JP2021092231A - Hydraulic driving device of traveling-type working machine - Google Patents

Abstract

To provide a hydraulic driving device capable of effectively utilizing a hydraulic fluid discharged from a hydraulic pump in a case when combined operation of only a traveling operation and a gripping operation, is performed.SOLUTION: A hydraulic driving device includes: a travel selector valve 39 capable of selecting a neutral position PN and a straight travel position PS; and a select control portion 51 performing a control to set the travel selector valve 39 to the neutral position in a single operation, performing a control to set the travel selector valve 39 to the straight travel position in performing a traveling/work arm combined operation in which a traveling operation and a work arm operation are simultaneously performed, and performing a traveling/gripping control as a control to set the travel selector valve 39 to the neutral position in an operation performing only the traveling operation and the gripping operation and in a traveling/gripping combined operation as an operation to move first and second travel bodies 11R, 11L while keeping a gripping portion at a gripping position.SELECTED DRAWING: Figure 3

Description

The present invention relates to a hydraulic drive device provided in a traveling work machine.

Conventionally, as a hydraulic drive device provided in a traveling work machine, those described in Patent Document 1 and Patent Document 2 are known.

The hydraulic drive system described in Patent Document 1 includes a left traveling motor and a right traveling motor that are supplied with hydraulic oil to travel a lower traveling body, and a working device that is supplied with hydraulic oil and includes a boom, an arm, and a bucket. It includes a boom cylinder, an arm cylinder, and a bucket cylinder that operate so as to move, a first hydraulic pump and a second hydraulic pump that discharge hydraulic oil, and a traveling switching valve (a traveling control valve in Patent Document 1). The traveling switching valve has a neutral position (a position of a neutral function in Patent Document 1) and a traveling straight-ahead position (a position of a traveling straight-ahead function in Patent Document 1). The traveling switching valve is switched to the neutral position when a single operation is performed in which only a traveling operation for traveling the lower traveling body or a working operation for moving the working device is performed, and the first hydraulic pump is switched to the neutral position. An oil passage for directly supplying hydraulic oil to the left traveling motor and the right traveling motor is formed from the second hydraulic pump and the second hydraulic pump, respectively. On the other hand, the traveling switching valve is switched to the traveling straight-ahead position when a combined operation in which the traveling operation and the working operation are performed at the same time is performed, and the left traveling motor and the right traveling motor are switched from the first hydraulic pump. A running oil passage for supplying hydraulic oil to both of the above, and a working oil passage for supplying hydraulic oil from the second hydraulic pump to the boom cylinder, the arm cylinder and the bucket cylinder independently of the traveling oil passage. To form. The hydraulic drive device described in Patent Document 2 also has the same configuration as the hydraulic drive device described in Patent Document 1 described above.

By the way, in a traveling work machine on which the hydraulic drive device is mounted, a gripping device such as a grapple is attached to the tip of the arm instead of the bucket, depending on the work content. This gripping device has a plurality of gripping claws, and these gripping claws have a gripping position for gripping a work object such as wood and a release position for releasing the gripped object. It is configured so that it can be displaced between them. Such a traveling work machine may grip the object by the gripping claw and perform a traveling operation (grasping traveling operation) to move the gripped object to another place.

Japanese Unexamined Patent Publication No. 2000-17693 Japanese Unexamined Patent Publication No. 2007-285520

However, conventional hydraulic drive devices such as Patent Document 1 and Patent Document 2 have a problem that the hydraulic oil discharged from the hydraulic pump cannot be effectively used in the gripping traveling operation. Specifically, it is as follows.

When the lower traveling body travels while the gripping claw grips the object in the gripping running operation, the operator holds the gripping claw so that the object is stably held by the gripping claw. Keep the gripping lever for movement in a tilted state. Therefore, in the gripping running operation, a combined operation in which only the running operation and the gripping operation for holding the gripping claw at the gripping position are performed is continuously performed. When such a combined operation is performed, in the conventional hydraulic drive system, the traveling switching valve is switched to the traveling straight traveling position to form the traveling oil passage and the working oil passage independent of the traveling oil passage. The hydraulic oil discharged from the second hydraulic pump and flowing through the working oil passage is used only for holding the gripping claw in the gripping position. In this state, since the gripping claw is stationary at the gripping position, the pressure of the hydraulic oil in the working oil passage reaches a preset relief pressure in the relief valve provided in the working oil passage. Therefore, the hydraulic oil discharged from the second hydraulic pump is effectively used because it continues to be released to the tank through the relief valve during the combined operation in the gripping traveling operation. Absent.

An object of the present invention is to provide a hydraulic drive device capable of effectively utilizing hydraulic oil discharged from a hydraulic pump when a combined operation in which only a traveling operation and a gripping operation are performed is performed.

What is provided is an aircraft having a first traveling body and a second traveling body which are arranged on the left and right and can travel on a traveling surface, and can be supported by the aircraft and displaced with respect to the aircraft. Displacement between a possible working arm and a gripping device supported by the working arm for gripping a work object and a release position for releasing the gripped object. It is a hydraulic drive device provided in a traveling work machine including a gripping device having a gripping portion capable of the displacement. This hydraulic drive receives the supply of at least one working arm actuator that moves the working arm by receiving the supply of hydraulic oil, the gripping actuator that moves the grip portion by receiving the supply of hydraulic oil, and the hydraulic oil. The first traveling motor that moves the first traveling body, the second traveling motor that moves the second traveling body by receiving the supply of hydraulic oil, the at least one working arm actuator, the gripping actuator, and the first. A first hydraulic pump and a second hydraulic pump for discharging hydraulic oil to be supplied to a plurality of hydraulic actuators including the one traveling motor and the second traveling motor, and discharging from the first hydraulic pump and the second hydraulic pump. A traveling switching valve capable of switching between a neutral position and a traveling straight-ahead position as a position for forming an oil passage for guiding the hydraulic oil to the plurality of hydraulic actuators. An oil passage that allows the hydraulic oil discharged from the pump to be supplied to the first traveling motor, and an oil that allows the hydraulic oil discharged from the second hydraulic pump to be supplied to the second traveling motor. An oil passage is formed to allow hydraulic oil discharged from the road and one of the first hydraulic pump and the second hydraulic pump to be supplied to the gripping actuator, and the first hydraulic pump is in the traveling straight position. (1) An oil passage that allows hydraulic oil discharged from the hydraulic pump to be supplied to the first traveling motor and the second traveling motor, and hydraulic oil discharged from the second hydraulic pump is the at least one working arm. Includes a traveling switching valve that forms an oil passage that is allowed to be supplied to the actuator and the gripping actuator, a working arm operation for moving the working arm, and a gripping operation for holding the grip portion in the grip position. When an independent operation is performed in which only one of the attachment operation and the traveling operation for traveling the first traveling body and the second traveling body is performed, the control for setting the traveling switching valve to the neutral position is performed. When the traveling work arm combined operation in which the traveling operation and the working arm operation are performed at the same time is performed, the operation of setting the traveling switching valve to the traveling straight-ahead position is performed, and only the traveling operation and the gripping operation are performed. When the traveling gripping combined operation, which is an operation for moving the first traveling body and the second traveling body, is performed while holding the gripping portion at the gripping position, the traveling switching valve is set to the neutral position. Running grip control It is provided with a switching control unit for performing the above.

In this hydraulic drive device, when the independent operation is performed, the working speed of each work is secured by setting the traveling switching valve to the neutral position, and the traveling operation and the working arm operation are performed at the same time. When the traveling work arm combined operation is performed, the traveling switching valve is set to the traveling straight-ahead position, so that good traveling performance of the aircraft is ensured. On the other hand, when the traveling gripping combined operation in which only the traveling operation and the gripping operation are performed is performed, the traveling switching valve is set to the neutral position. As a result, the hydraulic oil discharged from one of the first hydraulic pump and the second hydraulic pump is supplied to the corresponding traveling motor through the traveling oil passage connected to the one pump, and the traveling oil is supplied. The pressure of the hydraulic oil in the road can be effectively used as the pressure (holding pressure) for holding the grip portion at the grip position. This prevents the hydraulic oil discharged from the hydraulic pump from being continuously released to the tank through the relief valve in the gripping running work in which the machine body is run while holding the object by the gripping portion. This makes it possible to reduce the amount of hydraulic oil released to the tank through the relief valve as compared with the conventional case.

Moreover, in the hydraulic drive device, the traveling grip control has little influence on the traveling performance of the airframe. That is, the main operation of the gripping device in the gripping traveling operation is to hold the gripping portion at the gripping position, and the gripping actuator is stationary during this main operation. Therefore, even if the pressure of the hydraulic oil in the traveling oil passage is used as the holding pressure in the gripping traveling operation, the influence on the flow of the hydraulic oil supplied to the traveling motor through the traveling oil passage is small. This makes it possible to ensure stable running performance and suppress a decrease in running speed in the gripping running work.

The hydraulic drive system further includes a switch operation receiving unit capable of receiving a switch operation, and the switching control unit performs the traveling grip control only when the switch operation receiving unit receives the switch operation. Is preferable.

In this aspect, whether or not the traveling gripping control is performed when the traveling gripping combined operation is performed can be determined by the operator selecting the presence or absence of the switch operation as necessary.

The hydraulic drive has a meter-in passage, a meter-out passage, and a center bypass passage, and has a spool whose stroke position can be changed so as to change the opening area of these passages, and supplies the grip actuator. An operation having a gripping device control valve for controlling the flow of hydraulic oil, an operation control unit for controlling the operation of the spool in the gripping device control valve, and a center bypass passage, and being supplied to the first traveling motor. The first travel control valve that controls the flow of oil and a second travel control valve that has a center bypass passage and controls the flow of hydraulic oil supplied to the second travel motor are further provided. The center bypass passage of the travel control valve and one of the second travel control valves and the center bypass passage of the gripping device control valve are connected by a center bypass line extending to the tank, and the operation control unit. Is able to adjust the stroke position of the spool so that the meter-in passage and the meter-out passage are open and the center bypass passage is open when the traveling grip control is performed. preferable.

In this embodiment, when the traveling grip control is performed, the meter-in passage and the meter-out passage are opened in the gripping device control valve, so that the pressure of the hydraulic oil in the traveling oil passage is used as the holding pressure. The center bypass passage of the one traveling control valve is supplied with excess hydraulic oil when the traveling motor is driven by the center bypass passage being opened in the gripping device control valve. It will be possible to return it to the tank through. This makes it possible to adjust the traveling speed, acceleration, etc. when traveling the aircraft in the gripping traveling operation.

