Outboard engine

Abstract

To improve capture efficiency for micro dust while evading complication in structure of a micro dust capture device or enlargement, etc., of an outboard engine.SOLUTION: An outboard engine 1 includes micro dust capture device 21, the micro dust capture device 21 has a water inlet 26 for taking in water in the periphery of the outboard engine 1, a passage 27 where the water taken in from the water intake 26 is circulated, a filter for capturing the micro dust contained in the water circulating in the passage 27, and an outlet 29 for draining the water after passing the filter to the periphery of the outboard engine 1, the outlet 29 is positioned in front of the propeller 5, and at the same time is positioned inside a circle C having identical diameter as the diameter of the propeller 5 with center of rotation A of the propeller 5 as the center when seeing the outboard engine 1 from behind, and at the same time the outlet 29 faces behind the outboard engine 1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an outboard motor for propelling a boat. [Background technology]

[0002] In recent years, pollution by fine dust particles such as microplastics has become a problem in seas, lakes, rivers, etc., and there is a demand for collecting such fine dust particles from seas, lakes, rivers, etc., and purifying the seas, lakes, rivers, etc.

[0003] JP 2021-169240 A (Patent Document 1) describes an outboard motor that is capable of collecting fine dust contained in water such as the sea, lakes, and rivers. The outboard motor described in the above publication is provided with a fine dust capture device that captures fine dust. The fine dust capture device has a water intake, a capture device, and an outlet. When a ship is sailing, water from the sea, lake, river, etc. flows into the capture device from the water intake, passes through a filter provided in the capture device, and is then discharged from the outlet into the sea, lake, river, etc. When the water passes through the filter, fine dust contained in the water is captured by the filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-169240 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to promote the purification of oceans, lakes, rivers, etc., it is desirable to increase the amount of fine dust captured per unit sailing time of a ship or the amount of fine dust captured per unit sailing distance, and to improve the fine dust capture efficiency.

[0006] In the conventional fine dust capture device provided in an outboard motor described in JP 2021-169240 A, the water intake is disposed in a portion of the front of the outboard motor that is located below the water surface, and the discharge port is disposed in a portion of the outboard motor that is located above the water surface. Then, by utilizing the pressure of water flowing into the water intake when the ship moves forward, a flow of water is created from the time it flows into the capture device through the water intake to the time it is discharged through the discharge port.

[0007] In this configuration, the flow of water from when it flows into the trap through the intake port until it is discharged through the discharge port is generated only by the pressure of the water flowing into the intake port when the ship is moving forward, so it is difficult to increase the flow rate of water circulating in the trap, and therefore difficult to increase the flow rate of water passing through the filter. As a result, it is difficult to increase the amount of fine dust captured per unit sailing time or the amount of fine dust captured per unit sailing distance, and difficult to improve the efficiency of capturing fine dust.

[0008] In this regard, it is conceivable to add a pump to the fine dust capture device and use the pump to draw in water from the water intake to increase the flow rate of water circulating through the capture device, but adding a pump is not preferable because it complicates the structure of the fine dust capture device, increases the size of the outboard motor, and increases the manufacturing costs of the outboard motor.

[0009] The present invention has been made in consideration of problems such as those described above, and an object of the present invention is to provide an outboard motor that can improve the efficiency of capturing fine dust while avoiding complicating the structure of the fine dust capture device, increasing the size of the outboard motor, or increasing the manufacturing costs of the outboard motor. [Means for solving the problem]

[0010] In order to solve the above problem, the present invention provides an outboard motor for propelling a marine vessel, comprising: a propeller unit having a propeller shaft, a propeller fixed to the propeller shaft, and a case rotatably supporting the propeller shaft; a support part formed in a columnar shape extending in the vertical direction and having the propeller unit supported at its lower part; a bracket provided on the upper part of the support part for attaching the support part to the marine vessel; and a fine dust capture device provided on the propeller unit or the support part, wherein the fine dust capture device has a water intake port that takes in water around the outboard motor, a passage through which the water taken in from the water intake port flows, a filter that captures fine dust contained in the water by passing the water flowing through the passage, and an outlet port that discharges water after passing through the filter to the surroundings of the outboard motor, and the outlet port is located in front of the propeller and inside a circle having the same diameter as the diameter of the propeller, centered on the center of rotation of the propeller, when the outboard motor is viewed from the rear, and faces in a direction other than the front of the outboard motor. Effect of the Invention

