EP2725236B1 - Telesopic unit with additional function - Google Patents

Description

The present invention relates to a telescoping unit for telescoping means arranged on machines, comprising at least one telescopic hydraulic cylinder and at least one further hydraulic system (18), wherein the telescopic hydraulic cylinder (11) at least one in the cylinder chamber of the telescopic hydraulic cylinder arranged axially movable and connected to a piston rod piston, wherein the bottom side of the Teleskophydraulikzylinders is fixed to a bearing associated with the machine and at the exposed end of the piston rod, the at least one further hydraulic system is arranged, which is acted upon by a hydraulic medium with hydraulic energy wherein by placing the piston in the telescopic hydraulic cylinder, the hydraulic energy , Derived by the change in the operating condition and the resulting hydraulic pressure difference of the hydraulic medium in at least a first buffer and ges is accumulated, so as to pressurize the hydraulic system with the hydraulic energy from the first buffer in a case of need and wherein after consumption, the hydraulic medium stored in the hydraulic medium, the hydraulic medium is passed from the hydraulic system in at least a second buffer, and from there is returned to the telescopic hydraulic cylinder, where it is again subjected to hydraulic energy or supplied to a hydraulic primary circuit of the telescoping unit.

When parts of machines are telescopically connected and these parts are telescoped by means of a telescopic hydraulic cylinder, it is necessary to allow another function at the exposed end of the telescopic hydraulic cylinder, a hose guide (flange, drum, etc.), a separate hydraulic unit or to install a hydraulic cylinder with an internal oil passage.

For example, a mobile crane with telescopic boom, with small counterweight can lift large loads, the boom must be as small as possible. Especially with larger working radii, it is necessary to keep the weight of the outrigger parts projecting beyond the support base as small as possible. Even when transporting a mobile crane, it is cheaper if the lowest possible weight has to be moved.

Due to this, in the majority of single-cylinder telecopying units with a securing and bolting unit - hereinafter referred to as SVE - installed in such mobile cranes. In this system, a telescopic box is secured to the telescopic hydraulic cylinder using the SVE and then unbolted from the surrounding telescopic box. Now, the telescopic hydraulic cylinder with the telescopic box extends to the desired length and bolted the telescopic boxes together and unlocks the telescopic hydraulic cylinder from just moved telescope box. This process is repeated until all telescopic boxes of a telescopic boom have reached their working position. To reduce the boom side torque of the telescopic hydraulic cylinder is fully retracted to a starting position. Only now can the extended boom be loaded to the maximum.

In these systems, the SVE is located at the exposed end of the telescopic hydraulic cylinder. The hydraulic energy is therefore also needed at this point, so that the boxes can be unlocked or locked. The disadvantage here is that exactly this point is driven back and forth with the telescopic hydraulic cylinder. Thus, the SVE is not directly accessible for hydraulic lines.

From the prior art, at least two approaches are known to ensure the supply of oil and thus the supply of hydraulic energy: - A parallel to the telescopic hydraulic cylinder, by means of energy chain, guided hydraulic hoses.

The disadvantage here is that the leadership of these hydraulic hoses requires a lot of space, which is not available especially for smaller telescopic boxes. - A telescopic hydraulic line that passes directly through the telescopic hydraulic cylinder to direct hydraulic oil to the SVE.

Although this type of oil guide saves space, but has the disadvantage that such an arrangement is expensive and prone to failure (pressure transmission in the bushing lead to problems). In the event of an accident, this can be remedied only with a considerable, temporal and associated financial expense. For repair, the entire telescopic hydraulic cylinder must be removed and disassembled.

The publication DE 10 2009 048 763 A1 also proposes as another way of supplying additional consumers to a telescopic cylinder for telescopic shots of a mobile crane with pressurized oil, to connect the additional consumer with at least one cylinder chamber of the telescopic cylinder and over here with pressurized oil. The additional consumers are connected via buffer and non-return valves both on the high-pressure side and on the low-pressure side with the telescoping cylinder and there with a cylinder tube of the telescoping cylinder. Here, the consumers move with the telescoping cylinder.

It is therefore an object of the present invention to provide a telescoping unit of the type described above, with which the above-mentioned disadvantages can be overcome.

This object is achieved by the features specified in claim 1, in particular in that the supply of the hydraulic system with the hydraulic medium takes place through the piston rod of the telescopic hydraulic cylinder.

According to an advantageous embodiment, the hydraulic system, the control unit, as well as the first and second latches along with supply and return lines and check valves are designed to be movable together with the telescopic hydraulic cylinder.

Further, it is provided that the control unit, and the first and second latches are arranged together with supply and return lines and check valves at the exposed end of the telescopic hydraulic cylinder and thus at the exposed end of the piston rod.

According to a further advantageous embodiment of the telescoping unit according to the invention, pressures in the first and second latches are measured with pressure transducers and the measured pressure data are processed by a computer or sent directly to a control unit, the control unit causes the first latches to be automatically charged with the hydraulic medium becomes as soon as the pressure of the hydraulic medium in the telescopic hydraulic cylinder is higher than the pressure of the hydraulic medium in the first intermediate storage and, that the second buffer automatically discharged from the hydraulic medium when the pressure of the hydraulic medium in the telescopic hydraulic cylinder is smaller than the pressure of the hydraulic medium in the second buffer

For example, during load changes occur high and low pressures in the hydraulic system. The buffers act as storage tanks, which buffer the high and low pressures in the hydraulic system. The process of loading and unloading the buffer can, depending on the version, even occur at the same time.

In the telescoping unit according to the invention, it is provided to connect at least two buffer stores, one each for the high pressure and one for the low pressure, which are in operative connection with the hydraulic system (for example an SVE) with the telescoping unit hydraulically. The number of buffers should not be limited to this.

The supply of hydraulic power to the hydraulic system is ensured by the intermediate storage. The latches may be formed here as a bladder accumulator or piston accumulator or spring accumulator. The memory for the high pressure and for the different low pressure to be connected via check valves directly to the telescopic hydraulic cylinder.

In a particularly preferred embodiment of the telescoping unit according to the invention, the first buffer for the high pressure is automatically filled, or pressurized via the hydraulic medium, that is charged with hydraulic energy when the hydraulic pressure in the bottom space of the telescopic hydraulic cylinder is higher than the pressure in the first intermediate store itself. This can be the case, for example, during telescoping, under static load or during extension of the telescopic hydraulic cylinder in the bolted and secured state until it stops.

In a further advantageous embodiment of the telescoping unit according to the invention, the second buffer is automatically discharged from the hydraulic medium as soon as the pressure of the hydraulic medium in the telescopic hydraulic cylinder is smaller than the pressure of the hydraulic medium in the second Buffer. This may for example be the case when the bottom-side valve of the telescopic hydraulic cylinder is opened (ie, the friction is greater than the static load) or the telescopic hydraulic cylinder is retracted in the bolted and secured state to the stop.

So that the functionality of the hydraulic system - for example, the SVEs can be ensured, the pressures in the buffers can be measured with pressure transducers and processed in a controller.

In a further preferred embodiment of the telescoping unit according to the invention, the control unit and / or the computer controls the telescoping unit as a function of the pressure data determined and sent to it by the pressure transducers in order to load or load the buffer memories with hydraulic energy by changing the driving condition discharged.

This should also be possible that the controller controls the hydraulic system via the pressure transducer to pressurize the hydraulic system with hydraulic energy as soon as the controller determines in the first latch for the placement of the hydraulic system insufficient amount of hydraulic energy. The pressure transducers are designed so that they can convert the pressure of the hydraulic medium into a proportional electrical signal.

