JP4105416B2 - Engine water-cooled exhaust passage connection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionOutboard engineConnection structure of water-cooled exhaust passageSpecifically, the present invention relates to a connection structure for a water cooling jacket of an outboard motor formed by a mount case and its cover.
[0002]
[Prior art]
  Outboard motorIn the engine, outside water is taken in as engine cooling water. Further, a cooling water jacket is provided around the exhaust passage member exposed to high temperature, and outside water is taken into the cooling water jacket to cool the exhaust cooling member.
  In order to improve productivity, the above-described exhaust passage member is configured by assembling a plurality of parts such as an exhaust manifold on the exhaust upstream side and an exhaust guide connected to the exhaust manifold.
[0003]
  As a conventional technique, for example, Japanese Patent Application Laid-Open No. 09-303155 discloses the exhaust passage described above in FIG. Its structure is as follows. This will be described using the reference numerals in the publication.
  In this technology, the lower end portion of the exhaust collecting passage 19 communicates with the exhaust passage 43 of the exhaust guide 20 and is fitted to the collar 61, and the two are connected via a rubber hose 62. The rubber hose 62 is fixed. A fastening band 69 having a tool 63 is hermetically attached. Further, the cooling jacket 44 on the outer periphery of the exhaust collecting passage 19 is also connected via a rubber hose 67 to a collar 66 joined or integrally formed in communication with a cooling water passage 65 provided in the exhaust guide 20. The rubber hose 67 is hermetically fixed by a fastening band 69 having a fixing tool 68.
  Further, FIG. 7 of Japanese Patent Laid-Open No. 10-339162 discloses a structure in which cooling water is guided to a space 37 between the seal members 36 and 36.
[0004]
[Problems to be solved by the invention]
  In the above prior art, in the former (Japanese Patent Laid-Open No. 09-303155), both the upstream side and the downstream side are formed in a double tubular shape, and a band-shaped connection hose is provided at each of the connection portions. The place is fastened with a fixing band, and workability is poor. Further, since the elastic force of the rubber hose 62 and the binding force of the fixing band are opposed to the exhaust pressure leaking from the joint surface of the exhaust connection, workability is poor if each force is large.
  In the latter (Japanese Patent Laid-Open No. 10-339162), the seal 36 is in contact with the wall defining the exhaust passage of the exhaust manifold 31 and is therefore affected by the heat of the exhaust.
  Further, the exhaust seal 36 is easily displaced in the direction of the exhaust manifold 31. Furthermore, the seal configuration of the connecting portion between the two water jackets 32 and 35 is unknown.
[0005]
  The present invention has been made to solve the above problems,Outboard engineIn the exhaust passage connection structure, the exhaust seal is reliable, the exhaust seal is easy to assemble and cool, and the thermal effect is reducedOutboard motorEngine water-cooled exhaust passage connection structure,Specifically, the connection structure of the water cooling jacket of the outboard motor formed by the mount case and its coverI will provide a.
[0006]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the first aspect provides the first exhaust passage.Intermediate exhaust pipe (54)And a mount case (50) for supporting the engine (10) and a cylinder head (13) of the engine (10), the first exhaust passage(54d)Second exhaust passage connected to(41a)And an exhaust manifold (40) constituting the second exhaust passage member and a connecting portion of the mount case (50) are provided in the exhaust passage.(54d)A wall portion facing the exhaust passage (113) and an annular convex portion (114) outside the wall portion, and a connecting portion of the exhaust manifold (40) includes a wall portion facing the exhaust passage (41a) and an annular bank portion ( 41c) and a wall portion not facing the exhaust passage (41a), and the mount case (50)Intermediate exhaust pipe (54)And a second exhaust passage member (40) between the wall surfaces separated from the exhaust passage, a seal member (120) is interposed, and the cover (56) coupled to the mount case (50) A cooling water jacket (58) formed outside the seal member (120) is formed, and a cooling water jacket (42) is provided on the outer periphery of the exhaust passage of the exhaust manifold (40). The cooling water jacket (42) , Holes in the cover (56)(56e)The cooling water jacket (58) and the cooling water jacket (42) both communicate with each other,The space between the cover (56) and the exhaust manifold (40) is sealed with a seal member (116),And the sealing member(116)Part of the outer cooling water jacket (58)With the sealing member (116)It is characterized by being configured.
[0007]
  In Claim 1, since the outer side of the sealing member constitutes a cooling water jacket, the sealing member can be cooled. In addition, since the sealing member seals between the wall surfaces away from the exhaust passage, it is possible to reduce the thermal effect of the exhaust on the sealing member.
  Moreover, since the annular convex part has entered into the annular concave part, the thermal influence of the exhaust heat in the annular convex part can be reduced.
  Further, since the sealing member faces the cooling water jacket and a part of the cooling water jacket faces the outside of the sealing member, it is possible to cool the exhaust passage and the connection seal portion with a relatively simple structure. .
  Also,Outboard engineIs preferable because the exhaust is cooled.
  Further, the seal member can be reliably mounted, and the assembly work of two parts can be performed in a state where the seal member is mounted on one side, so that productivity is good.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals. In the figure, the front in the propulsion direction is represented by Fr, and the rear is represented by Rr.
  FIG. 1 is an external view of the entire outboard motor with the outboard motor attached to the stern of the hull.
  The outboard motor 1 is configured by an engine cover 2 covering the uppermost engine, an under cover 3 below this, an extension case 4 below this, and a gear case 5 having a screw 6 arranged at the rear below this hull. The stern 101 is attached to and supported by a stern 101 through a stern bracket 7 so as to be capable of tilting movement (vertical movement) and left-right swinging (steering movement). The extension case 4 and the gear case 5 constitute the main body case of the present invention.
  The tilt-up state is indicated by a chain line.
[0009]
  2 is a side view in which the engine cover at the top of the outboard motor is vertically cut, and FIG. 3 is a view taken along line 3-3 in FIG. 2, and is a plan view in which an intake silencer box 35 and an intake manifold 37, which will be described later, are removed. 4 and 4 are enlarged longitudinal sectional side views of the main part of FIG. The superstructure including the engine of the outboard motor will be described with reference to these drawings.
  The engine 10 includes a cylinder block 11, a front crankcase 12, a rear cylinder head 13, a cylinder head cover 14 disposed at the rear end of the cylinder block 11, and the like.
[0010]
  In the cylinder block 11, a plurality of cylinders 15 (... are represented in plural, the same applies hereinafter) are arranged in parallel in the vertical direction, and the internally mounted pistons 16 are vertically connected by a connecting rod 17. Is a vertical engine connected to
  In the embodiment, a three-cylinder engine having three cylinders on the upper and lower sides and an outboard equipped with a V-type six-cylinder engine having a cylinder row composed of three cylinders expanded left and right as shown in FIG. Indicates the machine.
  The engine subassembly is configured as described above.
[0011]
  As shown in FIG. 4, the cylinder head 13 includes combustion chambers 19 that constitute the ceiling of the cylinders 15. The combustion chambers 19 are provided with intake valves 20, exhaust valves 21, spark plugs 22, and a vertical camshaft 23 outside the combustion chambers 19, and a valve rocker arm driven thereby. A vertically supporting rocker arm shaft 24 is provided.
  A cylinder cooling water jacket 25 is provided around the cylinder 15 of the cylinder block 11 so as to surround the cylinder 15. The cylinder head cooling water jacket 26 is also provided around the combustion chamber 19 of the cylinder head 13. The cooling water jacket 25 is provided so as to communicate with the cooling water jacket 25.
[0012]
  Drive pulleys 27 and 28 are coaxially provided at the upper end of the crankshaft 18 projecting upward from the crankcase 12, and the upper pulley 28 is belted to the driven pulley 30 of the generator 29 installed on the upper front side of the crankcase 12. The generator 29 is driven by being connected via 31.
  The lower pulley 27 is connected to camshaft pulleys 33 and 33 provided at upper ends of the camshafts 23 and 23 of the left and right cylinder heads 13 via guide pulleys 32 by a belt 34 to drive the camshafts 23 and 23. .
[0013]
  An intake silencer box 35 is disposed above the belt-pulley mechanism, and the intake silencer box 35 is opened with the intake port facing rearward, and the intake port is disposed above the V bank between the left and right cylinders. Connected to the throttle valve device 36.
  The throttle valve device 36 is connected to an intake manifold 37 disposed in the longitudinal direction behind the V bank between the left and right cylinders, and the intake manifold 37 is connected to an intake passage formed in the cylinder head 13 so that the intake system is connected. Constitute. Intake is performed from the outside air inlet 2 a of the engine cover 2.
[0014]
  As shown in FIG. 2, exhaust manifolds 40, 40 connected to the exhaust passages of the combustion chambers 19 are disposed outside the cylinder heads 13, 13 of the left and right cylinder blocks 11, 11.
  The exhaust manifolds 40, 40 are provided with body portions 41 that are integrally assembled by bolts 40a ... on the outer sides of the cylinder heads 13, 13, and there are eight bolts 40a ... per bank in the drawing.
  A cooling water jacket 42 is provided around the exhaust passage 41a of each main body 41 to cool the exhaust discharged from the combustion chambers 19 at the most upstream part.
