VENTILATION CHAMBER STRUCTURE FOR INTERNAL COMBUSTION ENGINE

Abstract

Vent chamber structure for an internal combustion engine, wherein the vent chamber structure is applicable to a vent chamber (90) for the temporary storage in an internal combustion engine (1) of blow-by gas (G) generated during the operation of the internal combustion engine (1) and which is to be returned to an inlet channel, wherein the vent chamber structure in the vent chamber (90) has a two-stage section (80) formed by a first plate (60) and a second plate (70) attached to the rear surface of a cylinder head cover (2) attached to a cylinder head (3) of the internal combustion engine (1) and which are parallel to and spaced apart from each other, wherein the two-stage section (80) has a first chamber (A) and a second chamber (B) which are subdivided by the first plate (60). characterized by the fact that the venting chamber (90) comprises the first chamber (A) into which the blow-by gas (G) is first introduced, the second chamber (B) into which the blow-by gas (G) is introduced from the first chamber (A), and a third chamber (C) into which the blow-by gas (G) is introduced from the second chamber (B), the third chamber (C) is arranged on a lateral side of the two-stage section (80), the third chamber (C) is provided with an outlet pipe (31) that directs the blow-by gas (G) to the outside of the internal combustion engine (1), and a height dimension of the third chamber (C) is greater than a height dimension of each of the first chamber (A) and the second chamber (B).

Description

[0001] The present invention relates to a venting chamber structure for an internal combustion engine and, in particular, to a venting chamber structure for an internal combustion engine for temporarily storing blow-by gas generated during operation of the internal combustion engine and returning it to an inlet channel.

[0002] In recent years, research and development have been conducted to improve fuel efficiency, thereby increasing energy efficiency and ensuring that many people have access to affordable, reliable, sustainable, and modern energy. In this context, it is known to incorporate a venting chamber into a design for the recirculation of blow-by gas generated during the operation of an internal combustion engine. This chamber allows for the temporary storage of the blow-by gas within the engine, thus simplifying the oil separation process.

[0003] JP 2008- 223 596 A discloses a technology of providing a vent chamber as a storage space surrounded by a cylinder head cover attached to an upper area of ​​a cylinder head of an internal combustion engine and by a plate attached to a rear surface side of the cylinder head cover.

[0004] Furthermore, in the present technology, it is desirable for improving fuel efficiency to increase the channel length in a venting chamber in order to simplify the separation of oil from blow-by gas and to allow a larger quantity of clean fuel to be returned to an inlet channel. However, in order to provide a venting chamber with a longer channel length by using a single plate, as in JP 2008-223596A, the plate must be designed in a complex shape.

[0005] To overcome the aforementioned disadvantage, an objective of the present invention is to provide a ventilation chamber structure for an internal combustion engine designed to increase the channel length within a ventilation chamber with a simple structure. The present invention thus also contributes to an increase in energy efficiency.

[0006] JP 2006- 283 594 A and US 7 210 471 B2 each disclose a venting chamber structure for an internal combustion engine according to the preamble of independent claim 1.

[0007] To achieve the above objective, the present invention has a first feature directed to a venting chamber structure for an internal combustion engine, wherein the venting chamber structure is applicable to a venting chamber (90) for the temporary storage in an internal combustion engine (1) of blow-by gas (G) generated during the operation of the internal combustion engine (1) and which is to be returned to an inlet channel. The venting chamber structure has a two-stage section (80) in the venting chamber (90) formed by a first plate (60) and a second plate (70) which are attached to the rear surface of a cylinder head cover (2) attached to a cylinder head (3) of the internal combustion engine (1) and which are parallel to and spaced apart from each other, wherein the two-stage section (80) has a first chamber (A) and a second chamber (B) which are subdivided by the first plate (60).

[0008] According to the first feature, the venting chamber (90) further comprises the first chamber (A) into which the blow-by gas (G) is first introduced, the second chamber (B) into which the blow-by gas (G) is introduced from the first chamber (A), and a third chamber (C) into which the blow-by gas (G) is introduced from the second chamber (B), the third chamber (C) being arranged on a lateral side of the two-stage section (80), the third chamber (C) being provided with an outlet pipe (31) that discharges the blow-by gas (G) to the outside of the internal combustion engine (1), and a height dimension of the third chamber (C) being greater than a height dimension of each of the first chamber (A) and the second chamber (B).

