JP7275703B2 - front strut backstop - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front strut backstop that limits the pivoting range of the front strut of a crane.

In a crane in which a jib is attached to the tip of a boom so that it can be raised and lowered, a jib is attached to the tip of the boom, and struts (front strut and rear strut) that enable the jib to be raised and lowered are sometimes attached. In this strut installation work, it is necessary to repeat the raising and lowering of the strut by hanging the rope and installing the backstop, and there is a risk of interference with the strut, boom, jib, or between struts. Therefore, careful work was required, and the workability was not sufficient.
A rope for hoisting the jib is looped between the front strut and the rear strut. When this rope is wound by the jib hoisting winch, the front strut is pulled toward the rear strut and the rear strut is pulled. There is a risk of falling to the side, and more careful work was required in this work as well.

Here, Patent Document 1 discloses a crane in which a backstop is provided on the front strut.

JP 2014-43317 A

By the way, the backstop limits the rotation range of the hoisting member by coming into contact with the backstop receiver when the hoisting member such as the boom or jib tries to rotate beyond a predetermined range. However, if the backstop is short as in the prior art, the distance between the front (front) strut and the portion that fixes the backstop (the rear (rear) strut in the prior art) is extremely short. There is a possibility of interference with the rear strut. In addition, if the hoisting member or strut sways, or if the hoisting member or strut bends due to its long length, misalignment may occur between the backstop and the backstop support, causing the backstop to hit the backstop support. Since there is a risk that they will not come into contact with each other, there is a possibility that it will not be possible to restrict the rotation of the front strut.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a front strut backstop capable of reliably limiting the rotational range of the front strut.

The present invention provides a front strut backstop for a crane in which a front strut is attached to the tip of a boom so that it can be raised and lowered, the backstop body having one longitudinal end connected to the tip of the boom with a pin ; a link having one longitudinal end connected to the other longitudinal end of the backstop body with a pin and having the other longitudinal end connected to the front strut with a pin; an abutment portion with which the other longitudinal end portion of the backstop body abuts when the boom is raised at a predetermined angle or more; It is characterized in that the range of rotation of the front strut is restricted in a state in which the end portion abuts on the abutment portion.

According to the present invention, when the front strut is raised with respect to the boom by a predetermined angle or more, the other longitudinal end portion of the backstop body contacts the contact portion. Thereby, it becomes possible to limit the rotation range of the front strut by the backstop body. One longitudinal end of the backstop body is connected to the tip of the boom, and the other longitudinal end of the backstop body is connected to the front strut via a link. Therefore, even when the front strut is swayed laterally, the boom and the backstop main body or the front strut and the backstop main body are less likely to be displaced in the lateral direction. Therefore, the rotation range of the front strut can be reliably restricted by the backstop body.

1 is a side view of a luffing crane; FIG. FIG. 2 is an enlarged view of a main portion A of FIG. 1; 3 is an enlarged view of a main portion D of FIG. 2; FIG. It is an enlarged view of the longitudinal direction other end part of a backstop main body, (a) is a top view, (b) is a side view. FIG. 11 is a side view of the tip of the boom during the strut assembly operation; FIG. 6 is a side view of the tip of the boom in the strut assembly operation, showing the operation following FIG. 5; FIG. 7 is a side view of the tip portion of the boom during the strut assembly operation, showing the operation following FIG. 6 ; FIG. 8 is a side view of the tip portion of the boom in the strut assembly operation, showing the operation following FIG. 7; FIG. 9 is a side view of the tip portion of the boom in the strut assembly operation, showing the operation following FIG. 8; FIG. 10 is a side view of the tip portion of the boom during the strut assembly operation, showing the operation following FIG. 9; FIG. 11 is a side view of the tip portion of the boom in the strut assembly operation, showing the operation following FIG. 10; FIG. 12 is a side view of the tip portion of the boom during the strut assembly operation, showing the operation following FIG. 11; FIG. 13 is a side view of the tip portion of the boom during the strut assembly operation, showing the operation following FIG. 12; FIG. 14 is a side view of the tip portion of the boom in the strut assembly operation, showing the operation following FIG. 13; FIG. 10 is a side view of the tip of the boom during the jib assembly operation; FIG. 16 is a side view of the tip portion of the boom during the jib assembly operation, showing the operation following FIG. 15; It is an enlarged top view of the longitudinal direction other end part of the backstop main body in a modification.

Preferred embodiments of the present invention will be described below with reference to the drawings.

(Configuration of luffing crane)
A front strut backstop (backstop) 1 of the present embodiment is provided in a luffing crane, which is a working machine. As shown in FIG. 1, which is a side view of the luffing crane 10, the luffing crane 10 has a structure in which an upper revolving body 12 is rotatably mounted on a crawler-type lower traveling body 11. As shown in FIG. In addition, the luffing crane 10 may be a mobile crane using a moving means (for example, wheels) other than crawlers, or may be a fixed crane having no moving means. Further, the application target of the present invention is not limited to luffing cranes, and for example, it is possible to apply the present invention to tower cranes.

A luffing crane 10 includes an upper swing body 12 corresponding to a crane body, a lower traveling body 11 that rotatably supports the upper swing body 12, a hoisting member including a boom 14 and a jib 15, and a boom hoisting member. a mast 16; A counterweight 17 for adjusting the balance of the luffing crane 10 is loaded on the rear portion of the upper swing body 12 . A cab 13 is provided at the front end of the upper revolving body 12 . The cab 13 corresponds to the driver's seat of the luffing crane 10 .

The boom 14 is of a so-called lattice type, and is composed of a lower boom 14A, one or more (two in the example shown) intermediate booms 14B, and an upper boom 14C. Specifically, the lower boom 14A is connected to the front portion of the upper revolving body 12 so as to be rotatable in the up-and-down direction. The middle boom 14B is detachably added to the tip side of the lower boom 14A. The upper boom 14C is detachably added to the tip side of the intermediate boom 14B. A rear strut 18 and a front strut 19 for rotating the jib 15 as described later are rotatably connected to the tip of the upper boom 14C. The boom 14 is rotatably supported on the upper revolving body 12 with a boom foot pin 14s provided at the lower end as a fulcrum.

However, the specific structure of the boom is not limited in the present invention. For example, the boom may have no intermediate booms, or may have a different number of intermediate booms. Additionally, the boom may be constructed from a single piece.

The jib 15 is also of a so-called lattice type, and is composed of a lower jib 15A, one or more (one in the figure) intermediate jibs 15B, and an upper jib 15C. Specifically, the lower jib 15A is connected to the tip of the upper boom 14C so as to be rotatable in the undulating direction. The intermediate jib 15B is detachably added to the tip side of the lower jib 15A. The upper jib 15C is detachably added to the tip side of the intermediate jib 15B. The rotation center axis of the jib 15 is a horizontal axis parallel to the rotation center axis (boom foot pin 14 s ) of the boom 14 with respect to the upper swing body 12 .

The mast 16 has a base end and a rotating end, and the base end is rotatably connected to the upper revolving body 12 . The pivot axis of the mast 16 is parallel to the pivot axis of the boom 14 and positioned just behind the pivot axis of the boom 14 . That is, the mast 16 is rotatable in the same direction as the boom 14 is raised and lowered. On the other hand, the rotating end of the mast 16 is connected to the tip of the boom 14 via a pair of left and right boom guy lines 20 . This connection coordinates the rotation of the mast 16 and the rotation of the boom 14 .

A pair of left and right backstops 21 are provided on the upper revolving body 12 . These backstops 21 abut on both left and right sides of the lower boom 14A of the boom 14 when the boom 14 reaches the standing posture shown in FIG. This abutment prevents the boom 14 from being blown backward by strong wind or the like.

The rear strut 18 and the front strut 19 are rotatably supported at the tip of the boom 14 . The rear strut 18 is held in a posture protruding from the tip of the upper boom 14C toward the boom rising side (left side in FIG. 1). A pair of left and right backstops 22 and a pair of left and right guy links 23 are interposed between the rear strut 18 and the boom 14 as means for maintaining this posture. The backstop 22 is interposed between the upper boom 14C and the intermediate portion of the rear strut 18 and supports the rear strut 18 from below. The guy link 23 is stretched to connect the tip of the rear strut 18 and the lower boom 14A of the boom 14, and regulates the position of the rear strut 18 by its tension. Note that the rear strut 18 and the front strut 19 may be rotatably supported by the proximal end portion of the jib 15 . Alternatively, the rear strut 18 may be rotatably supported by the tip of the boom 14 , and the front strut 19 may be rotatably supported by the base of the jib 15 .

The front strut 19 is connected to the jib 15 so as to rotate (integrally) with the jib 15 . Specifically, a pair of left and right jib guy lines 24 are stretched so as to connect the front end of the front strut 19 and the front end of the jib 15 . Therefore, when the front strut 19 is driven to rotate, the jib 15 is also driven to rotate. The rear strut 18 described above is arranged behind the front strut 19 as shown in FIG.

Various winches are mounted on the luffing crane 10 . Specifically, a boom hoisting winch 25 for hoisting the boom 14, a jib hoisting winch 26 for rotating the jib 15 in the hoisting direction, and a main hoist for hoisting and lowering the suspended load. A hoisting winch 27 and an auxiliary hoisting winch 28 are mounted. In the luffing crane 10 according to this embodiment, the boom hoisting winch 25 is installed at a portion near the base end of the mast 16 . A jib hoisting winch 26 , a main hoisting winch 27 , and an auxiliary hoisting winch 28 are all installed on the lower boom 14 A of the boom 14 . These winches 25 , 26 , 27 , 28 may be mounted on the upper revolving body 12 .

The boom hoisting winch 25 winds up and lets out the boom hoisting rope 29 . The boom hoisting rope 29 is routed so that the mast 16 is rotated by this winding and unwinding. Specifically, sheave blocks 30 and 31 in which a plurality of sheaves are arranged in the width direction are provided at the rotating end of the mast 16 and the rear end of the upper revolving body 12, respectively. The drawn boom hoisting rope 29 is stretched between the sheave blocks 30 and 31 . Therefore, when the boom hoisting winch 25 winds up or feeds out the boom hoisting rope 29, the distance between the two sheave blocks 30 and 31 changes, thereby the mast 16 and the boom 14 interlocking therewith are moved. It rotates in the undulating direction.

The jib hoisting winch 26 winds up and lets out the jib hoisting rope 32 wound between the rear strut 18 and the front strut 19 . The jib hoisting rope 32 is routed so that the front strut 19 rotates by winding and unrolling. Specifically, a guide sheave 33 is provided on the upper boom 14C of the boom 14, and a plurality of sheaves are arranged in the width direction at the rotating end of the rear strut 18 and the rotating end of the front strut 19, respectively. Sheave blocks 34, 35 are provided. A jib hoisting rope 32 pulled out from a jib hoisting winch 26 is hung on a guide sheave 33 and stretched between sheave blocks 34 and 35 . Therefore, winding and unreeling of the jib hoisting rope 32 by the jib hoisting winch 26 changes the distance between the sheave blocks 34 and 35, and rotates the front strut 19 and the jib 15 interlocked therewith in the hoisting direction. Let

The main hoisting winch 27 hoists and lowers the suspended load by the main hoisting rope 36 . Main hoisting guide sheaves 37, 38, 39 are rotatably provided at a proximal end portion of the rear strut 18, a proximal end portion of the front strut 19, and a distal end portion of the jib 15, respectively, for the main hoisting. Further, a main hoisting sheave block in which a plurality of main hoisting point sheaves 40 are arranged in the width direction is provided at a position adjacent to the main hoisting guide sheave 39 . A main hoisting rope 36 pulled out from a main hoisting winch 27 is sequentially hooked on main hoisting guide sheaves 37, 38, 39, and is attached to a main hoisting point sheave 40 of the sheave block and a main hook 41 for hoisting cargo. It is spanned between the sheave 42 of the provided sheave block. Therefore, when the main hoisting winch 27 winds or pays out the main hoisting rope 36, the distance between the sheaves 40 and 42 changes, and the main hoisting rope 36 suspended from the tip of the jib 15 is connected to the main hoisting rope 36. Hoisting and lowering of the hook 41 are performed.

Similarly, the auxiliary hoisting winch 28 hoists and lowers the suspended load with the auxiliary hoisting rope 43 . For the auxiliary winding, auxiliary winding guide sheaves 44, 45, and 46 are rotatably provided coaxially with the main winding guide sheaves 37, 38, and 39, respectively. A point sheave 47 is rotatably provided. The auxiliary hoisting rope 43 pulled out from the auxiliary hoisting winch 28 is sequentially hung on the auxiliary hoisting guide sheaves 44 , 45 , 46 , and suspended from the auxiliary hoisting point sheave 47 . Therefore, when the auxiliary hoisting winch 28 winds or unwinds the auxiliary hoisting rope 43, the auxiliary hook 48 for hanging load connected to the end of the auxiliary hoisting rope 43 is hoisted or lowered.

(Backstop configuration)
As shown in FIG. 2, which is an enlarged view of the main portion A of FIG. 1, the backstop 1 has a backstop body 2, a link 3, and a contact portion 4. In FIG. 2, the front strut 19 is shown at three different angles B1 to B3. Also, in FIG. 2, the rear strut 18 is shown at three different angles C1 to C3, respectively. FIG. 2 also shows a state in which the boom 14 is laid down.

One longitudinal end of the backstop body 2 is connected to a boom head (tip) 14a of the boom 14 with a pin. The backstop body 2 has a known structure in which an inner cylinder is slidably fitted inside an outer cylinder, and a shock-absorbing coil spring is attached to the outer circumference of one end of the inner cylinder. In this embodiment, the outer cylinder of the backstop body 2 and the boom head 14a are connected.

The link 3 connects the other longitudinal end of the backstop body 2 and the front strut 19 . One longitudinal end of the link 3 is connected to the other longitudinal end of the backstop body 2 with a pin. The other longitudinal end of the link 3 is connected with a pin to a connecting portion 5 (see FIG. 3) provided on the surface of the front strut 19 on the rear strut 18 side. In this embodiment, the inner cylinder of the backstop body 2 and the link 3 are connected.

The contact portion 4 is provided on the front strut 19 . Specifically, the contact portion 4 is provided on the surface of the front strut 19 on the rear strut 18 side. When the front strut 19 is raised at a predetermined angle or more with respect to the boom 14 , the other longitudinal end of the backstop body 2 contacts the contact portion 4 . Specifically, as shown in FIG. 2, when the front strut 19 is raised from the state of B1 (the laid-down state) to the state of B2, the other longitudinal end of the backstop body 2 is positioned at the contact portion. 4 abuts.

As shown in FIG. 3, which is an enlarged view of the main portion D of FIG. 2, the contact portion 4 is formed with a concave portion 4a. The concave portion 4 a is formed on the connecting portion 5 side of the contact portion 4 . The distance between the concave portion 4a and the connecting portion 5 is approximately the same as the length of the link 3. As shown in FIG. The other longitudinal end of the backstop body 2 abuts against the concave portion 4a.

As shown in FIG. 2, when the front strut 19 is further raised from the state of B2, the coil spring of the backstop body 2 is compressed. Then, when the front strut 19 is in the state of B3, a limit switch (not shown) provided on the backstop body 2 is turned on. As a result, further rotation of the front strut 19 is restricted.

Thus, when the front strut 19 is raised with respect to the boom 14 by a predetermined angle or more, the other longitudinal end of the backstop body 2 contacts the contact portion 4 . As a result, the backstop body 2 can limit the rotation range of the front strut 19 . One longitudinal end of the backstop body 2 is connected to the boom head 14 a of the boom 14 , and the other longitudinal end of the backstop body 2 is connected to the front strut 19 via the link 3 . Therefore, even when the front strut 19 rolls sideways, the boom 14 and the backstop body 2 or the front strut 19 and the backstop body 2 are less likely to be displaced in the lateral direction. Therefore, the rotation range of the front strut 19 can be reliably restricted by the backstop body 2 .

FIG. 4 is an enlarged view of the other longitudinal end of the backstop body 2. As shown in FIG. FIG. 4(a) is a top view, and FIG. 4(b) is a side view. As shown in FIG. 4, a pin 3a is continuously inserted into a hole of a rib 2a provided at the other longitudinal end of the backstop body 2 and a hole provided at one longitudinal end of the link 3. passed through. Thereby, the other longitudinal end of the backstop body 2 and the one longitudinal end of the link 3 are connected.

A doubling plate 7 is arranged between the rib 2 a and the link 3 . A pin 3 a is inserted through the center of the doubling plate 7 . A doubling plate 7 is fixed to the side surface of the link 3 . A circular plate 6 is provided between the doubling plate 7 and the rib 2a. Plate 6 is fixed to the side of doubling plate 7 .

The hole in the link 3 through which the pin 3a is inserted is an elongated hole extending slightly in the longitudinal direction of the link 3. As shown in FIG. As a result, when the other longitudinal end of the backstop body 2 abuts against the concave portion 4a and the backstop body 2 restricts the rotation of the front strut 19, the link 3 is prevented from being pulled. .

(Strut assembly operation)
Next, the strut assembly operation will be described with reference to FIGS. 5 to 14. FIG. 5 to 14 are side views of the tip of the boom 14. FIG. The boom 14 is in a laid down state.

First, as shown in FIG. 5, the front strut 19 and the rear strut 18 are brought in by an auxiliary crane in a state in which the rear strut 18 is placed on the front strut 19 and integrated. Next, as shown in FIG. 6, the base end of the front strut 19 is connected to the boom head 14a with a pin. Then, the rear strut 18 is separated from the front strut 19. - 特許庁

Next, as shown in FIG. 7, the base end of the rear strut 18 is connected to the boom head 14a with a pin. At this time, the support member 51 provided on the front strut 19 supports the rear strut 18 from below. Next, as shown in FIG. 8, while suspending the backstop body 2 with an auxiliary crane, one longitudinal end of the backstop body 2 is connected to the boom head 14a with a pin. One end of a strut-side jib guy line 24 a that is part of the jib guy line 24 is connected to the front strut 19 .

Next, as shown in FIG. 9, while letting out the jib hoisting rope 32 that is hung between the rear strut 18 and the front strut 19, the end of the rear strut 18 is lifted by an auxiliary crane using a dedicated sling 52. hoist it up. Then, as shown in FIG. 10, the distance between the rear strut 18 and the front strut 19 is set to a predetermined length, and the rear strut 18 is raised.

Next, as shown in FIG. 11, the hoisting rope 53 and the lifting wire 54 are connected while maintaining a predetermined distance between the rear strut 18 and the front strut 19 . Then, as shown in FIG. 12, while maintaining a predetermined distance between the rear strut 18 and the front strut 19, the hoisting rope 53 is hoisted up to raise the rear strut 18, and the backstop 22 of the rear strut 18 is lifted. The ends are pinned to the boom head 14a.

Next, as shown in FIG. 13 , the hoisting rope 53 is hoisted up to further raise the rear strut 18 while maintaining a predetermined distance between the rear strut 18 and the front strut 19 . Then, a strut-side guy link 23 a which is part of the guy link 23 and whose one end is connected to the rear strut 18 is connected to the guy link 23 . At this time, the backstop 22 of the rear strut 18 is in the most retracted state. On the other hand, the backstop 1 of the front strut 19 limits the rotation of the front strut 19 when the limit switch is turned on. Next, as shown in FIG. 14 , the hoisting rope 53 and the lifting wire 54 are removed, and the special sling 52 is stored in the rear strut 18 . Then, the rear strut 18 is raised by laying down the front strut 19 while letting out the jib hoisting rope 32 .

(jib assembly operation)
Next, the jib assembly operation will be described with reference to FIGS. 15 and 16. FIG. 15 and 16 are side views of the tip of the boom 14. FIG. The boom 14 is in a laid down state.

First, as shown in FIG. 15, by hoisting the jib hoisting rope 32, the front strut 19 is raised with respect to the boom 14 at a predetermined angle or more. The other longitudinal end of the backstop body 2 contacts the contact portion 4 . Further, by raising the front strut 19, the limit switch provided on the backstop body 2 is turned on. As a result, further rotation of the front strut 19 is restricted. In this state, the lower jib 15A alone is suspended by an auxiliary crane, and the base end of the lower jib 15A is moved to the tip of the boom 14. - 特許庁Since the front strut 19 is sufficiently raised with respect to the boom 14, there is no possibility that the hook of the auxiliary crane will interfere with the front strut 19. - 特許庁

Next, as shown in FIG. 16, the jib 15 is assembled by connecting the intermediate jib 15B and the upper jib to the lower jib 15A. The backstop 55 of the jib 15 is then pinned to the boom head 14a. Then, the jib hoisting rope 32 is let out. Then, a strut-side jib guy line 24 a which is part of the jib guy line 24 and whose one end is connected to the front strut 19 is connected to the jib guy line 24 .

(effect)
As described above, according to the backstop 1 according to the present embodiment, when the front strut 19 is raised with respect to the boom 14 by a predetermined angle or more, the other longitudinal end of the backstop body 2 is brought into contact with the contact portion. 4 abuts. As a result, the backstop body 2 can limit the rotation range of the front strut 19 . One longitudinal end of the backstop body 2 is connected to the boom head 14 a of the boom 14 , and the other longitudinal end of the backstop body 2 is connected to the front strut 19 via the link 3 . Therefore, even when the front strut 19 rolls sideways, the boom 14 and the backstop body 2 or the front strut 19 and the backstop body 2 are less likely to be displaced in the lateral direction. Therefore, the rotation range of the front strut 19 can be reliably restricted by the backstop body 2 .

(Modification)
As shown in FIG. 17, which is an enlarged top view of the other longitudinal end of the backstop body 2, a roller 8 may be provided at the other longitudinal end of the backstop body 2. Two ribs 2a are arranged in the axial direction of the pin 3a at the other longitudinal end of the backstop body 2, and a roller 8 is arranged between these ribs 2a. A pin 3 a is inserted through the center of the roller 8 . The roller 8 is rotatable around the pin 3a.

When the front strut 19 is raised with respect to the boom 14 by a predetermined angle or more, the roller 8 comes into contact with the contact portion 4 (see FIG. 3). At this time, as the roller 8 rotates, the other longitudinal end of the backstop body 2 can be brought into contact with the contact portion 4 smoothly.

Although the embodiments of the present invention have been described above, the specific examples are merely illustrated, and the present invention is not particularly limited. In addition, the actions and effects described in the embodiments of the invention are merely enumerations of the most suitable actions and effects resulting from the present invention, and the actions and effects of the present invention are described in the embodiments of the invention. are not limited to those listed.

REFERENCE SIGNS LIST 1 backstop 2 backstop body 3 link 4 abutting portion 5 connecting portion 6 plate 7 doubling plate 8 roller 10 luffing crane 11 lower running body 12 upper rotating body 13 cab 14 boom 14a boom head 14A lower boom 14B intermediate boom 14C upper boom 15 Jib 15A Lower jib 15B Intermediate jib 15C Upper jib 16 Mast 17 Counterweight 18 Rear strut 19 Front strut 20 Boom guy line 21 Backstop 22 Backstop 23 Guy link 23a Strut side guy link 24 Jib guy line 24a Strut side jib guy line 25 For boom hoisting Winch 26 Jib hoisting winch 27 Main hoisting winch 28 Auxiliary hoisting winch 29 Boom hoisting rope 30, 31 Sheave block 32 Jib hoisting rope 33 Guide sheave 34, 35 Sheave block 36 Main hoisting rope 37, 38, 39 Main hoisting guide sheave 40 main hoisting point sheave 41 main hook 42 sheave 43 auxiliary hoisting rope 44, 45, 46 auxiliary hoisting guide sheave 47 auxiliary hoisting point sheave 48 auxiliary hook 49 sheave 51 supporting member 52 dedicated sling 53 hoisting rope 54 wire 55 backstop

Claims (2)

A backstop for a front strut in a crane having a front strut hoistably mounted at the tip of a boom, comprising:
a backstop body having one longitudinal end connected to the tip of the boom with a pin ;
a link having one longitudinal end connected to the other longitudinal end of the backstop body with a pin and having the other longitudinal end connected to the front strut with a pin ;
an abutting portion provided on the front strut and with which the other longitudinal end portion of the backstop body abuts when the front strut is raised with respect to the boom by a predetermined angle or more;
has
A backstop for a front strut, wherein the backstop body limits a rotational range of the front strut in a state where the other longitudinal end portion of the backstop body is in contact with the contact portion. A rotatable roller is provided at the other longitudinal end of the backstop body,
2. The front strut backstop according to claim 1, wherein the roller abuts against the abutting portion when the front strut is raised with respect to the boom by the predetermined angle or more.

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