JP4833723B2 - Outboard motor - Google Patents

Description

  The present invention relates to an outboard motor that achieves easy maintenance work such as extraction of a spark plug with a simple structure.

Conventionally, an outboard motor in which a cylinder axis is offset with respect to an axis passing through a crankshaft is known (see, for example, Patent Document 1).
JP 2001-115817 A

In this publication, the center line L2 of the cylinder 20 is offset in the direction of the thrust force acting on the piston 21 by a distance D1 with respect to the axis L1 passing through the crankshaft 22 (the reference numeral in the publication is used).
As shown in FIG. 3, the ignition plug 44 is provided on the side surface of the cylinder head 16 on the center line L2 side.
Therefore, to secure a space for maintenance work of the spark plug,
(A) Enlarge the bottom cowling 12 (lower cover) to secure enough space inside,
(A) When the lower end position of the top cowling 13 (engine cover) is lowered and the top cowling 13 is removed, the spark plug needs to be exposed to the side.

In (a), the bottom cowling becomes larger, which leads to an increase in the size of the outboard motor. At the same time, the top cowling and the bottom cowling have an opening structure, which leads to an increase in the size of the top cowling and increases the size of the outboard motor. And also increases the weight of the top cowling.
In (a), lowering the lower end position of the top cowling leads to a deeper bowl-shaped top cowling, which increases in weight as the size increases, and the top cowling removal work is cumbersome and cumbersome. It becomes.

By the way, the engine of the outboard motor is a vertical engine in which the crankshaft is placed vertically and the cylinder is oriented horizontally, and the outboard motor of high output employs a four-stroke engine with a plurality of cylinders.
In such an engine, the cylinder has a plurality of upper and lower cylinders with the cylinder axis oriented horizontally, for example, four cylinders are arranged vertically in a four-cylinder engine, and there is a large difference in height between the uppermost cylinder and the lowermost cylinder. Has been placed.
In such a multi-cylinder engine, the engine body is unavoidably vertically long, and the bowl shape of the top cowling tends to be deeper.
The present invention has been made in view of the above problems in the maintenance work of an ignition plug for an outboard motor.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an outboard motor by facilitating the maintenance work of a spark plug without significantly lowering the top cowling, that is, the lower end position of the upper engine cover, and maintaining a lower spark plug. It is an object of the present invention to provide an outboard motor that enables the bottom cowling to be disassembled and removed.

The invention according to claim 1 is a ship in which a vertical engine is mounted such that the crankshaft is vertically placed, the cylinder is horizontally placed, and the cylinder axis faces the front-rear direction of the outboard motor, and the engine is accommodated in the engine room. In the outboard motor, the cylinder center line of the engine faces the front and rear direction of the outboard motor, the center line of the left and right direction of the engine room faces the front and rear direction of the outboard motor, and the cylinder center line of the engine extends to the left and right direction of the engine room. place by biasing on one side in the engine room with respect to the center line, and biasing the side, characterized in that a spark plug on the other side.

  According to a second aspect of the present invention, in the first aspect, the engine room is composed of a lower cover and an engine cover that is fitted to the lower cover, and can be opened and closed with a lid at a portion of the lower cover facing the extraction direction of the spark plug. It is characterized by providing a notch portion.

  According to a third aspect of the present invention, in the second aspect, the lower cover is formed of a resin cover assembly including left and right cover halves constituting the port side and the starboard side, and a cutout portion is formed in one of the cover halves. And a lid.

  According to a fourth aspect of the present invention, in any one of the second or third aspect, the bracket is fixed to the rear half of the engine or the engine support structure, and the left and right cover halves constituting the cover assembly are mounted on the bracket. The body is fixed, and the direction in which the spark plug is pulled out does not coincide with the position of the bracket.

