JP4976213B2 - Hydraulic circuit of excavation turning work vehicle - Google Patents

Description

  The present invention relates to a technique of a hydraulic circuit configuration of an excavation turning work vehicle.

  Excavation swivel vehicles that can excavate and load earth and sand are well known. The excavation turning work vehicle is composed of a traveling device capable of self-propelling, a turning body capable of rotating 360 degrees thereon, and a working machine for performing excavation work. In general, excavation and turning work vehicles perform all operations of traveling and working by supplying hydraulic pressure to a hydraulic actuator (hydraulic cylinder, hydraulic motor, etc.) with a hydraulic pump driven by an engine. The work machine includes a boom, an arm, and a bucket that are rotated by a hydraulic cylinder. The revolving body is configured to revolve by a hydraulic motor. Thus, the excavation turning work vehicle includes a hydraulic circuit for driving the working machine or turning the turning body.

  Patent Document 1 discloses an example of a hydraulic circuit configuration of an excavation work vehicle. That is, the disclosed hydraulic circuit has three hydraulic pumps, and supplies hydraulic oil to a single hydraulic actuator from a plurality of hydraulic pumps when each hydraulic actuator is driven independently or when a plurality of hydraulic actuators are driven simultaneously. Constitutes a hydraulic circuit.

Patent Document 2 discloses a hydraulic circuit configuration obtained by improving the hydraulic circuit configuration of Patent Document 1. That is, the disclosed hydraulic circuit constitutes a hydraulic circuit in which a shuttle valve and a hydraulic pressure switching valve are added to the configuration example of Patent Document 1.
Japanese Patent Laid-Open No. 10-88627 JP 2003-301804 A

  The hydraulic configuration of Patent Document 2 aims to improve the boom driving speed when the boom and the swing are simultaneously driven. However, the hydraulic configuration of Patent Document 2 has a more complicated circuit configuration than the conventional one (hydraulic circuit configuration of Patent Document 1), although the above-mentioned object is solved. Therefore, the problem to be solved is to provide an excavation turning work vehicle that improves the boom driving speed when the boom and the turning are simultaneously driven in a simple hydraulic circuit configuration.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

The first switching valve of the boom cylinder (CY1) for driving the boom (21) by the first hydraulic pump (P1), the second hydraulic pump (P2), and the third hydraulic pump (P3). (V1), the second switching valve (V2) of the arm cylinder (CY2) that drives the arm (22), and the third switching valve (VM) of the turning motor (M) that drives the turning body (3) to turn. In the hydraulic circuit of the excavation turning vehicle (1) for supplying pressure oil to the hydraulic switching valve, the discharge port of the first hydraulic pump (P1) is connected to the pump port of the first switching valve (V1). The discharge port of the dual hydraulic pump (P2) is connected to the pump port of the speed increasing switching valve (Vz), and the first discharge port on the secondary side of the speed increasing switching valve (Vz) is the second switching valve ( V2) and the third hydraulic pump (P3 Is connected to the pump port of the third switching valve (VM), and the pump port of the first switching valve (V1) is connected to the second discharge on the secondary side of the speed increasing switching valve (Vz). A second discharge port on the secondary side of the third switching valve (VM) is also connected to the pump port of the second switching valve (V2), and when the boom (21) is driven alone, The pressure oil of the first hydraulic pump (P1) and the second hydraulic pump (P2) is pressurized to the operation side causing the boom (21) in the boom cylinder (CY1) through the speed increasing switching valve (Vz). When oil is supplied and the arm (22) is driven independently, the pressure oil of the second hydraulic pump (P2) and the third hydraulic pump (P3) is switched to the arm cylinder (CY2) by switching the second switching valve (V2). When the rotary body (3) is driven alone, (P3) supplies pressure oil to the swing motor (M), and when the boom (21) and the swing body (3) are driven simultaneously, the first hydraulic pump (P1) and the second hydraulic pump ( P2) pressure oil is supplied to the boom cylinder (CY1), and a third hydraulic pump (P3) supplies pressure oil to the swing motor (M), so that the boom (21) and the arm (22) simultaneously. At the time of driving, the pilot pressure of the speed increasing switching valve (Vz) is supplied so that the pressure oil of the second hydraulic pump (P2) is preferentially supplied to the arm cylinder (CY2) rather than the boom cylinder (CY1). Pressure oil when the first switching valve (V1) is operated to the side that raises the boom (21) is supplied to the (Pa) side, and the pilot pressure (Pb) side of the speed increasing switching valve (Vz) is supplied. Fold the arm (22) of the second switching valve (V2) The pressure oil when operated is supplied, and the speed increasing switching valve (Vz) is supplied with pressure oil from the second switching valve (V2) and is a spring as a biasing means on the pilot pressure (Pb) side (S) is provided, and when the pilot pressure is simultaneously applied to the pilot pressure (Pa) side and the pilot pressure (Pb) side, the pressures on both sides are offset, and the urging force of the spring (S) causes the second switching valve The speed increasing switching valve (Vz) is switched to the pilot pressure (Pb) side to which the pressure oil from (V2) is supplied, and the pressure oil of the second hydraulic pump (P2) is sent more than the boom cylinder (CY1). The arm cylinder (CY2) is configured to be supplied preferentially to the folding side of the arm (22) .

  As effects of the present invention, the following effects can be obtained.

In claim 1, when the boom cylinder CY1 and the arm cylinder CY2 are driven simultaneously, the first switching valve V1 and the second switching valve V2 are switched by the operation of the boom operation lever R1 and the arm operation lever R2. Pressure oil is supplied to the boom cylinder CY1 by the first pump P1, and pressure oil is supplied to the arm cylinder CY2 by the second hydraulic pump P2 and the third hydraulic pump P3. That is, priority is given to the operation of the arm 22.
By adopting such a configuration, the working machine 4 can be folded and stored. First, the arm 22 at a position away from the revolving unit 3 can be quickly folded and stored in the safe area.
Further, conventionally, in this case, the pressure oil is branched from the third hydraulic pump P3 and sent to the boom cylinder CY1, and the shortage is branched from the second hydraulic pump P2 and supplied to the turning motor M. The piping was complicated and pressure loss occurred.
However, by configuring as in the present invention, each hydraulic pump supplies pressure oil one by one to each hydraulic device, so that the hydraulic device can be operated efficiently without causing pressure loss.
The boom drive speed can be improved by supplying pressure oil from the two hydraulic pumps to the boom cylinder when the boom and the swivel are driven simultaneously.
That is, in the hydraulic circuit provided in the excavation turning work vehicle, the boom driving speed during simultaneous driving of the boom and the turning can be improved with a simple configuration.

  Next, embodiments of the invention will be described. FIG. 1 is a side view showing an overall configuration of an excavating and turning work vehicle according to an embodiment of the present invention, FIG. 2 is a hydraulic circuit configuration diagram showing the basic configuration of the hydraulic circuit, and FIG. FIG. 4 is a block diagram showing the configuration when the swinging body is driven alone, FIG. 5 is a block diagram showing the configuration when the boom and the swinging body are driven simultaneously, and FIG. 6 is the configuration showing the configuration when the arm is driven alone. FIG. FIG. 7 is a configuration diagram showing the configuration when the arm and the boom are simultaneously driven, and FIG. 8 is a configuration diagram showing the configuration when the arm, the boom and the swing motor are simultaneously driven.

  First, a schematic configuration of the excavation turning working vehicle 1 according to the embodiment of the present invention will be briefly described with reference to FIG. As shown in FIG. 1, the excavation turning work vehicle 1 includes a crawler type traveling device 2, a revolving body 3 that is supported at the upper center of the crawler type traveling device 2 so as to be able to turn left and right, and a front portion of the revolving body 3. The working machine 4 is mounted at the center of the left and right.

  The crawler type traveling device 2 is provided with a blade 6 on one side in the front-rear direction so as to be rotatable up and down. The blade 6 is used when performing leveling work accompanying excavation work. In addition, the crawler type traveling device 2 can use a crawler of a variable gauge, and stability can be ensured by widening the interval between the crawlers during work.

  The swivel body 3 is provided with a swivel motor M at the center of the swivel base 7 and is covered with a rear cover 11b on the rear side and side covers 11a on the left and right sides. The turning motor M is a motor that rotates the turning body 3 with respect to the traveling device. A driver seat support 12 is disposed above the turning motor M. A driver's seat 13 is disposed on the driver's seat support base 12, and a driving operation unit 15 is formed around the driver's seat 13.

