Snow groomer for the design and maintenance of snow-covered areas

Description

[0001] The invention relates to a snow groomer for shaping and maintaining snow terrain, comprising a chassis frame and a tracked undercarriage having two undercarriage sides on opposite longitudinal sides of the chassis frame, each undercarriage side having a sprocket wheel, a plurality of running wheels, a tensioning wheel and a track chain encircling the sprocket wheel, the running wheels and the tensioning wheel, as well as a drive system for driving the tracked undercarriage, and a front or rear attachment.

[0002] Such a snow groomer is known from DE 10 2020 206 710 A1. The known snow groomer has a chassis frame on which a driver's cab is positioned. Furthermore, a tracked drive system is provided with two drive sides, each with a track assigned to it. The tracked drive system is driven by a drive system. A rear tiller is arranged at the rear of the snow groomer, which is intended for processing a snow surface. A measuring sensor is provided on the rear tiller, which continuously penetrates a layer of snow on the snow surface while the snow groomer is in operation. The measuring sensor is equipped with a force sensor and a temperature sensor in order to detect the snow surface structure.

[0003] DE 10 2018 213 240 A1 discloses a snow groomer with a chassis frame and a tracked undercarriage, which has two track sides on opposite longitudinal sides of the chassis frame. Each track side is equipped with a sprocket wheel, a tensioning wheel, and several running wheels, as well as a track chain that encircles the sprocket wheel, the running wheels, and the tensioning wheel. A drive system is also provided to drive the tracked undercarriage. The snow groomer has a front-mounted clearing blade and a rear-mounted milling device.

[0004] JP 2011 011622 A discloses a monitoring system for a tracked vehicle. It includes sensors for detecting vibrations in the chassis frame. An electronic monitoring device evaluates the recorded vibration data.

[0005] DE 10 2017 002 163 A1 discloses a chain tensioning system for tracked vehicles for adjusting a chain pre-tension, which comprises an electromechanical adjusting device for variably adjusting the chain pre-tension and a control unit which is connected to the electromechanical adjusting device for measuring a motor current.

[0006] DE 41 09 257 C1 discloses a method for monitoring the chains of a tracked vehicle for malfunctions. During operation, the actual running noise of the chain is recorded and compared with the average running noise of a healthy chain. Depending on the result of the comparison, an error signal is triggered.

[0007] US 2021 / 0173399 A1 discloses a tracked vehicle in which the tracked undercarriage is monitored for several parameters such as temperature, pressure, acceleration, and the like. This also records the characteristics of the ground on which the tracked undercarriage rolls during operation.

[0008] The intermediate document EP4166721 A1 relates to a snow groomer with a structure-borne sound sensor.

[0009] The object of the invention is to create a snow groomer of the type mentioned above, which enables a good processing quality of a snow surface of the snow terrain.

[0010] This object is achieved by the features of claim 1. The inventive sensor system for detecting structure-borne sound frequencies makes it possible to detect the snow surface without, as in the prior art, a measuring sensor being immersed in the snow surface, which could cause damage to the snow surface. Rather, according to the invention, structure-borne sound waves are detected that arise during driving due to the inevitable immersion of track links into the snow surface. These sound waves are evaluated and signaled. This allows conclusions to be drawn about the snow conditions of the snow surface without having to damage the snow surface. Rather, according to the invention, detection is contactless.In particular, it is possible to detect an ice surface, artificial or natural snow conditions, fresh snow, powder snow, or slush, or even a differently structured layer structure of the snow surface. In the latter case, it is particularly possible to detect whether an icy surface layer with an underlying slush layer or a reverse layer structure is present. Furthermore, the invention allows the functional components themselves to be checked for proper operation, since damaged functional components emit different sound frequencies than undamaged functional components.According to the invention, it is additionally or alternatively provided to provide a corresponding sensor system on a front or rear attachment of the snow groomer in order, on the one hand, to be able to monitor the corresponding functional parts of this attachment for proper functioning and, on the other hand, to be able to adjust the corresponding functional parameters of the attachment accordingly based on the detected snow and layer formation conditions. Preferably, the attachment has at least one auger shaft rotating during operation.

