JPS6315549Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an intake system for a multi-cylinder engine, and in particular, when the engine is decelerating, the intake system cuts off the supply of intake air to some cylinders and sends the entire amount of intake air to the remaining cylinders. , relates to an intake system for a multi-cylinder engine that increases the filling efficiency of the cylinders.

For example, in an automobile engine, when the throttle valve is suddenly closed to decelerate the vehicle while the vehicle is running, there is a problem in that the filling efficiency of the cylinders decreases and the combustion state becomes unstable. Therefore, in order to solve this problem in multi-cylinder engines, when decelerating,
Intake negative pressure is introduced into the pressure chamber of the diaphragm device, and the diaphragm device closes the shutoff valve, thereby closing the intake passage to some cylinders and guiding the entire amount of intake air to the remaining cylinders. Attempts have been made to increase filling efficiency. In this case, in the operating range other than during deceleration, the pressure chamber of the diaphragm device is opened to the atmosphere, and the shut-off valve is opened to supply intake air to all cylinders as before, allowing operation with all cylinders. be. (For example, Mikoaki
56-4819) However, with such conventional intake systems, a large shock occurs in the vehicle when the operating state changes from a deceleration operating range to an accelerating operating range and then switches to an operating state using all cylinders. This causes a problem. This is because when atmospheric air is introduced into the pressure chamber of the diaphragm device that controls the opening and closing of the shutoff valve in order to transition from partial cylinder operation to all cylinder operation, the pressure inside the pressure chamber instantly changes to atmospheric pressure, causing the shutoff. This is thought to be caused by torque fluctuations caused by the sudden change in operating conditions from some cylinders to all cylinders due to the valve suddenly opening the intake passage.

The present invention was developed in response to the above-mentioned problems, and is designed to improve the efficiency of deceleration in a multi-cylinder engine equipped with a cutoff valve that cuts off the supply of intake air to some cylinders during deceleration and increases the filling efficiency of the remaining cylinders. The purpose is to prevent large fluctuations in engine output torque that occur when transitioning from engine to acceleration.

That is, in the intake system for a multi-cylinder engine according to the present invention, a restriction is formed in the communication passage having a control valve that communicates the pressure chamber of the diaphragm device with the atmosphere and closes during deceleration operation and opens at times other than deceleration operation. According to this configuration, the control valve is opened to open the shutoff valve to shift from deceleration operation to another operating state and from partial cylinder operation to full cylinder operation, and the pressure chamber of the diaphragm device is opened. When air is introduced into the engine, the air is gradually introduced through this throttle, which slows down the displacement of the diaphragm device and, in turn, the opening of the shutoff valve, and the sudden change to all-cylinder operation reduces torque. Fluctuations can be prevented as much as possible.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated based on drawing about an Example.

1 is a multi-cylinder engine consisting of multiple cylinders,
2 and 3 are first and second intake passages that respectively supply air-fuel mixture to the first cylinder 4 (some cylinders) and the second cylinder 5 (remaining cylinders) of the multi-cylinder engine 1;
First and second throttle valves 6 and 7 are provided, respectively, which are opened and closed in conjunction with an accelerator pedal (not shown). 8 is a cutoff valve provided in the first intake passage 2 downstream of the first throttle valve 6, and 10 is a communication passage, which connects the first and second intake passages 2 and 3 immediately upstream of the cutoff valve 8 in the fully closed state. It's communicating. An air passage 11 communicates the first intake passage 2 downstream of the cutoff valve 8 with the atmospheric chamber 12a of the diaphragm device 12. The negative pressure chamber (pressure chamber) 12b of the diaphragm device 12 is communicated with the first intake passage 2 downstream of the cutoff valve 8 and the atmospheric hole 16 via the electromagnetic valve (control valve) 13. The solenoid valve 13 is electrically connected to a battery 15 via a deceleration switch 14, and selectively switches the state of communication between the first intake passage 2 and the atmospheric hole 16 with respect to the negative pressure chamber 12b by opening and closing the switch 14. It is. Reference numeral 17 denotes a diaphragm, which is a characteristic feature of the present invention, and is provided at a position close to the air hole 16. 18 is the atmospheric chamber 1 of the diaphragm device 12
2a to the atmosphere via an air cleaner (not shown). Reference numeral 19 denotes an operating rod, which is connected to a connecting member 20 fixed to the diaphragm 12c of the diaphragm device 12 and the rotating shaft 8b of the cutoff valve 8. Note that 16a is a filter, and 12d is a negative pressure chamber 1 of the diaphragm device 12.
This is a spring compressed into 2b.

