JP2010168920A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost internal combustion engine easily and reliably connecting a ventilating pipe and a resonator to an intake pipe in a preferable installation posture, and having fewer fastening parts. <P>SOLUTION: This internal combustion engine is provided with: a ventilating pipe 41 which is interposed between an intake pipe and an engine body and forms a ventilating passage 43a ventilating an internal space in an engine body bottom part; and a resonator 50 having an opening 52 opened to an air cleaner hose 35. A connection pipe part 411 of the ventilating piping 41 is integrally coupled with a resonator case 51 of the resonator 50 to form a through passage 54 penetrating through the resonator 50. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine, and more particularly, to an internal combustion engine including a ventilation pipe that ventilates the inside of an engine body and a resonator that reduces intake noise and improves timbre.

  In an internal combustion engine (hereinafter simply referred to as an engine) mounted on an automobile or the like, for example, a gasoline engine, blow-by gas leaks from a combustion chamber through a gap between a cylinder and a piston into a crankcase. A PCV (Positive Crankcase Ventilation) type blow-by gas reduction device that forcibly ventilates the inside of the crankcase to prevent deterioration or corrosion is frequently used. In many cases, a so-called Helmholtz type resonator (Resonator) is connected to the intake pipe in order to mute the intake sound of a specific frequency and improve the tone.

  As a conventional internal combustion engine of this type, for example, the inner diameter of the connecting end portion of the auxiliary equipment connecting pipe interposed between the intake pipe and the auxiliary equipment is larger than that of other parts of the auxiliary equipment connecting pipe. A resonance tube portion is known (for example, see Patent Document 1).

  In addition, new air is introduced into the engine body from a sub-chamber formed on the clean side (downstream side of the filter element) in the air cleaner case, and blow-by gas generated inside the engine body is sublimated through the passage of the maze structure. There is one that is refluxed to the chamber (see, for example, Patent Document 2).

  Furthermore, a hole to the intake pipe side is opened upward at the lower part of the resonance chamber of the resonator, and a blow-by gas intake port located above the opening is provided, so that deposits due to oil mist adhering to the resonator are removed. There is one in which formation is suppressed (for example, see Patent Document 3).

  In addition, the resonance portion of the resonator is connected to the intake pipe in a double structure or the like to form a plurality of resonance chambers in a single resonator case, or the length of the resonance chamber on the outer side of the diaphragm of the sound generator is different. There are known ones provided with multiple resonance tubes (for example, see Patent Documents 4 and 5).

JP 2000-205069 A JP 2001-90623 A Japanese Patent Application Laid-Open No. 07-301165 JP 2008-184992 A JP 09-21364 A

  However, in the conventional internal combustion engine as described above, the PCV hose and the resonator for reducing the blow-by gas are connected to the intake pipe, respectively. Therefore, the ventilation pipe such as the PCV hose and the PCV hose are exclusively used. For the resonators to be studied later, the layout of the peripheral parts has been decided, so there is not enough space for connection to the intake pipe, and there is no gap between the resonator and the PCV hose, making connection difficult. There is a problem that both cannot be installed in a preferable posture.

  Further, since it is necessary to individually fix the connection portion of the resonator to the intake pipe and the connection portion of the PCV hose to the intake pipe, there is a problem that the number of parts for fixing them increases.

  Furthermore, when it is desired to connect both the resonator and the PCV hose to the air cleaner hose, the above-mentioned problem has become prominent.

  The present invention has been made to solve the above-described conventional problems, and it is possible to easily and reliably connect the ventilation pipe and the resonator to the intake pipe with a preferable installation posture, and further suppress the number of fastening parts. An object of the present invention is to provide a low-cost internal combustion engine that can perform the above-described operation.

  In order to achieve the above object, the internal combustion engine according to the present invention is (1) a ventilation pipe that is interposed between an intake pipe and an engine body and forms a ventilation passage for ventilating blow-by gas generated inside the engine body. And a resonator having an opening that opens to a part of a pipe wall of the intake pipe, wherein the resonator is configured such that a part of the ventilation pipe forms a through-passage that penetrates the resonator. It is characterized by being integrally coupled to the.

