JP2015078541A - Center-of-gravity variable device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a center-of-gravity variable device, which can effectively increase excavating force.SOLUTION: A center-of-gravity variable device 100, which is mounted on an excavator 5 comprising a self-travelling travel body 6, a swivel body 7 that is provided above the travel body 6 and rotates relative to a tilting central axis G, and an excavating body 10 that is provided in front of the swivel body 7 and performs excavation work, is comprised of a tilting mechanism 101 that is provided between the travel body 6 and the swivel body 7 and tilts the swivel body 7 relative to the travel body 6.

Description

  The present invention relates to a variable center of gravity device mounted on an excavator such as a hydraulic excavator.

  Generally, in an excavator, an upper swing body is provided so as to be capable of swinging on an upper portion of a lower traveling body that travels. The upper swing body is provided with an excavation body that performs excavation work, and is provided with a counterweight having a weight that balances the excavation body. As a result, the hydraulic excavator is balanced in weight so that it does not fall over even if the excavated body is swung forward.

  Patent Document 1 discloses a device in which a damper cylinder is interposed between an upper swing body of a hydraulic excavator and a counter weight, and the damper cylinder expands and contracts as the counter weight moves up and down to suppress the swing of the upper swing body. Is disclosed.

  The apparatus includes an acceleration sensor attached to the rear part of the upper swing body, and a controller that controls a pressure guided to the oil chamber of the damper cylinder in accordance with a signal from the acceleration sensor. The controller performs control so that the pressurized hydraulic fluid supplied from the hydraulic source is guided to the oil chamber of the damper cylinder when the swing of the upper swing body is detected according to the signal from the acceleration sensor. As a result, when the swing of the upper swing body occurs during excavation work, the counterweight is moved downward by the damper cylinder, and the swing of the upper swing body is suppressed.

JP-A-6-10374

  However, in such a conventional apparatus, the counterweight is moved in the vertical direction and the center of gravity of the hydraulic excavator moves in the vertical direction, but there is a problem that the excavation force cannot be effectively increased.

  The present invention has been made in view of the above problems, and an object thereof is to provide a center-of-gravity variable device that can effectively increase excavation force.

  The present invention includes a traveling body that is self-propelled, a revolving body that is provided at an upper portion of the traveling body and that revolves around a turning center axis, and a drilling body that is provided at a front portion of the revolving body and performs a digging operation. A center-of-gravity variable device mounted on a machine, characterized in that it is provided with a tilting mechanism that is provided between a traveling body and a revolving body and tilts the revolving body with respect to the traveling body.

  In the present invention, since the tilting mechanism tilts the turning body with respect to the traveling body, the center of gravity of the excavator on which the center-of-gravity variable device is mounted can be moved in the front-rear and left-right directions (horizontal plane direction). Thereby, for example, when the turning body is tilted forward with respect to the traveling body by the tilting mechanism, the center of gravity of the excavator moves forward, so that the excavating force by the excavating body can be increased.

1 is a side view of an excavator according to an embodiment of the present invention. It is a side view of an excavator which shows the time of excavation work. It is a perspective view of a traveling body and a tilting mechanism. It is a perspective view of the traveling body and tilting mechanism which show at the time of excavation work. It is a block diagram of a gravity center variable apparatus.

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

  As shown in FIGS. 1 and 2, the excavator (hydraulic excavator) 5 includes a traveling body (lower traveling body) 6 that travels, a revolving body (upper revolving body) 7 that revolves above the traveling body 6, An excavating body 10 extending forward from the body 7 and excavating earth and sand.

  The traveling body 6 includes left and right crawler devices 9 and a vehicle body 4 that supports the left and right crawler devices 9. The crawler device 9 travels by circulating a crawler belt (crawler belt) 19.

  The revolving unit 7 revolves around the vertical axis with respect to the traveling unit 6 by the operation of a turntable 40 described later. The swivel body 7 is mounted with an excavation body 10, an operator cab 20, a counterweight 21, an engine, a fuel tank, a battery, a hydraulic pressure source, and the like (not shown).

  The “vertical axis” means an axis extending in the vertical direction of the excavator 5 in a state where the excavator 5 is on a horizontal plane.

  The excavation body 10 includes a boom 11 that is rotatably supported around a horizontal axis that extends in the left-right direction of the swivel body 7, an arm 12 that is rotatably supported by the distal end portion of the boom 11, and a distal end portion of the arm 12. And a bucket 13 for excavating earth and sand. The boom 11, the arm 12, and the bucket 13 are each driven by a drive cylinder (not shown).

  The “horizontal axis” means an axis extending in the horizontal direction of the excavator 5 in a state where the excavator 5 is on a horizontal plane.

  The counterweight 21 is fixedly provided behind the revolving unit 7. When the weight of the counterweight 21 is balanced with the weights of the excavator 10 and the cab 20 and the like, the excavator 5 is prevented from falling.

  The excavator 5 travels by driving the traveling body 6 and moves to a place that becomes a scaffold during excavation work. During excavation work, the traveling by the traveling body 6 is stopped, and the revolving body 7 is swung to turn the excavating body 10 in the direction of excavation. In a state where the turning body 7 stops turning, the boom 13, the arm 12, and the bucket 13 of the excavation body 10 are operated to push the bucket 13 into the earth and sand, and then the excavation is performed by rotating the bucket 13. Scoop up etc. Thereafter, the swiveling body 7 is swung to turn the excavating body 10 in the other direction and the bucket 13 is rotated in the opposite direction to that during excavation, thereby discharging the earth and sand scooped up. During the excavation work, the excavator 10 is repeatedly operated.

  When excavating the bucket 13 into the earth or sand, if the earth or sand is hard, the reaction force received by the bucket 13 from the earth or sand causes the excavator 10 and the front part of the revolving body 7 to rotate upward, and the excavator 5 The front of is about to rise.

  In order to prevent the front portion of the excavator 5 from being lifted, the excavator 5 is provided with a center-of-gravity variable device 100 that makes the center of gravity of the revolving body 7 variable in conjunction with the operation of the excavator 10. As shown in FIG. 2, the center-of-gravity variable device 100 includes a tilt mechanism 101 that tilts the swivel body 7 about the horizontal axis, a controller 70 described later, a pressure sensor 75, and a tilt angle sensor 76.

  During excavation for pushing the bucket 13 into the earth or sand, the revolving structure 7 is tilted forward and stopped by the operation of the tilting mechanism 101. At this time, the center of gravity of the swing body 7 moves forward, so that the front portion of the excavator 5 can be prevented from floating and the excavation force for pushing the bucket 13 into the earth and sand can be increased.

  Hereinafter, a specific configuration of the tilt mechanism 101 will be described.

  The tilt mechanism 101 is supported by the traveling body 6 and rotates around the turning center axis O, and the tilt mechanism 101 is supported by the front portion of the turntable 40 and rotates around the tilt center axis G extending in the horizontal direction. And a tilting table 50.

  As shown in FIGS. 3 and 4, the turntable 40 is supported by the vehicle body 4 so as to be rotatable about a turning center axis O via a bearing (not shown).

  As a drive mechanism for rotating the turntable 40, an annular rack 42 fixed to the vehicle body 4 and a hydraulic motor 43 (see FIG. 5) that rotationally drives a pinion (not shown) engaged with the rack 42 are provided. When the pinion is rotationally driven by the hydraulic motor 43, the pinion that meshes with the rack 42 moves in the circumferential direction, and the turntable 40 rotates about the turning center axis O.

  On the plate-like tilting table 50, the revolving body 7 is mounted, and left and right support plates 57 and 58 are provided so as to protrude upward. A base end portion of the boom 11 is rotatably supported between the left and right support plates 57. A base end portion of a hydraulic cylinder that drives the boom 11 is rotatably supported between the support plates 57 and 58.

  At the front end of the turntable 40, left and right hinges 59 are provided as rotation support portions that rotatably support the tilting table 50. The tilt table 50 is supported so as to be rotatable about a tilt center axis G extending in the horizontal left-right direction via left and right hinges 59.

  Left and right hydraulic cylinders 53 that extend and contract between the rear part of the turntable 40 and the rear part of the tilting table 50 are provided as the rotating mechanism 60 that rotates the tilting table 50. On the rear portion of the tilting table 50, left and right support columns 56 are provided so as to protrude upward. The left and right hydraulic cylinders 53 have cylinder base ends connected to the rear portion of the turntable 40 and rod end portions connected to the left and right support columns 56. As the left and right hydraulic cylinders 53 extend and contract in synchronization, the tilt table 50 rotates about the tilt center axis G.

  The tilt mechanism for tilting the swing body 7 with respect to the traveling body 6 is not limited to the above-described configuration, and is not limited to the configuration in which the tilt table 50 rotates via the hinge 59. For example, the tilt table is formed by four hydraulic cylinders. It is good also as a structure to support.

  As shown in FIG. 5, hydraulic passages 45 and 55 connected to a hydraulic source (not shown) are connected to the hydraulic motor 43 and the left and right hydraulic cylinders 53, respectively. Electromagnetic switching valves 44 and 54 are interposed in the hydraulic passages 45 and 55, respectively.

  The electromagnetic switching valve 44 has positions a, b, and c, and switches supply and discharge of hydraulic oil to and from the hydraulic motor 43. In the operating position a, hydraulic oil from the hydraulic source is guided through the hydraulic passage 45 so as to rotate the hydraulic motor 43 in one direction. At the stop position b, the hydraulic passage 45 is blocked, and the rotation operation of the hydraulic motor 43 is stopped. In the operation position c, the hydraulic oil from the hydraulic source is guided through the hydraulic passage 45 so as to rotate the hydraulic motor 43 in the reverse direction.

  When the flow direction of the hydraulic oil in the hydraulic passage 45 that is supplied to and discharged from the hydraulic motor 43 is switched by the electromagnetic switching valve 44, the hydraulic motor 43 is rotated in both forward and reverse directions. As described above, the hydraulic motor 43 rotates the turntable 40 through the pinion that meshes with the rack 42.

  The electromagnetic switching valve 54 has positions d, e, and f, and switches supply and discharge of hydraulic oil to and from the hydraulic cylinder 53. In the operation position d, the hydraulic oil from the hydraulic source is guided to extend the hydraulic cylinder 53 through the hydraulic passage 55. At the stop position e, the hydraulic passage 55 is blocked, and the expansion / contraction operation of the hydraulic cylinder 53 is stopped. In the operating position f, hydraulic oil from the hydraulic source is guided through the hydraulic passage 55 so as to cause the hydraulic cylinder 53 to contract.

  When the flow direction of the hydraulic oil in the hydraulic passage 55 that is supplied to and discharged from the left and right hydraulic cylinders 53 is switched by the electromagnetic switching valve 54, the left and right hydraulic cylinders 53 are expanded and contracted. In the left and right hydraulic cylinders 53, as described above, the tilt table 50 is rotated about the tilt center axis G.

  In addition to the configuration described above, an electric actuator may be provided instead of the hydraulic motor 43 and the hydraulic cylinder 53.

  The center-of-gravity variable device 100 includes a controller 70 that controls the positions and opening degrees of the electromagnetic switching valves 44 and 54.

  The controller 70 receives the turning command signal T and the excavation command signal S output from the operation lever 74 operated by the driver, and outputs the driving pressure detection signal P output from the pressure sensor 75 and the tilt angle sensor 76. The tilt angle detection signal A is received, and the operation of the tilt mechanism 101 is controlled in accordance with these signals.

  The turning command signal T is output when the turning body 7 is turned based on the operation of the operation lever 74 by the driver.

  The controller 70 controls the position and opening of the electromagnetic switching valve 44 in accordance with the turning direction and turning speed commanded based on the turning command signal T, and controls the rotation direction and rotation speed of the hydraulic motor 43.

  Thereby, in the tilting mechanism 101, when the hydraulic motor 43 rotates, the turntable 40 rotates around the turning center axis O, and the turning body 7 is turned at the commanded turning direction and turning speed.

  The excavation command signal S is output when the excavation body 10 is excavated based on the operation of the operation lever 74 by the driver.

  The pressure sensor 75 detects a driving hydraulic pressure (fluid pressure) guided to a hydraulic cylinder that drives the bucket 13 for excavating earth and sand and outputs a driving pressure detection signal P corresponding to the driving hydraulic pressure.

  In response to the excavation command signal S, the controller 70 determines when the bucket 13 is moving toward the excavation part, and the driving pressure detection signal P is increased so that the bucket 13 is pushed into the excavation part (face). The position and opening of the electromagnetic switching valve 54 are controlled, and the left and right hydraulic cylinders 53 are extended and operated in synchronization with each other. In this way, the tilting mechanism 101 rotates the revolving body 7 and the excavating body 10 in the forward pitching direction, and the revolving body 7 and the excavating body 10 are switched from the postures shown in FIGS. 1 and 3 to the postures shown in FIGS. Stop. Thereby, it is possible to suppress the front portion of the excavator 5 from being lifted by the inertial force in the pitching direction that acts on the revolving body 7 and the excavating body 10, and the excavating force that pushes the bucket 13 into the earth and sand is increased.

  Further, the controller 70 determines when the bucket 13 is moving away from the excavation part according to the excavation command signal S, and performs control to rotate the revolving structure 7 in the post-pitching direction to return to the original posture. Thereby, the vertical line C and the turning center axis O extend coaxially, and the excavator 5 is prevented from falling forward due to the weight of the excavator 10 or the like.

  The controller 70 is not limited to the configuration in which the operating state of the swing body 7 and the excavation body 10 is determined according to the driving pressure detection signal P of the pressure sensor 75, and the detection signal of the acceleration sensor that rotates the swing body 7 in the pitching direction. It is good also as a structure which determines the operation state of the turning body 7 and the excavation body 10 according to.

  The tilt angle sensor 76 detects the tilt direction and tilt angle at which the traveling body 6 tilts with respect to the vertical line of the ground, and outputs a tilt angle detection signal A corresponding to the tilt direction and tilt angle.

  The controller 70 controls the tilt angle of the tilt table 50 according to the tilt angle detection signal A of the traveling body 6, and the tilt angle of the swing body 7 with respect to the rotation center axis O and the vertical line C of the ground by moving the center of gravity of the swing body 7. Tilt in the direction to reduce. When the excavator 5 goes up the hill, the center of gravity is applied behind the excavator 5. In that case, by tilting the revolving structure 7 forward, the balance can be maintained and the excavator 5 can be prevented from falling over. Further, when the excavator 5 goes down the slope, the center of gravity is applied in front of the excavator 5. Even in that case, by turning the revolving body 7 backward, the balance can be maintained and the excavator 5 can be prevented from falling over.

  In the control system, an inclination angle sensor 76 that detects an inclination angle at which the traveling body 6 is inclined with respect to the vertical line C of the ground is used as a detector that detects the attitude of the excavator 5. However, the present invention is not limited to this, and a tilt angle sensor that detects the tilt angle at which the revolving body 7 tilts with respect to the vertical line C of the ground may be used as a detector that detects the attitude of the excavator 5.

  According to the above embodiment, there exists an effect shown below.

  [1] The center-of-gravity variable device 100 of the excavator 5 is configured by a tilt mechanism 101 that is provided between the traveling body 6 and the revolving body 7 and tilts the revolving body 7 with respect to the traveling body 6. .

  Based on the above configuration, in the center-of-gravity variable device 100, the tilt mechanism 101 tilts the revolving body 7 with respect to the traveling body 6, so that the center of gravity of the excavator 5 on which the center-of-gravity variable device 100 is mounted is set in the front-rear and left-right directions (horizontal plane direction). Can be moved to. Thereby, for example, when the turning body 7 is tilted forward with respect to the traveling body 5 by the tilt mechanism 101, the center of gravity of the excavator 5 moves forward, so that the excavating force by the excavating body 10 can be increased.

  [2] The center-of-gravity variable device 100 further includes a turntable 40 that is supported by the traveling body 6 and rotates with respect to the tilting central axis G. The tilting mechanism 101 is provided above the turntable 40. Tilt table 50 that tilts relative to each other, a hydraulic cylinder 53 (actuator) that is provided between turn table 40 and tilt table 50 and that extends and retracts, and tilts extending horizontally between turn table 40 and tilt table 50. And a hinge 59 (rotation support portion) that is rotatably supported with respect to the central axis G.

  Based on the above configuration, in the center-of-gravity variable device 100, when the hydraulic cylinder 53 is driven to extend and contract, the tilt table 50 rotates around the tilt center axis G with respect to the turntable 40. Thereby, when the hydraulic cylinder 53 is extended, the tilting table 50 is rotated in a direction tilting with respect to the turntable 40. Further, when the hydraulic cylinder 53 contracts, the tilting table 50 rotates in a direction approaching the turntable 40. As a result, the center of gravity of the excavator 5 can be moved in the front-rear direction by the tilt mechanism 101. Therefore, since the position of the center of gravity can be moved according to the attitude of the excavator 5, stable running and excavation can be performed.

  [3] The excavated body 10 includes a drive cylinder that is driven by fluid pressure. The center-of-gravity variable device 100 further includes a controller 70 that controls the expansion and contraction drive of the hydraulic cylinder 53 and a pressure sensor 75 (drive pressure detector) that detects a fluid pressure when the drive cylinder is driven. The controller 70 is configured to extend the hydraulic cylinder 53 when the fluid pressure detected by the pressure sensor 75 is equal to or higher than a predetermined fluid pressure.

  Based on the above configuration, in the center-of-gravity variable device 100, when the excavation body 10 excavates, for example, earth and sand, the fluid pressure of the drive cylinder becomes equal to or higher than a predetermined fluid pressure. At that time, the controller 70 extends the hydraulic cylinder 53. Thereby, since the gravity center of the excavator 5 moves forward, excavation force can be increased when the excavator 10 excavates.

  [4] The excavated body 10 includes a cylinder driven by fluid pressure. The center-of-gravity variable device 100 further includes a controller 70 that controls the expansion and contraction drive of the hydraulic cylinder 53 and an inclination angle sensor 76 (posture detector) that detects the posture of the excavator 5. The controller 70 is configured to extend the hydraulic cylinder 53 when the posture detected by the tilt angle sensor 76 is a predetermined angle or more with respect to the horizontal plane.

  Based on the above configuration, the center of gravity is applied to the rear of the excavator 5 when the excavator 5 climbs the hill. Even in that case, the variable center-of-gravity device 100 can maintain the balance and prevent the excavator 5 from tipping over by extending the hydraulic cylinder 53.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  For example, the variable center-of-gravity device 100 may include a switch operated by the driver, and the controller 70 may receive a signal from the switch and control the operation of the tilt mechanism 101 based on the driver's command.

C Vertical line O Turning center axis G Tilt center axis 5 Excavator 6 Traveling body 7 Swing body 10 Excavating body 40 Turntable 50 Tilt table 53 Hydraulic cylinder (actuator)
59 Hinge (rotating support)
60 rotating mechanism 70 controller 75 pressure sensor (drive pressure detector)
76 Inclination angle sensor (Attitude detector)
100 Center of gravity variable device 101 Tilt mechanism

Claims (4)

An excavator comprising: a self-propelled traveling body; a revolving body that is provided on an upper portion of the traveling body and that revolves around a revolving center axis; A center-of-gravity variable device,
A center-of-gravity variable device comprising a tilting mechanism that is provided between the traveling body and the revolving body and tilts the revolving body with respect to the traveling body. A turntable supported by the traveling body and rotating with respect to the tilting central axis;
The tilting mechanism is
A tilting table provided above the turntable and tilting with respect to the turntable;
An actuator that is provided between the turntable and the tilting table and is driven to extend and contract;
The center-of-gravity variable device according to claim 1, further comprising a rotation support portion that rotatably supports the turntable and the tilt table with respect to a tilt center axis extending in a horizontal direction. The excavation body includes a drive cylinder driven by fluid pressure,
A controller for controlling expansion and contraction drive of the actuator;
A drive pressure detector for detecting a fluid pressure when the drive cylinder is driven,
The controller is
The center-of-gravity variable device according to claim 2, wherein the actuator is extended when a fluid pressure detected by the driving pressure detector is equal to or higher than a predetermined fluid pressure. A controller for controlling expansion and contraction drive of the actuator;
A posture detector for detecting the posture of the excavator;
The controller is
The center-of-gravity variable device according to claim 2, wherein the actuator is extended when the posture detected by the posture detector is equal to or greater than a predetermined angle with respect to a horizontal plane.

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