JP2017115412A - Lock structure of hook and work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lock structure of a hook capable of preventing a lock of the hook from being unintentionally released.SOLUTION: A hydraulic excavator comprises an arm 53, a bucket 55, a cylinder 6, a rotary link 7, a hook 8, hook holding means, and mode tip means. The mode tip means selects an ordinary mode for executing ordinary work by using the bucket 55 and a crane mode for executing suspension work by using the hook 8. A tip part of the cylinder 6 is provided with a regulation plate for moving to the rotary link 7 in response to an expansion of the cylinder 6. The regulation plate is arranged in a position for regulating the movement in the lateral direction of the hook holding means when the tip part of the cylinder 6 exists on the contraction side more than a first position. While, the regulation plate is arranged in a position for allowing the movement in the lateral direction of the hook holding means by interlocking with extension operation by which the tip part of the cylinder 6 extends to a second position from the first position.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hook locking structure for holding a hook of a work machine in a rotary link.

  Some hydraulic excavators are provided with a hook for carrying a load work in a rotation link that connects a bucket and a cylinder that rotates the bucket. In such a hydraulic excavator, the hook is fixed to the storage space of the rotating link by the hook holding means during excavation work, and the hook is taken out and used during the lifting work.

  For example, Patent Document 1 discloses a latch member (43, 61, 81) as a hook holding means. The latch member (43, 61, 81), as shown in FIG. 4 of Patent Document 1, etc., holds the hook (27) to the hook guide (36, 52) in the advanced position and holds it in the retracted position. In the retracted position, the hook (27) is allowed to move to the working position.

Japanese Patent No. 4271819

  However, in the invention described in Patent Document 1, when rocks or the like scattered during excavation work collide with the latch member, there is a possibility that the hook is unlocked unintentionally and the hook jumps out.

  Accordingly, an object of the present invention is to provide a hook locking structure that can prevent the hook lock from being unintentionally released.

  In order to achieve the above-described object, the present invention provides a working machine that is mounted to be rotatable about a left-right axis with respect to a tip of an arm of the working machine, and the working machine is rotated with respect to the arm by expansion and contraction A cylinder having a base end connected to the arm and a tip end opposite to the base end, and a rotation link connecting the tip end of the cylinder and the work implement. A hook that is pivotally attached to the pivot link and moves between a retracted state disposed in a storage space of the pivot link and an extended state protruding from the storage space; and the hook Hook holding means for holding in the storage space, mode selection means for selecting a normal mode for performing normal work using the work implement, and a crane mode for performing suspension work using the hook; , The tip of the cylinder can be extended to a first position in the normal mode, and can be extended to a second position on the extension side of the first position in the crane mode. Is configured to be switchable between a holding state in which the hook is held and a non-holding state in which the hook is not held by moving in the left-right direction. A restricting member that moves with respect to the rotation link as it expands and contracts is provided, and the restricting member holds the hook when the tip end portion of the cylinder is on the contraction side with respect to the first position. The tip of the cylinder is interlocked with the extension operation of extending from the first position to the second position, while being arranged at a position that restricts the movement of the means in the left-right direction, It provides a locking structure of the hook, characterized in that disposed in the position in the lateral direction to allow movement of the click holding means.

  Further, the hook holding means is a latch member that moves in the left-right direction between a holding position for holding the hook in the storage space and a non-holding position for allowing the hook to project from the storage space. And the restricting member is disposed at a position that restricts the movement of the latch member from the holding position to the non-holding position when the tip of the cylinder is on the reduction side with respect to the first position. The tip of the cylinder is arranged at a position allowing the movement of the latch member from the holding position to the non-holding position in conjunction with the extension operation from the first position to the second position. Is preferred.

  The restricting member has a shape that expands along the turning direction of the turning link, and the latch member has a protruding portion that protrudes toward the restricting member in a direction perpendicular to the left-right direction. In the holding position of the latch member, it is preferable that the protruding portion is disposed between the hook stored in the storage space and the restricting member.