  With this configuration, the connection part of the ventilation pipe to the intake pipe can be easily included in the connection part of the resonator to the intake pipe, the connection space between the two is greatly reduced, and the connection between the resonator and the ventilation pipe is reduced. The problem that a gap cannot be made between them or that both cannot be installed in a preferable posture is solved. In addition, since the connection of the ventilation pipe to the intake pipe can be achieved at the same time as the connection of the resonator to the intake pipe, the number of connection work steps and the number of fixing parts can be reduced.

  In the internal combustion engine according to the above (1), (2) the ventilation pipe is interposed between the intake pipe and the engine main body, and introduces air in the intake pipe into the engine main body. An introduction pipe, and a blow-by gas recirculation pipe interposed between the intake pipe and the engine main body for recirculating blow-by gas generated inside the engine main body to the intake pipe, and the ventilation pipe It is preferable that a part is constituted by the air introduction pipe.

  With this configuration, fresh air can be reliably introduced from the intake pipe into the engine body, and the intake noise can be reduced and the intake tone can be improved by the resonator.

  In the internal combustion engine described in (2) above, (3) an air cleaner having an air cleaner hose connected to the intake pipe is attached upstream of the intake pipe, and the resonator is attached to the air cleaner hose. Is more preferable.

  With this configuration, fresh air can be efficiently introduced into the engine body from the vicinity of an air cleaner that is unlikely to have a high negative pressure, and the effect of reducing the intake noise and adjusting the intake tone by the resonator can be exhibited.

  In the internal combustion engine according to the above (1) to (3), (4) a part of the ventilation pipe and the resonator at a part where the part of the ventilation pipe and the resonator are connected to the intake pipe. Constitutes a double pipe.

  With this configuration, the connection part of the ventilation pipe to the intake pipe is surrounded by the resonator, so that the connection part of the ventilation pipe that becomes the blow-by gas recirculation pipe to the intake pipe is appropriately kept warm, and the wet blow-by gas intake pipe Freezing or the like at the introduction portion is prevented. In addition, freezing or the like in the vicinity of the inflow portion of the blow-by gas into the intake pipe can be prevented even when a reverse flow is generated at a high load in the air introduction pipe for introducing fresh air.

  In the internal combustion engine according to the above (4), (5) a part of the ventilation pipe and the resonator form a double pipe, and a part of the ventilation pipe includes a plurality of radial support members. Is preferably supported by the resonator.

  With this configuration, the connection of the ventilation pipe to the intake pipe is reliably achieved when the resonator is connected to the intake pipe.

  In the internal combustion engine according to the above (1) to (5), (6) a part of the ventilation pipe projects from one end portion located inward of the opening of the resonator and an outer wall portion of the resonator. It is preferable that the other end of the ventilation pipe is configured by a flexible hose connected to the other end of the ventilation pipe.

  With this configuration, it is possible to facilitate the connection between a part of the ventilation pipe and the remaining part while ensuring a good connection posture of the resonator and the ventilation pipe to the intake pipe.

  According to the present invention, since a part of the ventilation pipe is integrally coupled to the resonator so as to form a through-passage in the resonator, the connection space to the ventilation pipe and the intake pipe of the resonator can be greatly reduced. In addition, the resonator and the ventilation pipe can be easily installed in a preferred posture with respect to the intake pipe, and the connection of the ventilation pipe to the intake pipe can be achieved at the same time when the resonator is connected to the intake pipe. Thus, it is possible to reduce the number of connecting work steps and the number of fixing parts. As a result, it is possible to provide a low-cost internal combustion engine in which the ventilation pipe and the resonator can be easily and reliably connected to the intake pipe with a preferable installation posture, and the number of fastening parts can be reduced.

1 is a schematic configuration diagram schematically showing an internal combustion engine according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows a resonator and a part of piping for ventilation with which the internal combustion engine which concerns on the 1st Embodiment of this invention is equipped, (a) is principal part sectional drawing seen in the cross section containing the channel | path center axis line, b) is a B2-B2 cross-sectional view of (a). It is the schematic block diagram which shows typically the internal combustion engine which concerns on the 2nd Embodiment of this invention.

