Technical Field
[0001] The present invention relates to a construction equipment comprising a working machine
and a quick coupler circuit for easily attaching or detaching an attachment such as
a bucket or a breaker.
Background Art
[0002] In the related art, as illustrated in FIG. 3, a hydraulic shovel (construction equipment)
1 includes a lower travelling body 2, an upper pivoting body 3 pivotably provided
on the lower travelling body 2, and a working machine 4 installed on the upper pivoting
body 3 which is free to be raised or lowered in a vertical direction. Furthermore,
the working machine 4 includes a boom 5, a rear end of which is supported by the upper
pivoting body 3 in a freely turnable manner, an arm 6, a rear end of which is supported
by a leading end of the boom 5 in a freely turnable manner, and a bucket (attachment)
7 installed on the leading end side of the arm 6 in a freely turnable manner. The
working machine 4 is formed in a multiple joint form. Moreover, hydraulic oil is supplied
and discharged depending on the lever operation of an operator, a boom cylinder 8,
an arm cylinder 9 and a bucket cylinder 10 (working actuator) are each extended and
retracted, and the boom 5, the arm 6 and the bucket 7 are each turned.
[0003] Meanwhile, the construction equipment 1 has been known which is configured so that
various attachments 7 such as a bucket, a breaker and a crusher can be attached to
and detached from the leading end of the arm 6. Since the attachments 7 can be exchanged
in this construction equipment 1, a piece of the construction equipment 1 can be used
for multiple purposes and multiple functions. In addition, construction equipment
1 has been known which includes a quick coupler circuit and easily and rapidly performs
attachment and detachment of attachment 7 by operation of a switch by the operator.
[0004] Generally, the quick coupler circuit (quick coupler B) is provided between the leading
end of the arm 6 and the attachment 7. Moreover, the quick coupler circuit includes
a quick coupler cylinder that is extended and retracted by supplying and discharging
of the hydraulic oil to hold/detach the attachment 7, a hydraulic pump, an electromagnetic
switching valve that switches a supplying direction of the hydraulic oil supplied
from the hydraulic pump to a working actuator (the boom cylinder 8, the arm cylinder
9 and the bucket cylinder 10) side or a quick coupler cylinder side, a coupler switching
valve for extending or retracting the quick coupler cylinder by switching the supplying
direction of the hydraulic oil to the quick coupler cylinder, and a control device
that switches and controls the electromagnetic switching valve and the coupler switching
valve based on a pilot signal (operation signal) that is output by operation of the
switch (for example, see Patent Document 1).
Citation List
Patent Document
[0005] [Patent Document 1] Japanese Unexamined Patent Application, First Publication No.
2007-327291
[0007] Patent Document 2 discloses an attachment control system including an electrical
control system and hydraulic control system. The electrical control system interfaces
with the hydraulic control system to ensure that attachment decoupling in response
to operator electrical control can occur only when at least two different hydraulic
threshold conditions are satisfied.
Summary of Invention
Problem to be solved by the Invention
[0008] Herein, in order that the extension and retraction operation (attachment and detachment
of the attachment 7) of the quick coupler cylinder is reliably performed, there is
a need for a pump pressure-raising operation of an operator. For this reason, in the
above-mentioned quick coupler circuit of the related art, the electromagnetic switching
valve has been used. Moreover, the pilot signal for forcibly raising the pressure
of the pump is controlled, and the pressure of the hydraulic pump is forcibly raised.
Furthermore, in the above-mentioned quick coupler circuit of the related art, the
electromagnetic switching valve and the coupler switching valve are switched and driven
depending on the switch operation, and a three- position switch and a relay circuit
are required so as to control two valves.
[0009] That is, in the quick coupler circuit of the related art, a switch operated by three
positions and a relay circuit are combined with each other to perform the control
of raising the pressure of the hydraulic pump. The three positions include a working
position when extending and retracting the working actuator to perform working, a
locked position when extending (or retracting) the quick coupler cylinder to hold
(install) the attachment 7, and an unlocked position when retracting (or extending)
the quick coupler cylinder to detach the attachment 7. Moreover, when exchanging the
attachment 7, the locked position and the unlocked position are used, and the pressure
of the hydraulic pump is always raised between the locked position and the unlocked
position.
