JPH0614038Y2 - Multi-cylinder engine for vehicles that can reduce interior noise - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a multi-cylinder engine for a vehicle, more specifically,
The present invention relates to a vehicle multi-cylinder engine capable of reducing vehicle interior noise caused by engine vibration.

[Prior Art and Problems] In-vehicle noise is an important element of vehicle performance, and various measures have been taken to reduce the in-vehicle noise in order to ensure more comfortable driving.

In-vehicle noise that has been taken up as a problem in recent vehicles, particularly passenger cars, includes noise commonly called engine transmitted sound. This is because the excitation force of the explosion pulse of the cylinders adjacent to both ends of the crankshaft (for example, in a 4-cylinder engine, # 1 cylinder and # 4 cylinder) causes the pulley and flywheel to resonate, and this vibration causes the cylinder block to vibrate. This is because the noise is generated inside the vehicle by being transmitted to the vehicle body through the engine mount.

In the vibration reduction device described in Japanese Utility Model Publication No. 59-86449,
By forming a hollow end of the crankshaft and filling the hollow portion with a diping member, the vibration exciting force of the combustion is absorbed by the damping member, and the swinging motion of the pulley is reduced.

Further, in the structure disclosed in Japanese Utility Model Publication No. 59-122432,
By connecting the crankshaft and the flywheel with an elastic member, noise caused by the flywheel is reduced.

An object of the present invention is to reduce the engine transmitted sound more simply and effectively by a principle different from the prior art.

[Means for solving problems]

The present invention, in a multi-cylinder engine for a vehicle in which an output pulley is connected to one end of a crankshaft and a flywheel or a torque converter is connected to the other end, limits an intake air amount of a cylinder adjacent to the end of the crankshaft. The intake air amount limiting means for controlling the intake air amount limiting means, and the control means for controlling the operation of the intake air amount limiting means to reduce the intake air amount of the cylinder adjacent to the end portion during the partial load operation of the engine. It is a feature.

[Action]

In this way, since the intake air amount of the cylinders at both ends is reduced in the partial load operation region of the engine where the vehicle interior noise becomes a problem,
The explosive excitation force of the cylinders at both ends is limited, and the resonance phenomenon of the pulley, flywheel, or torque converter is suppressed,
Engine transmission noise is reduced. When the engine is fully loaded, the restriction on the intake air amount can be stopped and high output can be achieved.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this embodiment, the engine 10 is constructed as a 4-cylinder engine, but the present invention is equally applicable to a 6-cylinder engine, an 8-cylinder engine and the like. The engine 10 includes a # 1 cylinder 12A, a # 2 cylinder 12B, a # 3 cylinder 12C, in order from the front part to the rear part.
It has a # 4 cylinder 12D. Engine crankshaft 1
An output pulley 16 is connected to the front end of 4 in a conventional manner,
A flywheel 18 is connected to the rear end. In an automatic transmission vehicle, the flywheel 18 replaces the input device of the torque converter.

The intake system of the engine 10 includes an air cleaner 20, a throttle valve 22, and an intake manifold 24, and the fuel supply device is not shown for simplification of the drawing. The exhaust system has an exhaust manifold 26.

One end of the throttle shaft 28 of the throttle valve 22 is connected to the accelerator pedal in a known manner by a link (not shown). At the other end of the throttle shaft 28,
Throttle sensor 30 for detecting throttle opening
Are connected, and the output signal is electronic control circuit (ECU) 32
Entered in. The control circuit 32 is composed of a conventional microcomputer and is composed of a memory, a CPU, and an I / O device. The rotation speed sensor 34 for detecting the engine rotation speed is incorporated in, for example, a distributor, and its output signal is also input to the ECU 32.

The engine 10 is provided with intake air amount limiting means 36 for limiting the intake air amounts of the # 1 cylinder 12A and the # 4 cylinder 12D. The intake air amount limiting means 36 includes intake control valves 40A and 40D provided in the intake passage 38A of the # 1 cylinder and the intake passage 38B of the # 4 cylinder, respectively, and these intake control valves 40A and 40D are common. Is attached to the valve shaft 42 of the.

As can be seen from FIG. 2, the valve shaft 42 is connected to the output rod 48 of the solenoid actuator 46 via the lever 44.
Is connected to the solenoid of the actuator 46.
The intake control valves 40A and 40D are opened and closed by N / OFF control. The solenoid actuator 46 is controlled by the ECU 32 as described below. A linear solenoid may be used instead of the solenoid actuator 46, and the opening degrees of the intake control valves 40A and 40D may be continuously changed.

The ECU 32 executes the program shown in the flowchart of FIG. 3 to control the intake air amount limiting means 36. The program of this flowchart is, for example, 50
It can be executed as a millisecond interrupt routine.

In the flowchart of FIG. 3, in step 100,
The engine speed N is calculated from the signal from the rotation speed sensor 34 and compared with a set value (for example, 1500 rpm). If the rotation speed N is 1500 rpm or more, the routine proceeds to step 110, where the throttle opening TH is calculated from the signal from the throttle sensor 30 and compared with the throttle opening lower limit design value TH _L for the measured engine rotation speed N. The throttle opening lower limit set value TH _L is preset for different engine speeds as shown in FIG. 4, and is stored in the memory of the ECU 32 in advance as a map or a table.

If TH> TH _L , in step 120, the measured throttle opening TH is set to the throttle opening upper limit set value TH _H.
Compare with. This upper limit set value TH _{H is} also set as shown in FIG. 4 and is stored in advance in the memory of the ECU.

If TH <TH _{H in} step 120, the solenoid actuator 46 is energized in step 130, and the intake control valve 40
Close A and 40D. As a result, # 1 cylinder 12A and # 4
Since the amount of intake air to the cylinder 12D is limited and the explosive excitation force of these cylinders is reduced, resonance of the pulley 16 and the flywheel 18 is suppressed. In this state, # 3
Since the amount of intake air to the cylinders and the # 4 cylinder is not limited, these cylinders output torque according to the opening degree of the throttle valve 22, but since these cylinders are separated from the pulley 16 and the flywheel 18, Does not resonate significantly.

As can be seen from the above steps, the intake control valves 40A, 40A
D is closed when the throttle opening and the engine speed correspond to the shaded area in FIG. This region corresponds to the most frequently used engine partial load operating state, and is the operating condition in which engine transmitted sound is the most problematic in practical use.

When the throttle opening and the engine speed are outside the above range, the routine proceeds to step 140, where the energization of the solenoid actuator 46 is stopped and the intake control valves 40A, 40D are fully opened. In this way, the intake air amount to the # 1 cylinder and the # 4 cylinder is not limited when the engine is under a high load and when the engine is idling. What does not limit the air volume at high load is
This is to reduce the intake resistance and secure the maximum torque.

Further, during idle operation, if there is a difference in the intake air amount between the cylinders, idle vibration will deteriorate, so the intake air amount is not limited.

[Effect of device]

As described above, the present invention is provided with the intake air amount limiting means for limiting the intake air amount of the cylinder adjacent to the end portion of the crankshaft, and the noise in the vehicle becomes a problem in practical use. Since the intake air amount of the cylinder is reduced under the engine partial load operating condition, resonance of the pulley 16 and the flywheel 18 is reduced, and engine transmitted noise is suppressed in a practical operating region without impairing the maximum torque of the engine. be able to.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an engine according to an embodiment of the present invention, a part of which shows a cross section, FIG. 2 is a side view of intake air amount limiting means, and FIG. 3 is an example of intake air amount control. FIG. 4 shows an example of a map of the intake air amount restriction region. 10 ... Engine, 14 ... Crankshaft, 16 ... Pulley, 18 ... Flywheel, 22 ... Throttle valve, 24 ... Intake manifold, 30 ... Throttle sensor, 32 ... Electronic control circuit, 36 ... Intake air amount limiting means, 38 ... Intake passage, 40 ... Control valve, 46 ... Actuator.

Claims (1)

[Scope of utility model registration request] 1. In a multi-cylinder engine for a vehicle, wherein an output pulley is connected to one end of a crankshaft and a flywheel or a torque converter is connected to the other end, the intake air amount of a cylinder adjacent to the end of the crankshaft is measured. Intake air amount limiting means for limiting and intake air amount limiting means for controlling the operation of the intake air amount limiting means to reduce the intake air amount of the cylinder adjacent to the end portion during partial load operation of the engine. A multi-cylinder engine for vehicles characterized by.