KR20240003322A - Apparatus for attaching and detaching attachment of construction machine and construction machine equipped with the same - Google Patents

Abstract

(Problem) In the attachment detachment device for construction machinery, it is possible to maintain the connected state of the attachment even when the power supply to the hydraulic cylinder is cut off, thereby achieving high safety.
(Solution) The attachment detachment device 30 includes a fixed frame 31 having a first hook 33, and a movable frame 32 having a second hook 34 and rotatably formed on the fixed frame 31. and a first hydraulic cylinder 55 that rotates the movable frame 32 with respect to the fixed frame 31, a rear lock member 48 formed on the fixed frame 31, and a lock member 48 formed on the fixed frame 31 and locking it. A second hydraulic cylinder (56) for rotating the rear lock member (48) elastically supported in the locked position by a spring to the non-locked position, and a front side formed on the movable frame (32) and elastically supported in the locked position by a lock spring. It is provided with a lock member 58 and a third hydraulic cylinder 57 which is formed on the movable frame 32 and rotates the front lock member 58 to the non-locked position.

Description

Attachment detachment device for construction machinery and construction machinery equipped with the same

The present invention relates to an attachment detachment device for a construction machine that connects a work attachment of the construction machine to an arm of the work device, and to a construction machine provided therewith.

Conventionally, for example, in an excavating machine, which is a type of construction machine, there is a configuration in which a working attachment is formed to be removable with respect to the arm constituting the excavating device as a front work device. Attachments such as a bucket for excavation work or a crushing device (breaker) for crushing work are replaced depending on the work content. The attachment is connected to the arm via an attachment detachment device provided at the front end of the arm, and is attached to and detached from the arm by operating the attachment detachment device.

As an attachment detachment device, there is a device that includes a fixed hook and a movable hook formed on a predetermined frame, and is connected to the attachment by engaging each hook with a support pin that the attachment has as an engaged portion. In this configuration, a configuration is known that includes a hydraulic cylinder for moving the movable hook and performs attachment and detachment operations of the attachment by expansion and contraction of the hydraulic cylinder (for example, see Patent Document 1).

In addition, in the attachment detachment device of Patent Document 1, a lock member is formed to prevent the support pin of the attachment from falling out of the hook, and the lock member automatically activates and releases the anti-removal function when attaching or detaching the attachment. It is structured as such.

Japanese Patent Publication No. 6284445

In the attachment detachment device of Patent Document 1, the lock members formed on each of the fixed hook and the movable hook are movable between the lock on position for preventing the attachment's support pin from falling and the lock off position for releasing the fall prevention. The lock member on the hook side is elastically supported toward the lock-on position by an elastic support member. Since the locking member on the fixed hook side and the locking member on the movable hook side are linked to each other through a hydraulic cylinder for moving the movable hook, if the elastic support member on the movable hook side is damaged, the locking member not only on the movable hook side but also on the fixed hook side. The fall-out prevention function is canceled. At this time, if the hydraulic pressure supply to the hydraulic cylinder is cut, a problem arises in that the attachment may be detached. In this way, in the conventional attachment detachment device, there is room for improvement in order to improve safety by preventing detachment of the attachment.

The present invention was made in consideration of the above problems, and provides an attachment detachment device for construction machinery that can maintain the connection state of the attachment even when the power supply to the hydraulic cylinder is cut off, thereby achieving high safety, and an attachment detachment device equipped with the same. The purpose is to provide construction machinery.

The attachment detachment device for a construction machine according to the present invention is an attachment detachment device for a construction machine that attaches and detaches a work attachment to an arm of a work device, and includes a first hook, a first member connected to the arm, and a second member. a second member having a hook and pivotably supported by the first member, one end of which is connected to a first support shaft formed on the first member, and the other end of which is a second support formed on the second member; A first hydraulic cylinder is connected to a shaft and rotates the second member with respect to the first member, and is rotationally supported on a third support shaft formed on the first member and disposed above the first hook, A first anti-falling member elastically supported by a first elastic support member so as to protrude from the opening of the first hook, and in conjunction with the operation of the first hydraulic cylinder, the first anti-falling member opposes the elastic force of the first elastic support member. a second hydraulic cylinder that moves the fall-off prevention member to retreat from the opening of the first hook, and a fourth support shaft formed on the second member and disposed above the second hook, the second hook being pivotably supported; A second anti-dropping member elastically supported by a second elastic support member so as to protrude from the opening, and in conjunction with the operation of the first hydraulic cylinder, the second anti-dropping member is positioned against the second elastic support member. It is characterized by having a third hydraulic cylinder that moves the hook to retreat from the opening of the second hook.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein the second hydraulic cylinder is disposed between the first support shaft and the third support shaft, The third hydraulic cylinder is disposed between the second support shaft and the fourth support shaft.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein the distance between the axes of the first support shaft and the second support shaft is equal to the distance between the axes of the third support shaft and the second support shaft. It is shorter than the distance between the axes of the fourth support axis.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention includes a fifth support shaft supporting the second hydraulic cylinder and a sixth support shaft supporting the third hydraulic cylinder. The distance between the axes of the support shafts is shorter than the distance between the axes of the third support shaft and the fourth support shaft.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein when the rod of the first hydraulic cylinder is fully extended, the tip of the second hook is positioned at the fourth hook. It is located ahead of the support axis.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein the first hydraulic cylinder is a double-acting hydraulic cylinder, the second hydraulic cylinder, and the third hydraulic cylinder. The hydraulic cylinder is a single-acting hydraulic cylinder, and inside the first member, hydraulic oil for contracting the rod of the first hydraulic cylinder is supplied to one cylinder chamber of the cylinder tube and the second hydraulic cylinder is supplied. Branching a path for supplying hydraulic oil for extending the rods of the hydraulic cylinder and the third hydraulic cylinder, and a path for supplying hydraulic oil for extending the rod of the first hydraulic cylinder to the other cylinder chamber of the cylinder tube. A branch block has been formed.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein the branch block is disposed above the cylinder tube of the first hydraulic cylinder.

In addition, an attachment detachment device for a construction machine according to another aspect of the present invention is an attachment detachment device for a construction machine, wherein the ends of each rod of the second hydraulic cylinder and the third hydraulic cylinder have a hemispherical shape. , when the second hydraulic cylinder and the third hydraulic cylinder are contracted, the end of the rod protrudes beyond the end of the cylinder tube.

A construction machine according to the present invention includes an attachment detachment device for the construction machine, a traveling device, and a front arm formed on a front side of the traveling device and detachably supporting the attachment by the attachment detachment device. Equipped with working equipment.

According to the present invention, even when the supply of power to the hydraulic cylinder is cut off, the connected state of the attachment can be maintained, thereby achieving high safety.

1 is a left side view of an excavating machine according to an embodiment of the present invention.
Fig. 2 is a left side view showing a part of an excavating device according to an embodiment of the present invention.
Fig. 3 is a perspective view showing the separated state of the attachment detachment device and bucket according to one embodiment of the present invention.
Fig. 4 is a perspective view of an attachment detachment device according to an embodiment of the present invention.
Fig. 5 is a plan view of an attachment detachment device according to an embodiment of the present invention.
Fig. 6 is a bottom view of an attachment detachment device according to an embodiment of the present invention.
Fig. 7 is a perspective view showing the internal configuration of the attachment detachment device according to one embodiment of the present invention.
Fig. 8 is an enlarged perspective view showing the lock member of the attachment detachment device according to one embodiment of the present invention.
Fig. 9 is an explanatory diagram of a second hydraulic cylinder and a third hydraulic cylinder of the attachment detachment device according to one embodiment of the present invention.
Fig. 10 is an explanatory diagram of a second hydraulic cylinder and a third hydraulic cylinder of the attachment detachment device according to one embodiment of the present invention.
Fig. 11 is a circuit diagram showing the hydraulic circuit configuration for the attachment detachment device according to one embodiment of the present invention.
Fig. 12 is a diagram illustrating the operation of an attachment detachment device according to an embodiment of the present invention.
Fig. 13 is a diagram illustrating the operation of an attachment detachment device according to an embodiment of the present invention.
Fig. 14 is a diagram illustrating the operation of an attachment detachment device according to an embodiment of the present invention.

The present invention relates to an attachment detachment device for attaching and detaching a work attachment to an arm in a front work machine of a construction machine, and aims to improve safety by studying the configuration for operating the hook on the movable side. . EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention will be described with reference to the drawings.

In this embodiment, as a construction machine related to the present invention, an excavating machine, which is a slewing work vehicle, will be described as an example. However, the construction machine according to the present invention is not limited to excavating machines, and is widely applicable to other construction machines, such as crane machines and wheel loaders, for example.

First, the overall structure of the excavating machine 1 according to this embodiment will be explained using FIG. 1. In addition, hereinafter, unless specifically specified when viewed from the direction, “front side”, “rear side”, “left and right sides”, “plane side” or “plane side”, based on the position of the operator seated in the driver's seat of the excavating machine 1. It is called “top side”, “bottom side” or “bottom side”.

As shown in FIG. 1, the excavating machine 1 includes a traveling device 2 as a self-propelled traveling body, an excavating device 3 as a working part mounted on the traveling device 2, and a topdressing device ( 4) It is provided.

The traveling device 2 is a part that forms the main body of the excavating machine 1, and includes a pair of crawler-type traveling parts 5, 5 on the left and right, and a base formed between the traveling parts 5, 5 on the left and right. It has a fuselage frame (6) and a turning table (7) formed on the fuselage frame (6). The swing table 7 is configured to have a substantially circular shape when viewed from the top, and is formed to be capable of turning in either left or right direction around the vertical axis by means of a swing support portion 6a formed on the fuselage frame 6. .

