JPS6366717B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a self-propelled surfjet that has a rope with a throttle grip attached to the tip of the surfboard and a waterjet propulsion device with an engine installed at the rear of the surfboard, and particularly relates to an engine mounted on the rear of the surfboard. This relates to the structure of the mounting box.

[Conventional technology]

In recent years, self-propelled surf jets have been developed as one of the leisure products for use in the sea, etc., in which a surfboard is equipped with a water jet propulsion device driven by an engine and a person rides on the surf board, and is attracting attention from the public. . However, it is still in the process of development, and in particular, the most important engine, the waterjet propulsion device driven by it, and the engine exhaust system have not been ideally completed. For example, at the rear of a surfboard, the engine is mounted via a sealed engine mounting box with a predetermined height and volume, and if the engine or the person riding on the board sinks in water, the engine mounting box It is designed to use buoyancy to reduce sinking and to prevent water from covering the engine.

[Problem to be solved by the invention]

Therefore, by using such an engine mounting box, there is a water jet propulsion device inside, and an exhaust system from the engine, which is designed to prevent water from entering the engine side through this exhaust system in the event of capsizing, etc. If it is possible to incorporate a shaft support for the crankshaft, etc. when connecting the crankshaft to the impeller of the waterjet propulsion device, a seal mechanism, a cooling water system path when cooling the engine using jet flow, etc., it will be possible to improve the structure. Very preferred. However, incorporating such various structures naturally makes the structure of the engine mounting box itself extremely complicated, and there is a need for a manufacturing method that can simplify this process. In addition, since the engine mounting box is submerged in water when in use, and has a complex internal system with high water pressure and high temperature gas pressure, it is necessary to periodically repair it. This is expected to occur, and it is conceivable that failures may occur. Therefore, it is necessary to have a structure that can be easily disassembled and assembled. The present invention has been made in view of the above circumstances, and the engine mounting box in which the engine is mounted has an overlapping structure of an upper case, a middle case, and a lower case, and the water jet propulsion device is connected between each of these cases. , consists of the engine exhaust system, engine crankshaft shaft support, seal mechanism, and engine cooling water system path, and although the engine mounting box has a complex configuration, the structure is simplified, and it is easy to disassemble and assemble for repairs etc. The purpose of this invention is to provide a surf jet that can be used for various purposes.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a waterjet propulsion device with an engine at the rear of a surfboard, mounts the engine through an engine mounting box of the surfboard, and installs the engine inside the engine mounting box. A case for accommodating an impeller driven by the engine, an exhaust gas inlet communicating with the exhaust gas passage of the engine, and an exhaust gas expansion chamber are formed, and a water jet injection nozzle of the case for accommodating the impeller is connected to the exhaust gas. In the waterjet propulsion device formed by penetrating the expansion chamber, the engine mounting box has an overlapping structure of an upper case, a middle case, and a lower case, and the impeller of the waterjet propulsion device is housed in the middle case and the lower case. The case and the water jet injection nozzle are formed, and the upper case and the middle case form a support pipe in which a bearing and a water seal for supporting the crankshaft of the engine are disposed. The cooling water inflow passage and the outflow passage are formed, and the upper, middle and lower cases form the exhaust gas expansion chamber and the exhaust passage.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. To explain the outline of the surfjet according to the present invention in FIG. 1, reference numeral 1 is a surfboard, and a strong and flexible cable body 3 is attached to the tip of the surfboard 1 by a fixing fitting 2. The first part has a throttle grip 4 which is large enough to be gripped with one hand. A hydraulic cylinder (not shown) is built into the throttle grip 4 so that a predetermined hydraulic pressure is generated when the throttle grip 4 is gripped strongly, and a hose 5 of this hydraulic pressure is connected to a part of the inside of the rope body 3, the fixing metal fittings 2, and the rear inside of the surfboard 1. attached to. The person riding on the surfboard 1 holds the throttle 4.