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

(First embodiment)
FIG. 1 and FIG. 2 are views showing an internal combustion engine according to a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram thereof, and FIG. 2 is a resonator and a ventilation device installed in the internal combustion engine. A part of the piping is shown. In the present embodiment, the present invention is applied to an internal combustion engine for a vehicle, for example, a 4-cycle gasoline engine.

  First, the configuration will be described.

  The engine 1 schematically shown in FIG. 1 includes an engine main body 11 having a head cover, a cylinder head, a cylinder block, a crankcase, and an oil pan in order from the top, although details are not shown. A plurality of cylinders 12 (only one is shown in FIG. 1). Each cylinder 12 houses a piston 16, and a crankshaft 17 is connected to the piston 16 via a connecting rod 18. Also, a known valve operating mechanism and ignition device are accommodated in the inner space 11 d above the engine body 11, and this valve operating mechanism is driven based on the power from the crankshaft 17. . An engine space (hereinafter also simply referred to as oil) L for lubrication / cooling is accommodated in an inner space 11 c below the engine body 11.

  Air is sucked into the combustion chamber 1a formed in the upper part of the piston 16 in each cylinder 12 through the intake passage 21 and the intake port 13 in accordance with the stroke of the piston 16, and after combustion in the combustion chamber 1a. The exhaust gas is exhausted through the exhaust port 14 and an exhaust passage 22 (not shown).

  The intake passage 21 is constituted by an intake pipe 31. A throttle valve 32 is housed in the intake pipe 31 so as to be able to rotate (open / close operation), and a surge tank 33 is formed downstream of the throttle valve 32. Yes.

  An air cleaner 34 is attached to the upstream end of the intake pipe 31. The air cleaner 34 incorporates a filter element 34 b inside a resin case 34 a, for example, and air from which dust or the like has been removed by the air cleaner 34 is taken into the intake pipe 31. The downstream end of the intake pipe 31 is fastened and fixed to the cylinder head forming the intake port 13 of the engine 1.

  On the other hand, blow-by gas leaks into the engine body 11 of the engine 1 through the clearance for sliding the piston 16 from the combustion chamber 1a into the lower inner space 11c in the crankcase during operation of the engine 1. For this reason, in order to prevent the engine oil L from deteriorating, to prevent the internal corrosion of the engine body 11, etc., the PCV blowby gas reduction device 40 that forcibly ventilates the lower inner space 11c is equipped.

  Specifically, the engine main body 11 includes ventilation passages 11a and 11b on the fresh air introduction side and the blow-by gas recirculation side for ventilating the lower inner space 11c in the block (not shown in detail), respectively. Is formed.

  Further, between the engine body 11 and the intake pipe 31, fresh air from the intake passage 21 a upstream of the throttle valve 32, that is, new air, passes through the ventilation passage 11 a on the fresh air introduction side and is located below the engine body 11. An air introduction pipe 41 to be introduced into the inner space 11c is interposed. Further, between the engine body 11 and the intake pipe 31, the blowby gas recirculation that recirculates the blowby gas from the lower inner space 11 c to the intake passage 21 b on the downstream side of the throttle valve 32 through the ventilation passage 11 b on the blowby gas recirculation side. A pipe 42 and a PCV valve 45 corresponding to a check valve that allows only the flow of the blow-by gas in the reflux direction on the upstream end side of the blow-by gas reflux pipe 42 are interposed.

  The air introduction pipe 41 and the blow-by gas recirculation pipe 42 are ventilation pipes interposed between the intake pipe 31 and the engine body 11, respectively. The fresh air introduction side ventilation passage 11a and the blow-by gas recirculation side ventilation passage. Two ventilation passages 43a and 43b for ventilating the inside of the engine body 11 are formed in cooperation with 11b.

  As a result, inside the engine body 11 of the engine 1, as shown by the black arrows in FIG. 1, fresh air is introduced into the inner space 11 c below the engine body 11 through the ventilation passages 11 a and 43 a on the fresh air introduction side. In addition, as indicated by white arrows in FIG. 1, blowby gas leaking from each cylinder 12 to the lower inner space 11 c is on the blowby gas recirculation side when the PCV valve 45 is opened due to negative intake pressure or the like. The air flows from the lower inner space 11c to the intake passage 21b downstream of the throttle valve 32 through the ventilation passages 11b and 43b.

