JP2609401B2 - Hydraulic drive in construction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive for a construction machine such as a power shovel used for construction work.

[0002]

2. Description of the Related Art For example, a power shovel which operates a hydraulic motor and a hydraulic cylinder of each work part with hydraulic oil generated from a hydraulic pump directly connected to an engine, as a construction earthmoving machine for performing excavation work in construction earthworks. The power shovel will be described with reference to FIG.

In FIG. 2, (1) is a power shovel body, which cab (3) is pivotably mounted on a crawler (2), and a first hydraulic motor () is provided on the crawler (2). 4) cab (3) to crawler (2)
It is designed to make a full 360 ゜ turn. (5) is a boom having a base end mounted on a cab (3) of the power shovel body (1) so as to be able to move up and down, and a first hydraulic cylinder (6) disposed between the boom and the cab (3). ) By cab (3)
Undulates. (7) is an arm having a base end swingably attached to a distal end of the boom (5). The boom is provided by a second hydraulic cylinder (8) disposed between the arm and the boom (5). Oscillates in response to (5). (9) is a bucket mounted on the distal end of the arm (7), and is provided by a third hydraulic cylinder (11) disposed between the bucket and the arm (7) via a link mechanism (10). A swing operation is performed in response to (7). (12) is a first main switching valve for operating the first hydraulic motor (4). The first primary switching valve (13) and the first secondary piping (13) are connected to the first hydraulic motor (4). 14) Connected via. (15) is a second main switching valve for operating the third hydraulic cylinder (11). A second primary pipe (16) and a second secondary pipe ( Connected via 17). (18) is a third main switching valve for operating the second hydraulic cylinder (8), and a third primary pipe (19) and a third secondary pipe ( 20) connected via. (21) is a fourth main switching valve for operating the first hydraulic cylinder (6),
The first hydraulic cylinder (6) is connected via a fourth primary pipe (22) and a fourth secondary pipe (23). (24) is a hydraulic source that generates hydraulic oil by a hydraulic pump (not shown) directly connected to an engine (not shown). 12), connected via a second main switching valve (15), a third main switching valve (18), a fourth main switching valve (21) and a pipe (27). Also,
The main switching valves (12), (15), (18), and (21) are respectively connected inside the valves.

In the above configuration, the first hydraulic motor (4), the third hydraulic cylinder (11), the second hydraulic cylinder (8), and the first hydraulic cylinder (6) have respective main switching valves (12). The first hydraulic motor (4), the third hydraulic cylinder (11), and the second hydraulic pressure are supplied by operating (15), (18), and (21) to supply hydraulic oil from the hydraulic pressure source (24). The cylinder (8) and the first hydraulic cylinder (6) are operated, whereby the turning operation of the cab (3) of the power shovel body (1), the raising / lowering operation of the boom (5), and the swinging of the arm (7) are performed. The moving operation and the swinging operation of the bucket (9) are performed, so that the excavation work at the destination can be freely performed.

In FIG. 2, reference numeral (28) denotes a first operating lever for switching the first main switching valve (12).
(29) is a second operating lever for switching the second main switching valve (15), (30) is a third operating lever for switching the third main switching valve (18), (31) is a fourth operation lever for switching the fourth main switching valve (21).

Incidentally, in the above-mentioned power shovel, work other than excavation work is also possible by attaching various tip tools other than the bucket (9) to the tip of the arm (7) as necessary. For example, as shown in FIG. 3, a gripping operation can be performed by attaching a grip hand (32).

The grip hand (32) has a support (33) which can be swung by a third hydraulic cylinder (11) via a link mechanism (10) at the tip of the arm (7). A main grip (34) is pivotally supported on the body (33), and a secondary grip (35) is attached to the main grip (34) so as to be openable and closable. By rotating the main grip (34) with respect to the support (33) by the hydraulic motor (36), the main grip (34) and sub-grip (35) secure the optimal position and angle for biting work. , And both grips (34)
The auxiliary grip (35) is opened and closed with respect to the main grip (34) by the fourth hydraulic cylinder (37) disposed between (35), so that the object is held by both grips (34) and (35). It is configured as follows.

