JPH10212925A - Breather device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a spot welded place and a cost and also enlarge the freedom of an auxiliary plate in comparison with an usual device. SOLUTION: In the breather device of an engine in which an engine having a cylinder block, a cylinder head mounted on the upper surface of the cylinder block, an oil pan mounted on the lower surface of the cylinder block and a cylinder head cover 8 mounted on the cylinder head is provided and also a breather plate 114 is arranged in the cylinder head cover 8 and the air liquid separation of an oil in the cylinder head cover 8 is carried out, a difference in level 142 considered the thickness of the auxiliary plate 134 is provided. The auxiliary plate 134 for improving the air liquid separation property of the oil is provided on the upper surface position 114a of the breather plate 114 and the auxiliary plate 134 is held and fixed by two parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather device for an engine, and in particular, can reduce the number of spot welds, reduce the cost, and increase the degree of freedom of the auxiliary plate as compared with the conventional breather device. The invention relates to a breather device for an engine.

[0002]

2. Description of the Related Art In a four-cycle engine mounted on a vehicle, fresh air is introduced into a cylinder head, and when ventilating the engine, engine oil (hereinafter simply referred to as "oil") and gas (blow-by) are used. In some cases, a breather device having a breather plate is provided to perform gas-liquid separation from gas and air.

A breather device for the engine is disclosed in Japanese Utility Model Publication No. 63-18746.
The baffle plate of the positive crankcase ventilation system disclosed in this publication has a ventilation plate having a suction port, and a U-shaped suction port cover attached to the lower surface of the ventilation plate so as to cover the suction port. A baffle plate of a positive crankcase ventilation system having: a cross-sectional area of a blow-by gas passage surrounded by a ventilation plate and a suction port cover; In front of the mouth, both side walls of the suction port cover are gently protruded so as to approach the blow-by gas passage axis, and are squeezed in a venturi shape to prevent oil from entering the blow-by gas suction system.

[0004]

By the way, in the conventional breather device of the engine, as shown in FIGS. 8 to 10, when the breather plate 314 is disposed in the cylinder head cover 208, the oil separating property is improved. For this purpose, an auxiliary plate 334 is provided.

The auxiliary plate 334 is provided on the upper surface of the breather plate 314 to cover the oil hole 326 formed in the breather plate 314.
As shown in the figure, four places marked with “*” are fixed by spot welding to the outer peripheral part of the upper surface of the breather plate 314 except for the seal part 340.

[0006] At this time, various arrangements and shapes of the auxiliary plate have been devised.

However, when attaching the auxiliary plate to the breather plate, the periphery of the auxiliary plate is fixed by spot welding at four places, so that the shape of the auxiliary plate is limited, which is disadvantageous in practical use. There are disadvantages that it is difficult to manufacture, the cost is high, and it is economically disadvantageous.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a cylinder block and a cylinder head mounted on an upper surface of the cylinder block, in order to eliminate the above-mentioned disadvantages.
An engine having an oil pan installed on the lower surface of the cylinder block and a cylinder head cover mounted on the cylinder head is provided, and a breather plate is arranged in the cylinder head cover to separate oil and gas in the cylinder head cover. In the breather device of the engine that performs, an auxiliary plate that improves gas-liquid separation of oil is provided on an upper surface portion of the breather plate,
The auxiliary plate is sandwiched and fixed by two parts.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above configuration,
When the auxiliary plate is sandwiched and fixed between two parts, the number of spot welding portions is reduced, the cost is reduced, and the degree of freedom of the auxiliary plate is increased as compared with the conventional one.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 7 show an embodiment of the present invention. 4 and 5, reference numeral 2 denotes an engine, 4 denotes a cylinder block, 6 denotes a cylinder head, 8 denotes a cylinder head cover, 10 denotes a combustion chamber, 12 denotes an intake valve, 14 denotes an exhaust valve, 16 denotes an intake manifold, and 18 denotes an intake passage. , 20 is a throttle valve, 22 is an air cleaner, 24 is an exhaust manifold, 26 is an exhaust passage, 28 is an exhaust pipe, and 30 is a catalyst.

A fuel injection valve 32 is provided in the intake passage 20 downstream of the air cleaner 22.

The intake manifold 16 is provided with a fast idle mechanism 34 for bypassing the throttle valve 20 and supplying air to the combustion chamber 10.

