JP2900270B2 - Vehicle engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-cylinder vehicle engine having a breather case in an intake system.

[Conventional technology]

Mist oil is mixed with blow-by gas generated by the engine. Such mist-like oil can be separated by providing a breather case, and the blow-by gas from which the oil has been removed by the breather case is circulated to an intake system and burned in a combustion chamber.

Since such a breather system has a structure in which only the mist-like oil is separated by compressing and expanding the flow of the blow-by gas, a large volume is required for this oil separation operation. . But,
The breather case having such a large volume has a problem that the storage space for other parts in the engine room is narrowed. Also, since the breather case needs to be connected to the intake system, the connecting pipe must be lengthened depending on the installation location, which also results in a reduction in the space of the engine room.

[Problems to be solved by the invention]

It is an object of the present invention to provide a vehicle engine in which, when a breather case having a large volume is provided in an engine room of a multi-cylinder engine, a connecting pipe for an intake system is shortened so that storage space is effectively used. is there.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a multi-cylinder engine mounted on a vehicle, wherein a single head cover that covers the entire cam chamber is disposed above a cylinder head, and a plurality of ignitions arranged in the crankshaft direction of the head cover. A breather case projecting to one side with a stopper interposed is provided, and a surge tank connected to an intake pipe is arranged in parallel with the breather case at the upper part on the other side, and the breather case is opened to the cam chamber. A first passage and a second passage opening to the cam chamber and closer to the surge tank than the first passage;
The first passage and the intake passage upstream of the throttle valve
And the second passage and the surge tank are connected by a second connection pipe, so that blow-by gas flowing into the breather case flows out to the intake passage or the surge tank. It is characterized by having done.

In this way, the upper part of the cylinder head covering the entire cam chamber 1
The two head covers are arranged, a breather case is provided on one side with the spark plug of the head cover interposed, and a surge tank is arranged on the other side in parallel with the breather caser. And the surge tank can be stored, and the second connection pipe is connected to the surge tank and the second passage close to the surge tank, so that the second connection pipe can be made very short. Therefore, the entire engine can be made compact.

〔Example〕

The figure shows an embodiment of the present invention mounted on an FF vehicle.

The direction of arrow F is the traveling direction of the vehicle body, and a four-cylinder engine E is mounted horizontally with its crankshaft orthogonal to the direction of arrow F. B is a hood covering the upper part of the engine E.

In the engine E, 1 is a cylinder block, 2
Is a cylinder head, and 3 is a mission case.

One head cover 2a that covers the entire cam chamber 44 is disposed above the horizontally placed cylinder head 2, and the upper end portions of the spark plugs 14, 14, 14, 14 of each cylinder protrude. A breather case 13 is provided in parallel and protrudes along the crankshaft direction. Further, a surge tank 9 is provided in parallel on an upper portion on the opposite side of the ignition plug row. Four intake pipes 4a, 4b, 4c, 4d extending from the surge tank 9 are connected to each cylinder on the front surface of the cylinder head 2, and the fuel injection valves 8a, 8b, 8c, 8d is installed. Further, exhaust pipes 5a, 5b, 5c, 5d are connected to the rear surface of the cylinder head 2, and these are converged to one exhaust pipe 6 via a turbocharger 7.

10 is an air cleaner, 11 is an intercooler, 12 is a throttle body, and 17 is an oil inlet. The throttle body 12 is connected to the suction side of the surge tank 9 and has a throttle valve 12a provided inside thereof. Air is sucked in from the air cleaner 10 according to the opening degree of the throttle valve 12a, and the air is supercharged to the turbocharger 7 and then intercooled.
The air is cooled at 11 and sent to each cylinder from each intake pipe 4a, 4b, 4c, 4d via a throttle body 12 and a surge tank 9. An idle speed control valve 15 is connected to the other end of the surge tank 9. The idle speed control valve 15 communicates with the air cleaner 10 via a bypass pipe 16.

As shown in FIG. 3 and FIG.
The inside is divided into right and left by a partition wall 30, and one side thereof is vertically divided by a partition plate 31, and the whole is divided into three, and the first passages 32 and 33 and the passages 32 and 33
A second passage 34 closer to the surge tank 9 is formed. Of these passages, passage 32 is the first connecting pipe.
It is connected to an intake passage 40 downstream of the air cleaner 10 by 41. The passage 34 is connected to the surge tank 9 by a second connection pipe 42 so as to have the shortest distance.
This connection portion is provided with a one-way valve 43 for preventing the flow from the surge tank 9 to the passage 34 side. The connecting pipe 42
The connection between the passage 34 and the surge tank 9 can be made arbitrarily as long as the two are connected at the shortest distance. For example, the position shown by a chain line may be used.

