DE102022003253A1 - Method for determining a cable pulling force of a traction device for a commercial vehicle - Google Patents

Abstract

The invention relates to a method for determining a cable pulling force (FO), a cable pulling force device (6) carried by a support structure of an agricultural vehicle via a power lift, in which, in simplified form, the power lift has at least one upper link (10) and at least one lower link (12) with lifting strut (13) and connecting joints.
[0002] The cable pulling force (FO) is determined depending on at least one of the following variables:
- a tensile load (FO) acting on a connection (21) between the upper link (10) and the traction device (9) and acting along the upper link (10).
- an angle (α) (11) with an offset of the force articulation points and a variable connection between the top link (10) and the cable tensile force direction horizontal (7).

Description

The invention relates to a method for determining a cable pulling force of a cable pulling force device carried by a support structure of an agricultural vehicle via a power lift.

An agricultural vehicle is, for example, a tractor or tractor. The supporting structure is a supporting structure of the vehicle, e.g. a frame or other supporting parts. The upper link and lower link of the power lift are preferably pivotally mounted or articulated on the support structure in order to move each into different positions if necessary. The tensile load is preferably a tensile force device, such as a three-point attachment winch with or without variable cable tensile force.

Out of DE 197 31 089 A1 EP 3 315 926 A1 a device for determining the weight of loads is known, which is articulated on a work vehicle designed as a tractor.

The invention is based on the object of being able to determine a cable pull force, brake holding force and cable pull brake holding force overlap of a cable traction device in a commercial vehicle with little or simple sensory effort.

This task is solved according to the features of claim 1. According to claim 1, the method for determining a cable pull force provides that the cable pull force is held in the direction from the cable attachment point to the force application point with a connection to the support structure in the cable pull direction. The cable pulling force with which a body is pulled in a certain direction is advantageously determined on the upper link of the support structure on the basis of relatively easy to determine physical variables. At least one of the following variables is determined:

A three-point power lift is usually integrated into tractors. The associated top link is a component in a three-point hydraulic system. The top link makes it possible to adjust the length and angle of inclination of the cable traction device.

• - ein Winkel (α) zwischen dem Kraftangriffspunkt und einer Zugkrafteinrichtung-Horizontalen,

In the simplest case, the cable pull direction and a predominantly horizontal holding force (FO) act on a connection between the top link and the cable tensile load and act along the top link.

• - an angle (α) between the force application point and a traction device horizontal,

• - momentane Hubhöhe des Krafthebers
• - Standfestigkeit des Nutzfahrzeuges oder/und formschlüssige Abstützung der angebauten Seilzugeinrichtung entgegen der Seilzugrichtung
• - Kraft bzw. Druck in einem Hubzylinder des hydraulischen Oberlenkers oder Tragstruktur des Krafthebers
• - Eine Stützkraft an der angebauten Seilzugeinrichtung und/oder Stütz/Zugkraft am Unterlenker des Krafthebers
• - Dynamik (insbesondere Beschleunigung) mindestens an einem der der Anlenkpunkte des Nutzfahrzeugs, zur Bestimmung der Brems-Reaktionszeit in Abhängigkeit der Seilzugkraft.
• - Ein hydraulischer Oberlenker unterstützt die komfortable Justierung/Verstellung der vertikalen Neigung der angekoppelten Seil-Zugkrafteinrichtung.

Apart from determining at least one of the aforementioned quantities, suitable calculation rules can also be drawn up, from which the cable pulling force with which a body is pulled in a certain direction results. The design of the power lift used (e.g. three-point rear power lift or three-point front power lift) or various physical variables on the three-point power lift are taken into account. Depending on the sensor concept used - apart from at least one of the aforementioned variables - at least one of the following physical variables is advantageously taken into account in the calculation rules:

• - current lifting height of the power lift
• - Stability of the commercial vehicle and/or positive support of the attached cable pull device against the direction of the cable pull
• - Force or pressure in a lifting cylinder of the hydraulic top link or support structure of the power lift
• - A supporting force on the attached cable pull device and/or supporting/tractive force on the lower link of the power lift
• - Dynamics (in particular acceleration) at least at one of the articulation points of the commercial vehicle, to determine the braking reaction time depending on the cable pull force.
• - A hydraulic top link supports the comfortable adjustment/adjustment of the vertical inclination of the coupled cable traction device.

The physical quantities or their amounts required to determine the cable pulling force with which a body is pulled in a certain direction can be:

At the connection between the upper link and the cable pull force with which a body is pulled in a certain direction, the force acting and acting along the upper link can be determined, for example by means of pressure sensors on a hydraulic upper link.

A pressure sensor is installed directly on the cylinder outlet of the cylinder ring surface to detect high-frequency cable pull peak loads, advantageously without the locking block that is common in such top link systems.