[0015]
  As for the lower part 41b of the main-body part 41 of each exhaust manifold 40, an internal exhaust passage inclines inside. Since the exhaust manifolds 40, 40 are installed on the outer sides of the left and right cylinder blocks 13, 13, the lower portions 41b, 41b of the left and right main body portions 41, 41 are symmetrically inclined inward.
  These exhaust manifolds 40, 40, an internal passage of a mount case described later, an exhaust pipe, an exhaust expansion chamber, and the like constitute an exhaust passage structure. That is, the exhaust passage is divided into these plural portions.
  In the present embodiment, as will be described later, the exhaust manifold and the internal passage of the mount case are connected, and the internal passage of the mount case and the downstream passage thereof, and the former connection portion is connected to the exhaust upstream side. The connecting portion and the latter connecting portion are used as the exhaust downstream connecting portion.
[0016]
  FIG. 5 is an enlarged vertical cross-sectional view of the main part showing the relationship between one lower part of the exhaust manifold 40 arranged on the left and right sides and the mount case internal passage connected to the lower part 41b, the exhaust pipe, and the exhaust expansion chamber. FIG. 6 is an enlarged vertical cross-sectional view of a main part showing a cooling water discharge port and an exhaust manifold of a cylinder block arranged on the left and right, and a discharge path of cooling water to an exhaust expansion chamber. It is the figure seen from the back of the machine.
  This will be described with reference to these drawings and FIG.
[0017]
  This will be described with reference to FIG.
  The engine 10 is composed of an engine assembly including a crankcase 12, a cylinder block 11, a cylinder head 13, a piston 15, a crankshaft 18, and the like, and is mounted on a mount case 50 disposed below the engine assembly. It is attached to and supported by the coupling surface 50p of the mount case 50. Since part of the oil pan and mount case also have an engine function, the upper half of the engine excluding them is a small assembly.
  On both sides of the mount case 50 in the left and right direction (outboard motor width direction), concave portions 51 and 51 opened upward are provided. Although the figure shows the recess 51 on the right side of the mount case, the recess 51 on the left side of the mount case (not shown) has a symmetrical shape and a symmetrical structure in which the left and right sides are interchanged. The concave portion 51 has a top opening 52 that is entirely open, the inner wall 51a is substantially vertical, the outer wall 51b is curved so as to dive inward in the width direction, and has a circular hole 51c (annular protrusion) at the bottom. 53.
[0018]
  The exhaust upstream connection portion in this embodiment will be described.
  The lower part 41b of the main body 41 of the exhaust manifold 40 is located on the outer side of the opening 52 of the recess 51, and is provided with annular dams 41c and 41d vertically inside and outside at the lower end of the lower part 41b.
  An internal passage of the mount case 50 to be described later is a first exhaust passage, which is used as a reference, a passage 41a in the exhaust manifold 40 is an upstream second exhaust passage, and members constituting the passage 41a are upstream second members. An exhaust passage member is used.
[0019]
  A substantially horizontal Z-shaped intermediate exhaust pipe 54 constituting an internal passage of the mount case 50 is disposed in the recess 51, and a main body portion of the upper exhaust manifold 40 is disposed in an annular groove 54 a provided on the upper portion of the exhaust pipe 54. The inner annular bank 41c of the lower part 41b of 41 is fitted. An annular groove 54b is provided at the lower end of the intermediate exhaust pipe 54, and a boss 54c is provided at a part of the inner portion.
  A first exhaust passage 54d is formed by connecting the upstream and downstream of the exhaust passage by the intermediate exhaust pipe 54, and the intermediate exhaust pipe 54 forming the exhaust passage 54d is defined as a first exhaust passage member. An inner peripheral surface of the exhaust passage 54d is formed by a wall 54e.
[0020]
  The annular groove 54b at the lower end of the intermediate exhaust pipe 54 is fitted into the annular bank 51c at the bottom of the recess 51 of the mount case, whereby the intermediate exhaust pipe 54 and the lower portion 41b of the main body 41 of the exhaust manifold 40 and the concave 51 And a circular hole 53 provided at the bottom of the base plate. That is, the exhaust downstream connection portion in the present embodiment is configured, the intermediate exhaust pipe 54 corresponds to the first exhaust passage member, and the peripheral portion of the circular hole 53 of the mount case 50 corresponds to the second exhaust passage member.
  The boss portion 54 c of the intermediate exhaust pipe 54 is engaged on a step portion 51 d provided at the bottom of the concave portion 51, is connected by a bolt 55, and is attached and supported in the concave portion 51.
[0021]
  A cover 56 is put on the upper surface opening 52 of the recess 51 to cover the entire surface. The cover 56 is partially provided with a circular hole 56a that fits with the outer annular bank portion 41d of the lower portion 41b of the main body portion 41 of the exhaust manifold 40 and the periphery of the upper end portion of the intermediate exhaust pipe 54. And the communication between the intermediate exhaust pipe 54 and the exhaust manifold 40 is ensured.
  A boss part 56 b is provided in the peripheral part of the cover 56, and a bolt 57 is vertically passed between a part of the inner part of the boss part 56 b and a part of the inner wall 51 a of the recess 51 to fix the cover 56 to the mount case 50. To do.
[0022]
  By the way, although there are a plurality of bolt coupling portions to the periphery of the recess 51 of the cover 56, the coupling portion is the periphery of the recess 51 excluding the outermost side of the recess 51 that affects the outer dimension in the width direction of the outboard motor. (Front and back of the figure). In FIG. 5, for the sake of convenience, the connecting portion with the other part 51e in the periphery of the recess 51 is shown by being biased to the right side of the drawing by the boss portion 56b and the imaginary line (chain line) of the bolt 57. By this bolt arrangement, interference between the outermost portion near the recess 51 of the mount case 50 and the under cover 3 is avoided, and the requirements for downsizing the outboard motor are achieved.
  As described above, the intermediate exhaust pipe 54 constitutes the internal passage of the exhaust manifold 40, and the cooling water chamber (see FIG. 5) surrounds the intermediate exhaust pipe 54 in the space in the recess provided in a part of the mount case 50 closed by the cover 56. Cooling water jacket) 58 is formed. That is, as the entire outboard motor, the mount case 50 and the intermediate exhaust pipe 54 are integrated to form a support case for the engine, but the exhaust passage has a connecting portion therebetween.
[0023]
  The extension case 4 is disposed on the lower surface of the mount case 50 and joined to each other, and a concave portion 59a is provided in the outer bottom 59 of the recess 51 of the mount case 50, and the upper surface of the extension case 4 including this portion. Join with.
  An oil pan 60 is joined to the lower surface of the mount case 50 via a metal gasket (not shown) inside the extension case 4. A part of the mounting flange to the oil pan mounting case is extended to form the mounting part 61 of the exhaust pipe 64.
[0024]
  The attachment portion 61 is provided with a communication portion 62 that constitutes an exhaust passage. The communication portion 62 has a wall surface 62 a that is connected to the wall surface of the exhaust passage of the circular hole 53 of the mount case 50 upstream and connected to the exhaust pipe 64 downstream.
  The upper end portion of the communication portion 62 communicates with and is connected to the downstream passage 54f of the intermediate exhaust pipe 54, and the upper end portion of the exhaust pipe 64 is attached to the lower end portion of the communication portion 62 with a stay 65 and a bolt 66. 54 to the exhaust pipe 64 are communicated.
  The exhaust pipe 64 discharges exhaust gas into an exhaust expansion chamber 67 that is a space in the main body case around the exhaust pipe 64.
  As already described, in this embodiment, the peripheral portion of the circular hole 53 of the mount case 50 corresponds to the second exhaust passage member in the downstream connection portion. For example, these exhaust pipe attachment portions 61 or The exhaust pipe 64 may constitute a second exhaust passage.
[0025]
  The mounting portion 61 of the oil pan 60 is provided with a recessed portion 61a that is recessed downward, and the bottom portion 59 of the recessed portion 51 of the mount case 50 is provided with a recessed portion 59b that is symmetrically recessed upward. Cooling water pumped up by a water pump, which will be described later, is sent to this recess portion to form a water passage 63. The water passage 63 is connected to the cooling water chamber 58 via the communication passage 68.
  A drive shaft 18 a that is connected to the crankshaft 18 and drives the screw 6 described above passes through the extension case 4 and the gear case 5 constituting the main body case, and is guided to a gear mechanism in the gear case 5.
[0026]
  FIG. 6 is an enlarged explanatory view of the cooling water chamber 58 surrounding the intermediate exhaust pipe 54 which is a first exhaust passage member constituting the first exhaust passage, and FIG. 7 is a diagram showing the intermediate exhaust pipe 54 and the downstream second exhaust passage. Further, the connection of the downstream second exhaust passage member constituting this, the enlarged view of the seal portion, FIG. 8 shows the intermediate exhaust pipe 54, the upstream second exhaust passage, and the upstream second exhaust passage constituting this. FIG. 9 is an enlarged vertical cross-sectional view of a main part showing an example of a seal member.
[0027]
  At the lower end of the intermediate exhaust pipe 54, as clearly shown in FIG. 7, a space is provided on the inner periphery of the boss 54c provided at a part of the outer periphery and above the outer peripheral wall 54g of the downstream passage 54f. An annular bank portion (annular convex portion) 110 is provided so as to project integrally.
