JPS61175236A - Engine with supercharger - Google Patents

Abstract

PURPOSE:To reduce discontinuous combustion due to a speed change in acceleration, by providing a means, which maintains a supercharger to be connected with an engine output shaft for a predetermined time after the speed change is started, in the case of an engine disconnecting the mechanical supercharger from the engine output shaft in a low load range. CONSTITUTION:An engine interposes a vane supercharger 14, driven by a crankshaft 5 through an electromagnetic clutch 22, in an intake passage 11 while a selector valve 18 in a bypass passage 17 connected with the intake passage 11 so as to detour around said supercharger 14. The engine, actuating the selector valve 18 to be opened and closed by a pulse motor 19, controls the pulse motor 19 with the electromagnetic clutch 22 by a control unit 30. The control unit 30 is constituted so as to control the electromagnetic clutch 22 to be disconnected in a low load range with an engine load smaller than a predetermined value while connected for a predetermined time (for instance, 2sec) after a speed change is started when speed change operation is detected from an output of a speed change sensor 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a supercharged engine equipped with a supercharger mechanically driven by an engine output shaft.

(Prior Art) Some supercharged engines are equipped with a so-called supercharger type supercharger that is mechanically driven by an engine output shaft.

In general, for such supercharged engines,
As seen in Publication No. 8-30415, a disconnection means such as an electromagnetic clutch is interposed in the power transmission path from the engine output shaft to the supercharger, and in the low engine load range, the connection between the two is disconnected to reduce output loss. The aim is to reduce the

By the way, as a supercharger type supercharger, for example, a displacement type supercharger such as a vane type is generally used, and this type of supercharger is designed to be as light as possible so that it can be driven with less power. There is. Therefore, the rotation of the supercharger after the connection with the engine output shaft is severed is significantly lower than that of the engine body, which is subjected to inertial force such as a flywheel.

From this, for example, when a gear shift is performed to obtain acceleration, the supercharger will start the engine in response to the return operation of the accelerator pedal required during the gear shift.

The connection with the engine output shaft is severed, and the rotational speed of the supercharger drops rapidly, resulting in a sudden drop in torque. Additionally, due to the response delay of the disconnection means interposed between the supercharger and the engine output shaft, there is a delay in the boost pressure A immediately after the gear shift, resulting in a 70% drop phenomenon during acceleration. Ta.

(Technical Problem to be Solved by the Invention) The technical problem to be solved by the present invention is to provide a supercharger system in which the connection between the engine output shaft and the mechanical supercharger is disconnected in the low engine load range. The object of the present invention is to propose a supercharged engine that improves acceleration responsiveness by reducing the breathing phenomenon that accompanies gear changes during acceleration as described in (1) above.

(Means for achieving the technical problem) In order to achieve the technical problem, the present invention includes the fifth
As shown in the figure, there is a shift detecting means for detecting the shift of the transmission, and a shift detecting means for maintaining the connection between the supercharger and the engine output shaft for a predetermined period of time after the start of shifting based on the confidence from the shift detecting means. The feeder operation maintaining means is also provided. Here, the -4-distribution predetermined time may be set, for example, taking into consideration the time required for shifting from normal dry to normal. In this manner, during gear shifting, the supercharger operation maintaining means maintains the connection between the engine output shaft and the supercharger, that is, maintains the rotational drive of the supercharger even if the accelerator pedal is released for gear shifting. In this way, a drop in the rotational speed of the supercharger is prevented, which is caused by a sudden drop in torque.

This is designed to reduce the breathing that accompanies gear changes during acceleration.

(Example) In Fig. 1, 1 is the engine body.
In this embodiment, the engine is of a reciprocating type in which a reciprocating movement of a piston 3 within a cylinder 2 rotates a crankshaft 5 serving as an engine output shaft via a connecting rod 4.

