JP2012127051A - Working machine having suspended grapple - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working machine having a suspended grapple that can incline the grapple at a predetermined angle, which is normally configured in such a manner that the shaft core of the grapple is oriented in a vertical direction.SOLUTION: A pair of swing prevention hydraulic cylinders F22 and B23 are arranged with an arm pin 51 at the center between them. A pair of swing prevention hydraulic cylinders L24 and R25 are arranged with a swing pin 52, oriented in the direction of orthogonally crossing the arm pin 51, as the center between them. A switching valve 65 is interposed between the bottom chambers of the swing prevention hydraulic cylinders F22 and B23. A switching valve 67 is interposed between the bottom chambers of the swing prevention hydraulic cylinders L24 and R25. When a switch A72 and a switch B73 are turned on, the bottom chambers of the respective cylinders are shut off by the switching valves 65 and 67, and a grapple 10 is held in a state of being inclined at a predetermined angle.

Description

  The present invention relates to a work machine provided with a hanging grapple.

  A work machine equipped with a hanging grapple performs operations such as loading, unloading, and accumulation of industrial waste on a truck. The grapple is attached to the tip of the arm so as to be swingable in the front-rear direction and the left-right direction via a horizontal pin (left-right pin) and a vertical pin (front-rear direction pin).

  The grapple has a swivel device and a plurality of claws attached to the swivel device and opened and closed on the tip side. The hanging grapple is attached to the arm by its own weight with the opening / closing tip side facing the lower surface (ground side) and collides with obstacles such as surrounding buildings during work. In order to prevent this, the central axes of the plurality of claws to be opened and closed are always oriented in the vertical direction. (For example, refer to Patent Document 1).

JP 2009-274806 A

  In the working machine provided with the hanging grapple described in Patent Document 1, the tip of the grapple including the claw is rotated by its own weight with the horizontal pin and the vertical pin as the center, so that the grapple is inclined. It cannot be stopped or held. For this reason, it is not possible to perform an operation of gripping or releasing an object in an inclined state.

  The work machine according to the present invention is a work machine having a grapple suspended from the tip of an arm, wherein the grapple has a plurality of claws supported to be openable and closable at the base, and an opening and closing device that is installed at the base and opens and closes the plurality of claws. A pair of first hydraulic cylinders having a mechanism, a pair of first hydraulic cylinders that swing the base in the front-rear direction of the work machine, and a pair of second hydraulic cylinders that swing the base in the left-right direction of the work machine. At least one of the cylinder and the pair of second hydraulic cylinders is provided so as to be able to communicate and block with each other via a switching valve.

  According to the working machine provided with the suspended grapple of the present invention, the grapple is stopped in an inclined state by connecting and shutting off the pair of first or second hydraulic cylinders by the switching valve. Or can be held.

BRIEF DESCRIPTION OF THE DRAWINGS The external appearance side view which shows one Embodiment of the working machine of this invention. The enlarged side view which looked at the grapple vicinity in the working machine shown in FIG. 1 from the side. The enlarged front view which looked at the grapple vicinity illustrated by FIG. 2 from the direction (front) orthogonal to FIG. The hydraulic circuit diagram of one Embodiment of the working machine of this invention. The figure which shows the first state for demonstrating an example of the operation | work by the working machine shown in FIG. The figure which shows the state following FIG. The figure which shows the state following FIG. The figure which shows the state following FIG. The figure which shows the state following FIG. The figure which shows the state following FIG. The figure which shows the state following FIG.

Hereinafter, an embodiment of a work machine provided with the hanging grapple of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing an embodiment of a work machine 100 according to the present invention, for example, a work machine provided with a hanging grapple for processing waste. In this work machine 100, an upper swing body 3 is installed on a lower traveling body 1 via a swing device 2, a hydraulic power unit 4 and an operator cab 5 are installed on the upper swing body 3, and a work front 6 is attached. Have a structure. The work front 6 has a long boom 7 and a long arm 8, and the boom 7 is attached to the upper swing body 3 by a boom hydraulic cylinder 7 a so that it can be raised and lowered (vertically turned). The arm 8 is attached by an arm hydraulic cylinder 8a so as to be rotatable up and down. The grapple 10 is suspended from the tip of the arm 8 via a suspension bracket 11.

