GB2462182A - Hydraulic controller of fork lift truck - Google Patents
Hydraulic controller of fork lift truck Download PDFInfo
- Publication number
- GB2462182A GB2462182A GB0912874A GB0912874A GB2462182A GB 2462182 A GB2462182 A GB 2462182A GB 0912874 A GB0912874 A GB 0912874A GB 0912874 A GB0912874 A GB 0912874A GB 2462182 A GB2462182 A GB 2462182A
- Authority
- GB
- United Kingdom
- Prior art keywords
- activation
- control valve
- control
- hydraulic cylinder
- prong
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/12—Platforms; Forks; Other load supporting or gripping members
- B66F9/14—Platforms; Forks; Other load supporting or gripping members laterally movable, e.g. swingable, for slewing or transverse movements
- B66F9/142—Movements of forks either individually or relative to each other
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/12—Platforms; Forks; Other load supporting or gripping members
- B66F9/14—Platforms; Forks; Other load supporting or gripping members laterally movable, e.g. swingable, for slewing or transverse movements
- B66F9/142—Movements of forks either individually or relative to each other
- B66F9/144—Movements of forks relative to each other - independent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/12—Platforms; Forks; Other load supporting or gripping members
- B66F9/14—Platforms; Forks; Other load supporting or gripping members laterally movable, e.g. swingable, for slewing or transverse movements
- B66F9/146—Side shift, i.e. both forks move together sideways relative to fork support
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/20—Means for actuating or controlling masts, platforms, or forks
- B66F9/22—Hydraulic devices or systems
Abstract
The invention relates to a hydraulic controller of an industrial truck with a side slide device and a prong adjusting device of a load receiving means. The load receiving means consists of two fork prongs (not shown), each fork prong being displaceable by means of a hydraulic cylinder 1a, 1b in the lateral direction. For the side slide device both fork prongs 1a, 1b are displaceable in the same lateral direction. For the prong adjustment device the fork prongs are displaceable in opposite lateral directions. Each hydraulic cylinder 1a, 1b can be actuated by means of a control valve device 2a, 2b, wherein, upon an activation of a single control valve device 2a, 2b, a fork prong adjustment of a single fork prong can be attained and/or the prong adjusting device and the side slide device can be attained by a simultaneous activation of the two control valve devices (2a, 2b). Each control valve device 2a, 2b may be an electrically activatable control valve throttling in intermediate positions, with a neutral position 12, 12b, a first control position 13a, 13b, and a second control position 14a, 14b, which is connected on the input side by means of a delivery branch line 4a, 4b. The hydraulic controller is said to have a simpler structure than currently employed to achieve the same effect.
Description
Description
Hydraulic controller of an industrial truck The invention relates to a hydraulic controller of an industrial truck with a side slide device and a prong adjusting device of a load receiving means consisting of two fork prongs, each fork prong being displaceable by means of a hydraulic cylinder in the lateral direction and the fork prongs being displaceable in the same direction, in the lateral direction, for the side slide device and the fork prongs being displaceable in the opposite direction, in the lateral direction, for the prong adjusting device.
In the case of industrial trucks, the two fork prongs of a load receiving means configured as a load fork can be displaced in parallel and in the same direction on both sides by means of a side slide device in order to facilitate the receiving and the depositing of a load by lateral displacement of the two fork prongs and therefore the load fork. The lateral spacing of the two fork prongs with respect to one another can be changed with a prong adjusting device by an opposite movement of the fork prongs in order to adapt the load receiving means consisting of the two fork prongs to changing dimensions of the load to be transported.
It is known for this purpose to adjust each fork prong in the lateral direction by means of a hydraulic cylinder and to attain a side slide device and a prong adjusting device by corresponding loading of the two hydraulic cylinders.
In the case of known hydraulic controllers, for this purpose, a control valve device is provided for the side slide device and a second control valve device is provided for the prong adjusting device. Using the control device for the side slide device, here, a pressure chamber of the first hydraulic cylinder acting in a first movement direction or a pressure chamber of the second hydraulic cylinder acting in a second movement direction are connected to a delivery line of a pump and, at the same time, a pressure chamber of the second hydraulic cylinder acting in the second movement direction or a pressure chamber of the first hydraulic cylinder acting in the first movement direction are connected to a container. The two further pressure chambers of the two hydraulic cylinders, namely a pressure chamber of the first hydraulic cylinder acting in the second movement direction and a pressure chamber of the second hydraulic cylinder acting in the first movement direction, are connected to one another here by means of a short-circuit line so that using this control valve device, the two hydraulic cylinders can be adjusted in parallel and in the same direction at the same speed on both sides. In this case, for the lateral movement of the two fork prongs, only one respective pressure chamber of a hydraulic cylinder is loaded with the delivery pressure of the pump, so that with correspondingly large loads, hydraulic cylinders with large dimensions are necessary, which have a high overall installation space requirement in the region of the load receiving means.
