JPH06308141A - Speed detection device for ship's propulsion unit - Google Patents

Abstract

PURPOSE:To accurately detect speed for display by filling, at least, a pressure transfer path in a ship body with non-compressive fluid for transferring water pressure through this fluid. CONSTITUTION:While a ship is running, the water pressure corresponding to ship's speed is applied to a pressure reception mouth. The water pressured is, through non-compressive fluid in a pressure transfer path 10 of an outboard/ inboard motor and a pressure transfer path 10A in a ship body, transferred to a diaphragm 38, and then, through a continuous tube path 32, to a pressure sensor 30. The pressure value sensed by the sensor 30 is displayed as a speed corresponding to pressure on a speed display meter 16. Since, at that time, the pressure is transferred by the non-compressive fluid filled in the path 10A, head difference based on remaining water, caused by water movement in the path 10A, does not take place, resulting in accurate display of speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed detecting device for a ship propulsion device, and more particularly to an improvement of a pressure transmitting mechanism for transmitting a water pressure corresponding to a ship speed to a speed display device.

[Detailed Description of the Invention] [0002] Conventionally, in this type of speed detecting device, a pressure receiving port for receiving a water pressure corresponding to the ship speed is opened at a lower end face of a marine vessel propulsion direction side, and water entering from the pressure receiving port is opened. Passes through the ship propulsion device and moves in the pressure transmission path inside the ship, and transmits the water pressure according to the ship speed to the speed display device at the tip of the pressure transmission path via the compressible fluid (air) in this path. Was configured to do. For example, JP-A-63-2107
No. 77 discloses a marine speedometer in which a dynamic pressure provided in front of a lower end portion of a lower case of an outboard motor is applied to the speedometer via a pressure guiding tube.

[0003]

However, in the conventional speed detecting device described above, water remains in the pressure guiding tube in the hull due to acceleration / deceleration, and the speed difference is displayed when the ship is stopped due to the head difference between the sea surface and the remaining water. There was a problem that it did not become zero. Then, this invention aims at providing the speed detection apparatus of the ship propulsion device which can detect and display an accurate speed.

[0004]

In order to achieve the above object, the present invention comprises a pressure receiving portion which receives a water pressure according to a boat speed,
A speed detection device for a marine propulsion device comprising a speed display device for converting this water pressure into a speed display, and a pressure transmission path for transmitting the water pressure to the speed display device, at least within a pressure transmission path inside the hull. It is characterized by being filled with an incompressible fluid and transmitting the water pressure through the incompressible fluid. A pressure transmission membrane device may be interposed in the middle of the pressure transmission path, and the water pressure may be transmitted to the speed display device via the pressure transmission membrane device.

[0005]

According to the present invention, at least the pressure transmission path in the ship is filled with the incompressible fluid, and the incompressible fluid is used to transmit the water pressure according to the ship speed. It is possible to display an accurate speed without the possibility of occurrence of.

[0006]

EXAMPLES Next, examples of the present invention will be described. Figure 1
1 shows a general outline of a ship 12 to which an embodiment of the present invention is applied. This boat is provided with a hull 11 and an outboard motor 12A as a boat propulsion device.
2A is attached to the stern plate 13 by the mounting unit 8 and the shaft 13A.
It is attached so as to be rotatable around.

The outboard motor has a casing 20 in which an engine is built on a propulsion unit 9, and a propulsion propeller 17 is provided near the lower end of the propulsion unit. Further, a pressure receiving port 14 for receiving water pressure applied according to the boat speed is opened near the lower end of the propulsion unit in the forward direction. Within the propulsion unit 9, a pressure transmission path 10 for transmitting the water pressure from the pressure receiving port 14 is provided along the longitudinal direction of the propulsion unit 9.
This pipe bends to the hull side when it gets over the stern plate 13, and is connected to the pressure transmission path 10A in the hull. The pressure transmission path 10A descends from the upper part of the stern plate 13 toward the bottom of the ship, extends to the side of the ship 15 and is connected to the speed display device 16 near the operation panel.

FIG. 2 shows a speed detecting device. The device is a pitot tube 14A constituting the pressure receiving port and a pressure transmission path 10 existing in the outboard motor connected thereto.
And the pressure transmission path 10A in the hull connected to this path
And a speed display device 16 connected to the pressure transmission path inside the hull.

The speed display device includes a pressure sensor 30 connected to the inboard pressure transmission path 10A, a connection conduit 32 connecting the pressure sensor and a pressure transmission membrane device described later, and the pressure sensor. And a built-in speedometer 34. A pressure transmission membrane device 34 is provided between the inboard pressure transmission path 10A and the connection conduit 32, and the pressure in the inboard pressure transmission path 10A passes through the connection conduit 32 via the device. , Is applied to the pressure sensor 30.

The pressure transmission membrane device is assembled by a bolt 36, has a diaphragm 38 in the center, and two spaces facing each other via the diaphragm are hermetically sealed. Therefore, this diaphragm 38
Is for enabling pressure transmission while shielding the pressure transmission path 10A and the connection conduit 32.

