JP6776604B2 - Engine equipment - Google Patents

Description

The present invention relates to an engine device, and more particularly to a PCV (Positive Crankcase Ventilation) device that returns blow-by gas generated in the engine to an intake system.

Conventionally, a PCV device that returns blow-by gas leaked into the crankcase from a gap between a cylinder and a piston to an intake system has been put into practical use.

In a low temperature environment such as a cold region, when the pipe that recirculates the blow-by gas is cooled by the outside air, the water contained in the blow-by gas freezes and blocks the pipe, increasing the pressure inside the crankcase. , Oil leakage and other problems may occur.

As a technique focusing on such a problem, for example, in Patent Document 1, an inner pipe for circulating blow-by gas is inserted into an outer pipe for circulating engine cooling water to exchange heat with blow-by gas for engine cooling water. The structure is disclosed. Further, Patent Document 2 discloses a structure in which substantially the entire blow-by gas flow path is arranged so as to fit within the projection plane of the intake manifold to suppress cooling of the blow-by gas flow path due to running wind. ing.

Japanese Unexamined Patent Publication No. 11-315928 JP-A-2002-106429

By the way, in the technique described in Patent Document 1, since the engine cooling water is used, there is a possibility that the temperature drop of the blow-by gas cannot be sufficiently prevented from the start of the engine to the warm-up when the cooling water temperature is low. Further, since the technique described in Patent Document 2 has a structure in which only the influence of the running wind is taken into consideration, a sufficient effect may not be obtained in an extremely cold environment where the outside air temperature is extremely low.

The technique of the present disclosure aims to effectively prevent a temperature drop of blow-by gas.

The technique of the present disclosure includes a blow-by gas pipe that connects the blow-by gas outlet of the engine and the intake system of the engine to guide the blow-by gas generated by the engine to the intake system, and at least fuel from the injector of the engine. A fuel return pipe that returns a part to the fuel tank, and a fuel that flows in the fuel return pipe and a blow-by gas that flows in the blow-by gas pipe by arranging at least a part of the fuel return pipe adjacent to the blow-by gas pipe. It is characterized by including a heat exchange unit for heat exchange.

Further, the heat exchange unit may be configured by inserting at least a part of the fuel return pipe into the blow-by gas pipe in the pipe axial direction.

Further, fins for heat exchange may be provided on the outer peripheral surface of the fuel return pipe inserted into the blow-by gas pipe.

Further, the fuel return pipe may be inserted into the blow-by gas pipe so that the flow of fuel is opposite to the flow of blow-by gas in the blow-by gas pipe.

Further, an oil separator that is interposed in the blow-by gas pipe to separate oil from the blow-by gas may be further provided, and the fuel return pipe may be inserted into the blow-by gas pipe on the upstream side of the oil separator.

Further, an oil separator that is interposed in the blow-by gas pipe to separate oil from the blow-by gas is further provided, and the fuel return pipe is inside the blow-by gas pipe on the upstream side of the oil separator and on the downstream side of the oil separator. It may be inserted in both of the blow-by gas pipes.

According to the technique of the present disclosure, it is possible to effectively suppress a decrease in the temperature of blow-by gas.

It is a schematic whole block diagram which shows the PVC apparatus which concerns on one Embodiment of this invention. It is a schematic whole block diagram which shows the fuel injection system which concerns on one Embodiment of this invention. It is a schematic cross-sectional view which shows the heat exchange part which concerns on one Embodiment of this invention. It is a schematic diagram which shows the heat exchange part which concerns on other embodiment. It is a schematic diagram which shows the heat exchange part which concerns on other embodiment. It is a schematic cross-sectional view which shows the heat exchange part which concerns on other embodiment.

Hereinafter, an engine device according to an embodiment of the present invention will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

FIG. 1 is a schematic view illustrating the overall configuration of the PCV device 30 according to the present embodiment. A cylinder head 12 is provided above the cylinder block 11 of the diesel engine (hereinafter, simply engine) 10. A cylinder head cover 13 is provided on the upper portion of the cylinder head 12. The cylinder block 11 is provided with a crankcase portion 11A for accommodating a crankshaft (not shown), and an oil pan 14 for storing oil is provided below the crankcase portion 11A.