• X -Wege ist die Anzahl der Verbindungen über die Rückschlagventile in die Zylinderräume des Telekophydraulikzylinders.
• Y-Raum ist die Anzahl der Zylinderinnenräume des Teleskophydraulikzylinders, wobei Ein-Raum die Boden- oder die Stangenseite darstellt. Zwei-Raum stellt die Boden- und die Stangenseite dar. Die normalen Zylinderanschlüsse zum Fahren des Zylinders werden hierbei nicht mitgezählt.

For a better understanding, an "X-way Y-space circuit is defined as:

• X-paths is the number of connections via the check valves in the cylinder chambers of the Telekophydraulikzylinders.
• Y-space is the number of cylinder interiors of the telescopic hydraulic cylinder, with one-space representing the bottom or the rod side. Two-chamber represents the bottom and the rod side. The normal cylinder connections for driving the cylinder are not counted here.

In another embodiment, the supply of the hydraulic system with the hydraulic medium via the bottom side by the piston rod of the telescopic hydraulic cylinder in a hydraulic two-way single-space circuit.

It is particularly advantageous to process these with the aid of the pressure sensor signals detected by the pressure transducer in the computer or in the control unit itself so as to use the values determined for setting electric valves (poppet valves) via which the loading and unloading of the intermediate memory is regulated or controlled can be controlled. This could replace conventional check valves. As a result, not only the loading and unloading of the buffer can be controlled, but it is also possible to limit the maximum pressure in the memories. Furthermore, when loading the buffer a certain pressure difference (Delta-P) can be maintained. Thus, the removable power for the hydraulic system is fixed and there is no need for any further pressure adjustment. Instead of the electric valves and hydraulically controlled valves can be used in a further embodiment.

It is also advantageous if the oil supply for the hydraulic system via the piston rod and bottom side of the Teleskophydraulikzylinders in a hydraulic three-way two-space circuit, the hydraulic system is connected to the piston rod of the telescopic hydraulic cylinder and the return oil only in the Bottom side can be passed. Also, the return oil could only be directed into the piston rod side.

Furthermore, the oil supply for the hydraulic system can be done via the piston rod and bottom side of the telescopic hydraulic cylinder in a hydraulic three-way two-space circuit, the hydraulic system is connected to the piston rod of the Teleskophydraulikzylinders and removed the pressure oil only from the rod side becomes.

• Fig. 1 die schematische Schaltskizze der erfindungsgemäßen Teleskopiereinheit in einer teilweise geschnittenen Ansicht, mit einer Ölversorgung für die Hydraulikanlage, die über die Stangenseite des Teleskophydraulikzylinders in einer hydraulischen Zwei-Wege-Ein-Raum-Schaltung erfolgt;
• Fig. 2 die schematische Schaltskizze der erfindungsgemäßen Teleskopiereinheit in einer teilweise geschnittenen Ansicht, mit einer Ölversorgung für die Hydraulikanlage, die über die Stangenseite des Teleskophydraulikzylinders in einer hydraulischen Zwei-Wege-Zwei-Raum-Schaltung erfolgt;
• Fig. 3 die schematische Schaltskizze der erfindungsgemäßen Telekopiereinheit, wobei die Hydraulikanlage an der Stangenseite des Teleskopierzylinders angeschlossen ist;
• Fig. 4 die schematische Schaltskizze der erfindungsgemäßen Telekopiereinheit gemäß Fig. 2, mit gedrehten Lade- bzw. Entladeanschlüssen an der Kolbenstangenseite;
• Fig. 5 die schematische Schaltskitzze der erfindungsgemäßen Teleskopiereinheit gemäß Fig. 1, wobei der Anschluss hier auch durch die Kolbenstange, aber nicht zur Bodenseite des Teleskopzylinders, sondern zu dessen Stangenseite erfolgt;
• Fig. 6 die schematische Schaltskizze der erfindungsgemäßen Teleskopiereinheit in einer teilweise geschnittenen Ansicht, mit einer Ölversorgung für die Hydraulikanlage, die über die Kolbenstangen- und Bodenseite des Teleskophydraulikzylinders in einer hydraulischen "drei Wege, zwei Raum" Schaltung erfolgt; die Hydraulikanlage ist an der Kolbenstange des Teleskopierzylinders angeschlossen, wobei im Unterschied zu Fig. 3 das Rücköl nur in die Bodenseite geleitet wird;
• Fig. 7 die schematische Schaltskitzze der erfindungsgemäßen Teleskopiereinheit gemäß Fig. 3, wobei hier das Rücköl nur in die Stangenseite geleitet wird;
• Fig. 8 die schematische Schaltskizze der erfindungsgemäßen Teleskopiereinheit in einer teilweise geschnittenen Ansicht, mit einer Ölversorgung für die Hydraulikanlage, die über die Kolbenstangen- und Bodenseite des Teleskophydraulikzylinders in einer hydraulischen "drei Wege, zwei Raum" Schaltung erfolgt; die Hydraulikanlage ist an der Kolbenstange des Teleskopierzylinders angeschlossen, wobei im Unterschied zu Fig. 3 das Drucköl nur aus der Bodenseite entnommen wird;
• Fig. 9 die schematische Schaltskitzze der erfindungsgemäßen Teleskopiereinheit gemäß Fig. 3, wobei hier das Drucköl nur aus der Bodenenseite entnommen wird.

The invention is explained in more detail below by means of exemplary embodiments with reference to the accompanying drawings. The figures show:

• Fig. 1 the schematic circuit diagram of the telescoping unit according to the invention in a partially sectioned view, with an oil supply for the hydraulic system, which takes place via the rod side of the Teleskophydraulikzylinders in a hydraulic two-way single-room circuit;
• Fig. 2 the schematic circuit diagram of the telescoping unit according to the invention in a partially sectioned view, with an oil supply for the hydraulic system over the rod side of the telescopic hydraulic cylinder takes place in a hydraulic two-way two-space circuit;
• Fig. 3 the schematic circuit diagram of the invention Telekopiereinheit, wherein the hydraulic system is connected to the rod side of Teleskopierzylinders;
• Fig. 4 the schematic circuit diagram of the Telekopiereinheit according to the invention Fig. 2 with rotated charge and discharge ports on the piston rod side;
• Fig. 5 the schematic Schaltskitzze the telescoping unit according to the invention according to Fig. 1 , wherein the connection also takes place here by the piston rod, but not to the bottom side of the telescopic cylinder, but to the rod side;
• Fig. 6 the schematic circuit diagram of the telescoping unit according to the invention in a partially sectioned view, with an oil supply for the hydraulic system, which takes place via the piston rod and bottom side of the Teleskophydraulikzylinders in a hydraulic "three way, two room"circuit; the hydraulic system is connected to the piston rod of the telescoping cylinder, unlike Fig. 3 the return oil is only directed to the bottom side;
• Fig. 7 the schematic Schaltskitzze the telescoping unit according to the invention according to Fig. 3 , whereby here the return oil is led only in the rod side;
• Fig. 8 the schematic circuit diagram of the telescoping unit according to the invention in a partially sectioned view, with an oil supply for the hydraulic system, which takes place via the piston rod and bottom side of the Teleskophydraulikzylinders in a hydraulic "three way, two room"circuit; the hydraulic system is connected to the piston rod of the telescoping cylinder, unlike Fig. 3 the pressure oil is taken only from the bottom side;
• Fig. 9 the schematic Schaltskitzze the telescoping unit according to the invention according to Fig. 3 , where here the pressure oil is taken only from the bottom side.

Like in the Fig. 1 illustrated, the telescoping unit 10 consists essentially of at least one telescopic hydraulic cylinder 11 and at least one axially movable in the cylinder tube 12 of the telescopic hydraulic cylinder 11 and connected to a piston rod 13 piston 14. The bottom side 15 of the telescopic hydraulic cylinder 11 is at one of a machine or a part the machine (not shown) associated bearing (not shown) attached. At least one hydraulic system 18 is assigned to the free end of the telescoping unit 10.

The hydraulic system 18 is formed in this embodiment as SVE. In For example, in other embodiments, the hydraulic system 18 may be configured to install / remove implements. The bolting and Entbolzen of equipment, for example, for turning, closing and opening of devices such as pliers, grippers, loading troughs and lifts, are conceivable. For this purpose, a hydraulic medium, acted upon by hydraulic energy and forwarded to the hydraulic system 18.

The hydraulic system 18 is, as in Fig. 1 shown connected to the piston rod side 16 of the telescopic hydraulic cylinder 11 via a line 19. The line 19 has a fork 20, which divides the line 19 into a feed line 21 and a return line 22. So that the hydraulic medium can flow in each case only in a predetermined direction in the feed line 21 and the return line 22, correspondingly designed valves 23 and 24 are provided. The valves 23 and 24 are formed in this embodiment as check valves.

In the following, the path of the hydraulic medium in the supply line 21 after the check valve 23 in the direction of the hydraulic system 18 is described first. The check valve 23 prevents the unwanted reflux of the hydraulic medium from the supply line 21 back to the piston rod side 16 of the telescopic hydraulic cylinder 11. The supply line 21 is associated with a bypass 25 which is connected to a first latch 26. The buffer 26 is designed as a bladder accumulator in this embodiment.

Due to the changing operating conditions, there are differences in pressure in the telescopic hydraulic cylinder 11 and thus also in the supply line 21. These pressure differences arise, for example, when loads are driven or when driven against Verbolzungslöcher or end stops and the like. Even if the load remains constant, different hydraulic pressures in the telescopic hydraulic cylinder 11 result from the different ground to ring surface ratios. These pressure differences represent an energy potential that can be used for additional work. The higher pressures in the hydraulic fluid are now passed through the bypass 25 in the buffer 26 and stored until further notice.

The supply line 21 is connected to a control unit 27. The control unit 27 is in turn connected to the hydraulic system 18 via the supply line 21a. The Control unit 27 detects and regulates the need for hydraulic energy and provides it to the hydraulic system 18, if necessary, from the buffer 26 is available.

After completed work, the "relaxed" hydraulic medium from the hydraulic system 18 is now directed into a return line 22a. The return flow of the hydraulic medium is regulated by the control unit 27 connected to the return line 22a. The expanded hydraulic medium is passed via a bypass 25a into a second intermediate store 28 with a hydraulic medium having a lower pressure than the first intermediate store 26 and stored therebetween. A backflow of the hydraulic medium by the control unit 27 and then further into the hydraulic system 18 is avoided by the control unit 27. The check valve 24 is connected to the supply line 19, from where the hydraulic medium is pushed back into the cylinder chamber 12 at the appropriate opportunity.

The hydraulic system 18, the control unit 27, and the latches 26, 28 together with the supply and return lines 19, 21, 21 a and 22, 22 a and the check valves 23 and 24 are formed movable together with the telescopic hydraulic cylinder 11. The hydraulic system 18 can be stored floating.

The hydraulic medium is stored in a reservoir 29, from where it is provided by means of a hydraulic pump 30 via adjusting and control means 31 to the telescopic hydraulic cylinder 11.

The Fig. 1 shows the telescoping unit 10 according to the invention in an embodiment in which the supply of the hydraulic system 18 with a hydraulic medium through the piston rod 13 with the bottom side of the telescopic hydraulic cylinder 11, with a hydraulic two-way one-space circuit. The hydraulic medium can be passed from the piston rod side 16 via a return line 32 to the adjusting and control means 31, from where it is pumped back into the reservoir 29.