  The work machine 100 rotates downward as shown by a two-dot chain line around a support shaft (not shown) provided in the upper swing body 3 by retracting the boom hydraulic cylinder 7a. Further, the arm 8 rotates downward (counterclockwise direction) as shown by a two-dot chain line around the support shaft 7b by retracting the arm hydraulic cylinder 8a. Reference numeral 8b denotes a link member that is swingably attached to the arm 8 and connected to a rod of the arm hydraulic cylinder 8a.

  When the boom hydraulic cylinder 7a and the arm hydraulic cylinder 8a are extended, the work front 6 returns to the state shown in the solid line. The grapple 10 has a plurality of claws 32 that open and close at the front end side, and is suspended from the bracket 11. The conventional hanging grapple 10 has a central axis for opening and closing the plurality of claws 32 in an operation state in which the boom hydraulic cylinder 7a and the arm hydraulic cylinder 8a are expanded and contracted to rotate the work front 6 in the vertical direction. It always faces in the vertical direction (the direction in which gravity acts). However, in the work machine 100 of the present invention, the grapple 10 can be stopped or held in an inclined state as described below.

FIG. 2 is an enlarged side view of the vicinity of the grapple 10 of the work machine 100 illustrated in FIG. 1 viewed from the side, and FIG. 3 illustrates the vicinity of the grapple illustrated in FIG. 2 in a direction orthogonal to FIG. FIG. 2 is an enlarged front view of the work machine 100 as viewed from the front side.
The grapple 10 has a two-stage structure including a steady rest 20 and a grip 30. The anti-sway part 20 includes a front-rear anti-sway part 20A having a front-rear swinging plate 21, an anti-sway hydraulic cylinder F22 and an anti-swaying hydraulic cylinder B23, a left-right swinging plate 26, an anti-swaying hydraulic cylinder L24, and It is composed of a left and right steadying portion 20B having a steadying hydraulic cylinder R25.

  The front / rear swing plate 21 of the front / rear steadying portion 20A is positioned at an angle of 90 ° with respect to the pair of upright pieces 21a and 21b that stand up on the arm 8 side (upper side) and the upright pieces 21a and 21b. The projecting pieces 21c and 21d are integrally formed. A pin hole 41 is provided in the upper part of the upright pieces 21 a and 21 b, and an arm pin 51 (horizontal pin) is inserted into the pin hole 41 and held by a mounting portion provided at the tip of the bracket 11. With this structure, the front / rear swing plate 21 can swing in the clockwise direction and the counterclockwise direction in FIG.

  Projection pieces 11 a and 11 b are integrally formed on the bracket 11 attached to the tip of the arm 8. The bottom side of the anti-sway hydraulic cylinder F22 is pivotally supported by the projecting piece 11a of the bracket 11, and the rod side is pivotally supported by the projecting piece 21c of the front / rear swing plate 21. The bottom side of the anti-sway hydraulic cylinder B23 is pivotally supported by the projecting piece 11b of the bracket 11, and the rod side is pivotally supported by the projecting piece 21d of the front / rear swing plate 21. The steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 are mounted in line symmetry with respect to a vertical axis ZZ passing through the center of the arm pin 51 (see FIG. 2). As will be described later, the other of the steady hydraulic cylinder F22 and the steady hydraulic cylinder B23 is retracted by the same length as one of the extended cylinders. As a result, the front / rear swing plate 21 swings in the front / rear direction (clockwise direction and counterclockwise direction in FIG. 2) by the length corresponding to the length by which the anti-rest hydraulic cylinders F22, B23 are retracted. A swing mechanism is configured.

  The front and rear rocking plate 21 is formed with a connecting piece 21e integrally formed downward on the axis ZZ. The left and right rocking plate 26 of the left and right steadying stop portion 20B has a pair of upright pieces 26a and 26b raised toward the front and rear rocking plate 21 and an angle of 90 ° with respect to the upright pieces 26a and 26b. Positioned projecting pieces 26c and 26d are integrally formed. A pin hole 42 is provided in the upper part of the standing pieces 26 a and 26 b, and a swing pin 52 (vertical pin) is inserted into the pin hole 42, and in an opening provided in the connection piece 21 e of the front and rear swing plate 21. Is retained. With this structure, the left / right swing plate 26 is connected to the front / rear swing plate 21, and the left / right swing plate 26 swings about the swing pin 52 in the clockwise direction and the counterclockwise direction in FIG. It is possible.

  The bottom side of the anti-sway hydraulic cylinder L24 is pivotally supported by the upright piece 21a of the front and rear rocking plate 21, and the rod side is pivotally supported by the protruding piece 26c of the left and right rocking plate 26. Yes. The bottom side of the anti-sway hydraulic cylinder R25 is pivotally supported by the upright piece 21b of the front and rear rocking plate 21, and the rod side is pivotally supported by the protruding piece 26d of the left and right rocking plate 26. Yes. The steadying hydraulic cylinder L24 and the steadying hydraulic cylinder R25 are mounted symmetrically with respect to a vertical axis XX passing through the center of the swing pin 52 (see FIG. 3). As will be described later, the other of the anti-sway hydraulic cylinder L24 and the anti-sway hydraulic cylinder R25 is retracted by the same length as one of the extension. As a result, the left / right swing plate 26 swings in the left / right direction (clockwise direction and counterclockwise direction in FIG. 3) by an amount corresponding to the length by which the anti-rest hydraulic cylinders L24, R25 are retracted. A swing mechanism is configured.

  The grip portion 30 includes a turning device 31, a plurality of claws 32, and a plurality of claw opening / closing hydraulic cylinders 33 interposed between the turning device 31 and the claws 32. The turning device 31 has a base 35 attached to the left and right swing plate 26 by a fastening member or the like (not shown), and has a turning motor inside the base 35 (not shown). The swivel device 31 rotates about the axis ZZ and the axis XX, and displaces the claw 32 to an arbitrary position in the circumferential direction. An opening / closing mechanism that opens and closes the claw 32 to open and close the claw 32 to grip and release the target member is provided at the lower part of the turning device 31.

  Since the grip portion 30 is attached to the left and right swing plate 26, it performs the same swing operation as the left and right swing plate 26. Further, since the left / right swing plate 26 is attached to the front / rear swing plate 21, the left / right swing plate 26 swings in the front / rear direction and the left / right direction. Therefore, the grapple 10 can be held toward an arbitrary inclination angle with respect to any angle in the circumferential direction.

  FIG. 4 shows an example of a hydraulic circuit diagram of the work machine 100. In the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 of the back-and-forth anti-sway part 20A, hydraulic oil is introduced only into the bottom chamber, respectively. An electromagnetic switching valve 65 is interposed in the middle of an oil passage 63 connected to the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23. As shown in the figure, the switching valve 65 is normally in a position where the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 communicate with each other. When the switch A72 is turned on, the switching valve 65 is switched to the position e according to a command from the control unit 71, and the oil path 63 between the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 is shut off.

  A spring 62 for urging the piston 61 toward the bottom chamber is mounted in the chambers of the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23. The spring 62 has a function of urging the piston 61 toward the bottom chamber so that the bottom chamber does not become negative pressure, thereby preventing negative pressure. An accumulator 66 is connected to the oil passage 63. The steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 are in direct communication with each other, so that the other contracts by the same volume as the one that expands. However, there may be a difference in volume change with respect to the amount of expansion / contraction between the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23. The accumulator 66 has a function of absorbing excess and deficiency of hydraulic oil that occurs in such a case.

The steadying hydraulic cylinder L24 and the steadying hydraulic cylinder R25 of the left and right steadying part 20B have the same configuration and function as the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 of the front and rear steadying part 20A. The only difference is that the switching of the switching valve 67 for connecting and blocking the oil passage 64 connecting the steadying hydraulic cylinder L24 and the steadying hydraulic cylinder R25 is performed in accordance with the ON operation of the switch B73. .
Since the other configuration is the same as that of the back-and-forth backrest 20A, the same reference numerals are assigned to the corresponding members, and description thereof is omitted.
Reference numeral 74 denotes a battery that supplies a power supply voltage to the control unit 71.

  The work machine 100 includes an engine (not shown) housed in the hydraulic power unit 4 and a main hydraulic pump 81 rotated by the engine. In addition, an arm hydraulic cylinder 8 a that rotates the arm 8 is provided. The main hydraulic pump 81 discharges the pressure oil and supplies it to the arm hydraulic cylinder 8 a via the direction control valve 82. The direction control valve 82 is switched to the position a or the position b by the pilot hydraulic oil supplied and discharged via the pilot valve 84 by the operation of the arm operation lever 91. When the direction control valve 82 is in the position a, the pressure oil flows into the bottom oil chamber of the arm hydraulic cylinder 8a, the arm hydraulic cylinder 8a extends, and the arm 8 faces upward (clockwise in FIG. 1). Rotate). When the direction control valve 82 is in the position b, the pressure oil flows into the rod side oil chamber of the arm hydraulic cylinder 8a, the arm hydraulic cylinder 8a is retracted, and the arm 8 is directed downward (counterclockwise in FIG. 1). Rotate).

One preferable example is that the switch A72 for switching the switching valve 65 and the switch B73 for switching the switching valve 67 are grip switches. In that case, one of the switch A72 and the switch B73 is integrated with a boom operation lever (not shown) for instructing to extend / contract the boom hydraulic cylinder 7a, and the other is instructed to extend / contract the arm hydraulic cylinder. The arm operating lever 91 can be integrated.
The work machine 100 has a boom hydraulic cylinder 7a for rotating the boom 7. However, the structure of the boom hydraulic cylinder 7a and the hydraulic drive are the same as those of the arm hydraulic cylinder 8a. In FIG. 2, illustration is omitted.

The work machine 100 includes a plurality of claw opening / closing hydraulic cylinders 33 provided corresponding to the plurality of claws 32, respectively. The hydraulic pump 85 discharges pressure oil and supplies it to the claw opening / closing hydraulic cylinder 33 via the direction control valve 86. By operating the claw opening / closing operation lever 92, the direction control valve 86 is switched to the position c or the position d by the pilot hydraulic oil supplied and discharged through the pilot valve 87. When the direction control valve 86 is in the position c, the pressure oil flows into the bottom oil chamber of the claw opening / closing hydraulic cylinder 33, the claw opening / closing hydraulic cylinder 33 extends, and the claw 32 rotates in the closing direction. Hold an object. When the direction control valve 86 is in the position d, the pressure oil flows into the rod-side oil chamber of the claw opening / closing hydraulic cylinder 33, the claw opening / closing hydraulic cylinder 33 is retracted, and the claw 32 rotates in the opening direction. Release things. The opening / closing operation of the claw 32 is performed simultaneously and in parallel.
In FIG. 4, 88 is a pilot hydraulic pump for discharging pilot hydraulic oil, and 89 is a relief valve for limiting the pressure of the discharged pilot hydraulic oil.

According to the working machine 100 in this embodiment, the following operations can be performed.
Work 1. The grasped object is thrown away farther than the point of arrival of the front end of the work front 6.
Work 2. The object is gripped or released with the grapple tilted with respect to the vertical direction.
Work 3. The work front 6 is rotated so that the grapple does not shake.
Hereinafter, each of the above operations will be sequentially described.

5 to 11 are diagrams for explaining the above-described operation 1. FIG.
First, the object W is gripped by the grapple 10. When gripping the object W, the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23 of the back and forth steadying portion 20A are brought into communication. Further, the steadying cylinder L24 and the steadying cylinder R25 of the left / right steadying part 20B are brought into communication. Then, the object is gripped in a state where the grapple 10 faces downward in the vertical direction, that is, in a state where the grapple 10 is stationary in the direction in which gravity acts.
After gripping the object, the switch A72 is turned on to switch the switching valve 65 to the position e, and the oil path 63 between the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 of the anti-swaying portion 20A. Is in a state of blocking. Thereby, grapple 10 is made into the state where it does not shake in the direction of order. Further, the switch B73 is turned on and the switching valve 67 is switched to the position f so that the oil path 64 between the anti-sway hydraulic cylinder L24 and the anti-sway hydraulic cylinder R25 of the left and right anti-sway part 20B is shut off. . As a result, the grapple 10 is not shaken in the left-right direction.

  Then, as shown in FIG. 5, the arm hydraulic cylinder 8a and the boom hydraulic cylinder 7a are extended by operating the arm operating lever 91 and a boom operating lever (not shown). Thereby, the arm 8 and the boom 7 are rotated upward. In this state, the oil path 63 between the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 of the anti-swaying portion 20A is blocked, so that the grapple 10 extends in the front-rear direction with respect to the bracket 11 at the tip of the arm 8. Move while keeping the angle constant. That is, the arm 8 rotates relatively upward with the upward rotation.

  Next, the arm hydraulic cylinder 8a is retracted, and as shown in FIG. 6, the arm 8 is rotated downward and stopped at a substantially vertical position. At this time, the switching valve 65 is switched to the communication position shown in FIG. 4 so that the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 of the anti-swaying portion 20A are in communication. Even in this case, the switching valve 67 remains at the position f, and the oil passage 64 between the anti-sway hydraulic cylinder L24 and the anti-sway hydraulic cylinder R25 of the left and right anti-sway part 20B is blocked, and the grapple 10 It should be in a state where it does not shake in the left-right direction.

  Even when the arm 8 is stopped, the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 of the anti-swaying portion 20A communicate with each other, and inertial force acts on the grapple 10 that holds the object W. Therefore, as shown in FIG. 7, the grapple 10 rotates backward (counterclockwise in FIG. 7) around the arm pin 51.

  Next, when the grapple 10 reaches a point where the rotation by the inertial force is almost finished, the switch A72 is turned on, the switching valve 65 is switched to the position e, and the oil passage 63 is shut off. . By this operation, as shown in FIG. 8, the grapple 10 stops in a state where the inclination angle inclined by the action of the inertial force is substantially maximized.

  Next, from the state of FIG. 8, the arm hydraulic cylinder is extended, and the arm 8 is rotated forward (clockwise in FIG. 8). During the rotation of the arm 8, the grapple 10 is maintained at the posture of the above-described maximum inclination angle due to the inertial force.

  Then, when the arm 8 rotates forward and reaches a predetermined angle, for example, when the arm 8 is in the posture shown in FIG. 9, the switch A72 is turned off, and the switching valve 65 is moved to a steady-state hydraulic pressure. The cylinder F22 and the steadying hydraulic cylinder B23 are switched to a communication state. By this operation, the grapple 10 can be rotated in the front-rear direction, and is rotated forward (counterclockwise in FIG. 10) by the inertial force as illustrated in FIG.

  When the grapple 10 reaches the required angle, the claw opening / closing operation lever 92 is operated in the OPEN direction. By this operation, the claw opening / closing hydraulic cylinders 33 are simultaneously reduced and rotated in the direction in which the claw 32 is opened, so that the object W is released and flies far away by inertial force as shown in FIG. In this case, since the inertial force accompanying the rotation of the arm 8 and the inertial force accompanying the rotation of the grapple 10 act on the object W, the distance that the object W flies can be increased.

  As a specific example of such an operation, for example, there is an operation of loading waste as the object W into a large ship where the tip of the arm 8 reaches only the front side region of the hull. In this operation, the waste can be loaded only on the near side of the hull unless the waste is blown away. In such a case, an operation that enables the waste to fly to the back of the hull is extremely important.

  In this case, if the grapple 10 always swings freely and cannot be stopped at a required inclination angle, for example, as shown in FIG. Thus, even if the grapple 10 is rotated backward due to the inertial force, the grapple 10 immediately starts to return to the front. For this reason, as shown in FIG. 9, it is difficult to take the start timing for turning the arm 8 forward. Even if it happens that the grapple 10 can start the forward rotation of the arm 8 at the highest point of the backward rotation, the grapple during the operation of rotating the arm 8 forward will occur. 10 is also starting to rotate. As a result, it is difficult to achieve the timing for turning the arm 8 forward to stop and subsequently turning the grapple 10 forward. This means that if the grapple 10 has a structure that cannot be stopped at a required inclination angle, a skill to skillfully throw the object W is required, and it is difficult to increase the flight distance of the object W. Means that.

On the other hand, according to the embodiment of the working machine provided with the hanging grapple of the present invention, the grapple 10 can be held in a state inclined to a required inclination angle. It is possible to easily and efficiently perform the work of throwing W away from the arrival point of the front end of the work front 6.
In the above-described embodiment, the case where the object is thrown far away is described in connection with the vertical movement of the work front 6. However, the object is thrown far away by the upper swing body 3. It is also possible to carry out with the swiveling motion.
Hereinafter, the operation of the target object W gripped by the grapple 10 will be described in the order of an example in which the upper swing body 3 is swung in the clockwise direction when viewed from above the work machine 100 illustrated in FIG. explain.

(A) The object W is gripped by the grapple 10. Once gripped, the switch A72 is turned on with the grapple 10 facing in the vertical direction, the switching valve 65 is switched to the position e, and the oil passage 63 between the steadying hydraulic cylinders F22 and B23 is shut off. Keep it. On the other hand, the steadying hydraulic cylinders L24 and R25 are kept in communication. The boom 7 is inclined forward by a predetermined angle as shown in FIG. The arm 8 may be inclined downward as shown in FIG. 6 or may be inclined a little more forward, depending on the height at which the object W is thrown. Just tilt it.
(B) Turn the upper swing body 3 by a predetermined angle in the counterclockwise direction and stop.
When the upper swing body 3 is stopped, the grapple 10 holding the object W is rotated counterclockwise about the swing pin 52 by the inertial force.

(C) When the rotation due to the inertial force of the grapple 10 reaches the maximum angle, the switch B73 is turned on to shut off the oil passage 64 between the hydraulic cylinders L24 and R25 for steadying. By this operation, the grapple 10 stops in a state in which the rotation angle in the counterclockwise direction due to the inertial force is substantially maximum.
(D) Next, the upper swing body 3 is swung clockwise by a predetermined angle.
(E) The upper swing body 3 is stopped, and the switch B73 is turned off to bring the steady hydraulic cylinder L24 and the steady hydraulic cylinder R25 into communication. By this operation, the grapple 10 holding the object W is rotated in the clockwise direction by the inertial force.
(F) When the rotation by the inertial force of the grapple 10 reaches a required angle, the claw opening / closing operation lever 92 is operated in the OPEN direction. By this operation, the claw opening / closing hydraulic cylinders 33 are simultaneously reduced and the claw 32 is rotated in the opening direction, so that the object W is released and flies far away by the inertial force.

  Also in this case, since the inertial force accompanying the turning of the upper turning body 3 and the inertial force accompanying the turning of the grapple 10 act on the object W, the flying distance can be increased.

Next, with the work machine 100 described above,
Work 2. A case where an operation of gripping or releasing an object is performed in a state where the grapple is inclined with respect to the vertical direction will be described.
The operation of holding the grapple 10 in an inclined state is the same as that described in connection with operation 1, but is summarized below.
The switch B73 (or the switch A72) is turned on so that the steadying hydraulic cylinder L24 and the steadying hydraulic cylinder R25 (or the steadying hydraulic cylinder F22 and the steadying hydraulic cylinder B23) are disconnected. In this state, the work front 6 (or the upper swing body 3) is driven and stopped. By this operation, the grapple 10 swings around the arm pin 51 (or the swing pin 52) due to inertial force. When the grapple 10 reaches the required inclination angle, the switch A72 (or switch B73) is turned on. By this operation, the position between the anti-sway hydraulic cylinder F22 and the anti-sway hydraulic cylinder B23 (or the anti-sway hydraulic cylinder L24 and the anti-sway hydraulic cylinder R25) is cut off and stopped in a state tilted to the required tilt angle. To do. Each claw 32 can be moved to a required position in the circumferential direction by rotating the grip portion 30 by the turning device 31.

  In this state, the gripping part 30 of the grapple 10 can be driven to grip or release the object W. This operation is required, for example, when there is an obstacle on a vertical line passing through the object W to be grasped or a place where the grasped object W is to be released. By making it possible to perform such operations that have been difficult in the past, work efficiency can be significantly improved.

Next, with the work machine 100 described above,
Work 3. A case where the work for rotating the work front 6 is performed in a state where the grapple is not shaken will be described.
The state where the grapple does not sway is, for example, a state where the central axis of opening and closing of the grapple 10 is parallel to the vertical axes ZZ and XX, in other words, in a direction where gravity acts. This is achieved by turning on the switch A72 and the switch B73. By this operation, the vibration prevention hydraulic cylinder F22 and the vibration prevention hydraulic cylinder B23 and the vibration prevention hydraulic cylinder L24 and the vibration prevention hydraulic cylinder R25 are cut off and the grapple is not shaken. This operation is required in an operation where the grapple 10 may swing and interfere with an obstacle on the transport path. Since the grapple 10 is not shaken, the work can be performed safely and efficiently.
In the above description, the case where the grapple 10 is not shaken with the central axis of opening and closing of the grapple 10 facing the vertical direction has been described. However, it is also possible to prevent the grapple 10 from shaking in a state where the central axis for opening and closing the grapple 10 is held at a required inclination angle. The operation of holding the central axis of opening and closing of the grapple 10 at a required inclination angle is as described for the operation 2 above.

As described above, in the embodiment of the working machine provided with the hanging grapple of the present invention, normally, the steady stop hydraulic cylinder F22, so that the central axis of the opening and closing of the grapple 10 is always in the vertical direction. The connection between B23 and the hydraulic cylinders L24 and R25 for steadying are in communication. However, by turning on the switch A72 or the switch B73, it is possible to switch between the steady-state hydraulic cylinders F22 and B23 or between the steady-state hydraulic cylinders L24 and R25.
For this reason, it becomes possible to hold | maintain the grapple 10 in the state inclined to arbitrary inclination angles.
This
(1) Throw the grasped object farther than the point of arrival at the tip of the work front 6.
(2) Hold the grapple in an inclined state with respect to the vertical direction.
(3) The work front 6 can be moved in a state where the grapple does not shake.
It is possible to perform operations such as the above, and there is an effect of improving the safety and efficiency of the operations.

  In the above embodiment, the case where both the front and rear hydraulic cylinders F22 and B23 and the left and right hydraulic cylinders L24 and R25 are provided has been described. However, only one of the front and rear hydraulic cylinders F22 and B23 or the left and right hydraulic cylinders L24 and R25 may be provided.

  Further, the grapple 10 has a structure attached to the bracket 11, but it may be attached directly to the tip of the arm 8. In addition, the working machine provided with the hanging grapple of the present invention can be variously modified within the scope of the gist of the invention. In short, the working machine provided with the grapple suspended at the tip of the arm. The grapple includes a plurality of claws supported at the base portion so as to be openable and closable, an opening / closing mechanism that opens and closes the plurality of claws, and a pair of first hydraulic cylinders that swing the base portion in the front-rear direction of the work machine And a pair of second hydraulic cylinders that swing the base in the left-right direction of the work machine, and at least one of the pair of first hydraulic cylinders and the pair of second hydraulic cylinders communicates with each other via a switching valve. And what is necessary is just to be provided so that interruption | blocking is possible.

6 Working Front 7 Boom 7a Boom Hydraulic Cylinder 8 Arm 8a Arm Hydraulic Cylinder 10 Grapple 20 Anti-sway part 20A Front and Back Anti-sway Part 20B Left and Right Anti-sway Part 21 Front and Back Oscillation Plates 21a and 21b Standing pieces 21c and 21d Projection piece 21e Connecting pieces 22 to 24 Stabilizing hydraulic cylinders 26 Left and right swing plates 26a and 26b Standing pieces 26c and 26d Protruding pieces 30 Holding parts 31 Swiveling devices 32 Claws 33 Claw opening / closing hydraulic cylinders 51 Arm pins 52 Swing pins 61 Pistons 62 Springs 65, 67 Switching valve 66 Accumulator 71 Control unit 72, 73 Switch 91 Arm operation lever 92 Claw opening / closing operation lever 100 Working machine

Claims (5)

In a work machine equipped with a grapple suspended from the arm tip,
The grapple is
A plurality of claws supported to be openable and closable at the base,
An opening / closing mechanism installed on the base and opening / closing the plurality of claws;
A pair of first hydraulic cylinders provided at the front and rear of a lateral pin that pivotally supports the base and the claw in the front-rear direction, or a vertical pin that pivotally supports the base and the claw in the left-right direction. Having at least one of a pair of second hydraulic cylinders provided on the left and right;
The working machine, wherein the pair of first hydraulic cylinders and / or the pair of second hydraulic cylinders are provided so as to be able to be switched between a communication state and a cutoff state via a switching valve.   The work machine according to claim 1, comprising both the pair of first hydraulic cylinders and the pair of second hydraulic cylinders, each of which can be switched between a communication state and a shut-off state via a switching valve. A working machine characterized by that.   3. The work machine according to claim 1, wherein bottom chambers of the pair of first hydraulic cylinders and / or the pair of second hydraulic cylinders are connected to each other.   4. The work machine according to claim 1, wherein the pair of first hydraulic cylinders and / or the pair of second hydraulic cylinders include a spring that biases the piston toward the bottom chamber. 5. Features a working machine. 5. The suspension work machine according to claim 3, wherein the pair of first hydraulic cylinders and / or the pair of second hydraulic cylinders includes an accumulator connected to an oil passage that connects bottom chambers to each other. Features a working machine.

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