One end of a pressure detection passage 36 communicates with the intake passage 18 downstream of the throttle valve 20. At the other end of the pressure detection passage 36, a pressure sensor 38 for detecting the intake pipe pressure is provided.

The engine 2 is provided with an exhaust gas recirculation device (EGR device) 40 for recirculating a part of the exhaust gas to the intake system of the engine 2.

The exhaust gas recirculation device 40 recirculates a part of the exhaust gas into the combustion chamber 10 of the engine 2 to lower the combustion temperature and reduce the generation of NOx.
In order to ensure the operability of the engine 2, the engine 2 is not operated when the engine 2 is cold, when the throttle valve 20 is fully closed, when the engine 2 is operating under a high load, and when the intake pipe pressure is low.

The exhaust gas recirculation device 40 has an EGR passage 42, an EGR control valve 44, an EGR modulator 46, and an EGR solenoid valve 48. EGR passage 4
2 is an EGR intake 5 whose one end is open to the exhaust passage 26.
0 and the other end is the throttle valve 20
It is open to an EGR recirculation port 52 that opens to the downstream intake passage 18. The EGR control valve 44 is connected to the intake manifold 16.
The EGR passage 42 is provided by the valve body 54 for the valve.
Is opened and closed to adjust the recirculation amount of the exhaust gas.

In the EGR control valve 44, a valve diaphragm (not shown) is displaced by a pressure (negative pressure) from a pressure passage 56 acting on a pressure chamber (not shown), and the EGR control valve 44 is fixed to the valve diaphragm. Valve element 54 for valve
The opening and closing of the EGR passage 42 is performed by the above operation. Pressure passage 5
Numeral 6 has one end connected to a pressure inlet (not shown) opened near the throttle valve 20, and the other end connected to a pressure chamber.

The pressure passage 56 has an EGR control valve 44
The EGR modulator 46 and the EGR solenoid valve 48 are provided sequentially from the side. The EGR modulator 46 displaces the modulator diaphragm (not shown) by the exhaust pressure from the exhaust introduction passage 58 acting on the exhaust pressure chamber (not shown), and the modulator valve element (not shown) operates to introduce the atmosphere. Thus, the pressure (negative pressure) in the pressure passage 56 is adjusted. The EGR solenoid valve 48 is electrically operated to open and close the pressure passage 56.

Therefore, the EGR solenoid valve 48 includes:
The control means 60 is in communication. The control means 60
The fuel injection valve 32, the pressure sensor 38, the control valve 62 provided in the fast idle mechanism 34, the exhaust sensor 64 provided in the exhaust manifold 24, and the throttle sensor 66 for detecting the opening of the throttle valve 20 , A crank angle sensor 68 also functioning as a rotation speed sensor for detecting the engine rotation speed, and a speed sensor 70 are in communication.

A main relay 72 is in communication with the control means 60. An ignition switch 74, a fuse 76, and a battery 78 are in communication with the main relay 72.

The fuel injection valve 32 has a fuel supply passage 8
One end of 0 is connected. The other end of the fuel supply passage 80 is connected to an oil pump 82. This oil pump 82 is installed in a fuel tank 84. In the middle of the fuel supply passage 80, a fuel filter 86 is provided.

In the middle of the fuel supply passage 80, a fuel pressure regulator 88 is provided. One end of a fuel return passage 90 communicates with the fuel pressure regulator 88. The other end of the fuel return passage 90 is provided to open into the fuel tank 84.

One end of a fuel return pressure passage (not shown) is connected to a regulator pressure chamber (not shown) of the fuel pressure regulator 88. The other end of the fuel return pressure passage communicates with the intake passage 18.

One end of a purge passage 92 communicates with the fuel tank 84. At the other end of the purge passage 92, a canister 94 is provided. Purge passage 92
Is provided with a two-way valve 96.

The canister 94 has an evaporation passage 9.
One end of 8 is in contact. The other end of the evaporation passage 98 communicates with the intake passage 18.

An opening / closing control valve 100 is provided in the middle of the evaporation passage 98.

Reference numeral 16S denotes the intake manifold 16
Is a communication passage connecting the surge tank 16S and a second breather chamber 122-2 described later, 102 is a PCV valve provided in the middle of the communication passage 101, and 103 is a throttle valve. An intake air temperature sensor mounted on the intake manifold 16 downstream of 22, an relay 104 connected to the oil pump 82, an engine check lamp 106, an ignition coil 108, a starter motor 110, and an electric load 112. .

