Linear Hall sensor assembly suitable for agricultural machinery gearbox under harsh working conditions

Abstract

The utility model belongs to the technical field of sensors, and particularly relates to an agricultural machinery gearbox linear Hall sensor assembly suitable for harsh working conditions, which comprises a sensor part and a magnet seat, the sensor part is used for sensing the position of the magnet seat, the sensor part comprises a shell and a coupler assembly, a support is arranged in the shell, and a printed board is installed on the support. A Hall chip is arranged on the printed board; the shell is made of a metal material; the steel blank and the plastic shell are integrally formed into the magnet seat through injection molding; the mounting plate is in compression joint with the shell; the joint of the shell and the coupler assembly is of a closing-in structure. According to the utility model, the sensor main body is made of a copper material, and the structural strength is improved by using crimping tool equipment, so that the sensor can be used under harsh working conditions; the magnet seat is subjected to saturated magnetization after being integrally formed through injection molding, demagnetization of the magnetic steel caused by high temperature in the injection molding process is avoided, meanwhile, the magnet seat is fastened through bolts, the air gap error between the magnet seat and the sensor body is reduced, and the precision of sensor signals is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to hall sensor technical field especially relates to a linear hall sensor assembly of agricultural machinery gearbox suitable for severe working condition. BACKGROUND

[0002] The gearbox of agricultural machinery changes the power and torque output by the engine through the working principle of gear mechanism and shift mechanism. It transmits the power of the engine to the transmission system of the vehicle to realize high speed and low speed work under different conditions. The main body of the linear hall position sensor of the gearbox is often made of plastic material, and the magnetic steel is often fixed by gluing with the piston rod. The sensor detects the magnetic flux of the magnetic steel at different positions, and outputs the signal to the ECU for shift position determination.

[0003] On the platform of high-power engine of agricultural machinery, the main body of the sensor of the conventional scheme is made of plastic material, and the strength and rigidity of the plastic material are low. Under heavy load working condition, it is easy to produce large deformation and fracture under impact, which affects the normal use of the sensor.

[0004] The magnetic steel matched with the sensor is often fixed in the movable piston rod groove by gluing, which has poor reliability. At the same time, the thickness of the glue will directly affect the air gap between the magnetic steel and the sensor, resulting in the decline of signal accuracy and ECU alarm.

[0005] For the magnet seat, the conventional scheme is designed as a split type, the magnetic steel is fixed in the plastic shell, and then the cover plate is buckled. The strength of the split type structure is low, and under heavy load working condition, the cover plate is easy to be buckled, which leads to the falling of the magnetic steel, the decline of the sensor signal accuracy or the direct loss, and the ECU alarm.

[0006] Under normal circumstances, copper and galvanized steel sheet are welded, welding will produce high temperature, high temperature may change the material performance, produce residual stress, at the same time, also may destroy the surface plating of steel sheet. UTILITY MODEL CONTENTS

[0007] The utility model aims at solving the problems in the prior art, and provides a linear hall sensor assembly of agricultural machinery gearbox suitable for severe working condition.

[0008] In order to realize the above purpose, the utility model adopts the following technical scheme:

[0009] A linear hall sensor assembly of agricultural machinery gearbox suitable for severe working condition, comprising a fixed sensor part and a movable magnet seat, and a mounting plate for fixing the sensor part, the sensor part is used for sensing the position of the magnet seat, the sensor part comprises a shell and a coupler assembly, the shell is internally provided with a support, the support is installed with a printed board, and the printed board is arranged with a hall chip;

[0010] The shell is made of metal material;

[0011] The magnet base comprises a plastic shell and a magnetic steel blank in the plastic shell, and the magnetic steel blank and the plastic shell are integrally formed by injection molding to form the magnet base;

[0012] The mounting plate is press-connected with the shell;

[0013] The connection between the shell and the coupling assembly is a closed structure.

[0014] As a further preferred solution, a mounting hole is formed in the mounting plate, and three diameter regions of R1, R2 and R3 from large to small are continuously formed on the outer surface of the shell, the R1 is the largest diameter, the R2 is the middle diameter, and the R3 is the smallest diameter, and the shell is press-connected with the mounting hole of the mounting plate;

[0015] The mounting hole of the mounting plate is located on the outer surface of R2, one side of the mounting plate is located on the step of R1, and the other side of the mounting plate is located on the positioning rib formed by the step of R2 to limit the axial movement of the sensor part.

