EP1600643B1 - Control device for a hydraulic load moving device, in particular a swivel arm assembly of a lifting device for a interchangeable container on a truck. - Google Patents

Abstract

The controller (34) has at least two hydraulic cylinders (28a,28b) that are supplied from a pressurized fluid source (55) with hydraulic fluid under pressure to drive the load movement device. The controller is designed to reduce or possibly stop the flow of fluid to a first cylinder to increase the flow to the other cylinder in order to adjust the rapid movement mode. An independent claim is also included for a goods vehicle with a container changing device.

Description

The invention relates to a hydraulic drive device of a load movement device, in particular a Schwenkarmanordnung as a lifting device for swap bodies on a load transport vehicle, wherein the hydraulic drive means comprises at least one control device for controlling the same and two hydraulic cylinders, under control by the control device from a pressurized fluid source with hydraulic fluid under pressure be powered to drive the load moving device, wherein the load moving device is different from its normal mode operable in a rapid traverse mode. In particular, the invention relates to a drive device according to the preamble of claim 1.

Drive devices are used eg for the hydraulic control of tilt cylinders on dump trucks. Hydraulically driven load-moving devices in the form of swivel arms can be found, for example, in so-called roll-off tipper vehicles (cf., for example, DE 33 32 275 A1, DE 29 03 462 C2 and DE 196 37 891 A1). Such roll-off tipper vehicles of conventional design have a pivotable load lifting arm provided in the vehicle longitudinal center, which is pivotable about a horizontal pivot axis extending transversely to the vehicle longitudinal direction between a first pivot position and a second pivot position and has a hook arm with a hook provided thereon at its end remote from the pivot axis. which is to be engaged with a complementary eye of a swap body. In a normal driving position, the swap body is supported on the vehicle body or a base frame, wherein the load lifting arm is substantially horizontal and the hook arm from the load lifting arm extends vertically upwards to the eye of the interchangeable container. Should now such a swap body from the vehicle be unloaded, this is achieved in that the load lifting arm is pivoted from its first pivotal position about its pivot axis and about an approximately upright dead center into a second pivot position. In such a pivoting operation of the swap body to roles that are located at the rear of the vehicle, unroll and gradually remove further from the vehicle body until the swap body has been completely discontinued on the ground behind the rear of the vehicle. As swivel drive means for the load-lifting arm, two double-acting hydraulic cylinders are normally provided on hook loader vehicles. The hydraulic cylinders are articulated with their opposite ends on the one hand on a frame-fixed structure of the vehicle - and on the other hand on the pivotable load lifting arm, wherein they are arranged substantially parallel to each other and mechanically coupled to synchronous operation. The pivoting of the load lifting arm is carried out by extending or retracting the piston rods of the hydraulic cylinder, for which purpose the double-acting cylinder are acted upon by hydraulic fluid from a hydraulic pump. The hydraulic pump is connected to the cylinders via a hydraulic line system with load-holding valves, etc. inside. Return lines with counter-holding valves located therein serve to return hydraulic fluid displaced from the cylinders to a tank.

From DE 100 63 610 A1 it is known that pivotable lifting arms can be operated in skip vehicles and dump trucks in rapid traverse mode. In the rapid traverse mode, which is usually to be selected over a limited pivot angle range, the load lifting arm arrangement can be pivoted at a higher speed than is the case in a normal operating mode. The rapid traverse mode is usually permitted only in the case of low load on the lifting arms. If a container loaded with a heavy load is to be unloaded from the vehicle or charged onto the vehicle by means of a relevant load lifting arm, this will take place in the normal operating mode. The pivoting of the lifting arm without container or with an unloaded Container can be carried out in contrast in rapid traverse mode.

In the case of the control device known from DE 100 63 610 A1, the rapid traverse operating mode is characterized in that the cylinder subspaces of each of the two drive cylinders of each of the two drive cylinders are virtually short-circuited during extension of the piston rod, so that pressurized fluid from the cylinder passing through the piston rod Partial space with a correspondingly high pressure via a rapid traverse connection line to the other cylinder subspace, which is exposed in rapid traverse operation of the instantaneous pressurization by the pump, is led to accelerate the extension of the piston rod. In the control device according to DE 100 63 610 A1 differential pressure monitoring means are provided for detecting the difference occurring between the pressure in the first cylinder subspace and the pressure in the second cylinder subspace of the hydraulic cylinder during extension of the piston rod, wherein the control means a Rapid traverse valve assembly controls depending on the pressure difference, to ensure that the rapid traverse mode is suppressed when the load lifting arm, for example is loaded by a heavy container.

A hydraulic drive device according to the preamble of claim 1 is known from DE-A-1 556 720. The known drive means controls a multi-purpose bucket loader using two hydraulic cylinders acting in parallel on a drive shaft and operating under control of a control means. To set a rapid traverse mode of the multi-purpose bucket loader at low load of the cylinder is provided to supply only one of the two cylinders with the hydraulic fluid, while the other cylinder is separated from the source of pressurized fluid. As soon as the load acting on the multi-purpose bucket loader exceeds a predetermined value, the second cylinder is switched on again, so that in case of load both cylinders operate in parallel.

Another hydraulic drive device is described in JP 57 072 600 A and comprises two cylinders connected in parallel to one another, which engage a lifting device of a forklift truck. Also in this known drive device, a control device is provided with a plurality of hydraulic valves for controlling the hydraulic fluid flow to the cylinders. The known control device is set up so that only one of the two cylinders is supplied with pressure, while the second cylinder is forcibly moved by the mechanical coupling of the two cylinders. When a load on the lifting device occurs, a pressure relief valve switches the second cylinder also, so that in the case of load, the lifting device can be driven by both cylinders simultaneously.

JP 63 247 430 describes a further hydraulic drive device in which two hydraulic cylinders are supplied with hydraulic fluid from a pressure fluid source under the control of a control device. The control device of this drive device is switchable between a first switching state, in which both cylinders are connected in parallel and supplied with hydraulic fluid, and a second switching state, in which only one hydraulic cylinder is operated, wherein the switching between these operating states based on the switching state of Sensor switch takes place.

For further illustration of the state of the art, reference may also be made to US-A-3 871 266, which describes the actuation of two cylinders to be driven out one after the other, which are arranged mechanically behind one another in a lifting device, by a total stroke corresponding to the sum of the individual lifting amounts of the two Cylinder ready to put.

The invention has for its object to provide a drive device of the type mentioned, which can be realized in a simple manner, which is a reliable operation of the load moving device both in the normal mode and in the rapid traverse mode and which enables efficient drive of the load movement device even in the rapid traverse mode.

To achieve this object, according to the present invention, a drive device with the features of claim 1 is provided. Such a drive device is adapted to reduce the hydraulic flow from the pressure fluid source to a first of the two cylinders or, if necessary, to block to adjust the rapid traverse mode of the load movement device to increase the hydraulic flow from the pressure fluid source to the other cylinder.

In a preferred embodiment, the first cylinder is hydraulically decoupled from the source of pressurized fluid when the rapid traverse mode is set. As a pressurized fluid source, e.g. a simple single-circuit pump may be used, e.g. Pumping oil as hydraulic fluid from a tank. In the hydraulic decoupling of the first cylinder thus funded by the pump oil for the application of the other hydraulic cylinder is available, so that the piston rod can be extended or retracted for a given pump power significantly faster than is the case in the normal mode.

In an alternative not covered by the present invention, the control device ensures that in the rapid traverse mode, the two cylinder subspaces of the first cylinder are hydraulically shorted by releasing a bypass line, so that displaced from the cylinder subspace displaced oil in the direction of the other cylinder subspace can flow. In this way, it should be ensured that the cylinder subspaces are always filled with oil. The bypass line may be connected via a return line and a throttle located therein or possibly a bias valve with a collecting tank for hydraulic fluid. Since the first hydraulic cylinder is mechanically coupled to synchronize with the other cylinder, the piston rod makes the first one Cylinder the faster movement of the piston rod of the other cylinder forcibly with.
Preferably, the hydraulic cylinders are double-acting cylinders.

Although hitherto always talked about two hydraulic cylinders, so the invention should not be limited thereto. The principle according to the invention can also be extended to a larger number of cylinders mechanically coupled to each other for synchronism, of which at least one in favor of the other is discriminated or completely decoupled from a common pump in the rapid traverse mode.

In the aforementioned alternative not according to the invention, the control device may comprise a valve arrangement which in a normal mode of the load moving device associated with the first valve switching position, the cylinder subspaces of operated in rapid traverse mode with reduced or possibly stopped hydraulic fluid supply first cylinder with the main lines for the hydraulic fluid inlet and connects the hydraulic fluid return and which in a rapid traction mode associated second valve switching position separates the cylinder subspaces of the first cylinder from the main lines and connects to the common bypass line. This valve arrangement may be e.g. to act two electrically, magnetically, hydraulically or pneumatically controllable directional control valves, in particular 3/2-way valves. With such a valve arrangement can be an existing, previously designed only for the normal mode hydraulic system of a load moving device with little equipment and low installation costs easily retrofitted, so that the system in question can then be operated in a rapid traverse mode.

Embodiments of the control device according to the invention enable rapid traverse operation in opposite directions of movement of the load movement device, So approximately in opposite pivot directions of a lifting arm.

According to the invention, the hydraulic cylinders are two mechanically-coupled to synchronous, double-acting hydraulic cylinders, each of which comprises a piston displaceably guided in the cylinder interior in question and dividing the cylinder interior into a first cylinder subspace and a second cylinder subspace wherein, for hydraulic loading of the pistons in the normal mode of the load moving device, hydraulic fluid under pressure from the source of pressurized fluid under control of the control means is to be commonly supplied to the first cylinder subspaces or the second cylinder subspaces of the hydraulic cylinders, respectively, while from the respective other cylinder subspaces of the pistons displaced hydraulic fluid is to be derived to a hydraulic fluid sink, wherein the control device is adapted to, in the rapid traverse mode, the hydraulic fluid-emitting cylinder subspace of the second cylinder with due to the Piston displacement enlarging and hydraulic fluid receiving cylinder subspace, the first cylinder to connect and restrict the hydraulic fluid from the hydraulic fluid dispensing cylinder subspace of the second cylinder to the hydraulic fluid sink or lock if necessary.

The pressure fluid source is also in the embodiment considered here, preferably a pump that provides oil from a tank as hydraulic fluid under pressure.

The invention is thus based on the concept, in rapid traverse operation, of discriminating the cylinders with regard to their supply of oil from the pump, so that the oil supply to the first cylinder is throttled and possibly blocked in comparison with the oil supply to the second cylinder.

An embodiment of the invention is characterized in that the The first cylinder is decoupled hydraulically from the pump in rapid traverse operation, while the second cylinder is supplied solely by the pump. Due to the supply of oil to the currently oil-absorbing cylinder subspace of the second cylinder of the piston located therein is acted upon hydraulically and thus shifted. The thereby displaced from the other cylinder subspace of the second cylinder oil passes in rapid traverse mode via a rapid traverse hydraulic line to the here due to the piston displacement in the first cylinder magnifying cylinder subspace of the first cylinder. The piston of the first cylinder displaces oil from the other cylinder compartment to the tank. It is thus transferred with respect to the hydraulic circuit and supply of the cylinder in the transition from the normal mode to rapid traverse mode of a hydraulic parallel connection to a hydraulic series connection of the cylinder and vice versa.

In addition to the mechanical synchronization coupling, the cylinders in the embodiment considered here are also "hydraulically coupled" in rapid traverse operation.

In this context, a variant of the invention can be realized in which the ratio of the quantities of oil fed directly from the hydraulic fluid source to the cylinders can be varied continuously or in steps, so that the expressive effect can also be variable in a corresponding manner. The setting of the ratio of the oil supply to the first cylinder and the oil supply to the second cylinder may also be automatically adjustable in dependence on the load state of the load movement device by means of the control device, so that an automatic variable rapid traverse operation is possible. Such a possibility of automatic variable rapid traverse operation is feasible in all basic variants of the present invention.

According to one embodiment of the invention, it is provided that the rapid traverse mode on the piston stroke of the common retraction of the Pistons is limited in the cylinder, it being assumed that the pistons have a respective, the second cylinder subspace of the respective cylinder passing through the piston rod, which is retractable depending on the direction of the piston stroke from the cylinder or retractable into the cylinder. In rapid traverse operation, the second cylinder subspace of the first cylinder penetrated by the piston rod is thus hydraulically connected downstream of the cylinder subspace of the second cylinder in the series connection, so that the oil quantity displaced from the first cylinder subspace of the second cylinder is greater than the amount of oil that can accommodate the first cylinder simultaneously in its second cylinder subspace. There is thus always enough oil for the supply of the first cylinder from the second cylinder in rapid traverse operation available.

So that the excess oil can flow out to the tank, a pressure valve connected to the rapid traverse hydraulic line is preferably provided which, when a limit pressure in the rapid traverse hydraulic line is exceeded, opens to the pressure fluid sink, ie to the tank.

• den ersten Zylinder-Teilraum des zweiten Zylinders mit dem zweiten Zylinder-Teilraum des ersten Zylinders über eine Eilgang-Hydraulikleitung verbindet,
• den zweiten Zylinder-Teilraum des zweiten Zylinders mit der Druckfluidquelle verbindet und
• den ersten Zylinder-Teilraum des ersten Zylinders mit der Druckfluidsenke verbindet.

The control device comprises in a hydraulic line system a valve arrangement, which in a rapid traverse mode associated valve switching position

• connects the first cylinder subspace of the second cylinder to the second cylinder subspace of the first cylinder via a rapid traction hydraulic line,
• connects the second cylinder subspace of the second cylinder with the source of pressurized fluid and
• connects the first cylinder subspace of the first cylinder with the pressure fluid sink.

According to one embodiment of the invention, it is provided that the rapid traverse mode is adjustable by means of a manually operated adjusting device of the control device. It is thus the choice of an operator It is up to you if you want to use rapid traverse or normal operation. In this case, however, safety devices can be provided which suppress the rapid traverse operation, for example, because an excessive load on the load moving device is given.

According to a development of the invention, the control device is set up to automatically set or suppress the rapid traverse mode as a function of the load state of the load movement device. The already mentioned aspect of the automatic variable rapid traverse operation is pointed out.

For this purpose, the control device can be equipped with pressure monitoring means, in particular differential pressure monitoring means for detecting the pressure, in particular the pressure difference, in the cylinder subspaces of at least one cylinder, in particular of the second cylinder - and be adapted to release the rapid traverse mode depending on the measured pressure or disable. Such monitoring of the pressure or the pressure difference as an indicator of the permissibility of rapid traverse operation is e.g. known from DE 100 63 610 A1.

According to a further variant of the invention, the control device is equipped with means for detecting positions of the load movement device and adapted to enable or disable the rapid traverse mode depending on the achievement of predetermined positions of the load movement device during its movement. In the case of a pivotable load lifting arm, for example, the rapid traverse mode can be limited to a limited angular range around a dead center position of the lifting arm. Such a restriction makes sense, for example, when the load moving device is a swivel arm assembly as a reciprocating swap body on a load transport vehicle, such as a swiveling load lifting arm of a container changing device of a hook lift truck or a pair of mechanically coupled swivel arms of a container changing device Dump truck is trading.

The invention is in this sense, a load transport vehicle, in particular Abrollkipperfahrzeug or Absetzkipperfahrzeug, with a changing device for swap bodies, which has a Schwenkarmanordnung as a lifting device for the swap body and a hydraulic drive means for the Schwenkarmanordnung, wherein the hydraulic drive means are two mechanically coupled to each other for synchronization hydraulic Cylinder comprises. For controlling the hydraulic drive device, a control device according to one of the claims is provided.

Fig. 1

zeigt eine Wechselvorrichtung eines Abrollkipperfahrzeuges in einer perspektivischen Darstellung mit in einer ersten Schwenkstellung (Grundstellung) befindlichem Schwenkarm.

Fig. 2

zeigt die Wechselvorrichtung aus Fig. 1 mit vollständig nach hinten in der zweiten Schwenkstellung ausgelenktem Schwenkarm.

Fig. 3a-3c

zeigen in skizzenhaften Momentaufnahmen den Absetzvorgang beim Abrollen eines Behälters vom Fahrzeug.

Fig. 4

zeigt die Wechselvorrichtung aus den Figuren 1 und 2 in einer Kippstellung.

Fig. 5

zeigt in einer skizzenhaften Darstellung ein Abrollkipperfahrzeug, bei dem ein Behälter mit einer betreffenden Wechselvorrichtung in die Kippstellung gebracht worden ist.

Fig. 6

zeigt ein Hydraulikschaltbild eines nicht gemäß der Erfindung gestalteten Illustrationsbeispiels einer Steuereinrichtung zur Steuerung des Schwenkarms der Wechselvorrichtung aus den Figuren 1, 2 und 4.

Fig. 7

zeigt ein Hydraulikschaltbild einer bevorzugten Ausführungsform einer Steuereinrichtung nach der Erfindung zur Steuerung des Schwenkarms der Wechselvorrichtung aus den Figuren 1, 2 und 4.

An embodiment of the invention will be explained below with reference to the figures.

Fig. 1

shows a changing device of a roll-off dump truck in a perspective view with in a first pivot position (basic position) befindlichem pivot arm.

Fig. 2

shows the changing device of FIG. 1 with fully pivoted to the rear in the second pivot position swivel arm.

Fig. 3a-3c

show in sketchy snapshots the settling process when rolling a container from the vehicle.

Fig. 4

shows the changing device of Figures 1 and 2 in a tilted position.

Fig. 5

shows in a sketchy representation of a hooklift vehicle in which a container has been brought with a respective changing device in the tilted position.

Fig. 6

1 shows a hydraulic circuit diagram of an illustration example not designed according to the invention of a control device for controlling the pivoting arm of the changing device from FIGS. 1, 2 and 4.

Fig. 7

shows a hydraulic circuit diagram of a preferred embodiment of a control device according to the invention for controlling the pivot arm of the changing device of Figures 1, 2 and 4.

The change device 2 illustrated in FIGS. 1-5 comprises a base frame 1 comprising longitudinal members 4 and transverse struts 6. The pivot arm 10 provided between the longitudinal members 4 extends forwardly from the rearward tilting axis 12 transverse to the vehicle longitudinal direction in the basic position shown in FIG and has at its end remote from the tilting axis 12 an orthogonal upwardly angled hook arm 14 with a hook 16 for engaging a complementary loop 18 of a container 20 (see Figures 3a-3c).

The swivel arm 10 has a tilting-arm-proximate swivel-arm section 10a and a second swivel-arm section 10b pivotally mounted at the end remote from the tilting axis 12 about a buckling axis 22 parallel to the tilting axis 12.

It can be seen from FIGS. 3a-3c that a container 20 accommodated on the vehicle 3 on the base frame of the changing device 2 can be lowered from the vehicle by pivoting the second pivot arm section 10b about the articulated axis 22. In this case, the second pivot arm section 10b passes from the basic position shown in FIG. 1 into the boom position shown in FIG. The container rolls when settling on the rollers 24 of the changing device with his container skids 26 from.

For receiving a standing behind the rear of a vehicle 3 container 20, the movements shown in FIGS. 3a-3c can be reversed.

In a tilting mode according to FIGS. 4 and 5, the two swivel arm sections 10a and 10b are rigidly locked together so that the buckling option of the swivel arm 10 used for depositing and picking up a container is suppressed. The container 20 can thus be brought to the vehicle 3 in a tilted position shown in FIG. 5.

Regardless of whether the pivot arm 10 is moved in the manner shown in FIGS. 1-3c or in the manner shown in FIGS. 4-5, two hydraulic cylinders 28a, 28b serve as drive means, with their piston rod ends 30 on the second pivot arm portion 10b are articulated. The two hydraulic cylinders 28a, 28b extend in the example parallel between the longitudinal members 4 of the base frame 1 and are hinged with their cylinder housing ends 32 on the base frame 1. The cylinders 28a and 28b are preferably the same type. They are mechanically coupled to the synchronization via the base frame 1 and the second pivot arm section 10b.

FIG. 6 shows a hydraulic circuit diagram for a control device 34 according to an illustrative example not designed according to the invention for the hydraulic control of the drive cylinders 28a, 28b. The by their pistons 36a, 36b in two cylinder subspaces 38a, 40a; 38b, 40b are divided at the hydraulic connection points 42a, 42b, 44a, 44b with branch lines 46a, 46b, 48a, 48b of hydraulic main lines 46, 48 for the hydraulic fluid inlet and the hydraulic fluid return. In the hydraulic main lines 46, 48 load holding valves with check function and counter-holding valves are provided, which are represented in Fig. 6 by the block 50. A directional control valve 52 can be actuated by means of an adjusting device (proportional generator) by the driver of the unrolling vehicle. In a first switching position of the directional control valve 52, the main line 48 to the pressure line 54, whereas the main line 46 is connected to the return line 56. In a second switching position of the directional control valve 52, the hydraulic main line 46 is connected to the pressure line 54, whereas the main line 48 is connected to the return line 56. In the illustrated neutral position or third switching position of the directional control valve 52, the main lines 46 and 48 are separated from the lines 54, 56. The pressure line 54 is connected to a one-circuit pump 55, which is driven by a power take-off of the vehicle and from a hydraulic tank 57 oil promotes. The return line 56 is connected to the hydraulic tank.

If the piston rods 60a, 60b are to be extended from the position shown in FIG. 6, such as about the pivot arm portion 10b of the changing device 2 from the position shown in Fig. 1 to the position shown in Fig. 2 to pivot, the directional control valve 52 is in to adjust the first switching position, so that the main line 48 is connected to the pressure line 54 and the main line 46 is connected to the return line 56. The pump may then deliver oil under pressure to the cylinder subspaces 38a, 38b to urge the pistons 36a, 36b.

To retract the piston rods 60a, 60b, the directional control valve 52 is to be transferred to the second switching position.

The previous explanations regarding the control device 34 have referred to the normal mode of the swing arm 10, which is then to choose when a heavy container is coupled to the pivot arm 10 and is to be handled with the changing device.

In particular, during the pivoting back of the Schwenkarmabschnittes 10b from the position shown in Fig. 1 in the position shown in Fig. 2 without load or with a very light, especially empty container, it makes sense to save time to choose the rapid traverse operation. The rapid traverse option is very simple in the described control device Means feasible, as can be seen from the example in Fig. 6. There are two 3/2-way valves 62, 64 in the branch lines 46b and 48b of the main lines 46 and 48, respectively, which in the illustrated first switch position for the normal mode, the branch lines 46b and 48b directly to the terminals 42b and 44b of the Connect hydraulic cylinder 28b.

In the second valve switching position, namely the valve switching position for rapid traverse operation, the valves 62, 64 connect the ports 42b, 44b via a bridging line 66 with each other. The two cylinder subspaces 38b, 40b are then decoupled from the main lines 46, 48. The amount of oil delivered by the pump is then essentially exclusively available for the operation of the other hydraulic cylinder 28a, so that its piston rod 60a can be extended or retracted faster for a given pumping power than is the case in the normal operating mode. Since the cylinders 28a and 28b are mechanically coupled for synchronism, the piston rod 60b of the hydraulically shorted cylinder 28b decoupled from the pump 55 forcibly communicates the movement of the piston rod 60a of the cylinder 28a.

The bypass line 66 is connected in the example of FIG. 6 via a return branch 68 to the return line 56 and thus to the tank. In the return branch 68 is a throttle valve or possibly biasing valve 70th

The rapid traverse valves 62, 64 may be electromagnetically actuated valves, which can be manually activated by means of an adjusting device. In alternative embodiments, it may be provided that respective rapid traverse valves are hydraulically or pneumatically vorsteuerbar.

As already explained above, the control device 34 may comprise means which are adapted to release the rapid traverse mode automatically depending on the load state of the pivot arm 10 and to suppress.

Fig. 7 shows a hydraulic circuit diagram for an embodiment of the invention. Elements in FIG. 7 which correspond objectively or functionally to elements in FIG. 6 are identified by corresponding reference numerals, but those in FIG. 7 are preceded by 1. Therefore, to explain the exemplary embodiment according to FIG 6, so that the following explanations can be limited essentially to the differences of the embodiment according to FIG. 7 to the illustration example according to FIG. 6. These differences relate in particular to the valve arrangement for switching between normal operation and rapid traverse operation of the load movement device. It should also be noted that in Fig. 7, the first cylinder 128 b on the left side - and the second cylinder 128 a are shown on the right side of the drawing. In Fig. 6, it is reversed.

If in the embodiment of FIG. 7, the piston rods 160a, 160b are extended from the retracted position shown, the directional control valve 152 is set in the switching position in which the main line 148 is connected to the pressure line 154 and the main line 146 with the return line 156th is connected. The pump 155 may then deliver oil under pressure to the cylinder subspaces 138a, 138b to hydraulically pressurize the pistons 136a, 136b in the first cylinder subspaces 138a, 138b.

To retract the piston rods 160a, 160b, the directional control valve 152 is to be transferred to the other active switching position, so that the pressure line 154 is connected to the main line 146 and the return line 156 communicates with the main line 148.

Whether the retraction of the piston rods 160a, 160b takes place in the normal mode or in the rapid traverse mode depends on the respective setting the controllable by means of the control valve assembly from the directional control valves 80, 82 and 84 from. If the piston rods 160a, 160b in the normal mode and thus are usually drawn slowly and under external load, the valves 80, 82 are switched from the normal switching position shown in the alternative switching position, so that via the main line 146 oil both to the line branch 146a can also pass to the line branch 146b and thus parallel to the second cylinder subspaces 140a, 140b of the cylinders 128a, 128b and on the other hand, the branch lines 148a, 148b are connected via the main line 148 to the return line 156, so that oil from the first cylinder Subspaces 138a, 138b can be removed from the main line 148a to the return line 156.

However, if the piston rods 160a, 160b are retracted from their extended position (not shown) in rapid traverse operation, the valves 80 and 82 should be left in the normal position shown, whereas, however, the directional control valve 84 moves out of the illustrated normal position into the alternative shift position is to switch. The directional control valve 84 is in a rapid traverse hydraulic line 86 which is connected between the valve 82 and the second cylinder 128a at the port 144a of the first cylinder subspace 138a at 88. The other connection point 90 of the rapid traverse hydraulic line is located in a connection line 92 between the ports 142b and 144b of the first cylinder 128b. In this connection line 92, a non-return valve 94 which opens in the direction of the connection 142b is also provided between the connection point 90 and the cylinder connection 142b. In the connecting line 92, a pressure valve 96 is further provided between the connection point 90 and the cylinder port 144b and the main line 148, which opens when exceeding a limit pressure in the rapid traverse hydraulic line to the main line 148 and thus in rapid traverse operation to the tank 157 out.

In the rapid traverse mode, the second cylinder subspace 140a of the second cylinder 128a becomes oil from the pump 155 via the main line 146 supplied so that the piston 160a is shifted in Fig. 7 in the downward direction. The thereby shrinking cylinder subspace 138a of the cylinder 128a are from the piston 136a displaced oil to the rapid traverse hydraulic line 86 from. The oil may then pass through the open valves 84 and 94 to the second cylinder subspace 140b of the cylinder 128b to urge the piston 136b displaceable therein. The piston 136b is thus displaced not only due to the mechanical synchronism coupling of the piston rods 160a and 160b of the preferably identically constructed cylinders 128a and 128b but also due to the hydraulic loading in the hydraulic series connection of the cylinders 128a and 128b set in rapid traverse operation. The oil displaced from the first cylinder subspace 138b by the piston 136b can flow out to the tank via the main line 148.

Since the amount of oil displaced from the cylinder subspace 138a is greater than the amount of oil that can be simultaneously received in the cylinder subspace 140b, the pressure valve 96 ensures that excess oil is discharged directly into the main conduit 148 toward the tank 157.

In the embodiment according to FIG. 7, rapid traverse operation is provided only for the piston stroke of the common retraction of the piston rods 160a, 160b into the cylinders 128a, 128b. This solution is very cheap. However, the invention should not be so limited.

In the examples of FIGS. 6 and 7, it has been assumed that in rapid traverse operation, the flow of oil from the pump to the first cylinders 28b, 128b is completely suppressed, so that the oil delivered by the pump at a given pump capacity is the second Cylinders 28a, 128a is supplied, so as to achieve a high speed of the system.

However, an important aspect of the invention is also the feasible in other variants possibility of possibly stepwise, but preferably continuous setting of the ratio of the cylinders of the pump supplied oil quantities. In this case, the second cylinder 28a, 128a in rapid traverse operation is usually supplied with a larger amount of oil directly from the pump than the first cylinder 28b, 128b; however, the first cylinder is not completely disconnected from the pump. The larger the ratio between the amount of oil supplied directly from the pump to the second cylinder and the amount of oil supplied directly from the pump to the first cylinder, the more effective (faster) is the rapid traverse operation. The smaller this ratio, the slower the pistons of the cylinders move, but the system allows for a heavier load on the load moving device.

This load can be monitored with the already mentioned detection means or possibly other detection means and used as a parameter for the control of the hydraulic drive means. Thus, in the above-mentioned sense, a variable and especially depending on the load condition of the load moving device dependent controlled rapid traverse operation can be realized.

If the operation is not automated, it is within the scope of the invention, the ability to use variable rapid traverse operation also on the basis of manual settings, ie, for example, by adjusting an actuator from an operator.

Claims (14)

1. Hydraulic drive device of a load moving device (10), in particular of a swivel arm assembly (10) as a lifting device for interchangeable containers (20) on a truck (3), wherein the hydraulic drive device has a control device for controlling the hydraulic drive device and at least two hydraulic cylinders (28a, 28b; 128a, 128b) which are to be supplied with pressurised hydraulic fluid from a pressure fluid source (55; 155) under the control of the control device (34; 134) in order to drive the load moving device (10), wherein, diverging from its normal operating mode, the load moving device (10) can be operated in a rapid-movement operating mode,
   wherein the control device (34; 134) is adapted, in order to set the rapid-movement operating mode of the load moving device (10), to reduce or optionally to block the hydraulic fluid inflow from the pressure fluid source (55; 155) to a first (28b; 128b) of the two cylinders (28a, 28b; 128a, 128b) in order to increase the hydraulic fluid inflow from the pressure fluid source (55; 155) to the other cylinder (28a; 128a),
   wherein the hydraulic cylinders (128a, 128b) are two double-acting hydraulic cylinders (128a, 128b) which are mechanically coupled for synchronous operation and each of which comprises a piston (136a, 136b) which is displaceably guided in the cylinder interior concerned and divides the cylinder interior into a first cylinder subchamber (138a, 138b) and into a second cylinder subchamber (140a, 140b), wherein, in order to hydraulically act on the pistons (136a, 136b) in the normal operating mode of the load moving device, pressurised hydraulic fluid is to be fed from the pressure fluid source (155) under the control of the control device in each case jointly to the first cylinder subchambers (138a, 138b) or the second cylinder subchambers (140a, 140b) of the hydraulic cylinders (128a, 128b), while hydraulic fluid which is displaced by the pistons (136a, 136b) is to be removed from the respective other cylinder subchambers (140a, 140b or 138a, 138b) to a hydraulic fluid sink (157),
   characterised in
   that the control device is adapted to connect the cylinder subchamber (138a), which is delivering hydraulic fluid, of the second cylinder (128a) to the cylinder subchamber (140b), which is enlarging and receiving hydraulic fluid on account of the piston displacement, of the first cylinder (128b) and to throttle or optionally to block the hydraulic fluid flow from the cylinder subchamber (138a), which is delivering hydraulic fluid, of the second cylinder (128a) to the hydraulic fluid sink (157) in the rapid-movement operating mode.
2. Hydraulic drive device of a load moving device according to Claim 1,
   wherein the pistons (136a, 136b) have a respective piston rod (160a, 160b) which passes through the second cylinder subchamber (140a, 140b) of the cylinder concerned and can be extended out of the cylinder (128a, 128b) or retracted into the cylinder according to the direction of the piston stroke, characterised in
   that the raid-movement operating mode is restricted to the piston stroke of the joint retraction of the piston rods (160a, 160b) into the cylinders.
3. Hydraulic drive device of a load moving device according to Claim 2,
   characterised in
   that the control device (134) comprises, in a hydraulic line system, a valve assembly (80, 82, 84, 92, 96) which, in a valve switched position associated with the rapid-movement operating mode,

   - connects the first cylinder subchamber (138a) of the second cylinder (128a) to the second cylinder subchamber (140b) of the first cylinder (128b) via a rapid-movement hydraulic line (86),

   - connects the second cylinder subchamber (140a) of the second cylinder (128a) to the pressure fluid source (155) and

   - connects the first cylinder subchamber (138b) of the first cylinder (128b) to the pressure fluid sink (157).
4. Hydraulic drive device of a load moving device according to Claim 3, characterised in that the valve assembly comprises a pressure valve (96) which is connected to the rapid-movement hydraulic line (86) and opens towards the pressure fluid sink when a limit pressure in the rapid-movement hydraulic line is exceeded.
5. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the control device is adapted to feed hydraulic fluid from the pressure fluid source (155) to both cylinders (128a, 128b) in the rapid-movement operating mode, wherein the quantity of hydraulic fluid which is fed to the second cylinder (128a) is greater than that which is fed to the first cylinder (128b).
6. Hydraulic drive device of a load moving device according to Claim 5, characterised in that the ratio between the quantity of hydraulic fluid which is fed to the second cylinder (128a) and the quantity of hydraulic fluid which is fed to the first cylinder (128b) in the rapid-movement operating mode is variable.
7. Hydraulic drive device of a load moving device according to Claim 6, characterised in that the ratio between the quantity of hydraulic fluid which is fed to the second cylinder (128a) and the quantity of hydraulic fluid which is fed to the first cylinder (128b) can in particular be varied automatically in accordance with operating parameters of the load moving device, in particular in accordance with the load state of the load moving device, under the control of the control device.
8. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the rapid-movement operating mode can be set by means of an actuating device, which can be manually operated, of the control device.
9. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the control device is adapted to automatically set the rapid-movement operating mode in accordance with the load state of the load moving device.
10. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the control device has pressure monitoring means, in particular differential pressure monitoring means for detecting the pressure, in particular the pressure difference, in the cylinder subchambers at least of one cylinder, in particular of the second cylinder, and is adapted to enable or to deactivate the rapid-movement operating mode according to the measured pressure.
11. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the control device comprises means for detecting positions of the load moving device and is adapted to enable or to deactivate the rapid-movement operating mode according to the attainment of predetermined positions of the load moving device when it moves.
12. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the load moving device is a swivel arm (10) of a container interchange apparatus (2) of a roll-off tipper.
13. Hydraulic drive device of a load moving device according to any one of the preceding Claims, characterised in that the load moving device is a pair of swivel arms, which are mechanically coupled for a joint swivelling movement, of a container interchange apparatus of a bucket tipper.
14. Truck, in particular roll-off tipper or bucket tipper, with an interchange apparatus (2) for interchangeable containers (20) which has a swivel arm assembly (10) as a lifting device for the interchangeable containers (20) and a hydraulic drive device for the swivel arm assembly, wherein the hydraulic drive device comprises two hydraulic cylinders (28a, 28b) which are mechanically coupled together for synchronous operation, characterised in that it has a hydraulic drive device according to any one of the preceding Claims.

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