High-pressure hose comprising several layers of reinforcing plies
The present invention relates to a high-pressure hose structure comprising several layers of reinforcing plies where the reinforcing fibers are spirally laid. The hose structure according to the invention is characterized by the odd number of its reinforcing plies.
1. A high-pressure hose comprising several layers of spirally laid reinforcing plies, wherein the number of reinforcing plies is odd, a lay angle (α k ) of at least one of said plies as measured from a cross section perpendicular to a hose axis is lower than 10 degrees, a number of fibres (N k ) in the at least one of said plies is lower than
ABS
(
∑
i
=
1
n
,
i
≠
k
3
mr
i
N
i
F
i
cos
a
1
r
k
F
k
)
>
N
k
(
1
)
where
index k refers to the low-angle at least one of said plies,
index i is a running index, except the low-angle at least one of said plies,
m is a sign function whose value is +1 for left-handed and −1 for right-handed plies,
r i and r k are the mean radii of the respective plies,
N i and N k are numbers of fibres in the respective plies,
F i and F k are the tensile breaking forces of the fibres in the respective plies,
n is the number of plies,
ABS means absolute value,
and all the plies together fulfill the following inequality
0
,
36
∑
j
=
1
n
N
j
F
j
sin
a
j
>
∑
j
=
1
n
N
j
F
j
sin
a
j
>
0
,
3
∑
j
=
1
n
N
j
F
j
sin
a
j
(
2
)
where
j is a running index, including the low-angle of the at least one of said plies.
2. A hose according to claim 1 , wherein the individual plies comprise essentially identical reinforcing fibres.
3. A hose according to claim 1 , wherein the number of fibres (n k ) in the at least one of said plies is not greater than 10% of all ply fibres and the other plies defining an average lay angle of higher than 35.26°.
4. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises three reinforcing plies, the uppermost ply is laid at a low angle and the angles of the two lower reinforcing plies do not differ by more than ±3 degrees from those determined by equations
sin α 1 =0.707+0.19 z
sin α 2 =0.707−0.19 z
where
z is the relative ply distance, i.e. the difference of the mean radii of the two extreme plies divided byte mean radius r 2 of the second ply, z=(r 3 −r 1 )/r 2 .
5. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises five reinforcing plies, the uppermost ply is laid at a low angle and the angles of the four lower reinforcing plies do not differ by more than ±3 degrees from those determined by equations
sin α 1 =0.646+0.28 z
sin α 2 =0.646+0.09 z
sin α 3 =0.646−0.08 z
sin α 4 =0.646−0.23 z
where
z is the relative ply distance, i.e. the difference of the mean radii of the two extreme plies divided by the mean radius of the third ply, z=(r 5 −r 1 )/r 3 .
6. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises seven reinforcing plies, the uppermost ply is laid at a low angle and the angles of the six lower reinforcing plies do not differ by more than ±3 degrees from those determined by equations
sin α 1 =0.624+0.34 z
sin α 2 =0.624+0.18 z
sin α 3 =0.624+0.06 z
sin α 4 =0.624−0.05 z
sin α 5 =0.624−0.15 z
sin α 6 =0.624−0.23 z
where
z is the relative ply distance, i.e. the difference of the mean radii of two extreme plies divided by the mean radius of the fourth ply, z=(r 7 −r 1 )/r 4 .
7. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises three reinforcing plies, the uppermost ply is laid at a low angle and the angles of the two lower reinforcing plies do not differ by more than +3 degrees from those determined by equations
sin α 1 =0.707+0.73 z
sin α 2 =0.707−0.39 z
where
z is the relative ply distance, i.e. the difference of the mean radii of the two extreme plies divided by the mean radius of the second ply, z=(r 3 −r 1 )/r 2 .
8. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises five reinforcing plies, the uppermost ply is laid at a low angle and the angles of the four lower reinforcing plies do not differ by more than ±3 degrees from those determined by equations
sin α 1 =0.646+0.59 z
sin α 2 =0.646+0.36 z
sin α 3 =0.646−0.09 z
sin α 2 =0.646−0.63 z
where
z is the relative ply distance, i.e. the difference of the mean radii of the two extreme plies divided by the mean radius of the third ply, z=(r 5 −r 1 )/r 3 .
9. A hose according to claim 1 , wherein the odd number of reinforcing plies comprises seven reinforcing plies, the uppermost ply is laid at a low angle and the angles of the six lower reinforcing plies do not differ by more than ±3 degrees from those determined by equations
sin α 1 =0.624+0.75 z
sin α 2 =0.624+0.58 z
sin α 3 =0.624+0.18 z
sin α 4 =0.624−0.17 z
sin α 5 =0.624−0.41 z
sin α 6 =0.624−0.46 z
where
z is the relative ply distance, i.e. the difference of the mean radii of the two extreme plies divided by the mean radius of the fourth ply, z=(r 7 −r 1 )/r 4 .
10. A hose according to claim 1 , wherein an uppermost one of the plies is laid at a low angle and angles of lower reinforcing ones of the plies fall between values determined by
sin α 1 =0.707+0.19 z
sin α 2 =0.707−0.19 z
and
sin α 1 =0.707+0.73 z
sin α 2 =0.707−0.39 z
where
z is a relative ply distance comprising a difference between mean radii of extreme ones of the plies divided by a mean radius of an intermediate one of the plies.
11. A hose according to claim 1 , wherein an uppermost one of the plies is laid at a low angle and angles of lower reinforcing ones of the plies fall between values determined by
sin α 1 =0.646+0.28 z
sin α 2 =0.646+0.09 z
sin α 3 =0.646−0.08 z
sin α 4 =0.646−0.23 z
and
sin α 1 =0.646+0.59 z
sin α 2 =0.646+0.36 z
sin α 3 =0.646−0.09 z
sin α 2 =0.646−0.63 z
where
z is a relative ply distance comprising a difference between mean radii of extreme ones of the plies divided by a mean radius of an intermediate one of the plies.
12. A hose according to claim 1 , wherein an uppermost one of the plies is laid at a low angle and angles of lower reinforcing ones of the plies fall between values determined by
sin α 1 =0.624+0.34 z
sin α 2 =0.624+0.18 z
sin α 3 =0.624+0.06 z
sin α 4 =0.624−0.05 z
sin α 5 =0.624−0.15 z
sin α 6 =0.624−0.23 z
and
sin α 1 =0.624+0.75 z
sin α 2 =0.624+0.58 z
sin α 3 =0.624+0.18 z
sin α 4 =0.624−0.17 z
sin α 5 =0.624−0.41 z
sin α 6 =0.624−0.46 z
where
z is a relative ply distance comprising a difference between mean radii of extreme ones of the plies divided by a mean radius of an intermediate one of the plies.
13. A high-pressure hose comprising several layers of spirally laid reinforcing plies, wherein the number of reinforcing plies is odd and a number of fibres (N k ) in at least one of said plies is lower than
ABS
(
∑
i
=
1
n
,
i
≠
k
3
mr
i
N
i
F
i
cos
a
1
r
k
F
k
)
>
N
k
(
1
)
where
index k refers to the low-angle at least one of said plies,
index i is a running index, except the low-angle at least one of said plies,
m is a sign function whose value is +1 for left-handed and −1 for right-handed plies,
r i and r k are the mean radii of the respective plies,
N i and N k are numbers of fibres in the respective plies,
F i and F k are the tensile breaking forces of the fibres in the respective plies,
n is the number of plies,
ABS means absolute value.
14. A high-pressure hose comprising several layers of spirally laid reinforcing plies, wherein the number of reinforcing plies is odd and all plies together fulfill the following inequality
0
,
36
∑
j
=
1
n
N
j
F
j
sin
α
j
>
∑
j
=
1
n
N
j
F
j
sin
α
j
>
0
,
3
∑
j
=
1
n
N
j
F
j
sin
a
j
(
2
)
where
j is a running index, including the low-angle of at least one of said plies,
N j is a number of fibres in the respective plies,
F j is the tensile breaking force of the fibres in the respective plies, and
n is the number of plies.