JP2976342B2 - Ship propulsion - Google Patents

Description

The present invention relates to a marine propulsion device such as a water jet propulsion ship and an outboard motor.

[Prior art] In a watercraft propulsion device such as a water jet propulsion ship, the engine is supported on the hull in a state of being mounted via a mounting rubber in order to prevent engine vibration from being transmitted to the hull and impairing the embarkation feeling. doing.

At this time, the engine has a resonance point determined by the spring constant of the mount rubber and the weight of the engine. For this reason, in an ordinary marine propulsion device, the resonance point of this engine is set outside the practical rotation range (low rotation range) to avoid discomfort to passengers due to resonance.

In order to set the resonance point of the engine outside the practical rotation range (low rotation range) as described above, it is necessary to use a soft mount rubber having a low spring constant.

[Problems to be Solved by the Invention] By the way, in a marine propulsion device having a high mobility such as in a water jet propulsion ship, the engine does not interfere with the hull even when the hull jumps and lands. In order to support the engine securely, the engine will be supported by hard mounting rubber.

However, when a hard mount rubber is used, the resonance point of the engine falls within a practical rotation range, and there is a disadvantage that large vibrations generated at the resonance point cause discomfort to a passenger.

An object of the present invention is to prevent the operation in an uncomfortable region due to hull vibration by using the engine at a rotational speed outside the resonance range when the engine is always reliably supported on the hull by the hard mount rubber.

Means for Solving the Problems The present invention relates to a marine propulsion device having a mount system including an engine and a mount rubber supporting the engine.
While setting the resonance range of the mount system to an intermediate rotation range between the low-speed rotation range and the high-speed rotation range of the engine, the engine speed control means for automatically adjusting the engine speed to outside the resonance range of the mount system is provided. It is characterized by having.

[Operation] According to the present invention, by using a hard rubber having a high spring constant and high rigidity as a mount rubber for supporting the engine on the hull, the engine can interfere with the hull even when the hull jumps and lands. The engine can always be reliably supported on the hull so as not to be disturbed.

In addition, paying attention to the fact that the rotation range of the engine actually used in the ship is mostly the low speed rotation range and the high speed rotation range, and the intermediate rotation range between them is hardly used, the resonance range of the mount system is Even if the resonance range of the mount system enters the practical rotation range due to the hardness of the mounting rubber because it is set to the intermediate rotation range, this is an intermediate rotation range that is not usually used. Can be prevented.

In addition, since the engine speed is automatically adjusted outside the resonance range of the mount system by the engine speed control means, if the engine is used in the intermediate rotation range, the engine speed is automatically adjusted outside the resonance range. Driving in an uncomfortable region due to resonance of the mounting system and, consequently, boat vibration can be prevented.

FIG. 1 is a side view showing a partially cutaway water jet propulsion boat to which the present invention is applied, FIG. 2 is a front view showing a mounted state of an engine, and FIG. FIG. 4 is a diagram showing a conventional automatic advance curve with respect to the engine speed, FIG. 5 is a diagram showing an automatic advance curve with respect to the engine speed in the first embodiment, FIG. 6 is a control system diagram of the second embodiment, and FIG. 7 is a flowchart of the second embodiment.

(First Embodiment) As shown in FIGS. 1 and 2, a water jet propulsion ship 10
A two-stroke engine 13 is supported by a mount rubber 11 via a mount rubber 12.

The water jet propulsion boat 10 has a water jet duct 14 provided at the rear of the hull 11. Water injection duct 14 has water inlet 15 and water outlet
A fixed wing 17 is fixedly provided at an intermediate portion of the fixed wing 16 and the impeller 18 is rotatably supported. Impeller
The rotational force of the engine 13 is transmitted to the output shaft 20 via the coupling 19 to rotate, and forms a jet in the water jet duct 14.

A steering nozzle 21 is provided around the water outlet 16 of the water injection duct 14.
Are pivotally mounted so as to be rotatable in a substantially horizontal direction. Steering nozzle
21 is turned by transmitting the steering operation force of the steering wheel device 22 by the cable 23, and changes the outflow direction of the jet flowing out from the water jet duct 14 in a substantially horizontal direction.
11 can be turned left and right.

Further, a forward / backward switching bucket 24 is pivotally attached to a middle portion on both sides of the steering nozzle 21 so as to be vertically rotatable. The bucket 24 applies the switching operation force of the forward / reverse switching lever 25 to the cable 26.
And the opening and closing of the outlet of the steering nozzle 21 to switch the outflow direction of the jet in the front-back direction. That is, the bucket 24 forms the forward jet at the forward position where the outlet of the steering nozzle 21 is opened, and forms the reverse jet at the reverse position where the outlet of the steering nozzle 21 is closed.

However, the water injection propulsion boat 10 is provided with the following automatic advancing device as engine rotation control means.

That is, the advance angle curve by the conventional general automatic advance device is as follows.
As shown in FIG. 4, in the low speed range, the phase is retarded to stabilize the rotation, in the high speed range, the phase is advanced to secure the output, and in the middle range, it changes gently. .