[0011] According to the present invention, it is possible to increase the efficiency of capturing fine dust while avoiding an increase in the complexity of the structure of the fine dust capturing device, an increase in the size of the outboard motor, or an increase in the manufacturing costs of the outboard motor. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view showing an outboard motor according to a first embodiment of the present invention. FIG. [Diagram 2] FIG. 1 is an explanatory diagram showing a lower part of an outboard motor according to a first embodiment of the present invention as viewed from the left. [Diagram 3] FIG. 2A is an explanatory diagram showing the lower part of an outboard motor according to a first embodiment of the present invention as seen from the front, and FIG. 2B is an explanatory diagram showing the lower part of the outboard motor as seen from the rear. [Figure 4](A) is a front view of a fine dust capture device in an outboard motor of the first embodiment of the present invention, (B) is a rear view of the fine dust capture device, (C) is a left side view of the fine dust capture device, and (D) is a plan view of the fine dust capture device. [Diagram 5] FIG. 4 is an explanatory diagram showing a second embodiment of an outboard motor of the present invention. [Figure 6] FIG. 4 is an explanatory diagram showing a third embodiment of an outboard motor of the present invention. [Figure 7] FIG. 11 is an explanatory diagram showing a fourth embodiment of an outboard motor of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An outboard motor according to an embodiment of the present invention includes a propeller unit, a support part formed in a vertically extending column shape with the propeller unit supported at its lower part, a bracket provided at the upper part of the support part for attaching the support part to a boat, and a fine dust capture device provided on the propeller unit or the support part. The propeller unit has a propeller shaft, a propeller fixed to the propeller shaft, and a case for rotatably supporting the propeller shaft.

[0014] In the outboard motor of this embodiment, the fine dust capture device has a water intake port that takes in water around the outboard motor, a passage through which the water taken in from the water intake port flows, a filter that captures fine dust contained in the water by passing the water through the passage, and a discharge port that discharges water around the outboard motor after it has passed through the filter.

[0015] The exhaust port is located in front of the propeller. When the outboard motor is viewed from the rear, the exhaust port is located inside a circle that has its center at the center of rotation of the propeller and has the same diameter as the diameter of the propeller. The exhaust port faces in a direction other than the front of the outboard motor, specifically, in the rear, upward, downward, left, right, upper left, lower left, upper right, lower right, upper rear, lower rear, left rear, right rear, upper left rear, lower left rear, upper right rear, or lower right rear of the outboard motor.

[0016] In the outboard motor of this embodiment, the discharge port of the fine dust trapping device is located in front of the propeller, and when the outboard motor is viewed from the rear, it is located inside a circle having the same diameter as the diameter of the propeller and centered on the rotation center of the propeller, and further, the discharge port of the fine dust trapping device faces in a direction other than the front of the outboard motor. With this configuration, a negative pressure is generated outside the discharge port of the fine dust trapping device by the water flow created by the rotation of the propeller, and the negative pressure causes the water in the passage of the fine dust trapping device to be sucked out of the passage through the discharge port. This makes it possible to increase the flow rate of water flowing through the passage of the fine dust trapping device, and therefore the flow rate of water passing through the filter. Therefore, it is possible to increase the amount of fine dust captured per unit sailing time of the ship or the amount of fine dust captured per unit sailing distance, and improve the efficiency of capturing fine dust.

[0017] Furthermore, with the outboard motor of this embodiment, the flow rate of water flowing through the passages of the fine dust capture device can be increased without adding a pump, thereby preventing the structure of the fine dust capture device from becoming more complicated due to the addition of a pump, the outboard motor from becoming larger, or the manufacturing costs of the outboard motor from increasing. EXAMPLES

[0018] An outboard motor according to a first embodiment of the present invention will be described with reference to Figures 1 to 4. In the first embodiment, when describing the directions of up (Ud), down (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd), they are indicated by arrows drawn at the bottom left or bottom right in Figures 1 to 3.

[0019] (Outboard motor) Fig. 1 shows an outboard motor 1 according to a first embodiment of the present invention as seen from the upper left front. Fig. 2 shows the lower part of the outboard motor 1 as seen from the left. Fig. 3(A) shows the lower part of the outboard motor 1 as seen from the front. Fig. 3(B) shows the lower part of the outboard motor 1 as seen from the rear.

[0020] The outboard motor 1 is a device that is attached to the transom of a boat to propel the boat. As shown in Fig. 1, the outboard motor 1 includes a propeller unit 2, a battery case 7, a support 8, a transom bracket 17, a swivel bracket 18, a bar handle 19, and a fine dust capture device 21.

[0021] The propeller unit 2 is disposed at the bottom of the outboard motor 1, and is located below the water surface when the outboard motor 1 is attached to the boat. As shown in FIG. 2, the propeller unit 2 includes a motor 3, a propeller shaft 4, a propeller 5, and a propeller unit case 6. The motor 3 is disposed at the front part of the propeller unit case 6. The propeller shaft 4 extends in the front-rear direction, and a front part of the propeller shaft 4 is rotatably supported at the rear part of the propeller unit case 6. The propeller shaft 4 is connected to the output shaft of the motor 3, or is formed integrally with the output shaft of the motor 3, and rotates by the power of the motor 3. The propeller 5 is fixed to the rear end of the propeller shaft 4, and rotates integrally with the propeller shaft 4. The propeller 5 has a hub 5A and a plurality of blades 5B. The propeller unit case 6 is a sealed cylindrical case.

