JPS6073012A - Method of controlling supercharger of mechanically supercharged engine - Google Patents

Abstract

PURPOSE:To improve acceleration response, and reduce frequency of use of a supercharger thereby to extend a useful life of the supercharger, by selecting one of predetermined plural throttle opening degrees with use of engine rotational speed and vehicle speed to engage and release an electromagnetic clutch. CONSTITUTION:A control device 17 receives a signal from an engine rotational speed sensor 18, a signal from a vehicle speed sensor 19 and a signal from a throttle sensor 16 to engage and release an electromagnetic clutch 6. Under a low engine speed and low vehicle speed condition, the electromagnetic clutch 6 is released. When a vehicle is accelerated from the above-mentioned condition, the electromagnetic clutch 6 is engaged at a predetermined throttle opening degree theta1. When the vehicle is further accelerated, the throttle opening degree exceeds a predetermined opening degree theta2, but the electromagnetic clutch continues to be engaged. After further acceleration, the vehicle is allowed to run at a constant speed, and a throttle is relatively closed. At this time, since the engine speed: the vehicle speed is rendered high, the electromagnetic clutch is released at the throttle opening degree theta2.

Description

[Detailed description of the invention] Technical field The present invention relates to a mechanical supercharged engine.

Prior art mechanical superchargers are connected to the engine crankshaft and use a portion of the engine power to drive the supercharger. An electromagnetic clutch is interposed to reduce the engine load in a low engine load range, and the electromagnetic clutch is controlled to be connected/disconnected (off-on) at a predetermined throttle opening.

Mechanical superchargers are mechanically connected to the engine crankshaft, so the speed of the supercharger is proportional to the engine speed and load, and if used over a wide range of speeds, it will wear out. It gets intense. Therefore, in order to obtain durability, it is preferable to use the supercharger only in areas where engine output is required, and not to use it during constant speed driving where engine output is relatively unrequired. Therefore, if the throttle opening degree that controls the connection and disconnection of the electromagnetic clutch is set high, there is a problem in that the response during acceleration deteriorates.

OBJECTS OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems and improve power performance and reliability of a supercharger.

Structure of the Invention In the present invention, a plurality of throttle openings are predetermined in order to connect and disconnect the electromagnetic clutch, engine rotation speed and vehicle speed are detected, and the detected engine rotation speed and vehicle speed are used to determine the predetermined opening degrees. The present invention is characterized in that one throttle opening degree is selected from a plurality of throttle opening degrees, and the electromagnetic clutch is connected and disconnected at the selected throttle opening degree.

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

The mechanical supercharger 1 shown in FIG.
and are connected via a belt 5. An electromagnetic clutch 6 is attached to the input shaft of the supercharger 1 so that it can be connected and disconnected from engine motion.

A fuel injection valve 8 is disposed in an intake passage 7 communicating with a combustion chamber of the engine 2, and is controlled by a computer based on the output of an air flow meter 9. A throttle valve 1o is arranged in the intake passage 7. Bypassing the suction passage 11 and discharge passage 12 of the supercharger 1 to create a bypass passage 1
3 is formed. A charge air control valve 14 is disposed in the bypass passage 13 and is interlocked with the throttle valve 10 by a link 15. As shown in FIG. 2, the charge air control valve 14 operates fully open while the opening of the throttle valve 10 is small, begins to open when it reaches a predetermined opening θ0, and fully closes when it reaches a predetermined opening θ4. become.

The electromagnetic clutch 6 of the mechanical supercharger 1 is connected and disconnected within the throttle opening range where the charge air control valve 14 changes from fully open θ0 to fully closed θ4. Therefore, when the throttle valve 10 is opened from the idle state, intake equivalent to non-supercharging is performed until the opening degree θ0. Next, the charge air control valve 14 begins to close, and the electromagnetic clutch 6 is connected before it is fully closed. Therefore, the supercharger 1 starts supercharging while increasing the rotation while the bypass passage 13 is partially opened. The reverse operation is similar.

In order to control the connection and disconnection of the electromagnetic clutch 6, a throttle sensor 16 is arranged in FIG.

An example of the output of the Throno I/Le sensor is shown in Fig. 3, and it generates a voltage that is almost proportional to the throttle valve opening.For example, when the opening is θ1, it outputs v11, and when the opening is θ2, it outputs ■2. . The output of this throttle sensor 1G is input to the control device I7. A signal from an engine rotation speed sensor 18 and a signal from a vehicle speed sensor 19 are further input to the 1++J fan device 17 . The control device 17 outputs an output to the relay 20, which connects and disconnects the solenoid valve 6.

A feature of the present invention is that a plurality of throttle opening degrees are predetermined for connecting and disconnecting the solenoid valve 6.

In FIG. 2, two opening degrees, θ1 and θ2, are shown.

These predetermined opening degrees θ1 and θ2 are selected depending on the driving state of the automobile, and the electromagnetic clutch 6 is connected/disconnected (on/off) at the selected predetermined opening degree.

