Marine propulsion system

Abstract

A ship propulsion device comprising: a motor that drives a propeller; a battery that supplies electric power to the motor; and a gas channel having one end that communicates with the battery and another end that communicates with a region on the outside of the hull and below the upper end of shell plating provided on the rim of the hull, the gas channel exhausting gas emitted from the battery to the outside of the hull from the other end.

Description

[Technical Field]

[0001] The present disclosure relates to marine propulsion devices. [Background technology]

[0002] Marine propulsion devices such as outboard motors generally use internal combustion engines such as gasoline engines as their power source. However, in recent years, marine propulsion devices that use electric motors as their power source have been attracting attention from the perspective of reducing environmental impact (see, for example, Patent Document 1). The electric outboard motor disclosed in Patent Document 1 includes an electric motor that rotates a propeller and a power supply unit that supplies power to the electric motor. The power supply unit also has a structure in which a battery pack is housed in a battery pack holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-186853 Summary of the Invention

[0004] If a battery in a battery pack catches fire due to an internal short circuit or other reason, the battery pack may emit large amounts of high-temperature, high-pressure, and toxic gas. Marine propulsion devices are often located close to the crew of the boat. Therefore, further improvements in safety are required for marine propulsion devices in terms of gas emissions from battery packs.

[0005] The present disclosure has been made in light of these circumstances, and one of its objectives is to provide a technique for improving the safety of an electric marine propulsion device.

[0006] One aspect of the present disclosure is a marine vessel propulsion device including a motor that drives a propulsion unit, a battery that supplies power to the motor, and a gas flow path that has one end connected to the battery and the other end connected to an area outside the hull below an upper end of an outer plating provided at an edge of the hull, and that discharges gas ejected from the battery from the other end to the outside of the hull.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0008] According to the present disclosure, the safety of an electric marine propulsion device can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a marine propulsion device. [Figure 2A] FIG. 2A is a schematic diagram showing a connection state of the gas flow passages and the cooling water flow passages. [Figure 2B] FIG. 2B is a schematic diagram showing a connection state of the gas flow passages and the cooling water flow passages. [Figure 2C] FIG. 2C is a schematic diagram showing a connection state of the gas flow passages and the cooling water flow passages. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] FIG. 1 is a schematic diagram of a marine vessel propulsion device 1. The marine vessel propulsion device 1 of this embodiment is an outboard motor, as an example. However, the marine vessel propulsion device 1 may also be an inboard motor or an inboard-outboard motor. The marine vessel propulsion device 1 includes an upper housing 2, an intermediate housing 4, and a lower housing 6. The upper housing 2 is generally rectangular and is positioned higher than the water surface WS. The lower housing 6 is positioned lower than the water surface WS. The intermediate housing 4 is tubular and extends vertically, connecting the upper housing 2 and the lower housing 6. A bracket device 8 is provided on the intermediate housing 4. The marine vessel propulsion device 1 is supported on a hull 100 via the bracket device 8. In this embodiment, the marine vessel propulsion device 1 is attached to a transom 102 of the hull 100.

[0012] The marine vessel propulsion device 1 can rotate horizontally and vertically. A steering wheel 10 extending toward the hull 100 is provided on the upper housing 2. The crew of the vessel can steer the hull 100 by swinging the steering wheel 10 horizontally to change the direction of the marine vessel propulsion device 1. A throttle grip for adjusting the output of the motor 16 is provided at the tip of the steering wheel 10. A shift switch for switching the motor 16 between forward and reverse rotation is also provided on the steering wheel 10.

[0013] The marine vessel propulsion device 1 also includes a battery 12, a power converter 14, a motor 16, a propulsion unit 18, and a gas flow path 20. The battery 12 is housed in the upper housing 2. Preferably, the battery 12 is housed in the upper housing 2 so as to be detachable. The battery 12 has a plurality of cells 22 and a battery pack 24. The plurality of cells 22 are housed in the battery pack 24 and connected in series and / or parallel to one another. The battery pack 24 is a container made of metal or resin. The battery pack 24 is preferably waterproof. However, the number of cells 22 may be one.

[0014] An example of the battery 22 is a rechargeable secondary battery such as a lithium-ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery. The battery 22 has a known structure. For example, the battery 22 has a structure in which an electrode group is housed in an outer can together with a nonaqueous electrolyte. The outer can is provided with a safety valve. The safety valve opens when the internal pressure of the outer can rises above a predetermined value, thereby allowing gas inside the battery 22 to be released.

[0015] The battery 12 supplies power to the motor 16 via the power converter 14. As an example, the power converter 14 is housed in the middle housing 4 or the lower housing 6, and the motor 16 is housed in the lower housing 6. The power converter 14 and the motor 16 may be integrated. Also, the power converter 14 may be omitted. The power converter 14 converts the power of the battery 12 and supplies it to the motor 16. For example, the power converter 14 is an inverter that controls the voltage and frequency of the battery 12 to change the output of the motor 16, etc. The motor 16 may have any structure as long as it can convert the power supplied from the battery 12 into motive power.

[0016] A propulsion unit 18 is connected to the motor 16. The motor 16 is driven by receiving a supply of electric power from the battery 12, thereby driving the propulsion unit 18. In this embodiment, the propulsion unit 18 is a propeller, and is connected to the output shaft of the motor 16 via a propeller shaft 26. Note that the propulsion unit 18 may also be a known propulsion unit other than a propeller, such as a water jet propeller. The power converter 14 and the motor 16 may also be housed in the upper housing 2. In this case, the output shaft of the motor 16 and the propeller shaft 26 are connected to each other via a drive shaft housed in the middle housing 4.

[0017] The gas flow path 20 is a conduit for discharging gas emitted from the battery 12 to the outside of the hull 100. The gas flow path 20 extends from inside the upper housing 2 to inside the lower housing 6. One end 20a of the gas flow path 20 is connected to the battery 12. For example, the battery pack 24 is provided with a through-hole that connects the inside and outside of the battery pack 24, and the one end 20a is connected to this through-hole.

[0018] The other end 20b of the gas flow path 20 is connected to an area outside the hull 100, below the upper end of a shell plate provided at the edge of the hull 100. The area outside the hull 100 is above the water surface WS or underwater. The shell plate provided at the edge of the hull 100 is, for example, a bulwark provided on the side of the ship or a transom 102 provided at the stern. The marine vessel propulsion device 1 of this embodiment is fixed to the transom 102. The other end 20b of the gas flow path 20 is connected to an area outside the hull 100, below the upper end of the transom 102. Furthermore, in this embodiment, the other end 20b of the gas flow path 20 is located below the water surface WS and connected to the water.

[0019] The other end 20b of the gas flow path 20 is disposed adjacent to the propulsion unit 18. As an example, the other end 20b extends along the propeller shaft 26 and is connected to the water. When viewed from the direction in which the propeller shaft 26 extends, the other end 20b is disposed inside the rotation range of the propeller. A check valve 28 is provided at the other end 20b. The check valve 28 allows gas to flow from the one end 20a to the other end 20b and restricts water from the other end 20b to the one end 20a. This prevents water from entering the battery pack 24.

[0020] When high-temperature, high-pressure gas is ejected from the battery 22, this gas flows from inside the battery pack 24 into the gas flow path 20. The gas that has flowed into the gas flow path 20 passes through the gas flow path 20 and is discharged from the other end 20b into the water and near the propulsion unit 18. The gas that has been discharged into the water is immediately diffused by the propulsion unit 18.

[0021] The marine vessel propulsion device 1 also includes a cooling water flow path 30, a pump 32, and a heat exchanger 34. The cooling water flow path 30 is a pipe through which cooling water flows to cool the battery 12. In this embodiment, the cooling water is water outside the hull 100. In other words, the water on which the hull 100 floats (seawater, lake water, river water, etc.) is used as the cooling water.

[0022] The coolant flow path 30 extends from inside the upper housing 2 to inside the lower housing 6. The coolant flow path 30 has a first flow path section 30a, a second flow path section 30b, and a third flow path section 30c. The first flow path section 30a extends from inside the lower housing 6 to inside the upper housing 2. One end of the first flow path section 30a is disposed inside the lower housing 6 and communicates with the water, forming a coolant intake. The first flow path section 30a extends upward inside the middle housing 4 to reach the upper housing 2. A pump 32 is provided midway along the first flow path section 30a. A known pump can be used as the pump 32. The pump 32 is driven by power supplied from the battery 12 and pumps coolant from one end of the first flow path section 30a. The pump 32 may be provided in the third flow path section 30c. The pump 32 may also be driven by rotation of the motor 16 or a drive shaft.

