JP2013234641A - Intake device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake device of an internal combustion engine, capable of preventing freezing of a throttle valve while suppressing an increase in the number of parts.SOLUTION: An intake device of an engine (internal combustion engine) 100 comprises: a throttle body 82a having a downstream intake passage 82c extending in the vertical direction of a vehicle; a throttle valve 82b provided to the throttle body 82a and opening and closing the downstream intake passage 82c; and an air hose 83 connected to an upper part of the throttle body 82a and having an upstream intake passage 83c for introducing intake air into the downstream intake passage 82c. The air hose 83 is provided with a PCV port 83a for bringing the inside of the air hose 83 into communication with the inside of the engine 100. A recess 83b is provided in the upstream intake passage 83c between the PCV port 83a of the air hose 83 and throttle body 82a.

Description

  The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake device that recirculates blow-by gas flowing into a crankcase of the internal combustion engine to the internal combustion engine via an intake passage.

  2. Description of the Related Art Conventionally, an internal combustion engine (engine) for an automobile has blow-by gas that is re-combusted by recirculating blow-by gas that flows into the crankcase (crank chamber) through a clearance between the cylinder and the piston into the combustion chamber via an intake passage. A gas reduction device (PCV: Positive Crankcase Ventilation) is provided.

  Blow-by gas contains a large amount of moisture (condensed water) generated by combustion, so if the ambient temperature falls below freezing in the winter, the blow-by gas may block the blow-by gas passage. there were. If the blow-by gas passage is blocked, the pressure inside the engine will rise, causing problems such as oil level gauge withdrawal, oil scattering, and oil leakage from the crank oil seal. Various measures have been taken to prevent freezing of water.

  As one of countermeasures, for example, Patent Document 1 provides a PCV negative pressure passage for introducing blow-by gas into an intake manifold (intake passage) on the downstream side of the throttle body (throttle valve). A configuration is disclosed in which a heater and a connector (heater unit) for heating blow-by gas are arranged at a connection portion connecting the negative pressure passage and the intake manifold. The blow-by gas introduced into the intake manifold is heated by the heater unit, thereby preventing moisture in the blow-by gas from freezing.

JP 2008-106637 A

  However, in Patent Document 1, a heater unit that heats the blow-by gas is provided (added) in the intake manifold, thereby causing a problem that the number of parts increases and a problem that fuel efficiency deteriorates. In addition, when the heater breaks down, when the condensed water contained in the blow-by gas adheres to the throttle valve, the condensed water adhering to the throttle valve freezes to cause a problem that the throttle valve is fixed. From the above viewpoint, it is desired to suppress freezing of the throttle valve while suppressing an increase in the number of parts.

  The present invention has been made to solve the above-described problems, and an object of the present invention is an internal combustion engine capable of suppressing freezing of a throttle valve while suppressing an increase in the number of parts. It is to provide an intake device.

  As means for solving the above-described problems, an intake device for an internal combustion engine according to the present invention is configured as follows.

  That is, an intake device for an internal combustion engine according to the present invention is premised on a configuration in which blow-by gas flowing into a crankcase of the internal combustion engine is recirculated to the internal combustion engine through an intake passage. An intake device for an internal combustion engine according to the present invention includes a throttle body having a downstream intake passage extending in the vertical direction of a vehicle, a throttle valve provided in the throttle body and opening and closing the downstream intake passage, An air hose connected above the throttle body and having an intake passage on the upstream side for introducing intake air into the intake passage on the downstream side, and the air hose includes an interior of the air hose, an interior of the internal combustion engine, A communication hole is provided, and a recess is provided in the intake passage on the upstream side or the downstream side between the communication hole of the air hose and the throttle body. .

  According to the intake device for an internal combustion engine having such a configuration, the condensed water flowing (dropping) into the intake passages on the upstream side and the downstream side through the communication holes provided in the air hose can be dispersed in the recesses. Condensed water can be reduced from adhering to components such as a throttle valve provided on the body and a shaft for supporting and fixing the throttle valve. Thereby, it is possible to prevent the throttle body (parts such as the throttle valve and the shaft) from freezing. Further, unlike the case where another component such as a heater is provided in the intake passage in order to prevent the condensed water from freezing, an increase in the number of components can be suppressed. Thereby, it is possible to suppress freezing of the throttle valve with a simple configuration while suppressing the complexity of the structure of the intake device.

