JPH025051Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a blowby gas reduction device for promoting ventilation of blowby gas generated in the crankcase of an internal combustion engine.

[Conventional technology]

Examples of conventional blow-by gas reduction devices include those shown in FIGS. 4 and 5, for example. In this device, an intake pipe 21 of the engine communicates with a rocker chamber 23 via a control valve 22 and a mixture outlet pipe 24. Also, air cleaner 2
The clean side of No. 5 is connected to the rocker chamber 23 through a fresh air introduction pipe 26, and these pipes 24 and 26 are connected to the rocker chamber 23 at a predetermined distance from each other.

As described above, in this device, although the connection positions of the pipes 24 and 26 to the rocker chamber 23 are separated from each other, they communicate through the rocker chamber 23, and the suction section of the suction path and the fresh air introduction pipe are connected to each other through the rocker chamber 23. Since the piping structure was such that the air cleaner 25 was provided in the same rocker chamber 23, most of the fresh air _g0 sucked through the air cleaner 25 passed through the rocker chamber 23 and was sent to the intake pipe 21 via the air-fuel mixture outlet pipe 24. Since the amount of fresh air g ₀ flowing into the crankcase 27 is small, the ventilation function of the crankcase 27 is poor. Note that g in FIGS. 4 and 5 indicates blow-by gas, and g ₁ indicates a mixture of fresh air and blow-by gas.

In order to eliminate such drawbacks, a partition wall is provided in the rocker chamber to divide the rocker chamber into a compartment that communicates with the fresh air introduction pipe and a compartment that communicates with the mixture outlet pipe. A blow-by gas reduction device has been proposed that reliably guides the gas into the crankcase.

[The problem that the idea attempts to solve]

However, this device has a problem in that the arrangement structure of the partition wall is complicated. The present invention solves the above problem by dividing the rocker chamber into a compartment communicating with the fresh air introduction pipe and a compartment communicating with the air-fuel mixture outlet pipe by a partition wall having a structure that also serves as a rocker shaft bracket. This solves the problem.

[Means to solve the problem]

The present invention provides a partition wall that also serves as a rocker shaft bracket in a rocker chamber that connects a fresh air introduction pipe that communicates with an air cleaner and a mixture outlet pipe, and creates a section that communicates the rocker chamber with the fresh air introduction pipe. The blow-by gas reducing device is characterized in that the blow-by gas reducing device is partitioned into a chamber and a compartment chamber communicating with the air-fuel mixture outlet pipe.

[Effect]

Since the rocker room is divided into the two compartments by the partition wall, the fresh air from the air cleaner will surely flow into the crankcase, venting the blow-by gas, and sucking it into the engine intake pipe, thereby reducing the blow-by gas. Reduction function is significantly improved. Furthermore, since the partition wall is structured to also serve as a rocker shaft bracket, the rocker chamber and its partition structure are extremely simple and can be provided at low cost.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. An engine head 2 and a rocker cover 3 are provided above a crankcase 1.
A locker chamber 4 is formed by the head 2 and the locker cover 3. A fresh air introduction pipe 5 communicating with an air cleaner (not shown) and a mixture outlet pipe 6 communicating with an intake pipe (not shown) are connected to the top of the rocker cover 3 at a predetermined distance from each other. There is. A valve drive mechanism 7 is provided in the rocker chamber 4, and a plurality of rocker shaft brackets 8 are provided on the upper surface of the head 2 at approximately equal intervals. It is worn. The rocker shaft 11 provided with the rocker arm 10 is attached to the rocker shaft bracket 8.
A push rod 13 and a valve 14 are connected to the rocker arm 10 via a valve adjustment screw 12.

As for the rocker shaft bracket 8 located in the center of the rocker chamber 4, the plate body 8 ₁
The head 2 is integrated with the head 2 by welding or the like, and a seal member 8 ₂ made of an elastic material such as rubber is fitted to the outer peripheral edge of the plate 8 ₁ , and the seal member 8 ₂ is attached to the rocker cover. 3 and fits into a groove formed on the inner surface of the head 2 to form a partition wall, whereby the rocker chamber 4 is divided into a partitioned chamber 4a communicating with the fresh air introduction pipe 5 and an air-fuel mixture. It is divided into a compartment 4b which communicates with the outlet pipe 6 in a sealed state, and the compartment 4a communicates with the communication passage 1.
5, the compartments 4b communicate with the crankcase 1 through communication passages 16, respectively. In addition, the first
In the figure, 17 is a block.

Next, to explain the operation of this embodiment, since the rocker chamber 4 is divided into two in a sealed state into a compartment 4a on the air cleaner side and a compartment 4b on the intake side, during operation of the engine, The entire amount of the air-fuel mixture g ₁ sucked into the intake pipe is sucked through the communication passage 16 that communicates with the crankcase 1, and all the fresh air g ₀ sucked through the air cleaner is drawn into the compartment 4.
A circulation path is formed which flows into the crankcase 1 through the communication passage 15 via the passage a.

That is, the entire amount of fresh air g ₀ introduced into the compartment 4a from the fresh air introduction pipe 5 flows into the crankcase 1 through the communication passage 15, and entrains the blow-by gas g in the case to become an air-fuel mixture. communication path 16,
Since the blow-by gas g is sucked into the intake pipe of the engine through the compartment 4b and the air-fuel mixture outlet pipe 6, the blow-by gas g has an extremely excellent reducing function.

In addition, under operating conditions that generate blow-by gas in an amount exceeding the measured value of the control valve installed in the intake system, fresh air from the air cleaner will not flow in, and the blow-by gas in excess of the measured value will flow back. do.

[Effect of idea]

As described above, the present invention uses a partition wall that also functions as a rocker shaft bracket to divide the rocker chamber into a compartment that communicates with the fresh air introduction pipe and a compartment that communicates with the air-fuel mixture outlet pipe. This simple and inexpensive configuration eliminates the need for a separate partition wall, and the fresh air drawn from the air cleaner passes through the crankcase and mixes with the blow-by gas, forming a mixture that is sucked into the intake system. This has the effect of greatly improving the blow-by gas reduction function. Further, since the rocker cover is provided through the elastic sealing member, not only the sealing effect of the rocker chamber becomes sufficient, but also the vibration of the cover can be reduced.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIG. 3 is a perspective view of FIG. FIG. 4 is a front sectional view of the conventional example, and FIG. 5 is a sectional view taken along the - line. 1...Crankcase, 2...Head, 3...
Locker cover, 4...Locker room, 4a, 4b
... Compartment chamber, 5 ... Fresh air introduction pipe, 6 ... Air mixture outlet pipe, 7 ... Valve drive mechanism, 8 ... Rocker shaft bracket, 8 ₁ ... Plate body, 8 ₂ ... Seal member, 9...Rotsuka bracket bolt, 10...
...Rotsuker arm, 11...Rotsuker shaft,
12...Valve adjustment screw, 13...Push rod, 14...Valve, 15, 16...Communication path, 17...Block.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A partition wall that also serves as a rocker shaft bracket is provided in the rocker chamber that connects the fresh air introduction pipe communicating with the air cleaner and the air-fuel mixture outlet pipe, and the rocker shaft bracket is connected to the rocker shaft bracket. A blow-by gas reduction device characterized in that the blow-by gas reduction device is partitioned into a compartment chamber communicating with the air introduction pipe and a compartment chamber communicating with the air mixture outlet pipe. (2) The blow-by gas reduction device according to claim 1, wherein an elastic seal member is provided on the outer peripheral edge of the partition wall.