The engine 2 includes a cylinder block 4
A cylinder head 6 mounted on the upper surface of the cylinder block 4, an oil pan (not shown) provided on the lower surface of the cylinder block 4, and a cylinder head cover 8 mounted on the cylinder head 6. As shown in FIG. 5, a breather plate 114 is provided in the cylinder head cover 8 to
Performs gas-liquid separation of the oil inside.

As shown in FIG. 5, a cam 118 is provided on a cam shaft 116 disposed above the cylinder head 6, and the breather plate 114
8 is partitioned into a cam chamber 120 and a breather chamber 122.

At this time, the breather plate 114
Has a partition wall 124 as shown in FIGS. 6 and 7,
This partition wall 124 allows the breather chamber 122 to be in the first position.
It is divided into the second breather chambers 122-1 and 122-2, and the plurality of oil holes 126 and the first breather chamber 12
A first cam chamber communication hole 128 communicating with 2-1 and a second cam chamber communication hole 130 communicating with the second breather chamber 122-2 are formed.

Reference numeral 132 denotes an air cleaner communication passage.

An auxiliary plate 1 for improving gas-liquid separation of oil is provided on the upper surface of the breather plate 114.
34, and the auxiliary plate 134 is sandwiched and fixed between two parts.

More specifically, the auxiliary plate 134 is
It is sandwiched and fixed by the cylinder head cover 8 and the breather plate 114.

That is, the auxiliary plate 134 is
As shown in FIG. 3, a concave portion 136 having a U-shaped cross section extending from a substantially central portion toward one side in the longitudinal direction is formed, and a flange-shaped peripheral portion 138 of the concave portion 136 is combined with the outer peripheral shape of the breather plate 114. It is formed so as to be laminated on the seal portion 140 near the outer periphery.

The upper surface 1 of the breather plate 114
14a, the auxiliary plate 134 is located at
8 are fixed by spot welding, and the inside of the periphery 138 is sandwiched between the cylinder head cover 8 and the breather plate 114.

The breather plate 114 is provided with a step 142 considering the thickness of the auxiliary plate 134 when sandwiching the auxiliary plate 134.
Is brought into flush contact with the cylinder head cover 8 by the step portion 142 of the breather plate 114.

At this time, by fixing the auxiliary plate 134 to the upper surface 114a of the breather plate 114, the concave portion 136 functions as an auxiliary passage for guiding blow-by gas mixed with oil passing through the oil hole 126.

The direction in which the oil is blown out from the recess 136 is a direction away from the air cleaner communication passage 132, for example, an upward direction in FIGS. 6 and 7.

When the auxiliary plate 134 is disposed on the upper surface 114a of the breather plate 114, it is fastened together with the breather plate 114.

In other words, when forming the auxiliary plate 134, as shown in FIGS. 1 and 2, a joint fastening hole 146 is formed at a position corresponding to the hole 144 formed in the breather plate 114. The auxiliary plate 134 and the breather plate 114 are jointly fastened by the joint fastening holes 146.

Next, the operation will be described.

During normal operation of the engine 2, the atmosphere is introduced from the air cleaner 22 to the first breather chamber 122-1 via the air cleaner communication passage 132, and the first cam chamber communication hole 12.
8 into the lower cam chamber 120, the blow-by gas in the cam chamber 120 enters the second breather chamber 122-2 from the second cam chamber communication hole 130, and enters the surge tank 16S via the PCV valve 102 and the communication passage 101. Guides blow-by gas.

Also, when the engine 2 is under high load and high speed, the blow-by gas pressure in the cam chamber 120 increases, and the blow-by gas is blown from the second breather chamber 122-2 to the surge tank 16S via the PCV valve 102 and the communication passage 101. Along with the flow of guiding the gas, a flow is generated from the first breather chamber 122-1 via the air cleaner communication passage 132 to the air cleaner 22.

The oil hole 126 for dropping the separated oil into the cam chamber 120 is also used for the cam chamber 12.
The blow-by gas in 0 flows into the first breather chamber 122-1.

At this time, the auxiliary plate 134 transfers the blow-by gas containing a large amount of oil blown out from the oil hole 126 closest to the air cleaner communication passage 132 to the upstream portion on the opposite side that is away from the air cleaner communication passage 132. I'm guiding you.

Thus, the auxiliary plate 134 is
It can be configured to be clamped and fixed by three parts, when fixing the auxiliary plate 134, compared with the conventional one,
The number of spot welds can be reduced, the cost can be reduced, and it is economically advantageous, and the degree of freedom of the auxiliary plate 134 can be increased, which is practically advantageous.

Further, by fixing the auxiliary plate 134 while holding it between the cylinder head cover 8 and the breather plate 114, the oil hole 126 can be brought close to the corner or the seal 140, and the camshaft 116 can be closed. It can be separated from the oil spill area such as the cam 118 and the tappet of the intake and exhaust 12 and 14,
The gas-liquid separation of the oil can be achieved more favorably.

Further, since the auxiliary plate 134 can be brought into contact with the cylinder head cover 8 in a flush state by the step 142 formed on the breather plate 114, there is no possibility that the sealability of the breather plate 114 is impaired. It is practically advantageous.

Further, when the auxiliary plate 134 is disposed on the upper surface 114 a of the breather plate 114, the auxiliary plate 134 is fastened together with the breather plate 114.
The number of spot welds can be reduced, the cost can be reduced, and the degree of freedom of the auxiliary plate 134 can be further increased.

[0051]

As described above in detail, according to the present invention, the cylinder block, the cylinder head mounted on the upper surface of the cylinder block, the oil pan mounted on the lower surface of the cylinder block, and the cylinder head mounted on the cylinder head. An engine having a cylinder head cover is provided, and a breather plate is disposed in the cylinder head cover to separate gas and liquid in oil in the cylinder head cover. Auxiliary plate is provided to improve the quality, and the auxiliary plate is sandwiched and fixed by two parts, so that when fixing the auxiliary plate, the number of spot welding portions can be reduced as compared with the conventional one. The cost can be reduced, it is economically advantageous, and the auxiliary plate Yoshido can be large, and it is practically advantageous.

[Brief description of the drawings]

FIG. 1 is a schematic enlarged sectional view showing a state in which a breather plate and an auxiliary plate are arranged on a cylinder head cover according to an embodiment of the present invention.

FIG. 2 is a plan view from a portion indicated by an arrow の in FIG.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a schematic configuration diagram of a breather device of the engine.

FIG. 5 is a schematic enlarged sectional view of a cylinder head and a cylinder head cover of the engine.

FIG. 6 is a bottom view of the cylinder head cover on which the breather plate is mounted.

FIG. 7 is an enlarged bottom view of the breather plate.

FIG. 8 is a schematic enlarged sectional view showing a state in which a breather plate and an auxiliary plate are arranged on a cylinder head cover according to the prior art of the present invention.

FIG. 9 is a plan view showing a state where a breather plate and an auxiliary plate are arranged on a cylinder head cover.

FIG. 10 is a cross-sectional view taken along line 〓X-〓X in FIG. 9;

[Explanation of symbols]

 Reference Signs List 2 engine 6 cylinder head 8 cylinder head cover 16S surge tank 22 air cleaner 40 exhaust gas recirculation device (EGR device) 60 control means 101 communication passage 102 PCV valve 114 breather plate 116 camshaft 120 cam chamber 122 breather chamber 122-1 first breather Chamber 122-2 Second breather chamber 124 Partition wall 126 Oil hole 128 First cam chamber communication hole 130 Second cam chamber communication hole 132 Air cleaner communication passage 134 Auxiliary plate 140 Seal portion 142 Step portion 144 Hole 146 Joint fastening hole

Claims (3)

[Claims] An engine having a cylinder block, a cylinder head mounted on an upper surface of the cylinder block, an oil pan installed on a lower surface of the cylinder block, and a cylinder head cover mounted on the cylinder head is provided. In a breather device of an engine in which a breather plate is disposed in a cylinder head cover to separate gas and liquid in oil in a cylinder head cover, an auxiliary plate for improving gas-liquid separation of oil is provided on an upper surface portion of the breather plate, A breather device for an engine, wherein the auxiliary plate is sandwiched and fixed between two parts. 2. The breather device for an engine according to claim 1, wherein the auxiliary plate is held and fixed by a cylinder head cover and a breather plate. 3. The breather device for an engine according to claim 1, wherein the auxiliary plate is fastened together with the breather plate when the auxiliary plate is disposed on an upper surface of the breather plate.