Mobile work machine

Abstract

The invention relates to a mobile work machine (10) which includes a frame ( 12 ), a cabin (14) arranged on top of the frame (12), a connection structure (16) arranged between the cabin (14) and the frame (12) which allows a limited movement between the cabin (14) and the frame (12), at least one articulated tilting joint (18) arranged between the connection structure (16) and the cabin (14), with respect to which articulated tilting joint (18) the cabin (14) is tiltable into a maintenance position, an actuator (22) for tilting the cabin (14) into the maintenance position with respect to the articulated tilting joint (18), a support member (72) connected on a side of the cabin (14) to the frame (12) or to the connection structure (16) for forming a support member for the actuator (22), and a play structure (42) for enabling a free movement of the actuator (22) when the cabin (14) moves relative to the frame (12), wherein the actuator (22) is arranged on the side of the cabin (14) between the support member (72) and the cabin (14) so as to be essentially perpendicular to a direction of movement between the cabin (14) and the frame (12) allowed by the connection structure (16) and so as to be essentially transverse to the articulated tilting joint (18) in order to produce a torque that is essentially perpendicular to an axis of rotation of the articulated tilting joint (18).

Description

[0001] MOBILE WORK MACHINE

[0002] The invention relates to a mobile work machine which includes

[0003] - a frame,

[0004] - a cabin arranged on top of the frame,

[0005] - at least one articulated tilting joint arranged between the frame and the cabin, with respect to which articulated tilting joint the cabin is tiltable into a maintenance position,

[0006] - an actuator for tilting the cabin into the maintenance position with respect to the articulated tilting joint, and

[0007] - a support member connected on a side of the cabin to the frame or to a connection structure, for forming the support member for the actuator, wherein the actuator is arranged on a side of the cabin between the support member and the cabin so as to be essentially transverse to the articulated tilting joint in order to produce a torque that is essentially perpendicular to an axis of rotation of the articulated tilting joint .

[0008] Figure 1 shows a Buffalo mobile work machine 10 manufactured by Ponsse Corporation, more specifically a forestry tractor, that is known from the prior art. The mobile work machine 10 includes a frame 12 and a cabin 14 supported in a suspended manner on top of the frame 12 by means of the connection structure 16 visible in Figures 2a - 2c. As shown in Figures 2a - 2c, the cabin 14 is attached on one side of the frame 12 in an articulated manner by means of an articulated tilting joint 18 to supporting elements 24 belonging to the connection structure 16 and on the other side of the frame 12 in a releasable manner by locking means 20 to other supporting elements 24. When the locking means 20 are unlocked, it is possible to tilt the cabin 14 with respect to the articulated tilting joint 18 from an operational position into a tilted maintenance position and back again by means of the actuator 22. In this case, the actuator 22 is a hydraulic cylinder which is supported in a vertical orientation underneath the cabin 14 between the cabin 14 and the frame 12.

[0009] A problem with this type of solution is that the actuator 22 arranged vertically underneath the cabin 14 takes up space underneath the cabin 14, which is particularly problematic with battery-powered work machines. A further problem is that the vertical movement hinders the action of the suspension structure located between the cabin and the frame and acts as a kind of shock absorber. The back-and-forth movement of the cylinder simultaneously causes a "pumping" effect on the hydraulic oil in the hydraulic system of the work machine.

[0010] An object of the present invention is to provide a mobile work machine that is simpler than the mobile work machines of the prior art, wherein the actuator intended for tilting the cabin does not take up space underneath the cabin and does not impair the shock-absorbing action of the cabin. The characteristic features according to the invention are set out in the attached patent claim 1.

[0011] The object of a mobile work machine according to the invention can be achieved with a mobile work machine which includes a frame, a cabin arranged on top of the frame, a connection structure arranged between the cabin and the frame which allows a limited movement between the cabin and the frame, and at least one articulated tilting joint arranged between the connection structure and the cabin, with respect to which articulated tilting joint the cabin is tiltable into a maintenance position. The mobile work machine further includes an actuator for tilting the cabin into the maintenance position around the articulated tilting joint, and a support member connected on a side of the cabin to the frame or to the connection structure for forming a support for the actuator. The actuator is arranged on the side of the cabin between the support member and the cabin so as to be essentially perpendicular to the direction of the movement between the cabin and the frame allowed by the connection structure and so as to be essentially transverse to the articulated tilting joint in order to provide a torque that is essentially perpendicular to the axis of rotation of the articulated tilting joint. The work machine further includes a play structure for enabling a free movement of the actuator when the cabin moves relative to the frame.

[0012] Surprisingly, the tilting of the cabin is carried out with an actuator which is not vertical but rather horizontal and which is arranged on the side of the cabin, so that the underside of the cabin remains free. Moreover, an actuator arranged on the side so as to be essentially parallel to the plane of the frame moves significantly less during a movement of the cabin permitted by the connection structure. A shock-absorbing action of the actuator is largely or entirely eliminated by the play structure, as the actuator can move freely within a limited range of flexibility of the play structure, whereby the connection structure can enable an unimpeded, limited movement between the cabin and the frame. In other words, the connection structure is a flexible connection structure.

