JP3864882B2 - Small planing boat - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a personal watercraft.
[0002]
[Prior art]
When increasing and decelerating the engine speed and transmitting it to the output shaft, there is a method of connecting the crankshaft (primary output shaft) and drive shaft (final output shaft) via gears with different number of teeth (drive gear and driven gear). It is common. At this time, as shown in, for example, Japanese Patent Laid-Open No. 9-315383 (see Patent Document 1), each gear is often formed integrally with each shaft.
[0003]
Further, the positional relationship between the shafts is such that, for example, as shown in Japanese Patent Application Laid-Open Nos. 9-315383 and 9-317431 (see Patent Document 2) when the axial direction of the drive shaft is parallel to the axial direction of the crankshaft, In general, the centers of both shafts are arranged on the split surface of the crankcase from the viewpoint of workability and assembly.
[0004]
[Patent Document 1]
JP-A-9-315383 (paragraph number [0020] and FIG. 4)
[0005]
[Patent Document 2]
Japanese Patent Laid-Open No. 9-317431 (FIGS. 2 to 13)
[0006]
[Problems to be solved by the invention]
However, when the gear on the crankshaft side (drive gear) is formed integrally with the crankshaft, the drive gear must be larger than the crank web due to processing restrictions. When the rotation of the crankshaft is decelerated and transmitted to the drive shaft, the gear on the drive shaft side (driven gear) must be larger than the drive gear, which increases the size of the engine and wastes space in the crankcase. Is called. In particular, when both shafts are arranged on the split surface of the crankcase, the lateral width of the engine becomes long.
[0007]
Although it is technically possible to make the drive gear smaller than the crank web, it is necessary to make the clearance of the machining cutter large on both sides of the drive gear, and as a result, the entire length of the crankshaft is extended or the gear part is swung. Problems such as enlargement occur.
[0008]
As a method of reducing the width of the engine, there is a method of arranging the center of the drive shaft below, for example, the split surface of the crankcase. In this case, the bearing that supports the drive shaft needs to be held by a separate holder. However, since the thrust force is applied to the drive shaft in the axial direction, the holder has a holding portion for holding the bearing and a holder for holding the holder. This is not preferable because the thickness of the holder increases and the holder becomes larger.
[0009]
Furthermore, if the gear is integrally formed on the shaft, the gear ratio cannot be changed unless the entire shaft is replaced.
[0010]
The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a small planing boat with a compact engine structure.
[0011]
Another object of the present invention is to provide a personal watercraft that effectively uses the space in the crankcase.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problems, a personal watercraft according to the present invention uses a dry sump type lubrication system as described in claim 1 and includes an engine in which cylinders are arranged in parallel along a traveling direction axis of a hull. The oil pump is driven using the output of the crankshaft disposed in the crankcase of the engine, and a drive gear is detachably provided at the end of the crankshaft, and is formed in the crankcase. The drive gear is arranged in a space formed by an opening and a case cover that closes the opening, and the rotation of the crankshaft is decelerated via the drive gear and transmitted to the oil pump. The above oil pump is used to collect the lubricating oil collected in the crankcase and send it to the oil tank. In a small planing boat composed of an oil pump and a sending oil pump that pumps lubricating oil in the oil tank to various parts of the engine, the oil tank is connected to the crankshaft on the opposite side of the starter clutch provided near one end of the crankshaft, etc. It is arranged near the end, and is provided so as to protrude from the other end of the crankshaft in the axial direction of the hull, and the engine is arranged shifted to one side in the width direction of the hull with respect to the axial direction of the hull. The recovery oil pump and the delivery oil pump are disposed below the intake device on the other side in the width direction of the hull, and transmit rotation from the drive gear below the split surface of the crankcase of the engine. Further, the recovery oil pump is disposed on the oil tank side and the delivery oil pump is disposed on the drive gear side. Arranged so that, respectively located, the pump drive shaft for driving by connecting the oil pump, the shaft is rotationally driven by the drive gear of the crankshaft is obtained provided separately.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 1 is a left side view showing an example of a personal watercraft equipped with an engine to which the present invention is applied. FIG. 2 is a plan view of the personal watercraft shown in FIG.
[0016]
As shown in FIGS. 1 and 2, the personal watercraft 1 includes a handlebar 2 at an upper center portion of a hull, and a straddle-type seat 3 is provided behind the handlebar 2. An engine room 4 is formed in the hull, and an engine 5, a heat exchanger 6, a silencer 7, a fuel tank 8, and the like are accommodated.
[0017]
From the rear part of the engine 5, an impeller shaft 9 extends rearward in parallel with the traveling direction axis 10 of the hull, and is inserted into a jet pump 11 provided at the bottom of the ship, and an impeller (not shown) is provided at the rear end. A jet nozzle 12 is provided at the rear of the jet pump 11 and protrudes to the rearmost part of the hull.
[0018]
When the engine 5 is operated and the impeller shaft 9 rotates, the water on the bottom of the ship is sucked into the jet pump 11 from the bottom of the ship by the action of the impeller and jetted rearward from the jet nozzle 12. And the personal watercraft 1 moves forward by the reaction of this injection. Further, the jet nozzle 12 is rotated to the left and right by the operation of the handle bar 2 so that the traveling direction of the personal watercraft 1 can be arbitrarily changed.
[0019]
FIG. 3 is a view taken in the direction of arrow III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is an enlarged view of the rear lower part of the engine 5, and FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. As shown in FIGS. 3 to 6, the engine 5 is an in-line four-cylinder engine, and a cylinder (not shown) is arranged on the upper surface of a crankcase 13 that can be divided into upper and lower parts along the axis 10 in the traveling direction of the hull. Block 14 is placed.
[0020]
An intake device 15 is disposed on the left side of the cylinder block 14 in the advancing direction of the hull, and an exhaust device 16 is disposed on the right side of the cylinder block 14. The silencer 7 is connected to the exhaust device 16.
[0021]
A crankshaft 17 serving as a primary output shaft is disposed in the crankcase 13. The crankshaft 17 is disposed on a split surface 18 of the crankcase 13 that is divided into upper and lower parts, and extends in parallel with the traveling direction axis 10 of the hull.
[0022]
In the crankcase 13, a drive shaft 19 that is a final output shaft is disposed at a position away from the split surface 18 of the crankcase 13, for example, downward and in parallel with the crankshaft 17. The impeller shaft 9 is connected to the output end of the drive shaft 19, in this embodiment, the rear end.
[0023]
For example, a drive gear 20 provided separately from the crankshaft 17 is detachably provided at the rear end of the crankshaft 17. Further, a driven gear 21 provided separately from the drive shaft 19 is detachably provided at a substantially intermediate portion of the drive shaft 19. Then, when the drive gear 20 and the driven gear 21 are operatively connected, the rotational force of the crankshaft 17 is transmitted to the driven gear 21 and the drive shaft 19 is rotationally driven. In the present embodiment, the driven gear 21 has a larger diameter and a larger number of teeth than the drive gear 20, and the rotational speed of the crankshaft 17 is decelerated via these gears 20, 21 and transmitted to the drive shaft 19. Is done.
[0024]
A drive shaft 19 disposed below the split surface 18 of the crankcase 13 is held by a bearing 22. The bearing 22 is press-fitted from the outside into a bearing mounting hole 23 provided at, for example, the lower portion of the crankcase 13, further pressed by a holder 24 from the outside, and fixed to the crankcase 13 by, for example, a bolt 25, thereby being predetermined. Held in the position. An oil seal 26 is press-fitted into the holder 24 in advance. The outer diameter of the holder 24 is an inlay relative to the bearing mounting hole 23 of the crankcase 13.
[0025]
By holding the drive shaft 19 with the bearing 22, a difference is generated between the end of the crankshaft 17 and the end of the driveshaft 19, and a space is generated in the crankcase 13. Therefore, for example, a starter clutch 27 is disposed in this space and is attached to the rear end portion of the crankshaft 17.
[0026]
The rear portion of the crankcase 13 is opened so that the starter clutch 27 can be attached from the outside of the crankcase 13, and the opening 28 is closed by a case cover 29. As clearly shown in FIG. 6, the drive gear 30 and the driven gear 21 are disposed in a space formed by the opening 13 formed in the crankcase 13 and the case cover 29 that closes the opening 13. The case cover 29 and the holder 24 of the bearing 22 are integrally formed.
[0027]
By the way, since this engine 5 employs a dry sump type lubrication system, an oil tank 30 is provided outside the engine 5, and the recovery oil that collects in the crankcase 13 and collects the lubricating oil that collects in the lower part of the oil is supplied to the oil tank 30. A pumping oil pump 32 that pumps the lubricating oil in the pump 31 and the oil tank 30 to each part of the engine 5 is provided as an engine accessory.
[0028]
These oil pumps are of a two-axis interlocking type, and one of the shafts 33 and 34 for driving both oil pumps 31 and 32 is opposite to the output end of the drive shaft 19, that is, the front end. Connected to The other shaft 34 is connected to a water pump 35 for circulating cooling water, which is an engine accessory. That is, when the drive shaft 19 rotates, both the oil pumps 31 and 32 are driven, and the water pump 35 is also driven simultaneously.
[0029]
Next, the operation of this embodiment will be described.
