CN101066703A - outboard engine unit - Google Patents

Abstract

The invention provides a outboard engine unit. In an outboard engine unit, a cover assembly (20), defining a lower half section of an engine room (2i), is composed of left and right cover members (21,25) each formed of resin, and a bracket (30) is fixed to a rear portion of the engine (5) or engine support structure (6). The left and right cover members are fixed at their respective rear portions to the bracket (30). Centerline (L2) of an engine cylinder (5d) is offset from a centerline (L1) of the engine room toward one of left and right sides of the unit, and an ignition plug (140) is provided on the other side opposite from the one side toward which the engine cylinder centerline (L2) is offset.

Description

outboard engine unit

technical field

The present invention relates to an outboard engine unit in which left and right cover members defining a lower half of an engine compartment are mounted to and supported by an engine or an engine support structure and which facilitates left and right Removal/reattachment of cover parts. The present invention also relates to an outboard motor unit that facilitates maintenance work such as detachment/attachment of spark plugs.

Background technique

In recent years, there has been known an outboard engine unit of the type in which the lower half of the engine room is defined by a lower cover including left and right (ie, port side and starboard side) cover members made of resin (for example, Japanese Patent Laid-Open 2004 -338463 and JP-A-2001-199393, hereinafter referred to as Patent Document 1 and Patent Document 2, respectively).

In the outboard motor unit disclosed in Patent Document 1, the left and right cover members of the lower cover are bolted together in a directly abutting relationship to each other. In the outboard engine unit disclosed in Patent Document 2, a bottom cover (ie, lower cover) is fixed to the engine main body, and left and right half covers (ie, left and right cover parts) of the bottom cover are bolted together in abutting relationship to each other.

With the outboard engine units disclosed in Patent Document 1 and Patent Document 2, it is necessary to position the fixed portion of the main body of the outboard engine unit close to the corresponding abutment portions of the left and right cover members to reliably achieve a gap between the abutment portions of the cover members. proper abutment; in fact, the left and right cover parts are fastened together by common bolts passing through their respective abutment and fixing parts.

However, with the above conventionally known outboard motor unit, when one of the left and right cover parts is removed or disassembled for desired maintenance work, fixing of the other cover part becomes unstable. Therefore, in the reassembly of the cover, considerable time and labor may be required for proper positioning of the left and right covers and the like, which disadvantageously results in poor workability.

In the above-mentioned conventionally known outboard engine unit, there are also provided an auxiliary exhaust outlet for discharging a part of the engine exhaust gas to the outside, and a water guide hole for discharging a part of the engine cooling water to the outside of the engine room. . A sealing structure for sealing the auxiliary exhaust outlet is attached to either or both of the abutting portions of the port side cover member and the starboard side cover member. Therefore, when any of the cover members is to be disassembled, the sealing structure must also be disassembled, so disassembly operations and subsequent reassembly operations are troublesome, which disadvantageously results in poor workability. In addition, the pipes of the water guide holes (hereinafter referred to as "water guide pipes") and the like are directly supported by the left and right cover members. Therefore, when any of the cover members is to be disassembled, the water guide pipe needs to be disassembled, so the disassembly operation and the subsequent reassembly operation are troublesome, which also disadvantageously results in poor workability.

There is also known an outboard engine unit of the type in which the axis of the engine cylinder is offset with respect to the axis of the crankshaft (for example, Japanese Patent Application Laid-Open No. 2001-115817, hereinafter referred to as Patent Document 3). According to the disclosure of Patent Document 3, the axis of the cylinder of the engine is shifted by a predetermined distance relative to the axis of the crankshaft in the direction of thrust acting on the piston. A spark plug is provided on the inner surface of the cylinder head. Therefore, in order to ensure sufficient space for maintenance work on the spark plugs, it is necessary to:

(a) increase the size of the bottom cover (i.e. the lower cover) so as to ensure sufficient space within the bottom cover, or

(b) Lower the position of the lower end of the top cover (ie, the engine cover) so that the spark plug is exposed laterally when the top cover is removed.

If item (a) above is taken, an increase in the size of the bottom cowl results in an increase in the size of the top cowl because the bottom and top cowls are joined together vertically in edge-to-edge abutting relationship, with the result that the overall size of the outboard motor unit The size and weight of the top cover will increase significantly. In addition, if the above item (b) is taken, lowering the position of the lower end of the top cover will not only result in a greater recessed depth of the top cover having a deep bowl shape, but also cause an increase in the size and weight of the top cover, resulting in the disassembly of the top cover. Operation will be very troublesome and loaded down with trivial details.

Typically, outboard engine units employ a vertical engine with a vertically oriented crankshaft and horizontally oriented cylinders; in particular, high power outboard engine units employ a four-stroke engine with multiple cylinders. In such outboard motor units, a plurality of cylinders are arranged in a vertical array (eg four cylinders in the case of a four cylinder engine) with a large vertical separation between the uppermost and lowermost cylinders. For such a multi-cylinder engine, the engine body inevitably has increased vertical length, with the result that the bowl-shaped top cover will have greater depth.

Contents of the invention

In view of the problems of the prior art described above, it is an object of the present invention to provide an improved outboard motor unit which enables easy removal and reattachment of either of the left and right cover parts without detrimental affect the other cover part and also not be interfered by the presence of the air outlet holes and the water guide holes, allowing disassembly/reassembly of the cover.

