JP3424622B2 - Hydraulic excavator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized hydraulic excavator in which a driver's seat is arranged on the upper surface of a shovel body and work attachments are arranged in front of the driver's seat.

[0002]

2. Description of the Related Art Conventionally, in a small hydraulic excavator called a mini excavator, as shown in FIGS. 4 and 5, an upper revolving structure 2 is mounted on a crawler-type traveling structure 1 so as to be rotatable about a vertical axis. The excavator body (base machine) 3 is configured.

A driver's seat 4 is provided in the center of the upper surface of the upper swing body 2 in the excavator body 3, and an engine and other devices (not shown) are provided below the seat of the driver's seat 4 as well as the driver's seat. An operating device (5 is a lever-type operating device as an example thereof) is provided around the device.

Further, a handrail 6 is attached to the front of the driver's seat 4 in the upper swing body 2 over substantially the entire width of the swing body, and a work attachment 7 indicated by a chain double-dashed line in FIG. Is installed.

The work attachment 7 is provided with a boom 8 which can be raised and lowered. In the standard specification (excavation specification), an arm 9 is attached to the tip of the boom 8 and a bucket 10 is attached to the tip of the arm 9. Reference numeral 11 is a boom hoisting cylinder that hoists the boom 8, 12 is an arm cylinder that operates the arm 9, and 13 is a bucket cylinder that operates the bucket 10.

The boom 8 is mounted so as to be swingable in the left and right directions about the vertical axis so that the groove digging work is facilitated.
It is driven by the swing cylinder 14.

[0007]

The handrail 6 is formed in an inverted U shape in which a horizontal rail 6b is horizontally bridged between the upper ends of the left and right vertical rails 6a, 6a so that the driver can lean forward. It is used as a handrail that supports the body by hand when embarking to check the excavated area and getting on and off.

However, in this case, the handrail 6
If the height of the handrail 6 is set to an appropriate size for fulfilling the handrail function, the horizontal rail 6b of the handrail 6 interferes with the boom 8 in a state where the boom 8 is maximally erected.

For this reason, the actual maximum standing angle of the boom 8 is limited to be equal to or less than the angle originally possessed by the shovel, which increases the minimum turning radius of the upper structure including the work attachment 7. there were.

Therefore, conventionally, the handrail 6 as a whole is inevitably lowered in height as shown to prevent interference with the boom 8. However, as a result, the handrail function originally intended for the handrail is significantly lowered. Especially, when the driver gets in and out of the vehicle, the grip portion of the hand is lowered, which makes it difficult to get in and out of the vehicle.

In view of the above circumstances, the present invention provides a hydraulic excavator capable of preventing the boom and the handrail from interfering with each other without significantly lowering the handrail's original handrail function.

[0012]

According to a first aspect of the present invention, a driver's seat is provided on an upper surface of a shovel body having a traveling body, and a work attachment having a hoisting boom is provided at a front portion of the shovel body. In the hydraulic excavator that is mounted, in front of the driver's seat on the upper surface of the excavator body and behind the boom, vertical handrails on both left and right sides and horizontal handrails bridged between the vertical handrails are provided. A handrail is provided, and the height of this handrail is set so that interference with the boom when the boom is in the upright position does not interfere with the boom when the boom is in the upright position. The portion where the interference with the boom does not pose a problem is formed as a higher portion higher than the lower portion.

According to a second aspect of the present invention, in the structure of the first aspect, the boom is arranged offset to the right side of the shovel body in the vehicle width direction when viewed from the driver's seat, and the lower portion is located on the right side of the handrail. , The higher part is formed on the left side.

According to a third aspect of the present invention, in the construction of the first or second aspect, the boom is mounted so as to be swingable right and left around the vertical axis, and the lower portion does not interfere with the boom throughout the entire swing operating range of the boom. It is provided in the range.

According to the above structure, the height of the handrail is lowered only in the portion where the interference with the boom is a problem (the lower portion) to avoid the interference with the boom, while in the other portion (the higher portion) the hand is lowered. It is possible to secure a sufficient height for sliding. That is, it is possible to prevent interference between the boom and the handrail while maintaining the required handrail function.

In particular, according to the second aspect of the invention, since the left side portion where the driver frequently gets on and off can be made high, it is possible to sufficiently secure the function as a grip portion for assisting getting on and off.

According to the structure of claim 3, in the so-called swing type shovel in which the boom swings left and right,
Interference between the boom and the handrail can be prevented throughout the entire swing operation range.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to FIGS.

In this embodiment, the same parts as those of the conventional hydraulic excavator shown in FIGS. 4 and 5 are designated by the same reference numerals, and their duplicate description will be omitted.

Boom 8 which constitutes work attachment 7
Is offset to the right with respect to the vehicle width center L as shown in FIG. 3 (right side when viewed from the driver's seat 4, the same with regard to the left-right directionality described below) (α in FIG. 3 is this offset). The amount of movement is shown), and the swing cylinder is configured to be swingable left and right around the vertical axis O by a swing cylinder (not shown).

In FIG. 3, the dotted line a indicates the front of the boom 8, the one-dot chain line b indicates the maximum leftward direction, and the two-dot chain line c indicates the maximum rightward state.

The handrail 15 is provided in front of the driver's seat 4 on the upper surface of the upper swing body 2 constituting the shovel body 3 and over the entire width of the swing body.

Since the handrail 15 is located right behind the boom 8, there is a problem of interference with the boom 8 when the boom 8 is in the maximum standing state as described above.

In this case, since the boom 8 is arranged offset to the right with respect to the center of the vehicle width, there is a problem of interference with the boom 8 on the right side portion of the handrail 15. Further, since the boom 8 swings left and right, this interference range occurs in the width direction range equal to or larger than the boom width dimension.

Therefore, in this hydraulic excavator, the right side portion 15A of the handrail, where the problem of interference with the boom 8 arises, does not interfere with the boom 8 in the maximum boom standing state throughout the entire swing operation range (for example, in FIG. 2). The height to ground (h1 = 1,033 mm) is set, and the left side portion 15B having no problem of interference with the boom 8 is higher than the right side portion 15A and is necessary and sufficient in height to fulfill the original handrail function. The dimensions (the same h2 = 1,153 mm) are set.

That is, the handrail 15 is formed in a stepped shape in which the lower portion 15A and the higher portion 16B are continuous with a step.

As a concrete configuration, as shown in FIG. 2, the lower portion 15A is formed in a hook shape in which a vertical handrail portion 16 and a horizontal handrail portion 17 are continuous at an obtuse angle. On the other hand, the higher part 15B
Is a vertical handrail portion 18 which is higher than the vertical handrail portion 16 of the lower portion 15A, a lower horizontal handrail portion 19 which is an extension of the horizontal handrail portion 17 of the lower portion 15A, and the lower horizontal handrail portion 1
9 and an upper horizontal handrail portion 20 which is parallel to the rail 9.

In this hydraulic excavator in which the boom 8 swings, the lower portion 15A is usually the higher portion 1A.
It is formed in a range wider than 5B in the width direction (for example, a size range about twice as large as the high-order portion 15B).

According to this structure, the left high-order portion 15B of the handrail 15 can secure a necessary and sufficient height for fulfilling the handrail function while preventing the boom 8 and the handrail 15 from interfering with each other. As a result, the handrail function is not significantly reduced.

In particular, in the case of this embodiment, the left side portion 15B of the handrail, which has a high frequency of getting on and off, has a high height, and this portion 15B effectively functions as a grip portion when getting on and off, so that the handrail function is actually deteriorated. It can be kept to a minimum.

By the way, in the above embodiment, the high-order portion 1
5B side handrail part, both lower and upper side handrail parts 1
It has a double structure consisting of 9 and 20, but upper handrail part 2
A single structure composed of only 0 may be used.

On the other hand, when the boom 8 is arranged offset to the left side contrary to the above embodiment, the left side portion on the side of the boom offset is the lower portion and the right portion is the higher portion, and the boom 8 is not offset. In the case of being arranged on the vehicle width center line L, the center portion of the handrail, which causes a problem of interference with the boom 8, may be the lower portion and the left and right side portions may be the higher portions.

Further, in the above-mentioned embodiment, the swing type hydraulic excavator is applied as an example, but the present invention can also be applied to a hydraulic excavator which does not perform a swing operation.

[0034]

As described above, according to the present invention, the portion of the handrail where interference with the boom poses a problem is set as the lower portion, and its height is set to a dimension that does not cause interference with the boom when the boom is upright. Since the part where the interference with the boom is not a problem is made higher than the low part, it avoids the interference between the handrail and the boom.
At other portions (higher portions) of the handrail, it is possible to secure a sufficient height as a handrail. That is, it is possible to prevent interference between the boom and the handrail while maintaining the required handrail function.

In particular, according to the second aspect of the present invention, the left side portion, where the driver frequently gets on and off, can be made higher, so that the function as a grip portion for assisting getting on and off can be sufficiently ensured.

According to the invention of claim 3, in a so-called swing type shovel in which the boom swings left and right,
Interference between the boom and the handrail can be prevented throughout the entire swing operation range.

[Brief description of drawings]

FIG. 1 is a side view of an upper swing body of a hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a plan view of the same.

FIG. 4 is a side view of a conventional hydraulic excavator.

FIG. 5 is a front view of the same.

[Explanation of symbols]

3 excavator body 1 Excavator body running body 2 Upper revolving structure of excavator body 4 driver's seat 7 work attachment 8 boom 15 Handrail 15A Lower part of the handrail 16 Vertical handrails in the lower part 17 Same side handrail Higher part of 15B handrail 18 Vertical handrails in the high part 19 Same as the lower horizontal handrail 20 Upper handrail part

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Claims (3)

(57) [Claims] 1. A hydraulic excavator in which a driver's seat is provided on an upper surface of an excavator body having a traveling body, and a work attachment having a hoisting boom is attached to a front portion of the excavator body. At the front of the driver's seat on the upper surface of and behind the boom, there are provided handrails having vertical handrails on both left and right sides and horizontal handrails bridged between the vertical handrails. , The part where interference with the boom is a problem in the standing state of the boom is set as a lower part and the height is set to a dimension that does not cause interference with the boom in the standing state of the boom,
A hydraulic excavator characterized in that a portion where interference with the boom does not matter is formed as a higher portion higher than the lower portion. 2. The hydraulic excavator according to claim 1,
A hydraulic excavator characterized in that a boom is arranged offset to the right side when viewed from the driver's seat with respect to the center of the excavator body in the vehicle width direction, and a low portion is formed on the right side of the handrail and a high portion is formed on the left side. 3. The hydraulic excavator according to claim 1, wherein the boom is swingably attached to the left and right around the vertical axis, and the lower portion is provided in a range that does not interfere with the boom throughout the entire swing operation range of the boom. A hydraulic excavator that is characterized.