KR100799487B1 - Driving device of solenoid valve in a vehicle - Google Patents

Abstract

The present invention provides a brake hydraulic control solenoid valve, a first switching unit for switching the supply of current to the coil in the solenoid valve, an overcurrent detection unit for detecting the overcurrent flowing in the first switching unit, the operation by the voltage across the overcurrent detection unit A second switching unit forcibly turning off the first switching unit and a control unit controlling the first switching unit to detect a current flowing through the first switching unit through the overcurrent detecting unit, and when the detected current is an overcurrent, use the second switching device. Thus, by forcibly turning off the first switching unit to protect the first switching unit, the stability and reliability of the vehicle brake device are improved.

Description

Solenoid valve drive device {Driving device of solenoid valve in a vehicle}

1 is a control block diagram briefly illustrating a driving device of a conventional solenoid valve.

Figure 2 is a simplified control block diagram of a drive device for a solenoid valve according to an embodiment of the present invention.

FIG. 3 is a control block diagram of a solenoid valve driving device connected to the overcurrent detector of FIG. 2 to provide an amplifier and a comparison unit to receive feedback of current flowing through the solenoid coil.

* Description of the symbols for the main functions of the drawings *

10: control unit 20: first switching unit

30: overcurrent detection unit 40: second switching unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a solenoid valve, particularly to an inflow or outflow into a wheel cylinder in an anti-lock brake system (hereinafter referred to as ABS) or a traction control system (hereinafter referred to as TCS). It relates to a device for driving a solenoid valve for regulating the brake hydraulic pressure.                         

In general, a vehicle brake system, for example, a vehicle equipped with an ABS system, is equipped with solenoid valves at the inlet and outlet sides of four wheels. In such ABS vehicles, when the braking force starts to slide beyond the friction force between the tire and the road surface of the vehicle, When the solenoid valve of the wheel is released to relieve pressure and the vehicle starts to roll again, the solenoid valve is actuated to apply pressure to the wheel. By this operation, the vehicle does not slip and braking is performed.

The anti-lock brake system for a vehicle includes a hydraulic pump for generating hydraulic pressure in the hydraulic modulator block, and a plurality of solenoid valves for supplying or blocking the hydraulic pressure generated by the hydraulic pump to the wheel cylinder on the wheel side, and the electronic control unit. Intermittent braking is achieved by controlling the supply or interruption of current flowing through the coil of the solenoid valve under the control of the Electronic Control Unit.

1 is a control block diagram of a driving device of a conventional solenoid valve.

As shown in FIG. 1, the control unit 1 which performs overall control of the vehicle, receives a control signal of the control unit 1, and the battery voltage (a) in the coil L in the solenoid valve to open or close the solenoid valve. And a switching unit 2 for switching the current supply by B +).

The switching unit 2 has a transistor (Q1) for the current flow from the collector stage (C) to the emitter stage (E) or cut off the current flow in accordance with the voltage value applied to the base terminal (B) Used.                         

However, conventionally, when the transistor is turned on to open the solenoid valve, if the excessive current flows for a long time due to a short circuit of the battery or other factors, the transistor may be damaged by the overcurrent.

If the transistor is damaged, there is a problem in that the normal brake operation is not performed, which impairs the stability of the vehicle.

The present invention is to solve the above problems, an object of the present invention is to provide a solenoid valve for protecting the switching device by forcibly turning off the switching device when the overcurrent is introduced to prevent the switching device for driving the solenoid valve is damaged by the overcurrent To provide a driving device of.

In addition, another object of the present invention is to provide a solenoid valve driving device which feeds back a current flowing through the solenoid coil without a separate current detecting device while protecting the solenoid valve driving switching device from overcurrent.

The driving device of the solenoid valve according to the present invention for achieving the above object is a brake hydraulic pressure control solenoid valve, the first switching unit for switching the current supply to the coil in the solenoid valve, the overcurrent flowing in the first switching unit And a control unit for controlling the first switching unit, the second switching unit for operating by the voltage across the overcurrent detection unit and forcibly turning off the first switching unit.                     

The overcurrent detector includes a resistance element, one end of the resistance element being connected to the emitter end of the first switching unit, and the other end of the resistance element being the base of the second switching unit connected to the base end of the first switching unit. The second switching unit is turned on or off according to the voltage across the resistance element, and when the second switching unit is on, the first switching unit is forcibly turned off.

In addition, the resistance value of the resistance element is a voltage for turning the second switching unit off when the normal voltage flows in the first switching unit, and the second switching unit on operation when the overcurrent flows in the first switching unit. It is set to have.

In addition, the driving device of the solenoid valve according to the present invention is a solenoid valve for brake hydraulic pressure control, a first switching unit for switching the current supply to the coil in the solenoid valve, an overcurrent detection unit for detecting an overcurrent flowing in the first switching unit, the A second switching unit operating by voltages at both ends of the overcurrent detection unit to forcibly turn off the first switching unit, an amplifying unit for amplifying the voltages at both ends of the overcurrent detection unit, a comparator comparing the output signal with the reference signal and the reference signal; And a control unit for controlling the switching unit and recognizing a current flowing in the solenoid coil based on the output signal of the comparing unit.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

2 is a control block diagram of a driving device of a solenoid valve according to an embodiment of the present invention.                     

As shown in FIG. 2, the driving apparatus of the solenoid valve according to the exemplary embodiment of the present invention includes a control unit 10 that performs overall control of the vehicle, and receives or receives a control signal from the control unit 10 to open or close the solenoid valve. The first switching unit 20 for switching the current supply by the voltage (B +) of the battery to the coil (L) in the solenoid valve, and the overcurrent detection unit 30 for detecting that the overcurrent flows through the first switching unit 20 ), A second switching unit 40 for forcibly turning off the first switching unit 20 when an overcurrent is detected in the overcurrent detecting unit 30.

The first switching unit 20 includes a first transistor Q1. The base terminal B of the first transistor Q1 is connected to the output side of the controller 10 to receive a control signal of a predetermined voltage level from the controller 10. In addition, the collector terminal C of the first transistor Q1 is connected to one side of the battery voltage B + via the coil L in the solenoid valve. Accordingly, the current due to the battery voltage B + reaches the collector terminal C of the first transistor Q1 via the solenoid coil L. Meanwhile, the emitter terminal E of the first transistor Q1 is connected to the ground side via the first resistor element R1 and the second resistor element R2. Accordingly, when the first transistor Q1 is turned on, the battery voltage B +, the solenoid coil L, the first transistor CE, the first resistor R1, and the second resistor R2 close the closed circuit. Configure.

The overcurrent detector 30 includes the first resistor element R1 described above. One end of the first resistor element R1 is connected to the emitter terminal E of the first transistor Q1. In addition, the other end of the first resistance element R1 is connected to the ground side via the second resistance element R2. Accordingly, the battery voltage B +, the solenoid coil L, the transistor CE, the first resistor element R1, and the second resistor element R2 constitute a closed circuit when the first transistor Q1 is turned on. When the first transistor is turned on, a predetermined voltage is applied to both ends of the first resistor element R1.

In addition, the second switching unit 40 includes the second transistor Q2. The base end B of the second transistor Q2 is connected to one end of the first resistor element R1 connected to the emitter end E of the first transistor Q1. Accordingly, the second transistor Q2 is turned on or off according to the voltage across the first resistor element R1. At this time, the collector terminal C of the second transistor Q2 is connected to the base terminal B of the first transistor Q1. Accordingly, when the second transistor Q2 is turned on, the first transistor Q1 is turned off, and the control unit 10, the second transistor Q2, and the second resistor element R2 form a closed circuit.

On the other hand, the resistance value of the first resistor element R1 of the overcurrent detector 30 maintains the second transistor Q2 in the off state when the constant current flows through the first transistor Q1. Is set to have a voltage value for operating the second transistor Q2 in the on state.

