JPH0783018A - Blow-by gas reflux device of v type engine - Google Patents

Abstract

PURPOSE:To arrange compactly a member to be equipped to the front bank side so as to be advantageous for making a bonnet low while maintaining performances such as blow-by gas leading-out, ventilation, oil separation, etc., when a V type engine equipped with a blow-by gas reflux device is arranged in lateral placement in an engine room in front of a vehicle. CONSTITUTION:Blow-by gas passages 21, 22 are respectively provided in regard to both banks 2A, 2B of a V type engine placed laterally, and out of these, the blow-by gas passage 21 on the front bank side is made to be a passage for blow-by gas leading-out equipped with a PCV valve 27, and the blow-by gas passage 22 on the rear bank side is made to be a passage that conducts fresh gas introduction at the time of low load and blow-by gas leading-out at the time of high load, and at the same time the passage sectional area of the blow-by gas passage 22 on the rear bank side is made larger than the passage sectional area of the blow-by gas passage 21 on the front bank side, and a main oil separator 25 of a comparatively large shape is provided at the head cover 4B of the rear bank 2B.

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 for a V-type engine, and more particularly to a device applied to a horizontal V-type engine.

[0002]

2. Description of the Related Art Conventionally, as a blow-by gas recirculation device for a V-type engine, for example, one disclosed in Japanese Utility Model Laid-Open No. 59-107012 is known. This device
The rocker chambers in the head covers of both banks of the V-type engine are communicated with the crankcases of the lower part of the engine through the communication passages, and the blow-by gas passages that connect the rocker chambers and the intake passages are provided for both banks. The blow-by gas passage for one bank is used as a blow-by gas outlet passage that connects the rocker chamber to the intake passage downstream of the throttle valve via the PCV valve, and the blow-by gas passage for the other bank has the rocker chamber upstream of the throttle valve. It is used as a passage for fresh air and blow-by gas that is connected to the intake passage. According to this device, at the time of low load, the blow-by gas guided from the crank chamber to the rocker chamber of the one bank is discharged to the intake passage downstream of the throttle valve through the blow-by gas discharge passage, and fresh air is discharged. Ventilation is performed by being introduced into the crank chamber through the rocker chamber of the other bank from the fresh air / blowby gas distribution passage. Further, at the time of high load in which the amount of blow-by gas in the crank chamber increases, the blow-by gas introduced into the rocker chambers of both banks is sucked from both the above-mentioned blow-by gas outlet passage and the above-mentioned fresh air / blow-by gas distribution passage. Be derived to.

[0003]

By the way, when the V-type engine equipped with the blow-by gas recirculation device as described above is horizontally arranged in a vehicle, there are problems such as an increase in bonnet height as described below. Occurs.

That is, when the V-type engine is horizontally arranged in the engine room below the bonnet, the bonnet is formed so as to fall forward, so that the space of the engine mounting portion below the bonnet is forward of the rear bank side. The bank side is restricted. Especially in vehicles, it is desirable to reduce the bonnet height as much as possible within the range that does not hinder the mounting of the engine, etc. from the viewpoints of reducing running resistance and appearance, etc. The side is greatly restricted by space. However, when providing blow-by gas passages for both banks of a horizontal V-type engine,
An oil separator that separates the oil in the blow-by gas is provided above each bank, increasing the height of the bank, and especially when the oil separator in the front bank takes up a relatively large space, it hinders the reduction of the bonnet. Becomes

Further, in the case where the supercharger for supercharging the intake air and the intercooler for cooling the supercharged air are provided, a large oil separator is required because the blow-by gas amount increases due to supercharging. Further, in order to effectively use the traveling wind for cooling by the intercooler, it is necessary to dispose the intercooler above the front bank, so it is easy to cause an increase in height on the front bank side.

In view of the above situation, the present invention ensures the performance of ventilation and blow-by gas discharge when the blow-by gas is recirculated in a V-type engine, while it is installed horizontally so as to be advantageous in reducing the bonnet. An object of the present invention is to provide a blow-by gas recirculation device in which members mounted on the front bank side of a V-type engine can be compactly arranged.

