JPH0756210B2 - Intake device for internal combustion engine with supercharger - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake device for an internal combustion engine with a supercharger, and in particular, a large amount of oil mixed in blow-by gas is not sucked into the supercharger. Regarding the intake device.

<Prior Art> By increasing the specific weight of the air-fuel mixture and increasing the packing density of the air-fuel mixture by pressurizing the intake air supplied to the combustion chamber of the engine, it is possible to increase the output of the engine in various modes. Has been converted. As a means for pressurizing the intake air, a positive displacement type compressor is also used in addition to the centrifugal type and axial flow type compressors. In order to drive such a compressor, a turbine driven by exhaust gas is used or the output of the engine is directly used.

When a mechanical compressor such as a vane pump is used as a supercharger for compressing intake air, so-called intake pulsation occurs, in which the intake flow velocity fluctuates at a constant cycle synchronized with the rotation speed, and noise due to resonance is generated. There is a case to let. Therefore,
In order to suppress such intake pulsation, a relatively large volume empty chamber is provided as a silencing chamber on the upstream side of the intake port of the supercharger, and the volume of intake air is rapidly expanded in the chamber, It is known to damp the above-mentioned inhalation pulsation.

In addition, if air containing a large amount of oil such as engine oil is sucked into the supercharger such as a vane pump, the grease on the bearing of the supercharger may be removed by the oil. There is an unfavorable effect on the durability of the supercharger, such as being washed out and accelerating the wear of the sealing member made of resin or carbon material.

By the way, in the internal combustion engine for a vehicle, when the unburned gas is directly introduced into the intake passage by the blow-by gas reducing device, the filter element is contaminated by the oil mixed in the gas or the carburetor is used. It may have an adverse effect, and it is indispensable to remove the oil component in blow-by gas not only in the internal combustion engine with a supercharger. For this reason, it has been conventionally practiced to provide an oil separator inside the head cover to remove oil, as disclosed in Japanese Utility Model Publication No. 55-37687.

<Problems to be Solved by the Invention> However, when a large amount of oil is contained in the blow-by gas, there is a possibility that the oil component not removed by the oil separator may be sucked into the supercharger. It is conceivable to provide a blow-by gas inlet for the air cleaner at the bottom of the cleaner case and an outlet for the air cleaner at the top of the cleaner case to prevent passage of oil.
You cannot always expect a sufficient effect.

Therefore, the present inventor can solve the above-mentioned problems and save space in the engine room by incorporating a structure for removing oil in a chamber for damping intake pulsation of a supercharger. I thought about it.

In view of such problems of the prior art and the findings of the inventor,
A main object of the present invention is to effectively remove oil in blow-by gas recirculated to an air cleaner, and at the same time, to effectively dampen intake pulsation of a supercharger, and an intake device in an internal combustion engine with a supercharger. To provide.

<Means for Solving the Problems> According to the present invention, such an object is to provide a pulsation absorbing inlet chamber provided between the downstream side of the air cleaner and the upstream side of the supercharger, and the downstream side of the air cleaner. Side casing and an upstream side of the inlet chamber, an intake device in a supercharged internal combustion engine having a blow-by gas returning passage connected to the inlet chamber, wherein the inlet chamber is a lower casing containing an oil adsorption filter. And an intake inlet provided on one side to be connected to the downstream side of the air cleaner, an intake outlet provided on the other side to be connected to the upstream side of the supercharger, and an intake air flow direction. An internal combustion engine with a supercharger, comprising: an upper casing that divides the interior and has a plurality of partition walls, each of which has an intake passage opening at a position that alternately rises and falls. This is accomplished by providing an intake system in the seki.

<Operation> As described above, the inlet chamber having a capacity capable of attenuating the intake pulsation of the supercharger is provided with the oil collecting means including the partition wall and the oil adsorption filter, so that the intake pulsation can be attenuated and the supercharger can be provided. Since it is possible to simultaneously prevent the oil content from entering, it is possible to save space in the engine room. In particular, since a plurality of partition walls having intake air inlets that are alternately opened in the upper and lower positions impart upward and downward bias to the intake air flow, the oil separated from the intake air flow reliably and sufficiently by synergizing with the oil separation effect by gravity. It is collected by the oil adsorption filter in the lower casing.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the accompanying drawings with reference to specific embodiments.

FIG. 1 shows a system diagram of the entire intake path of an internal combustion engine with a supercharger equipped with an adsorption device according to the present invention.

Air cleaner case 1 having an opening open to the atmosphere
A filter paper type filter element 2 is mounted inside the device to clean the air taken in. The air cleaned here is guided to the inlet chamber 4 through the conduit 3 and is sucked into the vane pump 5 as a supercharger.