An intake manifold 14 and an exhaust manifold 15 are provided on the side of the cylinder head 12. An intake pipe 16 for introducing fresh air is connected to the intake manifold 14, and the intake pipe 16 is provided with a compressor 21 of a turbocharger 20, an intercooler 17, and the like in order from the intake upstream side. An exhaust pipe 18 for leading out exhaust gas is connected to the exhaust manifold 15, and the exhaust pipe 18 is provided with a turbine 22 of the turbocharger 20 and the like.

The PCV device 30 includes an oil separator 31 that separates oil from blow-by gas, a first blow-by gas pipe 32 that connects a blow-by gas outlet of the cylinder head cover 13 and a blow-by gas inlet of the oil separator 31, and an oil separator 31. A second blow-by gas pipe 33 that connects the blow-by gas outlet and the intake pipe 16 on the upstream side of the compressor 21, and a check valve PCV valve 34 provided adjacent to the blow-by gas outlet of the oil separator 31. It is provided with a return pipe 35 that connects the oil outlet portion of the oil separator 31 and the oil inlet portion of the cylinder block 11 and returns the oil separated by the oil separator 31 to the oil pan 14. In the present embodiment, the first blow-by gas pipe 32 is provided with a heat exchange unit 60, which will be described in detail later.

Next, the detailed configuration of the fuel injection system 40 according to the present embodiment will be described with reference to FIG. The fuel injection system 40 injects fuel into the fuel tank 41, the fuel suction pipe 42, the fuel filter 43, the feed pump 44A, the high pressure pump 44B, the fuel supply pipe 45, the common rail 46, and each cylinder. It includes a plurality of injectors 47A to D, a pressure control valve 48, and return pipes 49A and B.

The fuel tank 41 stores fuel (for example, light oil). One end of the fuel suction pipe 42 is immersed in the fuel in the fuel tank 41, and the other end is connected to the suction port of the feed pump 44A. The fuel filter 43 is interposed in the fuel suction pipe 42, and removes foreign substances in the fuel pumped by the feed pump 44A.

The feed pump 44A and the high pressure pump 44B are driven by the power of the engine 10. The feed pump 44A supplies the fuel pumped from the fuel tank 41 through the fuel suction pipe 42 to the high pressure pump 44B. The high-pressure pump 44B includes a plunger that is reciprocated by the rotation of a shaft (not shown), and pressurizes and discharges fuel by the reciprocating motion of the plunger. The high-pressure fuel pressurized by the high-pressure pump 44B is supplied to the common rail 46 via the fuel supply pipe 45.

The common rail 46 accumulates the high-pressure fuel supplied from the high-pressure pump 44B and distributes the high-pressure fuel to the injectors 47A to D via the fuel distribution pipes 46A to D. The injectors 47A to D are connected to the fuel tank 41 via the first fuel return pipe 49A, and excess fuel is returned from the first fuel return pipe 49A to the fuel tank 41. Further, the common rail 46 is provided with a pressure control valve 48 so that the excess high pressure fuel in the common rail 46 is returned from the second fuel return pipe 49B to the fuel tank 41 via the first fuel return pipe 49A. It has become.

In the present embodiment, the first fuel return pipe 49A for returning fuel from the injectors 47A to D to the fuel tank 41 is provided with a heat exchange unit 60.

More specifically, as shown in FIG. 3A, the heat exchange unit 60 is a first fuel return pipe 49A formed in the first blow-by gas pipe 32 with a diameter smaller than that of the first blow-by gas pipe 32. A part (for example, the upstream side) is inserted in the pipe axis direction. Preferably, as shown in FIG. 3B, a plurality of fins 61 for expanding the heat exchange area are provided on the outer peripheral surface of the first fuel return pipe 49A inserted in the first blow-by gas pipe 32. ing.

As described in detail above, according to the present embodiment, the first fuel return pipe 49A for circulating the high temperature return fuel is inserted into the first blow-by gas pipe 32, so that the first blow-by gas pipe 32 flows through the first blow-by gas pipe 32. The temperature of the blow-by gas is raised by heat exchange with the high-temperature return fuel, and the temperature drop of the blow-by gas can be effectively suppressed. Further, by providing a plurality of fins 61 (see FIG. 3B) on the outer peripheral surface of the first fuel return pipe 49A, the heat exchange area between the high temperature return fuel and the blow-by gas can be effectively secured. Therefore, freezing of blow-by gas can be reliably prevented.

The present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present invention.