[0007]

In order to achieve the above object, the present invention arranges a V-type engine horizontally in a vehicle in an engine room in front of the vehicle, and for both banks of the V-type engine. Blow-by gas passages that connect the inside of the head cover that communicates with the crank chamber and the intake passages are provided. One of the blow-by gas passages is provided with a PCV valve and is connected to the intake passage downstream of the throttle valve for discharging the blow-by gas. And the other blow-by gas passage is used as a passage for fresh air / blow-by gas flow connected to the intake passage upstream of the throttle valve. And the blow-by gas passage on the rear bank side are used as the above-mentioned passage for fresh air and blow-by gas, and the blow-by gas on the rear bank side is used. The cross-sectional area of the gas passage was made larger than the cross-sectional area of the blow-by gas passage on the front bank side when the PCV valve was fully opened, and the head cover of the rear bank was provided with the main oil separator leading to the blow-by gas passage on the rear bank side. It is a thing.

In the present invention, in addition to the above construction, a fresh air introduction passage for introducing fresh air is provided in the head cover of the front bank, and the fresh air introduction amount from the blow-by gas passage on the rear bank side when the load is low. Is preferably set to be larger than the fresh air introduction amount from the fresh air introduction passage.

Further, the present invention is effectively applied to an engine equipped with a supercharger.

In this case, it is preferable to provide an intercooler in the intake passage downstream of the supercharger and arrange the intercooler so as to intervene in the air passage between the front bank and the hood of the vehicle. In particular, the intercooler is arranged on the head cover of the front bank offset to one end side in the crankshaft direction, and the blowby gas passage on the front bank side is communicated with the space on the other end side in the crankshaft direction caused by the offset arrangement of the intercooler. It is preferable to arrange the sub oil separator and the PCV valve.

[0011]

According to the present invention, when the load is low, the fresh air is introduced from the blow-by gas passage on the rear bank side to perform good ventilation, while the blow-by gas is discharged from the blow-by gas passage on the front bank side. Further, when the load is high, blow-by gas is led out from both blow-by gas passages. In this case, since the blow-by gas passage on the rear bank side has a larger passage cross-sectional area, the discharge amount of blow-by gas is larger, and in response to this, the main oil separator on the rear bank side sufficiently separates the oil in the blow-by gas. Be seen.
Therefore, it is not necessary to provide a large oil separator on the front bank side.

Further, when the fresh air introduction passage is provided on the front bank side, the inside of the head cover of the front bank is ventilated when the load is low, and the blow-by gas passage on the rear bank side when the load is low. Since the amount of fresh air introduced from the above is larger than the amount of fresh air introduced from the above-mentioned fresh air introduction passage, the ventilation effect on the rear bank side is also secured.

Further, particularly when the supercharger is provided, the amount of blow-by gas at the time of high load increases, but a large amount of blow-by gas is provided by the blow-by gas passage having a large passage sectional area on the rear bank side and the main oil separator. Good derivation of gas and oil separation.

When the intercooler is arranged so as to intervene in the air passage between the front bank and the hood of the vehicle, the cooling performance of the intercooler is enhanced by the traveling wind. Further, in this case, the intercooler is offsetly arranged on one end side in the crankshaft direction, and the sub oil separator and the PCV valve are arranged in the space on the other end side in the crankshaft direction generated by the intercooler. Layout is obtained.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

1 and 2 show the structure of the main part of a V-type engine equipped with a blow-by gas recirculation system according to an embodiment of the present invention. 1, the lower side is the vehicle front side, the upper side is the vehicle rear side, and the right side is the vehicle front side and the left side is the vehicle rear side in FIG. 2, where F is the vehicle front side and R is the vehicle rear side. Represents the side.

In these figures, a V-type engine has a pair of banks 2A and 2B protruding in a V-shape above a cylinder block 1, and the banks 2A and 2B are installed at the upper end of the cylinder block 1, respectively. Cylinder heads 3A, 3B and a head cover 4 connected to the upper end thereof
A and 4B are provided. A plurality of cylinders 5 are arranged in a V shape in the cylinder block 1, and a crank chamber 6 is provided below the cylinder block 1 (see FIG. 5).

This V-type engine is arranged laterally with respect to the vehicle in an engine room 9 below the hood 8 at the front of the vehicle, that is, the crankshaft extends in the vehicle width direction. One bank (front bank) 2A and the other bank (rear bank) 2B face each other in the front-rear direction.

An intake manifold 11 formed for each bank is arranged above the inner side (interbank side) of each bank 2A, 2B.
A branch pipe 1 comprising a surge tank 12 and a branch pipe 13.
The downstream end of the cylinder head 3 is connected to the side wall of the cylinder head 3 so as to communicate with the intake port of each cylinder. Further, a mechanical supercharger 15 is installed in the valley portion between the banks 2A and 2B. Further, an intercooler 16 is installed on the head cover 4A of the front bank 2A so as to intervene in the air passage between the front bank 2A and the hood 8.