In the above aspect, when the traveling gripping control is performed, the motion control unit has the opening area of the center bypass passage in the gripping device control valve larger than the opening area of the meter-in passage and the opening area of the meter-out passage. It is more preferable to adjust the stroke position of the spool so that the spool becomes larger.

In this aspect, the upper limit of the bleed-off flow rate in the one traveling control valve can be increased in the gripping traveling operation. This makes it possible to adjust the traveling speed, acceleration, etc. when traveling the aircraft in a wider range. Specifically, it is as follows. As described above, the main operation of the gripping device in the gripping traveling operation is to hold the gripping portion at the gripping position, and the gripping actuator is stationary during the main operation. That is, during this main operation, the pressure of the hydraulic oil in the traveling oil passage is used to hold the gripping actuator in a stationary state, not to move the gripping actuator. Therefore, in the gripping traveling operation, the pressure of the hydraulic oil in the traveling oil passage can be used as the holding pressure as long as the meter-in passage and the meter-out passage in the gripping device control valve are open. The opening area of the passage may be small. On the other hand, in the gripping running operation, the upper limit of the bleed-off flow rate of the hydraulic oil returned to the tank in the one running control valve is the center of the gripping device control valve connected to the center bypass passage of the running control valve. It depends on the opening area of the bypass passage. Therefore, the provision of the above configuration of the present embodiment increases the upper limit of the bleed-off flow rate in the one traveling control valve while utilizing the pressure of the hydraulic oil in the traveling oil passage as the holding pressure in the gripping traveling operation. Allows you to. As a result, in the gripping running work, it is possible to adjust the running speed, acceleration, etc. when running the machine in a wider range while effectively utilizing the hydraulic oil discharged from the hydraulic pump.

The hydraulic drive system further includes an operation detection unit capable of detecting whether or not the gripping actuator is operating, and the switching control unit performs the traveling gripping control only when the gripping actuator is not operating. Is preferable.

When the gripping operation is performed and the gripping actuator is not operating, the gripping portion of the gripping device is displaced from the release position to the gripping position and is stationary, that is, the object is It is assumed that the grip portion is in a gripped state. Therefore, the combination of the condition that the traveling gripping combined operation is performed and the condition that the gripping actuator is not operating can be an index for determining that the gripping traveling operation is performed. Therefore, in this embodiment, the switching control unit can set the traveling control valve to the neutral position at a more appropriate timing.

Further, in the present embodiment, it is possible to more accurately determine that the gripping running operation is performed based on the combination of the above conditions, so that the switching control unit can operate the switch as described above, for example. The traveling control valve can be set to the neutral position at an appropriate timing without determining whether or not the condition that the receiving unit receives the switch operation is satisfied. As a result, the burden on the operator can be reduced.

The hydraulic drive device includes a gripping operation device having a gripping operation member including at least one of a gripping operation lever and a gripping operation pedal, a switch operation receiving unit capable of receiving a switch operation, and an operation supplied to the gripping actuator. A gripping device control valve for controlling the flow of oil and an operation control unit for controlling the operation of the gripping device control valve are further provided, and the gripping operation is an operation for holding the gripping portion at the gripping position. The operation control unit includes the first gripping operation received by the gripping operation member and the second gripping operation which is the switch operation received by the switch operation receiving unit. And the operation in which only the second gripping operation is performed, and when the traveling gripping control is performed, preset release conditions are set regardless of whether or not the gripping operation member receives the first gripping operation. The operation of the gripping device control valve may be controlled so that the gripping portion is held at the gripping position until is satisfied.

In this aspect, the operator satisfies the release condition by giving the switch operation as the second gripping operation to the switch operation receiving unit without giving the first gripping operation to the gripping operation member. Until then, the object can be stably gripped by the gripping portion in the gripping running operation. As a result, the burden on the operator in the gripping running work can be reduced.

In the hydraulic drive device, the hydraulic oil discharged from the first hydraulic pump and the hydraulic oil discharged from the second hydraulic pump, whichever has the higher pressure, is selectively selected when the traveling grip control is performed. Is further preferably provided with a high selection portion that forms an oil passage that allows supply to the gripping actuator.

In this aspect, since the hydraulic oil having the higher pressure is selectively supplied to the gripping actuator by the high-level selection portion, the gripping force by which the gripping portion grips the object becomes small in the gripping traveling operation. Can be suppressed.

As described above, according to the present invention, there is a hydraulic drive device capable of effectively utilizing the hydraulic oil discharged from the hydraulic pump when the traveling gripping combined operation in which only the traveling operation and the gripping operation are performed is performed. Provided.

It is a side view which shows an example of the traveling type work machine which mounts the hydraulic drive device which concerns on embodiment of this invention. It is a hydraulic circuit diagram which shows the hydraulic circuit of the hydraulic drive device which concerns on 1st Embodiment of this invention, and the controller connected to this. It is a block diagram which shows the functional structure of the controller. It is a flowchart which shows the control operation executed by the controller. It is a hydraulic circuit diagram which shows the hydraulic circuit of the hydraulic drive device which concerns on 2nd Embodiment of this invention, and the controller connected to this. It is a block diagram which shows the functional structure of the controller which concerns on the 2nd Embodiment. It is a graph which shows the characteristic of the opening area of the gripping device control valve of the hydraulic drive device. It is a hydraulic circuit diagram which shows the hydraulic circuit of the hydraulic drive device which concerns on 3rd Embodiment of this invention, and the controller connected to this. It is a block diagram which shows the functional structure of the controller which concerns on the said 3rd Embodiment. It is a hydraulic circuit diagram which shows the hydraulic circuit of the hydraulic drive device which concerns on 4th Embodiment of this invention, and the controller connected to this. It is a block diagram which shows the functional structure of the controller which concerns on the 4th Embodiment.

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

FIG. 1 shows a traveling work machine 100 according to the embodiment. The present invention is not limited to the traveling work machine 100 shown here, but includes a machine having a first traveling body and a second traveling body, a working arm, and a gripping device, and uses hydraulic pressure as the main power source. It can be widely applied to operating traveling work machines.

The traveling work machine 100 is mounted on a lower traveling body 10 capable of traveling on the ground G (traveling surface) and the lower traveling body 10 so as to be able to turn around an axis in the vertical direction. It includes an upper swivel body 12 that constitutes the machine body together with the traveling body 10, a working arm 14 mounted on the upper swivel body 12, and a grapple 24. A cab 16 which is a driver's cab is provided on the front side portion of the upper swivel body 12 in the front-rear direction, the working arm 14 is mounted, and an engine room 18 is provided on the rear side portion. The working arm 14 and the grapple 24 (an example of a working device) form an attachment.

The lower traveling body 10 has a traveling frame (not shown) and a right crawler traveling body 11R and a left crawler traveling body 11L arranged on the left and right sides of the traveling frame, respectively. In FIG. 1, the right crawler traveling body 11R is located behind the left crawler traveling body 11L. The right crawler traveling body 11R and the left crawler traveling body 11L are individually driven in the forward direction or the reverse direction. The right crawler traveling body 11R and the left crawler traveling body 11L are examples of the first traveling body and the second traveling body.

The working arm 14 includes a boom 20 and an arm 22. The boom 20 has a base end portion supported on the front end portion of the upper swivel body 12 so as to be undulating, that is, rotatable in the vertical direction about a horizontal axis, and a tip end portion on the opposite side thereof. .. The arm 22 has a base end portion rotatably connected to the tip end portion of the boom 20 about a horizontal axis, and a tip end portion on the opposite side thereof.

The grapple 24 is an example of the gripping device. The grapple 24 is a tip attachment (optional attachment) attached to the tip of the arm 22, and mainly performs an opening / closing operation. This opening / closing operation includes a gripping operation for gripping an object to be worked on at a work site and a releasing operation for releasing the gripped object. Examples of the object include, but are not limited to, wood, waste materials, building materials, and the like.

The grapple 24 has a main body portion 241 and a plurality of gripping claws 242 extending downward from the lower end portion of the main body portion 241. In the present embodiment, the grapple 24 has four gripping claws 242, but is not limited to this, and may have, for example, only two gripping claws 242. The plurality of gripping claws 242 are examples of gripping portions. The main body portion 241 is rotatably supported around an arm top pin 22P provided at the tip end portion of the arm 22. The main body portion 241 and the arm 22 are connected via a link portion 28A. The tip of the cylinder rod of the tip attachment cylinder 28, which will be described later, is connected to the link portion 28A. The grapple 24 is rotated as the cylinder rod of the tip attachment cylinder 28 expands and contracts, whereby the inclination angle thereof is adjusted.

The plurality of gripping claws 242 can be displaced between the gripping position shown by the solid line in FIG. 1 and the release position shown by the alternate long and short dash line in FIG. The gripping position is a position for gripping the object, and the release position is a position for releasing the gripped object. The plurality of gripping claws 242 open and close between the gripping position and the releasing position by expanding and contracting the gripping cylinder 29 described later.

[First Embodiment]
FIG. 2 is a hydraulic circuit diagram showing a hydraulic circuit of the hydraulic drive device according to the first embodiment of the present invention and a controller 50 connected to the hydraulic circuit. As shown in FIGS. 1 and 2, the hydraulic drive system includes a plurality of hydraulic actuators, a plurality of hydraulic pumps, a plurality of actuator control valves, a plurality of actuator operators, a traveling switching valve 39, and a first. It includes a stroke operating valve 61, a plurality of sensors, and a transport switch 70. The hydraulic circuit shown in FIG. 2 is electrically connected to the controller 50 and has a function of supplying hydraulic oil to the plurality of hydraulic actuators and controlling the supply direction and flow rate based on a command from the controller 50. Have.

The plurality of hydraulic actuators include a plurality of working arm actuators, at least one gripping cylinder 29, a swivel motor (not shown) for swiveling the upper swivel body 12, a right traveling motor 25R, and a left traveling motor 25L. ,including. In FIG. 1, the right traveling motor 25R is located behind the left traveling motor 25L.

