HYDRAULIC EXCAVATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2011-116494 filed on May 22, 2012, the disclosure of which is hereby incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a hydraulic excavator that is equipped with various kinds of actuator that are driven by hydraulic fluid supplied through hydraulic lines.

2. Description of the Related Art

Hydraulic excavators have been used in the past which comprised an upper structure capable of revolving with respect to a lower traveling unit that travels by rotating crawler belts, and in which a boom, bucket, or other such work implement driven by hydraulic pressure was installed on the upper structure.

For example, the following Japanese Laid-Open Patent Application No. 2010-106450 (laid open on May 13, 2010) discloses a hydraulic excavator in which hydraulic hoses connected to a main valve disposed to the side of a work implement are disposed via an attachment component attached to the side face of the work implement (boom).

SUMMARY

However, the following problems were encountered with the conventional hydraulic excavator discussed above.

Specifically, with the hydraulic excavator disclosed in the above-mentioned publication, since the hydraulic hoses are attached to the side face of the boom, if the outer frame portion of the upper structure of the hydraulic excavator (such as cover of the operating fluid tank) happens to be large in size, then when the boom is driven up and down, there is the risk that the attachment component of the hydraulic hoses will interfere with part of the outer frame.

It is an object of the present invention to provide a hydraulic excavator with which interference between the hydraulic hoses and part of the outer frame can be avoided even when the outer frame of the upper structure is large, and thereby to extend the service life of the hydraulic hoses.

The hydraulic excavator pertaining to a first aspect comprises a lower traveling unit capable of traveling by rotating crawler belts, an upper structure, a boom, a work tool, a plurality of hydraulic cylinders, a main valve, hydraulic hoses, and an attachment component. The upper structure sits on the lower traveling unit in a revolvable state. The boom is attached on the upper structure in a state that allows it to be driven in the up and down direction around a rotational axis by hydraulic pressure. The work tool is mounted to the distal end of the boom and is used to perform various kinds of work. The hydraulic cylinders are provided along the boom to drive the boom and the work tool. The main valve is disposed to the side of the boom on the upper structure. The hydraulic hoses are connected at a first end to the main valve and at a second end to the hydraulic cylinders, and supply hydraulic fluid from the main valve to the hydraulic cylinders. The attachment component fixes the middle portion of the hydraulic hoses to the upper face of the boom.

With a hydraulic excavator that performs work by supplying hydraulic fluid to a hydraulic cylinder that drives a boom mounted on the upper structure, or a work tool attached to the distal end of the boom, an attachment component is provided so that the middle portion of the hydraulic hoses, which supply hydraulic fluid from a main valve disposed to the side of the boom on the upper structure, to the various hydraulic cylinders, will be disposed on the upper face of the boom.

The above-mentioned work tool includes a bucket, a ripper, a cutter, and the like. The “upper face of the boom” means the face on the cab side in the direction in which a boom with a box structure is driven up and down.

Consequently, since part of the hydraulic hoses is disposed on the upper face of the boom, the amount of bending of the hydraulic hoses that occurs when the boom is moved up or down can be controlled within the proper range better than with a conventional structure in which the middle portion of the hydraulic hoses is fixed to the side face of the boom.

As a result, even if the outer frame height of the upper structure should increase due to the installation of more devices on the upper structure as is common today, the hydraulic hoses can be prevented from interfering with part of the outer frame of the upper structure, and this extends the service life of the hydraulic hoses.

The hydraulic excavator pertaining to a second aspect is the hydraulic excavator pertaining to the first invention, wherein the hydraulic hoses are disposed along the outer frame portion of the upper structure in a state in which the boom has been raised as far as it will go.

Here, the hydraulic hoses are disposed along the outer frame portion of the upper structure in a state in which the boom has been lifted to its highest position.

Consequently, the hydraulic hoses can be prevented from interfering with the outer frame portion of the upper structure at the boom position with the greatest amount of bending of the hydraulic hoses.

The hydraulic excavator pertaining to a third aspect is the hydraulic excavator pertaining to the second invention, further comprising a bracket that is provided at a location opposite the attachment component and near the main valve. The hydraulic hoses are disposed linearly between the bracket and the attachment component.

