Outboard engine

Abstract

To improve capturing efficiency for micro dust while: evading complication in a structure of micro dust capture device; enlargement of an outboard engine; or rise in manufacturing cost for the outboard engine.SOLUTION: An outboard engine 1 includes a propeller unit 2, a support unit 8, and a micro dust capture device 21, the support unit 8 is formed to be columnar stretching in the vertical direction, and the propeller unit 2 is supported in a bottom end unit in the support unit 8. The micro dust capture device 21 has a passage 27 for having water in periphery of the outboard engine 1 circulated, and the micro dust contained in the water circulated in the passage 27 is captured. In addition, the micro dust capture device 21 is provided in between a bottom end unit of the support unit 8 and the propeller unit case 6 of the propeller unit 2 so that the stretching direction of the passage 27 is in the front to back direction of the outboard engine 1.SELECTED DRAWING: Figure 1

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 fine dust capture device provided in the conventional 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. The fine dust capture device is provided with a passage connecting the water intake and the discharge port, which passes through the trap. A filter is disposed in the middle of the passage in the trap. In the fine dust capture device, the water intake is located below the water surface, and the discharge port is located above the water surface, so that the passage connecting the water intake and the discharge port extends in the vertical direction.

[0007] When a boat moves forward, water flows around the outboard motor in the longitudinal direction from the front to the rear of the outboard motor. The fine dust trapping device provided in the conventional outboard motor uses the water pressure caused by the longitudinal water flow of the outboard motor to circulate water through the passage. However, while the water flow around the outboard motor is longitudinal, the passage of the fine dust trapping device extends in the vertical direction. This can make it difficult for water to flow through the passage, making it difficult to increase the flow rate of water flowing through the passage, 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 trapped per unit sailing time or the amount of fine dust trapped per unit sailing distance, making it difficult to improve the fine dust trapping efficiency.

[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 port to increase the flow rate of water circulating through the passageway, but adding a pump is not preferable because it would complicate the structure of the fine dust capture device, increase the size of the outboard motor, or increase 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 problems, the present invention provides an outboard motor for propelling a 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 end; a bracket provided on the upper part of the support part for attaching the support part to the vessel; and a fine dust capture device having a passage for circulating water around the outboard motor and capturing fine dust particles contained in the water flowing through the passage, wherein the fine dust capture device is provided between the lower end of the support part and the case so that the extension direction of the passage is in the fore-and-aft direction 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 an embodiment of the present invention; [Diagram 2] FIG. 2 is an explanatory diagram showing the lower part of the outboard motor according to the 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 an embodiment of the present invention as viewed from the front, and FIG. 2B is an explanatory diagram showing the lower part of the outboard motor as viewed from the rear. [Figure 4] (A) is a front view of a fine dust capture device in an outboard motor according to an 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] 3 is a cross-sectional view showing the lower part of the outboard motor taken along the cutting line VV in FIG. 2 as viewed from the front. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An outboard motor according to an embodiment of the present invention is an outboard motor for propelling a boat, and includes a propeller unit, a support part formed in a columnar shape extending in the vertical direction and having the propeller unit supported at its lower end, a bracket provided on an upper part of the support part for attaching the support part to the boat, and a fine dust capture device for capturing fine dust. The propeller unit has a propeller shaft, a propeller fixed to the propeller shaft, and a case for rotatably supporting the propeller shaft. The fine dust capture device has a passage through which water around the outboard motor flows, and captures fine dust contained in the water flowing through the passage.

[0014] In this embodiment, the fine dust capture device is disposed between the lower end of the support portion and the case of the propeller unit so that the extension direction of the passage for circulating water around the outboard motor is in the fore-and-aft direction of the outboard motor.

