Suspended agricultural machinery operating resistance measurement sensor device

Abstract

The invention discloses a sensor device for measuring the operating resistance of suspended agricultural machinery, comprising a pin-shaft radial two-axis force strain sensor structure, a cloth piece and a bridge connection method, and a positioning and orientation structure of a sensor and a suspension ear. The technical key points are as follows: three pin-shaft radial two-axis force sensors are installed on an upper U-shaped suspension ear and two lower U-shaped suspension ears of the suspended agricultural machinery, the pin-shaft sensor and the U-shaped suspension ear have a specific structural design to ensure the orientation and limit of the pin shaft, the pin-shaft sensor is a resistance strain force sensor, and the three pin-shaft sensors are connected by ingenious cloth pieces and bridge circuits to respectively sense the X-direction and Y-direction force components on the three U-shaped suspension ears of the agricultural machinery, and the three pin-shaft force sensors are connected in a specific connection order to form a total agricultural machinery X- and Y-direction total force measurement circuit, and the size and direction of the total resistance of the entire suspended agricultural machinery during operation can be accurately measured according to the force synthesis principle.

Description

Technical Field

[0001] The present invention relates to a sensor technology and device for measuring the operating resistance of suspended agricultural machinery, and in particular to a sensor method and device for measuring the operating resistance of a suspended machine set for field operations such as land preparation, sowing, rotary tillage, and intertillage. Background Art

[0002] The operating resistance of agricultural machinery is an important parameter in the development of new agricultural machinery and the selection of agricultural machinery power. If the changes in operating resistance can be monitored and mastered in real time during the operation of agricultural machinery, it will be of practical significance to improve the quality of operation and realize intelligent control. At present, most non-self-propelled field operation machinery are suspended agricultural machinery. The tractor is equipped with a standardized three-point hydraulic suspension mechanism. The agricultural machinery is connected to the upper and lower rod ends of the tractor hydraulic suspension mechanism through three hanging points on the frame. The ball joint three-point suspension is connected. When the tractor hydraulic suspension mechanism is lowered, the agricultural machinery falls to the ground and the working parts are buried in the soil. The tractor pulls the agricultural machinery forward to operate. When the tractor hydraulic suspension mechanism is raised, the agricultural machinery is lifted off the ground and the unit is transferred or transported in the field. The three hooking ears on the specific agricultural machinery frame are connected to the ball joints at the ends of the upper and lower tie rods of the tractor hydraulic suspension mechanism through pins and transmit lifting, pressing and traction. The existing agricultural machinery operation resistance measurement methods are: one is to make a force measuring frame separately, configure multiple force sensors on the force measuring frame, connect the force measuring frame to the tractor suspension device, and then fix the force measuring frame to the agricultural machinery; another is to replace the three ordinary connecting pins with three pin-type sensors, and then cooperate with the inclination sensor to measure the operation resistance; another is to install five tension and pressure sensors on an upper tie rod, two lower tie rods and two lower tie rod lifting arms of the tractor suspension device for measurement; the above-mentioned measurement devices have complex structures and require more than three sensors to measure each sensor separately and perform a more complex force solution process to obtain the operation resistance value. Therefore, it is necessary to develop a simple and easy agricultural machinery operation resistance measurement method and sensor device to meet the production and test detection needs. Summary of the invention

[0003] In view of the above problems, the present invention discloses a sensor device for measuring the operating resistance of suspended agricultural machinery, and its technical solution is as follows: three pin-type radial two-axis force sensors are installed on the upper U-shaped hanging ear and two lower U-shaped hanging ears of the suspended agricultural machinery, the pin-type sensors and the U-shaped hanging ears have a specific structural design, the pin-type sensors are resistive strain force sensors, and the three pin-type sensors are connected by cleverly connecting cloth pieces and bridge circuits to respectively sense the X-direction and Y-direction force components on the three U-shaped hanging ears of the agricultural machinery. Only three pin-type force sensors are used to respectively detect the radial force components in the X and Y directions on the three U-shaped hanging ears of the agricultural machinery, and the size and direction of the total resistance of the entire suspended agricultural machinery during operation can be accurately measured based on the force synthesis principle. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 It is a schematic elevation diagram of a tractor with three-point suspension of agricultural implements;

[0005] Figure 2 It is a top view of a tractor with three-point suspension of agricultural implements;

[0006] Figure 3 It is a schematic diagram of three U-shaped hanging ears and positioning limit screw holes on agricultural machinery;

[0007] Figure 4 It is a schematic diagram of the structure of a pin-type strain radial two-axis force sensor;

[0008] Figure 5 It is a schematic diagram of the X-axis and Y-axis strain gauges connected into a bridge measurement circuit, disclosing the bridge connection sequence of the strain gauges;