[0013] In other words, the actuator is arranged so as to be essentially perpendicular to the direction of movement of the cabin in relation to the frame that is enabled by the connection structure .

[0014] In the context of the invention, support member denotes a part in the forestry machine to which the opposite end of the actuator, with respect to the cabin, is attached. This point can be part of the frame, for example a hole in the frame, although, analogously, it can also be a separate element attached to the frame or a part of the connection structure between the cabin and the frame.

[0015] In the context of the invention, maintenance position denotes a position in which the floor of the cabin is essentially at an angle relative to the plane formed by the frame.

[0016] Preferably, the connection structure is an flexible shockabsorbing structure. In the context of the invention, flexible shock-absorbing structure denotes active or passive, or both, damping and suspension mechanisms which include structures, mechanisms and actuators that can be used between the cabin and the frame in order to connect the cabin to the frame in such a manner that it can move with a limited range of movement. An essentially horizontally arranged actuator is particularly advantageous in connection with a shock-absorbing structure, because an actuator according to the prior art, which is arranged essentially in the direction of the movement of the suspension, in part acts undesirably as a shock absorber, which impairs the independent action of the connection structure in damping shocks and vibrations of the cabin. As the shock absorption allows the cabin to move, the length of the cylinder acting as the actuator, which is connected between the cabin and the frame, changes by up to 100 - 200 mm, whereby the actuator pumps hydraulic oil, for which a compensation must occur later. In the solution according to the present invention, the actuator thus causes less of a shock-absorbing effect that impedes the action of the cabin connection structure or no such effect at all. In the context of the invention, shock-absorbing structure denotes a separate structure that dampens shocks, such as a hydraulic or pneumatic shock-absorbing structure, which differs from vibration-dampening structures based on a temporary deformation, such as bushings between articulated joints .

[0017] Preferably, the articulated tilting joint is arranged between the connection structure and the cabin. The connection structure is thus not subjected to the load of the cabin during tilting, which could deform parts of the connection structure.

[0018] In the context of the invention, the definition according to which the actuator is arranged so as to be essentially parallel to the plane formed by the frame or so as to be essentially perpendicular to the limited movement enabled by the connection structure means that the actuator is at an angle of at most 30° relative to the plane of the frame or to the perpendicular of the movement between the cabin and the frame that is enabled by the connection structure, preferably at an angle of less than 15°, most preferably at an angle between 0° and 10°, so that the movement of the cabin relative to the frame does not cause a significant movement of the actuator in the longitudinal direction, which could impair the action of the connection structure.

[0019] Plane formed by the frame denotes the plane formed between the upper surfaces of the two parallel frame beams, i.e. the direction perpendicular to the vertical direction of the work machine .

[0020] In the context of the invention, a location of the support member on the side of the cabin means that the support member is either next to the cabin in the longitudinal direction of the frame or, preferably, on a front side or rear side of the cabin. In other words, the actuator is arranged outside the surface area of the cabin, on the front side, the rear side or on a side around the cabin.

[0021] It is also possible to provide more than one actuator for tilting the cabin. Preferably, there are two actuators in total, one on each side of the cabin.

[0022] In particular, a position on the front side or on the rear side of the cabin renders possible an implementation of the support member that does not impede maintenance work carried out under the cabin when the cabin is tilted into the maintenance position .

[0023] According to one embodiment, the support member is a frame structure that can be attached to the frame for supporting an actuator. This type of structure allows the actuator to be elevated at a distance with respect to the articulated tilting joint, which increases the moment arm of the force produced by the actuator.

[0024] Preferably, the frame structure is arranged on the front side or on the rear side or both on the front and on the rear side of the cabin in the direction of travel of the mobile forestry machine. A frame structure arranged on both sides is necessary if two actuators are used for tilting the cabin.

[0025] In the context of the invention, plane of the frame denotes the plane formed between the upper surfaces of the beams belonging to the frame which run in the longitudinal direction of the mobile work machine. Preferably, the longitudinal beams are joined by further transverse beams so as to form a closed frame structure. Preferably, the axis of rotation of the articulated tilting joint is in the longitudinal direction of the frame of the mobile work machine. The cabin can thus be tilted in the lateral direction of the mobile work machine.

[0026] The connection structure can include four supporting elements which dampen shocks or vibrations or both. One supporting element can thus preferably be provided at each corner of the cabin .

[0027] Preferably, each supporting element includes a guide element, a spring element and a damping element.

[0028] Preferably, each supporting element has a first end and a second end, and each supporting element includes a first attachment element for attaching the cabin of the mobile work machine to the first end of the supporting element and a second attachment element for attaching the frame of the mobile work machine to the second end of the supporting element. The supporting element further includes a spring element or a damping element or both, which is or are mechanically connected between the first end of the supporting element and the second end of the supporting element. By means of this type of connection structure, an flexible support structure of the cabin can be implemented which, in combination with an actuator that is arranged to be essentially parallel to the plane of the frame, provides good operating comfort.

[0029] The supporting element additionally preferably includes a guide element, which includes a slide guide and a support arm arranged in the slide guide. The slide guide and the support arm are configured to move relative to each other. Alternatively, the supporting elements can be different from one another, for example in such a manner that each corner has a spring element while the damping elements are arranged differently. There can also be a different number of damping elements than spring elements, wherein the damping elements are arranged in different places than the spring elements.

[0030] Preferably, the structure of the base of the cabin is essentially polygonal, wherein the polygon has at least four corners, and the supporting elements are arranged at the four corners of the polygon or in the vicinity of the corners.

[0031] Preferably, the guide element has opposite ends, wherein one of the opposite ends is on the slide guide and the other is on the support arm, and wherein one of the opposite ends is mechanically connected to the first end of the supporting element and the other is mechanically connected to the second end of the supporting element.

[0032] In the context of the invention, play structure denotes a structure which allows the free movement of the actuator when the cabin moves relative to the frame without producing a significant damping action of the actuator. The play structure is thus a structure in which the free or limited movement of a certain part produces a play. Therefore, play structure does not denote bushings between articulated joints or other structures that produce a play through a reversible deformation. By means of the play structure, a length of play movement is achieved that is significantly greater than with vibration-damping structures.

[0033] The free movement of the actuator allowed by the play structure can be 2 - 20 mm, preferably 4 - 10 mm. This is a free movement that is large enough to eliminate a shock-absorbing action of the actuator when the actuator is positioned so as to be essentially parallel to the plane of the frame, i.e. essentially horizontal when the work machine is operating on a flat surface, so that a length of movement of the actuator during a suspension action of the connection structure is very small compared to the vertical actuators according to the prior art .

[0034] In other words, the actuator is advantageously arranged in a position essentially perpendicular to the supporting elements.

[0035] According to a preferred second embodiment, the play structure is integrated as part of the actuator, which is a hydraulic cylinder actuator attached in an articulated manner between the support member and the cabin. As an integrated structure, the play structure does not cause any rattling or other noise when it moves in response to the suspension.

[0036] Preferably, the cylinder actuator includes a cylinder part, a piston rod and a piston arranged on the piston rod so as to be slidable with a limited range of movement along the piston rod, wherein the slidably arranged piston forms the play structure. The attachment of the cylinder actuator between the frame and the cabin can thereby be implemented by means of an attachment with fixed articulation points.

[0037] Preferably, the cylinder actuator further includes a sliding surface, which includes a first end and a second end and which is arranged on the piston rod for the slidable piston, a pushing shoulder arranged on the piston rod at the first end of the sliding surface for transmitting a force to the piston when the piston is at the first end of the sliding surface, and a stop arranged on the piston rod at the opposite, in relation to the pushing shoulder, second end of the sliding surface. This kind of structure enables a limited free movement of the piston along the piston rod as well as the production of force in both directions of the cylinder actuator.

[0038] In other words, in the embodiment described in the foregoing, the play is in the longitudinal direction of the cylinder and of a magnitude that is sufficient to compensate for the movement of the cylinder caused by the limited movement between the cabin and the frame produced by the connection structure in such a manner that the cylinder does not create a pumping action on the hydraulic oil.

[0039] Preferably, the cylinder actuator further includes a stop shoulder arranged on the cylinder part in order to stop a movement of the piston rod before the piston rod comes into contact with the back wall belonging to the cylinder part. By means of this structure, it can be prevented that the piston stops when it reaches the back wall of the cylinder part, in which case the cylinder actuator cannot effectively produce a force in the opposite direction when starting a movement.

[0040] According to a third embodiment, the play structure is a slot arranged in the frame or in the cabin, to which slot the actuator is attached. A slot is a very simple way of implementing a play structure; however, as a structure outside the actuator, the use of a slot causes knocking and noise.

[0041] Preferably, the actuator is a hydraulic cylinder actuator attached in an articulated manner between the frame and the cabin by means of a slot. When a slot is used, the cylinder actuator can be a conventional actuator that does not include a separate play structure, as the slot forms the play structure . Alternatively to a cylinder actuator, the actuator can be a spindle motor attached in an articulated manner between the frame and the cabin by means of the aforementioned slot. The spindle motor can be driven by an electric motor.

[0042] Preferably, the mobile work machine includes locking means for locking the cabin in the operational position, and the articulated tilting joint is formed on at least one supporting element, preferably on two supporting elements, on one side of the cabin, and the locking means are formed between the cabin and one separate, with respect to the articulated tilting joint, supporting element, preferably two separate supporting elements, wherein the locking means are a lock mechanism for uncoupling the cabin from the two supporting elements during tilting. By releasing the locking means, the cabin can be uncoupled on one side of the frame from the connection structure and tilted by means of the actuator with respect to the articulated tilting joint.

[0043] The actuator can be attached to the cabin at a distance from the articulated tilting joint, which distance is 15 - 100 cm, preferably 20 - 40 cm, in order to form a moment arm that tilts the cabin, and the actuator is arranged in such a manner that the imaginary arm of the moment produced by the actuator is essentially perpendicular to the plane of the frame. As a result of this sufficient distance, the actuator that is arranged so as to be essentially parallel to the plane of the frame produces a sufficient torque to tilt the cabin into the maintenance position.

[0044] According to a fourth embodiment, the mobile work machine includes, as the support member, an auxiliary frame that joins the supporting elements, and the actuator is arranged between the auxiliary frame and the cabin. This enables the transmission of the force of the actuator to the cabin. In this implementation, it is not imperative to use a play structure as part of the mobile work machine; however, the adverse shockabsorbing and pumping action caused by the actuator cannot be completely eliminated in this case, even if it can be significantly reduced compared to the solutions of the prior art .

[0045] Preferably, the actuator is dimensioned in such a manner that, when the cabin is tilted into the maintenance position, the centre of gravity of the cabin crosses the line that runs through the support point of the articulated tilting joint perpendicularly to the plane of the frame. The actuator thus does not have to support the weight of the cabin during maintenance operations, but rather merely a slight pull acts on the actuator.

[0046] Preferably, the actuator is attached in an articulated manner between the cabin and the frame in such a manner that it is essentially parallel to the tangent to the trajectory of the rotational movement about the articulated tilting joint in all operational positions. In other words, the actuator is essentially parallel to the trajectory of the tilting movement of the cabin in all operational positions, so that its force output is optimal even in both end positions.

[0047] Preferably, the work machine includes a hydraulic circuit including a hydraulic oil tank, a pump for pumping hydraulic oil from the tank, and hydraulic lines from the hydraulic oil tank to the actuators for conveying pressurized hydraulic oil and returning hydraulic oil, wherein the aforementioned actuator that can tilt the cabin is part of the hydraulic circuit . Preferably, the direction of the axis of the articulated tilting joint is parallel to the frame. The cabin can thus be tilted to the side, which facilitates the performance of maintenance operations.

[0048] Preferably, the mobile work machine is a mobile work machine which includes at least one component within the frame that requires maintenance. In particular in this case, it is important to be able to turn the cabin over without an actuator arranged underneath the cabin and inside the connection structure, as this facilitates the maintenance of the component located within the frame. A component requiring maintenance can be, for example, a battery, or any hydraulic component.

[0049] The invention, which is not limited to the embodiments presented in the following, is described in more detail with reference to the accompanying figures, wherein

[0050] Figure 1 shows a side view of a mobile work machine according to the prior art,

[0051] Figure 2a shows a separate, front view of a cabin and a frame of a mobile work machine according to the prior art in an operational position,

[0052] Figure 2b shows a separate, front view of a cabin and a frame of a mobile work machine according to the prior art in a maintenance position,

[0053] Figure 2c shows a separate, axonometric view of a cabin and a frame of a mobile work machine according to the prior art in a maintenance position,

[0054] Figure 3 shows an axonometric view of the frame of a front frame and a cabin supported on the frame by means of a connection structure, of a mobile work machine according to the invention, separately from the rest of the mobile work machine and without an actuator,

[0055] Figure 4 shows a separate, axonometric view of a supporting element of the connection structure,

[0056] Figure 5a shows a separate, front view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in an operational position,

[0057] Figure 5b shows a separate, front view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in a maintenance position,

[0058] Figure 5c shows a separate, front view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in an operational position, without the support member,

[0059] Figure 5d shows a separate, front view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in a maintenance position, without the support member,

[0060] Figure 6a shows a separate, axonometric view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in a maintenance position,

[0061] Figure 6b shows a separate, axonometric view of a cabin and a frame of a mobile work machine according to a first embodiment of the invention in a maintenance position, without the support member,

[0062] Figures 7a - 7c show cross-sectional views of one embodiment of the actuator in different operating positions when the play structure is part of the actuator,

[0063] Figures 8a and 8b show side views of a structure according to a second embodiment of the play structure, when the play structure is a slot,

[0064] Figure 9a shows a separate, front view of a cabin and a frame of a mobile work machine according to a fourth embodiment of the invention in an operational position,

[0065] Figure 9b shows a separate, front view of a cabin and a frame of a mobile work machine according to a fourth embodiment of the invention in a maintenance position.

[0066] With reference to Figure 1, a mobile work machine 10 according to the invention is preferably a forestry machine 11, or a forestry tractor 11.1 as shown in the figure, although it can also be a harvester. Although Figure 1 shows a mobile work machine 10 according to the prior art, it is understood that the mobile work machine 10 according to the invention can correspond entirely with respect to its main features to a mobile work machine according to the prior art except for the actuator used to tilt the cabin and the manner of its support.

