JP2009121097A - Hydraulic system of working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic system of a working machine with two working fronts, which can suppress the scarcity of an oil quantity when combined operations are performed by the oneside working front. <P>SOLUTION: In this hydraulic system of the dual-armed working machine with the first and second working fronts A and B, the first state of supplying pressure oil from first and second hydraulic pumps 100A and 100B to arm cylinders 13a and 13b of the first and second working fronts A and B, respectively, the second state of supplying the pressure oil from the second hydraulic pump 100B to the arm cylinder 13a of the first working front A, and the third state of supplying the pressure oil from the first hydraulic pump 100A to the arm cylinder 13b of the second working front B are selected by a selection means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work machine used for structure demolition work, waste demolition work, road work, civil engineering work, and the like, and more particularly to a hydraulic system for a work machine provided with two multi-joint work fronts.

  In general, a work machine such as a hydraulic excavator is configured such that an articulated work front composed of a boom and an arm is connected to an upper swing body so as to be movable up and down, and a bucket is attached to the tip of the arm so as to be swingable up and down. Instead of installing breakers, crushers, grapples, etc., work machines used for structural demolition work, waste demolition work, road work, civil engineering work, etc. may be configured. In general, this type of work machine has only one work front. However, in recent years, for example, as described in Patent Document 1, two work fronts are provided on the front left and right sides of the upper swing body, respectively. Work machines (double-arm work machines) have also appeared.

JP 2005-232950 A

  When performing a dismantling work using a double-arm work machine, for example, one of the two work fronts (working arms) grips the object to be disassembled and dismantles the object to be disassembled at the other work front. Various operations, which were difficult with a single arm type work machine having a single work front, are possible, and there are advantages in terms of work stability and efficiency. However, since the conventional dual-arm work machine supplies pressure oil to each of the two work fronts using one hydraulic pump, a plurality of actuators are operated, for example, when the arm and boom are moved simultaneously. When performing a combined operation, the amount of oil supplied may be insufficient.

  An object of the present invention is to provide a hydraulic system for a work machine that can suppress a shortage of oil when a work front having only one side is operated in a work machine having two work fronts.

  (1) In order to achieve the above object, the present invention comprises a lower traveling body, an upper revolving body that is turnable with respect to the lower traveling body, a cab provided in the upper revolving body, Left working arm provided at the left front of the upper swing body, left actuator group for driving the left working arm, right working arm provided at the right front of the upper swing body, and driving the right working arm A hydraulic control system for a working machine including a right actuator group, a left control valve group for controlling pressure oil supplied to the left actuator group, and a first hydraulic pump for supplying pressure oil to the left control valve group; A right control valve group for controlling pressure oil supplied to the right actuator group; a second hydraulic pump for supplying pressure oil to the right control valve group; and the left actuator group. A first actuator that is one of the actuators, a pipe line that connects the first control valve corresponding to the first actuator and the second control valve group, and a second that is one of the actuators that configure the right actuator group A conduit that configures the actuator and the right control valve group and connects the second control valve corresponding to the second actuator, a communication line that includes the lines that connect these lines, and the communication line. A first state in which pressure oil from the first and second control valves is supplied to the first and second actuators, respectively, and a second state in which pressure oil from the second control valve is supplied to the first actuators. State and pressure oil from the first control valve is supplied to the second actuator. And channel switching means for switching the third state, provided in the cab, it is assumed that and selecting means for selectively instructing the first, second and third state of the flow path switching unit.

  That is, when the first state is selected with the intention of performing both-arm work with the left and right work arms, the left and right work arms are driven by the pressure oil from the first and second hydraulic pumps, respectively. On the other hand, when the second state is selected with the intention of one-arm work using only the left work arm, a part (first actuator) of the actuator group of the left work arm is taken from the second hydraulic pump. Driven with pressure oil. That is, since the pressure oil from the second hydraulic pump is assigned to the first actuator, the number of actuators to which the pressure oil from the first hydraulic pump is assigned in the left actuator group is reduced. In other words, at the time of one-arm work by the left working arm, the load on the first hydraulic pump is alleviated by causing the second hydraulic pump to bear a part of the load, and the first and second hydraulic pumps can increase the load on the left actuator group. The required flow rate can be accommodated. Similarly, when the third state is selected for the purpose of one-arm work using only the right work arm, the pressure oil from the first hydraulic pump is allocated to the second actuator to reduce the burden on the second hydraulic pump. However, the first and second hydraulic pumps can cope with more required flow rates for the right actuator group. Accordingly, it is possible to suppress an oil shortage when operating the working arm only on one side.

  (2) In the above (1), preferably, a left operating means provided in the cab and outputting an operation signal of the left working arm, and provided in the cab and outputting an operation signal of the right working arm. Controlling the left control valve group and the right control valve group in response to operation signals from the right operating means and the left operating means and the right operating means, respectively, and the selecting means instructs the second state. If the control signal from the right operation means is invalidated and the second control valve is controlled according to the operation signal from the left operation means, and the selection means indicates the third state, A control device that disables an operation signal from the left operation means and controls the first control valve in accordance with the operation signal from the right operation means;

  Thereby, since the working arm on the side corresponding to the state instructed by the selection means can be operated only with the corresponding operating means, the operator can intuitively operate the working arm, Since the operation signal from the operation means on the side not corresponding to the state instructed by the selection means becomes invalid, the work arm does not perform an unintended operation even if this operation means is operated unconsciously, and the work can be performed more efficiently. It can be carried out.

  (3) In any one of the above (1) or (2), preferably, the first and second actuators are arm cylinders for driving the left and right working arms, respectively. To do.

  (4) In any one of the above (1) to (3), preferably, a swing motor that drives the upper swing body to swing, and a third control that constitutes the left control valve group and corresponds to the swing motor. A pipe line connecting the valve and the swing motor, a switching pipe line comprising the right control valve group and a fourth control valve corresponding to the swing motor and a pipe line connecting the swing motor, and the switch pipe line And another flow path switching means for switching the supply source of the pressure oil to the swing motor to either the third or the fourth control valve, and the control means includes a second switching means. Is instructed, the other flow path switching means is controlled to supply pressure oil from the fourth control valve to the swing motor, and the selection means instructs the third state. If it has, it is assumed that control the other channel switching means for supplying the pressure oil of the third control valve to the swing motor.

  According to the present invention, in a work machine having two work fronts, it is possible to suppress a shortage of oil when a work front on only one side is operated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 are views showing the appearance of a double-armed hydraulic excavator 200 that is an example of a double-armed working machine equipped with a hydraulic system according to an embodiment of the present invention. FIG. 1 is a side view of a double-arm hydraulic excavator 200, and FIG. 2 is a top view of the double-arm hydraulic excavator 200.

  1 and 2, a hydraulic excavator 200 includes a lower vehicle body 2 provided with a traveling body 1, an upper swing body 3 that is turnably provided on the lower vehicle body 2, and a front center of the upper swing body 3. A driver's cab 4 provided in the vicinity, and a first work front A and a second work front B provided so as to be swingable up and down and left and right in the front left and right of the upper swing body 3 are provided.

  The first work front (left work arm) A includes a first bracket 6a provided on the left side of the front portion of the upper swing body 3, and a swing post attached to the first bracket 6a so as to swing left and right around the vertical axis. 7a, a boom 10a attached to the swing post 7a so as to be swingable up and down, an arm 12a attached to the boom 10a so as to be swingable in the front-rear direction, and attached to the arm 12a so as to be rotatable up and down. A work tool 14a (a grapple in the figure) is provided. The first work front A is connected to the swing post 7a and the upper swing body 3, and is connected to the swing post cylinder 9a that swings the swing post 7a in the horizontal direction around the vertical axis, and the swing post 7a and the boom 10a. The boom cylinder 11a that swings the boom 10a up and down, the boom 10a and the arm 12a are connected, the arm cylinder 13a that swings the arm 12a up and down, the arm 12a, and the work tool 14a. And a work tool cylinder 15a for rotating the work tool 14a in the vertical direction. That is, the first work front A is driven by each of these cylinders 9a, 11a, 13a, 15a.

  Here, the work tool 14a can be arbitrarily replaced with any one of a cutter, a breaker, a bucket, and other work tools in addition to the grapple shown in the drawing according to the work content of the work machine.

  The second work front (right work arm) B is provided on the front right side of the upper swing body 3. This is configured in the same manner as the first work front A, and the same members are indicated by changing the subscripts from “a” to “b”, and the description is omitted here.

  In the cab 4 of the excavator 200, operating devices 50a and 50b (see FIGS. 3 and 4) for operating the first and second work fronts A and B, and the first and second work fronts A, respectively. , B is provided with a front selection means 80 (see FIG. 5) for selecting an operation mode (described later in detail) of the operation devices 50a, 50b.

  3 and 4 are diagrams showing the operating device according to the present embodiment. FIG. 3 is a perspective view showing the operation devices 50a and 50b provided in the cab 4 together with the driver seat 49, and FIG. 4 is a top view of the operation device.

  3 and 4, the operating device 50 a for the first work front A and the operating device 50 b for the second work front B are provided on the left and right sides of the driver seat 49.

  The operating device 50a is provided with an operating arm bracket 51a provided on the left side of the driver's seat 49, and an operating arm 52a that is attached to the operating arm bracket 51a so as to be able to swing left and right, and that instructs the first working front A to swing left and right. And an armrest 53a attached to the upper part of the operation arm 52a. The armrest 53a has an elbow joint support 77a that assumes that the operator's elbow joint is located. The elbow joint support 77a is located on the swing center axis 73a of the operation arm 52a. The operation arm bracket 51a has an elbow joint position adjusting device 78a for adjusting the position of the elbow joint instruction section 77a (in accordance with the body shape of the operator).

  The operating device 50a is attached to the front end portion of the operating arm 52a so as to be rotatable up and down, and is provided with a horizontal operating lever 54a for instructing the operation of the boom 10a and the arm 12a of the first work front A, and this operation. Around the lever 54a, it is rotatably attached around the rotation center axis 74a of the operation lever 54a, and is attached to a work tool turning lever 55a for instructing turning of the work tool 14a, and a tip of the operation lever 54a. And a work tool operation switch 56a for instructing to drive and stop the work tool 14a.

  When not operated, the operation lever 54a is attached so that a straight line passing through the operator gripping point 72a and the swing center axis 73a (see FIG. 4) is along the front-rear direction as viewed from the operator seated on the driver seat 49. . The operator gripping point 72a is a point that assumes that the center of the palm is located when the operator grips the work tool turning lever 55a.

  The operating device 50a is provided on the operating arm bracket 51a, and is provided with an operating arm displacement detector 57a that detects a swing displacement amount of the operating arm 52a and transmits a signal, and an operating lever 52a. An operation lever vertical direction displacement detector 581a that detects a displacement amount in the vertical direction and transmits a signal and an operation arm 52a that detects a displacement amount in the front-rear direction of the operation lever 54a and transmits a signal. A lever front / rear direction displacement detector 582a, a work tool rotation lever displacement detector 59a that detects a rotational displacement amount of the work tool rotation lever 55a and transmits a signal, and is provided on the operation lever 54a. A displacement detector 60a for a work tool operation switch that detects a displacement amount of the work tool operation switch 56a and transmits a signal is provided on the moving lever 55a.

  The operating device 50 b is provided on the right side of the driver seat 49. This is configured in the same manner as the operation device 50a, and the same member is indicated by changing the subscript from “a” to “b”, and the description is omitted here.

  FIG. 5 is an explanatory view showing the front selection means 80 provided in the cab 4.

  In FIG. 5, the front selection means 80 includes an alternate type front selection switch 81. The front selection switch 81 can select any one of the three positions of both arms, left arm, and right arm. By switching this position, three operations of the two-arm mode, the left-arm mode, and the right-arm mode are performed. Select one of the modes. The both-arm mode is an operation mode in which the first and second work fronts A and B can be simultaneously operated by the operation devices 50a and 50b. The left arm mode is an operation mode in which only the work front on the left front side when viewed from the cab 4, that is, the first work front A can be operated. While the left arm mode is selected, the operation of the controller device 50b is invalid, and the second work front B maintains the state when the left arm mode is selected. Further, the right arm mode is an operation mode in which only the work front on the right front side as viewed from the cab 4, that is, the second work front B can be operated. While the right arm mode is selected, the operation of the controller device 50a is invalid, and the first work front A maintains the state when the right arm mode is selected.

  The front selection unit 80 outputs a front selection signal to a control device 161 (see FIGS. 7 to 9) described later according to the operation mode selected by the front selection switch 81.

  FIG. 6 is a hydraulic circuit diagram showing an extracted main part of the hydraulic circuit provided in the double-armed work machine of the present embodiment. As shown in FIG. 6, the work machine 200 includes variable displacement first and second hydraulic pumps 100A and 100B driven by a prime mover such as an engine, a fixed displacement pilot pump 105, and a first hydraulic pump 100A. Left actuator group 101A and travel motor 210L driven by pressure oil discharged from the second hydraulic pump 100B, right actuator group 101B and travel motor 210R driven by pressure oil discharged from the second hydraulic pump 100B, and first hydraulic pump 100A Alternatively, the swing motor 211 driven by the pressure oil discharged from the second hydraulic pump 100B and the left control for controlling the pressure oil supplied from the first hydraulic pump 100A to the left actuator group 101A, the travel motor 210L, and the swing motor 211. From the valve group 102A and the second hydraulic pump 100B, The right control valve group 102B for controlling the pressure oil supplied to the tutor group 101B, the traveling motor 210R and the swing motor 211, the hydraulic oil tank 212, the swing operation lever device 213 for instructing the rotation of the swing motor 211, and the travel motor And a travel operation device 214 for instructing rotation of 210L and 210R.

