JPH0826826B2 - Air cleaner for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air cleaner for an internal combustion engine.

[Prior art]

It is known that in a general internal combustion engine, its volume efficiency η _v (that is, axial torque) mainly depends on the rotational speed of the internal combustion engine and the length of the intake passage. And
When the rotational speed of the internal combustion engine for a vehicle changes over a wide range, if the length of the intake passage is constant, the volume efficiency peaks only in one limited rotational speed range. I can't get it. Therefore, it has been proposed to make the length of the intake passage variable in accordance with the number of revolutions of the engine in order to obtain the peaks of the volumetric efficiency in different regions of the number of revolutions.

For example, in Japanese Utility Model Laid-Open No. 60-12626, an inner cylinder provided with a protruding portion that fits between the partition walls is relatively arranged with respect to an outer cylinder provided with a spiral partition wall on the inner peripheral surface. Turn to
A configuration is disclosed in which the flow path length of the intake flow path portion defined by both of them is variable.

〔problem〕

However, in order to dispose such a structure in the middle of the intake passage, special consideration must be given to the disposition and mounting means. Therefore, there is a problem in mounting on a vehicle or the like where the occupied space is limited. Further, in order to provide a spiral partition wall on the inner peripheral surface, or to provide a protruding portion that fits between the partition walls and rotates in sliding contact, high-precision machining is required, leading to an increase in cost and failure. There is a problem that it is likely to happen.

[Means for solving problems]

Therefore, the present invention aims to solve such a problem.

In order to achieve this object, in the present invention, a movable member having a spiral groove formed on the outer peripheral surface is disposed in the casing of the air cleaner to form a spiral flow path between the two,
There is provided an air cleaner in which the movable member is translated in accordance with the state of the internal combustion engine.

[Action]

According to the present invention, the intake flow passage portion having a variable flow passage length is formed in the air cleaner, and the above-mentioned problems are solved.

The operation and effect of the present invention will be apparent from the description of the embodiments described in detail below with reference to the accompanying drawings.

〔Example〕

In FIG. 1, an air cleaner 1 is fitted to an upper case half 11 (made of metal in the illustrated embodiment) having a circular cross-sectional shape made of metal or resin and an upper case half 11 via a gasket 12. It has a casing 10 composed of a lower case half 13 made of metal or resin. The lower case half 13 of the casing 10 is composed of a large-diameter circular cross section 13L and a small-diameter circular cross section 13S connected thereto.

Inside the casing 10, a filter element element 20 folded concentrically has its outer peripheral edge portion in both case halves 1.
It is held between 1 and 13.

The upper case half 11 is provided with an air introduction opening 14 for inserting outside air toward the filter element element 20.

A hollow cylindrical guide member 15 is provided at the center of the bottom of the small-diameter circular cross-section 13S of the lower case half 13 to filter elements 20.
It is projected integrally toward. Also, small diameter circular cross section
At the edge of the bottom of 13S, a discharge opening 16 through which the air cleaned by the filter element element 20 is discharged toward the internal combustion engine is formed.

Further, a cylindrical member 30 having an open end portion and a closed end portion is fitted to the hollow cylindrical guide member 15 through a seal member 18 in an airtight and slidable manner. A series of spiral grooves 31 are formed on the outer peripheral surface of the cylindrical member 30. Cylindrical member 30
Forms a continuous spiral channel 40 in sliding contact with the inner peripheral surface of the small-diameter circular cross-section 13S of the casing 10. The spiral groove 31 may be formed by cutting the outer peripheral surface of the cylindrical member 30, or may be formed by spirally welding a single plate to the outer periphery of the cylindrical member and then adjusting the outer dimensions. It can also be formed by integral molding of resin or the like.

A stem 51 is fixed to the closed end of the cylindrical member 30 by an appropriate means, and a rack 51R is formed at the free end of the stem 51. Further, a stepping motor 52 is attached to the casing 10, and an output shaft thereof is provided with a pinion 53 that engages with the rack 51R. This stepping motor 52, stem 51 and rack
51R and the pinion 53 constitute a driving device 50 for the cylindrical member 30 that is a movable member. By operating the stepping motor 52, the cylindrical member 30 is moved and the casing 10 is moved.
The flow path length of the spiral intake air flow path 40 in the inside can be changed. That is, the cylindrical member 30 is placed at the position shown in FIG.
If so, the clean air passing through the filter element element 20 will flow along the spiral flow passage 40 formed over the entire axial length of the small-diameter circular cross-section 13S, as indicated by the arrow. .. On the contrary, when the cylindrical member 30 is located at the position shown in FIG.
It will flow through the short spiral channel 40 formed in a part of S.

The difference in the characteristics of the volume efficiency η _v due to the difference in the position of the cylindrical member 30 is shown in FIG. The cylindrical member 30 is the first
As shown in the drawing, the flow path length is increased when the small-diameter circular section 13S is housed. As a result, the characteristic of the deposition efficiency η _v has a peak at a low engine speed N _l , as shown by the broken line in FIG. In addition, as shown in FIG. 2, when the cylindrical member 30 projects into the large-diameter circular cross-section portion 13L, as shown by the alternate long and short dash line, the high engine speed Nh
It peaks at. Therefore, if the position of the cylindrical member 30 is changed according to the state of the engine, for example, the fluctuation of the engine speed, the characteristic that the maximum volumetric efficiency is always obtained as shown by the solid line in FIG.

Next, the operation of this air cleaner will be described with reference to FIGS. 1 and 2.