[0022] 1, the battery case 7 is disposed on top of the outboard motor 1 and is located above the water surface when the outboard motor 1 is attached to a boat. A battery that supplies power to the motor 3 to drive the motor 3 is housed inside the battery case 7.

[0023] The support part 8 is a member that connects the battery case 7 and the propeller unit 2 and supports them. The propeller unit 2 is supported on the lower part of the support part 8, and the battery case 7 is supported on the upper part of the support part 8. Specifically, the support part 8 is formed in a columnar shape extending in the vertical direction, and the propeller unit case 6 is fixed to the lower end part of the support part 8. Also, a mounting plate part 15 is fixed to the upper end part of the support part 8, and the battery case 7 is detachably attached to the mounting plate part 15. Also, an outboard motor transport handle 16 is provided at the rear part of the support part 8 to enable a user to transport the outboard motor 1 removed from the boat.

[0024] The transom bracket 17 is a clamp mechanism that attaches the outboard motor 1 to the transom of a boat. The transom bracket 17 is disposed at the front of the upper portion of the support portion 8.

[0025] The swivel bracket 18 is a bracket for enabling the outboard motor 1 attached to the transom to rotate left and right relative to the boat, and is formed integrally with the rear part of the transom bracket 17. A steering shaft (not shown) is rotatably attached to the swivel bracket 18, and the steering shaft is fixed to the front part of the upper part of the support part 8. The support part 8 can rotate with respect to the swivel bracket 18 about the axis of the steering shaft as the rotation axis, and as a result, the outboard motor 1 can rotate left and right relative to the boat.

[0026] The bar handle 19 is a handle for turning the outboard motor 1 left and right relative to the boat in order to steer the boat. The bar handle 19 is disposed above and in front of the support part 8. Specifically, a base end of the bar handle 19 is attached to an upper front end of the mounting plate part 15. A user can turn the outboard motor 1 right or left relative to the boat by gripping the tip of the bar handle 19 and moving the bar handle 19 left or right, thereby changing the direction of the propeller 5 to the right or left.

[0027] (fine dust capture device) As shown in Fig. 2, the outboard motor 1 is equipped with a fine dust capture device 21. The fine dust capture device 21 is a device that captures fine dust dispersed in a body of water such as the sea, a lake, or a river in which the ship navigates.

[0028] Microdust is, for example, minute dust with an outer diameter or maximum length of 0.1 mm or more and 5 mm or less. Plastic waste flows into the sea, lakes, rivers, etc., and is broken down by waves or water currents, or decomposed by ultraviolet rays, etc. into tiny plastic pieces, which may then be dispersed in the water of the sea, lakes, rivers, etc. Such tiny plastic pieces are generally called microplastics. This microplastic falls under the category of microdust.

[0029] Fig. 4 shows the fine dust capturing device 21. In detail, Fig. 4(A) is a front view of the fine dust capturing device 21, Fig. 4(B) is a rear view of the fine dust capturing device 21, Fig. 4(C) is a left side view of the fine dust capturing device 21, and Fig. 4(D) is a plan view of the fine dust capturing device 21.

[0030] 4(A) to (D), the fine dust capture device 21 comprises a main body 22, a water intake 26 that takes in water around the outboard motor 1, a passage 27 through which the water taken in from the water intake 26 flows, a filter 28 that captures fine dust contained in the water by passing the water through the passage 27, and a discharge outlet 29 that discharges the water after it has passed through the filter 28 around the outboard motor 1.

[0031] The main body 22 is formed of, for example, resin or metal. As shown in FIG. 4(C), the main body 22 has a passage forming portion 23, a water inlet forming portion 24, and a discharge port forming portion 25. The passage forming portion 23 is formed in a tubular shape that extends linearly. In this embodiment, the passage forming portion 23 is formed in a triangular tubular shape with a cross section that is substantially triangular. D in FIG. 4(C) or 4(D) is the axis of the passage forming portion 23. The water inlet forming portion 24 is attached and fixed to one axial end portion of the passage forming portion 23 so as to cover one axial end side of the passage forming portion 23. The discharge port forming portion 25 is attached and fixed to the other axial end portion of the passage forming portion 23 so as to cover the other axial end side of the passage forming portion 23.

