JP3469682B2 - Wheel crane boom support frame - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom support frame of a wheel crane that supports a boom so that the boom can be raised and lowered.

[0002]

2. Description of the Related Art Generally, a self-propelled crane is provided with a support frame 105 for supporting a boom 104 so that the boom 104 can be raised and lowered, as shown in FIG. Such a support frame 105
Is erected on a swivel base 106 rotatably installed on a vehicle body frame 107 with its front part supported, and has support side plates 105a, 105a on both left and right sides. At the upper end of each side plate 105a, 105a,
A boom foot portion 108 through which a support pin 109 that supports the boom 104 penetrates is provided, and the boom 104 is disposed between the support side plates 105a and 105a in a state in which the boom 104 is rotatable (wound) about the support pin 109. There is.

By the way, the boom 104 is generally hoisted by a hydraulically operated hoisting cylinder. In the case of a particularly large truck crane, this hoisting cylinder is mounted, for example, on the front side of the turning center of a swivel base 106 having high rigidity, but is equipped with a cab 102 that serves both as a crane cockpit and a driving cab. In the wheel crane of FIG. 6, the boom hoisting cylinder 110 is attached to the rear part of the side plates 105a and 105a as shown in FIG. 7 in order to improve the visibility during traveling and to secure the lifting height. . In this case, the undulating cylinder 11
0 is the swing center O of the swivel base 106 and the boom foot portion 10
8 is attached to the derrick foot portion 112 provided on the side plate 105a.

As described above, in the support frame 105 'for supporting the hoisting cylinder 110 at the portion of the side plate 105a between the swing center O of the swivel base 106 and the boom foot portion 108, the load applied to the boom 104 during the lifting work is side plate. 1
A large compressive load acts between the front part of the side plate 105a supported by the swivel 106 and the rear part of the side plate 105a that receives a load applied to the boom 104. That is, the component of the force acting on the support frame 105 'in the compression direction increases.

When a large compressive load acts on the support frame 105 ', in other words, when the support frame 105' receives a large load in the buckling direction, the side plates 105a, 105
The a receives a force in the direction of expanding it. Also,
When the side plates 105a and 105a bulge outward due to this force, the boom 104 itself bends accordingly, causing a problem that the load hoisted by the boom 104 shakes.

From the above, the support frame 105, particularly the undulating cylinder 110, is attached to the swivel center O of the swivel base 106.
In the support frame 105 'which is supported by the side plate 105a between the boom foot 108 and the boom foot 108, the side plates 105a and 105a are conventionally formed in a hollow box shape in order to increase the rigidity thereof. That is, by forming each of the side plates 105a and 105a by two plates, the load from the boom 104 is dispersed and received by the two plates.

On the other hand, the side plate 105a of the support frame 105
It has been proposed in Japanese Patent Laid-Open No. 6-135690 to construct a single plate. As shown in FIG. 8B, the support frame 105 includes side plates 105a and 105a each of which is a single plate. As shown in FIG.
Lower reinforcing members 115 for restricting lateral deformation of the side plates 105a, 105a are provided on the outer surfaces of the front portions of the 5a, 105a. In addition, the lower reinforcing member and the boom foot portion 108
A connecting reinforcing member 116 for connecting the side plates 105a, 10
It extends along the outer surface of the upper edge of 5a.

Further, in this structure, the boom foot portion 108 is composed of a cylindrical pin support member 108a into which the support pin 109 of the boom 104 can be inserted, and the side plate 105a,
It is joined to the outer surface of the upper end portion of 105a by welding or the like.

[0009]

By the way, as described above, in order to increase the rigidity of the support frame 105, the side plate 10 is provided.
When 5a is formed into a box shape with two plates, the supporting frame 105
The overall weight increases. In addition, the assembly work by welding becomes complicated, and the cost tends to increase.

In particular, in a wheel crane having a small upper limit of the total weight, in order to improve the crane capacity even when the total weight is limited, the weight of the support frame 105 is suppressed to some extent while ensuring the strength of the support frame 105. Therefore, it is also necessary to contribute the surplus weight to the improvement of the lifting capacity, and a lightweight and effective reinforced structure of the support frame 105 is desired.

Further, since the support frame 105 supports the boom 104 having a relatively large weight, it is desired to efficiently reinforce the load applied from the boom support pin 109.

On the other hand, the weight of the support frame 105 can be reduced with the single plate structure as shown in FIG. However, if this configuration is applied to the support frame 105 'that supports the undulating cylinder 110 at the side plate 105a portion between the swing center O of the swivel base 106 and the boom foot portion 108, it becomes insufficient in terms of buckling strength. That is, although the lower reinforcing member 115 can prevent the bulging of the front portions of the side plates 105a and 105a, the bulging outward of the other portions of the side plates 105a and 105a is prevented by the coupling reinforcing member 116.
It is difficult to prevent only by. In general, the longer the member length, the smaller the buckling resistance and the lower the buckling strength. Therefore, a relatively long member such as the coupling reinforcing member 116 may buckle due to a large compressive load. The possibility is high in the support frame 105 'as shown in FIG. 7 where a large compressive load acts.

Further, in the configuration of FIG. 8, the support frame 10
It is difficult to satisfactorily disperse and transmit the load acting on No. 5 to each part of the support frame 105, and the load cannot be satisfactorily received with a small stress.

Further, in the configuration of FIG. 8, the boom foot portion 1
The pin support member 108a of No. 08 is formed as a thick boss portion for reinforcement (see FIG. 8B). However, in this case, the boom support pin 109 must be long by that amount. I will have to do it. Boom support pin 10
Since 9 is relatively heavy, it is desirable to be short. However, when the configuration shown in FIG. 8B is used, the weight of the boom support pin 109 is increased as the length of the boom support pin 109 is increased. Even if one is used as a single plate to reduce the weight, an inconvenient situation that the weight becomes heavy at another place is caused.

The present invention has been made in view of the above circumstances, and its object is to support a hoisting cylinder at a side plate portion between a swing center of a swivel base and a boom foot portion while being lightweight. (EN) Provided is a boom support frame for a wheel crane, which can maintain a sufficient buckling strength even in the case of doing so.

[0016]

In order to solve the above-mentioned problems, the present invention relates to a boom support frame of a wheel crane that supports a boom so that the boom can be raised and lowered. A pair of side plates standing upright on the table with its front end supported, a boom support part provided above the rear ends of the side plates and supporting a boom, a swing center of the swivel base, and the boom. The undulating cylinder support part that is provided in the side plate part between the support part and supports the undulating cylinder that undulates the boom, and extends from near the front end of the side plate to near the boom support part to prevent side plate buckling. And a at least one rib that is provided on the side plate and extends on the side plate so as to connect to the buckling reinforcement portion and divide the buckling reinforcement portion.

[0017]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 5 shows the wheel crane 1. The wheel crane 1 includes a cab 2 that also serves as a crane operation room and a cab for traveling, and includes a carrier 1a as a traveling vehicle body having wheels 5, and a revolving structure 1b mounted on the carrier 1a.

The carrier 1a comprises a vehicle body frame 4,
A swivel base 6 is rotatably mounted on the body frame 4,
The swivel body 1b is mounted on the swivel base 6. Revolving structure 1b
Is provided with the cab 2 and a crane device having a telescopic boom 8.

The revolving structure 1b is provided with a support frame 10 for supporting the boom 8 so that the boom 8 can be raised and lowered. The support frame 10 is erected on the revolving base 6 that is rotatably installed on the vehicle body frame 4, with its front portion supported.

As shown in FIG. 1, the support frame 10 is
Supporting side plates 10a and 10a are provided on both left and right sides, respectively. The supporting side plates 10a, 10a are formed in a substantially triangular shape whose upper surface becomes lower toward the front, and their lower rear parts are connected by the connecting part 13, and their front end parts are connected by the connecting part 12. There is.

As shown in FIGS. 1 and 2, each side plate 10
The a and 10a are substantially one plate (hereinafter, referred to as a web) 1 except the front end portion 22 supported by the swivel 6.
It is formed by 9. The web 19 has an upper flange portion 20 and a lower flange portion 21 at its upper edge portion and lower edge portion, respectively. Side plate 10 supported by the swivel base 6
The front end 22 of a is formed by the web 19 and the outer plate 17 into a substantially box-shaped two-plate structure.

A boom foot portion 18 through which a support pin 9 for supporting the boom 8 passes is provided at the upper rear end of the side plates 10a, 10a, and the boom 8 can rotate about the support pin 9 (can be raised and lowered). ) Support side plate 10
It is arranged to be supported between a and 10a (see FIG. 5).

The web 19 has a boom foot portion 18
Two ribs 30a and 30b are formed in the vicinity of. One of the first ribs 30a is connected to the upper flange portion 20 and extends from here to the lower flange portion 21 in a diagonally lower left direction in the drawing. The other second rib 30b extends diagonally downward to the right in the drawing and extends toward the first rib 30a and the upper flange portion 20.
And are connected. Then, these ribs 30a, 30
b surrounds the boom foot portion 18 together with the upper flange portion 20 and closes the space around the boom foot portion 18 to form a boom foot reinforcing portion 30 for reinforcing the boom foot portion 18 in a block state. A third rib 45 is formed on the web 19 at a lower portion of the boom foot reinforcing portion 30, and the third rib 45 is connected to a lower extending portion of the first rib 30a.

The turning center O of the turning base 6 (see FIG. 2)
In the portion of the web 19 between the boom foot portion 18 and
A derrick foot portion 26 is provided for attaching a root end portion of a hoisting cylinder (not shown) for hoisting the boom 8. Further, the web 19 has side plates 10a, 10a.
A plurality of openings 25, 25 through which a supply pipe or the like for sending pressure oil is inserted to the undulating cylinders or the like arranged therebetween are provided. The outer diameters of the pipes inserted through the openings 25 are substantially the same as the inner diameters of the openings 25, 25, and the openings 25, 25 prevent the web 19 from being weakened in strength.

At the rear portion of the side plate 10a, a maintenance opening 24 for a winch 49 (see FIG. 2) and a foot portion 23 for supporting a sheave 40 (see FIG. 5) are provided. A wire 42 fed from a winch 49 is wound around the sheave 40 (see FIG. 5).

A connecting reinforcing member 35a for connecting the second rib 30b of the boom foot reinforcing portion 30 and the front end portion 22 to each other.
Extend along the outer surface of the upper edge of the web 19. As shown in FIG. 3, the coupling reinforcing member 35a is made of an L-shaped plate material and forms a buckling reinforcing portion 35 having a rectangular cross section together with the upper flange portion 20.

Further, the web 19 has a plurality of fourth ribs 27, 27 extending so as to divide the buckling reinforcement portion 35 in the middle thereof.
Is provided. These fourth ribs 27, 27 divide the buckling reinforcement portion 35 into substantially the same length (in the present embodiment, 3
Are located on both sides of the derrick foot portion 26, and extend downward substantially perpendicular to the buckling reinforcement portion 35.

FIG. 3 is a cross section taken along line AA of FIG.
FIG. 4 shows a cross section taken along the line BB of FIG. As can be seen from these figures, the ribs 27, 27 are L
The buckling reinforcing portion 35 is completely divided by penetrating the character-shaped connecting reinforcing member 35a. That is, the ribs 27, 27 are formed to have a predetermined thickness, for example, a wide portion 27a having a rectangular cross section having a width larger than the lateral width of the buckling reinforcement portion 35,
The taper portion 27b having a triangular cross-section whose width gradually decreases downward is formed into a wide portion 27b.
The upper end of a is connected to the upper flange portion 20, and the taper portion 27
The lower end of b is connected to the boss 25 a of the opening 25. In addition, the web 19 has an opening 25 far from the third rib 45.
The fifth rib 28 is formed on the lower side. This fifth
The rib 28 has a triangular cross section in which the width gradually increases in a downward tapered shape, and connects the boss 25 a of the opening 25 and the lower flange portion 21.

Next, the operation of the support frame 10 having the above structure will be described. Generally, in the support frame 10 like this embodiment in which the hoisting cylinder is supported at the portion of the side plate 10a between the swing center O of the swivel base 6 and the boom foot portion 18, the load applied to the boom 8 during the lifting operation is applied to the side plate 10a.
A large compressive load acts between the front end portion 22 of the side plate 10a supported by the swivel 6 and the rear portion of the side plate 10a receiving the load from the boom 8, which is received by the rear side.
A force acts on the side plates 10a, 10a so as to inflate them outward.

However, the support frame 10 of the present embodiment
Serves as a node that divides the buckling reinforcement portion 35 (the coupling reinforcement member 35a) by the fourth ribs 27, 27.
The force acting on each reinforcing partition portion 36 of the buckling reinforcing portion 35 divided by the ribs 7, 27 is transmitted to the upper flange portion 20 by each rib 27, 27 and is distributed to each portion of the web 19, so that the boom 8 Can be received with a small stress, so that buckling can be prevented and bulging outward of the side plates 10a, 10a associated therewith can be prevented.

In this way, the buckling reinforcement portion 35 is attached to the rib 27,
If the plurality of reinforcing partition portions 36 are divided by 27 to form the plurality of reinforcing partition portions 36, the buckling load of each reinforcing partition portion 36 increases due to the shortened member length, and the buckling strength of the buckling reinforcing portion 35 as a whole increases. growing. Then, the compressive load (stress) acting on the buckling reinforcement portion 35 can be received by the rib 27 which is a node in a short span, and the force is well dispersed and transmitted to each portion of the side plate 10a by the rib 27. be able to.

Further, the rib 27 in this embodiment distributes the force acting on the web 19 to the upper flange portion 20 to prevent the buckling of the web 19 and reaches the opening 25 without being cut in the middle thereof. The 25 arcuate portions release and disperse the stress to prevent stress concentration. In the present embodiment, the fifth rib 28 prevents the lower flange portion 21 from being deformed (turned over).

Further, the support frame 10 of this embodiment is
The side plates 10a, 10a are formed of a single plate 19 excluding the necessary reinforcing portions, and are therefore extremely lightweight.
Further, also in the reinforcing portion, since the buckling reinforcing portion 35 is connected to the rib 30a in front of the boom foot portion 18 without reaching the boom foot portion 18, the buckling reinforcing portion 35 is connected to the boom foot portion 1.
The weight can be reduced as compared with the conventional configuration of FIG.

Further, the support frame 10 of this embodiment is
Since the reinforcement around the boom foot portion 18 is reinforced by the reinforcement portion 30 including the ribs 30a and 30b, it is not necessary to form the boom foot portion 18 as a thick boss portion as in the conventional example shown in FIG. The boom support pin 9 can be shortened, and the boom support pin 9 can be prevented from taking weight.

[0035]

As described above, the boom support frame of the present invention can be made lightweight, and the hoisting cylinder is supported by the side plate portion between the turning center of the swivel base and the boom foot portion. Even in this case, sufficient buckling strength can be maintained.

[Brief description of drawings]

FIG. 1 is a perspective view of a boom support frame according to an embodiment of the present invention.

FIG. 2 is a side view of a side plate that constitutes the boom support frame of FIG.

FIG. 3 is a perspective view showing a cross section taken along line AA of FIG.

FIG. 4 is a perspective view showing a cross section taken along line BB of FIG.

5 is an overall view of a wheel crane including the boom support frame of FIG.

FIG. 6 is an overall view of a wheel crane including a conventional boom support frame.

FIG. 7 is a side view of a boom support frame having an undulating cylinder support portion at a side plate portion between a swing center of a swivel base and a boom support portion.

FIG. 8A is a side view showing an example of a boom support frame having a side plate having a single plate structure, and FIG. 8B is a CC view of FIG. 8A.
It is sectional drawing which follows the line.

[Explanation of symbols]

1 ... Wheel crane, 10 ... Support frame, 10a ...
Side plates, 18 ... Boom foot section (boom support section), 26 ...
Derrick foot part (relief cylinder support part), 27, 2
8, 30a, 30b, 45 ... Ribs.

Claims (5)

(57) [Claims] 1. A boom support frame for a wheel crane that supports a boom so that the boom can be raised and lowered. The boom support frame is erected with its front end supported on a swivel base rotatably installed on the body frame of the wheel crane. A pair of side plates, a boom support part provided above the rear end parts of the side plates to support the boom, and a side plate part between the swing center of the swivel base and the boom support part for undulating the boom. An undulating cylinder support part that supports the undulating cylinder, a buckling reinforcement part that extends from near the front end of the side plate to near the boom support part, and prevents buckling of the side plate. A boom support frame for a wheel crane, comprising: at least one rib extending on the side plate so as to connect to the reinforcing portion and divide the reinforcing portion. 2. The boom support frame for a wheel crane according to claim 1, wherein a rib that divides the buckling reinforcement portion is connected to a peripheral portion of an opening formed in the side plate. 3. The boom support frame for a wheel crane according to claim 1, wherein ribs that divide the buckling reinforcement portion are located on both sides of the undulating cylinder support portion. 4. A reinforcing means for reinforcing the boom support portion is provided by a plurality of ribs formed on a side plate portion near the boom support portion. Boom support frame of the wheel crane described in 1. 5. The boom support frame for a wheel crane according to claim 4, wherein one end of the buckling reinforcement portion is connected to one rib of the reinforcement means.