JP4554186B2 - Reverse mechanism for water jet propulsion type personal watercraft - Google Patents

Description

  The present invention relates to a reverse mechanism used by a water jet propulsion type personal watercraft during reverse travel.

  In recent years, water jet propulsion type personal watercraft has been widely used for leisure, sports or rescue. The small planing boat is equipped with an engine in a boat constituted by a hull and a deck, and in general, water sucked from a water suction port provided at the bottom of the rear portion of the hull is added by a water jet pump driven by the engine. The propulsion of the hull is obtained by injecting it backwards under pressure and acceleration.

  The water jet pump includes a steering nozzle that can swing left and right at the rear thereof, and the steering nozzle is connected to the handlebar by a cable. Accordingly, by operating the handle bar, the steering nozzle can be swung left and right, and the direction of water injection from the water jet pump can be changed.

  Some personal watercraft are equipped with a reverse mechanism for reverse travel. In this planing boat, a reverse bucket is provided behind the water jet pump so as to cover the steering nozzle (see, for example, Patent Documents 1 and 2). The reverse bucket is connected to a reverse lever provided on the deck via a cable, and can swing up and down within a predetermined range by operating the reverse lever.

When the boat is advanced, the reverse bucket is fixed at the upper position, the jet flow from the steering nozzle is directed rearward, and the reaction force is obtained forward. On the other hand, when the boat is moved backward, the reverse bucket is fixed at the lower position, the jet flow from the steering nozzle is reflected by the inner wall surface of the reverse bucket and is directed substantially forward, and the reaction force is obtained by the reaction.
Japanese Patent No. 2756434 Japanese Patent No. 3358718

  By the way, in the reverse mechanism mentioned above, it is necessary to temporarily fix a reverse bucket in an upper position and a lower position. That is, at the time of forward movement, it is necessary to fix the reverse bucket at the upper position so as not to hinder the jet flow toward the rear, while at the time of backward movement, in order to reflect the jet flow at the inner wall surface of the reverse bucket, It is necessary to fix the reverse bucket at the lower position.

  Therefore, in order to securely fix the reverse bucket at each position, the reverse mechanism is provided with a stopper mechanism. However, the stopper mechanism is assembled by a large number of parts and has a relatively complicated structure. In the case of such a stopper mechanism, not only does the number of parts increase and the cost increases, but it also tends to be difficult to improve the positioning accuracy regarding the upper and lower fixed positions of the reverse bucket.

  Accordingly, an object of the present invention is to provide a reverse mechanism capable of fixing a reverse bucket with a relatively simple configuration and improving positioning accuracy in a water jet propulsion type personal watercraft.

  The present invention has been made in view of the above circumstances, and a reverse mechanism for a water jet propulsion type personal watercraft according to the present invention includes a water jet pump constituting a propulsion mechanism of a boat, and the water jet pump. A reverse bucket that is disposed rearward of the water jet pump and a pump cover that covers a lower portion of the water jet pump, and the pump cover regulates an upward movement and / or a downward movement of the reverse bucket. The reverse bucket has a stopper that engages with the restricting portion, and the reverse bucket moves upward out of a predetermined swing range by engaging the stopper with the restricting portion. And / or the downward movement is restricted.

  In this case, it is possible to restrict the reverse bucket from moving upward and / or downward from a predetermined range by a simple configuration such as a stopper included in the reverse bucket and a restriction portion included in the pump cover. Further, with such a simple configuration, it is possible to improve the accuracy of the position where the reverse bucket is regulated.

  The pump cover includes a support portion that supports the reverse bucket in a swingable manner, and the stopper comes into contact with the support portion at an upper position and / or a lower position of a swing range, The reverse bucket may be lifted and / or lowered. In this case, the support portion for the reverse bucket can function as the restricting portion described above, and the number of parts can be further reduced and a simple configuration can be achieved.

  The pump cover includes a support portion that swingably supports the reverse bucket, and a support position of the reverse bucket by the support portion is an abbreviated cross-section of a flow path of a jet discharged from the water jet pump. It may be below the center.

  With such a configuration, when the reverse bucket is positioned downward, the jet flow from the water jet pump is blown onto the inner wall surface of the reverse bucket above the support position, so that the reverse bucket has a downward moment. Works. Accordingly, when the reverse bucket is lowered to reverse the boat, the reverse bucket is less likely to swing upward due to the action of the downward moment, and can be stably maintained at the lower position.

  Further, a flange portion extending rearward is provided at a rear portion of the reverse bucket, and the flange portion may be inclined so that a rear portion thereof is located outside the reverse bucket.

