Blowback prevention material

Abstract

To provide a blow-back preventive member capable of improving performance of collecting fuel.SOLUTION: A blow-back preventive member 100 is equipped with a wall body 101 that separates from an opening 25 and opposes to the opening 25, a first fuel receiving portion 105 that projects out from the wall body 101 toward an end wall 21a and is disposed below the opening 25 while a crank shaft 15 of an engine 1 extends in a horizontal direction, and a second fuel receiving portion 115 that projects out from the wall body 101 toward the end wall 21a and is disposed below the opening 25 while the crank shaft 15 of the engine 1 extends in a vertical direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a blowback prevention member. [Background technology]

[0002] Patent Document 1 discloses a blow-back prevention member. This blow-back prevention member is arranged in a space downstream of the filter of the air cleaner and upstream of the carburetor. The blow-back prevention member includes a backing plate against which fuel blown back from the carburetor hits, and a receiving plate provided below the backing plate to receive fuel adhering to the backing plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-345930 Summary of the Invention [Problem to be solved by the invention]

[0004] In the structure of Patent Document 1, a receiving plate provided below the backing plate is configured to collect fuel dripping down the surface of the backing plate. However, if the engine is positioned so that the crankshaft protrudes downward, for example, the ability of the receiving plate to collect fuel is thought to be reduced.

[0005] The present disclosure aims to provide a blow-back prevention member that can improve the ability to collect fuel. [Means for solving the problem]

[0006] An example of a blowback prevention member is a blowback prevention member provided at an opening (25) on the inlet side of an air intake passage communicating with a carburetor (30) provided in an engine (1), and includes: a wall (101) spaced apart from and facing the opening (25); a first fuel receiving portion (105) protruding from the wall (101) toward the wall surface (21a) on which the opening (25) is provided and positioned below the opening (25) when the crankshaft (15) of the engine (1) is aligned horizontally; and a second fuel receiving portion (115) protruding from the wall (101) toward the wall surface (21a) on which the opening (25) is provided and positioned below the opening (25) when the crankshaft (15) of the engine (1) is aligned vertically.

[0007] In this blow-back prevention member, fuel blown back from the opening (30) communicating with the carburetor (30) adheres to the wall (101) facing the opening (25). When the engine (1) is positioned so that the crankshaft (15) is aligned horizontally, the first fuel receiving portion (105) collects the fuel dripping down the wall (101). When the engine (1) is positioned so that the crankshaft (15) is aligned vertically, the second fuel receiving portion (115) collects the fuel. In this way, even if the position of the engine (1) is changed, the fuel adhering to the wall (101) can be easily collected. This improves the ability to collect fuel.

[0008] When viewed toward the opening (25), the first fuel receiving portion (105) and the second fuel receiving portion (115) may be connected at their ends via a connecting portion (110). In this configuration, spillage of fuel between the first fuel receiving portion (105) and the second fuel receiving portion (115) is suppressed.

[0009] The first fuel receiving portion (105) may be inclined upward from the connection portion (110) toward a first end portion (105a) opposite the connection portion (110) when the crankshaft (15) of the engine (1) is aligned horizontally, and the second fuel receiving portion (115) may be inclined upward from the connection portion (110) toward a second end portion (115a) opposite the connection portion (110) when the crankshaft (15) of the engine (1) is aligned vertically. In this configuration, the fuel collected in the first fuel receiving portion (105) and the second fuel receiving portion (115) is likely to collect at the connection portion (110).

[0010] The first end (105a) of the first fuel receiving portion (105) may form a first edge (106) that rises upward when the crankshaft (15) of the engine (1) is aligned horizontally, and the second end (115a) of the second fuel receiving portion (115) may form a second edge (116) that rises upward when the crankshaft (15) of the engine (1) is aligned vertically. In this configuration, fuel is prevented from spilling from the first edge (106) and the second edge (116).

[0011] A portion of the first fuel receiving portion (105) and a portion of the second fuel receiving portion (115) may be formed along a portion of the edge of the opening (25) when viewed toward the opening (25). In particular, the connection portion (110) may be formed along a portion of the edge of the opening (25). In this configuration, fuel collected in the first fuel receiving portion (105) and the second fuel receiving portion (115) is more likely to be sucked into the opening (25). [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide a blow-back prevention member that can improve the ability to collect fuel. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of an engine to which an example of a blowback prevention member is applied; [Figure 2]1 is a longitudinal cross-sectional view of an example engine. [Figure 3] FIG. 1 is an exploded perspective view of an example engine. [Figure 4] FIG. 1 is a view of an example engine viewed from the X direction. [Figure 5] 1 is a cross-sectional view of an example engine. DETAILED DESCRIPTION OF THE INVENTION

[0014] An example of an embodiment of the present disclosure will be described below with reference to the drawings. In the following embodiment, a case where a blowback prevention member is applied to a two-stroke engine (hereinafter simply referred to as an engine) will be described. Note that the drawings show a coordinate system having an X direction, a Y direction, and a Z direction. Hereinafter, the Z direction may be described as the up-down direction (vertical direction). Furthermore, one side and the other side of the X direction, the Y direction, and the Z direction may be described as the positive side and the negative side according to the orientation of each coordinate axis.