  In the annular groove 111 (annular concave portion) opened downward by the annular dam piece 110, the annular ridge portion 51c standing and installed around the circular hole 53 provided in the bottom of the concave portion 51 of the mount case 50 is set to 0. The fitting is performed with a slight gap of about 1 mm to 0.2 mm. Therefore, the annular groove 111 is fitted over the annular bank 51c from above, and the annular bank 51c corresponds to a wall portion in a range not directly facing the exhaust passage of the second exhaust passage member.
[0028]
  A ring-shaped seal member 120 having a concave cross section is fitted into and attached to the annular bank 110 at the lower end of the intermediate exhaust pipe 54. The seal member 120 has an inner peripheral surface 120a of the annular bank 51c on the recess 51 side. It abuts on the outer peripheral surface 51f and seals between the annular bank portions 51c and 110 in an airtight and watertight manner.
  As shown in FIG. 9, the seal member 120 is provided with a concave portion 120b in which an L-shaped metal core 120c is embedded and provided with an elastic force on the inside. Fit and fit to press fit.
  The inner peripheral surface 120a that is in contact with the outer peripheral surface 51f of the annular bank portion 51c includes a plurality of annular protrusions 120d that protrude in the inner peripheral direction in the height direction, and has a sealing property to the outer peripheral surface 51f of the annular bank portion 51c. Improved.
[0029]
  By the way, a locking recess 110a is provided on the outer peripheral surface of the annular bank 110 as shown on the left side of FIG. The locking recess 110a is provided as an annular locking recess on the entire outer periphery of the annular bank 110, and on the other hand, a locking protrusion (locking portion) is formed on the outer diameter side surface of the recess 120b of the sealing member 120 described above. ) 120f is provided, and the sealing member 120 is fitted to the annular bank 110 and locked in a mounted state.
  The locking recess 110a is engaged with the locking projection 120f of the seal member 120. When the intermediate exhaust pipe 54 is pulled out upward in FIG. 7, the locking projection 120f is in the locked state in the locking recess 110a. The seal member 120 can be extracted from the annular groove 111 together.
  The seal member 120 extends from the locking recess 110a of the annular bank 110 to at least two surfaces of the end surface 110b of the protrusion 110. In the illustrated example, the inner peripheral surface, end surface, and outer periphery of the bank 110 are illustrated. It is mounted over three surfaces.
[0030]
  The boss portion 54c is also provided in the space 112 between the cooling chamber 58 side portion 51h of the boss portion 51g provided with the step portion 51d coupled to the boss portion 54c by the bolt 55 and the annular bank portion 110 of the intermediate exhaust pipe 54. The cooling water in the cooling water chamber 58 circulates where there is no.
  Thus, the outer periphery of the ring-shaped sealing member 120 is exposed to the cooling water in the lower part of the cooling chamber 58. In addition, the annular bank 51c of the mount case 50 is separated from the outer peripheral wall 54g of the downstream passage 54f of the intermediate exhaust pipe 54 via a space, and the annular bank 110 of the intermediate exhaust pipe 54 is also directly separated from the exhaust passage 54d. The exhaust gas is not vented because it is sealed and hermetically sealed, so the supply of exhaust gas to the space is not active. Together, the wall temperature of the annular dam 110 is lower than the other wall temperatures, so that the first exhaust passage (passage 54d of the intermediate exhaust pipe 54) and the downstream second exhaust passage (the circular holes 53 of the mount case 53). The seal member 120 is thermally protected from the thermal effect of the portion 53a) directly facing the exhaust passage.
[0031]
  In this manner, the cooling water of the exhaust passage in the cooling water chamber 58 is used to cool the seal member 120 that hermetically seals the connection between the first exhaust passage member 54 and the second exhaust passage member 53 by the water cooling structure. Further, it is possible to prevent thermal deterioration of the seal member 120, improve durability, and improve exhaust sealability. The sealing member 120 also performs cooling water sealing at the same time.
  In the drawing, an annular bank 51c is provided in the second exhaust passage member on the downstream side, and a sealing material 120 is attached to the annular bank 110, and the annular bank 51 is fitted into the annular groove 11. Instead of this, a circular concave portion is provided in the connecting portion on the second exhaust passage member side so as to surround the circular hole 53 or the communication passage 62, and the sealing material 120 is mounted on the annular bank 110 in the concave step portion of the circular concave portion. A thing may be contacted and sealed, and in this case, the periphery of the sealing material 120 is immersed in the cooling water in the same manner as described above.
[0032]
  FIG. 8 shows a connection and seal structure between the intermediate exhaust pipe 54 as the first exhaust passage member and the lower end portion of the exhaust passage 41a of the main body 41 of the exhaust manifold 40 as the second exhaust passage member on the upstream side. This will be explained based on this in an enlarged view.
