Four-wheeled vehicle

Abstract

Herein described is a vehicle (10) comprising a bearing frame (12) of the tubular trestle type, two front steered wheels (14, 16), two rear wheels (18, 20) with fixed axis (144), an engine unit (22), steering means (24) through which it is possible to operate on the front wheels (14, 16), a front suspension unit (26), connecting the frame (12) to the front wheels (14, 16), a rear suspension unit (28), connecting the frame (12) to the rear wheels (18, 20), a transmission unit, interposed between the engine unit (22) and the axle shafts of the rear wheels (18, 20), a seat (44) for the driver of the vehicle (10), arranged at a central position with respect to such vehicle (10), and at least two seats (44') for the passengers of the vehicle (10) adjacent to each other, arranged laterally and receded according to a predefined distance with respect to the seat (44) for the driver of the vehicle (10). The engine unit (22) is elastically constrained with respect to the rear suspension unit (28) through at least one suspension mechanism (72, 74; 84, 90, 92), which provides a first level for filtering the stresses generated by the operation of the engine unit (22) and so that such rear suspension unit (28) is capable of supporting the overall weight of the engine unit (22). In turn, the rear suspension unit (28) is elastically constrained to the frame (12) through at least one auxiliary suspension mechanism (96, 98) which, alongside the elasticity of the tyres of the rear wheels (18, 20), forms a second level for filtering the stresses generated by the operation of the engine unit (22).; In the respective rebound and roll motions with respect to the frame (12) of the vehicle (10), the rear suspension unit (28) is vertically guided and constrained transversely by a leaf -spring- shaped flexible element (122). The rear suspension unit (28) is fixed to the frame (12) by means of only two bushings (138, 132), so as to reduce the times and costs of assembling the vehicle (10).

Description

technical field [0001] The present invention relates to four-wheeled vehicles, in particular four-wheeled vehicles falling within the category of so-called (heavy) "quadricycles". Background technique [0002] According to Framework Directive 2002 / 24 / EC (Framework Directive 2002 / 24 / EC), the term "light four-wheeled vehicle" is used to denote a curb weight (unladen mass) less than or equal to 350kg (in the case of electric vehicles, excluding batteries Weight), four-wheeled motor vehicles with a maximum design speed lower than or equal to 45Km / h. Depending on the engine type, light four-wheelers must also meet the following conditions: [0003] - for spark ignition engines, the engine cylinder is equal to or less than 50 cm3; or [0004] - in the case of other internal combustion engines, the maximum net power output is less than or equal to 4 kW; or [0005] - In the case of electric motors, the maximum continuous rated power is less than or equal to 4 kW. [0006] Such ...

AI Technical Summary

Problems solved by technology

All attempts to improve the filtration performance of such struts ultimately conflict with the unfavorable relationship between vehicle mass and engine mass, reaching inherent physical limits that jeopardize the end result, with dire consequences for passenger comfort and safety, The stress on all the mechanical structures of the vehicle itself is also considerable

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