JPH0737916B2 - Vehicle diagnostic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention outputs signals from switches and sensors that are input to a control device mounted on a vehicle, or outputs signals from the control device to actuators and the like. The present invention relates to a vehicle diagnostic device that checks output signals and the like.

[Problems to be Solved by Conventional Techniques and Inventions] In recent years, an engine mounted on a vehicle electronically controls an air-fuel ratio and the like to exhibit comfortable drivability, purify exhaust gas, and save energy. The fuel economy and engine output are being improved.

If the output signals of various sensors and switches that detect the engine state, or the output signals of various actuators such as injectors are not accurate, it will be difficult to control the engine accurately, which will reduce drivability, exhaust emissions or fuel consumption. Worse, and
It causes a reduction in engine output.

In recent complicated electronic control systems, it is difficult to immediately understand the cause of failure even if a failure occurs inside the control device, sensors, switches, actuators, etc. It is indispensable to equip a so-called hand computer, which is a vehicle diagnostic device that checks the data mode. This vehicle diagnostic device is disclosed, for example, in Japanese Patent Application Laid-Open No. 58-12848.

Conventionally, this type of vehicle diagnostic device includes a type having a power source inside the main body or an external connection type that takes in the power source mounted on the vehicle from a cigarette lighter or the like.

In the type having an internal power source, the size of the apparatus itself is increased and the total weight is increased accordingly, which causes inconvenience in operability and handling as a hand computer.

On the other hand, in the case of a type that receives an external voltage from a cigarette lighter or the like, it is necessary to separately connect the power supply connector and the communication connector at the time of vehicle diagnosis, which makes the connection work complicated.

[Object of the Invention] The present invention has been made in view of the above circumstances, and can reduce the size and weight of the device, is easy to handle, and has good connection workability and operability during diagnosis. The purpose is to provide a device.

[Means and Actions for Solving Problems] The present invention relates to a communication line provided in a main body of a vehicle diagnostic device which is connected to a control device mounted on a vehicle and checks an input signal and an output signal of the control device. And the power supply line are connected to the control device and the power supply of the vehicle through one connector, and the communication line and the power supply line of the device body can be connected to the vehicle side with one touch.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

The drawings show an embodiment of the present invention. FIG. 1 is an external view of a vehicle diagnostic device connected to a vehicle control device, FIG. 2 is a schematic block diagram of the vehicle diagnostic device, and FIG. 3 is vehicle control. It is a concrete block diagram of a device and a vehicle diagnostic device.

In the figure, reference numeral 1 is a vehicle such as an automobile, and 2 is a control device mounted on the vehicle 1 for performing air-fuel ratio control, etc. The central processing unit (CPU) 3 of this control device 2 and read / write memory (RAM) 4, a read-only memory (ROM) 5, an input interface 6, and an output interface 7 are connected via a bus line 8.

In addition, a cooling water temperature sensor 9 is connected to the input interface 6.
Water temperature signal Tw, the air-fuel ratio feedback signal λ of the O ₂ sensor 10, the intake air amount signal Q of the intake pipe negative pressure sensor 11, the vehicle speed signal S of the vehicle speed sensor 13, the throttle opening signal Trθ of the throttle opening sensor 15, the engine Data signals such as the rotation speed signal N of the rotation speed sensor 17, the air conditioner operation signal SWa of the air conditioner switch 12, and the idle operation signal S of the idle switch 14
Wi, neutral operation signal SW of neutral switch 16
Output signals of various sensors and switches that detect engine state parameters such as switch signals such as n are input.

The CPU 3 of the control device 2 performs arithmetic processing according to the program stored in the ROM 5 based on various signals such as the data signal and the switch signal, and outputs the data output value via the output interface 7 and the drive circuit 18. ,
It outputs to the canister control device 19, the EGR actuator 20, the idle control actuator 21, the ignition coil 22, and the injector 23, and controls the operations of these actuators.

Reference numeral 24 is a connector for external connection, which is a communication line 44 connected to the output interface 7 and the input interface 6.
And a power supply line 45 connected to the power supply Vcc of the vehicle 1 are connected.

Further, this external connection connector 24 is an input connector 26 of the vehicle diagnostic device body (so-called hand computer) 25.
To an adapter harness 27.

The vehicle diagnostic device main body 25 is permanently installed in a dealer service station or the like, and has a removable memory cartridge 34 mounted at its bottom via a connector 33. A plurality of the memory cartridges 34 are prepared corresponding to the programs of the control device 2 which differ for each model, and the internal ROM 41 stores a diagnostic program corresponding to each program.

Further, an ON / OFF operation switch 43 is provided on the upper portion of the vehicle diagnostic device body 25, and further an indicator unit 30 is provided on the front surface.
A display unit 31 and a keyboard unit 32 are provided.

In addition, inside the vehicle diagnostic device body 25, the bus line
A communication unit 28a, a calculation unit 28b, which are connected to each other via 35, and a power supply unit 29 which supplies a constant voltage flow to them are provided.

The power supply unit 29 and the input side of the communication unit 28a are connected to the input connector 26 via a power supply line 45a and a communication line 44a, respectively. The operation switch 43 is provided on the power line 45a.

Further, the communication unit 28a is provided with input / output units (I / O) 39, 40, and the arithmetic unit 28b is provided with a central processing unit (CPU) 36 and a read / write memory (RAM) 37. The ROM 41 is connected to the arithmetic unit 28b.

The switch signals of the switches 12, 14 and 16 are input to the input side of the input / output unit 40 from the output interface 7 of the control device 2 through the communication line 44a. Further, the indicator section 30 is connected to the output side of the input / output section 40. This indicator section 30 has the above switches 1
Multiple lamps corresponding to 2, 14 and 16 are installed, ON / OFF
The status is displayed by blinking.

On the other hand, the input side of the other input / output unit 39 is supplied with a work mode selection signal of the keyboard unit 32 and various data signals for driving actuators output from the output interface 7 of the control device 2. . Further, the output side of the input / output unit 39 is connected to the input interface 6 of the control device 2 via communication lines 44a, 44, and is also connected to the display unit 31.

Next, the operation of the embodiment having the above configuration will be described.

(Preparation Work) First, the model of the control device 2 of the vehicle 1 is identified, and the corresponding memory cartridge 34 is attached to the vehicle diagnostic device body 25. In addition, the external connection connector 24 of the control device 2
And the input connector 26 of the vehicle diagnostic device body 25 are directly connected to each other or via the adapter harness 27.

Then, when the operation switch 43 is turned on, the power source of the vehicle 1 is
The voltage of Vcc is direct or the above adapter harness 27
Is input to the power supply unit 29 of the vehicle diagnostic device main body 25 via the power supply unit 29, and a constant voltage is supplied from the power supply unit 29 to the communication unit 28a and the calculation unit 28b.

Therefore, it is not necessary for the vehicle diagnostic device main body 25 itself to have a power source, the size and weight can be reduced, and the diagnostic work can be performed while holding the device with one hand, so that the operability and handleability are good. Further, since the communication line 44a and the power supply line 45a share one input connector 26, the connection work is completed with one touch, and workability is good.

(Diagnosis work) For example, when diagnosing the air-fuel ratio during traveling, first, a key of the keyboard unit 32 is used to select a corresponding work mode (for example, F → 1 → 0).
→ ENT).

Then, the operation mode is read by the arithmetic unit 28b of the vehicle diagnostic device body 25, and the input / output unit (I / O) 39 of the communication unit 28a is read.
The output data request signal TX of the O ₂ sensor 10 is output from the above to the control device 2 of the vehicle 1 through the communication line 44a and the input connector 26.

Then, when the data signal RX of the O ₂ sensor 10 is input from the control device 2 to the calculation unit 28b of the vehicle diagnostic device body 25, the CPU 36 calculates this data, and the value is displayed on the display unit 31, for example, 0. , 75V, etc. are digitally displayed to inform the operator that the output value of the O ₂ sensor 10 is 0,75 (volt). The operator confirms this output value to diagnose whether the air-fuel ratio is rich or lean. When monitoring output signals of other sensors and output signals to actuators, a predetermined value is similarly displayed on the display unit 31 by pressing the corresponding mode key on the keyboard unit 32.

On the other hand, in the meantime, switch signals of various switches such as the air conditioner switch 12, the idle switch 14, the neutral switch 16 are input to the input / output unit 40 of the communication unit 28a, and the indicator unit 30 of the indicator unit 30 is supplied by these signals. The corresponding lamp turns on or off.

That is, for example, when the shift of the vehicle 1 is set to neutral, the neutral switch 16 is turned on, and the switch signal is transmitted from the input interface 6 of the control device 2 to the output interface 7 and the external connection connector 24. , Input to the input connector 26 of the vehicle diagnostic device body 25, and from the input connector 26, the communication unit 28a
Input to the input / output unit 40 of the indicator unit 30 connected to this input / output unit 40 Lights up.

Also, if the shift is set to a position other than neutral, the neutral switch 16 is turned off and the indicator unit 30 Turns off.

Although the operator has set the shift to neutral, Does not light up, or if the shift is not neutral If is lit, it is diagnosed that the neutral switch 16 is out of order.

Note that the operating states of other switches can be similarly checked.

[Effects of the Invention] As described above, according to the present invention, a communication line connected to a control device mounted on a vehicle and provided in a main body of a vehicle diagnostic device for checking an input signal and an output signal of the control device. Since the power supply line and the power supply line are connected to the control device and the power supply of the vehicle through one connector, it is not necessary to have a power supply in the device itself, and it is possible to reduce the size and weight and hold it with one hand. The handling becomes easier and the operability at the time of diagnosis is improved.

In addition, the connection between the signal line and the power line can be done with one touch, greatly improving the connection workability.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is an external view of a vehicle diagnostic device connected to a vehicle control device, FIG. 2 is a schematic block diagram of the vehicle diagnostic device, and FIG. 3 is vehicle control. It is a concrete block diagram of a device and a vehicle diagnostic device. 1 ... Vehicle, 2 ... Control device, 25 ... Vehicle diagnostic device main body, 26 ... Connector, 44a ... Communication line, 45a ... Power line,
Vcc ... power supply.

Claims (1)

[Claims] 1. A communication line and a power line provided in a main body of a vehicle diagnostic device, which is connected to a control device mounted on a vehicle and checks an input signal and an output signal of the control device, through one connector. A vehicle diagnostic device connected to the control device and a power source of the vehicle.