Water jet propulsion boat and ship

Abstract

To reduce a turning radius of a water jet propulsion boat.SOLUTION: A water jet propulsion boat comprises a hull, a first sponson provided laterally on the rear side of the hull, and a second sponson provided laterally on the rear side of the hull. The bottom face of the second sponson is located above the bottom face of the first sponson, and the rear end of the second sponson is located behind the rear end of the first sponson.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to water jet propulsion boats and ships. [Background technology]

[0002] A water jet propulsion boat has a hull and generates a propulsive force for the hull by generating a water current that flows rearward toward the hull. The water jet propulsion boat has sponsons at the rear of the left and right walls of the hull (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-205888 Summary of the Invention [Problem to be solved by the invention]

[0004] The sponsons create resistance between the water jet propulsion boat and the water when the water jet propulsion boat turns, thereby reducing the turning radius of the water jet propulsion boat. However, there is still room for further reduction in the turning radius of the water jet propulsion boat.

[0005] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The technology disclosed in this specification can be realized, for example, in the following forms.

[0007] The water jet propulsion watercraft disclosed in this specification includes a hull, a first sponson provided on a side of the aft portion of the hull, and a second sponson provided on a side of the aft portion of the hull, wherein the lower surface of the second sponson is located higher than the lower surface of the first sponson, and the rear end of the second sponson is located rearward of the rear end of the first sponson.

[0008] Because this water jet propulsion boat is equipped with a first sponson and a second sponson, the resistance between the water jet propulsion boat and the water is increased when the water jet propulsion boat turns, compared to a water jet propulsion boat equipped with only a first sponson, for example, and the turning radius of the water jet propulsion boat can be made smaller.

[0009] The techniques disclosed in this specification can be realized in various forms, such as a water jet propulsion boat, a ship, a method for manufacturing a water jet propulsion boat, a method for manufacturing a ship, etc. [Effects of the Invention]

[0010] Because this water jet propulsion boat is equipped with a first sponson and a second sponson, the resistance between the water jet propulsion boat and the water is increased when the water jet propulsion boat turns, compared to a water jet propulsion boat equipped with only a first sponson, for example, and the turning radius of the water jet propulsion boat can be made smaller. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view schematically illustrating a water jet propulsion boat 10. [Figure 2] FIG. 1 is an enlarged side view of the rear side of the hull 20 according to an embodiment. [Figure 3] FIG. 1 is a rear view of the water jet propulsion boat 10 according to an embodiment during straight planing. [Figure 4] 1 is a rear view of the water jet propulsion boat 10 according to an embodiment during a turn. [Figure 5] 1 is a rear view of a water jet propulsion boat 10a according to another embodiment during straight planing. [Figure 6]FIG. 10 is an enlarged side view of the rear side of the hull 20b in a modified example. [Figure 7] FIG. 10 is an enlarged side view of the rear side of the hull 20c in another modified example. [Figure 8] FIG. 10 is an enlarged side view of the rear side of the hull 20d in another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] FIG. 1 is a side view that schematically illustrates a water jet propulsion boat 10. Arrows indicating various directions relative to the position of the water jet propulsion boat 10 are appropriately shown in each of the following figures. More specifically, arrows indicating the forward, rearward, leftward, rightward, upward, and downward directions are appropriately shown in each figure. The forward-backward, leftward, and rightward directions, and the up-down direction (vertical direction) are perpendicular to each other. FIG. 1 also illustrates the waterline W of the water jet propulsion boat 10 when it is planing straight ahead.

[0013] The water jet propulsion boat 10 in this embodiment is, for example, a personal watercraft (PWC). The water jet propulsion boat 10 includes a hull 20, a drive unit 30, a jet propulsion mechanism 40, a jet flow adjustment mechanism 50, a displacement mechanism 60, a steering device 70, a control unit (ECU) 80, a first sponson 91, and a second sponson 92.