  Further, the hook holding means is configured as a holding pin that is inserted into a hook portion of the hook and holds the hook in the storage space, and a groove portion that engages with the regulating member is formed on an outer periphery of the holding pin. The restricting member is arranged at a position that engages with the groove and restricts the movement of the holding pin in the left-right direction when the tip end of the cylinder is on the reduction side with respect to the first position. In conjunction with the extension operation of the tip portion of the cylinder from the first position to the second position, the cylinder is disposed at a position allowing the movement of the holding pin in the left-right direction by detaching from the groove portion. preferable.

  The present invention is a work machine, comprising a machine main body and an attachment connected to the machine main body, the attachment rotating about a left-right axis with respect to the arm and the tip of the arm A work machine that can be mounted, a cylinder that rotates the work machine with respect to the arm by expansion and contraction, and a base end connected to the arm and a tip opposite to the base end A rotating link that connects the tip of the cylinder and the work implement, and a retracted state in which the rotating link is attached to the rotating link and is disposed in a storage space of the rotating link. And a hook holding means for holding the hook in the storage space, and the work machine uses the work machine to perform normal work. The Mode selection means is provided for selecting a normal mode for suspending and a crane mode for performing a lifting operation using the hook, and the tip of the cylinder is at a first position in the normal mode. In the crane mode, and can be extended to a second position on the extension side of the first position, and the hook holding means moves the hook in the left-right direction to move the hook. It is configured to be able to switch between a holding state that holds and a non-holding state that does not hold the hook, and the tip of the cylinder is restricted to move relative to the rotating link as the cylinder expands and contracts. A member is provided, and the restricting member is configured such that when the tip end portion of the cylinder is on the contraction side with respect to the first position, the left and right sides of the hook holding means are The front end of the cylinder is interlocked with the extension operation of extending from the first position to the second position, and the movement of the hook holding means in the left-right direction is allowed. There is further provided a work machine that is arranged at a position where

  According to the present invention, the restricting member is disposed at a position that restricts the movement of the hook holding means in the left-right direction when the tip end of the cylinder is on the reduction side with respect to the first position, while the tip end of the cylinder Is arranged at a position allowing the movement of the hook holding means in the left-right direction in conjunction with the extending operation of extending from the first position to the second position. Therefore, when the tip position of the cylinder is on the contraction side with respect to the first position, the hook is more reliably locked by the hook holding means, and the hook is not unlocked unintentionally.

A side view showing a hydraulic excavator concerning an embodiment of the present invention. The perspective view which shows a part of attachment including the hook in a retracted state. The perspective view which shows a part of attachment including the hook in an overhang | projection state. The perspective view which shows a rotation link. The perspective view which shows the latch member (A) in a holding position, and the latch member (B) in a non-holding position. The figure which shows the control circuit of a cylinder. The top view which shows the state arrange | positioned in the position where a control board controls rotation of a latch member. The top view which shows the state arrange | positioned in the position which a regulation board accept | permits rotation of a latch member. The top view which shows the state which rotated the latch member to the non-holding position. The figure which shows the positional relationship of the latch member of a cylinder most contracted state, and a control board. The figure which shows the positional relationship of the latch member and regulation board in the cylinder maximum extension state of excavation mode. The figure which shows the positional relationship of the latch member and regulation board in the cylinder maximum extension state of crane mode. The conceptual diagram which shows the hook holding means which concerns on a modification.

<1. Embodiment>
A working machine and a hook locking structure according to an embodiment of the present invention will be described with reference to FIGS. Hereinafter, a hydraulic excavator 1 will be described as an example of a work machine according to the present invention. In each drawing, the front-rear direction and the left-right direction of the excavator 1 are defined as necessary.

  As shown in FIG. 1, the excavator 1 includes a crawler type lower traveling body 2 and an upper swing body 3.

