JP2001294392A - Boom extension mechanism for mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boom extension device for a mobile crane provided with a structure surely preventing a boom from sliding down accidentally by linking a releasing action of an inter-boom connecting/disconnecting means used for fixing/releasing booms mutually and a connecting action of a cylinder- boom connecting means so that they work directly on a fixing pin in the inter- boom connecting/disconnecting means and a connecting pin in the cylinder-boom connecting means for surely restricting a relative action between both means. SOLUTION: In release of connection by means of the cylinder-boom connecting means 8, a connecting action controlling member 13 is positioned in a traveling path for fixing action controlling members 10, 11, so that a movement of the fixing action controlling members 10, 11 is restricted and release of the fixed fixing pin 9A is restricted. In release of the fixed fixing pin 9A, the fixing action controlling members 10, 11 are directly positioned in a traveling path for the connecting action controlling member 13, so that the connecting action controlling member 13 is restricted from moving and a connection releasing action by the cylinder-boom connecting means 8 is restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom extending and retracting device for a mobile crane, and more particularly, to a mechanism for preventing a boom from extending and retracting by using a single hydraulic cylinder.

[0002]

2. Description of the Related Art As is well known, in a boom extension / retraction mechanism used in a truck crane or the like, a hydraulic cylinder is provided for each of the booms to be extended / contracted, and each stage of the boom is extended and retracted in accordance with the extension / contraction operation of each hydraulic cylinder. There is a mechanism to expand and contract. The boom extension and contraction mechanism having the above configuration has a problem that the number of hydraulic cylinders is increased. Instead, a configuration in which a single hydraulic cylinder is used to perform extension and contraction operations of a plurality of stages of booms has been proposed (for example, JP-A-7-267584
No.). On the other hand, in this type of boom extension device, when the selected boom is extended in conjunction with the extension operation of the single-stage double-acting hydraulic cylinder, the connecting means for connecting the cylinder and the boom provided on the single-stage double-acting hydraulic cylinder side is used. It is designed to grab and change to the selected boom,
The fixing pin is maintained in a fixed state to prevent slipping. Conventionally, an interlock mechanism that operates with a correlation between the operation state of the connecting means between the cylinder and the boom and the operation state of the inter-boom fixing means may be provided (for example, EP 0754646A).
1).

[0003]

In the above-described interlock mechanism for preventing the boom from sliding down, the movement of the lock bolt on the cylinder / boom connecting means side through the release claw is used to stop the movement of the booms. Since the drive is transmitted to the bolt, and the drive of the release claw and the drive of the lock bolt are interlocked with each other, the transmission between the lock bolt and the stop bolt may become impossible when a failure occurs in the release claw. There is. As a result, the release of the lock bolt may not be restricted while the lock bolt is released, and there is a danger that the boom will slide down.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an operation for releasing a boom indirect disconnecting means and a connecting operation for a cylinder / boom connecting means used for fixing and releasing the booms from each other. Boom extension and contraction device for mobile crane with a structure that can prevent inadvertent boom sliding down by reliably restricting relative movement between both means by associating them directly with connection pins Is to provide.

[0005]

In order to achieve this object, according to the first aspect of the present invention, a plurality of intermediate booms and a top boom are arranged adjacent to each other in a base boom and sequentially expandable and contractable. A multi-stage telescopic boom inserted into the multi-stage telescopic boom, a single-stage double-acting hydraulic cylinder mounted on the multi-stage telescopic boom and having a rod end supported at the base end of the base boom, and a cylinder tube in the single-stage double-acting hydraulic cylinder Releasable cylinder / boom connecting means for selectively connecting the rod-side end and the base end of each stage intermediate boom and the top boom, and releasable inter-boom fixing means for fixing the adjacent booms, A boom extension and contraction device for a mobile crane, comprising boom-to-boom fixation releasing means for releasing the fixation of the booms by the boom-fixing means. A connecting pin, which is disposed at a rod-side end of a cylinder tube of the single-stage double-acting hydraulic cylinder and is capable of connecting and disconnecting by moving forward and backward with respect to a base end of each intermediate boom; Connecting pin driving means for driving the connecting pin forward and backward, wherein the inter-boom fixing means are respectively arranged at the base ends of the inner booms of the adjacent booms, and protrude from the inner boom and immerse in the inner boom side. It is provided with a fixing pin that engages with a hole provided in an appropriate position on the outer boom to fix the corresponding adjacent booms when it protrudes, and releases the fixing between the corresponding adjacent booms when it is immersed. The inter-boom fixation releasing means is arranged at a rod-side end of a cylinder tube of the single-stage double-acting hydraulic cylinder, and In a boom extending / contracting device comprising a fixed pin actuating means for operating a fixed pin to project / retract a fixed pin, a connecting operation control member interlocked with a connecting pin of the cylinder / boom connecting means, A fixing operation control member integrated with a fixing pin, wherein when the connection is released by the cylinder / boom connection means, the connection operation control member is located in a moving path of the fixing operation control member, whereby the fixing operation is performed. The movement of the control member is restricted, and the release by the inter-boom fixing means is restricted. When the fixing pin is released from the inter-boom fixing release means, the fixing operation control member is in the moving path of the connecting operation control member. , The movement of the connection operation control member is regulated, and the disconnection by the cylinder / boom connection means is regulated. It is a sign.