The Fig. 2 also shows an embodiment of the telescoping unit 10 according to the invention. The hydraulic system 18 is supplied with a hydraulic medium, as in Fig. 1 represented, also by the piston rod 13 to the bottom and rod side 15 and 16 of the telescopic hydraulic cylinder 11. In contrast to the Fig. 1 For example, the embodiment is designed as a two-way hydraulic two-space circuit.

In another embodiment, not shown, the check valves 23, 24 and 37, 38 are replaced by electric seat valves. These electric seat valves are then controlled by an electrical control, taking into account the pressure transducer signals of the pressure transducer 42, 42 a.

The Fig _. 3 also shows an embodiment of the telecopying unit 10 according to the invention. The supply of the hydraulic system 18 with a hydraulic medium takes place, as in the Fig. 2 represented, also by the piston rod 13 to the bottom and rod side 15, 16 of the telescopic hydraulic cylinder 11. In contrast to the illustration in Fig. 2 This embodiment is designed as a hydraulic four-way two-space circuit.

The Fig. 4 also shows an embodiment of the telescoping unit 10 according to the invention. The hydraulic system 18 is supplied with a hydraulic medium, as in FIG Fig. 2 also represented by the piston rod 13 to the bottom and rod side 15, 16 of the telescopic hydraulic cylinder 11. The embodiment is, as in Fig. 2 , designed as a hydraulic two-way two-space circuit. But unlike Fig. 2 Here are the charge-discharge lines connected to the piston rod 13 rotated. Thus, the hydraulic medium is pressed from the piston rod side 16 in the memory 26 and from the memory 28, the return takes place in the bottom side 15th

The Fig. 5 shows the telescoping unit 10 according to the invention in a further embodiment, in which the supply of the hydraulic system 18 with a hydraulic medium, by the piston rod 13 to the piston rod side 16 of the telescopic hydraulic cylinder 11, with a "two-way single-space circuit".

The Fig. 6 shows the telescoping unit 10 according to the invention in a further embodiment in the supply of the hydraulic system 18 with a hydraulic medium, analog Fig. 3 , So by the piston rod 13, takes place. In this variant, the medium from the reservoir 26 can only flow back into the bottom side 15 via the valve 24. Valve 38 is not installed. This is also a "three-way two-space circuit.

The Fig. 7 shows the telescoping unit 10 according to the invention in a further embodiment in the supply of the hydraulic system 18 with a hydraulic medium, analog Fig. 3 , he follows. In this variant, the medium from the reservoir 26 can only flow back into the rod side 16 via the valve 38. Here valve 24 is not installed. It is also a "three-way two-space circuit".

The Fig. 8 shows the telescoping unit 10 according to the invention in a further embodiment in the supply of the hydraulic system 18 with a hydraulic medium, analog Fig. 3 , he follows. In this embodiment, the reservoir 26 is pressurized only via the valve 23 from the bottom side 15. Here valve 37 is not installed. It is also a "three-way two-space circuit".

The Fig. 9 shows the telescoping unit 10 according to the invention in a further embodiment in the supply of the hydraulic system 18 with a hydraulic medium, analog Fig. 3 , he follows. In this circuit form, the pressure supply of the memory 26 takes place only via the valve 37 and only from the rod side 16. There is no charging connection to the bottom side 15. Again, there is a "three-way two-space circuit".