  The upper swing body 3 is mounted on the lower travel body 2 and can swing around the vertical axis with respect to the lower travel body 2. The upper swing body 3 includes a machine main body 4 and an attachment 5 attached to the machine main body 4 and used. The attachment 5 includes a boom 51, an arm 53, a bucket 55, and the like. The bucket 55 is an example of a work machine according to the present invention.

  As shown in FIGS. 2 and 3, the attachment 5 is provided with a cylinder 6 that rotates the bucket 55 relative to the arm 53. The cylinder 6 includes a cylinder tube 61 and a rod 63 that extends and contracts from the cylinder tube 61. The cylinder 6 is also referred to as a bucket cylinder.

  The rod 63 extends to the extending side C1 (FIG. 2) when extending, and contracts to the reducing side C2 (FIG. 2) when contracting. When the rod 63 extends to the extending side C1, the bucket 55 rotates in the direction B1 (FIG. 2). On the other hand, when the rod 63 contracts to the reduction side C2, the bucket 55 rotates in the direction B2 (FIG. 2). Moreover, the cylinder tube 61 is provided with the bottom chamber 61a and the rod chamber 61b, as shown in FIG. The bottom chamber 61a and the rod chamber 61b will be described later.

  Further, the attachment 5 is provided with a connection link 54 and a rotation link 7.

  Two connection links 54 are provided so as to be separated from each other on the left and right, and connect the arm 53 and the tip of the cylinder 6. One end side of the connection link 54 is connected to the side surface of the arm 53 by a connecting shaft 54A, and the other end side is connected to the tip end portion of the rod 63 by a connecting shaft 54B. The connection link 54 is also referred to as an idler link.

  The rotation link 7 connects the tip of the cylinder 6 and the bucket 55. One end side of the rotating link 7 is connected to the tip end portion of the rod 63 together with the connection link 54 by the connecting shaft 54B, and the other end side is connected to the back surface of the bucket 55 by the connecting shaft 7A. The rotation link 7 is also referred to as a bucket link or the like.

  A hook 8 used for a hanging work (hook work) is rotatably attached to the turning link 7. The hook 8 is rotatably connected to the rotation link 7 with the connecting shaft 7A as a support shaft.

  As shown in FIG. 4, the rotation link 7 includes a pair of side plates 71 </ b> A and 71 </ b> B, a first connection end 73, and a second connection end 75.

  The first connection end 73 is connected to the tip 63A of the rod 63 via the connecting shaft 54B (FIG. 2). The second connection end 75 is connected to the back surface of the bucket 55 via the connecting shaft 7A (FIG. 2).

  A storage space 70 for storing the hook 8 is formed between the side plate 71A and the side plate 71B. The hook 8 rotates between the storage state ST1 (FIG. 2) stored in the storage space 70 and the overhanging state ST2 (FIG. 3) protruding from the storage space 70. The hook 8 is attached using the connecting shaft 7A.

  As shown in FIG. 4, a hook holding member 77 is provided on the inner side of the side plate 71 </ b> B constituting the rotation link 7. In addition, a restriction plate 65 that extends along the rotation direction of the rotation link 7 is provided at the distal end portion 63 </ b> A of the rod 63. The hook holding member 77 is an example of a hook holding unit according to the present invention, and the restriction plate 65 is an example of a restriction member according to the present invention.

  As shown in FIG. 5, the hook holding member 77 includes a support member 771, a latch member 773, a contact member 775, and a bolt 777.

  The support member 771 is a member that rotatably supports the latch member 773. The support member 771 has a substantially L-shaped cross section, and is provided inside the side plate 71B (FIG. 4).

  The latch member 773 has a hook holding portion 774 and a protruding portion 776, and is a member that is rotatably supported by the support member 771. The hook holding portion 774 is a portion that holds the hook 8 stored in the storage space 70 and is formed in a tapered shape. The tapered tip end portion of the hook holding portion 774 engages with the inside of the hook portion of the hook 8 stored in the storage space 70 to hold the hook 8. An insertion hole for inserting the bolt 777 is provided in the approximate center of the hook holding portion 774.

