JPH074260U - Mobile crane frame structure - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to reduce the number of parts to reduce the cost and improve the welding workability and the welding work environment. [Structure] A pair of lower plates (21) are extended in the vehicle front-rear direction, webs (22) are erected on the outer side of each lower plate (21), and the inner side of the lower plate (21) is connected by a lower cross member (23). Further, the base plate 24 and the upper plate 25 are placed on the upper end of the web 22, the webs 22 are connected below the base plate 24 and the upper plate 25 by cross members 27 and 28, and the reinforcing member 30 is attached to the inner wall of the web 22 below the base plate 24. Install.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a frame structure for a mobile crane.

[0002]

[Prior art]

 As a conventional example of the frame structure of a mobile crane, there is one as shown in FIGS. 6 to 8 (see Japanese Utility Model Laid-Open No. 3-112476, Japanese Utility Model Laid-Open No. 3-113282, etc.). That is, a pair of lower plates 1 are provided so as to be spaced apart from each other and extend in the vehicle front-rear direction, and an outer web 2 and an inner web 3 are respectively erected on each lower plate 1. A base plate 4 is placed on the upper ends of the outer web 2 and the inner web 3, and a ring plate (not shown) for rotatably supporting the swivel base of the crane body is attached to the base plate 4. Upper plates 5 and 6 are mounted on the upper ends of the outer web 2 and the inner web 3 on both sides of the base plate 4.

Further, a lower cross member 7 is provided so as to be delivered to the inner portions of both the lower plates 1 and extend in the vehicle front-rear direction, and the inner web 3 and the upper plates 5 and 6 are welded to the lower cross member 7. A plurality of work holes 8 are formed at predetermined intervals. A first cross member 9 for mounting a ring plate is provided below the base plate 4 so as to be bridged between the inner webs 3, and a plate-shaped second cross member 10 is provided below the upper plates 5 and 6. It is provided by being delivered between 3. Further, a large number of restriction members 11 are attached between the outer web 2 and the inner web 3 at predetermined intervals. Further, vertical ribs 12 and membrane ribs 13 are provided on both lower sides of the base plate 4.

Here, the respective members are welded and connected.

[0005]

In such a conventional frame structure, work holes 8 are formed at a plurality of positions in the lower plate member 7 in order to weld the inner web 3 and the upper plates 5 and 6, and these work holes are formed. Since the head is put in the inside from 8 and welding work is performed, there is a problem that the welding work environment is bad. Further, since the work hole 8 is closed after the welding work is completed, there is a problem that the number of work steps is increased and the cost is increased. In addition, the number of parts such as the inner web 3 and the restricting member 11 is increased, which also causes a cost increase.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the welding work environment and welding workability, and to reduce the number of parts to reduce the cost.

[0007]

[Means for Solving the Problems]

 Therefore, according to the present invention, a pair of lower plates are arranged so as to extend toward the front of the vehicle at a predetermined distance from each other, and a lower cross member is passed between the inner portions of the lower plates and the outer side of each lower plate. Webs are erected on the respective parts, a base plate is placed on the upper end parts of the webs while being placed between the two webs, and upper plates are respectively placed on the upper end parts of the webs on the front and rear sides of the vehicle of the base plate, and A reinforcing member is attached to the inner wall of the web by extending it from the base plate to the lower plate, and a cross member is attached below the base plate and the upper plate by interposing it between the webs to weld and connect the members. did.

[0008]

[Action]

 The number of parts of the web is reduced by erected the webs one by one on the outer side of the lower plate, and the reinforcing material is attached below the base plate to reduce the restrictive material and reduce the cost and welding. I tried to simplify the work. Also, by dividing the upper plate on the front side and the rear side of the base plate, it is possible to perform welding work from above and improve the welding work environment.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, a pair of lower plates 21 are provided at predetermined intervals and extend in the vehicle front-rear direction, and a web 22 extends in the vehicle front-rear direction on the outer side of each lower plate 21. Each is set up. The lower cross member 23 is provided between the lower plates 21 and extends in the vehicle front-rear direction, and each side end portion of the lower cross member 23 is attached to each inner side portion of the lower plate 21. Here, the lower cross member 23 is formed so as to be bent at two places in the middle portion so that the central member is higher than both side portions. Further, the lower cross member 23 is appropriately divided into a plurality in the vehicle front-rear direction depending on the size of the bending die.

A base plate 24 is placed on the upper end side of the web 22 so as to be interposed between the webs 22, and an elliptic welding work hole 24 A larger than conventional is formed in the center of the base plate 24. Upper plates 25 are placed between the webs 22 at the upper ends of the webs 22 on the vehicle front side and the vehicle rear side of the base plate 24, respectively. Here, as shown in FIG. 4, the end portion of the base plate 24 and the end portion of the upper plate 25 are connected by butt welding by arranging a rib 26 made of L-shaped steel under the abutting portion thereof. .

Further, a plurality of L-shaped first cross members 27 for attaching ring plates are provided between the webs 22 on the lower portions of both sides of the base plate 24, and a plurality of them are attached at predetermined intervals in the vehicle front-rear direction. There is. Here, the second cross member 28 is attached to the upper plate 25 as shown in FIG. That is, the upper plate 25 is divided at each second cross member 28 mounting portion, the divided end portions of the upper plate 25 are abutted with a gap corresponding to the thickness of the second cross member 28, and the lower end of the gap is abutted. While holding the upper plate 25 by the holding member 29 temporarily welded to the upper end portion of the second cross member 28, as shown in FIG. Install cross member 28. Here, as shown in FIG. 5, the upper end portion of the second cross member 28 is attached so as to be slightly lower than the lower surface of the upper plate 25 so as to be melted into the holding member 29 as well. The 28 is easily attached to the upper plate 25.

A plurality of reinforcing members 30 extending from the lower plate 21 to the base plate 24 are attached inside the web 22 below the base plate 24. Vertical ribs 31 and membrane ribs 32 are attached to the outer wall of the web 22 below both sides of the base plate 24. Here, the lower plate 21 and the web 22 are welded from the outside by groove fillet welding, and the lower plate 21 and the lower cross member 23 are welded by fillet welding from one side or both sides. The web 22 and the base plate 24 or the upper plate 25 are welded from the outside by groove fillet welding. Further, the base plate 24 and the first cross member 27 are welded on one side by fillet welding from the welding work hole 24A, and on the other side, before the upper plate 25 is mounted, the base plate 24 and the first cross member 27 are separated from the divided portion of the upper plate 25 and the base plate 24. Weld by meat welding.

According to this structure, the lower plate 21 is connected at its lower end portion by the lower cross member 23, one web 22 is erected on each lower plate 21, and the base plate 24 and the upper plate 25 are provided at the upper ends of these webs 22. Since the web 22 is mounted and the web 22 is connected by the first and second cross members 27 and 28, the number of parts of the web 22 can be reduced as compared with the conventional one, and the restriction member is not required, and the cost can be reduced. The number of man-hours for welding work can be reduced, and the welding work can be simplified so that the welding workability can be improved. Further, since the inner web is eliminated, the opening area of the working hole 24A of the base plate 24 is increased, and the upper plate 25 is divided into the front side and the rear side of the vehicle of the base plate 24 and welded from above. The welding work environment can be improved because the welding work from the work hole of the lower cross member is eliminated.

[0014]

[Effect of device]

 As described above, the present invention connects a pair of lower plate inner parts by a lower cross member, stands one web on each lower plate, and places a base plate and an upper plate across the upper end of the web, In addition, since the cross members are installed between the webs below the base plate and the upper plate to weld them, the number of parts can be reduced, the cost can be reduced, and the welding workability can be greatly improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

[Fig. 2] Bottom view of the above

FIG. 3 is a sectional view taken along the line III-III in FIG.

4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a sectional view of the main part of the above.

FIG. 6 is a sectional view of another main part of the same.

FIG. 7 is a plan view showing a conventional example of a frame structure.

FIG. 8 is a bottom view of the above.

FIG. 9 is a sectional view taken along the line VIII-VIII of the above.

[Explanation of symbols]

 21 Lower plate 22 Web 23 Lower cross member 24 Base plate 25 Upper plate 27 First cross member 28 Second cross member 30 Reinforcing member

Claims (1)

[Scope of utility model registration request] 1. A pair of lower plates are arranged so as to extend in the vehicle front-rear direction at a predetermined interval from each other, and a lower cross member is passed between the inner parts of both lower plates and to the outer part of each lower plate. The webs are respectively erected, the base plates are placed on the upper end portions of the webs while being placed between the two webs, and the upper plates are placed on the upper end portions of the webs of the base plate on the vehicle front side and the rear side, respectively, and the inner wall of the webs is placed. A reinforcing member is extended from the base plate to the lower plate and attached, and a cross member is attached below the base plate and the upper plate by interposing them between the webs, and the respective members are welded and connected. Frame structure.