The vane pump 5 compresses and discharges the intake air by the movement of the rotor 5a and the vane 5b driven by the crankshaft of the engine via the pulley and the belt, but the pulsation sound is generated because the intake flow velocity changes periodically. . Therefore, the inlet chamber 4 acts to reduce this pulsating sound by defining an air reservoir immediately before the pump suction port.

As shown in FIG. 2, the inlet chamber 4 has a perforated plate having openings in an upper casing 41 and a lower casing 42, which are generally box-shaped die-cast light alloy members having an opening in only one surface. By connecting via 43, a vacant room is defined inside. At the lower part of the upper casing 41, a cylindrical intake port 44 is provided so as to project outward, and is connected to the conduit 3 by, for example, a hose. Outlet 45
Are similarly projected outward and are connected to the suction port of the vane pump 5.

On the inner surface of the upper casing 41, a rib 46 as a partition wall having an intake air flow opening 46a on the upper side and a rib 47 as a partition wall having an air intake flow path 47a on the lower side so that the intake air flow meanders vertically. Are connected in the front-rear direction, that is, in the intake air circulation direction so as to extend in the left-right direction. Upper casing
A lateral rib 48 inclined upward as viewed from the intake air flow is provided at the bottom of the intake air intake port 45 side of 41 to prevent oil from staying on the intake air intake port 45 side. An oil adsorption filter 49 whose main component is a lipophilic synthetic resin is filled in the lower casing 42, and is exposed to the intake air flow in the upper casing 41 through the holes of the perforated plate 43.

Therefore, while the intake air flow meanders by the ribs 46 and 47 as baffle plates, the mixed oil droplets settle down, the oil component in the intake air flow is removed, and the oil component once settled is absorbed by the oil. Since it is captured by the filter 49, it is not mixed again in the intake air flow. When a large amount of oil stays in the lower casing 42, it can be drained by the drain plug 50 at the bottom of the lower casing 42.

Now, the intake air pressurized by the vane pump 5 produces a pulsating sound on the discharge side as well as on the intake side. However, by rapidly expanding the pressurized air in the outlet chamber 6, the discharge pulsation is absorbed. is doing.

The intake air compressed by the vane pump 5 has a relatively high temperature due to adiabatic change and is thermally expanded, so that the specific weight thereof is relatively small. However, according to the purpose of the supercharger, which attempts to fill the cylinder with as much intake air as possible, it is desirable that the specific weight of the intake air be large, and that the intake air temperature is excessively high. It is harmful for the normal operation of the vessel and also for the engine performance to cause knocking easily. Therefore, the intercooler 7 for cooling the discharge air is arranged downstream of the discharge port of the vane pump 5.

The intercooler 7 is a kind of heat exchanger in which a radiator core 70 is formed of a large number of flat tubes 72 and corrugated fins 73 connecting adjacent ones of the tubes 72, and the core 70 is an engine. The heat is attached to the portion of the room where the outside air circulates relatively, and as the compressed and heated intake air passes through the tube 72, its heat is transferred to the outside air passing through the core 70 and the corrugated fins 73 Will be emitted from the surface of.

The intake air cooled by the intercooler 7 is then fed into the surge tank 8 through the upper inlet 8a,
At this time, the discharge pulsation still remaining is further attenuated by the volume of the surge tank 8 together with the suction pulsation due to the reciprocating motion of the piston 10 in the engine 13 generated at the suction port of the carburetor 9. Further, the surge tank 8 is provided with a relief valve 11 as a pressure adjusting valve, and the pressure in the surge tank 8 causes the coil spring 1 that closes the relief valve body 11a.
When the spring force of 1b rises above the set value, excess air is released and the boost pressure is prevented from rising excessively.

Inlet inlet 8a and outlet 8b in the above surge tank 8
Are arranged with a height difference in the vertical direction,
The intake air sent from the inlet 8a provided on the upper surface of the surge tank 8 is introduced into the intake passage 9a of the carburetor 9 from the outlet 8b which is located at the lower part of the surge tank 8 and which is directly connected to the inlet of the carburetor 9. Be sent to. In this way, intake air inlets / outlets 8a, 8b
Since the fuel cells are arranged with a height difference between the upper and lower sides, even if there is a blowback from the carburetor 9, the fuel will stop below the surge tank 8 due to gravity and will not reach the supercharger 5. To be

The intake air pumped to the carburetor 9 in this manner is finally mixed with fuel in the carburetor 9 and the intake manifold 12,
According to the movement of the intake valve 14 of the engine 13, it is sent to the combustion chamber 15 above the cylinder. Naturally, the gas after combustion is discharged to the exhaust manifold 17 by the movement of the exhaust valve 16 and the piston 10.

