JP2008280798A - Fixing structure of connecting shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing structure of a connecting shaft capable of locking the connecting shaft without applying rotation torque to a connecting bolt, and easy and surely fixing the connecting shaft in a narrow place. <P>SOLUTION: Shaft holes 2a and 3a of the connecting shaft 4 are formed at a pair of brackets 2 and 2 as first members and a cylindrical member 3 as a second member, respectively. The connecting shaft 4 includes a cylindrical shaft 4a inserted through the shaft holes 2a and 3a and a collar 4b provided at one end of the shaft 4a. One of the brackets 2 includes a cylindrical collar member 6 fixed thereto, and a rotation regulating surface 4c is formed on the collar 4b. The collar member 6 includes a projection 6c having a flat surface 6b which contacts with the rotation regulating surface 4c to lock the connecting shaft provided at the top end thereof, and a connecting bolt 5 inserted through the collar member 6 and the shaft 4a to fix the connecting shaft 4 to the collar member 6 is detachably attached thereto. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a connecting shaft fixing structure for rotatably attaching a cylinder or the like to a construction machine such as a crane or a hydraulic excavator. Specifically, the connecting shaft that rotatably connects two members is prevented. In addition, the present invention relates to a connecting shaft fixing structure for retaining the stopper.

As a fixing structure of the connecting shaft that rotatably connects the second member such as the cylinder to the first member provided in the construction machine such as a crane or a hydraulic excavator, the connecting shaft is connected to prevent the connecting shaft from coming off. A through hole is formed at the tip of the shaft, and a retaining pin is attached to the through hole (see, for example, Patent Document 1), or a collar member that is inserted through the end of the connecting shaft into the first member. There are some which fix the collar member and the connecting shaft with connecting bolts (see, for example, Patent Document 2).
JP 2000-92917 A Japanese Patent Laid-Open No. 11-343635

  However, in the above-mentioned Patent Document 1, a certain amount of space is required to insert the retaining pin, and it cannot be applied to a narrow portion without space. Moreover, in the thing of patent document 2, since the connecting bolt for retaining also served as the rotation prevention of the connecting shaft, excessive torque was applied to the connecting bolt, and it was necessary to increase the strength of the bolt.

  Accordingly, the present invention has an object to provide a connecting shaft fixing structure that can prevent the connecting shaft from rotating without applying rotational torque to the connecting bolt, and can easily and reliably fix the connecting shaft even in a narrow place. It is said.

  In order to achieve the above object, the connecting shaft fixing structure of the present invention includes a shaft hole provided in each of the pair of first members, and a shaft hole provided in a second member disposed between the pair of first members. In a connecting shaft fixing structure in which a connecting shaft is inserted to pivotally connect the first member and the second member about the connecting shaft, the connecting shaft is inserted into each shaft hole. A cylindrical collar member having a cylindrical shaft portion and a flange portion provided at one end of the shaft portion, and having a through hole through which the shaft portion of the connecting shaft is inserted on the side opposite to the second member of the first member. A protrusion provided with a flat surface that forms a flat rotation restricting surface in at least one portion of the collar, and abuts against the rotation restricting surface at the tip of the collar member to prevent the connecting shaft from rotating. And connecting the shaft with the collar member and the shaft portion in a radial direction. A bolt is detachably attached, and an insertion groove for a shaft removal tool is provided at the distal end of the collar member so as to contact the flange of the connecting shaft and move the flange toward the distal end of the collar member. You can also.

  According to the fixing structure of the connecting shaft of the present invention, the rotation of the connecting shaft is prevented by contacting the rotation restricting surface provided on the collar portion of the connecting shaft and the flat surface of the protrusion provided on the collar member, The bolt has a function only for retaining the connecting shaft. As a result, the connecting shaft that rotatably connects the second member to the first member can be prevented from being rotated and pulled out without applying excessive torque to the connecting bolt. Furthermore, since the connecting shaft and the connecting bolt can be attached and detached from the collar member side, the connecting shaft can be easily and reliably fixed even in a narrow place. Further, the connecting shaft can be easily extracted by inserting a shaft extraction tool such as a bar into the insertion groove of the shaft extraction tool formed at the tip of the collar member.

