JPH045425A - Cooling water detecting device - Google Patents

Abstract

PURPOSE:To positively detect the presence or absence of cooling water, by a cooling water detecting device for a marine engine, by flowing a part of cooling water, pumped by a cooling water pump, into a water detecting hose provided with a detecting port, and providing a pressure sensor in the intermediate part of the water detecting hose. CONSTITUTION:When an engine 60 starts a cooling water pump 2 starts to drive, and cooling water is fed to the cooling water passage of an engine part, and a part of the cooling water circulates a water detecting hose 63, and is discharged from a detecting port 64a to the outside. When the water pressure of the circulating cooling water (pressure above the detecting level of a pressure sensor) is detected by a pressure sensor 1 provided in the middle part of the water detecting hose 63, an On signal is inputted to an ignition control unit, and ignition control is performed in the usual manner. When cooling water is not fed for any reason, and as a result, no cooling water flows into the water detecting hose 63, the pressure of the pressure sensor 1 becomes below the detecting level (as high as the atmosphere), an OFF-signal is inputted to the ignition unit, and a control signal for thinning out the ignitions or delaying the ignition timing is outputted to reduced the engine speed below a fixed engine speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cooling water detection device, and more specifically, in a marine engine such as an outboard motor, detecting the presence or absence of cooling water to detect the absence of cooling water. If so, we will issue a warning and
The present invention relates to a cooling water detection device for reducing engine speed to a predetermined speed and preventing engine overheating.

(Background technology) As cooling methods for preventing overheating of internal combustion engines, there are two types of cooling methods: an air-cooling method that cools the cylinder by blowing air into it, and a water-cooling method that cools the engine by circulating water inside the engine. Because it is easy to introduce seawater, etc. into commercial engines, it is common practice to pump up seawater (cooling water) with a cooling water pump and discharge it to the outside after cooling the engine.However, Cooling water intake (Water
If the cooling water is not sent into the engine for some reason, such as a blockage in the engine, the engine will overheat. For this reason, in conventional marine engines, a temperature sensor is attached to the cylinder head, etc., and when the temperature exceeds a predetermined set temperature, the sensor detects this, and this detection signal activates an alarm device or activates a rev limiter. This was done to prevent the engine from overheating by operating the engine to limit the engine speed. However, with this temperature sensor method, it is difficult to set the operating temperature of the temperature sensor, and if the set temperature is low, the temperature sensor may operate in a normal state without overheating at all.
On the other hand, when the set temperature is high, there is an inconvenience that the temperature sensor operates after overheating. In addition, when using this temperature sensor, there is a fundamental problem that it cannot detect the presence or absence of cooling water when the engine is cold immediately after starting. The user has to visually check whether or not cooling water is coming out from a pilot water hole at the tip of the pilot water hole, making maintenance and inspection troublesome.

Recently, a number of inventions and inventions have been made to solve these problems.
An idea has been made.

5 to 8 show an example of such inventions using a float-type cooling water sensor, which has a relatively simple structure.

FIG. 5 shows an outboard motor 50 equipped with this cooling water sensor with the upper cover 51A cut away, and FIG. 6 shows a plan view of this. In FIG. 5, a so-called ■-shaped engine 6° is installed within a cowling portion 51 consisting of an upper cover 51A and a lower cover 51B of an outboard motor 50. As shown in FIG. A cooling water sensor 70 is attached to the cylinder head cover 62A of this engine 60. As shown in FIG. 6, two cooling water sensors 70 are provided. In FIG. 6, the symbol 6
1.61 indicates a cylinder, and 63 indicates a water test hose.

FIG. 7 shows a part of the engine as seen from the direction of arrow A in FIG. In this figure, one end 63a of a water test hose 63 is connected to the bottom of the engine 60, and a nozzle-like member 64 is connected to the other end of the water test hose 63 in a state that passes through the lower cover 51B. A water test port 64a is provided at the tip of the nozzle-shaped member 64.

The cooling water sensor 70 is attached to the cylinder head cover 62A in the state shown in FIG. A float 71 is movably mounted (see arrows B and B' in the figure) and is disposed in a cooling water passage 65 formed in the cylinder head cover 62A, and a float 71 is provided protruding from the main body 70B to the right in the figure. and float 71
A stopper portion 70C that restricts downward rotation of the holder 70C is configured. The float 71 has a built-in magnet 72, and the stopper portion 70C has a built-in reed switch 73 that detects the approach of the magnet 72.