FIG. 3 shows details of the control device 17 of FIG. 1. The control device 17 includes a comparator 21, the output signal of the throttle sensor 1G is inputted to the positive terminal of the comparator 21, and the output signal of the throttle sensor 1G is inputted to the negative terminal of the comparator 21.
A signal that has passed through 3 is input. AND times FIII22
A signal from the engine rotation speed sensor I8 and a signal from the vehicle speed sensor 19 are input to the input terminal 1, and output 1 when each of these signals is lower than a predetermined value. When both of these output 1, a current flows through the AND circuit 22 and the transistor 23, and at this time, the voltage at the negative terminal of the comparator 21 drops from the resistor 24L. It is a value, and it is in the level of analogy. The comparator 21 is configured to cause current to flow through the relay 20 and operate the electromagnetic clutch 6 when the voltage at the positive terminal is higher than the voltage at the negative terminal. Therefore, when the throttle sensor 10 is being opened, Swan 1~
When the output of the sensor 16 reaches a voltage V1 corresponding to the throttle/nottle opening degree θ1 shown in FIG. 3, the electromagnetic clutch 6 is turned on. As the throttle valve 1o is further opened, the electromagnetic clutch 6 remains engaged and the vehicle speed or engine speed increases, and the output of the AND circuit 22 becomes zero.

/ When the output of the IND circuit 22 becomes O, the transistor 2
Since no current flows through 3, the negative side of comparator 21:
Since there is no voltage drop due to the resistor 24, the voltage applied to the terminal 11i+ changes from, for example, 1 to a higher value v2. Therefore, the relay 2 for operating the electromagnetic clutch 6
In order to cause the current to flow to 0, the output voltage of the throttle sensor 16 applied to the positive terminal of the comparator 21 must be equal to or higher than the voltage 72 corresponding to the throttle opening θ2 in FIG.

A state in which both the engine rotation speed and vehicle speed are lower than their respective predetermined values (for example, 1.50 Orpm, 40 Km/H),
In other words, the state in which ANI') times +2322 outputs 1 and the electromagnetic clutch 6 is connected and disconnected at the lower throttle opening setting value θ1 is called a state immediately after starting or when driving in a low-speed city area in terms of the driving state of the car. be able to.

When accelerating from such a state, the electromagnetic clutch 6 is engaged at the lower throttle opening θ], and the activation timing of the supercharger 1 becomes earlier, improving the response of the engine.

As the acceleration continues, the engine speed or the vehicle speed becomes larger than their respective predetermined values, but at this time the throttle opening has already exceeded θ2, and the electromagnetic clutch 6 continues to be engaged. Acceleration.

Afterwards, the vehicle generally shifts to constant speed driving and the throttle opening is relatively closed. At this time, since the engine speed or vehicle speed is higher than the predetermined value, the electromagnetic clutch 6 is disengaged at the higher throttle opening θ2. In this way, the electromagnetic clutch 6 is engaged at the lower throttle opening θ1 and disengaged at the higher throttle opening θ2. Therefore, the acceleration response is improved, and the use of the supercharger 1 in a region where an output increase is relatively unnecessary is reduced. The electromagnetic clutch 6 may be engaged and disengaged at the throttle opening θ1, but such cases are thought to be rare. Also, there are cases where the throttle is turned on and off at the throttle opening θ2, but since the throttle opening θ2 is set relatively high, the frequency of connection/disconnection operation of the supercharger 1 in such a case is This will result in a decrease.

When selecting the throttle opening degree for connecting and disconnecting the electromagnetic clutch 6, the AND logic of the engine speed and vehicle speed was used in the above embodiment, but the control device 17 was replaced with a computer, and the engine speed and vehicle speed were changed to a variable speed. Of course, it is also possible to create a combination map that takes position into consideration.

As described above, according to the present invention, it is possible to improve acceleration response, reduce the frequency of use of the supercharger, extend the service life of the supercharger, and improve reliability.

[Brief explanation of the drawing]

Figure 1 is a system diagram of a mechanical supercharger engine according to the present invention, Figure 2 is a diagram explaining the relationship between the char share control valve of Figure 1 and the throttle valve opening, and Figure 3 is a diagram of the throttle sensor. FIG. 4 is a circuit diagram of the control device shown in FIG. 1. 1...Supercharger, 2...Engine, 3...Crankshaft, 6...Electromagnetic clutch, 7...Intake passage,
1o... Throttle sensor, 13... Charge air control valve, 15... Link, 16... Throttle sensor, 17... Control device, 18... Rotation speed sensor, 19... Vehicle speed sensor . Patent applicant Toyota Motor Corporation Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Kyosuke Donakayama Patent attorney Akira Yamaguchi Patent attorney Masaya Nishiyama 101 Figure 3 Figure 4 '” '"'JNji-111:! f7

Claims (1)

[Claims] An engine crankshaft via an electromagnetic clutch. In an engine that is equipped with a mechanical supercharger connected to the engine, and which connects and disconnects an electromagnetic clutch at a predetermined throttle opening, a plurality of throttle openings are predetermined to connect and disconnect the electromagnetic clutch, and the engine rotates. The engine speed and vehicle speed are detected, and the detected engine rotation speed and vehicle speed are used to select one or more throttle openings from among the plurality of predetermined throttle openings.
1. A supercharger control method for a mechanically supercharged engine, characterized in that a throttle opening of lil is selected, and an electromagnetic clutch is connected/disconnected at the selected throttle opening.