JP3232992B2 - Construction machine step equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping device mounted on a side frame of a lower traveling body for an operator or the like in a construction machine such as a hydraulic excavator to get on and off a driver's cab.

[0002]

2. Description of the Related Art A typical example of a construction machine is a hydraulic shovel. This hydraulic excavator has the configuration shown in FIG. In FIG. 1, reference numeral 1 denotes a lower traveling body, and 2 denotes an upper revolving superstructure. The undercarriage 1 has a sprocket 4 as a driving wheel and an idler 5 as a driven wheel rotatably supported at both front and rear ends of a side frame 3 connected to a main frame (not shown). A crawler belt 6 constituting an infinite traveling rail is wound and provided between the idler 5 and the idler 5. Although not shown, the sprocket 4 is connected to a hydraulic motor, and by operating this hydraulic motor, traveling by the crawler belt 6 is performed.

[0003] The upper swing body 2 is installed on the lower running body 1 via a swing device 7 so as to be swingable. The upper swing body 2 is provided with a driver's cab 8 for an operator to operate. And a front working mechanism 9 in front of the cab 8.
Is provided. The front working mechanism 9 includes a boom 9 a provided on the upper swing body 2 so as to be capable of raising and lowering.
arm 9b connected to the tip of a so as to be rotatable in the vertical direction
And a front attachment provided at the tip of the arm 9b. In the illustrated example, a bucket 9c is shown as the front attachment.

Since the upper revolving unit 2 is located at a position higher than the crawler belt 6, a scaffold for an operator or the like to get on and off the operator's cab 8 is required. As the scaffold, a step device 10 is attached to the side frame 3. . The step device 10 having the configuration shown in FIGS. 4 and 5 is conventionally used.

[0005] That is, as is apparent from the figure, the step device 10 is formed by bending both ends of a long metal plate having a predetermined thickness to thereby form flat bolt connection portions 1 at both ends.
The step plate 11 includes a step plate 11a and a scaffold portion 11b having a middle portion lifted from the bolt connection portion 11a by a predetermined amount, and an upper end surface of the scaffold portion 11b is formed with a non-slip uneven portion. Bolt connecting portions 1 at both ends of this step plate 11
1a is a pair of upper and lower bolt insertion holes 1 respectively.
2, 12 are drilled. Further, a bolt mounting seat 13 having a pair of screw holes 13a is fixedly provided on the side frame 3 by means such as welding. Therefore, the step plate 11 is brought into contact with the bolt mounting seat 13 so that the bolt insertion hole 12 coincides with the screw hole 13a, and the bolt 14 is inserted from the bolt insertion hole 12 into the screw hole 13a provided in the bolt mounting seat 13. The step board 11 is fixedly attached to the side frame 3 by screwing. In the drawing, reference numeral 15 denotes a reinforcing member provided at an intermediate position of the scaffold 11b of the step board 11.

[0006]

By the way, the above-described step device 10 of the prior art has various problems.
First, as is clear from FIG. 5, it is necessary to make a circular or long hole in the step plate 11 for the bolt insertion holes 12 at the upper and lower two places on both bolt connecting portions 11a, respectively, for a total of four places. There is a step board 11
To form the outer portion of the step board by gas cutting, or after bending both ends thereof to form a portion corresponding to the bolt connection portion and the scaffold portion,
Since four holes must be formed, the manufacturing process of the step plate 11 becomes complicated.

When the step plate 11 is mounted on the side frame 3, the step plate 11 is lifted so that at least one bolt insertion hole 12 is aligned with the screw hole 13 a of the bolt mounting seat 13. And a bolt 14 is screwed into the screw hole 13 a of the bolt mounting seat 13 from the bolt insertion hole 12. This bolt insertion hole 1
Until the bolt 14 is screwed into the screw hole 13a to some extent from the state where 2 is aligned with the screw hole 13a, it is necessary to hold the step plate 11 so as not to move. Since the step plate 11 is quite heavy, the step plate 1
There is also a point that the work of screwing in the bolt 14 while stabilizing the lifter 1 is almost impossible to be performed by one worker, and the work of attaching the step plate 11 is not easy. .

Further, since the bolt mounting seat 13 is fixed to the side frame 3 by welding or the like, it is extremely difficult to position the bolt mounting seat strictly. Therefore, even if there is some error, the bolt insertion hole 12 is formed outside the shaft of the bolt 14 so that the bolt 14 can be screwed into the screw hole 13 a of the bolt mounting seat 13 through the bolt insertion hole 12. It must be somewhat larger than the diameter. For this reason, although the step plate 11 is actually provided with a pair of upper and lower bolts 14 at each of the two front and rear positions, a total of four bolts are provided, the actual load is However, there is also a problem that only one of the upper and lower bolts, that is, two bolts can be received.

The present invention has been made in view of the above points, and an object of the present invention is to make it easy to manufacture a step board and to attach / detach it to / from a side frame. The purpose of the present invention is to allow all bolts to be fixed to receive the load by sharing the load.

[0010]

In order to achieve the above-mentioned object, the present invention provides a step board having a bolt insertion portion at a portion corresponding to a bolt mounting portion, and each of the bolt insertion portions is vertically It is characterized in that it has a notch shape from the end.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a step plate 21 constituting a step device 20 includes a flat bolt connecting portion 21a at both ends and a scaffold portion 21b having a middle portion raised by a predetermined amount from the bolt connecting portion 21a. And the scaffold 21b
The upper end surface of the is formed with a non-slip uneven portion.
As shown in FIG. 2, a bolt mounting seat 23 is fixedly provided on the side frame 22 by means of welding or the like. The bolt mounting seat 23 has two screw holes 23U, 23L are provided. Then, the screw hole 23 of the bolt mounting seat 23 is inserted through the bolt insertion portion 21a.
A bolt 24 is screwed into each of U and 23L, and the step plate 21 is fixed so as to sandwich the step plate 21 between the head 24a of the bolt 24 and the bolt mounting seat 23. In the above points, there is no particular difference from the above-mentioned prior art. Since the scaffolding portion 21b of the step board 21 is provided to separate from the side frame 22 by a predetermined distance, if the thickness of the bolt mounting seat is increased, the bolt connecting portion and the scaffolding portion of the step board are not necessarily required. There is no need to compose

The bolt connecting portion 21a located before and after the step plate 21 does not have a circular (or elongated) bolt insertion hole, but has bolt insertion portions 25U and 25L. The bolt insertion portion 25a located on the upper side
It is formed by cutting U-shaped downward from the upper end of the step plate 21, and the bolt insertion portion 25b located on the lower side is cut in an inverted U-shape from the lower end of the step plate 21 upward. It is formed by chipping. Here, the width of each of the bolt insertion portions 25U and 25L is equal to the shaft portion 2 of the bolt 24.
4b is slightly larger than the outer diameter.

Step plate 2 constituting step device 20
The step plate 21 is formed as described above. The step plate 21 is formed by processing a metal plate body by gas cutting or the like so as to conform to the outer shape of the step plate, and bending portions near both ends to form a bolt connection portion 21a.
To form This gas cutting process can be formed integrally with not only the outer portion of the step plate 21 but also the bolt insertion portions 25U and 25L in a so-called one-stroke state. Accordingly, the manufacture of the step plate 21, particularly the processing of the bolt insertion portions 25U and 25L through which the bolts 24 are inserted, can be extremely easily performed.

Next, the step plate 21 is connected to the side frame 2.
2, the bolt 24 (in the following description, the bolt insertion portion 25U is inserted into the lower screw hole 23L of each bolt mounting seat 23 fixed at the front and rear positions of the side step 22). In order to distinguish between the bolt to be inserted and the bolt to be inserted into the bolt insertion portion 25L, the symbols of the bolts 24U and 24L are used, respectively.
Is screwed in. However, the head 24a of the bolt 24L
The distance between the bolt and the surface of the bolt mounting seat 23 is
Is wider than the thickness. In this state, step plate 2
1 is lifted, and the bolts 24L are fitted into the respective bolt insertion portions 25L of the front and rear bolt connection portions 21a. Here, in order to easily fit the bolt 24L into the bolt insertion portion 25L, for example, as shown by an imaginary line in FIG. 1, a call-in portion where the end side of the bolt insertion portion 25L is expanded is formed. be able to. As a result, the load of the step plate 21 is supported by the front and rear bolts 24L, and even if the hand is released from the step plate 21, it does not fall off. Therefore, the bolt 2 inserted into the bolt insertion portion 25L
4L, and the bolt 24U is also inserted into the bolt insertion portion 25U side.
, The step plate 21 can be fixed.

When removing the step plate 21, the bolt 24U on the bolt insertion portion 25U side is removed, and the bolt 24L on the bolt insertion portion 25L side is loosened, so that the step plate 21 can be removed by lifting. Therefore, attachment and detachment of the step plate 21 to and from the side frame 22 become extremely easy.

When the hydraulic excavator is operated while the step board 21 is mounted on the side frame 22 to perform work such as excavation of earth and sand, impacts are applied to the step board 21 from various directions. That is, when climbing over a rock or a structure, an impact or a load acts on the step board 21 in a direction of pushing up from below. In addition, rocks and the like may fall from above, so that an impact or a load acts on the step plate 21 from above. When an upward load is applied to the step plate 21 from below, the wall surface of the bolt insertion portion 25U comes into pressure contact with the bolt 24U, and the load in this direction is supported by the bolt 24U. The direction of the load is such that the bolt 24 is inserted into the bolt insertion portion 25L.
Since L moves away, no load acts on the bolt 24L. Further, when a load acts on the step plate 21 downward from above, the wall surface of the bolt insertion portion 25L comes into pressure contact with the bolt 24L. Therefore, the load in this direction is received by the bolt 24L, and the load is applied to the bolt 24U. Does not work.

As described above, the upper bolt 24U and the lower bolt 24L are shared and received in accordance with the direction of the load acting on the step plate 21, so that either one of the bolts is repeated. Inconveniences such as breakage and other accidents caused by the load can be prevented. Here, in the case of a hydraulic excavator, the external force acting on the step plate 21 is not extremely different between that applied from below and that applied from above due to the characteristics of the work site and the like. 24
There is no significant difference in the load received by the U and 24L. Therefore, the life of the bolt for fixing the step plate 21 is extended.

[0018]

As described above, according to the present invention, the step plate is provided with the bolt insertion portions in the form of cutouts from the upper and lower end surfaces at the portions corresponding to the bolt mounting portions of the side frames. In addition, the step board can be easily manufactured and attached to and detached from the side frame, and the load can be shared and received by all bolts fixing the step board.

[Brief description of the drawings]

FIG. 1 is an external view of a main part of a step plate constituting a step device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along a line XX of FIG. 1 in a state where the step plate is mounted on the side frame.

FIG. 3 is an external view of a hydraulic shovel as an example of a construction machine provided with a step device.

FIG. 4 is an explanatory diagram showing a configuration of a conventional step device.

FIG. 5 is an external view of a main part of a step plate constituting a step device according to the related art.

[Explanation of symbols]

 Reference Signs List 20 Step device 21 Step plate 21a Bolt connecting part 21b Scaffold part 22 Side frame 23 Bolt mounting seat 23U, 23L Screw hole 24, 24U, 24L Bolt 25U, 25L Bolt insertion part

Continued on the front page (72) Inventor Yasuo Masukawa 650, Kunitachicho, Tsuchiura-shi, Ibaraki Pref. Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (JP, U) Japanese Utility Model 4-118835 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60R 3/00 E02F 9/00

Claims (2)

(57) [Claims] 1. A driver's cab and working means are mounted on a lower traveling body provided with driving wheels and driven wheels before and after a side frame, and a crawler belt wound between the driving wheels and driven wheels. The upper revolving superstructure was connected to the side frame,
At a position separated by a predetermined distance in the longitudinal direction, a pair of upper and lower bolt mounting portions are provided, and a step plate is fixed to this bolt mounting portion via a bolt,
A step device for a construction machine, wherein the step plate is provided with bolt insertion portions at portions corresponding to the bolt mounting portions, and each of the bolt insertion portions has a cutout shape from upper and lower ends. . 2. Each of the bolt insertion portions has a U-shaped notch formed from an upper end and an inverted U-shaped notch formed from a lower end. The step device for a construction machine according to claim 1, wherein: