Outboard engine and boat

Abstract

To inhibit air from accumulating in a water pipe or a coolant flow path.SOLUTION: An outboard engine includes: a drive source including an electric motor; a coolant tube through which a coolant to cool the drive source flows; a water tube through which water from the outside flows; and a heat exchanger provided with a coolant flow path through which the coolant from the coolant tube flows and a water flow path through which the water from the water tube flows. At least one of the coolant flow path and the water flow path includes a first flow path extending in a direction intersecting with a vertical direction, a second flow path located lower than the first flow path and extending in the direction intersecting with the vertical direction, and a first folded portion connecting one end of the first flow path with one end of the second flow path. The first flow path is provided with a first continuous hole communicating with the outside of the heat exchanger, and the ceiling surface forming the first flow path inclines obliquely upward toward the first continuous hole.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an outboard motor and a watercraft. [Background technology]

[0002] The boat includes a hull and an outboard motor attached to the rear of the hull. The outboard motor is a device that generates thrust to propel the boat.

[0003] Conventionally, outboard motors have been known that include a drive source including an electric motor and a configuration for cooling the drive source. Specifically, the outboard motor is equipped with a refrigerant pipe through which a refrigerant for cooling the drive source flows, a water pipe through which external water flows, and a heat exchanger. Inside the heat exchanger, a refrigerant flow path through which the refrigerant from the refrigerant pipe flows and a water flow path through which water from the water pipe flows are formed. The ceiling surface of the refrigerant flow path extends horizontally toward the refrigerant inlet and outlet. The ceiling surface of the water flow path also extends horizontally toward the water inlet and outlet (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-228528 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in a heat exchanger provided in a conventional outboard motor, the ceiling surface of the refrigerant passage and the ceiling surface of the water passage both extend horizontally toward the inlet / outlet of the refrigerant or water, so air is likely to accumulate in the refrigerant passage or the water passage. If air accumulates in the refrigerant passage or the water passage, for example, heat exchange between the refrigerant and the water is not performed in the portion where the air accumulates, so there is a risk of a decrease in the efficiency of heat exchange in the heat exchanger.

[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The technology disclosed in this specification can be realized, for example, in the following forms.

[0008] (1) An outboard motor disclosed in this specification includes a drive source including an electric motor, a refrigerant pipe through which a refrigerant for cooling the drive source flows, a water pipe through which external water flows, and a heat exchanger having a refrigerant flow path through which the refrigerant from the refrigerant pipe flows and a water flow path through which the water from the water pipe flows. At least one of the refrigerant flow path and the water flow path has a first flow path portion extending in a direction intersecting the vertical direction, a second flow path portion located below the first flow path portion and extending in a direction intersecting the vertical direction, and a first folded portion connecting one end of the first flow path portion and one end of the second flow path portion. A first communication hole communicating with the outside of the heat exchanger is formed in the first flow path portion, and a ceiling surface forming the first flow path portion is inclined obliquely upward toward the first communication hole.

[0009] In this configuration, since at least one of the refrigerant flow path and the water flow path has a shape with a folded portion, the efficiency of heat exchange in the heat exchanger can be improved by the amount of fluid flowing through the heat exchanger being larger than, for example, a configuration in which the flow path is linear. Also, with this configuration, it is possible to suppress air from accumulating in the first flow path portion, compared to, for example, a configuration in which the ceiling surface forming the first flow path portion extends along the horizontal direction or a configuration in which the ceiling surface is inclined obliquely upward toward a blocked portion different from the first communication hole.

[0010] (2) In the above outboard motor, the first communication hole may be an inlet or outlet hole for the fluid, which is the refrigerant or the water, and may be formed in an end of the first flow passage portion opposite the first turning portion. With this configuration, the inlet or outlet hole for the fluid can be used as an air bleed hole without providing a separate hole.

[0011] (3) In the above outboard motor, a ceiling surface of the second passage portion may be configured to be inclined obliquely upward toward the first turning portion. With this configuration, it is possible to prevent air from stagnating not only in the first passage portion but also in the second passage portion.

[0012] (4) In the above outboard motor, the bottom surface of the first flow passage portion may have a first inclined surface portion that inclines obliquely downward from the first bent portion along the ceiling surface of the second flow passage portion, and a first through-hole that penetrates the ceiling surface of the second flow passage portion is formed at a lower end of the first inclined surface portion. With this configuration, it is possible to increase the fluid storage capacity in the flow passage and prevent fluid from remaining in the first flow passage portion when the heat exchanger is stopped, compared to, for example, a configuration in which the bottom surface of the first flow passage portion inclines obliquely upward from the first bent portion.

[0013] (5) In the above outboard motor, the at least one flow passage has a third flow passage portion extending in a direction intersecting the vertical direction, a fourth flow passage portion located above the third flow passage portion and extending in a direction intersecting the vertical direction, and a second turn-back portion connecting one end of the third flow passage portion to one end of the fourth flow passage portion. A second communication hole communicating with the outside may be formed in an end of the third flow passage portion opposite to the second turn-back portion, and a bottom surface of the third flow passage portion may be inclined obliquely downward toward the second communication hole. This configuration can suppress fluid (refrigerant, water) from remaining in the second flow passage portion, compared to, for example, a configuration in which the bottom surface forming the third flow passage portion extends along the horizontal direction or a configuration in which the bottom surface is inclined obliquely downward toward a blocked portion different from the second communication hole.

[0014] (6) In the above outboard motor, a ceiling surface of the third passage portion may be configured to slope obliquely upward toward the second turning portion. With this configuration, it is possible to prevent air from stagnating not only in the first passage portion but also in the fourth passage portion.

[0015] (7) In the above outboard motor, the bottom surface of the fourth flow passage portion has a second inclined surface portion that inclines obliquely downward from the second turning portion along the ceiling surface of the third flow passage portion. A second through hole that penetrates the ceiling surface of the third flow passage portion may be formed at a lower end of the second inclined surface portion. With this configuration, it is possible to increase the fluid storage capacity of the flow passage and prevent fluid from remaining in the fourth flow passage portion when the heat exchanger is stopped, compared to, for example, a configuration in which the bottom surface of the fourth flow passage portion inclines obliquely downward toward the second turning portion.

[0016] (8) In the above outboard motor, both the refrigerant flow path and the water flow path have the first flow path portion, the second flow path portion, and the first turn portion. One of the refrigerant flow path and the water flow path may be configured so that the refrigerant flows from the first flow path portion to the second flow path portion via the first turn portion, and the other of the refrigerant flow path and the water flow path may be configured so that the water flows from the second flow path portion to the first flow path portion via the first turn portion. With this configuration, the flow of fluid in the refrigerant flow path and the water flow path is opposite to each other, so that the heat exchange efficiency of the heat exchanger can be improved compared to, for example, a configuration in which the flow of fluid in the refrigerant flow path and the water flow path is the same.

[0017] (9) In the above outboard motor, the water flow path may be configured such that a water inlet hole is formed at a lower end of the water flow path and a water outlet hole is formed at an upper end of the water flow path, and further includes a discharge pipe that communicates with the outlet hole and discharges water in the water flow path to the outside of the outboard motor, and a sub-discharge pipe that extends upward from a position in the water flow path higher than the outlet hole and opens into a space outside the heat exchanger. With this configuration, for example when the outboard motor is stopped, outside air flows into the water flow path through the sub-discharge pipe, so that the water in the water flow path can be discharged to the outside of the heat exchanger quickly.

[0018] (10) The watercraft may include a hull and the outboard motor attached to a rear portion of the hull. With this configuration, it is possible to prevent air from accumulating in the first flow passage portion of the heat exchanger.

