JPH0345214B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an internal combustion engine equipped with a mechanical supercharger that supercharges air into cylinders by transmitting rotational force through a clutch.

[Conventional technology]

An example of a mechanical supercharger is one in which the drive shaft is rotationally driven from the engine crankshaft via a belt, and the rotation of this drive shaft is transmitted to the pump element via an electromagnetic clutch. be. Furthermore, this supercharger is designed so that when the throttle valve opens beyond a predetermined level, an electromagnetic clutch is connected to start the engine, and when this opening becomes even larger, the supercharging control valve closes to a certain extent and supercharging takes place. It is configured to do the following.

[Problem to be solved by the invention]

A turbocharger with this configuration performs no-load operation from the time the electromagnetic clutch is engaged until the supercharging control valve is substantially closed. There was a problem with the engine output temporarily decreasing. That is, when the electromagnetic clutch is connected, the vehicle speed temporarily decreases, which adversely affects the drivability of the vehicle.

[Means to solve the problem]

As a means for solving the above-mentioned problems, the present invention provides a cylinder that accommodates a piston so as to be able to reciprocate;
an intake pipe that supplies air to the cylinder; a supercharger that is provided in the middle of the intake pipe and is rotationally driven via a clutch to supercharge air into the cylinder; and a supercharger connected in series to the supercharger. and a throttle valve provided in a part of the intake pipe, and the supercharger is configured to start when the clutch is connected and perform a supercharging operation after performing no-load operation. The internal combustion engine is provided with a bypass passage that communicates between the upstream side and the downstream side of the throttle valve, and an air control valve that controls opening and closing of the bypass passage, and the air control valve is configured to open and close the bypass passage after the clutch is connected. To provide an internal combustion engine equipped with a supercharger, characterized in that the valve is opened only until the supercharger substantially performs a supercharging action to supply air to the cylinder.

[Effect]

When the internal combustion engine is in a low-load operating state, the supercharger clutch is not engaged and the supercharger is not driven in rotation, so no supercharging is carried out and the engine is in a naturally aspirated state. .

When the internal combustion engine transitions from a low load operating state to a medium to high load operating state, the turbocharger clutch is connected and the turbocharger starts, but at the same time the turbocharger is started and the load is If the engine is
Initially, the engine is in a no-load operating state, and substantially no supercharging is performed. However, even in this state, although the engine is not being supplied with an increased amount of intake air due to supercharging, the load on the engine increases by the mechanical loss torque of the supercharger, so the engine speed tends to decrease.

However, in the present invention, the bypass passage that communicates the upstream and downstream sides of the throttle valve is provided only from the time when the clutch of the supercharger is connected until the supercharger substantially performs the supercharging action. The air control valve opens, and in addition to the normal amount of intake air that passes through the throttle valve, additional intake air is taken from the bypass passage, increasing the engine output and compensating for the torque loss of the supercharger. The engine speed will not drop.

The present invention will be explained below with reference to illustrated embodiments. 1st
In the figure, one side of the intake pipe 1 communicates with the atmosphere via an air filter 2, and the other side of the intake pipe 1 communicates with a cylinder 4 that supports a piston 3 so as to be able to reciprocate. An air amount detector 5 is provided on the air filter 2 side of the intake pipe 1, and on the downstream side of this air amount detector 5,
That is, the supercharger 6 is disposed on the cylinder 4 side.

The supercharger 6 is provided in an enlarged part 7 formed by expanding the intake pipe 1, and the upstream side of the enlarged part 7 functions as a supercharger intake passage 8, and the downstream side functions as a supercharger discharge passage 9. The supercharging control valve 10 is provided in the intake pipe 1 between the intake passage 8 and the discharge passage 9, and interlocks with a throttle valve 11 provided downstream thereof via a link 12. In other words, the supercharging control valve 10
is closed when the throttle valve 11 is opened more than a specified degree, and is fully opened when the throttle valve 11 is closed. On the other hand, as will be described later, an electromagnetic clutch (not shown) is connected when the throttle valve 11 is opened to a predetermined degree or more. Therefore, the turbocharger 6 has a throttle valve 1
1 reaches a predetermined opening, the engine starts via the electromagnetic clutch, and as this opening increases and the supercharging control valve 10 further closes, the supercharging action begins, and when the supercharging control valve 10 closes forward, it starts completely. becomes supercharged.

The driving force for the supercharger 6 is given from the crankshaft 13. That is, an endless belt 15 is wound around the drive shaft 14 and crankshaft 13 of the supercharger 6, and the rotation transmitted to the drive shaft 14 via the belt 15 is further transmitted via an electromagnetic clutch. Feeder 6
is transmitted to the pump member 16 of. The electromagnetic clutch is controlled intermittently by applying a clutch voltage from the clutch control section 17, and the application of the clutch voltage is performed when the throttle valve 11 is opened by a predetermined angle or more. That is, a valve detector 18 is provided near the throttle valve 11, and when the opening degree of the throttle valve 11 exceeds a predetermined value, the valve detector 18 detects this opening degree and sends the message to the clutch control section 17. A signal is sent, and the clutch control section 17 receives this signal and connects the electromagnetic clutch.

In addition to the intake pipe 1, a bypass passage 19 is provided as a means for supplying air to the cylinder 4. The upstream side of the bypass passage 19 communicates with the intake pipe 1 between the air amount detector 5 and the supercharger 6, and the downstream side communicates with the surge tank 20 downstream of the supercharger 6. communicate. This bypass passage 1
An air control valve 22 provided in the middle of the air control valve 9 to open and close the air control valve 22 is operated in response to a signal input from a computer 23. The computer 23 receives a signal from the valve detector 18 indicating that the opening degree of the throttle valve 11 is a predetermined size, and outputs a command signal to the air control valve 22. That is, the air control valve 22
is opened and the bypass passage 19 is opened from when the throttle valve 11 reaches a predetermined opening and the electromagnetic clutch is connected until the turbocharger 6 starts supercharging.
It is designed to communicate with each other.

The operation of the air control valve 22 will be explained with reference to FIG. FIG. 2 shows the opening degree of the throttle valve 11 on the horizontal axis and the opening degree of the supercharging control valve 10 on the vertical axis. As can be seen from this figure, the valve detector 18
When a signal indicating that the opening degree of the throttle valve 11 has reached a predetermined value A is input to the computer 23, the computer 23 opens the air control valve 22. Further, when the throttle valve 11 opens and its opening reaches the value B, that is, the supercharging control valve 1
0 closes to a certain extent and the supercharging action begins, the computer 23 closes the air control valve 22 as shown by the solid line R. In other words, the throttle valve 11
While the opening degree is between A and B, the supercharger 6 does not perform supercharging and is in no-load operation. During this time, the air control valve 22 opens and supplies air to the cylinder 4. This compensates for the equivalent mechanical loss torque due to load operation. In addition, in FIG. 2, the area S indicated by diagonal lines
indicates a portion where the supercharger 6 performs supercharging, that is, a supercharging region.

Therefore, it is desirable that the flow rate of air passing through the air control valve 22 has a size that accurately corresponds to the mechanical loss torque, and for this reason, in this embodiment, the flow rate of passing air is made to correspond to the engine rotation speed. . That is, the magnitude of the air flow rate passing through the air control valve 22 is determined by the magnitude of the control current input from the computer 23, as shown in FIG. As shown in the figure, it is determined based on the engine speed.

Since the apparatus of this embodiment has the above configuration, it operates as follows. That is, during normal operation when the supercharger 6 is not operating, air flowing through the intake pipe 1 does not pass through the bypass passage 19, but is supplied to the cylinder 4 through the supercharging control valve 10 and the throttle valve 11. At this time,
The drive shaft 14 of the supercharger 6 constantly rotates via the crankshaft 13, but since the electromagnetic clutch is open, the pump member 16 does not substantially rotate. When the throttle valve 11 opens by a predetermined opening degree A, the valve detector 18 detects this and sends a signal to the computer 23 and the clutch control section 17. As a result, the clutch control unit 17 connects the electromagnetic clutch to transmit the rotation of the drive shaft 14 to the pump member 16, while the computer 23 opens the air control valve 22. At this time, the supercharging control valve 10 is not closed enough for the pump member 16 to perform a supercharging action, so the supercharger 6 performs no-load operation, but the amount of air is equivalent to the mechanical loss torque caused by this. is sent to the cylinder 4 via the bypass passage 19. Therefore, the engine output does not decrease when the supercharger 6 starts. Now, throttle valve 11
When the opening degree becomes larger and reaches the size shown by B in FIG.
3, the air control valve 22 is closed. In other words,
At the same time as the supercharging action of the supercharger 6 starts, the supply of air to the cylinder 4 via the bypass passage 19 ends. Next, when the throttle valve 11 further opens and the supercharging control valve 10 is fully closed, the supercharger 6 enters a complete supercharging state.

It should be noted that a so-called idle speed control valve is conventionally provided in order to maintain the idle operating state of the engine in an optimum state, but this valve can also have the function of the air control valve 22 described above.

Further, in the above embodiment, the air control valve 22
The opening degree of the valve is configured to change depending on the engine speed, but it is also possible to simplify the valve and use a valve that simply opens and closes regardless of the engine speed. . In other words, the influence of the engine rotation on the mechanical loss torque of the supercharger 6 is relatively small, so if very high precision control is not required, the opening degree of the air control valve 22 can be kept constant regardless of the engine rotation speed. In this case, the opening degree of the valve 22 is determined by selecting an appropriate rotation speed from the normally used engine rotation speed of 1000 rpm to 4000 rpm, and adjusting the opening degree of the valve 22 as necessary to compensate for the mechanical loss torque at that rotation speed. It can be determined by calculating the amount of air.

As can be said in any of the embodiments described above, the air control valve 22 does not necessarily have to be configured to open in perfect alignment during no-load operation of the supercharger 6. For example, as shown by the dashed line I in FIG. 2, the air control valve 22 may be opened to a point C where the supercharging control valve 10 is completely closed.
Further, as shown by the two-dot chain line J, the opening degree of the throttle valve 11 changes from B to C, that is, from the time when the supercharger 6 starts supercharging to the time when it reaches a complete supercharging state. During this period, the air control valve 22 may be gradually closed.

〔Effect of the invention〕

As described above, in the present invention, even if the supercharger performs no-load movement and generates mechanical loss torque when starting the supercharger, the engine output corresponding to this loss torque is reduced.
The system compensates by opening the air control valve in the bypass passage that communicates the upstream and downstream sides of the throttle valve and supplying additional air to the cylinder. This has the effect of always providing comfortable driving control without causing a decrease in output.

[Brief explanation of drawings]

Figure 1 is a system diagram showing one embodiment of the present invention, Figure 2 is a system diagram showing an embodiment of the present invention.
The figure is a graph showing the opening/closing relationship of the throttle valve, the supercharging control valve, and the air control valve. FIG. 3 is a graph showing the relationship between the current value applied to the air control valve and the air flow rate in the first embodiment. FIG. is a graph showing the relationship between the engine speed input to the computer that controls the air control valve and the current value output from this computer. 1...Intake pipe, 3...Piston, 4...Cylinder,
6...Supercharger, 14...Drive shaft, 19...Bypass passage, 22...Air control valve.

Claims (1)

[Claims] 1. A cylinder that reciprocably accommodates a piston, an intake pipe that supplies air to the cylinder, and a supercharger that is provided in the middle of the intake pipe and is rotationally driven via a clutch to supercharge air into the cylinder. The turbocharger is equipped with a feeder and a throttle valve provided in a part of the intake pipe so as to be in series with the supercharger, and the supercharger is started when the clutch is connected, and the no-load operation is started. In an internal combustion engine configured to perform a supercharging action after performing a The control valve is configured to open only from when the clutch is connected until the supercharger substantially performs a supercharging action to supply air to the cylinder. Internal combustion engine with feeder.