  The driving operation unit 15 has a driver's seat 13 disposed at the left and right center of the rear side, and an operation lever, a lock lever, and the like are disposed on both the left and right sides. Step 17 is arranged to extend in the left-right direction in front of and below the driver's seat 13 (see FIG. 3). Further, on the step 17, a pedal, a travel lever and the like are arranged. Step 17 plays the role of a floor board in the driver's seat 13 and becomes a platform when the driver drives (operates). In addition, a canopy 18 is disposed above the driver seat 13 to cover the upper portion of the driver seat 13.

  The work machine 4 includes a boom 21, an arm 22, and a bucket 23. The boom 21, arm 22, and bucket 23 are connected to one ends of the cylinders CY 1, CY 2, and CY 3, respectively, and can be rotated by their expansion and contraction driving. These members are configured to rotate by operating the operation lever of the driving operation unit 15, and excavation work, loading work, and the like can be performed by the work machine 4.

  Next, the basic configuration of the hydraulic circuit 30 of the excavation turning work vehicle 1 will be briefly described with reference to FIG. As shown in FIG. 2, the basic configuration of the hydraulic circuit 30 of the present embodiment is that three hydraulic pressures of a first hydraulic pump P1, a second hydraulic pump P2, and a third hydraulic pump P3 driven by an engine (not shown). The pump, the boom cylinder CY1 driven by the hydraulic pumps P1, P2, and P3, the three hydraulic actuators of the arm cylinder CY2 and the swing motor M, and the first switching valve V1 that controls the direction and flow rate of the supplied pressure oil , The second switching valve V2, the third switching valve VM, and the speed increasing switching valve Vz, and an oil passage (solid line in the figure) connecting them.

  The switching valves V1, V2, VM, and Vz of the present embodiment are the operation valves (remote control valves) provided at the bases of the operation levers such as the boom operation lever R1, the arm operation lever R2, the turning operation lever RM, and the pilot oil passage. They are connected by a broken line in the figure. Further, the speed increasing switching valve Vz is provided with a spring S as an urging means on the Pb side. Therefore, when the pilot pressure is simultaneously applied to the Pa side and the Pb side, the pressures of the pilot pressure Pa and the pilot pressure Pb cancel each other and are positioned on the Pb side by the urging force of the spring S. In FIG. 2, the switching valves V1, V2, and VM each indicate a neutral state. Further, the speed increasing switching valve Vz indicates a state where the pilot pressure Pa is not applied (a state where the pilot pressure Pb is applied).

  The discharge port of the first hydraulic pump P1 is connected to the pump port of the first switching valve V1. The second hydraulic pump P2 is connected to the second switching valve V2 via the speed increasing switching valve Vz. Specifically, the discharge port of the second hydraulic pump P2 is connected to the pump port of the speed increasing switching valve Vz. The first discharge port on the secondary side of the speed increasing switching valve Vz is connected to the pump port of the second switching valve V2. The discharge port of the third hydraulic pump P3 is connected to the pump port of the third switching valve VM. The pump port of the first switching valve V1 is connected to the second discharge port on the secondary side of the speed increasing switching valve Vz via a check valve. Furthermore, the pump port of the second switching valve V2 is connected to the second discharge port on the secondary side of the third switching valve VM.

  By adopting such a configuration, the following effects can be obtained. That is, the discharge pressure oil from the first hydraulic pump P1 is supplied to the first switching valve V1. Further, when the speed change switching valve Vz is in a neutral state, that is, when only the pilot pressure Pb is applied or when the pilot pressure Pa and the pilot pressure Pb are applied, the discharge pressure oil from the second hydraulic pump P2 is increased. It is supplied to the second switching valve V2 via Vz. On the other hand, when only the pilot pressure Pa is applied to the acceleration switching valve Vz, the acceleration switching valve Vz is supplied to the first switching valve V1. Further, the discharge pressure oil from the third hydraulic pump P3 is supplied to the third switching valve VM. On the other hand, when VM is in a neutral state, it is supplied to the second switching valve V2.

  Next, five typical pressure oil supply patterns by the hydraulic circuit 30 will be described in detail with reference to FIGS.