On the other hand, most of the rotation range actually used in the water jet propulsion boat 10 is an extremely low speed range and a high speed range because of its mobility. Therefore, as shown in FIG. 5, the advancing curve of the water jet propulsion boat 10 by the automatic advancing device is retarded in the low speed range (A) to stabilize the rotation similarly to FIG. (C)
However, as in Fig. 4, it is advanced to secure output,
In the middle range (B), it started rapidly and changed suddenly.

Accordingly, in the water injection propulsion boat 10, when the engine speed shifts between the low speed range (A) and the high speed range (C), it is difficult to stabilize the ignition timing in the intermediate range (B). The low-speed rotation speed N1 or high-speed rotation speed in Fig. 5
Stabilize at N2. That is, the engine speed changes so as to jump between the low-speed speed N1 and the high-speed speed N2.

Therefore, the automatic advancing device of the water injection propulsion boat 10 is configured such that the resonance point N0 (see FIG.
The above-described advance angle curve is set so as to be located between N2, and as a result, the rotation speed of the engine 13 is automatically adjusted outside the resonance range.

In FIG. 3, N0 is a resonance point, Na to Nc are practical rotation ranges, Nd to Ne are hull vibration uncomfortable ranges (resonance ranges), and Nd to Ne are shown.
Is included in the range of N1 to N2.

 Next, the operation of the above embodiment will be described.

According to the above embodiment, by using a hard rubber having a high spring constant as the mount rubber 12 for supporting the engine 13 on the hull 11, the engine 13 can be mounted even when the hull 11 jumps and lands. The engine so as not to interfere with the body 11
13 can always be supported on the hull 11 reliably.

At this time, even if the resonance point of the engine 13 enters the practical rotation range due to the hardness of the rubber, in the above-described embodiment, the rotation speed of the engine 13 jumps over the resonance range and changes. Automatically adjusted out of range. This ensures that the engine 13 is used at a rotational speed outside the resonance range,
Driving in an uncomfortable area due to hull vibration can be prevented.

(Second Embodiment) In the second embodiment, as shown in FIG. 6, the throttle valve shaft 29 of the throttle valve 28 provided in the carburetor 27 of the engine 13 is provided in the water injection propulsion boat 10 of the first embodiment. A servo motor 30 that can be opened and closed is provided, and the servo motor 30 is controlled by a control device 31 including a microcomputer. That is, the engine rotation control means is constituted by the servo motor 30 and the control device 31. As shown in FIG. 7, the control device 31 obtains the detection signal of the engine speed detector 32 and It constantly monitors whether or not it is within the resonance range, and controls the servo motor 30 to control the opening of the throttle valve 28 when the engine speed enters or tries to enter the resonance range. Thus, the engine speed is automatically adjusted outside the resonance range.

In the embodiment of the present invention, there are various methods of adjusting the engine speed, such as adjusting the engine speed by adjusting the fuel injection amount in the fuel injection engine.

[Effect of the Invention] As described above, according to the present invention, the resonance range of the mount system is set to the intermediate rotation range that is not normally used in the engine, so that the engine can always be reliably supported on the hull by the hard mount rubber. In addition, it is possible to prevent the mount system from resonating with the rotational vibration of the engine.

Also, since the engine speed is automatically adjusted to be outside the resonance range of the mount system, even if the engine is used in the intermediate rotation range, the engine speed is automatically adjusted to be outside the resonance range. Driving in an uncomfortable area due to resonance and, consequently, hull vibration can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a water jet propulsion ship to which the present invention is applied, FIG. 2 is a front view showing a mounted state of an engine, and FIG. 3 is a relationship between engine speed and engine vibration. FIG. 4 is a diagram showing a conventional automatic advance curve with respect to the engine speed, FIG. 5 is a diagram showing an automatic advance curve with respect to the engine speed in the first embodiment,
FIG. 6 is a control system diagram of the second embodiment, and FIG. 7 is a flowchart of the second embodiment. 10 ... water jet propulsion boat, 11 ... hull, 12 ... mount rubber, 13 ... two-stroke engine, 29 ... throttle valve shaft, 30 ... servo motor, 31 ... control device.

Continuation of front page (56) References JP-A-59-156189 (JP, A) JP-A-61-98906 (JP, A) JP-A-3-194139 (JP, A) JP-A-2-102628 (JP) JP-A-3-275958 (JP, A) JP-A-49-71301 (JP, A) JP-A-3-129139 (JP, A) JP-A-2-146232 (JP, A) 61-215126 (JP, A) Fully open 1987-166150 (JP, U) Fully open 1987-128137 (JP, U) Fully open 60-170219 (JP, U) Fully open 1986-142151 (JP, U) U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B63H 21/30 F01D 21/00

Claims (1)

(57) [Claims] 1. A marine propulsion device having a mounting system including an engine and a mounting rubber supporting the engine.
While setting the resonance range of the mount system to an intermediate rotation range between the low-speed rotation range and the high-speed rotation range of the engine, the engine speed control means for automatically adjusting the engine speed to outside the resonance range of the mount system is provided. A ship propulsion machine characterized by comprising: