US4496020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
V-Type multi-cylinder engine for motorcycle
Assignee: Honda Motor Co Ltd
•
Filing: 1982-12-23
•
Granted: 1985-01-29
•
Expires: 2002-12-23
Abstract
Abstract Disclosed is an engine for motorcycles, having first and second engine blocks disposed in a form like V on the frame of the motorcycle. Pistons reciprocatably and slidably received in the engine blocks are connected to first and second crank pins of a crankshaft through respective connecting rods. Representing the included angle between the central axes of first and second cylinders for the first and second piston by α, the rotational phase of the second crank pin is offset from that of the first crank pin by an angle π-2α in the opposite side of the central axis of the first cylinder to the central axis of the second cylinder. A balancer weight is attached to that portion of the crank shaft positioned opposite to the first and second crank pins and on the bisector line of the angle formed between the first and second crank pins. With this arrangement, the primary inertia force as applied to the crankshaft by the mass of reciprocating parts such as pistons can be substantially eliminated to remarkably suppress the vibration of the engine.
Inventors
- 👤 Toshiro Mitsuishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:00
CPC Classifications
F; F02; F02B; F02B75/00; F02B75/16; F02B75/18; F02B75/22; B; B62; B62M; B62M7/00; B62M7/02; F02B61/00; F02B61/02; F02F; F02F7/00; F02F7/0002; F02F7/0019; F02B75/02; F02B2075/022; F02B2075/027; F02B2075/1804; F02B2075/1808; Y; Y10; Y10T; Y10T74/00; Y10T74/21; Y10T74/2173; Y10T74/2183; Y10T74/2184
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
158 words
A V-type multi-cylinder engine for motorcycles, including first and second engine blocks arranged on a frame so as to form a V shape, said engine blocks having first and second cylinders, respectively, pistons reciprocatably and slidably received by said first and second cylinders, and a crankshaft having first and second crank pins connected through piston rods to said pistons, wherein the improvement comprises that the rotational phase of said second crank pin is offset from that of said first crank pin by an angle π-2α in the opposite side of the central axis of said first cylinder to the axis of said second cylinder, α representing an angle included between the central axes of said first and second cylinders, and that a balancer weight is attached to that portion of said crank shaft positioned opposite to said first and second crank pins and on the bisector line of the angle formed between said crank pins around said crankshaft.
Claim 2
Dependent Claim
158 words
A V-type multi-cylinder engine for motorcycles, including first and second engine blocks arranged on a frame so as to form a V shape, said engine blocks having first and second cylinders, respectively, pistons reciprocatably and slidably received by said first and second cylinders, and a crankshaft having first and second crank pins connected through piston rods to said pistons, wherein the improvement comprises that the rotational phase of said second crank pin is offset from that of said first crank pin by an angle π-2α in the opposite side of the central axis of said first cylinder to the axis of said second cylinder, α representing an angle included between the central axes of said first and second cylinders, and that a balancer weight is attached to that portion of said crank shaft positioned opposite to said first and second crank pins and on the bisector line of the angle formed between said crank pins around said crankshaft.
Claim 3
Dependent Claim
32 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 1, wherein said first and second engine blocks are arranged on the frame of said motorcycle in the longitudinal direction thereof.
Claim 4
Dependent Claim
32 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 1 or 2, wherein the included angle between the central axes of said first and second cylinders is smaller than 90°.
Claim 5
Dependent Claim
28 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 3, wherein the included angle between the central axes of said first and second cylinders is 45°.
Claim 6
Dependent Claim
72 words
A V-type multi-cylinder engine for motorcycles as set forth in either one of claims 2, wherein said frame includes a downtube having first and second portions, the first portion extending downwardly and the second portion extending rearwardly with respect to a head pipe supporting a steering axle, and wherein said engine blocks are disposed in a space to the rear of the first portion and above the second portion of said downtube.
Claim 7
Dependent Claim
41 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 5, wherein said first and second engine blocks are arranged in symmetry with each other with respect to a vertical plane passing through the axis of rotation of said crankshaft.
Claim 8
Dependent Claim
27 words
A V-type multi-cylinder engine for motorcycles as set forth in any one of claims 1 or 2, wherein said engine blocks are rigidly fixed to said frame.
Claim 9
Dependent Claim
45 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 5, wherein said first and second cylinders in said first and second engine blocks are arranged symmetrically with respect to the longitudinal axis of said frame at equal distances offset sidewardly from that axis.
Claim 10
Dependent Claim
60 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 8, further comprising valve actuating cam shafts rotatably carried by said first and second engine blocks, respectively, driven sprockets attached to said valve actuating cam shafts, respectively, driving sprockets fixed to both ends of said crankshaft, and endless timing chains engaging respective combinations of said driving and driven sprockets.
Claim 11
Dependent Claim
42 words
A V-type multi-cylinder engine for motorcycles as set forth in claim 5, wherein said first cylinder is positioned closer to said downtube than said second cylinder and the axis of said first cylinder is parallel to the first portion of said downtube.
References Cited (Backward Citations)
US754929A
Cited
US1639165A
Cited
US2194022A
Cited
US4194469A
Cited
US4321978A
Cited
US4370953A
Cited
JPS5881250A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |