White radish leaf rigidity-variable clamping device and white radish harvester

Abstract

The utility model belongs to the field of agricultural automation equipment, and discloses a white radish leaf variable-rigidity clamping device which comprises a tensioning wheel set fixed on a conveying rack and a variable-rigidity elastic device used for adjusting the tensioning force of the tensioning wheel set, the tensioning wheel set is used for tensioning a clamping belt to clamp white radish leaves to complete pulling and conveying operation, and the variable-rigidity elastic device is used for adjusting the tensioning force of the tensioning wheel set. The tensioning wheel set comprises a fixed tensioning wheel and a movable tensioning wheel which are used in a paired mode, the rigidity-variable elastic device comprises a rigidity adjusting piece fixed to the conveying rack, an elastic piece connected with the rigidity adjusting piece and a supporting rod connected with the elastic piece, and the supporting rod is connected with the movable tensioning wheel. Tensioning force between the movable tensioning wheel and the fixed tensioning wheel is adjusted by adjusting the rigidity adjusting piece, and the torque provided by the elastic piece is determined according to the plastic deformation amount of the leaf in the clamping process. The utility model further provides a white radish harvester. According to the white radish leaf variable-rigidity clamping device and the white radish harvester, the pulling success rate of white radishes is high.

Description

Technical Field

[0001] The utility model belongs to the field of agricultural automation equipment, and particularly relates to a white radish tassel leaf variable-rigidity clamping device and a white radish harvester. Background Art

[0002] my country has a wide planting area for white radish. Although mechanized harvesting has a certain application scope, white radish is different from other root crops. It is large in size, has tubers of different sizes, grows deep into the soil, and mature white radishes have some tubers exposed to the ground, lush stems and leaves intertwined, and serious stem and leaf lodging. Existing pull-out white radish harvesters generally use a clamping and pulling conveying mechanism to clamp the radish tassels and leaves, combined with the inclined setting of the conveyor belt, to provide an upward force to pull out the white radish during operation.

[0003] CN118340014A discloses a root vegetable harvester, wherein the conveyor belt includes a driving pulley, a driven pulley, a synchronous belt and a driving motor, the driving pulley and the driven pulley are distributed on the conveyor frame in a direction inclined relative to the walking direction of the walking base, the driving motor is connected to the driving pulley for driving the driving pulley to rotate, the driving pulley and the driven pulley are connected by a synchronous belt, and the driving motor drives the synchronous belt to move through the driving pulley. The clamping of the synchronous belt to the white radish is ensured by setting a tensioning rod. However, in the process of clamping and pulling, the above-mentioned white radish is prone to the problem of improper grasping of the clamping force, for example, the clamping force is too large, resulting in overflow of the tassel leaf juice, which leads to a low success rate of pulling out the white radish. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the shortcomings and defects mentioned in the above background technology and provide a white radish tuft and leaf variable stiffness clamping device and a white radish harvester which can provide a suitable clamping force for the white radish tuft and leaf and thus improve the success rate of white radish extraction.

[0005] In order to solve the above technical problems, the technical solution proposed by the utility model is: a variable stiffness clamping device for white radish tassels, comprising: a tensioning wheel group fixed on a conveyor frame and a variable stiffness elastic device for adjusting the tensioning force of the tensioning wheel group, the tensioning wheel group is used to tension the clamping belt to clamp the white radish tassels to complete the pulling and conveying operations, the tensioning wheel group includes a fixed tensioning wheel and a dynamic tensioning wheel used in pairs, the variable stiffness elastic device includes a stiffness adjusting part fixed on the conveyor frame, an elastic part connected to the stiffness adjusting part and a support rod connected to the elastic part, the support rod is connected to the dynamic tensioning wheel, the stiffness adjusting part is adjusted to adjust the tensioning force between the dynamic tensioning wheel and the fixed tensioning wheel, and the torque provided by the elastic part is determined according to the plastic deformation of the tassels during the clamping process.

