JPH0242690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharged engine.

In the actuator for a constant speed traveling device that has been proposed in the past (for example, Japanese Utility Model Publication No. 15386/1986), the servo motor of the actuator is operated by negative pressure in the intake pipe. In the case of a normal engine, the negative pressure in the intake pipe is large, so the actuator can be operated sufficiently, but in the case of a supercharged engine, the negative pressure is smaller than that of a normal engine, or the pressure is positive. The actuator could not be operated sufficiently with this negative pressure. When using a negative pressure type actuator with a supercharged engine, the intake manifold does not have high negative pressure, so a method of creating negative pressure with a separate mechanism, as in the conventional method (Utility Model Application Publication No. 1983-9810), is required. If no precautions are taken, the actuator cannot be operated sufficiently.

The present invention aims to sufficiently operate the actuator even in a supercharged engine by utilizing the differential pressure between the upstream and downstream sides of the throttle valve. In a supercharged engine in which supply air from a turbine driven and rotated through a compressor is supplied from an intake pipe through a throttle valve, an air chamber, and an intake valve, an actuator for controlling the throttle valve is provided. , the actuator is separated into a sealed positive pressure chamber and a negative pressure chamber, and a diaphragm biased by a spring is provided on the positive pressure chamber side, and a diaphragm provided in the intake pipes on the upstream and downstream sides of the throttle valve. A first control unit for controlling the positive pressure and negative pressure outlets and the upstream and downstream outlets to communicate with the positive pressure chamber and the negative pressure chamber, respectively.
and a second valve, and by moving the actuator with a pressure difference corresponding to the opening degree of the throttle valve, it is an object of the present invention to provide a supercharged engine that can obtain sufficient operating force for the actuator. .

The present invention will be described below with reference to the embodiments shown in the drawings. Reference numeral 1 denotes a supercharger, which is composed of a turbine 2 and a compressor 3, and air supplied from the turbine 2 is supplied to an intake pipe 4.
The air is then supplied to an engine having a piston 8 via a throttle valve 5, an air chamber 6 and an intake valve 7. Further, the exhaust gas from the exhaust valve 9 of the engine is discharged from the exhaust pipe 10 via the compressor 3.

A positive pressure outlet 11 and a negative pressure (small) outlet 12 are attached to the intake pipe 4 on the upstream and downstream sides of the throttle valve 5.
It communicates with a first valve 16 and a second valve 17, which are operated simultaneously by a linear motor 15, via a linear motor 15.
The chamber 18 housing the first valve 16 and the chamber 19 housing the second valve 17 communicate with the first port 23 and second port 24 of the positive pressure chamber 21 and negative pressure chamber 22 of the actuator 20, respectively. are doing.

The actuator 20 is separated into a positive pressure chamber 21 and a negative pressure chamber 22 by a diaphragm 25. A rod 27 fixed via a retainer 26 extends from the positive pressure chamber 21 side, and a retainer is provided inside the negative pressure chamber 22. 2
A spring 29 is arranged between the housing 28 and the left end wall of the housing 28. Further, the rod 27 extends outside the housing 28, is fixed to the housing 28 and the other end of the rod 27, and has its outer periphery covered by a boot 31 whose expansion is limited by a ring 30. A wire 32 connected to the throttle valve 5 is fixed.
The opening of the throttle valve 5 is adjusted by an accelerator pedal (not shown), and after the vehicle is set to constant speed running, the opening is adjusted via the wire 32 in accordance with the left-right movement of the rod 27.

Next, the operation will be explained when the actuator 20 is used for constant speed driving.The vehicle speed is detected by a vehicle speed detector (not shown). When this vehicle speed is smaller than the set vehicle speed, the signal is sent to a computer (not shown). The computer is a linear motor 15
A signal is given to open the valves, and valves 16 and 17 are opened. From the valve 16, positive pressure from the outlet 11 enters the positive pressure chamber 21 via the first port 23, and at the same time, from the valve 17, the negative pressure from the outlet 12 enters the second port 21.
It is introduced into the negative pressure chamber 22 via the port 24.

Therefore, the diaphragm 25 moves to the left against the spring 29, and the throttle valve 5 opens via the rod 27 and wire 32. When the vehicle speed increases due to the opening of the throttle valve 5 and reaches the set vehicle speed, this signal is input to the computer, and the computer issues a command to the linear motor 15 to close the valve. Therefore valve 1
6 and 17 are closed, and the positive pressure chamber 21 and negative pressure chamber 22
The positive and negative pressures in the chambers 21 and 22 are kept at the same level as the set vehicle speed because the chambers 21 and 22 are sealed, and the diaphragm 25 is balanced between the spring 29 and the positive and negative pressures in the chambers. The throttle valve 5 remains at the same position, the throttle valve 5 maintains a constant opening state, and the vehicle can run at a constant speed.

Since the present invention is constructed as described in detail above, the negative pressure downstream of the throttle valve in a supercharged engine is small or becomes close to positive pressure, making it unstable. Unlike conventional actuators, the negative pressure is not directly introduced, but the actuator is actuated by the pressure difference between the upstream and downstream sides of the throttle valve.
Since it is possible to extract a pressure difference according to the opening degree of the throttle valve, control can be performed according to the opening degree of the throttle valve. Further, since there is no need for any new configuration, the system can be simplified, and factors such as the low negative pressure on the downstream side will not be a hindrance to the operation of the actuator of the present invention. Nothing happens.

In addition, since the present invention uses the pressure difference on both sides of the throttle valve, the engine pressure required to move the actuator is less consumed than in the past, which extracts negative pressure only from the downstream side of the throttle valve, which saves engine horsepower. It is possible to reduce energy consumption, resulting in energy savings.

[Brief explanation of drawings]

The drawing is a system diagram of a supercharged engine showing an embodiment of the present invention. Explanation of main parts of the diagram 1...Supercharger, 4...Intake pipe, 5...Throttle valve, 8...Piston, 11
...Upstream side outlet, 12...Downstream side outlet, 15
...Linear motor, 16...First valve, 17...Second
Valve, 20... actuator, 21... positive pressure chamber,
22...Negative pressure chamber, 25...Diaphragm, 27...Rod, 28...Housing, 29...Spring, 31
...Boots, 32...Wire.

Claims (1)

[Claims] 1. In a supercharged engine in which supply air from a turbine driven and rotated through a compressor driven by exhaust gas from an exhaust valve of the engine is supplied from an intake pipe through a throttle valve, an air chamber, and an intake valve, An actuator for controlling the throttle valve is provided, and the actuator is separated into a sealed positive pressure chamber and a negative pressure chamber, and a diaphragm biased by a spring is provided on the positive pressure chamber side, and a diaphragm is provided upstream of the throttle valve. A first control unit that controls communication between positive pressure and negative pressure outlets provided in the side and downstream intake pipes and the upstream and downstream side intake ports, respectively, to the positive pressure chamber and the negative pressure chamber.
and a second valve.