Title of the Invention
Intelligent Feedback Variable-Throttle Buffering System and
Buffering Method Thereof
I. Field of the Invention
The present invention relates to a variable-throttle buffering system and a
buffering
method thereof, particularly to an intelligent feedback variable-throttle
buffering
system and buffering method thereof.
II. Background of the Invention
Buffer devices are an indispensable part of various machines. However,
existing
buffer devices only support manual regulation of the buffer capacity within a
narrow
range, are at a low automation level, cannot support real-time regulation of
the buffer
capacity and stroke according to the impact load, cannot buffer against
overload, and
cannot protect the machines reliably; the buffer capacity can be used only
within its
rated buffer capacity, and cannot meet the requirement for buffering against
wide-span
impacts and uncertain impacts.
The Chinese Patent Publication No. CN202251621 has disclosed a hydraulic
buffer
which can regulate buffer power automatically. The structure of the hydraulic
buffer
mainly comprises a piston, a piston rod, a cylinder, a sponge, a seal ring, a
guide
sleeve, and a valve plate. The operating process of the hydraulic buffer is as
follows:
an oil drain passage is arranged in the piston, and the flow rate of the oil
flowing
through the oil drain passage is controlled by the valve plate; when the
external
impact force is increased suddenly, the rim of the valve plate will cling to
the piston
closely, the flow rate of the oil flowing through the oil drain passage will
be
decreased, and thereby the buffer power will be increased; when the external
impact
force is decreased, the rim of the valve plate will recover to the original
state slowly,
the flow rate of the oil flowing through the oil drain passage will be
increased, and the
buffer power will be decreased accordingly. In that way, the buffer power is
regulated
automatically as the impact force. However, the hydraulic buffer has the
following
=l=
CA 3002263 2018-04-20
drawbacks: the buffer capacity cannot be regulated, and buffering against
impact load
under an overload condition cannot be achieved effectively; not mention to
self-
adaptive regulation of buffering with the operating condition; in addition,
the
intelligent level is very low.
.. III. Summary of the Invention
The object of the present invention is to provide an intelligent feedback
variable-
throttle buffer system, which solves the problem that the existing buffer
devices can
be used only within their rated buffer capacity and cannot meet the
requirement for
buffering against wide-span impacts and uncertain impacts.
.. The object of the present invention is attained as follows: the present
invention
includes an intelligent feedback variable-throttle buffering system and a
buffering
method thereof.
The buffering system regulates the buffer capacity automatically within a wide
range
by means of closed-loop control with the speed sensor and pressure sensor. The
specific structure comprises: a linear motor, a linear cylinder, a stroke
control valve
block, a step motor, a throttle control valve block, an acquisition processor,
a
controller, a pressure sensor, a buffer cylinder, a cylinder head of the
buffer cylinder, a
speed sensor, and a displacement sensor.
One end of the linear cylinder is connected to the linear motor; the other end
of the
linear cylinder is connected to the stroke control valve block, and the stroke
control
valve block is connected through a pipeline to the buffer cylinder; one end of
the
buffer cylinder is connected to the throttle control valve block, and the
other end of
the buffer cylinder is connected to the cylinder head of the buffer cylinder;
the speed
sensor and the displacement sensor are connected on the cylinder head of the
buffer
cylinder; the acquisition processor, the controller and the pressure sensor
are
connected on the throttle control valve block; the step motor coaxial with the
buffer
cylinder is connected on the throttle control valve block; the output end of
the
controller is connected to the proportional control valves, the step motor,
and the
linear motor respectively; the output ends of the pressure sensor, the speed
sensor and
the displacement sensor are connected to the input end of the acquisition
processor,
.2.
CA 3002263 2018-04-20
and the controller controls the valves or motors respectively on the basis of
the input
signals of the acquisition processor.
The controller is a single-chip controller or PLC controller.
The buffer cylinder comprises: a support rod, a piston rod of the buffer
cylinder, a rod
cavity pipe of the buffer cylinder, an oil tank, a replenishing valve, a rod-
less cavity
pipe of the buffer cylinder, an oil return pipe, an outer cylinder of the
buffer cylinder,
a return spring, an inner cylinder of the buffer cylinder, a piston of the
buffer cylinder,
and a reset piston of the buffer cylinder.
