Cutting Unit Having Sensors for Height Control

Abstract

The present invention relates to a cutting unit (2) for attachment to the height-adjustable intake duct (6) of a harvester (4). In order to improve the sensor-supported height guidance of cutting units, it is proposed to provide at least one additional load sensor (26) which measures the load (28) with which the cutting unit (2) loads the intake duct (6), in order to calculate a height-control-relevant signal (32) from the transmitted sensor values (25) of the distance sensor (18) and the load sensor (26) via an evaluation device (24), which signal (32) is transmitted to the interface (34).

Claims

1.-6. (canceled)

7. A cutting unit comprising: a frame; an attachment device connected to the frame and configured to attach the cutting unit to a height-adjustable intake duct of a harvesting machine: cutting elements arranged on the frame; conveying devices arranged on the frame; drives arranged on the frame and configured to drive the cutting elements and/or the conveying devices; an interface configured to transmit height control-relevant signals to a control or regulating device of the harvesting machine; an evaluation device arranged upstream of the interface; a distance sensor configured to determine a distance of the cutting unit to the ground, wherein the distance sensor is connected by a first connection line to the evaluation device and transmits first sensor values measured by the distance sensor to the evaluation device via the first connection line; a load sensor configured to measure a load with which the cutting unit loads the intake duct of the harvesting machine, wherein the load sensor is connected by a second connection line to the evaluation device and transmits second sensor values measured by the load sensor to the evaluation device via the second connection line; wherein the evaluation device comprises a program that computes, by a suitable programming of the program, from the first sensor values of the distance sensor and from the second sensor values of the load sensor a height control-relevant signal that is transmitted to the interface.

8. The cutting unit according to claim 7, wherein the cutting unit comprises a spring system and is connected via the spring system to the intake duct of the harvesting machine, wherein the load sensor is a device configured to measure a spring travel of the spring system.

9. A method for height guidance of a cutting unit attached to a height-adjustable intake duct of a harvesting machine, the method comprising: determining a distance of the cutting unit to the ground by a distance sensor arranged at the cutting unit; generating, based on the distance determined by the distance sensor, a first sensor value and transmitting the first sensor value to an evaluation device; measuring a load with which the cutting unit loads the intake duct by a load sensor arranged at the cutting unit; generating, based on the load measured by the load sensor, a second sensor value and transmitting the second sensor value to the evaluation device; computing a height control-relevant signal from the first sensor value of the distance sensor and from the second sensor value of the load sensor with a program provided in the evaluation device by a suitable programming of the program and transmitting the height control-relevant signal to an interface configured to transmit the height control-relevant signal to a control or regulating device of the harvesting machine.

10. The method according to claim 9, further comprising averaging in the evaluation device the first sensor value and the second sensor value transmitted within a time interval to the evaluation device.

11. The method according to claim 9, further comprising increasing or decreasing the first sensor value of the distance sensor transmitted within a time interval to the evaluation device by a correction factor when the second sensor value of the load sensor signals a full load of the intake duct.

12. The method according to claim 9, further comprising increasing or decreasing the second sensor value of the load sensor transmitted within a time interval to the evaluation device by a correction factor when the first sensor value of the distance sensor signals no distance of the cutting unit to the ground.

13. The method according to claim 9, further comprising: increasing or decreasing the first sensor value of the distance sensor transmitted within a time interval to the evaluation device by a correction factor when the second sensor value of the load sensor signals a full load of the intake duct; and increasing or decreasing the second sensor value of the load sensor transmitted within a time interval to the evaluation device by a correction factor when the first sensor value of the distance sensor signals no distance of the cutting unit to the ground.

14. The method according to claim 7, wherein the first sensor value and the second sensor value are transmitted, respectively, as a percentage value between a respective minimum value and a respective maximum value to the evaluation device.

15. The method according to claim 7, further comprising converting the first sensor value and the second sensor value in the evaluation device into a percentage value, respectively, between a respective minimum value and a respective maximum value.

Description

[0029] The invention will now be explained in more detail with the aid of embodiments. It is shown in:

[0030] FIG. 1: a side view of a harvesting machine with a cutting unit that is spaced from the ground; and

[0031] FIG. 2: a side view of a harvesting machine with a cutting unit that has ground contact.

[0032] FIG. 1 shows a harvesting machine 4 to which is attached a cutting unit 2 at a side that is facing in travel direction. The cutting unit 2 is held with its frame 8 at the height-adjustable intake duct 6. The frame 8 comprises an attachment device 10 with which the cutting unit 2 can be attached to the harvesting machine 4.

[0033] At the front edge of the cutting unit 2, cutting elements 12 such as a cutter bar are located. Moreover, at the cutting unit there are conveying devices 14 provided, for example, screw conveyors and/or belt conveyors, with which the cut crop is conveyed in the direction toward the intake duct and is transferred thereto, or a reel that can be seen in the side views. Moreover, the cutting unit 2 comprises drives 16 with which the cutting elements 12 as well as the conveying devices 14 are driven. In the embodiment, the drives 16 are arranged behind the side flap, provided with reference character 16, at the side wall of the cutting unit 2.

[0034] As an example of a distance sensor 18, a sensing skid is illustrated in FIG. 1. For the purposes of the invention, any other sensor types can be used also, for example laser, ultrasonic sensors or distance sensors that operate according to other physical principles. In the working situation illustrated in FIG. 1, the cutting unit 2 is held at such a large distance 20 to the ground that a ground contact of the cutting unit 2 is excluded. The distance 20 is however still so small that the distance sensor 18 can measure the distance 20 to the ground.

[0035] The distance sensor 18 is connected by a connection line 22 to an evaluation device 24.

[0036] As a further sensor, a load sensor 26 is provided in the cutting unit 2 with which it is determined at which load 28 the intake duct 6 of the harvesting machine 4 is loaded by the weight of the cutting unit. Since the cutting unit in the working position illustrated in FIG. 1 is held at a large distance 20 to the ground, the intake duct 6 carries the full weight of the cutting unit 2. The load sensor 26 transmits the sensor values measured by it via a connection line 22 also to the evaluation device 24. In the embodiment, the load sensor 26 is a device for measuring the spring travel 44 of the spring system 42. Independent of this sensor type, other sensor types can be employed also in order to determine loading of the intake duct 6 by the weight of the cutting unit.

[0037] The evaluation device 24 comprises a program 30 that by means of a suitable programming can compute a height control-relevant signal 32 that is transmitted to the interface 34 from the sensor values 25 transmitted by the distance sensor 18 and load sensor 26. From the cutting unit-side interface 34, the height control-relevant signal 32 is transferred to the harvesting machine-side interface 36. The harvesting machine-side interface 36 is connected to a control or regulating device 38 that is provided on the harvesting machine 4. A part of the control or regulating device 38 is an adjusting drive 40; by means of its actuation, the intake duct 6 of the harvesting machine 4 can be adjusted in regard to height. The adjusting drive 40 can be comprised, for example, of hydraulic cylinders, not illustrated in more detail in the drawings, that by retraction and extension can lower or lift the intake duct 6, depending on the movement direction. The hydraulic cylinders are loaded by a corresponding hydraulic system with corresponding valves.

[0038] In the embodiment illustrated in FIG. 1, the distance sensor 18 signals, for example, a deflection of the sensing skid by 30% as a sensor value 25 of the distance sensor 18. Since the full weight of the cutting unit 2 is carried by the intake duct 6, the load sensor 26 signals as sensor value 25 a load of 100%.

[0039] Based on these two numerical values, the following calculation results:

30%+100%=130%:2=65%.