[0030]
The drive gear 20 is provided separately from the crankshaft 17, and the drive gear 20 is detachably provided on the crankshaft 17, so that there is no restriction on gear processing and the drive gear 20 having a smaller diameter than the crank web 17 a is provided. be able to. If the drive gear 20 has a small diameter, the driven gear 21 that meshes with the drive gear 20 can also have a smaller diameter than the conventional one, and the width of the engine 5 can be reduced. Further, if the drive shaft 19 is disposed not on the split surface 18 of the crankcase 13 but below the split surface 18, the drive shaft 19 can be disposed closer to the crankshaft 17, and the engine 5 can be further downsized. it can.
[0031]
Furthermore, the drive gear 20 is provided separately from the crankshaft 17, and the drive gear 20 is detachably provided on the crankshaft 17, so that the gear ratio can be easily changed and versatility is improved. Furthermore, if the driven gear 21 is also detachably provided on the drive shaft 19, the combination of gear ratios increases and versatility further increases.
[0032]
On the other hand, the bearing 22 for holding the drive shaft 19 is press-fitted from the outside into a bearing mounting hole 23 provided in the crankcase 13 and further pressed by a holder 24 in which an oil seal 26 is press-fitted in advance from the outside. Thus, one of the axial thrust forces applied to the drive shaft 19 is received by the crankcase 13 and the other is received by the holder 24. As a result, the thickness of the entire holder 24 can be made thinner than that of the conventional one, and the holder 24 is reduced in size and weight as the thickness is reduced.
[0033]
Further, the center position of the oil seal 26 can be easily aligned by setting the outer diameter of the holder 24 to be inward relative to the bearing mounting hole 23 of the crankcase 13.
[0034]
Furthermore, if the case cover 29 that closes the opening 28 of the crankcase 13 and the holder 24 of the bearing 22 are integrally formed, the number of parts can be reduced, and the number of fastening points, that is, the number of assembly steps can be reduced.
[0035]
If the starter clutch 27 is disposed in the space in the crankcase 13 generated by holding the drive shaft 19 by the bearing 22, the space in the crankcase 13 is effectively used.
[0036]
Further, by connecting engine auxiliary devices such as the oil pumps 31 and 32 and the water pump 35 to the opposite side of the output end of the drive shaft 19 and driving them, the engine auxiliary drive system and the like are simplified. In addition, the number of parts is reduced and the engine 5 can be downsized.
[0037]
【The invention's effect】
As described above, according to the small planing boat according to the present invention, a small-diameter gear can be provided, the engine can be downsized, the gear ratio can be easily changed, and the space in the crankcase is also increased. It can be used effectively. Further, the holder can be reduced in size and weight.
[0038]
Furthermore, the number of parts and the number of assembly processes can be reduced. Furthermore, the engine can be reduced in size and weight.
[Brief description of the drawings]
FIG. 1 is a left side view showing an embodiment of a personal watercraft according to the present invention.
FIG. 2 is a plan view of the personal watercraft shown in FIG.
FIG. 3 is a view taken in the direction of arrow III in FIG.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is an enlarged view of the rear lower part of the engine.
6 is a sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
1 Small personal watercraft 5 Engine 13 Crankcase 17 Crankshaft (primary output shaft)
19 Drive shaft (axis driven by drive gear, final output shaft)
20 Drive gear 28 Crankcase opening 29 Case cover 31 Oil pump for recovery 32 Oil pump for delivery (engine auxiliary equipment)
33, 34 Oil pump drive shaft

Claims (1)

A dry sump type lubrication system is used, and an engine in which cylinders are juxtaposed along the axis of the hull's traveling direction is mounted, and an oil pump is driven using the output of a crankshaft arranged in the crankcase of the engine, A drive gear is detachably provided at the end of the crankshaft, and the drive gear is disposed in a space formed by an opening formed in the crankcase and a case cover that closes the opening. A recovery oil pump configured to decelerate the rotation of the shaft via the drive gear and transmit it to the oil pump, and to collect the lubricating oil accumulated in the crankcase and send it to the oil tank; Sending oil that pumps lubricating oil in the oil tank to various parts of the engine In personal watercraft consist amplifier,
The oil tank is disposed in the vicinity of the other end of the crankshaft opposite to the starter clutch provided in the vicinity of one end of the crankshaft, and is provided so as to protrude from the other end of the crankshaft in the axial direction of the hull.
The engine is arranged so as to be shifted to one side in the width direction of the hull with respect to the advancing direction axis of the hull, and the recovery oil pump and the delivery oil pump are arranged below the intake device on the other side in the width direction of the hull. And provided to transmit rotation from the drive gear below the split surface of the crankcase of the engine,
Further, the recovery oil pump is disposed on the oil tank side and the delivery oil pump is positioned on the drive gear side, and a pump drive shaft for connecting and driving these oil pumps is provided on the crankshaft. A personal watercraft characterized in that it is provided separately from a shaft that is rotationally driven by a drive gear.

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