The control valve device for the prong adjusting device thus connects pressure chambers of the hydraulic cylinders acting in opposite directions to the delivery line or the container, so a movement in opposite directions of the two fork prongs can be attained at the same speed. For example, the control valve device for the prong adjusting device, for an adjustment of the two fork prongs in relation to each other, connects a pressure chamber of the first hydraulic cylinder acting in the second movement direction and a pressure chamber of the second hydraulic cylinder acting in a first movement direction to the delivery line and connects a pressure chamber of the first hydraulic cylinder acting in the first movement direction and a pressure chamber of the second hydraulic cylinder acting in the second movement direction to a container, or for an adjustment of the two fork prongs apart, connects a pressure chamber of the first hydraulic cylinder acting in the first movement direction and a pressure chamber of the second hydraulic cylinder acting in the second movement direction to the delivery line and connects a pressure chamber of the first hydraulic cylinder acting in the second movement direction and a pressure chamber of the second hydraulic cylinder acting in the first movement direction to a container.
As the two hydraulic cylinders are activated in each case here both by the control valve device for the side slide device and also by the control valve device for the prong adjusting device, a complex line guidance is produced between the control valve devices and the hydraulic cylinders and a complex locking valve block is required in the connection lines of the two hydraulic cylinders with the two control valve devices, which locking valve block has a plurality of pre-controlled locking valves, so an industrial truck of this type has a high construction outlay for the hydraulic controller of the side slide device and the prong adjusting device.
The present invention is based on the object of providing a hydraulic controller of an industrial truck of the type mentioned at the outset which, for the side slide device and the prong adjusting device, has a simple structure and entails a low construction outlay.
The object is achieved according to the invention in that each hydraulic cylinder can be actuated by means of a control valve device, a fork prong adjustment of a single fork prong being attainable upon an activation of a single control valve device and/or the prong adjusting device and the side slide device being attainable by a simultaneous activation of the two control valve devices. In the case of the hydraulic circuit according to the invention, each hydraulic cylinder is thus connected to only one control valve device and thus only one hydraulic cylinder is associated with each control valve, so a simple line guidance is produced between the control valves and the hydraulic cylinders with a low construction outlay. In addition, as a result, the previously required locking valve block and the short-circuit line between the two hydraulic cylinders can be dispensed with, so the construction complexity in the controller according to the invention is further simplified. By means of the simultaneous activation of the two control valve devices, for the side slide device here, the two hydraulic cylinders and therefore the fork prongs connected thereto can easily be adjusted in the same direction at the same speed on both sides. As two hydraulic cylinders are loaded with the delivery pressure of the pump here for the side slide device, in addition, the cylinder cross-section of the hydraulic cylinders can be reduced, so the overall installation space can be further reduced.
Correspondingly, by the simultaneous activation of the two control valve devices, a prong adjusting device can easily be attained, in which a movement in the opposite direction of the two hydraulic cylinders and therefore of the fork prongs can be attained at the same speed. By activating one control valve device alone, in addition, a fork prong adjustment of only one fork prong can be attained here so additional functions can be attained with the controller according to the invention.
According to a preferred embodiment of the invention, the control valve device is in each case configured as an electrically activatable control valve throttling in intermediate positions, with a neutral position, a first control position and a second control position, which is connected on the input side by means of a delivery branch line to a delivery line of a pump and, on the output side, to a container line and controls the connection of the delivery branch line and the container line to a first connection line guided to a first pressure chamber of the associated hydraulic cylinder, as well as to a second connection line guided to a second pressure chamber of the associated hydraulic cylinder, a respective pressure balance loaded by the load pressure of the associated hydraulic cylinder being arranged in the delivery branch line. The two control valves are therefore connected by two respective connection lines to the two pressure chambers of the associated hydraulic cylinders, so a simple line guidance can be attained between the hydraulic cylinders and the control valves with a low construction outlay. Activation of one control valve alone or a simultaneous activation of the two control valve devices can easily be attained here by the electric activation of the two control valves. By means of the pressure balance arranged in the delivery branch line, it can easily be ensured here that with the simultaneous activation of the two control valves, the two hydraulic cylinders are actuated in the prong adjusting device and in the side slide device at the same movement speed in the same direction or in the opposite direction.
Expediently, the pressure balance can be loaded by the load pressure of the associated hydraulic cylinder and a spring in the direction of a locking position and by the delivery pressure present in the delivery branch line in the direction of a through-flow position. It can easily be ensured with a pressure balance of this type that with different load pressures of the two hydraulic cylinders, the hydraulic cylinders are actuated at the movement speed adjusted at the control valves to ensure the same movement speeds of the two hydraulic cylinders in the side slide device and the prong adjusting device.
If the control valves according to a preferred embodiment of the invention can be actuated, in each case, by means of a first electric activation device in the direction of the first control position and, in each case, by means of a second electric activation device in the direction of the second control position, each control valve can be activated alone or the two control valves can be activated simultaneously, in a simple manner.