[0009] The present invention has a second feature in that the venting chamber structure further comprises an exchange channel (20) which establishes the exchange between the second chamber (B) and the third chamber (C), and the outlet pipe (31) is arranged in a position where the outlet pipe (31) does not overlap the exchange channel (20) when viewed in a direction from the third chamber (C) to the second chamber (B).

[0010] The present invention has a third feature in that a lower end of the outlet pipe (31) is located at a position lower than the first plate (60) in a side view of the internal combustion engine (1).

[0011] Furthermore, the present invention has a fourth feature in that the second plate (70) has a larger area than the first plate (60).

[0012] The first feature makes it possible to increase the channel length in the vent chamber by providing the two-stage section in the vent chamber through a simple design in which the two plates are attached to the rear surface of the cylinder head cover, since the vent chamber structure for an internal combustion engine, which is applicable to a vent chamber (90) for temporarily storing in the internal combustion engine (1) of blow-by gas (G) generated during the operation of the internal combustion engine (1) and which is to be returned to an inlet channel, has a two-stage section (80) in the vent chamber (90) formed by a first plate (60) and a second plate (70) which are attached to the rear surface of a cylinder head cover (2) attached to a cylinder head (3) of the internal combustion engine (1) and which are parallel to and spaced apart from each other, and which has the first chamber (A) and the second chamber (B),which are subdivided by the first plate (60). It is therefore possible to promote oil separation of the blow-by gas.

[0013] The first feature further makes it possible to reduce the amount by which the exhaust pipe provided in the third chamber protrudes from a surface of the cylinder head cover, since the venting chamber (90) has the first chamber (A) into which the blow-by gas (G) is first introduced, the second chamber (B) into which the blow-by gas (G) is introduced from the first chamber (A), and the third chamber (C) into which the blow-by gas (G) is introduced from the second chamber (B), wherein the third chamber (C) is arranged on a lateral side of the two-stage section (80), the third chamber (C) is provided with the exhaust pipe (31) which discharges the blow-by gas (G) to the outside of the internal combustion engine (1), and the height dimension of the third chamber (C) is greater than the height dimension of each of the first chamber (A) and the second chamber (B).

[0014] The second feature makes it possible to increase the channel length from the second chamber to the outlet pipe of the third chamber, since the exchange channel (20) which establishes the exchange between the second chamber (B) and the third chamber (C) is included, and the outlet pipe (31) is arranged in a position where the outlet pipe (31) does not overlap the exchange channel (20) when viewed in a direction from the third chamber (C) to the second chamber (B).

[0015] The third feature makes it possible to increase the channel length in order to reduce the amount by which the exhaust pipe protrudes from the cylinder head cover, and also to reduce the size of the cylinder head cover, since the lower end of the exhaust pipe (31) in a side view of the internal combustion engine (1) is located in a position below that of the first plate (60).

[0016] The fourth feature makes it easy to configure the first chamber, the second chamber and the third chamber in the vent chamber and to prevent incorrect assembly when the cylinder head cover is fitted, since the area of ​​the second plate (70) is larger than the area of ​​the first plate (60). Fig. Figure 1 is a right-side view of an internal combustion engine to which a ventilation chamber structure according to a present embodiment is applied; Fig. Figure 2 is a top view of a cylinder head cover as seen from the top of the internal combustion engine; Fig. 3 is a view from the rear of the cylinder head cover, viewed from a rear surface side; Fig. Figure 4 is a schematic view showing the structure of a venting chamber according to the present embodiment; Fig. Figure 5 is a rear view showing a state in which a first plate is attached to the cylinder head cover; Fig. 6 is a rear view showing a state in which a second plate is attached to the cylinder head cover; Fig. 7 is a sectional view along line VII-VII of Fig. 6; Fig. 8 is a sectional view along line VIII-VIII of Fig. 6, and Fig. Figure 9 is a sectional view along line IX-IX of Fig. 6.

