JPH10238425A - Air filter for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a proper air/fuel ratio at all times, increase power during the low speed rotation of an internal combustion engine and improve a fuel consumption during high speed rotation by housing a funnel in an air filter and letting air sucked during the operation of the internal combustion engine pass from the wide side to the narrow side of the funnel. SOLUTION: The case 1 of an air filter is covered with a lid 2 and has a filter medium 3 arranged in an outer peripheral side. A funnel 4 is housed in the air filter to divide the flow of air passing through the filter medium 3 in the air filter into one flowing outside the funnel 4 and one flowing inside the funnel 4. Then, the air flow passing outside the funnel 4 receives a straightening effect along the configuration of the funnel 4 to be supplied to a carburetor side from an outlet. The air flow entering the inside of the funnel 4 increases its flow velocity at the narrow outlet part of the funnel 4. Thus, the generation of the excessive composition of air during the low speed rotation of an internal combustion engine can be suppressed and power can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an air filter for an internal combustion engine used for an automobile or the like.

[Description of the Prior Art]

A conventional air filter only filters air with a suitable filter medium, and there is no member provided inside the filter to specifically control the flow of air. Therefore, the air flow inside the air filter was left in a natural state.

[0003] Alternatively, there were members, but only rectification, and none of them actively controlled the flow.

Therefore, when the internal combustion engine is rotating at a low speed,
The suction resistance inside the filter was low, and the air composition was likely to be excessive.

[0005] By the amount deviated from the proper (air / fuel) ratio,
Power loss was easy to occur.

[0006] Power loss during low-speed rotation of the internal combustion engine has been dangerous during operation.

On the other hand, when the internal combustion engine is rotating at a high speed, the suction resistance of the filter increases, and conversely, the air tends to be insufficient.

[0008] If the vehicle continues to run with an air-deficient composition, the fuel consumption rate increases, and it has been difficult to improve fuel efficiency.

Unless fuel efficiency is improved, it is not preferable from the viewpoint of energy saving.

That is, in summary, the conventional air filter could not solve the problem of power loss at the time of low-speed rotation of the internal combustion engine and the decrease of fuel consumption at the time of high-speed rotation.

[Operation of the present invention]

SUMMARY OF THE INVENTION The present invention has been made to overcome the drawbacks of the conventional air filter, and has been made with the object of increasing power at low speed rotation of the internal combustion engine and improving fuel economy at high speed rotation. In this case, a funnel is provided inside the air filter to specifically control the flow of air, and thereby the two objectives which are easily contradictory can be achieved.

The present invention will be described in detail with reference to the drawings. In the figure, 1 is a case of an air filter, 2 is a lid of the case, 3 is a filter material, and 4 is a funnel housed inside the filter.

[0013] Inside the filter, the flow of air that has passed through the filter medium is divided into one that flows outside the funnel and one that flows inside the funnel.

[0014] The air flow passing outside the funnel is subjected to a rectifying effect along the outside shape of the funnel and flows toward the outlet, that is, the inlet of the carburetor.

On the other hand, the air flow flowing into the funnel does not cause any change at the opening portion of the funnel, but its flow velocity increases as it approaches the narrow outlet portion of the funnel. That is, as a result of the cross-sectional area of the passage of air being reduced to several tenths, the flow velocity must be increased.

Therefore, near the outlet of the air filter, that is, near the inlet of the carburetor, the air flow is composed of two flows, a high-speed flow in the center and a rectified low-speed flow around the center.

The funnel provided inside the filter acts as a certain resistance increase against air intake when the internal combustion engine is rotating at a low speed.

Therefore, the occurrence of excess air composition during low-speed rotation of the internal combustion engine is suppressed, and as a result, power loss is less likely to occur and power is increased.

This leads to an improvement in safety during traveling.

On the other hand, when the internal combustion engine is rotating at a high speed, the speed of the airflow passing through the inside of the funnel increases, and as a result,
The intake air volume is increased compared to conventional air filters.

As a result, the air-deficient composition is eliminated, and the ratio approaches the proper (air / fuel) ratio, so that the fuel efficiency is greatly improved.

Such excellent performance of the air filter of the present invention is governed by the geometry of the funnel housed inside the filter and its location inside the filter.

As a result of the inventor's diligent research, the ratio of the cross-sectional area of the outlet opening of the filter to the cross-sectional area of the wide part of the funnel is:
It has been found that between 1: 1 and 1: 3 produces favorable results.

If the cross-sectional area ratio of the two is less than 1: 1, the ratio of the air flow controlled by the funnel is too small, which is not preferable for stable combustion of the internal combustion engine.

When the cross-sectional area ratio of both is 1: 3 or more, the proportion of the air flow controlled by the funnel increases, and it is difficult to achieve the initial purpose.

Therefore, the preferred cross-sectional area ratio between the two is:
It can be said that it is between 1: 1 and 1: 3.

It is difficult to determine the position of the inside of the funnel because it depends on the relationship with the carburetor of the internal combustion engine used and the intake manifold. However, basically, assuming that the height of the air filter is 1, the optimum position exists at about 0.8, that is, forward or upward as viewed from the outlet.

As a practical matter, it is desirable to make a decision after mounting on a vehicle to be used and then traveling and measuring its acceleration performance and fuel efficiency.

However, regarding the shape of the funnel to be used,
It has been found that a ratio of the cross-sectional area of the wide portion of the funnel to the cross-sectional area of the narrow portion of 20: 1 to 140: 1 is a desirable range for obtaining suitable performance.

If the ratio is less than 20: 1, it is not possible to expect a sufficient speed increase in the center air flow.

When the ratio is 140: 1 or more,
Although the increase in the speed of the center airflow itself is sufficient, the increase in the air suction resistance of the funnel itself is too large to obtain practical performance.

Although FIG. 1 is drawn so as to anticipate a round funnel, the shape of the funnel itself is not limited by the cross-sectional area ratio between the wide part and the narrow part.
It is free and any shape can be selected. The same applies to the shape of the conical portion and the shape in the vicinity of the outlet, and it is not necessary to provide an arbitrary slope or the shape of the outlet to be cylindrical.

Regarding the internal setting position of the funnel,
Although it has been described that a convenient position is determined by mounting it on the actual vehicle, some position variability may be provided inside the air filter depending on the degree of negative pressure of the internal combustion engine.
By such means, the effect of the present invention can be further ensured.

For example, through holes are provided at several locations on the outer frame of the funnel, and a support column for supporting the funnel is provided inside the filter through the through holes, and works in the compression direction on the upper and lower sides of the funnel. By providing a spring or a spring acting in the extension direction on the upper side and the lower side of the funnel, the position of balance with the negative pressure can be determined.

The variable distance of the funnel can be increased by reducing the force of the spring, and the variable distance can be reduced by increasing the force of the spring.

FIG. 2 shows an example. In FIG. 2, reference numeral 5 denotes a supporting column passed through a hole (not shown) in the outer frame of the funnel, and reference numeral 6 denotes a spring that works in a compression direction and is fitted into the supporting columns housed on both the upper and lower sides of the funnel.

As the rotational speed of the internal combustion engine increases, the movement of the funnel to move forward or upward of the air filter is in a direction desired to exert the performance of the air filter over the entire rotation speed of the internal combustion engine. is there.

[Effect of the present invention]

The air filter for an internal combustion engine according to the present invention can exhibit the following excellent performance. 1. Power up during low speed rotation of internal combustion engine. 2. Improve fuel efficiency when the internal combustion engine rotates at high speed. 3. Appropriate combustion over the entire rotation range of the internal combustion engine. 4. Very little cost increase.

The filter material used in the present invention can be selected arbitrarily, and its performance is not controlled by the type of the filter material.

As described above, the air filter for an internal combustion engine according to the present invention can greatly improve the performance with a slight increase in cost.

Example 1 The ratio of the cross-sectional area of the outlet of the air filter to the cross-sectional area of the wide side of the inner funnel was 1: 1, and the ratio of the cross-sectional area of the wide side of the funnel to the cross-sectional area of the narrow side was: A 140: 1 internal combustion engine (1220 cc, compression ratio 7.
5) When attached to the car carrying the car and fixing the funnel at the optimum position, the driver can feel that the power-up during low-speed rotation has increased by about 30% compared to the conventional model, and the speed is 100 km / h.
Fuel efficiency when driving on the road was improved by 20%.

Example 2 The ratio of the cross-sectional area of the outlet of the air filter to the cross-sectional area of the wide side of the inner funnel was 1: 3, and the ratio of the cross-sectional area of the wide side of the funnel to the cross-sectional area of the narrow side was: A 20: 1 air-cooled anti-four cylinder internal combustion engine (1300 cc, compression ratio 9.
0) When the vehicle is mounted on the vehicle and the funnel is fixed at the optimum position, the driver can feel that the power-up during low-speed rotation has increased by about 30% compared to the conventional model.
Fuel efficiency when driving on the road was improved by 20%.

Example 3 A hole for passing four support rods was made in the outer edge of the funnel of the air filter used in Example 1, and the funnel was set at an optimum position.
A squeeze spring was attached above and below the four support rods in the compression direction so that it could be moved somewhat. When the vehicle was mounted on the vehicle used in Example 1 and its response was examined, a better response was obtained over the entire rotation range of the internal combustion engine than in Example 1, and the fuel consumption during high-speed running was improved by 30%.

Example 4 The funnel of the air filter used in Example 2 having a hole with a diameter of 0.5 mm drilled at the conical part of the funnel was mounted on an injection specification automobile (2000 cc) to improve the running performance. Investigation revealed that the power-up during low-speed rotation of the internal combustion engine was 2
The fuel efficiency during high-speed driving was improved by 20%.

[Brief description of the drawings]

FIG. 1 is a sectional view of the present invention.

FIG. 2 is a cross-sectional view according to another embodiment of the present invention.

[Explanation of symbols]

(1) is an air filter case, (2) is a case lid,
(3) is a filter medium, (4) is a funnel housed inside the filter, (5) is a support column passed through a hole (not shown) of an outer frame of the funnel, and (6) is passed through a support column. A spring that acts in the compression direction placed on the upper and lower sides of the funnel.

Claims (4)

[Claims] 1. An air filter provided with a filter medium, wherein a funnel is housed inside, and the air to be sucked passes from the wide side to the narrow side of the funnel, and the cross-sectional area of the outlet of the filter and the wide part of the funnel are reduced. 2. The air filter for an internal combustion engine according to claim 1, wherein the ratio to the cross-sectional area is from 1: 1 to 1: 3. 2. The air filter for an internal combustion engine according to claim 1, wherein the ratio of the cross-sectional area of the wide part of the funnel to the cross-sectional area of the narrow part is from 20: 1 to 140: 1. vessel. 3. The air filter for an internal combustion engine according to claim 1, wherein the position of the funnel is adjustable or automatically changed according to a negative pressure or the like. 4. An air filter for an internal combustion engine according to claim 1, wherein a large number of small holes are formed in a conical portion of the funnel.