[0015] When the outboard motor is attached to the boat, the lower end of the support part of the outboard motor and the propeller unit are located below the water surface. The fine dust trapping device of the outboard motor of this embodiment is provided between the lower end of the support part and the case of the propeller unit, so that when the outboard motor is attached to the boat, the fine dust trapping device is located below the water surface. When the boat moves forward, water flows around the outboard motor in the front-to-rear direction from the front to the rear of the outboard motor. The fine dust trapping device of the outboard motor of this embodiment is placed in this water flow. Furthermore, the fine dust trapping device of the outboard motor of this embodiment is disposed so that the extension direction of the passage through which the water flows around the outboard motor is the front-to-rear direction of the outboard motor, and the extension direction of the passage coincides with the direction of the water flow around the outboard motor when the boat is moving forward. Therefore, according to the outboard motor of this embodiment, the water around the outboard motor can flow more easily through the passage of the fine dust trapping device than in a conventional outboard motor provided with a fine dust trapping device whose passage extension direction is vertical. Therefore, the flow rate of water flowing through the passage of the fine dust capture device can be increased, and the flow rate of water passing through the filter can be increased, which results in an increase in the amount of fine dust captured per unit sailing time or per unit sailing distance, thereby improving the fine dust capture efficiency.

[0016] 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

[0017] An outboard motor according to an embodiment of the present invention will be described with reference to the drawings. In the embodiment, when describing the directions of up (Ud), down (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd), refer to the arrows drawn at the bottom left or bottom right in Figs. 1 to 3 and 5.

[0018] (Outboard motor) Fig. 1 shows an outboard motor 1 according to an 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.

[0019] 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.

[0020] 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. The propeller unit 2 is disposed at the center of the outboard motor 1 in the left-right direction. 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 case having a cylindrical outer shape.

[0021] 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.

[0022] 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 at the lower end of the support part 8, and the battery case 7 is supported at 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 of the support part 8. Also, a mounting plate part 15 is fixed to the upper end 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 of the support part 8 to enable a user to transport the outboard motor 1 removed from the boat.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] (Configuration of micro-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 an ocean, lake, or river in which a ship navigates.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The main body 22 is formed of, for example, resin or metal. The main body 22 is formed into a tubular shape that extends linearly when viewed as a whole. In this embodiment, the main body 22 is formed into a tubular shape with a cross section that is approximately triangular. D in FIG. 4(C) or 4(D) is the axis of the main body 22. The main body 22 has a passage forming portion 23, a water intake forming portion 24, and a discharge port forming portion 25. The passage forming portion 23 is formed into a triangular tubular shape that extends linearly. The water intake 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.

[0031] 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 main body 22. 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 main body 22.

[0032] 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 main body portion 22. 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 main body portion 22.

[0033] 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 inside the passage forming portion 23 in the axial direction to reach the discharge port 29.

[0034] The filter 28 is provided in the main body 22, midway through the passage 27. 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 the fine dust cannot pass through the filter 28.

[0035] 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.

[0036] 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.

[0037] (Arrangement of micro-dust capture device) As shown in FIG. 1, the fine dust capture device 21 is provided between the lower end of the support portion 8 and the propeller unit case 6. As shown in FIG. 3(A), the fine dust capture device 21 is disposed at the center of the lower end of the support portion 8 in the left-right direction, and is located at the center of the outboard motor 1 in the left-right direction. As shown in FIG. 2, the fine dust capture device 21 is located rearward of the front end of the propeller unit 2 and forward of the rear end of the propeller unit 2. Specifically, the fine dust capture device 21 is located rearward of the front end of the propeller unit case 6 and forward of the propeller 5. The fine dust capture device 21 is provided outside the propeller unit case 6. When the outboard motor 1 is attached to the boat, the fine dust capture device 21 is entirely located below the water surface, and therefore the passage 27 of the fine dust capture device 21 is entirely located below the water surface.

[0038] The lower end of the support part 8 has a bifurcated structure branched in the left and right directions. FIG. 5 shows a cross section of the lower part of the outboard motor 1 cut along the cutting line VV in FIG. 2 as seen from the front (left in FIG. 2), and the bifurcated structure of the lower end of the support part 8 can be clearly seen from FIG. 5. Note that FIG. 5 shows a state in which the fine dust capture device 21 has been removed from the outboard motor 1, and components provided inside the propeller unit case 6 are not shown in FIG. 5. As shown in FIG. 5, two connecting parts 9 are provided at the lower end of the support part 8. Of the two connecting parts 9, one connecting part 9 connects the lower end of the support part 8 to the upper left part of the propeller unit case 6, and the other connecting part 9 connects the lower end of the support part 8 to the upper right part of the propeller unit case 6.