[0015] First, the engine 1 will be described. The engine 1 can be applied to, for example, agricultural machinery. 1, engine 1 has an engine cover 3 that covers the main body, an air cleaner 6 that is disposed adjacent to engine cover 3, and a fuel tank 5. A recoil starter 7 is provided on the positive side of engine cover 3 in the Y direction.

[0016] FIG. 2 is a longitudinal cross-sectional view of the engine 1 taken along line II-II in FIG. 1. FIG. 3 is an exploded perspective view of the engine 1 with the air cleaner cover removed. FIG. 4 is a view of the engine 1 with the air cleaner cover removed, viewed from the X direction. FIG. 5 is a cross-sectional view of the air cleaner cut at the position of the blowback prevention member. As shown in FIG. 2, the engine 1 includes a cylinder 11, a crankcase 13 connected to the lower part of the cylinder 11, and a crankshaft 15 protruding from the crankcase 13. When the cylinder 11 is disposed above the crankcase 13, i.e., when the engine 1 is disposed with the positive side in the Z direction facing upward, the crankshaft 15 protrudes horizontally from the crankcase 13. Hereinafter, this arrangement will be referred to as an "upright position." When the engine 1 is disposed with the positive side in the Y direction facing upward, the crankshaft 15 may protrude vertically downward from the crankcase 13. Hereinafter, this arrangement will be referred to as a "vertical position." In addition, in the vertical position, the recoil starter 7 is disposed above the crankcase 13.

[0017] The engine 1 includes an air cleaner 6 that purifies the intake air, a carburetor 30 that is connected to the air cleaner 6 and vaporizes fuel and mixes the fuel with air to generate an air-fuel mixture, and an insulator 35 that connects the cylinder 11 to the carburetor 30. The engine 1 burns the mixture of intake air and fuel in the cylinder 11, generates a rotational driving force by a crank mechanism in a crankcase 13, and transmits (outputs) the rotational driving force via a crankshaft 15.

[0018] The air cleaner 6 is connected to the carburetor 30. The air cleaner 6 includes a cylindrical air cleaner body 21 with a bottom, and an air cleaner cover 23 facing the air cleaner body 21. In the air cleaner 6, the peripheral edges of the air cleaner body 21 and the air cleaner cover 23 are screwed together to form a space for accommodating the cleaner element 24.

[0019] The example cleaner element 24 includes a first element 24a disposed upstream in the air flow direction and a second element 24b disposed downstream in the air flow direction. In the example air cleaner 6, a gap is formed between the air cleaner body 21 and the air cleaner cover 23 on the positive side in the Z direction, and external air is taken in through this gap, as shown by the arrow in FIG. 2 . That is, external air enters the air cleaner cover 23 through the gap on the positive side in the Z direction and flows along the end wall 23b along the YZ plane. A frame 23a is formed inside the air cleaner cover 23, surrounding the cleaner element 24 in the circumferential direction with the X direction as the axial direction. The frame 23a can hold the cleaner element 24 so that the first element 24a faces the end wall 23b and the second element faces the air cleaner body 21.

[0020] The first element 24a has a function of capturing large particles of dust in the air that is taken in, and is made of, for example, a sponge. The second element 24b has a function of capturing fine dust particles in the air that has passed through the first element 24a, and is made of, for example, filter paper folded in an accordion shape.

[0021] The air cleaner body 21 includes a substantially rectangular plate-shaped end wall 21a (wall surface) facing the carburetor 30, and a substantially rectangular cylindrical peripheral wall 21b connected to the outer periphery of the end wall 21a. A cylindrical opening 25 communicating with a flow path inside the carburetor 30 is provided in the center of the end wall 21a.

[0022] Opening 25 opens into air cleaner 6. Air cleaner 6 is provided with choke valve 26 for adjusting the amount of air flowing from opening 25 to carburetor 30. Choke valve 26 is made of, for example, resin. Choke valve 26 is operated by a user to displace within air cleaner 6 and open and close the inlet side of opening 25. For example, when the engine is started, choke valve 26 closes opening 25, thereby reducing the amount of intake air. This increases the fuel ratio in the air-fuel mixture.