  With such a configuration, even when the reverse bucket moves downward while moving the reverse bucket upward, the jet flow from the water jet pump is blown to the brim portion, and the brim portion Receives upward external force. Accordingly, the reverse bucket can be stably maintained at the upper position when the boat advances.

  According to the reverse mechanism for water jet propulsion type personal watercraft according to the present invention, the reverse bucket can be fixed at the upper position and / or the lower position with a relatively simple configuration, and the positioning accuracy can be improved. Can be planned.

  Hereinafter, a reverse mechanism for a water jet propulsion type personal watercraft according to an embodiment of the present invention will be described in detail with reference to the drawings. The planing boat shown in FIG. 1 is a riding type planing boat on which a rider rides on a seat 7, and a hull 1 thereof includes a hull 2 and a deck 3 that covers the top of the hull 2. A connection line between the hull 2 and the deck 3 over the entire circumference of the hull 1 is referred to as a gunnel line 4. The gunnel line 4 is located above the water line 5 when the boat is anchored. Note that the concept of orientation used in the following description is the same as the concept of direction viewed from the rider straddling the seat 7.

  As shown in FIG. 2, a substantially rectangular deck opening 6 in a plan view is provided in the longitudinal direction of the hull 1 at a substantially central position in the longitudinal direction of the deck 3 in the upper part of the hull 1. It is provided along the long side. A riding type seat 7 on which a rider sits is detachably attached above the deck opening 6.

  A space surrounded by the hull 2 and the deck 3 below the deck opening 6 forms an engine room 8, and an engine E for driving the planing boat is mounted in the engine room 8. Further, the engine room 8 has a convex cross section and is shaped so that the upper part is narrower than the lower part. Inside the engine E, as shown in FIG. 9 is stored along the front-rear direction of the hull 1.

  An output end portion of the crankshaft 9 is connected to a pump shaft 11 of a water jet pump P disposed at a rear portion of the hull 1 via a drive shaft 10. Accordingly, the pump shaft 11 rotates in conjunction with the rotation of the crankshaft 9. An impeller 12 is attached to the pump shaft 11, and a stationary blade 13 is disposed behind the impeller 12. A pump casing 14 is provided on the outer periphery of the impeller 12 so as to cover the impeller 12.

  A water inlet 15 is provided at the bottom of the hull 1. The water inlet 15 and the pump casing 14 are connected by a water absorption passage, and the pump casing 14 is further connected to a pump nozzle 16 provided at the rear part of the hull 1. The pump nozzle 16 is configured such that the nozzle diameter decreases toward the rear, and an injection port 17 is formed at the rear end as shown in FIG.

  The planing boat pressurizes and accelerates the water sucked from the water suction port 15 by the water jet pump P, rectifies the water by the stationary blade 13, and discharges the water backward from the jet port 17 through the pump nozzle 16. . The personal watercraft obtains a propulsive force by the reaction of water discharged from the injection port 17.

  A steering handle bar 19 is provided at the front of the deck 3, and the handle bar 19 is connected to a steering nozzle 20 (see also FIG. 3) disposed behind the pump nozzle 16 with a cable (not shown). Z)). By operating the handle bar 19 left and right, the steering nozzle 20 is swung left and right. Therefore, by operating the handle bar 19 while the water jet pump P is generating thrust, the direction of water discharged to the outside through the pump nozzle 16 can be changed, and the forward direction of the planing boat can be changed. it can.

  FIG. 4 is a rear enlarged side view of the water jet pump P. As shown in FIG. 4, a reverse bucket 22 having a bowl shape is disposed above the rear side of the steering nozzle 20. A pump cover 23 is provided below the pump casing 14 so as to cover the lower portion of the pump casing 14. On the upper surface of the rear portion of the pump cover 23, a pivot support portion (regulation portion, support portion) 25 that pivotally supports the reverse bucket 22 via a swing shaft 24 is erected. As shown in FIG. 3, this pivot part 25 is arrange | positioned at the right and left of the pump cover 23, and the pivot part 25 shown in FIG. 4 has shown the left side thing. As shown in FIG. 4, the reverse bucket 22 is connected to one end of a cable 26 at a position away from the swing shaft 24. The other end of the cable 26 is connected to the deck 3 as shown in FIG. It is connected to a reverse lever 27 provided in the vicinity of the handle bar 19.

  Therefore, by operating the reverse lever 27, the reverse bucket 22 can swing up and down about the swing shaft 24 as shown in FIG. When the reverse bucket 22 is swung downward about the rocking shaft 24 and positioned rearward of the steering nozzle 20, the water discharged rearward from the steering nozzle 20 changes its direction substantially forward and is injected. The Therefore, at this time, the planing boat can be moved backward. In FIG. 4, a center line 28 of a flow cross section of water sprayed from the steering nozzle 20 is indicated by a one-dot chain line.

  The configuration of the reverse bucket 22 will be described in detail with reference to FIGS. 5 and 6A and 6B. As shown in the perspective view of FIG. 5 and the side view of FIG. 6A, the reverse bucket 22 has a bowl-shaped main body portion 30. The rib 31 is provided. The reverse bucket 22 is made of synthetic resin, and the rigidity is ensured by the rib 31. However, when the reverse bucket 22 is configured using a material having sufficient rigidity, the rib 31 is not necessarily required.

  A pivotal support hole (supported part) 32 through which the above-described swing shaft 24 is inserted is provided on the side of the main body 30, and the reverse bucket 22 is pivoted at the position of the pivotal support hole 32. Is supported by The pivot holes 32 are provided symmetrically on the left and right of the main body 30 corresponding to the left and right pivots 25 (see FIG. 5). As shown in FIG. 6A, a cable connection portion 33 to which one end of the above-described cable 26 (FIG. 4) is connected is provided at a position separated from the right pivot support hole 32 by a predetermined distance. As shown in FIG. 4, in a state where the reverse bucket 22 covers the steering nozzle 20, the pivot support hole 32 and the cable connection portion 33 are disposed with the center line 28 of the jet flow from the steering nozzle 20 interposed therebetween, and The hole 32 is located below the center line 28.

  As shown in FIG. 6 (b), a flange portion 34 extends rearward from the rear portion of the main body portion 30. The flange portion 34 has an angle different from the inner wall surface 30 </ b> A of the main body portion 30, and the inner wall surface 34 </ b> A is formed. That is, the inner wall surface 34 </ b> A of the brim part 34 is formed so as to be inclined so that the rear end part thereof is located outside the main body part 30.

  In addition, a stopper 35 having a crank shape is erected on the inner wall surface of the reverse bucket 22 and in the vicinity of the left pivot support hole 32. As shown in FIG. 4, when the reverse bucket 22 is positioned below, the stopper 35 abuts on the lower side of the left pivotal support portion 25 and restricts the reverse bucket 22 from further swinging downward. Therefore, when the reverse bucket 27 is swung downward by operating the reverse lever 27 (FIG. 1), the reverse bucket 22 is fixed at a lower position where the pivot portion 25 and the stopper 35 abut.

  On the other hand, as shown in FIG. 4, when the reverse bucket 22 is positioned upward, the reverse bucket 22 abuts on the rear upper portion of the pivotal support portion 25 to restrict the reverse bucket 22 from further swinging upward. Accordingly, when the reverse lever 27 (FIG. 1) is operated to pull the cable 26 forward, the reverse bucket 22 is swung upward, and the reverse bucket 22 is at an upper position where the pivot portion 25 and the stopper 35 abut. Fixed. In this way, the reverse bucket 22 can swing up and down within a range defined by the pivot portion 25 and the stopper 35, and swinging outside this range is restricted, and by operating the reverse lever 27. The pivot portion 25 and the stopper 35 are fixed at the upper position and the lower position where they contact each other.

  Further, as shown in FIG. 6B, a large number of fins 40 are formed on the inner wall surface 30 </ b> A of the main body 30. That is, side fins 41 are provided on the left and right sides of the inner wall surface 30 </ b> A of the main body 30, and two center fins 42 are provided between the side fins 41. Both the side fins 41 and the center fins 42 are formed substantially along the front-rear direction of the main body 30, and both are formed so that the protruding amount is smaller in the rear part than in the front part. 6B illustrates the left side fin 41 and the center fin 42, the side fin 41 and the center fin 42 are provided symmetrically on the inner wall surface 30A of the main body 30.

  FIG. 7 is an enlarged rear side view of the water jet pump P showing the reverse mechanism when the boat is moving backward. As shown in FIG. 7, when the boat is moved backward, the reverse bucket 22 is swung around the swing shaft 24 by the operation of the reverse lever 27 (FIG. 1) and disposed below. The jet flow discharged from the steering nozzle 20 is reflected by the inner wall surface 30A of the reverse bucket 22, is changed in direction, and is jetted forward to generate a reverse thrust.

  The jet reflected from the inner wall surface 30A is rectified by the side fins 41 and the center fin 42 described above, and as a result, the direction of flow of the jet from the steering nozzle 20 is smoothly changed forward and left and right. Is also suppressed. Accordingly, the thrust generated by the water jet pump P is efficiently converted into a reverse thrust.

  Further, as described above, the pivot support hole 32 of the reverse bucket 22 is located below the center line 28 of the jet flow from the steering nozzle 20, so that the reverse bucket 22 that has received this jet has a downward moment. Works. Therefore, the reverse bucket 22 that receives the jet flow from the steering nozzle 20 at the lower position when the boat moves backward is moved to the lower position by the downward moment, the pivot portion 25 and the stopper 35 that restrict the downward swing. And stable.