By the way, when the grip hand (32) is attached to the tip of the arm (7) of the power shovel using the tip tool as a tip tool, the grip hand (3) is used.
Since 2) is provided with a second hydraulic motor (36) and a fourth hydraulic cylinder (37), the second hydraulic motor (36) and the fourth hydraulic cylinder (37) are controlled. It is necessary to add a hydraulic system for the existing excavator to the existing hydraulic system.

Thus, the second hydraulic motor (3) of the grip hand (32) is connected to the existing hydraulic system of the power shovel.
6) and a hydraulic system for controlling the fourth hydraulic cylinder (37) is to be added. In addition to the existing first to fourth operation levers (28) to (31) of the power shovel, the grip hand ( 32) the second hydraulic motor (36) and the fourth
5th and 6th for operating the hydraulic cylinder (37)
The two operation levers are added, and such an addition of the operation levers leads to an operation of switching the operation levers of the operator, and there is a problem that it takes time for the operation to become familiar.

In order to solve the above-mentioned problems, the applicant of the present invention has disclosed in Japanese Patent Application No. 3-199053 a hydraulic drive device for a construction and construction machine capable of operating a hydraulic actuator of an additional hydraulic system with an existing operation lever. Fig. 4 shows a hydraulic drive device for this construction machine.
The following is a description based on the above. The same members as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 4, reference numeral (38) denotes a first solenoid-operated directional control valve disposed in the middle of the first primary pipe (13), and a fifth hydraulic pipe (39) is connected to the second hydraulic motor (36). ). (40) is a second solenoid-operated directional control valve disposed in the middle of the first secondary pipe (14) and connected to the second hydraulic motor (36) via the fifth secondary pipe (41). Is done. (42) is the first
The first solenoid switch (43) and the second solenoid (44) of the first solenoid-operated switching valve (38) and the second solenoid-operated switch are provided by a first push-button switch mounted on the grip portion of the operating lever (28). The third solenoid (45) and the fourth solenoid (46) of the valve (40)
When the first push button switch (42) is turned on, the first solenoid (43) of the first electromagnetic switching valve (38) and the third solenoid of the second electromagnetic switching valve (40) are turned on. When the (45) is excited and the first push button switch (42) is turned off, the second solenoid (44) of the first electromagnetic switching valve (38) and the fourth solenoid of the second electromagnetic switching valve (40) are turned off. The solenoid (46) is excited. (47) is a third solenoid-operated switching valve disposed in the middle of the second primary pipe (16), and is connected to the fourth hydraulic cylinder (37) via the sixth primary pipe (48). .
(49) is the fourth pipe installed in the middle of the second secondary pipe (17).
Is connected to the fourth hydraulic cylinder (37) via the sixth secondary pipe (50). (51) is a second push button switch mounted on the grip portion of the second operation lever (29), and is a fifth solenoid (52) of the third electromagnetic switching valve (47).
And sixth solenoid (53) and fourth solenoid-operated directional control valve (49)
When the second push button switch (51) is turned on, the fifth solenoid (52) of the third electromagnetic switching valve (47) is electrically connected to the seventh solenoid (54) and the eighth solenoid (55).
And the seventh solenoid (54) of the fourth electromagnetic switching valve (49)
When the second push button switch (51) is turned off, the sixth solenoid (53) of the third electromagnetic switching valve (47) and the eighth solenoid (55) of the fourth electromagnetic switching valve (49) are excited. ) Is excited.

Next, the grip hand (3
The operation of 2) will be described.