[0011] According to the invention, the attachment is designed as a rear tiller, and the monitoring device stores structure-borne sound frequency ranges for the intended operation of at least one tiller shaft of the rear tiller and / or a smoothing device of the rear tiller. By comparing these target values ​​with recorded actual values ​​during actual tilling operation of the rear tiller, the functional parameters of the rear tiller can be adjusted accordingly.

[0012] In one embodiment of the invention, the monitoring device is coupled to the drive system to obtain driving speed or track speed data, and several characteristic curves of body frequency ranges for different driving or track speeds of the snow groomer are stored in the monitoring device. This embodiment takes into account that structure-borne sound frequencies vary at different speeds of the snow groomer, as well as depending on the slippage of the tracked drive system during operation of the snow groomer.

[0013] In a further embodiment of the invention, structure-borne sound frequency ranges for different surface or structure configurations of the snow terrain when the snow groomer's tracked drive system passes over them are stored in the monitoring system. If the attachment is designed as a rear-mounted tiller, structure-borne sound frequency ranges for different surface or structure configurations of the snow terrain can be stored alternatively or additionally during the tilling operation of the rear-mounted tiller. These serve as target values ​​for comparison with the actually recorded values.

[0014] In a further embodiment of the invention, the sensor system comprises at least one triaxial acceleration sensor for recording structure-borne sound frequencies. The triaxiality allows for three-dimensional detection of structure-borne sound waves. The acceleration sensor can be piezoelectric or based on quartz technology. Alternatively, the acceleration sensor can be capacitive or magnetically stabilized. With quartz technology, acceleration measuring systems with flexible quartz rods are used. Alternatively, it is possible to equip an acceleration sensor with magnetically stabilized masses, the deflection of which results in corresponding magnetic field changes that are detected. Piezoelectric acceleration sensors use piezoceramic sensor plates that convert dynamic pressure fluctuations into electrical signals, which are then further processed.The pressure fluctuation is generated by a mass attached to the piezoceramic.

[0015] In a further embodiment of the invention, the acceleration sensor is designed in a miniaturized form, particularly as a micro-electromechanical system (MEMS). Such MEMS acceleration sensors operate by changing the electrical capacitance. Such sensors are usually made of silicon.

[0016] In a further embodiment of the invention, the acceleration sensor is attached to a tensioning axle or a tensioning axle support of the tensioning wheel. The tensioning wheel is provided on each side of the snow groomer's undercarriage as the frontmost wheel around which the respective track rotates. It has been found that arranging an acceleration sensor on the tensioning axle or a support of the tensioning axle allows for particularly effective detection of structure-borne sound frequencies from the snow groomer's functional parts during operation.

[0017] In a further embodiment of the invention, parts or sections of the track sides of the tracked undercarriage, parts of the drive system, parts of the attachment, or bearing or pump components in the area of ​​the chassis frame are provided as functional parts. Corresponding functional parts are all parts or sections that are rotatable or otherwise movable during driving or working operation of the snow groomer.

[0018] In a further embodiment of the invention, at least one acceleration sensor for detecting structure-borne sound frequencies is attached to a support frame of the front or rear attachment. Preferably, the acceleration sensor is attached to a support frame of a rear tiller of the snow groomer. This embodiment enables control of functional components of the rear tiller depending on the analysis of the snow terrain structure based on the detected structure-borne sound frequencies.

[0019] In a further embodiment of the invention, the monitoring device is connected to a control device for controlling a milling drive of the milling shaft, for controlling the depth of penetration of the milling shaft, and for controlling the contact pressure of the smoothing device on the snow surface. These are typical functional parameters of the rear-mounted tiller, which can be controlled depending on the result of the monitoring device's evaluation.

[0020] 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 schematically in a side view an embodiment of a snow groomer according to the invention and Fig. 2 in an enlarged, perspective view a part of the snow groomer according to Fig. 1 in the area of ​​a tensioning wheel axle of the chassis frame.