  1 to 4 show one embodiment of a connecting member to which the connecting shaft fixing structure of the present invention is applied. FIG. 1 is an exploded perspective view of the connecting member, and FIG. 2 is a sectional view taken along line II-II in FIG. 3 is a plan view of the connecting member, and FIG. 4 is a side view of the connecting member.

  The connecting member 1 of the present embodiment is used, for example, in a portion that connects a hoisting cylinder for hoisting a boom of a crane to a work machine so as to be rotatable, and is provided on the work machine side at a predetermined interval. A pair of brackets 2 and 2 as members, a cylindrical member 3 as a second member provided on the cylinder side, a connecting shaft 4 for rotatably connecting the brackets 2 and 2 and the cylindrical member 3, and a connecting shaft 4 is provided with a connecting bolt 5 for retaining 4 and a collar member 6 for preventing the connecting shaft 4 from rotating.

  The connecting shaft 4 includes a columnar shaft portion 4a and a flange portion 4b provided at one end of the shaft portion 4a. A flat rotation restricting surface 4c is formed in a state parallel to each other at a position opposite to the flange 4b, and in the vicinity of the flange 4b, in a direction orthogonal to the rotation restricting surface 4c, and An insertion hole 4d for inserting the connecting bolt 5 is formed in the radial direction of the shaft portion 4a.

  Each of the brackets 2 and 2 has a shaft hole 2a through which the connecting shaft 4 is inserted in a substantially central portion, and a cylindrical collar having a shaft hole 6a continuous with the shaft hole 2a on the outer surface of one bracket 2. The member 6 is fixed by welding. At the tip of the collar member 6, a pair of protrusions 6 c, 6 c formed with horizontal flat surfaces 6 b, 6 b on the shaft hole 6 a side (center side) are provided facing each other, and the protrusions 6 c, 6 c In the vicinity, insertion holes 6d and 6d for inserting the connecting bolt 5 in the radial direction and the vertical direction are formed to face each other. Further, tool insertion grooves 6e and 6e for inserting a shaft punching tool such as a bar are formed between the front end protrusions 6c and 6c of the collar member 6, respectively.

  Further, the insertion hole 4d and the insertion hole 6d for inserting the connection bolt 5 make the flange portion 4b of the connection shaft 4 abut on the tip of the collar member 6, and the rotation restricting surface 4c and the flat surface 6b. It is provided at a position where the axes of the through holes 4d and 6d are aligned when they are brought into contact with each other.

  The cylindrical member 3 has a shaft hole 3a for inserting the connecting shaft 4 on the central axis, and each shaft hole 2a, 3a, 6a is substantially larger than the outer diameter of the connecting shaft 4. Have the same inner diameter. The axial length (thickness) of the cylindrical member 3 is slightly smaller than the distance between the spacers 2b, 2b provided on the inner surfaces of the brackets 2, 2.

  In the connecting member 1 formed as described above, the cylindrical member 3 is disposed between the brackets 2 and 2, the shaft portion 4 a of the connecting shaft 4 is connected to the shaft hole 6 a of the collar member 6, and the bracket 2 on the collar member 6 side. The shaft member 2 is inserted into the shaft hole 2 a of the bracket 2 on the distal end side through the shaft hole 2 a and the shaft hole 3 a of the cylindrical member 3, and the rotation restricting surfaces 4 c and 4 c formed on the flange portion 4 b of the connecting shaft 4 are protruded from the collar member 6. Insert between 6c and 6c. Thereby, rotation control surface 4c, 4c and flat surface 6b, 6b each contact | abut, and the connection shaft 4 is prevented from rotating.

  Next, the connection bolt 5 is inserted through the insertion holes 6 c and 6 c of the connection bolt 5 formed in the collar member 6 and the insertion hole 4 d of the connection bolt 5 formed in the connection shaft 4, and the connection bolt protruding from below the collar member 6. A nut 7 is screwed onto the male screw portion 5 a of 5, and the connecting shaft 4 is fixed to the collar member 6. Thereby, the connecting shaft 4 is prevented from coming off.