[0019] (11) An outboard motor disclosed in this specification includes a drive source including an electric motor, a refrigerant pipe through which a refrigerant for cooling the drive source flows, a water pipe through which external water flows, and a heat exchanger having a refrigerant flow path through which the refrigerant from the refrigerant pipe flows and a water flow path through which water from the water pipe flows. At least one of the refrigerant flow path and the water flow path has a third communication hole that communicates with the outside of the heat exchanger, and a ceiling surface that forms the flow path is inclined obliquely upward toward the third communication hole. This outboard motor can prevent air from accumulating in the first flow path portion of the heat exchanger.

[0020] The technology disclosed in this specification can be realized in various forms, for example, in the form of an outboard motor, a boat equipped with an outboard motor and a hull, etc. Effect of the Invention

[0021] According to this outboard motor, it is possible to improve the efficiency of heat exchange in the heat exchanger while preventing air from stagnation in the flow passages formed inside the heat exchanger. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a ship 10 according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a side view showing a schematic configuration of an outboard motor 100 according to an embodiment of the present invention. [Diagram 3] FIG. 2 is an explanatory diagram showing a schematic view of a part of the internal configuration of the outboard engine body 110. [Figure 4] FIG. 4 is an explanatory diagram showing a schematic configuration of the entire refrigerant flow path 400. [Diagram 5] FIG. 4 is an exploded view illustrating the configuration of the heat exchanger 440. [Figure 6] An explanatory diagram showing a detailed configuration of the water flow body 442W. [Figure 7] FIG. 4 is an explanatory diagram showing a detailed configuration of a refrigerant flow body 442C. [Figure 8] FIG. 13 is an explanatory diagram showing the function of the sub-exhaust pipe 700. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A. Embodiment: A-1. Ship 10 configuration: FIG. 1 is a perspective view showing a schematic configuration of a ship 10 according to the present embodiment. In FIG. 1 and other drawings described later, arrows are shown in each direction based on the position of the ship 10. More specifically, in each drawing, arrows are shown representing the front (FRONT), rear (REAR), left (LEFT), right (RIGHT), upper (UPPER), and lower (LOWER). The front-rear direction, left-right direction, and up-down direction are directions perpendicular to each other. In this specification, an axis, member, etc. extending in the front-rear direction does not necessarily have to be parallel to the front-rear direction. An axis or member extending in the front-rear direction includes an axis or member inclined within a range of ±45° with respect to the front-rear direction. Similarly, an axis or member extending in the up-down direction includes an axis or member inclined within a range of ±45° with respect to the up-down direction, and an axis or member extending in the left-right direction includes an axis or member inclined within a range of ±45° with respect to the left-right direction.

[0024] The boat 10 includes a hull 200 and an outboard motor 100. In this embodiment, the boat 10 includes one outboard motor 100, but the boat 10 may include a plurality of outboard motors 100.

[0025] (Configuration of hull 200) The hull 200 is a portion of the vessel 10 on which crew members board. The hull 200 has a hull main body 202 having a living space 204, a cockpit 240 installed in the living space 204, and a steering device 250 installed near the cockpit 240. The steering device 250 is a device for maneuvering the vessel, and has, for example, a steering wheel 252, a shift / throttle lever 254, a joystick 255, a monitor 256, and an input device 258. The hull 200 also has a partition wall 220 that defines the rear end of the living space 204, and a transom 210 located at the rear end of the hull 200. A space 206 exists between the transom 210 and the partition wall 220 in the fore-and-aft direction.

[0026] (Configuration of outboard motor 100) 2 is a side view showing a schematic configuration of the outboard motor 100 according to this embodiment. The following describes the outboard motor 100 in the reference position, unless otherwise specified. The reference position is a position in which the rotation axis Ac of the output shaft 123 (described later) extends in the vertical direction, and the rotation axis Ap of the propeller shaft 135 (described later) extends in the front-rear direction. The front-rear direction, the left-right direction, and the up-down direction are each determined based on the outboard motor 100 in the reference position.

[0027] The outboard motor 100 is a device that generates thrust to propel the boat 10. The outboard motor 100 is attached to a transom 210 at the rear of a hull 200. The outboard motor 100 has an outboard motor body 110 and a suspension device 150.

[0028] (Configuration of the outboard engine body 110) The outboard engine body 110 has a waterproof case 112 , a middle case 116 , a lower case 118 , a motor assembly 120 , a control assembly 500 , a transmission mechanism 130 , a propeller 111 , and a steering mechanism 140 .

[0029] The waterproof case 112 is a container arranged on the upper part of the outboard motor main body 110. The waterproof case 112 houses an electric motor 122 and electrical components, which will be described later, to protect the electric motor 122 and the electrical components from exposure to seawater. The waterproof case 112 has an upper cover 113 that forms the upper part of the waterproof case 112, and a lower box 114 that forms the lower part of the waterproof case 112. The lower box 114 has a box shape with an open top. The upper cover 113 is removably attached to the lower box 114 so as to cover the upper part (opening) of the lower box 114.

[0030] The middle case 116 is a housing located below the waterproof case 112 and disposed near the center in the up-down direction of the outboard motor main body 110. The upper part of the middle case 116 is connected to the lower box 114 of the waterproof case 112.

[0031] The lower case 118 is located below the middle case 116 and is a housing disposed at the bottom of the outboard motor main body 110.

[0032] The motor assembly 120 is housed inside the waterproof case 112. The motor assembly 120 includes an electric motor 122 as a drive source. The electric motor 122 is a prime mover that generates power. The electric motor 122 has an output shaft 123 that outputs the drive force generated by the electric motor 122. The output shaft 123 is disposed in a position in which its rotation axis Ac extends in the vertical direction.

[0033] The control assembly 500 is housed inside the waterproof case 112 and is disposed above the motor assembly 120. The control assembly 500 controls the rotation of the electric motor 122 and the like.

[0034] The transmission mechanism 130 is a mechanism that transmits the driving force of the electric motor 122 to the propeller 111. The transmission mechanism 130 has a primary reduction gear 300, a drive shaft 133, and a propeller shaft 135.

[0035] The primary reduction gear 300 is housed inside the waterproof case 112 and disposed below the motor assembly 120. The primary reduction gear 300 is coupled to the output shaft 123 of the electric motor 122 and the drive shaft 133. The primary reduction gear 300 reduces the driving force of the electric motor 122 and transmits it to the drive shaft 133. This makes it possible to rotate the propeller 111 with a desired torque.

[0036] The drive shaft 133 is a rod-shaped member that transmits power to the propeller shaft 135, and is disposed in a position extending in the vertical direction. The drive shaft 133 is housed so as to straddle the interior of the waterproof case 112, the interior of the middle case 116, and the interior of the lower case 118.

[0037] The propeller shaft 135 is a rod-shaped member and is disposed relatively below the outboard motor body 110 in a position extending in the fore-and-aft direction. The propeller shaft 135 rotates together with the propeller 111. A front end of the propeller shaft 135 is housed in the lower case 118, and a rear end of the propeller shaft 135 protrudes rearward from the lower case 118.

[0038] A gear is provided on each of the lower end of the drive shaft 133 and the front end of the propeller shaft 135. The gear of the drive shaft 133 and the gear of the propeller shaft 135 mesh with each other, whereby the rotation of the drive shaft 133 is transmitted to the propeller shaft 135.

[0039] The propeller 111 is a rotating body having a plurality of blades, and is attached to the rear end of the propeller shaft 135. The propeller 111 rotates in conjunction with the rotation of the propeller shaft 135 about the rotation axis Ap. The propeller 111 generates thrust for propelling the vessel 10 by rotating.

[0040] The steering mechanism 140 is a mechanism for controlling the change of the traveling direction of the boat 10. The steering mechanism 140 has a steering shaft 141. The steering shaft 141 is a hollow tubular member arranged so as to surround the outer periphery of the drive shaft 133. At least a part of the steering shaft 141 is housed in the middle case 116 and supported so as to be rotatable about a rotation axis As. A lower part of the steering shaft 141 protrudes downward from the middle case 116 and is connected to the lower case 118. The steering shaft 141 rotates about the rotation axis As by the driving force of a drive motor (not shown) housed in the middle case 116, for example. When the steering shaft 141 rotates, the lower case 118 connected to the steering shaft 141 also rotates, and the direction of the propeller 111 is changed. As a result, the direction of the thrust generated by the propeller 111 is changed, and the boat 10 is steered.

[0041] (Configuration of Suspension Device 150) The suspension device 150 is a device that suspends the outboard motor body 110 to the hull 200. The suspension device 150 has a pair of left and right clamp brackets 152, a tilt shaft 154, and a swivel bracket 156.

[0042] The pair of left and right clamp brackets 152 are disposed at the rear of the hull 200, spaced apart from each other in the left-right direction, and are fixed to the transom 210 of the hull 200, for example, by bolts.

[0043] The tilt shaft 154 is a rod-shaped member, and is rotatably supported by the clamp bracket 152. A tilt axis At, which is the center line of the tilt shaft 154, constitutes an axis in the horizontal direction (left-right direction) during tilt operation of the outboard motor 100.

[0044] The swivel bracket 156 is disposed so as to be sandwiched between a pair of clamp brackets 152, and is supported by the clamp brackets 152 via a tilt shaft 154 so as to be rotatable about the tilt axis At. The swivel bracket 156 is driven to rotate about the tilt axis At relative to the clamp brackets 152 by a tilt device (not shown) including an actuator such as a hydraulic cylinder.

[0045] When the swivel bracket 156 rotates about the tilt axis At relative to the clamp bracket 152, the outboard motor body 110 supported by the swivel bracket 156 also rotates about the tilt axis At. This achieves a tilt operation that rotates the outboard motor body 110 up and down relative to the hull 200. The tilt operation of the outboard motor 100 makes it possible to change the angle of the outboard motor body 110 about the tilt axis At within a range from a tilt down state in which the propeller 111 is located underwater (a state in which the outboard motor 100 is in a reference position) to a tilt up state in which the propeller 111 is located above the water surface. Note that a trim operation can also be performed to adjust the attitude of the boat 10 while traveling by adjusting the angle of the outboard motor body 110 about the tilt axis At.

[0046] A-2. Internal structure of the outboard engine body 110: Fig. 3 is an explanatory diagram that shows a schematic view of a portion of the internal configuration of the outboard motor main body 110. Fig. 4 is an explanatory diagram that shows a schematic view of the configuration of an overall refrigerant flow path 400. Figs. 3 and 4 show the internal structure housed inside the waterproof case 112. As shown in Figs. 3 and 4, the outboard motor 100 is formed with an overall refrigerant flow path 400, which is a series of flow paths through which coolant liquid C circulates.

[0047] The coolant C circulates inside the outboard motor body 110 to cool the electric motor 122 and the MCU 510 (described later). The coolant C is an antifreeze liquid containing, for example, ethylene glycol or propylene glycol as a main component. The coolant C is an example of a refrigerant.

[0048] As shown in FIG. 3, the control assembly 500 has a control case 502, an MCU (Motor Control Unit) 510, and a power supply line 520 (see FIG. 2). The MCU 510 is a circuit board that controls the rotation of the electric motor 122, etc. The control case 502 houses the MCU 510. Inside the control case 502, a space 512 that is a flow path through which the coolant liquid C flows is formed. In other words, the entire refrigerant flow path 400 includes the space 512 formed inside the control case 502. The power supply line 520 supplies power to the MCU 510 from a battery or the like (not shown) arranged in the hull 200.

[0049] As shown in FIG. 4, the outboard motor 100 further includes a motor cooling device 126, an air bleeder 420, a filler 450, a heat exchanger 440, a pump 410, and a plurality of refrigerant pipes 430a to 430f.

[0050] The motor cooling device 126 has an annular configuration when viewed in the up-down direction, and is disposed so as to surround the outer periphery of the electric motor 122. A space that is a flow path through which the coolant liquid C flows is formed inside the motor cooling device 126. In other words, the entire refrigerant flow path 400 includes the space formed inside the motor cooling device 126.

[0051] The air vent 420 has an opening for releasing air mixed in the entire refrigerant flow path 400 to the atmosphere. The air vent 420 expels air from the entire refrigerant flow path 400, thereby improving the cooling efficiency of the electric motor 122 and the MCU 510. The air vent 420 is located at the top of the entire refrigerant flow path 400.

[0052] The filler 450 has an opening that functions as a spout for the coolant liquid C in the entire refrigerant flow path 400. The opening of the filler 450 also has a function of releasing air mixed in the entire refrigerant flow path 400 to the atmosphere. The filler 450 is located relatively high in the entire refrigerant flow path 400, and more specifically, is located higher than the electric motor 122 and the motor cooling device 126.

[0053] The heat exchanger 440 is a device that exchanges heat between the coolant C and seawater W pumped up from outside the outboard motor 100 by, for example, a pump (not shown). The coolant C becomes relatively hot by passing near the electric motor 122 and the MCU 510, but is cooled by exchanging heat with seawater in the heat exchanger 440. The detailed configuration of the heat exchanger 440 will be described later.

[0054] The pump 410 is a device that pumps and delivers the coolant liquid C. The pump 410 is connected to a refrigerant pipe 430a (described later) and a refrigerant pipe 430f (described later). The coolant liquid C circulates through the entire refrigerant flow path 400 by the operation of the pump 410. The pump 410 is located relatively low in the entire refrigerant flow path 400, and more specifically, is located lower than the MCU 510 and the control case 502.

[0055] The plurality of refrigerant pipes 430a-430f are hollow tubular members extending from one end to the other, and the space formed inside each of them constitutes at least a part of the entire refrigerant flow path 400. Each of the refrigerant pipes 430a-430f is configured such that the coolant liquid C flows from one end to the other end by the operation of the pump 410.

[0056] The refrigerant pipe 430a constitutes a portion of the entire refrigerant flow path 400 that extends from the pump 410 to the control case 502. One end of the refrigerant pipe 430a is connected to the pump 410, thereby communicating with a flow path of the coolant liquid C formed in the pump 410. The other end of the refrigerant pipe 430a is connected to the control case 502, thereby communicating with a space 512 of the control case 502.

[0057] The refrigerant pipe 430b constitutes a portion of the entire refrigerant flow path 400 that extends from the control case 502 to the air vent 420. One end of the refrigerant pipe 430b is connected to the control case 502, thereby communicating with the space 512 of the control case 502. The other end of the refrigerant pipe 430b is connected to an end portion of one end of the refrigerant pipe 430c, thereby communicating with the refrigerant pipe 430c. The lower end of the refrigerant pipe 430b (the lowermost portion of the refrigerant pipe 430b) is the connection position with the control case 502.

[0058] The refrigerant pipe 430c constitutes a portion of the entire refrigerant flow path 400 that runs from the air vent 420 to the motor cooling device 126. One end of the refrigerant pipe 430c is connected to the air vent 420. The other end of the refrigerant pipe 430c is connected to the motor cooling device 126, and thereby communicates with a space formed inside the motor cooling device 126.

[0059] Refrigerant pipe 430d constitutes a portion of overall refrigerant flow path 400 that extends from motor cooling device 126 to filler 450. One end of refrigerant pipe 430d is connected to motor cooling device 126, thereby communicating with a space formed inside motor cooling device 126. The other end of refrigerant pipe 430d is connected to one end of refrigerant pipe 430e, thereby communicating with refrigerant pipe 430e. The lower end of refrigerant pipe 430d (the lowermost part of refrigerant pipe 430d) is the connection position with motor cooling device 126.

