JP4091971B1 - Air filter for engine - Google Patents

Abstract

To provide an air filter for an engine capable of reducing an intake resistance to an intake passage and promoting an inertial supercharging effect with a compact and simple configuration.
SOLUTION: An outer circumferential surface of a filter element 3 projects into an annular space 4 between a casing 1 and the filter element 3 and is directed upstream in the axial direction of an air flow introduced into the annular space 4 in the axial direction. A plurality of projecting bodies 9 having a spherical surface that recedes toward the inner diameter side of the annular space 4 are attached to the lower part, and a part of the flow of air hitting the spherical surface of the lower part of these projecting bodies 9 is provided in the intake hole 6 By changing the direction toward the inner diameter side of the annular space 4, the air introduced in the axial direction into the annular space 4 is actively guided to the intake hole 6, and the amount of air staying in the annular space 4 is reduced and the intake air is reduced. The intake resistance to the passage is reduced, and the inertial supercharging effect can be promoted.
[Selection] Figure 4

Description

  The present invention relates to an air filter for an engine that promotes an inertia supercharging effect.

  Engine air filters that are installed in the intake passages of engines for automobiles and generators have a large number of intake holes in the cylindrical body inside the cylindrical casing, and a filter medium is attached to the inner circumference of the cylinder. The inserted filter element is inserted into the casing so as to form an annular space, and external air introduced into the annular space between the casing and the filter element in the axial direction is supplied from the intake hole to the filter element. In many cases, the air is purified by being sucked inwardly and supplied to the intake passage of the engine from the air discharge port.

  On the other hand, in a naturally aspirated engine that does not use a turbocharger or compressor, a technology that increases the engine output by using the pulsation of the intake air generated in the intake passage to inertially charge as much air as possible into the cylinder of the engine is often used. Are known. When such inertia supercharging is performed, the engine air filter attached to the intake passage serves as an intake resistance to the intake passage and reduces the inertia supercharging effect.

  As a means for reducing the intake resistance to the intake passage of such an engine air filter and promoting the inertial supercharging effect, a resonance chamber is formed in the upper portion of the air filter case, and the resonance chamber and the filter of the air filter A means for reducing the intake resistance by attaching a resonance pipe communicating with the downstream side of the element and setting the inside of the filter element to a constant pressure has been proposed (for example, see Patent Document 1).

Japanese Utility Model Publication No. 6-58152

  The means for reducing the intake resistance of the engine air filter described in Patent Document 1 is that a resonance chamber is formed in the air filter case, and it is necessary to attach a resonance tube that communicates the resonance chamber and the downstream side of the filter element. There is a problem that the air filter becomes bulky with a complicated configuration.

  Accordingly, an object of the present invention is to provide an air filter for an engine that can reduce the intake resistance to the intake passage and promote the inertial supercharging effect with a compact and simple configuration.

  In order to solve the above-described problems, the present invention provides a plurality of intake holes provided in a cylindrical body portion inside a cylindrical casing attached to an intake passage of an engine, and a filter medium is attached to the inner peripheral side thereof. The inserted filter element is inserted into the casing so as to form an annular space, and air from the outside introduced into the annular space between the casing and the filter element in the axial direction is passed through the intake hole. In an engine air filter that sucks and purifies the inside of the filter element and supplies the purified air to the intake passage of the engine from an air discharge port, the air filter is axially introduced into an annular space between the casing and the filter element. A configuration is adopted in which air flow changing means is provided that changes the direction of a part of the air flow to the inner diameter side of the annular space provided with the intake holes.

  That is, there is provided air flow changing means for changing a part of the air flow introduced in the axial direction into the annular space between the casing and the filter element toward the inner diameter side of the annular space provided with the intake holes. As a result, the air introduced into the annular space in the axial direction is actively guided to the intake hole, the amount of air staying in the annular space is reduced, the intake resistance to the intake passage is reduced, and the inertia supercharging effect can be promoted I made it.

  The air flow changing means is provided with a plurality of protrusions protruding into the annular space from the inner diameter surface of the casing or the outer diameter surface of the filter element, and these protrusions are disposed on the upstream side in the axial direction of the air flow. By having the surface directed toward the inner diameter side of the annular space, the intake resistance to the intake passage can be reduced with a compact and simple configuration.

  An axial direction that hits the projecting body by forming a surface that recedes toward the inner diameter side of the annular space of the projecting body into a convex curved surface in the width direction of the projecting body toward the upstream side in the axial direction of the air flow. It is possible to suppress the turbulence of the air flow and to uniformly guide the air to the intake holes on the downstream side of the annular space.

  The convex curved surface may be a spherical surface.

  The convex curved surface may be a conical surface.

  By making the convex curved surface of the projecting body continue to the downstream side in the axial direction of the air flow, vortices are prevented from being generated on the downstream side of the projecting body, and the air flows downstream of the annular space. It is possible to guide more evenly to the air intake holes.

  Even if the shape of the projecting body on the downstream side in the axial direction of the air flow is a spindle shape in which the cross section in the width direction is tapered toward the downstream side in the axial direction, vortices are generated in the air flow on the downstream side of the projecting body. Generation | occurrence | production can be prevented and air can be guide | induced more uniformly to the inlet hole of the downstream of an annular space.

  By forming the projecting body integrally with the inner diameter surface of the casing or the outer diameter surface of the filter element, the projecting body can be easily formed at a low cost, and the projecting body can be prevented from falling off.

  The filter element intake hole is formed by partial cutting leaving an uncut portion on the downstream side in the axial direction of the air flow, and the projecting body is formed by cutting and raising a partially cut piece leaving the uncut portion. By retracting the front surface of the projecting body formed by cutting and raising toward the inner diameter side of the annular space, the intake hole and the projecting body can be efficiently formed simultaneously.

  By providing a guide vane that guides the air to be introduced into the annular space in the axial direction on the upstream side in the axial direction of the annular space, and by making the outlet side opening area of the guide vane smaller than the inlet side opening area The air flow rate in the annular space can be increased, and the air whose direction is changed to the inner diameter side of the annular space by the air flow changing means can be guided to the intake hole faster.

  In the air filter for an engine of the present invention, a part of the flow of the air introduced into the annular space between the casing and the filter element in the axial direction is changed to the inner diameter side of the annular space provided with the intake holes. Since air flow changing means is provided, the air introduced in the axial direction into the annular space is actively guided to the intake holes, the amount of air staying in the annular space is reduced, the intake resistance to the intake passage is reduced, and the inertia The supercharging effect can be promoted.

  The air flow changing means is provided with a plurality of protrusions protruding into the annular space from the inner diameter surface of the casing or the outer diameter surface of the filter element, and these protrusions are directed to the upstream side in the axial direction of the air flow. By having a surface that recedes toward the inner diameter side of the space, the intake resistance to the intake passage can be reduced with a compact and simple configuration.

  The surface of the projecting body that recedes toward the inner diameter side of the annular space has a convex curved surface that is convex in the width direction of the projecting body toward the upstream side in the axial direction of the air flow. And the air can be evenly guided to the intake holes on the downstream side of the annular space.

  By making the convex curved surface of the projecting body continue to the downstream side in the axial direction of the air flow, it is possible to prevent the vortex from being generated downstream of the projecting body, and to prevent the air from flowing downstream of the annular space. It can guide more evenly to the intake holes.

  A vortex is also generated in the air flow downstream of the projecting body by making the shape of the air flow downstream of the projecting body into a spindle shape in which the cross-section in the width direction is tapered toward the downstream side in the axial direction. The air can be guided more evenly to the intake holes on the downstream side of the annular space.

