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JP-2026075989-A - engine

JP2026075989AJP 2026075989 AJP2026075989 AJP 2026075989AJP-2026075989-A

Abstract

[Problem] To provide a technology that enables cooling or lubrication of engine components with a relatively simple configuration. [Solution] A four-stroke engine comprising: a ring gear member supported by a crankcase and having teeth on its inner circumference; a rotating member rotatably supported by a crank pin of the crankshaft and having teeth on its outer circumference that mesh with the teeth of the ring gear member; and a connecting rod having one end pivotably connected to a piston and the other end pivotably connected to a boss portion provided on the rotating member at an eccentric position from the rotation center of the rotating member, wherein the crankcase has a groove portion into which oil is supplied, and the ring gear member covers the groove portion into the crankcase and has at least one communicating portion that connects the groove portion to the inside of the crankcase. [Selection Diagram] Figure 1

Inventors

  • 長 正樹
  • 窪田 大輔
  • 伊能 悟

Assignees

  • 本田技研工業株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (14)

  1. A crankcase (2) that supports the crankshaft (7), A cylinder block (3) having a bore (30) housing a piston (5), A ring gear member (8) is supported by the crankcase (2) and has teeth (81) on its inner circumference, A rotating member (10) is rotatably supported by the crank pin (75) of the crankshaft (7) and has teeth on its outer circumference that mesh with the teeth (81) of the ring gear member (8), A connecting rod (6) having one end (60) that is pivotably connected to the piston (5), and the other end (61) that is pivotably connected to a boss portion (12) provided on the rotating member (10) at a position eccentric from the rotation center of the rotating member (10), A four-stroke engine (1) equipped with, The crankcase (2) has a groove (21) formed in it into which oil is supplied. The ring gear member (8) covers the groove (21) with respect to the inside of the crankcase (2) and has at least one communication portion (82-85) that allows the groove (21) to communicate with the inside of the crankcase (2). An engine characterized by the following features.
  2. The engine (1) according to claim 1, The at least one of the communication portions includes communication portions (83, 85) that expose a portion of the groove portion (21) into the crankcase (2), An engine characterized by the following features.
  3. The engine (1) according to claim 1, The at least one communication portion includes a first injection port (82) for injecting oil, The first nozzle (82) is Located in the axial direction of the bore (30) between the crankshaft (7) and the piston (5), In the radial direction of the bore (30), within the range of the width (W) of the bore (30), An engine characterized by the following features.
  4. The engine (1) according to claim 3, The first nozzle (82) is In the axial direction of the bore (30), it is directed toward the side of the bore (30), and The bore (30) is directed more towards the center than outward in the radial direction. An engine characterized by the following features.
  5. The engine (1) according to claim 1, The at least one of the communication sections has a second injection port (83) for injecting oil, The second injection nozzle (83) is formed in the upper part when the engine (1) is installed. An engine characterized by the following features.
  6. The engine (1) according to claim 1, The teeth (81) of the ring gear member (8) have a first tooth and a second tooth adjacent to the first tooth. The at least one communication portion is the gap between the first tooth and the second tooth, and includes a third nozzle (85) for spraying oil. An engine characterized by the following features.
  7. The engine (1) according to claim 1, The at least one communication portion is formed on the tooth root (81a) of the tooth portion (81) of the ring gear member (8) and includes a fourth injection port (84) for injecting oil. An engine characterized by the following features.
  8. The engine (1) according to claim 6, A gasket (50) is placed between the crankcase (2) and the ring gear member (8). The groove (21) is formed in the portion that overlaps with the gasket (50), The teeth (81) of the ring gear member (8) have a first tooth and a second tooth adjacent to the first tooth. The at least one communicating portion includes the gap between the first tooth and the second tooth, The gasket (50) has a portion that overlaps with the gap and has a hole (54) in that portion that forms a third injection port (85') for injecting oil. An engine characterized by the following features.
  9. The engine (1) according to claim 6 or claim 8, The torque generated in the rotating member (10) is The rotational member (10) reaches its maximum position when it is located at the first portion (P01-P03) of the ring gear member (8). The minimum value is reached when the rotating member (10) is positioned at the second portion (P11-P13) of the ring gear member (8). The third nozzle (85,85') is formed closer to the first portion (P01-P03) than the second portion (P11-P13). An engine characterized by the following features.
  10. The engine (1) according to claim 7, The torque generated in the rotating member (10) is The rotational member (10) reaches its maximum position when it is located at the first portion (P01-P03) of the ring gear member (8). The minimum value is reached when the rotating member (10) is positioned at the second portion (P11-P13) of the ring gear member (8). The fourth nozzle (84) is formed closer to the second portion (P11-P13) than to the first portion (P01-P03). An engine characterized by the following features.
  11. The engine (1) according to claim 6 or claim 8, Multiple third injection ports (85, 85') are formed at 120-degree intervals in the circumferential direction of the ring gear member (8). An engine characterized by the following features.
  12. The engine (1) according to claim 7, Multiple of the fourth injection nozzles (84) are formed at 120-degree intervals in the circumferential direction of the ring gear member (8). An engine characterized by the following features.
  13. The engine (1) according to claim 1, In the axial direction of the bore (30), the edge (8b) of the end (8a) of the ring gear member (8) is located closer to the bore (30) than the edge (5a) of the piston (5) at bottom dead center. An inclined surface (86) is formed on the end portion (8a) of the ring gear member. The at least one communication portion is formed on the inclined surface (86) and includes a first injection port (82') for injecting oil. An engine characterized by the following features.
  14. The engine (1) according to claim 13, A recess (87) is formed in the inclined surface (86). The first injection nozzle (82') is formed within the recess (87). An engine characterized by the following features.