According to a second aspect of the present invention, in the boom extending and retracting device for a mobile crane according to the first aspect, the fixing operation control member faces in response to the releasing operation of the fixing pin by the inter-boom fixing releasing means. The moving path of the connection operation control member can be opened and closed by changing the gap between the surfaces.

According to a third aspect of the present invention, in the boom extending and retracting device for a mobile crane according to the first aspect, the connecting operation control member is provided with an opposing surface in accordance with the advancing and retreating operation of the connecting pin by the cylinder / boom connecting means. The moving path of the fixed operation control member can be opened and closed by changing the gap between them.

According to a fourth aspect of the present invention, in the boom extending and retracting device for a mobile crane according to the first aspect, the connecting operation control member and the fixed operation control member are movable in directions orthogonal to each other. And

[0009]

According to the first aspect of the present invention, the movement of the fixed operation control member is restricted by disposing the connection operation control member in the moving path of the fixed operation control member when the connection is released by the cylinder / boom connecting means. Then, the release by the inter-boom fixing means is regulated, and at the time of the release by the inter-boom fixing means, the fixing operation control member is located in the moving path of the connection operation control member, whereby the connecting operation is performed. By restricting the movement of the control member and restricting the disconnection by the cylinder / boom coupling means, it is possible to prevent the cylinder / boom coupling means and the inter-boom fixing means from simultaneously coupling or releasing. Thus, it is possible to reliably prevent the boom from accidentally sliding down due to the simultaneous release of the above means.

According to the second and third aspects of the present invention, one of the fixing operation control member and the connecting operation control member is operated by one of the inter-boom fixing releasing means and the cylinder / boom connecting means, and the one of the fixing pin or the connecting pin is operated. The other movement path of the fixed operation control member or the connection operation control member is opened / closed in conjunction with performing the forward / backward movement, and the movement of the other member can be regulated. Movement can be regulated.

According to the fourth aspect of the present invention, since the connection operation control member and the fixed operation control member move in directions in which they easily interfere with each other, it is possible to reliably restrict the operation of the other party.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view in a side view for explaining a boom extension mechanism having six stages of extension booms including a top boom and a base boom. The four adjacent middle booms 2, 3, 4, 5 are telescopically inserted and telescopically inserted, and the top boom 6 is sequentially telescopically inserted into the intermediate boom 5 located at the foremost end of the intermediate booms. Has been inserted. Inside the boom, a single one-stage double-acting hydraulic cylinder 7 for moving the telescopic boom is arranged. The single-stage double-acting hydraulic cylinder 7 has a piston rod 7
The end of A is fixed to the base end of the base boom 1, and the cylinder tube 7B in which the piston rod 7A is inserted is extended and contracted by using the piston rod 7A as a guide. At the end, a cylinder / boom connecting means 8 described later is provided.

The cylinder / boom connecting means 8 includes connecting pins 8A which can be connected to engaging holes 2A, 3A, 4A, 5A and 6A formed on both sides at the base end of each step boom except the base boom 1. (See FIG. 2), the details of which are shown in FIGS. 2 and 3. FIG. 2 shows that the connecting pin 8A of the cylinder / boom connecting means 8 is connected to the engaging hole 2A.
A to 6A are shown in FIG.
Conversely, connecting pin 8A of cylinder / boom connecting means 8
Are inserted into the engagement holes 2A to 6A and connected. 2 and 3, an engagement hole 6A is shown for the top boom 6 and the intermediate boom 5 adjacent thereto. 2 and 3, the cylinder / boom connecting means 8 includes a single-stage double-acting hydraulic cylinder 7.
By moving together with the cylinder tube 7B, it is possible to move in the direction of expansion and contraction of the boom. The cylinder / boom connecting means 8 is swingably supported by a pair of connecting pins 8A which can be inserted into and removed from (retracted from) the engaging holes of the boom and a support shaft 8B1 provided on the bracket 50. A pair of link members 8B and a double-acting hydraulic cylinder 8C serving as a connecting pin driving means in which the expanding and contracting rod 8C1 and the interlocking member 8C2 are connected to the pair of link members 8B, respectively, are provided. The connecting pin 8A is a single-stage double-acting hydraulic cylinder 7
In the horizontal direction in the radial direction. The double-acting hydraulic cylinder 8C is disposed between the pair of link members 8B, and is positioned above the cylinder tube 7B.

In FIG. 2, cylinder / boom connecting means 8
Is provided near the rod-side end of the cylinder tube 7B, and is used for gripping of the intermediate boom selected at the time of expansion and contraction and expansion and contraction movement of the selected intermediate boom or top boom. When the expanding / contracting rod 8C1 of the double-acting hydraulic cylinder 8C is contracted, the link member 8B is swung outward in the radial direction of the cylinder tube 7B, and the connecting pin 8A is grasped among the bosses 2A to 6A to be re-engaged or expanded / contracted. The intermediate boom or the top boom is inserted into the engaging hole and engaged therewith. FIG. 3 showing a state in which the connection pin 8A is inserted into the engagement hole, shows a state in which the connection pin 8A is inserted into the engagement hole 6A for the top boom 6 adjacent to the intermediate boom 5. ing.

When the boom is gripped by the cylinder / boom coupling means 8 or when the telescopic operation is not performed, the fixed state of the boom is maintained by fixing pins 9A used to fix the adjacent booms. The fixed state is released by extracting the fixing pin 9A, which is a component of the inter-boom fixing means. The fixing pins 9A used for fixing the adjacent booms are arranged so as to face the base boom 1 and the holes 1B to 5B formed at the base ends of the intermediate booms 2 to 5 at each stage, and are fixed. When it is in the state, it is extracted from the holes 1B to 5B by the fixing pin operating means 9 which is a main part of the inter-boom fixing releasing means having a releasing function described later. The fixing pin operating means 9 includes:
The fixing pin 9A is moved forward and backward with respect to the holes 1B to 5B to move the fixing pin 9A from the inner boom to the outer boom.
9B which can project the fixing pin 9A from the outer boom toward the inner boom.
And a pair of link members 9C and 9D for transmitting the driving force of the driving device 9B to the fixing pin 9A.

The holes 2B to 5B of the intermediate booms 2 to 5 and the hole 1B of the base boom 1 of each stage are connected to the connecting pins 8A at positions different from the connecting pins 8A of the cylinder / boom connecting means 8.
Are penetrated in the same direction as the engagement holes 2A to 6A to be fitted. The fixing pin 9A can move in the same direction as the connecting pin 8A to advance and retreat with respect to the holes 1B to 5B. When the fixing pin 9A protrudes from the inner boom toward the outer boom hole, the fixing pin 9A moves from the outer boom hole to the inner boom. The case of immersion toward the boom side is set. FIG. 4 is a plan view showing a moving mechanism of the fixing pin 9A. In FIG. 4, as a driving device 9B used for the moving mechanism, an expansion / contraction rod 9B1 and an interlocking member 9 are used.
A double-acting hydraulic cylinder with B2 is used. A pair of swing link members 9C and 9D are connected to the expansion / contraction rod 9B1 and the interlocking member 9B2, respectively. These swing link members 9C and 9D have one swing end connected to the expansion / contraction rod 9B1 and the interlocking member 9B2 with a support shaft 51A provided on the support bracket 51 as a fulcrum, and the other swing end connected to a pair of fixed members. It can be inserted into the fixed operation control members 10 and 11 provided on the pin 9A. As shown in FIGS. 2 to 4, the fixing operation control members 10 and 11 are each formed of a receiving portion made of a hollow member integrally connected to the end of the fixing pin 9 </ b> A on the boom side. The surfaces facing the moving direction of the pin 9A are formed as guide surfaces 10A and 11A with their central portions bulging in the direction perpendicular to the moving direction.

In FIG. 4, when the expansion / contraction rod 9B1 of the driving device 9B is contracted, the fixing pin operating means 9 can swing the link members 9C and 9D outward.
As a result, the fixing pin 9A can move toward the hole of the boom, in FIG. 4, the hole 5B of the intermediate boom 5, and
Conversely, when the expansion / contraction rod 9B1 of the driving device 9B is expanded, it can escape from the hole 5B of the intermediate boom 5,
The boom moves in a direction according to the connection and release of the connection.

The fixing operation control member 10 on the fixing pin 9A side,
A coupling operation control member 13 is provided on the cylinder / boom coupling means 8 side opposite to 11 and movable in a direction orthogonal to the moving direction of the fixed operation control members 10 and 11. 2 and 3, a link operation control member 13 is arranged on the link member 8B of the cylinder / boom connection means 8 at the swinging end opposite to the connection pin 8A. The connection operation control member 13 is configured by a block body (see FIG. 4) fixed to the support bracket 13A and having a substantially rectangular shape in plan view. Since the support bracket 13A can move up and down according to the swing of the link member 8B, it functions as a member that moves the connection operation control member 13 up and down. The connection operation control member 13 formed of a block body can be interlocked with the advancing and retreating operation of the connection pin 8A, and is provided between the opposing surfaces of the fixed operation control members 10 and 11 whose interval changes according to the moving position of the fixing pin 9A. It is a member that is prevented from entering. For example, as shown by reference numeral L1 in FIG. 2, when the fixing pin 9A moves toward the hole 5B, the distance between the opposing surfaces of the fixing operation control members 10 and 11 increases. , The connection operation control member 13 can enter. Contrary to this, in FIG. 3, the distance between the opposing surfaces of the fixing operation control members 10 and 11 as in the case where the fixing pin 9A moves out of the hole 5B (the distance indicated by the symbol L2 in FIG. 3). As shown in FIG. 2), when the width is reduced unlike the case shown in FIG. 2, the connection operation control member 13 cannot enter between the opposing surfaces of the fixed operation control members 10 and 11.

The fixed operation control members 10 and 11 and the connection operation control member 13 have an interlock function of restricting the movement of the other party by directly entering or retreating from the movement path of the other party. That is, when the connecting pin 8A is pulled out of the engaging hole of the selected boom, the connecting operation control member 13 is turned to the fixing operation control member 10, 1.
1 and directly enters the moving path of the fixed operation control member 10, 1
Restrict the movement of 1. Separately, when the fixing pin 9A is pulled out from the hole between the booms, the fixing operation control members 10 and 11 directly close the moving path of the connection operation control member 13 to restrict the movement of the connection operation control member 13. As a result,
The fixing operation control members 10 and 11 and the connection operation control member 1 according to the movement of any one of the connecting pin 8A and the fixing pin 9A.
3 can directly control the movement of the other party.

In this embodiment, a mechanism is provided for preventing the movement of the fixing pin 9A when the booms are connected and fixed by the fixing pin 9A. As this mechanism,
The ball lock mechanism 14 located near the fixing pin 9A corresponds to this. In FIG. 4, the ball lock mechanism 14
A piston member 14C, which is a constituent member of the inter-boom fixing means together with the fixing pin 9A, is disposed within the tubular casing 14A and is urged toward the fixing pin 9A by a spring 14B, and a head of the piston member 14C. And a ball 14 </ b> D which is in contact with the part and has a movement behavior toward the fixing pin 9 </ b> A. On the peripheral surface of the fixed pin 9A of the ball lock mechanism 14 against which the ball 14D is pressed, there is provided a fitting portion 9A1 composed of a concave portion having an inclined surface against which the ball 14D is pressed. In FIG. 4, for convenience, the reference numeral of only the fitting portion is shown for one ball lock mechanism 14, and the reference numerals of the components are separately shown for the other ball lock mechanism 14.

Since the present embodiment has the above configuration,
When the selected boom is gripped by the cylinder / boom connecting means 8, the state where the booms are connected and fixed by the fixing pin 9A is maintained, and the connecting pin 8A on the cylinder / boom connecting means 8 side is engaged with the boom engaging hole. Can be extracted from

When the fixing pin 9A is engaged with the hole of the adjacent boom, its state is maintained by the ball lock mechanism 14, and the movement is prevented. When the fixing pin 9A is engaged with the hole of the boom, the distance between the opposing surfaces of the fixing operation control members 10 and 11 integral with the fixing pin 9A is widened as shown in FIG. Can be opened. Therefore, when the connecting pin 8A is pulled out from the engagement hole on the cylinder / boom connecting means 8 side, the connecting operation control member 13 integrated with the link member 8B directly enters the moving path of the fixed operation controlling members 10 and 11. When the connection operation control member 13 enters the movement path of the fixed operation control members 10 and 11, the movement of the fixed operation control members 10 and 11 is restricted, so that the fixing pin 9A does not accidentally come out of the boom hole. . As a result, when the cylinder / boom connecting means 8 changes the boom, the connecting pin 8A and the fixing pin 9A
Are prevented from being simultaneously released and the connected state of the boom is simultaneously released, and the boom is prevented from sliding down. In particular, the fixed operation control member 1 is moved by the movement of the connecting pin 8A.
Since the movement of 0 and 11 is directly restricted, there is no possibility that a malfunction of the transmission member causes an operation failure unlike a case where a transmission member is provided in the middle.

When the boom is replaced by the cylinder / boom connecting means 8, the connecting and fixing of the booms which have been connected and fixed is released, and the boom is selected according to the movement of the cylinder / boom connecting means 8. The boom expands and contracts. At this time, the fixing pin 9A of the boom to be released from the connection fixing is pulled out from the hole by the fixing pin operating means 9.

When the fixing between the booms is released,
The link member 9 of the fixing pin operating means 9 is fixed to the fixing operation control members 10 and 11 integrated with the fixing pin 9A which is maintained in a state where the fixing pin 9A does not come out of the hole by the ball lock mechanism 14.
C and 9D are fitted, and the driving device 9B is driven in a direction to pull out the fixing pin 9A from the hole. When the fixing pin 9A is pulled out of the hole, the moving path of the connecting operation control member 13 formed between the opposing surfaces of the fixing operation control members 10 and 11 is closed. As a result, the connection operation control member 13 cannot move in the direction in which the connection pin 8A can be pulled out from the engagement hole due to its own moving path being closed. The removal of the pin 8A is prevented. When the fixing pin 9A is pulled out, similarly to the case where the connecting pin 8A is pulled out, the movement of the connecting operation control members 10, 11 is directly restricted by the movement of the fixing pin 9A. As in the case where the transmission member is provided, an operation failure due to a failure of the transmission member does not occur.

Next, another embodiment of the present invention will be described below. FIG. 5 is a diagram showing a part of the inside of the boom. The boom includes a base boom 21, a plurality of intermediate booms 22 to 25 provided inside the base boom 21, and an intermediate boom located at the forefront among the intermediate booms. It includes, for example, six steps including a top boom (not shown) provided inside a boom (not shown). Inside the boom,
A single single-stage double-acting hydraulic cylinder for moving the telescopic boom (reference numeral 7 used in FIGS.
Are shown). One-stage double-acting hydraulic cylinder 7
The end of the piston rod 7A is fixed to the base end of the base boom 21, and the cylinder tube 7B in which the piston rod 7A is inserted is extended and contracted by using the piston rod 7A as a guide. At the rod-side end of 7B, a cylinder / boom connecting means 26 described later is provided.

The cylinder / boom connecting means 26 is provided with engaging holes (in FIG. 5, for convenience, reference numeral 2) formed on both side surfaces at the base end of each stage boom except the base boom 21 in FIG.
4A and 25A are shown, but are provided with connecting pins 26A (see FIG. 6) respectively connectable to booms other than the base boom, and details thereof are shown in FIGS. 6 and 7. It is shown. FIG. 6 shows a state in which the connecting pin 26A of the cylinder / boom connecting means 26 is inserted and connected to one of the engagement holes, and FIG. This shows a state in which the connection pin 26A of the connection means 26 is detached from any of the engagement holes and the connection is released. In FIGS. 6 and 7, the engagement holes 22 </ b> A are provided for the intermediate boom 22 adjacent to the base boom 21 because the arrows are viewed in the direction indicated by reference numeral (6) in FIG. 5. It is shown. 6 and 7, the cylinder / boom connecting means 26 can move in the direction of expansion and contraction of the boom by moving together with the cylinder tube 7B of the single-stage double-acting hydraulic cylinder 7. Cylinder / boom connecting means 2
6, a pair of connecting pins 26A provided in the single-stage double-acting hydraulic cylinder 7 so as to be able to advance and retreat in the horizontal direction in the radial direction and capable of being inserted into and disengaged (advancing and retracting) from the engagement holes 22A to 25A; A pair of swingable link members 26B whose ends and fixed ends are supported by a support bracket 30 via a support shaft 26B1 are disposed between the link members 26B, and are disposed above the cylinder tube 7B. And a double-acting hydraulic cylinder 26C corresponding to connection pin driving means connected to a pair of link members 26B via an expansion / contraction rod 26C1 and an interlocking member 26C2.

In FIG. 6, cylinder / boom connecting means 2
Reference numeral 6 is provided in the vicinity of the rod-side end of the cylinder tube 7B, and is used for gripping the selected intermediate boom at the time of expansion and contraction and performing expansion and contraction movement of the selected intermediate boom or top boom. When the expanding / contracting rod 26C1 of the drive cylinder 26C is expanded, the link member 26B is swung outward in the radial direction of the cylinder tube 7B, and the connecting pin 26A is gripped in the engaging hole or the intermediate boom to be expanded / contracted. Alternatively, it is made to enter and engage with the engagement hole of the top boom. FIG. 6 showing a state where the connecting pin 26A is inserted into the engaging hole, shows a state where the connecting pin 26A is inserted into the engaging hole 22A for the intermediate boom 2 adjacent to the base boom 21. ing.

As shown in FIG. 5, the inter-boom fixing means 27 used for fixing the adjacent booms includes holes formed at the base end of the base boom and the intermediate boom of each stage and at the appropriate position. 21B to 25B (in FIG. 5,
For convenience, only a few of the holes are shown), with opposing fixing pins 27A.
FIG. 8 shows details of the inter-boom fixing means 27 for the intermediate boom 22 adjacent to the base boom 21. In FIG. 8, the fixing pin 27A advances into the hole 21B of the base boom 21 to engage therewith. ing. The advancing direction of the fixing pin 27A is different from the connecting direction of the connecting pin 26A in the cylinder / boom connecting means 26.
This is a direction orthogonal to the axial direction of B, and is a vertical direction in the examples shown in FIGS. The fixed pin 27A is prevented from moving when it is advanced by a ball lock mechanism (indicated by reference numeral 14 shown in FIG. 4 for convenience) arranged in the vicinity thereof.

The fixing pins 27A for fixing the adjacent booms by moving out are released from the fixing between the booms by the inter-boom fixing releasing means 29. As shown in FIG. 8, the inter-boom fixation releasing means 29 is supported on the upper surface of the rod side end of the cylinder tube 7B in the vicinity of the cylinder tube 7B and serves as a fixing pin operating means, and is extendable and contractable from the cylinder 29A. Channel-shaped engaging member 2 provided at the tip of rod 29B1 and having a cross-sectional shape pointing upward.
9B. When the cylinder 29A contracts in a state where the T-shaped engaging piece 27B of the fixing pin 27A of the inter-boom fixing means 27 is fitted, the inter-boom fixing releasing means 29 is fixed against the bias of the ball lock mechanism 14. Pin 2
7A can be extracted from a hole (any one of 21B to 25B) formed on the boom side. As a result, the connection state with the boom by the inter-boom fixing means 27 (see FIGS. 6 and 7) is released.

The connecting pin 26A of the cylinder / boom connecting means 26 and the fixing pin 27A of the inter-boom fixing means 27
An interlock mechanism that regulates the operation of the other party by acting directly on each other is configured. The interlock mechanism includes a connecting pin 26A of the cylinder / boom connecting means 26.
A pair of link members 26B that swing in accordance with the movement of the link member, a coupling operation control member (indicated by reference numeral 13 'for convenience) provided at one of the swing ends of the link members 26B, and an inter-boom fixing means 27 And a fixing operation control member (indicated by reference numeral 10 'for convenience) located on the side of the fixing pin 27A.

The link member 26B is swingably supported by a support shaft 26B1 provided on the support portion 30, one of the swing ends is connected to the connecting pin 26A, and the other swing end is connected to the connecting operation control member. 13 'is provided. As the connection operation control member 13 ', a pair of hook-shaped flat plates having a longitudinal direction along the moving direction of the connection pin 26A in FIG. 6 is used, and as shown in FIG. It is located in. An end of the connection operation control member 13 'opposite to the opposing surface is connected to one swing end of the link member 26B by a pin 26B2. The connection operation control member 13 'can move in the same direction as the connection pin 26A in accordance with the swing of the link member 26B by partially fitting the guide pin 30A provided on the support portion 30. Can be opened and closed between the opposing surfaces.

When the space between the opposing surfaces of the coupling operation control member 13 'is opened, the moving path of the fixed operation control member 10' described later is opened and the fixed operation control member 10 'is inserted into the moving path.
When the space between the opposing surfaces is closed, the moving path of the fixed operation control member 10 'is closed to prevent the fixed operation control member 10' from entering.

As shown in FIG. 5, the fixed operation control member 10 'is constituted by an arm directed between the opposing surfaces of the connection operation control member 13' at a position offset from the position of the fixed pin 27A. When the fixed operation control member 10 'can enter a moving path formed by a gap between opposing surfaces of the connection operation control member 13' that opens and closes in accordance with the swing direction of the link member 26B on the cylinder / boom connection means 26 side. And if not possible are selected. That is, when the connecting pin 26A is pulled out when the fixing pin 27A is engaged with the hole between the booms and the booms are fixed to each other, the link member 26B is connected to the connecting operation control member 13 'as shown in FIG. The gaps between the facing surfaces are reduced by bringing them closer to each other. For this reason, the fixing operation control member 10 'cannot enter the moving path formed by the gap, so that the fixing pin 27A does not accidentally come out of the hole. When the connecting pin 26A moves toward the engaging hole of the boom and is connected, as shown in FIGS. 6 and 9, the space between the opposing surfaces of the connecting operation control member 13 'is widened. Thereby, the fixing operation control member 10 'can enter into the moving path formed by the gap between the opposing surfaces of the connecting operation control member 13', so that the fixing pin 27A can be pulled out from the boom hole and , Connecting pin 26
A does not accidentally slip out of the engagement hole of the boom.

In addition to the operation of the fixed operation control member 10 'by the connection operation control member 13', the fixed operation control member 1 '
The operation restriction of the connection operation control member 13 'by 0' is as follows. When the fixing pin 27A is pulled out of the boom hole when the connecting pin 26A is engaged with the engagement hole of the boom and the cylinder tube and the selected boom are connected, depending on the swing position of the link member 26B. The fixed operation control member 10 'can enter the gap of the connection operation control member 13' in which the distance between the opposing surfaces is wide. Therefore, the fixed operation control member 1 is inserted into the gap between the opposing surfaces of the connection operation control member 13 '.
When 0 'enters, the movement of the connection operation control member 13' is prevented, so that the connection pin 26A is prevented from being inadvertently pulled out, and the fixing pin 27A can be pulled out of the boom hole. As a result, the fixing operation control member 1 is moved in accordance with the movement of either the connecting pin 26A or the fixing pin 27A.
Either 0 ′ or the connection operation control member 13 ′ can directly restrict the movement of the other party.

Since the present embodiment has the above configuration,
When the selected boom is gripped by the cylinder / boom connecting means 26, the state where the booms are connected and fixed by the fixing pin 27A of the inter-boom fixing means 27 is maintained, and the connecting pin 26A on the cylinder / boom connecting means 26 side is maintained. Is extracted from the engagement hole of the boom.

The connecting pin 26A can be pulled out only when the fixed pin 27A is kept engaged with the hole between the booms by the ball lock mechanism 14. That is, since the fixed operation control member 10 'is maintained in the state shown in FIGS. 7 and 10, the fixed operation control member 10' is separated from the opposing surface of the connection operation control member 13 'and retracts. For this reason, the link member 26B can swing in a direction in which the connecting pin 26A can be pulled out from the engagement hole. Since the fixing operation control member 10 'cannot enter between the opposing surfaces of the coupling operation control member 13', the fixing pin 27A is not accidentally pulled out of the boom hole. As a result, it is premised that the fixing pin 27A is in a fixed state when the connecting pin 26A is pulled out, so that it is possible to prevent both members from coming off at the same time.

On the other hand, when releasing the fixing between the booms, the fixing pin 27A can be pulled out only when the connecting pin 26A is engaged. That is, since the connection operation control member 13 'is maintained in the state shown in FIGS. 6 and 9, the gap between the opposing surfaces of the connection operation control member 13' is widened. For this reason, since the fixed operation control member 10 'can enter between the opposing surfaces of the connection operation control member 13',
It can be pulled out of the boom hole by the inter-boom fixation releasing means 29. Since the fixed operation control member 10 'has entered the connection operation control member 13' between the opposing surfaces,
The link member 26B cannot swing in the direction in which the connecting pin 26A is pulled out from the engagement hole of the boom. As a result, when the fixing pin 27A is pulled out, the connecting pin 26
Since it is premised that A is in the connected state, both members will not come off at the same time.

In the above-described embodiment, the movement of the connecting pin in the cylinder / boom connecting means is performed via the link member. However, the present invention is not limited to this structure. For example, by providing a connection operation control member on the connection pin and directly operating the connection pin by the hydraulic cylinder, it is also possible to control the operation of the connection operation control member through the movement of the connection pin in conjunction with this. It is.

[0039]

According to the first aspect of the present invention, when the connection is released by the cylinder / boom connecting means, the connecting operation control member is located in the moving path of the fixing operation control member, so that the fixing operation control member is provided. The movement of the boom is restricted, and the release by the boom fixing means is restricted.When the fixing is released by the boom fixing means, the fixing operation control member is located in the moving path of the connection operation control member. Since the movement of the connection operation control member is restricted and the disconnection by the cylinder / boom coupling means is restricted, the cylinder / boom coupling means and the inter-boom fixing means are not simultaneously coupled or released. I can do it. Thus, it is possible to reliably prevent the boom from accidentally sliding down due to the simultaneous release of the above means.

According to the second and third aspects of the present invention, one of the fixing operation control member and the coupling operation control member is operated by one of the inter-boom fixing releasing means or the cylinder / boom coupling means, and thereby one of the fixing pin or the coupling pin is operated. The movement path of the other of the fixed operation control member or the connection operation control member is opened and closed in conjunction with the movement of the other member, so that the movement of the other member can be regulated. Preparatory movements can be regulated. This prevents the connecting pin and the fixing pin from being connected or unlocked at the same time, so that careless sliding of the boom can be prevented.