[0009] Figure 6 This is the circuit diagram of the total force measurement in the X direction of three pin force sensors

[0010] Figure 7 This is the circuit diagram of the total force measurement in the Y direction of three pin force sensors

[0011] Figure 1 to Figure 7 Chinese mark: 1-upper tie rod of tractor suspension, 2-right lower tie rod of tractor suspension, 3, 5 and 7-pin force sensor, 4, 6 and 8-U-shaped suspension ears on agricultural machinery frame, 9-left lower tie rod of tractor suspension, 10-small screw hole for orientation and limit on U-shaped suspension ear, 11-large screw hole for orientation and limit on U-shaped suspension ear, 101-pin head, 102-small notch for orientation and limit on pin head, 103-lead through hole on pin head, 104-large notch for orientation and limit on pin head, 110-left annular groove of pin, 111-right annular groove of pin, 112-limiting pin hole of pin, 130-axial lead groove, R1~R4-4 strain gauges pasted on the left annular groove, R5~R8-4 strain gauges pasted on the right annular groove, 803 - Full-bridge measurement circuit for radial force component in X direction, 804 - Full-bridge measurement circuit for radial force component in Y direction, A, B, C and D - are 4 nodes of the bridge circuit respectively. DETAILED DESCRIPTION

[0012] The specific implementation scheme and description of the present invention are given below in conjunction with the accompanying drawings:

[0013] The sensor device for measuring the operating resistance of suspended agricultural machinery includes a force sensor and a measurement circuit constructed by the force sensor. As shown in Figures 1 to 3, force sensors 3, 5 and 7 are pin-type strain radial two-axis force sensors. The specific structure is as follows Figure 4, respectively installed on the U-shaped hanging ear 6 and the two left and right lower U-shaped hanging ears 4 and 8 for hanging agricultural machinery, replacing the original hanging shaft pin; two directional and limiting screw holes 10 and 11, one small and one large, are opened on each U-shaped hanging ear, and the center line of the two limiting screw holes is parallel to the horizontal reference plane of the agricultural machinery frame. The pin shaft force sensor is fixed to the U-shaped hanging ear with bolts to prevent the pin shaft sensor from circumferential rotation and axial stringing; each pin shaft sensor can measure the radial component force in the X and Y directions; the three pin shaft sensors have the same structural parameters, strain gauge resistance and sensitivity coefficients in the X and Y directions.

[0014] like Figure 4 The pin-type strain two-axis radial force sensor of the present invention has a pin head 101 with a diameter larger than the pin cylinder diameter at one end, and two positioning and orientation notches 102 and 104, one small and one large, are symmetrically opened on the outer edge of the pin head at an interval of 180 degrees. Correspondingly, two orientation and limiting screw holes 10 and 11 are opened on the U-shaped hanging ear of the agricultural machinery. The pin sensor is fixed to the U-shaped hanging ear of the agricultural machinery by bolts through the two positioning notches to limit the circumferential rotation and axial stringing of the pin sensor.

[0015] like Figure 4 At both ends near the pin shaft, a left annular groove 110 and a right annular groove 111 are opened on the cylindrical surface of the pin shaft; four lead wire grooves 130 are opened axially at intervals of 90 degrees on the cylindrical surface of the pin shaft, and the opening angle of the lead wire grooves on the circumference is staggered by ±45 degrees from the two positioning notches 102 and 104; correspondingly, four lead wire through holes 103 are opened on the end face of the pin shaft head 101 for leading out the measurement leads.

[0016] like Figure 4 and Figure 5 On each annular groove of the pin, four uniaxial strain gauges are pasted at 90-degree intervals in the circumferential direction. R1 to R4 are pasted on the left annular groove, and R5 to R8 are pasted on the right annular groove. The four strain gauges on each annular groove are opposite to each other, among which R2 and R4 are opposite to each other, and R6 and R8 are opposite to each other, and the circumferential positions are consistent with the two positioning notches on the outer edge of the pin head; while R1 and R3 are opposite to each other, and R5 and R7 are opposite to each other, and the circumferential positions are staggered with the two positioning notches on the outer edge of the pin head. 90 degrees; the longitudinal axis of each strain gauge is arranged at an angle of ±45 degrees to the cylindrical element line of the annular groove; the eight strain gauges are connected in order to form two full-bridge measurement circuits, wherein the four strain gauges R1, R3 on the left annular groove 110 and R5, R7 on the right annular groove 111 are connected in the order of R1-R3-R7-R5 to form a full-bridge measurement circuit 803 for the radial component of the X direction, and the four strain gauges R2, R4 on the left annular groove 110 and R6, R8 on the right annular groove 110 are connected in the order of R2-R4-R8-R6 to form a full-bridge measurement circuit 804 for the radial component of the Y direction, and the two groups of X and Y bridges measure the radial components of the pin in the X and Y directions respectively.