The outer cylinder of the buffer cylinder is sleeved over the inner cylinder
of the
buffer cylinder, a return spring, a screw rod, and the reset piston of the
buffer cylinder
are disposed between the outer cylinder of the buffer cylinder and the inner
cylinder
of the buffer cylinder; the cylinder head of the buffer cylinder is arranged
on one end
of the outer cylinder of the buffer cylinder and the inner cylinder of the
buffer
cylinder, and the support rod connects the outer cylinder of the buffer
cylinder and the
inner cylinder of the buffer cylinder to the throttle control valve block via
the cylinder
head of the buffer cylinder; the piston of the buffer cylinder is disposed in
the inner
cylinder of the buffer cylinder; one end of the piston rod of the buffer
cylinder is
connected to the piston of the buffer cylinder, and the other end of the
piston rod of
the buffer cylinder protrudes through the cylinder head of the buffer
cylinder; the oil
tank is disposed at a side of the outer cylinder of the buffer cylinder, and
the oil return
pipe is connected between the oil tank and the stroke control valve block; the
rod-less
cavity pipe of the buffer cylinder is connected between the stroke control
valve block
and the throttle control valve block; the rod cavity pipe of the buffer
cylinder and the
replenishing valve are connected between the stroke control valve block and
the
cylinder head of the buffer cylinder.
The throttle control valve block comprises: a plug, a throttling orifice, a
coupling, a
screw rod and a valve spool.
The coupling, the screw rod, and the valve spool are connected sequentially at
the
center of the end of the throttle control valve block that is connected to the
step motor;
the plug and the throttling orifice are connected sequentially at the end of
the throttle
.3.
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control valve block that is connected to the buffer cylinder, one side of the
throttling orifice
communicates with a rod-less cavity of the buffer cylinder, and the other side
of the throttling
orifice communicates with a reset cavity of the buffer cylinder.
The linear cylinder comprises: a three-position two-way proportional valve of
the rod cavity, a
three-position two-way proportional valve of the rod-less cavity, a cylinder
head of the linear
cylinder, a piston of the linear cylinder, an oil circuit of the stroke
control valve block, a piston rod
of the linear cylinder, and a vent hole.
The three-position two-way proportional valve of the rod cavity and the three-
position two-way
proportional valve of the rod-less cavity are connected on the stroke control
valve block connected
to the linear cylinder; the oil circuit of the stroke control valve block is
disposed in the stroke
control valve block; the cylinder head of the linear cylinder is connected to
the other end of the
linear cylinder, and the cylinder head of the linear cylinder is disposed
between the linear cylinder
and the linear motor; the vent hole is arranged on the cylinder head of the
linear cylinder; the piston
of the linear cylinder is disposed in the linear cylinder, the piston rod of
the linear cylinder is
connected to the piston of the linear cylinder, and the piston rod of the
linear cylinder is connected
to the linear motor; the oil circuit of the stroke control valve block
communicates with the oil tank,
a rod cavity oil passage of the buffer cylinder, a rod-less cavity oil passage
of the buffer cylinder,
and the linear cylinder.
The speed sensor is mounted on the top of the buffer cylinder. The buffering
method is as follows:
(1) the speed sensor detects the speed of an impact object, and the buffer
stroke and initial
pressure are regulated in real time via the stroke control valve block;
(2) when the impact object comes into contact with the head of a piston
rod, the speed sensor
detects the speed of the impact object in real time, the pressure sensor
detects the pressure
in a buffer chamber in real time, the measured speed signal and pressure
signal are inputted
to the acquisition processor, the acquisition processor performs conversion
and calculation
of the data, and transmits the processed data to the controller, the
controller outputs a
CA 3002263 2019-04-26
control signal, and controls the throttling area of a buffer device via the
throttle control
valve block.