[0021] A snowcat 1 after the Fig. 1 and 2is equipped with a front-mounted attachment in the form of a dozer blade 2 and a rear-mounted attachment in the form of a rear tiller 3. The snow groomer 1 has a chassis frame 4 that supports a driver's cab 6 and a winch assembly 5. The chassis frame 4 is flanked on opposite longitudinal sides by a tracked drive train that has a left and a right track side - viewed in the normal direction of travel of the snow groomer 1. Each track side is equipped with a rear sprocket 9, a front tensioning wheel 7, and a total of four running wheels 8, around which a track chain 10 rotates. The track chain 10 is constructed from a plurality of track links 11 extending in the transverse direction of the vehicle and several track belts running in the longitudinal direction of the vehicle, to which the track links 11 are attached.The drive chain 10 is guided by means of track brackets, which are arranged on the inside of the chain links 11 and are firmly connected to the chain links 11 and the chain belts.

[0022] The crawler track is driven by a drive system which, with the aid of suitable drive motors, drives the two sprockets 9 on the opposite sides of the track for forward travel, reverse travel and steering movements of the snow groomer 1.

[0023] Based on the Fig. 1 It can be seen that the snow groomer 1, in the operational driving state, dips into a snow surface S of a snowy terrain with the chain links 11 of a lower run of the track chain 10 up to approximately a schematically shown snow layer S 1 . The height of the snow build-up between the snow surface S and the snow layer S 1 worked by the chain links 11 is the processing depth of the track chains 10 when the snow groomer 1 drives over the snow surface, i.e. the snowy terrain. The immersion of the chain links 11 with rotating track chains 10 creates, on the one hand, noise in the form of airborne sound waves, which are dependent on the nature of the layer structure of the snowy terrain starting from the snow surface S. On the other hand, structure-borne sound waves are created by the large number of moving functional parts of the snow groomer 1 during driving operation.Such functional parts include, in particular, the track chains 10, the running wheels 8, the tensioning wheels 7, and the sprocket wheels 9, as well as corresponding axle bearings and axle suspensions of the wheel bearings or hydraulic pumps for the working hydraulics or for the drive system of the snow groomer 1, to name just a few. These airborne and structure-borne sound waves are measured in the snow groomer 1 according to the . Fig. 1 and 2 detected by at least one acceleration sensor 12, which is based on the Fig. 2 can be seen. The acceleration sensor 12 is designed as a micro-electro-mechanical system and can record triaxial accelerations caused by corresponding structure-borne sound waves. The acceleration sensor 12 is attached to a tensioning axle support of a tensioning axle 14, which supports the left tensioning wheel 7 (as seen in the normal direction of travel).

[0024] The acceleration sensor 12 is connected to an electronic monitoring device Ü, in which target value ranges for structure-borne or airborne sound frequency ranges of various functional parts of the snow groomer are stored, which arise during normal operation of the snow groomer. Several characteristic curves of target value ranges can be stored, which represent different snow conditions, different layer structures of the snow terrain and / or different driving or track speeds of the snow groomer 1. In the monitoring device Ü, the recorded actual values ​​of structure-borne or airborne sound frequencies of the acceleration sensor 12 are compared with the target value ranges and evaluated. A signal line B 1 is provided for transmitting the actual values ​​of the acceleration sensor 12 to the monitoring device Ü.Depending on the result of the comparison, the monitoring device Ü outputs a signal that can be forwarded in the form of data information to an electronic control unit St of the drive system or to other control elements of functional parts of the snow groomer 1. Alternatively or additionally, a corresponding data signal can also be sent to a display device D in the driver's cab 6 of the snow groomer 1, so that a driver of the snow groomer 1 receives information about the condition of the snowy terrain or information in the form of an error message about possibly damaged functional parts of the snow groomer 1.This makes it possible for the driver to either adjust the driving function of the drive system accordingly based on the transmitted information, or for the control unit St of the drive system to directly and automatically make corresponding changes to the drive system in order to return the drive system to its intended operation. In particular, if excessive slip is detected on the drive chains 10, the drive system can be adjusted back to reduce the slip. The control variable in each case is the comparison between the target and actual values ​​of structure-borne sound frequencies or airborne sound frequencies.

[0025] The acceleration sensor 12 can also be provided to record structure-borne sound frequencies of the front-mounted dozer blade 2 or the rear-mounted rear tiller 3 and to adjust a corresponding control of the dozer blade 2 or the rear tiller 3 depending on the comparison between the corresponding target and actual values ​​of structure-borne sound frequencies. In the illustrated embodiment, the rear tiller 3 is additionally provided with a further acceleration sensor 13, which is coupled to the monitoring device Ü via a signal line B 2 . The acceleration sensor 13 is designed in the same way as the acceleration sensor 12, namely as a MEMS acceleration sensor with triaxial detection capability. The acceleration sensor 13 is attached to a support frame of the rear tiller 3.The acceleration sensor 13 records in particular structure-borne sound frequencies of at least one driven tiller shaft of the rear tiller 3, but also structure-borne sound frequencies that arise from the pressing of a rear-side smoothing device of the rear tiller 3 onto the snow surface.

[0026] The monitoring device Ü is in the illustrated embodiment according to the Fig. 1 and 2 Additionally, it is also connected to a rear tiller control HF, which controls a tiller shaft drive on the one hand and a corresponding control hydraulics on the other hand, which controls the immersion depth of at least one tiller shaft into the snow surface and the alignment of the smoothing device relative to the snow surface as well as the contact pressure of the smoothing device on the snow surface.

[0027] In addition, the monitoring device Ü stores target value ranges for structure-borne sound frequencies of the corresponding functional components of the rear tiller 3, preferably with different characteristic curves that cover different driving speeds and / or different snow conditions or layer structures of the snow surface. By comparing them with the recorded actual values, automatic control of the functional parameters of the rear tiller or support of the rear tiller control by a snow groomer driver is possible.

Claims

1. A snow groomer (1) for shaping and maintaining snow terrain with a chassis frame (4) and with a track having two chassis frames on opposite longitudinal sides of the chassis frame (4), wherein each track side has a sprocket wheel (9), several road wheels (8) and an idler wheel (7), and a drive chain (10) passing around the sprocket wheel (9), the road wheels (8) and the idler wheel (7), and with a drive system for driving the track, and with a front-mounted or rear-mounted attachment (3), characterized in that a sensor system for detecting structure-borne sound frequencies is arranged in the region of the chassis frame (4) and / or on the attachment (3) and is connected to an electronic monitoring device (Ü) in which set values for structure-borne sound frequency ranges of functional parts during operation of the snow groomer (1) as intended are stored and which compares the detected actual values of structure-borne sound frequencies with the set values and emits a signal dependinf on the result of the comparison; in that the attachment is designed as a rear-mounted tiller (3); and in that structure-borne sound frequency ranges for an operation as intended of the at least one tilling shaft of the rear-mounted tiller (3) and / or of a smoothing device of the rear-mounted tiller (3) are stored in the monitoring device (Ü).

2. The snow groomer (1) according to claim 1, characterized in that the monitoring device (Ü) is coupled to the drive system for receiving travel speed or track speed data and in that several characteristic curves of structure-borne sound frequency ranges for different travel or track speeds of the snow groomer are stored in the monitoring device (Ü).

3. The snow groomer (1) according to claim 1 or 2, characterized in that structure-borne sound frequency ranges for different surface or structure types of snow terrain (S) when it is passed over by the track of the snow groomer (1) or during tilling operation by the rear-mounted tiller (3) are stored in the monitoring device (Ü).

4. The snow groomer (1) according to any of the preceding claims, characterized in that the sensor system has at least one triaxial acceleration sensor (12, 13) for recording structure-borne sound frequencies.

5. The snow groomer (1) according to claim 4, characterized in that the acceleration sensor (12, 13) is designed miniaturized, in particular as a micro-electromechanical system (MEMS).

6. The snow groomer (1) according to claim 4 or 5, characterized in that the acceleration sensor (12) is fastened to an idler axle or to an idler axle support of the idler wheel (7).

7. The snow groomer (1) according to any of the preceding claims, characterized in that parts or sections of the track sides of the track, parts of the drive system, parts of the attachment or bearing or pump components are provided in the region of the chassis frame as functional parts.

8. The snow groomer (1) according to any of the preceding claims, characterized in that at least one acceleration sensor (13) for detecting structure-borne sound frequencies is fastened to a support frame of the front-mounted or rear-mounted attachment (3).

9. The snow groomer (1) according to any of the preceding claims, characterized in that the monitoring device (Ü) is connected to a control device (HF) of the rear-mounted tiller (3) for controlling a tiller drive of the tilling shaft, for controlling an insertion depth of the tilling shaft, and for controlling a contact pressure of the smoothing device on the snow surface.