In the invention according to claim 1, a vertical engine is mounted such that the crankshaft is placed vertically, the cylinder is placed horizontally, and the cylinder axis faces the front-rear direction of the outboard motor, and the engine is housed in the engine room. In the outboard motor, the cylinder center line of the engine faces the front and rear direction of the outboard motor, the center line of the left and right direction of the engine room faces the front and rear direction of the outboard motor, and the cylinder center line of the engine extends to the left and right direction of the engine room. place by biasing on one side in the engine room with respect to the center line, since the biasing to the side provided with the spark plug on the other side, the space of the spark plug side of the cylinder head to place the ignition plug of the engine This makes it easier to maintain the spark plug.

  According to a second aspect of the present invention, in the first aspect, the engine room is composed of a lower cover and an upper engine cover, and a notch that is openable and closable with a lid at a portion of the lower cover that faces the direction in which the spark plug is removed. Since the portion is provided, in addition to the effect of the first aspect, by providing the notch portion, it is not necessary to enlarge the above-described space more than necessary, and it is possible to easily ensure the sealing performance by the notch portion. At the same time, by opening and closing the notch portion with the lid, it is possible to open and close the spark plug extraction space and further facilitate the maintenance of the spark plug.

  According to a third aspect of the present invention, in the second aspect, the lower cover is constituted by a resin cover assembly including left and right cover halves constituting the port side and starboard side, and a cutout portion is formed in one cover half. Since the lid and the lid are provided, the cutout portion and the lid that closes the cover may be provided in one cover half, and when the left and right cover halves are removed, the cutout portion and the lid are connected to the one cover half. Since it can be handled as a single unit, it is not troublesome to remove and attach the left and right resin cover halves.

  According to a fourth aspect of the present invention, in any one of the second or third aspect, the bracket is fixed to the rear half of the engine or the engine support structure, and the left and right cover halves constituting the cover assembly are mounted on the bracket. Since the body is fixed and the direction in which the spark plug is pulled out does not coincide with the position of the bracket, in addition to the effect of any one of claims 2 and 3, the left and right cover halves made of resin covers When removing and assembling from the bracket, the left and right cover halves can be easily disassembled and assembled, improving disassembly and assembling workability, and there is no interference between the bracket and the spark plug. Sometimes the resin cover and bracket are left alone.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of an outboard motor according to the present invention, a diagram showing an internal mechanism by a broken line, FIG. 2 is an external rear view of the outboard motor, and FIG. 3 is an exploded perspective view of a lower cover of the outboard motor. FIG. 3 is a perspective view including an engine support member and front and rear brackets.
The schematic configuration of the outboard motor will be described with reference to FIGS. In FIG. 1 and other drawings, Fr indicates the front of the outboard motor (forward in the propulsion direction), and Rr indicates the rear.

The exterior of the outboard motor 1 is shown in the side view of FIG. 1 and the rear view of FIG. 2. The exterior configuration of the outboard motor 1 is the uppermost engine cover 2, the lower half part below this, The lower cover 3 which consists of a heel side structural member and comprises a lower cover assembly is provided.
An engine room 4 for accommodating the engine is formed in the interior, and a lower half extension case 5 is extended below the lower cover 3, and a lowermost gear case 6 is joined to the lower case 3. Configures the external appearance.

The structure of the outboard motor will be described including the configuration indicated by the broken line in FIG.
In the engine room 4 constituted by the upper and lower covers 2, 3, an engine 50 is mounted on the upper portion via a mount case 7 (engine support structure) disposed in the lower cover 3. Is composed of a multi-cylinder four-stroke engine composed of a so-called vertical engine with the crankshaft 51a placed vertically (vertically oriented).

  The engine 50 includes a front crankcase 51, an intermediate cylinder block 52, a rearmost cylinder head 53, and the like. The exhaust led downward from the cylinder head 53 passes through the exhaust passage in the mount case 7 and the exhaust pipe 8 downstream thereof. Through the space below the lower cover 3 (cover assembly), it passes through the lower extension case 5, passes through the gear case 6, and is discharged into the water as the main exhaust from the center of the screw 14.

The cylinder block 52 has a plurality of cylinders 52a (... represents a plurality. The same applies hereinafter. In the embodiment, a four-cylinder engine in which four cylinders are arranged in parallel vertically) It has combustion chambers 53a that are opened and closed by intake and exhaust valves.
An electrical component box 9 is disposed on one side of the cylinder block 5 b of the engine 5, and an intake silencer 10 is disposed in front of this from the side of the crankcase 51 to the front. A machine (ACG) 11 is provided.

A crankshaft 51 a that passes through the crankcase 51 of the engine 50 is connected to a drive shaft 12 that has a lower end portion that passes through the crankshaft 51, and a lower end portion of the drive shaft 12 is connected to a gear mechanism 13 that is housed inside the gear case 6. To do.
The gear transmission mechanism 13 transmits the power of the drive shaft 12 to a horizontal driven shaft 13a arranged in the front-rear direction in the gear case 4, and the rear end portion of the driven shaft 13a protrudes rearward from the rear portion of the gear case 6. The propeller 14 is fixed to the rear end, and the propeller 14 is driven by the power of the engine 5 and is switched by a pair of dog clutches, thereby switching the forward and reverse rotation of the propeller to obtain forward or reverse propulsive force.

Exhaust gas discharged from the main exhaust pipe 8 is guided downward as indicated by an arrow (A) and discharged from the central portion of the screw 14. However, a part of the exhaust is outboard as indicated by an arrow (A). Drain backward. That is, an exhaust passage is provided in the mount case 6 adjacent to the main exhaust pipe 8, and the sub exhaust pipe 15 is installed at the downstream outlet thereof. The sub exhaust pipe 15 is made of a synthetic material of vinyl chloride and rubber, is bent rearward, opens rearward of the lower cover 3, and discharges a part of the exhaust to the rear of the outboard motor as indicated by an arrow (A).
On the other hand, a water inspection port 16 is opened in a part of the lower cover 3, and the water inspection port 16 allows a part of the cooling water to be exposed to the outside in order to visually check whether or not the cooling water is flowing through the engine cooling part ( It is discharged to the rear of the lower cover.

  The stern bracket 17 is attached and supported to the front portion of the above outboard motor via a swivel case 18, 18a and 18b are mount rubbers for supporting the swivel case 18, and 7e in the figure is an oil pan. .

FIG. 2 is a rear view of the outboard motor. Of the upper and lower covers constituting the engine room, the upper engine cover 2 is formed of an integral or integral resin molded body, while the lower cover 3 is formed of left and right covers. It consists of left and right cover halves, and the left and right cover halves are joined together and joined together, and the left and right cover halves are made of resin molded products. The
The components of the cover half and the lower cover are as shown in FIG. 3, and the lower cover 3 will be described.

The lower cover 3 includes left and right halves 31 and 35 that are semi-oval in a plan view.
The upper half portions 31a and 35a are long in the front-rear direction, the lower half portions 31b and 35b are short in the front-rear direction, the lower portions 31c and 35c in the front portion are dive back, and the front portions 31d and 35d in the upper half portion. Is extended forward.
On the inner side surfaces of the left and right cover halves 31 and 35, there are provided symmetrical engagement grooves 31e on the left and right sides (the engagement groove of the starboard half 35 is not visible but is provided at the same position). When the left and right halves 31 and 35 are joined together, the seal member 7g fitted so as to surround the periphery of the peripheral flange portion 7f of the engine mount case 7 is fitted, and the seal between the mount case is secured. Do.

An engine mount case 7 has a hole 7b through which a shift rod in a swivel shaft (steering shaft) passes vertically, a drive shaft vertical hole 7a, an engine mounting flange 7c, a return opening to an oil pan 7e, and a hole in a main exhaust passage. 7d and the like.
Further, the front portion 35d of the upper half of the starboard cover half 35 is formed in the shape of a crawl underneath, and the harness concealment cover 32 is covered and joined together from above, so that the starboard half 35 is formed as a whole. Configure.