  The protruding portion 776 is a portion protruding from the end of the hook holding portion 774 in the holding position PA (FIG. 5A) holding the hook 8 toward the rod 63 from the end side on the rod 63 side.

  The latch member 773 is rotatably attached to the support member 771 by a bolt 777. Then, the latch member 773 rotates between the holding position PA shown in FIG. 5A and the non-holding position PB shown in FIG. Here, the holding position PA is a position for holding the hook 8 in the storage space 70, and the non-holding position PB is a position for allowing the hook 8 to protrude from the storage space 70. A biasing force is applied to the latch member 773 toward the direction D1. Therefore, the latch member 773 is normally disposed at the holding position PA by an urging force.

  However, in the case described below, the latch member 773 moves from the holding position PA to the non-holding position PB.

  For example, in the process of storing the hook 8 in the storage space 70 of the rotation link 7, the latch member 773 temporarily moves from the holding position PA to the non-holding position PB. Specifically, when the hook 8 is gradually moved toward the storage space 70, the oblique side 778 of the hook holding portion 774 is pushed by the outer periphery of the hook portion of the hook 8, and the latch member 773 rotates in the direction D2. As a result, the latch member 773 is temporarily disposed at the non-holding position PB.

  Thereafter, when the hook 8 is further moved toward the storage space 70, the hook outer periphery of the hook 8 is disengaged from the hook holding portion 774, and the latch member 773 is moved from the non-holding position PB to the holding position again. Return to PA. The tapered tip end portion of the hook holding portion 774 is disposed inside the hook portion of the hook 8, and the hook 8 is held in the storage space 70.

  In addition to the above, when the operator manually rotates the latch member 773 in the direction D2 in order to take out the hook 8 from the storage space 70, the latch member 773 moves to the non-holding position PB.

  The contact member 775 is a portion that is provided at the taper base end portion of the hook holding portion 774 and abuts against the support member 771 when the latch member 773 tries to rotate in the direction D2. The contact member 775 functions as a handle member (also referred to as a handle member) that is gripped and operated by the operator when the latch member 773 is manually rotated in the direction D2.

  Next, the restriction plate 65 (FIG. 4) provided at the tip 63A of the rod 63 will be described. As shown in FIG. 4, the restricting plate 65 is configured as a plate member that spreads from the distal end portion 63 of the rod 63 along the rotation direction of the rotation link 7 in a direction orthogonal to the left-right direction.

  As described above, the tip 63 </ b> A of the rod 63 rotates with respect to the rotation link 7 as the rod 63 expands and contracts. In conjunction with this, the restriction plate 65 also moves relative to the rotation link 7.

  Specifically, the restriction plate 65 moves in a direction away from the hook holding member 77 when the rod 63 extends, and moves in a direction approaching the hook holding member 77 when the rod 63 contracts. In this embodiment, as will be described in detail later, the rotation of the latch member 773 is controlled by using the movement of the restriction plate 65 with respect to the hook holding member 77.

  Next, “excavation mode” and “crane mode” will be described. The “excavation mode” is a mode for performing excavation work using the bucket 55, and is an example of a normal mode according to the present invention. In the “excavation mode”, the tip of the rod 63 can extend to the position Ca (see FIG. 6). The position Ca is an example of a first position according to the present invention.

  Further, the “crane mode” is a mode for performing a lifting work using the hook 8. In the “crane mode”, the tip of the rod 63 can extend to a position Cb (see FIG. 6) located on the extending side C1 from the position Ca. The position Cb is an example of a second position according to the present invention.

  The expansion / contraction operation of the cylinder 6 is controlled along the control circuit shown in FIG. Hereinafter, the cylinder control circuit 90 will be described in detail with reference to FIG.

  The cylinder control circuit 90 includes a pump 91, a control valve 93, an operation lever 95, pilot lines 95d and 95e, and a pilot pressure control valve 97.

  The pump 91 is a hydraulic pump that supplies hydraulic oil to the cylinder 6.

