Snow groomer with at least one working device

Abstract

2.1 A snow groomer with at least one implement pivotally mounted on the snow groomer, a drive unit for controlling the pivoting movement of the at least one implement, an inclination sensor for detecting inclinations of the snow groomer relative to the surface being traversed, and an electronic control unit for controlling the drive unit for the at least one implement is known. 2.2 According to the invention, the inclination sensor is connected to the control unit to transmit inclination data to the control unit. The control unit has a data processing unit to calculate the magnitude and direction of an instantaneous incline of the snow groomer during operation, depending on the inclination data. A mass of the implement and a distance of the implement's center of mass relative to the implement's pivot axis are stored in a memory of the control unit.Using the data processing unit, and taking into account the mass and distance data stored in the memory and the current incline of the snow groomer, a downward force and a resulting instantaneous torque acting around the pivot axis are calculated for the implement. Depending on the calculated instantaneous torque, the drive unit can be controlled in such a way that the respective instantaneous torque is compensated for. 2.3 Application for snow groomers for snow grooming,

Description

[0001] The invention relates to a snow groomer with at least one working device which is mounted on the snow groomer so as to be pivotable about a vehicle-side pivot axis, and with a working drive which is provided for controlling a pivoting movement of the at least one working device, with an inclination sensor system for detecting inclinations of the snow groomer about a vehicle longitudinal axis and a vehicle transverse axis relative to a traveled surface, and with an electronic control unit for controlling the working drive for the at least one working device.

[0002] Such a snow groomer is well known. A snow groomer is a tracked vehicle used for maintaining and cultivating snowy terrain. Such a snow groomer can have a snow blade as the front attachment and a rear tiller as the rear attachment. The rear tiller is attached to a carrier, which is mounted on the rear of the snow groomer's vehicle frame and can pivot about a pivot axis. Hydraulic cylinders of a working hydraulic system, controlled by a control unit, are provided to support and adjust the carrier.

[0003] The object of the invention is to create a snow groomer of the type mentioned above which enables economical and high-quality use of the working device regardless of the slope of the snow terrain to be worked on.

[0004] This object is achieved in that the inclination sensor is connected to the control unit in order to transmit inclination data to the control unit, in that the control unit has a data processing unit in order to calculate the amount and direction of a current incline when the snow groomer is in operation as a function of the incline data, in that a mass of the implement and a distance of a center of mass of the implement relative to the pivot axis of the implement are stored in a memory of the control unit, in that by means of the data processing unit, taking into account the mass and distance data stored in the memory and taking into account the current incline of the snow groomer when the snow groomer is in operation, a slope force and a resulting current torque for the implement acting around the pivot axis are calculated,and that, depending on the calculated instantaneous torque, the working drive can be controlled by the control unit in such a way that the respective instantaneous torque is compensated. The solution according to the invention enables compensation of the influence of the slope force on the working device when the snow groomer travels transversely or diagonally to a fall line of a slope in snowy terrain, so that additional damping measures for the working device are unnecessary. This ensures, with simple means, a smooth driving and slope maintenance operation of the snow groomer, even when traveling on slopes. The working device for the snow groomer is, in particular, a rear tiller,A front-mounted clearing blade or a winch positioned on the snow groomer is also provided. The working drive can be a hydraulic drive or an electric drive. The working drive can comprise actuating cylinders or adjusting spindles and / or electric or hydraulic motors. The inclination sensor system can comprise one or more inclination sensors.

[0005] In one embodiment of the invention, a current swivel angle of the implement relative to the vehicle's longitudinal axis is detected and taken into account when calculating the current torque. This embodiment utilizes the knowledge that when the snow groomer corners, a corresponding implement, in particular a rear tiller, is aligned at an angle to the vehicle's longitudinal axis to enable effective slope grooming even when cornering. The corresponding deflection also changes the position of the center of mass, so the described embodiment is helpful for achieving balanced support of the implement even when cornering.