The specific steps are as follows:
The speed sensor detects the speed v2 of the current impact object, the
pressure sensor in the buffer
cavity of the buffer device detects the internal pressure p2 in the buffer
cylinder, and the speed v2
and the internal pressure p2 are inputted to the acquisition processor; the
acquisition processor
automatically calculates optimal throttling area s2 for accomplishing current
buffering and current
throttling area s3 of the buffer device, automatically calculates a difference
between the optimal
throttling area s2 and current throttling area s3 of the buffer device, i.e.,
s2-s3, and then transmits
the processed data to the controller; the controller outputs a control signal;
If s2>s3, i.e., the optimal throttling area desired for accomplishing the
current buffering is greater
than the current throttling area, the controller controls the step motor to
drive a valve spool via a
lead screw so that the valve spool moves linearly and the area of the
throttling orifice covered by
the valve spool is decreased to the optimal throttling area s2 for
accomplishing the current
buffering;
If s2<s3, i.e., the optimal throttling area desired for accomplishing the
current buffering is smaller
than the current throttling area, the controller controls the step motor to
drive a valve spool via a
lead screw so that the valve spool moves linearly and the area of the
throttling orifice covered by
the valve spool is increased to the optimal throttling area s2 for
accomplishing the current
buffering;
Since oil has to be replenished to the rod cavity when the piston of the
buffer cylinder moves, a
replenishing valve is provided; when the piston rod of the buffer cylinder
moves quickly, the
replenishing valve is opened to replenish oil to the rod cavity of the buffer
cylinder.
Beneficial effects and advantages:
1. The buffer capacity varies with the impact load, and thereby efficient
buffering is realized;
2. A closed-loop control system is employed to realize automatic regulation
of buffer stroke
and throttling area;
.5.
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3. Buffering in a wide variation range of impact load is realized, and both
low impact load
and high impact load can be buffered;
4. Buffering against uncertain impact loads is realized by means of an
automatic detection
and control system;
5. A linear motor is employed to drive the linear cylinder to provide power
for stroke
adjustment, and thereby the size of the power source is decreased effectively.
IV. Brief Description of The Drawings
Fig. 1 is a structural diagram of the buffer system in the present invention;
Fig. 2 is a structural diagram of the buffer cylinder in the present
invention;
Fig. 3 is a structural diagram of the linear cylinder in the present
invention.
In the figures: 1 - linear motor; 2 - linear cylinder; 3 - stroke control
valve block; 4 - three-position
two-way proportional valve of the rod cavity; 5 - three-position two-way
proportional valve of the
rod-less cavity; 6 - step motor; 7 - throttle control valve block; 8 -
acquisition processor; 9 -
controller; 10 - pressure sensor; 11 - buffer cylinder; 12 - support rod; 13 -
buffer cylinder head;
14 - speed sensor; 15 - piston rod of the buffer cylinder; 16 - displacement
sensor; 17 - rod cavity
pipe of the buffer cylinder; 18 - oil tank; 19 - replenishing valve; 20 - rod-
less cavity pipe of the
buffer cylinder; 21 - oil return pipe; 22 - cylinder head of the linear
cylinder; 23 - outer cylinder
of the buffer cylinder; 24 - return spring; 25 - inner cylinder of the buffer
cylinder; 26 - piston of
the buffer cylinder; 27 - plug; 28 - throttling orifice; 29 coupling; 30 -
screw rod; 31 - valve spool;
32 - reset piston of the buffer cylinder; 33 - piston of the linear cylinder;
34 - oil circuit of the
stroke control valve block; 35 - piston rod of the linear cylinder; 36 - vent
hole.
V. Detailed Description of Preferred Embodiments
The present invention includes an intelligent feedback variable-throttle
buffering system and a
buffering method thereof.
The buffer system regulates the buffer capacity automatically within a wide
range by means of
closed-loop control with the speed sensor and pressure sensor. The specific
structure comprises: a
linear motor 1, a linear cylinder 2, a stroke control valve block 3, a step
motor 6, a throttle control
.6.
CA 3002263 2019-04-26
valve block 7, an acquisition processor 8, a controller 9, a pressure sensor
10, a buffer cylinder 11,
a cylinder head 13 of the buffer cylinder, a speed sensor 14, and a
displacement sensor 16.
