JP6334375B2 - Electronic control system - Google Patents

Description

  The present invention mainly relates to an electronic control device (hereinafter referred to as C / U) for controlling an engine and an automatic transmission, and more particularly to a control device mounted on an automobile, a marine machine, an agricultural machine, and a construction machine.

  In recent years, in an automatic transmission (hereinafter referred to as “AT”) and a continuously variable transmission (hereinafter referred to as “CVT”) for automobiles, control has become complicated and highly accurate for the purpose of improving fuel economy and comfort such as shift shock. Along with this, the number of input / output terminals of the control unit (hereinafter referred to as C / U) is also increasing. As a result, there is a problem that the number of C / U connector terminals is insufficient.

  Conventionally, measures such as adopting connectors with a large number of terminals and reducing the number of terminals by sharing input / output terminals have been taken. In any case, there was a trade-off relationship with disadvantages such as cost increase and function restrictions.

  In a circuit for driving a solenoid valve that controls A / T or CVT shift, for the purpose of reducing the number of terminals, the number of harnesses and terminals is reduced by dropping the GND side terminal of the solenoid valve to the transmission ground.

  Typical configuration diagrams are shown in FIGS. 2 and 3, the C / U 5 that operates upon receiving the power supply of the battery 1 includes a microcomputer 6 in which control software is installed, a switching circuit 11 for driving the solenoid valve 9, and a solenoid valve 9. There are a plurality of rectifying elements 10 for circulating current, the battery 1 and the C / U 5 are mounted in the engine room, the solenoid valve 9 for controlling the shift is mounted in the transmission, and is electrically connected by harnesses 14 and 16. Has been.

  In the configuration of FIG. 3, the solenoid valve drive signal output from the C / U 5 is configured to return to the C / U 5 via the harness 14, the solenoid valve 9, and the harness 16. This configuration is disclosed in Japanese Patent Application Laid-Open No. 2014-019398, and in Japanese Patent Application Laid-Open No. 2011-024383, although the polarity is opposite, the solenoid valve drive signal output from the C / U is returned to the C / U via the solenoid valve. This is a configuration conventionally used.

  In contrast, in the configuration of FIG. 2, the harness 16 that returns from the solenoid valve 9 of FIG. 3 to the C / U 5 is deleted, and instead, via the mission ground 4, the ground between the engine 3, the engine ground 2, and the harness 15, The structure which returns to GND of C / U5 is employ | adopted, and has become the structure which has enjoyed the merit which reduces a harness and the number of C / U5 terminals with respect to FIG. This configuration has also existed in the past and is also introduced in Japanese Patent Application Laid-Open No. 2014-019398.

  However, the circuit configuration of FIG. 3 has the following disadvantages compared to the circuit configuration of FIG.

  Regarding the current loop path when the switching circuit 11 is ON, the current loop path 20 in FIG. 2 is longer than the current loop path 22 in FIG. Is big. Further, the current loop path when the switching circuit 11 is OFF is longer than the current loop path 23 of FIG. 3 because the current loop path 21 of FIG. Large loop area. That is, FIG. 2 has a demerit that noise emission is larger and noise immunity is weaker than FIG.

JP2011-024383A JP 2014-019398 A

  An object of the present invention is to obtain a harness connection method capable of reducing noise emission of a solenoid valve control circuit and improving immunity by using a simpler technique than the prior art.

  In order to realize the above-described problem, the microcomputer 6 includes a solenoid valve 9 that performs a shift operation with the battery 1 and a C / U 5 that controls the solenoid valve, and the C / U 5 includes control software that controls the solenoid valve. And a switching circuit 11 and a reflux element 10 that recirculates the current flowing through the solenoid valve 9, the solenoid valve 9 GND side harness is connected to the mission earth 4, and the GND of the mission earth 4 and the C / U 5 is connected to the engine. A harness for a solenoid valve control circuit, wherein a harness branched from the GND harness 15 of the C / U 5 is connected to the mission ground 4 without passing through the engine ground 2 in a configuration in which the harness is connected via the ground 2. A connection method is proposed.

  By adopting the above configuration, it is possible to obtain a harness connection method capable of reducing noise emission of the solenoid valve control circuit and improving immunity by using a simpler technique than the conventional technique.

It is the harness connection method of the solenoid valve control circuit by the 1st Embodiment of this invention. It is the harness connection method of the solenoid valve control circuit by a prior art. It is the harness connection method of the solenoid valve control circuit by a prior art. 3 is a current loop path of a drainoid valve control circuit according to the prior art. 3 is a current loop path of a solenoid valve control circuit according to the first embodiment of the present invention;

  FIG. 1 is a first embodiment of a harness connection method for a solenoid valve control circuit according to the present invention. Hereinafter, the respective symbols will be described with reference to FIG.

  The C / U 5 operates with the battery 1 as a power source, controls the switching circuit 11 with the solenoid valve drive circuit 7 based on the instruction of the microcomputer 6 mounted on the C / U 5, and further supplies the current flowing through the solenoid valve 9 to the reflux element By recirculating at 10, the current flowing through the solenoid valve 9 mainly responsible for the shift control of the transmission is controlled.

  The battery 1 and the C / U 5 are mounted in the engine room, and the solenoid valve 9 is mounted in the mission, and is electrically connected between each of the harnesses.

  The current loop path flowing through the solenoid valve 9 is different when the switching circuit 11 is ON and OFF. As shown in FIG. 5, the current loop path 24 when the switching circuit 11 is ON and when the switching circuit 11 is OFF are shown. The current loop path 25 is divided.

  The current loop path 24 (see FIG. 5) when the switching circuit 11 is ON will be described.

  In the current loop path 24, the large loop area is the loop area of the power harness 13 and the GND harness 15, and the loop area of the solenoid valve control signal harness 14 and the current return harness 8. The former is the harness of the normal power supply and the GND. The loop area is small because of the parallel running, and the latter is the route from the engine room to the inside of the mission → the engine room, and there is a merit that the loop area becomes small because the harnesses run in parallel as in the former. (In the vehicle, an inefficient harness scooping that causes the harness to be broken apart is not employed.) This is easier to understand than FIG.

  In FIG. 2, when the switching circuit 11 is ON, the loop area of the current loop path 20 (see FIG. 4) includes the loop area of the power harness 13 and the GND harness 15, the solenoid valve control signal harness 14, and the ground 3 between the engine transmissions. Loop area. In both the former and the latter, the path for returning the current to the battery 1 flows through a path that continues from the mission ground 4 to the engine ground 2, and therefore does not run in parallel with the power supply harness 13 and the solenoid valve control signal harness 14. For this reason, since the return path from the load to the battery 1 passes through the vehicle-specific path with respect to the current forward path from the battery 1 to the load, a large loop area is formed. The current return harness 8 in FIG. 1 has the advantage that the current loop area is greatly reduced.

  Next, the current loop path 25 (see FIG. 5) when the switching circuit 11 is OFF will be described.

  The loop area of the current loop path 25 is the loop area of the solenoid valve control signal harness 14 and the current return harness 8. However, as described in the explanation at the time of turning on both harnesses, since the harnesses run together, the loop area is the loop area. Is small.

  On the other hand, in the current loop path 21 (see FIG. 4) of FIG. 2, the path after the solenoid valve 9 is mission ground 4 → engine ground 2 → GND harness 15 → C / U5. Form a large current loop without parallel running. It is clear that the current return harness 8 in FIG. 1 greatly reduces the current loop area.

  What is important in reducing the current loop area is the branch position of the GND branch point 16.

  The farther the branch position of the GND branch point 16 is from the GND terminal of the C / U5, the larger the current loop area becomes. Therefore, it is important that the branch position of the GND branch point 16 is as close as possible to the GND terminal of the C / U5. is there.

  By adopting the above harness connection configuration, the current loop area can be reduced without increasing the number of C / U terminals, and noise emission reduction and noise immunity improvement can be expected.

1 Battery 2 Engine Earth 3 Mission Ground between Engines 4 Mission Ground 5 C / U
6 Microcomputer 7 Solenoid valve drive circuit 8 Current return harness 9 Solenoid valve 10 Returning element 11 Switching circuit 12 Capacitor 13 Power supply harness 14 Solenoid valve control signal harness 15 GND harness 16 GND branch point 17 Solenoid valve GND side harness 20 Switching circuit of FIG. ON-state current loop path 21 FIG. 2 switching circuit OFF-state current loop path 22 FIG. 3 switching circuit ON-state current loop path 23 FIG. 3 switching circuit OFF-state current loop path 24 FIG. Current loop path when switching circuit of Fig. 1 is OFF

Claims (2)

A battery, a plurality of solenoid valves that perform a transmission speed change operation, a C / U that controls the plurality of solenoid valves, and a harness that connects the plurality of solenoid valves to the C / U or the ground,
The C / U includes a microcomputer in which control software for controlling the solenoid valve is mounted, a switching circuit for switching the current flowing through the solenoid valve, and a reflux element for returning the current flowing through the solenoid valve. ,
The solenoid valve GND side harness is connected to a mission ground, and the C / U GND harness branches and branches in a configuration in which the mission ground and the C / U GND are connected by a harness via an engine ground. An electronic control system characterized in that one harness is connected to a mission ground without passing through an engine ground.   2. The electronic control system according to claim 1, wherein a branch position of the GND harness is a distance within 10 cm from the GND terminal of the C / U.