[0023] An example of choke valve 26 is attached to end wall 21a by fastening member 26a such as a screw. Choke valve 26 has plate-shaped portion 26b that rotates around the position of fastening member 26a. Valve body 26c is provided on the tip side of plate-shaped portion 26b. Valve body 26c has a circular shape that is larger than opening 25 so that it can cover opening 25. For example, by operating a lever (not shown), plate-shaped portion 26b of choke valve 26 swings in an arc-like trajectory. The range of movement of choke valve 26 may be between an open position where opening 25 is completely opened and a closed position where opening 25 is completely closed.

[0024] The blow-back prevention member 100 is provided in the air cleaner 6 at an opening 25 on the inlet side of an air intake passage that communicates with the carburetor 30 provided in the engine 1. As a result, the blow-back prevention member 100 prevents fuel blown back from the carburetor 30 from adhering to the cleaner element 24 while the engine is running.

[0025] As shown in FIGS. 4 and 5 , the blowback prevention member 100 includes a wall body 101, a first fuel receiving portion 105, and a second fuel receiving portion 115. The wall body 101 faces the opening 25 while being spaced apart from the opening 25. That is, the wall body 101 covers the opening 25 when viewed from the X direction, and a gap is formed between the wall body 101 and the opening 25 when viewed from the Y direction and the Z direction. For example, the wall body 101 is a substantially fan-shaped plate having a predetermined central angle. The wall body 101 in the illustrated example has a substantially fan-shaped central angle of less than 90 degrees. The wall body 101 and the end wall 21a of the air cleaner body 21 are arranged parallel to each other. A portion of the wall body 101 corresponding to the central angle is arc-shaped along the periphery of the opening 25 and is arranged along the periphery of the opening 25 when viewed from the X direction.

[0026] The first fuel receiving portion 105 protrudes from the wall 101 toward the end wall 21a (wall surface) where the opening 25 is provided. For example, the first fuel receiving portion 105 is formed in a plate shape and is formed so as to be perpendicular to the wall 101. In the illustrated example, the first fuel receiving portion 105 is formed along a portion corresponding to the radius of the wall 101, which is substantially fan-shaped. The first fuel receiving portion 105 is disposed below the opening 25 when the engine 1 is in an upright position. That is, the first fuel receiving portion 105 is located on the negative side of the opening 25 in the Z direction. For example, the first fuel receiving portion 105 may be formed at approximately the same position as the lower end of the opening 25 on the negative side in the Z direction. That is, a portion of the first fuel receiving portion 105 may be formed along a portion of the edge of the opening 25 when viewed from the X direction.

[0027] The second fuel receiving portion 115 protrudes from the wall 101 toward the end wall 21a (wall surface) where the opening 25 is provided. For example, the second fuel receiving portion 115 is formed in a plate shape and is formed so as to be perpendicular to the wall 101. In the illustrated example, the second fuel receiving portion 115 is formed along a portion corresponding to the radius of the wall 101, which is substantially fan-shaped. The second fuel receiving portion 115 is disposed below the opening 25 when the engine 1 is in a vertical position. That is, the second fuel receiving portion 115 is located on the negative side of the opening 25 in the Y direction. For example, the second fuel receiving portion 115 may be formed at approximately the same position as the lower end of the opening 25 on the negative side in the Y direction. That is, a portion of the second fuel receiving portion 115 may be formed along a portion of the edge of the opening 25 when viewed from the X direction.

[0028] When viewed from the X direction, the first fuel receiving portion 105 and the second fuel receiving portion 115 have their ends connected to each other via a connecting portion 110. In the illustrated example, the end of the first fuel receiving portion 105 on the negative side in the Y direction and the end of the second fuel receiving portion 115 on the negative side in the Z direction are connected to each other. The connecting portion 110 is curved in an arc along the periphery of the opening 25.

[0029] When the engine 1 is in an upright position, the first fuel receiving portion 105 is inclined upward from the connection portion 110 toward the first end 105a on the opposite side from the connection portion 110. That is, the first fuel receiving portion 105 is inclined toward the positive side of the Z direction as it approaches the positive side of the Y direction. Similarly, when the engine 1 is in a vertical position, the second fuel receiving portion 115 is inclined upward from the connection portion 110 toward the second end 115a on the opposite side from the connection portion 110. That is, the second fuel receiving portion 115 is inclined toward the positive side of the Y direction as it approaches the positive side of the Z direction. Note that although it is difficult to distinguish from the drawings, the first fuel receiving portion 105 and the second fuel receiving portion 115 may be inclined at an angle of, for example, about 1 to 5 degrees.