Another object of the present invention is to provide an improved outboard engine unit which enables easier maintenance work on the spark plugs arranged in the lower area of the engine compartment without requiring a significant lowering of the engine cover ( top cover), and the outboard motor unit can easily perform spark plug maintenance work without dismantling or disassembling the lower cover (bottom cover).

According to one aspect of the present invention there is provided an improved outboard motor unit comprising: a cover assembly defining a lower half of the engine compartment in which the engine is housed, said cover assembly comprising right and left cover members formed of resin; and a bracket fixed to the rear of the engine or engine support structure, the left and right cover members fixed to the bracket at their respective rear parts.

In the outboard motor unit of the present invention, wherein the bracket is fixed to the rear of the engine or engine support structure, and the left and right cover members are fixed to the bracket at their respective rears, the Each of the left and right cover parts can be detached from and reattached to the bracket independently of the other of the cover parts. Thus, the present invention significantly facilitates disassembly and reassembly of the cover assembly, for example for maintenance work, and greatly improves workability compared to the prior art. In addition, since only the bracket needs to be provided, the bracket is fixed to the rear of the engine or the like, the respective joint edges are abutted against the bracket and then the joints of the cover members are respectively joined by bolts or the like. The edges are fastened to the brackets. Therefore, the present invention can significantly simplify the abutment engagement structure of the cover member, thereby simplifying the structure of the outboard motor unit.

In an embodiment of the present invention, the bracket has engaging grooves formed in opposite side edges thereof for engaging with predetermined engaging edges of the left and right cover members. By engaging the engaging grooves formed in the bracket with the engaging edges of the left and right cover members, the present invention can more reliably and easily attach the left and right covers through the guidance of the engaging grooves. A component is attached to the bracket.

In an embodiment of the present invention, the left and right cover parts have respective engaging portions overlapping each other, each of the engaging portions having a tapered hole. By screwing bolts through the tapered holes of the left and right cover members which are initially offset from each other in the left-right direction of the outboard motor unit to predetermined fixing threaded portions to abut against the brackets respectively The joint is tightened to press the left and right cover members toward each other, thereby fastening the left and right cover members together. The left and right cover parts are drawn toward each other by a wedging action by passing bolts through their initially horizontally offset tapered holes to tighten the respective joints against the brackets. Therefore, the present invention can more reliably and easily fix the left and right cover members to the bracket in a simplified manner. The bracket can be provided with a locking device for locking the engine cover. In this case, the present invention does not need to provide a base plate and a structure dedicated to the locking device on the cover assembly, and can be used between the bracket and the Components are shared among the cover assemblies.

According to another aspect of the present invention there is provided an improved outboard engine unit comprising: a cover assembly defining a lower half of an engine compartment in which the engine is housed, said cover assembly comprising left and right cover members each formed of resin; and a bracket fixed to the rear of the engine or the engine support structure, the bracket having an auxiliary exhaust port provided therein for exhausting the exhaust of the engine A portion is discharged to the outside of the engine compartment.

With the auxiliary exhaust port provided in the bracket for discharging part of the engine exhaust to the outside of the engine room, it is not necessary to provide an auxiliary exhaust port on either of the left and right cover members. Sealed structure. Therefore, the present invention makes it unnecessary to disassemble the auxiliary exhaust port and the elements of the sealing structure every time at least one of the left and right cover parts is to be disassembled, and also does not need to reattach the elements of the auxiliary exhaust port and the sealing structure when the cover assembly is reassembled. , thus improving the machinability.

According to yet another aspect of the present invention there is provided an improved outboard motor unit comprising: a cover assembly defining a lower half of the engine compartment in which the engine is housed, said cover assembly including left and right cover parts each formed of resin; and a bracket fixed to the rear of the engine or an engine support structure, the bracket having water guide holes provided therein for channeling cooling water of the engine A portion is discharged to the outside of the engine compartment.

With the water guide hole provided in the bracket for discharging a part of the engine cooling water to the outside of the engine room, unlike the prior art structure in which the water guide part etc. is directly supported by the left and right cover parts, it is not necessary to disassemble the water guide tube. Therefore, the present invention can greatly facilitate the detachment/reattachment of any one cover member, thereby improving workability.

According to yet another aspect of the present invention, there is provided an improved outboard motor unit comprising: an engine compartment inside which is housed an engine, the centerline of the engine cylinders facing said outboard motor one of the left and right sides of the unit is offset from the centerline of the engine compartment; and a spark plug is disposed on the other of the left and right sides, which is offset from the centerline of the engine cylinder The side to which the shift is facing is opposite. By providing the spark plugs on the side opposite to the side toward which the center line of the engine cylinder is offset, the side of the cylinder head where the spark plugs are located can have a larger space, thereby making it easier to Carry out the maintenance of the spark plug in a timely manner.

In one embodiment, the engine room is defined by a lower cover and an upper cover or engine cover joined to the lower cover from above, and the lower cover is formed in a portion thereof in line with the pull-out direction of the spark plug There is a recess which can be opened/closed by a cap. By providing the recess, the aforementioned space does not have to be larger than necessary, thus facilitating a reliable sealing of the recess. In addition, by causing the cap to open/close the recessed portion as desired, maintenance of the spark plug can be performed further more easily.