  Since the connecting member 1 is formed as described above, as shown in FIGS. 2 and 3, for example, even in a narrow space in the vicinity of the cab 8 of the work machine, the connecting member 1. Can be installed without problems. Further, the rotation of the connecting shaft 4 is prevented by bringing the rotation restricting surface 4c provided on the collar 4b of the connecting shaft 4 and the flat surface 6b provided on the collar member 6 into contact with each other. The connecting bolt 5 is not subjected to the rotational torque of the connecting shaft 4, and a small-diameter bolt can be used.

  Further, the axis of the insertion holes 4d, 6d, 6d of the connecting bolt 5 is provided so as to be orthogonal to the rotation restricting surface 4c and the flat surface 6b, and the flange portion 4b is brought into contact with the tip of the collar member 6 to thereby prevent the rotation restricting surface. Since the insertion holes 4d, 6d are provided at positions where the axes of the insertion holes 4d, 6d are aligned when the 4c is brought into contact with the flat surface 6b, The axes are aligned, and the connecting bolt 5 can be easily inserted.

  On the other hand, by providing the tool insertion groove 6e, by inserting a shaft removal tool such as a bar into the tool insertion groove 6e with the connecting bolt 5 removed, and moving the collar portion 4b in the direction of the collar tip, The connecting shaft 4 can be easily extracted, and workability can be improved.

  In addition, the number of the rotation restricting surface provided on the flange portion of the connecting shaft and the flat surface of the collar member formed corresponding to the rotation restricting surface is arbitrary, and the number may be provided in at least one place. When the surface is provided at a plurality of positions, the flat surface only needs to be provided so as to be able to abut against the at least one rotation restricting surface and prevent rotation. Moreover, it is also possible to make the outer periphery of the collar part into a polygonal shape such as a triangle or a quadrangle, and to use the entire outer surface of the collar part as a rotation restricting surface.

  Furthermore, the workability of each member can be improved by forming the connection bolt insertion hole so that the connection bolt is inserted in a direction orthogonal to the rotation regulating surface or the flat surface, or in a parallel direction. The insertion direction of the connecting bolt can be arbitrarily set according to conditions such as the installation position of the connecting member, the position of the rotation restricting surface, and the flat surface.

  In addition, the connecting shaft fixing structure of the present invention can be employed in various connecting portions that rotatably connect the first member and the second member.

It is a disassembled perspective view which shows one example of the connection member to which the fixing structure of the connection shaft of this invention is applied. It is II-II sectional drawing of FIG. It is a top view of a connection member similarly. It is a side view of a connection member similarly.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Connection member, 2 ... Bracket, 2a ... Shaft hole, 2b ... Spacer, 3 ... Cylindrical member, 3a ... Shaft hole, 4 ... Connection shaft, 4a ... Shaft part, 4b ... Collar part, 4c ... Rotation restriction surface, 4d ... Insertion hole, 5 ... Connection bolt, 5a ... Male screw part, 6 ... Collar member, 6a ... Shaft hole, 6b ... Flat surface, 6c ... Projection, 6d ... Insertion hole, 6e ... Tool insertion groove, 7 ... Nut, 8 …wall

Claims (2)

A connecting shaft is inserted into a shaft hole provided in each of the pair of first members and a shaft hole provided in the second member disposed between the pair of first members, and the first member and the second member In the fixing structure of the connecting shaft that is connected to be rotatable about the connecting shaft, the connecting shaft includes a columnar shaft portion that is inserted into each shaft hole, and a flange portion provided at one end of the shaft portion. A cylindrical collar member having a through hole through which the shaft portion of the connecting shaft is inserted on the side opposite to the second member of the first member, and a flat rotation restriction at least at one position of the flange portion Forming a surface, and providing a protrusion with a flat surface at the front end portion of the collar member that abuts against the rotation restricting surface and prevents the connection shaft from rotating, and the collar member and the shaft portion are arranged in the radial direction. A connecting shaft that is detachably attached with a connecting bolt that penetrates and prevents the connecting shaft. Fixed structure. The connecting shaft according to claim 1, wherein an insertion groove of a shaft removing tool is provided at a tip portion of the collar member so as to contact the flange portion of the connecting shaft and move the flange portion in the tip direction of the collar member. Fixed structure.

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