JP2005201224A - Cooling structure for outboard motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve pumping efficiency of a cooling water pump by suppressing suction of air during water suction process of the cooling water pump. <P>SOLUTION: A drive shaft housing 6 and a gear case 7 are provided below an engine cover 2 in an order. A partition plate 30 is fixed at a vertical direction roughly center position of a blade part of the gear case 7 and a water pump 32 driven by a drive shaft 11 is fixed on the partition plate 30. Namely, the water pump 23 is arranged at a water reservoir part 32 where water intrudes from an outside in the gear case 7. Almost whole body of the water pump 23 positions in the water reservoir part 32 filled with water and below water surface level since the water surface position 25 is roughly at a cavitation plate 26 of the gear case 7 during sailing. Consequently, air is rarely sucked during pumping process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an outboard motor cooling structure provided with a cooling water pump for supplying water taken from outside to various parts of an engine.

  2. Description of the Related Art Conventionally, in an outboard motor, a cooling water pump is provided and each part of the engine is cooled with water taken from the outside. For example, as exemplified in Patent Documents 1 and 2 below, in an outboard motor cooling structure equipped with a vertically mounted engine, a gear case is disposed below the drive shaft housing, and a cooling water pump is fixed to the upper end of the gear case. Is done. That is, because the cross-sectional shape of the wing part, which is the body part of the gear case, is a thin streamlined type for reducing resistance, and it is necessary to provide a gear oil reservoir in the gear case, the space in the gear case is It is narrow and it is difficult to accommodate the cooling water pump in the gear case. Therefore, normally, the cooling water pump is entirely disposed in the drive shaft housing.

Moreover, a water inlet is provided in the side part etc. of a gear case, and a cooling water pump takes in cooling water from this water inlet by negative pressure.
JP 2003-106150 A JP 2001-97281 A

  However, in the conventional cooling structures for outboard motors such as Patent Documents 1 and 2, the cooling water pump is located above the mating surface between the gear case and the drive shaft housing. On the other hand, during cruising, the position of the cavitation plate of the gear case is almost the water surface position. Therefore, during cruising, the entire cooling water pump is always located above the cavitation plate, that is, above the water surface, so that the sealing mechanism such as the mating surface between the cooling water pump case and the gear case is ensured. Otherwise, there was a problem that the cooling water pump sucked air during the water absorption process, resulting in a shortage of pumping capacity, which could reduce pumping capacity.

  The present invention has been made to solve the above-described problems of the prior art, and the object thereof is to suppress the intake of air in the water absorption process of the cooling water pump and to improve the pumping efficiency of the cooling water pump. It is to provide a cooling structure for an outboard motor.

  In order to achieve the above object, an outboard motor cooling structure according to claim 1 of the present invention is arranged in an engine mounted vertically, a drive shaft extending in the vertical direction, and disposed below the engine. A drive shaft housing; a gear case disposed below the drive shaft housing; and a cooling water pump driven by the drive shaft, wherein the cooling water pump is housed in the gear case. To do.

  In order to achieve the above object, an outboard motor cooling structure according to claim 6 of the present invention includes an engine mounted vertically, a drive shaft extending vertically, and cooling driven by the drive shaft. A cooling structure for an outboard motor having a water pump, characterized in that a water pool portion is provided in which external water enters and accumulates during sailing, and the cooling water pump is accommodated in the water pool portion.

  ADVANTAGE OF THE INVENTION According to this invention, the suction of the air in the water absorption process of a cooling water pump can be suppressed, and the pumping efficiency of a cooling water pump can be improved.

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

(First embodiment)
FIG. 1 is a left side view of an outboard motor to which an outboard motor cooling structure according to a first embodiment of the present invention is applied.

  As shown in the figure, the outboard motor 1 has a box-shaped engine cover 2 at the uppermost portion thereof, and the engine 3 is accommodated therein. In the engine 3, the crankshaft 10 is provided vertically (vertical) so as to face substantially the vertical direction. Hereinafter, with respect to the outboard motor 1, the left side (the hull side) of the figure is referred to as "front", the right side as "rear", and the upper side as "upward".

  The engine 3 is, for example, a four-cycle single-cylinder engine, and is divided into a vertically-divided crankcase 15 disposed at a front portion in the engine cover 2 and an upper portion of the crankcase 15 disposed behind the crankcase 15. The cylinder block 16 is formed, and the cylinder head 17 is arranged behind the cylinder block 16.