[0016] As a further preferred solution, the shell and the mounting plate hole are provided with a limiting block and a limiting groove which are locked with each other to limit the radial rotation of the sensor part.

[0017] As a further preferred solution, the magnet base is integrally formed by injection molding, then saturated magnetization is performed, and the magnet base is moved for calibration to obtain a displacement-voltage linear curve.

[0018] As a further preferred solution, the shell is a cylindrical structure with one open end and the other closed end, the closed end faces the magnet base, the coupling assembly is inserted into the open end and fixedly connected with the printed board, and the open end is closed to improve the structural strength of the sensor part.

[0019] As a further preferred solution, the material of the shell is copper.

[0020] The sensor body of the utility model adopts copper material, and uses press connection, closing and other tooling equipment to improve the structural strength of the sensor, and meets the use of the agricultural machine gearbox platform in harsh working conditions; the magnet base is integrally formed by injection molding of the magnetic steel blank and the plastic shell, then saturated magnetization is performed, the structural strength of the magnet base is improved, and the uniformity of the magnetic field distribution is improved, meanwhile, the magnet base adopts a bolt fastening mode, the air gap error between the magnet base and the sensor body is reduced, the precision of the sensor signal is improved, and the thickness inconsistency caused by gluing does not affect the precision of the signal. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is an internal structure schematic view of the utility model;

[0022] Figure 2 It is a press connection structure schematic view of the utility model;

[0023] Figure 3 It is an external structure schematic view of the utility model;

[0024] In the figure: 1, coupling assembly, 2, mounting plate, 3, shell, 4, printed board, 5, support, 6, hall chip, 7, plastic shell, 8, magnetic steel blank, 9, positioning rib. DETAILED DESCRIPTION

[0025] The technical scheme in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model, and apparently, the described embodiments are only part of the embodiments of the utility model, not all the embodiments.

[0026] The utility model discloses a linear hall sensor assembly of agricultural machine gearbox suitable for harsh working conditions, the utility model discloses a copper is changed as the shell material, uses the press joint, the mouth of the workpiece is made, improves linear hall position sensor structural strength, through magnetic steel blank 8 and plastic shell 7 injection moulding integrated, improve its structural strength, through bolt fastening magnet seat, reduce magnetic steel and sensor main body air gap error, improve the precision of sensor signal.

[0027] In the utility model, sensor assembly includes fixed sensor part and movable magnet seat and the mounting plate 2 for fixing sensor part, and the sensor part is used for sensing the position of the magnet seat, and the sensor part includes the shell 3 and the coupling assembly 1, the shell 3 is built-in support 5, the support 5 is installed with printed board 4, and the printed board 4 is arranged with hall chip 6 to detect the magnetic flux of magnetic steel at different positions.

[0028] Among them, the mounting plate 2 and the shell 3 are pressed, and the copper shell and the stainless steel galvanized mounting plate are pressed using a press joint, specifically, the mounting plate 2 is provided with a mounting hole, and the outer surface of the shell 3 is continuously provided with three diameter regions from large to small, respectively R1 of maximum diameter, R2 of intermediate diameter and R3 of minimum diameter, and the shell 3 is pressed and fixed in the mounting hole of the mounting plate 2.

[0029] The mounting hole of the mounting plate 2 is on the outer surface of R2, one side of the mounting plate 2 abuts against the step of R1, and the other side abuts against the positioning rib 9 formed by the step of R2, so as to limit the axial movement of the sensor part.

[0030] In addition, the shell and the mounting plate hole are provided with a limiting block and a limiting groove that are mutually locked, so as to limit the radial rotation of the sensor part.

[0031] Through the above mounting mode, the direction of the hall chip is unique.

[0032] The copper shell is fastened with the coupler through a closing tool, and a closing structure is formed at the connection between the shell 3 and the coupler assembly 1, specifically, the shell 3 is a cylindrical structure with one end open and the other end closed, and the closed end faces the magnet seat, and the coupler assembly 1 is inserted into the open end and fixedly connected with the printed board 4, preferably welded, and the open end is closed to improve the structural strength of the sensor part.

[0033] Installation process: the limiting block of the mounting plate and the limiting groove of the shell 3 are assembled, then the mounting plate 2 is crimped by the equipment to fasten the two, ensure the direction uniqueness while ensuring the holding force, then the components such as the Hall chip 6 are placed on the printed board 4 assembly, the magnetic flux of the magnetic steel in different positions is detected, the printed board 4 assembly is fixed on the bracket 5 and welded with the coupler assembly 1, then the coupler assembly 1 is assembled to the copper shell at the same time, wherein the coupler assembly 1 is provided with a positioning rib matched with the gap of the copper shell to ensure the accuracy of the Hall chip 6 in detecting the magnetic field direction, and finally the copper shell and the coupler assembly 1 are closed by the equipment.

[0034] In the utility model, the magnet seat comprises a magnetic steel blank 8, and the magnetic steel blank 8 and the plastic shell 7 are integrally formed into the magnet seat through injection molding, so that the structural strength of the magnet seat is improved, the uniformity of the magnetic field is ensured, and the magnet seat is saturatedly magnetized after being integrally formed through injection molding, and finally the magnet seat is moved according to requirements to be calibrated to obtain a displacement-voltage linear curve.

[0035] The structure of integrally formed through injection molding solves the problem that in the case of not using a self-calibration learning system, too thick glue can reduce the air gap between the magnet and the sensor and directly affect the output signal accuracy, and even if the self-calibration learning system is used, the slope of the output signal is also affected by the thickness of the glue, so the structure of integrally formed through injection molding can also solve the problem.

[0036] The shell 3 is made of metal, preferably copper, which can effectively shield electromagnetic interference.

[0037] The above only describes a preferred specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the technical field can make equivalent replacement or change according to the technical scheme and the utility model concept of the utility model within the technical range disclosed by the utility model, which should be covered in the protection scope of the utility model.

Claims

1. A linear Hall sensor assembly for agricultural machinery gearboxes under harsh operating conditions, comprising a fixed sensor part and a movable magnet base, and a mounting plate (2) for fixing the sensor part, wherein the sensor part is used to sense the position of the magnet base, characterized in that: The sensor part comprises a housing (3) and a coupler assembly (1), the housing (3) is internally provided with a support (5), a printed board (4) is mounted on the support (5), and a Hall chip (6) is arranged on the printed board (4); The housing (3) is made of metal; The magnet seat comprises a plastic housing (7) and a magnetic steel blank (8) in the plastic housing (7), and the magnetic steel blank (8) and the plastic housing (7) are integrally formed by injection molding to form the magnet seat; The mounting plate (2) and the housing (3) are press-connected; The connection between the housing (3) and the coupler assembly (1) is a closed structure.

2. The linear Hall sensor assembly for a gearbox of an agricultural machine in a severe working condition according to claim 1, characterized in that: The mounting plate (2) is provided with a mounting hole, and the outer surface of the housing (3) is continuously provided with three diameter regions from large to small, which are R1, R2 and R3, respectively, the mounting plate (2) is press-connected with the mounting hole of the housing (3); The mounting hole of the mounting plate (2) is located on the outer surface of R2, one side of the mounting plate (2) is located at the step of R1, and the other side is located at the positioning rib (9) formed by the step of R2, so as to limit the axial movement of the sensor part.

3. The linear Hall sensor assembly for a gearbox of an agricultural machine in a severe working condition according to claim 1, characterized in that: The housing and the mounting plate hole are provided with a limiting block and a limiting groove which are mutually locked, so as to limit the radial rotation of the sensor part.

4. The linear Hall sensor assembly for a gearbox of an agricultural machine in a severe working condition according to claim 2 or 3, characterized in that: After the magnet seat is integrally formed by injection molding, it is saturated and magnetized, and the magnet seat is moved for calibration to obtain a displacement-voltage linear curve.

5. The linear Hall sensor assembly for a gearbox of an agricultural machine in harsh operating conditions according to claim 4, characterized in that: The housing (3) is a cylindrical structure with one end open and the other end closed, and the closed end faces the magnet seat, the coupler assembly (1) is inserted into the open end and fixedly connected with the printed board (4), and the open end is closed to improve the structural strength of the sensor part.

6. The linear Hall sensor assembly for a severe working condition agricultural machine gearbox of claim 1, wherein: The material of the housing (3) is copper.

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