The control valves may be connected directly here to the electric activation devices, which are formed, for example, by proportional magnets.
Particular advantages are produced, however, when the control valves are configured as electro-hyd raulically precontrollable control valves, the activation devices being configured as electrically actuable pilot valves.
Expediently, the pilot valves are in each case configured as a proportional valve which produces a control pressure of the control valve and can be actuated by means of a proportional magnet. As a result, an electric activation device for the hydraulic precontrol of the control valve can easily be formed.
According to a preferred development of the invention, the activation devices can be activated by means of an electric control device as a function of the actuation of an actuating member, in particular a joystick. As a result, the control valves can easily be activated alone by corresponding actuation of the actuating member, in order to attain a corresponding fork prong adjustment of a fork prong, or be activated simultaneously to attain the prong adjusting device and the side slide device. With an actuating member configured as a joystick, in one actuating possibility, the side slide device to the left-hand side and to the right-hand side can thus be attained, in a further actuating possibility, the prong adjusting device with fork prongs moving toward one another and moving apart from one another can be attained, and in further actuating possibilities, the fork prong adjustment for the left-hand or the right-hand fork prong can be attained.
According to a preferred embodiment of the invention, a fork prong adjustment of a single fork prong can be attained here by the activation of the first activation device alone or of the second activation device alone of the first control valve or the second control valve. By means of the two control valves, which in each case activate a single hydraulic cylinder, which is connected to the corresponding fork prong, a fork prong adjustment can be attained by only activating a control valve for the left-hand or the right-hand fork prong.
According to a preferred embodiment of the invention, in the first control position of the first control valve, the first hydraulic cylinder can be actuated in the direction of a first movement direction and, in the second control position of the first control valve, the first hydraulic cylinder can be actuated in the direction of a second movement direction, and in the first control position of the second control valve, the second hydraulic cylinder can be actuated in the direction of the first movement direction, and in the second control position of the second control valve, the second hydraulic cylinder can be actuated in the direction of the second movement direction. The two hydraulic cylinders are generally arranged on the load receiving means with facing piston rods which can be moved in and out. The first and second connection lines of the two control valves are connected here to different pressure chambers of the hydraulic cylinders, for example the first control valve is connected by the first connection line to the pressure chamber on the piston rod side and by the second connection line to the pressure chamber of the first hydraulic cylinder on the piston side and the second control valve is connected by the first connection line to the pressure chamber on the piston side and by the second connection line to the pressure chamber of the second hydraulic cylinder on the piston rod side. Therefore, each hydraulic cylinder can be controlled in the two movement directions by the control valves, so by corresponding simultaneous activation of the two control valve devices, the side slide device and the prong adjusting device can easily be formed.
The side slide device, in which the fork prongs are adjusted to the left or right in the same direction at the same movement speed, can be attained by the simultaneous activation of the first activation device or the second activation devices of the two control valves, with a connection of this type of the control valves to the hydraulic cylinders with the two control valves, which in each case control one hydraulic cylinder.
The prong adjusting device, in which the two fork prongs move apart or together in the opposite direction at the same movement speeds can easily be achieved with a connection of this type of the hydraulic cylinders to the control valves by means of the simultaneous activation of the first activation device of the first control valve and the second activation device of the second control valve or the second activation device of the first control valve and the first activation device of the second control valve.
According to a further embodiment of the invention, in the first control position of the first control valve, the first hydraulic cylinder can be actuated in the direction of a second movement direction and, in the second control position of the first control valve, the first hydraulic cylinder can be actuated in the direction of a first movement direction, and, in the first control position of the second control valve, the second hydraulic cylinder can be actuated in the direction of the first movement direction and, in the second control position of the second control valve, the second hydraulic cylinder can be actuated in the direction of the second movement direction. The first and second connection lines of the two control valves connected here to the same pressure chambers of the hydraulic cylinders arranged with mutually facing piston rods, for example the first and second control valve, are connected by the first connection line to the respective pressure chamber of the associated hydraulic cylinder on the piston side and by the second connection line to the respective pressure chamber of the associated hydraulic cylinder on the piston rod side. As a result, each hydraulic cylinder can also be controlled in the two movement directions by the control valves, so, by corresponding simultaneous activation of the two control valve devices, the side slide device and the prong adjusting device can easily be formed.
With a connection of this type of the hydraulic cylinders to the control valves, the prong adjusting device can easily be attained by the simultaneous activation of the first activation devices or the second activation devices of the two control valves.
The side slide device, with a connection of this type of the control valves to the hydraulic cylinders, can be easily attained by the simultaneous activation of the first activation device of the first control valve and the second activation device of the second control valve or the second activation device of the first control valve and the first activation device of the second control valve.