[0006] In a further embodiment of the invention, a rear tiller mounted on a rear-mounted carrier of the snow groomer is provided as the working device, and the pivot axis of the working device is defined by a vehicle-side pivot axis of the carrier. This embodiment is particularly advantageous because a balanced, tracking rear tiller for a snow groomer enables good processing quality for the more or less steep snow terrain it travels over under all driving conditions. The rear tiller has one or more driven tiller shafts and a smoothing device connected to the tiller shafts at the rear.

[0007] In a further embodiment of the invention, a winch arm mounted on the snow groomer is provided as a working device. This winch arm is controlled by a rotary drive, which forms the working drive. The winch arm is part of a cable winch that supports the operation of the snow groomer on steep terrain. A rotation axis of the winch arm about a vehicle vertical direction forms the pivot axis of the winch arm relative to the snow groomer. The winch arm itself extends essentially radially to the corresponding rotation axis and thus essentially horizontally – relative to an orientation of the snow groomer in a horizontal plane.

[0008] In a further embodiment of the invention, a clearing blade mounted on the front of the snow groomer is provided as the working device. The clearing blade can be tilted in different orientations on the front of the snow groomer. The working drive is preferably provided by a working hydraulic system with several hydraulic cylinders that extend between a vehicle frame of the snow groomer and the clearing blade.

[0009] In a further embodiment of the invention, the working drive is hydraulically designed and has several hydraulic cylinders that can be electrically controlled by the control unit. The hydraulic cylinders are preferably assigned pressure control valves that are electrically controlled.

[0010] Further advantages and features of the invention emerge from the claims and from the following description of a preferred embodiment of the invention, which is illustrated with reference to the drawings. Fig. 1 shows a plan view of an embodiment of a snow groomer according to the invention, Fig. 2 schematically shows the snow groomer according to Fig. 1 in a driving operation across a slope of a snowy terrain, Fig. 3 schematically in an enlarged view a control of a tool carrier of the snow groomer, which carries a rear tiller, and Fig. 4 schematically a block diagram for controlling the tool carrier according to Fig.3 .

[0011] A snowcat 1 after Fig. 1has, in a basically known manner, a chassis frame 2, which is flanked on opposite longitudinal sides of the snow groomer 1 by a tracked unit 3. To drive the tracked units 3, a travel drive is provided, which is formed either by a central electric or combustion motor with a connected hydraulic circuit for driving sprockets of the tracked units 3 or by a purely electric travel drive. When the snow groomer 1 is in travel mode, the sprockets drive the tracked units, whereby the snow groomer 1 moves forward, in particular along the slope of a snow slope. On steep snow slopes, a winch can be positioned on the snow groomer 1, which guides a winch cable via a winch arm, which is fixedly suspended above the steep snow slope. When in travel mode, the snow groomer 1 travels up or down the slope, across the slope, or at an angle to the slope.A driver's cab 4 is arranged at the front of the chassis frame 2. A clearing blade 7 is also pivoted on the chassis frame 2 at a distance in front of the driver's cab 4. This clearing blade 7 is connected to the chassis frame 2 and thus to the snow groomer 1 by means of a support frame 8. The clearing blade 7 is pivotally adjustable relative to the support frame 8 about a pivot axis extending in the vertical direction of the vehicle as well as about a pivot axis extending in the transverse direction of the vehicle. For this purpose, hydraulic actuating cylinders of a working hydraulic system (only partially shown) are provided, which serve as the working drive for the clearing blade 7.

[0012] Behind the driver's cab 4, on a platform of the chassis frame 2 (not further specified), a cable winch 9 is arranged, which has a Fig. 1has a winch arm 10 projecting forward. The winch arm 10 is mounted so as to be rotatable by 360° relative to the platform of the chassis frame 2 about an axis of rotation extending in the vertical direction of the vehicle. The cable winch 9 carries a windable and unwindable winch cable which is guided over the winch arm 10 and, during winch operation of the snow groomer 1, is fixedly suspended at the end at the upper end of a steep slope of a snowy terrain. The cable winch supports the driving operation of the snow groomer 1 in steep areas of the snowy terrain being traveled over by placing tension on the winch cable fixed to the slope side and a winch drive of the cable winch 9 exerts a permanent tensile force on the winch cable in order to support the drive of the tracked undercarriage 3 of the snow groomer 1.The winch arm 10 forms a boom arm for the winch cable and, depending on the direction of travel of the snow groomer 1 relative to the slope, is always deflected in such a way that the winch arm 10 and the winch cable under tension are aligned with each other.

[0013] At the rear of the snow groomer 1, a rear tiller 5 is arranged as a working device. This device serves to crush and smooth the snow surface traveled over by the tracked drive 3. For this purpose, the rear tiller 2 has one or more driven tiller shafts. The at least one tiller shaft is driven by a tiller drive, which is designed hydraulically or electrically. At the rear of the tiller shafts, a smoothing device is provided, which compacts and smooths clumps of snow and ice crushed by the tiller shafts on the snow surface. The rear tiller 5 is suspended from an implement carrier 6, which is pivotally mounted on the chassis frame 2 at the rear about a pivot axis S extending at least substantially in the vertical direction of the vehicle.

[0014] When driving the snowcat 1 according to Fig. 1 Along a slope of a snowy terrain, the snowcat 1 is subjected to downhill forces ( Fig. 2) when the snow groomer 1 travels at an angle to a fall line F of the slope of the snow terrain. This includes both transverse travel and diagonal travel of the snow groomer uphill or downhill. Corresponding downhill forces therefore also act on the rear tiller 5, which is hinged to the chassis frame 2 of the snow groomer 1 via the equipment carrier 6. When the snow groomer 1 travels straight ahead, the equipment carrier 6 is aligned in the vehicle's longitudinal direction in alignment with a vehicle center longitudinal axis M. When the snow groomer 1 corners or turns, the equipment carrier 6 is deflected by a pivot angle in a horizontal vehicle plane relative to the vehicle center longitudinal axis M in order to be able to guide the rear tiller 5 in line with the curved path of the snow groomer 1.This ensures that even when the snow groomer 1 is cornering, the rear tiller 5 enables the snow surface to be crushed and smoothed over the entire width of the snow surface traveled over by the crawler track 3.

[0015] The snow groomer 1 according to the invention according to the Fig. 1 to 3 enables compensation of the effect of the slope force on the driving operation of the snow groomer 1 and in particular on the operation of the rear tiller 5, which represents a working device within the meaning of the invention.

[0016] For this purpose, an inclination sensor N is permanently installed in the snowcat 1 ( Fig. 2 to 4), which detects the inclinations of the snow groomer 1 in the vehicle's longitudinal direction NX and in the vehicle's transverse direction NY. The inclination sensor system N with the inclination detection NX in the longitudinal direction and the inclination detection NY in the transverse direction is connected to an electronic control unit St, which has a data processing unit and is also arranged on the snow groomer 1. The data processing unit is preferably implemented in the form of a software program.

[0017] The equipment carrier 6 is - as already explained - pivotally mounted on the rear of the chassis frame 2 of the snow groomer 1 about the pivot axis S. The respective orientation of the equipment carrier 6 relative to the vehicle's central longitudinal axis M ( Fig. 3 ) is detected by an angle sensor W. In the illustration according to the Fig. 2 and 3this swivel angle of the equipment carrier 6 relative to the vehicle's central longitudinal axis M is zero. As soon as the equipment carrier 6 is deflected relative to the vehicle's central longitudinal axis M of the snow groomer 1 when cornering, the swivel angle is greater than zero in magnitude. The direction of the deflection, counterclockwise or clockwise, is also detected by the angle sensor W. In particular, one direction of rotation can be marked with a minus sign and the other direction with a plus sign. The angle sensor W is also connected to the electronic control unit St and its data processing unit. The data processing unit within the electronic control unit St uses the sensor data supplied by the inclination sensor N to calculate both the magnitude and the direction of the currently applicable gradient of the snow groomer 1, both transversely and along the fall line F of the slope of the snow terrain being traveled on.The direction of the current gradient is understood to mean the direction of travel of the snow groomer 1, downhill or uphill.

[0018] The data processing unit within the electronic control unit St has a memory in which a mass of the rear tiller 5 and a distance of a center of mass of the rear tiller 5 relative to the pivot axis S of the implement carrier 6 are stored. These data are taken from fixed design data of the rear tiller and the implement carrier of the snow groomer, which are preferably available as CAD data.

