JP2021134025A - crane - Google Patents

Abstract

To provide a crane capable of facilitating the work of changing a position of an auxiliary sheave relative to a tip of a boom.SOLUTION: A crane 100 has an auxiliary sheave device 10 attached to a boom head 51. The auxiliary sheave device 10 has an auxiliary sheave 12, an auxiliary sheave bracket 11, and an expansion joint 20. The expansion joint 20 has a joint base 21 and a link 22. An advance position contact portion 21k and a retract position contact portion 21m of the joint base 21 limit a movement range of the link 22 in the advance/retreat direction between an advance position P3 and a retract position P4. The link 22 has: an advance position pin hole 22c through which a position fixing pin 24 is inserted together with a base pin hole 21f when the link 22 is arranged at the advance position P3 which is one end of the movement range; and a retreat position pin hole 22d through which the position fixing pin 24 is inserted together with the base pin hole 21f when the link 22 is arranged at the retreat position P4 which is the other end of the movement range.SELECTED DRAWING: Figure 5

Description

The present invention relates to a crane.

Conventionally, a work device such as a hammer grab for performing civil engineering work, a main hook device for performing normal hanging work, and an auxiliary hook device separate from the main hook device, which are provided so as to protrude from the tip of the boom. A crane equipped with an auxiliary sheave for suspending the crane so as to be able to move up and down via a rope is known.

Among the sites where the work is performed by the work device, there is a low-headed site where an obstacle exists in the sky, and in such a site, the work device is raised and lowered with the boom relatively laid down. At that time, it is preferable that the auxiliary sheave is located near the upper end of the tip of the boom in the vertical direction so as to secure the maximum lift of the working device.

On the other hand, at a work site where there are no obstacles in the sky, the work device may perform work with the boom upright rather than the posture of the boom at the low-flying site. As the boom is raised, the rope that hangs from the auxiliary sheave and suspends the work device approaches the lower end of the boom tip in the horizontal direction, and as a result, when the work device rises, the boom tip There is a risk of interfering with the lower end of the. Therefore, when the boom is raised and the work is performed in this way, the auxiliary sheave must be located near the lower end of the tip of the boom in the vertical direction and away from the lower end of the tip of the boom in the horizontal direction. Is preferable.

From the above, it is preferable that the position of the auxiliary sheave with respect to the tip of the boom can be changed to a preferable position according to the work mode at the work site. The following Patent Document 1 shows an example of a crane configured so that the position of such an auxiliary sheave can be changed.

Specifically, the crane disclosed in Patent Document 1 below has a tip that rotatably supports the auxiliary sheave via an auxiliary sheave pin and an end opposite to the tip, and is rotated to the lower part of the tip of the boom. It includes a lower link with a movably connected other end and an upper link connecting the upper end of the boom tip with an auxiliary sheave pin.

The upper link has a tip connected to an auxiliary sheave pin and the other end opposite to the tip. Further, the upper link has two pin holes, one of the two pin holes is provided at the other end of the upper link, and the other pin hole is the one pin hole. It is provided at a position separated from the above in the longitudinal direction of the upper link toward the tip of the upper link. An upper pin hole is provided at the upper end of the tip of the boom, and an upper link is inserted by inserting a connecting pin into either the upper pin hole or one of the two pin holes of the upper link. Is connected to the upper end of the tip of the boom.

Then, by changing the pin hole through which the connecting pin is inserted among the two pin holes of the upper link, it is possible to change the position of the auxiliary sheave with respect to the tip end portion of the boom. Specifically, when the connecting pin is inserted into the pin hole near the tip of the upper link among the two pin holes, the lower link is rotated from above to the rear and the auxiliary sheave is at the tip of the boom. It is placed in a position that is drawn to the upper end. On the other hand, when the connecting pin is inserted into the pin hole provided at the other end of the upper link among the two pin holes, the lower link is rotated from the front to the lower side and the auxiliary sheave is boomed in the vertical direction. It is arranged closer to the lower end of the tip and further away in the horizontal direction from the lower end of the boom tip.

Jikkenhei 3-82387 Gazette

However, in the crane configuration disclosed in Patent Document 1, there is a problem that the work of changing the position of the auxiliary sheave with respect to the tip end portion of the boom becomes a very troublesome work.

Specifically, in the crane disclosed in Patent Document 1, when the position of the auxiliary sheave with respect to the tip of the boom is changed, one of the two pin holes of the upper link and the upper part of the tip of the boom After pulling out the connecting pin inserted into the pin hole, the auxiliary sheave is hung and supported by an auxiliary crane or the like in order to insert the connecting pin into the other pin hole of the upper link and the upper pin hole at the tip of the boom. However, it is very troublesome because it is necessary to align the other pin hole so that the position of the other pin hole matches the upper pin hole, and the operator performs this alignment at a relatively high place. It will be a difficult task.

An object of the present invention is to provide a crane capable of facilitating the work of changing the position of an auxiliary sheave with respect to the tip of a boom.

The crane provided by the present invention is a boom that is rotatably attached to a crane body and a rotation axis extending in the left-right direction of the crane body and is undulating, and is a shaft of the boom. A device having a boom head which is a tip portion in a direction, an auxiliary sheave device attached to the boom head so as to project from the boom head in the axial direction of the boom, and a working device suspended from the auxiliary sheave device. , Equipped with. The auxiliary sheave device supports the auxiliary sheave that suspends the work device so as to be able to move up and down via a rope, and the auxiliary sheave so that the auxiliary sheave can rotate about an axis parallel to the rotation axis. A first rotation posture in which the auxiliary sheave is arranged at a first position away from the boom head in a direction along the axial direction of the boom, and the auxiliary sheave above the first position and in the axial direction of the boom. The boom head can be rotated about an axis parallel to the rotation axis so that the boom head can take a second rotation posture arranged at a second position closer to the boom head than the first position in the direction along the above. An extended state in which the connected auxiliary sheave bracket, the boom head, and the auxiliary sheave bracket are connected to keep the auxiliary sheave bracket in the first rotation posture and a contraction in which the auxiliary sheave bracket is held in the second rotation posture. It has an telescopic joint that is configured to be telescopic so that it can take a state. The expansion joint is capable of advancing and retreating between a joint base connected to the boom head, an advance position where the expansion joint is in the extended state, and an retractable position where the expansion joint is in the contracted state. It has a link attached to and connected to the auxiliary sheave bracket, and a position fixing pin for fixing the position of the link in the advancing / retreating direction with respect to the joint base. The joint base has an advance positioning portion that abuts on the link so as to prevent the link from moving in the advance direction from the joint base when the link is arranged at the advance position. One of the boom head and the joint base abuts on the link so as to prevent the link from moving to the joint base in the retracting direction when the link is placed in the retracted position. It has an on-positioning part. The advance positioning unit and the retreat positioning unit limit the moving range of the link in the advancing / retreating direction between the advancing position and the retreating position. The first member, which is one member of the joint base and the link, has a first member pin hole through which the position fixing pin is inserted. The second member, which is the other member of the joint base and the link, has the position fixing pin together with the first member pin hole when the link is arranged at the advance position which is one end of the movement range. An advance position pin hole through which the position fixing pin is inserted and an entry / exit position pin through which the position fixing pin is inserted together with the first member pin hole when the link is arranged at the retracted position which is the other end of the moving range. It has holes.

In this crane, the moving range of the link in the advancing / retreating direction is limited between the advancing position and the retreating position by the advancing positioning unit and the retreating positioning unit, and the advancing position and retreating at both ends of the moving range. Since the position fixing pin can be inserted into the corresponding pin hole at the insertion position, the work load required for aligning the pin holes can be reduced, and the work of changing the position of the auxiliary sheave with respect to the boom head can be facilitated.

Specifically, in this crane, in order to change the position of the auxiliary sheave from the first position away from the boom head along the axial direction of the boom to the second position above the first position and close to the boom head. When moving the link from the advance position to the retract position with respect to the joint base in order to rotate the auxiliary sheave bracket from the first rotation posture to the second rotation posture, the retract positioning portion abuts on the link and the link is released. It is positioned at the retreat position, and the first member pin hole and the retreat position pin hole match. Further, in order to change the position of the auxiliary sheave from the second position to the first position, the link retracts from the joint base to rotate the auxiliary sheave bracket from the second rotation posture to the first rotation posture. When moving from the position to the advance position, the advance positioning portion abuts on the link, the link is positioned at the advance position, and the first member pin hole and the advance position pin hole match. Therefore, in this crane, the operator can align the first member pin hole and the advance position pin hole and the first member pin hole and the retract position pin hole in the vicinity of the boom head where it is difficult for the operator to work. It is not necessary to perform the alignment with and after the position of the link with respect to the joint base is unstable, and the work load required for the alignment of the pin holes can be reduced. As a result, the work of changing the position of the auxiliary sheave with respect to the boom head can be facilitated.

The joint base has an elongated hole extending in the advancing / retreating direction of the link with respect to the joint base, and the link has a guide pin inserted into the elongated hole so as to be movable in the advancing / retreating direction. As the advance positioning portion, the base portion defines one end of the elongated hole in the advance direction of the link and moves the guide pin in the advance direction when the link is arranged at the advance position. It has an advance position contact portion that abuts on the guide pin so as to prevent it, and as the retract positioning portion, an end opposite to the one end of the elongated hole is defined and the link retracts. It may have an entry / exit position contact portion that abuts the guide pin so as to prevent the guide pin from moving in the retracting direction when it is arranged at the position.

Further, the link has an elongated hole extending along the advancing / retreating direction of the link with respect to the joint base, and the advancing side portion and the retreating of the link defining one end of the elongated hole in the advancing direction of the link. It has an entry / exit side that defines the other end of the elongated hole in the entry direction, and the joint base is inserted into the elongated hole so as to be movable relative to the link along the advance / retreat direction. When the link is placed in the advance position, it abuts on the retreat side portion so as to prevent the link from moving in the advance direction, while when the link is placed in the retreat position, the retreat A guide pin that abuts on the advance side portion may be provided as the advance positioning portion and the retract positioning portion so as to prevent the link from moving in the entry direction.

The expansion joint is provided at the base of the joint, and the link is pressed in an intersecting direction intersecting the advancing / retreating direction of the link in a state where the link is arranged at each of the advancing position and the retracting position. It is preferable to further have at least one restraint that constrains the movement of the link with respect to the base in the crossing direction.

According to this configuration, it is possible to prevent noise due to collision between the link and the joint base in a state where the link is arranged at each of the advance position and the retract position. Specifically, vibration is generated during work by the working device, and the vibration is transmitted to the link. At this time, if the link is in a state where it can move in the crossing direction, the link vibrates in the crossing direction and the joint is joined. It collides with the base and makes noise. On the other hand, in this configuration, the movement of the link in the crossing direction can be restrained by the restraint in the state where the link is arranged at the advance position and the retract position, respectively, so that noise due to the collision between the link and the joint base is generated. You can prevent it from happening. Further, in this configuration, the restraint presses the link in the crossing direction to prevent buckling in the crossing direction from occurring on the link when a compressive load is applied to the link in the direction along the advancing / retreating direction. be able to.

The restraint includes a case provided at the joint base and surrounding an internal space extending in the crossing direction, and a pad installed in the internal space of the case so as to be detachable from the link along the crossing direction. And a pressing member that presses the pad against the link along the crossing direction.

According to this configuration, the link can be pressed with a wider contact area by the pad as compared with the case where the link is pressed in the crossing direction by, for example, the tip of a bolt. Therefore, the stability of link restraint can be improved.

The pad is preferably made of an elastic body.

According to this configuration, the vibration transmitted from the working device to the link can be absorbed between the link and the joint member by a pad made of an elastic body.

The case has a screw hole extending in the crossing direction, and the pressing member is screwed into the screw hole so as to be able to advance and retreat along the crossing direction, and is a bolt protruding from the outer surface of the joint base. It is preferable that the restraint further has a cap attached to the joint base so as to surround a portion of the bolt that protrudes from the outer surface of the joint base.

According to this configuration, the cap can prevent the bolt from falling off and prevent the rope for suspending the working device from being caught by the bolt.

The at least one restraint preferably includes a plurality of restraints provided at a plurality of different positions along the advancing / retreating direction of the link at the joint base.

According to this configuration, a plurality of restraints can restrain the movement of the link in the crossing direction over a wider range in the direction along the advancing / retreating direction of the link, and prevent noise from being generated due to the collision between the link and the joint base. The effect can be further improved. Further, since the link can be pressed in the crossing direction over a wider range in the direction along the advancing / retreating direction of the link by a plurality of restraints, when a compressive load is applied to the link in the direction along the advancing / retreating direction, the link can be pressed. It is possible to suppress the occurrence of buckling of the link in the crossing direction over a wider range in the direction along the advancing / retreating direction.

As described above, according to the present invention, it is possible to provide a crane capable of facilitating the work of changing the position of the auxiliary sheave with respect to the boom head which is the tip end portion of the boom.

It is a schematic side view of the crane by 1st Embodiment of this invention, and is the figure which shows the state which the expansion joint of the auxiliary sheave device is in an extended state. It is a schematic side view of the crane by 1st Embodiment, and is the figure which shows the state which the expansion joint of an auxiliary sheave device is in a contracted state. It is a perspective view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the first embodiment, and is a diagram showing a state in which an expansion joint is in an extended state. It is a perspective view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the first embodiment, and is a diagram showing a state in which the telescopic joint is in a contracted state. FIG. 5 is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the first embodiment, showing a state in which the telescopic joint is in an extended state. It is a side view in the extended state of the expansion joint used for the crane by 1st Embodiment. It is a side view in the contracted state of the expansion joint used for the crane by 1st Embodiment. It is sectional drawing of the expansion joint along the line XIII-XIII in FIG. It is sectional drawing of the expansion joint along the IX-IX line in FIG. It is a side view in the extended state of the expansion joint used for the crane by 2nd Embodiment of this invention. It is a side view in the contracted state of the expansion joint used for the crane by the 2nd Embodiment of this invention. It is sectional drawing of the expansion joint along the line XII-XII in FIG. It is a side view in the extended state of the expansion joint used for the crane by the 3rd Embodiment of this invention. It is a side view in the contracted state of the expansion joint used for the crane by the 3rd Embodiment of this invention. It is sectional drawing of the expansion joint along the XV-XV line in FIG. It is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the 4th embodiment of the present invention, and is a view showing a state in which an expansion joint is in an extended state. It is a top view which shows the state which the expansion joint of 4th Embodiment is in an extended state. FIG. 5 is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the fourth embodiment, showing a state in which the telescopic joint is in a contracted state. It is a top view which shows the state which the expansion joint of 4th Embodiment is in a contracted state. It is sectional drawing of the expansion joint along the line XX-XX in FIG. It is sectional drawing of the expansion joint along the XXI-XXI line in FIG. FIG. 5 is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the fifth embodiment of the present invention, showing a state in which the telescopic joint is in an extended state. It is a top view which shows the state which the expansion joint of 5th Embodiment is in an extended state. FIG. 5 is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the fifth embodiment, showing a state in which the telescopic joint is in a contracted state. It is a top view which shows the state which the expansion joint of 5th Embodiment is in a contracted state. It is sectional drawing of the expansion joint along the line XXVI-XXVI in FIG. 23. It is sectional drawing of the expansion joint along the line XXVII-XXVII in FIG. 23. It is sectional drawing of the expansion joint along the line XXVIII-XXVIII in FIG. 23. It is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the sixth embodiment of the present invention, and is a view showing a state in which an expansion joint is in an extended state. It is a top view which shows the state which the expansion joint of 6th Embodiment is in an extended state. 6 is a side view of the vicinity of the boom head of the crane and the auxiliary sheave device according to the sixth embodiment, showing a state in which the telescopic joint is in a contracted state. It is a top view which shows the state which the expansion joint of 6th Embodiment is in a contracted state. It is sectional drawing of the expansion joint along the line XXXIII-XXXIII in FIG. It is a side view in the contracted state of the expansion joint by one modification of this invention. It is sectional drawing of the expansion joint along the line XXXXV-XXXV in FIG. 34. It is sectional drawing of the expansion joint by another modification of this invention.

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

(First Embodiment)
First, the configuration of the crane 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 9.

As shown in FIGS. 1 and 2, the crane 100 according to the first embodiment of the present invention includes a crawler traveling type lower traveling body 1 and an upper rotating body 2 rotatably mounted on the lower traveling body 1. , Is equipped. The upper swivel body 2 is mounted on the lower traveling body 1 via a swivel bearing 3, whereby the upper swivel body 2 can be swiveled with respect to the lower traveling body 1. The upper swing body 2 is an example of the crane main body in the present invention.

Further, the upper swing body 2 has a pair of plate-shaped frames 4 erected at the rear portion and a boom foot pin 4a attached to the pair of plate-shaped frames 4.

The pair of plate-shaped frames 4 are arranged at intervals in the left-right direction orthogonal to the front-back direction of the upper swivel body 2. Since FIGS. 1 and 2 show the upper swivel body 2 as viewed from the right side, only one of the pair of plate-shaped frames 4 on the right side is shown. Boom support holes (not shown) are formed in each of the pair of plate-shaped frames 4 at positions corresponding to each other, and boom foot pins 4a are inserted into the boom support holes of the plate-shaped frames 4. The boom foot pin 4a is attached to the pair of plate-shaped frames 4 in a posture extending in the left-right direction of the upper swing body 2.

Further, the crane 100 according to the first embodiment includes a boom 5, a driver's cab 6, a boom undulating cylinder 7, a gantry 8 and a counterweight 9 mounted on the upper swing body 2.

The boom 5 is a so-called box beam that can be expanded and contracted in multiple stages. The boom 5 is rotatably attached to the upper swivel body 2 around a rotation axis extending in the left-right direction of the upper swivel body 2 so as to be undulating. Specifically, the boom 5 has a base end portion arranged between the pair of plate-shaped frames 4. The base end portion of the boom 5 is supported by the pair of plate-shaped frames 4 via the boom foot pin 4a, and can rotate around the axis of the boom foot pin 4a extending in the left-right direction of the upper swing body 2. It has become. The rotation shaft of the boom 5 described below corresponds to the axis of the boom foot pin 4a. Since the base end portion of the boom 5 is rotatable in this way, the boom 5 can be undulated with the boom foot pin 4a as a fulcrum. The boom 5 has a boom head 51 which is a tip end portion opposite to the base end portion of the boom 5 in the axial direction of the boom 5. The axial direction of the boom 5 corresponds to the longitudinal direction of the boom 5, and the boom 5 which is a multi-stage telescopic box beam corresponds to the expansion / contraction direction.

Further, the crane 100 includes a plurality of point sheaves 52, point sheave support shafts 53, two idler sheaves 54 and idler sheave support shafts 55 provided on the boom head 51 (see FIGS. 3 and 4).

The point sheave support shaft 53 is provided on the boom head 51 in a posture extending parallel to the rotation shaft of the boom 5. The position where the point sheave support shaft 53 is provided in the boom head 51 is a position in the vicinity of a portion that becomes the lower end of the boom head 51 in a state where the boom 5 is laid down. Both ends of the point sheave support shaft 53 project to the left and right sides of the boom head 51.

The plurality of point sheaves 52 are arranged inside the boom head 51 and are rotatably supported around the axis thereof by the point sheave support shaft 53.

