JP2010185452A - Air filter for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air filter exhibiting a high effect with compact shape as an air filter for an internal combustion engine in a land grading machine. <P>SOLUTION: A filter housing 1 includes a housing lower member and a detachable housing cover placed on the housing lower member. A filter insert 4 is installed at the filter housing 1. A cyclone type pre-separator 6 formed to be integrated with the filter housing is built in an intake direction of the intake port side in the filter housing 1. The cyclone type pre-separator 6 exhibits a purifying function before a sponge filter, and the sponge filter functions before the filter insert 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air filter in an internal combustion engine according to claim 1.

  In the internal combustion engine, the intake air flows in through the air filter, and as a result, it is possible to prevent problems caused by dust contamination or dust contamination of the air sucked into the internal combustion engine. As a typical configuration of such an air filter, a filter housing includes a lower member and a detachable cover placed on the lower member, and a filter insert is installed in the filter housing. The filter insert that has passed the intake air flow holds the adsorbed dust particles, and the dust particles are fixed inside or outside the filter material. Since the flow resistance increases as the degree of contamination of the filter insert increases, it is necessary to replace the filter insert periodically or when the degree of contamination of the filter insert reaches a critical value. At this time, the housing cover is removed, and the filter insert is taken out and replaced.

  Under the operating conditions of the internal combustion engine where the dust load of the outside air is high, the conventional filter configuration is insufficient, and the filter material may be consumed quickly. Although pre-separators that preliminarily retain coarse dust and extend the life of filter inserts alleviate these problems, it is necessary to secure additional installation space for the introduction of pre-separators, which is not always available. . For example, construction machines, especially road leveling machines such as road rollers, are compact in order to increase the manual operability of the machine while at the same time exhibiting a high filter effect at low maintenance frequency even under operating conditions that are heavily loaded with dust. It must be in shape.

  In order to solve the above-described problems, the present invention discloses an air filter that exhibits a high effect in a compact shape.

  The object is solved by an air filter having the characteristics of claim 1.

The present invention discloses an air filter for an internal combustion engine. In the air filter, a centrifugal force type (hereinafter referred to as cyclone type) pre-separator formed so as to be integrated with the filter housing is built in the intake direction on the intake port side. Following the cyclone type pre-separator, a sponge-like filter and a filter insert function sequentially, so that filtering is performed in three stages. First, coarse dust is retained by the cyclone-type pre-separator, then medium-sized dust is retained by the sponge filter, and finally fine dust particles are retained by the filter insert so as not to be separated from the inflowing intake air or returned to the intake air. .
The cyclone type pre-separator is built into the filter housing, and it is assumed that each of the three filters or separators corresponds to a specific size of dust. Shape is realized.
Due to the functional condition that the separation effect lasts, the cyclone pre-separator does not require maintenance, and therefore the load on the sponge filter that functions after the cyclone pre-separator is reduced. Since the sponge filter also reduces the load on the subsequently functioning filter insert, the filter insert as well as the filter housing can be housed in a particularly compact shape.
For the above reason, it is possible to suppress the replacement of the filter insert at a low frequency even in an operating environment where the load due to dust is large, such as construction work, particularly leveling work as an example.

Various configurations are conceivable for the configuration of the filter insert (for example, a filter in which a filter material made of a non-woven fabric of chemical fiber or glass paper is radially folded and stored in a cylindrical frame). In relation to the first functioning cyclone pre-separator and sponge filter (for example, formed on the peripheral surface of the cylindrical frame), the filter insert is folded in a star shape radially from the viewpoint of installation space and filter effect. The filter material is preferably made of filter paper.
Alternatively, in order to allow air to flow in from the radially outer side to the inner side, the filter body may be basically formed in a cylindrical shape. In this case, the shape is compact, and the load applied to the filter material is uniform without causing unevenness depending on the location.