[0060] The refrigerant pipe 430e constitutes a portion of the entire refrigerant flow path 400 that extends from the filler 450 to the heat exchanger 440. One end of the refrigerant pipe 430e is connected to the filler 450. The other end of the refrigerant pipe 430e is connected to the heat exchanger 440, and thereby communicates with the flow path of the coolant liquid C formed in the heat exchanger 440.

[0061] The refrigerant pipe 430f constitutes a portion of the entire refrigerant flow path 400 that extends from the heat exchanger 440 to the pump 410. One end of the refrigerant pipe 430f is connected to the heat exchanger 440, thereby communicating with a flow path of the coolant liquid C formed in the heat exchanger 440. The other end of the refrigerant pipe 430f is connected to the pump 410, thereby communicating with the flow path of the coolant liquid C formed in the pump 410.

[0062] A-3. Details of cooling method for each device using coolant C: The entire refrigerant flow path 400 is configured such that the coolant liquid C pumped from the pump 410 flows through the MCU 510, the air vent 420, the motor cooling device 126, the filler 450, and the heat exchanger 440 in that order, and is circulated back to the pump 410.

[0063] Specifically, first, the coolant C flows out of the pump 410, passes through the refrigerant pipe 430a, and then flows into the space 512. The coolant C that has flowed into the space 512 flows near the MCU 510, thereby cooling the MCU 510.

[0064] Next, coolant C flows out of space 512, passes through refrigerant pipe 430b, and flows into refrigerant pipe 430c, and flows near air vent 420. At this time, if air is mixed into coolant C, the air flows toward air vent 420, which is located above the connection position between refrigerant pipe 430b and refrigerant pipe 430c, and is released into the atmosphere through air vent 420 (arrow A in FIGS. 3 and 4).

[0065] Next, the coolant liquid C passes through the refrigerant pipe 430c and flows into a space formed inside the motor cooling device 126. The coolant liquid C that has flowed into the space formed inside the motor cooling device 126 flows near the electric motor 122, thereby cooling the electric motor 122.

[0066] Next, coolant C flows out of a space formed inside motor cooling device 126, passes through refrigerant pipe 430d, flows into refrigerant pipe 430e, and flows near filler 450. At this time, if air is mixed into coolant C, the air flows toward filler 450 located above the connection position between refrigerant pipe 430d and refrigerant pipe 430e, and is released into the atmosphere through filler 450 (arrow A in FIGS. 3 and 4).

[0067] Next, the coolant C passes through the refrigerant pipe 430e and flows into the heat exchanger 440. In the heat exchanger 440, heat is exchanged with seawater pumped up from outside the outboard motor 100, and the coolant C is cooled.

[0068] Next, the coolant liquid C flows out of the heat exchanger 440, passes through the refrigerant pipe 430f, and flows into the pump 410. In this manner, the coolant liquid C circulates through the entire refrigerant flow path 400.

[0069] A-4. Detailed configuration of heat exchanger 440: FIG. 5 is an explanatory diagram showing an exploded configuration of the heat exchanger 440. As shown in FIG. 5, the heat exchanger 440 is disposed, for example, on the side of the motor assembly 120. The heat exchanger 440 has a water circulating body 442W, a refrigerant circulating body 442C, and a heat exchange plate 444. A water flow path 600W through which seawater W flows is formed inside the water circulating body 442W. A refrigerant flow path 600C through which coolant liquid C flows is formed inside the refrigerant circulating body 442C (see FIG. 6 described later). The heat exchange plate 444 is disposed between the water circulating body 442W and the refrigerant circulating body 442C, and exchanges heat between the water circulating body 442W and the refrigerant circulating body 442C.

[0070] (Heat Exchange Plate 444): The heat exchange plate 444 is a flat plate-like member arranged perpendicular to the opposing direction of the water flow body 442W and the refrigerant flow body 442C, and is made of a material with high thermal conductivity, such as metal.

[0071] (Water fluid 442W): FIG. 6 is an explanatory diagram showing a detailed configuration of the water flow body 442W. The water flow body 442W has a generally flat plate shape. FIG. 6 shows the configuration of the inner side surface 441W of the water flow body 442W that faces the heat exchange plate 444. A groove that constitutes a water flow path 600W is formed on this inner side surface 441W, and the heat exchange plate 444 is arranged so as to cover the inner side surface 441W including this groove. That is, the water flow path 600W is formed by the groove formed in the water flow body 442W and the left surface of the heat exchange plate 444, and the seawater W flowing through the water flow path 600W comes into direct contact with the heat exchange plate 444. Hereinafter, the groove formed in the water flow body 442W may be referred to as the water flow path 600W.

[0072] The water flow path 600W is an S-shaped flow path as a whole, and includes an upper flow path portion 610W, an interrupted flow path portion 620W, a lower flow path portion 630W, an upper turn-back portion 615W, and a lower turn-back portion 625W. The upper flow path portion 610W is an example of a first flow path portion, the interrupted flow path portion 620W is an example of a second flow path portion and a fourth flow path portion, and the lower flow path portion 630W is an example of a third flow path portion. The upper turn-back portion 615W is an example of a first turn-back portion, and the lower turn-back portion 625W is an example of a second turn-back portion.

[0073] The upper flow path portion 610W is located at the top of the water flow path 600W and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The lower flow path portion 630W is located at the bottom of the water flow path 600W and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The interrupted flow path portion 620W is located between the upper flow path portion 610W and the lower flow path portion 630W in the vertical direction and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The upper flow path portion 610W, the interrupted flow path portion 620W, and the lower flow path portion 630W are arranged to overlap each other when viewed in the vertical direction.

[0074] The upper turn-back portion 615W connects the ends (rear ends) of the upper flow path portion 610W and the interrupted flow path portion 620W that are on the same side. An outer peripheral surface 617W of the upper turn-back portion 615W is arc-shaped. The lower turn-back portion 625W connects the ends (front ends) of the interrupted flow path portion 620W and the lower flow path portion 630W that are on the same side. An outer peripheral surface 627W of the lower turn-back portion 625W is arc-shaped.

[0075] An outflow hole 612W communicating with the outside of the heat exchanger 440 is formed in the upper flow passage portion 610W. The outflow hole 612W communicates with a discharge pipe (not shown) that discharges the seawater W to the outside of the outboard motor 100. Moreover, the ceiling surfaces 614W, 616W forming the upper flow passage portion 610W are inclined obliquely upward toward the outflow hole 612W. The outflow hole 612W is an example of a first communication hole. Specifically, the outflow hole 612W is located at the highest position in the water flow passage 600W, and is formed so as to penetrate from the groove constituting the water flow passage 600W to the outer side surface 443W of the water flow body 442W. In other words, the outflow hole 612W faces the ceiling surfaces 614W, 616W.

[0076] The outlet hole 612W is formed on the end (front end) side opposite the upper folded portion 615W. The first ceiling surface 614W is inclined continuously and linearly obliquely upward from a position adjacent to the outer peripheral surface 617W of the upper folded portion 615W toward the outlet hole 612W. The second ceiling surface 616W is located on the opposite side of the first ceiling surface 614W with respect to the outlet hole 612W, and is inclined continuously and linearly obliquely upward toward the outlet hole 612W. The gradient of the first ceiling surface 614W (for example, the gradient angle θ1 is 5 degrees or more) is gentler than the gradient of the second ceiling surface 616W.

[0077] A ceiling surface 622W of the interrupted flow path portion 620W is inclined obliquely upward toward the upper turn-back portion 615W. A bottom surface 618W of the upper flow path portion 610W is inclined obliquely downward from the upper turn-back portion 615W along the ceiling surface 622W of the interrupted flow path portion 620W. A first through-hole 640W is formed at the lower end of the bottom surface 618W, penetrating the ceiling surface 622W of the interrupted flow path portion 620W. The bottom surface 618W is an example of a first inclined surface portion. Specifically, the upper flow path portion 610W and the interrupted flow path portion 620W are separated by a first partition wall 619W. The first partition wall 619W is linear when viewed in the left-right direction, and is inclined so as to be positioned higher as it approaches the upper folded back portion 615W. A first through hole 640W is formed in the lower end portion of the first partition wall 619W.