Owing to the arrangement of the two hydraulic cylinders with mutually facing piston rods on the load receiving means, in the two types of connection for the side slide device to the hydraulic cylinders, in each case, a pressure chamber on the piston side and a pressure chamber on the piston rod side, and therefore to the two hydraulic cylinders, pressure chambers of different sizes are loaded with pressure means. If, according to an advantageous development of the invention, for the activation of the side slide device, the activation devices can be loaded with different activation currents, even with pressure chambers of different sizes, loaded with pressure means, of the two hydraulic cylinders, which are connected by means of the corresponding control valve to the delivery line, the same movement speeds of the two hydraulic cylinders can easily be attained, in particular upon the activation of the hydraulic cylinders for the side slide device.
According to a preferred development of the invention, it is provided that at least one sensor device detecting an end stop of a hydraulic cylinder is provided. Using a sensor device of this type, the activation of the control valves and therefore the movement of the hydraulic cylinders can easily be ended if a hydraulic cylinder moves to an end stop, so that the movement of the hydraulic cylinder not located at the end stop can easily be ended upon the simultaneous activation of the two control valves in the prong adjusting device and in the side slide device.
For this purpose, a respective corresponding sensor device, for example a key switch, may be arranged on the two hydraulic cylinders for the two end stops.
Particular advantages can be attained when the sensor device according to an expedient embodiment of the invention, is configured as a pressure sensor detecting the highest load pressure of the two hydraulic cylinders. If a hydraulic cylinder moves to an end stop, the corresponding load pressure increases. As a result, the two end stops can easily be detected with only one sensor device in the two hydraulic cylinders.
The sensor device is expediently connected to the electronic control device, so in a hydraulic cylinder located at the end stop, the activation of the control valve controlling the other hydraulic cylinder, or the activation of the two control valves, can easily be ended.
The electronic control device is expediently configured here in such a way that when a pressure limit value detected by the pressure sensor is exceeded, the activation of the activation device is ended. With a corresponding pressure limit value, the end stops of the hydraulic cylinders can easily be detected, so the activation of the control valves can be ended by the electronic control device.
Further advantages and details of the invention will be described in more detail with the aid of the embodiments shown in the schematic figures, in which: Fig. I shows a first embodiment of the hydraulic controller of an industrial truck according to the invention and Fig. 2 shows a second embodiment of a hydraulic controller of an industrial truck according to the invention.
Figs 1 and 2 show the detail from the hydraulic circuit diagram of a hydraulic controller according to the invention of an industrial truck.
A first hydraulic cylinder Ia is connected to a first, left-hand fork prong for its lateral adjustment. Accordingly, a second hydraulic cylinder lb is connected to a second, right-hand fork prong of a load receiving means formed by the two fork prongs and configured as a load fork, for the lateral adjustment thereof. The two hydraulic cylinders Ia, lb are arranged here with mutually facing piston rods on the load receiving means of the industrial truck, the piston rods moving in and out being in operative connection with the corresponding fork prongs.
To control the first hydraulic cylinder la, a first control valve device 2a configured as a control valve 3a which throttles in intermediate positions is provided.
Correspondingly, a second control valve device 2b configured as a control valve 3b which throttles in intermediate positions is provided to control the second hydraulic cylinder 1 b.
The control valves 3a, 3b are connected on the input side by means of a respective delivery branch line 4a, 4b to a delivery line 5 of a pump, not further shown, and, on the output side, by means of two respective container branch lines 6a, 7a or 6b, 7b, which are connected to a container line 8 guided to a container, not shown further, to the container.
The control valves 3a, 3b are in each case connected by a first connection line lOa, I Ob to a first pressure chamber of the associated hydraulic cylinder I a or I b and by a second connection line 11 a, 11 b to a second pressure chamber of the associated hydraulic cylinder 1 a or lb. In the embodiment of the invention shown in Fig. 1, the first connection line lOa of the first control valve 3a is connected to the pressure chamber on the piston rod side and the second connection line 11 a of the first control valve la is connected to the pressure chamber of the first hydraulic cylinder la on the piston side. The first connection line lOb of the second control valve 3b is connected to the pressure chamber on the piston side and the second connection line Ii b of the second control valve 3b is connected to the pressure chamber of the second hydraulic cylinder I b on the piston rod side. In the embodiment shown in Fig. 2, the first connection line lOb of the second control valve 3b is also connected to the pressure chamber on the piston side and the second connection line 11 b of the second control valve 3b is connected to the pressure chamber of the second hydraulic cylinder lb on the piston rod side. Fig. 2 only differs from Fig. 1 by the connection of the connection lines lOa, ha of the first control valve 3a to the first hydraulic cylinder la, the first connection line lOa of the first control valve 3a being connected to the pressure chamber on the piston side and the second connection line 11 a of the first control valve 3a being connected to the pressure chamber of the first hydraulic cylinder la on the piston rod side. It is obviously also possible to leave the connection of the first hydraulic cylinder Ia to the first control valve 3a unchanged and to interchange the connections of the second hydraulic cylinder I b to the second control valve 3b.
