Speed detection system of vehicle

A speed measure system of a vehicle may include a drive shaft that rotates according to movement of a vehicle and a drive gear is formed along the outside thereof; a driven shaft to which a driven gear is formed, wherein the driven gear is engaged with the drive gear; a speed sensor that is disposed on the driven shaft and outputs a rotation signal according to the rotation of the driven shaft; and a jumper connector that is disposed on the speed sensor and transforms the frequency of the rotation signal output from the speed sensor with a predetermined ratio.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2011-0069547 filed in the Korean Intellectual Property Office on Jul. 13, 2011, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a speed measure system of a vehicle that detects rotations of a drive gear that is rotated by a movement of a vehicle and of a driven gear that is gear-meshed with the drive gear and has a speed sensor that transfers the detected rotation to pulse signal.

2. Description of Related Art

Generally, a speed of a vehicle is transferred to a driver through a speedometer or a tacho graph of an instrument panel.

Since this art has been developed to be suited to a vehicle speed signal of 5096 pulse per Kilometer, a driven gear and a gear ratio of a joint or a transmission itself are adjusted to set a vehicle speed ratio according to specifications of a rear axle or a tire of a vehicle.

However, specifications are increased in geometrical progression according to a rear axle ratio and a tire radius of a kind of a vehicle. Further, the number of the gear is used to adjust the gear ratio, and therefore it is hard to achieve an accurate speed ratio thereof.

BRIEF SUMMARY

Various aspects of the present invention are directed to provide a speed measure system of a vehicle having advantages of easily adjusting the pulse output to measure the speed of a vehicle regardless of a kind of a vehicle and a gear ratio thereof such that the design cost, the assembly cost, and the maintenance cost are saved.

In an aspect of the present invention, a speed measure system of a vehicle may include a drive shaft that rotates according to movement of a vehicle and a drive gear is formed along the outside thereof, a driven shaft to which a driven gear is formed, wherein the driven gear is engaged with the drive gear, a speed sensor that is disposed on the driven shaft and outputs a rotation signal according to the rotation of the driven shaft, and a jumper connector that is disposed on the speed sensor and transforms the frequency of the rotation signal output from the speed sensor with a predetermined ratio.

The jumper connector may include terminals that are formed corresponding to the predetermined ratio, and a jumper that is disposed on one of the terminals to adjust the predetermined ratios.

A pulse that is outputted from the speed sensor is differently changed according to a terminal that the jumper combines.

The drive gear is a worm gear and the drive gear is a worm wheel gear.

The gear ratio of the drive gear and the driven gear is 1.

A signal transmit portion is formed in the speed sensor to transmit signal to the jumper connector and a signal output portion is formed in the jumper connector to compensate the ratio of the signal to the predetermined ratio.

A screw portion is formed in the jumper connector, which is combined to one side of the speed sensor.

As described above, a jumper of a jumper connector is engaged with a selected terminal such that a pulse signal outputted from a speed sensor through the rotation of a driven shaft is easily changed in a speed measure system of a vehicle according to the present invention. Accordingly, it is unnecessary to change a gear ratio of a driven shaft and a drive shaft according to a vehicle.

DETAILED DESCRIPTION

FIG. 1is a partial exploded perspective view of a speed measure system of a vehicle according to an exemplary embodiment of the present invention.

Referring toFIG. 1, the speed measure system of a vehicle includes a drive shaft100, a drive gear110, a driven gear130, a driven shaft120, a speed sensor140, and a jumper connector150.

The drive shaft100rotates along the movement of the vehicle, which is proportional to the speed thereof, and the drive gear110is formed along the exterior circumference thereof. The driven gear130is formed along the exterior circumference of end portion of the driven shaft120and the driven gear130is gear-meshed with the driven gear110.

The driven gear130and the drive gear110have a worm and worm wheel gear structure in an exemplary embodiment of the present invention, if the drive shaft100rotates one cycle, the driven shaft120rotates one cycle such that the gear ratio is 1. Here, the drive gear is worm gear and the driven gear is a worm wheel gear.

While the vehicle moves, the drive shaft100rotates the driven shaft120. The speed sensor140generates rotation signals according to the driven shaft120. The jumper connector150transforms the rotation signal generated from the speed sensor140to raise or decrease to predetermined ratios.

The rotation signal that is outputted from the jumper connector150is transferred to a speedo meter that is disposed in an instrument panel (dash board) of a vehicle.

More particularly, if the drive gear110rotates at 1911 rpm, the driven gear130rotates at 1911 rpm. Accordingly, the rotation signal of 1911 rpm is input to the speed sensor140and 15288 (1911×8) pulse is output through a separate rotation plate (8 pulse).

And, the jumper connector150divides the pulse outputted from the speed sensor140by 3 to output this. Accordingly, about 5096 pulse is outputted through the jumper connector150such that an instrument panel of a driver displays 60 kilometers.

The jumper connector150uniformly changes the size of the outputted pulse from the speed sensor140, which can be applied to a different type of a speed sensor or a different speed system such that the pulse outputted is changed to a predetermined value.

FIG. 1is a partial exploded perspective view of a speed measure system of a vehicle according to an exemplary embodiment of the present invention.

Referring toFIG. 2, the jumper connector150is a socket type to be engaged with the speed sensor140through a thread, and a screw portion210is formed along the interior circumference thereof and the terminals200are formed on the inner side surface thereof. The jumper220is combined to one of the terminals200.

The pulse that is outputted from the speed sensor140is differently changed according to the terminal that the jumper220combines. For example, a first terminal of the terminals200divides the input pulse from the speed sensor140by 2.2 to output the divided pulse.

The second terminal200divides the input pulse by 2.4 to output the divided pulse, the third terminal200divides the input pulse by 2.6 to output this, the fourth terminal200divides the input pulse by 2.8 to output this, the fifth terminal200divides the input pulse by 3, and the sixth terminal200divides the input pulse by 3.2 to output this. The number of the terminal200can be varied according to design specifications of a vehicle.

Accordingly, the operator combines the jumper220on a predetermined terminal200according to a design specification of a system such that the pulse value outputted from the speed sensor140is varied at a regular ratio.

FIG. 3is a cross-sectional view of a jumper connector and a speed sensor that are disposed in a speed measure system of a vehicle according to an exemplary embodiment of the present invention.

Referring toFIG. 3, the speed sensor140is combined with the jumper connector150through a thread, a signal transmit portion300is formed to transfer the pulse from the speed sensor140to the jumper connector150, and a signal output portion310is formed in the jumper connector150so as to output the signal.

Further, the terminals200are formed in the jumper connector150and the jumper220is combined with one of the terminals200. Here, the jumper220can be attached or detached.

FIG. 4is a table showing data in a speed measure system of a vehicle according to an exemplary embodiment of the present invention.

Referring toFIG. 4, a vehicle speed is 60 km/h, a tire rotation speed is 382.1 rpm, a rotation speed (Np) of the drive shaft100is 1911, and a rotation speed of the driven shaft120(Nsc) is 1911 in an exemplary embodiment of the present invention.

The predetermined ratio of the jumper connector150is 3 in an exemplary embodiment of the present invention and the pulse outputted from the jumper connector150is 5096 rpm. Here, 1911*8/3=5096.

In the conventional art, it is impossible to change the frequency of the output pulse through the jumper and therefore there was a problem that the gear ratio of the driven shaft120and the drive shaft100was to be changed.