Crop pull resistance measuring device

Abstract

The present application relates to a kind of crop pull resistance measuring device, including frame, first guide rail slider mechanism and clamping assembly;The clamping assembly includes the clamp for clamping crop, connecting piece fixed with first guide rail and support installed on connecting piece, second guide rail and second slider are equipped on the support, two second sliders are spaced apart, and are respectively recorded as left slider and right slider, the tension spring that makes left slider and right slider approach each other is equipped on the second guide rail;Left mounting plate and right mounting plate are respectively fixed with left slider and right slider, left and right force sensors are respectively fixed with left mounting plate and right mounting plate, and the clamp is between left and right force sensors.This pull resistance measuring device can accurately measure the force condition of clamping point in the process of crop pulling, and the force of soil exerted on crop root system can be calculated through cantilever beam model, so as to provide basis for structural design and operation parameter setting of operation machine.

Description

Technical Field

[0001] This invention relates to a crop pulling resistance measuring device, belonging to the field of agricultural machinery technology. Background Technology

[0002] "Pulling up" is an action similar to "cutting," "beating," and "picking up," and is one of the common basic actions in agricultural production. It is widely used in crop production, especially in the harvesting stage, such as "pulling weeds," "pulling radishes," and "pulling cotton stalks."

[0003] To successfully pull crops out of the soil, it is necessary to overcome the pulling resistance (anchoring force) exerted by the soil on the crop's root system (rootstock). Pulling resistance is a primary basis for the design of pulling and harvesting machinery. Factors such as different pulling positions, pulling speeds, pulling angles, and pulling and harvesting times all affect the pulling resistance. Therefore, it is essential to accurately measure the force state of the crop during pulling. This directly impacts the rational control of the movement direction and speed of the working parts, as well as the clamping position and pulling time, thereby improving the efficiency and effectiveness of the pulling operation. Currently, the measurement of pulling resistance in China is mostly done manually. Manual measurement is not only time-consuming, labor-intensive, and inefficient, but also results in unstable force application and significant errors in the measured pulling resistance data.

[0004] The applicant's search revealed that Chinese patent CN108318173A discloses an adjustable cotton stalk pulling force measuring device. This device connects to a pulling rod via a wire rope that bypasses a pulley system. However, during the measurement process, as the crop is pulled out, the clamping position acting on the crop may move in an undefined direction, meaning the pulling angle of the crop will change unexpectedly. Since the working trajectory of harvesting machinery is fixed, this does not match the actual operating conditions. Therefore, the measured pulling resistance cannot accurately reflect the actual operating conditions, hindering the accurate optimization of the harvesting machinery's design parameters. Chinese patent CN110595659A, which connects the drive wheel and clamping mechanism via a rope, also exhibits a similar issue.

[0005] On the other hand, the anchoring effect of soil on crop roots can usually be simplified to a pair of orthogonal forces and a couple, i.e., a cantilever beam model. The measurement methods mentioned in the above patents can only measure forces in one dimension, and under normal circumstances, they obviously cannot deduce the stress situation on the root system.

[0006] In actual stalk pulling operations, the movement trajectory of the working parts of the machinery is fixed. However, in order to improve the quality and efficiency of stalk pulling and harvesting, it is necessary to measure the stalk pulling resistance of crops under different clamping heights, different pulling angles, and speed parameter combinations. This allows for the selection of a "safe and efficient" parameter range for the machinery. Therefore, a new crop pulling resistance measuring device is needed. By accurately measuring the pulling resistance under specified parameter conditions, the root system stress during the crop pulling process can be obtained, providing mechanical and structural parameter basis for the design of the machinery, thereby improving the efficiency of subsequent machinery operations. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a measuring device that can reflect the real-time soil resistance experienced by the roots (roots and stems) during the crop pulling process, which can provide mechanical and structural parameter basis for the design of operating machinery.

[0008] To solve the above-mentioned technical problems, the technical solution proposed by the present invention is: a crop pulling resistance measuring device, comprising a frame, a first guide rail slider mechanism and a clamping assembly; the first guide rail slider mechanism is composed of a first slider and a first guide rail, the clamping assembly is fixedly connected to the first guide rail, and the first slider is mounted on the frame; The clamping assembly includes a clamp for clamping crops, a connector fixed to the first guide rail, and a bracket mounted on the connector. The bracket is provided with a second guide rail and a second slider that cooperates with the second guide rail. Two second sliders are arranged at intervals along the second guide rail, referred to as the left slider and the right slider, respectively. A tension spring is sleeved on the second guide rail, and the tension spring is used to bring the left slider and the right slider closer to each other. The left and right sliders are respectively fixed to a left mounting plate and a right mounting plate. The left and right mounting plates are respectively fixed to a left force sensor and a right force sensor. The left and right force sensors are respectively provided with a left pin and a right pin. The fixture is provided with a left pin hole and a right pin hole that correspond one-to-one with the left pin and the right pin. The left pin is inserted into the left pin hole and the right pin is inserted into the right pin hole.