In the upper part of the combustion chamber 6 defined by the cylinder 2 and the screw I/N 3, there are an intake port 7 and an exhaust port 8.
are opened, the intake bows 1-7 are opened by the supercharging air valve 9, the exhaust port 8 is opened by the υ1 air valve 10, and the timing cams (not shown) are operated at well-known timing in synchronization with the rotation of the crank +115. It is designed to be opened and closed.

The intake port 7 is connected to an air cleaner 12 through an intake passage 11, and is provided with an air flow meter 13, a turbocharger 14, and a throttle valve 16 connected to an accelerator pedal 15 in order from the first stream side (from the air cleaner 12 side). The intake passage 11 is provided with a bypass passage 17 that bypasses the second stream and downstream of the supercharger 14.
A switching valve 18 is disposed in the bypass passage 17, and the switching valve 18 is opened and closed by a pulse motor 19. The pulse motor 19 is controlled based on an output signal from a control unit 30, which will be described later.

The supercharger 14 is mechanically driven by the crankshaft 5, and a vane type supercharger is used in the embodiment.

This vane type supercharger 14 is connected to the crankshaft 5 via a winding intermediate joint 21 such as a timing belt chain, and an electromagnetic clutch 22 is provided on the rigid shaft of the supercharger 14.

The electromagnetic flanch 22 is controlled based on the output from a control unit 30, as will be described later.

The control unit 30 includes a throttle valve 16
load signal S1 from the throttle sensor 23 that detects the opening of the transmission, and a gear position signal S2 from the shift sensor 24 that detects that the gear position of the transmission is in neutral. Additionally, a supercharging pressure signal S3 from a supercharging pressure sensor 25 provided downstream of the supercharger 14 is input, and from this control unit 30, a signal is sent to the pulse motor 19 and the electromagnetic clutch 22 described above. Output.

The control signal for the pulse motor 19 is the load signal S +
Based on this, the pulse motor 19 outputs a signal that causes the pulse motor 19 to operate to reduce the opening of the switching valve 18 as the opening of the throttle valve 16 becomes larger.

A control signal for the electromagnetic clutch 22 is output based on the load signal SI and the gear position signal S2. @Magnetic latch 22 made by this control unit 30
The following describes the control details.

``Ill control of the anti-magnetic clutch 22 includes basic control that disconnects the electromagnetic clutch 22 to reduce output loss when the engine load is smaller than a predetermined set value. , consists of auxiliary control that delays disengagement of the electromagnetic clutch 22 for a predetermined period of time to maintain operation of the supercharger 14.

That is, in this embodiment, in a gear change operation, the gear position must pass through neutral, and when the gear position of the transmission becomes neutral, a signal is sent from the control unit 30 to the electromagnetic clutch 22. cutting (O
The output of the F F) signal is delayed for a predetermined period of time, and the predetermined period of time is set to the time normally required by the driver to change gears, for example, about 2 seconds.

A flowchart for executing such control is shown in the second section.
It will look like the figure. 81 to SIO indicate each step.

First, in step Sl, the shift time (SO) required for a normal driver to change gears is set to, for example, about 2 seconds, and the throttle opening (θ0) for disengaging the electromagnetic clutch 22 is set. Next, step S2
The timer time (S) is reset in step S3.
In step S4, the gear position is read based on the gear position signal S2, and in step S4 it is determined whether the gear position is neutral.

If it is determined in step S4 that the gear position is not neutral, the process moves to step S5, where the throttle opening degree (θ) is read based on the load signal, and in step S6, the throttle opening degree (θ) is read based on the load signal. θ
) is a dog or not based on the set value (θ.). When the throttle/little opening (θ) is larger than the set value (θ0), that is, when the engine is under high load, the electromagnetic clutch 22
A signal for connecting (ON) is output, and the loop goes to step S2. As a result, the supercharger 14 and the crankshaft 5 are connected, and the supercharger 14 is rotationally driven. This state can be seen in Figure 3, which shows the relationship between gear position and throttle opening.
This corresponds to the shaded area indicated by 31 in the figure, where the accelerator pedal 15 is depressed while the vehicle is in a steady running state such as high speed.