[0078] An inlet hole 642W communicating with the outside of the heat exchanger 440 is formed in the lower flow path portion 630W. The inlet hole 642W is formed on the end (rear end) side opposite to the lower folded back portion 625W. A bottom surface 634W of the lower flow path portion 630W is inclined obliquely downward toward the inlet hole 642W. The gradient of the bottom surface 634W (for example, the inclination angle θ2 is 5 degrees or more) is approximately the same as the gradient of the first ceiling surface 614W of the upper flow path portion 610W. The inlet hole 642W communicates with a supply pipe 680 through which seawater W pumped up by the pump flows. The inlet hole 642W is an example of a second communication hole, and the supply pipe 680 is an example of a water pipe.

[0079] The ceiling surface 632W of the lower flow path portion 630W is inclined obliquely upward toward the lower turn portion 625W. The bottom surface 624W of the interrupted flow path portion 620W is inclined obliquely downward from the lower turn portion 625W along the ceiling surface 632W of the lower flow path portion 630W. A second through hole 650W is formed at the lower end of the bottom surface 624W, penetrating the ceiling surface 632W of the lower flow path portion 630W. The bottom surface 624W is an example of a second inclined surface portion. Specifically, the lower flow path portion 630W and the interrupted flow path portion 620W are partitioned by a second partition wall 629W. The second partition wall 629W is linear when viewed in the left-right direction, and is inclined so as to be located upward as it approaches the lower turn portion 625W. A second through hole 650W is formed at the lower end of the second partition wall 629W.

[0080] (Refrigerant 442C): FIG. 7 is an explanatory diagram showing a detailed configuration of the refrigerant circulating body 442C. The refrigerant circulating body 442C has a generally flat plate shape. FIG. 7 shows the configuration of the inner side surface 441C of the refrigerant circulating body 442C facing the heat exchange plate 444. A groove that constitutes the refrigerant flow path 600C is formed in the inner side surface 441C, and the heat exchange plate 444 is arranged so as to cover the inner side surface 441C including the groove. That is, the refrigerant flow path 600C is formed by the groove formed in the refrigerant circulating body 442C and the right side surface of the heat exchange plate 444, and the coolant liquid C flowing through the refrigerant flow path 600C comes into direct contact with the heat exchange plate 444. Hereinafter, the groove formed in the refrigerant circulating body 442C may be referred to as the refrigerant flow path 600C. A plurality of cooling fins F are provided on the outer side surface 443C of 442C (see FIG. 5).

[0081] The refrigerant flow path 600C is an S-shaped flow path as a whole, and includes an upper flow path portion 610C, an interrupted flow path portion 620C, a lower flow path portion 630C, an upper folded portion 615C, and a lower folded portion 625C. The upper flow path portion 610C is an example of a first flow path portion, the interrupted flow path portion 620C is an example of a second flow path portion and a fourth flow path portion, and the lower flow path portion 630C is an example of a third flow path portion. The upper folded portion 615C is an example of a first folded portion, and the lower folded portion 625C is an example of a second folded portion.

[0082] The upper flow path portion 610C is located at the top of the refrigerant flow path 600C and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The lower flow path portion 630C is located at the bottom of the refrigerant flow path 600C and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The interrupted flow path portion 620C is located between the upper flow path portion 610C and the lower flow path portion 630C in the vertical direction and extends substantially linearly in a direction (substantially horizontal) intersecting the vertical direction. The upper flow path portion 610C, the interrupted flow path portion 620C, and the lower flow path portion 630C are arranged to overlap each other when viewed in the vertical direction.

[0083] The upper turn-back portion 615C connects the ends (rear ends) of the upper flow path portion 610C and the interrupted flow path portion 620C that are on the same side. An outer peripheral surface 617C of the upper turn-back portion 615C is arc-shaped. The lower turn-back portion 625C connects the ends (front ends) of the interrupted flow path portion 620C and the lower flow path portion 630C that are on the same side. An outer peripheral surface 627C of the lower turn-back portion 625C is arc-shaped.

[0084] The upper flow passage portion 610C is formed with an inlet hole 612C communicating with the outside of the heat exchanger 440. Moreover, a ceiling surface 614C forming the upper flow passage portion 610C is inclined obliquely upward toward the inlet hole 612C. The inlet hole 612C is an example of a first communication hole. Specifically, the inlet hole 612C is located at the highest position in the refrigerant flow passage 600C and is formed so as to penetrate the heat exchange plate 444 constituting the refrigerant flow passage 600C (see FIG. 5). The inlet hole 612C communicates with the refrigerant pipe 430e. In this embodiment, the heat exchange plate 444 has a cylindrical portion 446 protruding toward the water flow body 442W side, and the inlet hole 612C communicates with the inside of the cylindrical portion 446. The cylindrical portion 446 is connected to the refrigerant pipe 430e via an insertion hole 660 formed in the water flow body 442W.

[0085] The inlet hole 612C is formed on the end (front end) side opposite to the upper folded portion 615C. The ceiling surface 614C is inclined continuously and linearly obliquely upward from a position adjacent to the outer peripheral surface 617C of the upper folded portion 615C toward the inlet hole 612C. The side surface 616C constituting the refrigerant flow path 600C is also inclined continuously and linearly obliquely upward toward the inlet hole 612C. The gradient of the ceiling surface 614C (for example, the gradient angle θ1 is 5 degrees or more) is gentler than the gradient of the side surface 616C.

[0086] A ceiling surface 622C of the interrupted flow path portion 620C is inclined obliquely upward toward the upper turn-back portion 615C. A bottom surface 618C of the upper flow path portion 610C is inclined obliquely downward from the upper turn-back portion 615C along the ceiling surface 622C of the interrupted flow path portion 620C. A first through-hole 640C is formed at the lower end of the bottom surface 618C, penetrating the ceiling surface 622C of the interrupted flow path portion 620C. The bottom surface 618C is an example of a first inclined surface portion. Specifically, the upper flow path portion 610C and the interrupted flow path portion 620C are separated by a first partition wall 619C. The first partition wall 619C is linear when viewed in the left-right direction, and is inclined so as to be positioned higher as it approaches the upper folded-back portion 615C. A first through hole 640C is formed in the lower end portion of the first partition wall 619C.

[0087] The lower flow passage portion 630C is formed with an outlet hole 642C communicating with the outside of the heat exchanger 440 and a coolant drain hole 660C communicating with the outside of the heat exchanger 440. The outlet hole 642C and the coolant drain hole 660C are formed on the end (rear end) side opposite to the lower folded portion 625C. The coolant drain hole 660C is disposed below the outlet hole 642C. The bottom surface 634C of the lower flow passage portion 630C is inclined obliquely downward toward the coolant drain hole 660C. The gradient of the bottom surface 634C (for example, the inclination angle θ2 is 5 degrees or more) is approximately the same as the gradient of the ceiling surface 614C of the upper flow passage portion 610C. The coolant drain hole 660C is used when discharging the coolant liquid C in the refrigerant flow passage 600C. The outflow hole 642C communicates with the refrigerant pipe 430f. In this embodiment, the heat exchange plate 444 has a cylindrical portion 448 protruding toward the water flow body 442W, and the outflow hole 642C communicates with the inside of the cylindrical portion 448. The cylindrical portion 448 is connected to the refrigerant pipe 430f via an insertion hole 670 formed in the water flow body 442W. The coolant drain hole 660C is an example of a second communication hole.

