JPH0463922A - Engine output control device - Google Patents

Abstract

PURPOSE:To suppress torque fluctuation caused by malfunction by changing a control condition of a normal output variable means to be a control condition of a malfunctioned output variable means when all other output variable means than at least one normally-operated output variable means are malfunctioned. CONSTITUTION:Control unit U achieves air/fuel ratio control, variable intake control and variable valve timing control. When the engine revolution by means of a sensor 60 is larger than the reference revolution NO, a control signal is outputted to solenoid valves 58, 59 with the judgement that the engine revolution is in a high-speed cam region, and a select pin of a valve timing variable means 12 in a bank 2 or 3 is set to a high speed mode. Judgement is made whether the select pin is actually set to a high speed mode by reading signals from a sensor 61, 62. When either of the right and left bank is not operated normally, the normally-operated bank 3 or 2 is changed to be set to a low speed cam mode so as to match it with the failured bank 2 or 3.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine output control device.

(Prior art) As seen in Japanese Patent Application Laid-Open No. 55-112814, the so-called so-called engine output is improved over a wide range by changing the valve timing of the intake valve or exhaust valve of the engine according to the operating condition. Engines equipped with variable valve timing mechanisms have been put into practical use. When this variable valve timing mechanism is applied to a so-called V-type engine, variable valve timing mW4 is provided in the - bank and the other banks, respectively.

However, in a device with multiple identical output variable means like this, if the output variable means of the - bank fails, the torque generated by this - bank and the other normally operating banks will be generated. There is a problem that the torque becomes different and the torque fluctuation becomes large.

To explain specifically using the above variable valve timing as an example,
If the - bank is stuck at the low-speed valve timing, and another bank becomes the high-speed valve timing, the - bank will be activated at the low-speed timing, and the other banks will be activated at the high-speed timing. Therefore, the torques generated between these two banks will be different.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to suppress the torque fluctuation caused by the failure of the - output variable means, assuming that the engine is equipped with a plurality of identical output variable means. An object of the present invention is to provide an engine output control device.

(Means for Solving the Technical Problem) In order to achieve the technical problem, in the present invention, in an engine provided with a plurality of identical output variable means, the control state of each of the output variable means is detected. a control state detection means for detecting a failure of each of the output variable means; and a failure detection means for detecting a failure of each of the output variable means; and a control state detecting means for detecting a failure of each of the output variable means; the control state of the output variable means.

A failure control means changes the control state of the failed output variable means.

(Operation, Effect) With the above configuration, if some of the output variable means fails, the normal control state of the output variable means is forced to be the same as the control state of the failed output variable means. will be changed to

Therefore, in the same operating state, the torque generated based on the normal output variable means and the torque generated based on the failed output variable means are the same, and the torque due to the failure of some output variable means is the same. Fluctuations can be prevented from occurring.

(Example) Hereinafter, an example of the present invention will be described based on the attached drawings.

In Fig. 1, 1 is the engine body;
is a so-called V-type engine having a right bank 2 and a left bank 3 arranged in a V-shape, each bank 2.
3 cylinder bore 4.

A piston 5 is fitted into each of the cylinders, and a combustion chamber 7 is defined by the piston 5 and the cylinder head 6. The cylinder head 6 has two intake ports 8 and one exhaust port 9, both of which open facing the combustion chamber 7. The intake port 8 is provided with an intake valve 10, and the exhaust port 9 is provided with an exhaust port 9. A valve 11 is provided to connect the intake valve 10 and the exhaust valve 11.
is opened and closed at a predetermined timing in synchronization with the rotation of the engine output shaft, and this timing is changed by a valve timing variable means 12, which will be described later.

The intake system 15 of the engine main body 1 includes, in order from the upstream side to the downstream side, a common intake pipe 16 and a surge tank 17.
, an independent intake pipe 18, and the common intake pipe 16 includes, in order from the upstream side to the downstream side, an air cleaner 19 and an air flow meter 2 for detecting the amount of intake air.
0, a throttle valve 21 as an output control valve is provided,
Further, a fuel injection valve 22 is provided at the downstream end of the independent intake pipe 18 so as to face the intake port 8 .

The independent intake pipes 18 are arranged to intersect with each other in the central space of the V bank sandwiched between the right bank 2 and the left bank 3, and have a long pipe length.
7 has an internal space divided by a partition wall 17a into an expansion chamber 23 for the right bank and an expansion chamber 24 for the left bank, and these expansion chambers 23 and 24 communicate with each other through a communication hole 25 formed in the partition wall 17a. has been done. Further, each of the enlarged chambers 23 and 24 is communicated with the longitudinally intermediate portion of the corresponding independent intake pipe 18 via a short conduit 26. A first on-off valve 27 is provided in the communication hole 25 provided in the partition wall 17a, and a second on-off valve 28 is provided in each of the conduits 26.

The first and second on-off valves 27.28 are both closed in the low-speed range to realize the intake dynamic effect under the long intake passage, while in the high-speed range, the two on-off valves 27.28 are closed together. are opened together to realize the intake dynamic effect under the short intake passage. Such a system is called a variable intake system and is well known in the art, so its details will be omitted.

An exhaust pipe 30 is connected to the exhaust port 9, and an 02 sensor 31 and a catalytic converter 32 are disposed in the exhaust pipe 30.

Regarding the valve timing variable means 12, FIG.
This will be explained based on FIG.

In FIGS. 2 and 3, reference numeral 40 is a camshaft;
This camshaft 40 is connected to the engine output shaft in a known manner.

The exhaust valve 11 includes a roller follower 41 that comes into sliding contact with an exhaust cam of a camshaft 40, and a rocker shaft 42.
It is driven to open and close via an exhaust rocker arm 43 pivotally connected to the exhaust rocker arm 43.

The intake valve 10 has a valve timing variable means 12 attached to its valve operating mechanism. That is, - intake valve 10
A low-speed rocker arm 44 that opens and closes the other intake valves 10, a low-speed rocker arm 45 that drives the other intake valves 10 to open and close, and a high-speed rocker arm 46 that drives these rocker arms 44 and 45 are provided. .4
5.46 is pivotally supported by the rocker shaft 47, and roller followers 44a, 4 of the low speed rocker arm 44.45
5a are in sliding contact with the low-speed cam of the camshaft 40, respectively, and are in sliding contact with the roller followers 46a of the high-speed rocker arm 46.
is in sliding contact with the high-speed cam of the camshaft 40 under the biasing force of a spring 48.

On the opposite side of the camshaft 40 from the rocker shaft 47, a first bottle hole 50 is formed across the high-speed rocker arm 46 and the low-speed rocker arm 44, and the first bottle hole 50 is formed between the high-speed rocker arm 46 and the low-speed rocker arm 45. A second bottle hole 51 is formed concentrically and on the same diameter as the first bottle hole 50, and a first select pin 52 is provided in the first bottle hole 50, and a first select pin 52 is provided in the second bottle hole 51. The second select pins 53 are respectively mounted movably in the axial direction,
Each of the select pins 52 and 53 is connected to a compression coil spring 54.
．． 55, it is biased towards the high speed rocker arm 46 side.

The bottle holes 50.51 are communicated within the high-speed rocker arm 46, and an oil chamber 57 is formed at the end of these bottle holes 50.51. Hydraulic oil is supplied and discharged by opening and closing valves 58 and 59 (see Figure 1). When the hydraulic oil in the oil chamber 57 is discharged, the select pin 52.53 is moved by the coil spring 54.5.
The intake valves 10 are moved to the bottle hole portion in the high-speed rocker arm 46 by the biasing force of 5, and the intake valves 10 are opened and closed by the low-speed rocker arms 44 and 45, respectively. On the other hand, when hydraulic oil is supplied to the oil chamber 57, the select pin 52.5
3 assumes the position shown in FIG. 3, and the intake valve lO is opened and closed by the high-speed rocker arm 28. That is, when the hydraulic oil in the oil chamber 57 is discharged, the low speed cam is selected, and when the hydraulic oil is supplied into the oil chamber 57, the high speed cam is selected. The characteristics of this low speed cam and high speed cam are:
The characteristics are as shown in FIG. 4, and in the case of a low-speed cam, the overlap period between intake and exhaust is shortened. Switching between the low-speed cam and the high-speed cam is based on the engine speed, and the low-speed cam is selected in a rotation speed range smaller than the reference rotation speed No. shown in Figure 5, and the high-speed cam is selected in a large rotation speed range. Ru.

In FIG. 1, reference numeral U indicates a control unit composed of, for example, a microcomputer, and the control unit U includes:
In addition to the intake air amount signal from the air flow meter 20 and the air-fuel ratio feedback signal from the 02 sensor, signals from sensors 60 to 62 are also input. The sensor 60 detects the engine rotation speed. The sensor 61 detects the position of the select pins 52 and 53 constituting the variable valve timing means 12 in the right bank 2. The sensor 62 detects the position of the select pins 52 and 53 forming the variable valve timing means 12 in the left bank 3.