An analog and/or digital data acquisition device with storage function and protocol software is assigned to the measuring sensor/pressure sensor/data sensor. The data can be displayed/saved directly with an IT device/PC/smartphone, further processed and transmitted via a cable connection or wirelessly as required. The data systems can be powered independently of the mains via battery operation/rechargeable battery from the data acquisition device.

Testing a higher braking holding force of the cable traction device than the maximum nominal traction force can be determined statically by adjusting the top link against the direction of the cable traction force.

The hydraulic pressure required for this comes from the commercial vehicle's integrated hydraulic system or is generated externally.

In the preferred variant, only the holding force (FO) of the upper link is determined, while the angle α of the upper link is not measured, so that the corresponding sensor system is unnecessary. With the help of suitable, adjustable data recording devices, the values of the cable pull force (FO) can then be determined.

One possibility is to use hydraulic top links with integrated damping through a vacuum created in the cylinder for a uniform pulling force and determining the pulling and braking holding force at the reaction time. This makes it possible to determine the damping rate individually according to the attached cable pull device.

In the case of cable winches with a constant tension device, with which cable pull transports are carried out, knowledge of changing tensile forces is useful and can be adapted according to the invention for the sensor system to change/compensate the cable pull force.

Another possibility is to determine a force at a different articulation point, for example at the supporting force of the lower links. Calculation and translation data and data from suitable sensors, such as inclination sensors, pressure sensors, angle sensors, force measuring bolts, can also be used to determine rope tensile force values.

Overall, the cable pulling force with which a body is pulled in a certain direction can be determined with a small number of sensors available as standard products and thus cost-effectively with a few sensed physical variables. In some cases, the sensors required for other purposes may already be present on the vehicle, so that in such cases the effort required for the determination is further reduced.

In a further embodiment, only the angle α of the top link to the horizontal of the traction device and the holding force (FO) of the top link are required to measure the cable pull force, or the cable pull force is determined with the help of suitable calculation rules.

The method according to the invention for determining a cable pulling force of an attached cable pulling device is explained in more detail below with reference to the accompanying drawings. Components that are the same or comparable in terms of their function are marked with the same reference numbers.

• 1 in der Seitenansicht ein landwirtschaftliches Nutzfahrzeug mit einem Dreipunkt-Kraftheber und angebauter Zugkrafteinrichtung in Zugkraft-Messposition,
• 2 ein schematischer Freischnitt des Zugkrafteinrichtunges,

Show it:

• 1 in the side view an agricultural vehicle with a three-point power lift and attached traction device in the traction measurement position,
• 2 a schematic free section of the traction device,

Tractor with a cabin (2), a front axle (3) and an engine (4) for driving at least one

Rear axle (5). The rear area of the commercial vehicle (1) is not shown to scale and in principle

Three-point power lift (6) attached. Additionally or alternatively, such a three-point power lift can also be attached to the

The front area of the commercial vehicle (1) must be attached. The three-point power lift (6) has flat kinematics in one

Plane spanned, the vehicle longitudinal direction or vehicle horizontal (7), while the vertical direction corresponds to a vehicle vertical direction or vehicle vertical (8). The three-point power lift (6) is used to lift or carry a traction device (9), which is referred to as a cable pull device.

The three-point power lift (6) comprises at least one top link (10), which is articulated via a linkage (15) in the rear area of a support structure (6) of the commercial vehicle (10). Furthermore, the three-point power lift (6) comprises a lower link (12), which is also articulated to the rear area of the support structure (6) via a support bearing (13).

The lower link (12) is connected via a lifting spindle acting in a lower link joint to one end of a lifting arm (11), which is articulated with its other end via a linkage is connected to the support structure (6) of the commercial vehicle (1).

The lifting arm (11) can be pivoted relative to the supporting structure (6) via a hydraulic cylinder (16) which engages in a lifting arm joint and is supported against the supporting structure (6).

The pivoting of the lifting arm (11) by means of the hydraulic cylinder (16) is transmitted to the lower link (12) via the lifting spindle (13).

The length of the lifting spindle (13) is adjustable so that the angular positions of the lifting arm (11) and the lower link (12) can be adjusted relative to one another.

The upper link (10) and lower link (12) are connected to the traction device (9) on the side facing away from the commercial vehicle (1) in the vehicle's longitudinal direction via an upper link articulation point or a lower link articulation point.

The upper link articulation point can be adjusted in the vertical direction of the vehicle, so that the upper link (10) can assume different vertical positions (not shown here) to adjust a mast height.

In 1 Several sensor means are provided on the commercial vehicle (1) schematically and not to scale, which are used to measure or record various physical variables on individual components of the power lift (6) in order to determine a cable pulling force of the traction device (6).

Further sensor means can be, for example, an acceleration sensor (inclination or yaw rate sensor) arranged on the vehicle. The hydraulic pressure on the lifting cylinder (16) is preferably measured by means of sensor means on the lifting cylinder (16). Before measuring the pressure in the lifting cylinder (16) to produce a defined state, friction compensation can be carried out by a defined, minimal movement of the cylinder piston.

Third sensor means (preferably inertial or inclination sensor) determine an angle (α) between the upper link (10) and the vehicle horizontal (7).

Other sensor means (e.g. force measuring pins, bending rods) can measure a tensile force on the lower link (12). Sensor means (preferably an existing sensor for measuring the hydraulic pressure in the hydraulic top link (10).

Depending on the embodiment of the tensile force device (9), individual sensor means mentioned can be dispensed with, so that different arrangements with a different combination of sensor means for carrying out the method for determining the cable tensile force or a mass derived therefrom can result. The measured values provided by the sensor means are fed to a control device for further processing. At the same time, this averages the measurement data to compensate for otherwise unconsidered rotational inertia forces that are induced by dynamic vibrations.

2 shows schematically the traction device (9) attached to the three-point power lift (6) with forces acting on it. Due to the different slopes of the commercial vehicle and additional acceleration components that occur while driving, there are variable acceleration components, which, however, are the same for all bodies considered. These already include the acceleration of gravity and are recorded by the sensor means attached to the support structure (6).

In an advantageous embodiment, the upper link holding force (FO) at the angle α of the upper link (10) is determined by means of hydraulic pressure sensors in the cylinder of the hydraulic upper link (8) and the display value of the cable pull force (25) (FO) with a at the articulation point (19) connected adjustment device (24). It is not necessary to determine other articulation points, as this is no longer necessary by placing the traction device on a horizontal plane (7) at the stop (22) with static fixation at the lower force contact point (23) and cable connection (19). The hydraulic power lift is in the floating position and the commercial vehicle does not generate any braking force via the axles. This means that the corresponding sensor means on the support bearing can also be omitted.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19731089 A1 [0003]
• EP 3315926 A1 [0003]

Claims (9)

Method for determining a cable pulling force of a payload for a commercial vehicle The invention relates to a method for determining a cable pulling force (FO), of a cable pulling force device (9) carried by a support structure of an agricultural commercial vehicle via a power lift, whereby, in simplified form, the power lift has at least one upper link (10) and at least one lower link (12) with lifting strut (13) and its connecting joints. The cable pull force (FO) is determined depending on at least one of the following variables: - A cable pulling force (FO) acting on a connection (21) between the upper link (10) and the cable traction device (9) and acting along the upper link (10). - taking into account the angle (α) (11) of variable offset height on the tension mast of the top link (10) and the force connection point in the cable traction device horizontal (7), - a positive parking of the traction device on a horizontal plane (7) with static fixation at the stop (22), lower force contact point (23) and rope fixation (19), with the hydraulic power lift being in the floating position and the commercial vehicle over its axles does not exert any braking force. Procedure according to Claim 1 , characterized in that to determine the cable pull force, the pressure in a hydraulic top link correlates with the cable pull force. Method according to one of the preceding claims, characterized in that the data recorder for cable tension and clutch control pressure of the traction device can be carried out simultaneously with an IT system with a diagram and storage function or via data transmission in a wired or wireless manner. Method according to one of the preceding claims, characterized in that the data acquisition systems can be supplied from the IT system itself. Method according to one of the preceding claims, characterized in that hydraulic system pressures of the support structure and further sensor data from an agricultural vehicle are used to control the pulling power of constant pulling traction devices. Method according to one of the preceding claims, characterized in that the supporting force or at least one of its force components is determined as a function of a tensile force at a connection of the support structure (6). Method according to one of the preceding claims, characterized in that - the amount of the holding force (FO) of the upper link (10) and the amount and direction of the supporting force of the lower link are combined (12). - the amount of the cable pulling force (FO) in a force triangle spanned by the direction of action of the cable pulling force (FO), the supporting force and the amount of the holding force (FO) is determined as the distance from the point of application of the supporting force to an intersection point on the direction of action of the cable pulling force (FO). is formed, whereby the intersection is formed by the amount of holding force (FO) between the supporting force and the direction of action of the cable pull force (FO). Method according to one of the preceding claims, characterized in that to determine the cable pulling force (FO), a coordinate system is defined parallel to a longitudinal direction (7) of the commercial vehicle. Method according to one of the preceding claims, characterized in that, if necessary, additional hydraulic pressures from external systems can be carried out mechanically, with muscle power or battery-operated.

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