  The upper portion of the passage 54d of the intermediate exhaust pipe 54 is a wall 54h that directly faces the exhaust, and an annular ridge portion 113 having the wall surface 54h as an inner peripheral surface, and an annular ridge portion 114 that is spaced from the annular ridge 113 with a space therebetween. An annular groove 54a is formed between the annular bank 113 and the annular bank 114 so as to open in the end face direction of the bank. An annular bank portion 41c provided at the lower end portion of the main body portion 41 of the exhaust manifold 40 is fitted into the annular groove 54a from above. The lower end portion of the exhaust manifold 40 includes a wall portion that forms an exhaust passage 41a and directly faces the exhaust, and an annular bank portion 41c that does not face the exhaust directly.
[0033]
  The inner annular dam 113 constituting the upstream portion of the intermediate exhaust pipe 54 is fitted to the inner circumference of the annular ridge 41c at the lower end of the main body 41 of the exhaust manifold 40 with a slight gap between the passage 41a and the passage 54d. Connect and connect.
  The above-described seal member 120 is fitted and attached to the upper end portion of the outer annular bank portion 114 spaced from the wall 54h of the exhaust passage of the intermediate exhaust pipe 54 so that the groove 120b faces downward, and the inner periphery 120a of the seal member 120 Is in contact with the outer periphery of the annular bank 41c at the lower end of the main body 41 of the exhaust manifold 40 and seals this space in an airtight and watertight manner.
[0034]
  By the way, the outer peripheral surface 120e of the seal member 120 also contributes to the sealing of the cooling water, that is, abuts against the inner peripheral portion 56d of the lower end of the cylindrical portion 56c constituting the circular hole 56e of the cover 56, and seals the space between them. .
  A communication path 56e is provided in a part of the inner part of the cylinder part 56c (left side of the cylinder part 56c in FIG. 8), and this is provided with a cooling water communication space 115 (cooling water jacket) surrounding the end surface and the periphery of the seal member 120. The cooling water in the cooling water chamber 58 is supplied to the end surface and the periphery of the seal member 120 to cool the seal member in the same manner as described above.
  The cooling water communication space 115 communicates with and connects to a cooling water jacket 42 provided in the main body 41 of the exhaust manifold 40 and surrounding the passage 41a.
[0035]
  An annular groove 56f facing in the outer peripheral direction is provided at the lower end of the exhaust manifold main body 41, and an O-ring 116 is attached to the annular groove 56f to seal the space between the circular hole 56a and the cover 56 and the mount case 50. Between the upper end surface of the concave portion 51, an annular concave portion was provided on the cover side downward, and an O-ring 117 was interposed and sealed.
[0036]
  FIG. 10 is an enlarged view of the main part of FIG. 3, a plan view of a portion of the exhaust manifold 40, and FIG. 11 is a cross-sectional plan view of this portion.
  The exhaust manifold 40 has been described with reference to FIGS. 5, 6, and 8, and will be described in detail here.
  The passage 41a of the exhaust manifold 40 is connected to the exhaust passage 19a of the combustion chamber 19 described above, is suspended downward from the side, and is connected to the intermediate exhaust pipe 54 described above.
[0037]
  A cooling water jacket 42 is provided around a passage 41a provided in the main body of the exhaust manifold 40. A broken line in FIG. 10 and 42 shown in FIG. 11 indicate an upper portion of the cooling water jacket. Is connected to the cooling water jacket of the cylinder block by the tubes 81 and 82 through the connection hole 81a.
[0038]
  FIG. 12 is an enlarged longitudinal sectional view of a main part showing a cooling water discharge port of the cylinder block, an exhaust manifold, and a cooling water discharge system to the exhaust expansion chamber.
  Referring to FIG. 12, the chamber 25 a communicating with the cooling water jacket 25 of the uppermost cylinder bore 15 of the cylinder block 11 of the engine 10 is connected to the drainage passage 72 of the exhaust manifold 40 by the thermostat cover 69 and the pipe 70 through the thermostat 71. Connect to.
  As a result, when the engine cooling water exceeds a predetermined temperature, the thermostat 71 is opened, and the cooling water in the cooling water jacket 25 is discharged to the drainage passage 72 of the exhaust manifold 40.
[0039]
  A lower portion of the exhaust manifold 40 communicates with a discharge port 72b (pipe), and is connected to a discharge passage 74 that opens on the lower surface of the mount case 50 and opens to the exhaust expansion chamber via an L-shaped joint 73.
  In FIG. 12, 82 functions as a discharge pipe for discharging the remaining water of the cooling water jacket 25 of the cylinder block 11 when the water pump 76 is stopped.
