JP3142128U - Breather structure of internal combustion engine and vehicle equipped with the same - Google Patents

Abstract

A breather structure for an internal combustion engine capable of suppressing the complexity of the structure.
A breather structure of an internal combustion engine (engine 13) includes an engine 13 including a crankcase 14 in which oil is stored, and an air cleaner unit 19 connected to the engine 13 to clean air flowing in from the outside. And a fuel gas containing oil that is disposed separately from the crankcase 14 and adjacent to the air cleaner portion 19 and into which oil gas existing inside the crankcase 14 of the engine 13 flows. An oil separation chamber 19g for separating the oil from the gas and allowing the fuel gas separated from the oil to flow into the air cleaner unit 19 is provided.
[Selection] Figure 1

Description

  The present invention relates to a vehicle, and more particularly, to a breather structure for an internal combustion engine including an oil separation chamber for separating oil from fuel gas containing oil and a vehicle including the breather structure.

  2. Description of the Related Art Conventionally, there is known a breather structure for a motorcycle including a breather chamber (oil separation chamber) that separates oil from blow-by gas (fuel gas) containing oil (see, for example, Patent Document 1). Patent Document 1 discloses an engine (internal combustion engine) including a crankcase, a fuel tank disposed above the engine, an air cleaner disposed at a predetermined distance from the fuel tank, and a blow-by including oil. A breather structure for a motorcycle is disclosed that includes a breather chamber provided inside a fuel tank in order to ensure a space for sufficiently separating oil from gas. Further, in the breather structure of the motorcycle disclosed in Patent Document 1, blowby gas containing oil existing in the crankcase is caused to flow into the breather chamber between the crankcase and the breather chamber provided in the fuel tank. The blow-by gas introduction pipe is connected. Further, a blow-by gas having a predetermined length for allowing the blow-by gas from which the oil has been separated by the breather chamber to flow into the air cleaner is provided between the breather chamber and the air cleaner disposed at a predetermined distance from the fuel tank. A gas supply pipe is connected. An oil return pipe is connected between the breather chamber provided in the fuel tank and the crankcase to return the oil separated from the blowby gas containing the oil to the crankcase.

Japanese Utility Model Publication No. 2-101007

  However, in the structure disclosed in Patent Document 1, since the air cleaner is disposed at a predetermined distance from the fuel tank in which the breather chamber is disposed, the oil is separated from the blow-by gas including the oil. In order for the blow-by gas to flow into the air cleaner, it is necessary to provide a blow-by gas supply pipe having a predetermined length that connects between the air cleaner and the breather chamber. For this reason, the breather structure of the motorcycle disclosed in Patent Document 1 has a problem that the structure becomes complicated because a blow-by gas supply pipe having a predetermined length is required.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a breather structure for an internal combustion engine capable of suppressing the complexity of the structure and the structure thereof. Is to provide a vehicle.

Means for solving the problems and effects of the device

  To achieve the above object, a breather structure for an internal combustion engine according to a first aspect of the present invention is connected to an engine including a crankcase in which oil is stored, and cleans the air flowing from the outside. A fuel gas containing oil that is arranged separately from the air cleaner portion and the crankcase and that is disposed adjacent to the air cleaner portion and that contains oil that is present in the crankcase of the engine. And an oil separation chamber in which fuel gas from which oil has been separated flows into the air cleaner section.

  In the breather structure of the internal combustion engine according to the first aspect, as described above, the oil is separated from the fuel gas containing oil so as to be separated from the crankcase and adjacent to the air cleaner portion. By providing an oil separation chamber that allows the fuel gas to flow into the air cleaner portion, it is possible to suppress an increase in the length of the piping that connects the air cleaner portion and the oil separation chamber. Complicating the breather structure can be suppressed.

  In the breather structure of the internal combustion engine according to the first aspect, the oil separation chamber is preferably formed integrally with the air cleaner portion. If comprised in this way, since it becomes unnecessary to provide piping which connects between an air cleaner part and an oil separation chamber, it can suppress more that the breather structure of an internal combustion engine becomes complicated.

  In the breather structure of the internal combustion engine according to the first aspect, preferably, the oil separation chamber includes a gas inlet portion into which the fuel gas containing oil flows, and a fuel gas from which the oil is separated from the fuel gas containing oil. A gas discharge port portion for discharging to the air cleaner portion side and an oil discharge port portion for discharging oil separated from the fuel gas including oil provided at the lower portion of the oil separation chamber are included. If comprised in this way, the oil isolate | separated from the fuel gas containing oil can be easily discharged | emitted by the oil discharge port part provided in the lower part of the oil separation chamber.

  In the breather structure of the internal combustion engine in which an oil discharge port is provided in the lower part of the oil separation chamber, preferably, an oil passage for returning oil from the oil discharge to the crankcase is further provided. The oil return portion to the crankcase is arranged to be positioned below the oil surface of the oil stored in the crankcase. With this configuration, the oil return portion can be closed by the oil stored in the crankcase, so that fuel gas containing oil existing inside the crankcase enters the oil passage portion. Can be suppressed.

  In the breather structure of the internal combustion engine provided with the oil passage portion having the oil return portion, preferably, the oil passage portion is provided outside the engine, and an oil separation portion is provided at one end portion of the oil passage portion. An oil separation chamber connecting portion connected to the oil discharge port portion of the chamber is provided, and the crankcase connection connected below the oil surface of the crankcase oil to the oil return portion at the other end of the oil passage portion Is provided. If comprised in this way, it can suppress that the fuel gas containing the oil which exists in the inside of a crankcase permeates into an oil passage part easily.

  In the breather structure of the internal combustion engine in which the oil passage portion is provided outside the engine, the oil passage portion is preferably disposed between one end portion and the other end portion of the oil passage portion and stored in the crankcase. The valve member which suppresses that the oil currently performed flows backward to the one end part side of an oil passage part is included. With this configuration, for example, even when a vehicle equipped with a breather structure for an internal combustion engine falls, the oil stored in the crankcase is prevented from flowing backward to one side of the oil passage portion. can do.

  In the breather structure of the internal combustion engine according to the first aspect, preferably, the air cleaner portion includes an air filter that is disposed inside the air cleaner portion and through which air that has flowed into the air cleaner portion passes, and the oil separation chamber includes: It arrange | positions so that it may adjoin to the area | region of the downstream of the air flow rather than the air filter of an air cleaner part. If comprised in this way, the fuel gas from which oil was isolate | separated can be easily flowed into the area | region downstream of the air flow rather than the air filter of an air cleaner part.

  In the breather structure of the internal combustion engine according to the first aspect, the oil separation chamber is preferably disposed below the air cleaner portion. If comprised in this way, the fuel gas from which the oil which moves easily upwards was isolate | separated can be easily flowed into an air cleaner part.

  In the breather structure of the internal combustion engine according to the first aspect, preferably, the region of the oil separation chamber is configured to be smaller than the region of the air cleaner portion in plan view. With this configuration, it is possible to suppress the oil separation chamber from protruding outward from the air cleaner portion. Therefore, even if the oil separation chamber is provided integrally with the air cleaner portion, the air cleaner portion is not enlarged. Can be suppressed.

  A vehicle according to a second aspect of the present invention includes the breather structure for an internal combustion engine according to any one of claims 1 to 9. If comprised in this way, the vehicle provided with the breather structure of the internal combustion engine which can suppress that a structure becomes complicated can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a side view showing the overall structure of a motorcycle according to a first embodiment of the present invention. 2 to 4 are diagrams for explaining in detail the breather structure of the engine of the motorcycle according to the first embodiment shown in FIG. In the first embodiment, a motorcycle will be described as an example of the vehicle of the present invention. In the figure, an arrow FWD indicates the front in the traveling direction of the motorcycle. First, the structure of the motorcycle according to the first embodiment of the present invention will be described with reference to FIGS.

  In the motorcycle 1 according to the first embodiment of the present invention, as shown in FIG. 1, a main frame 3 extending in the front-rear direction is disposed behind the head pipe 2. Further, a rear frame (not shown) extending in the rear upward direction is connected to the rear of the main frame 3. The head pipe 2, the main frame 3, and the rear frame (not shown) constitute a vehicle body frame.

  A handle 4 is rotatably attached to the upper part of the head pipe 2. A headlamp 5 is provided in front of the head pipe 2. A pair of front forks 6 having suspensions for absorbing vertical impacts are disposed below the head pipe 2. A front wheel 7 is rotatably attached to the lower part of the pair of front forks 6.