In one embodiment, the lower cover includes left and right cover members each formed of resin, and one of the left and right cover members has the concave portion formed therein and the cap provided thereon. Since the recess and cap have to be provided on only one of the cover parts, the recess and cap can be handled integrally with the cover part when the one cover part is to be detached or reattached, with the result Removal and reattachment of the cover part can be performed most easily.

In an embodiment, the outboard motor unit of the present invention may also include a bracket secured to the rear of the motor or motor support structure. In this case, the left and right cover parts of the lower cover are fixed to the bracket, and the spark plug is arranged such that the pulling-out (ie insertion/removal) direction of the spark plug does not coincide with the position of the bracket . Therefore, the present invention can facilitate not only the disassembly/reassembly of the lower cover but also the maintenance work of the spark plug without causing interference between the bracket and the spark plug for substantially the same reason as described above. The left and right cover parts and bracket can remain installed in place (ie, do not have to be disassembled) while maintenance work on the spark plug is performed.

Description of drawings

Certain preferred embodiments of the invention are described in detail below, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a side view showing an outboard motor unit according to an embodiment of the present invention, wherein internal mechanisms are indicated by dashed lines;

Fig. 2 is a rear view showing the appearance of the outboard motor unit of Fig. 1;

Fig. 3 is an exploded perspective view of the lower cover of the outboard engine unit, specifically showing engine support components, front and rear brackets, etc.;

Fig. 4 is an enlarged rear view of the main components of the outboard engine unit shown in Fig. 2, specifically showing the support of the left and right half covers of the lower cover and the upper cover through the rear bracket;

Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4;

Figure 6 is a cross-sectional view taken along line 6-6 of Figure 5;

Figure 7 is a cross-sectional view taken along line 7-7 of Figure 5;

8 is an internal perspective view showing components disposed on and near the inner surface of the rear bracket;

9 is a perspective view of the rear bracket with the auxiliary exhaust port and the water guide hole removed;

Figure 10 is a cross-sectional view taken along line 10-10 of Figure 9;

Figure 11 is a view showing the lower cover with the upper cover or engine cover removed and the front of the lower cover removed for clarity; and

FIG. 12 is an enlarged exploded explanatory view of main components shown in FIG. 11 .

Detailed ways

Referring now to the included FIGS. 1 to 3 , wherein FIG. 1 is a side view showing an outboard motor unit 1 according to an embodiment of the present invention, wherein internal mechanisms are shown in dashed lines, and FIG. 2 is a diagram showing an example external appearance of the outboard motor unit 1 . Rear view, and FIG. 3 is an exploded perspective view of the lower cover (or lower cover assembly) 20 of the outboard motor unit 1, specifically showing the engine support components, front and rear brackets, and the like.

In the drawings, "Fr" indicates the forward propulsion direction of the boat to which the outboard motor unit of the present invention is applied, and "Rr" indicates the rearward direction opposite to the forward propulsion direction of the boat.

An example appearance of the outboard motor unit 1 is shown in a side view of FIG. 1 and a rear view of FIG. 2 . As shown, the outboard motor unit 1 comprises a lower cover (assembly) 20 and a hood 2 arranged in the uppermost position of the unit 1 , and these upper hood 2 and lower cover 20 together define an engine compartment 2i. The extension case 3 is provided under the lower cover 20 , and the gear case 4 arranged at the lowermost position of the unit 1 is engaged with the lower end of the extension case 3 .

The engine 5 is accommodated and supported in the upper region of the engine room 2 i defined by the upper cover 2 and the lower cover 20 through an engine mounting case (ie, an engine support structure) 6 arranged in the lower cover 20 . The engine 5 in the form of a so-called vertical engine having a vertically oriented crankshaft 5f is a four-stroke engine having a plurality of cylinders (four cylinders in the present embodiment) 5d arranged in a vertical arrangement.

The engine 5 includes a crankcase 5a at the front, a cylinder block 5b in the middle, a cylinder head 5c at the rear, and the like. The exhaust gas directed downward from the cylinder head 5c successively passes through the exhaust passage in the engine mounting case 6, the exhaust pipe 7 downstream of the engine mounting case 6, the lower space in the lower cover 20, the extension case 3, and then Passes through the gearbox 4 to eventually discharge as main exhaust gas through the central area of the propeller 14 to the outside water.

A plurality of cylinders 5d are provided in the cylinder block 5b (in the present embodiment, four horizontally oriented cylinders 5d are arranged in a vertical array), and a plurality of intake and exhaust valves are provided in the cylinder head 5c. Open and close the combustion chamber 5e.

In the right side portion of the cylinder block 5b is accommodated an electronic component box 8 containing circuit boards for controlling the engine ignition device and the fuel injection device. In addition, an intake muffler 9 is provided in front of the electronics box 8 and extends along one side of the crankcase 5a to a region in front of the crankcase 5a, and a generator (alternator) 10 is arranged above the engine 5.

A lower end portion of a crankshaft 5 f extending vertically through the inside of a crankcase 5 a of the engine 5 is connected to a vertical drive shaft 12 , and a lower end portion of the drive shaft 12 is connected to a gear transmission mechanism 13 housed in the gear case 4 . The gear transmission mechanism 13 transmits power transmitted from the drive shaft 12 to a horizontal driven shaft 13a provided in the gear case 4 in a front-rear orientation. The rear end portion of the driven shaft 13a protrudes backward beyond the rear end of the gear case 4, and the propeller 14 is fixed to the rear end portion of the driven shaft 13a. The propeller 14 is driven by the power of the engine 5, and a pair of dog clutches are used to switch between the forward rotation direction and the reverse rotation direction of the propeller 14, so that forward or backward propulsion can be obtained as desired.

The exhaust gas from the above-mentioned main exhaust pipe 7 is guided downward as shown by arrow (a) and then discharged to the outside through the central area of the propeller 14, and a part of the exhaust gas is discharged to the outboard motor as shown by arrow (b). Unit 1 is then discharged to an external area. An exhaust passage is provided in the mounting housing 6 near the main exhaust pipe 7 and an auxiliary exhaust port or pipe 15 is provided near the downstream outlet of the main exhaust pipe 7 . The auxiliary exhaust pipe 15 formed of vinyl chloride and rubber extends inside the engine mounting case 6 while being bent backward, and opens to the outside through the wall of the lower cover 20, thereby discharging the exhaust gas to the outboard engine unit 1 It is then discharged to the external area as indicated by arrow (b).

The lower cover (assembly) 20 is provided with a water guide hole portion 16 in which a hole opening to the outside is formed, and the water guide hole portion 16 discharges a part of the engine cooling water to the outside (from the lower cover 20 to the outside). bottom) to allow a visual check that the cooling water is flowing properly to the engine cooling section.

The stern bracket 17 is supported on the front end of the outboard engine unit 1 by means of a rotating housing 18 . Reference numerals 18a and 18b denote mounting rubber for supporting the rotary housing 18, 5g denotes an oil pan, and 5h denotes a spark plug.

Referring now to FIG. 2 , the upper cover 2 of the covers defining the engine room 2i is integrally formed of resin, while the lower cover (assembly) 20 includes left and right (ie, port side and starboard sides) integrally joined together in abutting relationship. Cover parts (or half covers). Both the left and right cover parts or half covers are molded from resin.

The following paragraphs will describe an example structure of the lower cover (assembly) 20 mainly with reference to FIG. 3 .

The lower cover 20 includes left and right half covers 21 and 25 each having a semi-elliptical shape when viewed in a plan view. The shapes of the upper halves 21a and 25a of the left and right lower half covers 21 and 25 are elongated along the front-rear direction of the unit 1, and the lengths of the lower halves 21c and 25c of the left and right lower half covers 21 and 25 along the front-rear direction are longer than those of the upper halves. Portions 21a and 25a are short. More specifically, the front portions of the lower halves 21c and 25c of the left and right lower half covers 21 and 25 are recessed rearward, and the front portions 21d and 25d of the upper halves 21a and 25a protrude forward. The left and right lower half-covers 21 and 25 also have engaging portions in the form of grooves (only the groove 21e of the left half-cover 21 is shown in FIG. 3 ), which are formed in the opposite inner surfaces of the left and right lower half-covers and Positioned in bilaterally symmetrical relationship with each other (although not visible in the drawing, the inner engaging groove of the right half cover 25 is formed at a position corresponding to the inner engaging groove 21e of the left half cover 21). When the left and right half covers 21 and 25 are joined together in an edge-to-edge abutting relationship, the sealing member 6g provided along and on the peripheral flange portion 6f of the engine mounting case 6 is fitted in the above-mentioned inner joint recess. groove to provide an airtight seal between the engine mounting case 6 and the lower cover (assembly) 20 .

As further shown in FIG. 3, the engine mounting case 6 has: a hole 6b through which the shift lever passing through the rotating shaft extends vertically; a hole 6a through which the drive shaft extends vertically; an engine mounting flange 6c; The opening 6e back to the oil pan; the hole 6d through which the main exhaust pipe 7 extends vertically; and so on.

In addition, the front part 25d of the upper part 25a of the right half cover 25 is recessed downward, and the harness cover (harness cover) 22 is placed on the recessed part of the front part 25d and integrally fixed thereon, thereby providing a complete right Half cover 25.

In FIG. 3, the front bracket 24 is positioned between the front ends of the front parts 21d and 25d when the left and right cover halves 21 and 25 are joined together in an abutting relationship to each other. The front bracket 24 includes an upwardly oriented semicircular support arm 24a on its starboard side. A cable harness holder 23 made of rubber is held or sandwiched between an upwardly oriented semicircular support arm 24a and a downwardly oriented semicircular recess 22a formed in the front end portion of the harness cover 22 so as to The cable harness is held in such a way that it can be led into or out of the engine compartment 2i. The front bracket 24 also includes an operating arm 24b having a lock lever engageable with a hook 2a ( FIG. 1 ) provided on the front end portion of the upper cover 2 by operation of the handle.

The left and right half covers 21 and 25 of the lower cover 20 have rear upper abutting (joining) portions joined to the rear bracket 30 , which will be described in detail later.

FIG. 4 is an enlarged rear view of the main (or related) components shown in FIG. 2 , specifically showing the support of the left and right half covers of the lower cover 20 and the upper cover 2 by the rear bracket. 5 is a cross-sectional view taken along line 5-5 of FIG. 4, FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5, and FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. In addition, FIG. 8 is an internal perspective view showing components disposed on the inner surface of the rear bracket 30 and its vicinity, and FIG. 9 is a perspective view of the rear bracket 30 with the auxiliary exhaust ports and water guide holes removed, and 10 is a cross-sectional view taken along line 10-10 of FIG. 9 .