Reference numeral 19 denotes a front bracket, which faces as a bracket between the front end portions of the rear portions 31d and 35d of the upper portions 31a and 35a of the left and right half bodies 31 and 35 when the left and right half bodies 31 and 35 are joined to each other.
The front bracket 19 includes an upward semicircular receiving arm 19a on the starboard side, and a converging cable holder 20 made of rubber is sandwiched between the receiving arm 19a and the downward semicircular recess 32a of the front end portion of the concealing cover 32. The cable is introduced into the engine room and held out.
Reference numeral 21 provided on the front bracket 19 is an operation arm including a lock rod and a handle for engaging with the hook 2a provided on the front portion of the upper cover.

The upper half portions of the rear surfaces 31f and 35f of the left and right cover halves 31 and 35 are symmetrically provided with vertically long engagement recesses 31g and 35g, and the upper end portions thereof are provided with mounting holes 31i and 35i symmetrically. The mounting boss portions 31h and 35h are erected.
Reference numeral 23 denotes a rear bracket, which attaches and supports the upper rear surfaces of the left and right cover halves 31 and 35 to the engine side. The piping of the auxiliary exhaust port 15 and the piping of the water inspection port 16 are connected to the rear side of the rear bracket 23 (engine Appears outside the room).

The attachment and support structure of the rear portions of the left and right cover halves 31 and 35 constituting the lower cover 3 (cover assembly) will be described.
FIG. 4 is an enlarged view of the main part of FIG. 2, and is an enlarged view showing the support portion by the left and right half brackets of the upper cover and the lower cover. The bracket 23 is plate-like vertically long and the lower part is gently U-shaped. None, as a whole, includes a main body 24 having a bowl shape.

The plate-like body 24 is exposed at the center of the rear surface of the cover 3, and support arms 24 a, 24 a are protruded in a right and left shape on the back side of the plate-like body 24, that is, inside the engine room. The cylinder head 53 is fixed to the mounting seats 53b and 53b provided so as to protrude to the left and right of the lower half of the cylinder head 53 with bolts 25 and 25, and is supported. Thus, the bracket 23 is attached and supported on the engine side, and may be attached and supported on the rear surface of the engine mount case 7 instead of the engine.
Concave grooves 31j and 35j are provided on the left and right sides of the main body 24 of the bracket 23 described above, and the engaging concave portions 31g of the left and right cover halves 31 and 35 are provided through the concave grooves 31j and 35j and the gaps at the lower ends. , 35g edge is inserted.

  Standing pieces 24b, 24b are provided on the left and right of the upper portion of the bracket 23, and nuts (not shown) are embedded in the standing pieces 24b, 24b, and are set up in the vicinity of the joint portions of the left and right cover halves 31, 35. The above-described mounting boss portions 31h and 35h are overlapped from the left and right, the bolts 26 and 26 are passed through the mounting holes 31i and 35i, and the joints at the upper portions of the left and right cover halves 31 and 35 are coupled to the bracket 23, The vicinity of the joint portion of the upper half of the cover halves 31 and 35 is joined to the bracket 23 and assembled and supported.

Then, a decorative bolt is passed through the mounting hole 24c provided in the lower end portion of the bracket body 24, and the lower portions of the engagement recesses 31g and 35g of the left and right cover halves 31 and 35 are inserted into the nut 24d (see FIG. 3) provided on the back surface side. The attachment holes 31k (see FIG. 3, which also has the other cover half 35, which is also hidden in the figure) are overlapped with each other, and these portions are joined.
Thus, the lower cover assembly is configured.

  In the above, only the main body 24 of the bracket 23 is exposed on the rear surfaces of the upper cover 2 and the lower cover 3, and the mounting portion to the engine 50, the mounting portions to the bracket of the left and right cover halves 31, 35, etc. Hide by the cover.

