JPH075209Y2 - Oil flow sensor for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an oil flow sensor having a built-in filter, and more particularly to an oil flow sensor for an internal combustion engine capable of reliably detecting clogging of the filter.

(Prior Art) FIG. 2 shows an overall schematic view of a general internal combustion engine.

In FIG. 2, an internal combustion engine 10 used for an outboard motor or the like is
It has a two-cycle engine 15. An inlet case 17 is provided on the inlet side of the engine 15, and an oil tank 13 is provided near the inlet case 17. In addition, between the oil tank 13 and the inlet case 17,
Oil flow sensor 20, oil pump 12, check valve 19
And the atomizing valve 16 is in turn connected by a hose 18.

Among these, the check valve 19 is for preventing the reverse flow of oil, and the atomizing valve 16 is for mixing oil and gasoline.

Next, the oil flow sensor will be described in detail with reference to FIGS. 3 and 4. Here, FIG. 3 is a plan view of the oil flow sensor, and FIG. 3 is a side sectional view thereof.

The oil flow sensor 20 is configured by partitioning the inside of the casing 21 with a diaphragm 25 into oil chambers 33, 34 and a diaphragm chamber 35. Further, the oil chambers 33, 34 are separated by the filter 24 from the oil inflow chamber 33 having the inflow port 31,
It is partitioned into an oil outflow chamber 34 having an outflow port 32 and located on the diaphragm 25 side.

Further, in the diaphragm chamber 35, a fixed contact having an L-shaped cross section is provided.
38 are provided. On the other hand, a movable contact 37 is attached to a substantially central portion of the diaphragm 25 with a set screw 39 in a state of being arranged in parallel with the diaphragm 25.

Both the fixed contact 38 and the movable contact 37 described above penetrate the upper wall surface of the casing 21 and are connected to a wire harness 40 arranged above the upper wall surface of the casing 21.
Of these, the movable contact 37 bends downward when the diaphragm 25 moves to the oil outflow chamber 34 side, contacts the fixed contact 38, and outputs a signal to the outside.

Further, four openings 26 are provided on the side wall surface of the casing 21 of the diaphragm chamber 35.

Next, the operation of the conventional device having such a configuration will be described.

The oil sent from the oil tank 13 to the oil flow sensor 20 then flows through the hose 18 and the oil pump 1
2. After passing through the check valve 19 and the atomizing valve 16 in sequence, they flow into the engine 15 from the inlet case 17.

In the oil flow sensor 20, as shown by the arrow in FIG. 4, the oil that has flowed from the inflow port 31 into the oil inflow chamber 33 enters the oil outflow chamber 34 through the filter 24, and then from the outflow port 32 to the oil pump. It flows to the 12th side.

If the filter 24 is clogged during oil inflow, the oil outflow chamber 34 becomes negative pressure, and the diaphragm 25 moves into the oil outflow chamber.
Move to side 34. In this case, the movable contact 37 attached to the diaphragm 25 comes in contact with the fixed contact 38 which is bent downward. When the movable contact 37 comes into contact with the fixed contact 38 in this manner, the clogging alarm of the filter 24 is output to the outside.

(Problems to be Solved by the Invention) As described above, in the oil flow sensor 20, when the filter 24 is clogged during oil outflow, the oil outflow chamber
34 becomes negative pressure, the diaphragm 25 moves to the oil outflow chamber 34 side, and the clogging alarm is output to the outside.

By the way, since the diaphragm chamber 35 is communicated with the atmosphere through the opening 26, the pressure in the diaphragm chamber 35 does not change due to, for example, a change in temperature, and malfunctions due to the diaphragm 25 are prevented.

However, when the internal combustion engine 10 is used for an outboard motor or the like,
Salt water or air containing salt may flow into the diaphragm chamber 35 through the opening 26, and the salt may adhere to the movable contact 37 and the fixed contact 38. When salt is attached to the movable contact 37 and the fixed contact 38 in this way, rust occurs and causes conduction failure, or solidification of salt causes contact failure, resulting in a clogging alarm of the filter 24. It may not be output to the outside.

The present invention is made in consideration of such points,
An object of the present invention is to provide a flow sensor for an internal combustion engine that can reliably detect filter clogging.

[Constitution of device]

(Means for Solving the Problems) According to the present invention, a casing is divided into an oil chamber and a diaphragm chamber by a diaphragm, and the oil chamber is provided with an oil inflow chamber having an inflow port and an outflow port by a filter. An oil flow sensor for an internal combustion engine, which is partitioned into an oil outflow chamber located on the diaphragm side,
A fixed contact is provided in the diaphragm chamber, and a movable contact that is connected to the fixed contact when the diaphragm moves toward the oil outflow chamber is provided in the diaphragm, and an opening is provided in the casing wall surface of the diaphragm chamber, and the diaphragm is provided in the opening. It is characterized in that a closed type pressure buffering device for keeping the pressure of the chamber constant is connected.