With the above configuration, the deceleration switch 14 is closed during deceleration, and the solenoid valve 13 is energized to close the atmospheric hole 16 side while opening the first intake passage 2 side, thereby closing the negative pressure chamber of the diaphragm device 12. 12
Intake negative pressure in the first intake passage 2 downstream of the first throttle valve 6 is introduced into b. As a result, diaphragm 12c
is deflected against the elastic force of the spring 12d, and the shutoff valve 8 is fully closed via the operating rod 19. As a result, the entire amount of the air-fuel mixture that is about to flow down the first intake passage 2 flows into the second intake passage 3 through the communication passage 10, increasing the filling efficiency of the second cylinder 5 and ensuring good ignition performance. At the same time, air from an air cleaner (not shown) is supplied to the first intake passage 2 through the atmospheric passage 18, the atmospheric chamber 12a, and the air passage 11 due to the strong intake negative pressure generated downstream of the shutoff valve 8. This air improves the shutoff effect of the shutoff valve 8 and also functions as secondary air for exhaust gas purification.

Next, when the operating range changes to a state other than deceleration, such as when transitioning from deceleration to acceleration, the deceleration switch 14 opens and the solenoid valve 13 is activated by the elastic force of a built-in spring (not shown). , this time, the first intake passage 2 side is closed, while the air hole 16 side is opened,
The negative pressure chamber 12b is opened to the atmosphere through the atmospheric hole 16. At this time, the air is not introduced all at once but is gradually introduced into the negative pressure chamber 12b due to the action of the throttle 17, so that the opening operation of the cutoff valve 8 becomes slow. As a result, there is no sudden transition from partial cylinder (second cylinder 5) operation to full cylinder (first and second cylinders 4, 5) operation, and there is no large fluctuation in engine output.

The throttle 17 may be provided at a position 17' between the negative pressure chamber 12b of the diaphragm device 12 and the solenoid valve 13, or may be provided at both locations.

As described above, the present invention forms a restriction in the communication path through which the pressure chamber (negative pressure chamber) of the diaphragm device communicates with the atmosphere, so that it acts to gradually introduce the atmosphere into the pressure chamber, No shock occurs when transitioning from deceleration operation to other operation (especially acceleration operation), and smooth operation transition can be achieved. Furthermore, it is extremely excellent in practical use in that it can overcome the problems of the prior art by the simple and reliable means of forming a diaphragm.

[Brief explanation of drawings]

The drawing is an overall configuration diagram of a shutter valve device for a two-cylinder engine, which is an embodiment of the present invention. 1...Multi-cylinder engine, 2...First intake passage,
3... Second intake passage, 6... First throttle valve, 7... Second throttle valve, 8... Shutoff valve, 12... Diaphragm device, 12b... Negative pressure chamber (pressure chamber), 13... Solenoid valve (control valve), 14...Deceleration switch, 16...
Air hole, 17, 17'...aperture.

Claims (1)

[Scope of utility model registration request] a plurality of intake passages leading to each of the plurality of cylinders;
A shutoff valve is provided in the intake passage that communicates with some of the cylinders on the downstream side of the throttle valve, and the shutoff valve is operated by intake negative pressure during deceleration operation that acts on the pressure chamber through the negative pressure passage. A diaphragm device that closes to send intake air only to the remaining cylinders, a communication passage that introduces atmospheric air into the pressure chamber of the diaphragm device, and a control valve that closes the communication passage during deceleration operation and opens it when other than deceleration operation. What is claimed is: 1. An intake system for a multi-cylinder engine, characterized in that a throttle is provided in a communication path through which the pressure chamber of the diaphragm device communicates with the atmosphere.