JP2004362181A - Semiconductor relay - Google Patents

Abstract

Provided is a semiconductor relay capable of efficiently transmitting a failure diagnosis signal according to a plurality of types of failures without complicating the system.
A semiconductor relay (20) drives and controls an air pump (24) and an electromagnetic on-off valve (28) based on a drive request signal from a control computer (10). The failure diagnosis circuit 22 detects a plurality of types of failures of the air pump 24 and the solenoid on-off valve 28 and sends a failure diagnosis signal corresponding to the detected failure to the control computer 10. The failure diagnosis signal is determined according to the type of failure. Are set to different duties.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor relay that drives and controls a plurality of controlled objects, and more particularly, to a method of transmitting a plurality of types of failure diagnosis signals of the controlled objects.
[0002]
[Prior art]
Conventionally, in a facility or system including a terminal controller that drives and controls a plurality of control targets based on a drive request signal from a higher-level control computer, a terminal controller is used as a method of transmitting fault information occurring in a plurality of control targets. Detect various failures. Then, the terminal controller simultaneously sends a fault diagnosis signal composed of a plurality of bits and a clock signal (synchronization signal) for synchronizing to the host control computer in accordance with the detected fault, thereby simultaneously controlling a plurality of control targets. Failure information is transmitted (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-352358
[Problems to be solved by the invention]
However, in the above-described abnormality occurrence transmission method, the control computer needs to simultaneously transmit a clock signal (synchronization signal) for synchronization in order to detect a failure of a control target based on a failure diagnosis signal composed of a plurality of bits. There is a problem that the system becomes complicated.
[0005]
The present invention has been made in view of the above circumstances, and has as its object to provide a semiconductor relay capable of efficiently transmitting a failure diagnosis signal corresponding to a plurality of types of failures without causing a complicated system. Is to provide.
[0006]
[Means for Solving the Problems]
Hereinafter, the means for achieving the above object and the effects thereof will be described.
According to the first aspect of the present invention, a plurality of control targets are drive-controlled based on a drive request signal from a control computer, a plurality of types of faults of the control target are detected, and a fault diagnosis signal corresponding to the detected fault is detected. The fault diagnostic circuit outputs a fault diagnostic signal having a different duty according to the type of the detected fault.
[0007]
Therefore, according to the configuration of the first aspect, the failure diagnostic signal having a different duty is output according to the type of the failure detected for the control target. Therefore, it is necessary to transmit the synchronization signals for synchronization at the same time. Therefore, a failure diagnosis signal corresponding to a plurality of types of failures can be efficiently transmitted without causing the system to be complicated.
[0008]
According to a second aspect of the present invention, in the semiconductor relay according to the first aspect, the failure diagnosis circuit superimposes and outputs a plurality of failure diagnosis signals having different voltage levels according to the type of the detected failure. It is characterized by.
[0009]
When setting many types of faults to be detected by the fault diagnosis circuit, it is necessary to set a small duty interval of the fault diagnosis signal corresponding to each fault. In this case, the fault diagnosis on the control computer side is performed. The signal determination accuracy will be reduced.
[0010]
In this regard, according to the configuration of claim 2, since a plurality of failure diagnosis signals having different output levels and duties are superimposed on the type of failure detected by the failure diagnosis circuit and transmitted, Even if the duty interval is increased, the types of faults detected can be increased, and a detailed abnormal state can be detected.
[0011]
According to a third aspect of the present invention, a plurality of control targets are drive-controlled based on a drive request signal from a control computer, and failures of the plurality of control targets are detected, and a failure diagnosis signal corresponding to the detected failure is generated. In a semiconductor relay including a failure diagnosis circuit to be sent to the control computer, the failure diagnosis circuit includes a failure detection circuit that detects a failure of the plurality of control targets, and a failure diagnosis signal that is output in accordance with a type of the detected failure. A duty setting circuit for setting a duty, an oscillation circuit for outputting an oscillation pulse of a predetermined frequency, and the set duty while counting the number of oscillation pulses corresponding to the duty set by the duty setting circuit. A counter that outputs a failure diagnostic signal of the counter, and an output circuit that is driven based on the output of the counter. That.
[0012]
Therefore, according to the configuration of the third aspect, the failure diagnostic signal having a different duty is output according to the type of the failure detected for the control target. Therefore, it is necessary to simultaneously transmit synchronization signals for synchronization. Therefore, a failure diagnosis signal corresponding to a plurality of types of failures can be efficiently transmitted without causing the system to be complicated.
[0013]
According to a fourth aspect of the present invention, in the semiconductor relay according to the third aspect, the failure diagnosis circuit includes: a failure detection circuit that detects a failure of the plurality of control targets; A plurality of duty setting circuits for setting the duties of the plurality of failure diagnosis signals having different levels; an oscillating circuit for outputting an oscillation pulse having a predetermined frequency; and a number of oscillations corresponding to the duties set by the plurality of duty setting circuits A plurality of counters that output a failure diagnosis signal of the set duty while counting pulses; a plurality of output circuits each driven based on outputs of the plurality of counters; and a plurality of output circuits. A level setting resistor for setting the voltage level of the output signal to a different value.
[0014]
When setting many types of faults to be detected by the fault diagnosis circuit, it is necessary to set a small duty interval of the fault diagnosis signal corresponding to each fault. In this case, the fault diagnosis on the control computer side is performed. The signal determination accuracy will be reduced.
[0015]
In this regard, according to the configuration of claim 4, since a plurality of fault diagnosis signals having different output levels and duties are superimposed on the type of fault detected by the fault diagnosis circuit and transmitted, Even if the duty interval is increased, the types of faults detected can be increased, and a detailed abnormal state can be detected.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a semiconductor relay for controlling secondary air supply in an exhaust system of a vehicle-mounted engine will be described with reference to FIGS.
[0017]
In the present embodiment, a secondary air supply system is provided in the exhaust passage of the engine (not shown) in order to purify carbon monoxide and hydrocarbons in the exhaust gas, such as when starting the engine from a cold state. The air is supplied via. As shown in FIG. 1, such a secondary air supply system is opened and closed so as to permit or prohibit the flow of air in the supply passage and an air pump 24 that supplies air to a supply passage connected to the exhaust passage. And an electromagnetic opening / closing valve 28. When supplying air to the exhaust passage, the air pump 24 is driven with the electromagnetic on-off valve 28 opened. When air is supplied to the exhaust passage, carbon monoxide and hydrocarbons in the exhaust gas are oxidized by oxygen in the air to produce carbon dioxide and water, so the carbon monoxide and hydrocarbons in the exhaust gas are purified. You.
[0018]
As shown in FIG. 1, an engine computer 10 as a higher-level control computer performs various controls relating to an operating state of an engine (not shown). The engine computer 10 outputs a pump drive request signal for driving the air pump 24 to the semiconductor relay 20 via one control signal line CL1 and drives the electromagnetic on / off valve 28 to open and close. Is output via one control signal line CL2.
[0019]
The engine computer 10 is configured to input a failure diagnostic signal from the semiconductor relay 20 via one diagnostic signal line JL. In the engine computer 10, the diagnostic signal line JL is always connected to the pull-up resistor R0. Thus, the potential of the power supply V0 is maintained.
[0020]
The semiconductor relay 20 includes a drive control circuit 21 for controlling the drive of the electromagnetic on-off valve 28 and the air pump 24. The drive control circuit 21 controls the conduction of the drive transistor 27 based on the valve drive request signal input from the engine computer 10, thereby supplying power from the vehicle power supply 25 to the electromagnetic on-off valve 28 via the drive signal line DL2. The drive control of the electromagnetic opening / closing valve 28 is performed. The drive control circuit 21 controls the conduction of the drive transistor 23 based on the pump drive request signal input from the engine computer 10 to supply power from the vehicle power supply 25 to the air pump 24 via the drive signal line DL1. Then, drive control of the air pump 24 is performed.
[0021]
Further, the semiconductor relay 20 is provided with a failure diagnosis circuit 22. The failure diagnosis circuit 22 detects disconnection or short-circuit failure of the control signal lines CL1 and CL2, the diagnosis signal line JL, the drive signal lines DL1 and DL2, and the like, and detects abnormal heat generation of the semiconductor relay 20. Then, the failure diagnostic circuit 22 sends a failure diagnostic signal corresponding to the detected failure to the engine computer 10 via the one diagnostic signal line JL. In the present embodiment, the failure diagnosis circuit 22 outputs a failure diagnosis signal set in advance to a different duty in accordance with the type of the detected signal line failure.
[0022]
The failure diagnosis circuit 22 will be described in detail. The failure diagnosis circuit 22 includes a failure detection circuit 30, a duty setting circuit 31, an oscillation circuit 32, a counter 33, an output transistor 34, and the like. The failure detection circuit 30 detects which of the control signal lines CL1 and CL2, the diagnostic signal line JL and the drive signal lines DL1 and DL2 has failed, or whether the semiconductor relay 20 is in an abnormal heat generation state. In the present embodiment, for example, the disconnection / short fault of the control signal lines CL1 and CL2 and the diagnostic signal line JL is set to the same type of first fault. The disconnection / short fault of the drive signal line DL1 and the disconnection / short fault of the drive signal line DL2 are set to a second fault and a third fault, respectively, different from the first fault. The abnormal heat generation of the semiconductor relay 20 is set to a fourth failure different from the first, second, and third failures. When none of the first, second and third faults is detected by the fault detection circuit 30, it is detected that all the signal lines CL1, CL2, JL, DL1 and DL2 are normal.
[0023]
The duty setting circuit 31 sets the duty of the failure diagnosis signal to be transmitted based on the failure detected by the failure detection circuit 30. In the present embodiment, for example, the duty is set to 0% for a first failure that is a failure of the control signal lines CL1 and CL2 and the diagnosis signal line JL, and the duty is set for a second failure that is a failure of the drive signal line DL1. Is set to 20%, and the duty is set to 40% for the third failure which is a failure of the drive signal line DL2. The duty is set to 60% for the fourth failure when the semiconductor relay 20 generates abnormal heat. The duty is set to 80% for normal diagnosis of all signal lines CL1, CL2, JL, DL1, and DL2.
[0024]
The oscillating circuit 32 outputs an oscillating pulse of a predetermined frequency.
The counter 33 counts the number of oscillation pulses corresponding to the duty set by the duty setting circuit 31, and counts the duty corresponding to the first failure, the second failure, the third failure, and the normal diagnosis. A failure diagnosis signal is output to output transistor.
[0025]
The output transistor 34 is connected to the diagnostic signal line JL via a level setting resistor R1. Therefore, when the output transistor 34 is turned on based on the failure diagnosis signal output from the counter 33, as shown in FIG. 2, the voltage of the power supply V0 is divided by the pull-up resistor R0 and the level setting resistor R1. A level failure diagnosis signal is sent to the engine computer 10.
[0026]
In FIG. 2, (a) is a failure diagnosis signal of duty 0% corresponding to the first failure, (b) is a failure diagnosis signal of duty 20% corresponding to the second failure, and (c) is a failure diagnosis signal of the third failure. A corresponding failure diagnosis signal with a duty of 40%, and (d) is a failure diagnosis signal with a duty of 60% corresponding to the fourth failure. In FIG. 2, (e) is a failure diagnosis signal with a duty of 80% corresponding to a normal diagnosis.
[0027]
According to the semiconductor relay 20 of the first embodiment configured as described above, the following effects can be obtained.
In the present embodiment, a failure diagnosis signal having a different duty is transmitted to the engine computer 10 in accordance with the type of failure detected by the failure diagnosis circuit 22, so that synchronization for synchronizing the failure diagnosis signal is performed. There is no need to transmit signals at the same time. Therefore, it is possible to efficiently transmit a failure diagnosis signal corresponding to a plurality of types of failures without complicating the system.
[0028]
(2nd Embodiment)
Next, a second embodiment in which the present invention is embodied in a semiconductor relay for controlling secondary air supply in an exhaust system of a vehicle-mounted engine will be described with reference to FIGS. In order to avoid redundant description, the same elements as those described in FIG. 1 are denoted by the same reference numerals.
[0029]
In the first embodiment, the failure diagnosis circuit 22 outputs a failure diagnosis signal having a different duty according to the type of failure detected by the failure detection circuit 30. This is because the disconnection / short fault of the control signal lines CL1 and CL2 and the diagnostic signal line JL is set as the same type of first fault, and faults diagnosed by the fault diagnosis circuit 22 are first fault, second fault, Since there are only five failures, namely, a third failure, a fourth failure, and a normal diagnosis, a failure diagnosis signal having a different duty is output according to the type of the failure.
[0030]
However, when setting many types of faults detected by the fault diagnosis circuit, it is necessary to set a small interval between the duties of the fault diagnosis signal corresponding to each fault. In this case, the accuracy of the failure diagnosis signal determination on the engine computer 10 side is reduced.
[0031]
Therefore, in the present embodiment, a plurality of fault diagnosis signals having different output levels and duties are superimposed on the type of fault detected by the fault diagnosis circuit and transmitted.
[0032]
That is, as shown in FIG. 3, the engine computer 10 outputs a pump drive request signal for driving the air pump 24 to the semiconductor relay 40 via one control signal line CL1, and the engine computer 10 A valve drive request signal for opening and closing the on-off valve 28 is output via one control signal line CL2.
[0033]
The engine computer 10 is configured to input a failure diagnostic signal from the semiconductor relay 40 via one diagnostic signal line JL. In the engine computer 10, the diagnostic signal line JL is always connected to the pull-up resistor R0. Thus, the potential of the power supply V0 is maintained.
[0034]
A failure diagnosis circuit 41 provided in the semiconductor relay 40 detects a disconnection / short failure of the control signal lines CL1 and CL2, the diagnostic signal line JL, the drive signal lines DL1 and DL2, etc., and responds to the detected failure. A failure diagnostic signal is sent to the engine computer 10 via the one diagnostic signal line JL.
[0035]
In the present embodiment, the failure diagnosis circuit 41 is configured to superimpose a plurality of failure diagnosis signals having different output levels and duties on the detected failure type and output the resultant signal.
[0036]
The failure diagnosis circuit 41 will be described in detail. The failure diagnosis circuit 41 includes a failure detection circuit 42, a first duty setting circuit 43, a second duty setting circuit 44, an oscillation circuit 32, a first counter 45, a second counter 46, Output transistors 47 and 48 are provided. The failure detection circuit 42 detects which of the control signal lines CL1 and CL2, the diagnostic signal line JL, and the drive signal lines DL1 and DL2 has a failure. In the present embodiment, for example, the disconnection / short failure of the control signal line CL1 is set to a fourth failure, the disconnection / short failure of the control signal line CL2 is set to a fifth failure, and the disconnection of the diagnostic signal line JL is set. -The short-circuit fault is set as the fifth fault. The disconnection / short fault of the drive signal line DL1 and the disconnection / short fault of the drive signal line DL2 are set to a sixth fault and a seventh fault, respectively. When none of the fourth to seventh faults is detected by the fault detection circuit 42, it is detected that all the signal lines CL1, CL2, JL, DL1, and DL2 are normal. The disconnection of the control signal line CL1 is detected as a fifth failure, the short-circuit failure of the control signal line CL1 is detected as a sixth failure, and the disconnection failure of the control signal line CL2 is detected as a seventh failure. You can also.
[0037]
The first duty setting circuit 43 sets the duty of a failure diagnosis signal to be transmitted based on the failure detected by the failure detection circuit 42 to, for example, 0%, 50%, and 100%. Further, the second duty setting circuit 44 sets the duty of the failure diagnosis signal to be transmitted based on the failure detected by the failure detection circuit 42 to 0%, 50%, and 100%.
[0038]
While the first counter 45 counts the number of oscillation pulses corresponding to the duty set by the first duty setting circuit 43, the failure of the duty corresponding to the fourth failure to the seventh and the normal diagnosis is performed. The diagnostic signal is output to the output transistor 47. While the second counter 46 is counting the number of oscillation pulses corresponding to the duty set by the second duty setting circuit 44, the failure of the duty corresponding to the fourth failure to the seventh and the normal diagnosis is performed. The diagnostic signal is output to the output transistor 48.
[0039]
The output transistor 47 is connected to the diagnostic signal line JL via a level setting resistor R2, and the output transistor 48 is connected to the diagnostic signal line JL via a level setting resistor R3 (R3 ≠ R2).
[0040]
Accordingly, when only the output transistor 47 is turned on based on the failure diagnosis signal output from the first counter 45, the voltage of the power supply V0 is pulled up as shown in FIGS. 4 (b) and 4 (c). A fault diagnosis signal of a voltage level divided by the resistor R0 and the level setting resistor R2 is transmitted to the engine computer 10. When only the output transistor 48 is turned on based on the failure diagnosis signal output from the second counter 46, the voltage of the power supply V0 is pulled up as shown in FIGS. 4 (d) and 4 (e). A failure diagnosis signal of a voltage level divided by the resistor R0 and the level setting resistor R3 is transmitted to the engine computer 10. Further, the output transistor 47 is turned on based on the failure diagnosis signal output from the first counter 45, and the output transistor 48 is turned on based on the failure diagnosis signal output from the second counter 46. Then, as shown in FIG. 4 (f), FIG. 4 (g), FIG. 4 (h), and FIG. 4 (i), the voltage of the power supply V0 is changed to the combined resistance of the pull-up resistor R0 and the level setting resistors R2 and R3. As a result, a failure diagnosis signal of the divided voltage level is sent to the engine computer 10.
[0041]
FIG. 4A shows a failure diagnosis signal when the duties of the first counter and the second counter are 0%. 4B is a failure diagnosis signal when the duty of the first counter is 50% and the duty of the second counter is 0%, and FIG. 4C is the failure diagnosis signal when the duty of the first counter is 100% and the second. This is a failure diagnosis signal when the duty of the counter is 0%. FIG. 4D shows a failure diagnosis signal when the duty of the first counter is 0% and the duty of the second counter is 50%. FIG. 4E shows that the duty of the first counter is 0%. This is a failure diagnosis signal when the duty of the second counter is 100%. FIG. 4F shows a failure diagnosis signal when the duty of the first counter is 50% and the duty of the second counter is 50%, and FIG. 4G shows the failure diagnosis signal when the duty of the first counter is 50% and the second This is a failure diagnosis signal when the duty of the counter is 100%. FIG. 4H shows a failure diagnosis signal when the duty of the first counter is 100% and the duty of the second counter is 50%, and FIG. 4I shows that the duty of the first counter is 100%. This is a failure diagnosis signal when the duty of the second counter is 100%.