The pressure transmission membrane device is a joint 4
0 and is adapted to be connected to the passage 10A and the conduit 32 by the joint and the clip 42.

One end of the pressure transmission path 10A in the hull is
It is fitted in a joint 44 at the tip of the route 10 in the outboard motor. Reference numeral 46 is a joint of the pressure sensor 30, and one end of the connecting pipe 32 is connected to this joint.
Sealed and connected.

The pressure transmission path 10A in the hull and the pressure transmission path 10 in the inboard / outboard motor are preliminarily filled with an incompressible fluid (for example, water) by removing air from these pipes. The fluid is hermetically held between the pressure receiving port 14 and the pressure transmission membrane device 34. Further, air is sealed and held between the pressure transmission membrane device 34 and the pressure sensor 30.

Next, the operation of this embodiment will be described.
Now, assuming that the ship is in a running state, water pressure corresponding to the ship speed is applied to the pressure receiving port. This water pressure is transmitted to the diaphragm 38 via the incompressible fluid in the pressure transmission passage 10 of the inboard / outboard motor and the pressure transmission passage 10A in the hull,
Then, water pressure is transmitted from the diaphragm to the pressure sensor 30 via the continuous pipe 32. The pressure value sensed by the pressure sensor is displayed on the speed indicator at a speed corresponding to the pressure. A Bourdon tube or a semiconductor pressure sensor, for example, is selected as the speed indicator.

In this operation, the pressure is transmitted by the non-compressible fluid filled in the pressure transmission path, so that the water remains due to the movement of water in the pressure transmission path as in the conventional case. An accurate speed display can be performed without the occurrence of a head difference based on the above. That is, conventionally, there has been a problem that the water that has reached the inboard pressure transmission path 10A from the pressure transmission path 10 of the inboard / outboard motor to the inboard pressure transmission path 10A remains in the inboard pressure transmission path when the ship is stopped and causes a head difference. However, in this embodiment, since the pressure is transmitted without the movement of water as described above, accurate speed display can be executed.

Further, according to the present embodiment, the pressure corresponding to the velocity is transmitted by the static pressure of the incompressible fluid filled in the pressure transmission path, and the movement of water in the pressure transmission path as in the conventional case. Since the pressure is not transmitted by the dynamic pressure due to, the pressure transmission efficiency does not decrease due to the resistance between the inner wall of the passage and water.

Further, since gas is filled between the diaphragm and the pressure sensor so that the water filled in the pressure transmission path does not come into direct contact with the pressure sensor, deterioration of the pressure sensor can be avoided. In addition, since pressure is transmitted to the pressure sensor via gas, that is, compressible fluid, the pressure transmission is buffered by the gas even when a sudden pressure increase occurs, and accidental damage to the pressure sensor is avoided. You can

Next, a second embodiment will be described. Figure 3
As shown in FIG. 7, the present embodiment is different from the first embodiment in that a non-aqueous non-compressed fluid such as ethylene glycol or silicone oil is filled between the pressure sensor and the diaphragm instead of air. . Therefore, the pressure corresponding to the ship speed is transmitted to the pressure sensor via the non-aqueous incompressible fluid. By replacing the gas with the non-aqueous incompressible fluid, the incompressible fluid has a significantly smaller change in volume compression than the gas, and thus pressure transmission can be performed with a small volume. Therefore, it is possible to reduce the volume of the communication conduit and make the speed display device compact. In particular, in the case where the speed indicator 30A is an analog type, a large volume is required to transmit pressure by gas, whereas in the case of the non-compressed fluid as in this embodiment, this volume should be considerably reduced. You can

Next, a third embodiment of the present invention will be described. This embodiment is different from the above-mentioned one in that, as shown in FIG. 4, a branch pipe 50 is connected to the pressure transmission path in the hull and the other end 52 of this branch pipe is open to the atmosphere. . Further, in the case of the present embodiment, the pressure transmission membrane device is not provided in the middle of the path.

The operation of this embodiment will be described. The water that has entered from the pressure receiving port 14 passes through them while filling the pressure transmission paths inside and outside the inboard motor and the inside of the hull, and the branch pipe 50 on the way.
And the pressure sensor 30 is reached. Since the tip 52 of the branch pipe is open to the atmosphere, it is continuously discharged from the tip of the branch pipe. Open end 52 of the branch pipe
Has a jet shape in which the opening area is narrower than the area of the pressure receiving port 14, and a pressure higher than the pressure at the pressure receiving port is generated at the portion of the jet. This differential pressure is applied to the pressure sensor, and the differential pressure according to the boat speed is detected and the speed can be displayed.

Next, when the ship is stopped, even if air enters the pressure transmission path, one end of the branch pipe is open, so that the air in the path is released from the open end of the branch pipe when the ship is re-run. Water is not discharged and moves in a pipe line filled with air, and a pressure error due to a head difference does not occur.