[0088] The ceiling surface 632C of the lower flow path portion 630C is inclined obliquely upward toward the lower turn-back portion 625C. The bottom surface 624C of the interrupted flow path portion 620C is inclined obliquely downward from the lower turn-back portion 625C along the ceiling surface 632C of the lower flow path portion 630C. A second through-hole 650C is formed at the lower end of the bottom surface 624C, penetrating the ceiling surface 632C of the lower flow path portion 630C. The bottom surface 624C is an example of a second inclined surface portion. Specifically, the lower flow path portion 630C and the interrupted flow path portion 620C are separated by a second partition wall 629C. The second partition wall 629C is linear in left-right view and inclined upward toward the lower folded portion 625C. A second through hole 650C is formed at the lower end of the second partition wall 629C. The water flow path 600W and the refrigerant flow path 600C have substantially the same shape (S-shape) in left-right view.

[0089] (Sub-discharge pipe 700): The water flow body 442W further has a sub-discharge pipe 700 (see Figs. 5 and 6). The sub-discharge pipe 700 has an internal pipe 702 and an external pipe 704. The internal pipe 702 is a part formed inside the heat exchanger 440 (water flow body 442W). The internal pipe 702 extends continuously upward from the highest position (upper end of the ceiling surfaces 614W, 616W) of the water flow passage 600W and penetrates the outer circumferential surface of the water flow body 442W. The external pipe 704 is a part disposed outside the heat exchanger 440 (water flow body 442W). One end of the external pipe 704 is connected to the internal pipe 702 via a connecting member 706. The other end of the external pipe 704 is open to the atmospheric space outside the heat exchanger 440. The external pipe 704 is disposed so that it becomes continuously lower from one end connected to the connecting member 706 to the other open end. In short, the auxiliary discharge pipe 700 has a portion (connecting member 706) disposed at a position higher than the outflow hole 612W, and has a discharge portion (internal pipe 702) that opens into the water flow path 600W with that portion as its highest position, and a discharge portion (external pipe 704) that opens into the atmospheric space with that portion as its highest position.

[0090] A-5. Advantages of this embodiment: As described above, the outboard motor 100 of this embodiment includes a drive source, refrigerant pipes 430a-430f, water pipes (supply pipe 680, discharge pipe, etc.), and a heat exchanger 440. The drive source includes the electric motor 122. The refrigerant pipes 430a-430f configure at least a part of the overall refrigerant flow path 400 through which the coolant liquid C circulates to cool the electric motor 122 and the MCU 510. External water flows through the water pipe. The heat exchanger 440 is internally formed with a refrigerant flow path 600C through which the coolant liquid C from the refrigerant pipes 430a-430f flows, and a water flow path 600W through which seawater W from the water pipe flows.

[0091] (Water fluid 442W): In this embodiment, the water flow path 600W is an S-shaped flow path overall, and includes an upper flow path portion 610W, an interrupted flow path portion 620W, a lower flow path portion 630W, an upper turn-back portion 615W, and a lower turn-back portion 625W (see FIG. 6). Therefore, according to this embodiment, compared to a configuration in which the water flow path 600W has an overall linear shape, the efficiency of heat exchange in the heat exchanger 440 can be improved by the amount of seawater W flowing through the heat exchanger 440 being greater.

[0092] In this embodiment, an outlet hole 612W communicating with the outside of the heat exchanger 440 is formed in the upper flow path portion 610W of the water flow path 600W. Also, the ceiling surfaces 614W, 616W forming the upper flow path portion 610W are inclined obliquely upward toward the outlet hole 612W (see FIG. 6). Therefore, according to this embodiment, it is possible to suppress air from accumulating in the upper flow path portion 610W, compared to, for example, a configuration in which the ceiling surface forming the upper flow path portion 610W extends along the horizontal direction or a configuration in which the ceiling surface is inclined obliquely upward toward a blocked portion different from the outlet hole 612W.

[0093] In this embodiment, the ceiling surface 622W of the interrupted flow path portion 620W is inclined obliquely upward toward the upper turn-back portion 615W (see FIG. 6). This makes it possible to prevent air from accumulating in the interrupted flow path portion 620W. The ceiling surface 632W of the lower flow path portion 630W is inclined obliquely upward toward the lower turn-back portion 625W (see FIG. 6). This makes it possible to prevent air from accumulating in the lower flow path portion 630W. In short, in this embodiment, the ceiling surfaces 622W, 632W of the flow path portions 620W, 630W that are the second or lower tier from the top of the water flow path 600W are both inclined obliquely upward toward the turn-back portions 615W, 625W.

[0094] When the heat exchanger 440 is in operation, the water flow body 442W is configured such that the seawater W pumped up to the supply pipe 680 flows in through the inlet hole 642W formed at the lower end of the water flow path 600W, and the seawater W accumulates in the water flow path 600W in the order of the lower flow path portion 630W, the interrupted flow path portion 620W, and the upper flow path portion 610W. In contrast, as described above, the ceiling surfaces 614W and 616W forming the upper flow path portion 610W are inclined obliquely upward toward the outlet hole 612W, and the ceiling surfaces 622W and 632W of the flow path portions 620W and 630W below the second stage are both inclined obliquely upward toward the turn-back portions 615W and 625W. Therefore, when the heat exchanger 440 is in operation, air is prevented from accumulating in the water flow path 600W, and the entire water flow path 600W can be filled with seawater W.

[0095] In this embodiment, the outlet hole 612W is formed on the end (front end) side opposite the upper folded portion 615W (see FIG. 6). That is, the outlet hole 612W is formed at a high position in the upper folded portion 615W (water flow path 600W). Therefore, according to this embodiment, the outlet hole 612W can be used as an air vent hole without providing a separate hole.

[0096] Bottom surface 634W of lower flow path portion 630W is inclined obliquely downward toward inlet hole 642W (see FIG. 6). Therefore, according to this embodiment, it is possible to suppress seawater W from remaining in lower flow path portion 630W, compared to, for example, a configuration in which the bottom surface of lower flow path portion 630W extends along the horizontal direction or a configuration in which the bottom surface is inclined obliquely downward toward a blocked portion other than inlet hole 642W.

[0097] In this embodiment, the bottom surface 618W of the upper flow path portion 610W is inclined obliquely downward from the upper turn-back portion 615W along the ceiling surface 622W of the interrupted flow path portion 620W. A first through-hole 640W penetrating the ceiling surface 622W of the interrupted flow path portion 620W is formed at the lower end of the bottom surface 618W (see FIG. 6). Therefore, according to this embodiment, compared to a configuration in which the bottom surface of the upper flow path portion 610W is inclined obliquely upward from the upper turn-back portion 615W, it is possible to increase the capacity of the seawater W in the upper flow path portion 610W and prevent the seawater W from remaining in the upper flow path portion 610W when the heat exchanger 440 is stopped.

[0098] In this embodiment, the bottom surface 624W of the interrupted flow path portion 620W is inclined obliquely downward from the lower turnback portion 625W along the ceiling surface 632W of the lower flow path portion 630W. A second through hole 650W penetrating the ceiling surface 632W of the lower flow path portion 630W is formed at the lower end of the bottom surface 624W (see FIG. 6). Therefore, according to this embodiment, it is possible to increase the storage capacity of the seawater W in the interrupted flow path portion 620W, while suppressing the seawater W from remaining in the interrupted flow path portion 620W when the heat exchanger 440 is stopped.

[0099] When the heat exchanger 440 is stopped, the water flow body 442W is configured such that the seawater W stored in the water flow path 600W flows through the upper flow path portion 610W, the interrupted flow path portion 620W, and the lower flow path portion 630W in this order. As described above, the bottom surface 634W of the lower flow path portion 630W is inclined obliquely downward toward the inlet hole 642W. The bottom surfaces 618W, 624W of the flow path portions 610W, 620W that are the second or higher from the bottom are inclined obliquely downward from the turning back portions 615W, 625W along the ceiling surfaces 622W, 632W of the flow path portions 620W, 630W that are one level lower. The through holes 640W, 650W are formed at the lower ends of the bottom surfaces 618W, 624W. Therefore, when the heat exchanger 440 is stopped, it is possible to suppress the seawater W from remaining in the water flow path 600W.

