this and screwed into a provided with an internally threaded portion of the housing tube and supported therein rotatably and sealed with an external thread. Means of the drive device, in particular a shaft of an electric motor, the plug is coupled to a torque transmission is possible.

p0019The invention further ausgestaltend is provided that the throttle tip differently deep into an orifice that is located in a working space boundaries in axial direction orifice, which preferably has at least one radially extending outflow channel, which forms a connection between the throttle cross-section and the overflow.

p0020In order to simplify the construction of the shock absorber according to the invention, the drive means should be arranged on the side opposite the piston rod side of the housing tube. In principle, however, an arrangement on the opposite side where the piston rod exits the housing pipe, is possible. In this case, a sleeve-shaped transmission element of the drive device sealed penetrate the end face of the housing tube in order to effect, for example, a rotation of the pressure tube.

p0021An advantageous embodiment of the invention provides to equip the shock absorber having at least one measuring device, by means of which an operating temperature of the fluid and / or a pressure of the fluid in the working space measurable and having at least one control device by means of which the drive device depending on the operating temperature and / or is the pressure in the working chamber can be controlled to provide. The shock absorber according to the invention enables on the control of the effective throttle cross-section to compensate the temperature-induced change in the viscosity of the fluid, thus avoiding fluctuations of the effective characteristic curve of the shock absorber. If the pressure of the fluid measured in the work space, the measured maximum pressure is always decisive for the control of the drive means.

p0022The drive means of a shock absorber according to the invention allows the design of the bumper and its specific □ □ adjustment adapted motorized rotation and linear displacement of the corresponding component of the shock absorber. For example, by the drive means a □ twisted from the prior art known □ rotatable pressure pipe or a conical nozzle needle in the throttle to be moved linearly. The controller of a shock absorber according to the invention has an input for the operating temperature of the measuring device and an output for the control value of the drive means.

p0023Preferably, the measuring device of a shock absorber according to the invention at least one thermocouple and / or a piezoelectric pressure sensor. Thermocouples are inexpensive as mass products are available in a variety of styles. The thermocouple is attached (in the fluid directly or indirectly) in a bore in the housing in the vicinity of the fluid and allowed via the electrical thermal voltage between its terminals to draw conclusions about the temperature of the fluid. Alternatively, a bimetal, come as a measuring device with a mechanical output for use for example in the form of a coil spring.

p0024The controller of a shock absorber according to the invention is programmatically in an advantageous embodiment of a shock absorber according to the invention. In particular, such a control device on at least one integrated circuit and includes (for example in a separate memory space) a mapping rule of measured values ​​of operating to the manipulated variable of the drive means.

p0025To a shock absorber according to the invention the control means and the drive means in a structural unit are particularly preferably incorporated. The necessary external connections of the shock absorber according to the invention are thus reduced to a minimum □ connectors for the mechanical fixing and given case for the power supply □. When using thermocouples on the one hand and an electric drive on the other hand, the control means may alternatively be implemented also be removed by the shock absorber in a separate control cabinet, or in a central control.

p0026Furthermore, the driving means is integrated in a housing of the shock absorber in an advantageous embodiment of a shock absorber according to the invention. Thus, not only the handling of the shock absorber according to the invention is easier and less error prone. At the same time potentially interfering effects on the connection between shock absorber and drive device can be effectively prevented.

p0027Starting from the known methods, the invention proposes that the throttle cross-section from outside of the shock absorber is changed by means of a remotely controllable drive means, the inventive method with an inventive method is executed and the aforementioned advantages also result.

p0028A refinement of the method provides that an operating temperature of the fluid and / or a pressure of the fluid in the working space is measured and the throttle cross section is determined and adjusted depending on the operating temperature and / or the pressure in the working space. The inventive method is particularly feasible with an inventive shock absorber according to claims 12 to 14 and has the advantages mentioned for this on.

p0029Preferably, in the context of a method according to the invention a change in the operating temperature and / or a change of the maximum pressure that occur during a cycle of attenuation is measured and adjusted to the throttle cross-section depending on the change, wherein the throttle cross section is set automatically. The inventive method is particularly advantageously applied when the manipulated variable describes not an absolute position of the actuator, but an incremental change in position, such as a rotation of a rotatable pressure pipe to a setting angle. In addition, when in a control device, the absolute position of the actuator is stored in each case, the assignment of a measured value of the change to a manipulated variable and dependent on this absolute value can be formulated. The automatic adjustment of the throttle cross section allows for automatic operation of a shock absorber under widely fluctuating temperatures, for example, under fluctuating load a stopping point in a conveyor.