The control valves 3a, 3b in each case have a neutral position 12a, 12b, in which the connection of the delivery branch line 4a or 4b and the container branch lines 6a, 7a or 6b, 7b to the connection lines lOa, ha or lOb, lib are locked. In a first control position 13a, 13b of the control valves 3a, 3b, the first connection line lOa or lOb is connected to the delivery branch line 4a or 4b and the second connection line 11 a or II b is connected to the container branch line 7a or 7b. Accordingly, in a second control position l4a, 14b of the control valves 3a, 3b, the second connection line 1 la or 11 b is connected in each case to the delivery branch line 4a or 4b and the first connection line lOa or lOb is connected to the container branch line 7a or 7b.
The control valves 3a, 3b are electrically activatable and configured as electro hydraulically pre-controllable control valves. The first control valve 3a can be actuated here by means of a first activation device 15a in the direction of the first control position 13a and by means of a second activation device 16a in the direction of the second control position 14a. Accordingly, the second control valve 3b can be actuated by means of a first activation device I 5b in the direction of the first control position 13b and by means of a second activation device 16b in the direction of the second control position 14b. The activation devices 15a, 15b, 16a, 16b are formed here by electrically actuatable pilot valves, which are configured in each case as a proportional valve producing a corresponding control pressure for the control valve 3a, 3b, in particular a pressure reducing valve 17a, 17b, 18a, 18b, which are connected to a control pressure supply line 21 and a container line 22 and can be actuated by means of a respective proportional magnet 19a, 19b, 20a, 20b in the direction of a control circuit, in which a control pressure loading the control valve 3a, 3b is produced.
The activation devices 15a, 15b, 16a, 16b can be activated here by means of an electronic control device, not shown any further here, as a function of the actuation of an actuating member, for example a joystick.
Upon an activation of the first activation device I 5a and a loading of the first control valve 3a in the direction of the first control position 1 3a, the first hydraulic cylinder 1 a is loaded in a first movement direction 35a here in Fig. 1. Correspondingly, the first hydraulic cylinder la on an activation of the second activation device 16a moves in the direction of a second movement direction 35b when the control valve 3a is loaded in the direction of the second control position 14a.
In the hydraulic controller according to Fig. 2, the first hydraulic cylinder Ia, on activation of the first activation device 1 5a and with the control valve 3a loaded in the direction of the first control position 13a, moves in the direction of the second movement direction 35b. On an activation of the second activation device 16a and therefore with the control valve 3a loaded in the direction of the second control position 14a, the first hydraulic cylinder la can be moved in the direction of the first movement direction 35a.
In the two hydraulic controllers according to Figs. I and 2, by means of an activation of the first activation device 15b and a loading of the second control valve 3b in the direction of the first control position 13b, the second hydraulic cylinder lb can be moved in the direction of the first movement direction 35a. On an activation of the second activation device 16b and a loading of the second control valve 3b in the direction of the second control position 14b, a movement of the second hydraulic cylinder lb can be attained in the direction of the second movement direction 35b.
Arranged in the delivery branch lines 4a, 4b is, in each case, is a respective pressure balance 25a, 25b, which are loaded by the load pressure of the associated hydraulic cylinder la or lb guided in a load pressure branch line 26a, 26b, and a spring, in the direction of a locking position, and by the delivery pressure present in the delivery branch line 4a or 4b in the direction of a throughflow position.
In the neutral position 13a, 13b of the control valves 3a, 3b, the corresponding load pressure branch lines 26a, 26b are connected to the container branch line 6a, 6b.
The load pressure branch lines 26a, 26b are connected by means of an alternating check valve device 27 to a load pressure line 28 conducting the highest load pressure, which is used for the delivery volume control of the pump configured, for example, as a load-sensing pump. A sensor device 30 configured as a pressure sensor 29 and which is connected to the electronic control device, is associated with the load pressure line 28.
The lateral adjustment of the left-hand fork prong connected to the first hydraulic cylinder la can be attained by corresponding activation of the activation devices l5a or 1 6a alone, upon a corresponding actuation of the actuating member configured as a joystick. In the circuit according to Fig. Ia, on an activation of the first activation device 15a, a lateral adjustment of the left-hand fork prong is attained in the first movement direction 35a and on an activation of the second activation device 16a, a lateral adjustment of the fork prong in the second movement direction 35b is attained. In the circuit according to Fig. 2, on activation of the first activation device 15a, a lateral adjustment of the left-hand fork prong in the second movement direction 35b can be attained and on an activation of the second activation device 1 6a, a lateral adjustment of the fork prong in the first movement direction 35a can be attained.
The lateral adjustment of the right-hand fork prong, which is in operative connection with the second hydraulic cylinder Ib, can be attained by activating the activation devices 15b, 16b alone upon a corresponding actuation of the actuating member configured as joysticks. On activation of the first activation device 1 5b, the right-hand fork prong is laterally adjusted in the first movement direction 35a and, on activation of the second activation device 16b, the right-hand fork prong is laterally adjusted in the second movement direction 35b.