The following paragraphs will describe how the rear bracket 30 and the rear portions of the left and right half covers 21 and 25 of the lower cover (assembly) 20 are installed and supported with reference to the above-mentioned drawings.

The rear bracket 30 is provided for attaching the respective rear upper portions of the left and right half covers 21 and 25 with respect to the engine. The piping of the auxiliary exhaust port 15 and the water guide hole portion 16 is exposed on the inner (or facing) surface of the rear bracket 30 .

The shape of the rear bracket 30 is elongated along the vertical direction of the outboard motor unit 1 . The main body 31 of the rear bracket 30 is generally in the form of a plate (see FIG. 4 ) with a lower half that is gradually curved or tapered downward when viewed from the rear; Shield shape.

The plate-like main body 31 of the rear bracket 30 has a forwardly (ie inwardly) raised vertical middle concave portion 31 a, as clearly seen in FIGS. 8 and 9 . The recessed portion 31a constitutes a manual operation portion of a lock operation arm described later. The left and right mounting arms 32 that are laterally away from each other and protrude obliquely downward are integrally provided with the upper inner surface portion of the main body 31, and are exposed towards the middle area of the rear surface of the lower cover 20; the left and right mounting arms 32 together form a downward direction. polyline structure. The mounting arms 32 have respective mounting holes 32a at their respective distal ends, and are integrally formed as a reinforcing rib structure in a channel-like cross-sectional shape.

The intermediate portion 32b forming the base of the left and right mounting arm portions 32 is integrally formed with left and right vertical projecting portions 32c at their opposite ends. A lateral holding portion 32d extends between the protruding portions 32c, and mounting nuts 33 are fitted into opposite ends of the holding portion 32d. On the upper outer surface area of the plate-like main body 31 is provided a hinge support portion 32 e of the lock operating arm for supporting the pivotal base of the operating arm 40 .

Along the opposite side edges of the plate-shaped main body 31 and therein are provided grooves 34 recessed inward along the width direction of the main body 31 , and the width of the recessed groove 34 is slightly larger than the thickness of the half covers 21 and 25 .

In addition, the plate-shaped main body 31 is formed with bolt holes 35 in its lower end portion 31b, and is integrally provided with mounting boss portions 36 at positions corresponding to the bolt holes 35 on the inner surface area of the main body 31 . A nut 37 is embedded into the inner surface of the mounting boss portion 36 and fixed thereto by welding or the like.

The aforementioned operating arm 40 , operating rod 40 b and shaft 40 c all provided on the rear bracket 30 are combined with the locking hook 2 b on the engine cover 2 to form a locking device for the engine cover 2 .

A hole 38 for mounting the auxiliary exhaust port or pipe 15 is formed in the plate-shaped main body 31 below the above-mentioned recessed portion 31a, and a hole 39 for mounting the water guide hole portion 16 is formed below the mounting hole 38 . The auxiliary exhaust pipe mounting hole 38 has a larger diameter than the water guide portion mounting hole 39 . As can be seen from FIG. 4 , the auxiliary exhaust port or pipe 15 and the water guide hole portion 16 open to the rear surface of the bracket 30 .

The auxiliary exhaust port 15 has an upstream portion 15a positioned near the inner surface of the plate-shaped main body 31, and an upstream end opening portion having a flange 15b. The flange 15b abuts against the area of the main body inner surface surrounding the auxiliary exhaust pipe mounting hole 38 . In addition, the pipe 16a of the water guide hole portion 16 is indicated by a dotted line in FIG. As shown in Figure 8.

Referring now to FIGS. 4 to 7 , description will be given on how to install the rear bracket 30 and the engine 5 and how to connect the rear bracket 30 to the half covers 21 and 25 .

As shown in FIG. 4, mounting seat portions 5i projecting laterally outward away from each other are provided on left and right side regions of a rear surface 5k of the cylinder head 5c, and left and right mounting arm portions projecting laterally outward from the plate-shaped main body 31 32 is secured to the mount portion 5i by means of corresponding collars 41 by means of bolts 42 corresponding in size to the mounting holes 32a.

In the manner described above, the rear bracket 30 is attached (ie, mounted and supported) to the rear surface of the engine 5 . The rear bracket 30 may be attached to the engine mounting case 6 instead of the rear surface of the engine 5 .

Above the respective abutment joint edges 121c and 125c of the left and right half covers 21 and 25, there are provided vertically extending joint portions 121 and 125 in an opposite (left-right symmetrical) relationship to each other, each of which has a relatively large width along the left-right direction of the unit 1. small width. In addition, mounting bosses 121a and 125a through which horizontal mounting holes 121b and 125b are formed are provided so as to protrude vertically from opposite upper ends of the engaging parts 121 and 125;

The abutting joint edges 121c and 125c of the left and right half covers 21 and 25 abut against each other, and the side edges of the joint parts 121 and 125 are fittingly engaged with recesses formed in the left and right side edges of the plate-shaped main body 31 of the rear bracket 30 In the groove 34 (see Figure 7).

Mounting bosses 121 a and 125 a provided on upper end portions of the engaging portions 121 and 125 abut against corresponding vertical protrusions 32 c formed on an upper surface area of the rear bracket 30 . Then, the bolts 43 are inserted laterally from the outer ends of the bosses 121a and 125a into the mounting holes 121b and 125b of the mounting bosses 121a and 125a, and screwed into the mounting nuts 33 . In this way, the mounting bosses 121 a and 125 a are fixed to the left and right upper end portions of the rear bracket 30 so that the upper end portions of the left and right cover halves 21 and 25 are attached (ie, mounted and supported) to the bracket 30 .

Decorative bolts are passed through mounting holes formed in the lower end portion of the bracket main body 31, and mounting holes 31k (only visible in FIG. The mounting holes 31k) of the left half cover 21 are superimposed on each other on nuts 37 (see FIG. 3) and fixed together by means of nuts 37, which will be described later.

In the current embodiment constituted in the above manner, only the main body 31 of the bracket 30 is exposed on the rear surfaces of the upper and lower covers 20, and is used for mounting various components to the engine 5 and the left and right half covers 21 and 25. The elements are covered by the cover.

Engagement seat portions 121d and 125d are provided on and protrude from lower portions of the engagement portions 121 and 125 in horizontally opposed and superimposed relation to each other. One of the engaging seat portions 121d is formed as a concave portion bent inwardly into the engine room, and the other engaging seat portion 125d has a wall thickness corresponding to the recessed depth of the one engaging seat portion 121d. These engaging seat portions 121d and 125d have respective outer surfaces that are flush with each other.

As shown in (a) of FIG. 6, the engaging seat portions 121d and 125d have tapered hole portions 121e and 125e each having a larger diameter than the threaded portion 44a of the stepped bolt 44 and having a hole 121f formed therethrough. or 125f. The larger diameter portion 44b of the stepped bolt 44 closely passes through the through holes 121f and 125f.

The engaging seat portions 121d and 125d are initially positioned to partially overlap each other in the front-rear direction of the unit 1, and are offset from each other in the left-right direction of the unit 1; therefore, the tapered hole portions 121e and 125e are initially offset from each other in the left-right direction, as shown in FIG. 6 (a) shown.

The bolt 44 is inserted through the hole 39 formed in the lower end portion of the plate-like main body 31 of the bracket 30 so that the threaded portion 44a of the bolt is loosely passed through the holes 121f and 125f of the engaging seat portions 121d and 125d, and then screwed through The nut 37 is fixed by welding or the like to the mounting boss portion 36 fixedly provided on the inner surface area of the main body 31 . The nut 37 serves as a fixing screw member.

As the bolt 44 is screwed into the nut or fixed threaded part 37, the larger diameter portion 44b of the bolt 44 reaches the tapered hole portion 121e of the inner socket portion 121d by the tapered hole portion 125e of the outer socket portion 125d, so that The two seat parts 121d and 125d are gradually drawn closer to each other by the aligning action. Finally, the engaging portions 121 and 125 are engaged together in the lower end portion of the bracket 30 so that the holes 121f and 125f remain axially aligned and the seat portions 121d and 125d remain in a face-to-face relationship against each other, as shown in (b) of FIG. shown.

As shown in FIG. 5 , the locking hook 2 b is provided on the lower rear surface area of the upper cover 2 in a vertically opposite relationship to the operating arm 40 . The locking lever 40a is engaged with the locking hook 2b by pivoting the operating lever 40b of the operating arm 40 about the shaft 40c, thereby locking the back of the engine cover 2 in the closed position, ie fixing the upper cover 2 to the lower cover 20 in the closed position.

In FIG. 5, the locking hook 2b is fastened to the back of the engine cover 2 by a rivet 2c. In FIGS. 4 and 5 , reference numeral 6h denotes an auxiliary exhaust passage, which is provided in the engine mounting case 6 and communicates at one end with the most downstream portion 15c of the auxiliary exhaust port 15 so that a part of the engine exhaust is exhausted. Can flow to auxiliary exhaust port 15.

Since the auxiliary exhaust port 15 and the water guide hole portion 16 are provided in the rear bracket 30 supporting the lower cover 20 as described above, the present embodiment may not be detached from the lower cover 20 when detaching the lower cover 20 for a desired work. Piping that assists the exhaust port 15, the water guide hole portion 16, the sealing member, and the like. Therefore, in the present embodiment, operations for reattaching the pipes of the auxiliary exhaust port 15, the water guide hole portion 16, the sealing member, and the like are not required after desired work. Therefore, even in the case where the auxiliary exhaust port 15 and the water guide hole portion 16 are provided, only the operation of detaching the lower cover 20 is required for desired work.

In addition, in the current embodiment, the left and right cover halves 21 and 25 of the lower cover 20 are installed and supported on the rear bracket 30 independently of each other. Therefore, even when one of the left and right half covers 21 or 25 is detached from the bracket 30, the other left and right half cover 25 or 21 remains attached to the rear bracket 30, which facilitates the detachment of the one half cover and the subsequent description. Reattachment of a half cover.