According to the fourth aspect of the present invention, since the connection operation control member and the fixed operation control member move in directions in which they easily interfere with each other, it is possible to reliably restrict the operation of the other party.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a main configuration of a boom extension device of a mobile crane according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the boom extension device shown in FIG.

FIG. 3 is a cross-sectional view showing one embodiment of the boom extension device shown in FIG.

FIG. 4 is a partial plan view for explaining a configuration of a boom indirect cutting means used in the boom extension device shown in FIG.

FIG. 5 is a view illustrating a main configuration of a boom extension device of a mobile crane according to another embodiment of the present invention.

FIG. 6 is a sectional view taken in the direction indicated by (6) in FIG.

FIG. 7 is a cross-sectional view showing one embodiment of the boom extension device shown in FIG.

FIG. 8 is an arrow view in a direction indicated by (8) in FIG. 5;

FIG. 9 is a view in the direction of the arrow indicated by (9) in FIG.

FIG. 10 is an arrow view in a direction indicated by (10) in FIG. 7;

[Explanation of symbols]

1, 21 Base boom 2-5, 22-25 Intermediate boom 6 Top boom 2A-6A, 22A-25A Engagement hole 7 Single-stage double-acting hydraulic cylinder 7A Cylinder tube 7B Piston rod 8, 26 Cylinder / boom connecting means 8A, 26A Connecting pins 8B, 26B Link members 8C, 26C Double-acting hydraulic cylinders corresponding to connecting pin driving means 9 Fixing pin operating means 9A, 27A constituting a main part of boom fixing releasing means 9A, 27A Fixing which is a component of boom fixing means Pins 10, 10 ', 11 Fixed operation control member 13, 13 Connection operation control member

Claims (4)

[Claims] 1. A multi-stage telescopic boom in which a plurality of intermediate booms are arranged in a base boom and a top boom is arranged in the intermediate boom adjacent to each other, and is sequentially and elastically inserted and fitted therein. Select a single-stage double-acting hydraulic cylinder whose rod end is pivotally supported at the base end of the base boom, a rod-side end of the cylinder tube in the single-stage double-acting hydraulic cylinder, and a base end of each stage intermediate boom and top boom. Releasable cylinder / boom connecting means for electrically connecting, releasable inter-boom fixing means for fixing the adjacent booms, and inter-boom fixing releasing means for releasing the fixing of the booms by the inter-boom fixing means. A boom extending / contracting device for a mobile crane, comprising: a cylinder / boom connecting means, a cylinder of the single-stage double-acting hydraulic cylinder. A connecting pin that is arranged at a rod-side end of the tube and that can be connected and disconnected by moving forward and backward with respect to a base end of each intermediate boom, and a connecting pin driving unit that drives the connecting pin forward and backward, The boom-to-boom fixing means is disposed at the base end of the inner boom of the adjacent boom, and is provided so as to protrude from the inner boom and to be immersed on the inner boom side, and is provided at an appropriate position on the outer boom when protruding. A fixing pin for fixing the corresponding adjacent booms by engaging the corresponding holes, and releasing the fixing of the corresponding adjacent booms when immersed, wherein the inter-boom fixing release means is the single-stage double-acting hydraulic cylinder. Fixed pin operating means disposed at the rod side end of the cylinder tube of the above, and acting on the inner end of the fixed pin of each of the step booms to project and retract the fixed pin A boom extending / contracting device, comprising: a connecting operation control member interlocked with a connecting pin of the cylinder / boom connecting means; and a fixing operation control member integrated with a fixing pin of the inter-boom fixing means. When the connection is released by the boom connecting means, the movement of the fixing operation control member is regulated by the connection operation control member being located in the moving path of the fixing operation control member, and the fixing by the inter-boom fixing means is released. When the fixation of the fixing pin is released by the boom-to-boom fixation release unit, the movement of the connection operation control member is restricted by the fixing operation control member being located in the movement path of the connection operation control member. A boom extension and contraction device for a mobile crane, wherein disconnection by the cylinder / boom connection means is regulated. 2. The boom extending and retracting device for a mobile crane according to claim 1, wherein the fixing operation control member changes a gap between the opposing surfaces according to a releasing operation of the fixing pin by the inter-boom fixing releasing means. The movable path of the connection operation control member can be opened and closed to open and close. 3. The boom extension and contraction device for a mobile crane according to claim 1, wherein the connection operation control member changes a gap between the opposing surfaces in accordance with an advance / retreat operation of the connection pin by the cylinder / boom connection means. A movable path of the fixed operation control member can be opened and closed. 4. The mobile crane boom extension and contraction device according to claim 1, wherein the connection operation control member and the fixed operation control member are movable in directions orthogonal to each other. Boom extension device.