Arrangement and method for enabling rotation movement between tandem or caterpillar axle and body of vehicle

Abstract

An arrangement and method are provided for enabling rotation movement between a tandem or caterpillar axle and a body of a vehicle. This type of vehicle includes at least one body part that is provided with a tandem or caterpillar axle. At least one body part includes a main body and an auxiliary body connected to it to rotate around the longitudinal axis of the vehicle or an essentially parallel axis thereto. The tandem or caterpillar axle is connected substantially rigidly to the main body, and the body part has at least one actuator for controlling the rotation movement between the main body and auxiliary body. In this way, changes in the position and motion status of the auxiliary body, especially in relation to the rotation around the longitudinal axis of the vehicle, are arranged to cause in the actuator a pushing or pulling motion that steers the auxiliary body to a rotation movement for the purpose of arranging the auxiliary body to a substantially horizontal position.

Claims

1. An arrangement for enabling rotation movement between a tandem or caterpillar axle and a body of a vehicle, wherein the vehicle comprises at least two body parts connected to each other by a body joint, a body part is provided with a tandem or caterpillar axle, at least one body part comprises a main body and an auxiliary body connected to it to rotate around the longitudinal axis of the vehicle or an essentially parallel axis thereto, whereby the auxiliary body is arranged to the main body with a rotating joint, and the tandem or caterpillar axle is connected substantially rigidly to said main body, and the body part has at least one actuator to control the relative rotation movement of the main body and auxiliary body in such a manner that changes in the position and motion status of the auxiliary body especially in relation to the rotation around the longitudinal axis of the vehicle are arranged to cause in the actuator a pushing or pulling motion that steers the auxiliary body to a rotation movement for the purpose of arranging the auxiliary body to a substantially horizontal position, wherein the auxiliary body is arranged to the main body via substantially parallel crosswise structures in them such that at least two flanges extend from the auxiliary body against crosswise walls in the main body, wherein said crosswise walls and flanges are attached to each other by bearing systems forming rotating joints, whereby wherein the bearing systems are at a distance from each other in the direction of the longitudinal axis of the vehicle to permit their relative rotation in relation to this longitudinal axis, and wherein the rotation axis of the rotating joint is arranged to be substantially congruent with the rotation axis of the body joint.

2. The arrangement as claimed in claim 1, wherein the vehicle comprises a front body and a rear body connected to each other with a body joint having at least two degrees of freedom, the joint allowing the rotation of the front and rear bodies substantially in relation to the longitudinal axis of the vehicle and the rotation of the front and rear bodies in relation to each other and a vertical axis intersecting the body joint.

3. The arrangement as claimed in claim 2, wherein both the front and rear bodies are each provided with tandem axles or caterpillar axles.

4. The arrangement as claimed in claim 3, wherein the front and rear bodies are each provided with a main body, and the tandem axles or caterpillar axles of the vehicle are connected to the main body of the front body and the rear body.

5. A method for enabling rotation movement between a tandem or caterpillar axle and a body of a vehicle, comprising: forming the vehicle of at least two body parts connected to each other by a body joint, hereby providing a body part with a tandem or caterpillar axle, and forming at least one body part of a main body and an auxiliary body that is connected rotatably thereto, and the auxiliary body is rotatable in the transverse direction to the longitudinal axis of the vehicle, and arranging the auxiliary body to the main body with a rotating joint, and connecting the tandem axle to the main body substantially rigidly; providing the body part with at least one actuator for controlling the relative rotation movement of the main body and auxiliary body in such a manner that changes in the position and motion status of the auxiliary body especially in relation to the rotation around the longitudinal axis of the vehicle cause in the actuator a pushing or pulling motion that steers the auxiliary body to a rotation movement, the actuator movement steering the auxiliary body to a substantially horizontal position, wherein the auxiliary body is arranged to the main body via substantially parallel crosswise structures in them such that at least two flanges are extended from the auxiliary body against crosswise walls in the main body, wherein said crosswise walls and flanges are attached to each other by bearing systems forming rotating joints, wherein the bearing systems are set at a distance from each other in the direction of the longitudinal axis of the vehicle thus permitting their relative rotation in relation to this longitudinal axis, and wherein the rotation axis of the rotating joint is arranged to be substantially congruent with the rotation axis of the body joint.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, some preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawing, in which

(2) FIG. 1 shows a schematic axonometric figure of arranging the present body structure into a forest machine,

(3) FIG. 2 shows a partly cut detail view of the front body structure of the forest machine according to FIG. 1,

(4) FIG. 3 is a schematic representation of how the auxiliary body and main body are joined together,

(5) FIGS. 4 and 5 show how the present arrangement behaves when going over an obstacle,

(6) FIG. 6 shows an alternative embodiment of the body structure, and

(7) FIG. 7 shows a cargo space to be mounted on the auxiliary body according to FIG. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(8) The present figures do not show the arrangement for enabling rotation movement between a tandem or caterpillar axle and the body of a vehicle in scale but the figures are schematic, illustrating the structure and operation of the preferred embodiments in principle. Structural parts indicated by reference numerals in the accompanying figures then correspond to structural parts provided with reference numerals in this specification.