(Function) If the filter is clogged during the inflow of oil, the oil outflow chamber becomes a negative pressure and the diaphragm moves to the oil outflow chamber side, and the fixed contact and the movable contact are connected by the movement of this diaphragm, and the predetermined alarm signal Is output. Further, since the pressure in the diaphragm chamber is kept constant by the closed pressure buffer connected to the opening of the casing wall of the diaphragm chamber, malfunction does not occur due to changes in temperature, etc. Air containing salt will not flow in.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing an embodiment of an oil flow sensor for an internal combustion engine according to the present invention. The same parts as those of the conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, the oil flow sensor 20 is a casing 21.
The interior is divided by a diaphragm 25 into oil chambers 34, 35 and a diaphragm chamber 35, and the oil chambers 34, 35 are constituted by a filter 24 and an oil inflow chamber 33 having an inflow port 31.
And an oil outflow chamber 34 which has an outlet 32 and is located on the diaphragm 25 side.

A fixed contact 38 having an L-shaped cross section is provided in the diaphragm chamber 34.
On the other hand, the movable contact 37 is attached to the upper part of the center of the diaphragm 25 in a state of being arranged in parallel with the diaphragm 25.

Further, a single opening 45 is provided on the side wall surface of the casing 21 of the diaphragm chamber 35, and the bellows-shaped hermetic pressure buffer device 41 having one end sealed is connected to the opening 45. A pressure buffer chamber 43 is formed inside the pressure buffer device 41. The pressure buffer device 41 keeps the pressure in the diaphragm chamber 35 constant by changing the volume in the pressure buffer chamber 43 communicating with the diaphragm chamber 35.

Next, the operation of this embodiment having such a configuration will be described.

In the oil flow sensor 20 of FIG. 1, the oil flowing from the inflow port 31 into the oil inflow chamber 33 enters the oil outflow chamber 34 through the filter 24, and then flows out from the outflow port 32 to the oil pump 12 side. .

When the filter 24 is clogged during the oil inflow, the inside of the oil outflow chamber 34 becomes negative pressure, and the diaphragm 25 moves to the oil outflow chamber 34 side.

When the diaphragm 25 moves to the oil outflow chamber 34 side in this way, the bellows-shaped pressure buffer device 41 contracts and the pressure buffer chamber
The volume in 43 is reduced and the pressure in diaphragm chamber 35 is kept constant. At the same time, the movable contact 37 attached to the diaphragm 25 bends downward, contacts the fixed contact 38, and outputs the clogging alarm of the filter 24 to the outside.

During use, for example, when the temperature changes, the bellows-shaped pressure buffer device 41 expands and contracts, and the volume in the pressure buffer chamber 43 changes.
This keeps the pressure inside the diaphragm chamber 35 constant. Therefore, the diaphragm 25 does not malfunction due to changes in temperature or the like.

According to the present embodiment, since the bellows-shaped pressure buffer device 41 having one end sealed is connected to the opening 45 provided in the side wall surface of the casing 21 of the diaphragm chamber 35, the inside of the diaphragm chamber 35 is closed. Salt water or air containing salt will not flow in. Therefore, the movable contact 37 and the fixed contact
It is possible to prevent poor conduction and malfunction due to salt adhering to 38.

[Effect of device]

As described above, according to the book, the pressure in the diaphragm chamber is kept constant by the closed pressure buffer connected to the opening of the casing wall surface of the diaphragm chamber.
No malfunction occurs due to changes in temperature, and salt water or air containing salt does not flow into the diaphragm chamber. Therefore, it is possible to prevent poor conduction and defective operation due to salt adhering to the movable contact and the fixed contact.

[Brief description of drawings]

FIG. 1 is a partial side sectional view showing an embodiment of an oil flow sensor for an internal combustion engine according to the present invention, FIG. 2 is an overall schematic view of a conventional internal combustion engine, and FIG. 3 is a plan view of a conventional oil flow sensor. FIG. 4 is a side sectional view of a conventional oil flow sensor. 10 ... Internal combustion engine, 20 ... Oil flow sensor, 21 ... Casing, 24 ... Filter, 25 ... Diaphragm, 31 ...
… Inlet, 32 …… Outlet, 33 …… Oil inflow chamber, 34 ……
Oil outflow chamber, 35 …… diaphragm chamber, 37 …… movable contact, 38 …… fixed contact, 41 …… pressure buffer chamber, 43 …… pressure buffer chamber, 45 …… opening.

Claims (1)

[Scope of utility model registration request] 1. A casing is divided into an oil chamber and a diaphragm chamber by a diaphragm, and the oil chamber is divided by a filter into an oil inflow chamber having an inflow port, and an oil outflow chamber having an outflow port and located on the diaphragm side. In an oil flow sensor for an internal combustion engine that is partitioned into and, while providing a fixed contact in the diaphragm chamber,
The diaphragm is provided with a movable contact that is connected to the fixed contact when the diaphragm moves toward the oil outflow chamber, an opening is provided in the casing wall surface of the diaphragm chamber, and a closed type that maintains a constant pressure in the diaphragm chamber in the opening. An oil flow sensor for an internal combustion engine, characterized in that a pressure buffer device is connected.