NL1009507C2 - Hydraulic tilting device for tilting a vehicle cabin and vehicle provided with such a tilting device. - Google Patents

Description

Short designation: Hydraulic tilting device for tilting a vehicle cabin and vehicle provided with such a tilting device.

The present invention relates to a hydraulic tilting device for tilting a cabin of a vehicle between a driving position and a tilted position.

It is generally known from the prior art to tiltably connect a cabin of a (motor) vehicle to the chassis of the vehicle via hinge means in order to be able to tilt the cabin between a driving position in which the vehicle can be driven , 10 and a tilted position, in which, for example, maintenance can be carried out on the engine located under the cabin. Furthermore, it is generally known, for example from GB 2 079 378, DE 42 29 842 and EP 0 101 129, to resiliently support such a tilting cabin in the driving position on the chassis for the comfort of the occupants, with especially the driver, while driving.

For tilting such a resiliently arranged cabin, hydraulic tilting devices are known with one or more tilting cylinders arranged between the chassis and the tilting cabin. In order to prevent the tilting cylinder from interfering with the spring movement of the cabin relative to the chassis, the cabin tilting device has a "lost-motion operation" in such a vehicle. This type of tilting device 25 includes the tilting devices described in GB 2 079 378 and in DE 42 29 842. These known tilting devices have in common that they comprise the parts mentioned in the identical preamble of claims 1 and 2.

In the lost-motion mode of these known tilting devices, the pump is out of operation and the piston is located between the two ports of the lost-motion channel. If the piston rod is now pulled out by a movement of the cab while driving, the lost-motion channel will flow hydraulic fluid from the drawing chamber to the pressure chamber via 1 009507-2. If the piston rod is depressed by a movement of the cab, the hydraulic fluid is released to the reservoir 5 since the hydraulic pressure in the pressure chamber acts on the opening control surface of the slide valve and the slide body thereof against the force of the spring towards the open one. position moved. These known tilting devices therefore have the object that the piston / piston rod assembly can slide in and out practically unhindered within a range defined by the ports of the lost-motion channel.

In practice, the above-mentioned tilting devices known from GB 2 079 378 and DE 42 29 842 appear to have the drawback that the lost-motion movement of the piston / piston rod assembly nevertheless results in an undesired disturbance of the movement of the cabin.

The object of the present invention is to eliminate the above-mentioned drawback, so that in the lost-motion mode of the tilting device a smooth running in and out of the tilting cylinder (s) is possible. The object of the present invention is furthermore to ensure that if the piston / piston rod assembly is extended outside the "lost-motion range", a reliable "holding function" is obtained, that is to say that the tilt cylinder is secured against unintentional retraction. , for example, if the pump is stopped in a position that is not fully tilted forward from the cabin and the cabin is then supported on the tilt cylinder (s).

The present invention achieves these objectives by providing tilting devices according to claims 1 and 2.

The tilting devices according to claims 1 and 2 are based on the following common insight. In the tilting devices known from GB 2 079 378 and DE 42 29 842 it is only the spring pressing against the sliding body of the sliding valve, which in a 1 0 Π Q and 7 - 3 number of commonly occurring situations, moves the sliding body to the closed position. pressed and held in that closed position, so that the slide valve is and remains closed. In such cases, in order to ensure that the sliding valve is closed, the sliding body must be pressed to the closed position with a certain minimum closing force. With the known tilting devices, this requires that the spring of the slide valve is rigid, i.e. with a large spring constant. However, it has been found that a rigid design of this spring 10 has the drawback that in the lost-motion mode of these tilting devices, a considerable pressure must be exerted on the opening control surface of the sliding body in order to open the sliding valve against the force of the rigid spring. As a result, in the lost-15 motion mode the sliding valve opens only at a considerable hydraulic pressure, which hinders the movement of the piston / piston rod assembly and thus disturbs the movement of the associated spring-mounted cab.

Also, due to the stiff spring, the pressure in the cylinder space during the lost-motion mode always remains at an undesirably high level, which also hinders the lost-motion movement.