[0017] A preferred embodiment of the present invention is described in detail below with reference to the drawings. Fig. Figure 1 is a right-side view of an internal combustion engine 1 to which a ventilation chamber structure according to the present embodiment is applied. The internal combustion engine 1 according to the present embodiment is a 4-stroke, 2-cylinder in-line engine used as a drive unit for a saddle-seat vehicle. The internal combustion engine 1 is mounted on the saddle-seat vehicle in the position shown, and the directional arrows in the drawing indicate the position of the saddle-seat vehicle with the internal combustion engine 1 mounted on it.

[0018] A cylinder 4, which accommodates a piston that slides up and down along a cylinder axis O, is integrally formed with an upper portion of a crankcase 5, which accommodates a crankshaft and a gearbox. A cylinder head 3, which accommodates an intake / exhaust mechanism comprising an intake / exhaust valve, a camshaft, and the like, is attached to an upper portion of the cylinder 4, and a cylinder head cover 2 (area shown in gray in the drawing) is attached to an upper portion of the cylinder head 3.

[0019] An exhaust pipe 31 for venting blow-by gas generated during the operation of the internal combustion engine 1 to the outside is attached to an upper area of ​​the cylinder head cover 2, which is formed from a thin plate element, such as a metal, a synthetic resin or the like. A ventilation chamber, to which the ventilation chamber structure according to the present embodiment is applied, is formed in the cylinder head cover 2.

[0020] Fig. Figure 2 is a top view of a cylinder head cover 2 as seen from the top of the cylinder axis of the internal combustion engine 1. Likewise, Fig. Figure 3 shows a rear view of the cylinder head cover 2 from a rear surface. Three through-holes 11, through which screws for fastening the cylinder head cover 2 to the cylinder head 3 pass, and two through-holes 10, through which the spark plugs pass, are formed in the cylinder head cover 2. A continuation area 12, extending forward in a manner corresponding to the shape of a timing chain tunnel provided in the cylinder head 3, is formed at the left end of the cylinder head cover 2.

[0021] An exchange channel 20, which establishes an exchange between a second chamber and a third chamber in the venting chamber (as described later), is formed on a left-hand sloping front face of the passage opening 11 in the center. The exchange channel 20 is provided in a partition wall 21 that separates the second chamber from the third chamber. A cover is placed on the passage opening by a cap element (see Fig. 9) is installed when the cylinder head cover 2 is assembled. An exhaust port 30, to which the exhaust pipe 31 is attached, is formed on a left sloping front face of the exchange channel 20.

[0022] With reference to Fig. In the ventilation chamber structure according to the present embodiment, a ventilation chamber comprising a first chamber, a second chamber, and a third chamber is formed by two plates attached to the rear surface of the cylinder head cover 2, such that the two plates are parallel to and spaced apart from each other. An inner rib 42 (the obliquely dashed area in the drawing), which serves as a support for the attachment of a first plate, and an outer rib 40, which serves as a support for the attachment of a second plate, are formed on the rear surface of the cylinder head cover 2.

[0023] In the present embodiment, the second chamber is configured by having the first plate rest against and be attached to the inner rib 42, and the first and third chambers are configured by the second plate, which rests against and is attached to the outer rib 40. Four partitions 50, to provide labyrinthine structures in the first and second chambers, are integrally formed with the outer rib 40.

[0024] Fig. Figure 4 is a schematic view illustrating the structure of the vent chamber according to the present embodiment. As described above, in the present invention, the vent chamber 90, comprising the first chamber A, the second chamber B, and the third chamber C, is formed by the first plate 60 (the gray area in the drawing) and the second plate 70 (the dotted area in the drawing), which are attached to the rear surface of the cylinder head cover 2, such that the first plate 60 and the second plate 70 are parallel to and spaced apart from each other.

[0025] In the present embodiment, the design of the venting chamber 90, consisting of three spaces, enables the efficient absorption of pressure fluctuations in the blow-by gas G and the efficient separation of the oil from the blow-by gas G. The first plate 60 and the second plate 70 are made of thin plate elements with constant thicknesses.

[0026] The first chamber A and the second chamber B, subdivided by the first plate 60, are stacked in the direction of the cylinder axis O, forming a two-stage section 80. The third chamber (C) is arranged on a lateral side of the two-stage section (80). The blow-by gas G, introduced into the first chamber A from a space provided between the cylinder head cover 2 and the first plate 60, is guided to the second chamber B via the plurality of openings 62 provided in the first plate 60. The blow-by gas G introduced into the second chamber B is guided to the third chamber C via the exchange channel 20 provided in the partition 21. The blow-by gas G introduced into the third chamber C is directed to a portion below the exhaust pipe 31, which is attached to the exhaust port 30, and is then discharged to the outside of the internal combustion engine 1 via the exhaust pipe 31.