  The left actuator group 101A includes a boom cylinder 11a, an arm cylinder 13a, and a work tool cylinder 15a that constitute a part of the first work front A. The left actuator group 101A includes an actuator (not shown) that opens and closes the claws of the swing post cylinder 9a and the work tool 14a in addition to the above-described cylinders, but is not shown in FIG.

  The left control valve group 102A is a group of control valves that respectively control the flow of pressure oil supplied from the first hydraulic pump 100A to each actuator. The hydraulic cylinders 11a, 13a, 15a, the swing motor 211, and the traveling Control valves 63a to 65a, 67a, 68a for controlling the flow of pressure oil to the motor 211L are provided. In addition to this, actuators not shown in FIG. 6 other than the hydraulic cylinders 11a, 13a and 15a related to the operation of the first work front (left work arm) A, that is, the swing post cylinder 9a and the pawl opening / closing described above. The control valve (for example, control valve 66a) which controls the flow of the pressure oil to the actuator which is not illustrated for use is included.

  The control valve 67a controls the flow of pressure oil supplied from the first hydraulic pump 100A to the swing motor 211, and a position (neutral position) 672a that blocks the pressure oil supplied from the first hydraulic pump 100A; The three positions (distribution positions) 671a and 673a leading to the turning motor 211 are provided. The position of the control valve 67a is controlled by a control signal (pilot signal) from the turning operation lever device 213. When no control signal is input, the control valve 67a returns to the neutral position 672a by the biasing force of the spring.

  The control valve 68a controls the flow of pressure oil supplied from the first hydraulic pump 100A to the traveling motor 210L, and a position (neutral position) 682a that blocks the pressure oil supplied from the first hydraulic pump 100A. The three positions (distribution positions) 681a and 683a leading to the traveling motor 210L are provided. The position of the control valve 68a is controlled by a control signal (pilot signal) from the travel operation device 214. When no control signal is input, the control valve 68a returns to the neutral position 682a by the biasing force of the spring.

  The control valves 63a to 65a control the flow of pressure oil supplied from the first hydraulic pump 100A to the boom cylinder 11a, the arm cylinder 13a, and the work implement cylinder 15a, respectively. It has three positions: 632a to 652a, distribution positions 631a to 651a, and 633a to 653a. Similarly, the control valve 66a has three positions: a position (neutral position) 662a that blocks the flow of pressure oil to the corresponding hydraulic actuator, and flow positions 661a and 663a. The positions of the control valves 63a to 66a are switched according to the operation of the operating device 50a for the first work front A described above. However, strictly speaking, the control valves 63a to 66a are pilot-driven, and are operated as electromagnetic proportional valves (schematically indicated by symbol marks in FIG. 6) for controlling the pilot pressure supplied from the pilot pump 105 to each pressure receiving portion. A signal corresponding to the operation signal from the device 50a is input, whereby the pilot pressure is appropriately guided to switch to the flow positions 631a to 661a or 633a to 663a. When there is no operation signal from the operation device 50a, the neutral position 632a to 662a is returned by the biasing force of the spring.

  On the upstream side of the control valves 63a to 68a of the left control valve group 102A, a plurality of pressure compensation valves 123a to 128a for controlling the differential pressure across the control valves 63a to 68a are provided. The plurality of control valves 63a to 68a are each provided with a self-load pressure detection line, and the maximum load pressure among the load pressures detected by these detection lines is detected via the shuttle valves 143a to 148a. It is biased by 152a. Here, the switching valve 152a is an unsaturation valve, and plays a role of uniformly reducing the set pressure of the pressure compensation valve when the differential pressure across the control valve of the actuator at which the maximum load pressure acts cannot be kept constant. Yes.

  In addition, load check valves 133a to 138a for preventing backflow of pressure oil from the control valves 63a to 68a to the hydraulic pump 100A are provided between the first hydraulic pump 100A and the pressure compensation valves 123a to 128a, respectively. Yes. Further, the maximum pressure in the discharge line of the first hydraulic pump 100A is limited by the relief valve 150a. The relief pressure of the relief valve 150a is set by a spring provided on the relief valve 150a. The unload valve 151a plays a role of returning the excess oil amount from the first hydraulic pump 100A to the hydraulic oil tank 212.

  The right actuator group 101B and the right control valve group 102B are configured in the same manner as the left actuator group 101A and the left control valve group 102A, respectively, and the same members are denoted by reference numerals “a” to “b”, “A”. From “B” to “B” and from “L” to “R”, the description is omitted here.

  Here, as mentioned before, the turning motor 211 is driven by the pressure oil from the first hydraulic pump 100A or the second hydraulic pump 100B. That is, the pressure oil supply line to the swing motor 211 is connected to the control valves 67a and 67b of the left and right control valve groups 102A and 102B via the lines 33 and 34, respectively. Electromagnetic valves 90 and 91 that block the pipes 33 and 34 are provided in the pipes 33 and 34, respectively. These electromagnetic valves 90 and 91 have two positions, a position (flow position) 90B and 91A for blocking the pressure oil supplied from the control valves 67a and 67b to the turning motor 211, and a position (blocking position) 90A and 91B for blocking. Have. The positions of the electromagnetic valves 90 and 91 are controlled by a control signal from a control device 161 described later. FIG. 6 shows the positions when the control signals from the control device 161 to the electromagnetic valves 90 and 91 are OFF, respectively. The positions of the electromagnetic valves 90 and 91 are cut off positions 90A and 90A by the biasing force of the respective springs. The distribution position is 91A. When the control signals from the control device 161 to the electromagnetic valves 90 and 91 are ON, the electromagnetic valve 90 is switched to the flow position 90B and the electromagnetic valve 91 is switched to the cutoff position 91B.

  The positions of the control valves 67a and 67b are switched by a pilot signal guided through the turning operation lever device 213. The pilot pressure from the pilot pump 105 to the control valves 67a and 67b is switched in accordance with the operation direction of the operation lever 213a of the turning operation lever device 213, and the right side of the upper turning body 3 in accordance with the direction of the operation lever 213a. A pilot signal SR instructing turning or a pilot signal SL instructing left turning is output.

  At this time, although the illustration is schematically shown in FIG. 6, the pilot pipelines for transmitting the pilot signals SR and SL are connected to the electromagnetic valve 95. This electromagnetic valve 95 has two positions 95B for supplying the pilot signal SR or SL from the turning operation lever device 213 to the corresponding pressure receiving portion of the control valve 67a and the position 95A for supplying the corresponding pressure receiving portion of the control valve 67b. Has one position. The position of the electromagnetic valve 95 is controlled by a control signal from a control device 161 described later. FIG. 6 shows the position when the control signal from the control device 161 to the electromagnetic valve 95 is OFF, and the electromagnetic valve 95 is switched to the position 95A by the biasing force of the spring. When the control signal from the control device 161 to the electromagnetic valve 95 is ON, the electromagnetic valve 95 is switched to the position 95B.