In FIG. 4, reference numeral 2b denotes a hook provided on the upper cover. A concave locking rod 27a of an operating arm 27 swingably provided on the bracket 23 is engaged with the hook 2b by operating the handle 27b. The closed state of the cover 2 to the lower cover 3 is locked.
As is apparent from FIG. 4, the sub exhaust port 15 is opened on the rear surface of the bracket 23, and the water inspection port 15 is also opened on the rear surface of the bracket 23. In the figure, a sub exhaust pipe 15a connected to the sub exhaust port 15 is shown by a broken line, and communicates with a sub exhaust passage 7h provided in the mount case 7, and a tube 16a is shown by a broken line at a portion of the water inspection port 16. ing.

FIG. 5 is a view of the lower cover 3 (lower cover assembly) with the engine cover 2 being the upper cover removed, with the front portion of the lower cover omitted, and FIG. 6 being a main portion of FIG. It is explanatory drawing which removed the lid in the figure of.
In the engine 50, the crankcase 51 is located in the front part in the front-rear direction in the engine room 4, the cylinder block 52 is located in the middle part, and the cylinder head 53 and the cylinder head cover are located in the rear part.
A center line L2 extending in the front-rear direction of the cylinder 52a of the cylinder block 52 is configured to be offset by a distance D toward the port side with respect to the right side in the figure and the front-rear direction with respect to the left-right direction center line L1 of the outboard motor. The

The center line L1 in the left-right direction of the outboard motor is the center of the crankshaft 51a, the center of the drive shaft 12, and the center of the engine room 4 in the left-right direction.
As a result, the engine 50 including the cylinder head 53 is biased toward the right side of the figure, that is, the port side, and the space 4a on the left side of the opposite side figure and the starboard side of the outboard motor is wider than the other 4b. .
The crankshaft 51a rotates in the direction of the arrow.

The cylinder head 53 is provided with a spark plug mounting hole 53c leading to the combustion chamber 53a facing diagonally behind the wide space 4a. The spark plug 40 is inserted into the mounting hole 53c.
The spark plug 40 has the tip electrode portion 40a facing the combustion chamber 53a, and the shaft-shaped main body 40b including the insulator of the spark plug 40 extends obliquely upward through the mounting hole 53c, and the upper end of the shaft-shaped main body 40b. The terminal protruding from the terminal is connected to a high tension cord, connected to a terminal in a cap constituting the head 41, and supplied with power.

  A head 41 protruding outward from the cylinder head 53 of the spark plug 40 is formed between the exhaust passage 53d in the cylinder head 53 and the head of the cylinder head 53, that is, the mating surface with the cylinder head cover. Facing the shape space 53e, facing the rear surface 3a on the starboard side (left side in the figure) of the lower cover 3, the arrangement direction of the head 41 on the rear joint portion (joint portion by the bracket 23) of the left and right cover halves 31, 35 is Instead, the mounting hole 53c and the axis L3 of the spark plug 40 are directed to the rear side on the starboard side with the bracket 23 removed.

In the above, the half of the cover half of the lower cover 3 that is on the extension of the axis L3 of the spark plug 40, that is, the upper half of the rear half 135 of the left half (starboard side half) 35 in FIG. A notch 42 is provided.
The notch 42 is formed in a concave shape that opens upward, and is provided so as to coincide with the axis L3 of the ignition plug 40, that is, the extraction direction of the ignition plug 40. In the embodiment, the notch 42 is configured such that the outer edge 42a of the recess is linear, the inner edge of the bottom edge 42b is gently curved, and the inner edge 2c is curved upward and inward. Yes.

The left and right upper edges of the notch 42 join with the upper edge of the rear surface of the cover half 35 and open upward as described above. The notch 42 has a lid 43 that closes the lid 43. It can be opened and closed freely.
FIG. 6 shows a state in which the lid 43 has been removed. The lid 43 has a plate-like main body 43a having a shape that matches the notch 42, a reinforcing rib 43b around the back side, and an arm 43c on the top. Have.