Further, the passage 32 has a throttle hole 35 communicating with the lower passage 33 on the bottom surface opposite to the side to which the connection pipe 41 is connected. The lower passage 33 is provided with an oil hole 36 communicating with the lower cam chamber 44 on the bottom surface corresponding to the throttle hole 35, and a lower cam on the bottom surface opposite to the oil hole 36 in the longitudinal direction. Room 44
There is provided a throttle hole 37 communicating with. The passage 34 is provided with a throttle hole 38 communicating with the cam chamber 44 on the bottom surface opposite to the throttle hole 37 in the longitudinal direction, and an oil hole 39 at an end opposite to the throttle hole 38 in the longitudinal direction. Provided.

In such a structure, when the supercharging pressure of the turbocharger 7 is not applied to the surge tank 9, the connecting pipe 41
The fresh air is sucked from and flows in the order of the passages 32 and 33 as shown by white arrows (see FIGS. 4 and 5), and finally flows into the cam chamber 44 from the throttle hole 37. When the fresh air flows into the cam chamber 44 in this manner, the blow-by gas in the cam chamber 44 is released from the throttle hole 38.
When the oil is driven into the passage 34 and compressed and expanded by the throttle hole 38 and suddenly decelerates, the oil is separated, and only the remaining blow-by gas passes through the connecting pipe 42 as shown by a hatched arrow (see FIG. 5). It flows into the surge tank 9. As described above, in order to efficiently ventilate the fresh air flowing into the cam chamber 44 and the blow-by gas in the cam chamber 44, the throttle hole 37 is used.
And 38 are located on opposite sides of the crankshaft direction. On the other hand, the separated oil is
It flows down from 39 to the cam chamber 44.

The supercharging pressure of the turbocharger 7 is
When the load is applied, the pressure on the surge tank 9 side becomes higher than the pressure on the breather case 13, whereby the one-way valve 43 is closed and fresh air flows from the surge tank 9 to the breather case 13 side. Nor. By this backflow prevention, the blow-by gas in the cam chamber 44 flows back through the inside of the breather case 13 from the throttle hole 37 toward the flow paths 33 and 32 in the direction opposite to the white arrow, and flows toward the connecting pipe 41. Further, when the oil is compressed and expanded in the throttle hole 37 and suddenly decelerates, the oil is separated, and the separated oil flows down from the throttle hole 37 and the oil hole 36 to the cam chamber 44.

The engine E has an ignition plug above the cylinder head 2.
Since the head cover 2a provided with the breather case 13 protruding to one side with the 14 interposed therebetween is arranged, and the surge tank 9 is arranged in parallel with the breather case 13 on the upper side of the other side of the head cover 2a, so that the comparison is made. The breather case 13 having a large target capacity can be compactly stored in the engine room. In addition, since the surge tank 9 disposed in the recess 2a and the passage 34 near the surge tank 9 are connected by the second connection pipe 42,
Is extremely short. As a result, the entire engine E is compact.

Although the above-described embodiment has been described with respect to a case where the engine is mounted horizontally, the present invention can be applied to a case where the engine is mounted vertically.

〔The invention's effect〕

The present invention provides a multi-cylinder engine mounted on a vehicle as described above, in which a single head cover that covers the entire cam chamber is disposed above a cylinder head, and a plurality of spark plugs arranged in the crankshaft direction of the head cover. A breather case protruding to one side with a surge tank connected to an intake pipe arranged in parallel with the breather caser on the other side, and a first passage and a cam opening the breather case to the cam chamber. A second passage opening into the chamber and closer to the surge tank than the first passage, connecting the first passage and an intake passage upstream of the throttle valve with a first connection pipe and a second passage; And the surge tank are connected by a second connection pipe. Therefore, the breather case and the surge tank can be stored compactly in the upper part of the cylinder head, and the second connecting pipe connecting the breather case and the surge tank can be made very short, so that the entire engine can be made compact. .

[Brief description of the drawings]

FIG. 1 shows a vehicle engine according to an embodiment of the present invention. FIG. 1 is a plan view of the engine, and FIG. 2 is a side view. FIG. 3 is a plan view showing the upper part of the cylinder head of the engine, FIG. 4 is a view taken along the line IV-IV of FIG. 3, and FIG. 5 is a view taken along the line VV of FIG. E: engine, 2: cylinder head, 4a, 4b, 4c, 4d
... intake pipe, 9 ... surge tank, 13 ... breather case, 14 ... spark plug, 42 ... connecting pipe.

Claims (1)

(57) [Claims] In a multi-cylinder engine mounted on a vehicle, one head cover that covers the entire cam chamber is disposed above a cylinder head, and a plurality of spark plugs arranged in the crank axis direction of the head cover are sandwiched therebetween. Providing a breather case protruding on one side, a surge tank connected to an intake pipe at the top of the other side is arranged in parallel with the breather case,
The breather case is partitioned into a first passage opening to the cam chamber and a second passage opening to the cam chamber and closer to the surge tank than the first passage. And the surge tank are connected by a second connection pipe, and the blow-by gas flowing into the breather case is connected to the intake passage or the surge tank by a first connection pipe. A vehicle engine configured to flow out to the surge tank.