  The arm cylinders 13a and 13b are driven by pressure oil from the first hydraulic pump 100A and the second hydraulic pump 100B, respectively. That is, the pressure oil supply lines to the arm cylinders 13a and 13b are connected to the control valves 64a and 64b of the left and right control valve groups 102A and 102B via the lines 30 and 31, respectively. Electromagnetic valves 92 and 94 that block the pipes 30 and 31 are provided in the pipes 30 and 31, respectively. These electromagnetic valves 92 and 94 are respectively provided in two positions, positions (flow positions) 92A and 94A through which the pressure oil supplied from the control valves 64a and 64b to the arm cylinders 13a and 13b flows, and positions (blocking positions) 92B and 94B for blocking. Has a position. The positions of the electromagnetic valves 92 and 94 are controlled by a control signal from a control device 161 described later. FIG. 6 shows the positions when the control signals from the control device 161 to the electromagnetic valves 92 and 94 are OFF. The electromagnetic valves 92 and 94 are moved to the flow positions 92A and 94A by the biasing forces of the respective springs. It has become. When the control signals from the control device 161 to the electromagnetic valves 92 and 94 are ON, the electromagnetic valves 92 and 94 are switched to the cutoff positions 92B and 94B, respectively.

  Further, the pipe line on the upstream side of the electromagnetic valve 92 in the pipe line 30 and the pipe line on the upstream side of the electromagnetic valve 94 in the pipe line 31 are connected by a pipe line 32. The conduit 32 is provided with an electromagnetic valve 93 that blocks the conduit 32. The electromagnetic valve 93 has a position (blocking position) 93A for blocking the pressure oil flowing in the pipe line 32 and a position (flow position) 93B for flowing. The position of the electromagnetic valve 93 is controlled by a control signal from the control device 161 described later. FIG. 6 shows the position when the control signal from the control device 161 to the electromagnetic valve 93 is OFF, and the cutoff position 93A is obtained by the biasing force of the spring. When the control signal from the control device 161 to the electromagnetic valve 93 is ON, the electromagnetic valve 93 is switched to the flow position 93B.

  Here, the pipe lines 30 to 32 are communication pipe lines that connect the arm cylinders 13a and 13b of the left and right actuator groups 101A and 101B to both the pressure oil supply systems of the first and second hydraulic pumps 100A and 100B. 36 is constituted. Specifically, the pipe line 30 connects the arm cylinder 13a of the left actuator group 101A and the corresponding control valve 64a on the left control valve group 102A side. Further, the pipe line 31 connects the arm cylinder 13b of the right actuator group 101B and the corresponding control valve 64b on the right control valve group 102B side. And the pipe line 32 connects these pipe lines 30 and 31, and communicates the supply system of 100A, 100B pressure oil to the arm cylinders 13a, 13b.

  The electromagnetic valves 92 to 94 are provided in the communication pipe 36, and are supplied with pressure oil from the control valves 64a and 64b to the arm cylinders 13a and 13b, respectively, by a combination of switching positions (see FIG. 10). The flow path switching means is configured to switch between the second state in which the pressure oil from the control valve 64b is supplied to the arm cylinder 13a and the third state in which the pressure oil from the control valve 64a is supplied to the arm cylinder 13b. . Specifically, the electromagnetic valve 92 is provided in the pipeline 30 and communicates (circulates) or blocks the pipeline 30. The electromagnetic valve 93 is provided in the pipe line 32 and communicates or blocks the pipe line 32. The electromagnetic valve 94 is provided in the pipeline 31 and communicates or blocks the pipeline 31.

  The pipe lines 33 and 34 constitute a switching pipe line that connects the turning motor 211 that drives the upper turning body 3 to turn to both the pressure oil supply systems of the first and second hydraulic pumps 100A and 100B. Specifically, the pipe line 33 connects the turning motor 211 and the corresponding control valve 67a on the left control valve group 102A side. Further, the pipe line 34 connects the turning motor 211 and the corresponding control valve 67b on the right control valve group 102B side.

  The electromagnetic valves 90, 91, and 95 are provided in the switching pipeline, and the supply source of the pressure oil to the swing motor 211 is set to one of the control valves 67a and 67b depending on the combination of the switching positions (see FIG. 10). Another flow path switching means for switching is configured. Specifically, the electromagnetic valve 90 is provided in the pipeline 33 and communicates or blocks the pipeline 33. The electromagnetic valve 91 is provided in the pipe line 34 to communicate or block the pipe line 34. The electromagnetic valve 95 supplies the pilot signal SR or SL to either the corresponding pressure receiving portion of the control valve 67a or the corresponding pressure receiving portion of the control valve 67b.

  7 to 9 are functional block diagrams of the control device 161 that controls the operations of the first work front A and the second work front B. FIG. In FIG. 7, the second work front B is shown in parentheses in the drawing.

  7 shows the signals of the controller 161 for the input system and the output system when the both-arm mode is selected in the front selection means 80, FIG. 8 shows the case where the left-arm mode is selected, and FIG. The input / output relationship of each is shown.

  The control system shown in FIGS. 7 to 9 is roughly classified into the above-described displacement detectors provided in the operation devices 50a and 50b in the cab 4 and the front selection means 80 shown in FIG. System, a control device 161 for generating and outputting a drive signal by performing a predetermined calculation based on input signals (operation signal, front selection signal) from these input systems, and receiving a drive signal from the control device 161, The control system includes a control valve group 102A, 102B for operating each part of the first work front A and the second work front B, and an output system composed of electromagnetic valves 90-95.

  As an input system of the control device 161, displacement amounts 57a and 57b for operation arms that detect the swing displacement amounts of the operation arms 52a and 52b and transmit signals, and displacements in the vertical direction of the operation levers 54a and 54b. Operating lever vertical displacement detectors 581a and 581b that detect the respective signals and transmit the signals by detecting the longitudinal displacement amounts of the operating levers 54a and 54b, respectively. 582a, 582b, work tool turning lever displacement detectors 59a, 59b for detecting the rotational displacements of the work tool turning levers 55a, 55b and transmitting signals, and the work tool operation switches 56a, 56b. Are respectively detected by the work tool operation switch displacement detectors 60a and 60b and the first and second work fronts A and B. Operating device 50a, and a front selection means 80 for selecting the 50b mode of operation are provided that.

