CN211905037U

CN211905037U - Crop seed grain static friction coefficient measuring device

Info

Publication number: CN211905037U
Application number: CN202020487721.0U
Authority: CN
Inventors: 张正中; 田立权; 熊永森; 王金双
Original assignee: Jinhua Polytechnic
Current assignee: Jinhua Polytechnic
Priority date: 2020-03-29
Filing date: 2020-03-29
Publication date: 2020-11-10
Anticipated expiration: 2030-03-29

Abstract

The utility model relates to a crop seed grain static friction coefficient measuring device, including measuring device base, step motor, adjustable sloping arm, photoelectric switch, control chip, digital display panel etc.. The rotation through step motor drives adjustable tilting arm and waits that the rotation of measuring the board comes angle modulation, and when the seed grain that awaits measuring slides, the stall that the device can be accurate to record angle down on digital display panel. The device operates steadily, and the angular velocity of adjustable sloping arm pivoted is controlled to the high accuracy, is fit for measuring the static friction coefficient between different crop grain and the material of different materials.

Description

Crop seed grain static friction coefficient measuring device

Technical Field

The utility model relates to a measurement articles for use of agricultural production and research, especially a crop seed grain coefficient of friction measuring device.

Background

At present, in the research and design process of agricultural machinery production tools and equipment such as grain combine harvesters, seed scalers and the like, the static friction coefficient between seeds such as crop seeds and grains and equipment contact materials needs to be known, and the structural parameters of the equipment can be designed and optimized according to the specific static friction coefficient, so that the mechanical equipment can obtain better working effect on the seeds, and the static friction coefficient plays an important role in the fields of agriculture and food production. Meanwhile, even if the same metal and different surface roughness are used, the static friction coefficients of the grains are different. Therefore, a testing device capable of accurately, rapidly and conveniently measuring the static friction coefficient of crop grains is needed.

The principle of measuring the static friction coefficient by the slope method is very simple, and the gravity of the grains can be decomposed into two forces, namely a force F parallel to the slope and a force N perpendicular to the slope. When the inclination angle alpha of the inclined plane is very small, F is smaller than the static friction force F between the seed and the inclined plane, the seed keeps in a static state, F is larger and larger along with the increase of the inclination angle alpha of the inclined plane, when F is larger than the static friction force F between the sliding block and the inclined plane, the seed starts to move and slides downwards along the inclined plane, and thus the static friction coefficient is equal to the tangent value of the inclination angle of the inclined plane. The coefficient of static friction mu is dependent only on the inclination angle alpha of the ramp and not on other parameters. In the experiment, only the inclination angle of the inclined plane needs to be recorded at the moment of the sliding of the seeds, but the inclination angle is not easy to realize in the actual experiment process, and firstly, the moment of the sliding of the seeds is not easy to judge; secondly, the angular velocity omega of the rotation of the inclined plane can influence mu; it is difficult to accurately record the inclination angle of the inclined plane at the instant when the third slider slides. Therefore, the key point of the experiment is the instant judgment of the grain sliding, in the past, most of the grain sliding is judged by the experience of testers, the inclination angle of the inclined plane is measured by the dial scale, the angular speed of the inclined plane rotation is basically not considered, and thus, a large error is necessarily generated.

Disclosure of Invention

The utility model aims at to the gliding judgement in the twinkling of an eye of the key that lies in seed grain at measurement crop seed grain static friction experiment, accurate record inclined plane inclination guarantees measuring device's accuracy, reliable simultaneously.

In order to solve the technical problem, the utility model discloses a following technical scheme:

a crop seed static friction coefficient measuring device comprises a measuring device base, a stepping motor, an adjustable inclined arm, a photoelectric switch, a control chip and a digital display panel. The measuring device base is horizontally placed, the measuring device base can be adjusted horizontally by an adjustable base installed on the lower portion of the measuring device base, one end of the measuring device base is connected with a shell of the stepping motor, an output rotating shaft of the stepping motor is fixedly connected with an adjustable inclined arm, a clamping device is arranged on the adjustable inclined arm and used for clamping a board to be detected, a fixed photoelectric switch receiver and a photoelectric switch transmitter can be installed on the board to be detected, the photoelectric switch receiver and the photoelectric switch transmitter form a certain distance, the signal transmitting and triggering directions of the photoelectric switch receiver and the photoelectric switch transmitter are the same as the sliding direction of grains to be detected, the stepping motor is electrically connected with the control chip, the photoelectric switch receiver and the photoelectric switch transmitter are electrically connected with the control chip, and the digital display panel is electrically connected with the control.

According to the utility model discloses a crop seed grain coefficient of friction measuring device has following obvious characteristics:

(1) the measuring device can well judge the movement time of the crop seeds on the inclined plane;

(2) the rotation of the inclined plane of the measuring device can be accurately controlled, and the measuring quality is ensured;

(3) the measuring device can accurately judge the instant of the sliding of the seeds;

drawings

Fig. 1 is a schematic view of the overall structure of the embodiment of the present invention.