The prong adjusting device with fork prongs moving apart in the opposite direction can be attained in the circuit according to Fig. 1 by a simultaneous activation of the first activation device I 5a of the first control valve 3a and the second activation device 1Gb of the second control valve 3b on a corresponding actuation of the actuating member. A prong adjusting device with fork prongs moving together in the opposite direction can be attained on a corresponding actuation of the actuating member configured as joysticks by a simultaneous activation of the second activating device 1 6a of the first control valve 3a and of the first activation device I 5b of the second control valve 3b.
A side slide device in the hydraulic circuit of Fig. I can be attained by a simultaneous activation of the two first activation devices I 5a, I 5b of the two control valves 3a, 3b or the simultaneous activation of the two second activation devices 16a, 16b of the two control valves 3a, 3b on a corresponding actuation of the actuating member. On simultaneous activation of the two first activation devices 15a, 15b, a side slide device can be formed here, in which the two fork prongs move in the same direction in the first movement direction 35a. Accordingly, on the simultaneous activation of the two second activation devices 16a, 16b, a side slide device can be formed here, in which the two fork prongs move in the same direction in the second movement direction 35b.
In the hydraulic circuit according to Fig. 2, on the simultaneous activation of the two first activation devices 1 5a, I 5b of the two control valves 3a, 3b or the simultaneous activation of the two second activation devices 1 6a, 1 6b of the two control valves 3a, 3b on a corresponding actuation of the actuating member, a prong adjusting device can be attained. On the simultaneous activation of the two first activation devices 15a, 15b, the two fork prongs move toward one another in the opposite direction, and on simultaneous activation of the two second activation devices 16a, 16b they move apart from one another in the opposite direction.
The side slide device can be attained in the circuit according to Fig. 2 by a simultaneous activation of the first activation device 15a of the first control valve 3a and of the second activation device 16b of the second control valve 3b or, on a simultaneous activation of the second activation device I 6a of the first control valve 3a and the first activation device 15b of the second control valve 3b on a corresponding actuation of the actuating member. The two fork prongs, on simultaneous activation of the second activation device 16a of the first control valve 3a and the first activation device I 5b of the second control valve 3b move here in the same direction in the first movement direction 35a. On simultaneous activation of the first activation device 1 5a of the first control valve 3a and the second activation device I 6b of the second control valve 3b, a movement in the same direction of the two fork prongs in the second movement direction 35b can be attained.
If, on simultaneous activation of the two control valves 3a, 3b of the prong activating device or the side slide device in the circuits according to Fig. I and 2, a hydraulic cylinder la or lb moves to an end stop, the load pressure guided in the load pressure line 26a or 26b, of this hydraulic cylinder la or lb increases and is reported in the load pressure line 28. If the load pressure exceeds a pressure limit value detected by the pressure sensor 30, the activation of the activation devices is ended by the electronic control device, so the further movement of the hydraulic cylinder I a or 1 b not located at the stop is also ended by the loading being adjusted of the control valves 3a, 3b into the neutral position 13a, 13b.
By means of the pressure balances 25a, 25b, the same movement speed of the two hydraulic cylinders 1 a, I b and therefore the same movement speeds of the two fork prongs, is ensured here in the hydraulic circuits according to Figs. 1 and 2 with simultaneous activation of the two control valves 3a, 3b of the prong adjusting device or the side slide device.
On simultaneous activation of the two control valves 3a, 3b for the side slide device, in the circuits according to Figs. I and 2, the corresponding activation devices can also be activated by the electronic control device with different activation currents in order to compensate, by different opening cross-sections of the two control valves 3a, 3b, the speed differences of the two fork prongs resulting because of the pressure-loaded pressure chamber on the piston rod side or because of the pressure-loaded pressure chamber on the piston side of the two hydraulic cylinders 1 a, 1 b, and therefore to attain the same movement speeds of the two fork prongs.
Owing to the association according to the invention of a respective control valve 3a, 3b connected by means of the connection lines IOa, ha or lOb, lib to the corresponding hydraulic cylinder la, ib, a prong adjusting device and side slide device can be attained by the corresponding simultaneous activation of the activation devices 15a, 15b, 16a, 16b in a purely electric-hydraulic manner. For this purpose, no further locking valves are required, so the controller according to the invention has a simple structure with a low construction outlay. In addition, the cylinder cross-sections of the hydraulic cylinders la, lb can be reduced, as the two hydraulic cylinders 1 a, lb are loaded by pressure means of the pump in the side slide device, so the construction outlay is further reduced and the hydraulic circuit according to the invention has a low overall installation space requirement for the hydraulic cylinders la, lb arranged in the region of the load receiving means of the industrial truck. In addition, when a control valve 3a or 3b is activated alone, a fork prong adjustment can be attained for each fork prong as an additional function.