In step S6, if the throttle opening degree (θ) is smaller than the set value (θa), the process moves to step S8, in which the electromagnetic clutch 22 is disconnected (O
After the signal that causes F F) is output, step S2
The loop is turned. This OFF signal disconnects the electromagnetic clutch 22 and disconnects the supercharger 14 from the crankshaft 5. That is, this state corresponds to the low load range shown by 32 in FIG. 3, in which the gear position is in 1st speed, 2nd speed, etc., and the accelerator pedal is released. In addition to such basic control, as an auxiliary control, when a gear shift operation is started, in the embodiment, if it is determined in step S4 that the gear position is in neutral, a loop is executed to step S9. is passed around.

In step S9, the shift time (S) is set to the set value (So
) is larger than .

In the initial stage, since the shift time (S) is smaller than the set value (So), a loop is passed from step SIO to step S4, and a time count is performed. During this time, electromagnetic clutch 2
2 is in a connected state, and the rotational drive of the supercharger 14 is continued.

Any gear position (for example, 3) within the set time (So)
(speed, 4th speed, etc.), the process moves from step S4 to step S5, where the supercharger 14 is rotationally driven under the above-mentioned basic control and supercharging is performed. If the gear position is in neutral for more than the set time (so), it is determined in step S9 that this gear operation is not a gear shifting operation, and the process proceeds to step S8, in which the electromagnetic clutch 22 is disconnected ( After the signal to turn OFF) is output, a loop is passed to step S2. As a result, the rotational drive of the supercharger 14 is stopped.

Such control allows the supercharger and the engine output shaft to remain connected during gear changes (upshifts, downshifts). Figure 4 shows the torque fluctuation during gear shifting. Compared to the conventional model (broken line in the figure), the embodiment (solid line in the diagram) reduces the sudden drop in torque during gear shifting. . That is, the shaded area in FIG. 4 shows the effect of the embodiment.

Although the embodiments have been described above, the present invention is not limited thereto, and includes the following modifications.

(1) As a means for detecting the gear shift of the transmission, a sensor is provided to detect the depression of the clutch pedal, and upon receiving a signal from the sensor, the supercharger and the engine output shaft are It may also be possible to maintain the connection between the two.

That is, the depression of the Kurasochi pedal, which is required in the gear shifting operation, may be used as a signal to start the gear shifting operation.

(2) When the control unit 30 is configured by a microcomputer, it may be of either an analog type or a digital type.

(Effects of the Invention) As is clear from the explanation below, according to the present invention, the connection between the supercharger and the engine output shaft is maintained during gear shifting, so that the supercharging pressure immediately after shifting is reduced. It is possible to solve the problem of delay in raising the gears, reduce the one-shot phenomenon when changing gears during acceleration, and improve the acceleration responsiveness by -1.

[Brief explanation of drawings]

Fig. 1 is an overall system diagram showing one embodiment of the present invention, Fig. 2 is a flowchart showing an example of control contents of the present invention, Fig. 3 is a diagram showing the operating range of the supercharger, and Fig. 4 is a shift diagram. Fig. 5 is a block diagram showing the overall configuration of the present invention. 5: Crankshaft 14: Supercharger 22; Electromagnetic clutch 24: Speed change sensor (speed change detection means) 30; Control unit - m = 〇 section 1 m1 ¥ (Y rule ladder Δ

Claims (1)

[Claims] (1) In a supercharged engine that is equipped with a supercharger that is mechanically driven by the engine output shaft, and the supercharger is disconnected from the engine output shaft in a low engine load range, the transmission and a supercharger operation maintaining means that receives a signal from the shift detection means and maintains the connection between the supercharger and the engine output shaft for a predetermined period of time after the start of the shift. A supercharged engine characterized by: