CN2200174Y

CN2200174Y - Electronic vehicle-speed odometer

Info

Publication number: CN2200174Y
Application number: CN 94242144
Authority: CN
Inventors: 顾忠
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-06-27
Filing date: 1994-06-27
Publication date: 1995-06-07
Anticipated expiration: 2004-06-27

Abstract

The utility model relates to an electronic vehicle-speed odometer. The utility model makes use of a vehicle speed sensor to convert vehicle speed signals into electric signals with the adoption of a non-contact manner, and the electric signals are transmitted to an electronic drive circuit by cables to drive an electronic speedometer and a mileage summating meter. In this way, the purpose of indicating the instantaneous speed and the cumulative road mileage of automobiles is achieved.

Description

Electronic vehicle-speed odometer

The invention relates to a kind of electronic type speedometer that is used for vehicle.

The speedometer of prior art, be behind one group of worm gear, worm speed-down, to have the steel driving snake of certain-length to be connected with one by the vehicle part that can reflect the speed of a motor vehicle, in order to transmit speed of a motor vehicle torque, the other end of driving snake is connected with worm screw in the speedometer gauge outfit, these flexible axle two ends all adopt the square key that is threaded joint and the square hole in the worm screw to be slidingly connected, indicate the instantaneous speed of a motor vehicle by the speedometer that magnetic induction of the drive of the worm screw in the gauge outfit is shown, this worm screw drives mileage counter accumulative mileage simultaneously behind four groups of worm gears, worm speed-down.This speedometer transmits speed of a motor vehicle torque by driving snake and many group mechanical transmission components, and wearing and tearing in the speed of a motor vehicle transmission of torque and the phenomenons of bringing thus such as heating, noise and stall directly influence the precision and the reliability of speedometer.

Purpose of the present invention promptly designs the electronic type speedometer that a kind of drive disk assembly is extremely simple, reliability is high solving above-mentioned all problem.

Electronic type speedometer of the present invention is achieved through the following technical solutions.

Electronic type speedometer of the present invention, by vehicle speed sensor, two groups of electronic drive circuits, the electronic vehicle speed table, motor, mileage counter cooperation by driven by motor constitutes, by the described speed of a motor vehicle transmission rod vehicle speed signal is transferred to first group of electronic drive circuit, second group of electronic drive circuit is subjected to first group of electronic drive circuit control and drives the electronic vehicle speed table to indicate the instantaneous speed of a motor vehicle, by the mileage that is serially connected with two groups of driven by motor mileage counter accumulative total vehicle ' between the electronic drive circuit output terminal, above-mentioned vehicle speed sensor is contactless sensing, vehicle speed sensor is by speed disc, the magnet and the magnetic-sensitive elements that are embedded in the speed disc are formed, and vehicle speed signal is converted to electric signal transmission by magnetic-sensitive elements, the forward drive pulse of motor is provided by first group of electronic drive circuit, second group of electronic drive circuit provides the negative sense driving pulse of motor, the output shaft of motor is to drive mileage counter accumulative mileage by the reducing gear that certain speed ratio is arranged, the speed ratio that changes reducing gear can be used for the vehicle of different model, and this motor is the single-phase permanent stepper motor.

Electronic type speedometer of the present invention, be characterized in utilizing a vehicle speed sensor to adopt the noncontact mode that vehicle speed signal is converted to electric signal and transfer to electronic drive circuit driving electronic vehicle speed table and mileage counter, transmitting speed of a motor vehicle torque with the steel driving snake that certain-length is arranged in the prior art compares, not only solved the problems of bringing by speed of a motor vehicle transmission of torque wearing and tearing, and reliability and all being greatly enhanced serviceable life.

Performance of the present invention describes conjunction with figs. in detail one by one.

Fig. 1 is the structural representation of electronic speedometer vehicle speed sensor of the present invention, 1-cable wherein, 2-magnetic-sensitive elements, 3-magnet, 4-speed disc, 5-vehicle part.

Fig. 2 is the structural representation of electronic speedometer watch core of the present invention, 6-mileage counter wherein, 7-speed of a motor vehicle pointer, 8-index dial, 9-watch core support, 10-train of reduction gears, 11-synchronous motor, 12-reometer.

Fig. 3 is the circuit theory diagrams of electronic type speedometer of the present invention, and this circuit is called circuit (20).