LIST OF REFERENCE NUMBERS

• 10 telescope unit
• 11 Telescopic hydraulic cylinders
• 12 cylinder tube
• 13 piston rod
• 14 pistons
• 15 bottom side
• 16 piston rod side
• 18 hydraulic system
• 19 line
• 20 bifurcation
• 21, 21a supply line
• 22, 22a return line
• 23 valve
• 24 valve
• 25, 25a bypass
• 26 cache
• 27 control unit
• 28 cache
• 29 storage tank
• 30 pump
• 31 Adjusting agent / control agent
• 32 return line
• 33 bar side
• 34 axial direction / arrow
• 35 line
• 36 line
• 37 valve
• 38 valve
• 39 cache
• 40 buffers
• 41, 41a bypass line
• 42, 42a pressure transducer

Claims (19)

1. Telescopic unit (10) for telescoping means arranged on machines, comprising at least one telescopic hydraulic cylinder (11) and at least one additional hydraulic system (18), wherein the telescopic hydraulic cylinder (11) comprises at least one piston (14) arranged to be axially movable in the cylinder chamber of the telescopic hydraulic cylinder (11) and connected to a piston rod (13), wherein a bottom side (15) of the telescopic hydraulic cylinder (11) is configured to be fixable to a bearing allocated to the machine, and the at least one additional hydraulic system (18) is arranged on the exposed end of the piston rod (13) and is energised with hydraulic energy via a hydraulic medium, wherein by adjusting the piston (14) in the telescopic hydraulic cylinder (11), the hydraulic energy, which comes from by the change in the operating state and the resulting difference in hydraulic pressure of the hydraulic medium, is diverted to and stored in at least one first intermediate reservoir (26, 39), in order thereby to energise the hydraulic system (18) with the hydraulic energy from the first intermediate reservoir (26, 39) if necessary, and wherein, after consumption of the hydraulic energy stored in the hydraulic medium, the hydraulic medium is fed from the hydraulic system (18) into at least one second intermediate reservoir (28, 40), and from there is fed into the telescopic hydraulic cylinder (11), where it is again energised with hydraulic energy or conveyed to a primary hydraulic circuit of the telescopic unit (10), wherein the hydraulic system (18) is supplied with the hydraulic medium by the piston rod (13) of the telescopic hydraulic cylinder (11).
2. Telescopic unit as claimed in claim 1, characterised in that the pressures in the first and second intermediate reservoirs (26, 39, 28, 40) are measured with pressure sensors (42, 42a) and the measured pressure data are processed by a computer or are sent directly to a control unit (27), wherein the hydraulic system (18), the control unit (27) and the first and second intermediate reservoirs (26, 28, 39, 40) in addition to feed and return lines (19, 21, 21a, 22, 22a) and check valves (23, 24) are configured to be movable together with the telescopic hydraulic cylinder (11).
3. Telescopic unit as claimed in claim 1 or 2, characterised in that the pressures in the first and second intermediate reservoirs (26, 39, 28, 40) are measured with pressure sensors (42, 42a) and the measured pressure data are processed by a computer or are sent directly to a control unit (27), wherein the control unit (27) and the first and second intermediate reservoirs (26, 28, 39, 40) in addition to feed and return lines (19, 21, 21a, 22, 22a) and check valves (23, 24) are arranged on the exposed end of the telescopic hydraulic cylinder (11) and thus on the exposed end of the piston rod (13).
4. Telescopic unit as claimed in any one of claims 1 to 3, characterised in that the pressures in the first and second intermediate reservoirs (26, 39, 28, 40) are measured with pressure sensors (42, 42a) and the measured pressure data are processed by a computer or are sent directly to a control unit (27), the control unit (27) ensures that the first intermediate reservoir (26, 39) is automatically loaded with the hydraulic medium as soon as the pressure of the hydraulic medium in the telescopic hydraulic cylinder (11) is higher than the pressure of the hydraulic medium in the first intermediate reservoir (26, 39), and that the hydraulic medium is automatically unloaded from the second intermediate reservoir (28, 40) as soon as the pressure of the hydraulic medium in the telescopic hydraulic cylinder (11) is lower than the pressure of the hydraulic medium in the second intermediate reservoir (28, 40).
5. Telescopic unit as claimed in any one of claims 1 to 4, characterised in that the first and second intermediate reservoirs (26, 39, 28, 40) are configured as bladder reservoirs or as piston reservoirs or as spring reservoirs.
6. Telescopic unit as claimed in claim 4 or 5, characterised in that the control unit (27) or the computer, depending on the pressure data determined and transmitted by the pressure sensors (42, 42a) thereto, activates the telescopic unit (10) in order to load the intermediate reservoirs (26, 39, 28, 40) with hydraulic energy or unload hydraulic energy from them by changing the driving state.
7. Telescopic unit as claimed in claim 6, characterised in that, with processing of the data from the pressure sensors (42, 42a), the control unit (27) or the computer energies the hydraulic system (18) with hydraulic energy only when the pressure difference between the first intermediate reservoirs (26, 39) and the second intermediate reservoirs (28, 40) has reached a predefined minimum value.
8. Telescopic unit as claimed in claim 7, characterised in that the pressure sensors (42, 42a) convert the pressure of the hydraulic medium into a proportional electrical signal.
9. Telescopic unit as claimed in claim 7, characterised in that the hydraulic system (18) is supplied with the hydraulic medium from the bottom side (15) through the piston rod (13) of the telescopic hydraulic cylinder (11) in a hydraulic two-way single-chamber circuit.
10. Telescopic unit as claimed in claim 7, characterised in that the hydraulic unit (18) is supplied with the hydraulic medium from the bottom and rod sides (15, 16) of the telescopic hydraulic cylinder (11) by means of a hydraulic two-way two-chamber circuit through the piston rod (13).
11. Telescopic unit as claimed in claim 7, characterised in that the hydraulic system (18) is supplied from the bottom and rod sides (15, 16) through the piston rod (13) of the telescopic hydraulic cylinder (11) by means of a hydraulic four-way two-chamber circuit.
12. Telescopic unit as claimed in claim 7, characterised in that the hydraulic system (18) is supplied with the hydraulic medium from the rod side (16) through the piston rod (13) of the telescopic hydraulic cylinder (11) in a hydraulic two-way single-chamber circuit.
13. Telescopic unit as claimed in claim 4, characterised in that the pressure sensor signals measured by the pressure sensors (42, 42a) are transmitted to the computer or the control unit (27) and are used to actuate valves (23, 24) for the loading and unloading of the first and second intermediate reservoirs (26, 39, 28, 40).
14. Telescopic unit as claimed in claim 13, characterised in that the valves (23, 24) are electrical poppet valves or hydraulically actuated valves or mechanical check valves.
15. Telescopic unit as claimed in claim 7, characterised in that the pressure oil is only extracted from the piston rod side (13).
16. Telescopic unit as claimed in claim 7, characterised in that the oil for the hydraulic system (18) is supplied via the piston rod and bottom sides (16, 15) of the telescopic hydraulic cylinder (11) in a hydraulic three-way two-chamber circuit, wherein the hydraulic system (18) is connected to the piston rod (13) of the telescopic hydraulic cylinder (11) and the returning oil is fed only into the bottom side (15).
17. Telescopic unit as claimed in claim 16, characterised in that the returning oil is fed only into the piston rod side (16).
18. Telescopic unit as claimed in claim 7, characterised in that the oil for the hydraulic system (18) is supplied via the piston rod and bottom sides (16, 15) of the telescopic hydraulic cylinder (11) in a hydraulic three-way two-chamber circuit, wherein the hydraulic system (18) is connected to the piston rod (13) of the telescopic hydraulic cylinder (11) and the pressure oil is extracted only from the bottom side (15).
19. Telescopic unit as claimed in claim 7, characterised in that the oil for the hydraulic system (18) is supplied via the piston rod and bottom sides (16, 15) of the telescopic hydraulic cylinder (11) in a hydraulic three-way two-chamber circuit, wherein the hydraulic system (18) is connected to the piston rod (13) of the telescopic hydraulic cylinder (11) and the pressure oil is extracted only from the rod side (16).

Images