A driving unit (8) is formed on the turning table (7). In addition, in the latter half of the swivel base 7, a prime mover portion 9 is formed in which the engine and the like are covered with a bonnet or the like.

The operating unit 8 is for driving and operating the traveling device 2, the excavating device 3, and the topdressing device 4, and is formed in the cabin 10 formed on the turning table 7. The cabin 10 has a frame forming its outer shape and a plurality of window portions made of transparent members such as glass, and is structured as a whole in a substantially box shape.

In the driver's seat 8, a driver's seat support is formed on the floor, and a driver's seat 8a is formed on the driver's seat support. The operating unit 8 is provided with, for example, a pair of left and right travel levers extending upward from the floor unit, and a work operation pedal disposed on the floor unit. In addition, in the operating section 8, around the driver's seat 8a, there is a work operation lever for operating the working section (excavating device 3 or topdressing device 4) and an operation of the attachment detachment device 30. An operation panel unit having various operation units such as switches to change states is formed.

The proximal end portion of the excavating device 3 is mounted on the left and right central portions of the front end of the turning table 7. Additionally, a topdressing device 4 is mounted on the front side of the body frame 6. The topdressing device 4 includes a support frame 4a that extends in the front-back direction between the left and right running parts 5, 5, and a blade 4b as a topsoil plate formed on the front end side of the support frame 4a. ) has. The topdressing device 4 is formed to be capable of lifting and rotating by a cylinder mechanism formed between the support frame 4a and the body frame 6.

In the excavating machine 1 having the above configuration, the travel lever and/or the work operation lever, etc. are appropriately operated by the operator seated in the driver's seat 8a to perform the desired operation or work. Specifically, for example, by operating the travel lever, the travel device 2 is driven forward and backward and forward or turns left and right. Additionally, by operating the work operation lever, excavation work using the excavator 3 or topdressing work and/or grading work using the topdressing device 4 is performed.

Using FIGS. 1 to 3, the excavating device 3 will be described. The excavating device 3 is a front work device formed on the front side of the traveling device 2. At the left and right central portions of the front end of the turning table 7, support brackets 15 are formed to protrude forward, and the base end of the excavator 3 is mounted on the support bracket 15. The excavating device 3 has a boom support bracket 16 as a member constituting its base end. In the excavating device 3, the boom support bracket 16 is rotatably supported by the support bracket 15 on the main machine side with the vertical direction as the rotation axis direction.

The excavating device 3 is configured to swing left and right with respect to the swing table 7 by means of a swing cylinder (not shown) disposed on the right side of the boom support bracket 16. The swing cylinder is formed between the boom support bracket (16) and the swivel base (7).

The excavating device 3 includes a boom 17 constituting the base side portion, an arm 18 connected to the distal end of the boom 17, and a bucket 20 mounted on the distal end of the arm 18. have The excavator 3 includes a boom cylinder 21 that rotates the boom 17, an arm cylinder 22 that rotates the arm 18, and a work tool cylinder 23 that rotates the bucket 20. ) has.

The boom 17 has a boomerang-shaped curved shape when viewed from the side. The base end of the boom 17 is rotatably supported with the left and right directions as the rotation axis direction with respect to the boom support bracket 16. The boom cylinder 21 is disposed on the front side of the boom 17 in an upright state, and is installed between the boom support bracket 16 and the bracket 17a protruding inside the bent portion of the boom 17. As the boom cylinder 21 expands and contracts, the boom 17 rotates relative to the boom support bracket 16.

The proximal end of the arm 18 is connected to the distal end of the boom 17 so as to be rotatable with the left and right directions as the rotation axis. The arm cylinder 22 is disposed on the upper side (dorsal side) of the boom 17 in the upright state, and has a bracket 17b formed to protrude outward from the bent portion of the boom 17, and protrudes from the rear end of the arm 18. It is installed between the rear ends of the formed rear bracket 18a. As the arm cylinder 22 expands and contracts, the arm 18 rotates with respect to the boom 17.

The bucket 20 is connected to the distal end of the arm 18 via an attachment detachment device 30. In short, the attachment detachment device 30 is connected to the distal end of the arm 18 and is detachably connected to the bucket 20 .

The work tool cylinder 23 is disposed on the front side (dorsal side) of the arm 18 in a state of being lowered from the upper end of the boom 17. The work tool cylinder 23 has a cylinder 23a and a cylinder rod 23b which has a piston on one end side and is formed within the cylinder 23a to be able to slide through the piston. One end of the work tool cylinder 23, the bottom side (cylinder 23a side), is supported on the front bracket 18b so that it can be rotated in the left and right direction as the rotation axis. The front bracket 18b is formed to protrude in front of the rear bracket 18a at the rear end of the arm 18.

On the other hand, the end of the rod side (cylinder rod 23b side), which is the other end of the work tool cylinder 23, is connected to the attachment detachment device 30 through the first link 26. Additionally, the rod-side end of the work tool cylinder 23 is supported via the second link 27 against a portion near the distal end of the arm 18.

The second link 27 includes a pair of left and right link arms 27a, a base side support shaft 27b provided between one end of the pair of link arms 27a, and a pair of link arms 27a. ) has a front end support shaft (27c) installed between the other ends of the. The second link 27 is rotatably supported with respect to the arm 18 by the base side support shaft 27b.

The link arm 27a is comprised of an arm-shaped (in length) plate-shaped member whose left and right direction is the plate thickness direction. The pair of link arms 27a has one end side positioned on the left and right outside of the left and right side parts 18c of the arm 18, and has a base side support shaft ( It is supported rotatably with respect to the arm 18 by 27b).

The distal end of the cylinder rod 23b of the work tool cylinder 23 is rotatably supported on the distal support shaft 27c. At the distal end of the cylinder rod 23b, a boss portion 23c is formed to penetrate the distal end side support shaft 27c. Moreover, one end side (rear end side) of the first link 26 is rotatably supported on the front end side support shaft 27c. One end of the first link 26 is branched to the left and right, and a boss portion 26a that penetrates the distal end support shaft 27c is formed at each end of the left and right ends. On the distal end side support shaft 27c, the boss portion 23c of the cylinder rod 23b is located between the left and right boss portions 26a of the first link 26.

The other end side (front end side) of the first link 26 is connected to the attachment detachment device 30 by a link support shaft 28 formed at a predetermined portion of the attachment detachment device 30 with the left and right directions as the axial direction. It is connected to enable meetings. The distal end of the arm 18 is attached to the attachment by an arm support shaft 29 formed in the left-right direction in the axial direction at a different location from the arrangement portion of the link support shaft 28 in the attachment detachment device 30. It is rotatably connected to the attachment/detachment device (30).

In this configuration, the extension/contraction movement of the work tool cylinder 23 causes the first link 26 and the second link 27 to rotate, causing the attachment detachment device 30 to attach the arm support shaft ( 29) Rotate using as the rotation axis. In connection with this, the bucket 20 rotates integrally with the attachment detachment device 30.

In the excavator 3 having the above configuration, the bucket 20 is a work attachment and is detachably attached to the arm 18 by an attachment detachment device 30. And, depending on the work performed by the excavating machine 1, other devices such as a grapple or breaker are mounted instead of the bucket 20 as attachments for the work. In this way, the excavating device 3 includes an arm 18 that detachably supports a work attachment by means of an attachment detachment device 30, and the arm 18 has an attachment detachment device 30 formed at its distal end. ), the attachment is installed according to the work details.

The connection between the attachment detachment device 30 and the bucket 20 will be described. The attachment detachment device 30 is a device for attaching and detaching the bucket 20 of the excavator 1 to the arm 18 of the excavator 3.

As shown in FIG. 3, the attachment detachment device 30 includes a first hook 33 and a second hook 34, and a rear support pin 35 and a front support pin 36 that the bucket 20 has, respectively. It is connected to the bucket 20 by engaging it.

The front support pin 36 and the rear support pin 35 are straight rod-shaped members with the left and right directions as the axial direction, and each of the left and right sides protrudes from the rear portion 20a of the bucket 20 at a predetermined distance in the left and right directions. It is installed between a pair of support rib portions 37. The support rib portion 37 is a plate-shaped stone piece portion with the left and right direction being the plate thickness direction.

The left and right support rib portions 37 support the front support pin 36 and the rear support pin 35 at positions spaced apart from each other by a predetermined distance. The left and right support rib portions 37 penetrate both ends of the front support pin 36 and the rear support pin 35, and support these support pins in a fixed state. The left and right support rib portions 37 are formed on the base side (upper side in FIG. 3) of the back portion 20a of the bucket 20. Additionally, a plurality of claw portions 20b are formed at the front end of the rear portion 20a of the bucket 20 at predetermined intervals in the left and right directions (see Fig. 2).

The configuration of the attachment detachment device 30 will be described with reference to FIGS. 4 to 13. The attachment detachment device 30 includes a fixed frame 31 as a first member having a first hook 33 below, and a movable frame 32 as a second member having a second hook 34 below. do. The attachment detachment device 30 is generally configured to be left-right symmetrical.

The fixing frame 31 is a part of the attachment detachment device 30 that is connected to the arm 18 of the excavator 3. The fixed frame 31 is rotatably supported with respect to the arm 18 by the arm support shaft 29.

The arm support shaft 29 is rotatably supported at the distal end of the arm 18 while penetrating the arm 18 in the left and right directions.

The fixed frame 31 has a side wall frame portion 41 and a rear wall portion 44 as a pair of left and right wall portions. The left and right side wall frame portions 41 are plate-shaped parts with the left and right directions being the plate thickness direction, and when viewed from the side, have a roughly inverted trapezoidal outline with a concave upper edge, and the ends extend from the rear to the front. It has this tapered shape. The rear wall portion 44 is the rear end of the side wall frame portion 41 and is constructed between the left and right side wall frame portions 41. The vertical length of the rear wall portion 44 is shorter than the vertical length of the side wall frame portion 41, and the rear opening is formed by the rear ends of the left and right side wall frame portions 41 and the upper end of the rear wall portion 44. It is formed. At the rear of the left and right side wall frame portions 41, a cover plate 51 is formed to cover the rear opening to prevent dirt, etc. from flowing into the attachment detachment device 30.

In the rear upper portion of the side wall frame portion 41, a hole portion is formed to receive and support the ends of the arm support shafts 29 protruding on both left and right sides at the distal end of the arm 18. The side wall frame portion 41 is connected to the arm support shaft 29 without relative rotation, and rotates integrally with the arm support shaft 29 with respect to the arm 18. A cylindrical boss portion 41a is formed outside the side wall frame portion 41 on the right side with respect to the hole portion into which the arm support shaft 29 is inserted. The fixed frame 31 and the arm support shaft 29 are connected by a connecting bolt 42 and a nut 42a that penetrate the boss portion 41a and the arm support shaft 29 in the radial direction.

In the front upper portion of the side wall frame portion 41, a hole portion is formed to receive insertion of the left and right ends of the link support shaft 28 and support it. The left and right side wall frame portions 41 are connected to the link support shaft 28 without relative rotation, and rotate with respect to the first link 26 integrally with the link support shaft 28. As for the hole portion into which the link support shaft 28 is inserted, a cylindrical boss portion 41b is formed on the outside of the right side wall frame portion 41. The side wall frame portion 41 and the link support shaft 28 are connected by a connecting bolt 43 and a nut 43a that penetrate the boss portion 41b and the link support shaft 28 in the radial direction.

A first hook 33 is formed below the side wall frame portion 41. The first hook 33 is formed on the left and right inner sides of the side wall frame portion 41 as a portion having a predetermined thickness in the left and right directions. The first hook 33 has a locking portion 46 that extends curvedly to form a hook shape when viewed from the side.

In the locking portion 46, an engaging surface 46a is formed which has a concave shape with the rear side being the open side when viewed from the side. In the locking portion 46, the engaging surface 46a serves as a portion that is contacted by the rear support pin 35 of the bucket 20.

Above the locking portion 46 of the first hook 33, a rear lock member 48, which will be described later, is formed to face the engaging surface 46a. The rear lock member 48 is configured to be able to advance and retreat with respect to the opening 46b of the locking portion 46.

Between the hole portion for receiving the insertion of the arm support shaft 29 of the side wall frame portion 41 and the first hook 33, there is a hole for receiving the insertion of the left and right ends of the bottom side support shaft 81, which will be described later, and supporting it. Wealth is formed. For the hole portion into which the bottom side support shaft 81 is inserted, a cylindrical boss portion 41c is formed inside the left and right side wall frame portions 41. The side wall frame portion 41 and the bottom side support shaft 81 pass through the boss portion 41c and are screwed into a threaded hole 81b (see FIG. 7) formed on the peripheral surface of the bottom side support shaft 81. It is connected by a fixing screw (81a).

The first hook 33 is formed integrally with the left and right side wall frame portions 41, rear wall portion 44, and boss portion 41c by casting or the like.

The movable frame 32 is rotatably formed on the fixed frame 31 and has a second hook 34 below that engages the front support pin 36 of the bucket 20. The movable frame 32 has a mounting frame portion 45 and a front wall portion 47 as a pair of left and right wall portions. Additionally, the second hook 34 is installed between the left and right mounting frame portions 45.

The mounting frame portion 45 is a portion that rotatably mounts the movable frame 32 with respect to the fixed frame 31. Each of the left and right mounting frame portions 45 is a plate-shaped wall portion with the left and right direction being the plate thickness direction, and has a substantially triangular external shape when viewed from the side and a shape tapering from the bottom to the top. have The mounting frame portion 45 constitutes a frame body made of a pair of left and right plate-shaped wall portions.

A hole portion through which the link support shaft 28 can be inserted is formed in the upper part of the mounting frame portion 45. The mounting frame portion 45 is located on the left and right inner sides of the side wall frame portion 41, and when viewed from the side, the upper end along the cylindrical shape overlaps the portion where the hole portion is formed on the front side of the side wall frame portion 41.

As shown in FIG. 3, the link support shaft 28 penetrates in the left and right directions a boss portion 26b formed at the other end of the first link 26, one end of which is connected to the second link 27. , its left and right ends are inserted into the upper front hole of the side wall frame portion 41 and the upper front hole of the mounting frame portion 45. By rotatably connecting the mounting frame portion 45 to the link support shaft 28 fixed to the side wall frame portion 41 in this way, the movable frame 32 is formed to be rotatable with respect to the fixed frame 31.

The second hook 34 is formed on the left and right inner sides of the mounting frame portion 45 as a portion having a predetermined thickness in the left and right directions. The second hook 34, like the first hook 33, has a locking portion 49 that extends curvedly to form a hook shape when viewed from the side.

In the locking portion 49, an engaging surface 49a is formed which has a concave shape with the front side being the open side when viewed from the side. In the locking portion 49, the engaging surface 49a serves as a portion that is contacted by the front support pin 36 of the bucket 20.

Above the locking portion 49 of the second hook 34, a front lock member 58 described later is formed to face the engaging surface 49a. The front lock member 58 is configured to be able to advance and retreat with respect to the opening 49b of the second hook 34 that is open in the forward direction.

The second hook 34 is formed integrally with the left and right mounting frame portions 45 and the front wall portion 47 by casting or the like.

Between the upper hole of the mounting frame portion 45 and the second hook 34, a hole portion is formed to receive insertion and support the left and right end portions of the rod side support shaft 82, which will be described later. With respect to the hole portion through which the rod side support shaft 82 is inserted, a cylindrical boss portion 45a is formed on the inside of the left and right mounting frame portions 45 (see Fig. 5). The mounting frame portion 45 and the rod side support shaft 82 pass through the boss portion 45a and are screwed into a threaded hole 82b (see FIG. 7) formed on the peripheral surface of the rod side support shaft 82. It is connected by a fixing screw (82a).

The attachment detachment device 30 includes a first hydraulic cylinder 55 that rotates the movable frame 32 with respect to the fixed frame 31 . The first hydraulic cylinder 55 rotates the movable frame 32 back and forth around the axis of the link support shaft 28 by expanding and contracting.

The first hydraulic cylinder 55 is formed in the central portion in the left and right directions of the attachment detachment device 30 so that the expansion/contraction direction is front-to-back when viewed from the top. The first hydraulic cylinder 55 has a cylinder tube 61 and a piston rod 62 that is formed to be slidable relative to the cylinder tube 61, and the sliding motion of the piston rod 62 relative to the cylinder tube 61 It is newly built by. A piston 63 that slides within the cylinder tube 61 is formed on one end of the piston rod 62 located within the cylinder tube 61 (see Fig. 11).

As shown in FIG. 11, the first hydraulic cylinder 55 is a double-acting hydraulic cylinder, and the internal space of the cylinder tube 61 is on the cylinder tube 61 side (bottom side) by the piston 63. It is divided into a bottom side chamber 61a, which is a space, and a rod side chamber 61b, which is a space on the piston rod 62 side (rod side). The first hydraulic cylinder 55 is expanded and contracted by moving the piston rod 62 relative to the cylinder tube 61 by supplying and discharging hydraulic oil to each of the bottom side chamber 61a and the rod side chamber 61b.

The support structure of the first hydraulic cylinder 55 will be described. The first hydraulic cylinder 55 is formed between the left and right side wall frame parts 41 of the fixed frame 31 and between the left and right mounting frame parts 45 of the movable frame 32. The first hydraulic cylinder 55 is formed with the piston rod 62 side facing forward, and the piston rod 62 side is supported by the movable frame 32 and is positioned on the cylinder tube 61 side. is supported on the fixed frame 31. In short, the movable frame 32 and the fixed frame 31 are connected to each other by the first hydraulic cylinder 55.

The rear side of the first hydraulic cylinder 55 is rotatably supported with respect to the bottom side support shaft 81, which is the first support shaft. The bottom side support shaft 81 is installed between the left and right side wall frame portions 41 with the left and right direction as the axial direction. At the rear end of the cylinder tube 61, a substantially cylindrical boss portion 61d having a hole portion through which the bottom side support shaft 81 penetrates is formed. The boss portion 61d is located in the axial center of the bottom side support shaft 81 and is supported so as to be rotatable relative to the bottom side support shaft 81. The left and right ends of the bottom side support shaft 81 are supported by being inserted into holes formed in each of the left and right side wall frame portions 41 of the fixed frame 31.

Additionally, a branch block 61c is formed on the upper side of the first hydraulic cylinder 55 (see FIGS. 6 and 8). Additionally, as shown in Fig. 4, the upper part of the branch block 61c is covered with a cover plate 52. In the plan view of Fig. 5, for convenience, the front support pin 36, the rear support pin 35, and the cover plate 52 are indicated by dashed-dotted lines.

The bottom side support shaft 81 is a hole formed in the side wall frame portion 41 by a fixing screw 81a or the like that penetrates the boss portion 41c and is screwed along the radial direction of the bottom side support shaft 81. By being fixed to, it is supported so as not to rotate relative to the fixed frame 31. On the other hand, the cylinder tube 61 is supported so as to be relatively rotatable with respect to the bottom side support shaft 81.

The front side of the first hydraulic cylinder 55 is rotatably supported with respect to the rod side support shaft 82, which is the second support shaft. The rod side support shaft 82 is installed between the left and right mounting frame portions 45 with the left and right direction as the axial direction. That is, the rod side support shaft 82 is formed parallel to the bottom side support shaft 81. At the distal end of the piston rod 62, a substantially cylindrical boss portion 62a is formed, which has a hole portion that penetrates the rod side support shaft 82. The boss portion 62a is located in the axial center of the rod side support shaft 82 and is supported so as to be rotatable relative to the rod side support shaft 82. The left and right ends of the rod side support shaft 82 are supported by being inserted into holes formed in each of the left and right mounting frame portions 45 of the movable frame 32.

The rod side support shaft 82 is a hole formed in the mounting frame portion 45 by a fixing screw 82a or the like that penetrates the boss portion 45a and is screwed along the radial direction of the rod side support shaft 82. is fixed to Thereby, the rod side support shaft 82 is supported without relative rotation with respect to the movable frame 32. The piston rod 62 is supported so as to be relatively rotatable with respect to the rod side support shaft 82 inserted into the hole portion of the boss portion 62a.

According to the support structure of the first hydraulic cylinder 55 as described above, the first hydraulic cylinder 55 expands and contracts, accompanied by rotation of the first hydraulic cylinder 55 by the bottom side support shaft 81, causing the cylinder to The rod side support shaft 82 moves integrally with the piston rod 62 moving relative to the tube 61. Thereby, the movable frame 32 rotates around the axis of the link support shaft 28 with respect to the fixed frame 31 (see Fig. 13).

The configuration for rotating the rear lock member 48 and the front lock member 58 will be described.

The attachment detachment device 30 includes, in the fixing frame 31, a rear lock member 48 as a first anti-falling member, a second hydraulic cylinder 56, and a lock spring 83a as a first elastic support member. Equipped with In addition, the attachment detachment device 30 includes, in the movable frame 32, a front lock member 58 as a second fall-off prevention member, a third hydraulic cylinder 57, and a lock spring as a second elastic support member ( 83b) is provided. The rear lock member 48, the second hydraulic cylinder 56, and the lock spring 83a on the fixed frame 31 side, and the front lock member 58, third hydraulic cylinder 57, and lock spring on the movable frame side. (83b) is arranged in substantially mirror image symmetry in the front-back direction of the attachment detachment device 30.

The members constituting the rear lock member 48 and the front lock member 58 are members of the same shape. The second hydraulic cylinder 56 and the third hydraulic cylinder 57 are single-acting cylinders with the same specifications. Additionally, the lock spring 83a and the lock spring 83b are torsion coil springs of the same specification. Hereinafter, the details of each member will be described, but common members will be described by assigning the same symbol. Additionally, unless a distinction is made between the lock spring 83a and the lock spring 83b, they will be described as the lock spring 83.

The rear lock member 48 is rotatably formed on the fixed frame 31 and regulates the separation of the rear support pin 35 engaged by the first hook 33 from the first hook 33. It is absence. The rear lock member 48 is provided by a rear support shaft 91 as a third support shaft installed between the left and right side wall frame portions 41 in the fixed frame 31 with the left and right directions as the axial direction. (31) The possibility of meeting is supported.

The rear support shaft 91 is disposed above the first hook 33. The rear support shaft 91 is formed parallel to the bottom side support shaft 81 by supporting both ends at predetermined positions on the left and right side wall frame portions 41. For this reason, hole portions for supporting both ends of the rear support shaft 91 are formed in the left and right side wall frame portions 41.

The front lock member 58 is a member that regulates the separation of the front support pin 36 engaged with the second hook 34 from the second hook 34 in the movable frame 32 . The front lock member 58 is a fixed frame by means of a front support shaft 92 as a fourth support shaft installed between the left and right mounting frame portions 45 in the movable frame 32 with the left and right directions as the axial direction. (31) The possibility of meeting is supported.

The front support shaft 92 is disposed above the second hook 34. The front support shaft 92 is formed parallel to the rod side support shaft 82 by having both ends supported at predetermined positions on the left and right mounting frame portions 45. For this reason, hole portions for supporting both ends of the front support shaft 92 are formed in the left and right mounting frame portions 45.

The rear lock member 48 and the front lock member 58 are supported by a lock claw portion 93, which is a portion having a predetermined dimension in the left and right directions, and a rear support shaft 91 or a front support shaft 92, respectively. It has left and right support parts (94), which are the supporting parts. The lock claw portion 93 has a shape where the tip is tapered when viewed from the side. On one side (right side) of the left and right support portions 94, an abutting portion that receives pressure from the piston rod 77 of the second hydraulic cylinder 56 or third hydraulic cylinder 57, which will be described later, along the axial direction of the support shaft. (87) is formed. Between the left and right support portions 94, there is a concave portion 95 with the support portion 94 as the side wall and the base end of the lock claw portion 93 as the bottom.

The lock spring 83 is disposed in the concave portion 95 between the left and right support portions 94. The lock spring 83 has extension portions 84 and 85 on both ends of the coil-shaped portion. The lock spring 83 applies a force to press the lock claw portion 93 downward by an elastic force in the direction of separating the extension portions 84 and 85 from each other. The lock spring 83 is formed with its coil-shaped portion penetrating the rear support shaft 91 or the front support shaft 92 located between the left and right support portions 94.

The abutting portion 87 is a portion that receives an external force that rotates the rear lock member 48 or the front lock member against the elastic force of the lock spring 83. The abutting portion 87 is formed to protrude from one side of the left and right support portions 94 at an angle of approximately 90 degrees with the direction in which the lock claw portion 93 extends.

The rear lock member 48 has a hole in each support portion 94 that penetrates the rear support shaft 91. Each support portion 94 is fixed to the rear support shaft 91 by welding or the like, and the rear lock member 48 is configured as an integrated rotating body that rotates with respect to the rear support shaft 91.

Regarding the rotational movement of the rear lock member 48 around the rear support shaft 91, the lock claw portion 93 is positioned at the opening 46b of the first hook 33 from the lower side of the side wall frame portion 41 when viewed from the side. ) is set as a lock position that regulates the separation of the rear support pin 35 engaged with the first hook 33 from the first hook 33 (see Fig. 13). That is, the rear lock member 48 rotates in a range from a non-locked position hidden within the external shape of the fixed frame 31 when viewed from the side to the locked position, as shown in the drawings. The rear lock member 48 changes from the non-locked position to the locked position by rotating to the left (counterclockwise) when viewed from the left side shown in FIG. 13 .

The lock spring 83a is disposed in the concave portion 95 between the left and right support portions 94 of the rear lock member 48. The lock spring 83a is an elastic support member that elastically supports the rear lock member 48 in a rotational direction that is a position (lock position) that regulates the separation of the rear support pin 35 from the first hook 33. am. In short, the lock spring 83a elastically supports the rear lock member 48 in the rotation direction from the non-locked position to the locked position in response to the rotational movement of the rear lock member 48 around the rear support shaft 91. I'm doing it. In other words, the lock spring 83a elastically supports the rear lock member 48 in the rotation direction of left rotation when viewed from the left side.

The lock spring 83a locks one extension portion 84 located on the left and right outer sides of the coil-shaped portion to the rear wall portion 44 of the fixed frame 31, and the other extended portion 84 located on the left and right inner sides of the coil-shaped portion. The extension part (85) of is caught by the lock claw part (93). That is, the rear lock member 48 is elastically supported by the lock spring 83a in a rotational direction from the non-locked position to the locked position around the axis of the rear support shaft 91 with respect to the first hook 33.

When the abutting portion 87 of the rear lock member 48 rotates under the pressure of the piston rod 77 of the second hydraulic cylinder 56, the rear lock member 48 moves in the direction opposite to the direction in which the rear lock member 48 is in the lock position. have a meeting

The second hydraulic cylinder 56 is formed on the fixed frame 31 and, by expanding and contracting, rotates the rear lock member 48 around the axis of the rear support shaft 91 through the abutting portion 87. .

The front lock member 58 is formed to be rotatable integrally with the front support shaft 92 and, like the rear lock member 48, includes a lock claw portion 93, which is a portion having a predetermined dimension in the left and right directions. It has left and right support portions 94 that are supported by the front support shaft 92, and between the left and right support portions 94, a concave portion 95 in which a lock spring 83b is disposed is formed. In addition, on one side (left side) of the left and right support portions 94, an abutting portion ( 87) has been formed.

The lock spring 83b locks one extension portion 84 located on the left and right outer sides of the coil-shaped portion to the front wall portion 47 of the movable frame 32, and the other extended portion 84 located on the left and right inner sides of the coil-shaped portion. The extension part (85) of is caught by the lock claw part (93). That is, the front lock member 58 is elastically supported by the lock spring 83b in a rotational direction from the non-locked position to the locked position around the axis of the front support shaft 92 with respect to the second hook 34. In other words, the lock spring 83b elastically supports the front lock member 58 in the rotation direction of right rotation when viewed from the left side.

Regarding the rotational movement of the front lock member 58 around the front support shaft 92, the lock claw portion 93 is positioned at the opening 49b of the second hook 34 from the lower side of the mounting frame portion 45 when viewed from the side. ) is set as a lock position that regulates the separation of the front support pin 36 engaged with the second hook 34 from the second hook 34 (see Fig. 13). That is, the front lock member 58 rotates in a range from the non-locked position hidden within the range of the external shape of the movable frame 32 when viewed from the side to the locked position, as shown in FIGS. 12 and 13. The front lock member 58 changes from the non-locked position to the locked position by rotating to the left (counterclockwise) when viewed from the left side.

The third hydraulic cylinder 57 is formed on the movable frame 32 and, by expanding and contracting, rotates the front lock member 58 around the axis of the front support shaft 92 through the abutting portion 87. .

As shown in Figs. 7 and 12, the second hydraulic cylinder 56 and the third hydraulic cylinder 57 are hydraulic cylinders that are smaller than the first hydraulic cylinder 55, and have an expansion/contraction direction in the front-back direction when viewed from the top. It is formed in the direction of . The second hydraulic cylinder 56 and the third hydraulic cylinder 57 have a cylinder tube 76 and a piston rod 77 that is formed to be slidable with respect to the cylinder tube 76. It is expanded and contracted by the sliding action of the piston rod (77). To the piston rod 77, a piston 78 sliding in the cylinder tube 76 is connected on one end, and the other end is an abutting portion of the rear lock member 48 and the front lock member 58, respectively ( 87) It consists of an abutting end (77a) that abuts.

As shown in FIG. 11, in the internal space of the cylinder tube 76, a bottom side chamber 76a, which is a space on the bottom side of the cylinder tube 76, is formed by the piston 78. 9 and 10, the rod-side end portion of the cylinder tube 76 movably accommodates the piston rod 77 within the cylinder tube 76, and the piston 78 of the piston rod 77 ) is opened so that the end side opposite to the side to which this is connected protrudes from the cylinder tube 76. The end of the piston rod 77 protruding from the cylinder tube 76 has a hemispherical shape and has an abutting end that abuts the respective abutting portions 87 of the rear lock member 48 and the front lock member 58. It is written as (77a). By supplying and discharging the hydraulic oil to the bottom side chamber 76a, the piston rod 77 moves between the contracted state shown in the perspective view of FIG. 9A and the cross-sectional view of FIG. 9B and the extended state shown in the perspective view of FIG. 10A and the cross-sectional view of FIG. 10B. move When the piston rod 77 is contracted, the hemispherical abutting end 77a protrudes outward from the rod-side end of the cylinder tube 76. For this reason, for example, when excavating work is performed by operating the bucket 20, it is possible to prevent earth and sand from entering between the inside of the cylinder tube 76 and the sliding surface of the piston rod 77. In addition, in this embodiment, the seal member 79 is formed at the end of the cylinder tube 76 on the rod side, thereby further preventing foreign matter such as dirt and sand from entering the cylinder tube 76.

Regarding the second hydraulic cylinder 56 and the third hydraulic cylinder 57, one end of the branch pipes 80a and 80b branched from the rod side hydraulic pipe 66 is connected so as to communicate with the bottom side chamber 76a. there is. A connection port 76c through which the branch pipe 80a is connected is protruding from the cylinder tube 76. The branch pipes 80a and 80b are composed of hoses and the like. The other end of the branch pipe 80 is connected in communication with the rod side hydraulic pipe 66.

Branching from the rod-side hydraulic pipe 66 to the branch pipes 80a and 80b is realized by the branch block 61c. The branch block 61c is disposed on the upper side of the cylinder tube 61 of the first hydraulic cylinder 55 together with the check valve 65a shown in FIG. 11, and connects the bottom side hydraulic pipe 65 and the rod side hydraulic pipe ( 66) It is a member that is connected to. Branch pipes 80a and 80b that supply hydraulic oil to the second hydraulic cylinder 56 and the third hydraulic cylinder 57 are connected to the branch block 61c. The branch block 61c branches the hydraulic oil flowing through the rod-side hydraulic pipe 66 to the branch pipes 80a and 80b. That is, the branch block 61c supplies hydraulic oil for contracting the piston rod 62 of the first hydraulic cylinder 55 to one cylinder chamber (rod side chamber 61b) of the cylinder tube 61 and simultaneously supplies the first hydraulic oil to the cylinder chamber 61b. A path for supplying hydraulic oil for extending each piston rod 77 to the second hydraulic cylinder 56 and the third hydraulic cylinder 57, and a path for extending the piston rod 62 of the first hydraulic cylinder 55 The path for supplying hydraulic oil to the other cylinder chamber (bottom side chamber 61a) of the cylinder tube 61 is branched.

Additionally, when the hydraulic pressure supplied to the bottom side chamber 76a through the branch pipe 80 exceeds a predetermined value, the second hydraulic cylinder 56 and the third hydraulic cylinder 57 move the piston rod 77 into the cylinder tube. It is further protruded from (76) and elongated. On the other hand, the return of the piston rod 77 may be of the load return type or the spring return type. For example, in the case of the load return type, when the hydraulic pressure in the bottom side chamber 76a falls below a predetermined value, the rear lock member 48 and the front lock member 58 are rotated by the elastic force of the lock spring 83, The abutting portion 87 rotates to move the piston rod 77 in the direction of contracting by an external force that pressurizes the abutting end 77a of the piston rod 77. In addition, in the case of the spring return type, a coil spring is formed on the rear side of the piston 78 of the cylinder tube 76, and when the hydraulic pressure in the bottom side chamber 76a falls below a predetermined value, the piston ( 78) moves the piston rod (77) in the direction of contracting.

The positional relationship between the first hydraulic cylinder 55, the second hydraulic cylinder 56, and the third hydraulic cylinder 57 in the attachment detachment device 30 will be described.

In the attachment detachment device 30, the first hydraulic cylinder 55 is formed between the left and right side wall frame portions 41 and between the left and right mounting frame portions 45. In this embodiment, the first hydraulic cylinder 55 is arranged in the central portion of the left and right side wall frame portions 41 in the left and right directions.

In this configuration, the second hydraulic cylinder 56 is below the first hydraulic cylinder 55 and is provided as a fifth support shaft on the side of one of the left and right side wall frame parts 41. It is arranged through the second hydraulic cylinder support shaft 98. The second hydraulic cylinder support shaft 98 is located between the bottom side support shaft 81, which is the first support shaft, and the rear support shaft 91, which is the third support shaft, in the vertical direction, and the bottom side support shaft 81 ) and is formed parallel to the rear support shaft (91). In this embodiment, the second hydraulic cylinder 56 is disposed between the left side wall frame portion 41 and the first hydraulic cylinder 55 among the left and right pair of side wall frame portions 41 in the left and right direction. It is done.

In addition, the third hydraulic cylinder 57 is below the first hydraulic cylinder 55, and is provided as a sixth support shaft on the side of one of the left and right mounting frame parts 45. It is arranged through the support shaft (99). The third hydraulic cylinder support shaft 99 is located between the rod side support shaft 82, which is the second support shaft, and the front support shaft 92, which is the fourth support shaft, in the vertical direction, and the rod side support shaft 82 ) and is formed parallel to the front support axis 92. In this embodiment, the third hydraulic cylinder 57 is disposed between the left side wall frame portion 41 of the left and right pair of mounting frame portions 45 and the first hydraulic cylinder 55 in the left and right direction. It is done.

The hydraulic circuit that operates the first hydraulic cylinder 55, the second hydraulic cylinder 56, and the third hydraulic cylinder 57 will be further explained.

As shown in FIG. 11, with respect to the first hydraulic cylinder 55, one end of the bottom side hydraulic pipe 65 made of a hose or the like is connected so as to communicate with the bottom side chamber 61a. The other end of the bottom side hydraulic pipe 65 is connected to the bottom side cylinder port A of the electromagnetic switching valve 67 for switching the flow path. A check valve 65a is formed in the bottom side hydraulic pipe 65.

In addition, with respect to the first hydraulic cylinder 55, one end of the rod-side hydraulic pipe 66 made of a hose or the like is connected so as to communicate with the rod-side chamber 61b. The other end of the rod-side hydraulic pipe (66) is connected to the rod-side cylinder port (B) of the electromagnetic switching valve (67).

One end of the supply pipe 68 is connected to the supply port P of the electromagnetic switching valve 67. The other end of the supply pipe 68 is open facing the oil tank 69 formed on the traveling device 2 side. A hydraulic pump 64 is formed in the supply piping 68, and by the operation of the hydraulic pump 64, the hydraulic oil in the oil tank 69 flows into the first hydraulic cylinder 55 through the electromagnetic switching valve 67. ) is supplied to. In addition, one end of the discharge pipe 70, which is a return pipe to the oil tank 69, is connected to the discharge port T of the electromagnetic switching valve 67. The other end of the discharge pipe 70 is open facing the oil tank 69. Additionally, a relief valve 71 that controls the pressure of the hydraulic oil discharged from the hydraulic pump 64 is interposed between the supply pipe 68 and the discharge pipe 70.

The attachment and detachment operation of the bucket 20 by the attachment detachment device 30 will be explained using FIGS. 12 and 13. In addition, in these drawings, illustration of a part of the structure of the attachment detachment device 30 is omitted for convenience. In addition, in these drawings, the external shape of the attachment detachment device 30 is shown by a dashed-dotted line, and the rear support pin 35 and the front support pin 36 of the bucket 20 are shown by a dashed-dotted line.

In the following description, the state in which the bucket 20 is connected and supported in the excavator 3 and the state in which the attachment detachment device 30 is engaged with the bucket 20 is referred to as the “engaged state.” In the attachment detachment device 30 in the engaged state, the first hydraulic cylinder 55 is in an extended state, and the second hook 34 of the movable frame 32 is connected to the first hook 33 of the fixed frame 31. ) is the lowest for . At this time, as shown in Fig. 13, the distance L1 between the axes of the bottom side support shaft 81 and the rod side support shaft 82 is the distance between the axes of the rear support shaft 91 and the front support shaft 92. It is shorter than the distance (M1). In addition, the distance (N1) between the axes of the second hydraulic cylinder support shaft (98) and the third hydraulic cylinder support shaft (99) is the distance (M1) between the axes of the rear support shaft (91) and the front support shaft (92). shorter than

In addition, the state before or after the bucket 20 is mounted on the excavator 3 or after the bucket 20 is removed, and the state in which the attachment detachment device 30 has released the engagement with the bucket 20 is referred to as the “non-engaged state.” Do this. In the attachment detachment device 30 in the non-engaged state, the first hydraulic cylinder 55 is in a shortened state, and the second hook 34 of the movable frame 32 is connected to the first hook of the fixed frame 31 ( 33) It is the closest state to . At this time, as shown in Fig. 12, the distance L2 between the axes of the bottom side support shaft 81 and the rod side support shaft 82 is the distance between the axes of the rear support shaft 91 and the front support shaft 92. It is shorter than the distance (M2). In addition, the distance (N2) between the shafts of the second hydraulic cylinder support shaft (98) and the third hydraulic cylinder support shaft (99) is the distance (M1) between the shafts of the rear support shaft (91) and the front support shaft (92). shorter than

That is, the attachment detachment device 30 engages the first hook 33 and the second hook 34 with the rear support pin 35 and the front support pin 36 of the bucket 20, respectively. The engaged state is set, and the state in which the engagement with each support pin of the first hook 33 and the second hook 34 is released (not engaged) is set as the non-engaged state. In either the engaged state or the non-engaged state, in the front-back direction of the attachment detachment device 30, the distance between the axes of the rear support shaft 91 and the front support shaft 92 > bottom support shaft 81 and the distance between the axes of the rod side support shaft 82 > the distance between the axes of the second hydraulic cylinder support shaft 98 and the third hydraulic cylinder support shaft 99 is established. In addition, the magnitude of the distance between the shaft centers of the second hydraulic cylinder support shaft 98 and the third hydraulic cylinder support shaft 99 with respect to the distance between the shaft centers of the rear support shaft 91 and the front support shaft 92 is the first. It may be changed depending on the size of the hydraulic cylinder 55 and/or where the support shafts 98 and 99 are formed in the second hydraulic cylinder 56 and the third hydraulic cylinder 57.

The attachment and detachment operation of the bucket 20 using the attachment detachment device 30 involves placing the bucket 20 on the ground or the like with the front support pin 36 and the rear support pin 35 facing upward. In contrast, this is carried out by operating the boom 17 and arm 18 of the excavator 3 by operating the operation unit provided in the cabin 10, and moving the attachment detachment device 30.

That is, when attaching the bucket 20 to the attachment detachment device 30, the attachment in the non-engaged state is detached from the bucket 20 placed on the ground or the like by operating an operation unit provided in the cabin 10. By bringing the device 30 closer and engaging the attachment detachment device 30 with the bucket 20 in a predetermined order, the bucket 20 is placed in the attachment detachment device 30 by placing the attachment detachment device 30 in an engaged state. ) is installed.

On the other hand, when removing the bucket 20 from the attachment detachment device 30, the bucket 20 is placed on the ground, etc. by operating the operation unit provided in the cabin 10, and the bucket 20 is moved in a predetermined order. While releasing the engagement of the attachment detachment device 30, the attachment detachment device 30 is placed in a non-engaged state, and the attachment detachment device 30 is removed from the bucket 20 by operating the operation unit provided in the cabin 10. By removing, the bucket 20 is separated from the attachment detachment device 30.

The operation of the attachment detachment device 30 when the bucket 20 is mounted on the attachment detachment device 30 (when the bucket is mounted) will be explained. Additionally, in the non-engaged state of the attachment detachment device 30, when hydraulic pressure is not supplied to the attachment detachment device 30, the first hydraulic cylinder 55, the second hydraulic cylinder 56, and the third The hydraulic cylinder 57 is in a contracted state. That is, the rear lock member 48 on the first hook 33 side and the front lock member 58 on the second hook 34 side have the lock spring 83 such that the tip of the lock claw portion 93 faces downward. ) is in a locked position elastically supported by .

When attaching the bucket 20, the attachment detachment device 30 in the non-engaged state is brought close to the bucket 20 by operating an operation unit provided in the cabin 10, etc. (see FIGS. 3 and 13). . In the attachment detachment device 30 in the non-engaged state, the distance between the tip ends of the respective locking portions 46 and 49 of the first hook 33 and the second hook 34 is the rear support of the bucket 20. It is shorter than the distance between the pin (35) and the front support pin (36).

Next, the hydraulic circuit of the attachment detachment device 30 is operated in accordance with an operation command from the operation unit in the cabin 10 to move the rear lock member 48 and the front lock member 58 to the non-locked positions, The first hook 33 and the second hook 34 are brought into a state where they can accept the rear support pin 35 and the front support pin 36. At this time, in the hydraulic circuit, the electromagnetic switching valve 67 is in a flow path switching state and communicates the supply port P with the rod side cylinder port B and connects the discharge port T with the bottom side cylinder port. It is connected to (A). Therefore, by the operation of the hydraulic pump 64, hydraulic oil flows from the supply pipe 68 through the electromagnetic switching valve 67 to the rod side chamber 61b of the first hydraulic cylinder 55 from the rod side hydraulic pipe 66. As it is supplied, it is supplied to each bottom side chamber 76a of the second hydraulic cylinder 56 and the third hydraulic cylinder 57 via branch pipes 80, 80a, 80b branched from the rod side hydraulic pipe 66. Pressure oil is supplied.

That is, in the first hydraulic cylinder 55, the piston rod 62 is maintained in a contracted state, while in the second hydraulic cylinder 56 and the third hydraulic cylinder 57, each bottom side chamber 76a Pressure oil is supplied to, and the piston rod 77 expands. As a result, a pressing force is applied to the abutting portion 87 of the rear lock member 48, and the abutting portion 87 and the lock claw portion 93 rotate together with the rear support shaft 91, thereby forming the lock claw portion ( 93) is accommodated above the first hook 33. Similarly, a pressing force is applied to the abutting portion 87 of the front lock member 58, and the abutting portion 87 and the lock claw portion 93 rotate together with the front support shaft 92, thereby forming the lock claw portion. (93) is accommodated above the second hook (34). That is, the rear lock member 48 and the front lock member 58 move to the non-locked position.

By moving the rear lock member 48 and the front lock member 58 to the non-locked position, it becomes possible to receive the rear support pin 35 in the locking portion 46 of the first hook 33, and 2 It becomes possible to receive the front support pin 36 into the locking portion 49 of the hook 34.

When the rear lock member 48 and the front lock member 58 are moved to the non-locked position, the rear support pin 35 is first engaged with the first hook 33. Subsequently, with the rear support pin 35 engaged with the first hook 33, an operation is performed to extend the first hydraulic cylinder 55. That is, by the operation of the hydraulic pump 64, hydraulic oil is supplied from the supply pipe 68 through the electromagnetic switching valve 67 to the bottom side chamber 61a through the bottom side hydraulic pipe 65, as shown in FIG. 13. As shown, the first hydraulic cylinder 55 extends. Here, in the hydraulic circuit shown in FIG. 11, the electromagnetic switching valve 67 is in a flow path switching state and communicates the supply port P with the bottom-side cylinder port A and loads the discharge port T. It is connected to the side cylinder port (B).

As the first hydraulic cylinder 55 extends, the movable frame 32 rotates forward around the link support shaft 28, so that the locking portion 46 of the second hook 34 moves toward the front support pin 36. (see Figure 13). Here, with respect to the rotation direction of the movable frame 32, the direction in which the second hook 34 engages with the front support pin 36 is the direction of right rotation when viewed from the left side, and the second hook 34 The direction in which the engagement with the front support pin 36 is released is the direction of left rotation when viewed from the left side.

Additionally, during the extension operation of the first hydraulic cylinder 55, hydraulic oil is discharged from the rod side chamber 61b to the rod side hydraulic pipe 66 as the piston 63 moves. After that, the operating oil of the bottom side chamber 76a of the second hydraulic cylinder 56 and the third hydraulic cylinder 57 is discharged from the branch pipes 80a, 80b, and 80 to the rod side hydraulic pipe 66. Here, the shortening operation of the second hydraulic cylinder 56 and the third hydraulic cylinder 57 is performed after the extending operation of the first hydraulic cylinder 55 is performed. This is because the force to shorten the second hydraulic cylinder 56 and the third hydraulic cylinder 57 is sufficiently small relative to the force by the hydraulic pump 64 to extend the first hydraulic cylinder 55. This is because the discharge of hydraulic oil from the bottom side chamber 76a of the cylinder 56 and the third hydraulic cylinder 57 occurs more slowly than the discharge of hydraulic oil from the rod side chamber 61b of the first hydraulic cylinder 55.

When the additional extension of the first hydraulic cylinder 55 is restricted by engaging the second hook 34 with the front support pin 36, the bottom side chamber of the first hydraulic cylinder 55 is moved from the hydraulic pump 64. The pressure in the path leading to (61a) is maintained at a predetermined value by the action of the relief valve (71). That is, by the force that separates the first hook 33 and the second hook 34 from each other generated by the extension operation of the first hydraulic cylinder 55, the engaging surface 46a of the first hook 33 The rear support pin 35 and the front support pin 36 are respectively caught on the engaging surface 49a of the second hook 34.

As shown in FIG. 13, the first hook 33 is engaged with the rear support pin 35, the second hook 34 is engaged with the front support pin 36, and the first hydraulic cylinder 55 When the extension of , the second hydraulic cylinder 56 and the third hydraulic cylinder 57 automatically retract the piston rod 77 into the cylinder tube 76 and shorten it.

As the second hydraulic cylinder 56 is shortened and no pressing force is applied to the abutting portion 87, the elastic force of the lock spring 83a acts on the rear lock member 48, and the rear lock member 48 It rotates together with the rear support shaft (91). Thereby, the rear lock member 48 moves (rotates) from the non-locked position to the locked position. Likewise, the third hydraulic cylinder 57 is shortened and no pressing force is applied to the abutting portion 87, so that the elastic force of the lock spring 83 acts on the front lock member 58, and the front lock member ( 58) rotates together with the front support shaft (92). Thereby, the front lock member 58 moves (rotates) from the non-locked position to the locked position. In short, a locked state in which the rear support pin 35 engaged with the first hook 33 is restricted from being released from the first hook 33 by the rear lock member 48, and the front lock member 58 As a result, a locked state in which separation of the front support pin 36 engaged with the second hook 34 from the second hook 34 is restricted is obtained.

As described above, the attachment detachment device 30 is in an engaged state, and as a state in which the bucket 20 is attached to the attachment detachment device 30, the front and rear support pins 35 and 36 each have a second position. A state in which the hook 34 and the first hook 33 are engaged, and the front and rear lock members 58, 48 at the engaging portions of each hook 33, 34 with respect to the support pins 35, 36. A locked state is obtained.

The locked state by the front and rear lock members 58 and 48 is such that the front and rear locks are applied to the respective openings 49b and 46b of the second hook 34 and the first hook 33 by the elastic force of the lock spring 83. This is realized by protruding the members 58 and 48.

Next, the operation of the attachment detachment device 30 when the bucket 20 is detached from the attachment detachment device 30 (when the bucket is removed) will be described. The operation of the attachment detachment device 30 when the bucket is removed is basically in the opposite order to the operation when the bucket is installed.

As shown in Fig. 13, with the attachment detachment device 30 in the engaged state and the bucket 20 mounted, the second hydraulic cylinder 56 and the third hydraulic cylinder 57 are extended and the third hydraulic cylinder 57 is extended. 1 An operation is performed to shorten the hydraulic cylinder 55.

As shown in FIG. 11, by the operation of the hydraulic pump 64, the bottom side chamber ( Pressure oil is supplied to 76a), and the second hydraulic cylinder 56 and the third hydraulic cylinder 57 expand. Additionally, hydraulic pressure is supplied to the rod side chamber 61b of the first hydraulic cylinder 55, and the first hydraulic cylinder 55 is shortened. Here, the electromagnetic switching valve 67 is in a flow path switching state and communicates the supply port P with the rod side cylinder port B and the discharge port T with the bottom side cylinder port A. It is in the ordered state.

As the second hydraulic cylinder 56 extends, a pressing force is applied to the abutting portion 87 from the piston rod 77, and the rear lock member 48 moves against the elastic force of the lock spring 83a to move the rear support shaft. (91) We meet together. Thereby, the rear locking member 48 moves (rotates) from the locked position to the non-locked position. Similarly, when the third hydraulic cylinder 57 extends, a pressing force is applied to the abutting portion 87 from the piston rod 77, so that the front lock member 58 counteracts the elastic force of the lock spring 83a, It rotates together with the front support shaft (92). Thereby, the front lock member 58 moves (rotates) from the locked position to the non-locked position. In short, an unlocked state in which the rear support pin 35 engaged with the first hook 33 can be separated from the first hook 33 by the rear lock member 48 and the front lock member 58. , and an unlocked state in which the front support pin 36 in a state engaged with the second hook 34 can be released from the second hook 34 is obtained.

Here, according to the hydraulic circuit configuration (see FIG. 11) provided by the excavating machine 1, the shortening operation of the first hydraulic cylinder 55 and the extending operation of the second hydraulic cylinder 56 and the third hydraulic cylinder 57 is executed simultaneously by a command from the operation unit in the cabin 10 to switch the flow path of the electromagnetic switching valve 67, but there is a time difference in the start timing of these two operations. The second hydraulic cylinder 56 and the third hydraulic cylinder 57 are hydraulic cylinders that are sufficiently small compared to the first hydraulic cylinder 55 . For this reason, when hydraulic oil is supplied to the rod side chamber 61b of the first hydraulic cylinder 55 from the rod side hydraulic pipe 66, the branch pipes 80, 80a, 80b branched from the rod side hydraulic pipe 66. By the hydraulic oil supplied to the second hydraulic cylinder 56 and the third hydraulic cylinder 57, the second hydraulic cylinder 56 and the third hydraulic cylinder 57 precede the shortening motion of the first hydraulic cylinder 55. ) performs the stretching movement.

As the first hydraulic cylinder 55 is shortened, the movable frame 32 rotates rearward around the link support shaft 28 to engage the front support pin 36 of the locking portion 46 of the second hook 34. The alignment is canceled.

As described above, the attachment detachment device 30 is in a non-engaged state. Then, the boom 17 and/or arm 18 of the excavator 3 is operated in response to an operation command from the operation unit within the cabin 10, and the attachment detachment device 30 is moved to move the rear support pin 35. ) Releases the engagement of the first hook (33). Thereby, the bucket 20 is separated from the attachment detachment device 30.

In Fig. 14, an attachment having a rear support pin 35a and a front support pin 36a with a pin-to-pin distance longer than the distance between the rear support pin 35 and the front support pin 36 of the bucket 20 is attached. Indicates status.

The attachment detachment device 30 provides a space between the first hook 33 and the second hook 34 between the minimum contracted state and the maximum extended state of the piston rod 62 of the first hydraulic cylinder 55. The distance can be changed. When the first hydraulic cylinder 55 is fully extended, the tip E of the second hook 34 is positioned at the position of the front support shaft 92 (axial center position) with respect to the extension direction of the first hydraulic cylinder 55. It becomes more forward. The third hydraulic cylinder 57 formed on the movable frame 32 is connected to the branch block 61c on the cylinder tube 61 of the first hydraulic cylinder 55 through a flexible pipe. Since such piping is flexibly deformed when the movable frame 32 rotates with the extension of the first hydraulic cylinder 55, the extension of the first hydraulic cylinder 55 is not restricted. For this reason, the movable frame 32 is moved to the fixed frame 31 to a position where the tip E of the second hook 34 is forward of the front support shaft 92 with respect to the expansion/contraction direction of the first hydraulic cylinder 55. ) can be discussed. In this way, since the rotation angle of the movable frame 32 with respect to the fixed frame 31 can be made larger than before, the distance between the first hook 33 and the second hook 34 can also be made longer than before. It becomes possible. In this attachment detachment device 30, it is possible to connect a plurality of attachments with different distances between support pins.

According to the attachment detachment device 30 and the excavating machine 1 provided therewith according to the present embodiment as described above, in a state in which the bucket 20 is connected to the attachment detachment device 30, the first hydraulic cylinder 55 Even when the supply of hydraulic pressure to the ) and falling off from the second hook (34). Therefore, the connected state of the bucket 20 can be maintained, and high safety can be achieved.

The attachment detachment device 30 of the present embodiment supports the support pins 35 and 36 of the attachment by extending the first hydraulic cylinder 55, and locks the rear lock member 48 and the front lock member 58. It is held in the locked position by the elastic force of the lock springs 83 provided on the rear lock member 48 side and the front lock member 58 side, respectively. Then, the rear lock member 48 is moved from the locked position to the non-locked position by the operation of the second hydraulic cylinder 56, and the front lock member 58 is moved from the locked position to the non-locked position. This is carried out by the operation of the third hydraulic cylinder 57. At this time, the operations of the second hydraulic cylinder 56 and the third hydraulic cylinder 57 are linked to the operation of the first hydraulic cylinder 55.

According to this configuration, good workability is obtained with respect to the attachment and detachment operation of the bucket 20 with respect to the attachment detachment device 30, and, for example, damage to the second hydraulic cylinder 56 due to damage to the hydraulic equipment, etc. Even when the power supply is cut off, the elastic force of the lock spring 83 maintains the locked state of the first hook 33 with respect to the rear support pin 35 by the rear lock member 48 and the front lock member 58. ), the locked state of the second hook 34 with respect to the front support pin 36 is secured. Thereby, safety can be ensured.

In addition, the attachment detachment device 30 is configured to hold the rear lock member 48 in the locked position and the front lock member 58 in the locked position by members of the same function and shape. And they are arranged so that they are mirror image symmetrical in the front-to-back direction when viewed from the left side of the attachment detachment device 30. According to this configuration, the first hook 33 and the second hook 34 can be used as a common member for preventing the support pins 35 and 36 of the bucket 20 from coming off, so that the attachment detachment device 30 Assembly efficiency is improved. In addition, the double lock structure can be easily realized, and separation of the bucket 20 from the attachment detachment device 30 can be effectively prevented, thereby improving safety.