In the case of an engine having a blow-by gas returning device, the blow-by gas in the crankcase is separated into oil by a labyrinth-shaped oil separator 21 provided inside the cylinder head, and then guided to the air cleaner case 1 through the breather tube 22. , Is again sucked into the combustion chamber 15 together with the intake air.

Although not shown, the breather passage according to the present invention is similar to the conventional one, for example, through a breather chamber provided inside the head cover of the engine and a blow-by gas passage, and an air cleaner case 1 (particularly, a filter element in the air cleaner case 1). It has a communication port that communicates with the inside of the downstream clean side).

In the case of the supercharger that is driven by the driving force of the crankshaft of the engine as described above, the intake air is constantly compressed, and supercharging is performed even when the throttle valve 18 is closed, especially when the load is low. However, there is an inconvenience that the pump load deteriorates fuel efficiency. Therefore, a bypass passage 20 having a control valve 19 that is interlocked with the throttle valve 18 connects the passage at a portion adjacent to the inlet 8a of the surge tank 8 to the conduit 3 so as to bypass the supercharger 5. In this way, at the time of low load of the engine in which the throttle valve 18 is substantially closed, the control valve 19 is opened and the surge tank 8 and the conduit 3 are communicated by the bypass passage 20 to increase the boost pressure. The load is returned upstream from the supercharger 5 to reduce the pump load when the load is low.

As described above, the present invention enables the damping of the suction pulsation of the supercharger and the prevention of the intrusion of the oil component into the supercharger. It is also possible to apply the present invention to prevent the entry of oil in Further, the supercharger in the embodiment of the present invention is not limited to a supercharger such as a vane pump driven by the crankshaft of the engine, but may be a so-called turbocharger of a type driven by an exhaust flow. .

<Effects of the Invention> As described above, according to the present invention, it is possible to simultaneously achieve the damping of the suction pulsation of the supercharger and the prevention of the oil component from entering the supercharger with a single empty chamber. Therefore, the space of the engine room can be saved. Moreover, since the intake flow is biased upward and downward by the plurality of partition walls having the intake flow passages opened alternately at the upper and lower positions, the oil separated from the intake flow reliably and sufficiently in synergy with the oil separation effect by gravity. It is collected by the oil adsorption filter in the lower casing. Therefore, the oil once separated does not mix with the intake flow again, so that the effect of preventing oil from entering the supercharger is enhanced and the durability of the supercharger is improved.

[Brief description of drawings]

FIG. 1 is an intake path system diagram of an engine including an intake device according to the present invention. FIG. 2 is an exploded perspective view showing the inlet chamber of FIG. 1 partially broken away. 1 ... Air cleaner case 2 ... Filter element 3 ... Conduit, 4 ... Inlet chamber 5 ... Vane pump, 6 ... Outlet chamber 7 ... Intercooler, 8 ... Surge tank 8a ... Inlet, 8b ... Outlet 9 ...... carburetor, 10 ...... piston 11 ...... relief valve, 12 ...... intake manifold 13 ...... engine, 14 ...... intake valve 15 ...... combustion chamber, 16 ...... exhaust valve 17 ...... exhaust manifold 18 ...... throttle Valve, 19 ...... Control valve 20 ...... Bypass passage, 21 ...... Oil separator 22 ...... Breazer tube 41, 42 ...... Casing 43 ...... Perforated plate, 44 ...... Intake inlet port 45 ...... Intake outlet port, 46, 47, 48 ... Ribs 49 ... Oil absorption filter 50 ... Drain plug, 70 ... Core 72 ... Tube, 73 ... Corrugated fin

Claims (1)

[Claims] 1. A pulsation absorbing inlet chamber 4 provided between a downstream side of an air cleaner 2 and an upstream side of a supercharger 5.
And a blow-by gas returning passage connected between the downstream side of the air cleaner and the upstream side of the inlet chamber.
An inlet device in an internal combustion engine with a supercharger, the inlet chamber being provided on one side so as to be connected to a lower casing 42 containing an oil adsorption filter 49 and a downstream side of the air cleaner. Intake inlet 44, intake outlet 45 provided on the other side so as to be connected to the upstream side of the supercharger, and the inside of the intake passage divided in the direction of intake air flow, and the intake air flow alternates up and down. Multiple partitions 46 with openings 46a and 47b respectively
And an upper casing (41) provided with (47) an intake device in an internal combustion engine with a supercharger.