The sponge filter may be arranged in a plane as an example. Preferably, the sponge filter is formed in an annular shape so as to surround the filter insert, and is incorporated as a component that can be replaced simultaneously when the filter insert is replaced. By forming an annular shape, the sponge filter is placed under the same inflow conditions as in the case of the filter insert described above. In other words, the air flows radially from the outside to the inside, so that the load on the sponge material is made uniform without unevenness depending on the location, and the installation space is significantly saved by forming it coaxially with the filter insert. be able to.
Since the filter effect of the sponge filter and the included filter insert is influenced by each other, the filter life comes at the same time or at least near the same time. Incorporating the sponge filter as a component that can be exchanged at the same time as the filter insert not only saves space, but also ensures that the filter insert and sponge filter always have the same permeability and reduce the resistance to inflow. .

As an effective configuration of the filter insert, a closed bottom surface is formed, a cover is formed at a position facing the bottom surface, and the cover includes an exhaust port connected to a clean air passage of the housing lower member. The cover is in contact with the housing lower member, and the bottom surface is in contact with the housing cover, so that the filter insert is sandwiched and fixed between the housing lower member and the housing cover.
In such a configuration, it is important that the exhaust port of the filter insert and the clean air passage of the lower housing member are in close contact with each other so that there is no air leakage between them, but due to the clamping force between the lower housing member and the housing cover, The close contact between the exhaust port and the clean air passage can be maintained continuously. There is no need to take further measures for airtightness to avoid accidental ingress of dusty air.
The filter housing has a simple two-part configuration including the housing lower member and the housing cover, and the overall function of the air filter, that is, the dust holding function, the airtight function that does not allow dust to enter the clean air, and the air inflow function. And various functions of facilitating maintenance or replacement of the filter insert can be realized.

  It is also effective to fix the housing cover and the housing lower member with screws or to connect them with clips or the like. Preferably, as an embodiment, one of the housing covers is placed on the lower housing member in a rotatable state, and the other side is fixed with a fastening member. By installing the housing cover in a rotatable state, the housing cover remains on and remains connected to the housing lower member so that the filter insert can be easily replaced. After the new filter insert is installed, the housing cover is pressed against the filter insert only by the fixing force of the fastening member attached to one side of the housing. Therefore, even in an environment where installation is difficult, such as a construction site, handling becomes easy.

To install the housing cover in a rotatable state, a hinge or the like is required. Preferably, a plurality of or at least one hinge shaft is projected with a fixed surface, and the hinge shaft is fitted into a corresponding bearing hole. The housing cover and the lower housing member can be easily separated as required by the above method, although a reliable fixing effect is obtained in the state after installation.
In order to improve the movement condition in the housing cover, that is, the effect of fixing to the housing lower member and the center axis alignment, the hinge shaft may be configured as described in detail below. First, it is preferable that the face on the fixed side of the hinge shaft is chamfered. The chamfered round surface rotates the housing cover away from the housing lower member without the hinge shaft abutting against the inner surface of the bearing hole.
It is effective that the fixed side of the hinge shaft is angled in the opposite direction (to the split surface described later). In the fixed state, the respective cross sections of the housing cover and the housing lower member that are in contact with each other are attracted to each other with a split surface between them as a center, so that the detachment of the housing cover and the housing lower member is surely avoided. As a result, position tolerance or shape tolerance can be maintained.

  A toggle or the like is suitable as the fastening member, and it is particularly preferable that the fastening member is formed as a screw with a knob (tomy screw). In this case, the fastening force is applied accurately, and it can be reliably prevented from coming off unexpectedly during operation.

  Various embodiments can be considered for the location of the cyclone pre-separator. Preferably, the major axis of the cyclone pre-separator is installed on the tangent to the major axis of the filter insert at a distance in the radial direction. In this case, the dust-containing air flow that has flowed out of the cyclone type pre-separator is guided in a tangential direction to the filter housing internal space surrounding the filter insert. This configuration has the effect of avoiding the inflow of air directly in the radial direction without taking a large bypass space, and evenly flows air from all directions to the filter insert or the sponge filter surrounding the filter insert. Can be made. Therefore, it is possible to prevent an excessive burden due to contamination from being applied locally.

  In addition, it is effective to provide a lattice-shaped opening wall in order to allow air to flow in front of the cyclone type pre-separator. By only installing the lattice wall, excessively large dust particles are not sucked into the cyclone pre-separator, and the function of the cyclone pre-separator can be reliably ensured for a long time even in harsh environments.

  As a further effective embodiment, a clean air passage is incorporated in the bottom surface of the housing lower member, and the clean air passage is formed in a flat, particularly elliptical cross section instead of a full circle. Since the air intake surface functions sufficiently with the flat shape described above, when installing the clean air passage, it is not necessary to add an additional height to the bottom surface as an installation space, or it is only necessary to add a very small height. Accordingly, the spread in the height direction can be suppressed in the entire air filter.

  According to the air filter in the internal combustion engine of the present invention, the pre-separator can extend the life of the filter material of the filter insert, can effectively secure the installation space for the pre-separator, and has a high load due to dust and the like. Even if the air filter is used under the following operating conditions, it is possible to exhibit a high filter effect at a low maintenance frequency with a compact shape. Furthermore, the fact that the air filter has a compact shape means that, for example, a construction machine, particularly a load Even when incorporated in a leveling machine such as a roller, the manual operability of the machine can be improved.

It is the whole perspective view of the air filter provided with the housing lower member and housing cover which incorporated the cyclone with which the inlet port was covered with the lattice wall. It is a perspective view of the housing lower member in FIG. 1, and shows the detail of the air flow path in the state which installed the filter insert. It is sectional drawing which shows the member arrangement | positioning in FIG. 2, and shows the detail of the shape of a filter insert and the connection of this filter insert and a housing lower member. FIG. 2 is a cross-sectional view of the filter housing in FIG. 1, showing details of the housing cover being fixed to the housing lower member using a hinge shaft and a screw with a housing knob. FIG. 5 is an enlarged detail view of a hinge shaft in FIG. 4. It is a side view of the member arrangement | positioning in FIG. 1, and shows the detail of the clean air path.

  Embodiments of the present invention can be derived from FIGS.

FIG. 1 is a perspective view showing an embodiment of an air filter for an internal combustion engine according to the present invention. The embodiment is an air filter in a leveling machine, here a road roller internal combustion engine.
The air filter is shown at the same position as the normal operation position, and has a substantially rectangular parallelepiped outline extending in the height direction 37, the side direction 38 and the length direction 39. The air filter includes a housing lower member 2 and a housing cover 3 that is detachably mounted on the housing lower member. The housing cover 3 is fixed to the housing lower member 2 in particular by a fastening member 14, which is implemented as a knob screw 15 as shown. Further methods of fastening the housing cover 3 to the housing lower member 2 will be described in detail later in connection with FIGS.

  The combustion air taken in during operation flows into the filter housing 1 along the inflow direction 5 indicated by the arrow. The filter housing 1 is provided with a cyclone pre-separator 6 along the inflow direction 5 on the inlet side, and the cyclone pre-separator 6 is built in as a part of the filter housing 1. Although the housing cover 3 may contain the cyclone type pre-separator 6, the cyclone type pre-separator 6 is formed as a part of the housing lower member 2 in this embodiment. The cyclonic pre-separator 6 includes a lattice wall 21 on the outside, that is, on the peripheral wall of the housing cover 3. Therefore, the intake air containing dust first flows through the lattice wall 21 along the inflow direction 5 and then flows into the cyclone preseparator 6.

FIG. 2 is a detailed perspective view of the housing lower member 2 with the housing cover 3 (shown in FIG. 1) in FIG. 1 removed.
The cyclone type pre-separator 6 and the clean air passage 13 are integrally formed of the same material as that of the lower housing member 2, and are implemented as components formed by plastic injection molding.

A replaceable filter insert 4 is inserted into the housing lower member 2, and the filter insert 4 is basically formed in a cylindrical shape and includes a long axis 20 positioned parallel to the height direction 37. The diameter of the filter insert 4 is larger than the axial extent of the major axis 20, and is about twice in the illustrated embodiment.
Furthermore, in this embodiment, the sponge filter 7 formed in a hollow cylindrical shape is installed on the same axis so as to surround the long axis 20 of the filter insert 4 in an annular shape. The sponge filter is firmly connected to the filter insert 4 on the radially inner side, and is incorporated as a component that can be replaced simultaneously when the filter insert 4 is replaced.
Alternatively, it is also effective to form the filter insert 4 and the sponge filter 7 as two independent and separate members. Furthermore, it is good also as shapes other than a cylinder.