  A seat 8 is disposed on the upper rear portion of the main frame 3. A resin fuel tank 9 is disposed on the front side (arrow FWD direction side) of the seat 8. A pivot shaft 3 a is provided at the rear end (lower part) of the main frame 3. The pivot shaft 3a supports a front end portion of the rear arm 10 so as to be swingable up and down. A rear wheel 11 is rotatably attached to the rear end portion of the rear arm 10. A rear fender 12 that covers the upper portion of the rear wheel 11 is disposed above the rear wheel 11.

  An engine 13 is arranged on the main frame 3. As shown in FIG. 2, the engine 13 includes a crankcase 14, a cylinder 15, and a cylinder head 16. As shown in FIG. 1, the crankcase 14 is fixed to the lower portion of the main frame 3 using a plurality of screw members 17. Further, a drive mechanism (not shown) is disposed inside the crankcase 14, and oil for lubricating and cooling the drive mechanism (not shown) is stored so as to be at the position of the oil surface F1. As shown in FIG. 2, the cylinder 15 is attached to the upper part of the crankcase 14, and the cylinder head 16 is attached to the upper part of the cylinder 15. A throttle body 18 is connected to an intake port (not shown) of the cylinder head 16. The throttle body 18 is connected to an air cleaner section 19 (see FIG. 1), which will be described later, and mixes air that flows in from the air cleaner section 19 and fuel that is supplied from the fuel tank 9 (see FIG. 1). It is configured to supply a port (not shown).

  Further, as shown in FIG. 1, an air cleaner 19 is disposed behind the engine 13. The air cleaner unit 19 has a function of cleaning the air flowing from the outside and supplying the cleaned air to the throttle body 18. As shown in FIG. 3, the air cleaner 19 includes an upper case 19a and a lower case 19b. The upper case 19a is detachably attached to the lower case 19b.

  Further, as shown in FIGS. 3 and 4, the upper case 19a of the air cleaner section 19 is provided with an intake port 19c through which air flows in from the outside. The intake port 19c is connected to the traveling direction (arrow FWD direction). Are arranged so as to open in the opposite direction. Further, as shown in FIG. 3, an air filter unit 20 is provided below the intake port 19c so as to cover the upper opening of the lower case 19b. The air filter unit 20 is sandwiched between the upper case 19a and the lower case 19b, and can be replaced with a new air filter unit 20 when the upper case 19a is removed from the lower case 19b. The air filter unit 20 is an example of the “air filter” of the present invention. Further, the air filter unit 20 is provided with an element 20a for purifying the air that has flowed in. The air that has flowed from the air inlet 19c is supplied from the upstream portion 19d above the air filter unit 20 to the air filter. It passes through the element 20 a of the unit 20 and is circulated to the downstream portion 19 e below the air filter unit 20. Thus, the air on the upstream portion 19d side above the air filter unit 20 inside the air cleaner portion 19 can be circulated to the downstream portion 19e side below the air filter unit 20 to be cleaned.

  An air passage portion 21 is attached to the front side (arrow FWD direction side) of the lower case 19b of the air cleaner portion 19. As shown in FIG. 1, the air passage portion 21 is connected to the throttle body 18 and is configured to allow clean air to flow into the throttle body 18.

  In the first embodiment, as shown in FIG. 3, a flat partition wall member 19f is provided below the lower case 19b. Below the partition member 19f, blow-by gas containing oil is used. A breather chamber 19g for separating oil is provided. That is, the breather chamber 19g is provided so as to be adjacent to a region (downstream portion 19e) on the downstream side of the air flow from the air filter unit 20 of the air cleaner portion 19. The breather chamber 19g is an example of the “oil separation chamber” of the present invention, and the blow-by gas is an example of “fuel gas” of the present invention. Moreover, the breather structure of the internal combustion engine (engine 13) is comprised by the engine 13 (refer FIG. 1), the air cleaner part 19, and the breather chamber 19g. The breather chamber 19g is formed integrally with the air cleaner 19 and has a size sufficient to separate oil from blow-by gas containing oil. Further, as shown in FIG. 4, the breather chamber 19g is configured such that the area of the breather chamber 19g is smaller than the areas of the upstream portion 19d and the downstream portion 19e of the air cleaner portion 19 when viewed in plan.

  Further, in the first embodiment, as shown in FIG. 3, the breather chamber 19g includes a gas inlet 19h for introducing blow-by gas containing oil, and a blow-by gas in which the oil is separated from the blow-by gas containing oil. A gas discharge port portion 19i for discharging the oil, and an oil discharge port portion 19j for discharging the oil separated from the blow-by gas containing the oil.

  The gas inlet 19h is formed on the front side (arrow FWD direction side) of the breather chamber 19g. As shown in FIGS. 1 and 3, one end 22a (see FIG. 3) of the gas passage 22 is connected to the gas inlet 19h (see FIG. 3), and the other end of the gas passage 22 is connected. 22b (see FIGS. 1 and 2) is connected to a connection portion 14a (see FIGS. 1 and 2) on the upper side of the crankcase 14 of the engine 13. As a result, blow-by gas containing oil present in the crankcase 14 can be moved to the breather chamber 19g via the gas passage 22.

  In the first embodiment, as shown in FIG. 3, the gas outlet 19i is formed in the partition member 19f. That is, in the motorcycle 1 according to the first embodiment of the present invention, the breather chamber 19g is provided with a flat partition wall member 19f so as to be adjacent to the downstream portion 19e of the air cleaner portion 19, so that oil is supplied by the breather chamber 19g. The blow-by gas from which the oil has been separated from the blow-by gas that is contained easily flows into the downstream portion 19 e of the air cleaner portion 19.

  In the first embodiment, the oil discharge port 19j is formed in the lower part of the breather chamber 19g. One end 23a of the oil hose 23 is connected to the oil discharge port 19j, and the other end 23b (see FIGS. 1 and 2) of the oil hose 23 is connected to the oil surface F1 (see FIG. 1) of the crankcase 14. 1 and FIG. 2) is connected to a connecting portion 14b (see FIGS. 1 and 2) formed below. The oil hose 23 is an example of the “oil passage portion” of the present invention, and the end 23a is an example of the “oil separation chamber connecting portion” of the present invention. The other end 23b is an example of the “oil return part” of the present invention, and the connection part 14b is an example of the “crankcase connection part” of the present invention. The oil hose 23 is provided separately from the engine 13 (outside).

  In the first embodiment, as shown in FIG. 1, the oil hose 23 is a valve that prevents the oil stored in the crankcase 14 from flowing backward to the one end 23 a side of the oil hose 23. The member 24 is disposed between the one end 23a and the other end 23b. Thereby, even when the motorcycle 1 falls, it is possible to suppress the oil stored in the crankcase 14 from flowing into the breather chamber 19g.

  In the first embodiment, as described above, the blow-by gas separated from the crank case 14 and separated from the blow-by gas including the oil so as to be adjacent to the air cleaner 19 is separated from the blow-by gas. By providing the breather chamber 19g that flows into the air cleaner portion 19, it is possible to suppress an increase in the length of the pipe connecting the air cleaner portion 19 and the breather chamber 19g, so that the internal combustion engine (engine 13) It is possible to prevent the breather structure from becoming complicated.

  Further, in the first embodiment, by forming the breather chamber 19g integrally with the air cleaner portion 19, it is not necessary to provide a pipe for connecting the air cleaner portion 19 and the breather chamber 19g. It is possible to further suppress the complication of the breather structure of 13).

  In the first embodiment, the gas inlet 19h into which the blow-by gas containing oil flows into the breather chamber 19g and the blow-by gas from which the oil has been separated from the blow-by gas containing oil are discharged to the air cleaner 19 side. Oil provided at the lower part of the breather chamber 19g by providing a gas outlet 19i and an oil outlet 19j provided at the lower part of the breather chamber 19g for discharging the oil separated from the blow-by gas containing oil. By the discharge port part 19j, the oil separated from the blow-by gas containing oil can be easily discharged.

  In the first embodiment, the other end 23 b for returning the oil to the crankcase 14 of the oil hose 23 is disposed so as to be positioned below the oil surface of the oil stored in the crankcase 14. Thus, the other end 23 b of the oil hose 23 can be closed by the oil stored in the crankcase 14, so that blow-by gas containing oil existing inside the crankcase 14 enters the oil hose 23. Can be suppressed.

  Further, in the first embodiment, the breather chamber 19g is arranged so as to be adjacent to the region on the downstream portion 19e side of the air flow with respect to the air filter unit 20 of the air cleaner portion 19, so that the air cleaner portion 19 can be easily arranged. The blow-by gas from which the oil has been separated can flow into the region on the downstream portion 19e side of the air flow from the air filter unit 20.

