JPH08254113A - Blowby gas recovery device of engine - Google Patents

Abstract

PURPOSE: To securely conduct blowby gas onto a cylinder head using a simple architecture wherein a through hole is formed in a head bolt for fixing a cylinder head to a cylinder block, allowing the through hole to function as a blowby gas recovering passage. CONSTITUTION: Oil is sent to an oil reserving chamber 9 formed on a cylinder head 2 through an oil supplying passage 19, thereafter the oil returns to a crankcase 10 through an oil returning passage 8 lubricating here and there. On the other hand, blowby gas in the crankcase 10 is conducted to the oil reserving chamber 9 through a blowby gas recovering passage 16 in a head bolt 12, then further conducted to an intake system through a breather pipe 20 after eliminating the pulsation of the gas. However, because the head portion of the head bolt 12 projects upward on the base surface of the oil reserving chamber 9, the oil is prevented from flowing into the blowby gas recovering passage 16. Accordingly, the blowby gas can escape into an upward breather pipe 20, hardly suffering oil splash.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-by gas recovery system for an engine, and more specifically, it is provided with an oil return passage for returning lubricating oil from a cylinder head to a crank chamber provided below a cylinder block. The present invention relates to an engine blow-by gas recovery device having a blow-by gas recovery passage for guiding blow-by gas from a chamber onto the cylinder head.

[0002]

2. Description of the Related Art Conventionally, an oil return passage for returning lubricating oil from a cylinder head to a crank chamber disposed below a cylinder block is provided, and blow-by gas is guided from the crank chamber to the cylinder head. Blow-by gas recovery systems for engines have been proposed. In such a conventional blow-by gas recovery device, the oil return passage also serves as the blow-by gas passage. For this reason, when the engine speed is increased and the oil circulation amount or the blow-by gas flow rate is increased, the oil return passage is closed due to the flow in the phase directions, and there is a problem that oil is ejected from the oil passage onto the cylinder head. . Therefore, in order to solve such a problem, it has been conventionally proposed to provide a dedicated passage for blow-by gas that connects the crank chamber and the intake passage (Actual No. 60-70704). .

[0003]

By the way, in the structure proposed above, the provision of the dedicated passage for the blow-by gas has a drawback that the manufacturing cost of the vehicle is increased. Further, as in the structure proposed above, providing the exclusive passage for blow-by gas outside the engine complicates the structure and increases the number of assembly steps, which also increases the manufacturing cost of the vehicle. There was a problem that caused it. The present invention has been made in view of the above circumstances, and provides a blow-by gas recovery device for an engine, which has a simple configuration and can reliably guide blow-by gas onto a cylinder head without increasing vehicle manufacturing costs. The purpose is to do.

[0004]

In order to achieve the above object, the present invention provides an oil return passage for returning lubricating oil from a cylinder head to a crank chamber provided below a cylinder block, and the crank chamber is provided. In a blow-by gas recovery device for an engine having a blow-by gas recovery passage for guiding blow-by gas from the cylinder head to the cylinder head, a through hole is provided in a head bolt for fixing the cylinder head to the cylinder block, and the blow-by gas is provided by the through hole. The recovery passage is formed.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine blow-by gas recovery apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. 1 to 4 show an embodiment of the blow-by gas recovery device according to the present invention. In this embodiment,
A plurality of passages 3 vertically passing through a cylinder head 2 of an engine 1 of a vehicle (not shown) are provided, and a cylinder block 4 is provided.
In addition, a plurality of passages 5 are provided which vertically penetrate and correspond to the plurality of passages 3, respectively. Also, Engine 1
Of the cylinder head 2 are provided with a plurality of insertion holes 6 which penetrate vertically, and the cylinder block 4 is penetrated vertically and a plurality of insertion holes 7 corresponding to the plurality of insertion holes 6
Is provided. Cylinder head 2 to cylinder block 4
, The plurality of passages 3 and 5 communicate with each other to form a plurality of oil return passages 8. The oil return passage 8 connects an oil storage chamber 9 above the cylinder head 2 of the engine and a crank chamber 10 below the cylinder block 4.

When the cylinder head 2 is attached to the cylinder block 4, the plurality of insertion holes 6 and 7 are communicated with each other to form a plurality of bolt insertion holes 11. As shown in FIG. 3, the head bolt 12 used in this embodiment has a through hole 13 formed in the center thereof so as to penetrate therethrough in the axial direction. In the example shown in FIG. 3A, the head bolt 12
The upper portion of the through hole 13 located in the head portion 12a of the head is formed into a hexagonal shape in horizontal cross section so that a hexagon wrench (not shown) can be fitted therein, so that the head bolt can be easily attached.
In the example shown in (b), the head 12 a of the head bolt 12
A rubber plate 14 is attached to the upper part of the so as to function as a so-called check valve. In the example shown in (c), a cylindrical pipe 15 is fitted to the head portion 12a of the head bolt 12.