  FIG. 8 is a rear enlarged side view of the water jet pump P showing the reverse mechanism when the boat is moving forward. As described above, by operating the reverse lever 27 (FIG. 1) and pulling the cable 26 forward, the reverse bucket 22 is fixed at the upper position. As a result, the jet flow discharged from the steering nozzle 20 is Without being reflected by the inner wall surface 30 </ b> A of the reverse bucket 22, it is injected rearward to generate forward thrust.

  Here, a case will be described where the reverse bucket 22 slightly swings downward when the boat advances. In this case, as shown in FIG. 8, the jet flow from the steering nozzle 20 is blown to the inner wall surface 34 </ b> A of the flange portion 34 of the reverse bucket 22 to obtain upward lift. Accordingly, when the boat is moving forward, even if the reverse bucket 22 is slightly swung downward, the reverse bucket 22 is pushed upward by the lift obtained by the brim portion 34. The bucket 22 is stably maintained at the upper position.

  According to the reverse mechanism configured as described above, the reverse bucket 22 can be fixed at the upper position and the lower position by a relatively simple structure including the pivot portion 25 and the stopper 35. Further, since the configuration is simple, it is possible to easily improve the positioning accuracy at the upper position and the lower position. Further, since the pivotal support hole 32 is disposed below the center line 28 of the jet flow from the steering nozzle 20, the reverse bucket 22 is stably maintained at the lower position during reverse travel, and has a brim portion 34. Therefore, the reverse bucket 22 is stably maintained at the upper position during forward movement.

  In this embodiment, the pivot portion 25 pivotally supports the reverse bucket 22 and restricts the swing range of the reverse bucket 22 via the stopper 35. The swing range is regulated by the pivot portion 25. May be achieved by a separate configuration.

  The present invention can be applied to a water jet propulsion type personal watercraft, and in particular, to its reverse mechanism.

1 is a side view of a personal watercraft according to an embodiment of the present invention. It is a top view of the personal watercraft shown in FIG. It is a rear view of the personal watercraft shown in FIG. It is a rear part enlarged side view of the water jet pump shown in FIG. It is a perspective view of the reverse bucket shown in FIG. 6A and 6B are diagrams illustrating a configuration of the reverse bucket illustrated in FIG. 5, in which FIG. 5A is a side view thereof, and FIG. It is a rear part enlarged side view of the water jet pump which shows a reverse mechanism when a boat is moving backward. It is a rear enlarged side view of a water jet pump showing a reverse mechanism when a boat is moving forward.

Explanation of symbols

1 Hull 2 Hull 3 Deck 7 Seat 11 Pump Shaft 14 Pump Casing 16 Pump Nozzle 17 Injection Port 19 Handle Bar 20 Steering Nozzle 22 Reverse Bucket 23 Pump Cover 24 Oscillating Shaft 25 Pivoting Portion (Regulators, Supports)
26 Cable 27 Reverse lever 30 Body portion 32 Pivoting hole 33 Cable connection portion 34 Head portion 35 Stopper E Engine P Water jet pump

Claims (2)

A water jet pump that constitutes a boat propulsion mechanism, a steering nozzle that is disposed behind the water jet pump and that can swing left and right, and a reverse bucket that is disposed outside the steering nozzle and can swing up and down; A pump cover covering a lower portion of the water jet pump,
The pump cover has a support portion that regulates the upward and / or downward movement of the reverse bucket and supports the reverse bucket so as to be swingable. The reverse bucket is located above the swing range of the reverse bucket. Having a stopper that abuts against the support at a position and / or a lower position;
Furthermore, a flange portion extending rearward is provided at the rear portion of the reverse bucket, and the flange portion is inclined so that the rear portion is located outside the reverse bucket,
The reverse bucket has a cable connecting portion to which a cable for swinging the reverse bucket is connected, and the pump cover has a support portion that swingably supports the reverse bucket, and the reverse bucket When the lowering movement of the bucket is restricted by the stopper and the support portion, the support position of the reverse bucket by the support portion and the cable connection portion are the flow path cross-section of the jet flow discharged from the water jet pump. A reverse mechanism for a water jet propulsion type personal watercraft, characterized in that the water jet propulsion type personal watercraft is arranged above and below the substantial center. The support position and the cable connection portion are arranged above and below the substantial center of the cross section of the jet flow path even when the upward movement of the reverse bucket is restricted by the stopper and the support portion. The reverse mechanism of the water jet propulsion type personal watercraft according to claim 1.

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