[0006] In one embodiment, the elastic member is a tension spring, the support rod is a double-link mechanism, one end of the double-link mechanism is connected to the tension spring, and the other end is connected to the moving tension pulley. The stiffness adjusting member includes an adjusting nut and a tension spring stiffness adjusting bolt used in pair, and the tension spring stiffness adjusting bolt is connected to the tension spring.

[0007] In one embodiment, the equivalent elastic coefficient of the moving tension pulley is 7.6 N / mm to 21.2 N / mm, and the torque provided by the elastic member to the moving tension pulley is 8 to 25 N·m.

[0008] Based on a general inventive concept, a white radish harvester is further provided, including: a frame, a traveling chassis arranged on the frame, a subsoiling device, a leaf gathering device, a conveying device, a leaf cutting device and a sorting device, and further including the white radish leaf variable stiffness clamping device as described above, and the white radish leaf variable stiffness clamping device is fixed on the conveying device.

[0009] In one embodiment, the conveying device includes a conveying frame, two clamping belts arranged in pair on the conveying frame, the two clamping belts are inclined with the front end lower and the rear end higher and move in the same speed and opposite directions, and are used for clamping the white radish leaves during transportation for pulling and conveying. A feeding wheel used in pair is arranged at the inlet end of each clamping belt, and the white radish leaf variable stiffness clamping device is fixed on the conveying frame and located at the rear end of the feeding wheel.

[0010] In one embodiment, there are multiple groups of the white radish leaf variable stiffness clamping devices. The conveying frame includes a clamping and pulling section and a conveying section. The tension pulley groups of the white radish leaf variable stiffness clamping devices located in the clamping and pulling section are symmetrically arranged, and the tension pulley groups of the white radish leaf variable stiffness clamping devices arranged in the conveying section are arranged in a staggered manner. The tension force provided by the tension pulley group in the clamping and pulling section is greater than the tension force provided by the tension pulley group in the conveying section.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows: For the variable-stiffness clamping device for white radish leaves and the white radish harvester of the present application, under the adjustment of the variable-stiffness elastic device, the tensioning wheel set keeps the clamping belt in a proper tension state all the time. In the pulling section, it provides an appropriate (slightly larger) tension force for the leaves gathered into a bundle and conveyed from the front end, and combines with the backward force provided by the clamping belt conveying obliquely backward at a certain angle to pull up the radish fleshy root from the soil. In the conveying section, it provides a slightly smaller tension force to keep the leaves from falling and prevent the leaves from juicing, so as to successfully complete the pulling and harvesting of white radishes. Compared with the situation in the prior art where the tensioning wheel set is fixed on the conveying frame in a non-adjustable manner, or the adjustment method is complex or ineffective adjustment cannot be achieved, the tensioning wheel set of the present application is fixed on the conveying frame through a variable-stiffness elastic device. When it is necessary to adjust the tension force of the tensioning wheel set, the stiffness adjusting part is adjusted to adjust the tightness of the elastic part, and by changing the stretching angle of the support rod, finally the effective adjustment of the tension force between the moving tensioning wheel and the fixed tensioning wheel is realized, and the torque provided by the elastic part is determined according to the plastic deformation amount of the leaves during the clamping process. Therefore, the variable-stiffness clamping device for white radish leaves of the present application can control the magnitude of the acting force of the tensioning wheel set on the clamping belt, so that the acting force on the leaves always remains in a proper state, neither squeezing out the leaf juice due to too large a tension force resulting in a decrease in friction, nor being unable to complete the pulling and conveying due to too small a tension force, thereby improving the success rate of pulling white radishes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 Structural schematic diagram of the variable-stiffness clamping device for white radish leaves in one embodiment;

[0014] Figure 2 Top view of the force analysis during the variable-stiffness leaf clamping process in one embodiment;

[0015] Figure 3 Side view of the force analysis during the variable-stiffness leaf clamping process in one embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] For the convenience of understanding the present utility model, the following will describe the present utility model more comprehensively and meticulously in combination with the accompanying drawings of the specification and the preferred embodiments, but the protection scope of the present utility model is not limited to the following specific embodiments.

[0017] Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present utility model.

[0018] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present utility model can be obtained through market purchase or can be prepared by existing methods.