[0100] FIG. 8 is an explanatory diagram showing the function of the auxiliary discharge pipe 700. At the beginning of operation of the heat exchanger 440, seawater W flows from the supply pipe 680 into the water flow path 600W, and as shown in FIG. 8(a), the water level of the seawater W in the water flow path 600W rises. The heat exchanger 440 has the auxiliary discharge pipe 700. The auxiliary discharge pipe 700 opens from the water flow path 600W to the atmospheric space outside the heat exchanger 440, and therefore functions, together with the discharge pipe, as an air vent that discharges the air E remaining in the upper part of the water flow path 600W to the outside of the heat exchanger 440. Therefore, compared to a configuration in which the heat exchanger 440 does not have the auxiliary discharge pipe 700, the air E in the water flow path 600W can be discharged to the outside more smoothly.

[0101] Next, as shown in FIG. 8(b), when the water flow passage 600W is filled with seawater W, the seawater W is discharged from the discharge pipe and a small amount is also discharged from the auxiliary discharge pipe 700. After that, when the heat exchanger 440 is stopped, the pump is stopped and the inflow of seawater W into the water flow passage 600W is stopped. Then, as shown in FIG. 8(c), the seawater W in the water flow passage 600W flows back, and the water level of the seawater W in the water flow passage 600W starts to drop. At this time, the auxiliary discharge pipe 700 takes in the air E from the atmospheric space into the water flow passage 600W faster than the discharge pipe, as the seawater W in the water flow passage 600W is discharged from the inside. Therefore, according to this embodiment, the discharge speed of the seawater W from the water flow passage 600W is faster than, for example, a configuration in which the heat exchanger 440 does not have the auxiliary discharge pipe 700. As a result, for example, even when the outboard motor 100 is changed from a tilt-down state to a tilt-up state immediately after the operation is stopped, it is possible to suppress the seawater W from remaining in the water flow passage 600W.

[0102] (Refrigerant 442C): In this embodiment, the refrigerant flow path 600C is an S-shaped flow path overall, and includes an upper flow path portion 610C, an interrupted flow path portion 620C, a lower flow path portion 630C, an upper turn-back portion 615C, and a lower turn-back portion 625C (see FIG. 7). Therefore, according to this embodiment, compared to a configuration in which the refrigerant flow path 600C has an overall linear shape, the amount of coolant liquid C flowing through the heat exchanger 440 is greater, and the efficiency of heat exchange in the heat exchanger 440 can be improved accordingly.

[0103] In this embodiment, the upper flow path portion 610C is formed with an inlet hole 612C that communicates with the outside of the heat exchanger 440. Also, a ceiling surface 614C that forms the upper flow path portion 610C is inclined obliquely upward toward the inlet hole 612C. Therefore, according to this embodiment, it is possible to suppress air from accumulating in the upper flow path portion 610C, compared to, for example, a configuration in which the ceiling surface that forms the upper flow path portion 610C extends along the horizontal direction or a configuration in which the ceiling surface is inclined obliquely upward toward a blocked portion different from the inlet hole 612C.

[0104] In this embodiment, the ceiling surface 622C of the interrupted flow path portion 620C is inclined obliquely upward toward the upper turn-back portion 615C (see FIG. 7). Therefore, it is possible to suppress air from accumulating in the interrupted flow path portion 620C. The ceiling surface 632C of the lower flow path portion 630C is inclined obliquely upward toward the lower turn-back portion 625C (see FIG. 7). Therefore, it is possible to suppress air from accumulating in the lower flow path portion 630C. In short, in this embodiment, the ceiling surfaces 622C, 632C of the flow path portions 620C, 630C of the second and lower stages from the top of the refrigerant flow path 600C are both inclined obliquely upward toward the turn-back portions 615C, 625C. Therefore, for example, when the entire refrigerant flow path 400 is refilled with the coolant liquid C, it is possible to suppress air from accumulating in the refrigerant flow path 600C, and the entire refrigerant flow path 600C can be filled with the coolant liquid C.

[0105] In this embodiment, the inlet hole 612C is formed on the end (front end) side opposite to the upper folded portion 615C (see FIG. 7). That is, the inlet hole 612C is formed at a high position in the upper folded portion 615C (coolant flow path 600C). Therefore, according to this embodiment, the inlet hole 612C can be used as an air vent hole without providing a separate hole.

[0106] A bottom surface 634C of the lower flow path portion 630C is inclined obliquely downward toward the coolant drain hole 660C (see FIG. 7). Therefore, according to this embodiment, when the coolant C is discharged, it is possible to prevent the coolant C from remaining in the lower flow path portion 630C.

[0107] In this embodiment, the bottom surface 618C of the upper flow path portion 610C is inclined obliquely downward from the upper turnback portion 615C along the ceiling surface 622C of the interrupted flow path portion 620C. A first through hole 640C penetrating the ceiling surface 622C of the interrupted flow path portion 620C is formed at the lower end of the bottom surface 618C (see FIG. 7). Therefore, according to this embodiment, it is possible to increase the storage capacity of the coolant C in the upper flow path portion 610C and prevent the coolant C from remaining in the upper flow path portion 610C when discharging the coolant C.

[0108] In this embodiment, the bottom surface 624C of the interrupted flow path portion 620C is inclined obliquely downward from the lower turnback portion 625C along the ceiling surface 632C of the lower flow path portion 630C. A second through hole 650C penetrating the ceiling surface 632C of the lower flow path portion 630C is formed at the lower end of the bottom surface 624C (see FIG. 7). Therefore, according to this embodiment, it is possible to increase the storage capacity of the coolant C in the interrupted flow path portion 620C, while suppressing the coolant C from remaining in the interrupted flow path portion 620C when discharging the coolant C.

[0109] In this embodiment, the flow direction of the seawater W in the water flow path 600W and the flow direction of the coolant liquid C in the refrigerant flow path 600C are opposite to each other. Therefore, according to this embodiment, the heat exchange efficiency of the heat exchanger 440 can be improved compared to a configuration in which the flow direction of the seawater W in the water flow path 600W and the flow direction of the coolant liquid C in the refrigerant flow path 600C are the same.

[0110] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0111] The configurations of the boat 10 and the outboard motor 100 in the above embodiment are merely examples and can be modified in various ways. For example, in the above embodiment, only the electric motor 122 is included as the drive source, but the drive source may include both an electric motor and an internal combustion engine such as an engine.

[0112] In the above embodiment, the MCU 510 is disposed above the electric motor 122, but this is not necessarily limited thereto, and the MCU may be disposed below the electric motor.

[0113] In the above embodiment, a plurality of refrigerant pipes 430a to 430f are provided, but it is not necessary to provide a plurality of refrigerant pipes, and only one refrigerant pipe may be provided.

[0114] In the above embodiment, the water flow path 600W formed by the grooves formed on the inner side surface 441W of the water flow body 442W and the heat exchange plate 444 is exemplified as the water flow path, but the present invention is not limited to this and may be a through-path inside the water flow body 442W. In the above embodiment, the refrigerant flow path 600C formed by the grooves formed on the inner side surface 441C of the refrigerant flow body 442C and the heat exchange plate 444 is exemplified as the refrigerant flow path, but the present invention is not limited to this and may be a through-path inside the refrigerant flow body 442C.