[0039] Moreover, when viewed overall, the two connecting portions 9 have a shape that widens toward the bottom of the outboard motor 1. Specifically, of the two connecting portions 9, one connecting portion 9 extends linearly downward while sloping left from the lower end of the support portion 8 to reach the upper left part of the propeller unit case 6, while the other connecting portion 9 extends linearly downward while sloping right from the lower end of the support portion 8 to reach the upper right part of the propeller unit case 6. Moreover, both the outer surface 9A and the inner surface 9B of one connecting portion 9 extend downward while sloping left, while both the outer surface 9A and the inner surface 9B of the other connecting portion 9 extend downward while sloping right. The upper ends of the two connecting parts 9 are joined to each other at position P1, which is the center in the left-right direction of the lower end of the support part 8, and the lower end of one connecting part 9 is joined to the propeller unit case 6 at position P2, which is the upper left part of the propeller unit case 6, and the lower end of the other connecting part 9 is joined to the propeller unit case 6 at position P3, which is the upper right part of the propeller unit case 6. The two connecting parts 9 and the upper part of the propeller unit case 6 have a triangular structure with vertices at positions P1, P2, and P3.

[0040] A space R is formed between the lower end of the support portion 8 and the left-right center of the upper part of the propeller unit case 6. The fine dust capture device 21 is provided in this space R. When the outboard motor 1 is viewed from the front, the space R has a generally triangular shape with the inner surfaces 9B of the two connecting portions 9 and the upper surface 6A of the propeller unit case 6 as its sides. In the fine dust capture device 21, the main body 22 is formed into a tubular shape having a generally triangular cross section as described above, and the triangular shape of the main body 22 corresponds to the triangular shape of the space R. The fine dust capture device 21 is provided to fit into the space R so that the triangular cross section of the main body 22 matches the triangular shape of the space R. Furthermore, when the fine dust capture device 21 is installed in the space R, the outer peripheral surface of the fine dust capture device 21 (specifically, the outer peripheral surface of the water intake port forming portion 24 and the outer peripheral surface of the exhaust port forming portion 25) contacts the inner surface 9B of each connecting portion 9 and the upper surface 6A of the propeller unit case 6.

[0041] The main body 22 of the fine dust capture device 21 is disposed in the space R such that the water intake 26 faces the front of the outboard motor 1 and the passage 27 extends in the fore-and-aft direction of the outboard motor 1. The discharge port 29 faces the rear of the outboard motor 1.

[0042] As shown in Figure 3(A) when viewing the outboard motor 1 from the front, the water intake 26 is disposed above the propeller unit case 6 and vertically above the center of rotation A of the propeller 5. The water intake 26 is also located in front of the outboard motor 1 and faces in a direction parallel to the axis E of the propeller shaft 4 (see Figure 2).

[0043] 3(B), when the outboard motor 1 is viewed from the rear, the discharge port 29 is disposed above the propeller unit case 6 and vertically above the center of rotation A of the propeller 5. The discharge port 29 is also located in front of the propeller 5. The discharge port 29 is also located at the rear of the outboard motor 1 and faces in a direction parallel to the axis E of the propeller shaft 4.

[0044] In this embodiment, the passage forming portion 23 is made of a transparent resin. Also, as shown in Fig. 2, each connecting portion 9 is provided with a window 31. The window 31 is formed by a through hole penetrating the connecting portion 9. In each connecting portion 9, the window 31 is disposed at a position corresponding to the passage forming portion 23 when the fine dust capture device 21 is provided in the space R. This allows the user to check the amount of fine dust accumulated in the filter 28 by looking through the window 31 when the outboard motor 1 is pulled up onto land, for example.

[0045] In this embodiment, the fine dust capture device 21 can be removed from the space R. 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. The filter 28 is detachably attached to the rear of the passage forming portion 23, the front of the discharge port forming portion 25, or between the passage forming portion 23 and 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, he or she can remove the fine dust capture device 21 from the outboard motor 1 and replace the filter 28, for example.

[0046] (Capturing microscopic dust particles) When the outboard motor 1 is attached to the transom of a boat on the water, the propeller unit 2 and the fine dust capture device 21 are submerged below the water surface. When the propeller 5 rotates and the boat moves forward by the propulsive force generated by the propeller 5, water flows around the outboard motor 1 in the longitudinal direction from the front to the rear of the outboard motor 1. The fine dust capture device 21 is placed in this water flow. The water around the outboard motor 1 flows from the front of the outboard motor 1 through the water intake 26 into the passage 27. The water that flows into the passage 27 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.

[0047] The water intake 26 is located below the water surface, disposed at the front of the outboard motor 1, disposed in close proximity to the propeller unit case 6, and facing forward of the outboard motor 1. Therefore, water smoothly flows into the passage 27 through the water intake 26 as the boat moves forward.

[0048] The passage 27 is located entirely below the water surface and is disposed in close proximity to the propeller unit case 6. The passage 27 extends in the fore-and-aft direction of the outboard motor 1 as a whole, from the water intake 26 to the discharge outlet 29. Therefore, the resistance (flow path resistance) of the passage 27 is small, and water that flows into the passage 27 flows smoothly within the passage 27.

[0049] In addition, the outlet 29 is located below the water surface, in front of the propeller 5, and in a position close to the propeller unit case 6, facing the rear of the outboard motor 1. Therefore, the water in the passage 27 is smoothly discharged outside the passage 27 from the outlet 29 due to the negative pressure created by the water flow generated by the rotation of the propeller.

[0050] The water around the outboard motor 1 flows smoothly through the passage 27 from the intake 26 to the discharge outlet 29 due to the pressure of the water flowing into the passage 27 via the intake 26 and the negative pressure created by the water flow generated by the rotation of the propeller 5. The water then passes through the filter 28, where fine dust particles are captured.

[0051] As described above, in the outboard motor 1 according to the embodiment of the present invention, the fine dust trapping device 21 is disposed between the lower end of the support portion 8 and the propeller unit case 6 so that the extension direction of the passage 27 is the fore-aft direction of the outboard motor 1. With this configuration, when the outboard motor 1 is mounted on the boat, the fine dust trapping device 21 is located below the water surface. The fine dust trapping device 21 is placed in a water current that flows around the outboard motor 1 from the front to the rear of the outboard motor 1 when the boat moves forward. When the fine dust trapping device 21 is placed in this water current, the direction of this water current and the extension direction of the passage 27 of the fine dust trapping device 21 coincide with each other. Therefore, according to the outboard motor 1 according to the embodiment, the water around the outboard motor 1 flows more smoothly in the passage 27 of the fine dust trapping device 21 than in a conventional outboard motor provided with a fine dust trapping device whose passage extension direction is the up-down direction. Therefore, the flow rate of water flowing through the passage 27 of the fine dust trapping device 21 can be increased, and therefore the flow rate of water passing through the filter 28 can be increased. As a result, the amount of fine dust trapped per unit sailing time or the amount of fine dust trapped per unit sailing distance can be increased, and the fine dust trapping efficiency can be improved. Furthermore, in the outboard motor 1 of this embodiment, the flow rate of water flowing through the passage 27 of the fine dust trapping device 21 can be increased without adding a pump, so that it is possible to prevent the structure of the fine dust trapping device 21 from becoming complicated, the outboard motor 1 from becoming larger, or the manufacturing cost of the outboard motor 1 from increasing, which would be caused by adding a pump. In this way, according to the outboard motor 1 of this embodiment, it is possible to improve the fine dust trapping efficiency while avoiding the structure of the fine dust trapping device 21 from becoming complicated, the outboard motor 1 from becoming larger, or the manufacturing cost of the outboard motor 1 from increasing.

[0052] Furthermore, in the outboard motor 1 according to the embodiment of the present invention, the fine dust capture device 21 is disposed in the left-right center of the lower end of the support part 8. This allows the fine dust capture device 21 to be reliably placed in the fore-and-aft water flow that is formed around the outboard motor 1 when the boat is moving forward. This makes it possible to increase the flow rate of water that flows in from the water intake 26 and flows through the passage 27, thereby improving the efficiency of capturing fine dust.

[0053] In the outboard motor 1 according to the embodiment of the present invention, two connecting portions 9 are provided at the lower end of the support portion 8, one of which connects the lower end of the support portion 8 to the left portion (specifically, the upper left portion) of the propeller unit case 6, and the other connecting portion 9 connects the lower end of the support portion 8 to the right portion (specifically, the upper right portion) of the propeller unit case 6. A space R is formed between the lower end of the support portion 8 and the left-right center of the upper portion of the propeller unit case 6, and a fine dust capture device 21 is provided in the space R. With this configuration, the fine dust capture device 21 can be disposed at the left-right center of the lower end of the support portion 8.

[0054] In the outboard motor 1 according to the embodiment of the present invention, one of the two joints 9 extends downward from the lower end of the support part 8 while inclining to the left, and reaches the left part (specifically, the upper left part) of the propeller unit case 6, and the other joint 9 extends downward from the lower end of the support part 8 while inclining to the right, and reaches the right part (specifically, the upper right part) of the propeller unit case 6. With this configuration, the two joints 9 and the upper part of the propeller unit case 6 have a triangular structure with vertices at positions P1, P2, and P3, as shown in FIG. 5. This makes it possible to increase the joint strength between the support part 8 and the propeller unit case 6. That is, the support strength of the propeller unit 2 by the support part 8 is increased, and deformation or damage to the joint between the support part 8 and the propeller unit 2 can be suppressed when an external force is applied to the lower part of the outboard motor 1 from the left, right, above, or below, for example.

[0055] Furthermore, in the outboard motor 1 according to the embodiment of the present invention, the fine dust capturing device 21 is in contact with the upper 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 that is formed around the outboard motor 1 when the boat moves forward.

[0056] In the outboard motor 1 according to the embodiment of the present invention, the shape of the space R is triangular when the outboard motor 1 is viewed from the front, the main body 22 of the fine dust capture device 21 is formed in a cylindrical shape having a triangular cross section, and the fine dust capture device 21 is provided in the space R such that the triangular cross section of the main body 22 matches the triangular shape of the space R. This allows the cross-sectional area of ​​the main body 22 to be approximately equal to the area of ​​the space R when the outboard motor 1 is viewed from the front, and the cross-sectional area of ​​the main body 22 to be as large as possible. This allows the opening areas of the water intake 26 and discharge 29 of the fine dust capture device 21, and the flow passage area of ​​the passage 27 to be increased. This allows the flow rate of water flowing through the passage 27 to be increased.

[0057] In the outboard motor 1 according to the embodiment of the present invention, the fine dust capture device 21 includes a cylindrical main body 22, a water intake 26 provided at one axial end of the main body 22, a passage 27 extending axially within the main body 22, a filter 28 provided midway through the passage within the main body 22, and an outlet 29 provided at the other axial end of the main body 22. This configuration simplifies the structure of the fine dust capture device 21 and shortens the length of the passage 27. This reduces the resistance (flow path resistance) of the passage 27, making it easier for water to flow through the passage 27.

[0058] In the fine dust capture device 21 of the outboard motor 1 according to the embodiment of the present invention, the passage forming portion 23 of the main body 22 is made of a transparent material, each joint 9 is formed with a window 31 penetrating the joint 9, and when the fine dust capture device 21 is provided in the space R, the window 31 is disposed at a position corresponding to the transparent passage forming portion 23. When the outboard motor 1 is pulled up onto land, for example, the user can easily check the amount of fine dust accumulated in the filter 28 by looking through the window 31. This allows the user to recognize that a large amount of fine dust has accumulated (for example, that the filter 28 needs replacing) without providing the outboard motor 1 with a sensor or the like for detecting the accumulation state of fine dust.

[0059] In the above embodiment, the fine dust capture device 21 is in contact with the upper surface of the propeller unit case 6, but the fine dust capture device 21 does not have to be in contact with the upper surface of the propeller unit case 6 as long as it is positioned between the lower end of the support portion 8 and the propeller unit case 6.

[0060] In addition, in the above embodiment, the shape of the main body 22 of the micro-dust capture device 21 is a triangular tube, but the shape of the main body 22 is not limited to this and may be a cylinder or a polygonal tube with four or more sides in cross section.

[0061] In addition, in the above embodiment, an example was given of the case where the exhaust outlet 29 of the fine dust capturing device 21 faces directly rearward of the outboard motor 1, but the direction of the exhaust outlet 29 may be, for example, lower rear, upper rear, left rear, right rear or lower left rear, or it may be upward, downward, left or right.

[0062] In the above embodiment, the window 31 is provided in each of the two connecting portions 9, but the window 31 may be provided in only one of the connecting portions 9.

[0063] 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]

[0064] 1 Outboard motor 2 Propeller unit 4 Propeller shaft 5 Propeller 6 Propeller unit case (case) 8 Support part 9 Joint part 17 Transom bracket (bracket) 21 Fine dust capture device 22 Main body 23 Passage forming part 26 Water Intake 27 Passage 28 Filters 29 Outlet 31 Window (through hole) R space

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 a lower end thereof; A bracket provided on an upper portion of the support portion for attaching the support portion to the vessel; a fine dust capture device having a passage for circulating water around the outboard motor and capturing fine dust contained in the water flowing through the passage, an outboard motor, the fine dust trapping device being disposed between a lower end of the support portion and the case so that the passage extends in a fore-aft direction of the outboard motor;

2. 2. An outboard motor according to claim 1, wherein the fine dust trapping device is disposed at the center in the left-right direction of the lower end of the support portion.

3. 2. An outboard motor as claimed in claim 1, characterized in that the lower end of the support portion is provided with two connecting portions, one of which connects the lower end of the support portion to a left portion of the case and the other of which connects the lower end of the support portion to a right portion of the case, a space is formed between the lower end of the support portion and a left-right center portion of an upper portion of the case, and the fine dust capture device is provided in the space.

4. 4. An outboard motor according to claim 3, wherein one of the two connecting portions extends downward from the lower end of the support portion while slanting to the left and reaching the left part of the case, and the other connecting portion extends downward from the lower end of the support portion while slanting to the right and reaching the right part of the case.

5. 5. An outboard motor according to claim 3, wherein the fine dust trapping device is in contact with an upper surface of the case.

6. An outboard motor as described in claim 3 or 4, characterized in that the shape of the space is triangular when viewed from the front of the outboard motor, the fine dust capture device is formed in a cylindrical shape having a triangular cross-sectional shape, and the fine dust capture device is provided within the space such that the triangular cross-sectional shape of the fine dust capture device matches the triangular shape of the space.

7. The fine dust capturing device is A main body portion formed in a cylindrical shape; a water intake provided at one axial end of the main body for allowing water around the outboard motor to flow into the passage; a filter provided in the passage within the main body and configured to allow water flowing through the passage to pass therethrough and thereby capture fine dust particles contained in the water; a discharge port provided on the other axial end side of the main body for discharging water that has passed through the filter to an area around the outboard motor, 5. An outboard motor according to claim 3, wherein the passage extends within the body in an axial direction of the body.

8. 8. An outboard motor as described in claim 7, characterized in that at least a portion of the main body is made of a transparent material, at least one of the two connecting portions is formed with a through hole passing through the connecting portion, and when the fine dust capture device is provided in the space, the through hole is disposed at a position corresponding to the portion of the main body made of the transparent material.

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