[0010] For this reason, only the performed control is whether or not the pressure of the
hydraulic pump always rises or the pressure of the hydraulic pump does not always
rise so that the quick coupler cylinder is extended or retracted, depending on the
position of the switch. That is, it is impossible to control the time and the timing
of the pressure raising. As a result, the movements of working actuators 8, 9 and
10 (working machine 4) are unstable while the pressure of the pump rises. Furthermore,
unnecessary pump pressure raising time is generated, and thus fuel efficiency is degraded.
[0011] In view of the above, an object of the present invention is to provide a construction
equipment comprising a working machine and a quick coupler circuit that is able to
control the time and the timing of the pressure raising, stabilizes the operation
of the working machine while the pressure of the hydraulic pump rises, and is able
to improve the fuel efficiency. Solution to Problem
[0012] In order to achieve the above-mentioned object, the present invention provides a
construction equipment as defined by claim 1.
Advantageous Effects of Invention
[0013] In the quick coupler circuit for construction equipment of the present invention,
the quick coupler circuit transmits the operation signal of the switch to the electromagnetic
switching valve via the control device. For that reason, it is possible to control
the time when the electromagnetic switching valve is switched so as to raise the pressure
of the hydraulic pump. That is, the control device switches and controls the electromagnetic
switching valve so that the pressure of the hydraulic pump rises, based on the operation
signal that is output by operating the switch to the locked position or the unlocked
position. After that, at a stage when a predetermined time elapses, the control device
is able to control the pump pressure raising time and timing by switching and controlling
the electromagnetic switching valve so that the pressure raising of the hydraulic
pump is completed.
[0014] Thereby, it is possible to perform the control so that the pressure of the hydraulic
pump rises only while the quick coupler cylinder is moved, by operating the switch
operated with two positions of the locked position and the unlocked position. Thus,
since the pressure raising time can be minimalized compared to the quick coupler circuit
of the related art, it is possible to suppress the unstable movement of each actuator
(working machine) during pressure raising of the pump to the minimum. Furthermore,
since an unnecessary pressure raising time of the pump is reduced, the fuel efficiency
is improved.
Brief Description of Drawings
[0015]
FIG. 1 is a diagram that illustrates a quick coupler circuit for a construction equipment
according to an embodiment of the present invention.
FIG. 2 is a diagram that illustrates a quick coupler circuit for a construction equipment
according to modified example of an embodiment of the present invention.
FIG. 3 is a diagram that illustrates a hydraulic shovel (construction equipment).
Description of Embodiments
[0016] Hereinafter, a quick coupler circuit for construction equipment according to an embodiment
of the present invention will be described referring to FIGS. 1 and 3.
[0017] Construction equipment 1 of the present embodiment is a hydraulic shovel (see FIG.
3), and includes a quick coupler circuit A for easily attaching or detaching various
attachments 7 such as a bucket and a breaker to or from a leading end of an arm 6
(working machine).
[0018] Moreover, as illustrated in FIG. 1, the quick coupler circuit A of the present embodiment
includes a quick coupler cylinder 11, a hydraulic pump (for example, variable capacity
pump) 12, an electromagnetic switching valve (solenoid valve) 13, a coupler switching
valve 14, a switch 15, and a control device 16.
[0019] The quick coupler cylinder 11 is a member for holding (installing)/detaching the
attachments 7 to or from the leading end of the arm 6 by being extended and retracted
by supplying and discharging of the hydraulic oil. The quick coupler cylinder 11 is
built in an attaching and detaching apparatus attached to the leading end of the arm
6, and is provided between the leading end of the arm 6 and the attachment 7. Furthermore,
in the quick coupler circuit A of the present embodiment, hydraulic pipes are each
connected to a piston chamber 11a and a rod chamber 11b of the quick coupler cylinder
11 so that when the quick coupler cylinder 11 is extended, the attachment 7 is fixed,
and when the quick coupler cylinder 11 is retracted, the attachment 7 is removed.
[0020] The electromagnetic switching valve 13 is able to change a supplying direction of
the hydraulic oil supplied by the hydraulic pump 12 of a hydraulic source to a working
actuator (a boom cylinder 8, an arm cylinder 9 and a bucket cylinder 10) side of the
working machine 4 or the quick coupler cylinder 11 side. The electromagnetic switching
valve 13 is connected to the hydraulic pump 12, each of the working actuators 8, 9
and 10, and a coupler switching valve 14 via the hydraulic pipes.
[0021] The coupler switching valve 14 is a member for extending or retracting the quick
coupler cylinder 11. The coupler switching valve 14 is connected to the quick coupler
cylinder 11 by the hydraulic pipes, and is able to change the supplying direction
of the hydraulic oil supplied from the hydraulic pump 12 to the quick coupler cylinder
11.
[0022] The switch 15 is used when an operator changes the electromagnetic switching valve
13 and the coupler switching valve 14 at the time of exchanging (attaching or detaching)
the attachment 7. The switch 15 is connected to the control device 16 using a wire
harness. Furthermore, the switch 15 of the present embodiment is operated with two
positions of the locked position where extending the quick coupler cylinder 11 to
hold the attachment 7 and the unlocked position where retracting the quick coupler
cylinder 11 to detach the attachment 7.
[0023] The control device 16 is a member for switching and controlling the electromagnetic
switching valve 13 and the coupler switching valve 14, respectively. The control device
16 is connected to the electromagnetic switching valve 13 and the coupler switching
valve 14 using the wire harness. The control device 16 of the present embodiment switches
and controls the coupler switching valve 14 by receiving the operation signal that
is output by the operation of the switch 15 to the locked position or the unlocked
position. Furthermore, the control device 16 of the present embodiment switches and
controls the electromagnetic switching valve so that pressure raising of the hydraulic
pump 12 begins by the operation of the switch 15, and pressure raising of the hydraulic
pump 12 is stopped at a stage when a predetermined time elapses.
[0024] When exchanging (attaching or detaching) the attachment 7 with the quick coupler
circuit A of the present embodiment, firstly, an operator operates the lever, and
drives the working actuators 8, 9 and 10. Moreover, an operator places the attachment
7 attached to on the leading end of the arm 6 at a predetermined position.
[0025] Next, when an operator turns the switch 15 to the unlocked position, the operation
signal is input to the control device 16. Moreover, the switching signals are each
output to the electromagnetic switching valve 13 and the coupler switching valve 14
from the control device 16 based on the operation signal. Moreover, the electromagnetic
switching valve 13 is switched by the switching signal that is output from the control
device 16, and the pressure of the hydraulic pump 12 rises. Furthermore, the coupler
switching valve 14 is switched by the switching signal that is output from the control
device 16, and hydraulic oil is supplied and discharged so that the quick coupler
cylinder 11 is retracted. The holding state of the attachment 7 installed on the leading
end of the arm 6 is released by retraction of the quick coupler cylinder 11, and the
attachment 7 is detached from the leading end of the arm 6.
[0026] Furthermore, in the present embodiment, after the electromagnetic switching valve
13 is switched and controlled by the control device 16 (after an operator operates
the switch to the unlocked position), for example, at a stage when a predetermined
time of about 10 seconds elapses, the electromagnetic switching valve 13 is switched
and controlled, and the pressure raising of the hydraulic pump 12 is stopped. That
is, when an operator operates the switch to the unlocked position, the quick coupler
cylinder 11 is retracted, and the attachment 7 is detached from the leading end of
the arm 6, the electromagnetic switching valve 13 is automatically switched and controlled
by the control device 16, and the oil pressure returns to a normal pressure at the
time of work.
[0027] Thereby, as in the quick coupler circuit of the related art, when an operator turns
the switch 15 to the unlocked position, the pressure does not rise so as to always
contract the quick coupler cylinder 11. For that reason, the pressure raising time
of the hydraulic pump 12 becomes minimum. For this reason, the unstable movement is
also suppressed to the minimum when driving the respective working actuators 8, 9
and 10. Furthermore, the unnecessary pump pressure raising time is also reduced.
[0028] Next, when attaching a new attachment 7 to the leading end of the arm 6, firstly,
the working machine 4 is driven so that the new attachment 7 is placed at a predetermined
position of the leading end side of the arm 6 by the lever operation of the operator.
At this time, since the respective working actuators 8, 9 and 10 are not unstably
moved, it is possible to very suitably place the leading end side of the arm 6 at
a predetermined position.
[0029] Moreover, an operator operates the switch to the locked position in a state where
the leading end side of the arm 6 is placed at a predetermined position. Then, the
operation signal is input to the control device 16, and the switching signals are
output to the electromagnetic switching valve 13 and the coupler switching valve 14
from the control device 16 based on the operation signal, respectively. The pressure
of the hydraulic pump 12 rises by the switching signals that are output from the control
device 16. Furthermore, the coupler switching valve 14 is switched by the switching
signals that are output from the control device 16, and the hydraulic oil is supplied
and discharged so that the quick coupler cylinder 11 is extended. Moreover, a connection
pin and a wedge of the new attachment 7 is caught by the extension of the quick coupler
cylinder 11, and the new attachment 7 is connected to the leading end of the arm 6
and is held (installed).
[0030] Furthermore, even when the attachment 7 is installed, after the electromagnetic switching
valve 13 is switched and controlled (after an operator operates the switch to the
locked position) by the control device 16, for example, at a stage when a predetermined
time of about 10 seconds elapse, the electromagnetic switching valve 13 is switched
and controlled, and pressure raising of the hydraulic pump 12 is stopped. That is,
when an operator operates the switch to the locked position, the quick coupler cylinder
11 is extended, and the attachment 7 is installed to the leading end of the arm 6,
the electromagnetic switching valve 13 is automatically switched and controlled by
the control device 16, and the oil pressure returns to the normal pressure at the
time of work.
[0031] For that reason, when the switch 15 is turned to the locked position, the pressure
of the hydraulic pump 12 does not rise so as to always extend the quick coupler cylinder
11. For that reason, pressure raising of the hydraulic pump 12 is performed in a minimum
pressure raising time. Thus, even at the time of installing the attachment 7, the
unstable movement of the respective working actuators 8, 9 and 10 is suppressed to
the minimum when driving the respective working actuators 8, 9 and 10. Furthermore,
the unnecessary pressure raising time is also reduced.
[0032] Furthermore, when installing the attachment 7, after the electromagnetic switching
valve 13 is switched and controlled and the oil pressure returns to the normal pressure
at the time of work, the working actuators 8, 9 and 10 may be driven by the control
device 16, for a predetermined time, for example, 5 seconds. In this case, it is possible
to check whether or not the installed attachment 7 is reliably (suitably) connected
and installed.
[0033] Thus, in the quick coupler circuit A for construction equipment of the present embodiment,
each quick coupler circuit A transmits the operation signal output from the switch
15 to the electromagnetic switching valve 13 via the control device 16. For that reason,
it is possible to control the time when the electromagnetic switching valve 13 is
switched so as to raise the pressure of the hydraulic pump 12. That is, after the
control device 16 switches and controls the electromagnetic switching valve 13 so
as to raise the pressure of the hydraulic pump 12, based on the operation signal that
is output by operating the switch 15 to the locked position or the unlocked position,
by switching and controlling the electromagnetic switching valve 13 so as to finish
pressure raising of the hydraulic pump 12 at a stage when a predetermined time elapses,
the pump pressure raising time and timing can be controlled.
[0034] For that reason, it is possible to perform the control so that the pressure of the
hydraulic pump 12 rises only while the quick coupler cylinder 11 is moved, by operating
the switch 15 that is operated with two positions of the locked position and the unlocked
position. Thus, compared to the quick coupler circuit of the related art, pressure
raising of the hydraulic pump 12 is performed in a minimum pressure raising time in
the quick coupler circuit A of the present invention. For that reason, it is possible
to suppress the unstable movement of the respective working actuators 8, 9 and 10
(working machine 4) to minimum during pressure raising of the pump. Furthermore, since
the unnecessary pump pressure raising time is reduced, the fuel efficiency is improved.
[0035] Although an embodiment of the quick coupler circuit for construction equipment related
to the present invention has been described, the present invention is not limited
to the above-mentioned embodiment but may be suitably changed within a scope that
does not depart from the gist thereof. For example, in the present embodiment, although
the case where the construction equipment 1 is the hydraulic shovel has been described
the construction equipment related to the present invention may be other construction
equipments such as a shovel loader.
[0036] Furthermore, in the quick coupler circuit A of the present embodiment, the hydraulic
pipes are each connected to the piston chamber 11a and the rod chamber 11b of the
quick coupler cylinder 11 so that when the quick coupler cylinder 11 is extended,
the attachment 7 is fixed, and when the quick coupler cylinder 11 is retracted, the
attachment 7 is detached. On the contrary to the present embodiment, as illustrated
in FIG. 2, the hydraulic pipes may be each connected to the piston chamber 11a and
the rod chamber 11b of the quick coupler cylinder 11 so that when the quick coupler
cylinder 11 is extended, the attachment 7 is detached, and when the quick coupler
cylinder 11 is retracted, the attachment 7 is fixed.