In the figure: 1-measuring device base, 2-step motor, 3-adjustable tilting arm, 4-board to be measured, 5-photoelectric switch receiver, 6-photoelectric switch emitter, 7-adjustable base, 8-seed to be measured.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1, a crop seed friction coefficient measuring device comprises a measuring device base 1, a stepping motor 2, an adjustable inclined arm 3, a photoelectric switch, a control chip, a digital display panel and the like. The measuring device comprises a measuring device base 1, a stepping motor 2, an adjustable base 7, a clamping device, a photoelectric switch receiver 5 and a photoelectric switch emitter 6, wherein the measuring device base 1 is horizontally arranged, the adjustable base 7 is arranged at the lower part of the measuring device base 1 for adjusting the level, one end of the measuring device base 1 is connected with a shell of the stepping motor 2, an output rotating shaft of the stepping motor 2 is fixedly connected with an adjustable inclined arm 3, the adjustable inclined arm 3 is provided with the clamping device for clamping a board 4 to be measured which is made of different materials or has different surface roughness and needs to be measured, the board 4 to be measured can be fixedly provided with the photoelectric switch receiver 5 and the photoelectric switch emitter 6, a certain distance is formed between the photoelectric switch receiver 5 and the photoelectric switch emitter 6, the signal emitting and triggering directions of the photoelectric switch receiver 5 and the photoelectric switch emitter 6 are the same as, the digital display panel is electrically connected with the control chip.

The output rotating shaft of the stepping motor 2 is fixedly connected with the adjustable tilting arm 3, so that the adjustable tilting arm 3 rotates synchronously with the stepping motor 2, the control chip calculates the rotating angle by depending on the relation between the step angle and the pulse number, namely, the control chip gives each pulse of the stepping motor 2, the stepping motor 2 rotates by one step angle, and when the stepping motor 2 stops rotating, the numerical value obtained by multiplying the pulse number by the step angle is the rotating angle of the adjustable tilting arm 3. Different angular velocities of the adjustable tilting arm 3 can be obtained by adjusting the pulse frequency or the step angle sent to the stepping motor 2 by the control chip, and the angular velocity is adjusted to be smaller because the quality of common crop grains is very small, so that the precision of measurement work is improved.

Photoelectric switch receiver 5 and photoelectric switch transmitter 6 install and become the certain distance on waiting to detect board 4, photoelectric switch receiver 5 and photoelectric switch transmitter 6 are connected with the control chip electricity, the direction that photoelectric switch receiver 5 and photoelectric switch transmitter 6's signal triggered is the same with the gliding direction of the seed grain 8 that awaits measuring, rotate to certain angle when adjustable sloping arm 3, the seed grain 8 that awaits measuring begins to slide to the below of photoelectric switch transmitter 6, when having sheltered from the signal that photoelectric switch transmitter 6 sent to photoelectric switch receiver 5, the control chip can receive the instruction that photoelectric switch sent, then control chip stops step motor 2's work, and show the angle that current adjustable sloping arm 3 rotated on digital display panel.

The utility model relates to a crop seed grain friction coefficient measuring device theory of operation as follows:

before the measurement work starts, the level of the whole device platform is adjusted through the adjustable base 7, the plate to be measured 4 which needs to participate in the measurement work and is processed as required is clamped with the adjustable inclined arm 3, the photoelectric switch receiver 5 and the photoelectric switch emitter 6 are installed and fixed on the plate to be measured 4, then the seeds to be measured 8 are placed on the plate to be measured 4 and close to one end of the outer side of the photoelectric switch emitter 6, and then the power supply of the device is turned on to start the measurement work.

At the beginning, no shelter between photoelectric switch receiver 5 and the photoelectric switch transmitter 6, the signal of telecommunication that control chip sent is more stable, step motor 2 drives adjustable sloping arm 3 rotatory with certain angular velocity, at the seed grain 8 that awaits measuring slide photoelectric switch transmitter 6, the moment of sheltering from between photoelectric switch receiver 5 and the photoelectric switch transmitter 6, control chip's the signal of receiving photoelectric switch, can judge that the seed grain 8 that awaits measuring has produced the slip in view of the above, control chip simultaneously sends the signal to step motor 2, step motor 2 stall and get down the pivoted angle record, show angle when down through the digital display panel.

The grain 8 to be measured can be judged to slide instantly by the work of the crop grain friction coefficient measuring device, the inclination angle of the adjustable inclined arm 3 can be accurately recorded, stepless speed change is driven, the operation is stable, and the rotating angular speed of the adjustable inclined arm 3 can be controlled at high precision.

Claims

1. The utility model provides a crop seed grain static friction coefficient measuring device, includes measuring device base (1), step motor (2), adjustable sloping arm (3), photoelectric switch, control chip, digital display panel, characterized by: the measuring device comprises a measuring device base (1), wherein the measuring device base (1) is horizontally arranged, the level of the measuring device base (1) can be adjusted by an adjustable base (7) arranged on the lower portion of the measuring device base, one end of the measuring device base (1) is connected with a shell of a stepping motor (2), an output rotating shaft of the stepping motor (2) is fixedly connected with an adjustable inclined arm (3), a clamping device is arranged on the adjustable inclined arm (3) and used for clamping a plate (4) to be measured, a photoelectric switch receiver (5) and a photoelectric switch emitter (6) can be arranged on the plate (4) to be measured, the photoelectric switch receiver (5) and the photoelectric switch emitter (6) are arranged at a certain distance, the signal transmitting and triggering directions of the photoelectric switch receiver (5) and the photoelectric switch emitter (6) are the same as the sliding direction of a seed to be measured (8), the stepping motor (2) is electrically connected with a control chip, and the photoelectric switch receiver (5) and the photoelectric, the digital display panel is electrically connected with the control chip.