JPH11292470A - Self-propelled crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-propelled crane performing simple crane operation and hydraulic control in ensuring the high lift of a boom at the time of work, and foldedly housing an arm and the boom to suppress the protruded quntity of the boom from the front of a vehicle body at the time of travel. SOLUTION: In this self-propelled crane 1, by turning a boom 18 with a second fulcrum 11 as the center, also a second cylinder 19 with a third fulcrum 5 as the center by a first cylinder 15 through the flexible action of it, an arm 8 is given turning movement about a first fulcrum 7, consequently the boom and arm can be moved, between an housed position where the boom and arm are folded and fallen centered on the fulcrum 11 and an initial work position where the boom and arm rise, and when the boom and arm are fixedly connected in a condition where they are positioned at the initial work position, they can be integrally given turning movement about with the fulcrum 7 only by the flexible action of the cylinder 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a self-propelled crane.

[0002]

2. Description of the Related Art Generally, a self-propelled crane has a telescopic boom. The boom is mounted on a revolving structure rotatably mounted on the body of the self-propelled crane so as to be able to move up and down, and is extended and contracted by a telescopic cylinder. Also, the boom is stored in a contracted and laid-down state during traveling.

If the end of the boom projects greatly in front of the vehicle body in the retracted state of the boom, the end of the boom may collide with a preceding vehicle or an obstacle during traveling. In particular, at a corner of a narrow road, the tip of the boom may easily interfere with an obstacle, and smooth running may be impaired.
If the boom is made short so as not to protrude from the front of the vehicle body in order to avoid such a situation, there arises a problem that the lifting height of the crane, that is, the lifting head cannot be earned. Therefore, in order to suppress the amount of protrusion of the boom from the front of the vehicle body (the amount of protrusion at the time of storage) while securing the length of the boom to some extent, the boom's rotation fulcrum (attachment portion) should be provided as far as possible behind the revolving structure. Need to be located. However, when the length of the vehicle body is limited, there is also a limit.

Accordingly, Japanese Utility Model Laid-Open No. 3-125786 discloses a boom overhang (the amount of boom protruding from the size of the vehicle body) for securing safety during traveling and a long boom for securing a high head. A configuration that can be realized without being limited by the length of the vehicle body is disclosed. FIG. 6 shows the configuration.

[0005] As shown in FIG.
A bending link 107 is provided at the base of 01, and the boom 101 is turned by a lifting cylinder 102 around a foot pin 103 provided on the bending link 107 to be raised and lowered. In addition, the refraction link 107 is
8 is rotated by the refraction cylinder 109 and raised and lowered. In this case, the bending cylinder 109 is attached to the swivel 106.

The fulcrum 105 of the up-and-down cylinder 102 is connected to a swivel 106, and the fulcrum 1 of the
04 is connected to the boom 101, and the fulcrum 105 and the fulcrum 10
4 is configured so that a straight line extending therethrough passes above the foot pin 103.

Therefore, when the undulating cylinder 102 is extended from the retracted position shown in FIG. 6A, the extension line of the axis of the undulating cylinder 102 connecting the fulcrum 105 and the fulcrum 104 is above the foot pin 103. Boom 1
01 rotates rearward around the foot pin 103, and assumes the posture shown in FIG. When the bending cylinder 109 is extended from the retracted position shown in FIG. 6A, the bending link 107 rotates forward around the link pin 108, and accordingly, the undulating cylinder 102 also moves about the fulcrum 105. Since it rotates forward, it assumes the posture shown in FIG. Further, when the up-and-down cylinder 102 is extended from the posture shown in FIG.
6 to the rear, and the posture shown in FIG.

That is, according to such a configuration, the length of the boom 101 can be supplemented by the bending link 107 during crane operation without being limited by the length of the vehicle body, and a high head can be secured (see FIG. 6). At the same time, the traveling link 107 and the boom 101 can be stored in a folded state during traveling, so that the amount of protrusion of the boom from the front of the vehicle body can be suppressed (see FIG. 6A).

[0009]

By the way, in the case of the self-propelled crane shown in FIG. 6, the boom 101 moves the foot pin 103 only by expanding and contracting only the up-and-down cylinder 102 as shown in FIG. 6B. Since it only pivots about the center, the length of the boom 101 cannot be supplemented by the bending link 107. Therefore, in order to compensate the length of the boom 101 by the bending link 107 and secure a high head, the bending cylinder 109 must be extended.

However, the working posture in which the undulating cylinder 102 and the bending cylinder 109 are extended (see FIG. 6D).
Then, when the load is hung, the two cylinders 102, 1
09 at the same time, the undulating cylinder 10
It is necessary to provide not only 2 but also the refracting cylinder 109 with sufficient strength, and load control (hydraulic control) becomes complicated. That is, when the bending cylinder 109 is completely contracted or completely extended, the bending cylinder 1
09 can be calculated in advance, and the load control including the safety control regarding the limit load can be easily performed to some extent.
When the bending cylinder 109 is used at an intermediate extension position, the postures of the boom 101 and the refraction link 107 change variously according to the extension amount, so that the load calculation becomes troublesome, and a considerably complicated load control (hydraulic pressure) is performed. Control) is required. That is, there is a possibility that the cargo handling operation becomes very unstable.

Further, in order to raise and lower the boom 101 while making up the length by the bending link 107 (to raise and lower the boom 101 while maintaining a high head), for example, the boom 101 and the bending link 107 are integrally and substantially integrated. The boom 101 by rotating the link pin 108 around the
The link 107 must be raised and lowered in conjunction with the ups and downs of. In other words, the bending cylinder 109 must be expanded and contracted while the undulating cylinder 102 is expanded and contracted. In particular, in a cargo handling operation performed while changing the working posture in various ways, the amount of expansion and contraction of the two cylinders 102 and 109 needs to be changed in various ways, so that not only the hydraulic control but also the crane operation itself becomes considerably complicated. This is because the boom 101 rotates around the foot pin 103 which is a connection portion with the bending link 107 in the working state, and the movement of the bending link 107 is restrained by the bending cylinder 109.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is an object of the present invention to perform an integral rotation of an arm and a boom for supplementing the length of a boom at the time of work. A self-propelled crane with simple hydraulic control and easy crane operation that can be performed only by telescopic operation and can store the arm and boom in a folded state during traveling and suppress the amount of protrusion of the boom from the front of the vehicle body To provide.

[0013]

In order to solve the above-mentioned problems, a self-propelled crane according to the present invention is provided with a support standing upright on a swivel that is rotatably mounted on a vehicle body, and one end thereof. An arm rotatably attached to the support via a first fulcrum, a boom having a base end pivotally attached to the other end of the arm via a second fulcrum, and one end Is rotatably mounted on the boom, the other end is rotatably mounted on the arm, and the first extensible cylinder is rotatably mounted on the arm, and one end is rotatably mounted on the support via a third fulcrum,
A second cylinder, the other end of which is rotatably attached to the boom, and a connecting means for connecting the base end of the boom and the other end of the arm in a fixed state; The cylinder rotates the boom about the second fulcrum and the arm about the first fulcrum by rotating the boom about the second fulcrum by the expansion and contraction operation. Thereby, the boom and the arm are moved between a storage position where the boom and the arm are folded around the second fulcrum and fall down, and an initial work position where the boom and the arm are raised. The connecting means fixedly connects the boom and the arm in a state where the boom and the arm are located at the work initial position, and the first connecting point is centered on the first fulcrum only by the expansion and contraction operation of the second cylinder. Integrated arm and boom Characterized in that it permits dynamic.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. The wheel crane (rough terrain crane) 1 shown in FIG. 1 includes a combined cab (hereinafter, referred to as a cab) 14 that can perform both the crane operation and the traveling operation, and inclines a boom 18 to a lower side of the cab 14. It is possible to run while lying down. As a result, a sufficient lateral field of view during traveling can be ensured, and the center of gravity of the vehicle body is lowered, so that the stability of the vehicle body during traveling is improved.

The wheel crane 1 has a carrier 10 as a running vehicle body, and a turntable 12 is mounted on the carrier 10. A revolving unit 16 having a cab 14 and a telescopic boom 18 is mounted on the revolving base 12.
Is rotatably mounted. In this case, the telescopic boom 1
8 is constituted by a plurality of booms connected to each other so as to be extendable and contractible, and can be extended by a telescopic cylinder (not shown), and is provided by an up-and-down cylinder 19 bridged between the revolving body 16 and the lower surface of the base end boom 18a. The undulating operation is performed.

On both sides before and after the carrier 10,
Outrigger 26 is attached. These outriggers 26 project a beam to the side of the carrier 10 during crane operation, and a cylinder
By extending the jack portion 26a having the piston structure, the ground plate attached to the lower end of the jack portion 26a is pressed against the ground to support the carrier 10.

A support frame 3 and a fixed bracket 4 are erected on the swivel 12. One end of an arm 8 for supplementing the length of the boom 18 is rotatably attached to the support frame 3 via a fulcrum pin 7.
A bracket 9 is fixed to the other end of the arm 8,
A boom 18 is attached to this bracket 9 via a fulcrum pin 11.
Is rotatably mounted at the base end. The base end of the boom 18 and the bracket 9 are provided with pin insertion holes 13 and 14, respectively, which coincide with each other in a work state described later and into which a fixing pin (not shown) is inserted.

Between the arm 8 and the boom 18, a hydraulically operated attitude switching cylinder 15 for switching between the working attitude and the retracted attitude is bridged. Specifically, the attitude switching cylinder 15 is configured as a trunnion-type cylinder, is rotatably attached to the other end of the arm 8, and the end of the telescopic rod 15 a is located on the lower surface of the base end of the boom 18. It is rotatably attached to the bracket 17.

A fixed bracket 4 erected on the swivel table 12 is supported by a fulcrum pin 5 through a fulcrum pin 5.
The head-side end 9 is rotatably mounted. The end of the telescopic rod 19 a of the up-and-down cylinder 19 is rotatably attached to the bracket 6 attached to the lower surface of the boom 18.

That is, in such a configuration, the arm 8
, Boom 18, attitude switching cylinder 15 and undulating cylinder 1
8 constitute a link mechanism, and the link mechanism is operated by expanding and contracting the attitude switching cylinder 15 as described later. In the present embodiment, the position of the center of gravity G of the entire link is set forward of the fulcrum pin 7 on the vehicle body side.

A part of the wire rope W wound around a winch drum (not shown) is attached to each of the pin insertion holes 13 and 14.
Is extended to the tip side of the boom 18a while being bridged by sheaves 40 and 41 provided in the vicinity of the boom 18a (bridged over the sheave of the boom head). In the drawing, reference numeral 42 denotes an engine cover.

Next, the boom raising and lowering operation of the wheel crane 1 having the above configuration will be described. First, in the retracted position shown in FIG. 1, the up-and-down cylinder 19 and the posture switching cylinder 17 are both set to the most contracted state, and the arm 8 and the boom 18 are folded around the fulcrum pin 11 so that the boom 1
8 is tilted down to the lower side of the cab 14,
The amount of protrusion of the boom 18 from the front of the vehicle body is regulated. In this storage position, the storage position of the boom 18 is held by the arm 8 and the up-and-down cylinder 19 held in the most contracted state (movement of the boom 18 obliquely downward due to the position of the center of gravity G is restricted). ).

From this stored state, the attitude switching cylinder 15
Is extended, the boom 18 is moved forward while being raised (rotated) about the fulcrum pin 11 so as to be separated from the arm 8 (the position of the center of gravity G is closer to the vehicle body front side than the fulcrum pin 7). At the same time, the up-and-down cylinder 19 rotates forward around the fulcrum pin 5 while supporting and guiding the boom 18 in conjunction with the raising operation of the boom 18. When the boom 18 is guided by the up-and-down cylinder 19 while being pushed forward by the attitude switching cylinder 15 in this manner, the arm 8 connected to the boom 18 also moves forward about the fulcrum pin 7 with its movement. It is turned. The posture of the boom 18 and the arm 8 during such a series of movements is shown in FIG.

The attitude switching cylinder 1 is further changed from the state shown in FIG.
When the boom 18 is extended, the boom 18 and the arm 8 are moved forward while rotating, and the pin insertion hole 14 provided in the base end of the boom 18 and the pin provided in the bracket 9 of the arm 8 are provided. The insertion hole 13 matches. This state is shown in FIG. In the work posture shown in FIG. 3 (work initial position... Initial position where the crane work is actually started), the fixing pins 30 are inserted into the pin insertion holes 13 and 14 which coincide with each other so as to penetrate them. . Therefore, the rotation of the boom 18 with respect to the arm 8 is restricted.
When the up-and-down cylinder 19 is extended in this state, the boom 18 is rotated upward about the fulcrum pin 7 while its length is supplemented by the arm 8.

As described above, according to the wheel crane 1 of the present embodiment, in the working posture (see FIG. 3) in which the posture switching cylinder 15 is extended, the fixing pins 30 inserted into the pin insertion holes 13 and 14 are used. Arm 8 and boom 18
Relative rotation of the cylinder 19 is restricted.
Is extended and retracted, the boom 18 is rotated about the fulcrum pin 7 in a state where the boom 18 is integrated with the arm 8 and its length is supplemented by the arm 8. That is, during the operation, the posture switching cylinder 15 is idle, and the boom 18 is raised and lowered while its length is supplemented by the arm 8 only by the expansion and contraction of the raising and lowering cylinder 19 (the boom 18 is raised and lowered while the high head is maintained). Therefore, all the load when the object is hung acts only on the undulating cylinder 19 (no load is applied to the attitude switching cylinder 15).

Therefore, there is no need to perform complicated load control, the crane operation is simplified, and a stable cargo handling operation can be performed. Also, the attitude switching cylinder 15
Needs to have the necessary strength to change the position of the boom 18 from the retracted position to the working position.
Since it is not necessary to have the large strength required for the manufacturing, the manufacturing cost can be kept low.

These effects are obtained because the boom 18 rotates integrally with the arm 8 about the fulcrum pin 7 in the working state and the movement of the arm 8 is not restricted. In the wheel crane 1 of the present embodiment, the attitude switching cylinder 15 is
And to switch the arm 8 between the retracted posture and the working posture, and does not perform the restraining operation of the boom 18 (it is held in a completely idle state during the work). The raising and lowering operation of the boom 18 is performed only by the raising and lowering cylinder 19. In the configuration shown in FIG. 6, even if the boom 101 and the refraction link 107 are fixed with fixing pins as in the present embodiment, the refraction link 107 is constrained by the refraction cylinder 109 after all. Unless the cylinders 102 and 109 are extended and retracted, the boom 101 cannot be rotated about the fulcrum 108 integrally with the refraction link 107 (the boom 101 cannot be raised and lowered while supplementing the length by the refraction link 107). . As in the present embodiment, the boom 18 and the arm 8 are connected by the fixing pin 30, and the attitude switching cylinder 15 is disposed between the arm 8 and the boom 18, so that the arm 8 can be freely rotated without being restrained. The above-described operation and effect can be obtained for the first time by moving the moving body.

In the wheel crane 1 according to the present embodiment, a link mechanism is constituted by the arm 8, the boom 18, the attitude switching cylinder 15, and the undulating cylinder 18, and the position of the center of gravity G of the entire link is smaller than the fulcrum pin 7 in the vehicle body. It is set on the front side. Therefore, it is not necessary to set an extension of the axis center line of the undulating cylinder 102 connecting the fulcrum 105 and the fulcrum 104 above the foot pin 103 as in the configuration of FIG. The boom 18 and the arm 8 can be converted from the storage posture to the working posture.

In the present embodiment, the pin insertion holes 13 and 14 for inserting the fixed pins are provided on the arm 8 side and the boom 18 side, respectively.
A plurality of pin insertion holes are respectively provided on the arm 8 side and the boom 18 side, and the angle formed between the arm 8 and the boom 18 is changed by selecting a hole into which the fixing pin 30 is inserted, so that the working posture is stepwise. You may make it change.

FIGS. 4 and 5 show a second embodiment of the present invention. The wheel crane 1A according to the present embodiment includes:
This is a modification of the first embodiment, and the posture switching cylinder 15
The configuration is the same as that of the first embodiment except for the arm 8 and the arm 8. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, the attitude switching cylinder 15 for switching the attitude of the arm 8 and the boom 18 is rotatably attached to a bracket 51 whose head end protrudes from the arm 8. One end of a pair of links 53 and 54 is rotatably attached to the end of the telescopic rod 15a of the cylinder 15. One link 53
Is rotatably attached to a bracket 52 protruding from the arm 8, and the other end of the other link 54 is rotatably mounted to a bracket 17 protruding from the lower surface of the boom 18. ing.

The arm 8 is provided with two winch drums 60 and 61 arranged in front of and behind each other.
Wire rope W wound around winch drums 60 and 61
Is extended to the distal end side of the boom 18a in a state of being bridged by sheaves 40 and 41 provided near the pin insertion holes 13 and 14 (bridged over the sheave of the boom head). .

In such a configuration, when the attitude switching cylinder 15 is extended from the storage state shown in FIG.
The boom 18 is moved forward while being raised (rotated) around the fulcrum pin 11 so that the boom 18 is separated from the arm 8. In conjunction with the raising operation of the boom 18, the raising / lowering cylinder 19 rotates forward around the fulcrum pin 5 while supporting and guiding the boom 18. The subsequent operation is the same as that of the first embodiment, but in the working posture in which the pin insertion holes 13 and 14 match each other as shown in FIG.
54 are completely opened so as to form a straight line.

Therefore, the same operation and effect as in the first embodiment can be obtained by the configuration of this embodiment.
In the second embodiment, the arm 8 is provided with the two winch drums 60 and 61. However, even if the arm 8 is not provided with the winch drums 60 and 61 as in the first embodiment. good. Further, in the first embodiment, the arm 8 may be provided with two winch drums 60 and 61.

[0035]

As described above, according to the self-propelled crane of the present invention, at the time of work, the integral rotation of the arm and the boom, which makes up the length of the boom, is performed only by the extension and contraction operation of the hoist cylinder. When the vehicle travels, the arm and the boom can be stored in a folded state so that the amount of protrusion of the boom from the front of the vehicle body can be suppressed. Also,
Hydraulic control and crane operation are simplified.

[Brief description of the drawings]

FIG. 1 is a side view of a self-propelled crane (boom stored state) according to a first embodiment of the present invention.

FIG. 2 is a state diagram when the boom and the arm are operated from a stowed position in the self-propelled crane of FIG.

FIG. 3 is a state diagram when the boom and the arm are positioned at an initial operation position in the self-propelled crane of FIG. 1;

FIG. 4 is a side view of a self-propelled crane (boom stored state) according to a second embodiment of the present invention.

FIG. 5 is a state diagram when the boom and the arm are positioned at an initial operation position in the self-propelled crane of FIG. 4;

FIG. 6 is a side view of a conventional self-propelled crane.

[Explanation of symbols]

 1, 1A ... wheel crane 3 ... support frame (support) 8 ... arm 15 ... attitude switching cylinder (first cylinder) 18 ... boom 19 ... undulating cylinder (second cylinder)

Claims (1)

[Claims] A support that stands upright on a turntable that is pivotally mounted on a vehicle body, an arm having one end rotatably attached to the support via a first fulcrum, A boom whose base end is rotatably attached to the other end of the arm via a second fulcrum; one end is rotatably attached to the boom, and the other end is rotatably attached to the arm. A retractable first cylinder, one end of which is rotatably attached to the support via a third fulcrum, and the other end of which is rotatably mounted on the boom; Connecting means for connecting the base end of the boom and the other end of the arm in a fixed state, wherein the first cylinder pivots the boom about a second fulcrum by its expansion and contraction operation. Together with rotating the second cylinder about the third fulcrum. And pivoting the arm about the first fulcrum, whereby the boom and the arm are folded, and the boom and the arm are folded about the second fulcrum and fall down, Is moved up and down from a work initial position, wherein the connecting means fixedly connects the boom and the arm in a state where the boom and the arm are positioned at the work initial position; A self-propelled crane characterized in that the arm and the boom can be integrally rotated about a first fulcrum only by an extension / retraction operation of a cylinder.