The plurality of working arm actuators include a boom cylinder 26 for raising and lowering the boom 20, an arm cylinder 27 for rotating the arm 22 with respect to the boom 20, and the grapple 24 with respect to the arm 22. Includes a tip attachment cylinder 28 for rotating and rotating. Each of the boom cylinder 26, the arm cylinder 27, and the tip attachment cylinder 28 has a bottom chamber and a rod chamber on the opposite side thereof, although not shown in FIG. 2.

The boom cylinder 26 expands by supplying hydraulic oil to the bottom chamber to move the boom 20 in the upright direction and discharges the hydraulic oil from the rod chamber, and conversely, the hydraulic oil is supplied to the rod chamber. As a result, the boom 20 contracts to move the boom 20 in the lodging direction, and the hydraulic oil is discharged from the bottom chamber.

The arm cylinder 27 is extended by supplying hydraulic oil to the bottom chamber to move the arm 22 in a pulling direction in which the arm 22 approaches the boom 20 behind the arm cylinder, and the hydraulic oil is moved from the rod chamber. On the contrary, when the hydraulic oil is supplied to the rod chamber, the arm 22 contracts to move the arm 22 in the pushing direction in which the arm 22 moves forward from the boom 20, and the hydraulic oil is discharged from the bottom chamber. ..

The tip attachment cylinder 28 extends by supplying hydraulic oil to the bottom chamber, moves the grapple 24 in a pulling direction in which the grapple 24 approaches the boom 20 behind, and operates from the rod chamber. The oil is discharged, and conversely, when the hydraulic oil is supplied to the rod chamber, the grapple 24 is contracted to move the grapple 24 in a pushing direction in which the grapple 24 moves forward from the boom 20, and the hydraulic oil is discharged from the bottom chamber. To do.

The at least one gripping cylinder 29 is an actuator for opening and closing the plurality of gripping claws 242 of the grapple 24. In FIG. 1, the grapple 24 includes a plurality of gripping cylinders 29, but the grapple 24 is not limited to such a mode. The grapple 24 may include only one gripping cylinder 29, and the gripping cylinder 29 may be configured to open and close the plurality of gripping claws 242. Each of the plurality of gripping cylinders 29 is an example of a gripping actuator.

Since the plurality of gripping cylinders 29 have the same structure and function as each other, only one gripping cylinder 29 is shown in FIG. 2, and the other gripping cylinders 29 are not shown. Hereinafter, the functions, operations, and the like of one gripping cylinder 29 among the plurality of gripping cylinders 29 will be mainly described, but the functions, operations, and the like of the remaining gripping cylinders 29 are also the same as those described below.

As shown in FIG. 2, the gripping cylinder 29 has a bottom chamber 29a and a rod chamber 29b on the opposite side thereof. The gripping cylinder 29 is extended by supplying hydraulic oil to the bottom chamber 29a so that the corresponding gripping claw 242 of the plurality of gripping claws 242 closes from the release position toward the gripping position. The gripping claw 242 is moved and the hydraulic oil is discharged from the rod chamber 29b. On the contrary, the gripping cylinder 29 contracts due to the supply of hydraulic oil to the rod chamber 29b, and the corresponding gripping claw 242 of the plurality of gripping claws 242 opens from the gripping position toward the release position. As described above, the gripping claw 242 is moved and the hydraulic oil is discharged from the bottom chamber 29a.

The right traveling motor 25R is connected to the right crawler traveling body 11R so as to move the right crawler traveling body 11R. The left traveling motor 25L is connected to the left crawler traveling body 11L so as to move the left crawler traveling body 11L. In this embodiment, the right traveling motor 25R is an example of a first traveling motor that moves the right crawler traveling body 11R, and the left traveling motor 25L is an example of a second traveling motor that moves the left crawler traveling body 11L. Is.

The right traveling motor 25R and the left traveling motor 25L each have an output shaft that rotates in response to the supply of the hydraulic oil, and the output shaft advances the right crawler traveling body 11R and the left crawler traveling body 11L, respectively. It is connected to the right crawler traveling body 11R and the left crawler traveling body 11L, respectively, so that it can be moved in the reverse direction. Specifically, each of the right crawler traveling body 11R and the left traveling motor 25L has a pair of ports, and by receiving the supply of hydraulic oil to one of the ports, the direction corresponding to the one port is obtained. As the output shaft rotates, the hydraulic oil is discharged from the other port.

The plurality of hydraulic pumps include a first main pump 31, a second main pump 32, and a pilot pump 33. Each of these pumps 31, 32, 33 is driven by an engine (not shown), thereby discharging oil in the tank, respectively.

The first main pump 31 and the second main pump 32 discharge hydraulic oil for directly moving the hydraulic actuator to be driven among the plurality of hydraulic actuators. The first main pump 31 and the second main pump 32 are examples of the first hydraulic pump and the second hydraulic pump. The first main pump 31 and the second main pump 32 according to this embodiment are each composed of a variable displacement hydraulic pump, and the respective capacities, that is, the pump capacities are transferred from the controller 50 to the first main pump 31 and the second main pump 32. It is operated by the pump capacity command input respectively.

A relief valve 91 is provided on the line connected to the discharge port of the first main pump 31, and a relief valve 92 is provided on the line connected to the discharge port of the second main pump 32. When the hydraulic oil pressure in these lines reaches the relief pressure preset in the relief valves 91, 92, part or all of the hydraulic oil is released to the tank through these relief valves 91, 92.

The pilot pump 33 discharges pilot oil for supplying pilot pressure to the plurality of actuator control valves.

The plurality of actuator control valves are interposed between the first main pump 31 or the second main pump 32 and a plurality of hydraulic actuators corresponding to the plurality of actuator control valves, respectively, and the first main pump. It operates so as to control the direction and flow rate of the hydraulic oil supplied from the 31 or the second main pump 32 to the hydraulic actuator. Each of the plurality of actuator control valves is composed of a pilot-operated hydraulic switching valve, and corresponds to the stroke by receiving the supply of the pilot pressure and opening the valve with a stroke corresponding to the magnitude of the pilot pressure. Allows hydraulic fluid to be supplied to the hydraulic actuator at a flow rate. Therefore, the flow rate can be controlled by changing the pilot pressure.

The plurality of actuator control valves according to this embodiment belong to either the first group G1 or the second group G2. The actuator control valve belonging to the first group G1 receives the supply of hydraulic oil discharged from the first main pump 31 when a single operation is performed in which only the traveling operation or the attachment operation is performed, and the second group G2 The actuator control valve belonging to the above receives the supply of hydraulic oil discharged from the second main pump 32 when the independent operation is performed. In the present embodiment, the attachment operation includes a working arm operation, a grip opening / closing operation, and a turning operation. These operations will be described later.

Specifically, the first center bypass line CL1 connected to the tank T via the unload valve 38 is connected to the discharge port of the first main pump 31, and the actuator control valve belonging to the first group G1 is the first. 1 Arranged in tandem along the center bypass line CL1. Similarly, the second center bypass line CL2 connected to the tank T via the unload valve 38 is connected to the discharge port of the second main pump 32, and the actuator control valve belonging to the second group G2 is the second. It is arranged in tandem along the center bypass line CL2.

A first supply line SL1 is connected to the discharge port of the first main pump 31 in parallel with the first center bypass line CL1. The first supply line SL1 is further branched corresponding to a plurality of actuator control valves belonging to the first group G1, and hydraulic oil discharged from the first main pump 31 is controlled by an actuator belonging to the first group G1. It is connected to the actuator control valve so as to distribute to the valve.

A second supply line SL2 is connected to the discharge port of the second main pump 32 in parallel with the second center bypass line CL2. The second supply line SL2 further branches corresponding to a plurality of actuator control valves belonging to the second group G2, and hydraulic oil discharged from the second main pump 32 is controlled by an actuator belonging to the second group G2. It is connected to the actuator control valve so as to distribute to the valve.

The plurality of actuator control valves include a right traveling control valve 35R and a left traveling control valve 35L connected to the right traveling motor 25R and the left traveling motor 25L, respectively, and a plurality of operations connected to the plurality of working arm actuators, respectively. It includes an arm actuator control valve, a gripping device control valve 37 connected to the gripping cylinder 29, and a swivel control valve. In the first embodiment shown in FIG. 2, among these actuator control valves, the right traveling control valve 35R and the gripping device control valve 37 belong to the first group G1, and the left traveling control valve 35L is the second. It belongs to group G2.

The right traveling control valve 35R and the left traveling control valve 35L each use the hydraulic oil for driving the right traveling motor 25R and the left traveling motor 25L of the pair of ports of the right traveling motor 25R and the left traveling motor 25L, respectively. It is selectively guided to one side, and the right traveling flow rate and the left traveling flow rate, which are the flow rates of the hydraulic oil supplied to the right traveling motor 25R and the left traveling motor 25L, are controlled. The right travel control valve 35R and the left travel control valve 35L are examples of the first travel control valve and the second travel control valve.

Each of the right travel control valve 35R and the left travel control valve 35L is a pilot switching valve at three positions, and has a pair of forward pilot ports and a reverse pilot port. Specifically, the right travel control valve 35R has a forward pilot port 35a and a reverse pilot port 35b on the opposite side thereof, and the left travel control valve 35L has a forward pilot port 35c and a reverse pilot port 35d on the opposite side thereof. ..

Of the plurality of actuator control valves, the right travel control valve 35R and the left travel control valve 35L are larger than the other actuator control valves in the first center bypass line CL1 and the second center bypass line CL2, respectively. It is located on the upstream side.

The right travel control valve 35R is maintained in a neutral position when the pilot pressures supplied to the forward pilot port 35a and the reverse pilot port 35b are both 0 or minute, and the right travel motor 25R is used as its hydraulic source ( For example, the first main pump 31) is shut off and the first center bypass line CL1 is opened. When a certain amount of pilot pressure or more is supplied to the forward pilot port 35a or the reverse pilot port 35b, the right travel control valve 35R is neutral with a stroke corresponding to the magnitude of the pilot pressure in the direction corresponding to the pilot port. Shift from position to forward or backward position. As a result, the right traveling control valve 35R is a port corresponding to the pilot port among the pair of ports of the supply oil passage 36R branching from the first center bypass line CL1 and the right traveling motor 25R on the immediately upstream side thereof. Is communicated with the opening area corresponding to the stroke, whereby the right traveling motor 25R is operated in the direction corresponding to the stroke and at the speed corresponding to the stroke.

