Heavy vehicle tire to draw machinery
View Patent ↗A heavy vehicle comprising at least four mounted assemblies, intended to draw machinery. The properties of the vehicle satisfy the relationship: ( ρ ′ - κ · ( 1 - κ ) ) 2 + ( δ - h ′ · μ 2 ) 2 > ( h ′ · μ 2 ) 2 , where, ρ′=ρ/L, ρ being the turning radius of the vehicle and L being the wheelbase of the vehicle, K is the proportion of the total vertical stiffness under the front axle with respect to the sum of the total vertical stiffnesses under the front and rear axles of the vehicle, δ is the ratio between the forward offset of the center of gravity and the wheelbase, h′ is the ratio between the height of the draft line above the level of ground that forms a horizontal plane and the wheelbase of the vehicle, μ is the ratio between the longitudinal component of the resistive force applied by the drawn machinery to the vehicle, and the weight of the vehicle.
1. A heavy vehicle comprising at least four mounted assemblies, intended to draw machinery, wherein the properties of the vehicle satisfy the relationship:
(
ρ
′
-
κ
·
(
1
-
κ
)
)
2
+
(
δ
-
h
′
·
μ
2
)
2
>
(
h
′
·
μ
2
)
2
,
where,
ρ′=ρ/L, ρ being the turning radius of the vehicle and L being the wheelbase of the vehicle,
κ is the proportion of the total vertical stiffness under the front axle with respect to the sum of the total vertical stiffnesses under the front and rear axles of the vehicle,
δ is the ratio between the forward offset of the centre of gravity and the wheelbase,
h′ is the ratio between the height of the draft line above the level of ground that forms a horizontal plane and the wheelbase of the vehicle,
μ is the ratio between the longitudinal component of the resistive force applied by the drawn machinery to the vehicle, and the weight of the vehicle.
2. The heavy vehicle according to claim 1 , wherein ρ′ satisfies the relationship:
ρ′>0.525.
3. The heavy vehicle according to claim 1 , wherein ρ′ satisfies the relationship:
ρ′>0.395.
4. The heavy vehicle according to claim 1 , wherein the height of the sidewalls of the tyres fitted to the rear axle of the vehicle is at least 15% smaller than the height of the sidewalls of the tyres fitted to the front axle of the vehicle.
5. The heavy vehicle according to claim 4 , wherein the outside diameter of the tyres fitted to the rear axle of the vehicle is the same as the outside diameter of the tyres fitted to the front axle of the vehicle.
6. The heavy vehicle according to claim 4 , wherein the outside diameter of the tyres fitted to the rear axle of the vehicle is smaller than the outside diameter of the tyres fitted to the front axle of the vehicle.
7. The heavy vehicle according to claim 1 , wherein the height of the sidewalls of the tyres fitted to the rear axle of the vehicle is at least 15% greater than the height of the sidewalls of the tyres fitted to the front axle of the vehicle, and in that the axial width of the treads of the tyres fitted to the front axle of the vehicle is at least equal to the axial width of the treads of the tyres fitted to the rear axle of the vehicle.
8. The heavy vehicle according to claim 1 , wherein the wheelbase L of the vehicle satisfies the relationship:
L> 1.1×( m/d ) 1/3 ,
where,
m is the mass of the vehicle expressed in kg,
d is an average density equal to 300 kg/m 3 .
9. The heavy vehicle according to claim 1 , wherein the heavy vehicle is an agricultural tractor and in that the drawn machinery is an implement for working the land.