One end of the linear cylinder 2 is connected to the linear motor 1, the other
end of the linear
cylinder 2 is connected to the stroke control valve block 3, and the stroke
control valve block 3 is
connected through a pipeline to the buffer cylinder 11; one end of the buffer
cylinder 11 is
connected to the throttle control valve block 7, and the other end of the
buffer cylinder 11 is
connected to the cylinder head 13 of the buffer cylinder; the speed sensor 14
and the displacement
sensor 16 are connected on the cylinder head 13 of the buffer cylinder; the
speed sensor 14 is
mounted on the top of the buffer cylinder; the acquisition processor 8, the
controller 9 and the
pressure sensor 10 are connected on the throttle control valve block 7; the
step motor 6 coaxial
with the buffer cylinder 11 is connected on the throttle control valve block
7; the output end of the
controller 9 is connected to the proportional control valves, the step motor,
and the linear motor 1
respectively; the output ends of the pressure sensor 10, the speed sensor 13
and the displacement
sensor 15 are connected to the input end of the acquisition processor 8, and
the controller 9 controls
the valves or motors respectively on the basis of the input signals of the
acquisition processor 8.
The controller is a single-chip controller or PLC controller.
The buffer cylinder 11 comprises: a support rod 12, a piston rod 15 of the
buffer cylinder, a rod
cavity pipe 17 of the buffer cylinder, an oil tank 18, a replenishing valve
19, a rod-less cavity pipe
20 of the buffer cylinder, an oil return pipe 21, an outer cylinder 23 of the
buffer cylinder, a return
spring 24, an inner cylinder 25 of the buffer cylinder, a piston 26 of the
buffer cylinder, and a reset
piston 32 of the buffer cylinder.
The outer cylinder 23 of the buffer cylinder 11 is sleeved over the inner
cylinder 25 of the buffer
cylinder, the return spring 24, a screw rod 30, and the reset piston 32 of the
buffer cylinder are
disposed between the outer cylinder 23 of the buffer cylinder and the inner
cylinder 25 of the buffer
cylinder; the cylinder head 13 of the buffer cylinder is arranged on one end
of the outer cylinder
23 of the buffer cylinder and the inner cylinder 25 of the buffer cylinder,
and the support rod 12
connects the outer cylinder 23 of the buffer cylinder and the inner cylinder
25 of the buffer cylinder
-7.
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to the throttle control valve block 7 via the cylinder head 13 of the buffer
cylinder; the piston 26
of the buffer cylinder is disposed in the inner cylinder 25 of the buffer
cylinder, one end of the
piston rod 15 of the buffer cylinder is connected to the piston 26 of the
buffer cylinder, and the
other end of the piston rod 15 of the buffer cylinder protrudes through the
cylinder head 13 of the
buffer cylinder; the oil tank 18 is disposed at a side of the outer cylinder
23 of the buffer cylinder,
and the oil return pipe 21 is connected between the oil tank 18 and the stroke
control valve block
3; the rod-less cavity pipe 20 of the buffer cylinder is connected between the
stroke control valve
block 3 and the throttle control valve block 7; the rod cavity pipe 17 of the
buffer cylinder and the
replenishing valve 19 are connected between the stroke control valve block 3
and the cylinder head
13 of the buffer cylinder.
The throttle control valve block 7 comprises: a plug 27, a throttling orifice
28, a coupling 29, a
screw rod 30 and a valve spool 31.
The coupling 29, the screw rod 30, and the valve spool 31 are connected
sequentially at the center
of the end of the throttle control valve block 7 that is connected to the step
motor 6; the plug 27
and the throttling orifice 28 are connected sequentially at the end of the
throttle control valve block
7 that is connected to the buffer cylinder 11, one side of the throttling
orifice communicates with
a rod-less cavity of the buffer cylinder, and the other side of the throttling
orifice communicates
with a reset cavity of the buffer cylinder.
The plug isolates the external oil circuit of the valve block from the
environment in the processing
process to prevent oil leakage.
The linear cylinder 2 comprises: a three-position two-way proportional valve 4
of the rod cavity,
a three-position two-way proportional valve 5 of the rod-less cavity, a
cylinder head 22 of the
linear cylinder, a piston 33 of the linear cylinder, an oil circuit 34 of the
stroke control valve block,
a piston rod 35 of the linear cylinder, and a vent hole 36.
The three-position two-way proportional valve 4 of the rod cavity and the
three-position two-way
proportional valve 5 of the rod-less cavity are connected on the stroke
control valve block 3
connected to the linear cylinder 2; the oil circuit 34 of the stroke control
valve block is disposed
.8.
CA 3002263 2019-04-26
in the stroke control valve block 3; the cylinder head 22 of the linear
cylinder is connected to the
other end of the linear cylinder 2, and the cylinder head 22 of the linear
cylinder is disposed
between the linear cylinder 2 and the linear motor 1; the vent hole 36 is
arranged on the cylinder
head of the linear cylinder; the piston 33 of the linear cylinder is disposed
in the linear cylinder 2,
and the piston rod 35 of the linear cylinder is connected to the piston 33 of
the linear cylinder, and
the piston rod 35 of the linear cylinder is connected to the linear motor 1;
the oil circuit 34 of the
stroke control valve block communicates with the oil tank 18, a rod cavity
pipe 17 of the buffer
cylinder, a rod-less cavity pipe 20 of the buffer cylinder, and the linear
cylinder 2.
The speed sensor 14 is mounted on the top of the buffer cylinder. The
buffering method is as
follows:
(1) the speed sensor detects the speed of an impact object, and the buffer
stroke and initial
pressure are regulated in real time via the stroke control valve block;
(2) when the impact object comes into contact with the head of a piston
rod, the speed sensor
detects the speed of the impact object in real time, the pressure sensor
detects the pressure
in a buffer chamber in real time, a speed signal and a pressure signal are
inputted to the
acquisition processor, the acquisition processor performs conversion and
calculation of the
data, and transmits the processed data to the controller, the controller
outputs a control
signal, and controls the throttling area of a buffer device via the throttle
control valve block.
The specific steps are as follows:
The speed sensor 14 on the top of the buffer cylinder detects the speed v2 of
the current impact
object, the pressure sensor 10 in the buffer chamber of the buffer device
detects the internal
pressure p2 in the buffer cylinder, and the speed v2 and the internal pressure
p2 are inputted to the
acquisition processor 8; the acquisition processor 8 automatically calculates
optimal throttling area
S2 for accomplishing current buffering and current throttling area s3 of the
buffer device,
automatically calculates a difference between the optimal throttling area S2
and current throttling
area s3 of the buffer device, i.e., s2-s3, and then transmits the processed
data to the controller 9; the
controller 9 outputs a control signal.
-9.
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If s2>53, i.e., the optimal throttling area desired for accomplishing the
current buffering is greater
than the current throttling area, the controller 9 controls the step motor 6
to drive the valve spool
31 via the screw rod 30 so that the valve spool 31 moves linearly and the area
of the throttling
orifice 28 covered by the valve spool is decreased to the optimal throttling
area s2 for
accomplishing the current buffering.
If s2<53, i.e., the optimal throttling area desired for accomplishing the
current buffering is smaller
than the current throttling area, the controller 9 controls the step motor 6
to drive the valve spool
31 via the screw rod 30 so that the valve spool 31 moves linearly and the area
of the throttling
orifice 28 covered by the valve spool is increased to the optimal throttling
area S2 for accomplishing
the current buffering.
Since oil has to be replenished to the rod cavity when the piston of the
buffer cylinder 26 moves,
the replenishing valve 19 is provided; when the piston rod 15 of the buffer
cylinder moves quickly,
the replenishing valve 19 is opened to replenish oil to the rod cavity of the
buffer cylinder.
Embodiment 1
The speed sensor 14 on the top of the buffer cylinder detects the speed v2 of
the current impact
object, the pressure sensor 9 in the buffer chamber of the buffer device
detects the internal pressure
P2 in the buffer cylinder, and the speed V2 and the internal pressure p2 are
inputted to the acquisition
processor 8; the acquisition processor 8 automatically calculates optimal
throttling area s2 for
accomplishing current buffering and current throttling area s3 of the buffer
device, automatically
calculates a difference between the optimal throttling area s2 and current
throttling area s3 of the
buffer device, i.e., S2-S3;
if s2>s3, i.e., the optimal throttling area desired for accomplishing current
buffering is greater than
the current throttling area, the controller 9 controls the step motor 6 to
drive the valve spool 31 via
the screw rod 30, so that the valve spool 31 moves linearly, and the area of
the throttling orifice 28
covered by the valve spool is decreased to the optimal throttling area S2 for
accomplishing current
buffering;
= 1 0.
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if s2<s3, i.e., the optimal throttling area desired for accomplishing the
current buffering is smaller
than the current throttling area, the controller 9 controls the step motor 6
to drive the valve spool
31 via the screw rod 30 so that the valve spool 31 moves linearly and the area
of the throttling
orifice 28 covered by the valve spool is increased to the optimal throttling
area s2 for accomplishing
the current buffering.