(9) In the following, the structure and operation of the present arrangement is expressed in a forest machine environment. Even though the embodiment shown is a forest machine with articulated steering, the present arrangement is not restricted to this operating environment, but can also be utilized in other vehicles, both in one- and multi-body vehicles, whether they are provided with articulated steering or not.

(10) As can be seen in FIG. 1, a preferred embodiment of the arrangement for a vehicle comprises a forest machine, of which the figure shows a front body 1 and a cabin 2 arranged on the front body. The front body is provided with a tandem axle 3 extending to both sides thereof with only the right-hand-side tandem axle in its traveling direction equipped with wheels 4. A rear body 5 is connected to the front body with a body joint 6 of two degrees of freedom. The rear body is also provided with a tandem axle 7 extending to both sides thereof with only the right-hand-side tandem axle in its traveling direction equipped with wheels 8 in the figure. The joint connecting the front and rear bodies permits in a manner known per se both the rotation of the front and rear bodies essentially in relation to the longitudinal axis of the vehicle (a rotating joint enabling adaptation to the shape of the terrain) and the rotation of the front and rear bodies in relation to each other and the vertical axis intersecting the joint (articulated steering joint).

(11) Even though the solution is described in the following with reference to a tandem axle with wheels, the present arrangement can also be implemented with an axle that instead of a tandem axle with wheels is provided with caterpillars on the opposite sides of the body, for instance. This type of tandem or caterpillar axle preferably swings, but the operational idea disclosed in the following can also be implemented in a non-swinging tandem or caterpillar axle.

(12) At least one of the front body 1 or rear body 5 is formed of a main body 9 and an auxiliary body 11 connected to it to rotate laterally in relation to the longitudinal axis 10 of the vehicle or an essentially parallel axis. The longitudinal axis refers herein to an axis that is substantially parallel to the driving direction of the vehicle. As the front and rear bodies of the vehicle are preferably provided with tandem axles 3 and 7 and with preferably swinging wheel axles, at least one of these tandem axles are connected substantially rigidly to a main body 9 of said type. The body in question then also has at least one actuator 12 to control the rotation movement between the main body and auxiliary body. The lateral sway acting on the cabin 2 and the changes in motion status caused by them as well as positional changes taking place in view of the acceleration vector caused by earth gravity initiate in the actuator 12 a pulling movement to compensate for this positional change.

(13) Thanks to this rotational movement, the auxiliary body can be arranged to remain substantially horizontal and the lateral roll of the auxiliary body caused by the unevenness of the terrain to the vehicle can be reduced or eliminated. Herein, the horizontal position refers to a normal orientation of a space, in which the bottom surface of the space—in this case, the floor of the cabin, for example—is essentially horizontal and the driver driving the vehicle in the cabin sits in an essentially upright position.

(14) FIGS. 2 and 3, for instance, show in more detail the main body 9 forming the front and/or rear body and the auxiliary body 11 that rotates in relation to the longitudinal axis 10 of the vehicle or an essentially parallel axis. As indicated by the embodiment shown in the figures, the auxiliary body should preferably be connected to the main body by a rotating joint, which in the figures is formed by at least two bearing systems 13 and 14, to provide sufficient structural rigidity. Further, it is advantageous to arrange the rotation axis of the rotating joints to be substantially congruent with the rotation axis of the body joint 6 that permits the rotation of the front and rear bodies in relation to the longitudinal axis of the vehicle. The rotation axis of this rotating joint is represented herein by the longitudinal axis 10 of the main body marked in FIGS. 2 and 3. At its simplest, the rotating joint can be provided by using the body joint 6 that allows the rotation of the front and rear bodies in relation to the longitudinal axis of the vehicle as the second bearing system 14, as shown in FIG. 2.

(15) In the embodiment of FIG. 3, the auxiliary body 11 is arranged to the main body 9 via substantially parallel crosswise structures in them. Thus, at least two flanges 15 extend from the auxiliary body against the crosswise walls 16 in the main body; the figure showing only the front pair of the walls. The crosswise walls and flanges are attached to each other by bearings that are preferably at a slight distance from each other in the direction of the longitudinal axis of the vehicle to permit their relative rotation in relation to the longitudinal axis 10.

(16) In its simplest form, the actuator 12 controlling the relative rotation of the main body 9 and auxiliary body 11 comprises a hydraulic or pneumatic actuator connected to opposite lugs 17 and 18 in two body parts, as shown in FIG. 2. However, nothing prevents the use of a linear motor or some other actuator capable of sufficiently fast movement combined with a suitable transmission or operating mechanics.

(17) In an embodiment, where both tandem or caterpillar axles 3 and 7 in the vehicle are connected to a main body 9 and 9b in the body 1 and 5 receiving the tandem or caterpillar axle, both auxiliary bodies 11 and 11 b are also arranged to rotate in relation to the longitudinal axis 10 of the vehicle or an axis substantially parallel to it. This type of vehicle preferably has two control systems for the actuator 12 and 12b independent of each other. The first control system controls the lateral roll between the main and auxiliary bodies in the front body 1, for instance. The second control system controls the lateral roll between the main and auxiliary bodies in the rear body 5, for instance. This type of control system controlling the operation of a rear body actuator is at the same time preferably in cooperation with the control system of the body joint 6 that connects the front and rear bodies of the vehicle.

(18) This last-mentioned embodiment is shown in FIGS. 6 and 7. In this embodiment, the auxiliary body 11b fitted with bearings to the main body 9b is at its opposite end fitted with bearings to the front body via the body joint 6, which at the same time forms the second bearing system of the rotating joint required in the system. In accordance with FIG. 7, a cargo space 19 of the forest machine is arranged substantially rigidly to the auxiliary body, which means that maintaining the horizontal position of the cargo space during driving can be arranged to take place using both the actuators controlling the operation of the body joint and the actuator in connection with the main body 9b.

(19) FIGS. 4 and 5 express the operation of the present arrangement and method. Thus, in FIG. 4, the vehicle approaches an obstacle that rises vertically from the surrounding terrain 20 and is located on one side of the vehicle. As shown in FIG. 5, the left-hand-side wheel tandem axle of the vehicle begins to go over the obstacle 21 by evening with a swinging motion the lateral sway caused by the obstacle and directed, among other things, to the cabin 2. At the same time, the control system and the sensors controlling its operation in the vehicle detect a change in the motion status in the vehicle and especially a positional change taking place in view of the acceleration vector caused by earth gravity, and initiate a pulling movement in the actuator 12 to compensate for the positional change.

(20) The auxiliary body 11 is generally kept horizontal in the sideward direction and the angular velocity of the rotation around the longitudinal axis of the auxiliary body at zero. In some situations, it may also be preferable to tilt the auxiliary body temporarily, if this improves the compensation of the lateral sway. This can be done for example in situations, where the mechanical play of the controlled joint or actuator prevents a complete correction of the lateral roll to the horizontal, but the compensation of the lateral sway should be possible in both directions.

(21) The pulling movement of the actuator 12 causes in the auxiliary body 11 supporting the cabin 2 a rotation around the longitudinal axis 10, with which the otherwise harmful lateral sway is quickly and energy-efficiently compensated for. When the system works sufficiently quickly and appropriately, said auxiliary body 11 can preferably be kept substantially stationary at least in relation to axes parallel to the longitudinal axis 10 against rotation, and the main body 9 articulated below the auxiliary body 11 with its tandem axles moves in accordance with the shape of the terrain.

(22) It is obvious to a person skilled in the art that, as technology advances, the basic idea of the described solution may be implemented in various ways. The disclosed invention and its embodiments are thus not restricted to the above examples but may vary within the scope of the claims.

(23) Thus, the present arrangement may, in accordance with what is stated above, comprise a vehicle with just one body part 1 provided With a tandem axle 3 or caterpillar axle. This type of body part comprises a main body 9 and an auxiliary body 11 connected thereto to rotate in relation to the longitudinal axis in the main direction of travel of the vehicle, whereby a tandem or caterpillar axle is connected substantially rigidly to the main body.

(24) By providing the body part 1 with at least one actuator 12 located between the main body 9 and auxiliary body 11, it is possible to manage the relative rotation movement of the main body and auxiliary body in a controlled manner. This type of control takes place when forces are directed to the vehicle, which act in a direction transverse to the longitudinal axis of the vehicle. Thus, the position of the auxiliary body kept horizontal to earth gravity (horizontal plane) can for example be measured with inertia sensors known per se, such as an inclinometer, gyroscope, various one- or multi-axle acceleration sensors or a combination of one or more of the above. At the same time, it is also advantageous to monitor the angular velocity and angular acceleration of the auxiliary body at each time with a gyroscope, for example. On the basis of the measuring data, a pushing or pulling movement is achieved in the actuator 12 to steer the auxiliary body to rotate in relation to the main body so as to maintain the substantially horizontal position of the auxiliary body. To ensure that an appropriate pushing or pulling movement is achieved, it is also possible to measure the rotational angle between the main and auxiliary bodies.

(25) Preferably, it is possible to arrange and integrate said sensors as parts of a control module of an embedded control system known per se, inside said control module and in its immediate vicinity.

(26) In a preferred embodiment, the auxiliary body 11 is arranged to the main body 9 by a rotating joint, which may comprise at least two concentric bearing systems, for instance, at a distance from each other in the direction of the rotation axis.