  By forming the projecting body integrally on the inner diameter surface of the casing or the outer diameter surface of the filter element, the projecting body can be easily formed at a low cost, and the projecting body can be prevented from falling off.

  The filter element intake hole is formed by partial cutting leaving an uncut portion on the downstream side in the axial direction of the air flow, and the projecting body is formed by cutting and raising the partially cut piece leaving the uncut portion. By retracting the front surface of the projecting body formed in step 1 toward the inner diameter side of the annular space, the intake hole and the projecting body can be efficiently formed simultaneously.

  By providing guide vanes for guiding air to be introduced into the annular space in the axial direction on the upstream side in the axial direction of the annular space, and by making the outlet side opening area of this guide vane smaller than the inlet side opening area, The flow velocity of air in the annular space can be increased, and the air whose direction is changed to the inner diameter side of the annular space by the air flow changing means can be guided to the intake holes more quickly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show a first embodiment. As shown in FIGS. 1 and 2, this engine air filter has a cylindrical filter element 3 attached to a lid 2 inside a cylindrical casing 1 and an annular space 4 between the casing 1 and the casing 1. An air intake port 1a through which air is taken in from the outside is provided at one end side of the outer diameter surface of the casing 1, and an intake passage of the engine is provided at an end surface of one end side of the casing 1. An air discharge port 1b connected to (not shown) is provided. Further, on the upstream side of the annular space 4 where the air intake port 1a is provided, guide vanes 5 are provided for guiding the air taken in from the air intake port 1a so as to flow to the annular space 4 in the axial direction.

  A large number of intake holes 6 are provided in the body of the filter element 3, and a filter medium 7 that is pleated in the circumferential direction is attached to the inner periphery thereof. The filter element 3 is formed by bending a metal plate having a large number of intake holes 6 into a cylindrical shape and welding it. The air taken in from the air intake port 1a and introduced into the annular space 4 in the axial direction is sucked into the filter element 3 from the intake holes 6 and purified by the filter medium 7, and then the intake passage from the air discharge port 1b. To the engine. A seal member 8 seals between the end surfaces of the casing 1 and the filter element 3 around the air discharge port 1b.

  The guide vanes 5 are provided with radial guide plates 5a that are inclined in the axial direction on the upstream side of the annular space 4. By the inclination of the guide plates 5a in the axial direction, air is passed through the annular space 4. It is guided to flow in the axial direction while turning. Further, as shown in an enlarged view in FIG. 3, each guide plate 5 a has a thick outlet side, and an outlet side opening area of the guide blade 5 is narrower than an inlet side opening area. Therefore, the flow velocity of the air guided to the annular space 4 is increased.

  As shown in FIGS. 4 (a) and 4 (b), spherical protrusions 9 are attached to the outer diameter surface of the filter element 3 by using a part of the intake holes 6, and these annular spaces are provided. The lower part of the spherical surface directed toward the upstream side in the axial direction of the air flow of the projecting body 9 projecting toward 4 is retracted toward the inner diameter side of the annular space 4. Therefore, a part of the axial airflow that hits the lower portion of the spherical surface is changed in direction toward the inner diameter side of the annular space 4 in which the intake holes 6 are provided, and is actively sucked into the intake holes 6.

  Further, as shown in FIG. 5, the spherical surface of the spherical protrusion 9 is smoothly connected to the downstream side in the axial direction of the air flow, so that the disturbance of the air flow hitting the spherical surface is suppressed and the downstream of the protrusion 9 There is no vortex in the air flow on the side, and air is evenly guided to the intake holes 6 on the downstream side of the annular space 4.

  In this embodiment, the spherical projecting body 9 is attached to the outer diameter surface of the filter element 3 using the intake holes 6, but the bottom of the spherical projecting body 9 is cut flat, and the portion without the intake holes 6. And may be attached to the outer diameter surface of the filter element 3. Moreover, the protrusion 9 can also be made into the hemispherical thing which has a spherical surface only in the lower part.

  As an example, an air filter for an engine in which a large number of spherical protrusions 9 were attached to the outer diameter surface of the filter element 3 described above was prepared. As a comparative example, an engine air filter not provided with the protrusion 9 was prepared. The air filters of the example and the comparative example both have an outer diameter of the casing 1 of 165 mm, a length of 290 mm, a diameter of the air intake port 1a of 63 mm, and a diameter of the air discharge port 1b of 55 mm. In addition, 1081 intake holes 6 having a diameter of 7 mm were provided in a body portion having an outer diameter of 140 mm. Moreover, the diameter of the protrusion 9 of the example was 10 mm, and these were attached to 160 intake holes 6.

  The engine air filters of the above examples and comparative examples were attached to the intake passage of a diesel engine for a generator to conduct a power generation test, and the fuel consumption and power generation efficiency at each load factor were measured. The displacement of the diesel engine was 3.8 L, and the rated output of the generator was 36 kW at a load factor of 90%.

  As a result of the power generation test, the air filter of the example in which the protruding body 9 is attached to the outer diameter surface of the filter element 3 is compared with the air filter of the comparative example without the protruding body 9 at any load factor. The fuel consumption was reduced by about 0.5 to 1.0 L / H, and the power generation efficiency was improved by more than 10%. From this test result, it was confirmed that the air filter according to the present invention can promote the inertia supercharging effect and improve the output of the engine.

  FIGS. 6A and 6B show a second embodiment. This engine air filter has the same basic structure as that of the first embodiment, and the protrusion 9 is conical and formed integrally with the inner surface of the casing 1. Different. Each of the conical protrusions 9 is integrally formed by injection molding with a resin 10 lined on the inner diameter surface of the metal casing 1, and the tip is directed to the intake hole 6 of the filter element 3. A front portion of the conical surface directed upstream in the direction is set back to the inner diameter side of the annular space 4. Therefore, a part of the axial airflow that hits the front portion of the conical surface is changed in direction toward the inner diameter side of the annular space 4 in which the intake holes 6 are provided, and is actively sucked into the intake holes 6. Further, since the conical surface is smoothly connected to the rear side, which is the downstream side in the axial direction of the air flow, the turbulence of the air flow hitting the conical surface is suppressed as in the first embodiment shown in FIG. At the same time, no vortex is generated in the air flow on the downstream side of the projecting body 9, and the air is evenly guided to the intake holes 6 on the downstream side of the annular space.

  In this embodiment, the projecting body 9 has a conical shape and is integrally formed with the resin 10 lined on the inner diameter surface of the casing 1, but the projecting body 9 has a truncated cone shape or a hemispherical shape, and these are embossed. For example, it can be formed integrally with the inner surface of the metal casing 1. Of course, a separate protrusion 9 can be attached to the inner diameter surface of the casing 1 by bonding or the like.

  7A and 7B show a modification of the projecting body 9 according to the second embodiment. The projecting body 9 of this modified example is such that the shape of the conical projecting body 9 on the downstream side in the axial direction of the air flow is a spindle shape in which the cross section in the width direction is narrowed toward the downstream side. In this modified example, as shown in FIG. 7B, the airflow that flows around the downstream side of the protrusion 9 flows along the spindle shape, and the airflow does not occur in the airflow downstream of the protrusion 9. The air is evenly guided to the intake holes 6 on the downstream side of the annular space 4.

  FIGS. 8A and 8B show a third embodiment. This engine air filter has the same basic structure as that of the first embodiment, and each intake hole 6 of the filter element 3 is partially cut leaving an uncut portion on the downstream side in the axial direction of the air flow. The protrusion 9 is formed by cutting and raising a partially cut piece that leaves this uncut portion. The protrusion 9 has a cut-and-raised angle of about 40 to 70 °, and a part of the air flow hitting the front surface side is changed to the inner diameter side of the annular space 4 in which the intake holes 6 are provided. It is sucked into the hole 6. Further, as shown in FIG. 8B, the projecting body 9 formed by cutting and raising is formed so that both end portions are curved toward the rear surface side, and the air flow hitting the end portion on the front surface side is axially downstream. It is designed to escape smoothly to the side. Therefore, also in this embodiment, the turbulence of the air flow hitting the front surface of the protrusion 9 is suppressed, and the air is evenly guided to the intake holes 6 on the downstream side of the annular space 4.