The invention, as described in claims 1 and 2, provides measures whereby the spring which pushes the sliding body to its closed position can be made considerably less rigid than with the known tilting devices. The common starting point of the solutions according to claims 1 and 2 is to increase the hydraulic force which pushes the sliding body to its closed position relative to the known tilting devices. As a result, a weaker, less rigid spring or similar spring means is permissible in the sliding valve without the disadvantageous reduction of the closing force necessary in certain situations with which the sliding body is kept in its closed position is disadvantageously reduced.

Advantageous embodiments of the tilting device according to the invention will be described below on the basis of the drawing. In the drawing: Fig. 1 shows the hydraulic diagram of a first exemplary embodiment of the tilting device according to the invention, Fig. 2 shows in longitudinal section a preferred embodiment of the sliding valve that can be used in the scheme of Fig. 1, Fig. 3 shows the hydraulic scheme of a second exemplary embodiment of the tilting device according to the invention, and fig. 4 in longitudinal section a preferred embodiment of the sliding valve which is applicable in the scheme of figure 3.

The hydraulic tilting devices shown in the drawing are intended for tilting the driver's cab of a vehicle, in particular of a truck. Such cabs are usually mounted on the chassis of the vehicle and are connected to the chassis in a tilting manner via hinge means. The hinge means are designed such that the cabin can tilt between a driving position, in which the vehicle can be driven, and a tilted position, usually forward, in which, for example, maintenance can be carried out on the vehicle, in particular on the whole or engine located partly under the cabin.

Such vehicles are further usually provided with cab support means which support the cab in the driving position, such that the cab in the driving position can spring up and down relative to the chassis in order to increase the comfort of the driver.

A hydraulic tilting device is provided for tilting the cabin forward and back. Figure 1 schematically shows such a hydraulic tilting device. This tilting device comprises a reservoir 1 for hydraulic fluid and a preferably electrically driven pump 2 with reversible pumping direction, which pump 2 has a first port 3 and a second port 4. Depending on the direction of rotation of the drive motor, one port is suction port for drawing in liquid and the other port is pressing port for delivering liquid under pressure.

Figure 1 further shows a double-acting linear hydraulic tilting cylinder 5 for tilting the vehicle cabin (not shown). The cylinder 5 comprises a cylinder housing 6 with a cylinder space 7 therein, in which a piston / piston rod assembly can be moved to and fro.

The piston / piston rod assembly comprises a piston 8 and piston rod 9 fixedly connected thereto. A sealing ring 10 surrounds the piston 8, while the piston rod 9 projects out of the cylinder housing 6 through a seal 11. The cylinder 5 is usually arranged between the cabin and the chassis of the vehicle, usually the cylinder housing 6 is pivotally connected to the chassis and the end of the piston rod 9 is pivotally connected to the cabin.

The piston / piston rod assembly forms in the cylinder space 7 a drawing chamber 12, which retracts the piston / piston rod assembly when hydraulic fluid is supplied thereto, and a pressure chamber 13, which, when hydraulic fluid is supplied thereto, the piston / piston rod assembly 25 extends. For the drawing chamber 12 and the pressure chamber 13, an associated pulling connection 14 and pressure connection 15 are respectively provided.

The pull connection 14 is connected via a first hydraulic line 16 to the first port 3 of the pump 2. The first line 16 contains two counter-acting and parallel positioned check valves 17, 18, which together form a suction blocking device for a prevent unhindered intake of liquid via line 16.

The pressure connection 15 is connected via a second hydraulic line 20 to the second port 4 of the pump 2.

A non-return valve 21 closing in the direction of the pump 2 is accommodated in the second line 20. The check valve 21 is of the hydraulically operated type and can be opened by means of a control signal, which is achieved here with hydraulic control line 22, which transfers the pressure prevailing in the first line 16 to a control surface of the check valve 21.

The reservoir 1 is connected via a suction changeover valve 24 to both the first line 16 and to the second line 20. The suction changeover valve 24 has a bore with at each end thereof a seat for an associated closing member, here a ball, in which the there is a spacer which ensures that only one of the closing members fits on its seat and the other closing member is thus pushed off its seat.

The spacer fits into the bore with play, so that the reservoir 1 is always in communication with the first pipe 16 or the second pipe 20 via a pipe 25 opening into the bore.