  As shown in FIG. 3, the pressure oil supply pattern for independently driving the boom cylinder CY1 of the excavation turning work vehicle 1 will be described. When the boom cylinder CY1 is driven alone, the first switching valve V1 and the speed increasing switching valve Vz are switched by operating the boom operation lever R1, and the pressure oil from the first pump hydraulic pressure P1 and the second hydraulic pump P2 is switched. Is supplied to the boom cylinder CY1. By supplying the combined pressure oil of the two hydraulic pumps P1 and P2 in this way, a large amount of pressure oil can be supplied, and the operation of the boom 21 can be increased.

  As shown in FIG. 4, a pressure oil supply pattern for independently driving the turning motor M of the excavation turning work vehicle 1 will be described. When the swing motor M is driven alone, the third switching valve VM is switched by the operation of the swing operation lever RM, and pressure oil is supplied to the swing motor M from the third hydraulic pump P3.

  As shown in FIG. 5, the pressure oil supply pattern for simultaneously driving the boom cylinder CY1 and the turning motor M of the excavation turning work vehicle 1 will be described. When the boom cylinder CY1 and the swing motor M are driven simultaneously, the first switching valve V1, the speed increasing switching valve Vz, and the third switching valve VM are switched by the operation of the boom operation lever R1 and the swing operation lever RM. Pressure oil is supplied to the boom cylinder CY1 by the first hydraulic pump P1 and the second hydraulic pump P2, and pressure oil is supplied to the turning motor M by the third hydraulic pump P3. Thus, even during the turning drive, a large amount of pressure oil can be supplied to the boom 21 by supplying the combined pressure oil of the two hydraulic pumps P1 and P2 to the boom 21. Can be increased. For example, conventionally, in this case, the pressure oil of the third hydraulic pump P3 has been distributed and supplied to the boom 21, so that pressure loss has occurred. This driving pattern is one pattern of simulated operation under the test conditions of fuel consumption standardized by the Japan Construction Mechanization Association Standard (JCMAS).

  As shown in FIG. 6, the pressure oil supply pattern for independently driving the arm cylinder CY2 of the excavation turning work vehicle 1 will be described. When the arm cylinder CY2 is driven alone, the second switching valve V2 is switched by operating the arm operation lever R2, and pressure oil is supplied to the boom cylinder CY2 from the second hydraulic pump P2 and the third hydraulic pump P3. .

  As shown in FIG. 7, the pressure oil supply pattern for simultaneously driving the boom cylinder CY1 and the arm cylinder CY2 of the excavation turning work vehicle 1 will be described. When the boom cylinder CY1 and the arm cylinder CY2 are driven simultaneously, the first switching valve V1 and the second switching valve V2 are switched by the operation of the boom operation lever R1 and the arm operation lever R2, and the boom is driven by the first pump P1. Pressure oil is supplied to the cylinder CY1, and pressure oil is supplied to the arm cylinder CY2 by the second hydraulic pump P2 and the third hydraulic pump P3. That is, priority is given to the operation of the arm 22. By adopting such a configuration, the working machine 4 can be folded and stored. First, the arm 22 at a position away from the revolving unit 3 can be quickly folded and stored in the safe area.

  As shown in FIG. 8, the pressure oil supply pattern for simultaneously driving the boom cylinder CY1, the arm cylinder CY2, and the turning motor M of the excavation turning work vehicle 1 will be described. When the boom cylinder CY1, the arm cylinder CY2, and the turning motor M are driven simultaneously, the first switching valve V1, the second switching valve V2, the second switching valve V2, and the second switching valve RM are operated by operating the boom operation lever R1, the arm operation lever R2, and the turning operation lever RM. The three switching valve VM is switched, pressure oil is supplied to the boom cylinder CY1 by the first pump P1, pressure oil is supplied to the arm cylinder CY2 from the second hydraulic pump P2, and pressure oil is supplied to the swing motor M from the third hydraulic pump P3. Supply. With such a configuration, each hydraulic pump supplies pressure oil to each hydraulic device one by one, so that the hydraulic devices can be operated efficiently without causing pressure loss. For example, conventionally, in this case, the pressure oil is branched from the third hydraulic pump P3 and sent to the boom cylinder CY1, and the second hydraulic pump P2 is branched to supply the shortage to the turning motor M. The piping was complicated and pressure loss occurred.