By accompanying drawing 1 as can be known, the vehicle part 5 that can reflect the speed of a motor vehicle is mechanical connection with the speed disc of being made by non-magnet material 4, magnet 3 is embedded in the speed disc 4, magnetic-sensitive elements is arranged at magnet 3 to be had on the same axis of certain air gap, when vehicle ', vehicle part 5 and speed disc 4 are rotated synchronously with the speed of a motor vehicle together, magnet 3 triggers electric signal that magnetic-sensitive elements sends negative pulse during through axial location and transfers to circuit (20) in the accompanying drawing 3 by cable 1, when vehicle stops, magnetic-sensitive elements 2 and magnet 3 are if on same axis, magnetic-sensitive elements 2 output LOW voltages then, on the contrary be output as high voltage.IC1 in the circuit (20), IC2 is two typical time base circuit 5G555, all be set to the monostable duty, when circuit (20) is static, no matter the signal of magnetic-sensitive elements II (being the magnetic strength device 2 in the accompanying drawing 1) transmission is high voltage or low-voltage, two time base circuit IC1, output terminal 3 pin of IC2 are low-voltage output and (are common technique herein, principle repeats no more), be serially connected with two IC circuit 1, synchronous motor 11 between the IC2 output terminal is because of a of its winding M, the b both end voltage equates and makes the mileage counter 6 in the accompanying drawing 2 keep former accumulative mileage number constant, simultaneously reometer A does not flow through electronic vehicle speed list index 7 indications that make in the accompanying drawing 2 in reference position because of time base circuit IC2 output LOW voltage has drive current yet, when vehicle ', the magnetic-sensitive elements II is subjected to magnet 3 to trigger first negative pulse of output through capacitor C 1, resistance R 1 triggers input end 2 pin of time base circuit IC1, its output terminal 3 pin are exported a high voltage pulse immediately, there is direct impulse electric current to flow through among the synchronous motor winding M by a to b, synchronous motor 11 moves a fixing angle, the train of reduction gears 10 of this motor output shaft on watch core support 9 drives mileage counter 6 and rotates, make the reading of accumulative mileage increase to a certain reading, the transition later of the high voltage pulse of time base circuit IC1 output to moment of low-voltage through capacitor C 3, resistance R 4 triggers input end 2 pin of time base circuit IC2, its output terminal 3 pin are also exported a high voltage pulse, the adjustable constant-flow source circuit of forming through triode Q and adjustable resistance W is a reometer 12 in the accompanying drawing 3 to reometer A() drive current is provided, adjust adjustable resistance W and promptly change drive current, vehicle applicable to different model, drive 7 indications of speed of a motor vehicle pointer by reometer 12 and be scaled the instantaneous speed of a motor vehicle corresponding with this drive current by scaleplate 8, the high voltage pulse of time base circuit IC2 output provides reverse impulse electric current by b to a to synchronous motor winding M simultaneously, as mentioned above, the train of reduction gears 10 of synchronous motor 11 on support 9 drives mileage counter 6 and rotates, make the reading of accumulative mileage continue to increase to a certain new reading, the speed ratio that changes train of reduction gears 10 can be used for the vehicle of different model, the high voltage pulse of time base circuit IC2 output circuit (20) later returns to the arrival that the incipient stability state is waited for second negative pulse, and so far circuit (20) is finished once circulation.

In the circuit (20), the negative pulse gate circuit that capacitor C 1, C3 and resistance R 1, R4 constitute is to guarantee that two time base circuit IC1, IC2 are triggered by negative pulse, capacitor C 2, C5, C6, C7 are filter capacitor, the effect of diode D1 to D4 is the back-emf of synchronous motor 11 generations of releasing, and the duration of the high voltage pulse of two time base circuit IC1, IC2 outputs must be satisfied the requirement of formula 1 and be calculated by general formula 2:

Formula 1:t _High＜1/2f ₀

Formula 2:t _High=1.1RC

T in the formula _HighThe duration of-high voltage pulse, f ₀The frequency of magnetic-sensitive elements output negative pulse during-max. speed, R-resistance R 2, R3, C-capacitor C 4, C8.

Synchronous motor 11 in the accompanying drawing 3 is the single-phase permanent synchronous motor, drives with positive negative pulse stuffing, is characterized in making a move to a pulse, even continuously rotation also with the pulse strict synchronism, displacement accuracy height not only, and do not have accumulated error, guaranteed the accumulative total precision of mileage counter.

Claims

1, a kind of electronic type speedometer that is used for vehicle, it is by vehicle speed sensor, two groups of electronic drive circuits, the electronic vehicle speed table, motor, the mileage counter cooperation that reaches by driven by motor constitutes, it is characterized in that, by described vehicle speed sensor vehicle speed signal is transferred to first group of electronic drive circuit, second group of electronic drive circuit is subjected to first group of electronic drive circuit control and drives the electronic vehicle speed table to indicate the instantaneous speed of a motor vehicle, by the mileage that is serially connected with two groups of driven by motor mileage counter accumulative total vehicle ' between the electronic drive circuit output terminal.

2,, it is characterized in that vehicle speed sensor is contactless sensing according to the electronic type speedometer of claim 1.

3,, it is characterized in that vehicle speed sensor is made up of speed disc, the magnet and the magnetic-sensitive elements that are embedded in the speed disc, and vehicle speed signal is converted to the electric signal transmission by magnetic-sensitive elements according to the electronic type speedometer of claim 2.

4, according to the electronic type speedometer of claim 1, it is characterized in that providing the forward drive pulse of motor by first group of electronic drive circuit, the negative sense driving pulse of motor is provided by second group of electronic drive circuit.

5, according to the electronic type speedometer of claim 1, the output shaft that it is characterized in that motor drives mileage counter accumulative mileage by the reducing gear that certain speed ratio is arranged, and the speed ratio that changes reducing gear can be used for the vehicle of different model.

6,, it is characterized in that motor is the single-phase permanent stepper motor according to the electronic type speedometer of claim 1.