[0040]
  FIG. 13 is a schematic explanatory diagram of a cooling water circuit of an engine and an exhaust system.
  Exhaust manifolds 40 and 40 having cooling water jackets are provided on the outer sides of the cylinder blocks 11 and 11 having cooling water jackets 25 and 25, respectively.
  Seawater and the like are pumped up by a supply pipe 77 through a strainer 75 which is a water intake port at the lower end portion, and cooling water is introduced into the cooling water jacket 25 of the cylinder blocks 11 and 11 through the through holes 25b and 25b. Cooling water is introduced into the cooling water chambers 58 and 58 through the communication passages 68 and 68 to cool the internal passages 54 and 54 of the mount case 50.
[0041]
  In addition, the cooling water in the cooling water chambers 58 and 58 is introduced into the cooling water jackets 42 and 42 of the exhaust manifold 40 to cool the exhaust manifold 40. The arrows indicate the flow of the cooling water, and the cooling water jackets 42 and 42 of the exhaust manifold 40 flow into the cylinder heads 13 and 13 while cooling the exhaust passage.
  The waste water after the thermostat 71 passes through the drain passage of the exhaust manifold 40 and is drained from the discharge passage 74 while cooling a part of the exhaust passage.
[0042]
  Since the remaining water in the cooling water jackets 25 and 25 of the cylinder block 11 is connected to the water supply side via the tubes 81 and 82, the water is discharged from the water intake port 75 constituted by a strainer after the water pump is stopped. Is done.
  Further, the cooling water discharge of the cooling water jackets 42 and 42 of the exhaust manifold 40 and the cooling water discharge of the cylinder blocks 11 and 11 are also returned to the water supply side.
  In FIG. 7, reference numeral 78 denotes a vapor separator, which supplies a part of the cooling water to the surroundings via the branch pipe 79 to cool the sub fuel tank.
[0043]
  The assembly of the exhaust passage of the mount case 50 will be described.
  (1) Assembly of the exhaust passage of the mount case 50.
  The intermediate exhaust pipe 54 is set in the recess 51 of the mount case 50, and the opening 52 of the recess 51 is covered with the cover 56. At this time, the bolts 57 are temporarily fixed.
  (2) Place the engine assembly on the mount case.
  The engine assembly 10a is mounted on the coupling surface 50a of the mount case 50 by placing it on the coupling surface 50a of the mount case 50 of the aforementioned engine assembly 10a, which includes a cylinder block, cylinder head, crankcase, and the like.
  (3) Assembly of exhaust manifold.
  The exhaust manifold 40 is assembled to the cylinder head 13 and centered with the intermediate exhaust pipe 54 to fix the exhaust manifold 40 to the cylinder head 13. The cover 56 is fixed by tightening the bolts 57 of the cover 56 described above.
  (4) Installation of exhaust pipe.
  The oil pan 60 is coupled to the lower surface of the mount case 50, and finally the exhaust pipe 44 is attached and fixed.
  That's it.
[0044]
【The invention's effect】
  The present invention exhibits the following effects by the above configuration.
  Claim 1 is a connection structure for a water-cooled exhaust passage of an engine of an outboard motor, wherein the first exhaust passageIntermediate exhaust pipe (54)And a mount case (50) for supporting the engine (10) and a cylinder head (13) of the engine (10), the first exhaust passage(54d)Second exhaust passage connected to(41a)And an exhaust manifold (40) constituting the second exhaust passage member and a connecting portion of the mount case (50) are provided in the exhaust passage.(54d)A wall portion facing the exhaust passage (113) and an annular convex portion (114) outside the wall portion, and a connecting portion of the exhaust manifold (40) includes a wall portion facing the exhaust passage (41a) and an annular bank portion ( 41c) and a wall portion not facing the exhaust passage (41a), and the mount case (50)Intermediate exhaust pipe (54)And a second exhaust passage member (40) between the wall surfaces separated from the exhaust passage, a seal member (120) is interposed, and the cover (56) coupled to the mount case (50) A cooling water jacket (58) formed outside the seal member (120) is formed, and a cooling water jacket (42) is provided on the outer periphery of the exhaust passage of the exhaust manifold (40). The cooling water jacket (42) , Holes in the cover (56)(56e)The cooling water jacket (58) and the cooling water jacket (42) both communicate with each other,The space between the cover (56) and the exhaust manifold (40) is sealed with a seal member (116),And the sealing member(116)Part of the outer cooling water jacket (58)With the sealing member (116)It is characterized by being configured.
[0045]
  According to the first aspect, since the cooling water jacket is formed outside the sealing member, the sealing member is immersed in the cooling water by the cooling water jacket, so that the sealing member can be effectively cooled.
