Vehicle with track width adjustment

Abstract

Vehicle comprising a frame (1), a first chassis (2) and a second chassis (3), wherein the two chassis (2, 3) are arranged on opposite sides of the frame (1) and are slidably mounted relative to the frame (1) by means of hydraulic cylinders (4, 5) to change the track width, wherein each hydraulic cylinder (4, 5) comprises a component (6) fixed to the frame and at least one component (7a, 7b) slidable relative to the frame (1), and the first and second chassis (2, 3) are each attached to the slidable component (7a, 7b) of the hydraulic cylinders (4, 5), characterized in that the slidable component (7a, 7b) of the hydraulic cylinders (4, 5) is slidably guided in a guide (31) on the frame (1), wherein the guide (31) is transverse to the direction of movement of the slidable component (7a, 7b) for transmitting forces between the slidable component (7a, 7b) and the frame (1). is designed for a movable component (7a, 7b).

Description

The invention relates to a vehicle with adjustable track width according to the preamble of claim 1. Vehicles with adjustable track width are used, for example, in forestry and agriculture. These vehicles can usually be coupled with various attachments, such as a winch to assist with felling or skidding timber, or equipment for preparing and maintaining plantings, such as mulching, sowing, chipping, or the like. The ability to change the track width ensures that the vehicle maintains a stable footing even on difficult terrain. A radio-controlled vehicle is known from the generic patent EP 3 606 629 B1, which has a first and a second chassis, the two chassis being arranged on opposite sides of a frame. Each chassis has two spaced-apart rectangular tubes that are slidably guided in a guide tube fixed to the frame. The track width is adjusted by hydraulic cylinders that cause the chassis to shift relative to the frame. A similar design is disclosed in DE 10 2011 102 110 A1, wherein an undercarriage for a crawler crane comprises a frame center section and left and right crawler sections, each crawler section having two beams, which are slidably mounted on the frame center section. The frame center section has a separate recess for each slidably mounted beam to accommodate the beams. Hydraulic cylinders, arranged inside the frame center section in the area of ​​the slewing ring, are assigned to each crawler section for adjusting the track width. Further chassis with track width adjustment are known from the DE 42 10 532 A1 and the DE 20 47 480 A. Based on this, the invention aimed to provide a more cost-effective way to adjust track width. According to the invention, this problem is solved by the features of claim 1. The vehicle according to the invention comprises a frame, a first chassis, and a second chassis, wherein the two chassis are arranged on opposite sides of the frame and are mounted so as to be slidable relative to the frame by means of hydraulic cylinders in order to change the track width. Each hydraulic cylinder comprises a component fixed to the frame and a component slidable relative to the frame, wherein the first and second chassis are each attached to the slidable component of the hydraulic cylinders, and the slidable component of the hydraulic cylinders is slidably guided in a guide on the frame, the guide being designed to transmit forces between the slidable component and the frame transversely to the direction of displacement of the slidable component. According to the invention, the movable components of the hydraulic cylinders not only have the task of generating or absorbing forces in the direction of the cylinder axis, but also have the function of transmitting forces transversely to the direction of movement of the movable component and thus also serve to transmit the forces between the frame and the running gear. Further embodiments of the invention are the subject of the dependent claims. According to a preferred embodiment of the invention, the guide in the frame is a guide bore that is in direct contact with an outer circumferential surface of the movable component. If the component fixed to the frame is formed by a piston rod and the movable component by a cylinder pushed onto the piston rod, good stability of the connection of the chassis to the frame is ensured. Ideally, each chassis is connected to the frame—viewed in the direction of travel of the vehicle—by at least one front and at least one rear hydraulic cylinder.It can be provided that the front and rear hydraulic cylinders are each formed by a component fixed to the frame and two sliding components that are either attached to or inserted into opposite ends of the fixed component, with the first landing gear attached to one sliding component and the second landing gear to the other. Particularly good stability is achieved here as well if the component fixed to the frame is formed by a connecting rod and the two sliding components by cylinders that are slid onto it. The displacement of the movable component can be limited by a stop element to restrict the maximum adjustable track width. Hydraulic cylinders designed as double-acting hydraulic cylinders are preferred, enabling adjustments to both increase and decrease the track width. To allow relative displacement and force transmission between the cylinder and piston rod, spaced guide elements and spaced seals are provided. A first pressure chamber can be formed between a front end of the piston rod and a closed end region of the cylinder. A second pressure chamber is bounded by the spaced seals, an inner wall of the cylinder, and a circumferential surface of the piston rod.Furthermore, a first pressure medium channel, connected to the first pressure chamber by fluid, and a second pressure medium channel, connected to the second pressure chamber by fluid, can be provided inside the piston rod, with the first and second pressure medium channels each having a pressure medium connection at the end furthest from the first and second pressure chambers, respectively. This results in a particularly compact device for adjusting the track gauge. The chassis is preferably designed as a tracked or wheeled chassis. To enable versatile use of the vehicle, various attachments can be coupled to it, depending on the intended application. These can include, for example, a winch to assist with felling or skidding timber, or equipment for preparing and maintaining plantings, such as mulching, sowing, chipping, or similar tasks. A particularly compact vehicle can be achieved if it is remotely controlled, thus eliminating the need for a driver's cab or vehicle cabin. Each chassis can also incorporate a suitable drive motor, such as a hydraulic motor or an electric motor. However, an energy source (battery) connected to the chassis drive motors, or even the motor itself, can also be integrated into the frame. An embodiment of the invention is described in more detail with reference to the following description and drawing. In the drawing, Fig. 1 shows a three-dimensional representation of the vehicle according to the invention, Fig. 2 a rear view of the vehicle with narrow track width setting, Fig. 3 a rear view of the vehicle with wide track width setting, Fig. 4 a three-dimensional representation of the hydraulic cylinder, Fig. 5 a longitudinal section view of the hydraulic cylinder in the narrow track width setting, Fig. 6 a longitudinal section view of the hydraulic cylinder in the wide track width setting, Fig. 7 a detailed section view in the area of ​​a first guide bushing, Fig. 8 a detailed section view in the area of ​​a second guide bushing, Fig. 9 a rear view of the vehicle with a sectioned view of the chassis, Fig. 10 a detail view in the area of ​​the fixing of the fixed component to the frame, Fig. 11 a partially sectioned top view of the vehicle, Fig. 12 a section view in the area of ​​the guide of the hydraulic cylinder on the frame, Fig.13 Sectional view in the area of ​​the attachment of the hydraulic cylinder to the chassis. The embodiment of a vehicle according to the invention shown in Fig. 1 comprises a frame 1, a first chassis 2, and a second chassis 3, wherein the two chassis 2 and 3 are designed as crawler chassis and are arranged on opposite sides of the frame 1. As can be seen from Figs. 2 and 3, the chassis 2 and 3 are mounted so as to be slidable relative to the frame 1 in order to change the track width SW1 and SW2. The track width is defined here as the distance between the centers of the two chassis 1 and 2. Fig. 2 shows the vehicle with a narrow track width SW1, while Fig. 3 shows a wide track width SW2. The track width adjustment is achieved via a front hydraulic cylinder 4 and a rear hydraulic cylinder 5, each of which comprises a component 6 fixed to the frame 1 and a first component 7a and a second component 7b that are displaceable relative to the frame 1. In the illustrated embodiment, the component 6 fixed to the frame 1 is formed by a connecting rod, while the two displaceable components 7a and 7b are formed by cylinders slid onto opposite ends of the connecting rod. Thus, both the front hydraulic cylinder 4 and the rear hydraulic cylinder 5 each utilize a common connecting rod as the fixed component 6, onto which the two displaceable components 7a and 7b, designed as cylinders, are slid. The first chassis 2 is attached to the first movable component 7a of the front and rear hydraulic cylinders 4 and 5 respectively, while the second chassis 3 is coupled to the second movable components 7b of the front and rear hydraulic cylinders 4 and 5 respectively (Fig. 1, Fig. 2 to Fig. 3). The front and rear hydraulic cylinders 4, 5 are identical in the illustrated embodiment and are described in more detail below with reference to Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8. Both hydraulic cylinders 4, 5 are designed