In FIGS. 1 , 2 and 4 , reference numeral 26 denotes a spark plug maintenance cap provided on the uppermost region of the rear surface of one of the left and right lower half covers (right lower half cover 25 in the above embodiment). By removing the spark plug maintenance cap 26, the spark plug can be exposed to the engine combustion chamber defined in the cylinder head of any one of the cylinders arranged in a vertical arrangement, so that the spark plug can be inspected, replaced, etc.; Engine cover 2 above cover 20 .

In addition, when the spark plugs arranged in the vertical alignment corresponding to the cylinders are to be inspected with the engine cover 2 removed, etc., it may be difficult to inspect some of the spark plugs in the lower position of the vertical alignment due to the presence of the lower cover. . However, removing cap 26 may facilitate this spark plug inspection.

11 is a view showing the lower cover (assembly) 20 with the upper cover or engine cover 2 removed and the front portion of the lower cover 20 removed for ease of display, and FIG. 12 is an enlarged exploded explanatory view of main components shown in FIG. 11 .

A crankcase 5a of the engine 5 is located in the front area of the engine room 2i, a cylinder block 5b is located in the middle area of the engine room 2i, and a cylinder head 5c and a cylinder head cover (not shown) are located in the rear area of the engine room 2i .

The center line L2 of the cylinder 5d in the cylinder block 5b extending in the front-rear direction of the outboard engine unit 1 and the center line L1 of the unit 1 extending across the width of the unit 1 at the center are toward the left or port side of the unit 1 (Fig. 11) offset or offset by a distance D.

As shown in FIG. 11, the center line L1 of the outboard motor unit 1 corresponds to the center of the crankshaft 5f and the center of the drive shaft 12, and also coincides with the center line of the engine room 2i across the width of the engine room 2i at the center. The crankshaft 5f rotates in the direction of the arrow in FIG. 11 .

Therefore, the engine 5 including the cylinder head 5c is offset towards the left or port side (the right side in FIG. 11 ) of the unit 1, so that the right (ie, starboard side) space (the left space in FIG. 11 ) 4a is larger than The left (ie, port side) space (right space in FIG. 11 ) 4b is large.

A hole 53c for installing the spark plug 140 therein and communicating with the combustion chamber 5e is formed in the cylinder head 5c to extend obliquely rearward in the large space 4a, and the spark plug 140 passes through the hole 53c.

The spark plug 140 includes an electrode portion 140a provided at a distal end thereof within the combustion chamber 5e, and a shaft-shaped body 140b having an insulating material and extending obliquely upward through the mounting hole 53c. Terminals provided on top of the shaft body 140b are connected to terminals provided in the cup-shaped head portion 141 through high-tension wires, and are supplied with power from the terminals in the head portion 141 .

The spark plug head 141 protruding outward from the cylinder head 5c is located in an L-shaped space between the exhaust passage portion 53d defined in the cylinder head 5c and the top surface (ie, the surface abutting against the cylinder head cover) of the cylinder head 5c. 53e. The head 141 faces or faces the starboard or right (left in the drawing) rear surface 20 a, but it never faces the rear joint where the left and right half covers 21 and 25 are joined together by the rear bracket 30 . The axis L3 of the spark plug 140 and the mounting hole 53 c face the starboard side or the right rear area offset from the rear bracket 30 .

In the upper region of the rear surface 135 ( FIG. 4 ) of a lower half-cover (i.e., the right or starboard side half-cover (left half-cover in the figure) 25 ) located on the extension line of the axis L3 of the spark plug 140, a recess is formed. Entry 142.

The recessed portion 142 is in the form of an upwardly open notch, which is arranged to be aligned with the above-mentioned axis L3 of the spark plug 140, that is, the direction in which the spark plug 140 is pulled out from the hole 53c to be pulled out from the half cover 25 (ie, the “pulling out direction” of the spark plug 140 ")Corresponding. As shown in FIG. 4 , the recessed portion 142 in the current embodiment has a generally linear outer edge 142a, a gradually curved bottom edge 142b, and an upwardly and inwardly curved inner edge 142c.

The recessed portion 142 is open upward as described above so that its left and right upper edges merge with the rear upper edge of the half cover 25 and can be opened and closed by the aforementioned cap 26 corresponding in shape to the recessed portion 142 .

As shown in FIG. 12 , the cap 26 includes a plate-like body 26a having a shape corresponding to the concave portion 142, a reinforcing rib 26b formed thereon along the periphery of the inner surface of the cap 26, and an arm portion 26c. The arm portion 26c is formed with a mounting hole 26d in its one end region.

A supporting bar 144 is provided on the inner surface of the right half cover 25 adjacent to the outer edge of the recessed portion 142, and the supporting bar 144 has a mounting screw hole 144a. The bolt 45 passes through the mounting hole 26d of the cap 26 to threadably engage with the mounting screw hole 144a, thereby fixing the cap 26 to the recess 42 in the closed position. In FIGS. 11 and 12, reference numeral 53b denotes a camshaft.

The cap 26 can be detached from the recess 142 by removing the upper cover or engine cover 2 and the bolts 45 as shown in FIG. 12 .

The spark plug 140 with its axis L3 facing the recessed portion 142 can be pulled out from the recessed portion 142 as indicated by arrow (c). Because the space 4a is relatively large, not only the spark plug 140 can be easily inserted into and pulled out of the hole 53c, but also the exhaust passage portion 53d of the cylinder head 5c, etc. can be easily installed in place.

