Breather device

Abstract

To inhibit the inside of a breather hose from being frozen by temperature drop of a blow-by gas.SOLUTION: An engine (41) is inclined forward in a state that a cylinder axis is in a horizontal state or a state close to the horizontal state and an air cleaner (51) is installed above the engine. A breather device (61) for sending a blow-by gas to an intake system (54) is provided at the engine. The breather device is provided with: a breather hose (62) connecting the engine with the intake system; and a breather tank (65) disposed in the middle of the breather hose. A breather chamber which separates the blow-by gas into a gas and a liquid is formed at the breather tank. The air cleaner covers the breather tank from the front side.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a breather device. [Background technology]

[0002] The engine of a saddle-type vehicle is provided with a breather device that sends blow-by gas generated from the crankcase etc. to an air cleaner for re-burning. As this type of breather device, one in which a breather tank separate from the crankcase is installed above the crankcase is known (see, for example, Patent Document 1). In the breather device described in Patent Document 1, a breather chamber in the breather tank is connected to the air cleaner via a breather hose. Oil mist in the blow-by gas is captured in the breather chamber, and the blow-by gas that has passed through the breather chamber is sent to the air cleaner via the breather hose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-084782 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, blow-by gas contains moisture, and when the blow-by gas is cooled by low temperatures or the wind while driving, the inside of the breather hose may freeze and block the gas passage. In particular, in engines in which the cylinder assembly is tilted horizontally, the wind while driving easily hits the breather hose, and the combustion chamber, which is the heat source, is removed from the front of the breather tank, making it more likely to freeze.

[0005] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a breather device that can suppress freezing inside the breather hose due to a drop in the temperature of the blow-by gas. [Means for solving the problem]

[0006] One aspect of the present invention is a breather device in which an engine is tilted forward with the cylinder axis horizontal or close to horizontal, an air cleaner is installed above the engine, and blow-by gas is sent from the engine to an intake system, the breather device comprising a breather hose connecting the engine and the intake system, and a breather tank interposed midway along the breather hose, a breather chamber is formed in the breather tank to separate the blow-by gas into gas and liquid, and the breather tank is covered from the front by the air cleaner, thereby solving the above-mentioned problem. Effect of the Invention

[0007] According to the breather device of one aspect of the present invention, even if the breather tank is installed above the engine that is tilted forward with the cylinder axis line horizontal or close to horizontal, the air cleaner acts as a windscreen to prevent the breather tank from being exposed to the wind caused by running. Also, by installing the breather tank above the engine, the breather tank is warmed by the radiant heat of the engine. This suppresses the temperature drop of the blow-by gas and prevents the inside of the breather hose from freezing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a right side view of the vehicle internal structure of the present embodiment. [Diagram 2] FIG. 2 is a top view of the periphery of the engine according to the embodiment. [Diagram 3] FIG. 2 is a side view of the periphery of the engine according to the embodiment. [Figure 4] FIG. 2 is a rear view of the engine and its surroundings according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A breather device according to one aspect of the present invention sends blow-by gas from an engine to an intake system. The engine is inclined forward with its cylinder axis horizontal or close to horizontal, and an air cleaner is installed above the engine. A breather hose of the breather device connects the engine to the intake system, and a breather tank is interposed midway along the breather hose. A breather chamber that separates the blow-by gas into gas and liquid is formed in the breather tank, and the breather tank is covered from the front by the air cleaner. Even if the breather tank is installed above the engine, the air cleaner acts as a windbreak, making it difficult for the wind from traveling to hit the breather tank. In addition, by installing the breather tank above the engine, the breather tank is warmed by radiant heat from the engine. This suppresses a drop in the temperature of the blow-by gas, and prevents freezing inside the breather hose. EXAMPLES

[0010] Hereinafter, a saddle-type vehicle according to the present embodiment will be described with reference to the accompanying drawings. Fig. 1 is a right side view of the internal structure of the vehicle according to the present embodiment. In the following drawings, the arrow Fr indicates the front of the vehicle, the arrow Re indicates the rear of the vehicle, the arrow L indicates the left side of the vehicle, and the arrow R indicates the right side of the vehicle.

[0011] As shown in Fig. 1, a saddle-type vehicle 1 is configured by mounting various covers (not shown) as the exterior of the vehicle body to a body frame 10 made of steel or aluminum alloy. A head pipe 11 is provided at the front end of the body frame 10, and a support frame 12 extends diagonally rearward and downward from an upper portion of the head pipe 11. A pair of first down frames 13 branch off to the left and right and extend downward from a lower portion of the support frame 12, and a pair of second down frames 14 branch off to the left and right and extend downward from a lower portion of the head pipe 11. A pair of main frames 15 are connected to the lower portions of the pair of first and second down frames 13, 14.

[0012] The pair of main frames 15 extend toward the rear of the vehicle, and their middle portions are connected by an upper bridge 16. A pair of asymmetrical side frames 17 extend downward from the front ends of the pair of main frames 15. Each side frame 17 is bent rearward under the vehicle and then extends diagonally upward and rearward toward the rear portions of the pair of main frames 15. The pair of main frames 15 and the pair of side frames 17 form the front half of the body frame 10 into a cradle shape. A pair of footboards 18 are attached to the pair of side frames 17.

[0013] A pair of seat frames 19 extend rearward from the rear portions of the pair of main frames 15. The distance between the pair of seat frames 19 increases toward the middle of each frame and then decreases toward the rear ends of each frame. The pair of seat frames 19 are formed in an arch shape, and the rear ends of the pair of seat frames 19 are connected to each other. The front portions of the pair of seat frames 19 are connected by an upper bridge 21. The rear portions of the pair of side frames 17 are connected to the upper bridge 21, and the upper bridge 21 is supported from below by the pair of side frames 17.

[0014] A pair of asymmetric lower frames 22 extend rearward from the lower portions of the pair of side frames 17. The rear ends of the pair of lower frames 22 are connected by a lower bridge 23. A left subframe 26 extends diagonally upward and rearward from the left end of the lower bridge 23, and the left subframe 26 supports the seat frame 19 from below. A side bridge 25 connects the right end of the lower bridge 23 to an intermediate portion of the right side frame 17. A right subframe 27 extends diagonally upward and rearward from the intermediate portion of the side bridge 25, and the right subframe 27 supports the seat frame 19 from below.

[0015] A gas tank 31 is installed inside the cradle portion in the front half of the body frame 10. The gas tank 31 is formed in a cylindrical shape, and both ends of the gas tank 31 are bulged out in a hemispherical shape. The longitudinal direction of the gas tank 31 is oriented forward and backward, and the gas tank 31 is slightly tilted so that the front end of the gas tank 31 is higher than the rear end. A tank valve 32 is installed at the rear end of the gas tank 31. Gas fuel such as hydrogen is stored in the gas tank 31, and the inflow and outflow of the gas fuel is controlled by the tank valve 32. Gas fuel is supplied from the tank valve 32 to the unit swing engine 41 via supply system components (not shown).

[0016] A unit swing engine (engine) 41 is swingably supported on the support plates 29 of the left and right subframes 26, 27. The unit swing engine 41 is operated by combustion energy of gas fuel supplied from a gas tank 31. The unit swing engine 41 is tilted forward with the cylinder axis line close to horizontal, and a cylinder assembly 43 extends toward the front of the vehicle from a crankcase 42. Intake system parts such as an air cleaner 51 are connected to the upper part of the cylinder assembly 43, and exhaust system parts such as an exhaust pipe 56 and a muffler 57 are connected to the lower part of the cylinder assembly 43.