embodiment

p0030The invention will be explained in more detail with reference to several embodiments which are illustrated in the drawings.

p0031It shows:<dl id="dl0001" compact="compact"><dt>Fig. 1</dt><dd>a longitudinal section through a first embodiment of a shock absorber,</dd><dt>Fig. 1A</dt><dd>a cross-section through the shock absorber according to <figref idrefs="f0001">Fig. 1</figref>.</dd><dt>Fig. 1b □ 1e</dt><dd>four views of the pressure tube of the shock absorber in accordance with <figref idrefs="f0001">Fig. 1</figref>.</dd><dt>FIG. 2</dt><dd>a longitudinal section through an alternative embodiment of a shock absorber,</dd><dt>Fig. 2A</dt><dd>a cross-section through the shock absorber according to <figref idrefs="f0002">FIG. 2</figref>.</dd><dt>Fig. 2b □ 2e</dt><dd>as <figref idrefs="f0001">Fig. 1b to 1e</figref>.</dd><dt>Fig. 2f</dt><dd>a longitudinal section through a slotted cap sleeve of the shock absorber <figref idrefs="f0002">FIG. 2</figref>.</dd><dt>Fig. 2g</dt><dd>a cross-section through a slotted cap sleeve of the shock absorber <figref idrefs="f0002">FIG. 2</figref>.</dd><dt>Fig. 3</dt><dd>a longitudinal section through a further alternative embodiment of a shock absorber,</dd><dt>Fig. 3a</dt><dd>an enlarged detail view of the throttle cross-section with a conical closing body,</dd><dt>Fig. 4</dt><dd>a longitudinal section through a further alternative embodiment of a shock absorber,</dd><dt>FIG. 4a</dt><dd>an enlarged detail view of a spherical closing body,</dd><dt>Fig.5</dt><dd>a longitudinal section through a further alternative embodiment of a shock absorber,</dd><dt>Fig. 5a</dt><dd>the throttle of the shock absorber from <figref idrefs="f0005">figure 5</figref></dd><dt>Fig. 6</dt><dd>a schematic diagram of the shock absorber from <figref idrefs="f0005">figure 5</figref>. </dd><dt>Fig. 7</dt><dd>a longitudinal section through a final alternative embodiment of a shock absorber,</dd><dt>Fig. 7a</dt><dd>the throttle of the shock absorber from <figref idrefs="f0007">figure 7</figref> and</dd><dt>Fig. 8</dt><dd>a schematic diagram of the shock absorber from <figref idrefs="f0007">figure 7</figref>,</dd></dl>

p0032one in <figref idrefs="f0001">Fig. 1</figref> illustrated shock absorber 1 comprises an outer cylindrical casing tube 2 and a coaxially therein and rotatable about the common central axis 3 is mounted, likewise cylindrical pressure pipe 4, in which a piston 5 in the axial direction supported at its outer surface radially sealed in the pressure tube 4 slidably. 5 to the piston a piston rod 6 is connected with one side, by an in<figref idrefs="f0001">Fig. 1</figref> left end not shown of the housing tube 2 is fluid-tight sealed led out. In the left end face 7 of the housing tube 2 is a plug 8 is inserted that closes the interior of the shock absorber 1 fluid-tight. A pin-shaped front part 9 of the plug 8 is torque firmly coupled with a further plug 10 which closes the system located inside the pressure pipe 4 first workspace 11th

p0033From the cross-sectional representation according to <figref idrefs="f0001">Fig. 1A</figref> it follows that in the housing tube 2, a groove-like overflow duct 12 which is introduced into the inner circumferential surface of the housing tube 2, is located. The overflow channel 12 extends almost over the entire length of the pressure tube 4, located at least up to the pressure in tube holes 13, which form a connection between the overflow 12 and the end on the piston rod side of the second working chamber fourteenth

p0034As in the <figref idrefs="f0001">Fig. 1b to 1e</figref> is shown, are located along four axially parallel to the outer surface 15 of the pressure tube 4 extending lines 16b to 16e mutually spaced orifices 17 in the form of bores having different diameters. The holes on each of the lines 16b-16e define in combination the effective throttle cross-section and thus determine the damping characteristics of the shock absorber. 1

p0035Based on the in <figref idrefs="f0001">Fig. 1</figref> Position of the piston 5 shown is in its further insertion into the housing tube 2, ie, and also into the pressure tube 4, through the choke openings 17, which just correspond to the overflow channel 12, displaced located in the working chamber 11 fluid, in particular hydraulic oil in the latter flows from there via the holes 13 into the working space 14 and a storage room, not shown, which is able to compensate by said penetrating into the shock absorber 1 volume of the retracting piston rod. 6 Typically, the memory space is filled with a foam material which acts as a kind of gas spring.

p0036As long as the piston has not yet 5 to 16e the leftmost orifice 17 reaches at the relevant line 16b, all throttle openings 17 of the respective active set and simultaneously act to define in the sum of the effective throttle cross-section. This reduced continuously, the more throttle openings are covered or run over with continued retraction of the piston 5 in the pressure pipe 4 and therefore no longer available for an outflow of fluid from the decreasing working chamber 11 available. Since the orifices 17 also to the right become smaller, the effective throttle cross section decreases with increasing immersion of the piston 5 continuously in the shock absorber. 1 The damping characteristics of the shock absorber 1 is thus the end of the damping process, ie before reaching the end stop, particularly "hard" to reduce possibly remaining energy reliably.

p0037By suitable arrangement and size selection of the orifices 17 within each of the defined by the lines 16b-16e series, the path dependence of the damping characteristic can be adjusted. For the same number of orifices 17, however, the characteristic remains the same. In order to still have influence possibilities, ie for example by initially quite soft damping characteristics (hole series in<figref idrefs="f0001">FIG. 1b and 1c</figref>) According to consistently harder damping characteristic <figref idrefs="f0001">Fig. 1e</figref> being able to change, the pressure tube 4 is rotatably mounted within the housing tube. 2 As drive means 18 is a front end disposed adjacent to the shock absorber 1 or the housing tube 2 electric motor. An output shaft 19 of the engine torque is firmly inserted into an adapted hole 20 in the plug. 8 In the case of circular cross-sections, the output shaft 20 can be glued in the bore 19; Alternatively, it is also possible to choose a non-circular shape matching the cross-section of the output shaft 19 and bore 20 in order to achieve a required for the torque transmitting form-fit connection. is not shown in this connection a torque support between a housing 21 of the drive device 18 and the casing pipe 2 of the shock absorber. The plug 8 is provided in sections with an external thread which cooperates with an internal thread in the associated section of the housing tube second This has the result that the stopper 8 during the adjustment between the four alternative variants of damping corresponding to the lines, as in the<figref idrefs="f0001">Fig. 1b to 1e</figref> shown, moved due to the completed 360-degree turn around the slope of the thread in the axial direction, but this is no further influence. In the case of bonded output shaft 19 of the electric motor, the output shaft must have 19 over a sufficient axial play. It goes without saying that the drive device 18 has suitable means to 16b-16e to ensure the exact positioning of the lines along the center line of the overflow 12th A pivoting of the pressure tube 4 relative to the housing tube 2 has in this case each occur exactly in 90 ° increments.

p0038If a damping process is complete and the piston 5 has reached its end position, it is the force of a return spring, which is compressed to retract the piston 5 is moved back towards its initial position. This assumes of course that, for example, one on a roller conveyor moving Pallet, which is accrued for braking on a stop element of the piston rod has been removed, or may be, but moved back by the force of the return spring. When pushing back the piston 5, the hydraulic oil does not have the reverse path through the overflow 12 and the throttle openings 17 take, but may be substantially without throttling effect by in the flask 5 return hole 23 and a perpendicular thereto extending transverse bore 24 from the working space 14 in the working chamber 11 to overflow. To prevent a short circuit through the return bore 23 during retraction of the piston 5, is located in an enlarged end portion of the piston 5 a valve ball 25, operating at a pressure gradient between the working chamber 11 and the working chamber 14 to the return bore 23 tightly closes.

p0039The difference between the alternative embodiment of a shock absorber 1 'according to <figref idrefs="f0002">FIG. 2</figref> with respect to the in <figref idrefs="f0001">Fig. 1</figref> embodiment shown is that the overflow channel 12 is not arranged as a groove in the inner surface of the housing tube 2 ', rather than slot 26 (see. also <figref idrefs="f0002">Fig. 2g</figref>) In a coupling sleeve 27 which is located between the pressure pipe 4 and the casing pipe 2 '(see FIG. <figref idrefs="f0002">Fig. 2A</figref>). The cap sleeve assumes towards the orifices 17 of the pressure tube 4 has the same sealing function as otherwise the inner circumferential surface of the housing tube 2 in the embodiment of<figref idrefs="f0001">Fig. 1</figref>, That is only the number of orifices 17, which just corresponds to the slot 26 in the cap sleeve 27 is effective in each case as throttle opening. The union sleeve 27 is in relation to the housing tube 2 'in a rotationally mounted, whereas the pressure pipe 4 - again by means of the driving means 18 - relative to the housing tube 2' and the pressure tube 4 is rotated to select between the four variants of the damping characteristic in accordance with the<figref idrefs="f0002">Fig. 2b to 2e</figref> being able to change. Incidentally, the structure and operation of the shock absorber 1 'coincident according to the shock absorber 1<figref idrefs="f0001">Fig. 1</figref>,

p0040The shock absorber 1 'according to <figref idrefs="f0003">Fig. 3</figref> has a pressure tube 4 "that has not contained in the surface orifices, rather the pressure tube 4 is" closed in the region of the working space 11 running. The end-side closure on the side opposite the piston 5 side of the pressure tube 4 "is formed by an orifice plate 28 having a central bore 29th the in the housing tube 2" screwed plug 8 ", has a throttle point 30 in the form of a truncated cone, which in the bore 29 is disposed. in the area of ​​the frustoconical choke tip 30 go from the bore 29, two radially extending cross-bores 31 from the "lead, which as a shallow groove in the inner surface 32 of the housing tube 2 'in each case in an overflow channel 12 is formed. the overflow of the hydraulic oil from the working chamber 11 into the working chamber 14 is carried out by those released from the choke tip 30 remaining cross section of the bore 29 and then through the cross bores 31 and the channels 12 'in the opposite workspace 14th

p0041The adjustment of the damping characteristic, which does not have path-dependency is given by more or less wide advance of the choke tip 30 into the bore 29, since the effective throttle cross-section between the bore 29 and the transverse bores 31 is changed thereby. The axial displacement of the throttle top 30 is effected by a rotary movement of the plug 8 ", which with its external thread into an adapted female thread in the housing tube 2 'is stored. The output shaft 19 of the executed as an electric motor drive device 18 is a torque-resistant "coupled. A torque arm between the engine and the housing pipe 2" with the plug 8 is again not shown.

p0042The embodiment of the shock absorber 1 '' 'according to the <figref idrefs="f0004">FIGS. 4 and 4a</figref> differs only in that of the variant according to <figref idrefs="f0003">FIGS. 3 and 3a</figref>When the throttle tip 30 is formed there by a valve ball 33, which is the ending with a radially extending face 34 plug 8 'upstream. The valve ball 33 is not connected to the plug 8 '' ', but is prevented from 35 of the bore 29 at a creeping out by the conical shape of the piston 5 facing the front portion. Acting as a stop face end face 34 of the plug 8 '' 'is determined according to their axial position, the position of the valve ball 33, in which it can move under the action of the pressurized hydraulic oil in the working chamber 11 at most to the right. This results in a more or less large throttle cross-section 36 is shared between the valve ball 33 and the circumferential edge of the orifice.

p0043Again, there is a twisting of the plug 8 '' 'with the aid of the drive device 18, since the stopper with its external thread into a corresponding internal thread is mounted in the housing tube 2'.