[0014] The hull 20 is the main structure of the water jet propulsion boat 10. The hull 20 has a hull 21, a deck 22, and a seat 23. The hull 21 forms the bottom of the hull 20. The deck 22 forms the upper part of the hull 20. The seat 23 is located approximately in the center of the hull 20 in the fore-and-aft direction. An operator (crew member) (not shown) can sit in the seat 23.

[0015] The drive unit 30 is disposed below the hull 20. The drive unit 30 has an engine 31, a crankshaft 32, and a coupling 33. The engine 31 is a spark-ignition multi-cylinder internal combustion engine. The crankshaft 32 is a rotating shaft that outputs the drive torque generated by the engine 31. The crankshaft 32 extends rearward from the engine 31. The coupling 33 connects the crankshaft 32 to an impeller shaft 45, which will be described later. The coupling 33 transmits the drive torque of the crankshaft 32 to the impeller shaft 45.

[0016] The jet propulsion mechanism 40 is provided in the rear portion of the hull 21 of the body 20. The jet propulsion mechanism 40 has an impeller housing 43, an impeller 44, an impeller shaft 45, stator vanes 46, and a nozzle 47. The jet propulsion mechanism 40 also has a flow path 41 formed therein.

[0017] The flow path 41 is formed in the rear portion of the hull 21 of the hull 20, in the center portion in the left-right direction. One end of the flow path 41 opens downward from the hull 21 as a water intake 42 for sucking in water. The flow path 41 extends rearward from the water intake 42. The other end 49 of the flow path 41 opens rearward from the hull 21.

[0018] The impeller housing 43 is a generally cylindrical body extending in the front-to-rear direction. The impeller housing 43 is arranged to protrude rearward from the other end 49 of the flow path 41. The impeller 44 is accommodated within the impeller housing 43. The impeller 44 is connected to the rear end of the impeller shaft 45. The impeller 44 rotates integrally with the impeller shaft 45 around the central axis of the impeller shaft 45. The stator vanes 46 are arranged rearward of the impeller 44 within the impeller housing 43. The nozzle 47 is cylindrical. The nozzle 47 is fixed to the rear end of the impeller housing 43. The rear end of the nozzle 47 opens as an outlet 48 for spraying water.

[0019] When the driving torque from the engine 31 is transmitted to the impeller shaft 45 and the impeller 44 rotates accordingly, water is drawn into the flow path 41 from outside the hull 20 via the water intake 42. The water drawn into the flow path 41 is supplied from the impeller 44 to the stator vanes 46. The water supplied by the impeller 44 is rectified as it passes through the stator vanes 46. The rectified water passes through the nozzle 47 and is ejected from the ejection port 48 toward the rear of the hull 20. In this way, the jet propulsion mechanism 40 can generate a jet flow toward the rear of the hull 20.

[0020] The jet flow adjustment mechanism 50 has a deflector 51 and a reverse gate 52. The displacement mechanism 60 has a deflector moving mechanism 61 and a reverse gate moving mechanism 65.

[0021] The deflector 51 is substantially cylindrical (frusto-conical) and is formed so that its inner diameter decreases toward the rear. The deflector 51 is disposed rearward of the nozzle 47. The deflector 51 covers the outlet 48 of the nozzle 47. The jet flow emitted from the outlet 48 passes through the deflector 51 and is emitted from an outlet 53. The deflector 51 is rotatable about a vertical axis and a horizontal axis behind the outlet 48. Depending on the rotation position of the deflector 51, the left-right direction and the up-down direction of the jet flow emitted from the outlet 48 toward the rear of the hull 20 can be changed. The deflector moving mechanism 61 displaces the deflector 51 in response to operation by the ship steering device 70.

[0022] The reverse gate 52 is disposed on the rear side of the deflector 51. The reverse gate 52 is provided so as to be displaceable among a forward position, a neutral position, and a reverse position. The forward position is a position where the reverse gate 52 does not cover the discharge port 53 of the deflector 51. The neutral position is a position where the reverse gate 52 covers part of the discharge port 53 of the deflector 51. The reverse position is a position where the reverse gate 52 covers the entire discharge port 53 of the deflector 51.

[0023] The steering device 70 has, for example, a steering handle. The operator of the water jet propulsion boat 10 can rotate the steering handle by grasping grips provided on both ends of the steering handle. When the operator rotates the steering handle, the deflector 51 can be rotated left and right via the displacement mechanism 60. The steering device 70 also has multiple controls (not shown). By operating the controls, the operator can start and stop the engine 31, rotate the deflector 51 up and down, or rotate the reverse gate 52.

[0024] The ECU 80 is, for example, a CPU, a multi-core CPU, or a programmable device (such as a Field Programmable Gate Array (FPGA) or a Programmable Logic Device (PLD)). The ECU 80 operates the deflector moving mechanism 61 and the reverse gate moving mechanism 65 in response to an operation of the ship steering device 70, for example.

[0025] FIG. 2 is an enlarged side view of the rear side of the hull 20 in the embodiment. The first sponson 91 is provided on a lateral side of the rear side of the hull 20. The second sponson 92 is provided on a lateral side of the rear side of the hull 20. Specifically, the first sponson 91 protrudes outward from the hull 20 from the rear side of the hull 21 of the hull 20. The second sponson 92 protrudes outward from the hull 20 from the rear side of the hull 21 of the hull 20. The first sponson 91 has a shape that extends in the fore-and-aft direction as a whole. The second sponson 92 has a shape that extends in the fore-and-aft direction as a whole. The first sponson 91 is provided on both the left and right sides of the hull 20. The second sponsons 92 are provided on both the left and right sides of the hull 20.

[0026] As shown in FIG. 2 , the second sponson 92 is located above the first sponson 91. In other words, the lower surface S2 of the second sponson 92 is located above the lower surface S1 of the first sponson 91. The lower surface S2 of the second sponson 92 is located above the upper surface of the first sponson 91. The lower surface S2 of the second sponson 92 is spaced apart from the upper surface of the first sponson 91 in the up-down direction. The rear end of the second sponson 92 is located rearward of the rear end of the first sponson 91. In this embodiment, the front portion of the first sponson 91 and the front portion of the second sponson 92 are connected to each other. In other words, in this embodiment, the first sponson 91 and the second sponson 92 are formed integrally.

[0027] The first sponson 91 has a first fin 911 (see Figure 3). The first fin 911 is a portion that protrudes downward at the end opposite the hull 20 in the left-right direction. The first fin 911 extends in the fore-and-aft direction. The second sponson 92 has a second fin 921 (see Figure 3). The second fin 921 is a portion that protrudes downward at the end opposite the hull 20 in the left-and-right direction. The second fin 921 extends in the fore-and-aft direction.

[0028] The underside S1 of the first sponson 91 is a portion that generates resistance between the water jet propulsion boat 10 and the water to prevent the water jet propulsion boat 10 from skidding when the water jet propulsion boat 10 is turning. Similarly, the underside S2 of the second sponson 92 is a portion that generates resistance between the water jet propulsion boat 10 and the water to prevent the water jet propulsion boat 10 from skidding when the water jet propulsion boat 10 is turning. Specifically, the underside S1 of the first sponson 91 comes into contact with the water when the water jet propulsion boat 10 is turning, thereby generating resistance between the water jet propulsion boat 10 and the water, and thereby reducing the turning radius of the water jet propulsion boat 10. Similarly, the underside S2 of the second sponson 92 comes into contact with the water when the water jet propulsion boat 10 is turning, thereby generating resistance between the water jet propulsion boat 10 and the water, and thereby reducing the turning radius of the water jet propulsion boat 10. In this embodiment, the water jet propulsion boat 10 is equipped with a first sponson 91 and a second sponson 92. Therefore, when the water jet propulsion boat 10 turns, the resistance between the water jet propulsion boat 10 and the water increases, and the turning radius of the water jet propulsion boat 10 can be made smaller, compared to a water jet propulsion boat that is equipped with only a first sponson, for example.

[0029] Furthermore, in the water jet propulsion boat 10 of this embodiment, the first sponson 91 has the first fin 911 and the second sponson 92 has the second fin 921, which further reduces the turning radius of the water jet propulsion boat 10. That is, in the water jet propulsion boat 10, the first fin 911 and the second fin 921 each come into contact with the water when the water jet propulsion boat 10 turns, thereby increasing the resistance between the water jet propulsion boat 10 and the water, and more effectively reducing the turning radius of the water jet propulsion boat 10.

[0030] As shown in FIG. 2 , the front end of the second sponson 92 is located forward of the aft end of the first sponson 91. In other words, the first sponson 91 and the second sponson 92 face each other in the up-down direction. The aft end of the first sponson 91 is located forward of the transom 25, which is located at the aft end of the hull 20. The aft end of the second sponson 92 is located forward of the transom 25, which is located at the aft end of the hull 20. The first sponson 91 is positioned so that its front and aft ends are aligned horizontally or so that its front end is positioned higher than its aft end when the water jet propulsion boat 10 is planing straight ahead. The second sponson 92 is positioned so that its front and aft ends are aligned horizontally or so that its front end is positioned higher than its aft end when the water jet propulsion boat 10 is planing straight ahead. Moreover, the first sponson 91 and the second sponson 92 are disposed substantially parallel to each other when viewed in the left-right direction.

[0031] Fig. 3 is a rear view of the water jet propulsion boat 10 of the embodiment during straight planing. As shown in Fig. 3, the first sponson 91 disposed on the left side of the hull 20 and the first sponson 91 disposed on the right side of the hull 20 are symmetrical about the center line CL of the hull 20 in the transverse direction. Similarly, the second sponson 92 disposed on the left side of the hull 20 and the second sponson 92 disposed on the right side of the hull 20 are symmetrical about the center line CL of the hull 20 in the transverse direction. The underside S1 of the first sponson 91 is located below the waterline W when the water jet propulsion boat 10 is planing straight. The underside S2 of the second sponson 92 is located above the waterline W when the water jet propulsion boat 10 is planing straight. In the left-right direction, the end of the second sponson 92 opposite the hull 20 is at the same position as the end of the first sponson 91 opposite the hull 20. In other words, the first sponson 91 and the second sponson 92 protrude to the same positions in the left-right direction.

[0032] FIG. 4 is a rear view of the water jet propulsion boat 10 of the embodiment during a turn. FIG. 4 shows the water jet propulsion boat 10 banked (inclined) to the left. That is, FIG. 4 shows the state of the water jet propulsion boat 10 when turning left. When the water jet propulsion boat 10 turns left, the underside S2 of the second sponson 92 located on the left side of the hull 20 comes into contact with the water when the bank angle reaches a certain angle. That is, when the bank angle of the water jet propulsion boat 10 reaches or exceeds a certain angle, both the first sponson 91 and the second sponson 92 come into contact with the water. Note that the "certain angle" is not particularly limited, but is preferably greater than or equal to 20 degrees and less than or equal to 40 degrees. The action when the water jet propulsion boat 10 turns right is similar to the action when turning left.

[0033] 3 and 4, the underside S2 of the second sponson 92 does not come into contact with the water when the water jet propulsion boat 10 is planing straight, but comes into contact with the water when the water jet propulsion boat 10 is turning and the bank angle is equal to or greater than a certain angle. Therefore, the sponson 90 can reduce the turning radius of the water jet propulsion boat 10 while maintaining the light and agile running characteristics of the water jet propulsion boat 10 when planing straight. Furthermore, even when the water jet propulsion boat 10 is turning, the underside S2 of the second sponson 92 does not come into contact with the water if the bank angle is less than a certain angle. Therefore, the sponson 90 can maintain the light and agile running characteristics of the water jet propulsion boat 10 when turning gently.

[0034] 5 is a rear view of the water jet propulsion boat 10a of another embodiment during straight-line planing. In the following, parts of the water jet propulsion boat 10a of another embodiment that are common to the water jet propulsion boat 10 of the above-described embodiment are designated by the same reference numerals, and their description will be omitted where appropriate.

[0035] The water jet propulsion boat 10a of this embodiment differs from the water jet propulsion boat 10 of the embodiment in the configuration of the sponsons. Specifically, in the transverse direction, the end of the second sponson 92a opposite the hull 20a is located farther from the center line CL of the hull 20a than the end of the first sponson 91a opposite the hull 20a. In other words, the second sponson 92a protrudes outward in the transverse direction than the first sponson 91a.

[0036] The water jet propulsion boat 10a of the other embodiments also achieves the same effects as the water jet propulsion boat 10 of the embodiment. Specifically, because the water jet propulsion boat 10a includes a first sponson 91a and a second sponson 92a, the resistance between the water jet propulsion boat 10a and the water during turning is increased, and the turning radius of the water jet propulsion boat 10a can be reduced, compared to a water jet propulsion boat that includes only a first sponson. Furthermore, in the water jet propulsion boat 10a of the other embodiments, the second sponson 92a protrudes outward in the lateral direction more than the first sponson 91a. Therefore, the water jet propulsion boat 10a can come into contact with the water even at a relatively shallow bank angle, compared to a boat in which the first sponson and the second sponson protrude to the same position in the lateral direction.

[0037] The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified into various forms without departing from the spirit thereof, for example, the following modifications are also possible.

[0038] 6 is an enlarged side view of the rear side of the hull 20b of the modified example. In the following, parts of the hull 20b of the modified example that are common to the hull 20 of the above-described embodiment are given the same reference numerals and their description will be omitted as appropriate.

[0039] In the modified example shown in Fig. 6, the first sponson 91b and the second sponson 92b are not formed integrally. That is, the first sponson 91b and the second sponson 92b are formed separately from each other. Furthermore, the front end of the second sponson 92b is located rearward of the front end of the first sponson 91b. In this manner, the first sponson and the second sponson may be formed separately from each other.

[0040] 7 is an enlarged side view of the rear side of the hull 20c of another modified example. In the following, parts of the hull 20c of another modified example that are common to the hull 20 of the above-described embodiment are designated by the same reference numerals and their description will be omitted where appropriate.

[0041] In another modified example shown in FIG. 7, the first sponson 91c and the second sponson 92c are not formed integrally. That is, the first sponson 91c and the second sponson 92c are formed separately from each other. Furthermore, the front end of the second sponson 92c is located rearward of the rear end of the first sponson 91c. That is, the first sponson 91c and the second sponson 92c do not overlap each other in the up-down direction. In this way, the front end of the second sponson may be located rearward of the rear end of the first sponson. That is, the first sponson and the second sponson do not have to overlap each other in the up-down direction.

[0042] 8 is an enlarged side view of the rear side of a hull 20d according to another modified example. In the following, parts of the hull 20d according to another modified example that are common to the hull 20 according to the above-described embodiment are designated by the same reference numerals and their description will be omitted where appropriate.

[0043] 8, in addition to the first sponson 91d and the second sponson 92d, a third sponson 93 is provided on the side of the rear of the hull 20d. The third sponson 93 has a third fin 931 that protrudes downward at the end opposite the hull 20d in the transverse direction. In this way, the water jet propulsion boat may have three or more sponsons.

[0044] In the above embodiment, the engine 31 is exemplified as the drive source of the drive device 30. However, an electric motor or the like may be provided together with the engine 31 or instead of the engine 31.

[0045] In the transverse direction, the end of the second sponson opposite the hull may be located closer to the center line of the hull than the end of the first sponson opposite the hull.

[0046] In the above embodiment, the first sponson 91 is positioned so that its front end and rear end are horizontal or so that its front end is positioned higher than its rear end, but the first sponson may also be positioned so that its front end is positioned lower than its rear end.

[0047] In the above embodiment, the second sponson 92 is positioned so that its front and rear ends are horizontal or so that its front end is positioned higher than its rear end, but the second sponson may also be positioned so that its front end is positioned lower than its rear end.

[0048] In the above embodiment, the first sponson 91 and the second sponson 92 are arranged approximately parallel to each other when viewed in the left-right direction, but the first sponson and the second sponson do not have to be arranged approximately parallel to each other when viewed in the left-right direction.

[0049] In the above embodiment, a PWC is given as an example of an application of the technology disclosed in this specification, but the technology disclosed in this specification can also be applied to other watercraft, such as sports boats. [Explanation of symbols]

[0050] 10, 10a: Water jet propulsion boat 20, 20a to 20d: Hull 21: Hull 22: Deck 23: Seat 25: Transom 30: Drive unit 31: Engine 32: Crankshaft 33: Coupling 40: Jet propulsion mechanism 41: Flow path 42: Water intake 43: Impeller housing 44: Impeller 45: Impeller shaft 46: Stator vane 47: Nozzle 48: Jet outlet 49: Other end 50: Jet flow adjustment mechanism 51: Deflector 52: Reverse gate 53: Discharge port 60: Displacement mechanism 61: Deflector moving mechanism 65: Reverse gate moving mechanism 70: Ship steering device 80: ECU 91, 91a to 91d: First sponson 911: First fin S1: Underside 92, 92a-92d: Second sponson 921: Second fin S2: Lower surface 93: Third sponson 931: Third fin CL: Center line W: Waterline

Claims

1. A water jet propulsion boat, The hull and a first sponson provided laterally on the rear side of the hull; a second sponson provided laterally on the rear side of the hull; Equipped with a lower surface of the second sponson is located above a lower surface of the first sponson, The water jet propulsion boat, wherein a rear end of the second sponson is located rearward of a rear end of the first sponson.

2. The water jet propulsion watercraft according to claim 1, a lower surface of the first sponson is located below a waterline when the water jet propulsion boat is planing straight, The water jet propulsion boat, wherein a lower surface of the second sponson is located above the waterline when the water jet propulsion boat is planing straight ahead.

3. The water jet propulsion watercraft according to claim 1, The water jet propulsion watercraft, wherein a front end of the second sponson is located forward of a rear end of the first sponson.

4. The water jet propulsion watercraft according to claim 1, a water jet propulsion boat, wherein an end of the second sponson opposite the hull is located at the same position as an end of the first sponson opposite the hull in the transverse direction.

5. The water jet propulsion watercraft according to claim 1, a water jet propulsion watercraft, wherein an end of the second sponson opposite the hull is located farther from a center line of the hull in the transverse direction than an end of the first sponson opposite the hull.

6. The water jet propulsion watercraft according to claim 1, The first sponson is disposed so that its front end and rear end are aligned horizontally or so that its front end is positioned higher than its rear end.

7. The water jet propulsion watercraft according to claim 1, The second sponson is disposed so that its front end and rear end are aligned horizontally or so that its front end is positioned higher than its rear end.

8. The water jet propulsion watercraft according to claim 1, The water jet propulsion boat, wherein the first sponson and the second sponson are disposed substantially parallel to each other when viewed in the left-right direction.

9. The water jet propulsion watercraft according to claim 1, a rear end of the first sponson and a rear end of the second sponson are located forward of a transom located at the rear end of the hull.

10. A vessel, The hull and a first sponson provided laterally on the rear side of the hull; a second sponson provided laterally on the rear side of the hull; Equipped with a lower surface of the second sponson is located above a lower surface of the first sponson, The aft end of the second sponson is located rearward of the aft end of the first sponson.

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