JP5036673B2 - Joint parts and cab for construction machinery - Google Patents

Description

  The present invention relates to a joint member for connecting a hollow member and a cab for a construction machine using the joint member.

  In a cab for a construction machine having a framework, a high-stress is likely to be generated in a connecting portion of the framework, and thus a joint member having high rigidity is used in the connecting portion. For example, a casting joint is used for the joint member (see, for example, Patent Document 1).

However, as shown in FIG. 4 , the shape of the conventional joint member 1 is such that the insertion portion 3 is formed on one side and the other side of the joint body 2, and these insertion portions 3 are connected to each other. It has a straight shape along the inner surface of the hollow member 4 such as a post member or the like, and when the hollow member 4 is bent and deformed due to excessive external force on the cab, the tip of the insertion portion 3 is The corner 3a contacts the local area of the hollow member 4 with a minimal area, and stress concentration occurs in the hollow member 4.
JP 2000-198469 A (page 3, FIG. 3)

  Thus, since the insertion part 3 of the conventional joint member 1 is a shape along the inner shape of the counterpart hollow member 4, an excessive external force is generated in the cab, and the hollow member 4 is about to bend and deform. Furthermore, stress concentration may occur at the location of the hollow member 4 that contacts the corner 3a at the tip of the insertion portion 3, and the hollow member 4 may be damaged.

  The present invention has been made in view of the above points, and uses a joint member that can avoid stress concentration that tends to occur when the hollow member is about to bend and deform, and that can prevent damage to the hollow member, and the joint member. An object is to provide a cab for construction machinery.

The invention described in claim 1 includes a joint main body and an insertion portion that is integrally formed with the joint main body and is fitted into a hollow member that is a connection partner, and the insertion portion includes the insertion portion. Along the arc of a larger radius than the allowable bending radius of the hollow member as it starts to extend along the hollow member from the base of the joint body side where the insertion port of the hollow member fitted into the joint is abutted A base having a tapered outer shape to be reduced is provided , and a base on the joint body side of the insertion portion and an insertion port of the hollow member are joint members fixed by a welded portion welded along the insertion port .

The invention described in claim 2 is such that the outer shape of the insertion portion in the joint member according to claim 1 is formed in an arc shape along the arc of the allowable bending radius of the hollow member .

Invention described in 請 Motomeko 3, a joint member according to claim 1 or 2 wherein a cab for a construction machine provided with the hollow member connected to the frame shape by using the joint members.

According to the first aspect of the present invention, the insertion port of the hollow member fitted into the joint body and the integrally formed insertion portion is formed by the welded portion welded along the insertion port. As the hollow member is fixed to the base of the joint body side and is bent and deformed, the contact area between the hollow member and the insertion portion having a tapered outer shape along an arc having a radius larger than the allowable bending radius of the hollow member Therefore, the stress concentration that tends to occur when the hollow member is about to be bent and deformed can be avoided, and damage to the hollow member can be suppressed.

According to the invention described in claim 2, the outer shape of the insertion portion formed in an arc shape along the arc of the allowable bending radius of the hollow member is stress that is likely to occur when the hollow member is about to bend and deform. Concentration can be effectively avoided .

According to the invention described in 請 Motomeko 3, since the connecting hollow members for construction equipment cab using the above joint member, the hollow member bending when a load is applied to the cab, such as when the construction machine falls As the deformation increases, the contact area between the hollow member and the insertion portion having a tapered outer shape along the arc of the allowable bending radius of the hollow member increases, thereby preventing stress concentration in the hollow member. It is possible to suppress breakage of the hollow member due to stress concentration.

Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIGS.

In the construction machine 11 shown in FIG. 2 , an upper swing body 14 is turnably provided on a lower traveling body 12 via a swing bearing portion 13, and a work device 15 and a cab 16 are mounted on the upper swing body 14. It is a hydraulic excavator.

As shown in FIG. 3 , the construction machine cab 16 includes a front columnar hollow member 17, a rear columnar hollow member 18, and a rear transverse beam-shaped hollow member 19 formed of a deformed steel pipe. These are connected in a frame shape using the joint member 21.