[0030] When the engine 1 is in an upright position, the first end 105a of the first fuel receiving portion 105 forms a first edge 106 that rises upward. When viewed from the X direction, the first edge 106 is a portion that curves toward the positive side of the Z direction. Similarly, when the engine 1 is in a vertical position, the second end 115a of the second fuel receiving portion 115 forms a second edge 116 that rises upward. When viewed from the X direction, the second edge 116 is a portion that curves toward the positive side of the Y direction.

[0031] The blowback prevention member 100 of the example is fixed to the air cleaner body 21 with fastening members such as bolts. For example, a reinforcing rib 27 is formed on the end wall 21a of the air cleaner body 21. The rib 27 protrudes from the end wall 21a toward the positive side in the X direction. The rib 27 of the example includes a plurality of arc-shaped ribs 27a centered on the opening 25, a plurality of radial ribs 27b approximately centered on the opening 25, and a plurality of vertical ribs 27c formed along the Z direction. A protruding piece 28 is formed on the end wall 21a. The protruding piece 28 protrudes further toward the positive side in the X direction than the rib 27. The protruding piece 28 is formed to abut against the outer side surfaces of the first fuel receiving portion 105, the second fuel receiving portion 115, and the connecting portion 110 of the blowback prevention member 100 when viewed from the X direction. The outer side surface is the side opposite to the inner side surface facing the opening 25. The ends of the first fuel receiving portion 105, the second fuel receiving portion 115, and the connecting portion 110 on the negative side in the X direction can be positioned by abutting against the protruding piece 28. Furthermore, the first fuel receiving portion 105, the second fuel receiving portion 115, and the connecting portion 110 are formed continuously between the wall body 101 and the end wall 21a.

[0032] In the illustrated example, a retaining portion 107 for retaining a bolt is formed on the inner side surface of the first fuel receiving portion 105 facing the opening 25. Furthermore, a retaining portion 117 for retaining a bolt is formed on the side surface of the second fuel receiving portion 115 facing away from the opening 25. The retaining portions 107, 117 are formed to protrude from the first fuel receiving portion 105 and the second fuel receiving portion 115. Therefore, when viewed from the X direction, the protruding piece 28 abuts against the retaining portion 117 as well as the outer side surface of the blow-back prevention member 100. The blow-back prevention member 100 is fixed to the end wall 21 a by the bolts held by the retaining portions 107, 117 passing through the end wall 21 a and fastened to the carburetor 30. This also fixes the air cleaner body 21 to the carburetor 30.

[0033] As described above, one example of the blow-back prevention member 100 is a blow-back prevention member provided at the opening 25 on the inlet side of the air intake passage communicating with the carburetor 30 provided in the engine 1, and comprises: a wall body 101 that is spaced apart from and faces the opening 25; a first fuel receiving portion 105 that protrudes from the wall body 101 toward the end wall 21a in which the opening 25 is provided, and is positioned below the opening 25 when the crankshaft 15 of the engine 1 is aligned horizontally; and a second fuel receiving portion 115 that protrudes from the wall body 101 toward the end wall 21a in which the opening 25 is provided, and is positioned below the opening 25 when the crankshaft 15 of the engine 1 is aligned vertically.

[0034] In this blow-back prevention member 100, fuel blown back from opening 25 communicating with carburetor 30 adheres to the wall surface of wall body 101 facing opening 25. When engine 1 is positioned so that crankshaft 15 is aligned horizontally, fuel dripping down wall body 101 is collected by first fuel receiving portion 105, and when engine 1 is positioned so that crankshaft 15 is aligned vertically, the fuel is collected by second fuel receiving portion 115. The collected fuel can be sucked into opening 25.

[0035] In this way, according to the example of the blowback prevention member, even if the position of the engine 1 is changed, the fuel dripping down the wall body 101 can be collected. Therefore, the ability to collect fuel can be improved. Furthermore, since the fuel dripping down the wall body 101 can be collected in any position, the fuel adhering to the wall body 101 is prevented from scattering and adhering to the cleaner element 24 (particularly the second element 24b).

[0036] When viewed toward the opening 25, the first fuel receiving portion 105 and the second fuel receiving portion 115 may have their ends connected to each other via the connecting portion 110. In this configuration, spillage of fuel from between the first fuel receiving portion 105 and the second fuel receiving portion 115 is suppressed.