  The control valve 93 is a direction switching valve for controlling the direction and flow rate of the hydraulic oil supplied from the pump 91 to the cylinder 6. The control valve 93 is provided in the oil path between the pump 91 and the cylinder 6. The control valve 93 includes switchable oil passages 93a, 93b, and 93c that are switched by pilot oil pressure, and pilot ports 93d and 93e.

  The switchable oil passage 93a is an oil passage for operating the cylinder 6 to the extending side C1. The switchable oil passage 93a supplies hydraulic oil from the pump 91 to the bottom chamber 61a, while returning the hydraulic oil from the rod chamber 61b to the tank T.

  The switchable oil passage 93b is an oil passage for operating the cylinder 6 to the reduction side C2. The switchable oil passage 93b supplies hydraulic oil from the pump 91 to the rod chamber 61b, while returning the hydraulic oil from the bottom chamber 61a to the tank T.

  The switchable oil passage 93 c is an oil passage for stopping the expansion / contraction operation of the cylinder 6, and blocks between the pump 91 and the cylinder 6.

  Pilot oil pressure for switching the switchable oil passages 93a, 93b, 93c is input to the pilot ports 93d, 93e. When the pilot pressure is input to the pilot port 93e (when the pilot pressure of the pilot port 93e is larger than the pilot pressure of the pilot port 93d), the control valve 93 operates so that the switchable oil passage 93b is arranged at the center. . On the other hand, when the pilot pressure is input to the pilot port 93d (when the pilot pressure of the pilot port 93d is larger than the pilot pressure of the pilot port 93e), the control valve 93 is set so that the switchable oil passage 93a is arranged at the center. Operate.

  The operation lever 95 is a lever for operating the control valve 93 and is operated by an operator of the excavator 1.

  The pilot lines 95d and 95e are oil passages that connect the operation lever 95 and the pilot ports 93d and 93e. The pilot line 95d connects the operation lever 95 and the pilot port 93d, and the pilot line 95e connects the operation lever 95 and the pilot port 93e.

  The pilot pressure control valve 97 is an electromagnetic control valve for controlling (regulating or releasing the regulation) the operation of the cylinder 6 toward the extending side C1, and is provided on the pilot line 95d.

  As shown in FIG. 6, the cylinder control circuit 90 further includes a control device 92, mode selection means 94, and expansion / contraction position detection means 96.

  The control device 92 controls the pilot pressure control valve 97 according to the state of the mode selection means 94 and the expansion / contraction position detection means 96. Specifically, the control device 92 brings the pilot pressure control valve 97 into an excited state or a non-excited state.

  The mode selection means 94 is means for the operator to select either “excavation mode” or “crane mode”.

  The expansion / contraction position detection means 96 is a means for detecting the expansion / contraction position of the cylinder 6. Specifically, the expansion / contraction position detection means 96 detects whether or not the tip of the cylinder 6 exceeds the position Ca. The position Ca is a position where the tip of the cylinder 6 is most extended when the “excavation mode” is selected. The position Ca is also referred to as a normal stroke end.

  Next, the expansion / contraction operation of the cylinder 6 in the “excavation mode” and the expansion / contraction operation of the cylinder 6 in the “crane mode” will be described.

In the “excavation mode”, the cylinder control circuit 90 performs the following operations (a) to (d).
(A) The mode selection means 94 outputs the selection result (“excavation mode”) by the operator to the control device 92.
(B) The expansion / contraction position detecting means 96 outputs the detection result (tip position of the cylinder 6) to the control device 92.
(C) When the tip position of the cylinder 6 becomes the position Ca, the control device 92 puts the pilot pressure control valve 97 in a non-excited state. The pilot pressure control valve 97 in the non-excited state cuts off the pilot line 95d and makes the pilot port 93d and the tank T communicate with each other. As a result, the operation of the cylinder 6 toward the extending side C1 is restricted.
(D) When the tip of the cylinder 6 is on the reduction side C2 with respect to the position Ca, the control device 92 causes the pilot pressure control valve 97 to be in an excited state. The pilot pressure control valve 97 in the excited state causes the pilot port 93d and the operation lever 95 to communicate with each other (the pilot line 95d communicates). As a result, the restriction (c) is released. Then, in response to the operation of the operation lever 95, the cylinder 6 can be moved to the extending side C1.