To prevent excessive high pressure of the liquid in the hydraulic circuit, relief valves 27 and 28 are provided, which are placed between the first line 16 and the reservoir 1 and the second line 20 and the reservoir 1, respectively.

The tilting device also comprises a release-motion channel 30 with two ports opening into the cylinder space 7, respectively denoted 31 and 32, in this example the port 31 coinciding with the pressure connection 15 of the cylinder 5.

The release motion channel 30 is shown schematically in Figure 1 and can be designed in various ways. It is thus possible for the lost-motion channel 30 to be formed by a lost-motion conduit lying outside the cylinder housing 6. However, it is also conceivable that the lost-motion channel is arranged in the cylinder housing 6. In yet another variant, the lost-motion channel 30 is arranged in a tube directed upwards from the bottom of the cylinder housing 6 in the cylinder space.

1009507 - 7 -

The release motion channel 30 connects the drawing chamber 12 to the pressure chamber 13 when the piston 8 is located between the two ports 31, 32 of the channel 30, which is the case in a position associated with the driving position of the cab. piston rod assembly. While driving the vehicle, the pump 2 is out of operation and the tilting device functions in its "lost-motion mode". In the lost-motion channel 30, a non-return valve 33 is included, which closes in the direction of the gate 32, which gate 32 opens into the drawing chamber 12 in the lost-motion mode of the tilting device.

The hydraulic tilting device shown further comprises a hydraulically operated slide valve 40 of the two-way / two-position 2/2 type, of which valve 40 an exemplary embodiment is shown in figure 2. This valve 40 has a housing 41 with a first valve port 42, which is connected to the pressure chamber 13 of the cylinder 5, and a second valve port 43, which is connected to the reservoir 1 in at least the lost-motion mode. Furthermore, the valve 40 has a bore in the housing 41 and again movable sliding body 44. The sliding body 44 is movable between a closed position shown in figure 2, in which an axial end of the sliding body 44 sealingly abuts against a seat 45 in the connection between the first valve port 42 and second valve port 43, and a open position, wherein the sliding body 44 is spaced from the seat 45 and the first valve port 42 and the second valve port 43 are connected to each other. In figure 2 it can be recognized that a liquid pressure prevailing at the first valve port 42 also acts on an opening control surface 46 of the sliding body 44 in the closed position of the valve 40, so that a hydraulic pressure in the pressure chamber 13 acts on the opening control surface 46 for pushing the sliding body 44 into the open position. This is indicated in the diagram of figure 1 by control pressure line 47.

On the side of the sliding body 44 opposite the opening control surface 46, a light return spring 48 engages, which loads the sliding body 44 in the direction of its closed position. Furthermore, the side of the sliding body 44 remote from the seat 45 forms a closing control surface 50. The housing 41 is provided with a control line connection 51, to which a control line 52 connects, which communicates with the closing control surface 50. The control line 52 connects to a output 53c of an OR valve 53, also known as a shuttle valve. This OR valve 53 has a first inlet 53a, which connects to a control line 54, which is connected to the part of the lost-motion line 30 connecting to the port 32. Furthermore, the OR valve 53 has a second inlet 53b , which connects to a control line 55, which in turn connects to the second hydraulic pressure line 20.

The tilting device now described operates as follows. To extend the piston rod 9 from the position shown in figure 1, and thereby tilt the cabin forward, hydraulic fluid is supplied via the port 4 and the second line 20 to the pressure chamber 13. The non-return valve 33 closes the release valve. motion line 30. Also, the valve 40 remains closed because the hydraulic pressure on the closing control surface 50, together with a small load on the spring 48, is stronger than the hydraulic pressure on the opening control surface 25, which opening control surface 46 is smaller than the closing control surface 50.

If, during the forward tilting of the cabin, it is stopped, and the cabin would like to tilt back to the driving position under the influence of its own weight, then the non-return valve 21. closes if the piston 8 is above the gate 32 at the moment of stopping. valve 40 also remains closed, because then the hydraulic pressure in the pressure chamber 13 via the control line 54 and the shuttle valve 53 acts on the closing control surface 50 of the sliding body 44. Thus, the sliding body 44 is pressed firmly against the seat 45 and the piston / piston rod assembly is reliably held in place, which is of great importance for the safety of the persons who are then under the cabin or are there .