The blow-by gas recirculation device is constituted by connecting portions 23 and 24 for connecting the conduits forming blow-by gas passages 21 and 22 and main and auxiliary portions for removing oil in the blow-by gas. The respective oil separators 25 and 26, the PCV valve 27 for adjusting the flow rate of the blow-by gas according to the engine load, etc. are arranged as follows.

That is, in the upper portion of the head cover 4B of the rear bank 2B, a large-sized main oil separator 25 that covers most of the length (vehicle width direction) of the head cover 4B.
Is provided. As shown in FIG. 4, when viewed in cross section, a separator chamber 25a of the main oil separator 25 has a shape projecting upward at a rear side portion of the head cover 4B formed so as to cover the bearing caps 20 of the pair of cam shafts. It is formed integrally. A connecting portion 24 for the conduit forming the blow-by gas passage 22 is fixed to the upper end of the separator chamber 25a.

Further, the head cover 4A of the front bank 2A
A sub oil separator 26, which is smaller than the main oil separator 25, and a PCV valve 27 connected to the sub oil separator 26 are provided in the upper part of the. In particular, as a rational layout of these and the intercooler 16, the intercooler 16 is arranged offset to one end side in the crankshaft direction in the upper part of the head cover 4A, and the crank generated by the offset arrangement of the intercooler 16 is arranged. The sub oil separator 26 and the PCV valve 27 are arranged in the space on the other end side in the axial direction. When viewed in cross section, as shown in FIG.
A separator chamber 26a of the sub oil separator 26 is integrally formed in a front portion of the above with a shape protruding upward. Then, at the upper end portion of the separator chamber 26a, the connecting portion 2 for the conduit forming the blow-by gas passage 21 is formed.
3 is fixed and the PCV valve 27
Is built in.

Further, the head cover 4 of the front bank 2A
A is provided with a connecting portion 29 for connecting a conduit forming a passage 28 for fresh air introduction described later.

The passage structure of the intake system and the blow-by gas recirculation device is as shown in FIG. It should be noted that this diagram schematically shows the passage structure and does not show the actual layout.

In this figure, an upstream intake passage 31 communicating with a pair of intake manifolds 11 has an intake resonator 32, a throttle valve 33, and a supercharger 15 in order from the upstream side.
And an intercooler 16 are provided, and a bypass passage 34 that bypasses the supercharger 15 is provided, and a bypass valve 35 that opens when the load is low is provided in the bypass passage 34.
Is provided.

Further, the insides of the head covers 4A and 4B of both banks 2A and 2B and the crank chamber 6 communicate with each other through communication paths 210 and 220.
And the head covers 4A, 4
Blow-by gas passages 21 and 22 for the banks 2A and 2B are formed by arranging conduits so as to connect the inside of B and the intake passage 31.

Of the above blow-by gas passages 21 and 22, one end of the blow-by gas passage 21 on the front bank side is connected to the sub oil separator 26, and a PCV valve 27 is provided in this portion, and The end side is connected to the intake passage 31 downstream of the throttle valve 33, and is connected to, for example, the housing of the bypass valve 35. In addition, the blow-by gas passage 22 on the rear bank side
Has one end connected to the main oil separator 25 and the other end connected to the intake passage 31 upstream of the throttle valve 33, for example, to the intake resonator 32. Thus, the blow-by gas passage 21 on the front bank side is always used as a blow-by gas lead-out passage for leading the blow-by gas through the PCV valve 27, while the blow-by gas passage 22 on the rear bank side is
It is used as a passage for fresh air and blow-by gas distribution that introduces fresh air when the load is low and discharges blow-by gas when the load is high.

Blow-by gas passage 2 on the rear bank side
The passage cross-sectional area of No. 2 is set to be larger than the passage cross-sectional area of the blow-by gas passage 21 on the front bank side when the PCV valve is fully opened.

Further, the head cover 4 of the front bank 2A
One end of a fresh air introduction passage 28 is connected to A, and the other end of the passage 28 is connected to the intake resonator 32. The fresh air introduction passage 28 exclusively introduces fresh air, and a one-way valve 36 that allows only the flow of gas from the intake passage 31 side to the head cover 4A is provided in the middle of the passage. Has been. The passage cross-sectional area of the fresh air introduction passage 28 is made sufficiently smaller than the passage cross-sectional area of the blow-by gas passage 22 on the rear bank side.
Therefore, when the load is low, the fresh air introduced into the head cover 4B from the blow-by gas passage 22 on the rear bank side is sufficiently larger than the fresh air introduced into the head cover 4A from the fresh air introduction passage 28. , Has been set.