  In this embodiment, the protruding bodies 9 are formed by cutting and raising all the intake holes 6, but the protruding bodies 9 may be formed by cutting and raising only some of the intake holes 6. In addition, the intake holes 6 do not necessarily have to be circular, and may be rectangular or elliptical.

Cutout longitudinal sectional view showing an engine air filter according to the first embodiment Sectional view along the line II-II in FIG. FIG. 1 is an enlarged plan view showing the guide vanes of FIG. a is an enlarged longitudinal sectional view showing the main part of FIG. 1, and b is a perspective view of a. The top view which shows the flow of the air around the protrusion of FIG. a is a longitudinal sectional view showing an enlarged main part of an air filter for an engine according to the second embodiment, and b is a perspective view of a. a is a longitudinal sectional view showing a modification of the projecting body of FIG. 6, and b is a plan view showing the flow of air around the projecting body of a. a is a longitudinal sectional view showing an enlarged main part of an air filter for an engine according to the third embodiment, and b is a plan view showing a flow of air around a protrusion of a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1a Air intake 1b Air exhaust 2 Lid 3 Filter element 4 Annular space 5 Guide blade 5a Guide plate 6 Intake hole 7 Filter medium 8 Seal member 9 Protruding body 10 Resin

Claims (8)

Inside the cylindrical casing attached to the intake passage of the engine, a plurality of intake holes are provided in the cylindrical body, and a filter element having a filter medium attached to the inner periphery thereof is annularly formed between the casing and the casing. It is inserted so as to form a space, and external air introduced into the annular space between the casing and the filter element in the axial direction is purified by sucking it into the filter element from the intake hole. In the engine air filter that supplies the exhausted air to the intake passage of the engine from the air discharge port, a part of the flow of the air introduced into the annular space between the casing and the filter element in the axial direction It provided an air flow changing means for creating changing the orientation to the inner diameter side of the annular space provided, the air flow changing means, an inner diameter surface or the said casing A plurality of projecting bodies projecting from the outer diameter surface of the filter element into the annular space are provided, and these projecting bodies are directed to the upstream side in the axial direction of the air flow and have a surface that recedes toward the inner diameter side of the annular space. An air filter for an engine characterized by comprising the air filter. The surface to be retracted into the inner diameter side of the annular space of the projecting member toward the axially upstream side of the flow of the air, for engine according to claim 1 in which the convex surface of the convex in the width direction of the projecting member Air filter. The engine air filter according to claim 2 , wherein the convex curved surface is a spherical surface. The engine air filter according to claim 2 , wherein the convex curved surface is a conical surface. The engine air filter according to any one of claims 2 to 4 , wherein the projecting curved surface of the projecting body is continued to the downstream side in the axial direction of the air flow. 5. The engine air filter according to claim 2 , wherein the shape of the projecting body on the downstream side in the axial direction of the air flow is a spindle shape in which a cross-section in the width direction is tapered toward the downstream side in the axial direction. . The engine air filter according to any one of claims 1 to 6 , wherein the protruding body is formed integrally with an inner diameter surface of the casing or an outer diameter surface of the filter element. The filter element intake hole is formed by partial cutting leaving an uncut portion on the downstream side in the axial direction of the air flow, and the projecting body is formed by cutting and raising a partially cut piece leaving the uncut portion. The engine air filter according to claim 1 or 2 , wherein a front surface of the projecting body formed by cutting and raising is retracted toward an inner diameter side of the annular space.

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