FIG. 1 shows an embodiment of the joint member 21, and a joint body 22 and hollow members 17, 18, 19 which are integrally formed with the joint body 22 and connected thereto (however, the hollow member 19 appears in the figure). since no less, comprising a plug portion 23 which is fitted to) that "the hollow members 17 and 18", the insertion portion 23, along an arc of allowable bending radius of the hollow members 17 and 18 A side surface 24 having a tapered outer shape is provided.

  The side surface 24 of the insertion portion 23 in the joint member 21 is a curved surface formed in an arc shape along the arc of the allowable bending radius of the hollow members 17 and 18, and from the insertion port of the hollow members 17 and 18 to the back. It forms so that it may leave | separate from the inner surface of the hollow members 17 and 18 as it enters.

The joint member 21 and the hollow members 17 and 18 are abutted with each other at the insertion port of the hollow members 17 and 18, and are fixed by a welded portion 25 welded along the insertion port .

Axial cross-sectional shape of the insertion portion 23 of the di Yointo member 21 is connected party and the allowable bending shape similar to the radius of the hollow members 17 and 18 made of, most efficient allowable bending radius of the hollow member 17, 18 An arc shape along the arc is desirable.

Since the hollow members 17 and 18 formed of a deformed steel pipe have different allowable bending radii depending on the angle of the axial cross section, the side surface 24 of the insertion portion 23 in the joint member 21 is also shaped according to the angle of the axial cross section. Is different.

  Next, the function and effect of the illustrated embodiment will be described.

As shown in FIG. 1, when bending stress acts on the hollow member, deformation of the hollow member due to excessive external force occurs over a wide range without being concentrated locally, so that damage to the hollow member can be suppressed.

According to the embodiment shown in FIG. 1, according to the hollow member 17, 18 is fitted integrally molded spigot 23 and the joint body 22 is bending deformation allowable bending of the middle empty members 17 and 18 Since the contact area between the insertion part 23 having a tapered outer shape along a circular arc having a radius larger than the radius and the hollow members 17 and 18 expands, when the hollow members 17 and 18 try to bend and deform Breakage of the hollow members 17 and 18 can be suppressed by avoiding stress concentration that easily occurs.

In particular, according to the embodiment shown in FIG. 1, the outer shape of the insertion portion 23 formed in an arc shape along the arc of the allowable bending radius of the hollow members 17 and 18 is such that the hollow members 17 and 18 are bent. It is possible to effectively avoid stress concentration that tends to occur when trying to deform .

Et al is, as shown in FIGS. 2 and 3, since the connecting hollow members 17, 18, 19 of the construction machine cab 16 using the above joint member 21, the construction as shown in FIG. 1 machine An insertion portion 23 having a tapered outer shape along an arc of an allowable bending radius of the hollow members 17, 18 as the hollow members 17, 18 are bent and deformed when a load is applied to the cab 16 at the time of falling, etc. Since the contact area with the hollow members 17 and 18 increases, it is possible to prevent stress concentration from occurring in the hollow members 17 and 18 and to suppress damage to the hollow members 17 and 18 due to stress concentration .

The present invention can also be used for cabs other than hydraulic excavators.

It is sectional drawing which shows one Embodiment of the joint member which concerns on this invention. It is a side view of the construction machine with which the cab using a joint member same as the above was mounted. It is a perspective view of the cab comprised using the joint member same as the above. It is sectional drawing which shows the prior art example of a joint member.

11 Construction machinery
16 cab
17, 18 Hollow member
21 Joint members
22 Joint body
23 Plug
24 sides
25 welds

Claims (3)

The joint body,
It is integrally formed with this joint body and has an insertion part fitted into the hollow member of the connection partner,
This insertion part starts to extend along the hollow member from the joint body side where the insertion port of the hollow member fitted in the insertion part is abutted , and the allowable bending of the hollow member as it goes to the tip side. A side surface having a tapered outer shape that contracts along a circular arc having a radius larger than the radius ;
A joint member characterized in that a base on the joint body side of the insertion portion and an insertion port of the hollow member are fixed by a welded portion welded along the insertion port . The joint member according to claim 1, wherein the outer shape of the insertion portion is formed in an arc shape along an arc of an allowable bending radius of the hollow member. The joint member according to claim 1 or 2,
A cab for a construction machine, comprising: a hollow member connected in a frame shape using the joint member.

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