JPH0681915B2 - Reverse rotation prevention device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse rotation preventing device for an internal combustion engine that detects reverse rotation of the internal combustion engine and immediately stops the rotation thereof.

[Conventional technology]

Conventionally, as this kind of device, two position signals which are deviated by a predetermined angle in synchronization with the rotation of the internal combustion engine are generated in the position signal generating means, and each position generated in the position signal generating means in the forward rotation and the reverse rotation. It has been considered to detect the reverse rotation by utilizing the fact that the generation phases of the signals are opposite and to cut off the ignition of the internal combustion engine (for example, JP-A-55-13764).

[Problems to be solved by the invention]

However, in the above-described conventional one, since the reverse rotation can be discriminated only when the internal combustion engine reverses from the normal rotation and the generation phases of the two position signals are opposite to the normal rotation, the normal rotation is switched to the reverse rotation. In the case of crossing, there is a time delay in determining the reverse rotation, and there is a problem that the reverse rotation continues for a certain time.
There is also the problem that another position sensor is required to detect the reverse rotation.

Therefore, it is an object of the present invention to quickly determine the reverse rotation of an internal combustion engine, prevent the reverse rotation immediately, and not require a new position sensor to prevent the reverse rotation.

[Means for solving problems]

Therefore, according to the present invention, as shown in FIG. 1, reference signal generating means for generating a reference signal at a reference position in synchronism with the rotation of an internal combustion engine, and in one cycle of the reference signal in synchronism with the rotation of the internal combustion engine. Angle signal generating means for generating a plurality of angle signals of a predetermined value or more, and engine electronic control means for receiving at least one of the ignition timing and the fuel injection amount of the internal combustion engine by inputting the angle signal and the reference signal. An angle signal counting unit that counts the angle signal by being repeatedly reset in synchronization with the generation period of the reference signal, and whether the count value corresponding to the generation period of the reference signal in the angle signal counting unit is the predetermined value. If it is determined that the internal combustion engine is rotating in the reverse direction, the count value determining means determines whether the internal combustion engine is rotating in the reverse direction. And it provides a backstop for an internal combustion engine and a cutting means for cutting at least one of the fuel and.

[Action]

As a result, when the internal combustion engine switches from normal rotation to reverse rotation, the number of angle signals counted by the angle signal counting means during one cycle of the reference signal becomes smaller or larger than a predetermined value, and thus the count value becomes a predetermined value. When it is no longer the case, the count value determining means immediately determines that the internal combustion engine has reversed, and drives the cutting means to stop the rotation of the internal combustion engine. Further, since the angle signal and the reference signal input for detecting the reverse rotation are originally used for controlling the internal combustion engine, it is not necessary to provide a position sensor separately.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 2 is a block diagram showing the overall configuration of an embodiment of the device of the present invention, and a 2-cycle 2-cylinder will be described as an example. Reference numeral 1 denotes a reference signal signal rotor, which has two magnetic teeth on the outer circumference and is attached to the crankshaft so as to rotate once for each crankshaft rotation of the internal combustion engine. Reference numeral 2 is a reference signal pickup coil arranged at a position facing the teeth of the reference signal signal rotor 1. One end of an output end of the reference signal pickup coil is the reference signal G.
Is input to the engine control unit (hereinafter referred to as ECU) 11, and the other end is connected to the ground 9.
The reference signal G is output at a crank angle (CA) of 10 ° before the top dead center (BTDC) of the first and second cylinders of the internal combustion engine. 6 is a signal signal rotor for angle signals, which has 24 magnetic teeth on the outer periphery at equal intervals, and the crankshaft 1
It is attached to the crankshaft so that it rotates once per revolution.
Reference numeral 7 is an angle signal pickup coil arranged at a position facing each tooth of the angle signal signal rotor 6, one end of the output end of which is input to the ECU 11 as the angle signal Ne and the other end is connected to the ground 9. . This angle signal Ne is output every 15 ° CA crank. Reference numeral 10 is another sensor signal, which is the ECU 1 together with the reference signal G and the angle signal Ne.
1 is input, and based on the information, an optimal ignition timing and fuel injection amount are calculated by a microcomputer (not shown) built in the ECU 11, and the igniter 12 and the injector 13 are respectively driven by these calculation outputs. .

3 and 4 show the reference signal G, the angle signal Ne, and the output state of the Ne counter when the internal combustion engine rotates in the normal direction and when the reverse rotation occurs.

During normal rotation of the internal combustion engine, as shown in FIGS. 3 (a) and 3 (b), there are 12 angle signals Ne in one cycle of the reference signal G, and after the Ne counter generates the reference signal G. When reset (cleared) by the angle signal Ne next to, the count value immediately before the reset of the Ne counter is always 11 as shown in FIG. 3 (c).
Becomes

However, immediately after the rotation of the internal combustion engine is switched from normal rotation to reverse rotation, as shown in FIGS. 4 (a) and 4 (b), the last reference signal G during forward rotation and the first reference signal G during reverse rotation are provided. There is less or more than 12 angle signals Ne between and, and the count value immediately before the Ne counter is reset at this time is a value smaller or larger than 11 which is a predetermined value as shown in FIG. 4 (c). Becomes

Therefore, it is possible to immediately determine whether the internal combustion engine is rotating normally or reversely based on the count value of the Ne counter.

5 to 7 show respective flowcharts for determining the difference in signal output state, detecting reverse rotation and operating the reverse rotation preventing device. Hereinafter, description will be made from FIG.

FIG. 5 shows an initialization routine. In step 20, it is determined whether or not the starter has been turned on. When the starter is turned on, the routine proceeds to step 21, the value of the Ne counter is set to 11, and the routine proceeds to step 22 to clear the reverse rotation detection flag FR and proceed to step 23 to clear the G flag XG and proceed to step 30 in FIG.

FIG. 6 shows a reverse rotation determination routine. In step 30, it is determined whether or not the G signal is input. If the G signal has not been input, the routine proceeds to step 34, where it is judged if the G flag is 1 or not. At this time, the G signal has not been input even once, so XG
Returns 0 (waits for input of G signal). If the G signal is input again in step 30, the process proceeds to step 31, the G flag XG is set to 1, and the process proceeds to step 32. In step 32, it is judged whether or not the value of the Ne counter is 11. At this time, since the Ne counter is set to 11 in step 21 of FIG. 5, the process proceeds to step 33. In step 33, the Ne counter value is cleared (reset) by the Ne signal input immediately after the G signal.
Then, the routine proceeds to step 34, where it is judged if the G flag XG is 1 or not. At this time, since the flag XG is 1, the process moves to step 35 and counts up the Ne counter for each Ne signal input and returns. The process proceeds to step 30 again and it is determined whether or not the next signal is input. If it has not been input, the process proceeds from step 34 to step 35, in which the Ne counter is incremented for each Ne signal. When the next G signal is input in step 30, the process proceeds from step 31 to step 32. In step 32, it is determined whether or not the value of the Ne counter is 11, and if it is 11, steps 33, 34,
Proceed to 35. If it is not 11, the routine proceeds to step 36, where the reverse rotation detection flag FR is set to 1 and the routine returns.

FIG. 7 shows a reverse rotation prevention processing routine.
In step 36 of FIG. 6, it is determined whether the reverse rotation detection flag R has become 1. If 1, go to step 41,
The fuel is cut off by stopping the operation of the injector 13, and then the routine proceeds to step 42 where the ignition is cut by stopping the operation of the igniter 12 to stop the engine.

As described above, the present embodiment has the reference signal and the angle signal, counts the angle signal to determine whether the count value of the angle signal when the reference signal is generated is the predetermined value, and if the predetermined value is not obtained, It is characterized in that it is judged that reverse rotation has occurred, and either one or both of ignition and fuel are cut so that the reverse rotation does not continue.

Although the present invention is applied to the two-cycle, two-cylinder internal combustion engine in the above-described embodiments, the present invention can be applied to any number of cylinders of the internal combustion engine, and the reverse rotation of the internal combustion engine can be quickly determined. Therefore, if the present invention is applied to a 4-cycle internal combustion engine, it is possible to prevent backfire or the like that occurs during temporary reverse ignition of the 4-cycle internal combustion engine.

Further, in the above-described embodiment, it is determined whether or not the count value of the Ne counter is the predetermined value (11) from the generation of the reference signal 4 to the generation of the next angle signal Ne. , After the reference signal G is generated, n (where n is 2
If the Ne counter is cleared when the angle signals Ne are generated, a specific number of 1 to n-1 from the generation of the reference signal G until the Ne counter is cleared It may be possible to determine whether or not the count value of the Ne counter when a number of angle signals are generated is a predetermined value. In this case, it is necessary to reduce the predetermined value by the number of angle signals Ne that should be counted before the Ne counter is cleared.

〔The invention's effect〕

As described above, in the present invention, when the angle signal counted by the angle signal counting means does not reach the predetermined value during one cycle of the reference signal, the count value determining means immediately determines that the internal combustion engine has reversed. (Note that when the internal combustion engine switches from normal rotation to reverse rotation, it usually has a count value other than a predetermined value), the cutting means is driven to stop the rotation of the internal combustion engine, so the reverse rotation determination of the internal combustion engine can be performed quickly. Therefore, there is an excellent effect that the reverse rotation can be immediately prevented. Further, since the angle signal and the reference signal input for detecting the reverse rotation are originally used for controlling the internal combustion engine, it is not necessary to provide a position sensor separately.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a block diagram showing an embodiment of the device of the present invention, and FIGS. 3 and 4 are waveforms of respective parts at the time of forward rotation and when reverse rotation occurs in the above embodiment. Figure,
5 to 7 are flowcharts showing the initialization routine of the microcomputer, the reverse rotation determination routine, and the reverse rotation prevention processing routine in the above embodiment. 1 ... Reference signal signal rotor, 2 ... Reference signal pickup coil, 6 ... Angle signal signal rotor, 7 ... Angle signal pickup coil, 11 ... ECU, 12 ... Igniter, 13 ...
Injector.

Claims (4)

[Claims] 1. A reference signal generating means for generating a reference signal at a reference position in synchronism with the rotation of an internal combustion engine, and a plurality of reference signals having a predetermined value or more in one cycle of the reference signal in synchronism with the rotation of the internal combustion engine. An angle signal generating means for generating an angle signal, an engine electronic control means for inputting the angle signal and the reference signal to electronically control at least one of the ignition timing and the fuel injection amount of the internal combustion engine, and the reference signal An angle signal counting unit that repeatedly resets in synchronization with the generation period to count the angle signal, and determines whether or not the count value corresponding to the generation period of the reference signal in the angle signal counting unit is the predetermined value, If it is not the predetermined value, the count value determining means for determining that the internal combustion engine is reversely rotating, and if it is determined by the count value determining means that the internal combustion engine is reversely rotating, the ignition and fuel of the internal combustion engine are reduced. One backstop for an internal combustion engine and a cutting means for cutting. 2. The angle signal generating means is configured to generate angle signals that are n more than the predetermined value during one cycle of the reference signal, and the count value of the angle signal counting means is the reference signal. Is reset by the angle signal that is generated n times immediately after the occurrence of, and the count value determination means determines whether or not it is the predetermined value after the reference signal is generated and before the next angle signal is generated. The reverse rotation preventing device for an internal combustion engine according to claim 1 or 2. 3. The reverse rotation preventing device for an internal combustion engine according to claim 2, wherein n is 1. 4. The cutting of at least one of ignition and fuel by the cutting means is executed immediately when the count value judging means judges that the count value is not the predetermined value. The reverse rotation preventing device for an internal combustion engine according to any one of items 1 to 3.