  A drive shaft housing 6 is provided below the engine cover 2, and a gear case 7 is provided below the drive shaft housing 6. The engine 3 is fixed on an engine holder 18 provided at the upper end portion of the drive shaft housing 6.

  A propeller shaft 8 is pivotally supported inside the gear case 7 and a propeller 9 is provided at the rear end thereof. A drive shaft 11 connected to the lower end of the crankshaft 10 extends downward in the drive shaft housing 6, and the lower end of the drive shaft 11 is connected to the propeller shaft 8 via a bevel gear 12 in the gear case 7. The output of the engine 3, that is, the rotation of the crankshaft 10, is transmitted to the propeller shaft 8 via the drive shaft 11 and the bevel gear 12, and the propeller 9 rotates.

  A steering handle 4 extends forward from a lower front portion of the engine 3, and a throttle grip 5 for adjusting engine output is provided at the tip thereof. A rotation support portion 19 is rotatably supported on the upper portion of the drive shaft housing 6, and the clamp bracket 13 is supported to be rotatable with respect to the rotation support portion 19 through a tilt shaft 20 in the vertical direction. . By fixing the clamp bracket 13 to the transom 14 of the hull (not shown), the outboard motor 1 can be rotated in the horizontal direction (steering direction) and the vertical direction (tilt direction). By swinging the steering handle 4 in the horizontal direction, the direction of the entire outboard motor 1 can be changed to steer the hull.

  By the way, the engine 3 employs a water-cooled engine cooling system, and external water (seawater, lake water, river water, etc.) is taken into the gear case 7 as cooling water, and this cooling water is supplied to each part of the engine 3. A water pump 23 that pumps for cooling is installed (details will be described later).

  FIG. 2 is a longitudinal sectional view of the lower part of the outboard motor 1.

  The water pump 23 is disposed in the gear case 7. That is, in the gear case 7, the partition plate 30 is fixed at a substantially intermediate position in the vertical direction of the wing portion of the gear case 7, and the water pump 23 is fixed on the partition plate 30. A plate-like lid member 29 is provided at the position of the mating surface of the gear case 7 with respect to the drive shaft housing 6.

  In the space between the lid member 29 and the partition plate 30 in the gear case 7, outside water infiltrates from a water-absorbing opening 7 b (described later) during cruising. The space below the partition plate 30 in the gear case 7 is filled with oil for lubricating the gears, so that this is an oil reservoir 33. The partition plate 30 and the drive shaft 11 are sealed with an oil seal 36. Accordingly, the water reservoir 32 and the oil reservoir 33 are partitioned by the partition plate 30. The water pump 23 is entirely housed in the water reservoir 32 and is located below the cavitation plate 26 of the gear case 7.

  The lid member 29 partitions the space 31 in the drive shaft housing 6 and the water reservoir 32 so that the exhaust gas does not enter the water pump 23 side. The exhaust gas is discharged to the outside through the exhaust port 27 from the space 31.

  The drive shaft 11 passes through the water pump 23. The water pump 23 is driven by the drive shaft 11, and cooling water is pumped toward the engine 3 through a water tube 28 connected to the water pump 23.

  3A is a left side view of the pump case 24 of the water pump 23, FIG. 3B is a rear view of the pump case 24, and FIG. 3C is a bottom view of the pump case 24. FIG. 4 is a plan view of the pump case 24. The left side of FIG. 4 is the front.

  As shown in FIGS. 3C and 4, the pump case 24 is formed with insertion holes 24 a and 24 b through which the drive shaft 11 and the water tube 28 are inserted, respectively. Fastening holes 24 c and 24 d for being screwed to the partition plate 30 are also provided before and after the pump case 24. Further, as shown in FIG. 3A, the pump case 24 is integrally formed with a water absorbing portion 34 extending leftward, and the tip end surface 34a of the water absorbing portion 34 is composed of a plurality of small holes. The filter part 35 is integrally formed.

  As shown in FIG. 4, the opening 7 b described above is formed in the left side 7 a of the gear case 7. When the pump case 24 is fixed to the partition plate 30, the water absorbing portion 34 of the pump case 24 is engaged with the opening 7 b, and the front end surface 34 a of the water absorbing portion 34 is substantially flush with the left side surface 7 aa of the gear case 7. It has become. A gap is formed between the water absorbing portion 34 and the opening 7 b, and external water can enter the water pool portion 32 from this gap.

  Further, in the conventional outboard motor in which the water pump is accommodated in the drive shaft housing, the height of the water pump is generally suppressed due to space limitations. Since the pump 23 is accommodated in the gear case 7, the degree of freedom in the shape of the water pump 23 is increased. Therefore, the pump case 24 has a vertically long shape, and a sufficient pump capacity is ensured.

  In such a configuration, when the outboard motor 1 is tilted down and the hull is anchored, the gear case 7 is completely submerged and the water reservoir 32 is filled with water. On the other hand, while sailing, the water surface position 25 falls to the vicinity of the cavitation plate 26 of the gear case 7 (see FIG. 2), but the water reservoir 32 is still almost filled with water. Therefore, the water pump 23 is almost entirely located in the water during traveling.

  When a negative pressure is generated in the water pump 23 by the rotation of the drive shaft 11, the water is absorbed from the filter portion 35 of the water absorption portion 34. Although the sealing mechanism of the water pump 23 is not particularly provided, since the water pump 23 is in water, the water pump 23 hardly absorbs air during water absorption. Thereafter, the cooling water is sent from the water pump 23 to each part of the engine 3 through the water tube 28, and after cooling is performed, it is discharged outside through a predetermined path.

  According to the present embodiment, since the water pump 23 is almost entirely located in the water reservoir 32 filled with water during traveling, that is, almost under the water surface, the seal of the pump case 24 is sealed. Even if the mechanism is not strong or does not have a sealing mechanism, air is hardly sucked in the water absorption process. Therefore, the suction of air in the water absorption process of the water pump 23 can be suppressed, and the pumping efficiency of the water pump 23 can be improved.

  Further, since the water absorbing portion 34 is located in the opening 7b of the gear case 7, it is not necessary to provide a water jacket for guiding external water to the water pump 23. This contributes to weight reduction of the machine 1. In addition, since the opening 7b of the gear case 7 serves as a cooling water intake for the water pump 23, it is possible to avoid an increase in the size of the gear case 7 when the water pump 23 is accommodated in the gear case 7. In addition, since the filter portion 35 is integrally formed with the pump case 24, not only the configuration is simple and the assembly is easy, but also, for example, when water is absorbed from a water inlet provided in the gear case 7 via a water jacket. In comparison, there is less loss from water absorption to discharge.

  Furthermore, since the opening 7b of the gear case 7 is provided in the side part (left side part 7a) of the gear case 7, cooling water can be taken in efficiently using the dynamic pressure at the time of sailing, and water absorption efficiency is improved. be able to. The opening 7b may be provided on either the left or right side or on both sides. However, when the opening 7b is provided only on one side, the water on the surface of the side that is being crushed is provided for the opposite side. There is also an advantage that the flow is smooth and the fluid resistance is reduced.

  Moreover, since the pump case 24 of the water pump 23 is formed in a vertically long shape, when the water pump 23 is accommodated in the gear case 7, it is possible to avoid an increase in the size of the gear case 7 and to ensure an appropriate pump capacity. Can do.

  Further, as an incidental effect of providing the partition plate 30 in the gear case 7, the volume of the oil reservoir 33 in the gear case 7 can be reduced, which contributes to oil reduction.

  By the way, in this Embodiment, although the comparatively small outboard motor 1 was illustrated as an outboard motor to which the cooling structure of this invention is applied, it is applicable similarly to medium and large outboard motors. . In particular, in middle and large outboard motors, the water pump is conventionally located in the drive shaft housing, so that the lower mount provided on the drive shaft housing is located within the drive shaft housing to avoid interference with the water pump. Cannot be placed at the lowest position. For this reason, the distance between the upper mount and the lower mount has been reduced, and there is room for improvement from the viewpoint of vibration control and maneuverability of the outboard motor. However, as in the present embodiment, even in a medium-sized and large-sized outboard motor, if the water pump is accommodated in the gear case 7, the position of the lower mount can be lowered. It becomes possible to improve performance and maneuverability.