Claims (19)
- Claims 1. Hydraulic controller of an industrial truck with a side slide device and a prong adjusting device of a load receiving means consisting of two fork prongs, each fork prong being displaceable by means of a hydraulic cylinder in the lateral direction and the fork prongs being displaceable in the same direction, in the lateral direction, for the side slide device and the fork prongs being displaceable in the opposite direction, in the lateral direction, for the prong adjusting device, characterised in that each hydraulic cylinder (Ia, Ib) can be actuated by means of a control valve device (2a, 2b), wherein, upon an activation of a single control valve device (2a; 2b), a fork prong adjustment of a single fork prong can be attained and/or the prong adjusting device and the side slide device can be attained by a simultaneous activation of the two control valve devices (2a, 2b).
- 2. Hydraulic controller according to claim 1, characterised in that the control valve device (2a, 2b) is in each case configured as an electrically activatable control valve (3a; 3b) throttling in intermediate positions, with a neutral position (12a; 12b), a first control position (13a, 13b) and a second control position (14a; 14b), which is connected on the input side by means of a delivery branch line (4a; 4b) to a delivery line (5) of a pump and, on the output side, to a container line (8), and controls the connection of the delivery branch line (4a; 4b) and the container line (8) to a first connection line (ba; lOb) guided to a first pressure chamber of the associated hydraulic cylinder (la; ib), as well as a second connection line (ha; lib) guided to a second pressure chamber of the associated hydraulic cylinder (Ia; Ib), a respective pressure balance (25a; 25b) loaded by the load pressure of the associated hydraulic cylinder (la; ib) being arranged in the delivery branch line (4a; 4b).
- 3. Hydraulic controller according to claim 2, characterised in that the pressure balance (25a; 25b) can be loaded by the load pressure of the associated hydraulic cylinder (la; Ib) and a spring in the direction of a locking position as well as by the delivery pressure present in the delivery branch line (4a; 4b) in the direction of a through-flow position.
- 4. Hydraulic controller according to claim 2 or 3, characterised in that the control valves (3a; 3b) can in each case be actuated by means of a first electric activation device (15a; 15b) in the direction of the first control position (13a; 13b) and, in each case, by means of a second electric activation device (16a; 16b) in the direction of the second control position (14a; 14b).
- 5. Hydraulic controller according to claim 4, characterised in that the control valves (3a; 3b) are configured as electro-hydraulically precontrollable control valves, the activation devices (15a; 15b; 16a; 16b) being configured as electrically actuable pilot valves.
- 6. Hydraulic controller according to claim 5, characterised in that the pilot valves are in each case configured as a proportional valve (17a; 17b; 18a; 18b) which produces a control pressure of the control valve (3a; 3b) and can be actuated by means of a proportional magnet (1 9a; 19b; 20a; 20b).
- 7. Hydraulic controller according to any one of claims 4 to 6, characterised in that the activation devices (15a; 15b; 16a; 16b) can be activated by means of an electronic control device as a function of the actuation of an actuating member, in particular a joystick.
- 8. Hydraulic controller according to any one of claims 4 to 7, characterised in that a fork prong adjustment of a single fork prong can be attained by activating the first activation device (15a; 15b) alone or the second activation device (16a, 16b) alone of the first control valve (3a) or the second control valve (3b).
- 9. Hydraulic controller according to any one of claims 2 to 8, characterised in that in the first control position (13a) of the first control valve (3a), the first hydraulic cylinder (Ia) can be actuated in the direction of a first movement direction (35a) and, in the second control position (14a) of the first control valve (3a), the first hydraulic cylinder (la) can be actuated in the direction of a second movement direction (35b), and, in the first control position (13b) of the second control valve (3b), the second hydraulic cylinder (Ib) can be actuated in the direction of the first movement direction (35a) and, in the second control position (14b) of the second control valve (3b), the second hydraulic cylinder (ib) can be actuated in the direction of the second movement direction (35b).
- 10. Hydraulic controller according to claim 9, characterised in that the side slide device can be attained by the simultaneous activation of the first activation devices (1 5a, 1 5b) or the second activation devices (1 6a, I 6b) of the two control valves (3a, 3b).
- 11. Hydraulic controller according to claim 9 or 10, characterised in that the prong adjusting device can be attained by simultaneous activation of the first activation device (1 5a) of the first control valve (3a) and the second activation device (1 6b) of the second control valve (3b) or by simultaneous activation of the second activation device (16a) of the first control valve (3a) and the first activation device (15b) of the second control valve (3b).
- 12. Hydraulic controller according to any one of claims 2 to 8, characterised in that, in the first control position (13a) of the first control valve (3a), the first hydraulic cylinder (la) can be actuated in the direction of a second movement direction (35b), and in the second control position (14a) of the first control valve (3a), the first hydraulic cylinder (Ia) can be actuated in the direction of a first movement direction (35a), and in the first control position (13b) of the second control valve (3b), the second hydraulic cylinder (1 b) can be actuated in the direction of the first movement direction (35a) and, in the second control position (14b) of the second control valve (3b), the second hydraulic cylinder (1 b) can be actuated in the direction of the second movement direction (35b).