  Therefore, the exhaust passage is sealed with cooling water and the sealing member that is affected by heat is cooled, so that thermal deterioration of the sealing member can be suppressed and durability can be improved.
  In addition, since the sealing member seals between the wall surfaces away from the exhaust passage, the heat effect due to the exhaust to the sealing member can be further reduced, further suppressing thermal deterioration of the sealing member and improving durability. Can be planned.
  In the present invention, since the annular convex portion enters the annular concave portion, the annular convex portion is thermally blocked by the annular concave portion, and the thermal effect of the exhaust heat on the annular convex portion can be reduced.
  Further, the present invention is such that the sealing member faces the cooling water jacket and a part of the cooling water jacket faces the outside of the sealing member, so that the cooling of the exhaust passage and the cooling of the connection seal portion can be performed with a relatively simple structure. It can be performed.
  Further, the present invention is particularly preferable for an outboard engine because it cools the exhaust.
[Brief description of the drawings]
FIG. 1 is an external view of the entire outboard motor with the outboard motor mounted on the stern of the hull.
[Fig. 2] Side view of the engine cover at the top of the outboard motor.
3 is a view taken along the line 3-3 in FIG. 2 and is a plan view showing the intake silencer box and the intake manifold removed from FIG.
FIG. 4 is an enlarged vertical side view of the main part of FIG.
FIG. 5 is an enlarged vertical cross-sectional view of a main part showing a relationship between a lower part of an exhaust manifold, an internal passage connected to the lower part of the exhaust manifold, an exhaust pipe, and an exhaust expansion chamber.
FIG. 6 is an enlarged explanatory view of a cooling water chamber surrounding an intermediate exhaust pipe which is a first exhaust passage member constituting the first exhaust passage.
FIG. 7 is an enlarged view of an intermediate exhaust pipe, a downstream second exhaust passage, a connection between a downstream second exhaust passage member constituting the intermediate exhaust pipe, and a seal portion.
FIG. 8 is an enlarged view of an intermediate exhaust pipe, an upstream second exhaust passage, and an upstream second exhaust passage member constituting the intermediate exhaust pipe and a seal portion.
FIG. 9 is an enlarged vertical cross-sectional view of the main part showing an example of the seal part taste.
10 is an enlarged view of the main part of FIG. 3, and a plan view of an exhaust manifold portion.
11 is a cross-sectional plan view of FIG.
FIG. 12 is an enlarged longitudinal sectional view of a main part showing a cooling water discharge port of the cylinder block, an exhaust manifold, and a cooling water discharge system to the exhaust expansion chamber.
FIG. 13 is a schematic explanatory diagram of a cooling water circuit of an engine and an exhaust system.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 ... Outboard motor, 10 ... Engine, 11 ... Cylinder block, 13 ... Cylinder head, 40 ... Exhaust manifold which is 2nd exhaust passage member of upstream side, 41 ... Exhaust passage which is 2nd exhaust passage, 51c, 110, 113, 114 ... annular convex part, 54a, 111 ... annular concave part, 54 ... first exhaust passage part, 54d ... communication passage that is the first exhaust passage, 53 ... circular hole that is the second exhaust passage on the downstream side, 110b ... Locking part, 120 ... seal member, 58, 112, 115 ... cooling water jacket.

Claims (1)

The first exhaust is provided in a mount case (50) having an intermediate exhaust pipe (54) constituting the first exhaust passage and supporting the engine (10), and a cylinder head (13) of the engine (10). The connection part of the exhaust manifold (40) which has the 2nd exhaust passage (41a) connected with a passage (54d), and constitutes the 2nd exhaust passage member, and the mount case (50) is the exhaust passage (54d). ) Facing the wall (113) and the outer annular projection (114),
The connection portion of the exhaust manifold (40) includes a wall portion facing the exhaust passage (41a) and a wall portion not facing the exhaust passage (41a) by the annular bank portion (41c),
A seal member (120) is interposed between the wall surfaces of the intermediate exhaust pipe (54) and the second exhaust passage member (40) of the mount case (50) and away from the exhaust passage;
Forming a cooling water jacket (58) formed outside the seal member (120) with a cover (56) coupled to the mount case (50);
A cooling water jacket (42) is provided on the outer periphery of the exhaust passage of the exhaust manifold (40),
The cooling water jacket (42) communicates with both the cooling water jacket (58) and the cooling water jacket (42) through a hole (56e) in the cover (56).
The space between the cover (56) and the exhaust manifold (40) is sealed with a seal member (116),
And a portion of said sealing member (116) outside of the cooling water jacket (58) and to constitute with the sealing member (116),
A water-cooled exhaust passage connection structure for an outboard engine.

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