[0023] The second flow path portion 30b is disposed in the upper housing 2. The other end of the first flow path portion 30a is connected to one end of the second flow path portion 30b. The second flow path portion 30b is connected to the heat exchange member 34 so as to be able to exchange heat. The heat exchange member 34 is connected to the battery 12 so as to be able to exchange heat. Therefore, the coolant flow path 30 is connected to the battery 12 via the heat exchange member 34 so as to be able to exchange heat.

[0024] A known material can be used as the heat exchanger 34. For example, the heat exchanger 34 is made of a plate material with high thermal conductivity, such as a metal plate. The second flow path portion 30b is fixed to one main surface of the heat exchanger 34 with a thermally conductive adhesive or the like. The second flow path portion 30b and the heat exchanger 34 may be fixed by screws in direct contact or with a heat transfer material interposed therebetween, or by joining such as welding or brazing. The battery 12 is placed on the other main surface of the heat exchanger 34, and the bottom surface of the battery pack 24 contacts the heat exchanger 34. The method of connecting the coolant flow path 30 and the battery 12 to enable heat exchange is not limited to the above. For example, the heat exchanger 34 may be omitted.

[0025] The third flow path section 30c extends from inside the upper housing 2 to inside the lower housing 6. One end of the third flow path section 30c is disposed within the upper housing 2 and connected to the other end of the second flow path section 30b. The third flow path section 30c extends downward within the middle housing 4 to the lower housing 6. The other end of the third flow path section 30c is disposed within the lower housing 6 and communicates with the water, forming a cooling water outlet. The cooling water pumped up from one end of the first flow path section 30a by the pump 32 passes through the first flow path section 30a, the second flow path section 30b, and the third flow path section 30c, and is discharged from the other end of the third flow path section 30c. As the cooling water passes through the second flow path section 30b, it absorbs heat from the battery 12 via the heat exchange member 34. This cools the battery 12.

[0026] The gas flow path 20 of this embodiment is connected to the cooling water flow path 30 so as to be able to exchange heat. As an example, the gas flow path 20 is connected to the third flow path section 30c so as to be able to exchange heat within the intermediate housing 4. FIGS. 2A to 2C are schematic diagrams showing the connection between the gas flow path 20 and the cooling water flow path 30.

[0027] For example, as shown in FIG. 2A , the outer surfaces of the gas flow path 20 and the coolant flow path 30 are thermally coupled to each other by a heat transfer material 36. Examples of the heat transfer material 36 include a thermally conductive adhesive, a brazing material, and a solder material. The outer surfaces of both flow paths may be in direct contact with each other, or the heat transfer material 36 may be interposed between them. The heat transfer material 36 interposed between both flow paths can also be interpreted as a heat exchange member. Note that a heat exchange member other than the heat transfer material 36 may be interposed between both flow paths. Furthermore, the gas flow path 20 and the coolant flow path 30 may be thermally coupled by being wrapped in a sheet material or the like and bundled together.

[0028] 2B, the gas flow path 20 may be inserted into the cooling water flow path 30 to form a double-pipe structure, thereby thermally connecting the two. Also, as shown in Fig. 2C, the cooling water flow path 30 may be inserted into the gas flow path 20 to form a double-pipe structure, thereby thermally connecting the two. The connection modes shown in Figs. 2A to 2C are examples, and the method of connecting the gas flow path 20 and the cooling water flow path 30 to enable heat exchange is not particularly limited.

[0029] In this embodiment, the power converter 14 and the motor 16 are also connected to the coolant flow path 30 so as to be able to exchange heat. For example, the power converter 14 and the motor 16 are connected to the third flow path section 30c so as to be able to exchange heat. The power converter 14 and the motor 16 can be connected to the third flow path section 30c so as to be able to exchange heat in a manner similar to the manner in which the second flow path section 30b is connected to the heat exchange member 34. This allows the power converter 14 and the motor 16 to be cooled by the coolant. Note that the thermal connection of the power converter 14 and the motor 16 to the coolant flow path 30 is optional.

[0030] As described above, the marine vessel propulsion device 1 according to this embodiment comprises a motor 16 that drives the propulsion unit 18, a battery 12 that supplies power to the motor 16, and a gas flow path 20 that has one end 20a connected to the battery 12 and the other end 20b connected to an area outside the hull 100 below the upper end of an outer plate provided at the edge of the hull 100, and that discharges gas ejected from the battery 12 from the other end 20b to the outside of the hull 100.

[0031] With this configuration, if the batteries 22 in the battery pack 24 ignite due to an internal short circuit or the like and high-temperature, high-pressure gas is released from the batteries 22, the gas can be discharged to the outside of the hull 100 via the gas flow path 20. In addition, the gas can be discharged below the upper end of the outer plating that surrounds the outer periphery of the hull 100. This reduces the risk of gas released from the batteries 12 coming into contact with the crew of the vessel. This improves the safety of the vessel propulsion device 1.

[0032] In addition, the other end 20b of the gas flow path 20 in this embodiment is connected to the water. This allows the gas ejected from the battery 22 to be released into the water. This more reliably prevents the gas from directly contacting the crew. Furthermore, the gas released to the outside of the marine vessel propulsion device 1 can be immediately cooled. This further improves the safety of the marine vessel propulsion device 1.

[0033] Furthermore, in this embodiment, the other end 20b of the gas flow passage 20 is disposed close to the propulsion unit 18. This allows the gas released into the water to be immediately diffused. This prevents the gas released into the water from rising in clump form above the water surface WS. This further improves the safety of the marine vessel propulsion device 1.

[0034] The marine vessel propulsion device 1 of this embodiment also includes a cooling water passage 30 through which cooling water flows and which is connected to the battery 12 in a heat exchangeable manner. The gas passage 20 is then connected to the cooling water passage 30 in a heat exchangeable manner. This allows the gas to be cooled before being released to the outside of the marine vessel propulsion device 1. This further improves the safety of the marine vessel propulsion device 1. The gas can also be cooled using the cooling water that is used to cool the battery 12. Furthermore, the cooling water in this embodiment is water outside the hull 100. As a result, the gas cooling mechanism can be implemented at lower cost.

[0035] The above describes the embodiments of the present disclosure in detail. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content in which such design modifications are possible is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the above components is also valid as an aspect of the present disclosure. Hatching in cross sections in the drawings does not limit the material of the hatched object.

[0036] The embodiments may be specified by the following items.

[0037] [Item 1] a motor (16) that drives a propulsion unit (18); a battery (12) for supplying power to a motor (16); A marine propulsion device (1) comprising: a gas flow path (20) having one end (20a) connected to a battery (12) and another end (20b) connected to an area outside the hull (100) below the upper end of an outer plate (102) provided at the edge of the hull (100), and for discharging gas ejected from the battery (12) from the other end (20b) to the outside of the hull (100).

[0038] [Item 2] Item 2. The marine vessel propulsion device (1) according to item 1, wherein the other end (20b) of the gas flow path (20) is in communication with water.

[0039] [Item 3] 3. The marine vessel propulsion device (1) according to item 2, wherein the other end (20b) of the gas flow passage (20) is disposed adjacent to the propulsion unit (18).

[0040] [Item 4] a cooling water flow path (30) through which cooling water flows and which is connected to the battery (12) so as to be capable of heat exchange; 4. The marine vessel propulsion device (1) according to any one of items 1 to 3, wherein the gas flow path (20) is connected to the cooling water flow path (30) so as to be capable of heat exchange.

[0041] [Item 5] 5. The marine propulsion device (1) according to item 4, wherein the cooling water is water outside the hull (100). [Explanation of symbols]

[0042] 1 Marine propulsion device, 12 Battery, 16 Motor, 18 Propulsion unit, 20 Gas flow path, 20a One end side, 20b Other end side, 30 Cooling water flow path, 100 Hull

Claims

1. a motor that drives the propulsion unit; a battery for supplying power to the motor; a gas flow path having one end connected to the battery and the other end connected to a region outside the hull below an upper end of an outer plate provided at an edge of the hull, for discharging gas ejected from the battery to the outside of the hull from the other end; a cooling water flow path through which cooling water flows and which is connected to the battery so as to be able to exchange heat; the gas flow path is connected to the cooling water flow path so as to be able to exchange heat; The cooling water is water outside the hull.

2. The marine vessel propulsion device according to claim 1 , wherein the other end of the gas flow passage is connected to water.

3. The marine vessel propulsion device according to claim 2 , wherein the other end of the gas flow passage is disposed adjacent to the propulsion unit.

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