When the cabin is to be tilted from the tilted position to the driving position, i.e. the piston rod 9 must be retracted, liquid is supplied to the drawing chamber 12 via first port 3. Due to the pressure in the first line 16, the non-return valve 21 opens and liquid can flow out of the pressure chamber 13. If the tilt-back is interrupted in a position in which the piston 8 is located above the port 32, the pressure in the lost-motion conduit acting via conduit 52 on the body 44 of the valve 40 keeps the valve 40 closed. The valve 21 also closes, so that the cabin then remains stationary. When the piston 8 has already passed port 32 when the cabin is tilted back to the driving position, the pressure in the part of the lost-motion channel 30 between valve 33 and port 32 is released.

As a result, the pressure in line 52 is also released and the valve 40 is opened by the pressure prevailing in line 47. As a result, the liquid can flow from the pressure chamber 13 to the reservoir 1 and the cabin can tilt back further unhindered to the driving position, optionally providing an orifice to limit the speed of movement of the cabin. This "free" tilting movement of the cab is in many cases desirable for the cab to be locked with one or more cab locking devices mounted on the chassis, which lock the cab in the driving position. A relatively rapid tilting movement of the cab is often advantageous for the cab and such locking devices to engage with each other. When the cabin is in the driving position and the tilting device has been brought into the lost-motion mode, which here simply means that the pump 2 is switched off, the operation of the device shown in figure 1 is as follows.

When the cabin makes a spring movement such that the piston rod 9 is pulled out of the cylinder housing 6, fluid flows through the port 32 from the drawing chamber 12 and then passes through the line 30, through the opening check valve 33 into the pressure chamber 13. The valve 40 remains closed.

When the cabin moves in such a way that the piston rod 5 is pressed into the cylinder housing 6, liquid flows from the pressure chamber 13 via the opened valve 40 to the reservoir 1. The valve 40 opens in this situation because a hydraulic pressure is supplied via the control pressure line 47 applied to the control pressure opening surface 46 of the sliding body 44. At the same time, no hydraulic pressure acts on the closing surface 50, so that only the light spring 48 opposes opening of the valve 40.

The hydraulic scheme according to figure 1 described here deviates in particular from the scheme shown in GB 2 079 378 15, in that on the connection 51 of the sliding valve 40, which connection 51 is connected to the closing surface 50 of the sliding valve 40, not only connects the lost-motion channel 30 but also, via the intermediate OR valve 53, also the pipe 20, which connects the pump 20 2 to the pressure chamber 13 of the cylinder 5. Because of the additional hydraulic actuation in the closing direction of the sliding valve 40 as proposed by the present invention, the spring 48 of that sliding valve 40 can be considerably weaker than with the valve in the scheme of 25 GB 2 079 378. Because the spring 48 has a light spring, the valve 40 in the lost-motion mode of the device will open easily, thereby causing the cylinder 5 to interfere as little as possible with the spring movement of the cabin, and thus the comfort for the occupants. Also, the light spring 48 achieves that the pressure in the cylinder 5 during the lost-motion mode is low, which is advantageous for a smooth running movement of the piston / piston rod assembly.

In figure 2 it can further be recognized that the sliding body 44 of the sliding valve 40 is of stepped design and has a larger outer diameter on the side of the closing surface 50 than on the side of the opening surface 46, wherein the sliding body 44 has an annular shape. shoulder surface 49 has at the transition from the larger diameter to the smaller diameter. The bore in the housing 41 is also stepped, with a smaller diameter on the side of the seat 45, in which the part with the smaller diameter of the sliding body 44 fits slidingly, and with a part with a larger diameter, in which the part with the larger diameter of the sliding body slidingly fits. Both the smaller diameter part and the larger diameter part of the sliding body 44 are provided with a sealing ring, 58, 59, respectively, which seal against the bore in the housing 41.

