JPS61160519A - variable swirl device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a variable swirl system having an air passage in a cylinder head that swirls combustion air and supplies it to the combustion chamber and controls the swirl strength. In particular, the present invention relates to a variable swirl device that performs swirl control to follow sudden opening operations (sudden acceleration operations) of an axle system, suppresses noise and ignition delay, and achieves good combustion.

[Prior Art] In general, internal combustion engines have achieved suitable combustion by swirling combustion air and supplying it into the combustion chamber, thereby effectively mixing the swirl with fuel.

However, the swirling of the combustion air is not only good if it is too strong! ! It is required to control the swirl strength according to the load of one leap.

Therefore, in order to solve the above problem, Japanese Patent Laid-Open No. 58-195017 discloses a method for controlling the appropriate swirl strength.
A swirl control method for internal combustion engines is introduced in .

This proposal provides a pressure detector, which is a torque detection means, via a rubber mount between the engine mount of an internal combustion engine and a vehicle mount, and also controls the flow rate within the helical intake port to vary the flow velocity. A butterfly-type intake swirl variable means is provided, and a signal from the torque detection means is input to a control unit, which causes the unit to operate the intake swirl variable means.

[Problems to be Solved by the Invention] The proposal configured as described above is based on the imaging that is applied to the engine itself depending on the engine load and the fluctuation of the rotational speed.

It is considered to be an effective means for realizing stable combustion by measuring torsion, inertia, etc. using a pressure detection means, and controlling the intake swirl variable means in accordance with the measured values.

However, since the swirl control with the above configuration is a secondary control (feedback), there remains the problem that it cannot deal with the ignition delay that occurs when the engine is suddenly accelerated, and the resulting increase in noise.

Possible reasons for this include the relationship between the engine rotational speed (rpm) and the cylinder inner wall m (° C.) and the cylinder pressure, as shown in FIGS. 5 and 6.

That is, as shown in FIG. 5, in order for the engine to operate properly, the cylinder inner wall temperature must be high enough to sufficiently evaporate the fuel.

This wall temperature is defined as the steady temperature indicated by the solid line a.

Next, the engine is started and gradually accelerated as indicated by the dotted line, and the wall temperature increases accordingly.

However, as shown in Figure 6, the horizontal axis is the crank angle, and the vertical axis is the cylinder pressure, and if we look at the relationship between them, we can see that when the axle is suddenly depressed compared to the steady state cylinder pressure shown by the solid line C. When sudden acceleration is performed, an ignition delay Sl shown by the dotted line d occurs,
After that, due to rapid combustion, the pressure inside the cylinder increases abnormally, increasing noise.

In other words, during acceleration, the cylinder inner wall temperature does not become higher than the steady state, so that a sufficient evaporation wall temperature cannot be obtained for the supplied fuel. This problem has attracted particular attention in diesel internal combustion engines.

[Object of the Invention] The present invention was devised to solve the above-mentioned problems, and an object of the present invention is to provide a variable swirl device that suppresses ignition delay and reduces noise during rapid acceleration of diesel internal combustion engines, etc. It is on offer.

[Summary of the Invention] In order to achieve the above object, the present invention includes an air passage that opens into an intake port and introduces air that weakens the intake swirl strength, an on-off valve provided in the air passage, and an on-off valve that connects the on-off valve to an engine. a control device that detects an acceleration state and holds the valve in a closed state; a valve operating means for opening and closing the valve, and when the sensor detects that a predetermined acceleration is exceeded, the valve control means closes the opening and closing valve to supply combustion air into the air passage; This creates a high swirl inside the combustion chamber and burns! The purpose is to promote mixing and atomization of the fuel and combustion air supplied within the combustion chamber, thereby suppressing ignition delay and reducing noise.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described based on the accompanying drawings.

Inside the cylinder body of an internal combustion engine (diesel internal combustion engine), there is a piston with a recessed combustion chamber formed at the top.
It is provided reciprocally within the cylinder, and a cylinder head is freely attached to the upper end surface of the cylinder body via a gasket or the like.

As shown in FIGS. 1 and 2, a cylinder head 1 is formed with an opening from the outside and communicating in a helical manner toward the cylinder chamber, which swirls combustion air into the combustion chamber 2. An intake port 3 for supplying air is formed.

Further, the cylinder head 1 is formed with an exhaust port 4 for exhausting combustion gas from the combustion chamber 2, similar to the intake port 3 described above.

Further, in the communication portion between the intake/exhaust ports 3, 4 and the cylinder, a cam device (not shown) for internal combustion is connected.
An intake or exhaust valve 15 that opens and closes the communication portion is provided so as to be able to open and close freely.

In order to make the internal combustion engine configured as described above follow a sudden acceleration operation of the engine, and at the same time to prevent ignition delay and reduce noise, the variable swirl device of the present invention is configured as follows. Ru.

