JP2016135996A - Freezing preventive structure for blow-by gas pipe, internal combustion engine and freezing preventive method for blow-by gas pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freezing preventive structure for a blow-by gas pipe, in which freezing of the blow-by gas pipe for returning a blow-by gas from a crankcase of an engine to an intake system passage can be prevented by a relatively simple configuration, by utilizing not heat of the exhaust gas, heat of engine cooling water or electrical power, but heat inside a cylinder head of the engine, as a heat source for preventing freezing, and to provide an internal combustion engine and a freezing preventive method for the blow-by gas pipe.SOLUTION: In a freezing preventive structure for a blow-by gas pipe, a heat receiving passage 11c for heating a blow-by gas Gb is arranged in a cylinder head cover 21, and the freezing preventive structure is constituted of: first piping 11a for guiding the blow-by gas Gb from the cylinder head cover 21 to an external oil separation device 12; second piping 11b for guiding the blow-by gas Gb from the external oil separation device 12 to an inlet of the heat receiving passage 11c; and third piping 11d for guiding the blow-by gas Gb from an outlet of the heat receiving passage 11c to an intake system passage 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an anti-freezing structure for a blow-by gas pipe capable of preventing the freeze-by of a blow-by gas pipe (PCV pipe) for returning the blow-by gas from the crankcase of the engine to the intake system passage without requiring new energy. The present invention relates to an engine and a blow-by gas pipe freezing prevention method.

  In an engine, since the pressure of the mixed gas of intake air and fuel combusted in the combustion chamber is high, a part of the gas passes between the piston ring and the cylinder wall and leaks to the crank chamber side as blow-by gas. In order to process this blow-by gas, as shown in FIG. 4, blow-by gas pipes 11a and 11b for connecting the crank chamber on the engine 20 side and the intake pipe 30 are provided via the oil separator 13, and the blow-by gas is again supplied. It is circulated to the intake side of the engine 20 and burned in the combustion chamber.

  Since this blow-by gas contains a large amount of moisture, the blow-by gas pipe is cooled and the internal moisture freezes when the engine is stopped or when the engine is operated at a low load during severe cold weather in winter. It adheres as an ice block inside the gas pipe or the intake pipe to which the blow-by gas pipe is connected. In particular, in the intake pipe portion to which the blow-by gas pipe is connected, the blow-by gas is cooled while the blow-by gas flows through the inside of the blow-by gas pipe exposed to the outside air.

  When the adhering ice mass is peeled off when the engine starts or shifts to high-load operation, and mixed into the intake air and flows into the cylinder, the combustion in the cylinder deteriorates or the ice mass bites into the intake valve or the like. Since this causes damage to valves and the like, prevention of freezing of this blow-by gas pipe has been an important problem.

  In a blowby gas passage structure in which blowby gas leaking into the crankcase of the internal combustion engine is recirculated to the internal combustion engine through the intake passage, a first passage (blowby gas) for introducing the blowby gas into the intake passage downstream of the throttle valve. In order to heat the blow-by gas introduced into the intake passage at the connection portion of the intake passage of the pipe), a blow-by gas passage structure provided with a heater unit integrated with the intake passage is proposed. There has been proposed a blow-by gas passage structure in which a temperature-sensitive switch for turning on / off the energization of the heater according to the temperature is incorporated (see, for example, Patent Document 1).

  This heater unit heats the coil wire, and in order to reduce assembly man-hours, the heater is built in the intake manifold side of the intake port, and includes a connector for connecting the heater and the electric wire. It is integrated with the intake passage. In this heater unit, the assembly man-hour is reduced, but since the intake passage and the heater unit are manufactured integrally, there is a problem that the structure becomes complicated and the workability deteriorates.

  Also, a PCV passage is formed in the PCV hose with one end connected to the resin intake manifold and the other end connected to the cylinder head cover of the engine, and the resin intake manifold side union to which the PCV hose is connected is integrated with the intake manifold. An anti-freezing structure for a PCV passage provided for this purpose has been proposed (see, for example, Patent Document 2).

  In this anti-freezing structure for the PCV passage, a heating pipe is provided on the outer periphery of the PCV passage and heated by cooling water on the engine side, but there is a problem that the structure becomes complicated and the workability deteriorates.

  Further, a blow-by gas internal passage for guiding blow-by gas to the intake port of the cylinder head is provided in the cylinder head cover, and a discharge port for discharging the blow-by gas and a blow-by gas introduction port communicating with the blow-by gas internal passage are covered and communicated with each other. A gas-liquid separation chamber for separating the oil in the blow-by gas is provided upstream of the discharge port in the cylinder head cover, eliminating the need for engine external piping and reducing the moisture in the blow-by gas. There has been proposed a blow-by gas passage structure for an internal combustion engine that prevents icing and reduces the number of parts to make the engine compact (see, for example, Patent Document 3).

  However, in this blow-by gas passage structure of the internal combustion engine, since the blow-by gas is guided to the intake port in the blow-by gas internal passage in the cylinder head cover, the blow-by gas is passed through the compressor of the turbocharger in the engine with a turbo, There is a problem that an external oil separator cannot be used.

JP 2008-106637 A JP 2008-215191 A JP 2006-207437 A

  The present invention has been made in view of the above, and an object of the present invention is to use an anti-freezing of the blow-by gas pipe for returning the blow-by gas from the crankcase of the engine to the intake system passage as an anti-freezing heat source. Blow-by gas pipe anti-freezing structure that can prevent the blow-by gas pipe from freezing by using the heat inside the engine cylinder head, not the heat of the engine or the heat or power of the engine cooling water. An object of the present invention is to provide an internal combustion engine and a blow-by gas pipe freezing prevention method.

  In order to achieve the above object, the blow-by gas pipe freeze prevention structure of the present invention is a blow-by gas pipe freeze prevention structure for preventing the blow-by gas pipe from freezing to return the blow-by gas of the internal combustion engine to the intake system passage. A heat receiving passage for warming the blow-by gas is provided in the cylinder head cover, a first pipe for guiding the blow-by gas from the cylinder head or the cylinder head cover to the external oil separation device, and blow-by gas from the external oil separation device to the heat receiving passage. The second pipe leading to the inlet and the third pipe leading the blow-by gas from the outlet of the heat receiving passage to the intake passage. In other words, a heat receiving passage that passes through the cylinder head cover is provided between the second pipe and the third pipe.

  According to this configuration, inside the cylinder head cover, the blow-by gas after being once cooled by the external pipe and separated from the oil mist is warmed and then returned to the intake system passage, so that the exhaust gas is used as a heat source for preventing freezing. Efficient blow-by gas can be prevented and freezing can be prevented by using the internal heat of the cylinder head that transfers heat from the bottom to the top of the engine valve mechanism, etc. The blow-by gas pipe can be prevented from freezing with a relatively simple configuration in which the heat can be received by sufficient heat and a heat receiving passage is provided in the cylinder head cover.

  In addition, an external oil separator (external oil separator) can be used, and only a part of the blow-by gas pipe is replaced with a heat receiving passage in the cylinder head cover. There is no need to make major changes to the piping.

  In the blow-by gas pipe anti-freezing structure, when the third pipe is connected to the intake passage on the upstream side of the supercharging compressor, the blow-by gas can be sucked by the supercharging compressor, and the blow-by gas in the crank chamber is It becomes possible to suck out efficiently.

  In the anti-freezing structure of the blow-by gas pipe described above, the inlet of the heat receiving passage is formed on the side of the cylinder head cover on the same side as the side having the outlet for guiding the blow-by bus in the crank chamber to the first pipe. Is provided on the side surface of the cylinder head cover opposite to the side where the outlet leading to the first pipe is provided, and when the heat receiving passage is formed in a U shape, a heat receiving section capable of receiving heat can be provided long, The drastic change in the configuration of the piping for the blowby gas can be eliminated.

  In the above-described anti-freezing structure of the blow-by gas pipe, when the heat receiving passage and the cylinder head are partitioned by a metal plate, the heat receiving passage can be formed with a simple structure and simple work. The heat in the head can be efficiently transferred to the heat receiving passage.

  In order to achieve the above object, an internal combustion engine of the present invention is configured to include the above-described anti-freezing structure for blow-by gas pipes, and can achieve the same effects as the above-described anti-freezing structure for blow-by gas pipes.

  The blow-by gas pipe freeze prevention method of the present invention for achieving the above object is a blow-by gas pipe freeze prevention method for preventing the blow-by gas pipe from freezing to recirculate blow-by gas of an internal combustion engine to an intake system passage. The blow-by gas is guided to the external oil separator and then heated by using heat from the cylinder head in the heat receiving passage provided in the cylinder head cover to prevent the blow-by gas pipe from freezing. It is a method. According to this method, the same effect as the anti-freezing structure of the blow-by gas pipe can be obtained.

  According to the anti-freezing structure of the blow-by gas pipe, the internal combustion engine, and the anti-freezing method of the blow-by gas pipe of the present invention, the anti-freezing of the blow-by gas pipe that returns the blow-by gas from the crankcase of the engine to the intake system passage is prevented. By using not the heat of exhaust gas, the heat of engine cooling water, or the power as the heat source for the engine, but the heat inside the cylinder head of the engine, the blow-by gas pipe can be prevented from freezing with a relatively simple configuration.

It is a perspective view which shows typically the structure of the freeze prevention structure of the blowby gas pipe | tube of embodiment which concerns on this invention. It is the figure which shows typically the freeze prevention structure of the blow-by gas pipe of FIG. 1, and is the figure which looked at the cylinder head cover from the bottom. It is a figure which shows typically the antifreezing structure of the blowby gas pipe | tube of FIG. 1, and is AA sectional drawing of FIG. It is a figure which shows typically the structure of the blow-by gas pipe in a prior art.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a blow-by gas pipe anti-freezing structure, an internal combustion engine, and a blow-by gas pipe anti-freezing method according to embodiments of the present invention will be described with reference to the drawings. In addition, the internal combustion engine of embodiment which concerns on this invention is an internal combustion engine provided with the freezing prevention structure of the blowby gas pipe of embodiment which concerns on this invention.

  As shown in FIG. 1, a blowby gas pipe anti-freezing structure 10 according to an embodiment of the present invention has a blowby gas pipe 11 a for returning a blowby gas Gb of an internal combustion engine 20 to an intake pipe (intake system passage) 30. It is the freeze prevention structure of the blow-by gas pipe which prevents freezing of ˜11d.

  In this blowby gas pipe freezing prevention structure 10, a heat receiving passage 11 c for warming the blowby gas Gb is provided in the cylinder head cover 21, and the blowby gas Gb is transferred from the cylinder head (not shown) or the cylinder head cover 21 to the external oil separator 12. A first piping 11a for guiding, a second piping 11b for guiding the blow-by gas Gb from the external oil separator 12 to the inlet of the heat receiving passage 11c, and a third piping 11d for guiding the blow-by gas Gb from the outlet of the heat receiving passage 11c to the intake pipe 30 And consist of

  By providing the heat receiving passage 11c passing through the cylinder head cover 21 between the second pipe 11b and the third pipe 11d for the blow-by gas Gb, a significant change in the configuration of the conventional blow-by gas pipe is not required. . The first to third pipes 11a, 11b, and 11d are usually made of rubber, but may be made of synthetic resin or metal.

  In the heat receiving passage 11c, as shown in FIG. 2, the inlet of the heat receiving passage 11c is connected to the side surface 21a of the cylinder head cover 21 on the same side as the side having the outlet for guiding the blow-by bus Gb in the crank chamber to the first pipe 11a. The outlet of the heat receiving passage 11c is provided on the side surface 21b of the cylinder head cover 21 opposite to the side where the outlet leading to the first pipe 11a is located.

  At the same time, the heat receiving passage 11c is arranged along the side surface 21a of the cylinder head cover 21 on the inlet side of the heat receiving passage 11c, then traverses the inside of the cylinder head cover 21, and further, the side surface of the cylinder head cover 21 on the outlet side of the heat receiving passage 11c. The heat receiving passage 11c is formed in a U shape. With this configuration, a heat receiving section that can receive heat can be provided long.

  Further, as shown in FIG. 3, the heat receiving passage 11c and the cylinder head are partitioned by a metal plate 11cd. As a result, the heat receiving passage 11c can be formed with a simple structure and simple work, and the heat in the cylinder head can be efficiently transferred to the heat receiving passage 11c.

  Note that the thickness of the metal plate 11cd is sufficient to prevent the blow-by gas Gb from entering the cylinder head and structural strength is not required, so a thickness of about 0.5 mm to 2.0 mm is sufficient. Become. Moreover, heat conductivity can be improved by using a thin metal plate.

