JPH0248652Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a blow-by gas recirculation device for an engine.

(Prior art) Conventionally, the oil return passage that returns oil from the cam chamber formed by the cylinder head and head cover to the oil pan is used as a blow-by gas passage that releases blow-by gas from the crank chamber to the cam chamber. Are known.

(The problem that the invention aims to solve) However, with this structure, when the amount of oil returned increases, the oil return passage becomes filled with oil, and the blow-by gas cannot escape, causing the pressure in the crank chamber to increase. The problem is that it becomes large.

Therefore, a system in which the oil return passage and the blow-by gas passage are separated has been proposed, as described in, for example, Japanese Utility Model Application Publication No. 158207/1983.
Since both of the above passages are formed in the cylinder head and cylinder block, machining is troublesome.

The purpose of the present invention is to prevent the pressure increase in the crank chamber due to blow-by gas by using an oil level gauge pipe without any troublesome processing.

(Means for Solving the Problems) In order to achieve the above object, the present invention extends the upper part of the oil level gauge pipe whose lower end opens into the crank chamber to the vicinity of the cylinder head, and provides stay means to the cylinder head. The stay means has a communication hole that communicates between the cam chamber formed by the cylinder head and the head cover and the oil level gauge pipe, and the communication hole and the passage in the oil level gauge pipe. A blow-by gas passage is formed by.

(Function) In addition to the oil return passage, the blow-by gas passage is formed by the communication hole of the stay means and the passage in the oil level gauge pipe, so that regardless of the amount of oil return, the blow-by gas is The oil moves from the chamber through a passage in the oil level gauge pipe and a communication hole in the stay means to a cam chamber formed by the cylinder head and head cover. This prevents the pressure in the crank chamber from increasing due to blow-by gas.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the OHC type engine shown in Figure 1,
Reference numeral 1 denotes a hollow oil level gauge having a passage inside, the lower end of the oil level gauge pipe 2 is connected to a cylinder block 3, and an oil pan 4 is attached to the lower side of the cylinder block 3 to form a crankshaft. It opens into chamber 5. on the other hand,
The upper part of the oil level gauge pipe 2 extends to the vicinity of the cylinder head 6 and is supported by the cylinder head 6 via a stay means 7.

The stay means 7, as shown in detail in FIG.
A hollow fixing member 10 whose one end is screwed onto the cylinder head 6 via a sealing material 8 and a washer 9
and a hollow fitting member 12 fixed to the other end of the pipe member 11 whose one end is fixed to the oil level gauge pipe 2, rotatably engages with the flange 12a of the fitting member 12. The coupling member 13 is screwed onto the fixing member 10 to connect the fixing member 10 and the fitting member 12 with the distal end of the mating member 12 being fitted into the other end recess 10a of the fixing member 10. There is. Therefore, the pipe member 11 and the fitting member 1
A communication hole 14 is formed by the oil level gauge pipe 2 and the fixing member 10, and the communication hole 14 communicates the cam chamber 16 formed by the cylinder head 6 and the head cover 15 with the upper part of the oil level gauge pipe 2. There is.

Therefore, the blow-by gas passage 17 that communicates the crank chamber 5 with the cam chamber 16 is connected to the outside of the cylinder block 3 and the cylinder head 6 through the passage in the oil level gauge pipe 2 and the communication hole 14 of the stay means 7. will be formed.

Further, the cam chamber 16 is communicated with an intake passage 19 through a blow-by gas recirculation passage 18 connected to an opening 15a of the head cover 15.

The cam chamber 16 is provided with a camshaft 22 that drives intake and exhaust valves (only the intake valve 20 is shown) via a tappet 21.

With the above configuration, the blow-by gas passage 17 is formed separately from the oil return passage (not shown) using the oil level gauge pipe 2 and the stay means 7, so that the amount of oil returned can be adjusted. Regardless, the blow-by gas formed by the passage in the oil level gauge pipe 2 and the communication hole 14 of the stay means 7 moves to the cam chamber 16 through the blow-by gas passage 17, and the blow-by gas in the crank chamber 5 is Pressure increase can be prevented.

In addition, since the upper part of the oil level gauge pipe 2 is extended to the vicinity of the cylinder head 6, the oil level can be measured only halfway up the cylinder block 3 where many other parts are arranged around the pipe as in the past. The handling efficiency of gauge 1 is improved.

In the above embodiment, the oil level gauge pipe 2
is supported directly on the cylinder head 6 by the stay means 7, but it may of course be supported indirectly via the head cover 15.

(Effects of the invention) As described above, in the present invention, the blow-by gas passage is formed using the passage in the oil level gauge pipe and the communication hole of the stay means, so the blow-by gas passage can be easily formed. Moreover, since the oil return passage and the blow-by gas passage are separated, an increase in pressure in the crank chamber due to blow-by gas can be reliably prevented. Furthermore, since the oil level gauge pipe is extended to the vicinity of the cylinder head, the handling efficiency of the oil level gauge is improved.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of a blow-by gas recirculation device for an engine, and FIG. 2 is an enlarged sectional view of a stay means. DESCRIPTION OF SYMBOLS 1... Oil level gauge, 2... Oil level gauge pipe, 5... Crank chamber, 6... Cylinder head, 7... Stay means, 14... Communication hole, 16... Cam chamber, 17... Blow-by gas aisle.

Claims (1)

[Scope of utility model registration request] The upper part of the oil level gauge pipe whose lower end opens into the crank chamber is extended near the cylinder head and supported by the cylinder head via a stay means, and the stay means is formed by the cylinder head and a head cover. A blow-by gas for an engine, characterized in that it has a communication hole that communicates a cam chamber and an oil level gauge pipe, and a blow-by gas passage is formed by the communication hole and a passage in the oil level gauge pipe. Reflux device.