JPH06229221A - Blow-by gas circulating device - Google Patents

Abstract

PURPOSE:To reduce the number of components by providing the proximal end part of a PCV valve on a cylinder head cover, and by providing the distal end thereof on an intake-air system member so as to prevent blow-by gas from freezing. CONSTITUTION:A primary side surge tank 12 is arranged as a primary side intake-air system member is laid above a secondary engine bank. A secondary side surge tank is arranged as a secondary side intake-air system member. A primary side PCV valve 30 constituting a primary side blow-by gas circulating device is directly attached to a secondary cover side valve attaching part 20 and a primary tank side valve attaching part 22. An primary side gas intake port 42 in the proximal end part of the primary side PCV valve 30 is arranged so as to face the inside of a secondary cylinder head cover 10. Further, a primary side gas circulating port 50 in the distal end 30b of the primary side PCV valve 30 is laid so as to face the inside of the primary side surge tank 12. It is thus, possible to prevent blow-by gas from freezing.

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 recirculation device, and more particularly, to prevent blow-by gas from freezing by avoiding the blow-by gas from coming into contact with the outside air, and reducing the number of parts. Regarding the device.

[0002]

2. Description of the Related Art In an engine, blow-by gas leaks from a combustion chamber through a gap between a piston and a cylinder wall into a crankcase. This main component is an unburned gas and contains a large amount of HC, and it is necessary to guide it again to the combustion chamber and reburn it. For this reason, there is a blow-by gas recirculation device, and a commonly used method is to use the intake pipe negative pressure of the intake system as the load state of the engine to suck into the air cleaner or the intake passage, or both, and It recirculates and leads to the combustion chamber again for combustion. A PCV valve is provided in the blow-by gas recirculation device to adjust the amount of blow-by gas recirculated to the intake passage or the like.

Some blow-by gas recirculation devices are provided in the V-type engine 102, as shown in FIG. In this V-type engine 102, a primary side and a secondary side cylinder head (not shown) are mounted on a V-shaped primary side and a secondary side cylinder bank (not shown) above a cylinder block (not shown). It has primary side and secondary side engine banks 104 and 106 that are configured by being installed. Primary and secondary cylinder head covers 108 and 110 are attached to the primary and secondary cylinder heads.

Above the V-type engine 102, the primary and secondary engine banks 10 are provided as intake system members.
Primary side and secondary side distribution pipes 112 and 114 are provided to guide intake air to the primary side and secondary side cylinders (not shown) of 4, and 106.

The primary and secondary distribution pipes 112 and 114
A throttle body 116 having a throttle valve (not shown) is attached to the intake manifold connecting the respective upstream sides of the.

A primary surge tank 118 is connected to the downstream side of the primary distribution pipe 112 and is located above the secondary engine bank 106. The primary-side surge tank 118 is connected in parallel with primary-side intake introduction pipes 120-1, 120-2, 120-3 that guide intake air to the primary-side cylinders. On the downstream side of the secondary side distribution pipe 114, a secondary side surge tank 122 is arranged continuously above the primary side engine bank 104. In the secondary side surge tank 122, secondary side intake introducing pipes 124-1 to 124-2 for guiding intake air to the respective secondary side cylinders.
Are connected in parallel.

The throttle body 116 is provided with one end side of a suction pipe 126 connected upstream thereof. The suction pipe 126 is a V-shaped space formed between the primary engine bank 104 and the secondary engine bank 106, and is arranged so as to be oriented in the crankshaft axial direction. This suction pipe 1
A substantially central portion of 26 is bent at a substantially right angle with respect to the crankshaft axis direction. The suction pipe 126 guides air from an air cleaner (not shown) to the throttle body 116.

Above the primary side and secondary side cylinder head covers 108 and 110, the primary side and secondary side P constituting the primary side and secondary side blow-by gas devices 128 and 130 are provided.
The base ends of the CV valves 132 and 134 are attached, respectively. The primary side and secondary side PCV valves 132 and 134
One end side of each of the primary side and secondary side blow-by gas hoses 136 and 138 is attached to the respective tip portions of the. The primary and secondary blow-by gas hoses 136 and 138
The other end of each of the hose is attached to each hose union (not shown)
Is connected to the primary side and secondary side surge tanks 118 and 122 via.

The primary side and secondary side PCV valves 132,
When the blow-by gas generated in the V-type engine 102 is circulated to the primary side and secondary side surge tanks 118 and 122, respectively, the reference numeral 134 indicates the primary side, the secondary side depending on the load state of the V-type engine 102, that is, the intake pipe negative pressure state. The flow rate of blow-by gas to the secondary surge tanks 118 and 122 is adjusted.

Further, such a blow-by gas recirculation device is disclosed, for example, in Japanese Utility Model Laid-Open No. 1-61414. The one described in this publication has a branch pipe communicating with the intake manifold and a PCV housed inside the branch pipe.
It has a valve and is directly connected to the branch pipe by a flexible pipe with the engine unit.

[0011]

However, in the conventional blow-by gas recirculation apparatus, the base end of the PCV valve is attached to the cylinder head cover, and one end of the blow-by gas hose is connected to the tip of the PCV valve. Since the other end of the blow-by gas hose is connected to the surge tank, which is an intake system member, through the hose mounting union, blow-by gas from the PCV valve is supplied to the intake system through the blow-by gas hose. Since the gas is exposed to the outside air, there is a disadvantage that blow-by gas freezes just before flowing into the surge tank in a cold region.

In addition, the blow-by gas recirculation device requires parts such as a blow-by gas hose and a hose mounting union, which increases the number of parts, which complicates the structure, increases the size, and increases the cost. .

[0013]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention determines the amount of blowby gas recirculated when the blowby gas generated in the engine is recirculated to the intake system depending on the load condition of the engine. PCV to adjust
In a blow-by gas recirculation device provided with a valve, a base end portion of the PCV valve is provided on a cylinder head cover, and a tip end portion of the PCV valve is provided on an intake system member.

[0014]

According to the structure of the present invention, the blow-by gas is P
Since the blow-by gas is directly supplied from the CV valve to the intake system, the blow-by gas does not come into contact with the outside air, and therefore, the blow-by gas is not likely to freeze even in a cold region. Further, since parts such as a blow-by gas hose and a hose mounting union are unnecessary, the number of parts can be reduced, the structure can be simplified, the size can be reduced, and the cost can be reduced.

[0015]

Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 and 2 show an embodiment of the present invention. In FIG. 2, reference numeral 2 is a V-type engine mounted on the vehicle. This V-type engine 2 has a V-shaped primary side above a cylinder block (not shown),
It has primary side and secondary side engine banks 4 and 6 configured by mounting a primary side and a secondary side cylinder head (not shown) on a secondary side cylinder bank (not shown). Primary and secondary cylinder head covers 8 and 10 are attached to the primary and secondary cylinder heads.

Above the secondary engine bank 6,
A primary surge tank 12 is provided as a primary intake system member. Each of the primary side intake tanks 1 introduces intake air into each primary side cylinder (not shown) in the primary side surge tank 12.
4-1, 14-2, 14-3 are connected in parallel.
Intake is introduced into the primary side surge tank 12 from a primary side distribution pipe (not shown).

Above the primary engine bank 4,
A secondary surge tank 16 is provided as a secondary intake system member. The secondary side surge tank 16 has a secondary side intake introducing pipe 18 for guiding intake air to each secondary side cylinder (not shown).
-1, 18-2, 18-3 are connected in parallel. The secondary surge tank 16 has a secondary distribution pipe (not shown).
Intake is introduced from.

In the secondary side cylinder head cover 10, as shown in FIG. 1, a secondary cover side valve mounting portion 20 is formed flat on the V-shaped space side, that is, on the inner side and on the upper side.

Further, in the primary side surge tank 12, as shown in FIG. 1, between the primary side intake introducing pipe 14-1 and the primary side intake introducing pipe 14-2, on the space side of the V-shape, that is, inside, and A primary tank-side valve mounting portion 22 is formed flat at the lower portion and close to the secondary cover-side valve mounting portion 20.

In the primary-side cylinder head cover 8, a primary-cover-side valve mounting portion 24 is formed flat on the V-shaped space side, that is, on the inner side and at the upper portion.

In the secondary side surge tank 16, the secondary side intake introducing pipe 18-1 and the secondary side intake introducing pipe 18 are provided.
-2, the secondary tank side valve mounting portion 26 is formed flat on the side of the V-shaped space, that is, on the inner side and at the lower portion, and close to the primary cover side valve mounting portion 24.

A primary side PCV valve 30 constituting a primary side blow-by gas recirculation device 28 is directly attached to the secondary cover side valve mounting portion 20 and the primary tank side valve mounting portion 22.

Further, the primary side cover side valve mounting portion 2
A secondary-side PCV valve 34 that constitutes a secondary-side blow-by gas recirculation device 32 is directly attached to the 4 and the secondary-tank-side valve attachment portion 26.

Since the primary blow-by gas recirculation device 28 and the secondary blow-by gas recirculation device 32 have the same structure,
Here, only the structure of the primary side blow-by gas recirculation device 28 will be described.