p0044The in <figref idrefs="f0005">figures 5</figref>. <figref idrefs="f0006">5a and 6</figref> illustrated shock absorber according to the invention 1 □ consists of an outer cylindrical casing tube 2 and a in this coaxially mounted and about the common central axis 3 rotating, likewise cylindrical pressure pipe 4. In the pressure pipe 4, a piston 5 on its outer circumferential surface 6 is sealed radially and in the axial direction 38 slidably. The piston 5 has a piston rod 6 is connected, the only by (<figref idrefs="f0006">figure 6</figref> illustrated) left end of the housing 2 fluid-tightly sealed led out, and terminates in a stop element. 39

p0045Compared to the piston rod 6, the piston 5 is limited to the pressure tube 4 and a throttle a first working chamber 11 which is filled with a hydraulic fluid, not shown. At the right end face of a plug 8 is screwed into the housing 2 in the axial direction 38, of the first working chamber 11 fluid-tight manner to a. The choke consists of a supported in the axial direction 38 in the housing 2 further plug 10 with two radially extending transverse bores 31 and one affixed to the plug 8, truncated cone-shaped front part 9. By turning of the plug 8 about the central axis 3 is connected via the axial position of truncated cone-shaped front portion 9 in the further plug 10, the effective opening cross-section of the throttle can be set precisely for the flowing out of the first working chamber 11 in the transverse bores 31 hydraulic oil.

p0046Between the pressure pipe 4 and the housing 2 is not shown, likewise cylindrical and arranged in the axial direction 38 slotted cap sleeve. The transverse bores 31 of the other plug 10 open into an annular space 39 between the further plug 10 and the housing 2. The annular space 40 is about acting as overflow slot 26 in the cap sleeve 27 with a second working space 14 and storage space between the left end side and the piston 5. to reset the piston 5 in the in<figref idrefs="f0005">figure 5</figref> Standby position shown 5 is supported via a arranged in the first working chamber 11 formed as a helical spring return spring 22 at the other stopper 10 of the pistons. In addition, the second working chamber 14 is filled with a foam material, not shown, compressible to compensate for the volume of the entering piston 5 can.

p0047Upon the return of the piston 5, the hydraulic oil does not have to take the reverse path through the overflow and the throttle, but can pressure over flow through a mounted in the piston 5 return hole 23 from the second working chamber 14 in the first working chamber 11th A short-circuit through the return bore 23 in the opposite direction is prevented with a designed as a valve ball check valve 25.

p0048The plug 8 is connected via a coupling 41 to be axially displaceable to an output shaft 19 of an electric motor used as the driving means 18 and driven by means of this electric motor. The electric motor is powered via a power cable 42 with power and controlled through a control signal line 43rd

p0049The casing tube 2 of the shock absorber 1 □ diameter of the right end side of two mutually e-g compared arranged, extending in the axial direction 38 blind bores 44 which terminate near the annulus 40th In this blind holes 44, two thermocouples 45 are used as a measuring device, the measurement signal is then passed on via a sensor cable 46th (In<figref idrefs="f0005">figure 5</figref> is simplistic just one of the blind holes 44 and a thermocouple 45 shown with sensor cable. 46)

p0050As in <figref idrefs="f0006">figure 6</figref> shown, the power cable 42 and the control signal line 43 of the driving device 18 and the sensor cable 46 of the measuring device are connected to a control device 47th The controller 47 is a commercially available, programmable industrial computer with an A / D converter 48 for the connection of the measuring device and a line card 49 for the electric motor.

p0051In the control device 47 the required angular position of the plug 8 is stored as a function of the operating temperature of the fluid and of the pulse of light incident on the stop element 39, for example on a roller conveyor track conveyed. At the controller 47, the pulse is adjustable by means of a control panel, not shown.

p0052For initialization of the shock absorber 1 □ the controlling means 47 the plug 8 to the stop in the housing tube 2 into it. Out of the set pulse and the measured operating temperature of the fluid on the basis of a control program stored dependency determines the required angular position of the plug 8, the electric motor controls accordingly and saves the angular position reached in a storage area. When changing the operating temperature, the control program again determines the required angular position and controls after.

p0053The control device 47 is connected via an unillustrated bus to a likewise not illustrated system for the production controller. The bus one hand pulse data to the controller 47 and the other part status messages to the control device 47 to the superordinate system can be transmitted.

p0054In a not shown embodiment of the shock absorber according to the invention encapsulated actuating and control means are integrated into the housing. The encapsulated shock absorber still has only one terminal for the bus system via which the shock absorber is also supplied with electrical energy.

p0055The <figref idrefs="f0007">Figures 7 and 7a</figref> show a last embodiment of a shock absorber 1 according to the invention^VWhich, although similar to the shock absorbers 1 □ from <figref idrefs="f0005">figure 5</figref> is constructed, the measuring device, however, consists of a pressure sensor 50 in the form of a piezo-electric pressure sensor, which by an adapted bore in the housing 2 of the shock absorber 1^V is guided and extends into the working space 11 thereof.

p0056Based on the pressure sensor 50, the pressure curve is measured in each case during a damping process over time, wherein in each case the maximum pressure of the pressure curve, which is typically a value between 400 bar and may be 500 bar, is used as a value for controlling the drive means 18th Exceeds the maximum pressure of a specific selectable upper threshold value, the damping constant is reduced accordingly by driving the drive means 18th If it falls below a lower threshold value of the pressure, the damping is increased.

p0057<figref idrefs="f0007">7a</figref> shows an enlarged detail from <figref idrefs="f0007">figure 7</figref>In which the arrangement of the pressure sensor 50 in the housing 2 of the shock absorber 1^V is clearly visible.

p0058Finally goes <figref idrefs="f0008">figure 8</figref> a schematic diagram of the shock absorber 1^V forth, in addition to the shock absorbers 1^V also the drive means 18 and the control device are shown 47th The shock absorber according to the invention 1^V has both a thermocouple 45 and a pressure sensor 50, both of which are in each case two sensor cable 46, 46 connected to the control device 47th

LIST OF REFERENCE NUMBERS

p0059<dl id="dl0002" compact="compact"><dt>1,1 ', 1 ", 1"', 1 "", 1^V</dt><dd>shock absorber</dd><dt>2,2 ', 2 "</dt><dd>housing tube</dd><dt>. 3</dt><dd>central axis</dd><dt>4,4 "</dt><dd>pressure pipe</dd><dt>. 5</dt><dd>piston</dd><dt>. 6</dt><dd>piston rod</dd><dt>. 7</dt><dd>front</dd><dt>8.8 ", 8" '</dt><dd>to stuff</dd><dt>. 9</dt><dd>front</dd><dt>10th</dt><dd>to stuff</dd><dt>11th</dt><dd>working space</dd><dt>12.12 "</dt><dd>overflow</dd><dt>. 13</dt><dd>drilling</dd><dt>14th</dt><dd>working space</dd><dt>15th</dt><dd>lateral surface</dd><dt>16th</dt><dd>line</dd><dt>17th</dt><dd>throttle opening</dd><dt>18th</dt><dd>drive means</dd><dt>19th</dt><dd>output shaft</dd><dt>20th</dt><dd>drilling </dd><dt>21st</dt><dd>housing</dd><dt>22nd</dt><dd>return spring</dd><dt>23rd</dt><dd>Return hole</dd><dt>24th</dt><dd>transverse bore</dd><dt>25th</dt><dd>valve ball</dd><dt>26th</dt><dd>slot</dd><dt>27th</dt><dd>Cap sleeve</dd><dt>28th</dt><dd>orifice</dd><dt>29th</dt><dd>drilling</dd><dt>30th</dt><dd>throttle tip</dd><dt>31st</dt><dd>transverse bore</dd><dt>32nd</dt><dd>lateral surface</dd><dt>33rd</dt><dd>valve ball</dd><dt>34th</dt><dd>face</dd><dt>35th</dt><dd>section</dd><dt>36th</dt><dd>Throttle cross-section</dd><dt>37th</dt><dd>circumferential edge</dd><dt>38th</dt><dd>axially</dd><dt>. 39</dt><dd>stop element</dd><dt>40th</dt><dd>annulus</dd><dt>41st</dt><dd>coupling </dd><dt>42nd</dt><dd>power cable</dd><dt>43rd</dt><dd>Control signal line</dd><dt>44th</dt><dd>blind hole</dd><dt>45th</dt><dd>thermocouple</dd><dt>46, 46 □</dt><dd>sensor cable</dd><dt>47th</dt><dd>controller</dd><dt>48th</dt><dd>A / D converter</dd><dt>49th</dt><dd>line card</dd><dt>50th</dt><dd>pressure sensor</dd></dl>