Therefore, when there is no cooling water in the cooling water passage (water jacket) 65, the float 71 contacts the stopper portion 70C due to its own weight as shown by the solid line in the figure.
The reed switch 73 detects this and turns "ON".
becomes. On the other hand, when cooling water flows through the cooling water passage 65 as shown by arrow C in the figure, the water pressure (dynamic pressure) of the cooling water flow and the buoyancy of the float itself cause the float 7 to flow.
1 rotates in the direction of arrow B and moves to the position shown by the imaginary line in the figure, thereby setting the reed switch 73 to "0FF (off)".
”. In this way, the presence or absence of cooling water is detected. This float type cooling water sensor 70
If you use this, the coolant pump will normally be driven when the engine starts, and the coolant will flow into the coolant passage a few seconds later, so the reed switch 73 will switch to "○" a few seconds after the engine starts.
Becomes FFJ. For this reason, for example, the reed switch 73
By setting the buzzer to sound when it is "ON", the buzzer will sound immediately after the engine starts, and will stop sounding after a few seconds. It is possible to detect the presence or absence of In addition, if for some reason the cooling water is no longer sent into the cooling water passage 65 during high engine speed, the cooling water sensor 70 detects this and the buzzer sounds, so the driver can easily remove the cooling water. be able to recognize abnormalities in In this case, if the rev limiter is operated in conjunction with the cooling water sensor, the engine rotational speed is reduced and overheating of the engine can be prevented.

[Problems to be Solved by the Invention] However, in the cooling water detection device using the above-mentioned float-type cooling water sensor 70, the presence or absence of cooling water is detected by the up-and-down rotation of the float 71. As a result, the movement of the float 71 may become unstable due to disturbances in the flow of cooling water in the cooling water passage 65, and the movement of the float 71 may become unstable over time, or may become stuck, causing the presence or absence of cooling water to become unstable. It has become clear that there is an inconvenience in that it may be detected incorrectly.

[Purpose of the invention]

The present invention has been made in view of the inconveniences of the conventional examples, and its purpose is to provide a cooling water detection device that can effectively prevent malfunctions and detection errors over time caused by disturbances in the flow of cooling water. It is about providing.

[Means to solve the problem]

The present invention includes a cooling water passage that is pumped up by a cooling water pump and discharged to the outside after cooling the engine body and cylinders, and one end of the passage is connected to the engine part, and the other end is provided with a water test port. It has a hose for water testing. A pressure sensor for detecting the water pressure of the cooling water flowing through the hose is installed in the middle of the water test hose. This aims to achieve the above-mentioned objective.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

Here, the same reference numerals are used for the same or equivalent components as in the conventional example described above.

The outboard motor 50 of the embodiment shown in FIG. 1 is attached to the hull 30 with its clamp bracket section 59 fixed to the transom plate section 31 provided at a continuous section of the hull 30.

This outboard motor 50 has a propeller 58 and a gear case 5 that houses a power transmission device to the propeller 58, as usual.
7 and a drive unit case (with built-in drive shaft that transmits the engine's driving force to this power transmission device)
A drive shaft (wing) 56, an engine 60 mounted on the drive unit case 56 via an engine mount 55, a lower cover 51B that covers the lower half of the engine 60, and an upper cover 51A that covers the upper part. It is equipped with

Among these, a main water intake port 54 is provided at the front side of the gear case 57, and a propeller 58 at the rear of the gear case 57 is provided.
There is a shaft cooling water intake (Sub water) in the upper part of the
er 1nlet) 53 is provided.

A cooling water pump 2 is provided inside the drive unit case 56 and is driven by the rotation of the engine 60.
This cooling water pump 2 and both cooling water intake ports 53 and 54 are connected by a cooling water passage (water tube) 3A. Further, this cooling water pump 2 and a cooling water passage (water jacket) 65 provided in the engine section are connected by a cooling water passage 3B. Then, by driving the cooling water pump 2, cooling water is fed in the order of cooling water intake port 5354 → cooling water passage 3A → cooling water pump 2 → cooling water passage 3B → cooling water passage 65, and is fed to the engine body 60A and the cylinder 61. (See Figure 2) is cooled, and after cooling,
This cooling water is supplied to the propeller 58 through a drainage passage (not shown).
The drain port (Exh
The outside is discharged from the aust outlet. As described above, in this embodiment, the cooling water passage 10 (see FIG. ) is configured.

As shown in FIG. 3, one end 63a of a water test hose 63 is connected to a cooling water passage 65 provided in the engine 60 section, and the other end of this water test hose is connected to the cooling water passage 65 of the conventional example described above. A nozzle member 64 is provided in the same manner. Furthermore, in this embodiment, a pressure sensor 1 for detecting the water pressure of the cooling water flowing through the hose 63 is interposed in the middle part of the water test hose 63. The pressure sensor 1 used is one that outputs a high (H) level signal when it detects a pressure above a predetermined threshold level (here, it is assumed to be slightly above atmospheric pressure). ing.

The output line of this pressure sensor 1 is as shown in FIG.
It is connected to an ignition control unit 12 that controls the DI unit 11. In addition, a light emitting diode 13 and a buzzer 14 are connected to the ignition control unit 12, and the other ends of the light emitting diode 13 and the buzzer 14 are connected to a power source. Moreover, this ignition control unit 12
Although not shown here, in reality, a magneto balsa coil as an ignition signal output means and a gear count coil for detecting a crank angle are connected. The ignition control unit 12 includes a so-called microcomputer.