  For medium and large outboard motors, when the water pump is placed in the drive shaft housing, the shape of the pump case is reduced to avoid interference with the lower mount. There are many cases. However, as described above, the water pump 23 is accommodated in the gear case 7 so that the pump case 24 can be formed in a vertically long shape. As a result, it becomes easy to increase the pump capacity and ensure sufficient pumping capacity. This is particularly useful for medium and large outboard motors.

(Second Embodiment)
FIG. 5 is a longitudinal sectional view of the lower part of the outboard motor to which the outboard motor cooling structure according to the second embodiment of the present invention is applied.

  The outboard motor is different from the outboard motor 1 in the first embodiment in the configuration of the gear case and the configuration of the water pump, but the other configurations are the same as those in the first embodiment. In this outboard motor, the gear case 77 has a plurality of water-absorbing holes 80 formed in the vicinity of the tip portion and in the side portion instead of the opening portion 7b of the gear case 7 in the first embodiment. Unlike the above, the other configuration is the same as that of the gear case 7. It is sufficient to provide the water absorption holes 80 only on one side, but they may be provided on both sides. Further, the water pump 73 is different from the water pump 23 in the first embodiment in that a water absorption portion (not shown) does not extend to the side of the gear case (for example, provided on the outer peripheral surface of the pump case). Other configurations are the same as those of the water pump 23.

  The water that enters from the water absorption hole 80 always accumulates in the water reservoir 72 corresponding to the water reservoir 32 in the first embodiment, and the water pump 73 is accommodated in the water reservoir 72. The position of the water pump 73 in the height direction is the same as that of the water pump 23. Since the water absorption hole 80 is disposed in the vicinity of the front end of the gear case 77, the water reservoir 72 can be crushed without adopting a configuration in which a water absorption unit (not shown) of the water pump 23 faces the side surface of the gear case 77. Cooling water accumulates efficiently by the dynamic pressure at the time.

  In such a configuration, during cruising, almost the entire water pump 73 is located in the water reservoir 72 filled with water and is below the water surface. The water pump 73 takes in the cooling water filled in the water reservoir 72 from a filter unit (not shown). Since the water pump 73 is submerged in water, air is hardly sucked in the water absorption process.

  According to the present embodiment, the cooling water can be taken in more efficiently by using the dynamic pressure at the time of sailing, and the same effect as in the first embodiment can be achieved. Moreover, since it is not necessary to extend a water absorption part long, the water pump 73 can be made more compact.

(Third embodiment)
The configuration in which the water pump is disposed in the gear case is not limited to the outboard motor provided with the internal combustion engine as exemplified in the first and second embodiments. For example, the present invention can be applied to an electric outboard motor using an electric motor as power.

  FIG. 6 is a longitudinal sectional view of an electric outboard motor to which the outboard motor cooling structure according to the third embodiment of the present invention is applied.

  As shown in the figure, the electric outboard motor 100 is configured by arranging a control unit 103, an electric motor 101, and a battery 104 in this order from the front in an outboard motor cover 102. A display panel 105 is provided at the front of the outboard motor cover 102. A drive shaft housing 106 is provided below the outboard motor cover 102, and a gear case 110 is provided below the drive shaft housing 106.

  A propeller shaft 116 is pivotally supported inside the gear case 110, and a propeller 117 is provided at the rear end thereof. A drive shaft 107 connected to the output shaft 118 of the electric motor 101 extends downward in the drive shaft housing 106, and a lower end of the drive shaft 107 is connected to the propeller shaft 116 via a bevel gear 115 in the gear case 110. The The rotation of the electric motor 101 is transmitted to the propeller shaft 116 via the drive shaft 107 and the bevel gear 115, and the propeller 117 rotates.

  Further, the swivel bracket 111 is supported so as to be rotatable in the horizontal direction with respect to the upper portion of the drive shaft housing 106, and the clamp bracket 112 can be rotated in the vertical direction with respect to the swivel bracket 111 via the tilt shaft 119. Supported. By fixing the clamp bracket 112 to the transom of the hull (not shown), the electric outboard motor 100 can be rotated in the horizontal direction (steering direction) and the vertical direction (tilt direction).

  A steering handle 120 fixed to the electric motor 101 and the drive shaft housing 106 extends forward from an upper front portion of the electric outboard motor 100. By swinging the steering handle 120 in the horizontal direction, the direction of the entire electric outboard motor 100 can be changed to steer the hull. The steering handle 120 is provided with a forward / reverse switching switch 114 and a speed adjusting grip 113.

  The water pump 109 is housed in the gear case 110 and is located below the cavitation plate 121 of the gear case 110. The electric outboard motor 100 powered by electric power does not require an exhaust passage or a shift mechanism, so that the water pump 109 can be easily arranged in the gear case 110, and thus is particularly suitable for adopting such a configuration. It is.

  The configuration of the water pump 109 is the same as that of the water pump 23 in the first embodiment, and an opening similar to the water absorbing opening 7b is provided on the side of the gear case 110 (not shown). In addition, about the water inlet provided in the filter part of the water pump 109 and the side part of the gear case 110, you may employ | adopt the structure shown in 2nd Embodiment.

  In the outboard motor cover 102, a water jacket (not shown) is formed in the vicinity of the heat generating components such as the electric motor 101 and the battery 104.

  In such a configuration, the water pump 109 takes in the cooling water from the outside and pumps it upward through the water tube 108 as in the first embodiment. The sent cooling water fills the water jacket (not shown), cools the electric motor 101, the battery 104, and the like, and then is discharged to the outside through a predetermined path.

  According to the present embodiment, in the electric outboard motor, the first and second embodiments relate to improving the pumping efficiency of the water pump 109 by suppressing the suction of air in the water absorption process of the water pump 109. The same effect can be achieved.

  In the first to third embodiments, as the water pump 23, for example, a negative pressure is generated by eccentrically rotating a rubber impeller that slides against the inner peripheral surface of the pump case. If you pay attention to the fact that it is always submerged in the water while sailing, it is possible to adopt a pump that does not slide with the pump case, such as an axial pump Is possible. Employing an axial flow pump is advantageous in that mechanical loss can be reduced and no impeller replacement is required.

1 is a left side view of an outboard motor to which a cooling structure for an outboard motor according to a first embodiment of the present invention is applied. It is a longitudinal cross-sectional view of the lower part of an outboard motor. They are a left side view (figure (a)) of a pump case of a water pump, a rear view (figure (b)) of a pump case, and a bottom view (figure (c)) of a pump case. It is a top view of a pump case. It is a longitudinal cross-sectional view of the lower part of the outboard motor to which the cooling structure of the outboard motor which concerns on the 2nd Embodiment of this invention is applied. It is a longitudinal cross-sectional view of the electric outboard motor to which the cooling structure of the outboard motor which concerns on the 3rd Embodiment of this invention is applied.

Explanation of symbols

3 Engine 6 Drive shaft housing 7, 77 Gear case 7a Left side 7b Opening 11 Drive shaft 23, 73 Water pump (cooling water pump)
24 Pump case 26 Cavitation plate 32, 72 Water reservoir 35 Filter part (Water absorption filter part)

Claims (6)

An engine (3) mounted vertically,
A drive shaft (11) extending vertically,
A drive shaft housing (6) disposed below the engine;
A gear case (7, 77) disposed below the drive shaft housing;
A cooling water pump (23, 73) driven by the drive shaft,
The outboard motor cooling structure, wherein the cooling water pump is housed in the gear case.   The outboard motor cooling structure according to claim 1, wherein the cooling water pump is disposed below the cavitation plate (26) of the gear case.   The gear case is provided with an opening (7b) for water absorption, and a water absorption filter portion (35) is formed integrally with the pump case (24) of the cooling water pump, and the water absorption filter portion is connected to the gear case. The cooling of the outboard motor according to claim 1, wherein cooling water is taken into the cooling water pump from the water absorption filter portion. Construction.   The outboard motor cooling structure according to claim 3, wherein the opening is formed in a side portion (7a) of the gear case.   The outboard motor cooling structure according to any one of claims 1 to 4, wherein the pump case (24) of the cooling water pump is formed in a vertically long shape. An engine (3) mounted vertically,
A drive shaft (11) extending vertically,
A cooling structure for an outboard motor having a cooling water pump (23, 73) driven by the drive shaft,
A cooling structure for an outboard motor, characterized in that a water pool portion (32, 72) for storing external water invading during navigation is provided, and the cooling water pump is accommodated in the water pool portion.

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