The measure to design the slider body 44 with a stepped outer diameter, as described above, aims to increase the hydraulic force which keeps the slider body 44 in its closed position compared to conventional slider valves of this type, the slider body being the opening side and the closing side have the same diameter. By increasing the hydraulic closing force in this way, the spring 48 can again be lighter, weaker, than had been achieved with the previously described measure. As mentioned, this has a favorable effect on the lost-motion behavior of the cylinder 5 and thus on the spring behavior of the cabin.

Since a small amount of liquid can pass through the seals 58, 59, an additional channel 60 is provided in the housing 41 of this valve 40, which has a mouth 62 near the shoulder surface 61 of the bore for the sliding body 44. The channel 60 communicates with the reservoir 1, so that no liquid can accumulate in the space between the shoulder surfaces of the bore and of the sliding body 44. Such an accumulation of liquid would disturb the movement of the sliding body 44. Instead of the channel 60, an internal channel in the sliding body 44 may also be provided, which extends between point 60a in figure 2, which communicates with connection 43, and a point 60b near the shoulder 49.

In a variant (not shown) of the diagram of 1009507 - 12 - figure 1, the check valves 17 and 18 in the first pipe 16 are replaced by a hydraulically operated check valve, which closes in the direction of the pump, just like the valve 21. The control line of this check valve connects 5 to the second line 20

In another variant of the scheme of figure 1, a non-return valve is closed between the port 43 of the valve 40 and the reservoir 1, which closes in the direction of the valve 40 to prevent undesired suction of hydraulic fluid.

In yet another variant, the lost-motion channel 30 runs via the OR valve 53, which in the diagram of Figure 1 means that the non-return valve 33 connects on its seat side to the line 52 to the OR valve 53. This variant is constructionally easy to realize in a valve block.

It will be appreciated that the OR valve 53 may be constructed in many ways known to those skilled in the art to achieve the above described operation.

The tilting device shown in figure 3 as a hydraulic scheme is substantially the same as the scheme according to figure 1 of DE 42 29 842 and also comprises a large number of parts which have already been explained with reference to figure 1 of this application. In Figure 3, the parts corresponding to the parts of Figure 1 are indicated by the same reference numerals and will not be further elucidated.

Instead of the reversible pump 2, a one-way pump 65 with a discharge port 66 is now provided.

A return line 67 to the reservoir 1 is also provided. An operable two-position control valve 68 serves to optionally connect the discharge port 66 and the return line 67 to the first line 16 to the pull port 14 and the second line 20 to the pressure port 15.

Figure 3 furthermore shows a sliding valve 70, which is shown in detail in figure 4. Like the slide valve 40, the slide valve 70 is a hydraulically operated two-way / two-position type or 2/2 type slide valve. The valve 70 is received in the second conduit 20 between the valve 68 and the pressure connection 15 of the pressure chamber 13 of the cylinder 5. The valve 70 has a housing 71 with a first valve port 72, which is connected to the pressure chamber 13 of the cylinder 5, and a second valve port 73, which is connected to a port of the valve 68. Furthermore, the valve 70 has a sliding body 74 which is movable back and forth in the first bore in the housing 71 and which is movable between a figure 4 shown in figure 4. closing position, in which an axial end of the sliding body 74 sealingly abuts against a seat 75 in the connection between the first valve port 72 and second valve port 73, and an opening position, in which the sliding body 74 is spaced from the seat 75. The valve 70 further has a first control pressure connection 76 for a control line 77, which communicates with the first hydraulic line 16 between the valve 68 and the pull connection 14. In the housing 71, a second bore 78 is provided in the extension. narrow of the first bore with a reciprocally displaceable control piston 79, which is loaded on one side by the hydraulic pressure at the control pressure connection 76. The control pressure piston 79 is designed such that if the pump 2 supplies liquid to the first line 16, Sliding body 74 of its seat 75 is forced.

In figure 4 it can further be recognized that a liquid pressure prevailing at the first valve port 72 also acts in the closed position of the valve 70 on an opening control surface 80 of the sliding body 74, so that a hydraulic pressure in the pressure chamber 13 acts on the opening control surface 80 for pushing the sliding body 74 into the open position. This is indicated in the schematic of figure 3 by control pressure line 81. The opening control surface 80 is formed by the part of the conical tip of the sliding body 74, which is located in the bore. Incidentally, this point can also be provided with a ball which can lie sealingly against the seat 75 1009507-14.