[0017] like Figure 6 and Figure 7 The sensor measurement circuit constructed is as follows: The X-direction measurement bridge circuit 803 of the three pin-type force sensors is as follows: Figure 6 The three pin shaft sensors are connected in parallel, that is, the A, B, C, and D points of the measuring bridges are connected respectively, that is, the A, B, C, and D points of the measuring bridges of the three pin shaft sensors are connected respectively, to form a bridge circuit for measuring the total force component in the X direction of the entire agricultural implement; the Y direction measuring bridge 804 of the three pin shaft sensors is connected in parallel. Figure 7 The outputs of the X and Y total force measurement bridges can be used to obtain the magnitude and direction of the operating resistance of the rear-hook agricultural implement according to the principle of force synthesis.

Claims

1. A sensor device for measuring the operating resistance of a suspended agricultural implement, comprising a force sensor and a measuring circuit constructed by the force sensor, wherein: There are three force sensors, which are pin-type strain two-axis radial force sensors, respectively mounted on the upper U-shaped hanging ear and the left and right lower U-shaped hanging ears for hanging agricultural machinery; each U-shaped hanging ear is provided with one small and one large directional and limiting screw holes, and the center line of the two limiting screw holes is parallel to the horizontal reference plane of the agricultural machinery frame; each pin sensor is fixed to the U-shaped hanging ear with bolts to prevent the pin sensor from circumferential rotation and axial stringing; each pin sensor can measure the radial force components in the X and Y directions; the three pin sensors have the same structural parameters, strain gauge resistance and sensitivity parameters in the X and Y directions; A pin shaft head (101) having a diameter greater than that of the pin shaft cylinder is arranged at one end of the pin shaft type strain two-axis radial force sensor, and two positioning notches, one small and one large, are symmetrically opened on the outer edge of the pin shaft head at an interval of 180 degrees. Bolts are used to fix the pin shaft sensor to two corresponding directional and limiting screw holes on the U-shaped suspension ear of the agricultural machinery through the two positioning notches to limit the circumferential rotation and axial stringing of the pin shaft sensor. The pin-type strain two-axis radial force sensor is provided with a left annular groove (110) and a right annular groove (111) along the circumference at both ends close to the pin; four lead wire grooves (130) are provided on the cylindrical surface of the pin at intervals of 90 degrees along the axial direction, and the positions of the lead wire grooves on the circumference are staggered with the two positioning notches by an angle of ±45 degrees; correspondingly, four threading through holes (103) are provided on the end surface of the pin head (101) for leading out the measuring wires; The pin-type strain two-axis radial force sensor has four uniaxial strain gauges pasted on each annular groove surface of the pin at a circumferential interval of 90 degrees. The four strain gauges are opposite to each other in pairs, among which R2 and R4 are opposite to each other, R6 and R8 are opposite to each other and correspond to the two positioning notches on the outer edge of the pin head, while R1 and R3 are opposite to each other, and R5 and R7 are opposite to each other, and the circumferential positions are staggered by 90 degrees from the two positioning notches on the outer edge of the pin head; the longitudinal axis of each strain gauge on the two annular grooves is arranged at an angle of ±45 degrees to the cylindrical element line of the annular groove; the eight strain gauges are connected in order to form Two full-bridge measurement circuits, in which the four strain gauges R1, R3 on the left annular groove and R5, R7 on the right annular groove are connected in the order of R1-R3-R7-R5 to form a full-bridge measurement circuit for the radial component of the X direction, and the four strain gauges R2, R4 on the left annular groove and R6, R8 on the right annular groove are connected in the order of R2-R4-R8-R6 to form a full-bridge measurement circuit for the radial component of the Y direction. The output force components of the X and Y groups of bridges are used to obtain the magnitude and direction angle of the radial resultant force on the pin shaft sensor according to the force synthesis principle.

2. The sensing device for measuring the operating resistance of suspended agricultural machinery according to claim 1 is characterized in that: the measuring circuit constructed by the force sensor is composed of three X-direction measuring bridges of pin-type strain two-axis radial force sensors connected in parallel, and the A, B, C, and D nodes of the three pin-axis sensor measuring bridge circuits are respectively connected to form a measuring bridge circuit for the total X-direction force of the entire agricultural machinery; the Y-direction measuring bridges of the three pin-axis sensors are connected in parallel, and the A, B, C, and D nodes of the three pin-axis sensor measuring bridge circuits are respectively connected to form a measuring bridge circuit for the total Y-direction force of the agricultural machinery; the outputs of the X and Y total force measuring bridges can obtain the magnitude and direction angle of the operating resistance of the agricultural machinery hung behind the tractor according to the principle of force synthesis.

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