as double-acting hydraulic cylinders, wherein, for relative displacement and force transmission between the first or second displaceable component 7a or 7b (cylinder) and the fixed component 6 (connecting rod), two spaced-apart guide bushings 8, 9 and 10, 11 respectively are provided, wherein the guide bushings 8 and 10 (Fig. 8) are each pressed onto the opposite ends of the fixed component 6, while the guide bushings 9 and 11 (Fig. 7) are each fixed to the pushed-on end of the first or second displaceable component 7a, 7b respectively. Guide bushings 8 and 10 are each provided with guide elements 12 and seals 13. Similarly, guide bushings 9 and 11 provide guide elements 14 and seals 15 to ensure, on the one hand, sliding movement between the fixed component 6 and the two movable components 7a, 7b, and on the other hand, to enable the formation of the pressure chambers described below. Each side of the hydraulic cylinders 4, 5 has a first pressure chamber 16 or 17 and a second pressure chamber 18 or 19, which can be pressurized with a suitable pressure medium, in particular oil, for displacement of the movable components 7a, 7b via first pressure medium channels 20, 22 or second pressure medium channels 21, 23 and associated pressure medium connections 24, 25, 26, 27 arranged in the fixed component 6. The first pressure chamber 16 or 17 is bounded by the end face 6a of the fixed component 6, the inner wall of the movable components 7a, 7b, a closing element 34 or 37 enclosing the movable components 7a, 7b, and the seals 13. The second pressure chamber 18 or 19 is formed by the outer circumferential surface of the fixed component 6, the inner wall of the first or second movable component 7a, 7b and by the spaced seals 13, 15. Applying pressure to the first pressure chamber 16 or 17 causes the movable components 7a, 7b to extend, thus increasing the track width. The track width is returned to its original position or reduced by applying pressure to the second pressure chambers 18 or 19. These second pressure chambers 18, 19 are connected to the second pressure channels 21 and 23, respectively, via short transverse bores 38, 39. In the illustrated embodiment, the two sides can be controlled separately, so that, if necessary, only one of the two bogies 2, 3 could be adjusted relative to the frame. However, it would also be conceivable that the two pressure channels 20 and 22 or 21 and 23 could be jointly pressurized via a dedicated connection to effect a simultaneous adjustment. To limit the maximum extendable distance of the movable components 7a, 7b, stop elements 28 and 29 are provided, which are arranged in the outer wall of the fixed component 6 and form a stop for the movable component 7a and 7b in the area of ​​the guide bushings 9 and 11, respectively. In the illustrated embodiment, the fixed component 6 has a centrally arranged fastening pin 30, which serves to fix the component 6 to the frame 1 and is in particular screwed there (Fig. 9, Fig. 10). The following section explains in more detail the guidance of the hydraulic cylinders 4, 5 on the frame 1 and the attachment of the chassis 2, 3 to the hydraulic cylinders 4, 5 with reference to Fig. 11, Fig. 12 to Fig. 13. The movable components 7a, 7b of the hydraulic cylinders 4, 5 are slidably guided in a guide 31 on the frame 1. The guide is designed to transmit forces between the movable component 7a or 7b and the frame 1 transversely to the direction of movement of the movable component 7a, 7b. In the illustrated embodiment according to Fig. 12, the guide 31 is a guide bore formed in the frame 1, which is in direct contact with the outer circumferential surface of the movable component 7a or 7b. The two hydraulic cylinders 4, 5 thus project through the guide 31 on both sides of the frame 1. Appropriate tolerances result in a simple yet stable design for adjusting the track width. The chassis 2, 3 are attached to the ends of the movable components 7a, 7b protruding from the frame 1, as shown in Fig. 13. For this purpose, the movable components 7a, 7b are provided with end pieces 34 and 37, respectively, at their ends protruding from the frame and are inserted with these ends through precisely fitting openings 32 into the chassis frame 33 of the respective chassis 2, 3, where they are fixed to the chassis frame 33 by means of screws 35 in the area of ​​the end pieces 34 and 37, respectively. Preferably, each chassis 2, 3 has a separate drive motor 40, 41, which is, for example, a hydraulic motor or an electric motor. The required energy source (hydraulic pump, battery) is then expediently arranged in the frame 1 (not shown) and is appropriately connected to the drive motors 40, 41 of the chassis 2, 3. Any connecting lines (oil lines, electrical cables) between the frame 1 and the respective chassis 2, 3 are, for example, protected by connecting pipes 36 (Fig. 11) between the energy source and the drive motors 40, 41.

Claims

Vehicle comprising a frame (1), a first chassis (2) and a second chassis (3), wherein the two chassis (2, 3) are arranged on opposite sides of the frame (1) and are slidably mounted relative to the frame (1) by means of hydraulic cylinders (4, 5) to change the track width, wherein each hydraulic cylinder (4, 5) comprises a component (6) fixed to the frame and at least one component (7a, 7b) slidable relative to the frame (1), and the first and second chassis (2, 3) are each attached to the slidable component (7a, 7b) of the hydraulic cylinders (4, 5), characterized in that the slidable component (7a, 7b) of the hydraulic cylinders (4, 5) is slidably guided in a guide (31) on the frame (1), wherein the guide (31) is transverse to the direction of movement of the slidable component (7a, 7b) for transmitting forces between the slidable component (7a, 7b) and the frame (1). is designed for a movable component (7a, 7b). Vehicle according to claim 1, characterized in that the guide (31) in the frame (1) is a guide bore which is in direct guide contact with an outer circumferential surface of the movable component (7a, 7b). Vehicle according to claim 1, characterized in that the component (6) fixed to the frame (1) is formed by a piston rod and the movable component (7a, 7b) is formed by a cylinder pushed onto the piston rod. Vehicle according to claim 3, characterized in that a stop element (28, 29) is provided to limit the displacement distance of the displaceable component (7a, 7b). Vehicle according to claim 1, characterized in that the hydraulic cylinders (4, 5) - viewed in the direction of travel of the vehicle - are formed by at least one front and at least one rear hydraulic cylinder (4, 5). Vehicle according to claim 5, characterized in that the front and rear hydraulic cylinders (4, 5) are each formed by a component (6) fixed to the frame (1) and two movable components (7a, 7b) which are inserted or pushed onto opposite ends of the fixed component (6) and the first chassis (2) is attached to one movable component (7a) and the second chassis (3) to the other movable component (7b). Vehicle according to claim 6, characterized in that the component (6) fixed to the frame (1) is formed by a connecting rod and the two movable components (7a, 7b) are formed by cylinders pushed onto it. Vehicle according to claim 3, characterized in that the hydraulic cylinders (4, 5) are designed as double-acting hydraulic cylinders, wherein spaced-apart guide elements (12, 14) and spaced-apart seals (13, 15) are provided for relative displacement and force transmission between cylinder and piston rod, wherein a first pressure chamber (16, 17) is formed between a front end of the piston rod and an end region of the cylinder and a second pressure chamber (18, 19) is bounded by the two spaced-apart seals (13, 15), an inner wall of the cylinder and a circumferential surface of the piston rod. Vehicle according to claim 8, characterized in that inside the piston rod a first pressure medium channel (20, 22) in fluid communication with the first pressure chamber (16, 17) and a second pressure medium channel (21, 23) in fluid communication with the second pressure chamber (18, 19) are provided, wherein the first pressure medium channel (20, 22) and the second pressure medium channel (21, 23) have a pressure medium connection (24 - 27) at the end facing away from the first or second pressure chamber (16, 17; 18, 19) respectively. Vehicle according to one or more of the preceding claims, characterized in that it is a remotely controlled vehicle for coupling at least one attachment. Vehicle according to one or more of the preceding claims, characterized in that the first and second chassis (2, 3) are a tracked chassis or a wheeled chassis. Vehicle according to one or more of the preceding claims, characterized in that each chassis (2, 3) has a drive motor (40, 41). Vehicle according to claim 12, characterized in that at least one energy source connected to the drive motors (40, 41) of the chassis (2, 3) is provided in the frame (1).

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