The side view which showed the whole structure of the excavation turning working vehicle which concerns on the Example of this invention. The hydraulic circuit block diagram which similarly shows the basic composition of a hydraulic circuit. The block diagram which similarly shows the structure at the time of single drive of a boom. The block diagram which similarly shows the structure at the time of the independent drive of a turning body. The block diagram which similarly shows the structure at the time of the simultaneous drive of a boom and a turning body. The block diagram which similarly shows the structure at the time of single drive of an arm. The block diagram which similarly shows the structure at the time of the simultaneous drive of an arm and a boom. The block diagram which similarly shows the structure at the time of the simultaneous drive of an arm, a boom, and a turning motor.

DESCRIPTION OF SYMBOLS 1 Excavation turning work vehicle 2 Traveling apparatus 3 Rotating body 4 Working machine 21 Boom 22 Arm 23 Bucket E Engine P1 1st hydraulic pump P2 2nd hydraulic pump P3 3rd hydraulic pump CY1 Boom cylinder CY2 Arm cylinder M Turning motor V1 1st switching Valve V2 Second switching valve VM Third switching valve Vz Speed increasing switching valve S Spring

Claims (1)

The first switching valve (V1) and the arm (of the boom cylinder (CY1) that drives the boom (21) by the first hydraulic pump (P1), the second hydraulic pump (P2), and the third hydraulic pump (P3). 22) pressure is applied to each hydraulic switching valve of the second switching valve (V2) of the arm cylinder (CY2) that drives the rotating cylinder (CY) and the third switching valve (VM) of the swing motor (M) that drives the swing body (3) to rotate. In the hydraulic circuit of the excavation turning work vehicle (1) for supplying oil, the discharge port of the first hydraulic pump (P1) is connected to the pump port of the first switching valve (V1), and the second hydraulic pump (P2) Is connected to the pump port of the speed increasing switching valve (Vz), and the secondary first discharging port of the speed increasing switching valve (Vz) is connected to the pump port of the second switching valve (V2). Connected and the discharge port of the third hydraulic pump (P3) A second discharge port on the secondary side of the speed increasing switching valve (Vz) is also connected to the pump port of the first switching valve (V1). A second discharge port on the secondary side of the third switching valve (VM) is also connected to the pump port of the two switching valve (V2). When the boom (21) is driven alone, the first hydraulic pump (P1 ) And the second hydraulic pump (P2) through the speed changeover valve (Vz), the pressure oil is supplied to the triggering side of the boom (21) in the boom cylinder (CY1), and the arm During the single drive of (22), the pressure oil of the second hydraulic pump (P2) and the third hydraulic pump (P3) is supplied to the arm cylinder (CY2) by switching the second switching valve (V2), and the revolving body ( 3) When driving alone, the third hydraulic pump (P3) Pressure oil is supplied to the turbine (M), and when the boom (21) and the swing body (3) are driven simultaneously, the pressure oil from the first hydraulic pump (P1) and the second hydraulic pump (P2) is used. The boom cylinder (CY1) is supplied, the third hydraulic pump (P3) supplies pressure oil to the swing motor (M), and when the boom (21) and the arm (22) are simultaneously driven, In order to preferentially supply the pressure oil of the two hydraulic pumps (P2) to the arm cylinder (CY2) rather than the boom cylinder (CY1), on the pilot pressure (Pa) side of the speed increasing switching valve (Vz), Pressure oil is supplied when the first switching valve (V1) is operated to raise the boom (21), and the second switching valve is provided on the pilot pressure (Pb) side of the speed increasing switching valve (Vz). Supply the pressure oil when the arm (22) of (V2) is operated on the folding side. The speed increasing switching valve (Vz) is provided with a spring (S) as an urging means on the pilot pressure (Pb) side to which the pressure oil from the second switching valve (V2) is supplied. When pilot pressure is simultaneously applied to the pressure (Pa) side and the pilot pressure (Pb) side, the pressures on both sides are canceled and the pressure oil from the second switching valve (V2) is applied by the biasing force of the spring (S). The switching valve for acceleration (Vz) is switched to the pilot pressure (Pb) side to which pressure is supplied, and the pressure oil of the second hydraulic pump (P2) is supplied to the arm cylinder (CY2) rather than the boom cylinder (CY1). A hydraulic circuit for an excavating and turning work vehicle, wherein the hydraulic circuit is configured to be preferentially supplied to the folding side of the arm (22) .