That is, as shown in FIG. 1, the secondary cover side valve mounting portion 20 of the secondary side cylinder head cover 10 includes:
A secondary cover side valve mounting hole 36 is formed. A secondary cover side grommet 38 is fitted and provided in the secondary valve mounting hole 36. The primary valve base end portion 30a of the primary PCV valve 30 is inserted into the secondary cover side grommet 38. Secondary cover side grommet 38
The secondary cover side flange portion 38 a is fitted into the secondary cover side flange hole 40 formed on the outer surface of the secondary cover side valve mounting portion 20. As a result, the primary-side gas intake port 4 of the primary-side valve base end portion 30a of the primary-side PCV valve 30.
2 is disposed so as to face the inside of the secondary cylinder head cover 10.

In addition, in the primary tank side valve mounting portion 22 of the primary side surge tank 12, a primary tank side valve mounting hole 44 corresponding to the secondary cover side valve mounting hole 36 is formed.
Are formed. This primary tank side valve mounting hole 44
Includes a primary valve tip 3 of the primary PCV valve 30.
0b is inserted. The primary tank-side grommet 4 is attached to the primary-side valve tip portion 30b of the primary-side PCV valve 30.
6 is fitted. This primary tank side grommet 46 is
It is fitted into a primary tank side flange hole 48 formed on the outer surface of the primary tank side valve mounting portion 22. This allows
The primary-side gas recirculation port 50 of the primary-side valve tip portion 30b of the primary-side PCV valve 30 is disposed so as to face the inside of the primary-side surge tank 12.

The primary and secondary PCV valves 30, 3
4 is operated by the load state of the V-type engine 2, that is, the intake pipe negative pressure state, when the blow-by gas generated in the V-type engine 2 is recirculated to the primary side and secondary side surge tanks 12 and 16 which are intake systems. However, the flow-back amount of blow-by gas to the primary side surge tank 12 and the secondary side surge tank 16 is adjusted.

Next, the operation of this embodiment will be described.

The blow-by gas generated in the V-type engine 2 flows into the primary side and secondary side cylinder head covers 8 and 10, and then the primary side and secondary side PCV valves 30 and 3 are provided.
4 operates by the negative pressure of the intake pipe, the primary side,
The secondary surge tanks 12 and 16 are supplied.

At this time, the secondary cylinder head cover 1
0 and the primary surge tank 12 to the primary PCV valve 3
0 is directly attached, and the secondary side PC is attached to the primary side cylinder head cover 8 and the secondary side surge tank 16.
Since the V-valve 34 is directly attached, the blow-by gas is supplied to the primary side and secondary side surge tanks 12 and 16 without contacting the outside air, and there is no fear that the blow-by gas freezes even in cold regions.

Further, since the parts such as the blow-by gas hose and the hose mounting union as in the conventional case are not required, the structure can be simplified, the size can be reduced, and the cost can be reduced.

Further, the primary side and secondary side PCV valves 30,
Since 34 is disposed inside the V-shaped engine 2 which is the V-shaped space side, the primary side and secondary side PCV valves 3
0, 34 has excellent heat retention, prevents blow-by gas from freezing in the primary and secondary PCV valves 30, 34,
The functions of the primary and secondary PCV valves 30 and 34 can be satisfactorily ensured.

Although the surge tank is used as the intake system member in the above-described embodiment, it is needless to say that the intake system member may be another intake system member such as a distribution pipe or an intake introduction pipe.

[0034]

As is apparent from the above detailed description, according to the present invention, the base end portion of the PCV valve is provided on the cylinder head cover and the tip end portion of the PCV valve is provided on the intake system member. Since the blow-by gas is supplied directly from the PCV valve to the intake system, the blow-by gas does not come into contact with the outside air, and therefore the blow-by gas can be prevented from freezing even in cold regions.

Further, parts such as a blow-by gas hose and a hose mounting union are unnecessary, reducing the number of parts,
Simplify the configuration, thereby downsizing,
It can be cheap.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of the primary side blow-by gas recirculation device taken along line 〓-〓 of FIG.

FIG. 2 is a schematic plan view of a V-type engine.

FIG. 3 is a plan view of a V-type engine provided with a conventional blow-by gas recirculation device.

[Explanation of symbols]

 2 V-type engine 8 Primary side cylinder head cover 10 Secondary side cylinder head cover 12 Primary side surge tank 16 Secondary side surge tank 28 Primary side blow-by gas recirculation device 30 Primary side PCV valve 32 Secondary side blow-by gas recirculation device 34 Secondary side PCV valve

Claims (1)

[Claims] 1. A blow-by gas recirculation apparatus provided with a PCV valve for adjusting a recirculation amount of blow-by gas according to a load condition of the engine when recirculating blow-by gas generated in an engine to an intake system, a base end of the PCV valve. Part is provided on the cylinder head cover and
A blow-by gas recirculation device, wherein the tip of the CV valve is provided in an intake system member.