475
at the point x k = x k (t) is determined by the volume dv of the beaten coal during dt, depending on the working thickness of a seamh, the length of the screw l and the feed rate of the
harvester and will be equal to dv = hlV k dt. Taking into account the specific weight of coal γ,
the weight of the beaten coal volume will be dM = hγlV k dt. Defined in this way, the volume of
dv coal weighing dM moves within the bay on the flight conveyor at a speed of V sk . Then the
time to move it to the exit of the bay is determined from the equation
dx
dt
V sk
V V
= − ( )
t
(3)
by the ration
T
V
dx
i
T T
sk
V V x x
x x
i
= −
∫
1
0
(4)
here V sk = const – the speed of the flight conveyor, x i place of the breaking portion of the coal
dM, x 0 – coordinate of flight conveyor from belt entries. Total weight of broken coal in the
bay at time t j defines the integration of elementary portions broken coal, for which the condition – travel time from point of cutting to conveyor drift does not exceed the transportation
time by flight conveyor:
Q
d M
d d i
i n
i=
∫
1
(5)
for i satisfying the condition:
t j
t
x
x
x
x
t
V
sk
V
dx
i
− ≤
t
−
∫
0
1
0
(6)
or
dx
V
V
dx
k
s
V V
V V k
x
x
x x
x x
i
j
i
∫
∫
dx
V
t
V
t 0
1
0
(7)
If the feed rate of the harvester is constant (V sk = const), then the integral disappears in the
left part of the condition, and an easily calculated ratio
x x
V
j
i
x x
k
V V
⎛
⎝
⎛ ⎛ ⎛ ⎛
⎝ ⎝
⎛ ⎛ ⎛ ⎛
⎞
⎠
⎞ ⎞ ⎞ ⎞
⎠ ⎠
⎞ ⎞ ⎞ ⎞
is obtained. Then, knowing the speed of the combine harvester and flight conveyor is not
difficult to determine the weight of coal in the bay.
When considering the general case-determining the volume of coal on the flight conveyor,
it is enough to use a simplified scheme of its operation (Fig. 1). The flight conveyor is shown
by a horizontal line. The point x 0 corresponds to the joint of the crusher and flight conveyor.
Let during the cutting of coal, the harvester moves along the face line with some varying feed
rate V k (t). The coal repulsed by the combine is loaded on a flight conveyor, which in turn
moves at a constant speed V sk = const. By the time the approach the excavation of the harvester to the point with coordinates of x i as the result of blasting, loading of coal harvester
and moving the flight conveyor with submerged him coal, at time t i flight conveyor loaded
with coal, the volume of which (in Fig. 1 conditionally shown in gray) is described by the
function ϕ = ϕ (x). After a period of time dt flight conveyor moved the entire volume of coal
to the side of the conveyor belt (the lower part of the Figure 1). In this case, part of the coal
(after the point x 0 ) is overloaded to the next equipment in the transportation line (shown by a
at the point x k = x k (t) is determined by the volume dv of the beaten coal during dt, depending on the working thickness of a seamh, the length of the screw l and the feed rate of the
harvester and will be equal to dv = hlV k dt. Taking into account the specific weight of coal γ,
the weight of the beaten coal volume will be dM = hγlV k dt. Defined in this way, the volume of
dv coal weighing dM moves within the bay on the flight conveyor at a speed of V sk . Then the
time to move it to the exit of the bay is determined from the equation
dx
dt
V sk
V V
= − ( )
t
(3)
by the ration
T
V
dx
i
T T
sk
V V x x
x x
i
= −
∫
1
0
(4)
here V sk = const – the speed of the flight conveyor, x i place of the breaking portion of the coal
dM, x 0 – coordinate of flight conveyor from belt entries. Total weight of broken coal in the
bay at time t j defines the integration of elementary portions broken coal, for which the condition – travel time from point of cutting to conveyor drift does not exceed the transportation
time by flight conveyor:
Q
d M
d d i
i n
i=
∫
1
(5)
for i satisfying the condition:
t j
t
x
x
x
x
t
V
sk
V
dx
i
− ≤
t
−
∫
0
1
0
(6)
or
dx
V
V
dx
k
s
V V
V V k
x
x
x x
x x
i
j
i
∫
∫
dx
V
t
V
t 0
1
0
(7)
If the feed rate of the harvester is constant (V sk = const), then the integral disappears in the
left part of the condition, and an easily calculated ratio
x x
V
j
i
x x
k
V V
⎛
⎝
⎛ ⎛ ⎛ ⎛
⎝ ⎝
⎛ ⎛ ⎛ ⎛
⎞
⎠
⎞ ⎞ ⎞ ⎞
⎠ ⎠
⎞ ⎞ ⎞ ⎞
is obtained. Then, knowing the speed of the combine harvester and flight conveyor is not
difficult to determine the weight of coal in the bay.
When considering the general case-determining the volume of coal on the flight conveyor,
it is enough to use a simplified scheme of its operation (Fig. 1). The flight conveyor is shown
by a horizontal line. The point x 0 corresponds to the joint of the crusher and flight conveyor.
Let during the cutting of coal, the harvester moves along the face line with some varying feed
rate V k (t). The coal repulsed by the combine is loaded on a flight conveyor, which in turn
moves at a constant speed V sk = const. By the time the approach the excavation of the harvester to the point with coordinates of x i as the result of blasting, loading of coal harvester
and moving the flight conveyor with submerged him coal, at time t i flight conveyor loaded
with coal, the volume of which (in Fig. 1 conditionally shown in gray) is described by the
function ϕ = ϕ (x). After a period of time dt flight conveyor moved the entire volume of coal
to the side of the conveyor belt (the lower part of the Figure 1). In this case, part of the coal
(after the point x 0 ) is overloaded to the next equipment in the transportation line (shown by a