Shift fork position sensor structure
Technical Field
The utility model relates to a position sensor of car especially relates to a detect sensor structure of shift fork position in gearbox.
Background
In modern society, automobiles have become one of the first-choice transportation tools for the public. Automobiles can be roughly classified into automatic gears and manual gears. Of course, many automobiles have the driving experience which is forbidden and are self-contained. A transmission is installed in the automobile, and the switching of different gears is realized through the transmission.
The shift fork of the transmission is a component for pushing a synchronizer gear sleeve to be meshed with and separated from a gear shifting gear in the transmission to realize the gear change of the transmission, a magnet assembly of the shift fork is a component which is fixedly connected to the shift fork in the transmission and provides a magnetic field signal source, and the position sensor is a component which is used for monitoring the magnet signal output of the shift fork and carrying out signal conversion in the transmission.
In order to enable the transmission control system to monitor the position of the shift fork, a method is currently used in which a position sensor is mounted on the transmission housing, and a position signal of the shift fork is supplied to the control system via the position sensor.
The specific scheme is that a magnet is arranged on a shifting fork, the magnet and the shifting fork move together, a magnetic field signal of the position of a position sensor is changed, and the control system monitors the position of the shifting fork. In order to enable the position sensor to accurately sense the magnetic field signal generated by the magnet, except for the raw material used by the magnet, the process of magnetizing the magnet, the connection structure between the magnet and the shifting fork and the like can directly influence the quality of the magnet signal.
As in the Chinese patent: a "fork position sensor magnet fixing mechanism (CN 201720025218.1)", which comprises a magnet assembly and a magnet support; the magnet assembly be equipped with the guide way, magnet support top correspond and be equipped with the font backup pad of coving, the magnet assembly install in the font backup pad of coving of magnet support through the guide way plug-in. However, the structure has the problems that because the number of the shifting forks is large and the distance is long, a magnet needs to be arranged on each shifting fork, a plurality of separated sensors need to be manufactured, the cost is high, and the sensors are not easy to check after being damaged.
SUMMERY OF THE UTILITY MODEL
The utility model provides a shifting fork position sensor structure which has simple structure, high reliability, low cost, small occupied space and easy arrangement of components; the technical problems of large space occupation ratio, complex structure and high cost in the prior art are solved.
The above technical problem of the present invention is solved by the following technical solutions: the utility model provides a shift fork position sensor structure, is including being located a plurality of shift forks of gearbox, and wherein two at least shift forks are a set of, are connected with the piston shaft in the one end of every shift fork, install magnet in the piston shaft, and the piston shaft is along with shift fork axial displacement, and every piston shaft of group corresponds a control panel, is equipped with the hall chip that corresponds with magnet in the control panel. The motion of the shifting fork is converted into the motion of the piston shaft, the movement of the piston shaft drives the magnet in the piston shaft to displace, so that the change of a peripheral magnetic field is changed, the change is sensed by the Hall chip and converted into a linear signal to be output to the TCU, and the displacement and the position reading of the piston shaft are completed. Change original magnet and install the structure on the shift fork, install magnet in the piston shaft, distance between the piston shaft can design and adjust, can adopt a plurality of hall sensor of arrangement in the circuit board simultaneously, and the rational utilization space improves space utilization with the compact arrangement of each components and parts, and the cost is reduced to control accuracy is high, and circuit board design investigation is convenient.
Preferably, the number of the shifting forks is four, two shifting forks are in one group, piston shafts corresponding to the two shifting forks in one group are parallel to each other and are arranged in a staggered mode, and the control plate is located between the two piston shafts. Two cylindrical magnets are respectively arranged in two piston shafts in the same group, the distance between the center lines of the two magnets is not less than 37mm, and the distance between the upper end faces of the two magnets is not less than 14 mm. The influence of the magnetic field intensity of the two magnets on the induction point of the chip is calculated by using MAXWELL magnetic simulation software. Reducing mutual interference.
Preferably, one end of the shifting fork is provided with an open slot, the piston shaft is provided with a clamping slot, and the end part of the shifting fork is clamped in the clamping slot of the piston shaft. Through the cooperation of draw-in groove and open slot with shift fork and piston shaft cooperation, simple structure makes things convenient for dismantlement and connection between the two to shift fork axial displacement also can drive the axial motion of piston shaft.