[0037] Moreover, in the case of having the above-mentioned configuration, on the contrary
to the present embodiment, when an operator operates the switch to the unlocked position,
the switching signals are each output to the electromagnetic switching valve 13 and
the coupler switching valve 14 from the control device 16. Moreover, the electromagnetic
switching valve 13 is switched and the pressure of the hydraulic pump 12 rises. Furthermore,
the coupler switching valve 14 is switched by the switching signal that is output
from the control device 16, and the hydraulic oil is supplied and discharged so that
the quick coupler cylinder 11 is extended. In this manner, the holding state of the
attachment 7 installed to the leading end of the arm 6 is released by the extension
of the quick coupler cylinder 11, and the attachment 7 is detached from the leading
end of the arm 6.
[0038] Furthermore, after the electromagnetic switching valve 13 is switched and controlled
(after an operator operates the switch to the unlocked position) by the control device
16, for example, at a stage when a predetermined time of about 10 seconds elapses,
the electromagnetic switching valve 13 is switched and controlled, and pressure raising
of the hydraulic pump 12 is stopped.
[0039] That is, when an operator operates the switch to the unlocked position, the quick
coupler cylinder 11 is extended, and the attachment 7 is detached from the leading
end of the arm 6, the electromagnetic switching valve 13 is automatically switched
and controlled by the control device 16, and the oil pressure returns to the normal
pressure at the time of work.
[0040] For that reason, pressure raising of the hydraulic pump 12 is performed in a minimum
pressure raising time. As a result, when driving the respective working actuators
8, 9 and 10, the unstable movement of the respective working actuators 8, 9 and 10
is suppressed to the minimum. Furthermore, the unnecessary pump pressure raising time
is reduced.
[0041] Furthermore, even when a new attachment 7 is installed to the leading end of the
arm 6, on the contrary to the present embodiment, an operator operates the switch
to the locked position in a state where the leading end side of the arm 6 is placed
at a predetermined position. Then, the switching signals are each output to the electromagnetic
switching valve 13 and the coupler switching valve 14 from the control device 16,
and thus the pressure of the hydraulic pump 12 rises. Furthermore, the coupler switching
valve 14 is switched by the switching signal that is output from the control device
16, and the hydraulic oil is supplied and discharged so that the quick coupler cylinder
11 is retracted. In this manner, the connection pin or the wedge of the new attachment
7 is caught by the retraction of the quick coupler cylinder 11, and the new attachment
7 is connected to the leading end of the arm 6 and is held (installed).
[0042] Furthermore, even when installing the above-mentioned attachment 7, after the electromagnetic
switching valve 13 is switched and controlled by the control device 16, for example,
at a state when a predetermined time of about 10 seconds elapses, the electromagnetic
switching valve 13 is switched and controlled, and pressure raising of the hydraulic
pump 12 is stopped. That is, when an operator operates the switch to the locked position,
the quick coupler cylinder 11 is retracted, and the attachment 7 is installed to the
leading end of the arm 6, the electromagnetic switching valve 13 is automatically
switched and controlled by the control device 16, and the oil pressure returns to
the normal pressure at the time of work.
[0043] For that reason, when the switch 15 is turned to the locked position, the pressure
of the hydraulic pump 12 does not rise so as to always contract the quick coupler
cylinder 11. As a result, the hydraulic pump 12 is performed in a minimum pressure
raising time. Thus, even at the time of installing the attachment 7, when driving
the respective working actuators 8, 9 and 10, the unstable movement of the respective
working actuators 8, 9 and 10 is suppressed to the minimum. Furthermore, the unnecessary
pump pressure raising time is reduced.
Industrial Applicability
[0044] According to the present invention, there is provided a quick coupler circuit that
is able to control the time when the electromagnetic switching valve is switched so
as to raise the pressure of the hydraulic pump.
[0045] Furthermore, according to the present invention, in the quick coupler circuit for
construction equipment, the pressure raising time of the hydraulic pump can be reduced
to the minimum level. For that reason, it is possible to suppress the unstable movement
of each actuator to the minimum during pressure raising of the pump. Furthermore,
since the unnecessary pump pressure raising time is reduced, the fuel efficiency is
improved.
Reference Signs List
[0046]
1 hydraulic shovel (construction equipment)
2 lower travelling body
3 upper pivoting body
4 working machine
5 boom
6 arm
7 bucket (attachment)
8 boom cylinder (working actuator)
9 arm cylinder (working actuator)
10 bucket cylinder (working actuator)
11 quick coupler cylinder
11a piston chamber
11b rod chamber
12 hydraulic pump
13 electromagnetic switching valve
14 coupler switching valve
15 switch
16 control device
A quick coupler circuit for construction equipment
B quick coupler