First, when the grip hand (32) is turned in order to secure an optimum position and angle for the biting operation, the first operation lever (28) is held while holding the first operation lever (28). By turning on the first push button switch (42) to excite the first solenoid (43) of the first electromagnetic switching valve (38) and the third solenoid (43) of the second electromagnetic switching valve (40), The first electromagnetic switching valve (38) and the second electromagnetic switching valve (40) are switched from the parallel position to the cross position, respectively, and the first primary pipe (13) and the fifth primary pipe (39)
Are connected via a first electromagnetic switching valve (38), and the first secondary pipe (14) and the fifth secondary pipe (41) are connected via a second electromagnetic switching valve (40). In this state of being connected,
By switching the first main switching valve (12) from the shut-off position to the crossing position or the parallel position by the first operating lever (28), the hydraulic oil from the hydraulic power source (24) is switched to the first main switching position. After passing through the valve (12), the first primary pipe (13)
Through the electromagnetic switching valve (38) and the fifth primary pipe (39) or the first secondary pipe (14), the second electromagnetic switching valve (40) and the fifth secondary pipe (41). The second hydraulic motor (36) allows the gripping hand (32) to rotate in an arbitrary direction by the second hydraulic motor (36), thereby ensuring an optimal position and angle for the biting operation.

Further, as described above, the first operation lever (2
When the first push button switch (42) is turned off in the state where the first main switching valve (12) is switched from the shut-off position to the crossing position or the parallel position according to 8), the first electromagnetic switching valve (38) The first solenoid (43) and the third solenoid (45) of the second electromagnetic switching valve (40) are demagnetized.
The second solenoid (22) and the second solenoid of the electromagnetic switching valve (38)
Since the fourth solenoid (46) of the electromagnetic switching valve (40) is excited, the first electromagnetic switching valve (38) and the second electromagnetic switching valve (40) are switched from the cross position to the parallel position, After passing through the main switching valve (12), the hydraulic oil flows into the first primary pipe,
Alternatively, the cab (3) of the power shovel body (1) is supplied to the first hydraulic motor (4) through the first secondary pipe (14), and the cab (3) is crawled by the first hydraulic motor (4). It is possible to turn in any direction with respect to 2).

As described above, while the first operation lever (28) is being held, the first push button switch (4
By turning on / off 2), the first operating lever (2
Since the first hydraulic motor (4) and the second hydraulic motor (36) can be operated in 8), when switching the operation of the first hydraulic motor (4) and the second hydraulic motor (36), There is no need to change the operation lever.

Next, when the auxiliary grip (35) of the grip hand (32) is opened and closed to hold an object, the second
The second push button switch (51) mounted on the grip portion is turned on while holding the operation lever (29), and the fifth solenoid (52) and the fourth solenoid of the third electromagnetic switching valve (47) are turned on. By exciting the seventh solenoid (54) of the switching valve (49), the third electromagnetic switching valve (47) and the fourth electromagnetic switching valve (49) are switched from the parallel position to the cross position, respectively, The primary pipe (16) and the sixth primary pipe (48) are connected via a third electromagnetic switching valve (47), and the second secondary pipe (17) and the sixth secondary pipe ( 50) is connected via a fourth electromagnetic switching valve (49). In this state, by switching the second main switching valve (15) from the shut-off position to the cross position or the parallel position by the second operation lever (29),
After passing the hydraulic oil from the hydraulic pressure source (24) through the second main switching valve (15), the second primary pipe (16), the third electromagnetic switching valve (47) and the sixth primary pipe ( 48) Alternatively, the fourth hydraulic cylinder (37) is supplied to the fourth hydraulic cylinder (37) through the second secondary pipe (17), the fourth electromagnetic switching valve (49), and the sixth secondary pipe (50). The sub-grip (35) of the grip hand (32) can be opened and closed by the hydraulic cylinder (37), and an object can be held by the main grip (34).

Further, as described above, with the second main switching valve (15) being switched from the shut-off position to the cross position or the parallel position by the second operation lever (29), the second push button switch is turned on. When (51) is turned off, the third electromagnetic switching valve (47)
Fifth solenoid (52) and fourth solenoid-operated directional control valve (49)
The seventh solenoid (54) is demagnetized, and at the same time, the sixth solenoid (53) of the third solenoid-operated switching valve (47) and the eighth solenoid (55) of the fourth solenoid-operated switching valve (49) are excited. Therefore, the third electromagnetic switching valve (47) and the fourth electromagnetic switching valve (49) are switched from the intersection position to the parallel position, and the hydraulic oil after passing through the second main switching valve (15) is discharged. It is supplied to the third hydraulic cylinder (11) through the second primary pipe (16) or the second secondary pipe (17), and the grip hand (32) is supplied by the third hydraulic cylinder (11). Can swing with respect to the arm (7).

As described above, while holding the second operation lever (29), the second push button switch (5
By turning on / off 1), the second operating lever (2
Since the third hydraulic cylinder (11) and the fourth hydraulic cylinder (37) can be operated in 9), when switching the operation of the third hydraulic cylinder (11) and the fourth hydraulic cylinder (37), There is no need to change the operation lever.

According to the hydraulic drive device for a construction machine described above, the grip hand (32) can be operated without increasing the number of operation levers. The operation can be mastered in time.

[0020]

By the way, the grip hand (32) has a strong gripping force and cannot be adjusted. For this reason, there is no problem when gripping a rigid object, but there is a problem in that when gripping a soft object, the gripping force is too strong and the object is crushed.

The present invention has been proposed in view of the above problems, and an object of the present invention is to provide a construction and construction machine capable of adjusting the output of an additional hydraulic actuator in accordance with the conditions at that time. It is intended to provide a hydraulic drive device.

[0022]

In order to achieve the above object, the present invention provides a construction machine for supplying hydraulic oil generated from a hydraulic pump directly connected to an engine to hydraulic actuators of respective working parts via a main switching valve. In the hydraulic drive device according to the above, an electromagnetic switching valve is respectively disposed in the middle of the primary pipe and the secondary pipe connecting the above-mentioned existing hydraulic actuator and the main switching valve, and the two electromagnetic switching valves are respectively connected to the additional hydraulic actuator. Connected via
The operation lever of the main switching valve is provided with a pushbutton switch for electrically switching between the two electromagnetic switching valves, and an electromagnetic proportional pressure reducing valve is provided in the middle of a pipe connecting the primary side of the additional hydraulic actuator and the electromagnetic switching valve. And a setting potentiometer for remotely adjusting the pressure reduction amount of the electromagnetic proportional pressure reducing valve is provided in a driver's seat or the like.

[0023]

According to the present invention, when the pressure reducing amount of the electromagnetic proportional pressure reducing valve is adjusted by the setting potentiometer, the pressure of the hydraulic oil supplied to the primary side of the additional hydraulic actuator is reduced. The output can be adjusted to the conditions at that time.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, an embodiment in which a hydraulic drive device for a construction machine according to the present invention is applied to a case where a grip hand (32) is attached as a tip tool to the tip of an arm (7) of a power shovel. Will be explained. still,
FIG. 1 is a hydraulic circuit diagram showing only a hydraulic system of a main part of the hydraulic circuit. The same members as those in FIG. 4 described in the related art are denoted by the same reference numerals, and description of the same items will be omitted.

In FIG. 1, reference numeral (56) denotes an electromagnetic proportional pressure reducing valve disposed in the middle of the sixth primary pipe (50), which operates on the primary side of the fourth hydraulic cylinder (37). The pressure of the hydraulic oil supplied to the pressure reducing side is reduced to a required pressure. (57) is a setting potentiometer arranged in the driver's seat or the like, and is a seventh solenoid (58) of the electromagnetic proportional pressure reducing valve (56).
Is electrically connected to an amplifier (59), and by changing the resistance value of the setting potentiometer (57), the electromagnetic force of the seventh solenoid (58) is changed to change the electromagnetic proportional pressure reducing valve (56). Adjust the amount of vacuum. Incidentally, (60) is a pilot check valve disposed between the electromagnetic proportional pressure reducing valve (56) of the sixth primary pipe (50) and the fourth hydraulic cylinder (37).
The check action is released by the hydraulic pressure generated in the sixth secondary pipe (48).

In the above configuration, the electromagnetic force of the seventh solenoid (58) of the electromagnetic proportional pressure reducing valve (56) is changed by the setting potentiometer (57) via the amplifier (59) to change the electromagnetic force of the electromagnetic proportional pressure reducing valve (56). Is adjusted, the pressure of the hydraulic oil supplied to the primary side of the fourth hydraulic cylinder (37) is reduced, whereby the gripping force of the clip hand (32) is adjusted. Therefore, when biting a soft object,
When the pressure reducing amount of the electromagnetic proportional pressure reducing valve (56) is increased by the setting potentiometer (56), the pressure of the hydraulic oil supplied to the primary side of the fourth hydraulic cylinder (37) is greatly reduced, and the grip hand (32) ) The biting force becomes weaker,
It can hold soft objects. The pressure of the hydraulic oil supplied to the primary side of the fourth hydraulic cylinder (37) is adjusted by adjusting the pressure reduction amount of the electromagnetic proportional pressure reducing valve (56) by the setting potentiometer (57) according to the object to be held. By adjusting the strength of the gripping force of the grip hand (32) by reducing the pressure, it is possible to optimally grip a rigid object to a soft object.

According to the apparatus of the present invention, the clip hand (3
Since the gripping force of 2) can be easily adjusted by remote control according to the conditions of the gripping object, it is possible to grip a rigid object to a soft object in an optimal state.

In the above embodiment, the case where the gripping force of the grip hand (32) attached to the tip of the arm (7) of the power shovel as a tip tool is adjusted, but the present invention is not limited to this. Instead, when a tip tool having a hydraulic actuator other than the grip hand (32) is attached, the output of the tip tool can be adjusted according to the conditions at that time. It can be widely applied to civil engineering machines.

[0029]

According to the present invention, the output of the tip tool can be easily adjusted remotely according to the conditions at that time. For example, when a clip hand is attached as the tip tool, the gripping force By adjusting the strength of the device according to the conditions of the object to be held, it is possible to obtain an effective effect as a device of this kind that it is possible to hold from a rigid object to a soft object.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit showing only a hydraulic system of a main part of an embodiment in which a hydraulic drive device for a construction earth-moving machine according to the present invention is applied to a case where a grip hand is attached to a tip of an arm of a power shovel as a tip tool. FIG.

FIG. 2 is a schematic configuration diagram of a hydraulic drive device of the power shovel.

FIG. 3 is a schematic configuration diagram of a hydraulic drive device of a power shovel in which a grip hand is attached to a tip end of an arm.

FIG. 4 is a schematic configuration diagram showing a hydraulic drive device in a construction machine capable of operating a hydraulic actuator of an added hydraulic system with an existing operation lever.

[Explanation of symbols]

 13 First primary pipe 14 First secondary pipe 16 Second primary pipe 17 Second secondary pipe 36 Second hydraulic motor 37 Fourth hydraulic cylinder 38 First electromagnetic switching valve 39 Fifth primary Piping 40 Second electromagnetic switching valve 41 Fifth secondary pipe 42 First push button switch 43 First solenoid 44 Second solenoid 45 Third solenoid 46 Fourth solenoid 47 Third electromagnetic switching valve 48 Sixth secondary Piping 49 Fourth electromagnetic switching valve 50 Sixth primary piping 51 Second pushbutton switch 52 Fifth solenoid 53 Sixth solenoid 54 Seventh solenoid 55 Eighth solenoid 56 Electromagnetic proportional pressure reducing valve 57 Setting potentiometer 58 Seventh solenoid 59 Amplifier 60 Pilot operated check valve

Claims (1)

(57) [Claims] 1. A hydraulic drive device for a construction machine for supplying hydraulic oil generated from a hydraulic pump directly connected to an engine to hydraulic actuators of respective working parts via a main switching valve, wherein the existing hydraulic actuator and the main switching valve are provided. An electromagnetic switching valve is disposed in the middle of the primary pipe and the secondary pipe for connecting the electromagnetic switching valves, and both of the electromagnetic switching valves are connected to additional hydraulic actuators via respective pipes, and the operation lever of the main switching valve is connected to the operation lever. A push button switch for electrically switching between the two electromagnetic switching valves is provided, and an electromagnetic proportional pressure reducing valve is provided in the middle of a pipe connecting the primary side of the additional hydraulic actuator and the electromagnetic switching valve. An oil in a construction machine, wherein a setting potentiometer for remotely adjusting a pressure reducing amount of a proportional pressure reducing valve is provided in a driver's seat or the like. Drive.