[0067] In this application, mobile work machine denotes a self- propelled work machine supported on a wheeled or tracked chassis, said work machine preferably also including an articulated frame joint 17, an implement 78 for handling trees, and a boom assembly or crane 80 for the implement 78. The basic parts of the mobile work machine 10 of Figure 1 include a frame 12, which includes a front frame part 13 and a rear frame part 15 connected by means of the articulated joint between them, and a cabin 14 arranged on top of the frame 12. In contrast to the figures, the cabin can also be arranged on top of the rear frame part .

[0068] Figure 3 shows the frame 12 and the attached cabin 14 separately from the rest of the mobile work machine, without the components belonging to the wheeled chassis and the actuator for tilting the cabin 14. Preferably, the cabin 14 is connected to the frame 12 by means of a connection structure 16. The actuator 22 is shown in Figures 5a - 6b. The connection structure 16 preferably includes supporting elements 24 arranged at the corners 68 of the cabin 14, which supporting elements 24 enable a suspension movement of the cabin 14 relative to the frame 12 when the mobile work machine is moving on uneven ground, mainly in the forest. Although the wheeled or tracked chassis intrinsically acts as a shock absorber for the mobile work machine, the vibrations and shocks acting on a driver of the mobile work machine can be significantly reduced by means of the connection structure 16 between the frame 12 and the cabin 14.

[0069] Figure 4 shows in greater detail one way of implementing the supporting element 24. The supporting element 24 enables both a suspension action between the cabin and the frame and a shock absorption of the movement of the suspension action. Preferably, both a spring and a shock absorber are integrated in the supporting element together with a sliding element. More specifically, the supporting element 24 in this embodiment includes a first end 21 and a second end 23, a first attachment element 26 for attaching the cabin to the first end 21 of the supporting element 24, and a second attachment element 28 for attaching the frame to the second end 23 of the supporting element 24. The supporting element 24 includes a guide element 30, which includes a slide guide 32 and a support arm 34 arranged in the slide guide 32. The slide guide 32 and the support arm 34 are configured to move relative to each other during a movement of the suspension. The guide element 30 has opposite ends, wherein one of the opposite ends is on the slide guide 32 and the other is on the support arm 34, and one of the opposite ends is mechanically connected to the first end 21 of the supporting element 24 and the other is mechanically connected to the second end 23 of the supporting element 24. The range of movement of the support arm is configured to extend at least over the first attachment element or the second attachment element. The supporting element 24 further includes a spring element 36, which is mechanically connected between the first end 21 of the supporting element 24 and the second end 23 of the supporting element 24, and a damping element 38, which is mechanically connected between the first end 21 of the supporting element 24 and the second end 23 of the supporting element 24.

[0070] The supporting elements 24 belonging to the connection structure 16 can differ from the structure shown in Figure 4 and Figures 5a - 7b; however, in all embodiments that allow a suspension action, the supporting element includes a guide element, a spring element and a damping element, either integrated into a unit or supported separately between the cabin and the frame, either directly or indirectly. Alternatively, it is also possible for the connection structure to be implemented solely by means of the articulated tilting joint, without dampening supporting elements.

[0071] Figures 5a and 5c show an embodiment according to a first embodiment of the mobile work machine according to the invention in an operational position of the cabin 14. The actuator 22 is connected on a side of the cabin 14 so as to be essentially parallel to the plane formed by the frame 12 and so as to be essentially transverse to the frame 12 in order to produce a torque that is essentially perpendicular to the axis of rotation of the articulated tilting joint 18. More specifically, in this embodiment, a separate support member 72 is attached on a side of the cabin 14 to the frame 12, to which support member 72 the actuator 22 is attached at one end while the other end is attached to the cabin 14. In this case, "on a side" preferably denotes a location in front of the cabin 14 in the longitudinal direction of the frame 12 as shown in Figures 5a, 5b and 6a. This is a particularly advantageous location for the support member 72, as the support member 72 is thereby out of the way of maintenance work carried out in the transverse direction of the frame 12. Moreover, there is generally more space on the front side of the cabin than on the rear side. Figures 5c and 5d show more precisely the location of the actuator 22, which is illustrated without the support member 72.

[0072] In other words, in this embodiment, the support member 72 includes legs 73 attached to the frame 12 and a transverse support 75 arranged between them, as shown in Figure 6a. These make it possible to form a support point for the actuator 22 on a side of the cabin 14 at a sufficient distance from the articulated tilting joint 18 so that the actuator 22 is arranged in such a manner that its longitudinal direction is essentially parallel to the tangent to the arc of rotation of the cabin 14 around the articulated tilting joint.