The left travel control valve 35L is maintained in a neutral position when the pilot pressures supplied to the forward and reverse pilot ports 35c and 35d are both 0 or minute, and the left travel motor 25L is used as its hydraulic source (for example,). The second main pump 32) is shut off and the second center bypass line CL2 is opened. A branch line BL2 branching from the second supply line SL2 is connected to the left travel control valve 35L, and when the left travel control valve 35L is kept in a neutral position, the branch line BL2 and the left travel motor It shuts off 25L. When a certain amount of pilot pressure or more is supplied to the forward pilot port 35c or the reverse pilot port 35d, the left travel control valve 35L is neutral with a stroke corresponding to the magnitude of the pilot pressure in the direction corresponding to the pilot port. Shift from position to forward or backward position. As a result, the second center bypass line CL2 and the branch line BL2 communicate with each other by the port corresponding to the pilot port and the opening area corresponding to the stroke among the pair of ports of the left traveling motor 25L, whereby the left The traveling motor 25L is operated in the direction corresponding to the stroke and at the speed corresponding to the stroke.

The plurality of working arm actuator control valves include a illustrated boom control valve for guiding hydraulic oil to the boom cylinder 26, a schematic arm control valve for guiding hydraulic oil to the arm cylinder 27, and hydraulic oil. The tip attachment control valve (not shown) for guiding the tip attachment cylinder 28 to the tip attachment cylinder 28. The swivel control valve is a control valve for guiding hydraulic oil to the swivel motor.

The gripping device control valve 37 is a valve that guides the hydraulic oil discharged from the first main pump 31 to the gripping cylinder 29 as the main hydraulic oil for expanding and contracting the gripping cylinder 29. The gripping device control valve 37 is interposed between the first main pump 31 and the gripping cylinder 29. The gripping device control valve 37 is a pilot switching valve at three positions, and has a gripping operation pilot port 37a and a release operation pilot port 37b on the opposite side thereof.

The gripping device control valve 37 is maintained in a neutral position when the pilot pressures supplied to the gripping operation pilot port 37a and the release operation pilot port 37b are both 0 or minute, and the first main pump 31 and the gripping device control valve 37 are kept in a neutral position. The connection with the gripping cylinder 29 is cut off, and the first center bypass line CL1 is opened. On the other hand, when a certain level of pilot pressure or more is supplied to the gripping operation pilot port 37a, the gripping device control valve 37 has a stroke corresponding to the magnitude of the pilot pressure from the neutral position to the gripping operation position (in the figure). Shift to the left position of). At this gripping operation position, the gripping device control valve 37 allows the hydraulic oil from the first main pump 31 to be supplied to the bottom chamber 29a of the gripping cylinder 29 at a flow rate corresponding to the stroke. The first supply line SL1 and the bottom chamber 29a are communicated with each other.

On the contrary, when a pilot pressure equal to or higher than a certain level is supplied to the release operation pilot port 37b, the gripping device control valve 37 moves from the neutral position to the release operation position (in the figure) with a stroke corresponding to the magnitude of the pilot pressure. Shift to the right position). In this release operation position, the gripping device control valve 37 allows the hydraulic oil from the first main pump 31 to be supplied to the rod chamber 29b of the gripping cylinder 29 at a flow rate corresponding to the stroke. The first supply line SL1 and the rod chamber 29b are connected.

The plurality of actuator operators are connected to the plurality of actuator control valves, respectively, and receive an operation for moving a hydraulic actuator connected to the actuator control valve, and a pilot pressure corresponding to the operation is applied to the actuator control valve. Enter in the pilot port. Specifically, the plurality of actuator operators are provided between the pilot pump 33 and the plurality of actuator control valves, respectively, and the pilot primary pressure output from the pilot pump 33 is adjusted to a degree corresponding to the operation. The pressure is reduced to generate a pilot secondary pressure, and the pilot secondary pressure is input to the pilot port of the actuator control valve as the pilot pressure of the actuator control valve.

The plurality of actuator operators include a right traveling operator 45R, a left traveling operating device 45L, and a gripping operating device 47.

The right traveling actuator 45R and the left traveling actuator 45L are traveling actuators that receive a traveling operation for moving the right traveling motor 25R and the left traveling motor 25L, respectively. Specifically, each of the right traveling controller 45R and the left traveling actuator 45L generates a pedal 45a that receives a stepping operation as the traveling operation and a traveling pilot pressure corresponding to the stepping operation given to the pedal 45a. It also has a traveling pilot valve 45b that inputs to the pilot ports of the right traveling control valve 35R and the left traveling control valve 35L, respectively.

When a forward stepping operation is given to the pedal 45a of the right traveling controller 45R, the traveling pilot valve 45b of the right traveling controller 45R moves the right traveling motor 25R in the forward direction at a speed corresponding to the magnitude of the stepping operation. A forward traveling pilot pressure for rotating is input to the forward traveling pilot port 35a of the right traveling control valve 35R. When a reverse stepping operation is given to the pedal 45a of the right traveling controller 45R, the traveling pilot valve 45b of the right traveling controller 45R moves the right traveling motor 25R in the reverse direction at a speed corresponding to the magnitude of the stepping operation. The reverse travel pilot pressure for rotating is input to the reverse pilot port 35b of the right travel control valve 35R.

Similarly, when a forward stepping operation is given to the pedal 45a of the left traveling controller 45L, the traveling pilot valve 45b of the left traveling controller 45L drives the left traveling motor 25L at a speed corresponding to the magnitude of the stepping operation. A forward travel pilot pressure that rotates in the forward direction is input to the forward pilot port 35c of the left travel control valve 35L. When the pedal 45a of the left traveling actuator 45L is given a reverse stepping operation, the traveling pilot valve 45b of the left traveling actuator 45L moves the left traveling motor 25L in the reverse direction at a speed corresponding to the magnitude of the stepping operation. The reverse travel pilot pressure for rotating is input to the reverse pilot port 35d of the left travel control valve 35L.

The traveling operation is not limited to the stepping operation given to the pedal 45a as described above. The traveling operation may be a rotation operation given to the traveling operation lever.

The gripping operator 47 is for opening and closing the plurality of gripping claws 242 by expanding and contracting the gripping cylinder 29 (a plurality of gripping cylinders 29 when the hydraulic drive device includes a plurality of gripping cylinders 29). Upon receiving the grip opening / closing operation, the corresponding pilot pressure is input to the grip device control valve 37. The grip opening / closing operation includes a grip operation and a release operation. The gripping operation is an operation for moving the plurality of gripping claws 242 from the release position to the gripping position, and is an operation for holding the plurality of gripping claws 242 at the gripping position. The release operation is an operation for moving the plurality of gripping claws 242 from the gripping position to the release position, and is an operation for holding the plurality of gripping claws 242 at the release position.

The gripping operation device 47 generates a gripping operation lever 47a that receives the gripping operation and the releasing operation, and a pilot pressure corresponding to the gripping operation or the releasing operation given to the gripping operation lever 47a to generate the pilot pressure. It has a gripping pilot valve 47b to be input to the gripping device control valve 37. The gripping operation lever 47a is an example of a gripping operation member.

When the gripping operation is given to the gripping operation lever 47a, the gripping pilot valve 47b applies a gripping operation pilot pressure that extends the gripping cylinder 29 at a speed corresponding to the magnitude of the gripping operation. Input to the gripping operation pilot port 37a of 37. When the release operation is given to the grip operation lever 47a, the grip pilot valve 47b applies a release operation pilot pressure that causes the grip cylinder 29 to contract at a speed corresponding to the magnitude of the release operation. Input to the release operation pilot port 37b of 37.

The gripping operation and the releasing operation are not limited to the rotation operation given to the gripping operation lever 47a as described above. The gripping operation and the releasing operation may be a stepping operation given to the gripping operation pedal as the gripping operation member.

Although not shown, the plurality of actuator operators receive a boom operator for undulating the boom cylinder 26 and an arm operation for rotating the arm cylinder 27. Further includes an arm actuator, a tip attachment operator that receives a tip attachment operation for rotating the tip attachment, and a swivel actuator that receives a swivel operation for moving the swivel motor.

The traveling switching valve 39 and the first stroke operating valve 61 switch oil passages for guiding hydraulic oil discharged from the first main pump 31 and the second main pump 32 to each of the plurality of hydraulic actuators. It constitutes a switching operation unit which is a means.

The traveling switching valve 39 is composed of a pilot-operated switching valve having a single pilot port 39a, and can be switched between the neutral position PN and the traveling straight position PS by the pilot pressure input to the pilot port 39a. Is. FIG. 2 shows a state in which the traveling switching valve 39 is set to the neutral position PN.

The traveling switching valve 39 according to this embodiment is provided in the middle of the first supply line SL1 and the middle of the second center bypass line CL2, and is provided with a first input port, a second input port, and a first output port. And a second output port.

The first input port is a pump line PL2 which is an upstream portion of the first supply line SL1 and an upstream portion of the first center bypass line CL1 (a portion upstream of the right traveling control valve 35R). It is connected to the discharge port of the first main pump 31 via the pump line PL1. The pump line PL2 connects the pump line PL1 and the first input port.

The second input port is connected to the discharge port of the second main pump 32 via the pump line PL3 which is an upstream portion of the second center bypass line CL2.

The first output port is connected to a downstream portion of the first supply line SL1. The downstream portion of the first supply line SL1 is branched for each actuator control valve other than the right traveling control valve 35R among the plurality of actuator control valves belonging to the first group G1 and connected to these actuator control valves. It is the part to be done. A check valve 34 is provided in the branch line BL1 that branches from the downstream portion of the first supply line SL1 and is connected to the gripping device control valve 37. The check valve 34 allows the hydraulic oil to flow from the downstream portion of the first supply line SL1 to the gripping device control valve 37, while blocking the flow in the opposite direction.

The second output port is connected to a downstream portion of the second center bypass line CL2. The downstream portion of the second center bypass line CL2 is a portion in which the actuator control valve belonging to the second group G2 is arranged in tandem.

The traveling switching valve 39 is maintained at the neutral position PN as shown in FIG. 2 when the pilot pressure supplied to the pilot port 39a is 0 or very small.

In the neutral position PN, the traveling switching valve 39 guides the hydraulic oil discharged from the first main pump 31 to a hydraulic actuator belonging to the first group G1 including the right traveling motor 25R and the gripping cylinder 29. On the other hand, it prevents the hydraulic oil discharged from the second main pump 32 from being guided to the hydraulic actuator belonging to the first group G1. Further, the traveling switching valve 39 allows the hydraulic oil discharged from the second main pump 32 to be guided to the hydraulic actuator belonging to the second group G2 including the left traveling motor 25L at the neutral position PN. On the other hand, it prevents the hydraulic oil discharged from the first main pump 31 from being guided to the hydraulic actuator belonging to the second group G2. That is, in the traveling switching valve 39, the hydraulic oil discharged from the first main pump 31 is supplied only to the hydraulic actuator belonging to the first group G1 at the neutral position PN, and the second main pump 32 It forms an oil passage that allows the hydraulic oil discharged from the engine to be supplied only to the hydraulic actuators belonging to the second group G2.

Specifically, the traveling switching valve 39 communicates with the first input port and the first output port at the neutral position PN, while shuts off the second input port and the first output port. While communicating the second input port and the second output port, the first input port and the second output port are blocked. As a result, the traveling switching valve 39 has the first traveling oil passage that allows the hydraulic oil discharged from the first main pump 31 to be supplied to the right traveling motor 25R at the neutral position PN, and the said. The second traveling oil passage that allows the hydraulic oil discharged from the second main pump 32 to be supplied to the left traveling motor 25L, and the hydraulic oil discharged from the first main pump 31 are supplied to the gripping cylinder 29. A gripping oil passage, which is allowed to be supplied, is formed.

The first traveling oil passage includes the pump line PL1 that connects the first main pump 31 and the right traveling motor 25R. The second traveling oil passage includes the pump line PL3 that connects the second main pump 32 and the traveling switching valve 39, and the traveling switching valve 39 in the downstream portion of the second center bypass line CL2. Includes a portion that connects to the left traveling motor 25L. The gripping oil passage includes the pump line PL1, the pump line PL2 branched from the pump line PL1 and connected to the traveling switching valve 39, and a part of the downstream side portion of the first supply line SL1. , The branch line BL1 that branches from the downstream portion.

In the present embodiment, since the pump line PL1 is directly connected to the right traveling control valve 35R, the first main pump is connected to the right traveling control valve 35R regardless of the position of the traveling switching valve 39. The hydraulic oil discharged from 31 is guided. Further, in the present embodiment, among the plurality of actuator control valves belonging to the second group G2, the actuator control valve on the downstream side of the left travel control valve 35L has the travel switching regardless of the position of the travel switching valve 39. The hydraulic oil discharged from the second main pump 32 is directly guided by bypassing the valve 39.

When a pilot pressure equal to or higher than a certain level is input to the pilot port 39a, the traveling switching valve 39 has a stroke corresponding to the magnitude of the pilot pressure from the neutral position PN shown in FIG. 2 to the traveling straight position shown in FIG. Shift to PS.

The traveling switching valve 39 communicates with the first input port and the second output port at the traveling straight-ahead position PS, and communicates with the second input port and the first output port, while communicating with the first output port. The input port and the first output port are blocked. As a result, the traveling switching valve 39 discharges the hydraulic oil discharged from the second main pump 32 to the gripping cylinder 29 and the working oil passage from the first main pump 31 at the traveling straight-ahead position PS. A traveling oil passage that prevents the hydraulic oil from being supplied to the gripping cylinder 29 and guides the hydraulic oil to the left traveling motor 25L is formed.

That is, the traveling switching valve 39 allows the hydraulic oil discharged from the first main pump 31 to be supplied to the right traveling motor 25R and the left traveling motor 25L at the traveling straight-ahead position PS. And, an oil passage that allows the hydraulic oil discharged from the second main pump 32 to be supplied to the plurality of working arm actuators and the gripping cylinder 29 is formed.

In the specific example shown in FIG. 2, in the traveling straight-ahead position PS, a throttle connecting the second input port and the second output port is provided, so that the traveling switching valve 39 is the traveling straight-ahead position PS. The hydraulic oil discharged from the second main pump 32 is partially allowed to be supplied to the right traveling motor 25R and the left traveling motor 25L. An oil passage is formed to allow supply to the plurality of working arm actuators and the gripping cylinder 29. The traveling switching valve 39 prevents the hydraulic oil discharged from the second main pump 32 from being supplied to the right traveling motor 25R and the left traveling motor 25L at the traveling straight-ahead position PS. An oil passage may be formed to allow the hydraulic oil discharged from the second main pump 32 to be supplied to the plurality of working arm actuators and the gripping cylinder 29.

The first stroke operation valve 61 receives the input of the first stroke command from the controller 50 and changes the magnitude of the pilot pressure input to the travel switching valve 39 to change the stroke of the travel switching valve 39. It constitutes a stroke operation unit that changes the position. Specifically, the first stroke operation valve 61 includes a solenoid valve having a solenoid 61a that receives an input of an exciting current corresponding to the first stroke command, and is the pilot port of the pilot pump 33 and the traveling switching valve 39. It is provided in the middle of the pilot line 41 connecting the 39a. The first stroke operation valve 61 generates a secondary pressure corresponding to the first stroke command and inputs this as a pilot pressure of the travel switching valve 39 to the pilot port 39a of the travel switching valve 39.

The plurality of sensors include a right traveling pilot pressure sensor 65R, a left traveling pilot pressure sensor 65L, a gripping operation pilot pressure sensor 67, and a release operation pilot pressure sensor 68. Each of these sensors inputs an electric signal corresponding to the detected pressure to the controller 50 as a pressure detection signal.

The right traveling pilot pressure sensor 65R detects the right traveling pilot pressure (forward traveling pilot pressure, reverse traveling pilot pressure) input to the forward pilot port 35a and the reverse pilot port 35b of the right travel control valve 35R, respectively. is there. The left travel pilot pressure sensor 65L detects the left travel pilot pressure (forward travel pilot pressure, reverse travel pilot pressure) input to the forward pilot port 35c and the reverse pilot port 35d of the left travel control valve 35L, respectively. is there. The gripping operation pilot pressure sensor 67 detects the pilot pressure input to the gripping operation pilot port 37a of the gripping device control valve 37. The release operation pilot pressure sensor 68 detects the pilot pressure input to the release operation pilot port 37b of the gripping device control valve 37.

The plurality of sensors include a boom pilot pressure sensor (not shown) for detecting whether or not a boom operation for undulating the boom 20 has been performed, and an arm operation for rotating the arm 22. An arm pilot pressure sensor (not shown) for detecting whether or not it has been performed, and a tip attachment pilot (not shown) for detecting whether or not a tip attachment operation for rotating the grapple 24 has been performed. Further includes a pressure sensor and a swivel pilot pressure sensor (not shown) for detecting whether or not the swivel operation for swiveling the upper swivel body 12 has been performed. Each of these sensors inputs an electric signal corresponding to the detected pressure to the controller 50 as a pressure detection signal.

The transport switch 70 is an example of a switch operation receiving unit capable of receiving a switch operation performed by an operator, and has a button pressed by the operator. The transport switch 70 is provided at a position in the cab 16 that can be operated by an operator. The button of the transport switch 70 may be provided on, for example, the gripping operation lever 47a, or may be displayed on the screen of a display device (touch panel) in the cab 16. When the operator performs the switch operation on the transport switch 70, an electric signal corresponding to the switch operation is input to the controller 50 as a switch operation signal.

The controller 50 controls the operation of the traveling switching valve 39 based on a detection signal such as a pressure detection signal input from the plurality of sensors and a signal such as the switch operation signal input from the transport switch 70. ..

FIG. 3 is a block diagram showing a functional configuration of the controller 50. The controller 50 is composed of a computer including, for example, a CPU and a memory, and includes a switching control unit 51.

The switching control unit 51 includes the traveling pilot pressure sensors 65R and 65L, the gripping operation pilot pressure sensor 67, the release operation pilot pressure sensor 68, the boom pilot pressure sensor, the arm pilot pressure sensor, and the tip attachment pilot pressure sensor. In order to switch the position of the traveling switching valve 39 based on the operating state grasped by the pressure detection signal of the swivel pilot pressure sensor and the switch operating signal, the first stroke operating valve 61 has the first stroke. Input the 1-stroke command. The first stroke operation valve 61 receives the input first stroke command and inputs the pilot pressure to the traveling switching valve 39.

The switching control unit 51 controls to set the traveling switching valve 39 to the neutral position PN when the independent operation is performed, and a traveling working arm combined operation in which the traveling operation and the working arm operation are performed at the same time is performed. At that time, the traveling switching valve 39 is controlled to be set to the traveling straight-ahead position PS, and when the traveling gripping combined operation is performed, the traveling switching valve 39 is controlled to be set to the neutral position PN (traveling grip control). These controls are performed based on the first stroke command input from the switching control unit 51 to the first stroke operation valve 61.

In the present embodiment, the independent operation is an operation in which only one of the traveling operation and the attachment operation is performed as described above, and the attachment operation is the working arm operation and the gripping portion opening / closing operation. And the turning operation. The traveling operation is an operation given to the traveling actuators 45R and 45L for traveling the right crawler traveling body 11R and the left crawler traveling body 11L of the lower traveling body 10. The working arm operation includes the boom operation, the arm operation, and the tip attachment operation. The gripping portion opening / closing operation is an operation for opening / closing the plurality of gripping claws 242 as described above, and includes the gripping operation and the releasing operation. The turning operation is an operation for turning the upper swing body 12 together with the attachment.

In the present embodiment, a plurality of operations among the working arm operation, the grip portion opening / closing operation, and the turning operation included in the attachment operation are performed at the same time, and the traveling operation is not performed. Is also included in the single operation. Specifically, for example, an operation in which only the boom operation and the arm operation are performed at the same time is included in the independent operation, and for example, an operation in which only the boom operation and the turning operation are performed at the same time is also included in the independent operation.

The traveling work arm combined operation is an operation in which the traveling operation and the working arm operation are performed at the same time. Specifically, in the present embodiment, the traveling work arm combined operation includes the traveling operation, the boom operation included in the working arm operation, the arm operation, and at least one of the tip attachment operations. Is an operation performed at the same time. The traveling work arm combined operation may further include the gripping portion opening / closing operation.

The traveling gripping combined operation is an operation in which only the traveling operation and the gripping operation are performed, and the right crawler traveling body 11R and the left crawler traveling body 11L are held while holding the plurality of gripping claws 242 at the gripping position. It is an operation to move.

Next, a specific arithmetic control operation performed by the controller 50 will be described with reference to the flowchart of FIG.

The controller 50 determines whether or not the control mode is set to the transport mode (step S1). Specifically, it is as follows. In the traveling work machine 100, a plurality of modes including a transport mode are preset as control modes (control modes) performed by the controller 50. The transport mode is started, for example, by switching the control mode to the transport mode in the controller 50 of the traveling work machine 100. Specifically, when the operator performs a preset operation for starting the transport mode, for example, on the operation panel provided in the cab 16, a signal for starting the transport mode is sent to the controller 50. Is entered in. As a result, the control mode is set to the transport mode.

When the control mode is set to the transport mode (YES in step S1), the switching control unit 51 of the controller 50 determines whether or not the transport switch 70 (transport SW) has received the switch operation (YES in step S1). Step S2). In this switch operation, for example, an operator who operates the traveling type work machine 100 at a work site starts a gripping traveling operation in which the machine body is traveled while holding the object by the plurality of gripping claws 242 of the grapple 24. This is an operation that is sometimes performed. When the operator performs a switch operation to press the button of the transport switch 70, an electric signal corresponding to the switch operation is input to the controller 50 as a switch operation signal, and the switching control unit 51 said. It is determined that the transport switch 70 has received the switch operation (YES in step S2).

When the switch operation signal is not input to the controller 50 (NO in step S2), the switching control unit 51 places the traveling switching valve 39 in the neutral position even when the traveling gripping combined operation is subsequently performed. The control set to PN (running grip control) is not performed (step S7). Specifically, when the operator does not operate the switch of the transport switch 70, the following control is performed. The switching control unit 51 controls to set the traveling switching valve 39 to the neutral position PN when the independent operation is performed, and at least one operation included in the attachment operation and the traveling operation are performed in combination. When the operation is performed, the traveling switching valve 39 is uniformly controlled to be set to the traveling straight-ahead position PS. As described above, in the present embodiment, the attachment operation includes the working arm operation, the gripping portion opening / closing operation, and the turning operation, and the working arm operation includes the boom operation, the arm operation, and the tip. The gripping portion opening / closing operation includes the attachment operation, and includes the gripping operation and the releasing operation.

Next, the switching control unit 51 determines whether or not the traveling operation has been performed (step S3). When the operator does not perform the traveling operation, the pressure detection signal is not input to the controller 50 from the right traveling pilot pressure sensor 65R and the left traveling pilot pressure sensor 65L, so that the switching control unit 51 can perform the traveling operation. It is determined that this has not been done (NO in step S3). In this case, since the condition that the traveling gripping combined operation is performed is not satisfied, the switching control unit 51 does not perform the traveling gripping control (step S7).

On the other hand, when the operator performs the traveling operation, the pressure detection signal detected by at least one of the right traveling pilot pressure sensor 65R and the left traveling pilot pressure sensor 65L is input to the controller 50, and the switching control unit 51 Determines that the traveling operation has been performed (YES in step S3).

Next, the switching control unit 51 determines whether or not the gripping operation has been performed (step S4). When the operator does not perform the gripping operation, the pressure detection signal is not input from the gripping operation pilot pressure sensor 67 to the controller 50, so that the switching control unit 51 determines that the gripping operation has not been performed ( NO in step S4). In this case, since the condition that the traveling gripping combined operation is performed is not satisfied, the switching control unit 51 does not perform the traveling gripping control (step S7).

Next, the switching control unit 51 determines whether or not any operation other than the gripping operation has been performed in the attachment operation (ATT operation) (step S5). When the operator performs at least one of the boom operation, the arm operation, the tip attachment operation, and the turning operation, the pressure detection signal detected by the corresponding pilot pressure sensor is input to the controller 50. The switching control unit 51 determines that an operation other than the gripping operation has been performed among the attachment operations (YES in step S5). In this case, since the condition that the traveling gripping combined operation is performed is not satisfied, the switching control unit 51 does not perform the traveling gripping control (step S7).

On the other hand, when the operator does not perform any of the boom operation, the arm operation, the tip attachment operation, and the turning operation, the pressure detection signal is not input to the controller 50, so that the switching control unit 51 uses the switching control unit 51. It is determined that no operation other than the gripping operation is performed among the attachment operations (NO in step S5). If NO in step S5, only the traveling operation and the gripping operation are performed, and the right crawler traveling body 11R and the left crawler traveling body 11L are held at the gripping positions while holding the plurality of gripping claws 242. This is the time when the running grip compound operation, which is an operation for moving the crawler, is performed. In this case, the switching control unit 51 performs the traveling grip control, that is, the control for setting the traveling switching valve 39 to the neutral position PN shown in FIG. 2 (step S6).

Further, after starting the traveling gripping control (step S6), the controller 50 repeatedly performs the determinations shown in steps S1 to S5 shown in FIG. Then, when the condition for performing the traveling grip control, that is, the condition that steps S1 to S4 are YES and step 5 is NO is not satisfied, the switching control unit 51 ends the traveling grip control. (Step S7), the following control is performed. That is, the switching control unit 51 controls to set the traveling switching valve 39 to the neutral position PN when the independent operation is performed, and at least one operation included in the attachment operation and the traveling operation are performed. When the combined operation is performed, the traveling switching valve 39 is uniformly controlled to be set to the traveling straight-ahead position PS.

In the hydraulic drive device according to the first embodiment described above, when the independent operation is performed, the traveling switching valve 39 is set to the neutral position, so that the working speed of each operation is secured, and the traveling operation is performed. When the traveling work arm combined operation in which the working arm operation is performed at the same time is performed, the traveling switching valve 39 is set to the traveling straight-ahead position, so that good traveling performance of the aircraft is ensured. On the other hand, when the traveling gripping combined operation in which only the traveling operation and the gripping operation are performed is performed, the traveling switching valve 39 is set to the neutral position. As a result, the hydraulic oil discharged from the first main pump 31 is supplied to the corresponding right traveling motor 25R through the traveling oil passage connected to the first main pump 31, and the pressure of the hydraulic oil in the traveling oil passage is applied. , The plurality of gripping claws 242 can be effectively used as a pressure (holding pressure) for holding the plurality of gripping claws 242 at the gripping position. This means that the hydraulic oil discharged from the first main pump 31 escapes to the tank through the relief valve as in the conventional case in the gripping running work in which the machine body is run while holding the object by the plurality of gripping claws 242. It is possible to prevent the pump from being continuously pumped or to reduce the amount of hydraulic oil released to the tank through the relief valve as compared with the conventional case.

Moreover, in the hydraulic drive device, the traveling grip control has little influence on the traveling performance of the airframe. That is, the main operation of the grapple 24 in the gripping traveling operation is to hold the plurality of gripping claws 242 at the gripping position, and the gripping cylinder 29 is stationary during this main operation. Therefore, even if the pressure of the hydraulic oil in the traveling oil passage is used as the holding pressure in the gripping traveling operation, the influence on the flow of the hydraulic oil supplied to the right traveling motor 25R through the traveling oil passage is small. .. This makes it possible to ensure stable running performance and suppress a decrease in running speed in the gripping running work.

Further, in the first embodiment, the hydraulic drive device includes a transport switch 70 capable of receiving the switch operation, and the changeover control unit 51 only when the transport switch 70 receives the switch operation. The traveling grip control is performed. Therefore, whether or not the traveling gripping control is performed when the traveling gripping combined operation is performed can be determined by the operator selecting the presence or absence of the switch operation as necessary.

[Second Embodiment]
FIG. 5 is a hydraulic circuit diagram showing a hydraulic circuit of the hydraulic drive device according to the second embodiment of the present invention and a controller 50 connected to the hydraulic circuit. FIG. 5 shows a state in which the traveling switching valve 39 is set to the neutral position PN.

The hydraulic circuit of the hydraulic drive device according to the second embodiment has the same basic configuration as the hydraulic circuit of the hydraulic drive device according to the first embodiment shown in FIG. Therefore, in the following, the configuration of the second embodiment different from the first embodiment will be mainly described, and the configuration of the second embodiment similar to the first embodiment is designated by the same reference numerals in FIG. The explanation is omitted.

As shown in FIG. 5, in this second embodiment, the first hydraulic pump and the second hydraulic pump are integrally configured by a split flow type pump 30 having two discharge ports. Further, the hydraulic drive system according to the second embodiment further includes a second stroke operation valve 62 and a stroke sensor 63. The two lines connected to the two discharge ports of the pump 30 are provided with relief valves 91 and 92, respectively, as in the first embodiment shown in FIG. 2, but in FIG. 5, The illustration is omitted. The same applies to the hydraulic circuits of FIGS. 8 and 10.

FIG. 6 is a block diagram showing a functional configuration of the controller 50 according to the second embodiment. As shown in FIG. 6, in the second embodiment, the controller 50 further includes an operation control unit 52 that controls the operation of the spool in the gripping device control valve 37.

FIG. 7 is a graph showing the characteristics of the opening area of the gripping device control valve 37. The gripping device control valve 37 has a meter-in passage, a meter-out passage, and a center bypass passage, and has a spool (not shown) whose stroke position can be changed so as to change the opening area of these passages.

The second stroke operation valve 62 is an operation valve for adjusting the stroke position of the spool of the gripping device control valve 37 in response to a second stroke command from the operation control unit 52. The second stroke operation valve 62 includes a solenoid valve having a solenoid 62a that receives an input of an exciting current corresponding to the second stroke command, and is the gripping operation pilot port 37a of the pilot pump 33 and the gripping device control valve 37. It is provided in the middle of the pilot line 42 connecting the and. The second stroke operation valve 62 generates a secondary pressure corresponding to the second stroke command and uses this as a pilot pressure of the gripping device control valve 37 to the gripping operation pilot port 37a of the gripping device control valve 37. input.

The motion control unit 52 is in a state where the meter-in passage and the meter-out passage of the grip device control valve 37 are opened when the traveling grip control is performed based on the opening characteristic shown in FIG. 7, for example. , The second stroke command is input to the second stroke operation valve 62 so that the center bypass passage is opened. As a result, the stroke position of the spool of the gripping device control valve 37 is adjusted.

In particular, in the present embodiment, when the traveling gripping control is performed, the motion control unit 52 determines that the opening area of the center bypass passage in the gripping device control valve 37 is the opening area of the meter-in passage and the meter-out passage. The stroke position of the spool is adjusted so as to be larger than the opening area. The range of the stroke position such that the meter-in passage and the meter-out passage are open and the opening area of the center bypass passage is larger than the opening area of the meter-in passage and the opening area of the meter-out passage is , The range R indicated by the arrow in FIG.

The stroke sensor 63 constitutes an motion detection unit capable of detecting whether or not the grip cylinder 29 is operating. The stroke sensor 63 can detect the stroke position of the cylinder rod of the gripping cylinder 29, and inputs an electric signal corresponding to the detected stroke position to the controller 50 as a stroke detection signal.

The switching control unit 51 determines whether or not the gripping cylinder 29 is operating based on the stroke detection signal, and the traveling gripping control, that is, the said Control is performed to set the traveling switching valve 39 to the neutral position PN.

Since the other configurations in the second embodiment are the same as those in the first embodiment described above, the description thereof will be omitted.

In the second embodiment described above, in addition to the effects obtained by the first embodiment described above, the following effects can be further obtained.

In the second embodiment, when the traveling gripping control is performed, the pressure of the hydraulic oil in the traveling oil passage is held by opening the meter-in passage and the meter-out passage in the gripping device control valve 37. The right travel control valve uses excess hydraulic oil when driving the right travel motor 25R by opening the center bypass passage in the grip device control valve 37 while allowing it to be used as pressure. It becomes possible to return to the tank T through the center bypass passage of 35R. This makes it possible to adjust the traveling speed, acceleration, etc. when traveling the aircraft in the gripping traveling operation.

Further, in the second embodiment, when the traveling gripping control is performed, the motion control unit 52 determines that the opening area of the center bypass passage in the gripping device control valve 37 is the opening area of the meter-in passage and the meter-out passage. The stroke position of the spool is adjusted so as to be larger than the opening area of. Therefore, the upper limit of the bleed-off flow rate in the right traveling control valve 35R can be increased in the gripping traveling operation. This makes it possible to adjust the traveling speed, acceleration, etc. when traveling the aircraft in a wider range. In particular, when the gripping cylinder 29 is in operation and the stroke position is adjusted as described above, it is suppressed that the discharge pressure of the pump 30 is increased more than necessary, and the machine body is driven. It is possible to prevent the traveling motor from rotating suddenly.

Further, in the second embodiment, the hydraulic drive device includes a stroke sensor 63 capable of detecting whether or not the gripping cylinder 29 is operating, and the switching control unit 51 is operating the gripping cylinder 29. The traveling grip control is performed only when there is no such operation.

When the gripping operation is performed and the gripping cylinder 29 is not operating, the plurality of gripping claws 242 of the grapple 24 are displaced from the release position to the gripping position and are stationary, that is, It is assumed that the object is in a state of being gripped by the plurality of gripping claws 242. Therefore, the combination of the condition that the traveling gripping combined operation is performed and the condition that the gripping cylinder 29 is not operating can be an index for determining that the gripping traveling operation is performed. Therefore, in the second embodiment, the switching control unit 51 can set the traveling switching valve 39 to the neutral position at a more appropriate timing.

Further, in the second embodiment, it is possible to more accurately determine that the gripping running operation is performed based on the combination of the above conditions, so that the switching control unit 51 can be used as described above, for example. The traveling switching valve 39 can be set to the neutral position at an appropriate timing without determining whether or not the condition that the transport switch 70 receives the switch operation is satisfied. As a result, the burden on the operator can be reduced.

[Third Embodiment]
FIG. 8 is a hydraulic circuit diagram showing a hydraulic circuit of the hydraulic drive device according to the third embodiment of the present invention and a controller connected to the hydraulic circuit. FIG. 8 shows a state in which the traveling switching valve 39 is set to the neutral position PN.

The hydraulic circuit of the hydraulic drive device according to the third embodiment has the same basic configuration as the hydraulic circuit of the hydraulic drive device according to the first embodiment shown in FIG. Therefore, in the following, the configuration of the third embodiment different from the first embodiment will be mainly described, and the configuration of the third embodiment similar to the first embodiment is designated by the same reference numerals in FIG. The explanation is omitted.

As shown in FIG. 8, in the third embodiment, similarly to the second embodiment, the first hydraulic pump and the second hydraulic pump are integrally configured by a split flow type pump 30 having two discharge ports. ing. Further, the hydraulic drive system according to the third embodiment includes a second stroke operation valve 62 similar to that of the second embodiment, and further includes a shuttle valve 64 as a high-level selection unit.

FIG. 9 is a block diagram showing a functional configuration of the controller 50 according to the third embodiment. In the third embodiment, the controller 50 further includes an operation control unit 52 that controls the operation of the spool in the gripping device control valve 37, similarly to the second embodiment.

Similar to the second embodiment, the second stroke operation valve 62 adjusts the stroke position of the spool of the gripping device control valve 37 in response to a second stroke command from the operation control unit 52.

The shuttle valve 64 is in the middle of the pilot line 42 connecting the pilot pump 33 and the gripping operation pilot port 37a of the gripping device control valve 37, and the second stroke operation valve 62 and the gripping device control. It is provided between the valve 37 and the gripping operation pilot port 37a. The shuttle valve 64 has a pair of first input port and second input port, and one output port. The first input port of the shuttle valve 64 is connected to the output port of the second stroke operation valve 62, and the second input port of the shuttle valve 64 is the output of the grip pilot valve 47b of the grip operation device 47. Connected to the port. The output port of the shuttle valve 64 is connected to the gripping operation pilot port 37a of the gripping device control valve 37 via an oil passage.

The hydraulic drive device according to the third embodiment further includes a grip switch 71. The grip switch 71 constitutes a switch operation receiving unit capable of receiving the grip switch operation. When the operator performs the switch operation on the grip switch 71, an electric signal corresponding to the switch operation is input to the controller 50 as a switch operation signal.

In the third embodiment, the gripping operation for holding the plurality of gripping claws 242 of the grapple 24 at the gripping position includes a first gripping operation and a second gripping operation. The first gripping operation is an operation received by the gripping operation lever 47a of the gripping operation device 47, as in the first embodiment. The second gripping operation is the switch operation received by the gripping switch 71.

When the traveling gripping combined operation is an operation in which only the traveling operation and the second gripping operation are performed and the traveling gripping control is performed, the motion control unit 52 performs the gripping operation of the gripping operation device 47. Regardless of whether the lever 47a receives the first gripping operation, the gripping device control so that the plurality of gripping claws 242 are held at the gripping position until the preset release condition is satisfied. Controls the operation of the valve 37.

Specifically, the motion control unit 52 is the gripping device control valve when the traveling gripping combined operation is an operation in which only the traveling operation and the second gripping operation are performed and the traveling gripping control is performed. The second stroke command is input to the second stroke operation valve 62 so that the meter-in passage and the meter-out passage of 37 are in the open state and the center bypass passage is in the open state. As a result, the stroke position of the spool of the gripping device control valve 37 is adjusted. The operation control unit 52 continues to input the second stroke command to the second stroke operation valve 62 until the release condition is satisfied.

In the third embodiment as well, as in the second embodiment, the motion control unit 52 has an opening area of the center bypass passage in the gripping device control valve 37 when the traveling gripping control is performed. It is preferable to adjust the stroke position of the spool so as to be larger than the opening area of the meter-in passage and the opening area of the meter-out passage.

The release condition may include, for example, a condition that an operation other than the traveling operation and the gripping operation is performed when the traveling gripping control is performed. Operations other than the gripping operation include, for example, the working arm operation, the turning operation, and the like. Further, as the release condition, for example, a condition that a preset release operation is performed when the traveling grip control is performed can be mentioned. The release operation may be, for example, an input operation input to the release input receiving unit provided for the release operation. The release input receiving unit may also be used as the gripping switch 71.

Further, in the third embodiment, since the shuttle valve 64 is provided, the shuttle valve 64 has the pilot pressure output from the second stroke operation valve 62 and the grip pilot valve of the grip operation device 47. It is allowed that the higher pilot pressure output from 47b is selectively supplied to the gripping operation pilot port 37a of the gripping device control valve 37. Thereby, the operator can arbitrarily select the first gripping operation and the second gripping operation as the gripping operation according to the situation at that time.

In the hydraulic drive device according to the third embodiment, the step S4 can be omitted in the flowchart of FIG. 4 referred to in the description of the first embodiment.

In the third embodiment, the operator does not need to give the first gripping operation to the gripping operation lever 47a, but by giving the switch operation as the second gripping operation to the gripping switch 71, the release condition. The object can be stably gripped by the plurality of gripping claws 242 in the gripping running operation until is satisfied. As a result, the burden on the operator in the gripping running work can be reduced.

[Fourth Embodiment]
FIG. 10 is a hydraulic circuit diagram showing a hydraulic circuit of a hydraulic drive device according to a fourth embodiment of the present invention and a controller 50 connected to the hydraulic circuit. FIG. 10 shows a state in which the traveling switching valve 39 is set to the neutral position PN. FIG. 11 is a block diagram showing a functional configuration of the controller 50 according to the fourth embodiment.

The hydraulic circuit of the hydraulic drive device according to the fourth embodiment has the same basic configuration as the hydraulic circuit of the hydraulic drive device according to the first embodiment shown in FIG. Therefore, in the following, the configuration of the fourth embodiment different from the first embodiment will be mainly described, and the configuration of the fourth embodiment similar to the first embodiment is designated by the same reference numerals in FIG. The explanation is omitted.

As shown in FIG. 10, in the fourth embodiment, similarly to the second embodiment, the first hydraulic pump and the second hydraulic pump are integrally configured by a split flow type pump 30 having two discharge ports. ing. Further, the hydraulic drive system according to the fourth embodiment further includes a second shuttle valve 65 and an on-off valve 66 capable of opening and closing an oil passage between the second shuttle valve 65 and the gripping cylinder 29. .. The second shuttle valve constitutes a high-level selection unit.

The second shuttle valve 65 has a pair of first input port and second input port, and one output port. The first input port of the second shuttle valve 65 is connected to the first branch line BL11. The first branch line BL11 is an oil passage that branches from the first pump line PL11 connected to the first discharge port 30a of the two discharge ports in the split flow type pump 30. The second input port of the second shuttle valve 65 is connected to the second branch line BL12. The second branch line BL12 is an oil passage that branches from the second pump line PL12 connected to the second discharge port 30b of the two discharge ports in the split flow type pump 30. The output port of the second shuttle valve 65 is connected to the bottom chamber 29a of the gripping cylinder 29 via a supply line SL11.

The on-off valve 66 is provided on the supply line SL11. The on-off valve 66 is configured to be able to switch between an open position and a closed position in response to an input of an open / close command from the controller 50. At the open position, the hydraulic oil having the higher pressure selected in the second shuttle valve 65 among the hydraulic oils discharged from the pair of discharge ports 30a and 30b of the pump 30 is the bottom of the gripping cylinder 29. It is a position that allows supply to the chamber 29a. On the other hand, the closed position is a position that prevents the hydraulic oil having the higher pressure selected in the second shuttle valve 65 from being supplied to the bottom chamber 29a of the gripping cylinder 29.

Specifically, the on-off valve 66 is composed of a solenoid valve having a solenoid 66a that receives an input of an exciting current corresponding to the on-off command, and switches between the open position and the closed position in response to the on-off command. It is possible.

The second shuttle valve 65 determines the pressure of the hydraulic oil discharged from the first discharge port 30a of the pump 30 and the hydraulic oil discharged from the second discharge port 30b when the traveling grip control is performed. An oil passage is formed that allows the higher hydraulic oil to be selectively supplied to the bottom chamber 29a of the gripping cylinder 29.

In the fourth embodiment, the switching control unit 51 controls to set the traveling switching valve 39 to the neutral position PN when the independent operation is performed, as in the first embodiment, and the traveling working arm. Control to set the traveling switching valve 39 to the traveling straight-ahead position PS when the combined operation is performed, and control to set the traveling switching valve 39 to the neutral position PN when the traveling gripping combined operation is performed (traveling grip control). )I do.

When the traveling grip control is performed, the operation control unit 52 inputs the opening / closing command to the solenoid 66a of the on-off valve 66 to set the on-off valve 66 to the open position as shown in FIG. .. As a result, the hydraulic oil having the higher pressure is selectively supplied to the bottom chamber 29a of the gripping cylinder 29 by the second shuttle valve 65, so that the plurality of gripping claws 242 are said to be in the gripping traveling operation. It is possible to prevent the gripping force for gripping the object from becoming small. On the other hand, when the traveling grip control is not performed, the operation control unit 52 does not input the opening / closing command to the solenoid 66a of the on-off valve 66, whereby the on-off valve 66 is set to the closed position. To.

In the fourth embodiment, the hydraulic drive device includes the second shuttle valve 65 and the on-off valve 66, and the operation control unit 52 is the pump 30 when the traveling grip control is performed. Of the hydraulic oil discharged from the first discharge port 30a and the hydraulic oil discharged from the second discharge port 30b, the hydraulic oil having the higher pressure is selectively supplied to the bottom chamber 29a of the gripping cylinder 29. The on-off command is input to the on-off valve 66 so that an oil passage that allows this is formed. Therefore, since the hydraulic oil having the higher pressure is selectively supplied to the bottom chamber 29a of the gripping cylinder 29 by the second shuttle valve 65, the plurality of gripping claws 242 are the objects in the gripping traveling operation. It is possible to prevent the gripping force for gripping an object from becoming small.

The present invention also includes, for example, the following aspects.

(A) First and Second Travel Motors In the above embodiment, the right travel motor 25R corresponds to the first travel motor and the left travel motor 25L corresponds to the second travel motor, but conversely, the left travel motor 25L. Corresponds to the first traveling motor, and the right traveling motor 25R may correspond to the second traveling motor.

(B) Gripping device In the above embodiment, the gripping device is a grapple 24, but the present invention is not limited to this. The gripping device may be another gripping device such as a fork or a nibbler.

(C) Operator The plurality of actuator operators are composed of a pilot type actuator, but the present invention is not limited to this, and may be composed of an electric operator.

10 Lower traveling body 11R, 11L Right crawling traveling body, Left crawling traveling body 12 Upper swivel body 14 Working arm 24 Grapple 25R, 25L Right traveling motor, Left traveling motor 29 Gripping cylinder 30 Split flow type pump (first hydraulic pump and Example of the second hydraulic pump)
31 1st main pump (an example of the 1st hydraulic pump)
32 Second main pump (an example of the second hydraulic pump)
33 Pilot pump 35L Left travel control valve 35R Right travel control valve 37 Gripping device control valve 39 Travel switching valve 47 Gripping actuator 47a Gripping operation lever 47b Gripping pilot valve 49 First stroke operation valve 50 Controller 51 Switching control unit 52 Operation control unit CL1 1st center bypass line CL2 2nd center bypass line PN Neutral position PS Running straight position

Claims (7)

An aircraft having a first traveling body and a second traveling body arranged on the left and right and capable of traveling on a traveling surface, a working arm supported by the aircraft and capable of being displaced with respect to the aircraft, and a working arm capable of being displaced with respect to the aircraft. A gripping device supported by the working arm that can be displaced between a gripping position for gripping a work object and a release position for releasing the gripped object. A hydraulic drive device provided in a traveling work machine including a gripping device having a gripping device.
At least one working arm actuator that moves the working arm by receiving the supply of hydraulic oil,
A gripping actuator that moves the gripping portion by receiving the supply of hydraulic oil,
The first traveling motor that moves the first traveling body by receiving the supply of hydraulic oil, and
A second traveling motor that moves the second traveling body by receiving the supply of hydraulic oil, and
A first hydraulic pump and a second hydraulic pump that discharge hydraulic oil to be supplied to a plurality of hydraulic actuators including the at least one working arm actuator, the gripping actuator, the first traveling motor, and the second traveling motor. ,
Travel switching that can be switched between a neutral position and a traveling straight position as a position for forming an oil passage for guiding the hydraulic oil discharged from the first hydraulic pump and the second hydraulic pump to the plurality of hydraulic actuators. A valve, an oil passage that allows hydraulic oil discharged from the first hydraulic pump to be supplied to the first traveling motor at the neutral position, and hydraulic oil discharged from the second hydraulic pump. Allows the oil passage to be supplied to the second traveling motor and the hydraulic oil discharged from one of the first hydraulic pump and the second hydraulic pump to be supplied to the gripping actuator. An oil passage and a second hydraulic pump that form an oil passage and allow hydraulic oil discharged from the first hydraulic pump to be supplied to the first traveling motor and the second traveling motor at the traveling straight position. A traveling switching valve that forms an oil passage that allows hydraulic oil discharged from the hydraulic pump to be supplied to the at least one working arm actuator and the gripping actuator.
An attachment operation including a work arm operation for moving the work arm and a grip operation for holding the grip portion at the grip position, and a running operation for running the first traveling body and the second traveling body. When a single operation is performed in which only one of them is performed, control is performed to set the traveling switching valve to the neutral position, and when a traveling working arm combined operation in which the traveling operation and the working arm operation are performed at the same time is performed, the above The first traveling body and the second traveling body and the second traveling body are controlled to set the traveling switching valve to the traveling straight-ahead position, and only the traveling operation and the gripping operation are performed while holding the gripping portion at the gripping position. A hydraulic drive system including a switching control unit that performs traveling gripping control, which is a control for setting the traveling switching valve to the neutral position when a traveling gripping combined operation, which is an operation for moving a traveling body, is performed. The hydraulic drive device according to claim 1.
It also has a switch operation reception unit that can receive switch operations.
The switching control unit is a flood control drive device that performs the traveling grip control only when the switch operation receiving unit receives the switch operation. The hydraulic drive device according to claim 1 or 2.
It has a meter-in passage, a meter-out passage, and a center bypass passage, and has a spool whose stroke position can be changed so as to change the opening area of these passages, and a flow of hydraulic oil supplied to the gripping actuator. Gripping device control valve to control
An operation control unit that controls the operation of the spool in the gripping device control valve,
A first travel control valve that has a center bypass passage and controls the flow of hydraulic oil supplied to the first travel motor.
A second travel control valve having a center bypass passage and controlling the flow of hydraulic oil supplied to the second travel motor is further provided.
The center bypass passage of one of the first travel control valve and the second travel control valve and the center bypass passage of the gripping device control valve are connected by a center bypass line extending to the tank.
The motion control unit sets the stroke position of the spool so that the meter-in passage and the meter-out passage are open and the center bypass passage is open when the traveling grip control is performed. A hydraulic drive to adjust. The hydraulic drive device according to claim 3.
When the traveling grip control is performed, the motion control unit makes the opening area of the center bypass passage larger than the opening area of the meter-in passage and the opening area of the meter-out passage in the gripping device control valve. A hydraulic drive that adjusts the stroke position of the spool. The hydraulic drive device according to any one of claims 1 to 4.
A motion detection unit capable of detecting whether or not the gripping actuator is operating is further provided.
The switching control unit is a flood control drive device that performs the traveling grip control only when the grip actuator is not operating. The hydraulic drive device according to claim 1.
A gripping actuator having a gripping operating member including at least one of a gripping operating lever and a gripping operating pedal,
A switch operation reception unit that can receive switch operations and
A gripping device control valve that controls the flow of hydraulic oil supplied to the gripping actuator, and
An operation control unit that controls the operation of the gripping device control valve is further provided.
The gripping operation is an operation for holding the gripping portion at the gripping position, and is a first gripping operation received by the gripping operation member and a second gripping operation which is a switch operation received by the switch operation receiving unit. , Including
In the motion control unit, when the traveling gripping combined operation is an operation in which only the traveling operation and the second gripping operation are performed and the traveling gripping control is performed, the gripping operation member performs the first gripping operation. A hydraulic drive system that controls the operation of the gripping device control valve so that the gripping portion is held at the gripping position until a preset release condition is satisfied regardless of whether or not the gripping device is received. The hydraulic drive device according to any one of claims 1 to 6.
When the traveling grip control is performed, the hydraulic oil discharged from the first hydraulic pump and the hydraulic oil discharged from the second hydraulic pump, whichever has the higher pressure, is selectively supplied to the gripping actuator. A hydraulic drive that further comprises a high-level selection that forms an oil passage that allows it to be.

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