As shown in FIGS. 1 and 2, an introduction section 3b is formed by expanding the inner wall 3a on the upstream side of the intake port 3 radially outward, and one end is opened from the introduction section 3b. An on-off valve 6 is provided at one end of the air passage 5 and is operable to open and close freely.

Therefore, by closing the on-off valve 6, combustion air is taken in only into the intake port 3, combustion air with high swirl strength is supplied into the combustion chamber 2, and the fuel and combustion air are mixed. are mixed effectively, and ignition delay and noise during rapid acceleration can be suppressed.

Therefore, in the present invention, a valve control device 7 is configured that closes the on-off valve 6 by sensing sudden acceleration of the engine.

Specifically, the valve control device 7 senses the acceleration of the opening and closing of the axle based on the depression speed of the valve operating means 8 and the axle of the engine in order to open and close the on-off valve 6, and the detected acceleration is determined in advance by the engine. It is comprised of a sensor 9 that operates the valve actuating means 8 when the acceleration exceeds a set acceleration set based on the water temperature and the outside air temperature.

The valve operating means 8 includes, for example, a fluid cylinder 10 for operating the on-off valve 6, a pressure accumulation means 11 for supplying a predetermined fluid pressure to operate the cylinder rod 10a of the fluid cylinder 10, and a pressure accumulation means 11 for supplying a predetermined fluid pressure to operate the cylinder rod 10a of the fluid cylinder 10. A connecting pipe 13 formed from an air hose or the like and having a solenoid valve 12 connecting the means 11, and an opening/closing device 1 for opening and closing the solenoid valve 12.
It consists of 4.

Specifically, as shown in FIG. 2, a fluid means having an on-off valve 6 integrally provided at the tip of the cylinder rod 10a is screw-fitted into the engagement portion 16 of the cylinder head 1, so that the fluid means is integrated with the cylinder head 1. and the on-off valve 6 is connected to the cylinder rod 10.
It is configured to appear and retract together with a to open and close one end of the air passage 5.

Therefore, as shown in Figure 3, when the engine is suddenly accelerated,
Based on the axle depression speed, the sensor 9 detects the acceleration d.
0/dt is sensed and the detected d o/dt is input to the switching device 14. The opening/closing device 14 performs a comparison calculation of the input value de/dt with respect to the set acceleration C input in advance.

As a result, if d/dt>C, it is determined that there has been sudden acceleration, and the Ifl valve 12 is opened, thereby operating the fluid cylinder 10 and closing the on-off valve 6. Therefore, high swirl combustion air is supplied into the combustion chamber 2, preventing ignition delay and suppressing noise.

When do/dt<C, it is determined that the state is normal or normal acceleration, and the on-off valve 6 is opened, and the air passage 5 weakens the intake swirl from the intake port 3 in the combustion chamber 2. Combustion air will be supplied.

FIG. 4 shows a flowchart based on input values (Ijl water iw, , atmospheric pressure IAt, and acceleration d0/dt of the sensor 9) that are input to the opening/closing device 14 and are calculated and compared, and d0/dt+1/ When WT > C, it is determined that the water temperature is low, and the swirl is made even higher than in the above example, and when do/dt+1/^Tic,
・In this case, it is determined that the atmospheric temperature is low and the stool is set higher.

The solenoid valve 12 opens or closes when the sensor 9 outputs an operation signal, and at the same time, the solenoid valve 12 opens or closes at the same time.
It has a built-in timer to maintain operation for ~2 seconds.

[Effects of the Invention] As detailed above, according to the present invention, the following excellent effects can be exhibited.

(1) When an internal combustion engine is suddenly accelerated by an axle, etc., the acceleration can be detected from the speed at which the axle is depressed, and the combustion air supplied to the combustion chamber can be supplied with a high swirl. , thereby preventing ignition delay and reducing noise.

(2) Since noise can be suppressed, costs can be reduced by removing noise countermeasure covers and the like, and high-quality internal combustion engines can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a preferred embodiment of the variable swirl device of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG.
4 are flowcharts showing the control contents of the variable swirl device, and FIGS. 5 and 6 are diagrams showing the relationship between the engine speed and the cylinder inner wall temperature and the relationship between the cylinder pressure and the engine speed. In the figure, 1 is a cylinder head, 2 is a combustion chamber, 3 is an intake port, 4 is an exhaust port, 5 is an air passage, 6 is an on-off valve, 7 is a valve control device, 8 is a valve operating means, 9 is a sensor, 10 1 is a fluid cylinder, 12 is an electromagnetic valve, and 14 is an opening/closing device.

Claims (1)

[Claims] An air passage that opens to an intake port and introduces air that weakens intake swirl strength, an on-off valve provided in the air passage, and a control device that detects an acceleration state of an engine and holds the on-off valve in a closed state. Variable swirl device with.