[0019] In addition, the swivel angle data supplied by the angle sensor W is processed in the data processing unit, calculating the magnitude and direction of the swivel angle. Using the data calculated from the sensor data of the inclination sensor N and the angle sensor W, the slope force currently acting on the rear tiller 5 is to be calculated. From this, with the aid of the data stored in the memory of the data processing unit regarding the distance of the center of mass of the rear tiller 5 relative to the swivel axis S and the mass of the rear tiller 5, a resulting torque acting on the implement carrier 6 at the swivel axis S is calculated.

[0020] The implement carrier 6 is supported on opposite sides - seen in the transverse direction of the vehicle - and controlled by two hydraulic actuating cylinders A 1 and A 2 , as Fig. 3can be seen. The hydraulic actuating cylinders A 1 , A 2 form a working drive for the rear tiller 5 in the sense of the invention. The actuating cylinders A 1 and A 2 are electrically controlled by the electronic control unit St via pressure control valves D 1 and D 2 . The control unit St controls these pressure control valves D 1 , D 2 in such a way that the respective slope force currently acting on the rear tiller 5 during driving of the snow groomer 1 is balanced out, so that the rear tiller 5 can be stabilized via the two actuating cylinders A 1 , A 2. The rear tiller 5 is thus also stabilized in the case of a Fig. 2 The perceptible transverse travel of the snow groomer 1 on a slope of snowy terrain is not affected by the inevitably acting downhill force. The downhill force H is eliminated by controlling the actuating cylinders A 1 , A 2 via the control unit St.

[0021] In a manner not shown, the winch arm 10 or the clearing blade 7 can also be controlled alternatively or additionally according to the same principle in order to also compensate for the effect of the slope force when the snow groomer 1 travels transversely or diagonally on the slope.

Claims

1. Snow groomer (1) with at least one working device which is mounted on the snow groomer (1) so as to be pivotable about a vehicle-side pivot axis (S), and with a working drive which is provided for controlling a pivoting movement of the at least one working device, with an inclination sensor system (N) for detecting inclinations of the snow groomer about a vehicle longitudinal axis (M) and a vehicle transverse axis relative to a traveled surface, and with an electronic control unit (St) for controlling the working drive for the at least one working device, characterized in thatthe inclination sensor (N) is connected to the control unit (St) in order to transmit inclination data to the control unit (St), that the control unit (St) has a data processing unit in order to calculate the amount and direction of a current incline of the snow groomer (1) as a function of the incline data when the snow groomer (1) is in operation, that a mass of the implement and a distance of a center of mass of the implement relative to the pivot axis (S) of the implement are stored in a memory of the control unit (St), that by means of the data processing unit, taking into account the mass and distance data stored in the memory and taking into account the current incline of the snow groomer (1) during operation, a slope force and a resulting current torque for the implement acting about the pivot axis (S) are calculated,and that, depending on the calculated instantaneous torque, the working drive can be controlled by the control unit (St) in such a way that the respective instantaneous torque is compensated., 2. Snow groomer (1) according to claim 1, characterized in that a momentary swivel angle of the implement relative to the vehicle's longitudinal axis (M) is recorded and taken into account when calculating the momentary torque.

3. Snow groomer (1) according to claim 1 or 2, characterized in that a rear tiller (5) arranged on a rear-side implement carrier (6) of the snow groomer (1) is provided as the working device, and that the pivot axis (S) of the working device is defined by a vehicle-side pivot axis of the implement carrier (6).

4. Snow groomer (1) according to claim 1 or 2, characterized in that as a working device, a winch arm (10) mounted on the snow groomer is provided, which is controllable by a rotary drive which forms the working drive.

5. Snow groomer (1) according to claim 1 or 2, characterized in that a clearing blade (7) mounted on the front of the snow groomer (1) is provided as a working device.

6. Snow groomer (1) according to one of the preceding claims, characterized in that the working drive is hydraulic and has several hydraulic actuating cylinders (A1, A2) which can be electrically controlled by means of the control unit (St).

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