Preferably, the piston shafts are located in the same plane, the control plate is higher than the plane where the piston shafts are located, and the height of the shifting fork is larger than that of the plane where the control plate is located. The transverse and longitudinal spaces are reasonably utilized, and the space utilization rate is improved.
Preferably, the distance between the Hall chip and the magnet is 8-15 mm. On the premise of ensuring enough magnetic field intensity, the arrangement between the chip position and other parts is more reasonable, and the space utilization rate is high.
Preferably, a blind hole is formed in the piston shaft, and the magnet is installed in the piston shaft and sealed by glue pouring. Convenient processing and simple process.
Preferably, the relative position of each magnet corresponding to each shift fork in the same group is designed according to the magnetic field strength sensed by the hall chips, after the first magnetic field strength of the first magnet corresponding to the first hall chip is set, the magnetic field strength of the rest magnets in the same group at the position of the first hall chip is smaller than the set first magnetic field strength. Therefore, the magnets are not influenced mutually, and the detection precision is ensured. For example, after the position of the first magnet is determined, the magnetic field strength at a position 12mm around the first magnet is 20mT, the first hall chip is located in the magnetic field range, and the magnetic field strength at a position other than 12mm is less than 20mT, so that according to the design of magnetic field simulation software, the influence of the rest magnets on the first hall chip can be ignored, the positions of the rest magnets are designed, and the magnets located in the same group are ensured not to interfere with each other.
Therefore, the utility model discloses a shift fork position sensor structure possesses following advantage: the structure is simple, the two shifting forks are arranged into a group, the movement of the shifting forks drives the piston shafts to move, the two piston shafts share one control panel, the cost is low, and the controllability is good; two parallel and the dislocation of piston axle are arranged, utilize the space installation control panel between two piston axles, and the space ratio is little, improves the convenience of installation.
Drawings
Fig. 1 is a perspective view of the structure of the shift fork position sensor of the present invention.
Fig. 2 is a perspective view of fig. 1 with the fork removed.
FIG. 3 is a top view of FIG. 1 with the fork and housing removed.
Fig. 4 is a schematic view of the fork of fig. 1.
Fig. 5 is a schematic view of the piston shaft in fig. 1.
Detailed Description
The technical solution of the present invention is further specifically described below by way of examples and with reference to the accompanying drawings.
Example (b):
as shown in fig. 1, 2, 3 and 4, a shift fork position sensor structure comprises a gearbox housing 4, four shift forks 3 are arranged in the gearbox housing 4, two shift forks 3 are in one group, one group of shift forks 3 is positioned on the left side of the gearbox housing 4, and the other group of shift forks 3 is positioned on the right side of the gearbox housing 4.
The lower end of each shifting fork 3 is integrally formed with a circular arc-shaped open slot 6, a piston shaft 2 is correspondingly arranged below each shifting fork 3, and two ends of each piston shaft 2 are arranged on shaft seats 1 on the gearbox shell. An annular clamping groove 8 is formed in the middle of the piston shaft 2, the shifting fork 3 is connected with the piston shaft 2 through the matching of the open groove 6 and the clamping groove 8, and the shifting fork 3 moves along the axis of the piston shaft 2 to drive the piston shaft 2 to move axially. A blind hole is formed in one end of the piston shaft 2, after the magnet 7 is installed in the blind hole, the magnet is sealed in the piston shaft 2 through glue pouring, and therefore the magnet 7 is driven to move through the movement of the piston shaft, and a magnetic field changes.
The two piston shafts 2 in one group are parallel to each other and are arranged in a staggered mode, the distance between the center lines of the magnets 7 in the piston shafts 2 is not less than 37mm, and the distance between the upper end faces of the two magnets 7 is not less than 14 mm. Thereby ensuring that the two magnets 7 do not interfere with each other.
A circuit board 5 is arranged in a space between the two piston shafts 2, two Hall sensors are arranged on the circuit board 5, and each Hall sensor corresponds to one magnet in one group. The Hall sensor senses the change of the magnetic field, so that the movement distance of the piston shaft is determined, and the movement track of the shifting fork is determined. The distance of the circuit board from the piston shaft is 10 mm.
The movement of the shifting fork drives the piston shaft to move and guides the magnet in the piston shaft to move. And the shifting fork position sensor senses the magnetic field change of the magnet, converts the magnetic field change into a linear signal and outputs the linear signal to the TCU, and the reading of the displacement and the position of the piston shaft is completed.