(Second Embodiment)
FIG. 5 is a side view showing the overall structure of a moped type motorcycle according to a second embodiment of the present invention. 6 to 9 are diagrams for explaining in detail the breather structure of the engine of the moped type motorcycle according to the second embodiment shown in FIG. In the second embodiment, unlike the first embodiment, an example will be described in which the air cleaner unit 68 is disposed not in the rear of the engine 63 but in front of the engine 63. In the second embodiment, a moped type motorcycle having an underbone frame structure will be described as an example of the vehicle of the present invention. In the drawing, an arrow FWD indicates the front in the traveling direction of the moped type motorcycle. A structure of a moped type motorcycle according to a second embodiment of the present invention will be described with reference to FIGS.

  In the motorcycle 51 according to the second embodiment of the present invention, a main frame 53 is fixed behind the head pipe 52 as shown in FIG. The main frame 53 is formed in an underbone shape extending rearward from below. The head pipe 52 and the main frame 53 constitute a vehicle body frame.

  A handle 54 is pivotably attached to the upper portion of the head pipe 52. A front cowl 55 that covers the front of the head pipe 52 is provided in front of the head pipe 52. A pair of front forks 56 having suspensions for absorbing vertical impacts are disposed below the head pipe 52. A front wheel 57 is rotatably attached to the lower part of the pair of front forks 56. A front fender 58 is disposed above the front wheel 57.

  A seat 59 is disposed above the rear portion of the main frame 53. Further, a front end portion of the rear arm 60 is supported on a pivot shaft (not shown) provided at the rear portion (lower portion) of the main frame 53 so as to be swingable up and down. A rear wheel 61 is rotatably attached to the rear end portion of the rear arm 60. A rear fender 62 that covers the upper portion of the rear wheel 61 is disposed above the rear wheel 61.

  An engine 63 is disposed below the main frame 53. The engine 63 includes a crankcase 64, a cylinder 65 attached in front of the crankcase 64 (in the arrow FWD direction), and a cylinder attached so as to close an opening on the front side (in the arrow FWD direction) of the cylinder 65. A head 66. A drive mechanism (not shown) is disposed inside the crankcase 64, and oil for lubricating and cooling the drive mechanism (not shown) is stored so as to be at the position of the oil surface F2. A throttle body 67 is connected to an intake port (not shown) of the cylinder head 66. The throttle body 67 is connected to an air cleaner section 68, which will be described later, and mixes the air flowing from the air cleaner section 68 with the fuel supplied from a fuel tank (not shown), and an intake port (not shown). It is comprised so that it may supply.

  Further, an air cleaner portion 68 is disposed behind the head pipe 52. As shown in FIGS. 5 and 6, the air cleaner 68 is configured to have a substantially trapezoidal shape when viewed from the side, and the front side (arrow FWD direction side) of the air cleaner 68 is a front fender 58 (see FIG. 5). 5)) is arranged so as not to contact the rear part. Further, as shown in FIG. 7, the air cleaner portion 68 includes a dirty side case 68 a on the arrow L direction side in the vehicle width direction (arrow L direction and arrow R direction) and a clean side case 68 b on the arrow R direction side. The dirty side case 68a is detachably attached to the clean side case 68b.

  In addition, as shown in FIGS. 7 and 9, an air inlet 68 c is provided on the front side (arrow FWD direction side) of the dirty side case 68 a of the air cleaner 19 to allow air to flow in from the outside. An air filter unit 69 is provided in the opening on the arrow R direction side of the dirty side case 68a. The air filter unit 69 is attached so as to be sandwiched between the dirty side case 68a and the clean side case 68b. When the dirty side case 68a is removed from the clean side case 68b, a new air filter unit 69 and It is exchangeable. The air filter unit 69 is an example of the “air filter” of the present invention. Further, as shown in FIGS. 8 and 9, the air filter unit 69 is provided with an element 69a for cleaning inflowed air. Further, as shown in FIG. 9, the air flowing in from the intake port 68 c passes through the element 69 a of the air filter unit 69 from the upstream portion 68 d on the arrow L direction side of the air filter unit 69, and the arrow of the air filter unit 69. It is distributed to the downstream portion 68e on the R direction side. Thereby, the air on the upstream portion 68d side in the arrow L direction side of the air filter unit 69 inside the air cleaner portion 68 is circulated to the downstream portion 68e side in the arrow R direction side of the air filter unit 69 to be cleaned. It becomes possible.

  An air passage 70 is attached to the rear side of the clean side case 68b of the air cleaner 19. As shown in FIG. 5, the air passage portion 70 is connected to the throttle body 67 and is configured to allow clean air to flow into the throttle body 67.

  Here, in the second embodiment, as shown in FIG. 8, a flat partition member 68f is provided below the clean side case 68b, and a blow-by gas containing oil is provided below the partition member 68f. A breather chamber 68g for separating the oil from the oil is provided. That is, the breather chamber 68g is provided so as to be adjacent to a region on the downstream side (downstream portion 68e) of the air flow with respect to the air filter unit 69 of the air cleaner portion 68. The breather chamber 68g is an example of the “oil separation chamber” in the present invention, and the blow-by gas is an example of the “fuel gas” in the present invention. The engine 63 (see FIG. 5), the air cleaner section 68, and the breather chamber 68g constitute a breather structure of the internal combustion engine (engine 63). The breather chamber 68g is formed integrally with the clean side case 68b of the air cleaner section 68, and is formed to have a size sufficient to separate oil from blow-by gas containing oil. Further, as shown in FIG. 9, the breather chamber 68g is configured such that the area of the breather chamber 68g is smaller than the area of the downstream portion 68e of the air cleaner section 68 when viewed in plan.

  In the second embodiment, as shown in FIG. 8, the breather chamber 68g includes a gas inlet 68h for introducing blow-by gas containing oil, and a blow-by gas in which the oil is separated from the blow-by gas containing oil. A gas discharge port 68i for discharging the oil and an oil discharge port 68j for discharging the oil separated from the blow-by gas containing the oil.

  The gas inlet 68h is formed on the rear side of the breather chamber 68g. As shown in FIGS. 5 and 8, one end 71 a of the gas passage 71 is connected to the gas inlet 68 h, and the other end 71 b (see FIG. 5) of the gas passage 71 is connected to the engine 63. Is connected to a connecting portion 64a (see FIG. 5) on the upper side of the crankcase 64. As a result, blow-by gas containing oil present in the crankcase 64 can be moved to the breather chamber 68g via the gas passage 71.

  In the second embodiment, the gas discharge port 68i is formed in the partition member 68f. In other words, in the motorcycle 51 (see FIG. 5) according to the second embodiment of the present invention, the breather chamber 68g is provided with the flat partition member 68f so as to be adjacent to the downstream portion 68e of the air cleaner portion 68. The blow-by gas from which the oil is separated from the blow-by gas containing oil by the chamber 68 g easily flows into the downstream portion 68 e of the air cleaner portion 68.

  In the second embodiment, the oil discharge port 68j is formed in the lower part of the breather chamber 68g. One end 72a of the oil hose 72 is connected to the oil discharge port 68j, and the other end 72b (see FIG. 5) of the oil hose 72 is connected to the oil surface F2 (see FIG. 5) of the crankcase 64. Is also connected to a connecting portion 64b (see FIG. 5) formed below. The oil hose 72 is an example of the “oil passage portion” in the present invention, and the one end 72a is an example of the “oil separation chamber connecting portion” in the present invention. The other end 72b is an example of the “oil return part” of the present invention, and the connection part 64b is an example of the “crankcase connection part” of the present invention. The oil hose 72 is provided separately (outside) from the engine 63.

  In the second embodiment, the oil hose 72 is a valve that suppresses the oil stored in the crankcase 64 from flowing backward to the one end portion 72a of the oil hose 72, as shown in FIG. A member 73 is disposed between one end 72a and the other end 72b. Thus, even when the motorcycle 51 falls, it is possible to suppress the oil stored in the crankcase 64 from flowing into the breather chamber 68g.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the utility model registration request, and further includes all modifications within the meaning and scope equivalent to the scope of the utility model registration request.

  For example, in the above-described embodiment, a motorcycle is shown as an example of a vehicle having an engine breather structure, but the present invention is not limited to this, and any vehicle, tricycle, ATV, etc. can be used as long as the vehicle has an engine breather structure. It can also be applied to other vehicles such as (All Terrain Vehicle; rough terrain vehicle).

  In the above embodiment, an example in which the breather chamber is provided integrally with the air cleaner portion has been described. However, the present invention is not limited thereto, and the breather chamber may be provided separately from the air cleaner portion.

  Moreover, although the example which provided the gas inflow port part in the side surface of the breather chamber was shown in the said embodiment, this invention is not restricted to this, You may make it provide a gas inflow port part other than the side surface of a breather chamber. .

  In the above embodiment, an example in which the gas discharge port portion is provided in the partition member in the upper part of the breather chamber has been described. However, the present invention is not limited to this, and the gas discharge port portion is provided in other than the upper portion of the breather chamber. May be.

  In the above embodiment, the oil hose (oil passage part) for returning the oil from the oil discharge port part to the crankcase is shown separately from the engine, but the present invention is not limited to this. The oil passage portion may be formed integrally with the engine.

1 is a side view showing an overall structure of a motorcycle according to a first embodiment of the present invention. FIG. 2 is a side view showing the engine periphery of the motorcycle according to the first embodiment shown in FIG. 1. FIG. 2 is a cross-sectional view showing an air cleaner section and a breather chamber of the motorcycle according to the first embodiment shown in FIG. 1. FIG. 2 is a plan view showing an air cleaner portion of the motorcycle according to the first embodiment shown in FIG. 1. It is the side view which showed the whole structure of the moped type motorcycle by 2nd Embodiment of this invention. It is the side view which showed the air cleaner part of the moped type motorcycle by 2nd Embodiment of this invention. It is sectional drawing along the 100-100 line of FIG. FIG. 9 is a cross-sectional perspective view taken along line 200-200 in FIG. 7. It is sectional drawing along the 300-300 line of FIG.

Explanation of symbols

1,51 Motorcycle (vehicle)
13, 63 Engine 14, 64 Crankcase 14b, 64b Connection part (crankcase connection part)
19, 68 Air cleaner 19g, 68g Breather chamber (oil separation chamber)
19h, 68h Gas inlet 19i, 68i Gas outlet 19j, 68j Oil outlet 20, 69 Air filter unit (air filter)
23, 72 Oil hose (oil passage)
23a, 72a One end (oil separation chamber connection, one end)
23b, 72b The other end (oil return part, the other end)
24, 73 Valve member

Claims (10)

An engine including a crankcase in which oil is stored;
An air cleaner that is connected to the engine and purifies air flowing from outside;
A fuel gas that is separate from the crankcase and that is disposed adjacent to the air cleaner unit and that contains the oil gas that is present inside the crankcase of the engine and that contains the oil. A breather structure for an internal combustion engine, comprising: an oil separation chamber for separating the oil from the oil separation chamber and allowing the fuel gas separated from the oil to flow into the air cleaner section.   The breather structure for an internal combustion engine according to claim 1, wherein the oil separation chamber is formed integrally with the air cleaner portion. The oil separation chamber is
A gas inlet part into which fuel gas containing the oil flows, and
A gas discharge port for discharging the fuel gas from which the oil is separated from the fuel gas containing the oil to the air cleaner unit;
2. The breather structure for an internal combustion engine according to claim 1, further comprising an oil discharge port provided at a lower portion of the oil separation chamber and configured to discharge oil separated from fuel gas containing the oil. An oil passage for returning oil to the crankcase from the oil outlet,
4. The internal combustion engine according to claim 3, wherein an oil return portion of the oil passage portion to the crankcase is arranged to be positioned below an oil surface of the oil stored in the crankcase. Breather structure. The oil passage portion is provided outside the engine,
At one end of the oil passage portion, an oil separation chamber connection portion connected to the oil discharge port portion of the oil separation chamber is provided,
5. The internal combustion engine according to claim 4, wherein an oil return portion at the other end of the oil passage portion is provided with a crankcase connection portion that is connected below an oil surface of the oil of the crankcase. Breather structure.   The oil passage portion is disposed between the one end portion and the other end portion of the oil passage portion, and the oil stored in the crankcase flows backward to the one end portion side of the oil passage portion. The breather structure for an internal combustion engine according to claim 5, further comprising a valve member that suppresses this. The air cleaner portion includes an air filter that is disposed inside the air cleaner portion and through which air that has flowed into the air cleaner portion passes,
2. The breather structure for an internal combustion engine according to claim 1, wherein the oil separation chamber is disposed adjacent to a region on the downstream side of the air flow with respect to the air filter of the air cleaner portion.   The breather structure for an internal combustion engine according to claim 1, wherein the oil separation chamber is disposed below the air cleaner portion.   2. The breather structure for an internal combustion engine according to claim 1, wherein an area of the oil separation chamber is configured to be smaller than an area of the air cleaner portion when viewed in a plan view.   The vehicle provided with the breather structure of the internal combustion engine of any one of Claims 1-9.

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