First, a rotational speed of the engine is selected as one of the states of the internal combustion engine, a rotational speed sensor 61 for detecting the rotational speed detects a signal In corresponding to the rotational speed of the engine, and a position detection sensor for detecting the position of the cylindrical member 30. The position signal Ip from 62 is the control unit.
Sent to 63. The control unit 63 determines the position (target position) of the cylindrical member 30 where the peak of volumetric efficiency comes to the engine speed region from the signal In. Then, the difference between the current position obtained from the position signal Ip and the target position is calculated, and the operation amount to the stepping motor 52 is determined. Then, the cylindrical member 30
A command signal C is sent to the stepping motor 52 in order to move the required amount. The rotation speed sensor 61, the position detection sensor 62, and the control unit 63 constitute the control device 60, and actuate the drive device for the cylindrical member 30.

Another embodiment is shown in FIGS. 4 and 5. This embodiment air cleaner 101 includes an upper case half 111
And a casing 110 composed of a lower case half 113 fitted into the upper case half 111 via a gasket 112, and a double cylindrical member 115 arranged concentrically. The double cylindrical member 115 is integrally formed with the lower case half 113. The open end of this double cylindrical member 115 projects into the casing 110, and the closed end projects outside the casing 110.

An annular filter element element 120 is hermetically held in the casing 110 with annular seal members 121 and 121 interposed between the annular filter element element 120 and both end surfaces thereof.

The lower case half 113 has a filter element element 120
An air introduction opening 114 for introducing the outside air toward is formed.

A discharge opening 116 for discharging the air cleaned by the filter element element 120 toward the internal combustion engine is formed at the edge of the bottom of the closed end of the double cylindrical member 115.

A cylindrical member 130 having an open end and a closed end is fitted to the inner wall of the double cylindrical member 115 in a hermetically slidable manner via a seal member 118. A series of spiral grooves 131 are formed on the outer peripheral surface of the cylindrical member 130. Cylindrical member 1
The outer peripheral surface of 30 is in sliding contact with the outer peripheral wall of the double cylindrical member 115 of the casing 110 to form a continuous spiral flow path 140.

A stem 151 is fixed to the closed end of the cylindrical member 130, and a rack 151R is formed at the free end of the stem 151. Further, a stepping motor 152 is attached to the casing 110, and a pinion 153 that engages with the rack 151R is provided on its output shaft. By operating the stepping motor 152, the cylindrical member 130 can be moved to change the flow path length of the spiral intake flow path 140 in the casing 110. That is, with the cylindrical member 130 in the position shown in FIG. 4, the clean air passing through the filter element element 120 is
The outer peripheral wall of the double cylindrical member 115 and the spiral groove 13 of the cylindrical member 130.
With 1, the flow will be along the longest spiral flow path 140 formed over the entire length of the double cylindrical member 115. Conversely, with the cylindrical member 130 in the position shown in FIG. 5, the clean air is defined by a portion of the outer peripheral wall of the double cylindrical member 115 and a portion of the spiral groove 131 of the cylindrical member 130. After flowing through the short spiral flow path 140, it immediately flows toward the discharge opening 116. That is, in this case, the air flows through the short intake passage.

The operation of this embodiment is the same as that described above, and the description thereof is omitted.

〔The invention's effect〕

As described above, in the present invention, the intake passage portion is provided in the air cleaner, and the length of the intake passage portion can be changed by the translational movement of the movable member. Therefore, unlike the conventional case, it is not necessary to provide a special device in the middle of the intake passage. Further, since it is not necessary to fit and rotate the members to change the flow path length, it is possible to suppress an increase in cost. That is, in the case of the one described in the above-mentioned publication, it is necessary to improve the processing accuracy of the inner peripheral surface of the outer cylinder and the inner peripheral surface of the partition wall, and also to increase the dimensional accuracy between the partition walls. . On the other hand, in the present invention, the width of the spiral groove (corresponding to the space between the partition walls)
It is not necessary to increase the dimensional accuracy of the above, and it is only necessary to increase the processing accuracy of the outer peripheral dimension of the movable member, which is easier than the inner peripheral surface. Therefore, there are significant advantages in terms of both structure and cost.

[Brief description of drawings]

1 and 2 are vertical cross-sectional views of an air cleaner according to an embodiment of the present invention, FIG. 3 is a graph showing the relationship between the peak of volumetric efficiency and the engine speed, and FIGS. FIG. 5 is a vertical sectional view of another embodiment. 1,101 ...... Air cleaner, 10,110 ...... Casing, 14,114 ...... Air introduction opening, 16,116 ...... Discharge opening, 20,120 ...... Filter element element, 30,130 ...... Cylindrical member which is a movable member, 40,140 ...... Helix flow path, 50 ...... Drive device, 51,151 …… Stem, 52,152 …… Stepping motor, 60 …… Control device, 61 …… Rotational speed sensor, 62 …… Position detection sensor, 63 …… Control unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Obayashi 1-1, Showa-cho, Kariya city, Aichi Prefecture Nihon Denso Co., Ltd. (72) Inventor, Kazuyuki Horie 1-1-cho, Showa-machi, Kariya city, Aichi prefecture Within the corporation (56) References

Claims (1)

[Claims] 1. A casing, a filter element element disposed in the casing, an air introduction opening formed in the casing for introducing air toward the filter element element, and passing through the filter element element. A discharge opening formed in the casing for sending the purified air to the internal combustion engine, and a spiral shape arranged in the casing and slidably contacting an inner peripheral surface of the casing to form a continuous spiral flow path. A movable member having a groove formed on the outer peripheral surface thereof, a drive device that translates the movable member in the axial direction by an arbitrary distance, and the moving distance is determined according to the state of the internal combustion engine and the drive is performed. An air cooler for an internal combustion engine, comprising: a control device for operating the device.