  On the other hand, as shown in FIG. 1, the air cleaner 34 has an air cleaner hose 35 that connects the case 34 a to the intake pipe 31, and the air cleaner hose 35 is located near the filter element 34 b of the air cleaner 34. A part 35a of the tube wall is formed. The air cleaner hose 35 is equipped with a Helmholtz resonator 50 that functions as a silencer for intake noise of a specific frequency.

  The resonator 50 includes a resonator case 51 fixed to the annular connecting portion 35b (a part of the pipe wall) of the air cleaner hose 35, and a hose band or a hose clamp (not shown) that fixes the resonator case 51 to the annular connecting portion 35b. The resonator case 51 is configured to communicate with the opening 52 that opens inside the annular connecting portion 35 b of the air cleaner hose 35, the intake passage 21 that is inside the intake pipe 31 through the opening 52, and the opening 52. And a resonance chamber 53 having a larger diameter.

  Further, a part of the air introduction pipe 41 and the blow-by gas recirculation pipe 42 that are ventilation pipes, for example, the connection pipe portion 411 on the intake pipe 31 side of the air introduction pipe 41 forms a through-passage 54 that penetrates the resonator 50. It is integrally coupled to a resonator case 51 of the resonator 50.

  Specifically, the air introduction pipe 41 and the resonator 50 are connected to the respective intake pipes 31, that is, the connection pipe part 411 of the air introduction pipe 41 and the neck part 51 a of the resonator case 51 are located in the opening part 52. The connection pipe part of the air introduction pipe 41 is formed at a site where the connection pipe part 411 of the air introduction pipe 41 and the neck part 51a of the resonator case 51 of the resonator 50 constitute a double pipe. 411 is supported by the resonator case 51 of the resonator 50 by a plurality of radial support members 55. The neck 51a of the resonator case 51 is provided with a stopper 51b for defining the insertion position into the annular connecting portion 35b. The stopper 51b has, for example, a plurality of radial protrusions or flanges. .

  Further, the connection pipe portion 411 (a part of the ventilation pipe) of the air introduction pipe 41 has one end portion 411 a located inside the opening 52 of the resonator 50 and the other end portion 411 b protruding from the outer wall portion of the resonator case 51. The remaining part other than the connection pipe part 411 of the air introduction pipe 41 is constituted by a flexible hose 412 connected to the other end part 411b of the connection pipe part 411 of the air introduction pipe 41. The hose 412 is constituted by, for example, a rubber hose in which reinforcing fibers are embedded.

  Next, the operation will be described.

  In the present embodiment configured as described above, during operation of the engine 1, inside the engine body 11 of the engine 1, the fresh air introduction side ventilation passages 11 a and 43 a are passed through the inner space 11 c below the engine body 11. As fresh air is introduced, blow-by gas leaking from each cylinder 12 to the lower inner space 11c passes through the ventilation passages 11b and 43b on the blow-by gas return side when the PCV valve 45 is opened due to intake negative pressure or the like. The air flows back from the lower inner space 11 c to the intake passage 21 b on the downstream side of the throttle valve 32. Further, when the opening degree of the throttle valve 32 reaches the opening degree of the high load region exceeding the specific opening degree, the engine 1 becomes a high speed, the negative pressure in the intake passage 21a on the upstream side increases, and the throttle valve 32 When the front-rear differential pressure decreases, a large amount of blow-by gas is generated in the engine body 11 of the engine 1, so that fresh air is not taken into the engine body 11 from the air introduction pipe 41, and the intake passage through the air introduction pipe 41. The blow-by gas flows backward to the 21 side.

  In the engine 1 according to the present embodiment, the intake pipe of the resonator 50 while the connection pipe portion 411 (connection portion to the intake pipe 31) of the air introduction pipe 41, which is a ventilation pipe, has a preferable connection posture to the intake pipe 31. 31 can be included in the neck portion 51a, which is a connection portion to 31. Therefore, there is a problem that the connection space between the air introduction pipe 41 and the resonator 50 is greatly reduced, and that there is no gap between the resonator 50 and the air introduction pipe 41, or that both cannot be installed in a preferred posture. Will be resolved.

  In addition, since the connection of the air introduction pipe 41, which is a ventilation pipe, to the intake pipe 31 can be achieved at the same time when the resonator 50 is connected to the intake pipe 31, the number of connection work steps and the number of fixing parts can be reduced. become. Moreover, fresh air is surely introduced into the engine body 11 from the intake pipe 31 to promote ventilation of the inner space 11 c below the engine body 11, and the intake sound is reduced and the intake tone is improved by the resonator 50. Is possible.

  Further, since an air cleaner 34 having an air cleaner hose 35 connected to the intake pipe 31 is mounted on the upstream side of the intake pipe 31, and the resonator 50 is mounted on the air cleaner hose 35, the vicinity of the air cleaner 34 that is unlikely to become a high negative pressure. As a result, fresh air can be introduced efficiently into the engine body 11 and the effect of reducing the intake noise and adjusting the intake tone by the resonator 50 can be exhibited.

  In addition, in the present embodiment, the connection pipe portion 411 of the air introduction pipe 41 and the resonator 50 constitute a double pipe at a portion connected to the intake pipe 31. Is surrounded by the resonator case 51 of the resonator 50 and is less susceptible to the influence of outside air. Therefore, the connecting pipe portion 411 of the air introduction pipe 41 to the intake pipe 31 is kept warm, and the blow-by gas flows backward rather than introducing fresh air. Even in this case, freezing or the like in the portion where the wet blow-by gas is introduced into the intake pipe 31 is prevented.

  Further, the connection pipe portion 411 of the air introduction pipe 41 and the resonator 50 constitute a double pipe, and the connection pipe section 411 of the air introduction pipe 41 is attached to the resonator case 51 of the resonator 50 by a plurality of radial support members 55. Since it is reliably supported, when the resonator 50 is connected to the intake pipe 31, the connection of the air introduction pipe 41 to the intake pipe 31 is reliably achieved.

  In addition, the connection pipe part 411 of the air introduction pipe 41 of the present embodiment includes one end part 411 a positioned inside the opening 52 of the resonator 50 and the other end part 411 b protruding from the outer wall part of the resonator case 51 of the resonator 50. And the remaining part of the air introduction pipe 41 is constituted by a flexible hose 412 connected to the other end part 411b of the connection pipe part 411. Therefore, to the connection pipe part 411 of the resonator 50 and the air introduction pipe 41 The connection tube portion 411 of the air introduction tube 41 and the flexible hose 412 can be easily connected while ensuring both of the connection postures of the above.

  As described above, in the internal combustion engine of the present embodiment, the connection pipe portion 411 of the air introduction pipe 41 is integrally coupled to the resonator case 51 so as to form the through passage 54 in the resonator 50. 41 and the connection space of the resonator 50 to the intake pipe 31 can be greatly reduced, and the air introduction pipe 41 and the resonator 50 can be easily installed in a preferable posture with respect to the intake pipe 31, and the resonator The connection of the air introduction pipe 41 to the intake pipe 31 can be achieved at the same time when the 50 intake pipes 31 are connected, and the number of connecting work steps and the number of fixing parts such as a hose band can be suppressed. As a result, it is possible to provide a low-cost internal combustion engine in which the air introduction pipe 41 and the resonator 50 can be easily and reliably connected to the intake pipe 31 with a preferable installation posture, and the number of fastening parts can be reduced. .

  In the above-described embodiment, fresh air is introduced from the intake passage 21a upstream of the throttle valve 32 into the lower inner space 11c inside the engine body 11 of the engine 1, and the inside of the engine body 11 is Although the blow-by gas is recirculated to the intake passage 21b downstream from the throttle valve 32, the fresh air is not directly taken into the engine body 11 and the internal pressure of the lower inner space 11c is used. The blow-by gas may be returned to the upstream side or the downstream side of the throttle valve 32, and in that case, a part of the ventilation pipe for returning the blow-by gas into the intake pipe 31 penetrates the inside of the resonator 50. . Hereinafter, such an embodiment will be briefly described.

(Second Embodiment)
FIG. 3 is a schematic configuration diagram schematically showing an internal combustion engine according to the second embodiment of the present invention. Since the present embodiment has a configuration similar to that of the first embodiment described above, the same or similar components correspond to those of the first embodiment shown in FIGS. 1 and 2. Description will be made using the same reference numerals as the constituent elements.

  In FIG. 3, the engine 1 is provided with an intake manifold 15 that forms a main portion of an intake pipe 31 downstream of the throttle valve 32, and the intake pipe 31 upstream of the intake manifold 15 is connected to an air cleaner hose 35. The air cleaner 34 and the inlet duct 36 are configured.

  The air cleaner hose 35 is equipped with a resonator 60 that functions as a silencer for intake noise of a specific frequency.

  The resonator 60 is obtained by integrally combining a resonator case 61 and a connecting pipe portion 711 similar to the connecting pipe portion 411 in the first embodiment. The connecting pipe portion 711 includes the air cleaner hose 35 and the engine 1. A ventilation pipe 70 is configured together with a blow-by gas recirculation pipe 71 interposed between the engine bodies 11.

  The blow-by gas flow path 72 formed by the ventilation pipe 70 communicates the intake passage 21 upstream of the throttle valve 32 and the lower inner space 11 c inside the engine body 11. However, unlike the above-described first embodiment, the blow-by gas flow path 72 of the present embodiment penetrates the skirt portion or the crankcase of the cylinder block on the lower side of the engine body 11 and extends to the lower inner space. The blow-by gas separated from the oil mist by the oil separator 73 is recirculated to the intake passage 21 side. Here, the ventilation pipe 70 and the oil separator 73 constitute a blow-by gas reduction device 80 in the present embodiment.

  The resonator case 61 of the resonator 60 is similar to the resonator 50 of the first embodiment shown in FIG. 2 with respect to the annular connecting portion 35b (part of the tube wall) of the air cleaner hose 35, or a hose type clamp. The resonator case 61 communicates with an opening 62 that opens inward of the air cleaner hose 35, and the intake passage 21 that is inward of the intake pipe 31 through the opening 62 and from the opening 62. And a resonance chamber 63 having a large diameter.

  Further, the through passage 64 formed in the connection pipe portion 711 so as to penetrate the resonator 60 is shown as a straight passage in FIG. 3, but may be bent, and the connection pipe portion 711 is formed of the resonator case 61. It may be held at a position offset from the center with respect to the neck 61a, which is a connecting portion to the intake pipe 31. However, the connecting pipe part 711 and the neck part 61a of the resonator case 61 constitute a double pipe located in the opening 62, and the one end part 711a of the connecting pipe part 711 and the neck part 61a of the resonator case 61 are double pipes. The connecting pipe portion 711 is supported by the resonator case 61 by at least one support member 55 (not shown in FIG. 3). The blow-by gas reflux pipe 71 is a flexible hose interposed between the oil separator and the air cleaner hose 35.

  Also in the present embodiment, the connection pipe portion 711 is integrally coupled to the resonator case 61 so as to form the through passage 64 in the resonator 60. Therefore, the connection space to the intake pipe 31 of the ventilation pipe 70 and the resonator 60 And the ventilation pipe 70 and the resonator 60 can be easily installed in a preferable posture with respect to the intake pipe 31, and the ventilation pipe is connected when the resonator 60 is connected to the intake pipe 31. Connection to 70 intake pipes 31 can be achieved at the same time, and the number of connection work steps and the number of fixing parts such as a hose band can be suppressed. As a result, it is possible to provide a low-cost internal combustion engine in which the ventilation pipe 70 and the resonator 60 can be easily and reliably connected to the intake pipe 31 with a preferable installation posture, and the number of fastening parts can be suppressed. .