The control unit U outputs control signals to the solenoid valve 58 for the right bank 2 and the solenoid valve 59 for the left bank 3 as described above.
1 control 4g force ≦ is output to 65.

The actuator 63 is connected to the first on-off valve 21.
It is something that moves. The actuator 64 drives the second on-off valve 28 for the right bank 2. The actuator 65 is a second on-off valve 2 for the left bank 3.
8.

The control unit U performs variable valve timing control in addition to conventionally known air-fuel ratio control and variable intake control.

FIG. 6 is a flowchart showing an example of variable valve timing control, and the details of the control will be specifically explained based on this flowchart.

First, in SL, the reference rotation speed No., engine rotation speed, etc. are read, and then in S2, it is determined whether the current engine rotation speed is greater than the reference rotation speed N0, that is, the area where the high-speed cam is set. A determination is made as to whether or not the
At S, it is assumed that the high-speed cam region is reached, and the process proceeds to S3, where a control signal is output to the solenoid valves 58 and 59, and the select bins 52 and 53 are placed in the high-speed cam mode. Then, in the next step S4, the signals from the sensors 61 and 62 are read, and it is determined whether or not the select bins 52 and 53 are actually in the high-speed cam mode. is not working properly,
' Proceeding to S5, first, the select bin 52. of the left bank 3 is selected based on the signal of the position sensor 62 for the left bank 3.
It is determined whether or not 53 has operated normally, and it is determined that it is normal (Y
ES), select bin 52 of right bank 2
．． 53 does not operate normally, that is, the right bank 2 remains in the low speed cam mode, the select bins 52 and 53 of the left bank 3 are changed to the low speed cam mode in S6. As a result, the normally operating left bank 3 is changed to a low speed cam mode in accordance with the right bank 2 in which the failure has occurred. When the answer in S5 is NO, the process proceeds to S7, where the select bin 5 of the right bank 2 is selected based on the signal of the position sensor 61 for the right bank 2.
2.53 is operated normally, and if it is normal (YES), it is assumed that the select bin 52.53 of the left bank 3 did not operate normally, that is, the left bank 3 is the low speed cam. Assuming that it remains the same, in S8,
The select bins 52 and 53 of right bank 2 are changed to low speed cam mode. As a result, the normally operating right bank 2 is changed to a low speed cam mode in accordance with the left bank 3 in which the failure has occurred.

When it is determined in S2 that the current cam is in the low speed cam region, steps S9 to S1 are performed in the same way as S3 to S8 above.
4, the left bank 3, which operates normally, is changed to a high-speed cam mode to match the malfunctioning right bank 2 (S
12), or the normally operating right bank 2 is changed to a high-speed cam mode in accordance with the left bank 3 in which the failure has occurred (S14).

With the above configuration, when a failure occurs in the valve timing variable means 12 of negative bank 2 or 3, the normally operating valve timing variable means 12 of the bank side is forced to change the cam mode of the failed bank. Therefore, it is possible to equalize the torques generated by both banks 2.3. In addition, - the valve timing variable means is a high-speed cam! If the cam mode of the valve timing variable means of the normally operating bank is adjusted to the high speed cam mode when a failure occurs in type g, as is clear from Figure 15, the torque will drop at low rotations, and the stability will be affected, especially at idle. Since this is a concern, when a failure occurs in the high-speed cam mode, nothing can be done and the system can be operated normally.

Although the present invention has been described in detail above, it can also be applied to the case where one of the bank-side on-off valves 28 among the second on-off valves 28 in the variable intake system fails.

[Brief explanation of the drawing]

Figure 11 is an overall system diagram of the embodiment, Figure 2 is a vertical sectional view showing the variable valve timing mechanism, Figure 3 is a partially cutaway plan view of the variable valve timing mechanism, and Figure 4 is the intake air intake. FIG. 5 is a characteristic diagram of the engine generated torque when a low-speed cam and a high-speed cam are used. FIG. 6 is a flowchart showing an example of control. :V-type engine body: Right bank: Left bank: Intake valve: Exhaust valve: Variable valve timing mechanism 2nd 3rd

Claims (1)

[Claims] (1) In an engine provided with a plurality of identical output variable means, the control state detection means detects the control state of each of the output variable means, the failure detection means detects a failure of each of the output variable means, and the output Among the variable means, when at least one output variable means and the other output variable means fail, the control state of the normal output variable means is changed to the control state of the failed output variable means. An engine output control device comprising: a control means;