- 13. Hydraulic controller according to claim 12, characterised in that the prong adjusting device can be attained by the simultaneous activation of the first activation devices (15a, 15b) or the second activation devices (16a; 16b) of the two control valves (3a, 3b).
- 14. Hydraulic controller according to claim 12 or 13, characterised in that the side slide device can be attained by simultaneous activation of the first activation device (15a) of the first control valve (3a) and the second activation device (16b) of the second control valve (3b) or by simultaneous activation of the second activation device (16a) of the first control valve (3a) and the first activation device (15b) of the second control valve (3b).
- 15. Hydraulic controller according to claim 10 or 14, characterised in that the activation devices (15a; 15b; 16a; 16b) can be loaded with different activation currents to activate the side slide device.
- 16. Hydraulic controller according to any one of claims 1 to 15, characterised in that at least one sensor device (30) detecting an end stop of a hydraulic cylinder (1 a; ib) is provided.
- 17. Hydraulic controller according to claim 16, characterised in that the sensor device (30) is configured as a pressure sensor (29) detecting the highest load pressure of the two hydraulic cylinders (Ia; I b).
- 18. Hydraulic controller according to claim 15 or 16, characterised in that the sensor device (30) is connected to the electronic control device.
- 19. Hydraulic controller according to claim 17 or 18, characterised in that the electronic control device is configured in such a way that when a pressure limit value detected by the pressure sensor (29) is exceeded, the activation of the activation device (15a; 15b; 16a; 16b) is ended.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE200810034780 DE102008034780A1 (en) | 2008-07-25 | 2008-07-25 | Hydraulic control of a truck |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0912874D0 GB0912874D0 (en) | 2009-08-26 |
| GB2462182A true GB2462182A (en) | 2010-02-03 |
| GB2462182B GB2462182B (en) | 2012-06-27 |
Family
ID=41058472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0912874A Expired - Fee Related GB2462182B (en) | 2008-07-25 | 2009-07-23 | Hydraulic controller of an industrial truck |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE102008034780A1 (en) |
| GB (1) | GB2462182B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102795578A (en) * | 2011-05-23 | 2012-11-28 | 杭州友高精密机械有限公司 | Fork laterally-moving distance-adjusting device of fork truck |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102014006970A1 (en) * | 2014-05-14 | 2015-11-19 | Kaup Gmbh & Co. Kg | Hitch to be attached to a lift truck and method of operating a hitch |
| DE102016110310A1 (en) * | 2016-06-03 | 2017-12-07 | Still Gesellschaft Mit Beschränkter Haftung | Hydraulic drive system of a truck |
| CN114955942B (en) * | 2022-05-31 | 2023-07-18 | 杭叉集团股份有限公司 | Fork space adjustment hydraulic system for forklift |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3692198A (en) * | 1970-12-28 | 1972-09-19 | Clark Equipment Co | Hydraulic lift truck with small number of fluid lines |
| JPS51162474U (en) * | 1975-06-19 | 1976-12-24 | ||
| JPS58109399A (en) * | 1981-12-24 | 1983-06-29 | 日産自動車株式会社 | Forklift device |
| EP0489255A1 (en) * | 1990-12-03 | 1992-06-10 | Caterpillar Industrial Inc. | Fluid operated fork positioning control system |
| JP2005200164A (en) * | 2004-01-15 | 2005-07-28 | Nippon Yusoki Co Ltd | Fork lift |
-
2008
- 2008-07-25 DE DE200810034780 patent/DE102008034780A1/en not_active Withdrawn
-
2009
- 2009-07-23 GB GB0912874A patent/GB2462182B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3692198A (en) * | 1970-12-28 | 1972-09-19 | Clark Equipment Co | Hydraulic lift truck with small number of fluid lines |
| JPS51162474U (en) * | 1975-06-19 | 1976-12-24 | ||
| JPS58109399A (en) * | 1981-12-24 | 1983-06-29 | 日産自動車株式会社 | Forklift device |
| EP0489255A1 (en) * | 1990-12-03 | 1992-06-10 | Caterpillar Industrial Inc. | Fluid operated fork positioning control system |
| JP2005200164A (en) * | 2004-01-15 | 2005-07-28 | Nippon Yusoki Co Ltd | Fork lift |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102795578A (en) * | 2011-05-23 | 2012-11-28 | 杭州友高精密机械有限公司 | Fork laterally-moving distance-adjusting device of fork truck |
Also Published As
| Publication number | Publication date |
|---|---|
| DE102008034780A1 (en) | 2010-01-28 |
| GB0912874D0 (en) | 2009-08-26 |
| GB2462182B (en) | 2012-06-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20150723 |