[0032] As shown in Fig. 4(A), the water intake 26 is formed in the water intake forming portion 24. The water intake 26 is a hole penetrating the water intake forming portion 24. The water intake 26 is disposed such that its center is located above the center of the water intake forming portion 24, and the center of the water intake 26 is located above the axis D of the passage forming portion 23. In this embodiment, the water intake 26 has a substantially triangular shape that is a reduced version of the substantially triangular cross-sectional shape of the passage forming portion 23.

[0033] 4(B), the discharge outlet 29 is formed in the discharge outlet forming portion 25. The discharge outlet 29 is a hole penetrating the discharge outlet forming portion 25. The discharge outlet 29 is disposed such that its center is located lower than the center of the discharge outlet forming portion 25, and the center of the discharge outlet 29 is located lower than the axis D of the passage forming portion 23. In this embodiment, the discharge outlet 29 has a rectangular shape with each corner chamfered, and extends in a direction parallel to the base of the approximately triangular cross section of the passage forming portion 23.

[0034] 4(C), the passage 27 is provided inside the passage forming portion 23 of the main body 22. One end of the passage 27 is connected to the water intake 26, and the other end of the passage 27 is connected to the discharge port 29. In addition, the passage 27 extends from the water intake 26 through the inside of the passage forming portion 23 in the axial direction to reach the discharge port 29.

[0035] The filter 28 is provided midway through the passage 27. In this embodiment, the filter 28 is disposed in a portion of the passage 27 that is rearward of the center in the axial direction. The filter 28 is provided so as to block the entire cross section of that portion of the passage 27. The filter 28 is a filter capable of capturing fine dust, and is formed, for example, in a sheet or plate shape from nonwoven fabric. Water can pass through the filter 28, but fine dust cannot pass through the filter 28.

[0036] In this embodiment, the filter 28 has a multi-layer structure. For example, the filter 28 has a first layer with a coarse mesh and a second layer with a fine mesh. The filter 28 is arranged in the passage 27 so that the first layer is located on the water intake side and the second layer is located on the discharge side. According to such a structure and arrangement of the filter 28, when the water flows backward through the passage 27 and flows from the discharge port 29 toward the water intake 26, it is possible to suppress the fine dust captured by the filter 28 from being separated from the filter 28 and being diffused. That is, when the water flows in the forward direction from the water intake 26 to the discharge port 29 in the passage 27, the fine dust contained in the water is captured by the first layer or the second layer, but as the forward water flow continues, the fine dust accumulates in the intermediate portion between the first layer and the second layer or inside the second layer. On the other hand, when water flows backward in passage 27 from outlet 29 toward intake 26, the fine dust accumulated inside the second layer or in the intermediate portion between the first and second layers is pushed toward intake 26 by the water. However, since the fine dust cannot easily pass through the first layer at this time, most of the fine dust remains inside the second layer or in the intermediate portion between the first and second layers. Therefore, the fine dust captured by filter 28 is prevented from diffusing away from filter 28 due to the reverse flow of water.

[0037] The material of the filter 28 is not limited to nonwoven fabric, but may be woven fabric, sponge, glass mat, etc. The filter 28 may be a single layer.

[0038] As shown in FIG. 1, the fine dust capture device 21 is provided at the lower end of the support part 8, specifically, between the lower end of the support part 8 and the propeller unit case 6. In this embodiment, the lower end of the support part 8 has a bifurcated structure branched in the left and right directions. Specifically, as shown in FIG. 3(A), the lower end of the support part 8 is provided with two connecting parts 9 that are respectively connected to the upper left and upper right parts of the propeller unit case 6. One connecting part 9 extends downward from the left part of the lower end of the support part 8 while inclining leftward, and its lower end is connected to the upper left part of the propeller unit case 6 at approximately the middle part in the front-rear direction. The other connecting part 9 extends downward from the right part of the lower end of the support part 8 while inclining rightward, and its lower end is connected to the upper right part of the propeller unit case 6 at approximately the middle part in the front-rear direction. With this structure, a triangular space is formed between the lower end of the support part 8 and the upper surface (outer surface) of the propeller unit case 6 in a front view. The fine dust capture device 21 is disposed in this space.

[0039] In the fine dust capture device 21, the passage forming portion 23 of the main body 22 is formed in a triangular tube shape as described above, and the shape of this passage forming portion 23 corresponds to the shape of the space between the lower end of the support portion 8 and the upper surface of the propeller unit case 6. Therefore, the fine dust capture device 21 is provided so as to fit into the space formed between the lower end of the support portion 8 and the upper surface of the propeller unit case 6. With the fine dust capture device 21 provided in the space between the lower end of the support portion 8 and the upper surface of the propeller unit case 6, the outer circumferential surface of the fine dust capture device 21 (specifically, the outer circumferential surface of the water intake forming portion 24 and the outer circumferential surface of the discharge port forming portion 25) contacts the inner surface of each joint portion 9 and the upper surface of the propeller unit case 6.

[0040] The main body 22 of the fine dust capture device 21 is disposed in the space between the lower end of the support part 8 and the upper surface of the propeller unit case 6 so that the water intake 26 faces the front of the outboard motor 1 and the discharge port 29 faces the rear of the outboard motor 1. The main body 22, the water intake 26, the passage 27, the filter 28 and the discharge port 29, i.e., the entire fine dust capture device 21, is located in front of the propeller 5 as shown in Fig. 3(A) or 3(B), and is located inside a circle C having a diameter equal to that of the propeller 5 and centered on the rotation center A of the propeller 5 when the outboard motor 1 is viewed from the front or rear.

[0041] 3(A), when the outboard motor 1 is viewed from the front, the water intake 26 is disposed inside the circle C, above the propeller unit case 6, and vertically above the center of rotation A of the propeller 5. The water intake 26 is oriented forward of the outboard motor 1 from that position, and in a direction parallel to the axis E of the propeller shaft 4.

[0042] 3(B), when the outboard motor 1 is viewed from the rear, the exhaust port 29 is disposed inside the circle C, above the propeller unit case 6, and vertically above the center of rotation A of the propeller 5. The exhaust port 29 is oriented rearward of the outboard motor 1 from that position and in a direction parallel to the axis E of the propeller shaft 4.

[0043] In this embodiment, the passage forming portion 23 is made of a transparent resin. Also, as shown in Fig. 2, each joint 9 is provided with a window 31. The window 31 is formed by a hole penetrating the joint 9. The transparent passage forming portion 23 is disposed at a position corresponding to the window 31. This allows the user to check the amount of fine dust accumulated in the filter 28 by looking through the window 31 when, for example, the outboard motor 1 is pulled up onto land.

[0044] In this embodiment, the fine dust capture device 21 can be removed from the space formed between the lower end of the support portion 8 and the upper surface of the propeller unit case 6. In the main body 22 of the fine dust capture device 21, the discharge port forming portion 25 is detachably attached to the rear of the passage forming portion 23. In addition, the filter 28 is detachably attached to the main body 22 between the rear end portion of the passage forming portion 23 and the front end portion of the discharge port forming portion 25. When a user pulls the outboard motor 1 onto the ground, looks through the window 31, and finds that a large amount of fine dust has accumulated in the filter 28, for example, the user can remove the fine dust capture device 21 from the outboard motor 1 and replace the filter 28.

[0045] In the fine dust capturing device 21 having such a configuration, when the outboard motor 1 is attached to the transom of a boat on the water, the propeller unit 2 and the fine dust capturing device 21 are submerged below the water surface. Then, when the propeller 5 rotates and the boat moves forward by the thrust generated by the propeller 5, water flows into the water intake 26 from the front of the outboard motor 1. The water that flows into the water intake 26 flows rearward through the passage 27 toward the discharge port 29. The water that flows through the passage 27 toward the discharge port 29 passes through the filter 28. As the water passes through the filter 28, fine dust contained in the water is captured by the filter 28. The water that has passed through the filter 28 is discharged rearward from the discharge port 29.

[0046] The water intake 26 is located below the water surface, disposed at the front of the outboard motor 1, and faces forward of the outboard motor 1. Therefore, water flows into the passage 27 through the water intake 26 as the boat moves forward. The discharge outlet 29 is located below the water surface, forward of the propeller 5, and, when the outboard motor 1 is viewed from the rear, inside a circle C that is centered on the rotation center A of the propeller 5 and has the same diameter as the propeller 5. The discharge outlet 29 faces rear of the outboard motor 1. Therefore, a negative pressure is created outside the discharge outlet 29 by the flow of water created by the rotation of the propeller 5, and the water in the passage 27 is sucked out of the passage 27 through the discharge outlet 29 due to the negative pressure. The pressure of the water flowing into the passage 27 through the intake 26 and the negative pressure created outside the discharge port 29 by the water flow produced by the rotation of the propeller 5 cause the water to flow through the passage 27 from the intake 26 to the discharge port 29, and the water passes through the filter 28 to capture fine dust particles.

[0047] As described above, in the outboard motor 1 of the first embodiment of the present invention, the discharge port 29 of the fine dust capture device 21 is located in front of the propeller 5, and when the outboard motor 1 is viewed from the rear, it is located inside the circle C having the same diameter as the diameter of the propeller 5 and centered on the rotation center A of the propeller 5, and the discharge port 29 faces the rear of the outboard motor 1. With this configuration, the water in the passage 27 of the fine dust capture device 21 can be sucked out of the passage 27 through the discharge port 29 by utilizing the negative pressure formed outside the discharge port 29 by the water flow created by the rotation of the propeller 5. This makes it possible to increase the flow rate of water flowing through the passage 27 of the fine dust capture device 21, and therefore the flow rate of water passing through the filter 28. Therefore, the amount of fine dust captured per unit sailing time of the ship or the amount of fine dust captured per unit sailing distance can be increased, and the efficiency of capturing fine dust can be improved. Furthermore, with this configuration, the flow rate of water flowing through the passage 27 of the fine dust capture device 21 can be increased without adding a pump, thereby preventing the addition of a pump from complicating the structure of the fine dust capture device 21, increasing the size of the outboard motor 1, or increasing the manufacturing costs of the outboard motor 1. As described above, with the outboard motor 1 of the first embodiment of the present invention, it is possible to increase the fine dust capture efficiency while avoiding the structure of the fine dust capture device 21 from becoming complicated, the size of the outboard motor 1, or increasing the manufacturing costs of the outboard motor 1.

[0048] In the outboard motor 1 of this embodiment, the discharge port 29 of the fine dust capture device 21 is located at the rear of the outboard motor 1 and faces in a direction parallel to the axis E of the propeller shaft 4. With this configuration, compared to when the discharge port 29 is located at the rear of the outboard motor 1 and faces in a direction not parallel to the axis E of the propeller shaft 4 or in a direction parallel to a line perpendicular to the axis E of the propeller shaft 4, for example, the negative pressure formed outside the discharge port 29 by the water flow generated by the rotation of the propeller 5 is larger, and therefore the force with which the water in the passage 27 is sucked out of the passage 27 through the discharge port 29 is larger. This makes it possible to further increase the flow rate of water flowing through the passage 27, and further improve the efficiency of capturing fine dust.

[0049] In the outboard motor 1 of this embodiment, the fine dust capture device 21 has a main body 22 formed in a cylindrical shape extending linearly, the water intake 26 is provided at one axial end of the main body 22, the discharge port 29 is provided at the other axial end of the main body 22, the passage 27 passes axially from the water intake 26 through the main body 22 to the discharge port 29, and the filter 28 is provided midway through the passage 27. With this configuration, in the fine dust capture device 21, the passage 27 from the water intake 26 to the discharge port 29 can be shortened, and the entire passage 27 can be made nearly linear. Therefore, the resistance of water flowing through the passage 27 can be reduced. By disposing the fine dust capture device 21 having such a configuration in a position forward of the propeller 5 and inside the circle C when the outboard motor 1 is viewed from the rear, with the water intake 26 facing the front of the outboard motor 1 and the discharge port 29 facing the rear of the outboard motor 1, when the boat is moving forward, the water around the outboard motor can be made to smoothly flow into the passage 27 of the fine dust capture device 21, the water that has flowed into the passage 27 can be made to smoothly flow toward the discharge port 29, and the water in the passage 27 can be made to smoothly flow out from the discharge port 29 by utilizing the negative pressure. This increases the flow rate of water passing through the filter 28 and improves the efficiency of capturing fine dust.

[0050] Furthermore, in the outboard motor 1 of this embodiment, the fine dust capture device 21 is provided at the lower end of the support part 8, specifically, between the lower end of the support part 8 and the propeller unit case 6. This makes it possible to easily position the fine dust capture device 21 in front of the propeller 5 and inside the circle C when the outboard motor 1 is viewed from the rear.

[0051] Furthermore, the fine dust capturing device 21 is in contact with the outer surface of the propeller unit case 6. This allows the fine dust capturing device 21 to be placed very close to the propeller unit 2, and ensures that the fine dust capturing device 21 is placed in the water flow created by the rotation of the propeller 5. EXAMPLES

[0052] An outboard motor according to a second embodiment of the present invention will be described with reference to Fig. 5. In the second embodiment, the directions of up (Ud), down (Dd), front (Fd) and rear (Bd) are described according to the arrows drawn at the bottom left of Fig. 5. The outboard motor according to the second embodiment of the present invention differs from the outboard motor 1 according to the first embodiment of the present invention mainly in that the discharge port of the fine dust trapping device faces the rear of the outboard motor in a direction that is not parallel to the axis of the propeller shaft.

[0053] Fig. 5 shows the lower part of an outboard motor 41 according to a second embodiment of the present invention as viewed from the left. In Fig. 5, the outboard motor 41 has a fine dust capture device 51, which is provided at the lower end of the support portion 48 and in the vicinity of the propeller unit case 46 of the propeller unit 42. The fine dust capture device 51 is located in front of the propeller 45 and is located inside a circle having the same diameter as the propeller 45 and centered on the center of rotation of the propeller 45 when the outboard motor 41 is viewed from the rear. The fine dust capture device 51 has a main body 52 formed in a cylindrical shape. A water intake is provided on the front of the main body 52, and a plurality of discharge ports 59 are provided around the rear of the main body 52. ​​A passage is provided in the main body 52 from the water intake to the discharge port 59, and a filter is provided midway along the passage.

[0054] Specifically, six exhaust ports 59 are arranged at 60 degree intervals around the periphery of the rear of the main body 52. ​​The outer diameter of the rear of the main body 52 decreases toward the rear, and as a result, the outer surface of the periphery of the rear of the main body 52 is inclined. The six exhaust ports 59 open on the inclined outer surface of the periphery of the rear of the main body 52. ​​The six exhaust ports 59 face rear of the outboard motor 41 and in a direction that is not parallel to the axis E of the propeller shaft 44. That is, the six exhaust ports 59 face left rear, upper left rear, lower left rear, right rear, upper right rear, and lower right rear, respectively.

[0055] In the outboard motor 41 of the second embodiment of the present invention having such a configuration, when the boat moves forward, the water in the passage of the fine dust capture device 51 is sucked out of the passage through the outlet 59 due to the negative pressure created by the water flow generated by the rotation of the propeller 45. Therefore, the flow rate of water flowing through the passage of the fine dust capture device 71 can be increased, and the fine dust capture efficiency can be improved. EXAMPLES

[0056] An outboard motor according to a third embodiment of the present invention will be described with reference to Fig. 6. In the third embodiment, the directions of up (Ud), down (Dd), front (Fd) and rear (Bd) are described according to the arrows drawn at the bottom left of Fig. 6. The outboard motor according to the third embodiment of the present invention differs from the outboard motor 1 according to the first embodiment of the present invention mainly in that the discharge port of the fine dust trapping device faces in a direction parallel to a straight line perpendicular to the axis of the propeller shaft.

[0057] Fig. 6 shows the lower part of an outboard motor 61 according to a third embodiment of the present invention as viewed from the left. In Fig. 6, the outboard motor 61 is obtained by replacing the fine dust capture device 51 in the outboard motor 41 according to the second embodiment of the present invention shown in Fig. 5 with a fine dust capture device 71 having an outlet facing in a different direction. The fine dust capture device 71 has a main body 72 formed in a cylindrical shape. A water intake is provided on the front side of the main body 72, and a plurality of outlets 79 are provided around the rear part of the main body 72. A passage is provided within the main body 72 from the water intake to the outlet 79, and a filter is provided midway along the passage.

[0058] Specifically, eight exhaust ports 79 are arranged at 45-degree intervals around the periphery of the rear part of the main body 72. The eight exhaust ports 79 are oriented in a direction parallel to a straight line perpendicular to the axis E of the propeller shaft 44. That is, the eight exhaust ports 79 are oriented upward, downward, left, right, upper left, lower left, upper right, and lower right, respectively.

[0059] In the outboard motor 61 of the third embodiment of the present invention having such a configuration, when the boat moves forward, the water in the passage of the fine dust capture device 71 is sucked out of the passage through the outlet 79 due to the negative pressure created by the water flow generated by the rotation of the propeller 45. Therefore, the flow rate of water flowing through the passage of the fine dust capture device 71 can be increased, and the fine dust capture efficiency can be improved. EXAMPLES

[0060] An outboard motor according to a fourth embodiment of the present invention will be described with reference to Fig. 7. In the fourth embodiment, the directions of up (Ud), down (Dd), left (Ld) and right (Rd) are described according to the arrows drawn at the bottom left of Fig. 7. The outboard motor according to the fourth embodiment of the present invention differs mainly from the outboard motor 1 according to the first embodiment of the present invention in that the fine dust capturing device is disposed at a position that does not intersect with the axis of the support part.

[0061] FIG. 7 shows the lower part of an outboard motor 81 according to a fourth embodiment of the invention, as viewed from the front. In FIG. 7, the lower end of a support part 88 of the outboard motor 81 is fixed to a propeller unit case 86 of a propeller unit 82, and the lower end of the support part 88 does not have a bifurcated structure, unlike the support part 8 shown in FIG. 3(A). Two fine dust capture devices 91 are provided at the lower end of the support part 88, one of which is disposed on the left side of the lower end of the support part 88, and the other fine dust capture device 91 is disposed on the right side of the lower end of the support part 88. Each fine dust capture device 91 has the same configuration as the fine dust capture device 21 shown in FIG. 4. Each fine dust capture device 91 is located in front of the propeller 85, and is located inside a circle C having a diameter equal to that of the propeller 85 and centered on the rotation center A of the propeller 85 when the outboard motor 81 is viewed from the rear. In addition, each fine dust capture device 91 is positioned so that its water intake faces the front of the outboard motor 81 and its discharge port faces the rear of the outboard motor 81.

[0062] In the outboard motor 81 of the fourth embodiment of the present invention having such a configuration, when the boat moves forward, the water in the passage of the fine dust capture device 91 is sucked out of the passage through the outlet by the negative pressure created by the water flow generated by the rotation of the propeller 85. Therefore, the flow rate of water flowing through the passage of the fine dust capture device 91 can be increased, and the fine dust capture efficiency can be improved.

[0063] Furthermore, according to the outboard motor 81 of the fourth embodiment of the present invention, it is possible to easily form an outboard motor having a configuration in which a motor or an internal combustion engine is provided at the top of the outboard motor, a drive shaft is provided in the support part, and a gear mechanism is provided in a propeller unit case of the propeller unit, and power of the motor is transmitted to the propeller shaft via the drive shaft and the gear mechanism. That is, in the outboard motor 81, since the fine dust capture device 91 is disposed at a position that does not intersect with the axis F of the support part 88, if a drive shaft is provided in the support part 88, the drive shaft can be extended to the inside of the propeller unit case 86 of the propeller unit 82. Therefore, the lower end of the drive shaft can be easily connected to the gear mechanism provided in the propeller unit case 86.

[0064] In the above embodiments, the case has been described where the entire fine dust capture device 21 (51, 71, 91) is located inside a circle having a diameter equal to that of the propeller 5 (45, 85) and centered on the center of rotation of the propeller 5 (45, 85) when viewed from the rear of the outboard motor 1 (41, 61, 81), but the present invention is not limited to this. When viewed from the rear of the outboard motor, parts of the fine dust capture device other than the part where the discharge port is located may be located outside a circle having a diameter equal to that of the propeller and centered on the center of rotation of the propeller. For example, the water intake, part of the passage, or the filter may be located outside the circle.

[0065] In the above embodiment, the fine dust capturing device is provided between the lower end of the support part and the propeller unit as shown in Fig. 2, or the fine dust capturing device is provided at the lower end of the support part as shown in Fig. 5, but the present invention is not limited to these. The fine dust capturing device may be provided at the propeller unit case of the propeller unit.

[0066] Furthermore, the present invention can be modified as appropriate without departing from the spirit or concept of the invention as can be read from the claims and the entire specification, and outboard motors incorporating such modifications are also included within the technical concept of the present invention. [Explanation of symbols]

[0067] 1, 41, 61, 81 Outboard motor 2, 42, 82 Propeller Unit 4, 44 Propeller shaft 5, 45, 85 Propeller 6, 46, 86 Propeller unit case (case) 8, 48, 88 Support part 11 Transom bracket (bracket) 21, 51, 71, 91 Fine dust capture device 22, 52, 72 Main body 26 Water Intake 27 Passage 28 Filters 29, 59, 79 outlet

Claims

1. An outboard motor for propelling a boat, a propeller unit including a propeller shaft, a propeller fixed to the propeller shaft, and a case that rotatably supports the propeller shaft; A support part formed in a columnar shape extending in the vertical direction and having the propeller unit supported at its lower part; A bracket provided on an upper portion of the support portion for attaching the support portion to the vessel; A fine dust capture device is provided on the propeller unit or the support part, the fine dust capture device has a water intake port for taking in water around the outboard motor, a passage through which the water taken in from the water intake port flows, a filter for capturing fine dust contained in the water by passing the water through the passage, and a discharge port for discharging the water after it has passed through the filter to the surroundings of the outboard motor, the exhaust outlet is located forward of the propeller, inside a circle having the same diameter as the propeller and centered on the center of rotation of the propeller when the outboard motor is viewed from the rear, and faces in a direction other than the front of the outboard motor.

2. 2. The outboard motor of claim 1, wherein the exhaust port faces aft of the outboard motor.

3. 2. The outboard motor according to claim 1, wherein the exhaust port is located at the rear of the outboard motor and faces in a direction parallel to an axis of the propeller shaft.

4. 2. An outboard motor according to claim 1, wherein the water intake, the passage, the filter and the discharge port are located forward of the propeller and inside a circle having a diameter the same as a diameter of the propeller and centered on the center of rotation of the propeller when the outboard motor is viewed from the rear.

5. 2. An outboard motor as claimed in claim 1, characterized in that the fine dust capture device has a main body formed into a cylindrical shape extending linearly, the water intake is provided at one axial end of the main body, the discharge outlet is provided at the other axial end of the main body, the passage runs axially from the water intake through the main body to the discharge outlet, and the filter is provided midway through the passage.

6. 6. An outboard motor according to claim 5, wherein the main body is provided on the propeller unit or the support so that the water intake faces a front of the outboard motor and the discharge outlet faces a rear of the outboard motor.

7. 2. An outboard motor according to claim 1, wherein the fine dust trapping device is provided at a lower end of the support portion.

8. 8. An outboard motor according to claim 7, wherein said fine dust trapping device is in contact with an outer surface of said case.

Images