KR100196801B1 - Fail detection device of solenoid valve - Google Patents

Abstract

The present invention relates to a device for detecting a failure of a solenoid valve, which is turned on when a high level voltage is applied and turned off when a low level voltage is applied. A test voltage is applied to the solenoid valve and the gate terminal, and a solenoid valve is connected to the source source. When the gate voltage is at the low level, the drain-source is turned off and is proportional to the magnitude of the drain current through the mirror terminal. A sense transistor for generating and outputting a voltage; A voltage having a predetermined magnitude connected to a gate terminal of the sense transistor so that an input test voltage is distributed and a drain-source is not turned on even when a low level voltage is applied to the gate terminal. A bias resistor; Three transistors connected in parallel with each base short wave connected to the mirror terminal of the sense transistor, the collector-emitter being turned on / off according to the voltage of the base terminal; It is connected to each base terminal of the three transistors, and consists of a voltage distribution resistor for determining the switching state of the three transistors by distributing the mirror terminal voltage of the sense transistor, and whether the solenoid valve is driven or not, Since the short circuit condition can be distinguished accurately, it is easy to determine the cause of the failure of the solenoid valve.

Description

Fail detection device of solenoid valve

1 is a detailed circuit diagram of a fail detection device of a solenoid valve according to an embodiment of the present invention,

2 is a detailed circuit diagram of a fail detection device of a solenoid valve according to the prior art.

* Explanation of symbols for main parts of the drawings

1: sense transistor 2: solenoid valve

Q1, Q2, Q3: transistors R1 to R12: resistors

D: Diode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a failure of a solenoid valve applied to the field of shift control or pressure control of an automatic transmission of a vehicle, and more specifically, a solenoid valve. The present invention relates to a fail detection device capable of accurately determining a fail regardless of an on / off state.

The automatic transmission of the vehicle is equipped with a shift control solenoid valve (SCSV) and a hydraulic control solenoid valve (PCSV), which are located in a transmission control unit (TCU). The circuit includes a circuit for detecting whether the solenoid valve fails, that is, short or open.

First, a fail detection apparatus according to the related art will be described with reference to the accompanying road surface.

2 is a detailed circuit diagram of a fail detection device of a solenoid valve according to the related art.

Referring to FIG. 2, the signal of the input terminal IN is a test signal provided from the shift control unit, and the signal of the output terminal OUT is output to the shift control unit as a test result value.

If it is assumed that the solenoid valve 31 is normal, the transistor Q31 is turned on and the solenoid valve 31 is turned on when the input terminal IN signal is at a high level. Emitter voltage VB appears at point B due to ON of transistor Q31, AU, diode D31 are turned on, and output terminal OUT signal becomes high level. Accordingly, the shift control unit determines that the solenoid valve 31 is normal from the high level output terminal OUT signal.

When the signal supplied from the shift control unit to the input terminal in is at the low level, the transistor Q31 is turned off, and the voltage at the point A is close to zero. The solenoid valve 31 is off. The voltage at this point A is provided to the output terminal OUT via the resistor R4 and the diode D31, and the shift control unit determines that the solenoid valve 31 is normal from the low level signal of the output terminal OUT.

However, in the fail detection circuit, if the solenoid valve 31 is disconnected at the A point or less, and a high level test signal is input from the shift control unit, the fail detection information is not fed back to the shift control unit.

This is because the transistor Q31 is turned on even when disconnection occurs below the point A, and because the collector voltage VB is applied to the point B by turning on the transistor Q31, a high level is detected at the output terminal OUT. to be. That is, if disconnection occurs below point A and a test voltage for turning on the solenoid valve is applied, the fail detection device does not detect the disconnection.

If the automatic transmission is determined by two solenoid valves, the diagram below is an example.

As described above, the two solenoid valves are set to ON and ON in the first stage so that the driving time in the first stage is usually the least, so that the current consumption is small, and the solenoid is set to OFF and OFF in the third stage. In the event of a valve failure, the fail-safe function maintains three speeds, allowing the car to travel to repairable areas such as workshops.

However, as pointed out above, in the conventional fail detection apparatus, since the solenoid valve fails to detect when the vehicle fails in the early stage of departure of the vehicle, driving of the vehicle becomes impossible. Because if you fail to fail from the beginning, the fail safe function will not work.

Therefore, an object of the present invention is to solve the conventional technical problems as described above, and the fail detection device of the solenoid valve capable of detecting both disconnection or short circuit regardless of the driving state (On or Off) of the solenoid valve. To provide.

As a means for achieving the above object, the configuration of the fail detection device of the solenoid valve according to the characteristics of the present invention is turned on when a high level voltage is applied, and turned off when a low level voltage is applied. The solenoid valve is turned off, the test voltage is applied to the gate terminal, the power supply voltage is applied to the drain board, the solenoid valve is connected to the source terminal, and the drain-source is turned on when the gate voltage is high level. When the gate voltage is low level, the drain-source is turned on; when the gate voltage is low level, the drain-source is turned off, and a sense transistor for forming and outputting a voltage proportional to the magnitude of the drain current through the mirror terminal Wow; A voltage having a predetermined magnitude within a range connected to a gate terminal of the sense transistor so that an input test voltage is distributed and a drain-source is not turned on even when a low level voltage is applied to the gate terminal. A bias resistor to be applied, each base terminal is connected to the mirror terminal of the sense transistor, each collector throw is used as an output terminal, and the collector-emitter is turned on / off according to the voltage of the base terminal. Three transistors connected in parallel; It is connected to each base terminal of the three transistors, and comprises a voltage distribution resistor for determining the switching state of the three transistors by distributing the mirror terminal voltage of the sense transistor.

According to the above feature of the present invention, by properly selecting the resistance value of the distribution resistor, the normal, disconnection or short circuit of the solenoid valve can be distinguished according to the collector terminal voltage of three transistors.

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

1 is a detailed circuit diagram of a fail detection device of a solenoid valve according to an embodiment of the present invention.

First, referring to FIG. 1, a configuration of a fail detection device for a solenoid valve according to an exemplary embodiment of the present invention will be described.

As shown in FIG. 1, a fail detection device for a solenoid valve according to an embodiment of the present invention includes: resistors R1, R2, and R3 connected to an input terminal IN; A sense transistor (1) having a gate terminal connected to the contacts of the two resistors (R2 and R3), a power supply voltage (VB) applied to the drain terminal, and a solenoid valve (2) connected to the source terminal; A diode (D) connected between the drain terminal and the source terminal of the sense transistor (1); Three transistors Q1, Q2 and Q3 having a base terminal connected to the mirror terminal of the sense transistor 1, and resistors R4 to R9 connected to the base terminals of the transistors Q1, Q2 and Q3; Resistor R10, R11, and R12 are respectively connected to the collector terminals of the three transistors Q1, Q2, and Q3.

Although not shown in the drawing, a test voltage generated in the shift control unit is applied to the input terminal IN, and the output terminals OUT1, OUT2, and OUT3 voltage are fed back to the shift control unit.

In addition, although CASE 314B, which is a TMOS SENSEFET of Motopola, was used as the sense transistor, the technical scope of the present invention is not limited thereto, and other types of sense transistors may be used.

Next, the operation of the fail detection device of the solenoid valve according to the embodiment of the present invention will be described based on the above configuration.

When battery power is supplied, operation of the circuit begins. When the operation of the circuit starts, the test voltage generated in the shift control unit is applied to the gate terminal of the sense transistor 1 through the input terminal IN.

The sense transistor 1 is turned on when the gate voltage is high level, and turned off when the gate voltage is low level. When the drain-source between the sense transistors 1 is turned on, the power supply voltage VB is applied to the solenoid valve 2 so that the valve is turned on. The diode D connected between the drain terminal and the source terminal is for preventing the noise component included in the power supply voltage from being applied to the solenoid valve 2.

On the other hand, at the mirror terminal of the sense transistor 1, a voltage having a magnitude proportional to the drain current is generated.

The resistors R2 and R3 connected to the gate terminal of the sense transistor 1 have a drain current of a predetermined magnitude flowing in a range in which the sense transistor 1 is not turned on when the input terminal IN voltage is at a low level. This is for biasing the input terminal IN voltage.

The mirror terminal voltage of the sense transistor 1 is applied to the base terminals of the three transistors Q1, Q2, and Q3, and the three transistors Q1, Q2, and Q3 are turned on / off according to the base voltage. When each of the transistors Q1, Q2, Q3 is turned on, the current from the power supply voltage VB connected to the collector terminal passes through the corresponding resistors R10, RE11, R12 to the transistors Q1, Q2, Q3. As a result, the voltage at the output terminals OUT1, OUT2, OUT3 goes low. In contrast, when the transistors Q1, Q2, and Q3 are turned off, the voltages of the corresponding output terminals OUT1, OUT2, and OUT3 become high levels.