[0027] Fig. Figure 5 is a rear view showing the state in which the first plate 60 is attached to the cylinder head cover 2. Although the first plate 60 is made of metal, a synthetic resin, or the like, it is shown in the drawing as a semi-transparent element colored gray for illustrative purposes.

[0028] The second chamber B of the vent chamber 90 is formed by attaching the first plate 60 to the cylinder head cover 2. The first plate 60 is fastened with two screws 61. Three openings 62 are formed in the first plate 60, and the blow-by gas G, which flows to the second chamber B from the first chamber A (see Fig. 4) is guided through the openings 62, flows through the labyrinth structure formed by the partitions 50, and is then directed to the exchange channel 20. The blow-by gas G, guided from an upper end of the third chamber C through the exchange channel 20, is introduced from the bottom of the outlet pipe 31 and is then discharged upwards. In this way, a variety of structures for increasing the channel length in the venting chamber 90 are also applied to the portion from the second chamber B to the third chamber C.

[0029] Fig. Figure 6 is a rear view showing the state in which the second plate 70 is attached to the cylinder head cover 2. Although the second plate 70 is made of metal, a synthetic resin, or a similar material, the first plate 70 is shown in the drawing, for illustrative purposes, as a semi-transparent element hatched with dots. The second plate 70, with a larger surface area than the first plate 60, completely covers the first plate 60 and, in particular, has a shape with dimensions that extend to the left.

[0030] The first chamber A and the third chamber C of the ventilation chamber 90 are formed by attaching the second plate 70 in contact with a ceiling surface of the outer rib 40. The second plate 70 is fastened with three screws 71. The first chamber A is in contact with a horizontally elongated area A1, which is adjacent to a rear surface (the bottom in the drawing) in the third chamber.

[0031] The blow-by gas G generated during the operation of the internal combustion engine 1 is directed to the first chamber A through gaps provided between the outer rib 40 and the second plate 70. These gaps comprise a first gap 90 located at the right rear end of the first chamber A and a second gap 91 located at the left end of the extended area A1. The blow-by gas G introduced into the first chamber A from the first gap 90 and the second gap 91 is guided into the openings 62 in the first plate 60 via the labyrinthine structure formed by the partitions 50.

[0032] Fig. 7 is a sectional view along line VII-VII of Fig. 6. As described above, the present invention is characterized in that the vent chamber 90, which has the two-stage section 80 comprising the first chamber A and the second chamber B, is formed by the first plate 60, which is fastened by the screws 61, and by the second plate 70, which is fastened by the screws 71 to the rear surface of the cylinder head cover 2. In this way, it is possible to provide that the two-stage section 80 in the vent chamber 90 increases the channel length in the vent chamber and promotes oil separation from the blow-by gas G with a simple design in which the two plates are attached to the rear surface of the cylinder head cover 2.

[0033] Fig. 8 is a sectional view along line VIII-VIII of Fig. 6. With reference to Fig. The third chamber C is arranged to be adjacent to the left side of the two-stage section 80, which comprises the first chamber A and the second chamber B. The height dimension of the third chamber C in the cylinder axis direction is set to be greater than the height dimension of both the first chamber A and the second chamber B. This reduces the amount by which the exhaust pipe 31 provided in the third chamber C protrudes from the surface of the cylinder head cover 2.

[0034] Furthermore, the outlet pipe 31 is arranged in a position where the outlet pipe 31 is separated from the exchange channel 20 (see Fig. 5) The channels deviate forward and backward and do not overlap in the direction of the second chamber B when viewed from the third chamber C. It is therefore possible to extend the channel from the second chamber B to the exhaust pipe 31 in the third chamber C. Furthermore, the lower end of the exhaust pipe 31 is positioned lower than the first plate 60, thus making it possible to extend the channel to reduce the amount by which the exhaust pipe 31 protrudes from the cylinder head cover 2 and to reduce the size of the cylinder head cover 2.

[0035] Fig. Figure 9 is a sectional view along line IX-IX of Fig.6. The exchange channel 20 is formed from a through-opening provided by cutting out the top of the cylinder head cover 2, and a cover is placed on it as a cap element 22. In this way, the blow-by gas G flows through a gap provided between a bottom surface of the cap element 22 and a top surface of the partition 21.

[0036] As described above, according to the vent chamber structure for an internal combustion engine of the present embodiment, it is possible to provide the two-stage section in the vent chamber 90 to increase the channel length in the vent chamber and to promote the oil separation from the blow-by gas with a simple design in which the two plates are attached to the rear surface of the cylinder head cover 2, since the vent chamber 90, which has the two-stage section 80, has the first chamber A and the second chamber B, which are subdivided by the first plate 60, wherein the first plate 60 and the second plate 70 are attached to the rear surface of the cylinder head cover 2, which is attached to the cylinder head 3 of the internal combustion engine 1, such that the first plate 60 and the second plate 70 are parallel to each other and spaced apart from each other.

[0037] It should be emphasized that the shape of the internal combustion engine, the shape of the cylinder head cover, the shapes of the first chamber, the second chamber and the third chamber, the shape of the partitions for providing the labyrinth structures, the shapes and materials of the first plate and the second plate, the mounting structure of the first plate and the second plate and similar features are not limited to those in the above embodiment and various modifications can be made.

[0038] Although in the above embodiment each of the first and second plates is fastened with screws, a structure can be used, for example, in which no screw fastening structure is used for the first plate and the second plate is fastened with screws, while the first plate is pressed against a rib that serves as a support for the second plate. With this design, it is possible to reduce the number of screws and to create labyrinthine structures through the rib for pressing the first plate. The venting chamber structure according to the present invention can be applied not only to an internal combustion engine installed in a saddle-seat vehicle such as a motorcycle or a three-wheeled vehicle, but also to various internal combustion engines used as propulsion sources for a ship, a cultivator, and the like. List of reference symbols:

[0039] 1...Internal combustion engine, 2...Cylinder head cover, 3...Cylinder head, 20...Exchange channel, 31...Exhaust pipe, 60...First plate, 70...Second plate, 80...Two-stage section, 90...Ventilation chamber, G...Blow-by gas, A...First chamber, B...Second chamber, C...Third chamber

Claims

[1] Vent chamber structure for an internal combustion engine, wherein the vent chamber structure is applicable to a vent chamber (90) for the temporary storage in an internal combustion engine (1) of blow-by gas (G) generated during the operation of the internal combustion engine (1) and which is to be returned to an inlet channel, wherein the vent chamber structure in the vent chamber (90) has a two-stage section (80) formed by a first plate (60) and a second plate (70) attached to the rear surface of a cylinder head cover (2) attached to a cylinder head (3) of the internal combustion engine (1) and which are parallel to and spaced apart from each other, wherein the two-stage section (80) has a first chamber (A) and a second chamber (B) which are subdivided by the first plate (60). characterized by , that the venting chamber (90) comprises the first chamber (A) into which the blow-by gas (G) is first introduced, the second chamber (B) into which the blow-by gas (G) is introduced from the first chamber (A), and a third chamber (C) into which the blow-by gas (G) is introduced from the second chamber (B), the third chamber (C) is arranged on a lateral side of the two-stage section (80), the third chamber (C) is provided with an outlet pipe (31) that directs the blow-by gas (G) to the outside of the internal combustion engine (1), and a height dimension of the third chamber (C) is greater than a height dimension of each of the first chamber (A) and the second chamber (B). [2] Venting chamber structure according to claim 1, further comprising: an exchange channel (20) that establishes an exchange between the second chamber (B) and the third chamber (C), wherein the outlet pipe (31) is arranged in a position where the outlet pipe (31) does not overlap with the exchange channel (20) when viewed in a direction from the third chamber (C) to the second chamber (B). [3] Vent chamber structure according to claim 2, wherein a lower end of the outlet pipe (31) is located at a position lower than the first plate (60) in a side view of the internal combustion engine (1). [4] Venting chamber structure according to one of claims 1 to 3, wherein the second plate (70) has a larger area than the first plate (60).

Images