Since oil has to be replenished to the rod cavity when the piston of the
buffer cylinder 26 moves,
the replenishing valve 19 is provided; when the piston rod 15 of the buffer
cylinder moves quickly,
the replenishing valve 19 is opened to replenish oil to the rod cavity of the
buffer cylinder.
The specific operation process is as follows:
I. Regulation of buffer stroke
The speed sensor 14 on the top of the buffer cylinder detects the speed of the
impact object in real
time, and transmits a speed signal to the acquisition processor 8; the
acquisition processor 8
performs conversion and calculation of the speed signal, and transmits a
calculation result to the
controller 9; the controller 9 drives the linear motor 1, the linear motor 1
directly drives the piston
of the linear cylinder 33 to move, and the linear cylinder 2 outputs hydraulic
oil; the flow rate of
the outputted hydraulic oil is regulated via the three-position two-way
proportional valve of the
rod-less cavity 5 and the three-position two-way proportional valve of the rod
cavity 4, the flow
rate of the hydraulic oil to the buffer cylinder 11 is regulated, and thereby
the stroke of the buffer
cylinder 11 is regulated. The specific regulation process is as follows: the
speed sensor 14 detects
the speed of the impact object, and transmits a speed signal to the
acquisition processor 8; the
acquisition processor 8 performs conversion and calculation of the speed
signal, and transmits a
calculation result to the controller 9; the controller 9 calculates a buffer
stroke x required for
accomplishing current buffering; the displacement sensor 15 on the top of the
buffer cylinder
detects the current stroke xi of the buffer device, and the acquisition
processor 8 automatically
calculates a difference between x and x 1, i.e., x-xi.
If x>xi, i.e., the stroke required for accomplishing current buffering is
greater than the current
stroke of the buffer device, the buffer stroke of the buffer cylinder 11 must
be increased; in that
=11=
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case, the three-position two-way proportional valve 5 of the rod-less cavity
connects hydraulic oil
to the rod-less cavity pipe 20 of the buffer cylinder 11, the three-position
two-way proportional
valve 4 of the rod cavity connects the rod cavity pipe 17 of the buffer
cylinder 11 to the oil tank
18; thus, the hydraulic oil pushes the piston rod 15 of the buffer cylinder
outward, till the
displacement sensor 16 detects a stroke x enough to accomplish current
buffering; at that point,
the controller 9 sends a signal to return the three-position two-way
proportional valve 5 of the rod-
less cavity and the three-position two-way proportional valve 4 of the rod
cavity to a middle
position respectively and stop the movement of the linear motor 1; thus,
stroke regulation is
accomplished.
If x<x , i.e., the stroke required for accomplishing current buffering is
smaller than the current
stroke of the buffer device, the buffer stroke of the buffer cylinder 11 must
be decreased; in that
case, the three-position two-way proportional valve 5 of the rod-less cavity
connects hydraulic oil
to oil tank 18, the three-position two-way proportional valve 4 of the rod
cavity connects the rod
cavity of the buffer cylinder 11 to the rod-less cavity of the buffer cylinder
11; thus, the hydraulic
oil causes the piston rod 15 of the buffer cylinder to retract inward, till
the displacement sensor 16
detects a stroke x enough to accomplish current buffering; at that point, the
controller sends a
signal to return the three-position two-way proportional valve 5 of the rod-
less cavity and the three-
position two-way proportional valve 4 of the rod cavity to a middle position
respectively and stop
the movement of the linear motor; thus, stroke regulation is accomplished; the
median function of
all control valves are of 0-type.
IL Setting of initial pressure
The speed sensor 14 on the top of the buffer cylinder detects the speed of the
impact object in real
time, and transmits a speed signal to the acquisition processor 8; the
acquisition processor 8
performs conversion and calculation of the speed signal, and transmits a
calculation result to the
controller 9; the controller 9 calculates an optimal initial pressure p
desired for accomplishing
current buffering according to the current speed of the impact object, the
pressure sensor 10 in the
buffer cylinder detects the current internal pressure pi in the buffer
cylinder, and the acquisition
= 12.
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processor 8 automatically calculates a difference between p and pi, i.e., p-
pi.
If p>pi, i.e., the optimal initial pressure p desired for accomplishing
current buffering is greater
than the current internal pressure pi in the buffer cylinder 11, the internal
pressure in the buffer
cylinder 11 must be increased so as to accomplish current buffering in the
most effective way; in
that case, the controller 9 controls the linear motor 1, the linear motor 1
directly drives the piston
33 of the linear cylinder to move, the linear cylinder 2 outputs hydraulic
oil, the three-position
two-way proportional valve 5 of the rod-less cavity connects the hydraulic
oil, the three-position
two-way proportional valve of the rod cavity 4 is in a middle position, and
the hydraulic oil in the
rod-less cavity of the buffer cylinder compresses the return spring 24, till
the internal pressure
sensor 10 of the buffer cylinder 11 detects that the internal pressure in the
buffer cylinder 11 has
reached the optimal initial pressure p desired for accomplishing current
buffering; the controller 9
sends a signal to return the linear motor 1 and all control valves to their
middle position.
If p<pi, i.e., the optimal initial pressure p desired for accomplishing
current buffering is smaller
than the current internal pressure pi in the buffer cylinder 11, the internal
pressure in the buffer
cylinder 11 must be decreased so as to accomplish current buffering in the
most effective way; in
that case, the controller 9 controls the linear motor 1, the linear motor 1
directly drives the piston
33 of the linear cylinder to move, the linear cylinder 2 sucks oil from the
buffer cylinder, the three-
position two-way proportional valve 5 of the rod-less cavity connects the
linear cylinder, the three-
position two-way proportional valve 4 of the rod cavity is in a middle
position, and the hydraulic
oil in the rod-less cavity of the buffer cylinder releases the return spring
24, till the internal pressure
sensor 10 of the buffer cylinder 11 detects that the internal pressure in the
buffer cylinder 11 has
reached the optimal initial pressure p desired for accomplishing current
buffering; the controller
sends a signal to return the linear motor 1 and all control valves to their
middle position.
= 13
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III. Regulation of throttling area
(1) The impact object has not come into contact with the piston rod of the
buffer cylinder
The speed sensor 14 on the top of the buffer cylinder detects the speed of the
impact object
in real time, and transmits a speed signal to the acquisition processor 8; the
acquisition
processor 8 performs conversion and calculation of the speed signal, and
transmits a
calculation result to the controller 9; the acquisition processor 8 calculates
optimal
throttling area s desired for accomplishing current buffering and the current
throttling area
Si of the buffer device, and automatically calculates a difference between the
optimal
throttling area s and the current throttling area Si of the buffer device,
i.e., s-si; the
controller 9 controls the step motor 6 to drives a valve spool 31 via the
screw rod 30, so
that the valve spool 31 moves linearly and thereby the area of the throttling
orifice 28
reaches the optimal throttling area s for accomplishing current buffering, to
avoid excessive
regulation against instantaneous impacts.
If s>si, i.e., the optimal throttling area desired for accomplishing the
current buffering is
greater than the current throttling area, the controller 9 controls the step
motor 6 to drive
the valve spool 31 via the screw rod 30 so that the valve spool 31 moves
linearly and the
area of the throttling orifice 28 covered by the valve spool is decreased to
the optimal
throttling area s for accomplishing the current buffering.
If s<si, i.e., the optimal throttling area desired for accomplishing the
current buffering is
smaller than the current throttling area, the controller 9 controls the step
motor 6 to drive
the valve spool 31 via the screw rod 30 so that the valve spool 31 moves
linearly and the
area of the throttling orifice 28 covered by the valve spool is increased to
the optimal
throttling area s for accomplishing the current buffering.
(2) The impact object comes into contact with the piston rod of the buffer
cylinder
When the impact object comes into contact with the piston rod 15 of the buffer
.14.
CA 3002263 2019-04-26
cylinder, the speed of the impact object and the pressure in the buffer
chamber
change continuously; in addition, the key factors that have influence on the
buffering efficiency are the speed of the impact object and the pressure in
the
buffer chamber; the throttling surface is controlled by detecting the speed of
the impact object and the pressure in the buffer chamber, and thereby the
buffering efficiency of the buffer device is maximized.
= 15.
CA 3002263 2018-04-20