The idler receive support shaft 55 is provided on the boom head 51 in a posture extending parallel to the rotation shaft of the boom 5. The position where the idler receive support shaft 55 is provided on the boom head 51 is a position near a portion that becomes the upper end of the boom head 51 in a state where the boom 5 is laid down. In other words, the idler sheave support shaft 55 is provided at a portion of the boom head 15 that is above the point sheave support shaft 53 and away from the point sheave support shaft 53 in a state where the boom 5 is lying down. There is. Both ends of the idler receive support shaft 55 project to the left and right sides of the boom head 51.

The two idler sheaves 54 are arranged coaxially inside the boom head 51, and are rotatably supported around the axis thereof by the idler sheave support shaft 55.

The driver's cab 6 (see FIG. 1) is a portion in which the operator operates the crane 100, and is provided on the right side of the boom 5 of the upper swing body 2 at the frontmost portion of the upper swing body 2. A pump device, an engine, and the like (not shown) are installed at a position behind the driver's cab 6 in the upper swing body 2.

The boom undulating cylinder 7 is provided on the lower side of the boom 5 and expands and contracts, thereby causing the boom 5 to undulate. The boom undulating cylinder 7 allows the boom 5 to undulate between a horizontal posture and an upright posture standing at a predetermined angle.

The gantry 8 is arranged behind the pair of plate-shaped frames 4 of the upper swing body 2 and mounted on the plate-shaped frames 4. A main winding rope 101 drawn from a main winding winch (not shown) mounted on the upper swing body 2 is hung on one of the two idler sheaves 54 via the gantry 8 and is hung on the idler sheave 54. One of the idler sheaves 54 is passed over to one of the auxiliary sheaves 12 described later. Further, the auxiliary winding rope 102 pulled out from the auxiliary winding winch of the drawing mounted on the upper swing body 2 is hung on the other idler receive 54 of the two idler sheaves 54 via the gantry 8. At the same time, the idler sheave 54 of the other side is hung from the other auxiliary sheave 12 described later.

The counterweight 9 is mounted on the rearmost portion of the upper swing body 2 in order to ensure the stability of the crane 100.

The auxiliary sheave device 10 is attached to the boom head 51 so as to project from the boom head 51 in the axial direction of the boom 5. The crane 100 includes a grab bucket 104, which is a civil engineering work device suspended from the auxiliary sheave device 10, and a crown 105, which is a device for opening and closing the grab bucket 104. The auxiliary sheave device 10 suspends the grab bucket 104 and the crown 105 at positions separated from the boom head 51 in the axial direction of the boom 5. The auxiliary sheave device 10 is detachably attached to the boom head 51.

The auxiliary sheave device 10 includes an auxiliary sheave bracket 11, two auxiliary sheaves 12, an auxiliary sheave support shaft 13, and a pair of telescopic joints 20.

The auxiliary sheave bracket 11 supports the two auxiliary sheaves 12 so that the two auxiliary sheaves 12 can rotate around an axis parallel to the rotation axis of the boom 5. Then, the auxiliary sheave bracket 11 arranges the first rotation posture S1 in which the two auxiliary sheaves 12 are arranged at the first position P1 away from the boom head 51 in the direction along the axial direction of the boom 5, and the auxiliary sheave 12 is arranged. The boom head can take a second rotation posture S2 arranged at the second position P2 which is above the first position P1 and closer to the boom head 51 than the first position P1 in the direction along the axial direction of the boom 5. It is rotatably connected to 51 around an axis parallel to the rotation axis of the boom 5.

Specifically, as shown in FIG. 3, the auxiliary sheave bracket 11 has a pair of base end portions 11a and a pair of tip end portions 11b which are ends opposite to the base end portion 11a.

The pair of base end portions 11a of the auxiliary sheave bracket 11 are separately arranged on the left and right sides of the boom head 51, and are attached to both ends of the point sheave support shaft 53 projecting on the left and right sides of the boom head 51. Each base end portion 11a is rotatably and detachably attached to the end portion of the corresponding point sheave support shaft 53 around the axis of the point sheave support shaft 53.

The pair of tip portions 11b of the auxiliary sheave bracket 11 are separately arranged on the left and right outer sides of the two auxiliary sheaves 12, and support the two auxiliary sheaves 12 via the auxiliary sheave support shaft 13. Specifically, the auxiliary sheave support shaft 13 is erected on a pair of tip portions 11b of the auxiliary sheave bracket 11 in a posture extending parallel to the rotation axis of the boom 5, that is, a posture extending in the left-right direction. The two auxiliary sheaves 12 are attached so as to be rotatable around the axis of the auxiliary sheave support shaft 13 between a pair of tip portions 11b of the auxiliary sheave bracket 11. As a result, the pair of tip portions 11b of the auxiliary sheave bracket 11 can rotate the two auxiliary sheaves 12 around the axis of the auxiliary sheave support shaft 13 parallel to the rotation axis of the boom 5. Supports the sheave 12. Both ends (left and right ends) of the point sheave support shaft 53 in the axial direction project to the left and right outside of the pair of tip ends 11b of the auxiliary sheave bracket 11.

One of the two auxiliary sheaves 12 is for suspending the grab bucket 104 so as to be able to move up and down via the main winding rope 101, and the other auxiliary sheave 12 is suspended via the auxiliary winding rope 102. The crown 105 is suspended (see FIGS. 1 and 2). Specifically, the main winding rope 101 is hung from the one idler sheave 54 to the one auxiliary sheave 12, and the main winding rope 101 is hung from the one auxiliary sheave 12. Further, a supplementary winding rope 102 is hung from the other idler sheave 54 to the other auxiliary sheave 12, and the supplementary winding rope 102 is hung from the other auxiliary sheave 12. Then, the grab bucket 104 is connected to the hanging main winding rope 101, and the crown 105 is connected to the hanging auxiliary winding rope 102. As a result, the grab bucket 104 and the crown 105 are suspended from the auxiliary sheave 12.

The pair of telescopic joints 20 connect the boom head 51 and the auxiliary sheave bracket 11, and hold the auxiliary sheave bracket 11 in the first rotation posture S1 (see FIGS. 1 and 3) and the auxiliary sheave bracket 11. It is configured to be expandable and contractible so that it can take a contracted state (see FIGS. 2 and 4) kept in the second rotating posture S2. The pair of expansion joints 20 are separately arranged on the left and right sides of the boom head 51.

Each expansion joint 20 has a joint base 21, a link 22, a position fixing pin 24, and two restraints 30.

The joint base 21 is rotatably connected to the boom head 51 around an axis parallel to the rotation axis of the boom 5, and has a substantially square tubular shape in the first embodiment. The joint base 21 in the first embodiment is an example of the first member in the present invention. The joint base portion 21 has a base end portion 25 which is one end portion in the longitudinal direction thereof, and a tip end portion 26 which is an end portion opposite to the base end portion 25.

The base end portion 25 of the joint base portion 21 is attached to the end portion of the idler receive support shaft 55 protruding from the boom head 51 in the left-right direction. The base end portion 25 is rotatably attached to the end portion of the idler sheave support shaft 55 around the axis of the idler sheave support shaft 55. As a result, the base end portion 25 is rotatably connected to the boom head 51 via an idler receive support shaft 55 so as to be rotatable around an axis parallel to the rotation shaft of the boom 5. Further, the base end portion 25 is detachably attached to the end portion of the idler receive support shaft 55.

Further, the tip portion 26 of the joint base portion 21 is open in the longitudinal direction of the joint base portion 21.

As shown in FIGS. 6 to 9, the joint base portion 21 has a top plate 21a, a bottom plate 21b, and a pair of side plates 21c.

The top plate 21a and the bottom plate 21b are arranged parallel to each other and separated from each other in the vertical direction.

The pair of side plates 21c are arranged parallel to each other and separated from each other in the direction in which the rotation axis of the base end portion 25 (the axis of the idler receive support shaft 55) extends. The upper edge of the pair of side plates 21c is joined to the top plate 21a, and the lower edge of the pair of side plates 21c is joined to the bottom plate 21b to form a square tubular joint base 21.

Each of the pair of side plates 21c has one end portion constituting the base end portion 25 of the joint base portion 21. One end of each side plate 21c is provided with a shaft mounting hole 21d that penetrates the one end in the thickness direction of the side plate 21c. The end of the idler receive support shaft 55 protruding from the boom head 51 is inserted into each of the shaft mounting holes 21d of the pair of side plates 21c to prevent them from coming off, so that one end of the pair of side plates 21c, that is, the joint base 21 The base end portion 25 of the idler receive support shaft 55 is attached to the end portion of the idler receive support shaft 55.

Further, each of the pair of side plates 21c has an elongated hole 21e that penetrates the side plates 21c in the thickness direction. The elongated hole 21e is provided in the region between the shaft mounting hole 21d and the tip end portion 26 of the joint base portion 21, and extends along the longitudinal direction of the side plate 21c, that is, the longitudinal direction of the joint base portion 21. The extending direction of the elongated hole 21e corresponds to the advancing / retreating direction of the link 22 and the expanding / contracting direction of the telescopic joint 20. The guide pin 23 of the link 22, which will be described later, is inserted into the elongated hole 21e to guide the movement of the guide pin 23 as the link 22 moves back and forth with respect to the joint base 21.

Further, each of the pair of side plates 21c has a base pin hole 21f for inserting the position fixing pin 24. The base pin hole 21f is an example of the first member pin hole in the present invention. The base pin hole 21f is provided at a position of each side plate 21c separated from the elongated hole 21e toward the tip 26 of the joint base 21, and penetrates each side plate 21c in the thickness direction thereof.

Further, each of the pair of side plates 21c has an advance position contact portion 21k and a retract position contact portion 21m.

The advance position contact portion 21k defines one end of the elongated hole 21e of the link 22 in the advance direction described later, and when the link 22 is arranged at the advance position P3 described later, the guide pin 23 in the advance direction is defined. It is a portion that comes into contact with the guide pin 23 so as to prevent the movement of the guide pin 23. That is, the advance position contact portion 21k is the link 22 from the joint base 21 when the link 22 is arranged at the advance position P3 where the base pin hole 21f and the advance position pin hole 22c described later of the link 22 match. It abuts on the guide pin 23 of the link 22 so as to prevent movement in the advancing direction, and is an example of the advancing positioning portion in the present invention.

The retreat position contact portion 21m defines an end of the elongated hole 21e opposite to the one end, that is, the end of the elongated hole 21e in the retreat direction of the link 22 described later, and the link 22 retreats as described later. It is a portion that comes into contact with the guide pin 23 so as to prevent the guide pin 23 from moving in the retracting direction when it is arranged at the entry position P4. That is, the retreat position contact portion 21m enters the joint base 21 when the link 22 is arranged at the retreat position P4 where the base pin hole 21f and the retreat position pin hole 22d described later of the link 22 match. It abuts on the guide pin 23 of the link 22 so as to prevent the link 22 from moving in the retreat direction, and is an example of the retreat positioning unit in the present invention.

Further, one side plate 21c of the pair of side plates 21c has a plurality of restraint installation holes 21g which penetrate the one side plate 21c in the thickness direction and the restraint 30 is provided inside. In the first embodiment, one side plate 21c has two restraint installation holes 21g. The two restraint installation holes 21g are arranged at intervals in the longitudinal direction (axial direction of the joint base 21) of one side plate 21c. One of the two restraint installation holes 21g, the restraint installation hole 21g, is arranged between the elongated hole 21e and the base pin hole 21f, and the other restraint installation hole 21g is from the base pin hole 21f. Is also arranged near the tip of the joint base 21.

The link 22 is attached to the joint base 21 so as to be able to move forward and backward along the longitudinal direction of the joint base 21 between the advance position P3 (see FIG. 6) and the retract position (see FIG. 7), and the auxiliary sheave bracket. It is connected to 11 (see FIG. 5). The advance position P3 is a position where the expansion joint 20 is in the extended state, and a position where the link 22 greatly protrudes from the joint base 21. The retracted position P4 is a position where the expansion joint 20 is in the contracted state, and a position where the link 22 retracts into the joint base 21 from the advanced position P3. The link 22 in the first embodiment is an example of the second member in the present invention. The link 22 has a link body 29 and a guide pin 23.

The link main body 29 is an elongated plate-shaped member, and is inserted into the joint base 21 so as to be able to advance and retreat with respect to the joint base 21 along the longitudinal direction of the joint base 21. As shown in FIGS. 6 and 7, the link main body 29 has a base end portion 27 which is one end portion in the longitudinal direction thereof and is an end portion inserted into the joint base portion 21, and is opposite to the base end portion 27. It has a tip portion 28, which is the other end portion of the joint and is an end portion protruding from the joint base portion 21.

As shown in FIG. 3, the tip portion 28 is arranged outside the tip portion 11b of the auxiliary sheave bracket 11 in the left-right direction, and is connected to the tip portion 11b of the auxiliary sheave bracket 11 via the auxiliary sheave support shaft 13. There is. Specifically, as shown in FIG. 6, the tip 28 of the link main body 29 is provided with a mounting hole 22a that penetrates the tip 28 in the thickness direction thereof, and the auxiliary sheave bracket is provided in the mounting hole 22a. The end portion of the auxiliary sheave support shaft 13 (see FIG. 3) protruding outward in the left-right direction from the tip end portion 11b of 11 is inserted and prevented from coming off. As a result, the tip 28 of the link body 29 is connected to the tip 11b of the auxiliary sheave bracket 11 via the auxiliary sheave support shaft 13. The tip 28 of the link body 29 is rotatable about the axis of the auxiliary sheave support shaft 13. As a result, the link 22 is rotatable with respect to the auxiliary sheave bracket 11 around the axis of the auxiliary sheave support shaft 13.

Further, the link main body 29 has a guide pin mounting hole 22b, an advance position pin hole 22c, and a retract position pin hole 22d that penetrate the link main body 29 in the thickness direction thereof.

The guide pin mounting hole 22b is a hole through which the guide pin 23 is inserted and the guide pin 23 is mounted on the link main body 29. The guide pin mounting hole 22b is provided in the base end portion 27 of the link main body 29.

The advance position pin hole 22c is a hole through which the position fixing pin 24 is inserted together with the base pin hole 21f in order to fix the link 22 at the advance position P3 when the link 22 is arranged at the advance position P3. The advance position pin hole 22c is provided at a position of the link main body 29 away from the guide pin mounting hole 22b toward the tip portion 28. Specifically, the advance position pin hole 22c is provided at a position that matches the base pin hole 21f of the joint base portion 21 with the link 22 arranged at the advance position P3.

The retreat position pin hole 22d is a hole through which the position fixing pin 24 is inserted together with the base pin hole 21f in order to fix the link 22 at the retreat position P4 when the link 22 is arranged at the retreat position P4. .. The retracting position pin hole 22d is provided at a position between the mounting hole 22a and the advancing position pin hole 22c near the base end portion 27 of the link main body 29 with respect to the mounting hole 22a. Specifically, the retreat position pin hole 22d is provided at a position that matches the base pin hole 21f of the joint base 21 with the link 22 arranged at the retreat position P4.

The guide pin 23 guides the advance / retreat movement of the link 22 with respect to the joint base 21. Specifically, the guide pin 23 is inserted into the guide pin mounting hole 22b and attached to the link main body 29 as described above, and is also inserted into each elongated hole 21e of the pair of side plates 21c of the joint base 21. (See FIG. 8). Further, a pair of washers W are attached to the guide pin 23 on both outer sides of the pair of side plates 21c of the joint base portion 21. The guide pin 23 is prevented from coming off from each of the elongated holes 21e of the pair of side plates 21c and the guide pin mounting holes 22b of the link main body 29. The guide pin 23 is inserted into the elongated hole 21e so as to be movable along the advancing / retreating direction of the link 22, that is, the longitudinal direction of the elongated hole 21e. As a result, the link 22 has a joint base 21 between the advance position P3 where the guide pin 23 abuts on the advance position contact portion 21k and the retreat position P4 where the guide pin 23 abuts on the retract position contact portion 21m. It is possible to move forward and backward.

The position fixing pin 24 is used to fix the position of the link 22 with respect to the joint base 21 in the advancing / retreating direction. When the link 22 is arranged at the advance position P3, the position fixing pin 24 is inserted into the respective base pin holes 21f of the pair of side plates 21c of the joint base 21 and the advance position pin holes 22c of the link body 29 to prevent them from coming off. The link 22 is thereby fixed at the advance position P3. Further, when the link 22 is arranged at the retreat position P4, the position fixing pin 24 is inserted into the respective base pin holes 21f of the pair of side plates 21c of the joint base 21 and the retreat position pin holes 22d of the link main body 29. The link 22 is fixed at the entry / exit position P4.

The two restraints 30 are provided at the joint base 21, and the link 22 intersects the advancing / retreating direction of the link 22 in a state where the link 22 is arranged at each of the advancing position P3 and the retracting position P4 (in the first embodiment). The link body 29 is pressed down in the left-right direction) to restrain the movement of the link 22 with respect to the joint base 21 in the crossing direction. The two restraints 30 are installed in the two restraint installation holes 21g, respectively. Each restraint 30 has a case 31, a pad 32, a bolt 34, and a locknut 35, as shown in FIG.

The case 31 is provided at the joint base 21 and surrounds an internal space extending in the intersecting direction. The case 31 has a case body 31a and a lid member 31b.

The case body 31a is tubular and is fitted and fixed in the restraint installation hole 21g. The case body 31a is arranged in a posture in which its axial direction extends in the crossing direction.

The lid member 31b is attached to an end portion of the case body 31a located outside in the crossing direction among both ends in the axial direction to close the opening of the end portion. The lid member 31b has a disk shape and has a screw hole 31c at the center thereof that penetrates the lid member 31b in the crossing direction.

The pad 32 comes into contact with and presses the link main body 29 in order to press the link main body 29. The pad 32 has a columnar shape and is made of steel. The pad 32 is installed in the internal space of the case 31 so as to be detachable from the link main body 29 along the crossing direction.

The bolt 34 is a member for pressing the pad 32 against the link main body 29 along the crossing direction, and is an example of the pressing member in the present invention. The bolt 34 is screwed into the screw hole 31c from the outside of the case 31 and screwed into the screw hole 31c so as to be able to advance and retreat in the crossing direction. When the bolt 34 is tightened, the bolt 34 presses the pad 32 against the side surface of the link body 29 at its tip, thereby causing the pad 32 to have a joint base 21 on the opposite side of the pad 32. The link main body 29 is sandwiched between the side plate 21c and the link main body 29 to restrain the movement of the link main body 29.

The locknut 35 is screwed onto the bolt 34 on the outside of the case 31 to prevent the bolt 34 from being loosened.

Next, a method of changing the position of the auxiliary sheave 12 with respect to the boom head 51 in the crane 100 according to the first embodiment will be described. Specifically, as shown in FIG. 2, when working at a site where there is an obstacle 200 such as a bridge girder above the boom 5, the auxiliary sheave 12 is located near the height position of the point sheave 52. If there is, the work lift of the grab bucket 104 cannot be sufficiently secured, and the civil engineering work by the grab bucket 104 becomes difficult. Therefore, the position of the auxiliary sheave 12 with respect to the boom head 51 is changed from the first position P1 to the second position P2. ..

At this time, the locknut 35 of each restraint 30 is loosened and the bolt 34 is loosened, thereby releasing the pressure of the pad 32 on the link 22. That is, the restraint of the link 22 by each restraint 30 is released. Then, the auxiliary sheave bracket 11 is suspended and supported by the auxiliary crane, and the position fixing pin 24 is pulled out from the advance position pin hole 22c and the base pin hole 21f.

After that, the auxiliary sheave bracket 11 is lifted by the auxiliary crane until the link 22 moves from the advance position P3 to the retreat position P4 and the guide pin 23 abuts on the retreat position contact portion 21 m. At this time, the auxiliary sheave bracket 11 rotates from the first rotation posture S1 to the second rotation posture S2, and the auxiliary sheave 12 moves from the first position P1 to the second position P2 with respect to the boom head 51.

In a state where the link 22 is arranged at the retreat position P4 and the guide pin 23 is in contact with the retreat position contact portion 21 m, the base pin hole 21f and the retreat position pin hole 22d are aligned with each other. The position fixing pin 24 is inserted into the pin hole 21f and the retracting position pin hole 22d. As a result, the link 22 is fixed at the retracting position P4, the expansion joint 20 is fixed in the contracted state, and the auxiliary sheave bracket 11 is held in the second rotation posture S2. As a result, the position of the auxiliary sheave 12 with respect to the boom head 51 is held at the second position P2.

After that, the bolts 34 of each restraint 30 are tightened to press the pad 32 against the link body 29, thereby restraining the movement of the link 22. Then, the locknut 35 is tightened to prevent the bolt 34 from loosening.

As described above, the work of changing the position of the auxiliary sheave 12 with respect to the boom head 51 from the first position P1 to the second position P2 is performed.

In the crane 100 according to the first embodiment, the moving range of the advancing / retreating method of the link 22 is restricted between the advancing position P3 and the retreating position P4 by the advancing position contact portion 21k and the retreating position contact portion 21m. In addition, since the position fixing pin 24 can be inserted into the corresponding pin hole at the advance position P3 and the retract position P4 at both ends of the moving range, the work load required for aligning the pin holes can be reduced. The work of changing the position of the auxiliary sheave 12 with respect to the boom head 51 can be facilitated.

Specifically, in the crane 100 according to the first embodiment, the auxiliary sheave bracket 11 is rotated from the first rotation posture S1 to the second rotation in order to change the position of the auxiliary sheave 12 from the first position P1 to the second position P2. When the link 22 is moved from the advance position P3 to the retract position P4 with respect to the joint base 21 in order to rotate to the posture S2, the retract position contact portion 21 m abuts on the guide pin 23 of the link 22 and the link 22 comes into contact with the guide pin 23. It is positioned at the retreat position P4, and the base pin hole 21f and the retreat position pin hole 22d match. Further, in order to change the position of the auxiliary sheave 12 from the second position P2 to the first position P1, the link 22 is connected to the joint base so as to rotate the auxiliary sheave bracket 11 from the second rotation posture S2 to the first rotation posture S1. When moving from the retreat position P4 to the advance position P3 with respect to 21, the advance position contact portion 21k abuts on the guide pin 23 of the link 22 and the link 22 is positioned at the advance position P3, and advances to the base pin hole 21f. It matches the position pin hole 22c. Therefore, in the crane 100 according to the first embodiment, the operator can align the base pin hole 21f and the advance position pin hole 22c and the base pin hole 21f in the vicinity of the boom head 51, which is relatively high and difficult to work with. It is not necessary to align the link 22 with the retracting position pin hole 22d in an unstable state with respect to the joint base 21, and the alignment and the base of the base pin hole 21f and the retracting position pin hole 22d. It is possible to reduce the work load required for aligning the pin hole 21f and the advance position pin hole 22c. As a result, it is possible to facilitate the work of changing the position of the auxiliary sheave 12 with respect to the boom head 51.

Further, in the crane 100 according to the first embodiment, in a state where the links 22 are arranged at the advance position P3 and the retract position P4, the crossing direction (left-right direction) intersecting the advance / retreat direction of the link 22 by the restraint 30. ), The link 22 can be pressed to restrain the movement of the link 22 with respect to the joint base 21 in the crossing direction. Therefore, it is possible to prevent noise due to collision between the link 22 and the joint base 21 in a state where the link 22 is arranged at each of the advance position P3 and the retract position P4. Specifically, vibration is generated during work by the grab bucket 104, and the vibration is transmitted to the link 22. At this time, if the link 22 is in a state where it can move in the crossing direction, the link 22 is in the crossing direction. It vibrates and collides with the joint base 21, and noise is generated. On the other hand, in the crane 100 according to the first embodiment, the movement of the link 22 in the crossing direction can be restrained by the restraint 30 in a state where the link 22 is arranged at each of the advance position P3 and the retract position P4. It is possible to prevent noise from being generated due to the collision between the link 22 and the joint base 21.

Further, in the crane 100 according to the first embodiment, by pressing the link main body 29 in the crossing direction by the restraint 30, the crossing is applied to the link main body 29 when a compressive load is applied to the link main body 29 in the direction along the advancing / retreating direction of the link 22. It is possible to prevent buckling in the direction from occurring in the link body 29.

Further, the restraint 30 has a pad 32 installed in the internal space of the case 31 so as to be detachable from the link main body 29 along the crossing direction, and the pad 32 with respect to the link main body 29 along the crossing direction. Since the link body 29 is pressed by the pad 32, the link body 29 can be pressed by the pad 32 with a wider contact area than when the link body 29 is directly pressed by the tip of the bolt 34 without using the pad 32, for example. Therefore, the stability of the restraint of the link 22 can be improved.

Further, in the first embodiment, the two restraints 30 are provided at two different locations along the advancing / retreating direction of the link 22 at the joint base 21. Therefore, the two restraints 30 can restrain the movement of the link 22 in the crossing direction over a wider range in the direction along the advancing / retreating direction of the link 22, and the noise caused by the collision between the link main body 29 and the joint base 21 can be suppressed. The effect of preventing the occurrence can be further improved. Further, since the link 22 can be pressed in the crossing direction over a wider range in the direction along the advancing / retreating direction of the link 22 by the two restraints 30, the compressive load in the direction along the advancing / retreating direction is applied to the link main body 29. When applied, it is possible to suppress the occurrence of buckling of the link main body 29 in the crossing direction over a wider range in the direction along the advancing / retreating direction.

(Second Embodiment)
Next, the configuration of the crane 100 according to the second embodiment of the present invention will be described with reference to FIGS. 10 to 12.

The crane 100 according to the second embodiment differs from the crane 100 according to the first embodiment only in the configuration of the telescopic joint 20, and in the telescopic joint 20 according to the second embodiment, the link 22 has an elongated hole 22e. The joint base 21 has a guide pin 23 to be inserted into the elongated hole 22e.

Specifically, in the second embodiment, the elongated hole 22e of the link 22 extends in the advancing / retreating direction of the link 22 with respect to the joint base 21, that is, in the longitudinal direction of the link 22, and the link 22 is extended in the thickness direction (horizontal direction). It penetrates. Further, as shown in FIGS. 10 and 11, the link 22 has a link pin hole 22f provided at the base end portion 27 and penetrating the base end portion 27 in the thickness direction of the link 22. In the second embodiment, the link 22 is an example of the first member pin hole in the present invention, and the link pin hole 22f is an example of the first member pin hole in the present invention.

Further, the link 22 defines an advancing side portion 22g that defines one end of the elongated hole 22e in the advancing direction of the link 22 and a retreating portion that defines the other end of the elongated hole 22e in the retracting direction of the link 22. It has an entry side portion 22h and.

Further, in the second embodiment, the joint base 21 is an example of the second member in the present invention. The joint base 21 of the second embodiment has a substantially square tubular joint base main body 21p similar to the joint base 21 of the first embodiment, and a guide pin 23 provided on the joint base main body 21p. ..

The joint base body 21p has a pair of side plates 21c similar to the pair of side plates 21c of the joint base 21 of the first embodiment. However, the elongated holes 21e are not provided in the pair of side plates 21c of the joint base body 21p. Further, in the tip portion 26 of the joint base main body 21p, guide pin mounting holes 21h are provided in the pair of side plates 21c, respectively. The guide pin mounting hole 21h penetrates each side plate 21c in the thickness direction thereof. The guide pins 23 are inserted into the guide pin mounting holes 21h of the pair of side plates 21c and the elongated holes 22e of the link 22 to prevent them from coming off.

The guide pin 23 is inserted into the elongated hole 22e of the link 22 so as to be relatively movable with respect to the link 22 along the advancing / retreating direction of the link 22 (longitudinal direction of the elongated hole 22e). Then, the guide pin 23 abuts on the retreat side portion 22h of the link 22 so as to prevent the link 22 from moving in the advancing direction when the link 22 is arranged at the advancing position P3 (see FIG. 10). On the other hand, when the link 22 is arranged at the retreat position P4 (see FIG. 11), it comes into contact with the advance side portion 22g of the link 22 so as to prevent the link 22 from moving in the retreat direction. The guide pin 23 in the second embodiment is an example of the advance positioning unit and the retractable positioning unit in the present invention.

Further, each of the pair of side plates 21c of the joint base 21 is provided with an advance position pin hole 21i and an advance position pin hole 21j. The advance position pin hole 21i and the retract position pin hole 21j penetrate each side plate 21c in the thickness direction thereof. The advance position pin hole 21i is provided at a position where the link 22 is arranged at the advance position P3 and coincides with the link pin hole 22f in a state where the entry / exit side portion 22h is in contact with the guide pin 23. Further, the retreat position pin hole 21j is provided at a position where the link 22 is arranged at the retreat position P4 and coincides with the link pin hole 22f in a state where the advance side portion 22g is in contact with the guide pin 23.

Then, with the link 22 arranged at the advance position P3, the position fixing pin 24 is inserted into the link pin hole 22f and the advance position pin hole 21i, so that the link 22 is fixed at the advance position P3 and the link 22 retracts. The link 22 is fixed to the entry / exit position P4 by inserting the position fixing pin 24 into the link pin hole 22f and the entry / exit position pin hole 21j while being arranged at the entry position P4.

Further, in the second embodiment, the diameter of the pad 32 of the restraint 30 (see FIG. 12) of the telescopic joint 20 is larger than the diameter of the pad 32 of the restraint 30 of the first embodiment. This is because, in the second embodiment, since the long hole 22e is provided in the link 22, the pad 32 extends over both outer sides of the long hole 22e in the width direction orthogonal to the longitudinal direction of the long hole 22e. This is so that 22 can be suppressed.

The configuration other than the above configuration of the crane 100 according to the second embodiment is the same as that of the crane 100 according to the first embodiment.

In this second embodiment, the same effect as that of the first embodiment can be obtained.

(Third Embodiment)
Next, the configuration of the crane 100 according to the third embodiment of the present invention will be described with reference to FIGS. 13 to 15.

In the crane 100 according to the third embodiment, only the configuration of the expansion joint 20 is different from the crane 100 according to the first embodiment. The basic configuration of the expansion joint 20 of the third embodiment is the same as that of the expansion joint 20 of the second embodiment, but in the third embodiment, the restraint 30 is the top plate 21a and the bottom plate of the joint base 21. It is provided in 21b, and is different from the expansion joint 20 of the second embodiment in that respect.

Specifically, in the third embodiment, as shown in FIGS. 13 and 14, restraints 30 are provided on the top plate 21a and the bottom plate 21b at two positions separated in the longitudinal direction of the joint base 21, respectively. There is. A screw hole 21s (see FIG. 15) that penetrates the top plate 21a in the thickness direction is provided at a portion of the top plate 21a where the restraint 30 is provided. Further, a screw hole 21t (see FIG. 15) that penetrates the bottom plate 21b in the thickness direction is also provided in a portion of the bottom plate 21b where the restraint 30 is provided.

Each restraint 30 has a bolt 34 and a locknut 35.

The bolt 34 of the restraint 30 provided on the top plate 21a is screwed into the screw hole 21s of the top plate 21a from the outside of the joint base 21, and the link 22 is pressed by the tip thereof. In this state, the lock nut 35 screwed into the bolt 34 prevents the bolt 34 from loosening, and the state in which the bolt 34 presses the link 22 is maintained.

The bolt 34 of the restraint 30 provided on the bottom plate 21b is screwed into the screw hole 21t of the bottom plate 21b from the outside opposite to the bolt 34 of the restraint 30 provided on the top plate 21a, and the link 22 is screwed at the tip thereof. Press. In this state, the lock nut 35 screwed into the bolt 34 prevents the bolt 34 from loosening in the same manner, and the state in which the bolt 34 presses the link 22 is maintained.

Therefore, in the third embodiment, the restraint 30 provided on the top plate 21a and the restraint 30 provided on the bottom plate 21b are used to both sides of the link 22 in a direction orthogonal to both the advancing / retreating direction and the left-right direction. The movement of the link 22 is restrained from the above.

The configuration other than the above configuration of the crane 100 according to the third embodiment is the same as that of the crane 100 according to the first embodiment.

In the third embodiment, the restraint 30 can firmly restrain the movement of the link 22 in the orthogonal direction orthogonal to both the advancing / retreating direction and the left-right direction. Therefore, the link 22 collides with the top plate 21a or the bottom plate 21b due to the movement of the link 22 in the orthogonal direction, rattling in a minute gap between the guide pin 23 and the inner surface of the elongated hole 22e, and the position. It is possible to prevent rattling in a minute gap between the fixing pin 24 and the inner surface of the link pin hole 22f. Further, in the third embodiment, the restraint of the link 22 by the restraining tool 30 is restrained from the orthogonal direction, but the movement of the link 22 in the left-right direction is also restrained by the tightening by the bolt 34 from the orthogonal direction. It is also possible to prevent the link 22 from colliding with the side plate 21c of the joint base 21 due to the movement of the link 22 in the left-right direction. Therefore, in the third embodiment, it is possible to more effectively prevent the generation of noise due to the collision and the rattling.

In the configuration of the third embodiment, it may be installed on only one of the top plate 21a and the bottom plate 21b of the joint base 21.

(Fourth Embodiment)
Next, the configuration of the crane 100 according to the fourth embodiment of the present invention will be described with reference to FIGS. 16 to 21.

In the crane 100 according to the fourth embodiment, only the configuration of the expansion joint 20 is different from the crane 100 according to the first embodiment. In the fourth embodiment, one of the pair of side plates 21c of the joint base 21 of the expansion joint 20 is separated from the joint base 21, and the link 22 is pressed by the pressing side plate 21w, which is the separated side plate. It is designed to restrain the movement of 22.

Specifically, in the fourth embodiment, the joint base portion 21 has a shape that is opened in one of the left-right directions by the top plate 21a, the bottom plate 21b, and the side plate 21c (see FIGS. 20 and 21). The link 22 is inserted into a space surrounded by the top plate 21a, the bottom plate 21b, and the side plate 21c of the joint base 21.

Then, in the fourth embodiment, the restraint 30 that restrains the movement of the link 22 has a pressing side plate 21w, a guide fastener 71, and a position fixing fastener 72.

The pressing side plate 21w has the same configuration as the side plate 21c of the joint base 21. The pressing side plate 21w is provided with a shaft insertion hole (not shown) at a base end portion 25a, which is one end portion in the longitudinal direction thereof. The idler sheave support shaft 55 is inserted into the shaft insertion hole so that the pressing side plate 21w can move with respect to the idler sheave support shaft 55 in the axial direction thereof. Further, the pressing side plate 21w is rotatable around the center of the idler receive support shaft 55. The pressing side plate 21w is fitted into one opening of the joint base 21 in the left-right direction.

The guide fastener 71 is a fastener for pressing the pressing side plate 21w against the link 22 in the direction along the left-right direction. Further, the guide fastener 71 also has a function of guiding the advance / retreat movement of the link 22. The guide fastener 71 has a bolt pin 71a, two nuts 71b, and a washer 71c.

The bolt pin 71a is inserted into the elongated hole 21e of the side plate 21c of the joint base 21, the elongated hole 21e of the pressing side plate 21w, and the guide pin mounting hole 22b of the link 22, and can move in the elongated hole 21e along the longitudinal direction thereof. It functions as a guide pin. The bolt pin 71a has a screw portion 71d from its tip to an intermediate portion.

The two nuts 71b are screwed and tightened to the screw portion 71d of the bolt pin 71a to press the pressing side plate 21w against the link 22 in the left-right direction and restrain the movement of the link 22. When moving the link 22 forward and backward, the two nuts 71b are loosened to release the pressure, and the restraint of the link 22 is released so that the link 22 can be moved forward and backward.

The washer 71c is attached around the bolt pin 71a between the nut 71b and the pressing side plate 21w.

Further, in the fourth embodiment, the link 22 has a guide pin 23 similar to the guide pin 23 in the first embodiment, and the guide pin 23 is a side plate 21c of the joint base 21 and a pressing side plate 21w. Each elongated hole 21e is movably inserted in the longitudinal direction of the elongated hole 21e. The guide pin 23 and the bolt pin 71a of the guide fastener 71 guide the advance / retreat movement of the link 22.

The position fixing fastener 72, together with the guide fastener 71, is a fastener for pressing the pressing side plate 21w against the link 22 in the direction along the left-right direction. Further, the position fixing fastener 72 also has a function of fixing the position of the link 22 with respect to the joint base 21 in the advancing / retreating direction at the advancing position P3 and the retreating position P4. The position fixing fastener 72 has a bolt pin 72a, a nut 72b, and a washer 72c.

The bolt pin 72a is inserted into the base pin hole 21f and the advance position pin hole 22c when the link 22 is arranged at the advance position P3 (see FIGS. 16 and 17), and fixes the link 22 at the advance position P3. When the link 22 is arranged at the retreat position P4 (see FIGS. 18 and 19), the link 22 is inserted into the base pin hole 21f and the retreat position pin hole 22d to fix the link 22 at the retreat position P4. In this way, the bolt pin 72a functions as a position fixing pin. The bolt pin 72a has a screw portion 72d from its tip to an intermediate portion.

The nut 72b is screwed and tightened to the screw portion 72d of the bolt pin 72a to press the pressing side plate 21w against the link 22 in the left-right direction and restrain the movement of the link 22.

The washer 72c is attached around the bolt pin 72a between the nut 72b and the pressing side plate 21w.

The configuration other than the above configuration of the crane 100 according to the fourth embodiment is the same as that of the crane 100 according to the first embodiment.

(Fifth Embodiment)
Next, the configuration of the crane 100 according to the fifth embodiment of the present invention will be described with reference to FIGS. 22 to 28.

In the fifth embodiment, the boom head 51 abuts on the link 22 so as to prevent the link 22 from moving to the joint base 21 in the retreat direction when the link 22 is arranged at the retreat position P4. It has a positioning portion 51a (see FIG. 24), and the joint base 21 hits the link 22 so as to prevent the link 22 from moving from the joint base 21 in the advancing direction when the link 22 is arranged at the advancing position P3. It has an advance positioning unit 21u (see FIGS. 22 and 23) that is in contact with it.

Specifically, the joint base portion 21 has a side plate 21c, a top plate 21a, a bottom plate 21b, and an end side plate 21v. The side plate 21c extends over the entire longitudinal direction of the joint base 21, and the base end thereof is attached to the upper end of the boom head 51. In the fifth embodiment, the base end portion of the side plate 21c is not attached to the idler receive support shaft 55, and the upper end portion of the boom head 51 protrudes from the idler receive 54 in the axial direction of the boom 5. It is rotatably attached around an axis extending parallel to the rotation axis of the boom 5. The retractable positioning portion 51a of the boom head 51 is a portion near a portion where the base end portion (base end portion 25 of the joint base portion 21) of the side plate 21c is attached.

In the fifth embodiment, the top plate 21a and the bottom plate 21b are provided only in the vicinity of the tip portion 26 of the joint base portion 21, as shown in FIGS. 23 to 25. The end side plate 21v is provided only on the tip portion 26 of the joint base portion 21, and the length of the joint base portion 21 in the longitudinal direction is smaller than that of the top plate 21a and the bottom plate 21b. The end side plate 21v is arranged in parallel with the side plate 21c. Only the tip portion 26 of the joint base portion 21 is formed in a square tube shape by the top plate 21a, the bottom plate 21b, the side plate 21c, and the end side plate 21v. In the range where the top plate 21a and the bottom plate 21b are provided closer to the base end portion 25 with respect to the tip end portion 26, the joint base portion 21 has a shape in which one side is open in the left-right direction. In the range of the side plates 21c where the top plate 21a and the bottom plate 21b are provided, two base pin holes 21f (see FIG. 27) are provided side by side at intervals in the longitudinal direction of the joint base 21.

Of the top plate 21a and the bottom plate 21b, the end portion of the joint base portion 21 near the base end portion 25 is the advance positioning portion 21u (see FIGS. 24 and 25). As shown in FIGS. 22 and 23, the advance positioning portion 21u comes into contact with the base end contact portion 27a provided at the base end portion 27 of the link 22 when the link 22 is arranged at the advance position P3. .. The base end contact portion 27a of the link 22 is a pair of plate-like portions of the base end portion 27 of the link 22 protruding from both end edges in the width direction orthogonal to the longitudinal direction of the link 22 toward the side plate 21c of the joint base portion 21. It consists of parts. When the link 22 is arranged at the advance position P3, the base end contact portion 27a contacts the advance positioning portion 21u of the joint base 21 in the advance direction of the link 22, and the link 22 comes into contact with the retract position P4 (FIG. 24). When arranged in (see), it comes into contact with the retracting positioning portion 51a of the boom head 51 in the retracting direction of the link 22.

The link 22 is provided with two advance position pin holes 22c (see FIG. 24) and two retract position pin holes 22d (see FIG. 22). The two advance position pin holes 22c are provided at positions closer to the base end portion 27 of the link 22, and are arranged side by side at intervals in the longitudinal direction of the link 22. Further, the two retracting position pin holes 22d are provided at positions closer to the tip end portion 28 of the link 22, and are arranged side by side at intervals in the longitudinal direction of the link 22. The two advance position pin holes 22c are provided at positions that match the two base pin holes 21f when the link 22 is arranged at the advance position P3, and the two entry position pin holes 22d have the link 22 at the entry position P4. It is provided at a position that matches the two base pin holes 21f when arranged in.

Further, in the fifth embodiment, the expansion joint 20 has two sets of position fixing fasteners 72.

The position fixing fastener 72 is for fastening the joint base 21 and the link 22 in order to fix the position of the link 22 with respect to the joint base 21 in the advancing / retreating direction at the advancing position P3 and the retreating position P4. Further, the position fixing fastener 72 also has a function as a restraint that restrains the movement of the link 22 in the left-right direction by fixing the link 22 in a state of being pressed against the side plate 21c of the joint base 21 in the direction along the left-right direction. ing. The two sets of position fixing fasteners 72 each have a bolt pin 72a, two nuts 72b, and a washer 72c (see FIG. 27).

The bolt pins 72a of the two sets of position fixing fasteners 72 are inserted into the advance position pin holes 22c corresponding to each of the two base pin holes 21f when the link 22 is arranged at the advance position P3, and the link 22 is inserted. Is fixed at the advance position P3. Further, the bolt pins 72a of the two sets of position fixing fasteners 72 are inserted into the retreat position pin holes 22d corresponding to each of the two base pin holes 21f when the link 22 is arranged at the retreat position P4. The link 22 is fixed at the retreat position P4. In this way, the bolt pin 72a functions as a position fixing pin. The bolt pin 72a has a screw portion 72d from its tip to an intermediate portion.

The two nuts 72b are screwed and tightened to the screw portion 72d of the bolt pin 72a to press the link 22 against the side plate 21c of the joint base 21 in the left-right direction, thereby restraining the movement of the link 22 in the left-right direction. At the same time, the movement of the link 22 in the advancing / retreating direction is also restrained.

The washer 72c is attached around the bolt pin 71a between the nut 72b and the pressing side plate 21w.

The configuration other than the above configuration of the crane 100 according to the fifth embodiment is the same as that of the crane 100 according to the first embodiment.

(Sixth Embodiment)
Next, the configuration of the crane 100 according to the sixth embodiment of the present invention will be described with reference to FIGS. 29 to 33.

In the sixth embodiment, the expansion joint 20 presses the link 22 with the pressing side plate 21w to restrain the movement of the link 22, as in the fourth embodiment. Then, in the sixth embodiment, the guide pin 23 is omitted, and only the bolt pin 71a of the guide fastener 71 is inserted into the elongated hole 21e to guide the forward / backward movement of the link 22.

Specifically, in the sixth embodiment, the joint base portion 21 has a shape that is opened in one of the left-right directions by the top plate 21a, the bottom plate 21b, and the side plate 21c (see FIG. 33). The link 22 is inserted into a space surrounded by the top plate 21a, the bottom plate 21b, and the side plate 21c of the joint base 21.

Then, in the sixth embodiment, the restraint 30 that restrains the movement of the link 22 has a pressing side plate 21w, a guide fastener 71, and a position fixing fastener 72.

The pressing side plate 21w has the same configuration as the side plate 21c of the joint base 21. The pressing side plate 21w is provided with a shaft insertion hole (not shown) at a base end portion 25a, which is one end portion in the longitudinal direction thereof. The idler sheave support shaft 55 is inserted into the shaft insertion hole so that the pressing side plate 21w can move with respect to the idler sheave support shaft 55 in the axial direction thereof. Further, the pressing side plate 21w is rotatable around the center of the idler receive support shaft 55. The pressing side plate 21w is fitted into one opening of the joint base 21 in the left-right direction.

The guide fastener 71 is a fastener for pressing the pressing side plate 21w against the link 22 in the direction along the left-right direction. Further, the guide fastener 71 also has a function of guiding the advance / retreat movement of the link 22. The guide fastener 71 has a bolt pin 71a, two nuts 71b, and a washer 71c.

The bolt pin 71a is inserted into the elongated hole 21e of the side plate 21c of the joint base 21, the elongated hole 21e of the pressing side plate 21w, and the guide pin mounting hole 22b of the link 22, and can move in the elongated hole 21e along the longitudinal direction thereof. It functions as a guide pin. The bolt pin 71a has a screw portion 71d from its tip to an intermediate portion.

The two nuts 71b are screwed and tightened to the screw portion 71d of the bolt pin 71a to press the pressing side plate 21w against the link 22 in the left-right direction and restrain the movement of the link 22. When moving the link 22 forward and backward, the two nuts 71b are loosened to release the pressure, and the restraint of the link 22 is released so that the link 22 can be moved forward and backward.

The washer 71c is attached around the bolt pin 71a between the nut 71b and the pressing side plate 21w.

The position fixing fastener 72, together with the guide fastener 71, is a fastener for pressing the pressing side plate 21w against the link 22 in the direction along the left-right direction. Further, the position fixing fastener 72 also has a function of fixing the position of the link 22 with respect to the joint base 21 in the advancing / retreating direction at the advancing position P3 and the retreating position P4. The position fixing fastener 72 has a bolt pin 72a, two nuts 72b, and a washer 72c.

The bolt pin 72a is inserted into the base pin hole 21f and the advance position pin hole 22c when the link 22 is arranged at the advance position P3 (see FIGS. 29 and 30), and fixes the link 22 at the advance position P3. When the link 22 is arranged at the retreat position P4 (see FIGS. 31 and 32), the link 22 is inserted into the base pin hole 21f and the retreat position pin hole 22d to fix the link 22 at the retreat position P4. In this way, the bolt pin 72a functions as a position fixing pin. The bolt pin 72a has a screw portion 72d from its tip to an intermediate portion.

The two nuts 72b are screwed and tightened to the screw portion 72d of the bolt pin 72a to press the pressing side plate 21w against the link 22 in the left-right direction and restrain the movement of the link 22.

The washer 72c is attached around the bolt pin 71a between the nut 72b and the pressing side plate 21w.

The configuration other than the above configuration of the crane 100 according to the sixth embodiment is the same as that of the crane 100 according to the first embodiment.

(Modification example)
The crane according to the present invention is not necessarily limited to the one having the above-described configuration. As the configuration of the crane according to the present invention, for example, the following configuration can be adopted.

As shown in FIGS. 34 and 35, even if the expansion joint 20 has a cap 76 for preventing the bolt 34 of the restraint 30 from falling off and for preventing the wire rope from being caught on the bolt 34. good. FIG. 34 is a side view of the expansion joint 20 according to this modified example, and FIG. 35 is a cross-sectional view of the expansion joint 20 along the line XXXV-XXXV in FIG. 34.

In this variant, the telescopic joint 20 has two caps 76 that correspond to the two restraints 30. Further, in this modification, the expansion joint 20 has the same joint base 21, the link 22 and the two restraints 30 as the joint base 21, the link 22 and the two restraints 30 of the expansion joint 20 of the second embodiment. Have.

As shown in FIG. 35, each cap 76 is attached to the joint base 21 so as to surround a portion of the bolt 34 of the corresponding restraint 30 that protrudes from the outer surface of the joint base 21. In this modification, two upper screw seats 77 are provided at positions corresponding to each of the two restraints 30 on the top plate 21a of the joint base 21, and two restraints on the bottom plate 21b of the joint base 21. Two lower screw seats 78 are provided at positions corresponding to each of the thirty. Then, one end of the cap 76 is fastened to the upper screw seat 77 by a mounting bolt 79, and the other end of the cap 76 is fastened to the lower screw seat 78 by a mounting bolt 80. In this way, each cap 76 is attached to the joint base 21.

According to this modification, each cap 76 can prevent the bolt 34 of the corresponding restraint 30 from falling off, and the main winding rope 101 and the auxiliary winding rope 102 for suspending the grab bucket 104 and the crown 105 are the restraint 30. It is possible to prevent the bolt 34 from being caught in the bolt 34.

Further, the joint base 21 and the link 22 of the expansion joint 20 may both be cylindrical. FIG. 36 shows a cross section orthogonal to the expansion / contraction direction of the expansion / contraction joint 20 according to such a modification. In the expansion joint 20 according to this modification, the joint base 21 is made of a cylindrical outer pipe, and the link 22 is made of a cylindrical inner pipe inserted into the joint base 21.

Further, as shown in FIG. 36 of this modified example, the restraint 30 may be such that the bolt 34 comes into direct contact with the link 22 and restrains the movement of the link 22 with respect to the joint base 21. Specifically, the expansion joint 20 according to this modification includes a first restraint 30a and a second restraint 30b as restraints 30. The pipe wall of the joint base 21 is provided with a first restraint installation hole 81a and a second restraint installation hole 81b that penetrate the pipe wall in the radial direction, respectively. The first restraint 30a is installed in the first restraint installation hole 81a, and the second restraint 30b is installed in the second restraint installation hole 81b.

The first restraint 30a is a screw seat 36 that is inserted and fixed in the first restraint installation hole 81a, a bolt 34 that is screwed into the screw seat 36, and the bolt 34 for preventing loosening of the bolt 34. It has a locknut 35 screwed into a bolt 34. In the first restraint 30a, when the bolt 34 is tightened, the tip portion 34a of the bolt 34 comes into contact with the outer peripheral surface of the link 22 and presses the link 22, thereby restraining the movement of the link 22. It has become like.

The second restraint 30b is a screw seat 36 that is inserted and fixed in the second restraint installation hole 81b, a bolt 34 that is screwed into the screw seat 36, and the bolt 34 to prevent the bolt 34 from loosening. It has a locknut 35 screwed into a bolt 34. In the second restraint 30b, the tip portion 34a of the bolt 34 is tapered. Further, a tapered hole 22k is formed in a portion of the pipe wall of the link 22 corresponding to the tip end portion 34a of the bolt 34, which becomes smaller in diameter toward the inside in the radial direction of the link 22. Then, in the second restraint 30b, the tip portion 34a is press-fitted into the tapered hole 22k of the link 22 by tightening the bolt 34, thereby restraining the movement of the link 22. The hole of the link 22 into which the tip portion 34a of the bolt 34 is press-fitted may be a round hole having a uniform diameter in the radial direction of the link 22.

When the wall thickness of the pipe wall of the joint base 21 is large, the screw seat 36 of the first restraint 30a and the second restraint 30b is omitted, and the screw hole into which the bolt 34 is screwed is provided in the joint base 21. It may be formed on the tube wall.

Further, the link 22 may be a tubular member, and the joint base 21 may be a member inserted into the link 22 so as to be able to advance and retreat.

Further, the pad 32 may be made of something other than steel. For example, the pad 32 may be made of an elastic body. Examples of the material of the elastic body include rubber and elastic resin. Since the pad 32 is made of an elastic body, the vibration transmitted from the grab bucket 104 to the link 22 can be absorbed by the pad 32 between the link main body 29 and the joint base 21.

Further, the pad 32 may be made of a hard resin or a metal other than steel.

The lower traveling body 1 is not limited to the crawler traveling type, and may be a tire traveling type.

The boom 5 is not limited to the multi-stage telescopic box boom, and may be a lattice assembly type boom.

2 Upper swivel body (crane body)
5 Boom 10 Auxiliary sheave device 11 Auxiliary sheave bracket 12 Auxiliary sheave 20 Telescopic joint 21 Joint base 21e Long hole 21f Base pin hole (first member pin hole)
21k advance position contact part (advance positioning part)
21m retreat position contact part (retraction positioning part)
22 Link 22c Advance position pin hole 22d Exit position pin hole 22f Link pin hole (first member pin hole)
22g Advance side 22h Exit side 24 Position fixing pin 30 Restraint 31 Case 31c Screw hole 32 Pad 34 Bolt (pressing member)
51 Boom head 51a Retracting positioning part 76 Cap 100 Crane 101 Main winding rope (rope)
102 Supplementary winding rope (rope)
104 Grab bucket (working equipment)

Claims (8)

With the crane body
A boom that is rotatably attached to the crane body around a rotation axis extending in the left-right direction of the crane body and is undulating, and has a boom head that is a tip portion in the axial direction of the boom.
An auxiliary sheave device attached to the boom head so as to project from the boom head in the axial direction of the boom.
A work device suspended from the auxiliary sheave device is provided.
The auxiliary sheave device supports the auxiliary sheave that suspends the work device so as to be able to move up and down via a rope, and the auxiliary sheave so that the auxiliary sheave can rotate about an axis parallel to the rotation axis. A first rotation posture in which the auxiliary sheave is arranged at a first position away from the boom head in a direction along the axial direction of the boom and the auxiliary sheave above the first position and in the axial direction of the boom. The boom head can be rotated about an axis parallel to the rotation axis so that the boom head can take a second rotation posture arranged at a second position closer to the boom head than the first position in the direction along the above. An extended state in which the connected auxiliary sheave bracket, the boom head, and the auxiliary sheave bracket are connected to keep the auxiliary sheave bracket in the first rotation posture and a contraction in which the auxiliary sheave bracket is held in the second rotation posture. Has a telescopic joint, which is configured to be telescopic so that it can take a state and
The expansion joint is capable of advancing and retreating between a joint base connected to the boom head, an advance position where the expansion joint is in the extended state, and an retractable position where the expansion joint is in the contracted state. It has a link attached to the auxiliary sheave bracket and connected to the auxiliary sheave bracket, and a position fixing pin for fixing the position of the link in the advancing / retreating direction with respect to the joint base.
The joint base has an advance positioning portion that abuts on the link so as to prevent the link from moving in the advance direction from the joint base when the link is arranged at the advance position.
One of the boom head and the joint base abuts on the link so as to prevent the link from moving to the joint base in the retracting direction when the link is placed in the retracted position. It has an on-positioning part and
The advance positioning unit and the entry / exit positioning unit limit the movement range of the link in the advance / retreat direction between the advance position and the entry / exit position.
The first member, which is one of the joint base and the link, has a first member pin hole through which the position fixing pin is inserted.
The second member, which is the other member of the joint base and the link, has the position fixing pin together with the first member pin hole when the link is arranged at the advance position which is one end of the movement range. An advance position pin hole through which the position fixing pin is inserted and an entry / exit position pin through which the position fixing pin is inserted together with the first member pin hole when the link is arranged at the retracted position which is the other end of the moving range. A crane with holes. The joint base has an elongated hole extending along the advancing / retreating direction of the link with respect to the joint base.
The link has a guide pin inserted into the elongated hole so as to be movable along the advancing / retreating direction.
The joint base portion defines one end of the elongated hole in the advance direction of the link as the advance positioning portion of the guide pin in the advance direction when the link is arranged at the advance position. The link has an advance position contact portion that abuts on the guide pin so as to prevent movement, and defines an end opposite to the one end of the elongated hole as the retract positioning portion. The crane according to claim 1, further comprising an entry / exit position contact portion that abuts the guide pin so as to prevent the guide pin from moving in the entry direction when the crane is arranged at the entry position. The link has an elongated hole extending along the advancing / retreating direction of the link with respect to the joint base, and the advancing side portion defining one end of the elongated hole in the advancing direction of the link and the retreating direction of the link. Has an entry / exit side that defines the other end of the elongated hole in
The joint base is inserted into the elongated hole so as to be movable relative to the link along the advancing / retreating direction, and prevents the link from moving in the advancing direction when the link is arranged at the advancing position. A guide pin that abuts on the retreat side portion so as to abut on the advance side portion so as to prevent the link from moving in the retreat direction when the link is arranged at the retreat position. The crane according to claim 1, further comprising the advance positioning unit and the retractable positioning unit. The expansion joint is provided at the base of the joint, and the link is pressed in an intersecting direction intersecting the advancing / retreating direction of the link in a state where the link is arranged at each of the advancing position and the retracting position. The crane according to any one of claims 1 to 3, further comprising at least one restraint that constrains the movement of the link with respect to the base in the crossing direction. The restraint includes a case provided at the joint base and surrounding an internal space extending in the crossing direction, and a pad installed in the internal space of the case so as to be detachable from the link along the crossing direction. The crane according to claim 4, further comprising a pressing member that presses the pad against the link along the crossing direction. The crane according to claim 5, wherein the pad is made of an elastic body. The case has a screw hole extending in the crossing direction.
The pressing member is a bolt that is screwed into the screw hole so that it can move forward and backward along the crossing direction and protrudes from the outer surface of the joint base.
The crane according to claim 5 or 6, wherein the restraint further includes a cap attached to the joint base so as to surround a portion of the bolt protruding from the outer surface of the joint base. The crane according to any one of claims 4 to 7, wherein the at least one restraint includes a plurality of restraints provided at a plurality of different locations along the advancing / retreating direction of the link at the joint base.

Images