JPH0117823Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a vehicle electronic control device, and more particularly to a vehicle electronic control device installed in a vehicle equipped with a radio or an ignition device.

[Background of the idea]

The engine control system is equipped with a solenoid valve to control the ignition device and fuel system.
High frequency noise is generated when it is OFF.

On the other hand, digital control is employed in engine control systems to perform engine control with high precision. In this case, engine control is performed based on a control program created in advance to perform control according to each operating state of the engine. Therefore, if the high frequency noise flows into the control circuit of the engine control system through the signal line, it will cause malfunction.
For example, even though the engine is rotating at high speed, a malfunction of the control circuit may cause the engine to be controlled as if it were in a stopped state, which could lead to a car accident.

Recently, radio wave interference due to high frequency noise generated by automobiles has become a problem in automobile radios, etc., and there is a trend toward legal regulation.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic control device for a vehicle that prevents malfunctions caused by high frequency noise in an engine control system and eliminates high frequency noise in order to cope with the above-mentioned radio interference.

[Summary of the idea]

In order to achieve this purpose, the present invention
The vehicle is equipped with a radio or ignition device, and consists of an electronic circuit to which at least the sensor, actuator, and wiring from the power source can be connected, and the electronic circuit is mounted on an insulating substrate, and the insulating substrate is shielded. In a vehicle electronic control circuit enclosed in a case, each of the wirings is connected to the electronic circuit via a connector whose part is exposed on the surface of the shield case, and from the connector inside the shield case. The connection wiring to the electronic circuit is made to pass through a hole in ferrite fixed to the surface of the insulating substrate.

[Example of idea]

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows a control device for the entire engine system. In the figure, intake air passes through an air cleaner 2, a throttle chamber 4, an intake pipe 6, and is supplied to a cylinder 8. The gas burned in the cylinder 8 passes through the exhaust pipe 10 from the cylinder 8 and is discharged into the atmosphere.

The throttle chamber 4 is provided with an injector 12 for injecting fuel, and the fuel injected from the injector 12 is atomized within the air passage of the throttle chamber 4 and mixed with intake air. A mixture is formed, and this mixture is supplied to the combustion chamber of the cylinder 8 through the intake pipe 6 when the intake valve 20 is opened.

A throttle valve 14 is located near the outlet of the injector 12.
16 are provided. The throttle valve 14 is configured to mechanically interlock with the accelerator pedal and is driven by the driver. On the other hand, the throttle valve 16 is arranged so as to be driven by the diaphragm 18, and is fully closed when the air flow rate is small.As the air flow rate increases, the negative pressure on the diaphragm 18 increases, so that the throttle valve 16 It begins to open and suppresses the increase in inhalation resistance.

An air passage 22 is provided upstream of the throttle valves 14 and 16 of the throttle chamber 4.
2 is an electric heating element 2 that constitutes an air flow rate detector.
4 is disposed, and a periodic electric signal that changes depending on the air flow rate determined from the relationship between the air flow rate and the amount of heat transfer of the heating element 24 is extracted. Since the heating element 24 is provided within the air passage 22, it is protected from high-temperature gas generated when the cylinder 8 backfires, and is also protected from being contaminated by dust in the intake air. The outlet of the air passage 22 is opened near the narrowest part of the bench lily, and the inlet thereof is opened on the upstream side of the bench lily.

Fuel supplied to the injector 12 is supplied from a fuel tank 30 to a fuel pressure regulator 38 via a fuel pump 32, a fuel damper 34, and a filter 36. On the other hand, pressurized fuel is supplied from the fuel pressure regulator 38 to the injector 12 via a pipe 40.
From the fuel pressure regulator 38 to the fuel tank 3 so that the difference between the pressure in the intake pipe 6 where fuel is injected from the fuel tank 3 and the fuel pressure to the injector 12 is always constant.
0 through a return pipe 42.

The air-fuel mixture taken in from the intake valve 20 is transferred to the piston 5.
0 and is combusted by the spark from the ignition plug 52, and this combustion is converted into kinetic energy. The cylinder 8 is cooled by cooling water 54,
The temperature of this cooling water is measured by a water temperature sensor 56, and this measured value is used as the engine temperature. A high voltage is supplied to the ignition plug 52 from an ignition coil 58 in accordance with the ignition timing.

Further, the crankshaft (not shown) is provided with a crank angle sensor that outputs a reference angle signal and a position signal at every reference crank angle and every fixed angle (for example, 0.5 degrees) according to the rotation of the engine.

The output 60 of the crank angle sensor, the output 56A of the water temperature sensor 56, and the electrical signal 24A from the heating element 24 are input to a control circuit 70 consisting of a microcomputer, etc., and are processed by the control circuit 70, and the output of this control circuit 70 is The injector 12 and the ignition coil 58 are driven by the injector 12 and the ignition coil 58.

The operation of the engine described above will be explained with reference to FIG. 2. FIG. 2A shows the timing of fuel injection from the injector in a four-cylinder engine. The horizontal axis is the rotation angle of the engine crankshaft, and hatching indicates the intake stroke of each cylinder. As is clear from the figure, the crank angle
There is an intake stroke for every 180 degrees, cylinder 1 between 0 degrees and 180 degrees, cylinder 3 between 180 degrees and 360 degrees, cylinder 4 between 360 degrees and 540 degrees, and cylinder 4 between 540 degrees and 720 degrees. Between degrees is the second cylinder.

As shown in FIG. 2B, a reference crank angle pulse is generated every 180 degrees of the crank angle, the injector 12 is opened based on this pulse, and the calculation is processed by the control circuit 70 based on the already measured data. Based on the result, the opening time of the injector 12 is determined. The fuel injection time, which is the valve opening time of the injector 12, is shown in FIG. 2C.

Next, the control circuit 70 will be explained based on FIG. FIG. 3 shows a concrete block of the control circuit 70, and in the figure, the input signals can be roughly classified into three types. That is, first, there are analog inputs sent from the output 24A of the heating element 24 that detects the amount of intake air, the output 56A of the sensor 56 that detects engine cooling water, and the like. These analog inputs are input to a multiplexer (hereinafter referred to as MPX) 100, and the output of each sensor is selected in parts from time to time and sent to an analog-to-digital converter (hereinafter referred to as ADC) 102.
2, it is converted to a digital value. The second information is input as an on/off signal, which is, for example, a signal θTH indicating the fully closed state of the throttle valve.
There is a signal 104A sent from a switch 104 that operates in conjunction with the throttle valve. This signal can be handled as a 1-bit digital signal.

Furthermore, the third possible input signal is a signal input as a pulse train, such as a reference crank angle signal (hereinafter referred to as CRP) or a position pulse signal (hereinafter referred to as CPP).
These signals are sent from 06. In the case of a 4-cylinder engine, CRP is output every 180 degrees of crank angle.
For 6 cylinders, the output is every 120 degrees, and for 8 cylinders, it is output every 90 degrees. CPP is output every 0.5 degree of crank angle, for example.

The CPU 108 is a processing central unit that performs digital arithmetic processing, and the ROM1
10 is a storage element for storing control programs and fixed data, and RAM 112 is a readable and writable storage element. The input/output interface circuit 114 inputs the input signal to the ADC1.
02 and sensors 104 and 106, and sends the signal to the CPU 108. Also, CPU10
The signal from 8 is sent to the injector 12 and the ignition coil 58 as a signal INJ or IGN. Note that voltage is applied from the power supply terminal 116 to each circuit and element constituting the control circuit 70, but their description is omitted in the drawing. Furthermore, the injector 12 and the ignition coil 58 are each provided with an electromagnetic coil for driving the valve and a primary coil for accumulating electromagnetic energy, one end of which is connected to the power supply terminal 116, and the other end of the coil. It is connected to the input/output interface circuit 114, and the current flowing into the injector 12 and the ignition coil 58 is controlled.

Next, an embodiment of the vehicle electronic control device according to the present invention will be described based on FIGS. 4 to 12. FIG. 4 is an explanatory diagram showing the mounting structure of the control circuit 70 shown in FIG.
It is stored in 2. And shield case 20
A connector 206 fixed to the side of the connector 2 connects an external signal line to the control circuit 70.

In the above configuration, the signal is generated within the control circuit 70 and flows out of the control device 208, or is generated from the outside via the signal line 204 to the control device 208.
As a means of removing high frequency noise flowing into the
As shown in FIGS. 5 and 6, the terminal conductor (hereinafter referred to as connector pin) of the connector 206 is connected to the signal line 204 from the outside and the control circuit 70 via an LC filter for blocking high frequency components. It is proposed to do so.

This includes the connector pins Tx (x=1, 2,..., n) of the connector 206 and the input terminals of the printed pattern of the internal circuit (control circuit 70) as shown in FIG. (not shown) Sx (x=1,
2, . It is removed by bypassing with Cx.

However, when using an LC filter, as mentioned above, the number of connector pins of the connector is
It is necessary to provide an LC filter, which results in an increase in the number of parts and an increase in the space occupation rate of the control circuit, which is disadvantageous when considering cost and the limited space of the engine control device.

7 and 8 are explanatory diagrams showing the mounting structure of the control circuit 70 showing one embodiment of the present invention, and FIG.
The difference from this figure and FIG. 6 is that LC filters are not provided for the connector pins T ₁ to _{T o} of the connector 206, and the connector pins T ₁ are attached to a plate 214 of a ferromagnetic material such as ferrite as shown in FIG. 10. Through-holes P 1 to _{P o} are bored corresponding to the through-holes P ₁ to _{P o} , and the connector pins T ₁ to _{T o} are passed through the through-holes P ₁ to _{P o} , respectively, to connect the signal line 204 from the outside and control. This is the point connected to the input terminal Sx (x=1, 2, . . . n) of the printed pattern of the printed circuit board 200 on which the circuit 70 is mounted.

FIG. 11 shows an equivalent circuit in which the above connector pins (T ₁ -T _o ) are inserted into the through holes P ₁ -P _o of the ferrite plate 214. In the same figure, the terminal
High frequency noise voltage that enters from the outside through Tx (corresponds to connector pins T ₁ to _{T o} ) or that occurs inside the control circuit 70 and flows out to the outside is induced in the equivalent primary coil, and is induced in the equivalent secondary coil L2. A back electromotive force is generated, but since the coil L2 is short-circuited, the high frequency noise voltage disappears. According to experiments
It has been found that high frequency noise can be removed more effectively than when using an LC filter.

Next, another embodiment of the present invention is shown in FIG. In this embodiment, as shown in FIG. 10, _the connector pins _Tx ( _x =1, ₂ , …
Through hole Px (x=1, 2,...n) for inserting n)
A hollow cylindrical body made of ferrite with
Connect FBx (x=1, 2,...n) to the connector pin T ₁
~ disposed at a position opposite to T _o , and the hollow cylindrical body
The outer peripheral walls of the FBx are integrally molded with resin 216 or the like. This embodiment has the same effects as the previous embodiment, but is further advantageous in terms of cost compared to the previous embodiment which uses ferrite plates because it is configured to partially use ferrite.

[Effect of idea]

In the embodiment of the vehicle electronic control device according to the present invention, ferrite is used as the ferromagnetic material for the purpose of explanation, but the present invention is not limited to this. It goes without saying that the vehicle electronic control device according to the present invention can also be used in general electronic devices other than engine control systems.

As described above, according to the present invention, high frequency noise generated in the engine control system can be removed, so malfunction of the control circuit can be prevented, and safety in driving the vehicle can be ensured.

Furthermore, compared to the case where an LC filter is used, the number of parts can be reduced, and the number of manufacturing steps can also be reduced, leading to cost reductions.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the control device for the entire engine system, Fig. 2 is a time chart showing the operation of the engine, Fig. 3 is a block diagram of the engine control circuit, and Fig. 4 is the implementation structure of the engine control circuit. Fig. 5 is a plan view showing the mounting structure of the control circuit when using an LC filter, Fig. 6 is its front view, and Fig. 7 is the implementation of the control circuit showing an embodiment of the present invention. A plan view showing the structure, FIG. 8 is a front view thereof, FIG. 9 is an explanatory diagram when an LC filter is used, and FIG. 10 is an explanation showing the structure of a ferrite plate used in an embodiment of the present invention. 11 is a diagram showing an equivalent circuit of ferrite, and FIG. 12 is an explanatory diagram showing a main part of another embodiment of the present invention. 70...control circuit, 200...printed circuit board,
202... Shield case, 204... Signal line,
206... Connector, 214... Ferrite plate, T ₁ to _{T o} ... Conductor for connector terminal, P ₁ to _{P o} ...
...through hole.

Claims (1)

[Scope of utility model registration request] The vehicle is equipped with a radio or ignition device, and consists of an electronic circuit to which at least the sensor, actuator, and wiring from the power source can be connected, and the electronic circuit is mounted on an insulating substrate, and the insulating substrate is shielded. In a vehicle electronic control circuit enclosed by a case, each of the wirings is connected to the electronic circuit via a connector whose part is exposed on the surface of the shield case, and from the connector inside the shield case. An electronic control device for a vehicle, wherein each connection wiring to the electronic circuit is made to pass through each hole formed in a ferrite fixed to the surface of the insulating substrate.