Here, the bracket is provided near the main valve in order to linearly guide the hydraulic hoses connected at a first end to the main valve toward the upper face (attachment component) of the boom.

Consequently, the hydraulic hoses connected at the first end to the main valve can easily be guided linearly via the bracket toward the upper face (attachment component) of the boom.

The hydraulic excavator pertaining to a fourth aspect is the hydraulic excavator pertaining to any of the first to third inventions, wherein the bracket has a seat part that is attached along the forward and backward direction of the body, and a guide part that is disposed at an angle to the seat part and guides the hydraulic hoses.

Here, a bracket is used which has a seat part that is attached along the forward and backward direction of the body, and a guide part that is disposed at an angle to the seat part.

The “forward and backward direction of the body” here refers to the forward and backward direction in a state in which an operator is sitting in the driver's seat of the cab of the hydraulic excavator.

Consequently, the use of a bracket with a simple structure allows the hydraulic hoses to be disposed linearly from the main valve to the attachment component by guiding the hydraulic hoses, which are connected at the first end to the main valve disposed to the side of the boom, toward the upper face of the boom.

The hydraulic excavator pertaining to a fifth aspect is the hydraulic excavator pertaining to any of the first to fourth inventions, wherein the attachment component has a connector that is fixed to the side face of the boom, and a fixing part that fixes the hydraulic hoses so that they are disposed on the upper face of the boom.

Here, an attachment component is used which has a connector that is fixed to the side face of the boom, and a fixing part that fixes the hydraulic hoses so that they are disposed on the upper face of the boom.

Consequently, the fixing site of the attachment component itself can be provided to the boom side face, and the hydraulic hoses can be fixed to the upper face of the boom.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an overall oblique view of the configuration of the hydraulic excavator pertaining to an embodiment of the present invention;

FIG. 2 is an oblique view of the internal configuration around a work implement in a state in which the outer frame of the hydraulic excavator in FIG. 1 has been removed;

FIG. 3 is a side view of the configuration around the work implement of the hydraulic excavator in FIG. 1;

FIG. 4 is a rear view of the configuration around the work implement of the hydraulic excavator in FIG. 1;

FIG. 5 is a cross section of the configuration around an attachment component for fixing a plurality of hydraulic hoses to the boom upper face in the hydraulic excavator in FIG. 1;

FIG. 6 is a plan view of the internal configuration around the work implement in a state in which the outer frame of the hydraulic excavator in FIG. 1 has been removed;

FIG. 7 is an oblique view of the configuration around a bracket that fixes the hydraulic hoses in the configuration in FIG. 5;

FIG. 8 is an oblique view of the configuration of the bracket in FIG. 6;

FIG. 9 is a side view of the bending state of the hydraulic hoses when the boom of the hydraulic excavator in FIG. 1 is driven up and down; and

FIG. 10 is an oblique view of the movement of the hydraulic hoses when the boom of the hydraulic excavator in FIG. 1 is moved up and down between the upper and lower ends.

DETAILED DESCRIPTION OF THE INVENTION

The hydraulic excavator 1 pertaining to an embodiment of the present invention will now be described through reference to FIGS. 1 to 10.

The “forward and backward” and “left and right” directions used in the following description refer to the directions as seen by the operator seated in the seat inside the cab 10 of the hydraulic excavator 1.

Overall Configuration of Hydraulic Excavator 1

The hydraulic excavator 1 pertaining to this embodiment is a short rear-end swing type of hydraulic excavator, and as shown in FIG. 1, comprises a lower traveling unit 2, an upper structure 3, a work implement (actuator) 4, a counterweight 5, an engine compartment 6, and a cab 10.

The lower traveling unit 2 moves the hydraulic excavator 1 forward and backward by rotating crawler belts P wrapped around the left and right end portions in the travel direction, and has the upper structure 3 installed in a revolvable state on top.

The upper structure 3 is able to revolve in any direction on top of the lower traveling unit 2, and is equipped on its upper face with the work implement 4, the counterweight 5, the engine compartment 6, the cab 10, and a main valve 22 (see FIG. 2). As shown in FIG. 2, the upper structure 3 has a work implement mounting component 3a to which the end of a boom 11 included in the work implement 4 is fixed in a rotatable state. The work implement mounting component 3a is provided to as to protrude upward from a main boom of the upper structure, on the upper face of the upper structure 3, and a rotary shaft that serves as the rotational axis of the boom 11 is mounted.

As shown in FIG. 2, the work implement 4 is attached in a rotatable state to the work implement mounting component 3a provided in the approximate center of the upper face of the upper structure 3. As shown in FIG. 1, the work implement 4 has the boom 11, which is bent at its center portion, an arm 12 attached to the distal end of the boom 11, and a bucket (work tool) 13 attached to the distal end of the arm 12. The hydraulic excavator 1 drives hydraulic cylinders 11a, 12a, and 13a by hydraulic fluid supplied through hydraulic hoses 20, and thereby performs work at a construction site, in which the boom 11, the arm 12, the bucket 13, etc., are moved up and down while excavating dirt, gravel, etc. The configuration around this work implement 4 will be discussed in detail below.

The counterweight 5 consists, for example, of a box made of sheet metal and filled with scrap iron, concrete, or the like, and is provided to the rear of the engine compartment 6 on the upper structure 3 to balance the body during digging or the like.

As shown in FIG. 1, the engine compartment 6 is disposed adjacent to the counterweight 5, and has a top opening that is used for inspection and is covered by an engine hood 14 that can be opened and closed. The engine compartment 6 internally houses an engine (not shown) that serves as the power source for driving the lower traveling unit 2 and the work implement 4, a cooling core (not shown), and so forth.

The cab 10 has an interior space in which the operator of the hydraulic excavator 1 rides. The cab 10 has on its left side face an access door for ingress and egress to and from the interior space by the operator.

As shown in FIG. 2, the main valve 22 is disposed to the side of the work implement mounting component 3a on the upper structure 3 in order to supply hydraulic fluid from a hydraulic pump to the hydraulic cylinders 11a, 12a, and 13a via the plurality of hydraulic hoses 20. The disposition of the main valve 22 will be discussed in detail below.

Because the hydraulic excavator 1 in this embodiment is a short rear-end swing type, there is less space on the upper face side of the upper structure 3 than with an ordinary hydraulic excavator. Therefore, in this embodiment, the main valve 22 is provided to the right, rather than to the rear, of the work implement mounting component 3a on the upper face side of the upper structure 3.

Configuration Around Work Implement 4

As discussed above, the hydraulic excavator 1 in this embodiment has the hydraulic cylinders 11a, 12a, and 13a for respectively driving the boom 11, the arm 12, and the bucket 13 that constitute the work implement 4.

The hydraulic cylinders 11a, 12a, and 13a are driven by hydraulic fluid supplied from the plurality of hydraulic hoses 20, which are each connected at one end (first end) to the main valve 22 disposed to the right of the work implement mounting component 3a on the upper structure 3, and at the other end (second end) to the hydraulic cylinders 11a, 12a, and 13a.

As shown in FIG. 2, the hydraulic hoses 20 are connected at their first end to the main valve 22, are fixed at their middle portions to the upper face 11b of the boom 11, and are connected at their second end to the hydraulic cylinders 11a, 12a, and 13a. As shown in FIG. 3, the hydraulic hoses 20 are disposed conforming to the shape of a outer frame portion H of the upper structure 3 so as not to come into contact with the outer frame portion H, due to the disposition of an attachment component 21 (discussed below), etc., in a state in which the boom 11 has been raised as far as it will go. Consequently, damage to the hydraulic hoses 20 can be prevented even when the boom 11 is repeatedly moved up and down to and from the highest position of the boom 11 at which there is the most bending of the hydraulic hoses 20.

The attachment component 21, which gathers and fixes the hydraulic hoses 20, is provided at a location slightly lower than the center of the boom 11. A bracket 23 and a hose clamp 24 that gather the hydraulic hoses 20 and guide them to the upper face 11b side of the boom 11 are provided to a first end side of the hydraulic hoses 20.

As shown in FIG. 4, the attachment component 21 is provided in order to gather the hydraulic hoses 20 and fix them on the upper face 11b of the boom 11. As shown in FIG. 5, the attachment component 21 has a connector 21a fixed to the side face 11c of the boom 11, and a fixing part 21b that gathers the hydraulic hoses 20 and fixes them on the upper face 11b of the boom 11.

The connector 21a is formed from a flat steel plate, and is fixed to the side face 11c of the boom 11 with a plurality of bolts 31. The fixing part 21b is the portion that gathers the hydraulic hoses 20 and fixes them on the upper face 11b of the boom 11, and is formed by bending the flat steel plate in an approximate U shape. That is, in this embodiment, the attachment component 21 itself is fixed to the side face 11c of the boom 11 at the portion of the flat connector 21a. On the other hand, the attachment component 21 gathers the hydraulic hoses 20 and fixes them on the upper face 11b of the boom 11 at the portion (the fixing part 21b) connected to the flat connector 21a.

As shown in FIG. 6, the main valve 22 is disposed to the side of the boom 11 on the upper structure 3. “Is disposed to the side of the boom 11” means that it is disposed at a location that is offset from the center line of the boom 11.

As shown in FIG. 6, the bracket 23 is provided near the main valve 22 in order to gather the hydraulic hoses 20 connected at their first end to the main valve 22 disposed to the right of the work implement mounting component 3a, and guide them substantially linearly toward the upper face 11b of the boom 11, that is, the fixing part 21b of the attachment component 21 fixed to the boom 11. More specifically, as shown in FIG. 7, the bracket 23 is attached to the side face on the main valve 22 side of the work implement mounting component 3a disposed in the forward and backward direction of the hydraulic excavator 1. The bracket 23 is a member obtained by bending a flat steel plate, and has a seat part 23a and a guide part 23b, as shown in FIG. 8.

The seat part 23a is part of a flat steel plate having a plurality of holes into which bolts are inserted, and as shown in FIG. 7, it is fixed with these bolts to the side face of the work implement mounting component 3a.

As shown in FIG. 8, the guide part 23b is part of a flat steel plate formed so as to be inclined at a specific angle to the seat part 23a fixed to the side face of the work implement mounting component 3a, and the hose clamp 24 is attached thereto. The bending angle of the guide part 23b with respect to the seat part 23a, as shown in FIG. 6, is set so as to gather the hydraulic hoses 20 and guide them substantially linearly toward the upper face 11b of the boom 11. That is, the guide part 23b is set with respect to the seat part 23a attached in the forward and backward direction of the hydraulic excavator 1, so that it faces the direction in which the hydraulic hoses 20 are to be guided toward the upper face 11b of the boom 11.

As shown in FIG. 7, the hose clamp 24 is attached to the guide part 23b in order to gather the hydraulic hoses 20 and guide them substantially linearly toward the upper face 11b of the boom 11. That is, the hose clamp 24 is attached to the guide part 23b that is bent at a specific angle to the seat part 23a, which allows the hydraulic hoses 20 to be gathered and guided substantially linearly toward the upper face 11b of the boom 11.

Movement of Hydraulic Hoses 20 as Boom 11 Moves Up and Down

As discussed above, the hydraulic excavator 1 in this embodiment comprises the main valve 22 installed to the right of the work implement 4 on the upper structure 3, and the attachment component 21 that gathers the middle portion of the hydraulic hoses, which are connected at their first end to the main valve 22, and fixes them on the upper face 11b of the boom 11.

Therefore, as shown in FIG. 9, the amount of bending of the hydraulic hoses 20 can be controlled so that it is within a suitable range, from the position S1 of the boom 11 during transportation of the hydraulic excavator 1 (see the solid lines in the drawing), to the position S2 at which the boom 11 has been lowered as far as it will go, and to the position S3 at which the boom 11 has been raised as far as it will go.

Specifically, at the position S2 of the boom 11 at which the boom 11 has been lowered as far as it will go, the distance from the bracket 23 attached near the main valve 22 to the attachment component 21 attached to the boom 11 is at its maximum. Therefore, the amount of bending of the hydraulic hoses 20 is at its minimum. At this point a suitable amount of bending of the hydraulic hoses 20 is maintained as shown in FIG. 9.

Next, at the position S1 of the boom 11 during transportation of the hydraulic excavator 1, the distance from the bracket 23 to the attachment component 21 is slightly shorter than at the position S2 of the boom 11, so the amount of bending of the hydraulic hoses 20 increases slightly, but there is not enough bending for the hoses to come into contact with the outer frame portion H of the upper structure 3.

Next, at the position S3 at which the boom 11 has been raised as far as it will go, the distance from the bracket 23 attached near the main valve 22 to the attachment component 21 attached to the boom 11 is at its minimum. Therefore, the amount of bending of the hydraulic hoses 20 is at its maximum. However, in this embodiment, as shown in FIG. 3, the hydraulic hoses 20 with their greatest amount of bending can be disposed along the outer frame portion H of the upper structure 3 even at the position S3 of the boom 11 at which the amount of bending of the hydraulic hoses 20 is greatest.

Consequently, the amount of bending of the hydraulic hoses 20 can be kept within a suitable range during the raising and lowering of the boom 11, and since the hydraulic hoses 20 are disposed so as not to come into contact with the outer frame portion H of the upper structure 3 even at the position S3 of greatest bending, the hydraulic hoses 20 can be prevented from coming into contact with part of the outer frame portion H as the boom 11 moves up and down, which could damage the hydraulic hoses 20.

Also, with the hydraulic excavator 1 in this embodiment, the range of fluctuation in the amount of bending of the hydraulic hoses 20 accompanying the up and down movement of the boom 11 can be kept within a suitable range without moving the attachment position of the attachment component 21, which gathers the hydraulic hoses 20 and fixes them on the upper face 11b of the boom 11, with respect to the boom 11 to a higher position than in the past.

Consequently, there is no impingement on the height restriction during transportation, when the hydraulic excavator 1 is transported in a state of being loaded onto the bed of a trailer.

Furthermore, with the boom 11 in this embodiment, as shown in FIG. 6, the hydraulic hoses 20 are disposed substantially linearly from the bracket 23 disposed near the main valve 22, toward the upper face 11b of the boom 11.

Consequently, twisting of the hydraulic hoses 20 that occurs when the boom 11 is moved up and down can be kept to a minimum.

Also, with the hydraulic excavator 1 in this embodiment, as shown in FIG. 3, the hydraulic hoses 20 are disposed along the outer frame portion H so as not to come into contact with the outer frame portion H of the upper structure 3 at the position of the hydraulic excavator 1 that has been raised as far as it will go.

Consequently, even when the boom 11 is repeatedly moved up and down to the highest position of the boom 11 at which there is the greatest amount of bending of the hydraulic hoses 20, the hydraulic hoses 20 can be prevented from coming into contact with the outer frame portion H of the upper structure 3, which would damage them.

Other Embodiments

An embodiment of the present invention was described above, but the present invention is not limited to or by the above embodiment, and various modifications are possible without departing from the gist of the invention.

In the above embodiment, an example was given of using the attachment component 21, which included the connector 21a composed of a flat steel plate, and the fixing part 21b formed by working the flat steel plate into an approximate U shape, but the present invention is not limited to this.

The shape of the attachment component 21 can be suitably changed according to the number and shape of the hydraulic hoses 20 and the direction in which they are to be guided.

In the above embodiment, an example was given in which the bracket 23 that gathered the hydraulic hoses 20 and guided them onto the upper face 11b of the boom 11 was formed by bending a flat steel plate, but the present invention is not limited to this.

The shape of the bracket 23 can be suitably changed according to the number and shape of the hydraulic hoses 20 and the direction in which they are to be guided.

In the above embodiment, an example was given of a hydraulic excavator 1 to which a bucket 13 was mounted as a work tool (attachment) that was attached to the distal end of the work implement 4, but the present invention is not limited to this.

For example, the present invention may be applied to a hydraulic excavator in which a ripper, cutter, or some other such work tool is mounted to the distal end of the work implement.

The hydraulic excavator of the present invention has the effect of avoiding interference between the hydraulic hoses and part of the outer frame of the upper structure, which prevents damage to the hydraulic hoses, so it can be widely applied to construction machines that supply hydraulic fluid to various kinds of actuator via hydraulic hoses.

HYDRAULIC EXCAVATOR

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