JP4171161B2 - Hydraulic circuit of construction machine for foundation work - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic circuit of a construction machine for foundation work in which a leader is provided with two working devices that are moved up and down by driving a hydraulic motor.
[0002]
[Prior art]
For example, in a gravel ground or hard ground mixed with cobblestone, it is not possible to excavate only with an auger screw. Yes.
[0003]
As shown in FIG. 4, the construction machine used for this work is provided with working devices 3 and 4 for rotating and driving the auger screw 5 and the casing 6 on a leader 2 erected on the base machine 1. As shown in FIG. 5, the work device 3 is engaged with the leader 2 by engaging guide guides 3 a and 3 b provided on the work device 3 with two guide rails 2 a attached to the entire length of the reader 2. Pinion 8a, 8b driven by a hydraulic motor A (22a, 22b) mounted on the work device 3 is provided on both sides of a double-sided rack 7 provided vertically in the center between the guide rails 2a. Engagement of the casing with the work device 4 to the reader 2 is the same as that of the work device 3. In FIG. 5, 9 is a casing driving device.
[0004]
The working device 3 and the working device 4 may be used singly or two at the same time. The hydraulic circuit that drives the pinions 8a and 8b of the working device 3 and the pinions 8c and 8d of the working device 4 (not shown). Are provided independently.
As shown in FIG. 6, the hydraulic circuit that drives the pinions 8 a and 8 b includes a variable discharge hydraulic pump 15, an elevating switching valve 17, and an elevating device 21, and the elevating device 21 is mounted on the work device 3. Then, by operating the operation lever 17a of the elevating switching valve 17, pressure oil is sent to the ascending or descending side of the hydraulic motor A (22a, 22b) of the elevating device 21 to drive the pinions 8a, 8b.
[0005]
The hydraulic motor A (22a) for driving the pinion 8a and the hydraulic motor A (22b) for driving the pinion 8b are connected in parallel to the hydraulic pump 15 and are driven simultaneously by operating the elevation switching valve 17.
The hydraulic motor A (22a, 22b) is provided with brake valves 25a, 25b and relief valves 27, 28 for releasing excessive load, respectively.
[0006]
The brake valves 25a and 25b are for holding the hydraulic motor A (22a and 22b) from rotating when the switching valve 17 is in the neutral position. 26, the output shaft of the hydraulic motor A (22a, 22b) is fixed so as not to rotate.
[0007]
Further, the working device 4 is provided with the same hydraulic circuit as the working device 3 of the auger by a variable discharge hydraulic pump having the same capacity different from the hydraulic pump 15.
[0008]
[Problems to be solved by the invention]
As described above, the two working devices may be lifted and lowered at the same time, but usually use two left and right plunger pumps for traveling of the base machine, so the hydraulic pump and the hydraulic motor have the same capacity. Things are provided.
[0009]
However, the maximum output of the engine that drives the hydraulic pump is usually smaller than the sum of the maximum outputs of each hydraulic pump, and if the work device is under heavy load, the hydraulic output is not exceeded. The pump discharge is controlled to decrease.
[0010]
Therefore, when both the working devices 3 and 4 are operated, when the load on one lifting device increases, the discharge amount of the hydraulic pump decreases, so the lifting speeds of the two working devices are different. There is a problem that synchronized work cannot be performed.
[0011]
In addition, although the conventional lifting device has the same speed of ascending and descending, for example, there is a demand to increase the working efficiency when the excavation work is not performed as in the case of raising the auger screw.
Therefore, the present invention provides a hydraulic circuit for a construction machine for foundation work that is inevitably synchronized when the working device is lifted and lowered simultaneously by two independent plunger pumps, and can be raised or lowered at high speed or low speed as necessary. It is for the purpose.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following measures. That is,
In the hydraulic circuit of a construction machine for foundation work that has two working devices that move up and down by driving a hydraulic motor that engages with a leader standing on the base machine, one of the two hydraulic pumps is switched to lift A valve and a hydraulic motor A of one working device and a hydraulic motor B of the other working device are piped in series, and the other hydraulic pump is piped to the output side of the elevation switching valve via a merging switching valve; The electromagnetic on-off valve A is connected to the flow path connecting the lift switching valve and the hydraulic motor A, the electromagnetic open / close valve B is connected to the flow path connecting the hydraulic motor A and the hydraulic motor B, and the flow path connecting the hydraulic motor B and the lift switching valve. An electromagnetic on-off valve C, a branch passage communicating from the passage connecting the electromagnetic on-off valve B and the hydraulic motor B to the passage connecting the lift switching valve and the electromagnetic on-off valve A, the hydraulic motor A and the electromagnetic Switching up and down from the flow path connecting on-off valve B And a branch flow passage communicating with the flow passage connecting the electromagnetic on-off valve C, and an electromagnetic on-off valve D and an electromagnetic on-off valve E are provided on both branch passages, respectively. Both or one of the hydraulic motors B is operated.