  Further, when the third pipe 11d is connected to the intake pipe 30 upstream of the supercharging compressor (not shown), the blowby gas Gb can be sucked by the supercharging compressor, and the blowby gas Gb in the crank chamber can be efficiently collected. Can be sucked out.

  Next, the freeze prevention method of the blowby gas pipe of embodiment which concerns on this invention is demonstrated. This method is an anti-freezing method for the blow-by gas pipes for preventing the blow-by gas pipes 11a to 11d from freezing to return the blow-by gas Gb of the engine 20 to the intake pipe 30. In this method, the blow-by gas Gb is removed from the outside. This is a method of preventing the blow-by gas pipes 11a to 11d from freezing by being heated using heat from the cylinder head in the heat receiving passage 11c provided in the cylinder head cover 21 after being guided to the attached oil separating device 12.

  According to the anti-freezing structure 10 for the blow-by gas pipe, the engine 20, and the anti-freezing method for the blow-by gas pipe having the above-described configuration, the cylinder head cover 21 is once cooled by the external pipes 11a and 11b to separate the oil mist. After the blow-by gas Gb is warmed, it is returned to the intake pipe 30 so that the heat source for freezing prevention is not from exhaust gas heat, engine cooling water heat or power but from the valve mechanism of the engine 20 from below. The blow-by gas Gb can be heated and received with sufficient heat to prevent freezing by utilizing the internal heat of the cylinder head that conducts heat upward, and the heat receiving passage 11c is provided in the cylinder head cover 21. The blowby gas pipes 11a to 11d can be prevented from freezing with a relatively simple configuration.

  Further, since the external oil separation device 12 can be used and only a part of the piping for the blow-by gas Gb is replaced with the heat receiving passage 11c in the cylinder head cover 21, the conventional blow-by gas Gb is used. There is no need to greatly change the pipes 11a and 11b for use.

  Therefore, the freezing prevention of the blowby gas pipes 11a to 11d for returning the blowby gas Gb from the crankcase of the engine 20 to the intake pipe 30 is used as a heat source for freezing, not the heat of exhaust gas or the heat or power of engine cooling water, By utilizing the heat inside the cylinder head of the engine 20, the blow-by gas pipes 11a to 11d can be prevented from freezing with a relatively simple configuration.

10 Blow-by gas pipe freezing prevention structure 11a First piping (blow-by gas pipe)
11b Second pipe (blow-by gas pipe)
11c Heat receiving pipe (blow-by gas pipe)
11d 3rd piping (blow-by gas pipe)
12 Oil separator 20 Engine (Internal combustion engine)
21 Cylinder head cover 30 Intake pipe (intake system passage)

Claims (6)

In the anti-freezing structure of the blow-by gas pipe for preventing freezing of the blow-by gas pipe for returning the blow-by gas of the internal combustion engine to the intake system passage,
A heat receiving passage for warming the blow-by gas is provided in the cylinder head cover, a first pipe for guiding the blow-by gas from the cylinder head or the cylinder head cover to the external oil separation device, and an inlet of the heat reception passage from the external oil separation device to the blow-by gas An anti-freezing structure for a blow-by gas pipe, comprising: a second pipe that leads to the intake pipe; and a third pipe that guides the blow-by gas from the outlet of the heat receiving passage to the intake system passage.   The blow-by gas pipe freezing prevention structure according to claim 1, wherein the third pipe is connected to an intake system passage on the upstream side of the supercharging compressor.   There is an outlet for guiding the outlet of the heat receiving passage to the first piping on the side of the cylinder head cover on the same side as the outlet where the outlet for guiding the blow-by bus in the crank chamber to the first piping is located. The blow-by gas pipe freezing prevention structure according to claim 2, wherein the structure is provided on a side surface of the cylinder head cover opposite to the side and the heat receiving passage is formed in a U-shape.   The blow-by gas pipe freezing prevention structure according to claim 3, wherein the heat receiving passage and the cylinder head are partitioned by a metal plate.   An internal combustion engine comprising the blow-by gas pipe freezing prevention structure according to any one of claims 1 to 4. In the freeze prevention method of the blowby gas pipe for preventing the freeze of the blowby gas pipe for returning the blowby gas of the internal combustion engine to the intake system passage,
After the blow-by gas is guided to the external oil separator, the blow-by gas pipe is prevented from freezing by being heated using heat from the cylinder head in a heat receiving passage provided in the cylinder head cover. To prevent freezing of blow-by gas pipes.

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