[0115] In the above embodiment, both the refrigerant flow path 600C and the water flow path 600W have two turn-back portions. However, for example, they may have no turn-back portion, one turn-back portion, or three or more turn-back portions. The first ceiling surface 614W may be inclined in a stepwise upward direction toward the outlet hole 612W, or may be inclined in a curved shape. The bottom surface 634W of the lower flow path portion 630W may be inclined in a stepwise upward direction toward the inlet hole 642W, or may be inclined in a curved shape. The bottom surface 634C of the lower flow path portion 630C may be inclined in a stepwise upward direction toward the coolant drain hole 660C, or may be inclined in a curved shape. The ceiling surfaces 632W, 632C of the lower flow path portions 630W, 630C may be inclined in a stepwise upward direction toward the lower turn-back portions 625W, 625C, or may be inclined in a curved shape. The bottom surfaces 624W, 624C of the interrupted flow path portions 620W, 620C may be inclined stepwise or curvedly from the lower turnback portions 625W, 625C obliquely downward along the ceiling surfaces 632W, 632C of the lower flow path portions 630W, 630C.

[0116] In the above embodiment, the outlet hole 612W and the inlet hole 612C are exemplified as the first communication hole, but the present invention is not limited thereto, and may be, for example, a through hole that opens into the flow path (water flow path 600W, refrigerant flow path 600C) at a position higher than the outlet hole 612W and the inlet hole 612C and opens into the atmospheric space outside the heat exchanger 440. In the above embodiment, the inlet hole 642W is exemplified as the second communication hole, but the present invention is not limited thereto, and may be, for example, a through hole that opens into the flow path (water flow path 600W) at a position lower than the inlet hole 642W and opens into the atmospheric space outside the heat exchanger 440.

[0117] In the above embodiment, the flow direction of the seawater W in the water flow path 600W and the flow direction of the coolant liquid C in the refrigerant flow path 600C may be the same.

[0118] In the above embodiment, the coolant liquid C (antifreeze liquid mainly composed of ethylene glycol or propylene glycol) is exemplified as the coolant, but the type of coolant is not particularly limited as long as it cools the electric motor and the motor control device. In the above embodiment, the seawater W is introduced through the inlet hole 642W formed at the lower end of the water flow path 600W to fill the water flow path 600W. This makes it possible to fill the water flow path 600W with seawater W while suppressing air from accumulating in the water flow path 600W, even if the water flow path 600W is filled with seawater W every time the outboard motor 100 changes from the chilled-up state to the chilled-down state. However, the water flow path 600W may be filled with seawater W by introducing it through a hole formed at the upper end of the water flow path 600W. Meanwhile, in the above embodiment, the coolant liquid C is introduced through the inlet hole 612C formed at the upper end of the coolant flow path 600C. The entire refrigerant flow path 400 is basically sealed, and there is no need to fill the refrigerant flow path 600C with the coolant C every time the outboard motor 100 switches from the chilled-up state to the chilled-down state. However, the coolant C may be introduced through a hole formed at the lower end of the refrigerant flow path 600C.

[0119] In the above embodiment, the heat exchanger 440 may not have the secondary discharge pipe 700. The secondary discharge pipe 700 may not have the outer pipe 704. Moreover, the inner pipe 702 may extend obliquely upward. [Explanation of symbols]

[0120] 10: Ship 100: Outboard motor 110: Outboard motor body 122: Electric motor 440: Heat exchanger 442C: Refrigerant circulating body 442W: Water circulating body 444: Heat exchange plate 600C: Refrigerant flow path 600W: Water flow path 610C, 610W: Upper flow path portion 612C: Inlet hole 612W: Outlet hole 614C, 614W, 616W, 622W, 622C, 632W, 632C: Ceiling surface 615C, 615W: Upper folded portion 616W: Second ceiling surface 618C, 618W, 624W, 624C: Bottom surface 620W, 620C: Interrupted flow path portion 625W, 625C: Lower folded portion 630W, 630C: Lower flow path portion 640W, 640C: First through hole 642C: Outlet hole 642W: Inlet hole 650W, 650C: Second through hole 660C: Coolant drain hole W: Seawater

Claims

1. An outboard motor, A drive source including an electric motor; a refrigerant pipe through which a refrigerant for cooling the driving source flows; A water pipe through which external water flows; a heat exchanger having a refrigerant flow path through which the refrigerant from the refrigerant pipe flows and a water flow path through which the water from the water pipe flows; Equipped with At least one of the refrigerant flow path and the water flow path is a first flow path portion extending in a direction intersecting the up-down direction; a second flow path portion located below the first flow path portion and extending in a direction intersecting the up-down direction; a first folded portion connecting one end of the first flow path portion and one end of the second flow path portion, a first communication hole communicating with an outside of the heat exchanger is formed in the first flow passage portion, and a ceiling surface forming the first flow passage portion is inclined obliquely upward toward the first communication hole.

2. 2. An outboard motor according to claim 1, the first communication hole is an inlet or outlet hole for a fluid, which is the refrigerant or the water, and is formed at an end of the first flow path portion on an opposite side to the first turned portion.

3. 3. An outboard motor according to claim 1 or 2, a ceiling surface of the second flow passage portion inclined obliquely upward toward the first turning portion.

4. 4. An outboard motor according to claim 3, a bottom surface of the first flow path portion has a first inclined surface portion that is inclined obliquely downward from the first folded portion along the ceiling surface of the second flow path portion, a first through hole penetrating through the ceiling surface of the second flow passage portion is formed at a lower end of the first inclined surface portion.

5. An outboard motor according to any one of claims 1 to 4, The at least one flow path is a third flow path portion extending in a direction intersecting the vertical direction; a fourth flow path portion located above the third flow path portion and extending in a direction intersecting the up-down direction; a second folded portion connecting one end of the third flow path portion and one end of the fourth flow path portion, an end of the third flow passage portion opposite the second folded portion, the end having a second communication hole communicating with the outside, and a bottom surface of the third flow passage portion inclined obliquely downward toward the second communication hole.

6. 6. An outboard motor according to claim 5, a ceiling surface of the third flow passage portion inclined obliquely upward toward the second turning portion.

7. 7. An outboard motor according to claim 6, a bottom surface of the fourth flow path portion has a second inclined surface portion that is inclined obliquely downward from the second turning portion along the ceiling surface of the third flow path portion, a second through hole penetrating through the ceiling surface of the third flow passage portion is formed at a lower end of the second inclined surface portion.

8. An outboard motor according to any one of claims 1 to 7, each of the refrigerant flow path and the water flow path has the first flow path portion, the second flow path portion, and the first turn back portion; one of the refrigerant flow path and the water flow path is configured such that the refrigerant flows from the first flow path portion to the second flow path portion via the first turning portion, the other of the refrigerant flow path and the water flow path is configured so that the water flows from the second flow path portion to the first flow path portion via the first turning portion.

9. An outboard motor according to any one of claims 1 to 8, The water flow path has a water inlet hole at a lower end thereof and a water outlet hole at an upper end thereof, a discharge pipe communicating with the outlet hole and discharging water in the water flow passage to the outside of the outboard motor; a secondary discharge pipe extending upward from a position higher than the outlet hole in the water flow path and opening into a space outside the heat exchanger; An outboard motor.

10. The hull and an outboard motor according to any one of claims 1 to 9 attached to a rear part of the hull; A vessel comprising:

11. An outboard motor, A drive source including an electric motor; a refrigerant pipe through which a refrigerant for cooling the driving source flows; A water pipe through which external water flows; a heat exchanger having a refrigerant flow path through which the refrigerant from the refrigerant pipe flows and a water flow path through which the water from the water pipe flows; Equipped with an outer circumferential surface of the heat exchanger that is inclined obliquely upward toward the third communication hole is formed in at least one of the refrigerant flow path and the water flow path, and the third communication hole is formed in the outer circumferential surface of the heat exchanger that is inclined upward toward the third communication hole.

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