  The output system of the control device 161 includes swing post cylinder control valves 62a and 62b for driving the swing post cylinders 9a and 9b, and boom cylinder control valves 63a and 63b for driving the boom cylinders 11a and 11b. The arm cylinder control valves 64a and 64b for driving the arm cylinders 13a and 13b, the work tool cylinder control valves 65a and 65b for driving the work tool cylinders 15a and 15b, and the work tools 14a and 14b are driven. The work tool control valves 66a and 66b, the electromagnetic valves 90 to 94 for shutting off the pipes 30 to 34, respectively, and the pilot signal supplied from the turning operation lever device 213 to one of the control valves 67a and 67b. switching And the electromagnetic valve 95 is provided.

  The control device 161 includes a swing drive signal generator 161A that generates drive signals to the swing post cylinder control valves 62a and 62b based on input signals (operation signals) from the operation arm displacement detectors 57a and 57b, and an operation A boom drive signal generator 161B that generates a drive signal to the boom cylinder control valves 63a and 63b based on input signals from the lever vertical displacement detectors 581a and 581b, and an operating lever longitudinal displacement detector 582a and Based on input signals from arm drive signal generator 161C that generates drive signals to arm cylinder control valves 64a and 64b based on input signals from 582b and displacement detectors 59a and 59b for work implement rotation levers Generates drive signals to work tool cylinder control valves 65a and 65b A bucket drive signal generation unit 161D, and a work tool drive signal generation unit 161E that generates drive signals to the work tool control valves 66a and 66b based on input signals from the work tool operation switch displacement detectors 60a and 60b. A drive signal generator 161F that generates a drive signal (see FIG. 10) to the solenoid valves 90 to 95 based on an input signal (front selection signal) from the front selection means 80, and an input signal ( And an input / output control unit 161G that controls output signals (drive signals) to the control valves based on input signals (operation signals) to the signal generation units 161A to 161E in accordance with the front selection signal). .

  When the both-arms mode is selected in the front selection means 80 (FIG. 7), the input / output control unit 161G causes the displacement detectors 57a, 581a, 582a, 59a provided in the operating device 50a for the first work front A. , 60a enable the input of operation signals to the drive signal generators 161A to 161E, and based on the operation signals from the displacement detectors 57a, 581a, 582a, 59a, 60a, the drive signal generators 161A to 161E A drive signal is generated and output to each control valve 62a, 63a, 64a, 65a, 66a for the first work front A. Similarly, input of operation signals from the displacement detectors 57b, 581b, 582b, 59b, and 60b provided to the operation device 50b for the second work front B to the drive signal generation units 161A to 161E is enabled, Based on the operation signals from the displacement detectors 57b, 581b, 582b, 59b, 60b, the drive signal generators 161A to 161E generate drive signals, and control valves 62b, 63b, 64b, 65b for the second work front B are generated. , 66b.

  When the left arm mode is selected in the front selection means 80 (FIG. 8), the input / output control unit 161G has the displacement detectors 57a, 581a, 582a, 59a, provided in the operating device 50a for the first work front A. While enabling the input of the operation signal from the signal generator 60A to the signal generators 161A to 161E from the sensor 60a, the displacement detectors 57b, 581b, 582b, 59b, 60b provided in the operation device 50b for the second work front B are used. The operation signal input to each of the signal generators 161A to 161E is invalidated. At this time, when operation signals are input from the displacement detectors 57a, 581a, 59a, and 60a of the operation device 50a, the drive signals generated by the drive signal generation units 161A, 161B, 161D, and 161E are the first work front. Output to each control valve 62a, 63a, 65a, 66a for A, but when an operation signal is input from the operation lever longitudinal displacement detector 582a to the arm drive signal generator 161C, an arm drive signal is generated. The drive signal generated by the part 161C is output to the arm cylinder control valve 64b of the second work front B. However, as will be described later with reference to FIG. 10, as a result of the switching control of the electromagnetic valves 90 to 95 by the input / output control unit 161G at the same time, the pressure oil path through the pipe lines 30 to 32 is switched, and the second work front B Since the supply destination of the pressure oil of the control valve 64b is changed to the arm cylinder 13a, the drive signal to the control valve 64b is output as the operation of the arm 12a of the first work front A. On the other hand, even if an operation signal is input from each of the displacement detectors 57b, 581b, 582b, 59b, and 60b of the disabled operation device 50b, the drive corresponding to the operation signal is output from each of the drive signal generators 161A to 161E. No signal is output.

  When the right arm mode is selected in the front selection means 80 (FIG. 9), the input / output control unit 161G has the displacement detectors 57b, 581b, 582b, 59b, provided in the operation device 50b for the second work front B. While enabling the input of the operation signal from each of the signal generators 161A to 161E from 60b to the displacement detectors 57a, 581a, 582a, 59a, and 60a provided in the operation device 50a for the first work front A, The operation signal input to each of the signal generators 161A to 161E is invalidated. At this time, when an operation signal is input from each displacement detector 57b, 581b, 59b, 60b of the operating device 50b, the drive signal generated by each drive signal generator 161A, 161B, 161D, 161E is the second work front. B is output to the control valves 62b, 63b, 65b, 66b for B. When an operation signal is input from the operation lever longitudinal displacement detector 582b to the arm drive signal generator 161C, an arm drive signal is generated. The drive signal generated by the section 161C is output to the arm cylinder control valve 64a of the first work front A. However, as will be described later with reference to FIG. 10, as a result of the switching control of the electromagnetic valves 90 to 95 by the input / output control unit 161G at the same time, the path of the pressure oil by the pipe lines 30 to 32 is switched, and the first work front A Since the supply destination of the pressure oil to the control valve 64a is changed to the arm cylinder 13b, the drive signal to the control valve 64a is output as the operation of the arm 12b of the second work front B. On the other hand, even if an operation signal is input from each of the displacement detectors 57a, 581a, 582a, 59a, and 60a of the disabled operation device 50a, the drive corresponding to the operation signal is output from each of the drive signal generators 161A to 161E. No signal is output.

  10 (a) to 10 (c) are diagrams in which the switching states of the control valve and the electromagnetic valves 90 to 95 that are the targets of drive control by the control device 161 in each operation mode are summarized in a tabular form. (A) is a both-arm mode, FIG. 10 (b) shows the left arm mode, and FIG. 10 (c) shows the state when the right arm mode is selected. First, the notations in FIGS. 10A to 10C will be described.

  10 (a) to 10 (c), the upper diagram is a diagram summarizing the control valves to be subject to drive control, and the lower diagram is a diagram summarizing the switching states of the electromagnetic valves 90-95. In each column in the above figure, the operation of the corresponding hydraulic actuator is described in place of the name of the control valve, and the control valve that is not subject to drive control is shaded. In addition, the control valve shown in the upper part in the upper diagram is a control valve that controls the flow of pressure oil from the first hydraulic pump 100A including the left control valve group 102A and the like. The control valve controls the flow of pressure oil from the second hydraulic pump 100B including the control valve group 102B and the like. Here, the expressions “upper swing body swing (1)” and “upper swing body swing (2)” represent different control valves that drive the same swing motor 211, specifically “upper swing body swing (1)”. The control valve represented as “swivel body swing (1)” refers to the control valve 67a for controlling the pressure oil from the first hydraulic pump 100A to the swing motor 211, and the control valve represented as “upper swing body swing (2)”. The valve indicates the control valve 67b that controls the pressure oil from the second hydraulic pump 100B to the swing motor 211. In addition, the notations “arm (1)” and “arm (2)” represent the control valves 64a and 64b belonging to the left and right control valve groups 102A and 102B, respectively. Are switched to one of the arms 12a, 12b of the work front A, B. For example, in the right arm mode, the control target when the operation device 50b for the second work front (right work arm) B is commanded is not the control valve 64b of the right control valve group 102B, but the left control valve group. It becomes the control valve 64a of 102A. However, since the connection state of the hydraulic circuit by the electromagnetic valves 90 to 95 is switched simultaneously by the drive signal generation unit 161F of the control device 161, the pressure oil from the first hydraulic pump 100A controlled by the control valve 64a is supplied to the arm cylinder 13b. The supplied body motion is the motion of the arm 12b of the second work front (right work arm) B.

  First, the both-arm mode will be described with reference to FIG.

  In FIG. 10A, the input / output control unit 161G of the control device 161 excludes the “upper swing body turning (1)” of the left control valve group 102A and targets other control valves for drive control. . Further, the control signals to the electromagnetic valves 90 to 95 are all OFF, and the switching states of the electromagnetic valves 90 to 95 are as shown in FIG.

  At this time, the left actuator group 101A and the traveling motor 210L are driven by the pressure oil discharged from the first hydraulic pump 100A and supplied through the corresponding control valve of the left control valve group 102A, and the right actuator group 101B and the traveling motor 210R. Are driven by pressure oil discharged from the second hydraulic pump 100B and supplied through the corresponding control valve of the right control valve group 102B. The swing motor 211 is driven by pressure oil discharged from the second hydraulic pump 100B and supplied via the control valve 67b.

  Next, the left arm mode will be described with reference to FIG.

  In FIG. 10B, the input / output control unit 161G of the control device 161 includes the “running (left)”, “swing (left)”, “boom (left)”, “bucket (left)”, “attachment” of the left control valve group 102A. “Swivel (left)”, “attachment open / close (left)” and “upper swing body swing (2)”, “travel (right)”, “arm (2)” of the right control valve group 102B are subject to drive control. The control valve is not subject to drive control. Further, the control signals to the electromagnetic valves 90, 91, 92, and 95 are OFF, and the control signals to the electromagnetic valves 94 and 93 are ON. That is, the solenoid valves 91, 92, and 93 are switched to the flow positions 91A, 92A, and 93B, the solenoid valves 90 and 94 are switched to the cutoff positions 90A and 94B, respectively, and the solenoid valve 95 is switched to the position 95A.

  At this time, the arm cylinder 13a of the left actuator group 101A is driven by pressure oil discharged from the second hydraulic pump 100B and supplied via the control valve 64b and the pipe line 32 of the right control valve group 102B. In addition, an actuator (not shown) that opens and closes and swings the claws of the travel motor 210L, the swing post cylinder 9a, the boom cylinder 11a, the work tool cylinder 15a, and the work tool 14a of the left actuator group 101A is discharged from the first hydraulic pump 100A. And driven by pressure oil supplied through the corresponding control valve of the left control valve group 102A. The turning motor 211 is driven by pressure oil that is discharged from the hydraulic pump 100B and supplied via the control valve 67b.

  Next, the right arm mode will be described with reference to FIG.

  In FIG. 10C, the input / output control unit 161G of the control device 161 includes the “upper swing body turning (1)”, “running (left)”, “arm (1)” and the right control valve group of the left control valve group 102A. 102B “travel (right)”, “swing (right)”, “boom (right)”, “bucket (right)”, “attachment turning (right)”, and “attachment opening / closing (right)” are targets of drive control. Other control valves are not subject to drive control. Further, the control signal to the electromagnetic valve 94 is OFF, and the control signal to the electromagnetic valves 90, 91, 92, 93, 95 is ON. That is, the solenoid valves 90, 93, 94 are switched to the flow positions 90B, 93B, 94A, the solenoid valves 91, 92 are switched to the cutoff positions 91B, 92B, respectively, and the solenoid valve 95 is switched to the position 95B.

  At this time, the arm cylinder 13b of the right actuator group 101B is driven by pressure oil discharged from the first hydraulic pump 100A and supplied via the control valve 64a and the pipe line 32 of the left control valve group 102A. Further, an actuator (not shown) that opens and closes and rotates the claws of the travel motor 210R, swing post cylinder 9b, boom cylinder 11b, work tool cylinder 15b, and work tool 14b of the right actuator group 101B is discharged from the second hydraulic pump 100B. Then, it is driven by the pressure oil supplied through the corresponding control valve of the right control valve group 102B. The turning motor 211 is driven by pressure oil that is discharged from the hydraulic pump 100A and supplied via the control valve 67a.

  Next, the relationship between the operation of the operation devices 50a and 50b and the operation of the first work front A and the second work front B in each operation mode will be described with reference to FIGS. FIG. 11 is a diagram illustrating the operation directions of the operation devices 50a and 50b, and FIG. 12 is a diagram illustrating the operations of the first work front A and the second work front B corresponding to the operation directions of the operation devices 50a and 50b. The second work front B is shown in parentheses in the figure.

  In order to move the first work front A and the second work front B by operating the operation devices 50a and 50b, the operator sits on the driver's seat 49, and the elbow joint of the left arm is connected to the elbow joint of the armrest 53a on the operation arm 52a. The work tool rotation lever 55a is gripped by the palm part on the support part 77a, and the thumb is put on the work tool operation switch 56a. Similarly, the elbow joint of the right arm is placed on the elbow joint support portion 77b of the armrest 53b on the operation arm 52b, the work tool turning lever 55b is gripped by the palm, and the thumb is put on the work tool operation switch 56b.

<Both arms mode>
Both arms mode is selected by the front selection switch 81 of the front selection means 80.

  In this state, when the operator swings the operating arms 52a and 52b of the operating devices 50a and 50b left and right on the forearm (see w in FIG. 11), the operating arm displacement detectors 57a and 57b are controlled by the control device 161. A detection signal (operation signal) is transmitted to the swing drive signal generator 161A. The swing drive signal generator 161A calculates a drive signal based on the received detection signal and transmits the drive signal to the swing post cylinder control valves 62a and 62b. Upon receipt of this drive signal, the swing post cylinder control valves 62a and 62b expand and contract the swing post cylinders 9a and 9b. Accordingly, the swing posts 7a and 7b are swung in a direction that coincides with the displacement direction of the operation arms 52a and 52b (see W in FIG. 12).