As a result, when the switching states of the transistors Q1, Q2, and Q3 are induced to be different from each other according to the normal, short circuit, or disconnection state of the solenoid valve 2, an output terminal obtained at the collector terminal of each transistor Q1, Q2, Q3 is obtained. It may be determined whether the solenoid valve is failing through the voltages OUT1, OUT2, and OUT3. Here, inducing the switching states of the transistors Q1, Q2, and Q3 to be different according to the normal, short circuit, or disconnection state of the solenoid valve 2 is a resistance connected to the base terminal of the transistors Q1, Q2, and Q3. It can be achieved by adjusting the resistance value of (R4 ~ R9).

The resistors R4 to R9 connected to the base terminals of the transistors Q1, Q2 and Q3 distribute the mirror terminal voltage of the sense transistor 1 to the base terminals of the corresponding transistors Q1, Q2 and Q3. do.

For example, when the input terminal IN is at a low level and the solenoid valve 2 is normal, the resistance values of the two resistors R4 and R5 are turned off so that only the transistor Q1 is turned off by the mirror terminal voltage of the sense transistor 1. This is determined.

In addition, since the drain current of the sense transistor 1 increases regardless of the low or high of the gate voltage when the solenoid valve 2 is short-circuited, the resistances of the two resistors R6 and R7 that cause the transistor Q2 to turn off. The value is determined.

When the input terminal IN voltage is high level and the solenoid valve is short-circuited, the resistance values of the two resistors R8 and R9 that cause the transistor Q3 to turn off are determined.

The bias conditions of the transistors Q1, Q2, and Q3 for distinguishing between normal, short circuit, and disconnection states of the solenoid valve 2 can be variously modified. Table 2) shown below shows an example of the bias condition described above.

Referring to Table 2, when a high level voltage is applied to the input terminal IN for the test, the two output terminals OUT2 and OUT3 are inspected to determine whether the solenoid valve is failing. That is, the state of the two output terminals OUT2 and OUT3 is a normal state when (H, L), a disconnection state when (L, L), and a short circuit state when (H, H).

In addition, when a low level is applied to the input terminal, the two output terminals OUT1 and OUT2 are inspected to determine whether the solenoid valve is failing. More specifically, the two output terminals OUT1 and OUT2 are in a normal state when (H, L), in a disconnected state when (L, L), and in a short state when (H, H). .

Therefore, in the shift control unit, when the high level is applied as the input terminal IN voltage, the output terminal OUT2 and OUT3 voltages are checked. When the low level is applied as the input terminal IN voltage, the output terminal OUT1 and OUT2 are applied. The voltage can be checked to determine whether the solenoid valve is failing.

As described above, according to the exemplary embodiment of the present invention, it is possible to accurately distinguish between normal, disconnected or short-circuit states regardless of whether the solenoid valve is driven, and thus it is easy to determine the cause of failure of the solenoid valve. In addition, since the short circuit state of the solenoid valve can be determined, the short circuit state of the solenoid valve can be used to switch to a fail-safe load so that an overcurrent does not flow through the sense transistor for a long time.

Claims (5)

A solenoid valve that is turned on when a high level voltage is applied and turned off when a low level voltage is applied; When the gate voltage is high level, the drain-source is turned on. When the gate voltage is low level, the drain-source is turned off. A sense transistor generates and outputs a voltage proportional to the magnitude of the drain current through the mirror terminal. Wow; A voltage having a predetermined size within a range of being connected to a gate terminal of the sense transistor so as to distribute an input tesuit voltage and preventing a drain-source from turning on even when a low-level voltage is applied to the gate terminal. A bias resistor adapted to be applied to the terminal; Three transistors connected in parallel with each base terminal connected to the mirror terminal of the sense transistor, each collector terminal used as an output terminal, and the collector-emitter turned on / off according to the voltage of the base terminal; And a voltage divider resistor connected to each base terminal of the three transistors and configured to divide a mirror terminal voltage of the sense transistor to determine a switching state of the three transistors. The method of claim 1, further comprising a diode connected between the drain terminal and the source terminal of the sense transistor to prevent noise component included in the power supply voltage of the drain terminal from being applied to the solenoid valve. The fail detection device of the solenoid valve, characterized in that. The solenoid of claim 1, wherein the resistance value of the distribution resistor is selected to provide a bias condition in which a normal, disconnected, or shorted state of the solenoid valve may be distinguished according to the switching states of the three transistors. Fail detection device of the valve. The apparatus of claim 1, further comprising a shift control unit configured to apply a test voltage to the gate terminal of the sense transistor and to connect the voltages of the collector terminals of the three transistors as a test result. And failing to determine normal, disconnection and short circuit of the solenoid valve from the collector terminal voltages of the three transistors obtained by applying the voltage. The fail detection device of claim 1, wherein the sense transistor is configured such that a test voltage is applied to a gate terminal, a power supply voltage is applied to a train terminal, and the solenoid valve is connected to a source terminal. .