[0017] Incidentally, the unit swing engine 41 of this embodiment is provided with a breather device (not shown) that is integrated with the crankcase 42, and blow-by gas is sent from the crankcase 42 to the air cleaner 51 through a breather hose 60 (see FIG. 2). However, the unit swing engine 41 of this embodiment is a CVT engine, and there is no transmission chamber in the crankcase 42. Since the case volume is small compared to the displacement, the pressure fluctuations in the crankcase 42 are large, and the blow-by gas discharge capacity is insufficient. For this reason, it is desirable to add a breather device.

[0018] Usually, an additional breather device is provided inside the cylinder head cover 46, and a structure is adopted that separates oil mist from blow-by gas inside the engine, but if the cylinder head cover 46 is placed close to the gas tank 31, it is difficult to secure the space to install the breather device. A structure in which the additional breather device is installed separately from the unit swing engine 41 is considered, but depending on the location of the breather device, the breather device may be separated from the combustion chamber, and the blow-by gas may be cooled by the wind while traveling. The blow-by gas contains moisture, which may freeze and block the gas passage. In particular, hydrogen contains a lot of moisture in the blow-by gas.

[0019] If the gas passage is blocked by the freezing of the blow-by gas, the internal pressure of the crankcase 42 may become excessively high, and oil may leak from each mating surface of the unit swing engine 41. In addition, the throttle body of the intake system, to which the breather device is connected, may freeze, causing the engine to function abnormally. Therefore, the breather device 61 of this embodiment, except for some parts, is concentrated behind the air cleaner 51, so that each part of the breather device 61 is less likely to be exposed to the wind caused by running. In addition, by installing the breather device 61 above the crankcase 42, the drop in temperature of the blow-by gas is suppressed by radiant heat from the engine.

[0020] The breather device will be described below with reference to Figures 2 and 3. Figure 2 is a top view of the engine and its periphery in this embodiment. Figure 3 is a side view of the engine and its periphery in this embodiment.

[0021] 2 and 3, a cylinder assembly 43 is installed in front of a crankcase 42 of a unit swing engine 41. The cylinder assembly 43 is formed by stacking a cylinder 44, a cylinder head 45, and a cylinder head cover 46 on the front surface of the crankcase 42. The crankcase 42 has a left-right split structure consisting of left and right case halves, with the left case half extending further rearward than the right case half. A CVT cover 47 is attached to the open left side surface of the left case half, and a magneto cover 48 is attached to the open right side surface of the right case half.

[0022] An air cleaner 51 is installed above the cylinder head 45. The air cleaner 51 is connected to the cylinder head 45 via an outlet tube 52, a throttle body 53, and an intake pipe 54. More specifically, the left front side of the air cleaner 51 protrudes forward, and a U-shaped outlet tube 52 is connected to the front side of the protruding part of the air cleaner 51. The outlet tube 52 is connected to the throttle body 53 above the cylinder head cover 46, and the throttle body 53 and the cylinder head 45 are connected to the upper surface of the cylinder head 45 via an intake pipe 54 that is curved in an arc shape.

[0023] In this way, an intake passage is formed between the air cleaner 51 and the cylinder head 45 by the outlet tube 52, the throttle body 53, and the intake pipe 54. Air is sent from the air cleaner 51 to the throttle body 53 via the outlet tube 52, and after the intake amount is adjusted by the throttle body 53, the air is supplied to the cylinder head 45 through the intake pipe 54. An injector (not shown) is fixed to the intake pipe 54 by an injector joint 55, and gas fuel from the gas tank 31 (see FIG. 1) is injected from the injector toward the intake port.

[0024] An exhaust pipe 56 is connected to the underside of the cylinder head 45. The exhaust pipe 56 curves rearward from the cylinder head 45, then passes through the right side of the crankcase 42 (one side in the vehicle width direction) and extends toward the rear of the vehicle. A muffler 57 inclined diagonally upward and rearward on the right side of the rear wheel (not shown) is connected to the rear end of the exhaust pipe 56. The muffler 57 is supported from the inside in the vehicle width direction by a muffler bracket 58 fixed to the crankcase 42. Exhaust gas discharged from the cylinder head 45 flows through the exhaust pipe 56 and the muffler 57, and the exhaust gas warms the exhaust pipe 56 and the muffler 57 to a high temperature.