The CDI unit 11 includes an ignition capacitor and a thyristor for controlling the discharge of the ignition capacitor, and is connected to a capacitor charging coil (not shown). Further, an ignition coil 15 and a spark plug 16 are connected to the CDI unit 11.

The ignition control unit 12 calculates the ignition timing based on the output of the pulsar coil and the number of output pulses of the gear count coil, outputs a control signal to the CDI unit 11, and controls the ignition timing of the spark plug 16 and the engine rotation speed. It is meant to be controlled.

Next, the overall operation of this embodiment configured as described above will be explained.

When the engine 60 starts, the cooling water pump 2 starts driving, and the cooling water passage 65 of the engine section is operated as described above.
Cooling water is supplied inside. A part of the cooling water that has flowed into the cooling water passage 65 flows through the water test hose 63 and is discharged to the outside from the water test port 64a. At this time, the pressure sensor 1 installed in the middle of the water test hose 63 detects the water pressure of the cooling water flowing inside the water test hose 63 (a pressure higher than the detection level of the pressure sensor), and the pressure sensor "
ON” signal is sent to the ignition control unit 12. In the CPU (not shown) which constitutes the main control section of the ignition control unit 12, by inputting the rON'' signal from the pressure sensor 1,
It determines that "cooling water is present (no abnormality)" and performs the same ignition control as normal.

On the other hand, if for some reason the cooling water is not supplied to the cooling water passage 65 of the engine section, the water test hose 6
3, the pressure applied to the pressure sensor 1 becomes below the above detection level (same level as atmospheric pressure), and the pressure sensor 1 sends an rOFFJ signal to the ignition control unit 12. By inputting this rOFF signal,
The CPU of the ignition control unit 12 determines that "there is no cooling water and there is an abnormality" and outputs a control signal to the CDI unit 11 to thin out the ignition or delay the ignition timing, so that the engine speed remains constant. Try to keep it below the number. This prevents the engine from overheating and protects the engine. In addition, the CPU of the ignition control unit 12
Now, at the same time as this ignition timing control, light emitting diode 1
3 lights up and the buzzer 14 sounds. The driver is
This makes it possible to recognize "anomalies in the cooling water" through sound and light, and to take necessary measures.

According to the embodiment described above, since the pressure sensor 1 is used for detecting cooling water, if cooling water flows through the water test hose 63, it can be detected almost reliably. It is possible to effectively prevent the inconvenience of erroneously detecting the presence or absence of cooling water due to turbulence of the cooling water, which is the case with conventional float sensors. Since the direction from the direction toward the water test port 64a is constant, stable operation of the pressure sensor 1 can be ensured. Furthermore, a water test hose 63
Since it is sufficient to simply insert the pressure sensor 1 in the middle of the engine, there is no need to make any modifications to the engine side, which is simple and inexpensive. Furthermore, since the cooling water is discharged to the outside from the water inspection port 64a, it is also possible to visually check the cooling water.

[Effects of the Invention] As explained above, according to the present invention, a pressure sensor for detecting the water pressure of the cooling water flowing through the hose is installed in the middle part of the hose for water testing. When cooling water flows through the test hose, the water pressure of the cooling water inside the water test hose is applied to the pressure sensor, but if for some reason the cooling water is no longer being fed into the engine cooling water passage. In some cases, water pressure is no longer applied to the pressure sensor, so
It is desirable for the pressure sensor to reliably detect the presence or absence of cooling water, which can effectively prevent the inconvenience of erroneously detecting the presence or absence of cooling water due to turbulence in the cooling water, which is the case with conventional float sensors. provides an unprecedented and excellent cooling water detection device that can be easily and inexpensively implemented without requiring any modification on the engine side, since it is only necessary to insert a pressure sensor in the middle of the water test hose. be able to.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing an outboard motor according to an embodiment of the present invention, FIG. 2 is a partially broken and partially omitted plan view of FIG. 1, and FIG. 4 is a circuit diagram showing the ignition system portion of the outboard motor of FIG. 1; FIG. 5 is a partially cutaway side view of a conventional outboard motor; Fig. 6 is a partially cutaway and partially omitted plan view of Fig. 5, Fig. 7 is an explanatory diagram showing a part of the engine section seen from the direction of arrow A in Fig. 6, and Fig. 8 is a float type FIG. 2 is an explanatory diagram showing a specific configuration of a sensor. 1...Pressure sensor, 2...Cooling water pump, 10...Cooling water passage, 60A...
・Engine body, 61... Cylinder, 63...
...Water test hose, 64a...Water test port. Patent applicant Suzuki Motor Co., Ltd. Agent Patent attorney Isamu Takahashi Figure 4 Figure 4

Claims (1)

[Claims] (1) A test system equipped with a passage for cooling water that is pumped up by a cooling water pump and discharged to the outside after cooling the engine body and cylinders, one end of which is connected to the engine part, and a water inspection port is provided at the other end. A cooling water detection device comprising a water hose, and a pressure sensor disposed in the middle of the water test hose for detecting the water pressure of cooling water flowing through the hose.