[0013]
The present invention is a construction machine for foundation work in which a leader is provided with two working devices on the top and bottom, such as a medium excavation method, a sheet press-fitting method, and a lock auger method, and the lifting and lowering of the working device is hydraulically applied to a chain or rack attached to the leader. Applicable to motor driven sprockets or pinions.
[0014]
The electromagnetic open / close valve provided in each flow path may be a simple open / close valve that opens or closes the flow path by excitation of a solenoid.
The hydraulic pump is of a variable discharge type and is generally used for running a base machine, but other hydraulic pumps may be used. In this case, the two hydraulic pumps do not have to have the same capacity.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on an embodiment applied to the construction machine for foundation work described in FIGS. 4 and 5.
FIG. 1 is a hydraulic circuit of a lifting device of the working devices 3 and 4 provided to be engaged with a reader, and the same reference numerals as those in FIG. 6 denote the same components.
[0016]
This hydraulic circuit is a variable discharge type and the same capacity hydraulic pumps 15 and 16, a lift switching valve 17 and a merging switching valve 18 that are switched by operating the operating levers 17a and 18a, and a plurality of electromagnetic switching valves that open and close the flow path. The valve block 20 provided by combining the valves 20a to 20e, the lifting device 21 of the working device 3, and the lifting device 31 of the working device 4 are connected by piping. Although not shown, the hydraulic pumps 15 and 16 are also used to drive a hydraulic motor for traveling of the base machine 1.
[0017]
The elevating device 21 is connected in parallel with hydraulic motors A (22a, 22b) that drive pinions 8a, 8b meshed so as to be sandwiched from both sides by a double-sided rack 7 (see FIG. 5) attached to the leader. The hydraulic motor A (22a, 22b) is provided with brake valves 25a, 25b, and relief valves 27, 28 and a cylinder 26, which are not shown, and are the same as those of the conventional FIG.
[0018]
The lifting device 31 has the same configuration as the lifting device 21 described above, and hydraulic motors B (32a, 32b) that drive the pinions 8c, 8d are connected in parallel. The hydraulic pump 15 is connected in parallel to the hydraulic motor A (22a) and the hydraulic motor A (22b) of the lifting device 21 via the lift switching valve 17 by a pipe 41. The hydraulic motor A (22a) and the hydraulic motor A ( 22b) is connected to the hydraulic motor B (32a) and the hydraulic motor B (32b) by a pipe 42, and the lower side of the hydraulic motor B (32a) and the hydraulic motor B (32b) is connected to the lift switching valve 17 by a pipe 43. Connected by.
[0019]
The hydraulic pump 16 is connected to the pipe 41 and the pipe 43 via the junction switching valve 18 by the pipe 46 and the pipe 47, respectively.
The pipe 41 is provided with an electromagnetic on-off valve A (20a), the pipe 42 is provided with an electromagnetic on-off valve B (20b), the pipe 43 is provided with an electromagnetic on-off valve C (20c), and the electromagnetic on-off valve B ( 20b) is connected to the piping 45 connecting the hydraulic motor B (32a) and the hydraulic motor B (32b) from the piping 42 to the piping 41 connecting the electromagnetic on-off valve A (20a) and the elevation switching valve 17, and this branch flow An electromagnetic on-off valve D (20d) is provided on the road, and an electromagnetic on-off valve C (20c) and an up / down switching valve are connected from a pipe 42 connecting the electromagnetic on-off valve B (20b) to the hydraulic motor A (22a) and the hydraulic motor A (22b) A piping 44 communicating with the piping 43 connecting 17 is connected, and an electromagnetic on-off valve E (20e) is provided in this branch flow path.
[0020]
The cab is provided with a controller 53 for opening and closing the electromagnetic on-off valves A to E (20a to 20e) and a switching operation panel 50 connected thereto.