[0042]
According to the semiconductor relay 40 of the second embodiment configured as described above, the following effects can be obtained.
In the present embodiment, a plurality of fault diagnosis signals having different output levels and duties are superimposed on the type of fault detected by the fault diagnosis circuit 41 and transmitted. Therefore, it is possible to increase the types of detected faults while suppressing a decrease in the accuracy of determining the fault diagnosis signal on the engine computer 10 side.
[0043]
The embodiment is not limited to the above, and can be modified as follows.
In each of the above embodiments, the semiconductor relay for controlling the secondary air supply in the exhaust system of the vehicle-mounted engine is embodied. However, a plurality of control targets are drive-controlled based on a drive request signal from a control computer, and the control target is controlled. The present invention may be applied to a semiconductor relay that detects a plurality of types of faults and sends a fault diagnosis signal to a control computer.
[0044]
Next, other technical ideas that can be grasped from the above embodiments will be described below.
(A) Drive control of a plurality of control targets based on a drive request signal from a control computer, detection of a plurality of types of faults of the control target, and transmission of a fault diagnosis signal corresponding to the detected fault to the control computer. A failure diagnosis signal having a different duty depending on the type of the detected failure.
[0045]
(B) A method for transmitting fault information in a semiconductor relay according to (a), wherein a plurality of fault diagnostic signals having different voltage levels are superimposed and output.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a semiconductor relay according to a first embodiment.
FIGS. 2A to 2E are explanatory diagrams showing a failure diagnosis signal according to the first embodiment.
FIG. 3 is a schematic view showing a semiconductor relay according to a second embodiment.
FIGS. 4A to 4I are explanatory diagrams illustrating a failure diagnosis signal according to the second embodiment.
[Explanation of symbols]
Reference numeral 10: an engine computer as a control computer; 20, 40: a semiconductor relay; 22, 41: a failure diagnosis circuit; 24, an air pump as a control target; 28, an electromagnetic on-off valve as a control target; 31, 43, 44: duty setting circuit, 32: oscillation circuit, 33, 45, 46: counter, 34, 47, 48 ... output transistors as output circuits, R1, R2, R3 ... level setting resistors.

Claims (4)

Fault diagnosis for controlling a plurality of control targets based on a drive request signal from a control computer, detecting a plurality of types of faults of the control target, and transmitting a fault diagnosis signal corresponding to the detected faults to the control computer. In a semiconductor relay with a circuit,
The semiconductor relay, wherein the failure diagnosis circuit outputs a failure diagnosis signal having a different duty according to the type of the detected failure. The semiconductor relay according to claim 1,
The semiconductor relay, wherein the failure diagnosis circuit superimposes and outputs a plurality of failure diagnosis signals having different voltage levels according to the type of the detected failure. A failure diagnosis circuit for controlling the drive of a plurality of control targets based on a drive request signal from a control computer, detecting a failure of the plurality of control targets, and transmitting a failure diagnosis signal corresponding to the detected failure to the control computer. In a semiconductor relay with
The failure diagnosis circuit,
A failure detection circuit that detects a failure of the plurality of control targets;
A duty setting circuit that sets the duty of the failure diagnosis signal according to the type of the detected failure;
An oscillation circuit that outputs an oscillation pulse having a predetermined frequency;
A counter that outputs a failure diagnosis signal of the set duty while counting the number of oscillation pulses corresponding to the duty set by the duty setting circuit;
An output circuit driven based on an output of the counter. The semiconductor relay according to claim 3,
The failure diagnosis circuit,
A failure detection circuit that detects a failure of the plurality of control targets;
A plurality of duty setting circuits for setting duties of a plurality of failure diagnosis signals having different voltage levels according to the type of detected failure;
An oscillation circuit that outputs an oscillation pulse having a predetermined frequency;
A plurality of counters that output a failure diagnosis signal of the set duty while counting the number of oscillation pulses corresponding to the duty set by the plurality of duty setting circuits,
A plurality of output circuits each driven based on the outputs of the plurality of counters,
And a level setting resistor for setting voltage levels of output signals of the plurality of output circuits to different values.

Images