It maintains stability by tightening the cable 3 by gripping it, and adjusts the water jet propulsion force by adjusting the throttle valve opening of the carburetor, which will be described later, through the hydraulic pressure of the hose 5 depending on the degree of grip. It is. Further, a mountain portion 6 is formed at the rear of the surfboard 1, and a hood 7 is removably attached thereto, and a propulsion unit such as an engine, which will be described later, is housed inside the mountain portion 6 and the hood 7. There is. There is a control panel 8 on the mountain part 6 facing forward of the surfboard 1, and this panel 8 has a starter knob 9 for starting the engine and a string 10 tied to the body of the rider to stop the engine in the event of capsizing, etc. It has a kill switch 11, etc. To explain the propulsion section in FIGS. 2 to 4, a storage chamber 12 for an engine, etc., which is open at the top and rear, is formed in the mountain part 6 at the rear of the surfboard 1, and the bottom of this storage chamber 12 is made up of three layers (described later). ) A rectangular engine mounting box 13 is placed, and the engine 14 is mounted horizontally on this engine mounting box 13 with the crankshaft 21 perpendicular. A synthetic resin cover 15 is attached to the peripheral edge of the engine mounting box 13 so as to cover the area around the engine 14 up to the upper limit.
A fuel tank 16 having the same shape as the engine mounting box 13 and cover 15 is installed between the L-shaped bottoms in front of the engine mounting box 13 and the cover 15. As detailed in FIGS. 3 and 4, the engine 14 is, for example, a reed valve type two-stroke, two-cylinder engine, and is placed horizontally with one side of the crankcase 17 and cylinder 18 directly fixed to the engine mounting box 13. The lower end of a crankshaft 21, which stands perpendicularly to the piston 19 in this horizontal cylinder 18 via a connecting rod 20, is inserted into the engine mounting box 13, and the upper end of the crankshaft 21 is fitted with a magnet 22 and a recoil coil. A starter 23 is installed. An intake manifold 25 is connected to the side of the crankcase 17 opposite to the piston 19 via a reed valve 24, a carburetor 26 is attached to the intake manifold 25, and an exhaust port 27 that opens on the back side of the cylinder 18 is connected to the cylinder 18. An exhaust gas passage 29 formed by the exhaust manifold 18 itself and the exhaust manifold 28 guides exhaust gas toward the engine mounting box 13 below. Furthermore, the base plate 31 having the coil 30 of the magneto 22, etc. controls the ignition timing by rotating, and the throttle lever 32 protruding from the base plate 31 is integrated with the valve shaft 33 of the throttle valve of the carburetor 26. The arm 34 is interlocked with the arm 34. In addition, the base plate 31
A hydraulic cylinder 36 is attached to the ear part 35 by a bracket 37, and a hose 5 from the throttle grip 4 at the tip of the surfboard 1 is connected to this hydraulic cylinder 36, and the piston 19 side of the hydraulic cylinder 36 is connected to the ear part by a rod 38. 35, so that when the throttle grip 4 is squeezed, the hydraulic pressure generated in the hose 5 moves the rod 38 on the piston 19 side via the hydraulic cylinder 36, and rotates the base plate 31 of the magneto 22 to advance. At the same time, when the throttle lever 32 operates the arm 34 of the carburetor 26 to open the throttle valve and release the throttle grip 4, the base plate 31 and the arm 34 open.
are returned by spring force. The starter knob 9 is connected to the recoil starter 23 via a rope 39, and the kill switch 11 is operated to stop the generation of sparks on the plug 41 side in the electrical system including the magneto 22. The cylinder head, 41 is a plug, and 42 is a cooling water passage. The engine mounting box 13 has an overlapping structure of an upper case 43, a middle case 44, and a lower case 45, as detailed in FIGS. It has a mounting part 43a and a peripheral part 43b to which the cover 15 is screwed, and recesses 46 are provided at six locations at the rear corners, the middle part, and the front of the lower left and right ends of the lower case 45. By tightening them together, the three-layered upper case 43, middle case 44, and lower case 45 are integrally connected. Further, bolts 48 are attached to two places on the rear end of the lower case 5 on the side of the surfboard 1, and two places on the protruding edge 45a on the front end, and a bolt 49 which also serves as an intermediate drain plug is attached to the surfboard 1.
It is fixed to. And these upper case 43 and middle case 4
4 and the lower case 45, the middle and lower cases 44 and 45 form a spiral case 52 having an impeller 51 of the waterjet propulsion device 50.
A water jet nozzle 53 and a water jet nozzle 53 are stacked vertically, and the center of the case 52 communicates with a water intake port 54 that opens toward the surfboard 1 directly below. Here, the water jet injection nozzle 53
Considering that a very high water pressure is applied inside, the mating parts 53a and 53b of the middle case 44 and the lower case 45 at two places on the left and right of the water jet nozzle 53 are shown in FIGS. 6 and 7. are firmly fastened with bolts 56 in a recess 55 on the lower case 45 side. Next, a support tube 57 is formed by the upper and middle cases 43 and 44, and a support tube 57 is formed by the upper and middle cases 43 and 44, and
1 is connected to the impeller 51 through this support tube 57, and within such support tube 57, the crankshaft 21 is rotatably supported by a non-lubricated plain bearing 58, and a water seal 59 prevents water leakage. It's starting to stop. Similarly, the impeller 5 of the water jet injection nozzle 53 is connected to the upper and middle cases 43 and 44.
A cooling water inflow passage 60 that rises from the discharge port side of No. 1 and supplies cooling water to the cooling water passage 42 of the engine 14.
is formed, and at the same time an outlet 61 on the engine 14 side is formed.
A cooling water outflow passage 62 communicates with the cooling water outflow passage 62 to lead the cooling water to the peripheral edge of the upper case 43, and further communicates with the cooling water outflow passage 62 to flow the cooling water to the peripheral edge of the upper case 43 and exits from the discharge port 63. A cooling water outflow passage 64 is formed to allow the cooling water to be discharged. And impeller 51
With the discharge pressure, a part of the jet flow is sequentially caused to flow from the cooling water inflow passage 60 to the cooling water passage 42, the cooling water outflow passages 62, 64, and the drain port 63 of the engine 14 for cooling. Further, the upper, middle, and lower cases 43 to 45 form a substantially water jet injection nozzle 53.
The exhaust system of the engine 14 is constructed around the engine 14, which consists of two horizontal partitions 65, which are installed between the upper case 43, the middle case 44, and the lower case 45, as shown in FIG. A first expansion chamber 68, a second expansion chamber 69 and a third expansion chamber 70 is arranged in a U-shape in plan view, and an exhaust gas inlet 71 is formed in the first expansion chamber 68 and is provided in the upper case 43 and communicates with the exhaust gas passage 29. Further, the first and second expansion chambers 68 and 69 communicate with each other through an exhaust communication hole 72 in the middle case 44 of the partition 66, and the second and third expansion chambers 6 communicate with each other through an exhaust communication hole 73 and a bent passage 74.
9 and 70 are in communication with each other, and the third expansion chamber 70 has a vertical passage 75 between the middle and lower cases 44 and 45,
Surfboard 1 directly below water jet nozzle 53 via horizontal passage 76 of lower case 45
It communicates with an exhaust gas outlet 77 that opens to the side. In this way, a three-dimensionally bent exhaust gas path is formed from the exhaust gas inlet 71 to the exhaust gas outlet 77 via the first to third expansion chambers 68, 69, 70 and passages 75, 76, thereby causing the overturning. This prevents water from entering the engine 14 from the exhaust system when the engine is stopped. Since the present invention is constructed in this way, when using the surf jet, first, by strongly pulling the starter knob 9, the recoil starter 23 starts the engine 14.
However, when the engine is started, the engine output is small and the impeller 51 of the waterjet propulsion device 50 rotates at a very low speed together with the crankshaft 21. Therefore, water simply passes through the water inlet 54 to the case 52 of the waterjet propulsion device 50 and the waterjet injection nozzle 5.
3 and does not generate a jet flow, it can be easily stopped by holding the surfboard 1 by hand. Next, a person rides on the surfboard 1 while the engine is operating at low speed, and grips the throttle grip 4 while maintaining stability with the cable 3. Then, in response to the grip, the ignition timing in the magnet 22 is advanced as described above, and at the same time, the throttle valve opening of the carburetor 26 is increased, the output of the engine 14 is increased, and the crankshaft 21
At the same time, the impeller 51 rotates at high speed. Therefore, the case 52 of the waterjet propulsion device 50
A jet stream is ejected backward from the water jet through the water jet injection nozzle 53, and the surfboard 1 travels on the water surface at high speed due to the reaction force of the ejected water. At this time, inside the engine mounting box 13, in addition to the operation by the waterjet propulsion device 50, the plain bearing 58 of the support tube 57, the water seal 59 that supports the crankshaft 21 and the sealing action, and the waterjet propulsion device 50 are utilized. Cooling water inflow passage 60 and its outflow passages 62, 6
4. A cooling effect is performed by flowing cooling water into the cooling water passage 42 of the engine 14 through the drain port 63. Further, exhaust gas from the engine 14 enters the first expansion chamber 68 through the exhaust gas inlet 71, then enters the second expansion chamber 69 through the exhaust communication hole 72,
It enters the third expansion chamber 70 through the exhaust communication hole 73 and the bent passage 74, and further passes through the passages 75 and 76 to reach the exhaust gas outlet 77. During this process, the jet flow flows into the cooled water jet injection nozzle 53. It is cooled by constant contact and is guided to be safely discharged from the exhaust gas outlet 77 into the water on the back side of the surfboard 1.