[0025] As described above, a breather device (not shown) is provided inside the crankcase 42, and the engine-integrated breather device and the air cleaner 51 are connected via a breather hose 60. In addition, above the unit swing engine 41, a separate engine breather device 61 is provided for sending blow-by gas from the unit swing engine 41 to the intake system. In the breather device 61, the cylinder head cover 46 and the intake pipe 54 are connected by a breather hose 62, and a resin breather tank 65 is provided in the middle of the breather hose 62 behind the air cleaner 51 and above the crankcase 42.

[0026] Half of the breather hose 62 is formed by a first breather hose 63 upstream of the breather tank 65. The first breather hose 63 extends from the right side of the cylinder head cover 46, passing to the right and rear of the air cleaner 51, to an upper part of the right side of the breather tank 65. The blow-by gas in the cylinder head cover 46 is introduced into the breather tank 65 through the first breather hose 63. A breather chamber is formed inside the breather tank 65, and oil mist in the blow-by gas is captured in the breather chamber, separating the blow-by gas into gas and liquid.

[0027] The breather tank 65 and the crankcase 42 are connected by an oil return hose 66. The oil return hose 66 extends from the lower part of the right side of the breather tank 65, passing through the left side of the cylinder 44, to the lower part of the left side of the crankcase 42. When the oil component is separated from the blow-by gas in the breather chamber of the breather tank 65, the oil component is returned to an oil reservoir in the lower part of the crankcase 42 through the oil return hose 66. An L-shaped PCV valve 68 is attached to a pipe 67 protruding from the front surface of the breather tank 65, and the flow of the blow-by gas in the breather hose 62 is adjusted by the PCV valve 68.

[0028] The remaining half of the breather hose 62 is formed by a second breather hose 64 downstream of the breather tank 65. The second breather hose 64 extends from the PCV valve 68, passing behind and to the right side of the air cleaner 51, to the right side of the intake pipe 54. The blow-by gas that has passed through the breather tank 65 is sent to the intake pipe 54 through the second breather hose 64. When the intake pipe 54 becomes negative pressure, the blow-by gas is sent to the intake port through the second breather hose 64 and the intake pipe 54 and is re-burned.

[0029] The layout of the breather device will be described with reference to Figures 2 and 4. Figure 4 is a rear view of the engine and its periphery in this embodiment.

[0030] 2, an intake passage connecting the air cleaner 51 and the cylinder head 45, i.e., an outlet tube 52, a throttle body 53, and an intake pipe 54, are installed in front of the air cleaner 51. By concentrating the components of the intake passage in front of the air cleaner 51, a sufficiently large installation space for the breather tank 65 is ensured behind the air cleaner 51. The capacity of the breather chamber of the breather tank 65 is increased to improve gas-liquid separation performance. In addition, the freedom of installation of the breather tank 65 is improved, and the breather tank 65 can be installed in a place that is more difficult to cool.

[0031] 2 and 4, a breather tank 65 is installed behind the air cleaner 51, and the breather tank 65 is covered from the front by the air cleaner 51. In a rear view, the breather tank 65 is accommodated between the upper end position and the lower end position of the air cleaner 51 in the vertical direction, and between the left end position and the right end position of the air cleaner 51 in the vehicle width direction, so that the entire breather tank 65 overlaps the air cleaner 51. In addition, a PCV valve 68 is installed between the air cleaner 51 and the breather tank 65, and the entire PCV valve 68 also overlaps the air cleaner 51 in a rear view.

[0032] The air cleaner 51 acts as a windscreen, making it difficult for the wind during travel to hit the breather tank 65 and PCV valve 68, thereby suppressing a drop in temperature of the blow-by gas. The PCV valve 68 is sandwiched between the air cleaner 51 and the breather tank 65 from the front and rear, improving the protection performance of the PCV valve 68. The breather tank 65 is attached to the top surface of the crankcase 42 via a metal bracket 69 at the center of the crankcase 42 in the vehicle width direction. The heat of the crankcase 42 is transferred to the breather tank 65 via the metal bracket 69, thereby suppressing a drop in temperature of the blow-by gas in the breather tank 65.

[0033] As described above, the exhaust pipe 56 extends rearward from the cylinder head 45 through the right side. The first breather hose 63 extends from the cylinder head cover 46 through the right side of the air cleaner 51 to the rear breather tank 65, and the second breather hose 64 extends from the breather tank 65 through the right side of the air cleaner 51 to the front intake pipe 54. The first and second breather hoses 63, 64 pass above the exhaust pipe 56 on the right side of the air cleaner 51. The first and second breather hoses 63, 64 are exposed to the wind while traveling, but the first and second breather hoses 63, 64 are warmed by the heat of the exhaust pipe 56, so that a drop in the temperature of the blow-by gas is suppressed.

[0034] As described above, according to the breather device 61 of this embodiment, even if the breather tank 65 is installed above the unit swing engine 41 that is tilted forward with the cylinder axis line approaching horizontal, the air cleaner 51 acts as a windbreak and prevents the breather tank 65 from being exposed to the wind caused by traveling. In addition, by installing the breather tank 65 above the unit swing engine 41, the breather tank 65 is warmed by the radiant heat of the unit swing engine 41. Therefore, a decrease in the temperature of the blow-by gas is suppressed, and freezing inside the breather hose 62 can be prevented.

[0035] In this embodiment, a unit swing engine is exemplified as the engine, but the engine may have a cylinder axis that is horizontal or close to horizontal and inclined forward.

[0036] Furthermore, in this embodiment, gas fuel is exemplified as the fuel, but the fuel may be liquid fuel.

[0037] In addition, in this embodiment, the cylinder head cover and the intake pipe are connected by a breather hose, but it is sufficient that the engine and the intake system are connected by a breather hose. For example, any of the crankcase, cylinder, cylinder head, and cylinder head cover may be connected by a breather hose to any of the air cleaner, outlet tube, throttle body, and intake pipe.

[0038] In addition, in this embodiment, the breather tank is attached to the crankcase via a metal bracket, but the breather tank may be attached to the air cleaner or the vehicle frame.

[0039] The breather device of the present embodiment may be used in other types of saddle-ride vehicles as well as the above-mentioned saddle-ride vehicles. Note that the saddle-ride vehicles are not limited to vehicles in general in which the rider sits astride the seat, but also include scooter-type vehicles in which the rider does not sit astride the seat.

[0040] As described above, the first embodiment is a breather device (61) for sending blow-by gas from the engine to an intake system, in which the engine (unit swing engine 41) is tilted forward with the cylinder axis line horizontal or close to horizontal, the air cleaner (51) is installed above the engine, and the breather device (61) includes a breather hose (62) connecting the engine to the intake system (intake pipe 54) and a breather tank (65) interposed in the middle of the breather hose, a breather chamber for separating the blow-by gas into gas and liquid is formed in the breather tank, and the breather tank is covered from the front by the air cleaner. According to this configuration, even if the breather tank is installed above the engine tilted forward with the cylinder axis line horizontal or close to horizontal, the air cleaner acts as a wind shield, making it difficult for the breather tank to be exposed to the wind caused by traveling. In addition, by installing the breather tank above the engine, the breather tank is warmed by the radiant heat of the engine. Therefore, the temperature drop of the blow-by gas is suppressed, and freezing in the breather hose can be prevented.