[0073] As shown in Figures 5a, 5b and 6a, according to a preferred first embodiment, the support member 72 is attached to the frame 12 and extends, as shown in Figure 5c, in such a manner that the end of the actuator 22 that is attached in an articulated manner to the support member 72 forms the support member at a distance d from the articulated tilting joint 18. In other words, the moment arm L of the actuator 22 which turns the cabin around the pivot point of the articulated tilting joint 18 is preferably of the same length as the distance d. The distance d can be 15 - 100 cm, preferably 20 - 40 cm, in length so that the force output required from the actuator remains moderate while, on the other hand, the support member does not have to be too elevated. Moreover, the moment arm L is preferably essentially perpendicular to the plane of the frame. Figures 5b and 5d show the cabin 14 tilted into the maintenance position.

[0074] Preferably, the articulated tilting joint 18 is formed as shown in Figures 6a and 6b on one side of the frame 12 of the mobile work machine on the upper end of two supporting elements 24 in a row, while on the other side a forked attachment element 74 is provided, to which a lug 76 belonging to the base of the cabin 14 can be fastened, for example, by means of a pin or the like. The tilting axis of the articulated tilting joint 18 is preferably in the longitudinal direction of the mobile work machine 10.

[0075] In a mobile work machine according to the invention, a movement of the actuator caused by the suspension of the cabin and occurring in the longitudinal direction of the actuator is very small compared to a solution according to the prior art, in which the longitudinal direction of the actuator is essentially the same as the direction of the suspension action of the connection structure. In the simplest embodiment, the length of this movement causes a change in volume so that, when the actuator is a hydraulic cylinder, hydraulic oil has to be transferred from the cylinder to the tank and pumped back again. The volumetric flow is, however, significantly lower than in the solutions according to the prior art, and the problem is less pronounced than in the solutions of the prior art. Preferably, however, the mobile work machine according to the invention further includes a play structure of the actuator, which enables a movement of the actuator during a suspension action of the cabin with ideally no change in the length of the actuator.

[0076] The embodiment of Figures 5a - 6b shows a first embodiment of the play structure in which the actuator is preferably a hydraulic cylinder actuator that includes the integrated play structure 42 shown in Figures 7a - 7c. When an integrated play structure is used, the articulation points of the actuator 22 on the cabin 14 and on the support member 72 can be fixed in their position as shown in Figures 5a - 6b.

[0077] Figures 7a - 7c show an implementation according to a first embodiment of the play structure 42, which is integrated as part the cylinder actuator 44. Figure 7a shows a so-called floating suspended position of the cylinder actuator 44, in which the attachment points 45 of the cylinder actuator 44 can move relative to each other, i.e. the length of the cylinder actuator can change without causing a change in volume of the cylinder actuator 44. Figure 7b in turn shows the position in which the cylinder actuator 44 raises the cabin from an operational position into a maintenance position. Figure 7c shows the position in which the cylinder actuator 44 pulls the cabin from a maintenance position into an operational position.

[0078] Preferably, the maintenance position is such that the centre of mass G of the cabin 14 moves to the other side of the articulated tilting joint 18 shown in Figures 5a and 5b in the transverse direction of the frame, so that the actuator 22 is essentially not under pressure during maintenance, and the power unit of the mobile work machine can be switched off. Work of the actuator 22 is subsequently also required when the cabin is rotated from the maintenance position into the operational position, whereby the centre of mass G of the cabin 14 is moved from one side of the pivot point of the articulated tilting joint 18 to the other.

[0079] As shown in Figures 7a - 7c, the cylinder actuator 44 preferably includes a cylinder part 46, a piston rod 48 and a piston 50 arranged on the piston rod 48 so as to be slidable with a limited range of movement along the piston rod 48, wherein the slidably arranged piston 50 forms the play structure 42. As shown in Figure 7a, the piston 50 can move along the piston rod 48 with a limited range of movement, so that a small movement of the attachment point 45 of the cylinder actuator

[0080] 44 formed on the piston rod 48 relative to the attachment point

[0081] 45 of the cylinder part 46 during a suspension action of the cabin only causes a movement of the piston rod 48 relative to the piston 50, but does not cause a movement of the piston 50 relative to the cylinder part 46. This is the so-called free movement, which does not cause a significant change in volume in the cylinder or a movement that pumps hydraulic oil.

[0082] More specifically, the limited free movement of the piston 50 along the piston rod 48 is achieved by a sliding surface 52, a pushing shoulder 58, a stop 60, and a stop shoulder 62, which the cylinder actuator 44 preferably includes. The sliding surface 52 includes a first end 54 and a second end 56 and is arranged on the piston rod 48 for the slidable piston 50. The sliding surface 52 can act in the manner of a plain bearing; it can be formed on the piston rod 48 by turning or chrome plating and preferably includes a sliding strip in order to enable a sliding of the piston 50 as well as seals for sealing the piston 50 on the piston rod 48. The piston 50 in turn preferably includes sliding rings and seals on both its inner and outer surfaces.

[0083] The free movement of the piston can be 2 - 20 mm, preferably 5 - 10 mm, which means that the sliding surface 52 is 2 - 20 mm longer than the length of the piston 50 in the longitudinal direction of the piston rod 48.

[0084] The pushing shoulder 58 is in turn formed in the piston rod 48 at the first end 54 of the sliding surface 52 in order to transmit a force to the piston 50 when the piston 50 is at the first end 54 of the sliding surface 52, as shown in Figure 7b, i.e. when the cabin is moved from an operational position to a maintenance position. The stop 60 is in turn formed on the piston rod 48 at the opposite, in relation to the pushing shoulder 58, second end 56 of the sliding surface 52, as shown in Figure 7c, and enables a force output of the cylinder actuator 44 when the cabin is moved from the maintenance position to the operational position. The stop 60 can be a washer attached on the piston rod 48 by means of, for example, a threaded sleeve or a weld 71.

[0085] The stop shoulder 62 is formed in the cylinder part 46 in order to stop a movement of the piston rod 48 before the piston rod 48 comes into contact with the back wall 64 belonging to the cylinder part 46. It is thus possible to produce a force in the end position of the cylinder actuator 44 in which the piston rod 48 is as close as it can get to the back wall 64.

[0086] The cylinder actuator including the play structure shown in Figures 7a - 7c of this application can also be used independently of a work machine according to the invention in completely different applications as an independent invention. Figures 8a and 8b show a second, alternative way of implementing the play structure 42, wherein, in the connection of the actuator 22, the articulated connection of one end of the actuator 22 occurs by means of a slot 66. In this embodiment, it is possible to use, for example, a conventional hydraulic cylinder or even a linear actuator, such as a combination of a spindle and an electric motor. In Figures 8a and 8b, the slot 66 is formed in connection with the cabin 14, while the second end of the actuator 22 is connected to the frame 12 by means of a conventional circular opening that fixes the position of the second end. Alternatively, the slot 66 of the play structure 42 can also be implemented in connection with the frame 12 or some analogous structure, to which the actuator 22 is attached in an articulated manner at the opposite end with respect to the cabin 14. As illustrated in Figures 8a and 8b, the length of the actuator 22 can remain unchanged, as the attachment point of the actuator in the slot 66 can move from one end of the slot 66 to the other as the cabin 14 moves relative to the frame due to the range of movement of the connection structure. Only when a lateral movement of the cabin 14 exceeds the length of the slot 66 does the movement of the cabin 14 relative to the frame 12 begin to change the length of the actuator 22 and cause a movementdecelerating force in the manner of a shock absorber.

[0087] The direction of movement shown in Figures 8a and 8b, which in reality is more a tilting of the cabin than a straight lateral translation, is for illustrative purposes only.

[0088] Figures 9a and 9b show a fourth embodiment of a mobile work machine according to the invention, in which there is no separate play structure for the actuator 22. In this case, the mobile work machine includes an auxiliary frame 40 that joins the supporting elements 24 belonging to the connection structure 16. The auxiliary frame 40 preferably includes a closed frame structure essentially parallel to the plane of the frame 12, as well as a support member 72 connected essentially perpendicularly thereto. This type of implementation also makes it possible to arrange the actuator 22 for tilting the cabin 14 in such a manner that said actuator 22 is mainly parallel to the plane of the frame 12 and on a side of the cabin 14, so that the underside of the cabin 14 remains free so that maintenance objects are accessible. Moreover, the actuator 22, which is installed so as to be essentially parallel to the plane of the frame 12, needs a remarkably small length of movement during a suspension action of the cabin, which significantly reduces a shock-absorbing and pumping action of the actuator. The purpose of the auxiliary frame 14 is to join the supporting elements 24 to one another, so that the actuator 22 does not necessarily have to be connected directly to the frame 12, but rather can be connected to the auxiliary frame 14.

[0089] Advantageously, in the mobile working machine according to the invention, the requirements of the actuator with respect to length and speed of movement are significantly reduced compared to those of analogous actuators of mobile working machines according to the prior art. In the actuators according to the prior art, which are essentially perpendicular to the plane of the frame, a speed of movement can be as high as 50 cm / s, whereas in a mobile work machine according to the invention the corresponding speed can be 0.5 cm / s, because the required distance of movement in the direction of the plane of the frame during a suspension action of the cabin is remarkably small.

Claims

CLAIMS1. A mobile work machine (10) which includes- a frame ( 12 ) ,- a cabin (14) arranged on top of the frame (12) ,- at least one articulated tilting joint (18) arranged between the frame (12) and the cabin (14) , with respect to which articulated tilting joint (18) the cabin (14) is tiltable into a maintenance position,- an actuator (22) for tilting the cabin (14) into the maintenance position with respect to the articulated tilting joint (18) , and- a support member (72) connected on a side of the cabin (14) to the frame (12) or to a connection structure (16) for forming a support point for the actuator (22) , wherein the actuator (22) is arranged on the side of the cabin (14) between the support member (72) and the cabin (14) so as to be essentially transverse to the articulated tilting joint (18) in order to produce a torque that is essentially perpendicular to an axis of rotation of the articulated tilting joint (18) , characterized in that the work machine (10) further includes- the connection structure (16) arranged between the cabin (14) and the frame (12) which allows a limited movement between the cabin (14) and the frame (12) , and- a play structure (42) for enabling a free movement of the actuator (22) as the cabin (14) moves relative to the frame (12) , and wherein the actuator (22) is arranged to be essentially perpendicular to a direction of movement between the cabin (14) and the frame (12) allowed by the connection structure (16) .