【Effect of the invention】

As explained above, according to the present invention, the engine mounting box 13 has the upper, middle and lower cases 43, 44, 4
Each case has a superimposed structure in which a water jet propulsion device 50, a bearing 58 for the crankshaft 21, a water seal 59, and a cooling and exhaust system for the engine 14 are provided in combination with each other, resulting in a complex configuration of each part. It has a simple structure, is accurately formed, is easy to manufacture, and is easy to mass-produce. Moreover, since the upper, middle, and lower cases 43, 44, and 45 are integrated by bolting, they can be disassembled and assembled very easily.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the external appearance of a surfjet to which the present invention is applied, Fig. 2 is a perspective view schematically showing the propulsion section, Fig. 3 is a sectional view of the main part of the present invention, and Fig. 4 is one of the parts. 5 is a sectional view of FIG. 3, and FIGS. 6 to 10 are a sectional view of FIG. FIG. 11 is a cross-sectional perspective view of the engine mounting box, and FIG. 12 is a perspective view showing the external appearance. 1...Surfboard, 3...Cable body, 4...Throttle grip, 13...Engine mounting box, 14...
Engine, 43... Upper case, 44... Middle case, 45... Lower case, 50... Water jet propulsion device, 51... Impeller, 52... Case, 53... Water jet injection nozzle, 57
... Support pipe, 58 ... Plain bearing, 59 ... Water seal, 60 ... Cooling water inflow passage, 62,
64... Cooling water outflow passage, 71... Exhaust gas inlet, 68 to 70... Expansion chamber, 77... Exhaust gas outlet.

Claims (1)

[Claims] 1. A waterjet propulsion device with an engine is provided at the rear of the surfboard, and the engine is mounted through an engine mounting box of the surfboard,
A case for accommodating an impeller driven by the engine, an exhaust gas inlet communicating with the exhaust gas passage of the engine, and an exhaust gas expansion chamber are formed inside the engine mounting box to accommodate the impeller. In the waterjet propulsion device in which the waterjet injection nozzle of the case is formed by penetrating the exhaust gas expansion chamber, the engine mounting box has an overlapping structure of an upper case, a middle case, and a lower case, and the middle case and the lower case The case housing the impeller of the waterjet propulsion device and the waterjet injection nozzle are formed, and the upper case and the middle case provide a bearing and a water seal for pivotally supporting the crankshaft of the engine. A surfjet, characterized in that it forms a support pipe, an inflow passage and an outflow passage for cooling water of the engine, and the upper, middle and lower cases form the exhaust gas expansion chamber and the exhaust passage.