  As specific configurations of the present invention, the following plural ones are listed.

  The intake device for an internal combustion engine according to the present invention is preferably characterized in that a chamfered portion is provided at an end of the throttle body on the communication hole side. With this configuration, the chamfered portion makes it difficult for the condensed water flowing (dropped) from the communication hole provided in the air hose to stay at the end of the throttle body on the communication hole side. It can suppress that the edge part of this freezes.

  According to the present invention, it is possible to suppress freezing of the throttle valve while suppressing an increase in the number of parts.

It is sectional drawing which shows schematic structure of the internal combustion engine by this embodiment. It is a figure which shows the connection part of a throttle body and an air cleaner hose. It is sectional drawing which shows the connection part of the throttle body and air cleaner hose along the 200-200 line | wire of FIG. It is the figure which looked at the connection part of the throttle body and air cleaner hose along the 300-300 line | wire of FIG. 3 from the upper surface.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  An example in which the present invention is applied to an internal combustion engine for an automobile (vehicle) will be described with reference to FIGS.

-Engine-
First, a schematic configuration of an internal combustion engine (engine) 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of the interior of the engine 100 and the intake system when the engine 100 is viewed from a direction along the axis of the crankshaft 1.

  As shown in FIG. 1, the engine 100 includes a cylinder head 3 installed at the upper end of the cylinder block 2 and a head cover 4 attached to the upper end of the cylinder head 3. A cylinder 5 is disposed in the cylinder block 2. Inside these cylinders 5, pistons 51 are accommodated so as to be able to reciprocate.

  The piston 51 is connected to a small end (not shown) of the connecting rod 52 by a piston pin 53. Further, the large end portion 52 a of the connecting rod 52 is connected to the crankshaft 1. The reciprocating motion of the piston 51 is converted into the rotational motion of the crankshaft 1 through the connecting rod 52.

  A crankcase 6 is attached to the lower side of the cylinder block 2. A space extending from the lower part in the cylinder block 2 to the inside of the crankcase 6 is configured as a crank chamber 61. An oil pan 7 serving as an oil reservoir is disposed below the crank chamber 61.

  The cylinder head 3 is assembled with an intake valve 32 for opening and closing the intake port 31 and an exhaust valve 34 for opening and closing the exhaust port 33, respectively. The valves 32 and 34 are opened and closed by the rotation of the camshafts 35 and 36 disposed in the cam chamber (inside space of the cylinder head 3) 3a formed between the cylinder head 3 and the head cover 4. It is like that.

  An intake manifold 8 is connected to an intake port 31 formed in the cylinder head 3. A surge tank 81 is connected to the upstream side of the intake manifold 8. An electronic throttle device 82 equipped with a downdraft is connected to the upstream side of the surge tank 81. The electronic throttle device 82 includes a throttle body 82a and a throttle valve 82b provided inside the throttle body 82a. An air cleaner hose 83 is connected to the upstream side of the electronic throttle device 82. An air cleaner 84 is provided on the upstream side of the air cleaner hose 83. With the above configuration, the air introduced from the air cleaner 84 into the electronic throttle device 82 via the air cleaner hose 83 is introduced into the intake manifold 8 through the surge tank 81. The air cleaner hose 83 is an example of the “air hose” in the present invention.

  The air cleaner hose 83 has a PCV port 83a. The PCV port 83a is an example of the “communication hole” in the present invention. The PCV port 83a is connected to the inside of the engine 100 (separator chamber 93b) via a fresh air introduction pipe 95 described later. By the way, the condensed water contained in the blow-by gas generated inside the engine 100 is dripped into the electronic throttle device 82 from the PCV port 83a, and each component of the electronic throttle device 82 is frozen in a low temperature environment region such as below freezing point. A malfunction occurs.

  In this regard, in the present embodiment, the condensed water flowing into the intake passage 82c of the electronic throttle device 82 from the PCV port 83a is dispersed by a later-described recess 83b provided between the air cleaner hose 83 and the electronic throttle device 82. Thus, the components of the electronic throttle device 82 can be prevented from freezing. A detailed description of this point will be described later.

  The cylinder head 3 is provided with an injector (fuel injection valve) 37, and the air introduced into the intake port 31 is mixed with the fuel injected from the injector 37 to become an air-fuel mixture. As the valve is opened, it is introduced into the combustion chamber 38.

  A spark plug 39 is disposed at the top of the combustion chamber 38. In the combustion chamber 38, the piston 51 reciprocates due to the combustion of the air-fuel mixture accompanying the ignition of the spark plug 39. The reciprocating motion of the piston 51 is transmitted to the crankshaft 1 through the connecting rod 52. Then, after being converted into rotational motion, it is taken out as an output of the engine 100.

  The combustion gas generated by the combustion of the air-fuel mixture passes through the exhaust port 33 as exhaust gas when the exhaust valve 34 is opened, and is then discharged to an exhaust manifold (not shown). The discharged exhaust gas passes through the exhaust pipe and is discharged to the outside. The exhaust pipe is provided with a catalytic converter to purify hydrocarbons (HC), carbon monoxide (CO), nitrogen oxide components (NOx) and the like contained in the exhaust gas.

-Blow-by gas reduction device-
Next, the blow-by gas reduction device 9 provided in the engine 100 will be described. The blow-by gas reduction device 9 extracts blow-by gas generated inside the crank case 6 (in the crank chamber 61) of the engine 100, returns it to the intake system (surge tank 81 or intake manifold 8) of the engine 100, and re-combusts it. PCV (Positive Crankcase Ventilation) which introduces clean outside air filtered by the air cleaner 84 (clean air from which impurities contained in the outside air are removed) into the crankcase 6 to ventilate the crankcase 6 It is a device.

  That is, the blow-by gas reduction device 9 guides the fuel (blow-by gas) blown into the crank chamber 61 from the gap between the inner surface 5a of the cylinder 5 and the outer surface 51a of the piston 51 to the intake system of the engine 100. It is for introducing new air inside and ventilating.

  Specifically, the blow-by gas reduction device 9 includes a blow-by gas recovery passage 91, a first oil separator (negative pressure side oil separator) 92, a second oil separator (atmosphere side oil separator) 93, and a blow-by gas supply pipe 94. And a fresh air introduction pipe 95 and a fresh air introduction passage 96.

  The blow-by gas recovery passage 91 is for extracting blow-by gas blown into the crank chamber 61 toward the inside of the cam chamber 3a. The first oil separator (negative pressure side oil separator) 92 is for separating the oil mist from the blow-by gas after the blow-by gas extracted by the blow-by gas recovery passage 91 is introduced through the cam chamber 3a. The second oil separator (atmosphere side oil separator) 93 mainly has a function of introducing outside air (fresh air).

  The blow-by gas supply pipe 94 is for guiding blow-by gas from the first oil separator 92 to the intake system. The fresh air introduction pipe 95 has a function of introducing fresh air mainly toward the second oil separator 93. The fresh air introduction passage 96 is for introducing fresh air from the cam chamber 3 a into the crank chamber 61.

  The blow-by gas recovery passage 91 is formed as a passage extending in a substantially vertical direction from the cylinder block 2 to the cylinder head 3. That is, the passage 91 a formed in the cylinder block 2 and the passage 91 b formed in the cylinder head 3 both extend in the vertical direction on the same axis, and communicate with each other via the blow-by gas recovery passage 91. 61 communicates with the cam chamber 3a. Thereby, at the time of blow-by gas recovery, the blow-by gas in the crank chamber 61 is introduced into the cam chamber 3 a through the blow-by gas recovery passage 91.

  The first oil separator 92 is attached to one side (the left side in FIG. 1) of the inner surface of the head cover 4. The first oil separator 92 includes a separator case (breather case) 92a and a plurality of baffle plates (not shown) arranged in the separator case 92a.

  The separator case 92a is a substantially rectangular parallelepiped box-shaped member made of metal or resin with the upper side opened. The open side of the separator case 92 a is attached to the inner surface of the head cover 4, thereby forming a separator chamber (blow-by gas flow path) 92 b that is substantially sealed with the head cover 4. The separator case 92a is formed with a blow-by gas introduction hole 92c and an oil recovery part 92d, and a PCV (Positive Crankcase Ventilation) valve 92e is attached.

  The blow-by gas introduction hole 92c is formed on the bottom surface of one side of the separator case 92a in the longitudinal direction (cylinder arrangement direction when attached to the head cover 4). The internal space (separator chamber 92b) of the first oil separator 92 communicates with the cam chamber 3a through a blow-by gas introduction hole 92c.

  The oil recovery part 92d is configured as a so-called oil pool provided on the bottom surface of the separator case 92a. That is, the oil recovery part 92d is configured by forming a relatively small-diameter opening on the bottom surface of the concave portion formed on a part of the bottom surface of the separator case 92a. As a result, the internal space of the separator case 92a communicates with the cam chamber 3a, and oil is stored in the oil pool, so that oil mist or the like in the cam chamber 3a is separated from the oil recovery portion 92d from the separator case 92a. It is suppressed from flowing into the interior space.

  The PCV valve 92e is configured to open according to the pressure in the internal space of the separator case 92a and the intake negative pressure of the intake system. When the PCV valve 92e is opened, the blow-by gas after the oil is separated and removed in the separator case 92a is introduced into the intake system of the engine 100 (downstream of the throttle valve 82) via the PCV valve 92e. Become. As the PCV valve 92e, a solenoid valve that can be freely opened and closed may be used.

  The second oil separator 93 has substantially the same configuration as the first oil separator 92 described above. That is, the second oil separator 93 is attached to the other side (the right side in FIG. 1) of the inner surface of the head cover 4. The second oil separator 93 includes a separator case 93a and a plurality of baffle plates (not shown) disposed in the separator case 93a.

  The separator case 93 a forms a separator chamber 93 b that is substantially sealed with the head cover 4. A fresh air introduction hole 93c is formed in the separator case 93a. The fresh air introduction hole 93c is formed at a position corresponding to the cam chamber 3a on the bottom surface of the separator case 93a. That is, the fresh air introduction hole 93c allows the separator chamber 93b of the second oil separator 93 and the cam chamber 3a to communicate with each other.

  The blow-by gas supply pipe 94 is a pipe for guiding the blow-by gas after the oil is separated and removed to the intake system in the separator case 92a of the first oil separator 92. The upstream end of the blowby gas supply pipe 94 is connected to the PCV valve 92e, while the downstream end of the blowby gas supply pipe 94 is connected to the downstream side (lower side) of the throttle valve 82 in the electronic throttle device 82. Yes. Thus, blow-by gas is returned to the intake system of engine 100 via surge tank 81 as PCV valve 92 e is opened.

  One end of the fresh air introduction pipe 95 is connected to the upstream side (upper side) of the throttle valve 82 in the electronic throttle device 82. The other end of the fresh air introduction pipe 95 communicates with the separator chamber 93 b of the second oil separator 93. The new air introduction pipe 95 mainly has a function of introducing outside air (fresh air) for ventilating the crank chamber 61 from the intake system. The fresh air introduction pipe 95 introduces fresh air into the crank chamber 61 from the second oil separator 93 via the fresh air introduction passage 96 when the engine 100 is lightly loaded (solid line shown in FIG. 1). As a result, the pressure in the crank chamber 61 is kept constant. On the other hand, when the engine 100 is at a high load (broken line shown in FIG. 1), the introduction of fresh air is stopped, and a large amount of blow-by gas is sucked into the intake manifold 8 from the throttle body 82a via the PCV port 83a. Then, it is introduced into the combustion chamber 38 together with the intake air.

  The fresh air introduction passage 96 is formed as a passage extending in a substantially vertical direction from the cylinder head 3 to the cylinder block 2. That is, the passage 96 a formed in the cylinder head 3 and the passage 96 b formed in the cylinder block 2 are both communicated extending in the vertical direction on the same axis, and the cam is passed through the fresh air introduction passage 96. The chamber 3a and the crank chamber 61 are communicated with each other. As a result, fresh air introduced from the second oil separator 93 into the cam chamber 3a is introduced into the crank chamber 61 through the fresh air introduction passage 96, and the crank chamber 61 is ventilated. The fresh air introduction passage 96 also serves as an oil return passage. That is, the oil separated and removed by the first oil separator 92 and flowing down to the cam chamber 3a is recovered in the oil pan 7 by its own weight.

-Intake device (electronic throttle device and air cleaner hose)-
Next, with reference to FIG. 2 and FIG. 3, the intake device (electronic throttle device and air cleaner hose) according to the present embodiment will be described in detail.

  As shown in FIG. 3, the electronic throttle device 82 includes a throttle body (housing) 82a that is airtightly coupled to the downstream end of the air cleaner hose 83 in the middle of the intake duct of the engine 100, and the intake air inside the throttle body 82a. A throttle valve (butterfly type valve) 82b for opening and closing the passage 82c (throttle bore), a shaft 82d for supporting and fixing the throttle valve 82b, and an actuator (valve driving device) (not shown) including a motor for driving the throttle valve 82b; In addition, the power supplied to the motor coil is controlled according to the operating state of the engine, and the throttle opening corresponding to the valve angle of the throttle valve 82b is controlled in association with each system such as the ignition device and the fuel injection device. Engine control unit (E It is provided with a U) and. The intake passage 82c is an example of the “downstream intake passage” in the present invention.

  The above-described electronic throttle device 82 drives the motor according to the accelerator operation amount of the driver, changes the throttle opening corresponding to the valve angle of the throttle valve 82b, and enters the combustion chamber 38 of each cylinder of the engine 100. By variably controlling the flow rate of intake air to be supplied (intake air amount, intake air amount), it functions as an intake device that controls the engine rotation speed or engine output shaft torque. The accelerator operation amount corresponds to the amount by which the driver depresses the accelerator pedal.

  In addition to the throttle body 82a and the throttle valve 82b, the electronic throttle device 82 includes a return spring that urges the throttle valve 82b in the valve closing operation direction (the direction in which the valve is fully closed), and the rotational axis direction of the shaft 82d. And a pair of bearings (not shown) that slidably support both ends of the shaft in the rotational direction.

  The throttle body 82a is a die-cast product made of an aluminum alloy mainly composed of aluminum, for example, and is formed into a predetermined shape by the aluminum die-cast. The throttle body 82a is a housing that holds the throttle valve 82b rotatably in the rotational direction from the fully closed position to the fully open position, and uses a bolt or the like for the intake manifold 8 (see FIG. 1) of the engine 100. Tightened and fixed.

  In the present embodiment, the intake air filtered by the air cleaner 84 passes through the intake passage 83c of the air cleaner hose 83, and enters the intake passage 82c (throttle bore) from the inlet portion 82e opened at the upper end in the gravity direction of the throttle body 82a. Into the intake port 31 and the combustion chamber 38 of each cylinder of the engine 100 through the intake manifold 8 (see FIG. 1) connected to the outlet 82f opened at the lower end in the direction of gravity of the throttle body 82a. It is configured to be. The intake passage 83c is an example of the “upstream intake passage” in the present invention.

  Further, a chamfered portion 821e formed so that the inner diameter gradually increases toward the upstream side (upward) is formed at the inlet portion 82e of the throttle body 82a. As shown in FIG. 4, the chamfered portion 821 e is formed in an annular shape in plan view (as viewed from the upstream side) and is disposed along the inner peripheral surface of the air cleaner hose 83.

  As shown in FIG. 3, the throttle body 82a has a cylindrical portion (throttle bore wall) 82g in which an intake passage 82c (throttle bore) having a circular cross section is formed. The cylindrical portion 82g is formed so as to have a predetermined circular pipe shape made of, for example, a metal material. As shown in FIG. 2, a sensor cover 82h for holding and fixing the throttle opening sensor is attached to one end of the cylindrical portion 82g in the rotation axis direction. The sensor cover 82h is made of, for example, a resin material.

  As shown in FIG. 3, the cylindrical portion 82g has a downdraft type intake passage 82c (throttle bore) extending in the vertical direction of the automobile. This intake passage 82c extends from the inlet portion 82e of the throttle body 82a toward the outlet portion 82f in the axial direction perpendicular to the rotational axis of the throttle valve 82b and the central axis of the shaft 82d (the flow direction of the cylindrical portion 82g, It extends straight in the vertical direction.

  Further, the cylindrical portion 82g of the throttle body 82a is provided with a pair (two) of shaft bearing portions 82i that are arranged to face each other with an intake passage 82c therebetween (backward direction and frontward direction with respect to the paper surface). .

  A bearing (sliding bearing) (not shown) that pivotally supports one end side of the shaft 82d in the rotation axis direction is provided on the inner periphery (accommodation hole wall surface) of the shaft bearing hole 82i provided on one end side of the shaft 82d in the rotation axis direction. ) Is fitted and held. Further, the other end side of the shaft 82d in the rotation axis direction is also supported on the inner circumference (the wall surface of the hole) of the shaft receiving hole of the shaft bearing portion 82i provided on the other end side in the rotation axis direction of the shaft 82d. A bearing (sliding bearing) is fitted and held. That is, the pair of shaft bearing portions 82i supports the shaft 82d so as to be slidable in the rotation direction via the pair of bearings.

  The throttle valve 82b is installed in an intake passage 82c communicating with the combustion chambers 38 and the intake ports 31 of all the cylinders of the engine 100 so as to be freely opened and closed. The throttle valve 82b is a rotary intake control valve that is housed in a cylindrical portion 82g (intake passage 82c) of the throttle body 82a so as to be openable and closable and rotates relative to the cylindrical portion 82g of the throttle body 82a. That is, the throttle valve 82b is a disk-shaped butterfly valve that rotates around the central axis of the shaft 82d to open and close the intake passage 82c.

  The throttle valve 82b rotates (changes the rotation angle) in the valve operating range from the fully closed position to the fully open position based on a control signal from the ECU when the engine is operating, thereby opening the opening area of the intake passage 82c (changing the rotation angle). The flow rate of intake air is variably controlled by changing the intake air flow area. Further, when engine 100 is stopped, throttle valve 82b is returned to the fully closed position (or an intermediate opening state (intermediate position) slightly opened from the fully closed position) by an urging force such as a return spring.

  The throttle valve 82b has a disk-like portion extending radially outwardly in the radial direction around the intersection of the central axis in the flow path direction of the cylindrical portion 82g of the throttle body 82a and the central axis of the shaft 82d. Yes.

  When the throttle valve 82b is set to the fully closed position, the front and back surfaces of the disk-shaped portion of the throttle valve 82b are perpendicular to the flow direction of the cylindrical portion 82g of the throttle body 82a (the axial direction of the intake passage 82c). It is arranged so as to be slightly inclined by a predetermined rotation angle in the valve opening operation direction with respect to the vertical line.

  The flow direction of the cylindrical portion 82g of the throttle body 82a (the axial direction of the intake passage 82c) refers to the vertical direction when the electronic throttle device 82 is mounted on the vehicle (the vertical direction of the vehicle or the vertical direction in the direction of gravity). ).

  The disc-shaped portion of the throttle valve 82b is fastened and fixed using a fastening screw or the like while being inserted into the valve insertion hole of the shaft 82d. Further, the disc-shaped portion of the throttle valve 82b has two semi-disc-shaped portions (a first semi-disc-shaped portion 82j and a second semi-disc-shaped portion 82k) on both sides of the shaft 82d with the shaft 82d as a boundary. have. Note that when the throttle valve 82b is fully closed, the first semi-disc-shaped portion 82j is disposed on the upper side (upstream side) with respect to the direction of gravity with respect to the second semi-disc-shaped portion 82k and the shaft 82d.

  The air cleaner hose 83 is formed of a flexible rubber-based elastic body (or a resin material such as a flexible synthetic resin). As shown in FIGS. 2 and 3, the air cleaner hose 83 includes a straight pipe portion 83d coupled to the downstream end of the case where the air cleaner 84 is disposed, and a bent portion 83e provided on the downstream side of the straight pipe portion 83d. A straight pipe part 83f provided on the downstream side of the bent part 83e, a concave part 83b provided on the downstream side of the straight pipe part 83f and having an inner diameter larger than the inner diameter of the straight pipe part 83f, and the concave part 83b And a straight pipe portion 83g having an inner diameter smaller than the inner diameter of the recess 83b. Moreover, the recessed part 83b is formed so that it may have a shape (taper shape) which tapers from the inner side to the outer side of the air cleaner hose 83, as shown in FIG.

  As shown in FIG. 2, the straight pipe portion 83d is fitted on the outer periphery of the downstream end of the air cleaner case, and is fastened and fixed to the downstream end of the air cleaner case by an air hose band (not shown). The bent portion 83e connects the straight pipe portion 83d and the straight pipe portion 83f at a substantially right angle by being bent in an arc shape. The straight pipe portion 83g is fitted on the outer periphery of the upstream end of the throttle valve 82b and is fastened and fixed to the upstream end of the throttle valve 82b by an air hose band 85.

  As shown in FIG. 3, the air cleaner hose 83 is airtightly coupled to the upper end of the throttle body 82a in the gravitational direction. Further, a chamfered portion 821e (inlet portion 82e) of the throttle body 82a is disposed at a boundary portion between the straight pipe portion 83g and the recessed portion 83b of the air cleaner hose 83. The outer peripheral surface of the inlet portion 82e of the throttle body 82a is disposed so as to contact the inner peripheral surface of the straight pipe portion 83g of the air cleaner hose 83.

  Further, a convex portion 831b is formed at a portion corresponding to the concave portion 83b on the outer peripheral surface of the air cleaner hose 83 so as to protrude outward along the shape of the concave portion 83b. The convex portion 831b has a function of regulating the upstream position of the air hose band 85.

  An intake passage 83c is formed in the air cleaner hose 83 on the upstream side of the throttle valve 82b. A PCV port 83 a having a circular cross section is formed in the bent portion 83 e of the air cleaner hose 83. A fresh air introduction pipe 95 is inserted into the PCV port 83a.

  The PCV port 83a is connected to the inside of the engine 100, in particular, the inside of the crankcase 6 (inside the crank chamber 61) and the inside of the air cleaner hose 83 (the intake passage 83c on the upstream side of the throttle valve 82b) via the fresh air introduction pipe 95. It is a fresh air introduction port that communicates with

  Here, the condensed water contained in the blow-by gas generated inside the engine 100 is dropped from the PCV port 83a onto each component (throttle valve 82b, shaft 82d, etc.) of the electronic throttle device 82, thereby, for example, a low temperature environment such as below freezing point. In the region, there is a problem that each part of the electronic throttle device 82 is frozen. In this regard, in the present embodiment, the condensed water dripping from the PCV port 83a into the intake passage 82c of the electronic throttle device 82 is dispersed by the recess 83b provided between the air cleaner hose 83 and the electronic throttle device 82. The components of the electronic throttle device 82 are prevented from freezing.

  Specifically, as shown in FIG. 3, the condensed water dropped from the PCV port 83a to the intake passage 83c of the air cleaner hose 83 drops downstream along the inner surface of the straight pipe portion 83f and reaches the recess 83b. . And the condensed water which reached the recessed part 83b is dripped at the downstream side in the dispersed state in the surface of the chamfer 821e of the recessed part 83b and the inlet part 82e.

  This makes it possible to vary the dripping position (attachment position) to the condensed water throttle valve 82b (particularly, the second semicircular disk-shaped portion 82k). Further, due to the shape (chamfered shape) of the chamfered portion 821e of the inlet portion 82e, condensed water dripping downstream from the concave portion 83b is near the chamfered portion 821e of the inlet portion 82e (engagement between the air cleaner hose 83 and the throttle body 82a). It is possible to suppress staying (collecting) in the vicinity of the portion. Thereby, it is possible to suppress the vicinity of the chamfered portion 821e of the inlet portion 82e (near the engagement portion between the air cleaner hose 83 and the throttle body 82a) from freezing.

  As described above, according to the intake device (the electronic throttle device 82 and the air cleaner hose 83) of the engine 100 according to the present embodiment, the effects listed below can be obtained.

  In the present embodiment, as described above, the recess 83b is provided in the intake passage 83c between the PVC port 83a of the air cleaner hose 83 and the throttle body 82a. Thus, the condensed water flowing into the intake passage 83c and the intake passage 82c via the PCV port 83a provided in the air hose 83 can be dispersed in the recess 83b, so that the throttle valve 82b and the throttle valve provided in the throttle body 82a can be dispersed. Condensed water can be reduced from adhering to each component such as the shaft 82d for supporting and fixing 82b. As a result, the throttle body 82a (parts such as the throttle valve 82b and the shaft 82d) can be prevented from freezing. Further, unlike the case where another component such as a heater is provided in the intake passage 83c and the intake passage 82c in order to prevent the condensed water from freezing, an increase in the number of components can be suppressed. Thereby, it is possible to suppress freezing of the throttle valve 82d with a simple configuration while suppressing the complexity of the structure of the intake device (the electronic throttle device 82 and the air cleaner hose 83).

  In the present embodiment, as described above, the chamfered portion 821e is provided at the end of the throttle body 82a on the PCV port 83a side. As a result, the chamfer 821e makes it difficult for the condensed water flowing in (dropped) from the PCV port 83a provided in the air cleaner hose 83 to stay in the inlet 82e (the end of the throttle body 82a on the PCV port 83a side). , Freezing of the inlet portion 82e (the end portion of the throttle body 82a on the PCV port 83a side) can be suppressed.

-Other embodiments-
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 embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the example in which the chamfered portion (inlet portion) of the throttle body is arranged at the boundary portion between the straight pipe portion and the recessed portion of the air cleaner hose is shown, but the present invention is not limited to this. In the present invention, the chamfered portion (inlet portion) of the throttle body may be arranged to be shifted in the vertical direction from the boundary portion between the straight pipe portion and the recessed portion of the air cleaner hose.

  Moreover, although the example which forms a chamfering part over the whole inlet part of a throttle body was shown in the said embodiment, this invention is not limited to this. For example, a chamfered portion may be partially formed in a portion located below the PCV port of the inlet portion of the throttle body. Also by this, the condensed water dripped from the PCV port can be effectively dispersed by the chamfered portion.

  The present invention can be used for an intake device of an internal combustion engine, and more specifically, can be used for an intake device that recirculates blow-by gas flowing into a crankcase of the internal combustion engine to the internal combustion engine through an intake passage.

1 engine (internal combustion engine)
6 Crankcase 82 Electronic throttle device 82a Throttle body 82b Throttle valve 82c Inlet passage on the downstream side 83 Air cleaner hose (air hose)
83a PCV port (communication hole)
83b Concave portion 83c Upstream intake passage

Claims (2)

In an intake device for an internal combustion engine that recirculates blowby gas flowing into a crankcase of the internal combustion engine to the internal combustion engine via an intake passage,
A throttle body having a downstream intake passage extending in the vertical direction of the vehicle, a throttle valve provided in the throttle body and opening and closing the downstream intake passage, and connected to the upper side of the throttle body and the downstream side An air hose having an upstream intake passage for introducing intake air into the intake passage,
The air hose is provided with a communication hole that communicates the inside of the air hose and the inside of the internal combustion engine,
An intake device for an internal combustion engine, wherein a recess is provided in the upstream or downstream intake passage between the communication hole of the air hose and the throttle body. The intake device for an internal combustion engine according to claim 1,
An intake device for an internal combustion engine, wherein a chamfered portion is provided at an end of the throttle body on the communication hole side.

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