  At this time, the swing speed of the swing posts 7a and 7b is in a simple increase relationship, for example, a proportional relationship with the displacement amount of the operation arms 52a and 52b, and the displacement of the operation arms 52a and 52b is the swing motion of the swing posts 7a and 7b. Speed control the movement.

  Further, when the operating levers 54a and 54b are displaced in the vertical direction by the palm portion (see y in FIG. 11), the vertical displacement detectors 581a and 581b for the operating lever are detected by the boom drive signal generation unit 161B of the control device 161. Send a signal. The boom drive signal generation unit 161B calculates a drive signal based on the received detection signal and transmits it to the boom cylinder control valves 63a and 63b. The boom cylinder control valves 63a and 63b that have received this drive signal expand and contract the boom cylinders 11a and 11b. Thereby, the booms 10a and 10b are swung (see Y in FIG. 12).

  At this time, the swinging speed of the booms 10a and 10b is in a proportionally increasing relationship with the amount of displacement of the operating levers 54a and 54b in the vertical direction (y direction), for example, the vertical displacement of the operating levers 54a and 54b. Controls the swing of the booms 10a, 10b.

  Similarly, when the operation levers 54a and 54b are displaced in the front-rear direction by the palm (see x in FIG. 11), the operation lever front-rear direction displacement detectors 582a and 582b are connected to the arm drive signal generation unit 161C of the control device 161. Send a detection signal. The arm drive signal generation unit 161C calculates a drive signal based on the received detection signal and transmits it to the arm cylinder control valves 64a and 64b. Upon receiving this drive signal, the arm cylinder control valves 64a and 64b expand and contract the arm cylinders 13a and 13b. As a result, the arms 12a and 12b are swung (see X in FIG. 12).

  At this time, the swinging speed of the arms 12a and 12b is in a proportionally increasing relationship with the amount of displacement of the operation levers 54a and 54b in the front-rear direction (x direction), for example, a proportional relationship. Controls the swing of the arms 12a, 12b.

  Further, when the work tool turning levers 55a and 55b are turned around the turning center axes 74a and 74b with a palm (see z in FIG. 11), the work tool turning lever displacement detectors 59a and 59b are controlled by a control device. A detection signal is transmitted to the bucket drive signal generator 161D of 161. The bucket drive signal generator 161D calculates a drive signal based on the received detection signal, and transmits the drive signal to the work tool cylinder control valves 65a and 65b. Upon receiving this drive signal, the work tool cylinder control valves 65a and 65b expand and contract the work tool cylinders 15a and 15b. Thereby, the work tools 14a and 14b are swung (see Z in FIG. 12).

  At this time, the swinging speed of the work tools 14a and 14b is in a proportionally increasing relationship with the displacement amount of the work tool rotating levers 55a and 55b, for example, the displacement of the work tool rotating levers 55a and 55b is The speed of the swinging of the tools 14a and 14b is controlled.

  When the work tool operation switches 56a and 56b are displaced by the finger parts, the work tool operation switch displacement detectors 60a and 60b transmit a detection signal to the work tool drive signal generation unit 161E of the control device 161. The action tool drive signal generation unit 161E calculates a drive signal based on the received detection signal and transmits the drive signal to the work tool control valves 66a and 66b. Upon receiving this drive signal, the work tool control valves 66a and 66b drive the work tools 14a and 14b. For example, when the grapple shown in FIG. 1 is handled as the work tools 14a and 14b, the grapple is opened and closed according to the operation of the work tool operation switches 56a and 56b.

At this time, the opening / closing speed of the grapples (work tools 14a, 14b) has a simple increase relationship with the displacement amount of the work tool operation switches 56a, 56b, for example, a proportional relationship, and the displacement of the work tool operation switches 56a, 56b is the work tool 14a. , 14b is controlled in speed.
<Left arm mode>
The left arm mode is selected with the front selection switch 81 of the front selection means 80.

  The relationship between the operation of the operating device 50a and the operation of the first work front (left work arm) A in this state is the same as when the both-arm mode is selected.

At this time, even if the operator operates the operation device 50b, the operation is invalid, and the second work front (right work arm) B does not operate. The second work front B maintains the state when the left arm mode is selected while the left arm mode is selected.
<Right arm mode>
The right arm mode is selected with the front selection switch 81 of the front selection means 80.

  The operation of the operating device 50b and the operation of the second work front (right work arm) B in this state are the same as in the both-arm mode.

  At this time, even if the operator operates the operation device 50a, the operation is invalid, and the first work front (left work arm) A does not operate. The first work front A maintains the state when the right arm mode is selected while the right arm mode is selected.

  In the present embodiment configured as described above, when the both-arm mode is selected with the intention of both-arm work by the first and second work fronts A and B, the first and second work fronts A and B is driven by pressure oil from the first and second hydraulic pumps 100A and 100B, respectively. On the other hand, when the left arm mode is selected with the intention of one-arm work using only the first work front A, the arm cylinder 13a of the left actuator group 101A is driven by the pressure oil from the second hydraulic pump 100B. That is, since the pressure oil from the second hydraulic pump is allocated to the arm cylinder 13a, the number of actuators to which the pressure oil from the first hydraulic pump 100A in the left actuator group 101A is allocated decreases. In other words, at the time of one-arm work by the first work front A, the load on the first hydraulic pump 100A is reduced by causing the second hydraulic pump 100B to partially bear the load, and the first and second hydraulic pumps 100A and 100B Therefore, it is possible to cope with a more required flow rate for the left actuator group 101A. Similarly, when the right arm mode is selected with the intention of performing one-arm work using only the second work front B, the pressure oil from the first hydraulic pump 100A is assigned to the arm cylinder 13b of the right actuator group 101B in the second way. The burden on the hydraulic pump 100B can be reduced, and the first and second hydraulic pumps 100A and 100B can cope with more required flow rates for the right actuator group 101B. Therefore, it is possible to suppress an oil shortage when performing a combined operation at the work front on one side.

  In addition, if the configuration is such that pressure oil is supplied to each of the two work fronts A and B by one hydraulic pump, work that uses two work fronts A and B alternately one by one. While focusing on the operation of one work front A (B) in the operation of gripping on the one hand and crushing on the other hand, the operating device 50b (50a) of the other work front B (A) is unconsciously used. In some cases, the operation front B (A) may perform an unintended operation. On the other hand, in the present embodiment, only one operation can be validated and the other operation can be invalidated. Therefore, even if the operation device 50b (50a) is operated unconsciously, the other work front B (A ) Does not operate, and the work can be performed more efficiently.

  In the present embodiment, the case where the hydraulic circuit of the present invention is applied to the arm cylinders 13a and 13b has been described as an example. However, the present invention is not limited to this. For example, the boom cylinders 11a and 11b, the work tool cylinders 15a and 15b, etc. In the left arm and right arm modes, the pressure oil discharged from the first hydraulic pump 100A or the second hydraulic pump 100B is selectively selected with respect to other actuators related to the operations of the left and right work fronts (work arms) A and B. You may comprise so that it may be supplied.

1 is a side view showing an external appearance of a double-armed hydraulic excavator provided with a hydraulic system according to an embodiment of the present invention. 1 is a top view showing an external appearance of a double-armed hydraulic excavator provided with a hydraulic system according to an embodiment of the present invention. It is a perspective view which shows the operating device provided in the driver's cab. It is a top view which shows the operating device provided in the cab. It is explanatory drawing which shows the front selection means provided in the driver's cab. It is a hydraulic circuit diagram which extracts and shows the principal part of the hydraulic circuit with which the double arm type working machine of one embodiment of this invention was equipped. It is a functional block diagram of a control device for controlling the operation of the work front, and shows a case where the both-arm mode is selected by the front selection means. It is a functional block diagram of a control device for controlling the operation of the work front, and shows a case where the left arm mode is selected by the front selection means. It is a functional block diagram of a control device for controlling the operation of the work front, and shows a case where the right arm mode is selected by the front selection means. It is the figure which put together the switching state of the control valve and solenoid valve which become the object of drive control by a control device at the time of each operation mode in a tabular form. It is a figure explaining the relationship between operation of the operating device and operation | movement of a work front in each operation mode, Comprising: It is a figure which shows the operating direction of an operating device. It is a figure which shows operation | movement of the work front corresponding to the operation direction of an operating device.

Explanation of symbols

A First work front B Second work front

DESCRIPTION OF SYMBOLS 1 Traveling body 2 Lower vehicle body 3 Upper turning body 4 Driver's cab 6a 1st bracket 6b 2nd bracket 7a, 7b Swing post 9a, 9b Swing post cylinder 10a, 10b Boom 11a, 11b Boom cylinder 12a, 12b Arm 13a, 13b Arm cylinder 14a, 14b Work tools 15a, 15b Work tool cylinders 30 to 34 Pipe line 36 Connection pipe line 49 Driver's seat 50a, 50b Operation devices 51a, 51b Operation arm brackets 52a, 52b Operation arms 53a, 53b Armrests 54a, 54b Operation levers 55a, 55b Work tool rotation levers 56a, 56b Work tool operation switches 57a, 57b Operation arm displacement detectors 581a, 581b Operation lever vertical displacement detectors 582a, 582b Operation lever longitudinal displacement detectors 59a, 59b Displacement detectors 60a and 60b for working tool rotation levers Displacement detectors 62a and 62b for working tool operation switches Swing post cylinder control valves 63a and 63b Boom cylinder control valves 64a and 64b Arm cylinder control valves 65a and 65b Working tools Cylinder control valves 66a and 66b Work implement control valves 72a and 72b Operator grip points 73a and 73b Oscillation center axis lines 74a and 74b Pivot center axis lines 75a and 75b Front and rear direction extension lines 77a and 77b Elbow joint support portions 78a and 78b Elbow joint position adjusting device 80 Front selection means 81 Front selection switches 90-95 Solenoid valve 100A First hydraulic pump 100B Second hydraulic pump 101A Left actuator group 101B Right actuator group 102A Left controller Valve group 102B Right control valve group 105 Pilot pump 161 Control device 161A Swing drive signal generation unit 161B Boom drive signal generation unit 161C Arm drive signal generation unit 161D Bucket drive signal generation unit 161E Work implement drive signal generation unit 161F Drive signal generation unit 161G Input / output control unit 200 Hydraulic excavators 210R and 210L Traveling motor 211 Turning motor 212 Hydraulic oil tank 213 Turning operation lever device 213a Operation lever 214 Traveling operation device

Claims (4)

A lower traveling body, an upper revolving body provided so as to be able to swivel with respect to the lower traveling body, a driver's cab provided in the upper revolving body, and a left working arm provided at a left front portion of the upper revolving body. A hydraulic system for a working machine comprising: a left actuator group that drives the left working arm; a right working arm that is provided at a right front portion of the upper swing body; and a right actuator group that drives the right working arm.
A left control valve group for controlling the pressure oil supplied to the left actuator group;
A first hydraulic pump for supplying pressure oil to the left control valve group;
A right control valve group for controlling the pressure oil supplied to the right actuator group;
A second hydraulic pump for supplying pressure oil to the right control valve group;
A first actuator that is one of the actuators constituting the left actuator group, a pipe line that constitutes the left control valve group and connects the first control valve corresponding to the first actuator, and an actuator that constitutes the right actuator group A second actuator that is one of the above and the right control valve group and a pipe that connects the second control valve corresponding to the second actuator, and a communication pipe that includes the pipe that connects these pipes,
A first state is provided in the communication pipe and supplies pressure oil from the first and second control valves to the first and second actuators, respectively. Pressure oil from the second control valve is supplied to the first state. Channel switching means for switching between a second state of supplying to the actuator and a third state of supplying pressure oil from the first control valve to the second actuator;
A hydraulic system for a working machine, comprising: a selection unit that is provided in the cab and selectively indicates the first to third states of the flow path switching unit. The hydraulic system for a work machine according to claim 1,
Left operation means provided in the cab and outputting an operation signal of the left work arm;
A right operation means provided in the cab and outputting an operation signal of the right working arm;
When the left control valve group and the right control valve group are respectively controlled according to operation signals from the left operation means and the right operation means, and the selection means indicates the second state, the right operation When the second control valve is controlled according to the operation signal from the left operation means by disabling the operation signal from the means, and the selection means indicates the third state, the operation from the left operation means A hydraulic system for a working machine, comprising: a control device that disables the signal and controls the first control valve in accordance with an operation signal from the right operation means. The hydraulic system for a work machine according to claim 1 or 2,
The hydraulic system for a working machine, wherein the first and second actuators are arm cylinders that drive the left and right working arms, respectively. In the hydraulic system of the working machine according to any one of claims 1 to 3,
A turning motor for driving the upper turning body to turn;
A third control valve constituting the left control valve group and corresponding to the turning motor and a pipe line connecting the turning motor, a fourth control valve constituting the right control valve group and corresponding to the turning motor, and the turning A switching pipe consisting of a pipe connecting the motor;
Another flow path switching means provided in the switching line, for switching the supply source of the pressure oil to the swing motor to either the third or the fourth control valve;
When the selection means indicates the second state, the control device controls another flow path switching means to supply pressure oil from the fourth control valve to the swing motor, and the selection means When the is instructing the third state, the hydraulic system for the working machine is characterized in that the other flow path switching means is controlled to supply the hydraulic oil from the third control valve to the swing motor.

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