An attachment hole 43d is provided at the end of the arm portion 43c, while a support stay 44 is provided on the back side of the periphery of the notch portion 42 and on the outer side, and is attached to the support stay 44. A screw hole 44a is provided, and the lid 43 is fixed to the cutout portion 42 in a closed state through a bolt 45 in the mounting hole 43d of the arm 43c.
In FIGS. 4 and 5, reference numeral 53b denotes a camshaft.

In the above, the upper engine cover 2 is removed, and the exposed bolt 45 is removed, whereby the lid 43 can be removed from the notch portion 42. This state is shown in FIG.
The spark plug 40 has the axis L3 directed toward the notch 42, and the spark plug 40 can be extracted from the notch 42 as shown by an arrow (c).
At this time, since the space 4a on this side is large, it is possible to easily dispose and insert / remove the spark plug and also facilitate the disposition of the exhaust portion 53d of the cylinder head and the like.

The spark plug 40 is inserted / removed so that the upper and lower cover halves 31 and 35 are attached and supported by the bracket 23 so that the insertion / removal directions of the bracket 23 and the spark plug do not coincide with each other, thereby avoiding mutual interference. Since it comprised, when inserting / removing a spark plug, a bracket does not become obstructive.
In addition, since the upper portions of the left and right cover halves 31 and 35 are fixed by the bracket 23, it is necessary to maintain the other cover half supported by the bracket when removing one cover half. In addition, the left and right cover halves do not fall apart, and the cover can be easily removed and reassembled.

  The arrangement of the spark plug and the notch for maintenance of the spark plug and the lid for opening and closing the spark plug according to the present invention are suitable for an outboard motor.

It is the side view of the outboard motor which concerns on this invention, and is the figure which showed the internal mechanism with the broken line. It is an appearance rear view of an outboard motor. It is a disassembled perspective view of the lower cover of an outboard motor, and is a perspective view including an engine support member and front and rear brackets. It is an enlarged view of the principal part of FIG. 2, and is an enlarged view which shows the support part by the bracket of the left-right half body of an upper cover and a lower cover. It is the figure which removed the engine cover which is an upper cover, and looked at the lower cover (lower cover assembly), and is the figure which abbreviate | omitted the front part of the lower cover. It is explanatory drawing which removed the lid in the figure of the principal part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outboard motor, 2 ... Engine cover, 3 ... Lower cover, 4 ... Engine room, 31, 35 ... Left and right cover half body of lower cover, 7 ... Engine support structure, 23 ... Bracket, 40 ... Spark plug, 42 ... cutout portion, 43 ... lid 50 ... engine, 51a ... crankshaft, 52 ... cylinder block, 52a ... cylinder, L1 ... engine centerline, the centerline of the L 2 ... cylinder.

Claims (4)

An outboard motor in which the crankshaft (51a) is installed vertically, the cylinder (52a) is installed horizontally, and a vertical engine is mounted so that the cylinder axis faces the front-rear direction of the outboard motor. In
The cylinder center line (L2) of the engine faces the longitudinal direction of the outboard motor,
The center line (L1) in the left-right direction of the engine room faces the front-rear direction of the outboard motor,
The engine cylinder center line (L2) is arranged so as to be offset to one side in the engine room with respect to the center line (L1) in the left-right direction of the engine room ,
And biasing the side provided with a spark plug on the other side,
Outboard motor characterized by that. The engine room is composed of a lower cover and an engine cover that fits from above, and a notch portion that is openable and closable with a lid is provided in a portion of the lower cover that faces the direction of extraction of the spark plug. The outboard motor according to claim 1, wherein The lower cover is constituted by a resin cover assembly including left and right cover halves constituting the port side and starboard side, and the cutout portion and the lid are provided in one cover half. The outboard motor according to Item 2. A bracket is fixed to the rear half of the engine or the engine support structure, and the left and right cover halves constituting the cover assembly are fixed to the bracket so that the direction in which the spark plug is pulled out does not coincide with the position of the bracket The outboard motor according to any one of claims 2 and 3, wherein the outboard motor is configured as described above.

Images