Description

This invention relates to a four-stroke engine. Research and development on reducing carbon dioxide emissions is being continuously conducted with the aim of mitigating and reducing the impact of climate change. As one such initiative, the Atkinson cycle engine has been proposed, which attempts to improve thermal efficiency by varying the piston stroke between strokes to enhance combustion efficiency (for example, Patent Document 1). Japanese Patent Application Publication No. 4-241740 An explanatory diagram of the internal structure of an engine according to one embodiment of the present invention.Cross-sectional view along line II-II in Figure 1.A diagram showing the displacement of the piston relative to the crank angle.(A) is a cross-sectional view taken along line A-A in Figure 1, and (B) is a cross-sectional view taken along line B-B in Figure 1.(A) is a partial perspective view of the tooth area, and (B) is a cross-sectional view along line C-C in Figure 1.(A) is a partially enlarged view of Figure 1, and (B) is a cross-sectional view of line D-D in Figure 6(A).A diagram showing the relationship between crank angle and the maximum torque of a rotating member.A diagram showing the relationship between crank angle and the minimum torque of a rotating member.A diagram showing an example of a gasket.(A) is a partially enlarged view of Figure 1 when the gasket in Figure 9 is used, and (B) is a cross-sectional view of the line E-E in Figure 10(A).A diagram illustrating the internal structure of an engine according to another embodiment.Figure 11 shows a cross-sectional view along the line F-F. The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features from the multiple features described in the embodiments may be arbitrarily combined. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted. <First Embodiment> (Engine structure) Figure 1 is an explanatory diagram of the internal structure of engine 1 according to one embodiment of the present invention, and also shows an enlarged view of the injection nozzle 82. Figure 2 is a cross-sectional view taken along line II-II of Figure 1, and is an explanatory diagram of the components of engine 1 (piston 5, connecting rod 6, crankshaft 7, ring gear member 8, rotating member 10). Engine 1 is a four-stroke, single-cylinder Atkinson cycle engine, and is mounted on a vehicle, for example, to serve as a power source for driving. The vehicle on which it is mounted is, for example, a motorcycle. Arrows X and Y are in the horizontal direction, perpendicular to each other, and arrow Z is in the vertical direction. Figure 1 shows the posture when engine 1 is mounted on a motorcycle, and the reciprocating direction of piston 5 is approximately in the Y direction (the front-rear direction of the motorcycle). The engine 1 comprises a crankcase 2 supporting the crankshaft 7, a cylinder block 3 having a bore 30 housing the piston 5, and a cylinder head 4 forming the combustion chamber 41. In Figure 1, the cylinder head 4 is shown in a partially cutaway view. The cylinder head 4 has an intake port 43, an exhaust port 44, and a valve train (not shown) that opens and closes these ports. The fuel-air mixture in the combustion chamber 41 is ignited and combusted by a spark plug 42. The cylinder block 3 is positioned between the crankcase 2 and the cylinder head 4, forming a cylindrical bore 30. The bore 30 has a diameter W. Arrow R indicates the radial direction of the bore 30, and the dashed line L indicates the central axis of the bore 30. The piston 5 housed in the bore 30 is shown with a solid line at top dead center and a dashed line at bottom dead center. The crankshaft 7 is supported in the crankcase 2 so as to be rotatable around the central axis C1. The crankshaft 7 has left and right main shaft portions 70 and journal portions 71 and 72. Journal portion 71 is supported in the crankcase 2 via bearing 24, and journal portion 72 is supported in the crankcase 2 via bearing 25. A pair of weights 73 and a crank web 74 are provided between the left and right journal sections 71 and 72, and a crank pin 75 is supported between the pair of crank webs 74. The central axis C2 of the crank pin 75 is eccentric with respect to the central axis C1. The crankpin 75 supports the rotating member 10 via a bearing 14, and the rotating member 10 has a spur gear portion with teeth 11 on its outer circumference. The side of the spur gear portion has a cylindrical boss portion 12 protruding in the X direction. The central axis C3 of the boss portion 12 is eccentric from the central axis C2. The connecting rod 6 has one end 60 and the other end 61. The one end 60 is a small-diameter end