[0019] Please refer to Figures 1-3 , a variable stiffness clamping device 100 for white radish leaves in one embodiment includes a tension wheel group fixed on a conveying frame 24 and a variable stiffness elastic device for adjusting the tension force of the tension wheel group. The tension wheel group is used to tension a clamping belt to clamp the white radish leaves to complete the pulling and conveying operations. The tension wheel group includes a fixed tension wheel 10 and a movable tension wheel 12 used in pair. The variable stiffness elastic device includes a stiffness adjusting member fixed on the conveying frame 24, an elastic member 14 connected to the stiffness adjusting member, and a support rod 13 connected to the elastic member 14. The support rod 13 is connected to the movable tension wheel 12. By adjusting the stiffness adjusting member, the tension force between the movable tension wheel 12 and the fixed tension wheel 10 is adjusted, and the torque provided by the elastic member 14 is determined according to the plastic deformation amount of the leaves during the clamping process.

[0020] For the variable stiffness clamping device 100 for white radish leaves of the present application, compared with the prior art where the tension wheel group is fixed on the conveying frame in a non-adjustable manner or the adjustment method is complex or ineffective adjustment cannot be achieved, the tension wheel group of the present application is fixed on the conveying frame through a variable stiffness elastic device. When it is necessary to adjust the tension force of the tension wheel group, the stiffness adjusting member is adjusted to adjust the tightness of the elastic member 14. By changing the stretching angle of the support rod 13, the effective adjustment of the tension force between the movable tension wheel 12 and the fixed tension wheel 10 is finally realized, and the torque provided by the elastic member is determined according to the plastic deformation amount of the leaves during the clamping process. Therefore, the variable stiffness clamping device 100 for white radish leaves of the present application can control the magnitude of the acting force of the tension wheel group on the clamping belt 20, so that the acting force on the leaves always remains in a proper state, neither squeezing out the juice of the leaves due to too large a tension force resulting in a decrease in friction, nor being unable to complete the pulling and conveying due to too small a tension force, thereby improving the success rate of white radish pulling.

[0021] Specifically, in one embodiment, the tension pulley set includes a fixed tension pulley 10 and a movable tension pulley 12 used in pair. The movable tension pulley 12 and the fixed tension pulley 10 are fixed on the conveying frame. The elastic member 14 is a tension spring, and the support rod 13 is a double-link mechanism. One end of the double-link mechanism is connected to the tension spring, and the other end is connected to the movable tension pulley 12. The stiffness adjusting member includes a tension spring stiffness adjusting bolt 15 and an adjusting nut 16 used in pair. The tension spring stiffness adjusting bolt 15 is connected to the tension spring. The variable stiffness clamping device 100 for white radish leaves mainly relies on the pulley set of the movable tension pulley 12 and the fixed tension pulley 10 to provide a tension force to the clamping belt 20. The cross-section of the clamping belt 20 in contact with the leaves evenly transmits the tension force to the white radish leaf stalks here. When the tension force needs to be adjusted, the adjusting nut 16 is adjusted. Combining the cooperation of the adjusting nut 16 and the tension spring stiffness adjusting bolt 15, the tightness of the tension spring is adjusted, thereby adjusting the stretching angle of the support rod 13, and finally effectively adjusting the magnitude of the tension force between the movable tension pulley 12 and the fixed tension pulley 10.

[0022] In one embodiment, when used in a white radish harvester, there are multiple variable stiffness clamping devices 100 for white radish leaves. In the variable stiffness clamping devices 100 at different positions, the setting methods of the tension pulley sets are different. Since it is necessary to pull the white radish out of the ground to the ground in the clamping and pulling section of the conveying frame, a greater tension force is required. At this time, the fixed tension pulley 10 and the movable tension pulley 12 in the tension pulley set are symmetrically arranged. After the white radish is pulled out, it continues to run in the conveying section of the conveying frame. At this time, it is only necessary to ensure that the white radish leaves do not fall from the clamping belt. Therefore, the tension force can be relatively smaller. At this time, the fixed tension pulley 10 and the movable tension pulley 12 of the tension pulley set can be arranged in a staggered manner to reduce the tension force between the tension pulley sets, so that each variable stiffness elastic device can adopt the same structure and parameters, simplifying the adjustment and setting process of the variable stiffness clamping device 100 for white radish leaves.

