JPS6214335Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting lubricating oil shortage in an internal combustion engine, particularly in a general-purpose internal combustion engine.

As this type of detection device, the present applicant has
No. 26495, No. 55-26496, No. 55-26497, etc., an oil level fluctuation damping chamber is provided in the lubricating oil reservoir at the bottom of the crankcase and communicates with the lubricating oil reservoir, and the lower end is inserted into the chamber. The open upper end of the detection pipe is communicated with a pressure response mechanism provided at the top of the crankcase, and when the lubricating oil decreases below a predetermined level, the pressure response mechanism detects pressure fluctuations in the crankcase due to the reciprocating movement of the piston. We proposed a device that detects the lack of lubricating oil.

In the conventional device described above, the upper surface of the oil level fluctuation damping chamber is open, but in order to minimize the fluctuation of the oil surface within the chamber, it is more preferable to cover the upper surface as well.

Further, the lower end opening of the detection pipe must be reliably positioned at a predetermined level of lubricating oil.

This invention was proposed in view of the above points,
The above-mentioned chamber is configured to surround almost the entire surface including the upper surface, and the purpose is to use the upper wall surface to easily and securely position and hold the lower end of the detection pipe, and to arrange the detection pipe compactly inside the crankcase. shall be.

In order to achieve this purpose, the following configuration has been adopted.

That is, an oil level fluctuation damping chamber 5 is provided in the lubricating oil reservoir at the bottom of the crankcase 2 and communicates therewith, and the upper end 4b of the detection pipe 4, which has its lower end 4a opened in the chamber 5, is connected to the upper end of the crankcase 2. The lubricating oil O
decreases below a predetermined level L, piston 1
In a device that detects a lack of lubricating oil O by applying pressure fluctuations in the crankcase 2 due to the reciprocating motion of the oil to the pressure response mechanism 3, the oil level fluctuation damping chamber 5 is formed into a substantially box-shaped chamber with an opening 5a on one side. A lid 11 is formed integrally with the crankcase 2 and closes the side opening 5a of the chamber 5 by engaging the groove 10 formed on the upper surface of the chamber 5 with the recess 9 formed at the lower end of the detection pipe 4. The lower end 4a of the detection pipe 4 is opened at a predetermined level L position of the lubricating oil in the chamber 5 by communicating the chamber 5 with the lubricating oil reservoir through the small hole 14. Upper part 4b of detection pipe 4
is characterized in that it is communicated with the pressure responsive mechanism 3 through a space outside the rotation locus of the crankshaft 6 in the crankcase 2 to reach the upper wall surface 21 of the crankcase 2 at the shortest distance.

The figure shows an example in which the upper part 4b of the detection pipe 4 is guided to the upper wall 21 of the crankcase 2 and communicated with the pressure response mechanism 3 via the connecting pipe 7, as shown in FIGS. The connecting tube 7 is made of, for example, a rubber tube, and the connecting end 7a of the connecting tube 7 with the detection pipe 4 is airtightly fitted into a hole 8 formed in the upper wall surface 21 of the crankcase 2. The upper end 4b of the pipe 4 is airtightly inserted into the portion 7a and fixed.

As shown in Fig. 2, when forming an inclined portion 4c on the detection pipe 4 to avoid interference with the crankshaft 6, it is necessary to prevent oil from accumulating in the pipe and causing malfunction even if the engine is inclined. It is preferable that the angle of inclination θ of the crankcase 2 with respect to the bottom wall 22 is at least 15°.

In the illustrated example, the small holes 14 communicating the chamber 5 and the lubricating oil reservoir at the bottom of the crankcase are formed by cutting off the four corners of the lid 11. 1
2 is a mounting screw for the lid 11, and 13 is a screw hole.

In the above configuration, when the engine is operated and the lubricating oil O decreases below the predetermined level L and the lower end opening 4a of the detection pipe 4 is exposed above the oil level L, the reciprocating movement of the piston 1 in the crankcase 2 The pressure response mechanism 3 is activated in response to pressure fluctuations, and the pressure response mechanism 3 indicates a lack of lubricating oil O, or grounds the ignition circuit of the engine to stop the engine.

In the figure, 15 is a cooking rod, 15a is a cooking rod dipper, 16 is a recoil starter, 17 is a cooling fan that also serves as a flywheel and has a built-in generator 18, 19 is a fan cover, and 20 is a fuel tank.

As described above, the present invention uses the oil level fluctuation damping chamber 5.
Since it is formed into a substantially box shape that also covers the upper surface, fluctuations in the oil level caused by the stove dropper 15a etc. are reliably prevented from spreading into the chamber 5, and fluctuations in the oil level in the chamber are minimized. be able to.

Further, a groove 10 for locking the detection pulp is formed using the upper surface of the chamber 5, and a recess 9 formed at the lower end of the detection pipe 4 is engaged with the groove 10 to open the side opening 5a of the chamber 5. Since the closing lid 11 prevents the detection pipe 4 from falling off, it is easy to attach the detection pipe 4 to the chamber 5, and the lower end opening 4a of the detection pipe 4 can be easily and reliably positioned and held at the predetermined level position L.

Furthermore, the upper part of the detection pipe 4, which has its lower end opened in the chamber, passes through the space outside the crankshaft rotation locus in the crankcase 2, penetrates the upper wall surface 21 of the case 2, and communicates with the pressure response mechanism. , the detection pipe 4 can be arranged compactly by utilizing the open space inside the crankcase. Moreover, since the detection pipe 4 is made of a metal pipe or the like, corrosion is prevented by splashed oil in the crankcase 2, and the detection pipe 4 is durable.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of an internal combustion engine equipped with the lubricating oil shortage detection device of the present invention, and Fig. 2 is a longitudinal sectional side view thereof.
FIG. 3 is an exploded perspective view of the oil level swing damping chamber section. 1 is a piston, 2 is a crankcase, 3 is a pressure reciprocating mechanism, 4 is a detection pipe, 5 is an oil level fluctuation damping chamber, 6 is a crankshaft, 9 is a recess, 10 is a groove, 11 is a lid, 14 is a small Hole.

Claims (1)

[Scope of Claim for Utility Model Registration] An oil level fluctuation damping chamber is provided in the lubricating oil reservoir at the bottom of the crankcase and communicates with the lubricating oil reservoir, and the upper end of the detection pipe whose lower end is opened inside the chamber is provided.
In the lubricating oil shortage detection device for an internal combustion engine, which communicates with a pressure responsive mechanism provided in the upper part of the crankcase, the oil level fluctuation damping chamber is formed into a substantially box-like shape with one side open and integrally formed with the crankcase, A recess formed at the lower end of the detection pipe is engaged with a groove formed on the upper surface of the chamber to prevent the chamber from coming off with a lid that closes the side opening of the chamber, and the chamber is connected to the lubricating oil reservoir through a small hole. The lower end of the detection pipe is opened at a predetermined level of the lubricating oil in the chamber, and the upper part of the detection pipe is passed through a space outside the crankshaft rotation locus inside the crankcase. A lubricating oil shortage detection device for an internal combustion engine, characterized in that the device communicates with the pressure response mechanism through an upper wall surface.