In the “crane mode”, the cylinder control circuit 90 performs the following operations (e) to (f).
(E) The mode selection means 94 outputs the selection result (“crane mode”) by the operator to the control device 92.
(F) The control device 92 brings the pilot pressure control valve 97 into an excited state regardless of the detection state of the expansion / contraction position detection means 96. As a result, the restriction (c) is released. Then, in response to the operation of the operation lever 95, the cylinder 6 can be moved to the extending side C1. That is, the tip of the cylinder 6 can extend to the position Cb. The position Cb is a position where the tip of the cylinder 6 is most extended when the “crane mode” is selected by the mode selection means 94. The position Cb is also referred to as a crane stroke end.

  By performing the control as described above, the tip of the rod 63 extends to the position Ca at the longest in the “excavation mode”, and the tip of the rod 63 extends to the position Cb at the longest in the “crane mode”.

  When the tip of the rod 63 is on the reduction side C2 with respect to the position Ca, the restriction plate 65 protrudes when the hook holding member 77 is about to rotate in the direction D2 (FIG. 5) as shown in FIG. It is disposed at a position where it abuts against the portion 776. That is, the restricting plate 65 is disposed at a position that restricts the movement of the hook holding portion 774 of the latch member 773 in the left-right direction.

  In addition, when the tip of the rod 63 is on the extending side C1 from the position Ca, the restriction plate 65 does not contact the protruding portion 776 when the hook holding member 77 rotates in the direction D2, as shown in FIG. Placed in position. That is, the restriction plate 65 is disposed at a position that allows the left and right movements of the hook holding portion 774 of the latch member 773. In other words, the restricting plate 65 is disposed at a position that allows the hook holding portion 774 to move in the left-right direction in conjunction with the extension operation from the position Ca of the tip 63A of the rod 63 to the position Cb.

  When the restriction on the rotation of the latch member 773 in the direction D2 (that is, the movement of the hook holding portion 774 in the left-right direction) is released, the operator rotates the hook holding member 77 as shown in FIG. Is possible. Therefore, the hook 8 can be taken out from the storage space 70 and can be shifted from the storage state ST1 (FIG. 2) to the overhanging state ST2 (FIG. 3).

  When the above is summarized, as shown in FIG. 10, when the cylinder 6 is in the most contracted state, the restricting plate 65 is disposed at a position that restricts the rotation of the latch member 773 in the direction D2 (FIG. 5). . Further, as shown in FIG. 11, the same applies when the cylinder 6 extends to the maximum extension state in the excavation mode.

  On the other hand, as shown in FIG. 12, when the cylinder 6 extends to the maximum extension state in the crane mode, the restriction plate 65 is disposed at a position that allows the latch member 773 to rotate in the direction D2.

<2. Effects of the embodiment>
In the present embodiment, as shown in FIG. 7, the restricting plate 65 rotates in the direction D <b> 2 of the latch member 773 when the distal end portion 63 </ b> A of the rod 63 is on the reduction side with respect to the position Ca, that is, The hook holding portion 774 is disposed at a position that restricts movement in the left-right direction. On the other hand, as shown in FIGS. 8 and 9, the restricting plate 65 is interlocked with the extending operation from the position Ca of the tip 63 </ b> A of the rod 63 to the position Cb and allows the hook holding portion 774 to move in the left-right direction. Placed in. Therefore, when the tip end position of the rod 63 is closer to the reduction side than the position Ca (in the excavation mode), even if the rock collides with the latch member 773 during excavation work, the latch member 773 does not rotate freely. . Therefore, it is possible to prevent the hook 8 from being unlocked unintentionally.

  Further, since the rotation of the latch member 773 is restricted in the excavation mode, there is no possibility that the operator accidentally releases the lock of the hook 8, and it is possible to prevent the suspension work from being performed in the excavation mode. .

  A hook holding member 77 is provided in advance on the side plate 71B of the rotation link 7. Therefore, the problem that the fixing pin is lost does not occur as in the case of using the detachable fixing pin.

  In addition, a restriction plate 65 that moves in accordance with the expansion and contraction of the cylinder 6 is provided at the tip 63A of the rod 63 (see FIG. 4). In the excavation mode, the restriction plate 65 prevents the latch member 773 from rotating. On the other hand, in the crane mode, the restriction plate 65 is retracted to a position that does not hinder the rotation of the latch member 773. Therefore, the holding ability of the hook 8 in the excavation mode can be improved without impairing the workability of the rotation operation of the latch member 773 in the crane mode.

  Further, the latch member 773 is provided with a protruding portion 776. For this reason, it is possible to secure the contact area between the restriction plate 65 and the latch member 773 without making the restriction plate 65 larger than necessary. In particular, when the distance between the hook 8 and the distal end portion of the rod 63 is large, if the restriction plate 65 is enlarged, the restriction plate 65 greatly protrudes from the rotation link 7 as the cylinder 6 expands and contracts. Providing the portion 776 is very effective.

<3. Modification>
The hook locking structure according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims.

  For example, in the above embodiment, the case where the hook 8 is held using the hook holding member 77 provided with the latch member 773 is illustrated, but the present invention is not limited to this, and the hook 8 is attached using the holding pin 79 shown in FIG. You may make it hold | maintain.

  As shown in FIG. 13, the holding pin 79 is inserted into the hook portion of the hook 8 and holds the hook 8 in the storage space 70. A groove portion 790 that engages with the regulation plate 65 is formed on the outer periphery of the holding pin 79. When the tip 63A of the rod 63 is on the reduction side with respect to the position Ca (FIG. 6), the restriction plate 65 is disposed at a position that engages with the groove 790 to restrict the movement of the holding pin 79 in the left-right direction. The On the other hand, the restricting plate 65 is arranged at a position where the holding pin 79 is allowed to move in the left-right direction in conjunction with the extending operation from the position Ca of the tip 63A of the rod 63 to the position Cb (FIG. 6). Is done. Also in this modification, the same effect as the above-described embodiment can be obtained.

  As described above, the configuration according to the present invention is suitable for use in a hydraulic excavator or the like that holds the hook in the storage space of the rotation link.

1 hydraulic excavator, 2 lower traveling body, 3 upper turning body, 4 machine body,
5 Attachment, 6 Cylinder, 7 Rotating link, 7A Connecting shaft, 8 Hook,
51 boom, 53 arm, 54 connecting link, 54A, 54B connecting shaft,
55 bucket, 61 cylinder tube, 61a bottom chamber, 61b rod chamber,
63 Rod, 63A tip, 65 Restriction plate, 70 Storage space, 71A, 71B Side plate,
73,75 connection end, 77 hook holding member, 79 holding pin,
90 cylinder control circuit, 91 pump, 92 control device, 93 control valve,
93a, 93b, 93c switchable oil passage, 93d, 93e pilot port,
94 mode selection means, 95 operation lever, 95d, 95e pilot line,
96 expansion / contraction position detection means, 97 pilot pressure control valve, 771 support member,
773 latch member, 774 hook holding portion, 775 contact member, 776 protruding portion,
777 bolt, 790 groove, C1 extending side, C2 reducing side, Ca, Cb position,
PA holding position, PB non-holding position, ST1 retracted state, ST2 overhanging state, T tank

Claims (5)