  In each of the above-described embodiments, the engine 1 that is an internal combustion engine is a gasoline engine. However, the present invention can also be applied to other internal combustion engines that use fuel other than gasoline. Further, the neck portions 51a and 61a of the resonator cases 51 and 61 are respectively inserted into the annular connection portion 35b, but the annular connection portion on the air cleaner hose 35 (part of the pipe wall of the intake pipe 31) side is the neck portion. It can also be surrounded by 51a, 61a. Needless to say, the shape of the resonator cases 51 and 61 of the resonators 50 and 60 does not have to be a bottle shape whose axial direction is substantially orthogonal to the intake pipe 31 as shown in FIGS. It may be curved or bent so as to face the axial direction of 35 or other directions. Further, the direction in which the other end portions 411b, 711b of the connecting pipe portions 411, 711 protrude outward from the resonator cases 51, 61 is not limited to the direction orthogonal to the axial direction of the air cleaner hose 35, but any other direction. Can be. It goes without saying that the ventilation pipe in the present invention is not limited to the air introduction pipe 41 but may be a blow-by gas recirculation pipe 42.

  As described above, in the internal combustion engine of the present invention, a part of the ventilation pipe is integrally coupled to the resonator so as to form a through passage in the resonator. Therefore, the space for connecting the ventilation pipe and the intake pipe of the resonator to the intake pipe The resonator and the ventilation pipe can be easily installed in a preferred posture with respect to the intake pipe, and when the resonator is connected to the intake pipe, the ventilation pipe is connected to the intake pipe. By achieving the connection at the same time, it is possible to reduce the number of connecting work man-hours and the number of parts for fixing, and as a result, the ventilation pipe and the resonator can be easily and reliably connected to the intake pipe with a preferable installation posture. The effect of providing a low-cost internal combustion engine that can also suppress the number of fastening parts is provided, and the inside of the engine body is ventilated. It is useful for an internal combustion engine in general and a resonator for performing reduction and tone improvement of the ventilation pipe and the intake sound that.

1 engine (internal combustion engine)
1a Combustion chamber 11 Engine body 11a, 43a Ventilation passage (ventilation passage) on the fresh air introduction side
11b, 43b Blowby gas recirculation side ventilation passage (ventilation passage)
11c Lower inner space 12 Cylinder 18 Connecting rod 21 Intake passage 21a Upstream intake passage 21b Downstream intake passage 31 Intake pipe 32 Throttle valve 33 Surge tank 34 Air cleaner 35 Air cleaner hose 35b Annular connection 40, 80 Blow-by gas reduction Equipment 41 Air introduction pipe (pipe for ventilation)
42 Blowby gas recirculation pipe (pipe for ventilation)
45 PCV valve 50, 60 Resonator 51, 61 Resonator case 51a, 61a Neck 51b Stopper 52, 62 Opening 53, 63 Resonance chamber 54, 64 Through passage 55 Support member 70 Ventilation pipe 71 Blow-by gas recirculation pipe 72 Blow-by gas flow path (Ventilation passage)
411, 711 Connecting pipe part 411a One end part 411b, 711b The other end part

Claims (6)

A ventilation pipe that is interposed between the intake pipe and the engine body and forms a ventilation passage for ventilating the inside of the engine body; and a resonator having an opening that opens in a part of a pipe wall of the intake pipe. In the internal combustion engine provided,
An internal combustion engine, wherein a part of the ventilation pipe is integrally coupled to the resonator so as to form a through passage that penetrates the resonator. The ventilation pipe is interposed between the intake pipe and the engine body, and introduces air in the intake pipe into the engine body, and between the intake pipe and the engine body. A blow-by gas recirculation pipe that intervenes and recirculates the blow-by gas generated inside the engine body to the intake pipe;
The internal combustion engine according to claim 1, wherein a part of the ventilation pipe is constituted by the air introduction pipe.   3. The internal combustion engine according to claim 2, wherein an air cleaner having an air cleaner hose connected to the intake pipe is attached upstream of the intake pipe, and the resonator is attached to the air cleaner hose.   The part of the ventilation pipe and the resonator form a double pipe at a portion where the part of the ventilation pipe and the resonator are connected to the intake pipe. The internal combustion engine according to any one of claims 3 to 5.   The part of the ventilation pipe is supported by the resonator by a plurality of radial support members at a portion where the part of the ventilation pipe and the resonator constitute a double pipe. 5. The internal combustion engine according to 4. A part of the ventilation pipe has one end located inside the opening of the resonator and the other end protruding from the outer wall of the resonator,
The remaining portion of the ventilation pipe is constituted by a flexible hose connected to the other end of a part of the ventilation pipe. An internal combustion engine according to claim 1.

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