When the lever 51 of the switching operation panel 50 is set to “A only”, the hydraulic motor A (22a) and the hydraulic motor A (22b) are set. When “B only” is set, the hydraulic motor B (32a) and the hydraulic motor B (32b) are set to hydraulic pressure. The controller 53 opens or shuts off the electromagnetic on-off valves A to E (20a to 20e) according to the table shown in FIG. 2B so that the pressure oil is sent from the pump 15. Similarly, when “AB simultaneous” is selected, the pressure oil is sent to the hydraulic motor A (22a, 22b) and the hydraulic motor B (32a, 32b).
[0021]
Next, the operation of the hydraulic circuit configured as described above will be described.
First, when raising the working device 3 and the working device 4 simultaneously, the lever 51 of the switching operation panel 50 is switched to “AB simultaneous”, and the elevation switching valve 17 is switched to the ascending side. Thereby, the electromagnetic on-off valve A (20a), the electromagnetic on-off valve B (20b), and the electromagnetic on-off valve C (20c) are opened. As shown in FIG. 3, the pressure oil from the hydraulic pump 15 is sent to the piping 41 through the up / down switching valve 17 and passes through the electromagnetic on-off valve A (20a) to the hydraulic motor A (22a) and the hydraulic motor A ( 22b) is sent to the ascending port via the brake valves 25a and 25b to rotate the pinion 8a and the pinion 8b. The hydraulic oil that has flowed out of the hydraulic motor A (22a) and the hydraulic motor A (22b) passes through the pipe 42, passes through the electromagnetic on-off valve B (20b), and rises in the hydraulic motor B (32a) and the hydraulic motor B (32b). Then, the pinion 8c and the pinion 8d are rotated.
[0022]
And from the outflow side of hydraulic motor B (32a) and hydraulic motor B (32b), it passes through piping 43, passes electromagnetic on-off valve C (20c), and is returned to the oil tank from up-down switching valve 17. Moreover, when raising the raising speed of the working device 3 and the working device 4, the merging switching valve 18 is switched to the ascending side. As a result, the pressure oil from the hydraulic pump 16 flows into the pipe 41 through the pipe 46. Therefore, double the amount of oil is sent to the hydraulic motor A (22a, 22b) and the hydraulic motor B (32a, 32b), and the oil rotates at a high speed. At this time, the ascending / descending speed of the working devices 3 and 4 is doubled as compared with the conventional circuit (FIG. 6).
[0023]
Moreover, when lowering | hanging the working apparatus 3 and the working apparatus 4 simultaneously, the raising / lowering switching valve 17 is switched to the descent | fall side. As a result, the pressure oil from the hydraulic pump 15 is sent from the up / down switching valve 17 to the pipe 43, and the pressure oil flows in the direction opposite to the arrow in FIG. 3, and the hydraulic motor A (22a, 22b) and the hydraulic motor B (32a, 32b) rotates in the opposite direction.
[0024]
Next, when only the work device 3 is raised, the lever 51 of the switching operation panel 50 is switched to “A alone”, and the elevation switching valve 17 is switched to the ascending side. Thereby, the electromagnetic on-off valve A (20a) and the electromagnetic on-off valve E (20e) are opened. Then, the pressure oil from the hydraulic pump 15 is sent to the pipe 41 through the up / down switching valve 17 and passes through the electromagnetic on-off valve A (20a) to the ports on the ascending side of the hydraulic motor A (22a) and the hydraulic motor A (22b). Is sent via the brake valves 25a and 25b to rotate the pinion 8a and the pinion 8b (the same as in FIG. 3 so far). The oil on the outflow side of the hydraulic motor A (22a) and the hydraulic motor A (22b) is returned from the lift switching valve 17 to the oil tank through the pipe 42, the pipe 44 (branch flow path), and the pipe 43.
[0025]
When only the work device 4 is raised, the lever 51 of the switching operation panel 50 is switched to “B alone”, and the elevation switching valve 17 is switched to the ascending side. Thereby, the electromagnetic on-off valve C (20c) and the electromagnetic on-off valve D (20d) are opened. Then, the pressure oil from the hydraulic pump 15 passes through the elevation switching valve 17 and is sent from the pipe 41 to the pipe 45 (branch flow path) to the pipe 42, where the hydraulic motor B (32a) and the hydraulic motor B (32b) rise. The pinion 8c and the pinion 8d are rotated. The oil on the outflow side of the hydraulic motor B (32a) and the hydraulic motor B (32b) is returned to the oil tank from the elevation switching valve 17 through the pipe 43.
[0026]
When increasing the ascent speed, the merging switching valve 18 is switched to the ascending side and the pressure oil of the hydraulic pump 16 is merged. Moreover, what is necessary is just to switch the raising / lowering switching valve 17 to the downward side, when lowering | hanging the working apparatus 3 or the working apparatus 4. FIG.
In the above embodiment, two pinions are engaged with a double-sided rack attached to the leader. However, a single-sided rack is attached to the leader and a single pinion is used, and a chain is fixed to the leader. Naturally, the present invention can also be applied to a system in which a sprocket that is installed and engaged with the sprocket is driven by a hydraulic motor.
[0027]
Further, the two hydraulic pumps have been described as driving hydraulic motors for traveling, but other hydraulic pumps may be used, and in this case, they may not have the same capacity.
The present invention is not limited to such an embodiment as described above, and can be implemented in various modes without departing from the gist of the present invention.
[0028]
【The invention's effect】
As described above, the hydraulic circuit of the working device of the construction machine for foundation work according to the present invention includes one hydraulic pump of two hydraulic pumps, a lift switching valve, the hydraulic motor A of one working device, and the other working device. The other hydraulic pump is connected to the output side of the up / down switching valve via a merging switching valve, and a plurality of electromagnetic opening / closing valves are provided in combination with the piping. Since the apparatus can be moved up and down alone or both, the both working apparatuses can be moved up and down synchronously even if the load on one hydraulic motor is large. In addition, since the pressure oil of the other hydraulic pump is joined and used, the ascending / descending speed of the merging work device can be increased compared to the conventional hydraulic circuit, and work suitable for the situation at the construction site can be performed. And work efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a lifting device of a working device of a construction machine for foundation work as one embodiment of the present invention.
FIG. 2 is an operation explanatory diagram of an electromagnetic on-off valve provided in the hydraulic circuit.
FIG. 3 is a flowchart showing the flow of pressure oil when two working devices are lifted simultaneously in FIG. 1;
FIG. 4 is a side view showing the entire foundation construction machine.
FIG. 5 is a side view showing details of a mounting portion of the working device 3 to the reader.
FIG. 6 is a hydraulic circuit diagram of a lifting device of a conventional work device 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base machine 2 ... Leader 2a ... Guide rail 3 ... Working device 3a, 3b ... Guide give 4 ... Working device 5 ... Auger screw 6 ... Casing 7 ... Double-sided rack 8a, 8b ... Pinion 8c, 8d ... Pinion 9 ... Casing drive device DESCRIPTION OF SYMBOLS 15, 16 ... Hydraulic pump 17 ... Elevation switching valve 17a ... Operation lever 18 ... Confluence switching valve 18a ... Operation lever 20 ... Valve block 20a ... Electromagnetic switching valve A 20b ... Electromagnetic switching valve B
20c: Electromagnetic on-off valve C 20d: Electromagnetic on-off valve D
20e ... Electromagnetic on-off valve E21 ... Elevating devices 22a, 22b ... Hydraulic motor A
25a, 25b ... Brake valve 26 ... Cylinder 27, 28 ... Relief valve 31 ... Lifting device 32a, 32b ... Hydraulic motor B
35a, 35b ... Brake valves 41, 42, 43 ... Piping 44, 45 ... Piping (branch flow path)
46, 47 ... Piping 50 ... Switching operation panel 51 ... Lever 53 ... Controller

Claims (1)

In the hydraulic circuit of a construction machine for foundation work that has two working devices that move up and down by driving a hydraulic motor that engages with a leader standing on the base machine, one of the two hydraulic pumps is switched to lift A valve and a hydraulic motor A of one working device and a hydraulic motor B of the other working device are piped in series, and the other hydraulic pump is piped to the output side of the elevation switching valve via a merging switching valve; The electromagnetic on-off valve A is connected to the flow path connecting the lift switching valve and the hydraulic motor A, the electromagnetic open / close valve B is connected to the flow path connecting the hydraulic motor A and the hydraulic motor B, and the flow path connecting the hydraulic motor B and the lift switching valve. An electromagnetic on-off valve C, a branch passage communicating from the passage connecting the electromagnetic on-off valve B and the hydraulic motor B to the passage connecting the lift switching valve and the electromagnetic on-off valve A, the hydraulic motor A and the electromagnetic Switching up and down from the flow path connecting on-off valve B And a branch flow passage communicating with the flow passage connecting the electromagnetic on-off valve C, and an electromagnetic on-off valve D and an electromagnetic on-off valve E are provided on both branch passages, respectively. A hydraulic circuit for a construction machine for foundation work, wherein both or one of the hydraulic motors B is operated.

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