A working machine mounted so as to be rotatable about a left-right axis with respect to the tip of the arm of the working machine;
A cylinder for rotating the working machine with respect to the arm by expansion and contraction, and a cylinder having a proximal end connected to the arm and a distal end opposite to the proximal end;
A pivot link connecting the tip of the cylinder and the work implement;
A hook that is pivotally attached to the pivot link and moves between a retracted state disposed in a storage space of the pivot link and an extended state protruding from the storage space;
Hook holding means for holding the hook in the storage space;
Mode selection means for selecting a normal mode for performing normal work using the work implement, and a crane mode for performing suspension work using the hook;
With
The tip of the cylinder can be extended to a first position in the normal mode, and can be extended to a second position on the extension side of the first position in the crane mode,
The hook holding means is configured to be able to switch between a holding state in which the hook is held and a non-holding state in which the hook is not held by moving in the left-right direction,
The tip of the cylinder is provided with a restricting member that moves relative to the rotation link as the cylinder expands and contracts.
The regulating member is
When the tip of the cylinder is on the reduction side with respect to the first position, the cylinder is disposed at a position that restricts the movement of the hook holding means in the left-right direction,
The hook is disposed at a position allowing the movement of the hook holding means in the left-right direction in conjunction with an extension operation in which the tip of the cylinder extends from the first position to the second position. Lock structure. The hook holding means is configured as a latch member that moves between a holding position for holding the hook in the storage space and a non-holding position for allowing the hook to protrude from the storage space in the left-right direction. ,
The regulating member is
When the tip of the cylinder is on the reduction side with respect to the first position, the cylinder is disposed at a position that restricts movement of the latch member from the holding position to the non-holding position;
The cylinder is disposed at a position allowing the movement of the latch member from the holding position to the non-holding position in conjunction with the extension operation of the tip portion from the first position to the second position. The hook locking structure according to claim 1. The regulating member has a shape that spreads along the turning direction of the turning link,
The latch member is provided with a protruding portion that protrudes toward the regulating member in a direction orthogonal to the left-right direction,
The hook locking structure according to claim 2, wherein, in the holding position of the latch member, the protrusion is disposed between the hook stored in the storage space and the restricting member. The hook holding means is configured as a holding pin that is inserted into a hook portion of the hook and holds the hook in the storage space.
A groove that engages with the restriction member is formed on the outer periphery of the holding pin,
The regulating member is
When the tip of the cylinder is on the reduction side with respect to the first position, the cylinder is disposed at a position that engages with the groove and restricts the movement of the holding pin in the left-right direction;
In conjunction with the extension operation of the tip of the cylinder from the first position to the second position, the cylinder is disposed at a position allowing the movement of the holding pin in the left-right direction by moving away from the groove. The hook locking structure according to claim 1. A working machine,
The machine body,
An attachment connected to the machine body;
With
The attachment is
Arm,
A working machine mounted so as to be rotatable around a left-right axis with respect to the tip of the arm;
A cylinder for rotating the working machine with respect to the arm by expansion and contraction, and a cylinder having a proximal end connected to the arm and a distal end opposite to the proximal end;
A pivot link connecting the tip of the cylinder and the work implement;
A hook that is pivotally attached to the pivot link and moves between a retracted state disposed in a storage space of the pivot link and an extended state protruding from the storage space;
Hook holding means for holding the hook in the storage space;
With
The work machine is provided with a mode selection means for selecting a normal mode for performing normal work using the work implement and a crane mode for performing suspension work using the hook,
The tip of the cylinder can be extended to a first position in the normal mode, and can be extended to a second position on the extension side of the first position in the crane mode,
The hook holding means is configured to be able to switch between a holding state in which the hook is held and a non-holding state in which the hook is not held by moving in the left-right direction,
The tip of the cylinder is provided with a restricting member that moves relative to the rotation link as the cylinder expands and contracts.
The regulating member is
When the tip of the cylinder is on the reduction side with respect to the first position, the cylinder is disposed at a position that restricts the movement of the hook holding means in the left-right direction,
The working machine is arranged at a position allowing the movement of the hook holding means in the left-right direction in conjunction with an extending operation in which the tip of the cylinder extends from the first position to the second position. .

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