In addition, because the left and right half covers 21 and 25 are attached to the rear bracket 30 at their respective upper parts, and because the bracket 30 is not positioned in the direction in which the spark plug 140 is inserted into the hole 53c and pulled out from the hole 53c (that is, the spark plug 140 The insertion/extraction direction of the spark plug 140 does not correspond to the position of the rear bracket 30), so the insertion/removal of the spark plug 140 never interferes with the existence of the rear bracket 30.

The above-described lower cover mounting structure can be suitably applied to the lower cover of the outboard engine unit. In addition, the above-described positioning and orientation of the spark plug, the recess for maintaining the spark plug, and the cap for opening/closing the recess can be suitably applied to the outboard motor unit.

Claims (16)

1. An outboard engine unit, the outboard engine unit comprising: a cover assembly (20) defining a lower half of the engine compartment (2i) in which the engine (5) is housed, the cover assembly including left and right cover members (21, 25) each formed of resin; and A bracket (30) secured to the rear of said engine (5) or engine support structure (6), said left and right cover parts being secured to said bracket at their respective rears. 2. The outboard motor unit according to claim 1, wherein said bracket (30) has grooves (34) formed in its opposite side edges for mating with said left and right cover parts (21, 25) ) of the predetermined joint edge joint. 3. The outboard motor unit according to claim 1, wherein said left and right cover members (21, 25) have respective joint portions (121d, 125d) superimposed on each other, each said joint portion having a cone shaped holes (121e, 125e), By screwing bolts (44) through corresponding said tapered holes initially offset from each other in the left-right direction of said outboard motor unit to predetermined fixing threaded parts (37) to abut against said bracket The respective joints are tightened to press the left and right cover parts toward each other, thereby fastening the left and right cover parts together. 4. The outboard motor unit according to claim 1, wherein said bracket is provided with locking means (40, 40b, 40c) for locking the engine cover (2). 5. An outboard motor unit, the outboard motor unit comprising: a cover assembly (20) defining a lower half of the engine compartment (2i) in which the engine (5) is housed, the cover assembly including left and right cover members (21, 25) each formed of resin; and a bracket (30), which is fixed to the rear of the engine (5) or the engine support structure (6), and an auxiliary exhaust port (15) is provided in the bracket for connecting the engine A part of the exhaust gas is discharged to the outside of the engine room. 6. The outboard motor unit according to claim 5, wherein the left and right cover members are connected to the bracket at their respective rear portions. 7. The outboard motor unit according to claim 6, wherein said left and right cover members (21, 25) have respective joint portions (121d, 125d) superimposed on each other, each said joint portion having a cone shaped holes (121e, 125e), By screwing the bolts (44) through the tapered holes that are initially offset from each other in the left-right direction of the outboard motor unit to predetermined fixing threaded portions (37) to abut against the brackets to place the respective The joint is tightened to press the left and right cover members toward each other, thereby fastening the left and right cover members together. 8. The outboard motor unit according to claim 6, wherein said bracket (30) is provided with locking means (40, 40b, 40c) for locking the engine cover (2). 9. An outboard motor unit comprising: a cover assembly (20) defining a lower half of an engine compartment (2i) in which an engine is housed, the cover assembly including left and right cover members each formed of resin; and A bracket (30), which is fixed to the rear of the engine (5) or the engine support structure (6), and is provided with water guide holes (16) in the bracket for cooling the engine A part of the water is discharged to the outside of the engine room. 10. The outboard motor unit according to claim 9, wherein the left and right cover members are connected to the bracket at their respective rear portions. 11. The outboard motor unit according to claim 10, wherein said left and right cover members (21, 25) have respective joint portions (121d, 125d) superimposed on each other, each said joint portion having a cone shaped holes (121e, 125e), By screwing bolts (44) through corresponding said tapered holes initially offset from each other in the left-right direction of said outboard motor unit to predetermined fixing threaded parts (37) to abut against said bracket The respective joints are tightened to press the left and right cover parts toward each other, thereby fastening the left and right cover parts together. 12. The outboard motor unit according to claim 10, wherein a locking device for locking the engine cover is provided on the bracket. 13. An outboard motor unit comprising: an engine room (2i) in which an engine (5) is accommodated, and the center line (L2) of the engine cylinder (5d) faces one of the left and right sides of the outboard engine unit from the side of the engine room centerline (L1) offset; and A spark plug (140) provided on the other side of the left and right sides, the other side being opposite to the side toward which the center line (L2) of the cylinder of the engine is offset. 14. The outboard motor unit according to claim 13, wherein said engine compartment (2i) is defined by a lower cover (20) and a motor cover (2) joined to said lower cover from above, and said lower The cover is formed with a recessed portion (42) in a portion thereof in line with the pulling-out direction of the spark plug, and the recessed portion is openable/closed by the cap (26). 15. The outboard motor unit according to claim 14, wherein the lower cover (20) includes left and right cover parts (21, 25) each formed of resin, and one of the left and right cover parts is formed therein There is said recess (142) and said cap (26) is disposed thereon. 16. An outboard engine unit according to claim 15, wherein the outboard engine unit further comprises a bracket (30) secured to the rear of the engine (5) or engine support structure (6), and Wherein, the left and right cover parts of the lower cover are fixed to the bracket, and the spark plug (140) is arranged such that the pull-out direction does not coincide with the position of the bracket (30).

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