According to the blow-by gas recirculation apparatus of the present embodiment as described above, when the load is low, the flow of blow-by gas shown by the solid line arrow and the flow of fresh air shown by the broken line in FIG. 6 occur. That is, the blow-by gas passes from the crank chamber 6 through the communication passage 210 of the front bank 2A and the head cover 4A.
And the throttle valve 3 through the blow-by gas passage 21 on the front bank side which further has a PCV valve 27.
3, while fresh air is introduced into the intake passage 31 downstream of the throttle valve 33 from the intake passage 31 upstream of the throttle valve 33 through the blow-by gas passage 22 on the rear bank side, the head cover 2B, and the communication passage 220. Will be introduced to.

In this way, the blow-by gas is discharged while the ventilation is favorably performed by the air flow from the rear bank 2B side to the front bank 2A side. Further, fresh air is introduced from the fresh air introduction passage 28 to the head cover 4A of the front bank 2A.
When the head cover 4A is introduced into the inside, ventilation is also performed inside the head cover 4A. This is done to prevent the blow-by gas from staying in the head cover 4A and deteriorating the oil for lubricating the valve operating mechanism. However, since the fresh air introduction amount from the fresh air introduction passage 28 is sufficiently smaller than the fresh air introduction amount from the blow-by gas passage 22 on the rear bank side, the air flow from the rear bank side to the front bank side described above is generated. It will not be damaged.

The amount of blow-by gas discharged from the front bank side is adjusted by the PCV valve 27 so as to increase as the load increases.

When the load is high, the flow of blow-by gas indicated by the solid arrow in FIG. 7 occurs. That is, the blow-by gas in the crank chamber 6 passes through the communication passages 210 and 220 of both banks 2A and 2B, the head covers 4A and 4B, and then the blow-by gas passages 21 and 22 to the intake passage 31.
Is derived to.

In this case, since the passage area of the blow-by gas passage 22 on the rear bank side is larger than the passage area of the blow-by gas passage 21 on the front bank side when the PCV valve is fully opened, the blow-by gas passage on the rear bank side is relatively present. A large amount of blow-by gas is derived from 22. Corresponding to this, the large main oil separator 25 on the rear bank side
As a result, the oil in the blow-by gas is sufficiently separated, and on the front bank side, the small auxiliary oil separator 26 separates the oil. At this time, the fresh air introduction passage 28 does not lead out the blow-by gas because the one-way valve 36 is provided in the passage 28. Therefore, it is not necessary to provide an oil separator for this passage 28.

By doing so, even when the bonnet is to be made low, the oil separator and the like are rationally arranged in the limited space below the bonnet. That is, since the bonnet 8 has a front-lowering shape, the space above the engine is limited particularly on the front bank side. However, a small auxiliary oil separator 26 and a PCV valve 27 are provided above the head cover 4A on the front bank side. Is arranged compactly, and a large-sized main oil separator 25 is arranged above the head cover 4A of the rear bank, which has more space than the front bank side, so that a rational layout can be obtained.

In particular, when the supercharger 15 is provided, the amount of blow-by gas at the time of high load increases due to supercharging, but accordingly a sufficiently large main oil separator 25 is provided on the rear bank side. While the oil separation function is satisfied, the front bank side has a compact structure.

Further, on the front bank 2A side, the intercooler 16 is offsetly arranged at one end side above the head cover 4A, and the sub oil separator 26 and the PCV valve 27 are arranged in the space at the other end side formed by this. As a result, the traveling wind is effectively used to enhance the cooling performance of the intercooler 16, and the sub oil separator 26 and the PCV valve 27 are compactly arranged above the intercooler 16 without taking an extra space. It will be.

[0038]

As described above, according to the present invention, blow-by gas passages are provided for both banks of a horizontal V-type engine, and the blow-by gas passage on the front bank side is a blow-by gas outlet provided with a PCV valve. The blow-by gas passage on the rear bank side is a passage for introducing fresh air at low load and for discharging blow-by gas at high load, and the blow-by gas passage on the rear bank side has a large cross-sectional area. The main oil separator chamber is provided in the head cover of the rear bank. Therefore, functions such as ventilation at low load, derivation of a large amount of blow-by gas at high load, oil separation, etc. can be exhibited well, and moreover,
The front bank side has a compact structure, and the members constituting the blow-by gas recirculation device can be rationally laid out so as to satisfy the demand for a low bonnet.