[0023] By establishing a Burgers rheological model for white radish leaves, obtaining the creep parameters of the leaves through creep tests to obtain the constitutive equation of the leaves and the clamping and pulling device, analyzing the plastic deformation amount of the leaves during clamping, constructing the relationship formula of the deformation amount of the leaves during the clamping and pulling process, and analyzing the force condition during the variable stiffness clamping process of the leaves. Combining the test results of the clamping and pulling force, the magnitude of the torque that the elastic member 14 (such as a tension spring) of the variable stiffness clamping device 100 for white radish leaves needs to provide is obtained. In summary, the specific parameters of the elastic member 14 (such as a tension spring) of the variable stiffness clamping device 100 for white radish leaves, such as material selection, spring mean diameter, material diameter, number of active coils, etc., can be obtained.

[0024] Please refer to Figures 2-3, During the variable stiffness clamping process, the relevant parameters when the white radish leaf variable stiffness clamping device 100 is working: R is the initial diameter of the leaf petiole, in mm; l is the conveying distance of the leaf during feeding, in mm; δ is the thickness of the leaf petiole after being squeezed, in mm; D0 is the floating amount of the moving tension pulley, in mm; r is the radius of the moving tension pulley, in mm; L is the length of the variable stiffness support rod (the straight-line distance between the two end points at the end), in mm; L1 is the projected distance of the axes at both ends of the variable stiffness support rod in the direction of the frame, in mm; is the angle between the variable stiffness support rod and the frame, in mm; θ is the floating angle, (°); F N is the clamping force, in N; F is the force exerted by the variable stiffness tension pulley group on the leaf petiole, in N; F N and F are the acting force and the reaction force, F s is the pulling resistance of the white radish, in N; F f is the pulling force of the white radish, in N.

[0025] When the white radish leaf variable stiffness clamping device 100 is working, there is a relationship that satisfies the following:

[0026]

[0027] The change magnitudes of the deformation amount D of the leaf petiole and the floating amount D0 of the moving tension pulley can be expressed as

[0028] D = D0 = 2R - δ (2)

[0029] During operation, the ratio of the extrusion speed v1 of the white radish leaf variable stiffness clamping device 100 on the leaf petiole to the leaf conveying speed v2 during feeding is expressed as

[0030]

[0031] During the variable stiffness clamping process, the deformation amount of the leaf petiole satisfies the relational expression

[0032]

[0033] In the formula, D f is the total deformation amount, including the deformation amount of the leaf petiole and the deformation amount of the tension spring, in mm; k0 is the equivalent elastic coefficient of the moving tension pulley, in N / mm.

[0034] The tensile moment M generated by the tension spring in the white radish leaf variable stiffness clamping device 100 n is

[0035]

[0036] In the formula, G is the shear modulus of the tension spring material, and for common spring materials, it is taken as 79 GPa; d is the diameter of the tension spring, in mm; D is the mean diameter of the spring, in mm; x is the elongation, in mm; n is the number of effective turns of the tension spring.

[0037] The moment generated by the extension spring on the moving tension pulley is

[0038] M' n = FL1 (6)

[0039] From the above formula, the equivalent elastic coefficient k0 of the moving tension pulley is:

[0040]

[0041] It can be seen from this that the equivalent elastic coefficient k0 of the moving tension pulley is closely related to the structural parameters of the extension spring.

[0042] Therefore, the material and size parameters of the extension spring can be determined according to the equivalent elastic coefficient k0 of the moving tension pulley.

[0043] The clamping force required for successful clamping and pulling out the white radish with the tassel needs to meet

[0044]

[0045] In the formula, γ is the safety factor, which is the ratio of the friction force provided by the tassel clamping mechanism to the tassel leaf to the pulling resistance of the white radish; μ is the friction coefficient between the petiole of the tassel leaf and the clamping belt. Through measurement, μ = 1.29 is taken.