For example, as shown in FIG. 4, the heat exchange unit 60 is formed by branching the first fuel return pipe 49A and forming a rubber hose or the like between the two branched first fuel return pipes 49A. The first blow-by gas pipe 32 may be sandwiched and configured. In this case as well, the same effects as those in the above embodiment can be obtained.

Further, as shown in FIG. 5, the heat exchange unit 60 can be applied to both the first blow-by gas pipe 32 and the second blow-by gas pipe 33. In this case, the first fuel return pipe 49A may be curved in a substantially U shape and inserted into the first and second blow-by gas pipes 32 and 33, respectively. With this configuration, the blow-by gas is heated by the high-temperature return fuel in two stages, the upstream side and the downstream side of the oil separator 31, and the temperature drop and freezing of the blow-by gas are more effectively prevented. Will be possible.

Further, as shown in FIGS. 6A and 6B, the first fuel return pipe 49A is inserted so that the return fuel flows in the opposite direction to the flow of the blow-by gas in the first blow-by gas pipe 32. May be configured. By flowing the return fuel and the blow-by gas in opposite directions in this way, the high-temperature return fuel before heat exchange can be applied to the low-temperature blow-by gas on the downstream side, and the effect of raising the temperature of the blow-by gas is surely improved. can do.

Further, the portion to which the heat exchange unit 60 is applied is not limited to the first fuel return pipe 49A for returning fuel from the injectors 47A to D, and can also be applied to the second fuel return pipe 49B for returning fuel from the common rail 46. ..

Further, the engine 10 is not limited to a diesel engine, and can be widely applied to other engines such as a gasoline engine.

10 Engine 11 Cylinder block 12 Cylinder head 13 Cylinder head cover 14 Intake manifold 15 Exhaust manifold 16 Intake pipe 17 Intercooler 18 Exhaust pipe 20 Turbocharger 21 Compressor 22 Turbine 30 PCV device 31 Oil separator 32 1st blow-by gas piping 33 2nd blow-by gas Piping 40 Fuel injection system 41 Fuel tank 42 Fuel suction piping 43 Fuel filter 44A Feed pump 44B High pressure pump 45 Fuel supply piping 46 Common rail 47A to D injector 48 Pressure control valve 49A, B Return piping 60 Heat exchange part 61 Fins

Claims (4)

A blow-by gas pipe that connects the blow-by gas outlet of the engine and the intake system of the engine and guides the blow-by gas generated by the engine to the intake system.
A fuel return pipe that returns at least part of the fuel from the engine injector to the fuel tank,
An oil separator that is interposed in the blow-by gas pipe to separate oil from the blow-by gas,
At least a part of the fuel return pipe is inserted into the blow-by gas pipe in the pipe axis direction to exchange heat between the fuel flowing in the fuel return pipe and the blow-by gas flowing in the blow-by gas pipe. With a part ,
The fuel return pipe is inserted into a blow-by gas pipe on the upstream side of the oil separator, and the blow-by gas flowing on the upstream side of the oil separator is heated by a fuel having a temperature higher than that of the blow-by gas. Engine device. A blow-by gas pipe that connects the blow-by gas outlet of the engine and the intake system of the engine and guides the blow-by gas generated by the engine to the intake system.
A fuel return pipe that returns at least part of the fuel from the engine injector to the fuel tank,
An oil separator that is interposed in the blow-by gas pipe to separate oil from the blow-by gas,
At least a part of the fuel return pipe is inserted into the blow-by gas pipe in the pipe axis direction to exchange heat between the fuel flowing in the fuel return pipe and the blow-by gas flowing in the blow-by gas pipe. With a part,
The blow-by gas and the oil that are inserted into both the blow-by gas pipe on the upstream side of the oil separator and the blow-by gas pipe on the downstream side of the oil separator and flow on the upstream side of the oil separator. Both blow-by gas flowing downstream of the separator is heated by a fuel having a temperature higher than that of the blow-by gas.
An engine device characterized by that . The engine device according to claim 1 or 2, wherein a fin for heat exchange is provided on an outer peripheral surface of the fuel return pipe inserted into the blow-by gas pipe. The invention according to any one of claims 1 to 3, wherein the fuel return pipe is inserted into the blow-by gas pipe so that the flow of fuel is opposite to the flow of blow-by gas in the blow-by gas pipe. Engine device.

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