In the intake direction 5, a cyclone pre-separator 6 that functions before the sponge filter 7 is formed, and the sponge filter 7 functions before the filter insert 4.
Accordingly, the air flows in the air filter in stages, that is, the intake air first flows into the cyclone pre-separator 6, then flows into the sponge filter 7, and finally flows into the filter insert 4.

The cyclonic pre-separator 6 is basically cylindrical and extends along the long axis 23 located parallel to the length direction 39, and is formed perpendicular to the long axis 20 of the filter insert 4 and at a distance in the radial direction. . Therefore, the cyclone pre-separator 6 is disposed on the tangent line of the filter insert 4 and in the internal space of the filter housing 1 surrounding the filter insert 4.
The air flowing into the cyclone type pre-separator 6 is rotationally moved by a known method. In this way, by applying centrifugal force, coarse dust particles are separated and guided in the direction of arrow 40.

The air previously purified by the above method flows along the arrow 24 on the tangent line of the inner space of the filter housing 1 at least in the vicinity of the tangential line so as to surround the member composed of the filter insert 4 and the sponge filter 7. , Guided in the circumferential direction of the member.
The air then passes through the sponge filter 7 along the arrow 25, that is, in the radial direction, and the medium-sized dust particles are held by the filter so as not to return to the purified air.

  Thereafter, the air flows in the radial direction along the arrow 25 similarly to the filter element 8 in the filter insert 4 shown in detail in FIG. 3, and fine dust particles remaining in the air being purified are removed. .

  The air flow purified by the above-described method is guided along the arrow 26 and directed downward in the height direction 37, and subsequently discharged as clean air from the clean air passage 13 of the filter housing 1 along the arrow 27. It flows into an internal combustion engine (not shown).

  Further, the following detailed configuration can be seen from FIG. A metal insert coil 28 is inserted in front of the housing lower member 2 in the length direction 39 as a screw receiver for the knob screw 15 (shown in FIG. 1). In the housing lower member 2, at least one hinge shaft 16 in the present embodiment is formed on the rear side opposite to the front side. The function of the hinge shaft 16 will be described later in detail in connection with FIGS.

FIG. 3 is a cross-sectional view showing the arrangement of members in FIG. 2 and shows details of the shape of the filter insert 4 and the connection between the filter insert 4 and the housing lower member 2. The filter insert 4 includes a cylindrical filter element 8, and the filter element 8 is constituted by a filter material 9. The filter material 9 is formed in an annularly closed shape and is folded in a star-shaped radial shape as schematically illustrated by a zigzag line. In the present embodiment, filter paper is selected as the filter material 9, but other materials may be used.
The filter material 9 is supported radially inward by a central tube 29 through which air flows and the central tube 29 surrounds the clean side space of the filter insert 4. The filter material 8 and the axially upper surface of the clean side space are closed by a bottom surface 10 made of polyurethane foam. The lower surface of the filter element 8 on the opposite side is sealed with a cover 11 made of polyurethane foam.
The bottom surface 10 and the cover 11 are attached to a filter material 9, and the filter material 9 includes a central tube 29. A support ring 30 is fitted on the inner side of the central tube 29 in the cover 11 in the radial direction, and the support ring 30 surrounds the exhaust port 12 in the center of the cover 11.
The sponge filter 7 formed in an annular shape on the outer side in the radial direction includes the filter element 8, the bottom surface 10 of the filter element 8 and the cover 11.

The housing lower member 2 includes a housing bottom surface 22 at a lower portion, and the housing bottom surface 22 is formed integrally with a connection path 32 arranged coaxially with the long axis 20. The filter insert 4 is fitted to the connection path 32 via the support ring 30, while the cover 11 of the filter insert 4 is radially separated from the connection path 32 by the support ring 30. Incidentally, since the cover 11 and the bottom surface 10 are entirely sealed so as not to mix air, it is sufficient to realize a close connection between the filter insert 4 and the filter housing 1 in order to avoid air mixing. That is, it is only necessary to install the support ring 30 so as to contact the connecting path 32.
The clean air passage 13 as well as the connection passage 32 is formed so as to be integrated with the housing bottom surface 22. The connecting passage 32 and the clean air passage 13 are connected so as to conduct air, and the clean air passage 13 is divided in the radial direction of the connecting passage 32.

FIG. 4 is a cross-sectional view of the filter housing 1 in FIG. 1 and shows details of the housing cover 3 being fixed to the housing lower member 2 using the hinge shaft 16 and the knob screw 15. When the housing cover 3 is attached, a boundary surface between the housing cover 3 and the housing lower member 2 appears so as to surround the surface of the outer peripheral wall 34 of the housing lower member 2. The flat boundary surface is defined as a dividing surface 35.
In order to fix the housing cover-3 and the housing lower member 2 to each other, a strip frame 33 surrounding the dividing surface 35 is installed. The strip frame 33 is annularly applied to the range of the dividing surface 35 in the outer peripheral wall 34, and both members can be prevented from falling off at the dividing surface 35 as a boundary.

The strip frame 33 includes bearing holes 18 corresponding to the number of hinge shafts 16, and the hinge shafts 16 are fitted into the bearing holes 18. It is also possible to reverse the arrangement of the hinge shaft 16 and the bearing hole 18. In this case, the hinge shaft 16 is installed on the housing cover 3 side and is fitted in the bearing hole 18 arranged in the housing lower member 2.
A screw 15 with a knob is disposed on the opposite side of the hinge shaft 16 and the bearing hole 18, and the screw 15 with the knob is screwed into an insert coil 28 in the housing lower member 2.
As described above, the housing cover 3 is fixed on the housing lower member 2 with the split surface 35 sandwiched between the hinge shaft 16, the bearing hole 18 and the knob screw 15.

  A further configuration of the hinge shaft 16 will be described below in relation to the myopic view in FIG. The housing cover 3 is rotatably installed on the lower housing member 2 on the corresponding side. When the knob screw 15 is loosened, the housing cover 3 rotates about the hinge shaft 16, but the hinge shaft 16 is fitted in the bearing hole 18, so that the housing cover 3 and the housing lower member 2 are connected. Can be kept. If the bearing hole 18 is removed from the hinge shaft 16, the housing cover 3 can be completely removed. When the housing cover is mounted again, the hinge shaft 16 is fitted into the bearing hole 18 and the knob screw 15 is tightened.

When the housing cover 3 is mounted, the filter insert 4 including the sponge filter 7 is clamped and fixed in the axial direction by the housing cover 3 and the housing lower member 2. As shown in FIG. 4, the closed bottom surface 10 is in plan contact with the ring edge of the housing cover 3, while the support ring 30 in the opposite cover 11 (shown in FIG. 3) is installed to surround the central tube 32. It is in pressure contact with the surface 31.
By fastening the screw 15 with the knob, the housing cover 3 is not only fixed to the housing lower member 2, but also the filter insert 4 (shown in FIG. 3) is sandwiched in the axial direction by the housing cover 3 and the housing lower member 2. It is fixed.

Further, the following detailed configuration can be seen from FIG. The clean air passage 13 is installed in the radial direction of the central tube 32 along the long axis 36, and the installation position is further at a position of α ° C. in a horizontal angle from the length direction 39. Therefore, the clean air passage 13 is formed not at the center of the filter housing 1 but at a position shifted rearward from the filter housing 1 in the range of the side wall.
Further, the clean air passage 13 has a flat shape instead of a full circle, and in this embodiment has an elliptical cross section, and the major axis of the ellipse is on the same horizontal plane as the housing bottom surface 22.

FIG. 5 is an enlarged detailed view of the hinge shaft 16 and the corresponding bearing hole 18 in FIG.
The hinge shaft 16 is loosely fitted in the bearing hole 18, and the fixed side 17 of the hinge shaft 16 is brought into close contact with the inner surface of the corresponding bearing hole 18 by an axial clamping force. In the hinge shaft 16, the side 19 opposite to the fixed side 17 is implemented as a chamfered round shape. Thereby, as described above, the housing cover 3 can be rotated on the housing lower member 2 with the range of the fixed side 17 as a fulcrum.
Since the fixed side 17 is formed with an angle in a direction opposite to the dividing surface 35, the fixed side 17 has an acute angle of γ ° C. radially inward toward the dividing surface 35. Therefore, when the axial clamping force is applied to the corresponding surfaces of the fixed side 17 and the bearing hole 18, the clamping force is decomposed by the angle of γ ° C. and the strip frame 33 of the housing cover 3 is attached to the outer periphery of the housing lower member 2. A component force that attracts radially inward toward the wall 34 is generated. As a result, the housing cover 3 is prevented from being separated from the housing lower member 2, and a predetermined position tolerance or shape tolerance can be maintained. There is no need to take further measures to bring the housing cover 3 and the housing lower member 2 into close contact.