[0040] This value of 65% is transmitted from the evaluation device 24 as a height control-relevant signal 32 to the interface 34. This percentage value can be further processed by the control or regulating device 38 to an adjusting signal to the adjustment drive 40 if this appears necessary after the evaluation of the height control-relevant signal 32 by the control or regulating device 34.

[0041] In the embodiment illustrated in FIG. 2, the sensing skid of the distance sensor 18 is completely folded due to ground contact that it is experiencing. Accordingly, its deflection has the value 0%. Due to the ground contact of the cutting unit 2, the intake duct 6 is partially relieved with respect to weight. In the embodiment illustrated in FIG. 2, the intake duct 6 carries still 20% of the weight of the cutting unit 2. The sensor value 25 of the load sensor 26 amounts thus to 20%. When offsetting the two sensor values 25 in the evaluation device, the following calculation results:

0%+20%=20%:2=10%.

[0042] The height control-relevant signal 32 determined by the evaluation device 24 thus amounts to 10% in the second embodiment illustrated in FIG. 2.

[0043] Depending on the height adjustment of the cutting unit 2 at the intake duct 6, the afore described sensor values 25 of the distance sensor 18 and of the load sensor 26 can vary, of course. Depending on the magnitude of the sensor values 25, a corresponding different height control-relevant signal 32 is then provided.

[0044] Due to the division by 2 of the sum of the two sensor values 25, they are weighted identically. In deviation from the embodiment, it is, of course, also possible to weight the distance sensor 18 or the load sensor 26 higher in relation to the other sensor. The respective weighting of the sensor values 25 can be programmed either fixedly in the program 30, or a possibility is provided for the operator of the harvesting machine 4 to change the weighting as he desires. In any case, due to offsetting the sensor values, a break is avoided at the point at which the values of one sensor no longer change, as is the case for the distance sensor 18 when the distance to the ground is 0 and for the load sensor 26 when the intake duct 6 carries 100% of the weight of the cutting unit 4.

[0045] Likewise, in an embodiment it can be provided that the evaluation device 24 averages the sensor values 25 that are transmitted within a time interval.

[0046] The invention relates also to a method that, in accordance with the afore described pattern, determines a height control-relevant signal 32 and transmits the latter to a control or regulating device 38 arranged on the harvesting machine 4.

[0047] With the method, it is possible that the evaluation device 24 increases or decreases the sensor value 25 of the distance sensor 18 transmitted within a time interval by a correction factor when the sensor value 25 of the load sensor 26 signals full load 28 of the intake duct, and/or the evaluation device 24 increases or decreases the sensor value 25 of the load sensor 26 transmitted within a time interval by a correction factor when the sensor value 25 of the distance sensor 18 signals no distance 20 of the cutting unit 2 to the ground.

[0048] According to a further embodiment, the sensor values 25 are transmitted as percentage values between the respective minimum value and the maximum value to the evaluation device 24 and/or converted by the latter into percentage values between the respective minimum value and the maximum value in order to transmit then the result of this calculation as a height control-relevant signal 32 to the interface 34.

[0049] The invention is not limited to the afore described embodiments. A person of skill in the art will have no difficulties to modify the embodiments in a manner appearing suitable to him in order to adapt them to a concrete application situation.

LIST OF REFERENCE NUMERALS

[0050] 2 cutting unit [0051] 4 harvesting machine [0052] 6 intake duct [0053] 8 frame [0054] 10 attachment device [0055] 12 cutting element [0056] 14 conveying device [0057] 16 drive [0058] 18 distance sensor [0059] 20 distance [0060] 22 connection line [0061] 24 evaluation device [0062] 25 sensor value [0063] 26 load sensor [0064] 28 load [0065] 30 program [0066] 32 height control-relevant signal [0067] 34 interface (cutting unit) [0068] 36 interface (harvesting machine) [0069] 38 control or regulating device [0070] 40 adjustment drive (harvesting machine) [0071] 42 spring system [0072] 44 device for spring travel measurement