When the cylinder head 2 is attached to the cylinder block 4 by using the head bolt 12 of this embodiment, blow-by gas is blown from the crank chamber 10 to the oil reservoir 9 on the cylinder head 2 by the through hole 13 of the head bolt.
A blow-by gas recovery passage 16 that leads up to is formed.
In FIG. 1, 17 is an oil element, 18 is an oil pump, 19 is an oil supply passage, and 20 is a breather pipe. In FIG. 4, a portion indicated by a cross hatch is a portion preferable for forming the plurality of oil return passages 8. The head bolts used at the two upper right portions of the cylinder head 2 shown in FIG. 4 may be ordinary ones that have been used in the past, but may be improved in breathability, assembly workability, and simplification of parts management. From the viewpoint, all the head bolts may be replaced with the head bolt 12 of this embodiment.

Next, the operation of this embodiment will be described.
That is, in this embodiment, the oil sent to and stored in the oil sump chamber 9 on the cylinder head 2 through the oil supply passage 19 returns to the crank chamber 10 through the oil return passage 8 while lubricating each place. On the other hand, the blow-by gas in the crank chamber 10 is guided to the oil sump chamber 9 through the blow-by gas recovery passage 16 in the head bolt 12, where its pulsating flow is absorbed and then to the intake system through the breather pipe 20. . At this time, the head portion 12a of the head bolt 12 is higher than the floor surface of the oil sump chamber 9, so that the oil is prevented from entering the blow-by gas recovery passage 16. Therefore, the blow-by gas is hardly scattered by the oil, and the upper breather pipe 2
You can escape to 0. This action extends the check valve as shown in FIG. 3 (b) and the height as shown in FIG. 3 (c) more than the case where the shape of the head 12a of the head bolt 12 is as shown in FIG. 3 (a). The more remarkable the structure is, the more remarkable the effect can be obtained. Further, in the present embodiment, the partition wall 21 is erected on the cylinder head 2 with its upper side facing upward, and the oil storage chamber 9 is formed by being surrounded by the partition wall 21 (see FIG. 2). Therefore, even if the vehicle body is tilted and the oil level 22 of the oil is tilted, a large amount of oil can be prevented from flowing from the inside of the oil sump chamber 9 to the head bolt 12 side at a time.

[0009]

As described above, according to the blow-by gas recovery apparatus for an engine of the present invention, the oil return passage for returning the lubricating oil is provided from the cylinder head to the crank chamber provided below the cylinder block. In a blow-by gas recovery device for an engine having a blow-by gas recovery passage for guiding blow-by gas from the crank chamber onto the cylinder head, a through hole is provided in a head bolt for fixing the cylinder head to the cylinder block. Since the blow-by gas recovery passage is formed by the above, the following effects can be obtained.

That is, in the present invention, since the blow-by gas recovery passage is formed separately from the oil return passage, oil is prevented from entering the blow-by gas recovery passage. Therefore, even if the engine speed increases, the blow-by gas recovery passage and the oil return passage are not blocked, and the blow-by gas can be reliably guided upward with almost no oil scattering. Moreover, since the blow-by gas recovery passage uses the through hole formed in the head bolt, it can be formed without increasing the number of parts. For this reason, the engine can be assembled in the same process as before without increasing the manufacturing cost of the vehicle, and the parts management is easy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a blow-by gas recovery device for an engine according to the present invention.

FIG. 2 is a sectional view showing a main part of an embodiment of an engine blow-by gas recovery apparatus according to the present invention.

FIG. 3 is a perspective view showing head bolts of an embodiment of an engine blow-by gas recovery apparatus according to the present invention.

FIG. 4 is a plan view showing a cylinder head of an embodiment of an engine blow-by gas recovery apparatus according to the present invention.

[Explanation of symbols]

 1 Engine 2 Cylinder Head 4 Cylinder Block 8 Oil Return Passage 9 Oil Storage Device 10 Crank Chamber 12 Head Bolt 13 Through Hole 14 Blow-by Gas Recovery Passage

Claims (1)

[Claims] 1. An oil return passage for returning lubricating oil from a cylinder head to a crank chamber provided below a cylinder block, and a blow-by gas recovery passage for introducing blow-by gas from the crank chamber onto the cylinder head. A blow-by gas recovery apparatus for an engine, wherein a through hole is provided in a head bolt for fixing the cylinder head to the cylinder block, and the blow-by gas recovery passage is formed by the through hole. .