JP2010084468A - Joint member, and cab for construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint member capable of suppressing damage to a hollow member by avoiding a stress concentration which is liable to be generated when the hollow member is bent and deformed. <P>SOLUTION: An insertion part 23 is integrally formed in a joint body 22 fit into the hollow members 17, 18 to be connected. The insertion part 23 includes a side face 24 whose leading end at least has an external form in a tapered shape along a circular arc of a diameter larger than permissible bend radii of the hollow members 17, 18. The side face 24 is a curved face formed in a circular shape along arcs of the permissible bend radii of the hollow members 17, 18. <P>COPYRIGHT: (C)2010,JPO&INPIT

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 at the connecting portion of the framework, and thus a joint member having high rigidity is used at 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. 5, 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 3 a 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 of a connection partner, and the insertion portion has at least a distal end portion. It is a joint member having a tapered outer shape along an arc having a radius larger than the allowable bending radius of the hollow member.

  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.

  According to a third aspect of the present invention, the outer shape of the insertion portion of the joint member according to the first aspect is formed in a linear shape that approximates an arc of an allowable bending radius of the hollow member.

  The invention described in claim 4 is a cab for a construction machine including the joint member according to any one of claims 1 to 3 and a hollow member connected in a frame shape using the joint member.

  According to the first aspect of the present invention, as the hollow member fitted to the joint body and the integrally formed insertion portion is bent and deformed, at least the tip portion has a larger radius than the allowable bending radius of the hollow member. Since the contact area between the insertion part having a tapered outer shape along the arc and the hollow member expands, the hollow member is broken by avoiding stress concentration that tends to occur when the hollow member is bent and deformed. 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 claim 3, the outer shape of the insertion portion formed in a linear shape that approximates the arc of the allowable bending radius of the hollow member can be easily formed.

  According to the invention described in claim 4, since the hollow member of the cab for construction machinery is connected using the joint member, the hollow member is bent and deformed when a load is applied to the cab when the construction machinery falls. As a result, the contact area between the insertion part having a tapered outer shape along the arc of the allowable bending radius of the hollow member and the hollow member increases, so that stress concentration in the hollow member can be prevented. The damage of the hollow member due to stress concentration can be suppressed.

  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. 3, 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. 4, the construction machine cab 16 includes a front columnar hollow member 17 formed of a deformed steel pipe, a rear columnar hollow member 18, and a rear transverse beam-shaped hollow member 19. 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). Therefore, it is hereinafter referred to as “hollow members 17, 18”), and the insertion portion 23 is an allowable bending radius (or fracture bending radius) of the hollow members 17, 18. Side surface 24 having a tapered outer shape along the arc.

  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.

  FIG. 2 shows another embodiment of the joint member 21, which includes a joint body 22 and an insertion portion 23 that is integrally formed with the joint body 22 and is fitted into the hollow members 17 and 18 to be connected. The insertion portion 23 includes a side surface 26 having a tapered outer shape along an arc having a large radius not less than the allowable bending radius (or breaking bending radius) of the hollow members 17 and 18 at least at the distal end portion. .

  A side surface 26 of the insertion portion 23 in the joint member 21 is a tapered surface formed in a straight line that approximates an arc of the allowable bending radius of the hollow members 17 and 18.

  In short, the axial cross-sectional shape of the insertion portion 23 of the joint member 21 may be a curve or a straight line, but the shape approximates the allowable bending radius of the hollow members 17 and 18 to be connected, and is the most efficient hollow member An arc shape along an arc with an allowable bending radius of 17, 18 is desirable.

  The hollow members 17 and 18 formed of deformed steel pipes have different allowable bending radii depending on the angle of the axial cross section. The shape is different.

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

  As shown in FIG. 1 or FIG. 2, 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 or FIG. 2, at least the tip part is a hollow member as the hollow members 17 and 18 fitted to the joint body 22 and the insertion part 23 integrally formed are bent and deformed. Since the contact area between the insertion member 23 having a tapered outer shape along a circular arc having a radius larger than the allowable bending radius of 17, 18 and the hollow members 17, 18, the hollow members 17, 18 are bent. By avoiding stress concentration that tends to occur when trying to deform, the hollow members 17 and 18 can be prevented from being damaged.

  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.

  Further, according to the embodiment shown in FIG. 2, the outer shape of the insertion portion 23 formed in a linear shape approximating the arc of the allowable bending radius of the hollow members 17 and 18 can be easily formed.

  Further, as shown in FIGS. 3 and 4, since the hollow members 17, 18, 19 of the construction machine cab 16 are connected using the joint member 21, the construction as shown in FIG. 1 or FIG. As the hollow members 17 and 18 are bent and deformed when a load is applied to the cab 16 such as when the machine is overturned, the insertion portion 23 has a tapered outer shape along the arc of the allowable bending radius of the hollow members 17 and 18. Since the contact area between 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 insertion portion 23 may have a tapered outer shape at least at the distal end, a base having a linear shape, and only a distal end having a tapered outer shape.

  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 sectional drawing which shows other embodiment of a joint member same as the above. 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.

Explanation of symbols

11 Construction machinery
16 cab
17, 18 Hollow member
21 Joint parts
22 Joint body
23 Plug

Claims (4)

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 has a taper-shaped outer shape along an arc with a large radius at least at the tip part greater than or equal to the allowable bending radius of the hollow member. 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, wherein an outer shape of the insertion portion is formed in a linear shape that approximates an arc of an allowable bending radius of the hollow member. The joint member according to any one of claims 1 to 3,
A cab for construction machinery, comprising: a hollow member connected in a frame shape using the joint member.

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