JPH0710058U - Swivel joint mounting structure - Google Patents

Abstract

(57) [Summary] [Purpose] The conventional swivel joint mounting part is
A plate-shaped bracket is welded to the inner surface of the center frame standing plate, and a reinforcing rib is provided between the bracket and the lower plate. However, the thickness of the bracket is thin, the screw depth is not sufficient, and the portion holding the swivel joint is hung over the reinforcing rib. Due to the above causes, the mounting bolt may be loosened or the welded portion may be cracked. This problem is solved. [Structure] In the present invention, a longitudinal support plate is fixedly attached to the bottom surface of the swivel joint, and the front and rear portions of the support plate are fixed to the undercarriage so as to fix the undercarriage of the undercarriage. A thick plate block is welded to the front mounting position and the rear mounting position of the center frame, respectively, and the front and rear portions of the supporting plate are screwed to the thick plate blocks before and after that.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a mounting structure for a swivel joint mounted on a construction machine such as a hydraulic excavator or a work vehicle.

[0002]

[Prior art]

 FIG. 3 is a partially cutaway side view of the lower traveling body 1 of the hydraulic excavator. In the figure, 2 is a lower frame, 3 is a swivel bearing, 4 is a swivel joint, 5 is a support plate of the swivel joint 4, 6 and 7 are bolts, 8 is a center frame of the lower frame 2, and 9 is a center frame. Front and rear standing plates of the frame 8, 10 are lower plates, 11 is a bracket welded to the standing plate 9, and 12 is a reinforcing rib of the bracket 11. FIG. 4 is a plan view of a main part of the lower traveling body 1 in FIG. FIG. 5 is an enlarged perspective view of a portion A of the center frame 8 in FIG. As shown in FIGS. 3 to 5, the swivel bearing 3 is attached to the upper part of the lower traveling body 1, and the swivel joint 4 is arranged at the axis of the swivel bearing 3. Also, the support plate 5 is attached to the bottom surface of the swivel joint 4 with bolts 6, and the front and rear parts of the support plate 5 are mounted on the bracket 11 welded to the front of the center frame 8 and the rear standing plates 9 and 9. It is fixed with bolt 7.

[0003]

[Problems to be solved by the device]

 When using a hydraulic excavator, vertical movement or shock is generated in the swivel joint section due to the operation of an attachment (not shown) or traveling on uneven terrain, and the center plate is attached via the support plate attached to the bottom of the swivel joint. − Apply an excessive moment load to the attachment part on the worm side. However, the conventional mounting portion is formed by welding a plate-shaped bracket to the inner surface of the center frame standing plate and inserting a reinforcing rib between the bracket and the lower plate and welding. However, the thickness of the bracket is thin, and the threaded portion for holding the support plate is hung over the reinforcing rib. As a result, cracks may occur at the weld between the bottom surface of the bracket and the reinforcing rib where the maximum bending moment acts. In addition, the thickness of the bracket was small and the screw depth could not be sufficiently secured, which sometimes caused loosening of the bolt. The present invention aims to solve the above problems.

[0004]

[Means for Solving the Problems]

 According to the present invention, longitudinal support plates are fixedly attached to the bottom surface of the swivel joint, and the front and rear portions of the support plates are fixed to the undercarriage so that the center frame of the undercarriage is fixed. A thick plate block was welded to each of the front and rear mounting positions of the frame, and the front and rear portions of the supporting plate were screwed to the front and rear thick plate blocks.

[0005]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial cutaway side view of a lower traveling body 13 showing attachment of a swivel joint of the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. Reference numeral 14 is a lower frame, 15 is a center frame of the lower frame 14, and 16 is a thick plate block. FIG. 2 is an enlarged perspective view of a portion B of the center frame 15 in FIG.

Next, the mounting structure of the swivel joint of the present invention will be described with reference to FIGS. The undercarriage 13 of the present invention is a swivel joint in which a slewing bearing 3 is attached to an upper part of a lower frame 14, and an axis of the slewing bearing 3 is provided near an upper part of the lower frame 14 and a supporting plate 5 is attached to a bottom part thereof. 4 are arranged. Further, thick plate blocks 16 are arranged on the front and rear upper surfaces of the lower frame 10 of the center frame 15, which correspond to the front and rear mounting positions of the support plate 5, respectively, and on the inner surfaces of the standing plates 9 and 9. They are brought into contact with each other and welded, and the support plate 5 is attached with bolts 7.

Next, the operation of the swivel joint mounting structure of the present invention will be described. In the present proposal, the thick plate blocks 16 are provided on the front and rear upper surfaces of the lower plate 10 of the center frame 15, which correspond to the front and rear mounting positions of the support plate 5 mounted on the bottom surface of the swivel joint 4. , The lower plate 10 and the standing plate 9 are welded all around. As described above, vibrations and impact loads that are exerted on the swivel joint 4 by the operation of the attachment and traveling on uneven terrain act on the threaded portion of the thick plate block 16 via the support plate 5, and the thick plate block 16 Bending moment is generated. However, since the bending strength of the thick plate block 16 is very high and the depth of the screw hole can be sufficiently set, the loosening of the mounting bolt can be prevented. Furthermore, since welding is performed over the entire circumference of the contact area between the lower plate 10 and the upright plate 9, the welding strength can be increased.

[0008]

[Effect of device]

 In the prior art, a thin plate bracket is welded to the center frame and a reinforcing rib is provided. However, the wall thickness of the bracket was thin and the screw depth was not sufficient. In the present invention, a thick plate block is used instead of the bracket and the reinforcing rib. As a result, the problem of strength against bending load was solved, the screw depth was sufficient, the bolt was prevented from loosening, and the strength of the weld was improved. Furthermore, the cost was reduced by reducing the number of parts. Also, by preventing distortion of the brackets, loosening of bolts, and cracks in the welded parts, uneven wear of the seal inside the swivel joint or the sliding parts of the inner and outer joints is prevented to prevent oil leakage, At the same time, it is possible to prevent the hydraulic pipe joint from loosening and prevent oil leakage.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a lower traveling body showing mounting of a swivel joint of the present invention.

FIG. 2 is an enlarged perspective view of a B portion of the center frame in FIG.

FIG. 3 is a partially cutaway side view of a lower traveling body showing attachment of a conventional swivel joint.

FIG. 4 is a plan view of a lower traveling body in FIG.

5 is an enlarged perspective view of a portion A of the center frame in FIG.

[Explanation of symbols]

 1,13 Lower traveling body 2,14 Lower frame 3 Slewing bearing 4 Swivel joint 5 Support plate 8,15 Center frame 9 Stand plate 10 Lower plate 11 Bracket 12 Reinforcing rib

Claims (1)

[Scope of utility model registration request] 1. An upper slewing construction machine in which a swivel joint is arranged near the upper portion of a lower traveling structure at the axis of a slewing bearing.
In order to fix the longitudinal support plates to the front and rear and to fix the front and rear parts of the support plates to the undercarriage, the front and rear mounting positions of the center frame of the undercarriage are respectively set. A swivel joint mounting structure characterized in that a thick plate block is welded, and front and rear portions of a support plate are screwed to the thick plate blocks before and after it.