KR100709470B1 - Current Control Circuit of MR Damper - Google Patents

Abstract

The present invention is a current control circuit of the MR CDC damper which is driven and controlled through the switching elements FET1 and FET2, the configuration of which receives the signal applied to the gate (G) terminal of the FET1 to perform a signal conversion and then the source of the FET1 ( An inverter for converting a signal input to the gate (G) terminal of FET1; It is characterized in that the circuit is composed of FET3, the switching element for receiving the output of the inverter is turned on or turned off to output a signal to the source (S) of the FET1 through the drain (D) stage.

FET, MR, Damper, Current, Inverter

Description

A circuit for control current of MR damper

1 is a configuration diagram of a current control circuit of a conventional MR CDC damper.

Figure 2 is a graph of the current control time of a conventional damper.

3 is a block diagram of a current control circuit of the MR CDC damper according to the present invention.

Figure 4 is a graph of the current control time of the damper according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10, 20: damper equivalent circuit 30: current control circuit

35: inverter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current control circuit of an MR damper, and more particularly, to a current control circuit of an MR damper including a circuit configuration for reducing back EMF in a driving circuit of an MR CDC damper used in a vehicle air suspension system. will be.

In general, an air spring, a continuous damping control (CDC) damper, or the like is used for the air suspension electronic control apparatus of a vehicle.

The CDC damper is mounted between the body and the axle of the car to control the movement of both tension and compression of the spring, and to control the damping force according to the driving state to maximize the road's traction, braking force, steering stability and ride comfort. . On the other hand, MR (Magnetic Rheological) CDC damper achieves the damping force control through the fluid resistance control using the viscosity change characteristics of the MR fluid. Therefore, although the damping force of the reaction speed is faster than that of the CDC damper using the proportional solenoid valve, in order to implement a suspension system that can be controlled quickly according to the road condition, the fast current control responsiveness of the ECU and the corresponding MR CDC damper Responsiveness is required.

The drive control of the conventional MR CDC damper is controlled using two switching elements FET1 and FET2, as shown in FIG. That is, FET1 is used for fail on / off control of the system, and FET2 controls damping force of the damper through PWM current control.

In addition, the MR CDC damper may be represented by the equivalent circuit 10 of R3 and L1. When the damping force of the damper is controlled to 0 [A], the gate of FET2 or FET1 is controlled. ) Turn off FET1 or FET2 by applying 0 [V] to the input terminal. The current flowing through the damper has a long time (50 ms) to reach 0 [A] due to the counter electromotive force by the inductance (L1) (see Fig. 2, in Fig. 2, A is the control signal of the controller and B is the control of the controller). Damper response characteristics according to signal). In this way, when the time to reach 0 [A] is long, the damping force of the damper is gradually changed to decrease the response of the system, which adversely affects the ride comfort of the vehicle.

The present invention has been made to solve the problems of the prior art, the object of the present invention is to control the driving time of the damper in the drive circuit of the MR CDC damper used in the air suspension of the vehicle to control the time to 0 [A] In order to shorten, to provide a current control circuit of the MR damper to reduce the back EMF generated by the inductance on the equivalent circuit of the MR CDC damper.

In order to achieve the above object, the current control circuit of the MR CDC damper driven and controlled through the switching elements FET1 and FET2 according to the present invention receives a signal applied to the gate (G) terminal of the FET1, and then performs signal conversion. A current control circuit unit for outputting a signal converted to a source S terminal of FET1, wherein the current control circuit unit includes an inverter for converting a signal input to the gate G terminal of FET1; It is characterized in that the circuit is composed of FET3 which is a switching element that receives the output of the inverter is turned on or turned off to output a signal to the source (S) of the FET1 through the drain (D) stage.

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Hereinafter, with reference to the drawings will be described a preferred embodiment according to the present invention.

The current control circuit configuration of the vehicular MR CDC damper according to the present embodiment will be described with reference to FIG. 3.

As shown in FIG. 3, the circuit configuration according to the present embodiment is a gate G of the FET1 for controlling the current of the MR CDC damper 20 (damper equivalent circuit) driven and controlled through the switching elements FET1 and FET2. It is configured to include a current control circuit 30 for receiving a signal applied to the stage to perform a signal conversion and then output the converted signal to the source (S) stage of the FET1.

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In the above configuration, the current control circuit section 30 according to the present embodiment includes an inverter 35 for converting a signal input to the gate G terminal of the FET1; The circuit configuration is composed of FET3, which is a switching element that receives the output of the inverter 35 and outputs a turn on or turn off signal through the drain (D) stage to the source (S) stage of the FET1. In the circuit, there is further included a resistance means R4 connected in series between the inverter 35 and the FET3.

The operation of the current control circuit of the MR CDC damper according to the present embodiment having the circuit configuration as described above will be described with reference to FIG.

As shown in FIG. 3, in the present embodiment, the current control circuit unit 30 is added to the existing damper current control circuit in order to reduce the counter electromotive force generated by the inductance L1.

That is, when it is necessary to control the driving state of the MR damper 20 (which is a damper equivalent circuit) with a current of 0 [A], when a low voltage is applied to the gate G terminal of the switching element FET1, FET1 is turned off accordingly. The low voltage applied to the gate (G) terminal of the FET1 is applied to the switching device FET3 in the high voltage state through the inverter 35 of the current control circuit unit 30.

Then, after the FET3 is turned on, a signal corresponding thereto is output to the source S terminal of the FET1, so that the back EMF generated by the inductance L1 in the damper equivalent circuit 20 is reduced. This reduces the time taken to control the current of the damper 20 to 0 [A] as much as possible. This is as shown in the graph diagram of FIG. 4. In FIG. 4, A 'is a control signal of the controller and B' is a response characteristic of the damper according to the control signal of the controller.

As shown in Fig. 4, after the control signal A 'of the controller is applied, the current response (current control to 0 [A]) B' at the damper (20 in Fig. 3) is 0.5 ms. It can be seen that it occurred earlier than the conventional one (see FIG. 2).

As described above, in the present invention, the current control circuit unit is configured to reduce the back EMF generated by the inductance of the MR CDC damper so that the response from the damper can be generated quickly when the controller is driven off.

In interpreting the technical scope of the present invention, it should not be construed as being limited to the embodiments described above, and the technical scope of the present invention should be determined by reasonable interpretation of the matters described in the claims.

According to the current control circuit of the MAL damper of the present invention, when controlling the driving of the damper to 0 [A] by reducing the time to reach to several tens or hundreds of msec to improve the response characteristics of the damper, ride comfort and steering stability while driving the vehicle There is an effect that can be improved.

Claims (3)

In the current control circuit of the MR CDC damper driven and controlled through the switching elements FET1 and FET2, A current control circuit unit for receiving a signal applied to the gate (G) terminal of the FET1 and performing signal conversion, and then outputting the converted signal to the source (S) terminal of the FET1, wherein the current control circuit unit includes a gate of the FET1 ( An inverter for converting a signal input to the G) stage; And a FET3, which is a switching device that receives the output of the inverter and is turned on or turned off to output a signal to the source S of the FET1 through the drain D. delete The method according to claim 1, And a resistance means connected between the inverter and the FET3 of the current control circuit part.

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