2. The mobile work machine according to claim 1, characterized in that the connection structure (16) includesfour supporting elements (24) which dampen shocks and vibrations or both.

3. The mobile working machine according to claim 2, characterized in that each supporting element (24) has a first end (21) and a second end (23) , and each supporting element (24) includes- a first attachment element (26) for attaching the cabin (14) to the first end (21) of the supporting element (24) ,- a second attachment element (28) for attaching the frame (12) to the second end (23) of the supporting element (24) , and- a spring element (36) or a damping element (38) or both, which are mechanically connected between the first end (21) of the supporting element (24) and the second end (23) of the supporting element (24) .

4. The mobile work machine according to claim 1, characterized in that the play structure (42) is an integrated part of the actuator (22) , which is a hydraulic cylinder actuator (44) attached in an articulated manner between the support member (72) and the cabin (14) .

5. The mobile work machine according to any one of claims 1 - 4, characterized in that the free movement of the actuator (22) allowed by the play structure (42) is 2 - 20 mm, preferably 4 - 10 mm.

6. The mobile work machine according to claim 4, characterized in that the cylinder actuator (44) includes a cylinder part (46) , a piston rod (48) and a piston (50) arranged on the piston rod (48) so as to be slidable with a limited range of movement along the piston rod (48) , wherein the slidably arranged piston (50) forms the play structure (42) .

7. The mobile work machine according to claim 6, characterized in that the cylinder actuator (44) further includes- a sliding surface (52) , which includes a first end (54) and a second end (56) and which is arranged on the piston rod (48) for the slidable piston (50) ,- a pushing shoulder (58) arranged on the piston rod (48) at the first end (54) of the sliding surface (52) for transmitting a force to the piston (50) when the piston (50) is at the first end (54) of the sliding surface (52) , and a stop (60) arranged on the piston rod (48) at the opposite, in relation to the pushing shoulder (58) , second end (56) of the sliding surface (52) .

8. The mobile work machine according to claim 7, characterized in that the cylinder actuator (44) further includes a stop shoulder (62) arranged on the cylinder part (46) in order to stop a movement of the piston rod (48) before the piston rod (48) comes into contact with a back wall (64) belonging to the cylinder part (46) .

9. The mobile work machine according to claim 1 or 5, characterized in that the play structure (42) is a slot (66) arranged in the frame (12) or in the cabin (14) , to which slot (66) the actuator (22) is attached, wherein the actuator (22) is a linear actuator.

10. The mobile work machine according to any one of claims 29, characterized in that the mobile work machine (10) includes locking means (20) for locking the cabin (14) in an operational position, and the articulated tilting joint (18) is formed on at least one supporting element (24) , preferably on two supporting elements (24) , on one side of the cabin (14) , and the locking means (20) are formed between the cabin (14)and one separate, with respect to the articulated tilting joint(18) , supporting element (24) , preferably two supporting elements (24) , wherein the locking means (20) are a lock mechanism for uncoupling the cabin (14) from the two supporting elements (24) during tilting.

11. The mobile work machine according to any one of claims 1 - 10, characterized in that the actuator (22) is attached to the cabin (14) at a distance (d) from the articulated tilting joint (18) , which distance (d) is 15 - 100 cm, preferably 20 - 40 cm, in order to form a moment arm that tilts the cabin (14) , and the actuator (22) is arranged in such a manner that the imaginary arm (L) of the moment produced by the actuator (22) is essentially perpendicular to the plane of the frame (12) .

12. The mobile working machine according to claim 1, characterized in that the mobile working machine (10) includes, as the support member (72) , an auxiliary frame (40) that joins the supporting elements (24) , and the actuator (22) is arranged between the auxiliary frame (40) and the cabin (14) .

13. The mobile work machine according to any one of claims 1- 12, characterized in that the mobile work machine (10) is a mobile work machine (11) which includes at least one component within the frame (12) that requires maintenance.

14. The mobile work machine according to any one of claims 1- 13, characterized in that the actuator (22) is attached in an articulated manner between the frame (12) and the cabin in such a manner that it is essentially tangential to the trajectory of the rotational movement about the articulated tilting joint (18) in all operational positions.

15. The mobile work machine according to claim 6, characterized in that the play of the play structure (42) is in the longitudinal direction of the cylinder actuator (44) .

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