  FIG. 6 is a side view of the member arrangement in FIG. 1 and shows details of the clean air passage 13. The long axis 36 of the clean air passage 13 is installed opposite to the horizontal housing bottom surface 22 or inclined by β ° C. from the length direction 39 as shown in the figure. The flow is tilted in the direction of the height direction 37. When viewed in relation to the plan view shown in FIG. 4, it can be seen that the housing bottom surface 22 is integrated with the housing lower member 2. Therefore, the clean air passage 13 does not protrude from the outer surface of the housing lower member 2 or the housing bottom surface 22 built in the housing lower member in the height direction 37.

DESCRIPTION OF SYMBOLS 1 Filter housing 2 Housing lower member 22 Housing bottom surface 13 Clean air passage 12 Exhaust port 3 Housing cover 14 Fastening member 15 Screw with knob 4 Filter insert 5 Intake port 6 Cyclone preseparator 21 Grid wall 7 Sponge filter 8 Filter element 10 Bottom surface 11 Cover 20 Long shaft 16 Hinge shaft 17 Fixed side 18 Bearing hole

Claims (12)

In particular, an air filter for an internal combustion engine in a leveling machine,
The filter housing includes a housing lower member and a removable housing cover mounted on the housing lower member, and a filter insert is installed in the filter housing,
In the filter housing, a cyclone pre-separator formed so as to be integrated with the filter housing is built in the intake direction on the intake port side,
The air filter for an internal combustion engine, wherein the cyclone pre-separator exhibits a purification function prior to the sponge filter, and further the sponge filter functions prior to the filter insert.   2. The air filter for an internal combustion engine according to claim 1, wherein the filter element in the filter insert is formed of a filter material folded in a star radial shape. 3.   The air filter for an internal combustion engine according to claim 1 or 2, wherein the sponge filter is formed in an annular shape so as to surround the filter insert, and is incorporated as a component that can be replaced simultaneously when the filter insert is replaced.   The filter insert includes a closed bottom surface, and a cover is formed at a position facing the bottom surface, and the cover includes an exhaust port connected to a clean air passage of the housing lower member. The cover is in contact with the lower housing member, and the bottom surface is in contact with the housing cover, and the filter insert is sandwiched and fixed between the lower housing member and the housing cover. Item 4. The air filter for an internal combustion engine according to any one of Items 1 to 3.   5. The air filter for an internal combustion engine according to claim 4, wherein one of the housing covers is mounted on the lower member of the housing in a rotatable state, and one of the opposite sides is fixed by a fastening member.   A plurality of or at least one hinge shaft is protruded with a fixed side, and the hinge cover is fitted into a corresponding bearing hole, thereby fixing the housing cover in a rotatable state. 6. An air filter for an internal combustion engine according to claim 5, wherein   The air filter for an internal combustion engine according to claim 6, wherein the fixed side has a rounded surface that is chamfered.   The air filter for an internal combustion engine according to claim 6 or 7, wherein the fixed side has an angle in a direction opposite to the dividing surface.   The air filter for an internal combustion engine according to any one of claims 5 to 8, wherein the fastening member is a screw with a knob.   The air filter for an internal combustion engine according to any one of claims 1 to 9, wherein the cyclone type pre-separator is installed on a tangent line of a long axis of the filter insert.   The air filter for an internal combustion engine according to any one of claims 1 to 10, wherein the cyclone type pre-separator has a lattice wall on the outside, and the lattice wall functions first.   12. A clean air passage is incorporated in a housing bottom surface of the housing lower member, and the cross section of the clean air passage is formed not flat but in a flat shape, particularly in an elliptical shape. An air filter for an internal combustion engine according to claim 1.

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