Referring to the operation of FIG. 2, when a normal current flows through the first transistor Q1 of the first switching unit 20, the voltage across the first resistor element R1 of the overcurrent detecting unit 30 is determined by the second switching unit 40. Since the second transistor Q2 is lower than the voltage value for turning on the second transistor Q2, the second transistor Q2 is maintained in the off state. Accordingly, the battery voltage, the solenoid coil, the first transistor Q1, the first resistor element, and the second resistor element form a closed circuit.

However, when an overcurrent flows through the first transistor Q1 due to a battery short circuit or other factors, the voltage across the first resistor element R1 rises above the voltage value at which the second transistor Q2 is turned on to operate. Transistor Q2 is turned on. Accordingly, as the voltage applied to the base terminal B of the first transistor Q1 is grounded, the first transistor Q1 is turned off to block the inflow of overcurrent, thereby damaging the first transistor Q1 by the overcurrent. To prevent them.

FIG. 3 is a control block diagram of a solenoid valve driving device connected to the overcurrent detector of FIG. 2 to provide an amplifier and a comparison unit to receive feedback of current flowing through the solenoid coil.

As shown in FIG. 3, the amplifier 50 is connected to both ends of the first resistance element of the overcurrent detector 30 to amplify the voltage across the first resistance element. The amplifier 50 is connected to a comparator for comparing the output signal with the reference signal and outputting the corresponding output signal to the controller.

Therefore, when a steady current flows through the first transistor Q1 of the first switching unit 20, the current flowing through the solenoid coil L is controlled by using the first resistor element R1 of the overcurrent detector 30. The feedback can be made in 10), so the solenoid valve can be checked.

In addition, since the current flowing through the solenoid coil L may be fed back using the first resistance element R1, a separate current detecting device may be provided as in the past to detect the current flowing through the solenoid coil L. FIG. There is no need to reduce manufacturing costs.

 As described above in detail, the present invention has the effect of improving the stability and reliability of the brake device by preventing the solenoid valve driving switching device from being damaged by overcurrent.

In addition, the present invention can feed back the current flowing through the solenoid coil by using the overcurrent detection device, there is no need for a separate current detection device has the effect of reducing the manufacturing cost.

Claims (4)

Solenoid valve for brake hydraulic control, First switching unit 20 for switching the current supply to the coil (L) in the solenoid valve, An overcurrent detection unit 30 for detecting an overcurrent flowing in the first switching unit 20, A second switching unit 40 operated by the voltage across the overcurrent detector 30 to forcibly turn off the first switching unit 20, It includes a control unit 10 for controlling the first switching unit 20, The overcurrent detector 30 includes resistance elements R1 and R2, and one end of the resistance elements R1 and R2 is connected to the emitter end E of the first switching unit 20, and the resistance element ( The other end of R1, R2 is a solenoid characterized in that the collector end C is connected to the emitter end E of the second switching part 40 connected to the base end B of the first switching part 20. Drive of the valve. delete The resistance value of the resistors R1 and R2 is set so that the second switching unit 40 is turned off when a normal current flows through the first switching unit 20. The driving device of the solenoid valve, characterized in that it is set to have a voltage to turn on the second switching unit (40) when overcurrent flows in the switching unit (20). Solenoid valve for brake hydraulic control, First switching unit 20 for switching the current supply to the coil (L) in the solenoid valve, An overcurrent detection unit 30 for detecting an overcurrent flowing in the first switching unit 20, A second switching unit 40 operated by the voltage across the overcurrent detector 30 to forcibly turn off the first switching unit 20, An amplifier 50 for amplifying the voltages at both ends of the overcurrent detector 30; Comparator 60 for comparing the output signal and the reference signal of the amplifier 50, And a controller 10 for controlling the first switching unit 20 and recognizing a current flowing in the solenoid coil L based on the output signal of the comparator 60. Drive system.

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