[0037] The first fuel receiving portion 105 may be inclined upward from the connection portion 110 toward the first end 105a opposite the connection portion 110 when the crankshaft 15 of the engine 1 is aligned vertically, and the second fuel receiving portion 115 may be inclined upward from the connection portion 110 toward the second end 115a opposite the connection portion 110 when the crankshaft 15 of the engine 1 is aligned horizontally. In this configuration, the fuel collected in the first fuel receiving portion 105 and the second fuel receiving portion 115 is more likely to collect at the connection portion 110.

[0038] The first end 105a of the first fuel receiving portion 105 may form a first edge 106 that rises upward when the crankshaft 15 of the engine 1 is aligned vertically, and the second end 115a of the second fuel receiving portion 115 may form a second edge 116 that rises upward when the crankshaft 15 of the engine 1 is aligned horizontally. With this configuration, spillage of fuel from the first edge 106 and the second edge 116 is suppressed.

[0039] A portion of the first fuel receiving portion 105 and a portion of the second fuel receiving portion 115 may be formed along a portion of the edge of the opening 25 when viewed toward the opening 25. In this configuration, the fuel collected in the first fuel receiving portion 105 and the second fuel receiving portion 115 is more likely to be sucked into the opening 25. In one embodiment, the connecting portion 110 is formed along a portion of the edge of the opening 25. In this case, the fuel flowing down the fuel receiving portion is more likely to accumulate near the opening 25 in both the upright position and the vertical position.

[0040] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, the shape of the wall 101 of the blowback prevention member 100 is not limited to a generally sector shape. The wall 101 may have another shape, such as a rectangular plate. Furthermore, the wall 101 does not have to be parallel to the end wall 21a of the air cleaner body 21. For example, the wall 101 may be inclined at a predetermined angle relative to the end wall 21a.

[0041] The engine 1 is not limited to a two-stroke engine, but may be a four-stroke engine. The engine displacement is not particularly limited. The present disclosure is applicable to any internal combustion engine in which spit-back may occur.

[0042] The first edge 106 and the second edge 116 may not be curved when viewed from the X direction. For example, the first edge 106 may be linearly inclined toward the positive side of the Z direction when viewed from the X direction. The second edge 116 may be linearly inclined toward the positive side of the Y direction when viewed from the X direction. [Explanation of symbols]

[0043] 1...engine, 15...crankshaft, 21a...end wall (wall surface), 25...opening, 30...carburetor, 100...blowback prevention member, 101...wall body, 105...first fuel receiving portion, 115...second fuel receiving portion.

Claims

1. A blowback prevention member provided at an inlet side opening (25) of an air intake passage communicating with a carburetor (30) provided in an engine (1), a wall (101) spaced apart from and facing the opening (25); a first fuel receiving portion (105) that protrudes from the wall body (101) toward the wall surface (21 a) on which the opening (25) is provided, and that is disposed below the opening (25) when the crankshaft (15) of the engine (1) is aligned horizontally; a second fuel receiving portion (115) that protrudes from the wall body (101) toward the wall surface (21 a) on which the opening (25) is formed, and that is disposed below the opening (25) when the crankshaft (15) of the engine (1) is aligned vertically; When viewed toward the opening (25), the first fuel receiving portion (105) and the second fuel receiving portion (115) are connected at their ends to each other via a connecting portion (110); the first fuel receiving portion (105) is inclined upward from the connecting portion (110) toward a first end (105a) on the opposite side to the connecting portion (110) when the crankshaft (15) of the engine (1) is aligned horizontally; the second fuel receiving portion (115) is inclined upward from the connecting portion (110) toward a second end (115a) on the opposite side to the connecting portion (110) when the crankshaft (15) of the engine (1) is aligned vertically; The first fuel receiving portion (105) and the second fuel receiving portion (115) are formed continuously between the wall body (101) and the wall surface (21 a) by abutting their outer side surfaces, which are opposite to their inner side surfaces facing the opening (25), against a protruding piece (28) protruding from the wall surface (21 a).

2. The first end (105a) of the first fuel receiving portion (105) forms a first edge (106) that rises upward when the crankshaft (15) of the engine (1) is aligned horizontally, 2. The blowback prevention member according to claim 1, wherein the second end (115a) of the second fuel receiving portion (115) forms a second edge portion (116) that rises upward when the crankshaft (15) of the engine (1) is aligned vertically.

3. 3. The blowback prevention member according to claim 1, wherein a portion of the first fuel receiving portion (105) and a portion of the second fuel receiving portion (115) are formed along a portion of the edge of the opening (25) when viewed toward the opening (25).

4. The blowback prevention member according to any one of claims 1 to 3, wherein the connection portion (110) is formed along a portion of the edge of the opening (25) when viewed toward the opening (25).

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