[0041] In the second embodiment, an intake passage (outlet tube 52, throttle body 53, intake pipe 54) that connects the air cleaner to the engine is installed in front of the air cleaner in the first embodiment. With this configuration, the components of the intake passage are concentrated in front of the air cleaner, so that a sufficiently large installation space for the breather tank can be secured behind the air cleaner. The capacity of the breather chamber of the breather tank is increased to improve gas-liquid separation performance. In addition, the freedom of installation of the breather tank is improved, and the breather tank can be installed in a place that is more difficult to cool.

[0042] In the third aspect, in the first or second aspect, a PCV valve (68) that adjusts the flow of blow-by gas in the breather hose is provided between the air cleaner and the breather tank. With this configuration, the PCV valve is also less likely to be exposed to the wind during travel, and a drop in the temperature of the blow-by gas is suppressed. In addition, the protection performance of the PCV valve is improved by sandwiching the PCV valve between the air cleaner and the breather tank from the front and rear.

[0043] A fourth aspect is any one of the first to third aspects, in which the breather hose has a first breather hose (63) on the upstream side of the breather tank and a second breather hose (64) on the downstream side of the breather tank, an exhaust pipe (56) extends rearward from the engine through one side in the vehicle width direction, and the first breather hose and the second breather hose pass above the exhaust pipe on one side in the vehicle width direction of the air cleaner. According to this configuration, the first and second breather hoses are exposed to wind while traveling, but the first and second breather hoses are warmed by the heat of the exhaust pipe, thereby suppressing a decrease in the temperature of the blow-by gas.

[0044] A fifth aspect is any one of the first to fourth aspects, in which the breather tank is attached to the crankcase (42) of the engine via a metal bracket (69). According to this configuration, heat from the crankcase is transferred to the breather tank via the bracket, thereby suppressing a decrease in the temperature of the blow-by gas in the breather tank.

[0045] Although the present embodiment has been described, other embodiments may be made by combining the above-described embodiments and modifications in whole or in part.

[0046] In addition, the technology of the present invention is not limited to the above examples, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to the progress of technology or a different technology derived therefrom, the invention may be implemented using that method. Therefore, the claims cover all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0047] 1: Saddle-type vehicle 41: Unit Swing Engine (Engine) 42: Crankcase (engine) 43: Cylinder assembly (engine) 44: Cylinder (engine) 45: Cylinder head (engine) 46: Cylinder head cover (engine) 51: Air cleaner (intake system) 52: Outlet tube (intake system, intake passage) 53: Throttle body (intake system, intake passage) 54: Intake pipe (intake system, intake passage) 55: Injector joint 56: Exhaust pipe 61: Breather device 62: Breather hose 63: First breather hose 64: Second breather hose 65: Breather tank 68: PCV valve 69: Metal bracket

Claims

1. A breather device in which an engine is tilted forward with a cylinder axis line horizontal or close to horizontal, an air cleaner is installed above the engine, and blow-by gas is sent from the engine to an intake system, a breather hose connecting the engine and the intake system; A breather tank is provided in the middle of the breather hose. The breather tank is provided with a breather chamber for separating blow-by gas into gas and liquid. A breather device, wherein the breather tank is covered from the front by the air cleaner.

2. 2. The breather device according to claim 1, further comprising an intake passage disposed in front of said air cleaner for connecting said air cleaner to said engine.

3. A PCV valve is provided to adjust the flow of blow-by gas through the breather hose.

3. The breather device according to claim 1, wherein the PCV valve is disposed between the air cleaner and the breather tank.

4. The breather hose includes a first breather hose on the upstream side of the breather tank and a second breather hose on the downstream side of the breather tank, 3. The breather device according to claim 1, wherein an exhaust pipe extends rearward from the engine through one side in the vehicle width direction, and the first breather hose and the second breather hose pass above the exhaust pipe on one side in the vehicle width direction of the air cleaner.

5. 3. The breather device according to claim 1, wherein the breather tank is attached to a crankcase of the engine via a metal bracket.

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