[0046] The pulling resistance F of the white radish s is related to factors such as the self-weight of the white radish, the soil friction force, the adhesion force between the soil and the fleshy root, the adhesion force between the root system and the soil, and the pulling angle. The pulling resistance varies significantly under different soil types. In this study, white radishes planted in sandy soil were selected as the research object, and the pulling force F s was measured in the field to be 52.1 - 86.5 N. To ensure smooth clamping and pulling out, it is necessary to meet γ > 1; the larger the γ value, the greater the clamping force, which is likely to cause extrusion damage to the petiole of the tassel leaf and is not conducive to stable and continuous operation. Considering comprehensively, γ = 3 is taken.

[0047] To sum up, the practical significance of the variable stiffness tassel clamping and pulling conveying device in production is: through variable stiffness tassel clamping, it is possible to avoid the reduction of the friction coefficient between the petiole of the tassel leaf and the clamping belt during the continuous tassel clamping and pulling operation of the white radish combine harvester, thereby avoiding a series of adverse consequences.

[0048] For example, in one embodiment, when the elastic member 14 is a tension spring, according to the change magnitudes of the deformation amount D of the white radish leaf petiole and the floating amount D0 of the movable tension pulley, the equivalent elastic coefficient of the movable tension pulley is 7.6 N / mm to 21.2 N / mm, and the torque provided by the elastic member to the movable tension pulley is 8 to 25 N·m. The tension spring is made of ordinary carbon steel wire, with a diameter of 1.5 mm, a mean coil diameter of 10 mm, and 28 active coils. In other embodiments, according to the changes in the corresponding parameters, a suitable elastic member 14 can be selected and corresponding parameters can be set, all aiming to adjust the magnitude of the force exerted by the tension pulley set on the clamping belt.

[0049] The present utility model also provides a white radish harvester, which mainly consists of a subsoiling device, a leaf gathering device, the above-mentioned white radish leaf variable stiffness clamping device 100 of the present application, a conveying device, a leaf cutting device, a sorting device, and a traveling chassis, etc. The subsoiling device, the leaf gathering device, the white radish leaf variable stiffness clamping device 100, the leaf cutting device, and the sorting device are arranged on the left / right side of the frame, that is, on the outer edge of the left / right traveling crawler, so as to avoid rolling on the white radish during field walking or harvesting. The white radish leaf variable stiffness clamping device 100 has been described in detail above and will not be elaborated here.

[0050] The white radish leaf variable stiffness clamping device 100 is fixed on the conveying device. The conveying device includes a conveying frame 24 and two clamping belts 20 arranged on the conveying frame. The two clamping belts 20 are inclined and move in the same speed and opposite directions. The inclined clamping belts drive the white radish to move from low to high, and can provide a backward and upward force during the clamping and conveying of the white radish, so as to pull out the white radish while transporting. A feeding wheel 22 is provided at the front end of each clamping belt 20, and the two feeding wheels 22 are symmetrically arranged. Preferably, there are multiple white radish leaf variable stiffness clamping devices 100. The multiple white radish leaf variable stiffness clamping devices 100 are arranged on the conveying frame 24 and at the rear end of the feeding wheels 22. Specifically, the tension pulley set is fixed on the conveying frame 24 and at the rear end of the feeding wheels 22, and the tension between the tension pulley sets is adjusted by a variable stiffness elastic device, so as to clamp the white radish leaves with variable stiffness.

[0051] Preferably, the conveying frame 24 includes a clamping and pulling section and a conveying section. The tension pulley sets of the white radish leaf variable stiffness clamping device 100 located in the clamping and pulling section are symmetrically arranged, and the tension pulley sets of the white radish leaf variable stiffness clamping device 100 arranged in the conveying section are arranged in a staggered manner. The tension provided by the tension pulley sets in the clamping and pulling section is greater than the tension provided by the tension pulley sets in the conveying section.