In addition, in the attachment detachment device 30, the second hydraulic cylinder 56 is located between the left and right side wall frame portions 41 of the fixed frame 31, and is located between the first hydraulic cylinder 55 and the right side wall frame. It is arranged between the parts 41, and the third hydraulic cylinder 57 is between the left and right mounting frame parts 45 of the movable frame 32, and is connected to the first hydraulic cylinder 55 and the right mounting frame part ( 45) is placed in between.

According to this configuration, the space between the first hydraulic cylinder 55 and the side wall frame portion 41 can be used as an operating space for the second hydraulic cylinder 56, and the first hydraulic cylinder 55 and the movable frame can be used as an operating space. Since the space between 32 can be used as the operating space of the third hydraulic cylinder 57, the attachment detachment device 30 can be designed compactly.

The description of the above-described embodiment is an example of the present invention, and the attachment detachment device and construction machine related to the present invention are not limited to the above-described embodiment. For this reason, it goes without saying that even in addition to the above-described embodiments, various changes are possible depending on the design, etc., as long as they do not deviate from the technical idea related to the present invention.

For example, in the above-described embodiment, the second hydraulic cylinder 56 is disposed on the right side wall frame portion 41 among the left and right side wall frame portions 41 through the second hydraulic cylinder support shaft 98. The third hydraulic cylinder is disposed on the right mounting frame portion 45 among the left and right mounting frame portions 45 through the third hydraulic cylinder support shaft 99, but is disposed on the left side wall frame portion 41, respectively. It may also be placed in the mounting frame portion 45 on the left side.

In addition, in the above-described embodiment, the hydraulic circuit configuration (see FIG. 11) for operating the first hydraulic cylinder 55 and the second hydraulic cylinder 56 is only an example. That is, if the operation of each hydraulic cylinder of the first hydraulic cylinder 55, the second hydraulic cylinder 56, and the third hydraulic cylinder 57 can be obtained when the bucket is mounted and when the bucket is removed, these hydraulic pressures The configuration of the hydraulic circuit for operating the cylinder is not particularly limited.

Additionally, the present invention can take the following aspects.

(One)

An attachment detachment device for a construction machine that attaches and detaches a work attachment to an arm of a work device, comprising:

a first member having a first hook and connected to the arm;

a second member having a second hook and pivotably supported by the first member;

First hydraulic pressure that has one end connected to a first support shaft formed in the first member and the other end connected to a second support shaft formed in the second member, and that rotates the second member relative to the first member. cylinder,

a first anti-falling member formed on the first member, pivotably supported by a third support shaft disposed above the first hook, and elastically supported by a first elastic support member so as to protrude from an opening of the first hook; ,

A second hydraulic cylinder that, in conjunction with the operation of the first hydraulic cylinder, moves the first anti-dropping member to retreat from the opening of the first hook against the elastic force of the first elastic support member;

a second anti-falling member formed on the second member, pivotably supported on a fourth support shaft disposed above the second hook, and elastically supported by a second elastic support member so as to protrude from an opening of the second hook; ,

A third hydraulic cylinder that, in conjunction with the operation of the first hydraulic cylinder, moves the second anti-dropping member against the second elastic support member to retreat from the opening of the second hook.

Attachment detachment device for construction machinery, comprising:

(2)

The second hydraulic cylinder is disposed between the first support shaft and the third support shaft,

The third hydraulic cylinder is disposed between the second support shaft and the fourth support shaft,

(1) Attachment detachment device for construction machinery described in .

(3)

The distance between the axes of the first support shaft and the second support shaft is shorter than the distance between the axes of the third support shaft and the fourth support shaft,

Attachment detachment device for construction machinery according to (1) or (2).

(4)

The distance between the axes of the fifth support shaft supporting the second hydraulic cylinder and the sixth support shaft supporting the third hydraulic cylinder is shorter than the distance between the axes of the third support shaft and the fourth support shaft.

(2) Attachment detachment device for construction machinery described in .

(5)

When the rod of the first hydraulic cylinder is fully extended, the tip of the second hook is forward of the fourth support shaft,

An attachment detachment device for a construction machine according to any one of (1) to (4).

(6)

The first hydraulic cylinder is a double-acting hydraulic cylinder,

The second hydraulic cylinder and the third hydraulic cylinder are single-acting hydraulic cylinders,

Inside the first member, hydraulic oil for contracting the rod of the first hydraulic cylinder is supplied to one cylinder chamber of the cylinder tube, and at the same time, the rods of the second hydraulic cylinder and the third hydraulic cylinder are extended. A branch block is formed to branch a path for supplying hydraulic oil for extending the rod of the first hydraulic cylinder and a path for supplying hydraulic oil for extending the rod of the first hydraulic cylinder to the cylinder chamber on the other side of the cylinder tube.

An attachment detachment device for a construction machine according to any one of (1) to (5).

(7)

The branch block is disposed above the cylinder tube of the first hydraulic cylinder,

(6) Attachment detachment device for construction machinery described in .

(8)

An end of each rod of the second hydraulic cylinder and the third hydraulic cylinder has a hemispherical shape, and when the second hydraulic cylinder and the third hydraulic cylinder are contracted, the end of the rod is connected to an end of the cylinder tube. more protruding,

(6) Attachment detachment device for construction machinery described in .

(9)

An attachment detachment device for a construction machine according to any one of (1) to (8),

a running device,

A front working device is provided on the front side of the traveling device and includes the arm that detachably supports the attachment by the attachment detachment device,

Construction machinery.

1: Excavating machine (construction machinery)
2: Travel device
3: Excavating device (front working device)
18: arm
20: Bucket (attachment)
30: Attachment detachment device
31: Fixed frame (first member)
32: Movable frame (second member)
33: 1st hook
34: 2nd hook
35: front support pin
36: rear support pin
41: Side wall frame part (wall part)
44: rear wall
45: Mounting frame part (wall part)
47: anterior wall
48: Rear lock member (first release prevention member)
55: first hydraulic cylinder
56: second hydraulic cylinder
57: third hydraulic cylinder
58: Front lock member (second release prevention member)
81: Bottom side support shaft (first support shaft)
82: Rod side support shaft (second support shaft)
86: Lock spring (first elastic support member, second elastic support member)
87: Contact part
77a: Contact end (end of piston rod)
91: Rear support shaft (3rd support shaft)
93: Front support axis (4th support axis)
98: 2nd hydraulic cylinder support shaft (5th support shaft)
99: Third hydraulic cylinder support shaft (6th support shaft)

Claims (9)

An attachment detachment device for a construction machine that attaches and detaches a work attachment to an arm of a work device, comprising:
a first member having a first hook and connected to the arm;
a second member having a second hook and pivotably supported by the first member;
First hydraulic pressure that has one end connected to a first support shaft formed in the first member and the other end connected to a second support shaft formed in the second member, and that rotates the second member relative to the first member. cylinder,
a first anti-falling member formed on the first member, pivotably supported by a third support shaft disposed above the first hook, and elastically supported by a first elastic support member so as to protrude from an opening of the first hook; ,
A second hydraulic cylinder that, in conjunction with the operation of the first hydraulic cylinder, moves the first anti-dropping member to retreat from the opening of the first hook against the elastic force of the first elastic support member;
a second anti-falling member formed on the second member, pivotably supported on a fourth support shaft disposed above the second hook, and elastically supported by a second elastic support member so as to protrude from an opening of the second hook; ,
and a third hydraulic cylinder that, in conjunction with the operation of the first hydraulic cylinder, moves the second anti-dropping member against the second elastic support member to retreat from the opening of the second hook. Machine attachment detachment device. According to claim 1,
The second hydraulic cylinder is disposed between the first support shaft and the third support shaft,
The attachment detachment device for a construction machine, wherein the third hydraulic cylinder is disposed between the second support shaft and the fourth support shaft. According to claim 1,
An attachment detachment device for a construction machine, wherein the distance between the axes of the first support shaft and the second support shaft is shorter than the distance between the axes of the third support shaft and the fourth support shaft. According to claim 2,
The distance between the axes of the fifth support shaft supporting the second hydraulic cylinder and the sixth support shaft supporting the third hydraulic cylinder is shorter than the distance between the axes of the third support shaft and the fourth support shaft. Attachment detachment device. According to claim 1,
An attachment detachment device for a construction machine, wherein when the rod of the first hydraulic cylinder is fully extended, the tip of the second hook is located ahead of the fourth support shaft. The method according to any one of claims 1 to 5,
The first hydraulic cylinder is a double-acting hydraulic cylinder,
The second hydraulic cylinder and the third hydraulic cylinder are single-acting hydraulic cylinders,
Inside the first member, hydraulic oil for contracting the rod of the first hydraulic cylinder is supplied to one cylinder chamber of the cylinder tube, and at the same time, the rods of the second hydraulic cylinder and the third hydraulic cylinder are extended. An attachment detachment device for a construction machine, wherein a branch block is formed to branch a path for supplying hydraulic oil for extending the rod of the first hydraulic cylinder and a path for supplying hydraulic oil for extending the rod of the first hydraulic cylinder to the other cylinder chamber of the cylinder tube. According to claim 6,
The branch block is disposed above the cylinder tube of the first hydraulic cylinder. According to claim 6,
An end of each rod of the second hydraulic cylinder and the third hydraulic cylinder has a hemispherical shape, and when the second hydraulic cylinder and the third hydraulic cylinder are contracted, the end of the rod is connected to an end of the cylinder tube. A more protruding attachment detachment device for construction machinery. An attachment detachment device for the construction machine according to claim 1,
a running device,
A construction machine comprising a front work device formed on a front side of the traveling device and including the arm that detachably supports the attachment by the attachment detachment device.

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