[0009] This invention controls the lifting angle of the clamp through a first guide rail slider mechanism. Since the angle between the first guide rail and the horizontal plane remains constant, the angle between the clamping point's trajectory and the horizontal plane remains constant throughout the crop lifting process. This overcomes the defect in existing technologies where the crop's lifting angle changes unexpectedly as it is pulled out. This invention does not directly measure the force on the root system, but rather simplifies the calculation by measuring the force at the clamping point and combining it with the crop's bending force, converting it into a cantilever beam model. Therefore, when measuring the force on the clamping point during crop lifting, determining the clamping point's trajectory is crucial. This allows the force exerted by the soil on the crop roots to be calculated using the cantilever beam model, providing a reliable basis for the structural design and operational parameter setting of the machinery.

[0010] Therefore, the lifting resistance measured by this invention can accurately reflect the actual operation, accurately optimize the design parameters of subsequent harvesting machinery, provide a real basis for the design and use of lifting machinery, prevent the crop from breaking due to excessive lifting resistance during the lifting process, and help maintain the integrity of the harvested crop.

[0011] This invention, by setting a second guide rail and a second slider on a bracket connected to the first guide rail, and applying a preload force to the left and right force sensors during installation using a tension spring, not only meets the installation and usage requirements of the force sensors, but also facilitates the replacement of the lifting clamps. Different lifting clamps can be selected for different crops, thereby improving measurement efficiency and reducing measurement costs. Attached Figure Description

[0012] The invention will now be further described with reference to the accompanying drawings.

[0013] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the clamping assembly installation.

[0015] Figure 3 This is a schematic diagram showing the height and angle adjustment of the first guide rail slider mechanism.

[0016] Reference numerals: 1. Frame; 2. Power supply; 3. Reducer; 4. Winch; 5. Motor; 6. Pull rope; 7. Ground support; 9. Clamping assembly; 10. Second guide rail; 11. Crossbar; 12. Connector; 13. Fixture; 14. First guide rail; 15. First slider; 16. Angle adjustment plate; 17. Displacement sensor; 18. Pulley block; 19. Data acquisition card; 20. Transmitter; 22. Height adjustment plate; 23. Angle adjustment hole; 30. Bracket; 31. Left tension spring; 32. Right tension spring; 33. Left slider; 34. Right slider; 35. Left mounting plate; 36. Right mounting plate; 37. Left force sensor; 38. Right force sensor; 39. Left pin; 40. Right pin. Detailed Implementation

[0017] This embodiment relates to a crop pull-out resistance measuring device, such as... Figure 1 As shown, the device includes a frame 1, a first guide rail slider mechanism, and a clamping assembly 9. The first guide rail slider mechanism consists of a first slider 15 and a first guide rail 14. The clamping assembly 9 is fixed to the first guide rail 14, and the first slider 15 is mounted on a crossbar 11. In this embodiment... Figure 1As shown, the first guide rail 14 is driven by the pull rope 6 to slide along the first slider 15. One end of the pull rope 6 is connected to the first guide rail 14, and the other end passes over the pulley block 18 and is wound around the winch 4. The winch 4 is driven by the motor 5 through the reducer 3, and the motor 5 is powered by the power supply 2. Of course, the first guide rail 14 can also be driven by other mechanisms, such as a crank-slider mechanism, a hydraulic cylinder, or a linear motor. To improve the stability of the frame 1, preferably, the bottom of the frame 1 is provided with multiple foot supports 7.

[0018] like Figure 2 As shown, the clamping assembly 9 includes a clamp 13 for clamping crops, a connector 12 fixedly connected to the first guide rail 14, and a bracket 30 mounted on the connector 12 (the connector 12 and the bracket 30 can be manufactured as a single unit). The bracket 30 is provided with a second guide rail 10 and a second slider that cooperates with the second guide rail 10. Two second sliders are spaced apart along the second guide rail 10, respectively designated as the left slider 33 and the right slider 34. A tension spring is fitted on the second guide rail 10, which is used to bring the left slider 33 and the right slider 34 closer together. Figure 2 As shown in the figure, in this embodiment, the second guide rail 10 adopts a sliding shaft, and the tension spring includes a left tension spring 31 and a right tension spring 32, both of which are pressure springs and are sleeved on the second guide rail 10; of course, a tension spring can also be used, in which case the tension spring is located between the left slider 33 and the right slider 34.

[0019] It should be noted that the clamp 13 in this embodiment is existing technology, such as the clamp with publication number CN220087956U and name "A Cotton Stalk Pulling Clamp". Taking the measurement of the pulling resistance of cotton stalk as an example, the top tip, side branches and other parts of the cotton stalk that affect the measurement are removed, leaving only the main stem. In use, the clamping platform is first inserted into the cotton stalk from top to bottom, and the cotton stalk clamp is used to clamp the cotton stalk after the side branches have been removed. Then the clamping platform is moved up to further tighten the cotton stalk clamp. Because the cotton stalk clamp is inserted into the tapered hole that is larger at the top and smaller at the bottom, the clamping platform will gradually form a squeezing force on the cotton stalk clamp during the upward pulling process, ensuring that the clamping force of the cotton stalk clamp on the cotton stalk gradually increases during the pulling process, and slippage will not occur, avoiding the phenomenon of pull-out due to the cotton stalk not being clamped tightly.

[0020] like Figure 2As shown, the left slider 33 and the right slider 34 are respectively fixed to the left mounting plate 35 and the right mounting plate 36. The left force sensor 37 and the right force sensor 38 are respectively provided with a left pin 39 and a right pin 40. The clamp 13 is provided with a left pin hole and a right pin hole (not shown in the figure) corresponding to the left pin 39 and the right pin 40. The left mounting plate 35 is fixed to the left force sensor 37 by bolts, and the right mounting plate 36 is fixed to the right force sensor 38 by bolts. The left pin 39 is inserted into the left pin hole, and the right pin 40 is inserted into the right pin hole. When installing clamp 13, first insert the left pin 39 into the left pin hole and the right pin 40 into the right pin hole. Then, use the tension spring to bring the left slider 33 and the right slider 34 closer together, thereby applying a preload force to fix the left force sensor 37 and the right force sensor 38. When replacing or removing clamp 13, simply move the left slider 33 and the right slider 34 in the direction of separation to make the left pin 39 leave the left pin hole and the right pin 40 leave the right pin hole, thereby removing clamp 13.

[0021] The left and right force sensors 37 and 38 can reliably and stably measure the three forces in orthogonal directions during crop removal. For example... Figure 1 As shown, the left force sensor 37 and the right force sensor 38 are connected to the data acquisition system. The data acquisition system consists of a host computer, a transmitter 20, a data acquisition card 19, etc., and can control the start, stop, and speed of the motor 5. It can also connect to a host computer program to collect and save the data from the left and right force sensors 37 and 38 in real time. This is existing technology and will not be described in detail. For measuring the crop removal distance, preferably, the first guide rail slider mechanism is equipped with a displacement sensor 17 for measuring the distance the first guide rail 14 moves along the first slider 15. Figure 1 and Figure 3 As shown, the main body of the displacement sensor 17 is fixed to the first slider 15; the other end is fixed to the first guide rail 14, and slides synchronously with the first guide rail 14 under the action of the pull rope 6, thereby measuring the crop removal distance.

[0022] It should be noted that, under normal circumstances, the left force sensor 37 and the right force sensor 38 are three-dimensional force sensors. However, the force state of the crop during the pulling process is related to the crop itself, the clamping method and the pulling action. When it is necessary to consider the influence of the torsion on the crop during the pulling process, the left force sensor 37 and the right force sensor 38 can be replaced with a six-dimensional force sensor.

[0023] This embodiment can also be improved in the following ways: 1) such as Figure 1 and Figure 3As shown, the frame 1 is equipped with a pair of circular angle adjustment plates 16, which are fixed together by a crossbar 11. The first slider 15 is mounted on the crossbar 11. The frame 1 is also equipped with a height adjustment plate 22 for fixing the angle adjustment plates 16. The angle adjustment plates 16 have a ring of angle adjustment holes 23, and are fixed to the height adjustment plate 22 by bolts passing through the angle adjustment holes 23. Rotating the angle adjustment plate 16 adjusts the angle of the first slider 15, thereby adjusting the crop's starting angle according to experimental needs. The starting angle can be adjusted within the range of 0°-90°.

[0024] 2) such as Figure 1 and Figure 3 As shown, the frame 1 has multiple mounting positions in the vertical direction for fixing the height adjustment plate 22. This allows the lifting height to be adjusted according to experimental needs, and the lifting height can be set based on the crop lifting clamping position and the lifting distance. In this example, the height adjustment plate 22 is bolted to the frame 1. By installing the height adjustment plate 22 in different mounting positions, the lifting height can be adjusted.

[0025] The operating procedure of the device in this embodiment (taking cotton stalk pulling as an example) is as follows: Before the start of the pulling resistance measurement test, adjust the pulling angle and pulling height according to the test requirements, use clamp 13 to clamp the main stem of the cotton stalk, pull the left mounting plate 35 and right mounting plate 36 on both sides of the left and right force sensors 37 and 38, so that the left and right positioning pins 39 and 40 are inserted into the corresponding left and right pin holes on both sides of the clamp 13, thereby installing the clamp 13 on the resistance measurement device. Power is connected to 2. The pulling speed and distance are set via the host computer. Motor 5 jogs, driving the pull rope 6 to the pre-tensioned state. After the preliminary preparations are completed, the program button on the host computer is activated. Motor 5 starts to drive the winch 4 to rotate according to the set speed and number of rotations. The winch 4 winds the pull rope 6, which pulls the first guide rail 14 backward. The pull rope 6 of the displacement sensor 17 moves backward synchronously with the first guide rail 14. The first guide rail 14 pulls the clamp 13 to completely remove the cotton stalk. The entire pulling process ends. Motor 5 stops rotating according to the displacement signal or according to the set time. During the pulling process, the cotton stalk pulling resistance signal collected by the left and right force sensors 37 and 38, and the cotton stalk pulling distance signal collected by the displacement sensor 17 are converted and amplified by the transmitter 20 and transmitted to the host computer via the data acquisition card 19. The data can also be displayed in real time in the form of a waveform graph. The measurement data is saved in a designated path for subsequent result analysis.

[0026] The overall structure of this embodiment is reasonably designed, lightweight and aesthetically pleasing, easy to manufacture and maintain, has strong parts versatility, low overall cost, can adapt to the diversity of crop varieties, and can clamp and remove crops of different diameters.

[0027] This invention can achieve independent adjustment of different lifting angles, lifting speeds, and lifting heights, and can be tested according to different parameter combinations. It has good adaptability, is easy to operate, can simulate the field operation state of a harvester, and meets the needs of crop lifting resistance measurement.

Claims

1. A device for measuring crop pulling resistance, characterized in that: It includes a frame, a first guide rail slider mechanism, and a clamping assembly; the first guide rail slider mechanism consists of a first slider and a first guide rail, the clamping assembly is fixed to the first guide rail, and the first slider is mounted on the frame; The clamping assembly includes a clamp for clamping crops, a connector fixed to the first guide rail, and a bracket mounted on the connector. The bracket is provided with a second guide rail and a second slider that cooperates with the second guide rail. Two second sliders are arranged at intervals along the second guide rail, referred to as the left slider and the right slider, respectively. A tension spring is sleeved on the second guide rail, and the tension spring is used to bring the left slider and the right slider closer to each other. The left and right sliders are respectively fixed to a left mounting plate and a right mounting plate. The left and right mounting plates are respectively fixed to a left force sensor and a right force sensor. The left and right force sensors are respectively provided with a left pin and a right pin. The fixture is provided with a left pin hole and a right pin hole that correspond one-to-one with the left pin and the right pin. The left pin is inserted into the left pin hole and the right pin is inserted into the right pin hole.

2. The crop pulling resistance measuring device according to claim 1, characterized in that: The first guide rail slider mechanism is equipped with a displacement sensor for measuring the distance the first guide rail moves along the first slider.

3. The crop pulling resistance measuring device according to claim 1 or 2, characterized in that: The frame is provided with a pair of circular angle adjustment plates, which are fixed together by a crossbar. The first slider is set on the crossbar. The frame is provided with a height adjustment plate for fixing the angle adjustment plate. The angle adjustment plate has a ring of angle adjustment holes. The angle adjustment plate is fixed to the height adjustment plate by bolts passing through the angle adjustment holes.

4. The crop pull-out resistance measuring device according to claim 3, characterized in that: The frame has multiple mounting positions in the vertical direction for fixing the height adjustment plate.

5. The crop pulling resistance measuring device according to claim 1 or 2, characterized in that: The bottom of the frame is equipped with multiple foot supports.

6. The crop pulling resistance measuring device according to claim 1 or 2, characterized in that: The left and right force sensors are either three-dimensional or six-dimensional force sensors.

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