Next, a fourth embodiment will be described. The configuration of this embodiment different from the third embodiment is opened when a pressure of a predetermined value or more is applied from the pressure transmission path toward the branch pipe in the middle of the branch pipe 50, as shown in FIG. This is the point where a check valve (check valve) 54 is provided. The check valve is in a closed state when the ship is in a stopped state, and the check valve is opened when the ship is in a sailing state and a certain speed or more. The pressure sensor is
As in the case of the third embodiment, the differential pressure can be detected, and as a result, the speed can be displayed by the speedometer.

When the ship is in a stopped state, the check valve is closed, and air does not enter the pressure transmission path from the open end of the branch pipe into the pipeline, and the pressure transmission path is constantly filled with water. Is in a closed state. Therefore, the pressure display error due to the water remaining in the route does not occur.

Next, a fifth embodiment will be described. In this embodiment, as shown in FIG. 6, a check valve 56 having a double seal mechanism on both sides is provided in the middle of the branch pipe 50.
In addition, an incompressible fluid storage tank 5 is provided in the middle of the pressure transmission path.
8 is provided, and the pressure transmission path 10A in the hull is filled with water.

A compressive fluid such as air is filled in the pressure transmission path 10 of the inboard / outboard unit between the pressure receiving port 14 and the storage tank 58. The pressure transmission path from the pressure receiving port is connected to the tank from the upper surface of the tank, and the pressure transmission path from the tank is connected to the lower surface of the tank.

The operation of this embodiment will be described. When the ship is stopped, the check valve 56 causes the branch pipe 50 to move.
Is in the closed position and the pressure transmission path inside the hull is filled with water. When the vessel is traveling, a pressure corresponding to the vessel speed is applied to the pressure receiving port 14 and transmitted to the pressure transmission path, and the check valve 56 moves to the seal position on the opening end side of the branch pipe even if the pressure exceeds a predetermined pressure. By simply doing so, the seal of the branch pipe is maintained and the applied pressure is transmitted to the pressure sensor.

Therefore, in this embodiment, since the pressure is transmitted by the filled water, accurate speed display can be performed. If the ship is stopped or the ship runs at low speed,
Even if water may enter the tank through the pressure transmission path, the pressure transmission from the tank is transmitted by the water in the pressure transmission path. It never happens. In addition, the presence of the tank makes it possible to keep the pressure transmission path filled with water at all times. That is, it is possible to compensate for the shortage of the amount of water due to the leakage of water in the pressure transmission path. Even if air is mixed in the pressure transmission path on the hull side, it can be discharged to the outside of the system when the check valve moves from the seal position on the pressure transmission path side to the seal position on the opening 52 end side.

Next, a seventh embodiment of the present invention will be described. As shown in FIG. 6, this embodiment shows a modification of the first and second embodiments, and a pressure film having a similar structure between the pressure film device 34 and the pressure receiving port 14. The point is that the device 70 is provided.

A non-compressible fluid is filled between the pressure transmission membrane devices 34 and 70, but a pressure transmission membrane device 70 is formed by residual water between the pressure receiving port 14 and the pressure transmission membrane device 70. There is no possibility of causing a difference, for example, if it is installed in the inboard / outboard motor, it may be filled with air. Also in this embodiment, since the incompressible fluid is filled in the pressure transmission path inside the hull, and the pressure transmission is executed by this,
It is possible to display an accurate speed as in the above-mentioned embodiment.

[0028]

As described above, according to the present invention,
It is possible to provide a speed detection device for a ship propulsion device that can detect and display an accurate speed.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a ship to which the present invention is applied.

FIG. 2 is a configuration diagram of a speed detection device according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a speed detection device according to the second embodiment.

FIG. 4 is a configuration diagram of a speed detection device according to the third embodiment.

FIG. 5 is a configuration diagram of a speed detection device according to the fourth embodiment.

FIG. 6 is a configuration diagram of a speed detection device according to the fifth embodiment.

FIG. 7 is a configuration diagram of a speed detection device according to the sixth embodiment.

[Explanation of symbols]

 10 Pressure Transmission Path (Inside of Ship Propulsion Machine) 10A Pressure Transmission Path (Inside of Ship) 14 Pressure Receiving Port 16 Speed Display Device 34, 70 Pressure Transmission Membrane Device

Claims (2)

[Claims] 1. A marine propulsion apparatus comprising: a pressure receiving portion for receiving water pressure according to a ship speed; a speed display device for converting the water pressure into a speed display; and a pressure transmission path for transmitting the water pressure to the speed display device. The speed detection device for a marine vessel propulsion device, wherein at least the pressure transmission path in the hull is filled with an incompressible fluid and the water pressure is transmitted through the incompressible fluid. 2. The device according to claim 1, wherein a pressure transmission membrane device is interposed in the middle of the pressure transmission path, and the water pressure is transmitted to the speed display device through the pressure transmission membrane device. .