As in Figure 2, the sliding body 74 of the valve 70 is stepped, as is the associated first bore. As a result, the sliding body 74 on the side 5 of the seat 75 has a smaller diameter than on the opposite side with an annular shoulder surface 83 which forms the transition. The first bore is correspondingly formed with a shoulder surface 84 between the parts of different diameters. A connecting channel 85 is formed in the housing 71, which connects to the connection 73 and opens into the first bore near the shoulder surface 84. This connecting channel 85 achieves that if the pump 65 is in operation and delivers liquid to the pipe 20, this hydraulic pressure acts both on the surface of the sliding body 74, which covers the opening of the seat 75, and on the annular shoulder surface 83 of the sliding body 74. This is schematically indicated in Figure 3 with control line 87.

On the side of the sliding body 74 opposite the opening control surface 80, a light return spring 88 engages, which loads the sliding body 74 in the direction of its closed position. Furthermore, the side of the sliding body 74 remote from the seat 75 forms a closing control surface 89. The housing 71 is provided with a control line connection 90, to which a control line 91 connects, which communicates with the closing control surface 89. The control line 91 connects to the lost-motion line 30.

In figure 4 it can also be recognized that the sliding body 74 is provided with a through bore 92, which extends between the closing control surface 89 and the opening control surface 80 of the sliding body 74. The non-return valve 33 is placed in that bore 92.

An important difference between the device shown with reference to Figures 3 and 4 and the device which is known from DE 42 29 842 lies in the stepped version of the sliding body 74 of the valve 70, which sliding body 1009507 - 15 - at the known device has the same diameter on both sides. Due to the stepped design of the sliding body 74, the closing control surface 89 is considerably larger in relation to the opening control surface 80 than in the known sliding valve. As a result, the spring 88 can be considerably weaker than with the known valve, which has the advantages already described with reference to Figure 2 for the lost-motion operation of the cylinder 5. Furthermore, the presence of the connecting channel 85 ensures that the valve 70, despite the extra large hydraulic force on the sliding body 74 in the closing direction, opens easily when the pump 2 releases liquid under pressure through the line 20.

In a variant of the device according to figure 3, an anti-suction device is included at reference number 22, just like the valves 17 and 18 in figure 1.

It will be clear that the measure to design the sliding body of the sliding valve in stages is also advantageous with the tilting device shown in GB 2 079 378, so that a light spring for the sliding body will suffice in that case as well.

1009507

Claims (6)

Hydraulic tilting device for tilting a cabin of a vehicle between a driving position and a tilted position, which tilting device comprises: - a reservoir (1) for hydraulic fluid, 5. a pump (2) with at least one discharge port (3, 4) for dispensing hydraulic fluid under pressure, - a double-acting hydraulic tilting cylinder (5) for tilting the cabin, comprising a cylinder housing (6) containing a cylinder space (7), in which a piston / piston rod assembly (8) , 9) is movable to and fro, the piston rod (9) of which protrudes from the cylinder housing, the piston / piston rod assembly in the cylinder space forming a drawing chamber (12) which, when hydraulic fluid is supplied thereto, 15, and a pressure chamber (13), which extends the piston / piston rod assembly upon supply of hydraulic fluid, whereby for the drawing and pressure chamber, respectively, an associated pulling and pressure connection (14,15) are provided, which are optionally connectable to the discharge port of the pump and to the reservoir, and furthermore a lost-motion channel (30) is provided with ports (31,32) opening into the cylinder space, which lost-motion channel (30) connects the drawing chamber (12) and the pressure chamber (13) in a lost-motion mode of the tilting device, wherein the piston / piston rod assembly is in a position associated with the driving position of the cabin, - a hydraulically operated slide valve (40), which slide valve (40) has a first valve port (42), which is connected to the pressure chamber (13), a second valve gate (43), which is at least in the lost-motion mode connected to the reservoir, and a sliding body (44) movable between a closed position in which the first and second valve ports (42, 43) are closed from each other, and an opening position, in which the first and second valve ports (42, 43) ) 1009507 - 17 - are connected, whereby the slide valve p (40) is provided with a spring means (48), which loads the sliding body (44) in the direction of its closing position, and wherein the sliding body (44) has an opening control surface (46) connected to the pressure chamber (13), so that a hydraulic pressure in the pressure chamber acts on the opening control surface for pushing the sliding body to the opening position, and a closing control surface (50), which is connected to the cylinder space (7), so that a hydraulic pressure in the cylinder space (7) acts on the closing control surface for pushing the sliding body towards the closing position, characterized in that an OR valve (53) associated with the closing control surface (50) of the sliding valve (40) is provided with a first and a second inlet port (53a, 53b), which are respectively connected to the cylinder space and with a conduit (20) extending between the pressure connection of the tilt cylinder and a discharge port of the pump, said OR valve an outlet port (5 3c), which is connected to the slide control surface (50) of the slide valve. Hydraulic tilting device for tilting a cabin of a vehicle between a driving position and a tilted position, the tilting device comprising: 25. a reservoir (1) for hydraulic fluid, - a pump (2; 65) with at least one discharge port ( 3,4, -66) for dispensing hydraulic fluid under pressure, - a double-acting hydraulic tilting cylinder (5) for tilting the cabin, comprising a cylinder housing (6) 30 containing a cylinder space (7), in which a piston / piston rod assembly (8,9) is reciprocable, the piston rod (9) of which extends out of the cylinder housing, which piston / piston rod assembly in the cylinder space forms a drawing chamber (12), which is supplied with hydraulic fluid the piston / piston rod assembly retracts thereto, and a pressure chamber (13) which extends the piston / piston rod assembly 1009507 - 18 when hydraulic fluid is supplied thereto, wherein for the drawing and pressure chamber respectively n associated pull and pressure connection (14,15) are provided, which are optionally connectable to the discharge port of the pump and to the reservoir, and furthermore a lost-motion channel (30) is provided with ports opening into the cylinder space ( 31,32), which lost-motion channel (30) connects the drawing chamber (12) and the pressure chamber (13) in a lost-motion mode of the tilting device, wherein the piston / piston rod assembly 10 is in a position at the driving position of the cabin associated position, - a hydraulically operated slide valve (40, -70), which slide valve (40; 70) has a first valve port (42; 72), which is connected to the pressure chamber (13), a second valve port 15 (43 , -73), which is connected to the reservoir at least in lost-motion mode, and a sliding body (44, -74), which is movable between a closed position, in which the first and second valve ports (42, -43, -72.73) are closed from each other, and an opening position, in which the first and second valve ports (42.43, -72.73) with e are connected together, the slide valve (40, -70) being provided with a spring means (48, -88), which loads the slide body (44, -74) in the direction of its closing position, and the slide body (44, -74) includes an opening control surface 25 connected to the pressure chamber (13) so that a hydraulic pressure in the pressure chamber acts on the opening control surface for pushing the slide body to the opening position, and a closing control surface (89), which is connected to the cylinder space (7) so that a hydraulic pressure in the cylinder space (7) acts on the closing control surface for pushing the sliding body towards the closing position, characterized in that the sliding body (44, -74) is stepped is equipped with a first part with a first outer diameter on the side of the closing control surface 35 (50, -89) and on the side of the opening control surface (46, -80) a second part with a second outer diameter, the 1009507 - 19 - first outside diameter g rotator than the second outside diameter. 3. Device according to claim 2, wherein the sliding body (44, -74) has an annular shoulder surface (49; 83) at the transition from the first part to the second part. 4. Device according to claims 1 and 2. 10 The device of claim 4, wherein the housing (41) of the slide valve (40) includes an additional connection (60), which has a mouth (62) near a shoulder face (61) of the bore for the slide body (44). and 15 which communicates with the reservoir (1) at least in lost-motion mode. Vehicle comprising a tiltable cabin, a chassis and hinge means connecting the cabin to the chassis 20, the cabin tiltable relative to the chassis about an articulation axis defined by the hinge means between a driving position and a tilted position, and wherein a hydraulic tilting device according to one or more of the preceding claims is provided for tilting the cabin. 1009507