[0052] During the mechanical harvesting process of white radishes, when the extrusion pressure of the clamping belt is too high, the leaves are easily damaged and the juice overflows, reducing the friction coefficient between the "leaves - clamping belt". If the pressure is too low, it is difficult to meet the pulling force required for pulling out white radishes. Therefore, whether the clamping force is too high or too low will directly or indirectly cause the pulling failure, resulting in a high mechanical harvesting loss rate of white radishes. In the white radish harvester of this application, the white radish leaves are gathered from the "scattered in all directions" state into a bundle by the leaf gathering device, and the variable stiffness leaf clamping device 100 is used for clamping, pulling and conveying. By adjusting the adjusting nut 16 and cooperating with the tension spring stiffness adjusting bolt 15, the tightness of the spring is adjusted, and then the angle of the support rod 13 is adjusted. Finally, the tension force between the movable tension pulley 12 and the fixed tension pulley 10 is adjusted. Considering the specific situation of the leaves, the torque provided by the elastic member is determined according to the plastic deformation amount of the leaves during the clamping process. The clamping belt 20 evenly applies the tension force on the white radish leaves, which can better keep the clamping force on the leaves at a moderate state, neither squeezing out the leaf juice due to too large a tension force, resulting in a decrease in friction, nor being unable to complete the pulling and conveying due to too small a tension force, thus improving the success rate of pulling out white radishes.

Claims

1. A variable stiffness clamping device for white radish leaves, characterized in that Including: A tension pulley set fixed on a conveying frame and a variable stiffness elastic device for adjusting the tension force of the tension pulley set. The tension pulley set is used to tension and clamp a belt to clamp the white radish leaves to complete the pulling and conveying operations. The tension pulley set includes a fixed tension pulley and a movable tension pulley used in pairs. The variable stiffness elastic device includes a stiffness adjusting member fixed on the conveying frame, an elastic member connected to the stiffness adjusting member, and a support rod connected to the elastic member. The support rod is connected to the movable tension pulley. By adjusting the stiffness adjusting member, the tension force between the movable tension pulley and the fixed tension pulley is adjusted. The magnitude of the torque provided by the elastic member is determined according to the plastic deformation amount of the leaves during the clamping process.

2. The white radish leaf variable stiffness clamping device according to claim 1, wherein The elastic member is a tension spring, and the support rod is a double-link mechanism. One end of the double-link mechanism is connected to the tension spring, and the other end is connected to the movable tension pulley. The stiffness adjusting member includes a pair of adjusting nuts and a tension spring stiffness adjusting bolt, and the tension spring stiffness adjusting bolt is connected to the tension spring.

3. The white radish leaf variable stiffness clamping device according to claim 1, wherein The equivalent elastic coefficient of the movable tension pulley is 7.6 N / mm to 21.2 N / mm, and the magnitude of the torque provided by the elastic member to the movable tension pulley is 8 to 25 N·m.

4. A white radish harvester, characterized in that, Including a frame, a walking chassis arranged on the frame, a subsoiling device, a leaf gathering device, a conveying device, a leaf cutting device, and a sorting device, and further including a white radish leaf variable stiffness clamping device according to any one of claims 1-3. The white radish leaf variable stiffness clamping device is fixed on the conveying device.

5. The white radish harvester according to claim 4, wherein The conveying device includes a conveying frame and two clamping belts arranged on the conveying frame in pairs. The two clamping belts are inclined with the front end lower and the rear end higher and move in the same speed and opposite directions, and are used to clamp the white radish leaves during transportation for pulling and conveying. A pair of feeding wheels are arranged at the inlet end of each clamping belt. The white radish leaf variable stiffness clamping device is fixed on the conveying frame and is located at the rear end of the feeding wheels.

6. The white radish harvester according to claim 5, characterized in that, The white radish leaf variable stiffness clamping devices are multiple groups. The conveying frame includes a clamping and pulling section and a conveying section. The tension pulley sets of the white radish leaf variable stiffness clamping devices located in the clamping and pulling section are symmetrically arranged, and the tension pulley sets of the white radish leaf variable stiffness clamping devices arranged in the conveying section are staggeredly arranged. The tension force provided by the tension pulley sets in the clamping and pulling section is greater than the tension force provided by the tension pulley sets in the conveying section.

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