In the present invention, a fresh air introduction passage for introducing fresh air is provided in the head cover of the front bank, and the fresh air introduction amount from the blow-by gas passage on the rear bank side at the time of low load is introduced as the fresh air introduction. If it is set to be larger than the fresh air introduction amount from the dedicated passage, the ventilation function and the like at the time of low load can be further improved. In addition, this fresh air introduction passage only introduces fresh air when the load is low, and it is not necessary to provide an oil separator in this passage, so the compactness of the front bank side is not impaired. Absent.

Further, especially when the supercharger is provided, the blow-by gas generation amount at the time of high load increases, but in this case as well, the blow-by gas passage having a large passage area on the rear bank side and the main oil separator. Thus, the front bank side can be made compact while fully satisfying the mechanism of blow-by gas derivation and oil separation.

Further, if the intercooler for cooling the supercharged air is arranged so as to intervene in the air passage between the front bank and the hood of the vehicle, the cooling performance of the intercooler can be improved. In this case, the intercooler is arranged on the head cover of the front bank while being offset to one end in the crankshaft direction, and the blowby gas passage on the front bank side is communicated with the space on the other end side in the crankshaft direction caused by the intercooler. Sub oil separator and PCV
When the valve is arranged, the member on the front bank side of the blow-by gas recirculation device can be arranged compactly while avoiding the intercooler.

[Brief description of drawings]

FIG. 1 is a plan view of a V-type engine equipped with a blow-by gas recirculation device according to an embodiment of the present invention.

FIG. 2 is a side view of the V-type engine.

FIG. 3 is an enlarged sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG.

FIG. 5 is an explanatory diagram showing a passage configuration of an intake system and a blow-by gas recirculation device.

FIG. 6 is an explanatory diagram showing flows of fresh air and blow-by gas at low load.

FIG. 7 is an explanatory diagram showing a flow of blow-by gas under high load.

[Explanation of symbols]

 1 Cylinder Block 2A, 2B Bank 3A, 3B Cylinder Head 4A, 4B Head Cover 6 Crank Chamber 8 Bonnet 15 Supercharger 16 Intercooler 21, 22 Blow-by Gas Passage 25 Main Oil Separator 26 Sub Oil Separator 27 PCV Valve 28 Dedicated to Introduction of Fresh Air aisle

Claims (5)

[Claims] 1. A V-type engine is disposed laterally on the vehicle in an engine room in front of the vehicle, and both the banks of the V-type engine are connected to the inside of a head cover communicating with the crank chamber and the intake passage. A blow-by gas passage is provided, one of the blow-by gas passages is a passage for deriving a blow-by gas that is connected to an intake passage downstream of the throttle valve via a PCV valve, and the other blow-by gas passage is provided upstream of the throttle valve. The blow-by gas passage on the front bank side is connected to the intake passage, and the blow-by gas passage on the front bank side is used as the blow-by gas passage, and the blow-by gas passage on the rear bank side is used as the fresh air / blow-by gas. In addition to providing a gas distribution passage, the cross-sectional area of the blow-by gas passage on the rear bank side is adjusted to the blow-by gas on the front bank side. Blow-by gas recirculation of V-type engine, characterized in that it is larger than the cross-sectional area of the PCV valve in the main passage at the time of maximum opening, and the head cover of the rear bank is provided with a main oil separator leading to the blow-by gas passage on the rear bank side. apparatus. 2. A fresh air introduction passage for introducing fresh air is provided in the head cover of the front bank, and the fresh air introduction amount from the blow-by gas passage on the rear bank side when the load is low is set to the fresh air introduction passage. The blow-by gas recirculation system for a V-type engine according to claim 1, wherein the blow-by gas recirculation device is set to be larger than the fresh air introduction amount from the. 3. The blow-by gas recirculation system for a V-type engine according to claim 1, further comprising a supercharger in an intake passage of the engine. 4. The V-type engine according to claim 3, wherein an intercooler is provided in an intake passage downstream of the supercharger, and the intercooler is arranged so as to intervene in an air passage between a front bank and a hood of a vehicle. Blow-by gas recirculation device. 5. An intercooler is arranged offset on one end side in the crankshaft direction on the head cover of the front bank, and a blowby gas on the front bank side is placed in a space on the other end side in the crankshaft direction caused by the offset arrangement of the intercooler. Sub oil separator and P leading to the passage
The blow-by gas recirculation device for a V-type engine according to claim 4, wherein a CV valve is arranged.