JP2000230241A - Working machine structure of revolving working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the strength of a boom and improve the working property of piping by extending an angle rib fixed to the tip of the boom in the boom base end direction along the upper back surface of the boom, and arranging a bucket cylinder hydraulic hose arranged within the boom through the opening of the extension part. SOLUTION: An angle rib 50 formed by bending a sheet member is fixed to the tip of a boom 6, and the angle rib 50 is extended toward the base end of the boom 6 to form an extension part 50a along the inside surface of the upper back surface 6e of the boom 6. A substantially circular opening allowing the communication between the inside and outside of the boom 6 is formed on the extension part 50a of the angle rib 50, and a working machine driving bucket cylinder hydraulic hose 21 arranged within the boom 6 is connected to a bucket cylinder 9-side hydraulic piping through the opening. A cover 55 is attachably and detachably mounted on the opening from the outside. According to this, the boom strength can be ensured, and the hydraulic hose 21 arranged within the boom can be maintained through this opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a working machine such as a backhoe mounted on a turning work vehicle, and more particularly, to a configuration of a boom tip of the working machine.

[0002]

2. Description of the Related Art Conventionally, in a turning work vehicle equipped with a working machine such as a backhoe, a boom constituting the working machine,
The arm, the work attachment, and the like are driven by a hydraulic device such as a hydraulic cylinder. Hydraulic oil is supplied from a hydraulic pump disposed on the revolving unit to the hydraulic device of the work machine through a hydraulic hose. A hydraulic hose that extends from the revolving structure and supplies hydraulic oil to hydraulic equipment such as a bucket cylinder when a bucket is mounted as an arm cylinder or a work attachment extends along the back of the boom from the lower end of the boom upward. The hydraulic hose that supplies hydraulic oil to the bucket cylinder has been piped along the back of the boom to the end of the boom. An arm fulcrum bracket for rotatably supporting the arm is fixedly provided at the boom tip, and a portion of the arm fulcrum bracket projecting forward from the boom tip is formed of a thick plate-like member. Was.

[0003]

However, as described above,
When a hydraulic hose that supplies hydraulic oil to the working machine is piped along the back of the boom, the hydraulic hose approaches the cabin or the canopy when the boom is lifted, so that the rising angle of the boom is limited. Further, since it is necessary to secure a space for disposing the hydraulic hose between the boom and the cabin or the like, the amount of forward projection of the boom bracket supporting the boom has been increased. As a result, the turning radius of the turning work vehicle is increased, and the front-rear balance of the vehicle body is deteriorated, so that the stability is reduced. Then, when trying to pipe a hydraulic hose inside the boom in order to increase the rising angle of the boom, etc., it is necessary to form an opening for performing maintenance and the like of the hydraulic hose at the end of the boom, etc. Forming the opening would reduce the strength of the boom. In addition, in order to make the hydraulic hose that supplies hydraulic oil to the bucket cylinder follow the pivoting operation of the arm, it is necessary to bend the hydraulic hose at the connection between the boom and the arm. Since the piping is provided along the back of the boom, the degree of bending when the hydraulic hose is bent becomes large, and the life of the hydraulic hose is shortened. Furthermore, the protruding part of the arm fulcrum bracket composed of the thick plate-like member from the boom tip is chamfered with a milling cutter or the like so that the cross-sectional area becomes gradually smaller in order to avoid concentration of stress at the joint with the boom. Since the machining was performed, many man-hours were required for machining the arm fulcrum bracket.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, according to claim 1, a boom rotatably attached to a revolving body configured to be pivotable, an arm rotatably attached to the boom, and a work implement attachment rotatably attached to the arm. In a turning work vehicle equipped with a working machine having a working machine, a hydraulic hose for working machine drive extending from the revolving unit is piped inside the boom, and an angle rib fixed to the end of the boom is provided along the back of the boom. An opening hole extending toward the boom base end portion and communicating the outside and the inside of the boom was formed in the extending portion of the angle rib.

According to a second aspect of the present invention, a boom rotatably mounted on a revolving body which is configured to be rotatable, an arm rotatably mounted on the boom, and a rotatably mounted on the arm. In a turning work vehicle equipped with a working machine having a working machine attachment, a hydraulic hose for working machine driving extending from the revolving unit is piped in the boom,
The hydraulic hose is taken out from the upper inclined surface of the angle rib fixed to the boom tip, the hydraulic hose is divided at the upper inclined surface, and the hydraulic hose is taken out to the outside with the hydraulic hose that is piped into the boom. The hydraulic hose on the other side was detachably connected to the upper inclined surface.

According to a third aspect of the present invention, a boom rotatably attached to a revolving body which is configured to be pivotable, an arm rotatably attached to the boom, and a rotatably attached to the arm. In a turning work vehicle provided with a working machine having a working machine attachment, a portion of an arm fulcrum bracket fixed to a boom tip portion and supporting an arm, which protrudes forward from the boom tip, is formed by a plurality of thin plate-shaped members. It was constructed by pasting each other.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a turning work vehicle having a working machine structure of the present invention, FIG. 2 is a side view showing a support portion of a boom by a turning body, FIG. 3 is a plan view thereof, and FIG. 4 is a side view showing a boom bracket. FIG. 5 is a front view showing a boom bracket and a boom support, FIG. 6 is a side view showing a hose guide mounting structure and a swing pin position fixing structure, and FIG. 7 is a hydraulic hose for an arm cylinder in the middle of the boom. FIG. 8 is a side view showing a piping structure, FIG. 8 is a plan view thereof, FIG. 9 is a side view showing a connection portion between a boom and an arm, and FIG. 10 is a plan view thereof.

First, the configuration of a turning work vehicle having a working machine structure according to the present invention will be described. In FIG. 1, the turning work vehicle supports a revolving unit 2 at the upper center of the crawler type traveling device 1 so as to be able to turn left and right. Arranged freely. Above the revolving superstructure 2, a hood 4 for covering the engine is disposed, and above the revolving superstructure 2, a cabin 8 for covering the operation unit is disposed. A boom bracket 12 is attached to the front end of the swing body 2 so as to be rotatable left and right. The lower end of the boom 6 is supported by the boom bracket 12 so as to be rotatable up and down. The boom 6 is bent forward at an intermediate portion, and is formed in a substantially “C” shape having a bent portion 6 d in a side view. The arm 5 is rotatably supported at the upper end of the boom 6, A bucket 4 as a work attachment is rotatably supported at the tip of the arm 5. A working machine 7 is configured by the boom 6, the arm 5, the bucket 4, and the like.

The boom 6 is connected to the boom cylinder 1
1, the arm 5 is rotated by the arm cylinder 10
The bucket 4 is rotated by the
Is rotated. The boom cylinder 11, the arm cylinder 10, and the bucket cylinder 9 are configured as hydraulic cylinders.
The hydraulic pump is arranged in the hood 4 and supplies hydraulic oil through a hydraulic hose to be driven to expand and contract. The boom cylinder 11 is a boom bracket 1
The arm cylinder 10 is interposed between the cylinder supporting portion 12b of the second boom 2 and a boom cylinder bracket 36 provided on the front of the middle of the boom 6, and the arm cylinder 10 is provided with an arm cylinder bottom bracket 31 and an arm 5 provided on the back of the middle of the boom 6.
The bucket cylinder 9 is interposed between the bucket cylinder bracket 30 and the bucket bracket 29 connected to the bucket 4.

Next, as the structure of the working machine 7, the structure of a support portion of the lower end of the boom 6 by the revolving unit 2 is shown in FIGS.
This will be described below. Swing pin 1 at the front end of revolving unit 2
The boom bracket 12 is pivotally supported via 3 through the left and right sides. The lower end of the boom 6 branches into two branches to form support portions 6a, respectively, and the upper end of the boom bracket 12 branches into two branches corresponding to the respective support portions 6a.
Are supported, and the boom 6 is supported by the boom bracket 12 by rotatably connecting each support portion 6a and the support bracket 12a with a pivot pin 18. In addition, each support bracket 12a is further formed to be branched into two branches, and supports the support portion 6a of the boom 6 so as to sandwich the support portion 6a from both right and left sides. Also, the boom 6 and the boom bracket 12
The lower end of the boom cylinder 11 interposed therebetween is rotatably supported by the cylinder support portion 12b of the boom bracket 12.

A hydraulic hose 23 for a boom cylinder, a hydraulic hose 22 for an arm cylinder, and a hydraulic hose 21 for a bucket cylinder extend forward from the front of the revolving unit 2. The arm cylinder hydraulic hose 22 and the bucket cylinder hydraulic hose 21 are piped into the boom 6 from between the support portions 6a of the boom 6 branched into two branches.
Hydraulic oil pumped from a hydraulic pump disposed in the bonnet 9 is supplied to the arm cylinder 10 and the bucket cylinder 9.

A guide hole 12 is provided below each support bracket 12a of the boom bracket 12.
c, and a hydraulic hose 21 for the boom cylinder from the front of the revolving unit 2 penetrates the guide hole 12c forward. The boom cylinder hydraulic hose 21 that has passed through the guide hole 12c extends downward and bypasses the cylinder support portion 12b of the boom bracket 12, and then the boom cylinder 11
It is connected to the. Further, ribs 12d protruding forward are formed downward from both left and right sides of each support bracket of the boom bracket 12, respectively.
A valley 12e formed between the ribs 12d on the left and right sides.
Are piped so that the hydraulic hose 21 for the boom cylinder that passes through the guide hole 12c passes therethrough.

Further, the cylinders 11 and 11
Since the lengths of the hydraulic hoses 21, 22 and 23 required by 10.9 are different depending on the rotation posture state of the boom 6, each hydraulic hose 21, 22 and 23 has a front part of the revolving unit 2, the boom 6 and Between the hydraulic hoses 21, 22, and 23 near the support portion 6 a serving as the pivot of the boom 6 or the cylinder support portion 1 of the boom bracket 12.
2b.
It is configured to reduce the deflection allowance of 2.23.

The front end of the revolving unit 2 and the boom bracket 12
A swing pin 13 connected to the boom bracket 12 penetrates the boom bracket 12 in the up-down direction, and an upper end portion of the swing pin 13 projects above the upper surface of the boom bracket 12 between the support brackets 12a. A notch 13a is formed on the side of the protrusion of the swing pin 13,
A detent plate 15 fixed with bolts or the like on the upper surface of the boom bracket 12 is engaged with the notch 13a so that the swing pin 13 does not rotate with respect to the boom bracket 12, that is, the swing pin 13 and the boom bracket 12. 12 are configured to rotate integrally.

On the upper surface of the swing pin 13, a base plate 14b of a hose guide 14 is fixed by bolts or the like. In plan view, the outer shape of the base plate 14b is formed larger than the outer shape of the swing pin 13, and when the swing pin 13 moves downward, the base plate 14b is locked on the upper surface of the boom bracket 12. It has become possible. On the upper surface of the base plate 14b, for example, a guide portion 14a, which is a guide member formed by bending a rod-shaped member to have a substantially "U" shape, is provided in an upright manner.
And each hydraulic hose 21.2 extended from the revolving superstructure 2
2 and 23 are piped into the boom 6 after passing through the guide portion 14a, or pass through the guide hole 12c of the boom bracket 12. That is, the hose guides 14 guide the hydraulic hoses 21, 22 and 23 to regulate the piping positions in the horizontal direction and the vertical direction.

As described above, the hose guide 14 regulates the piping positions of the hydraulic hoses 21, 22 and 23, so that when the boom bracket 12 rotates left and right or when the boom 6 rotates vertically, Hydraulic hose 21
22 and 23 are the support brackets 12a and 12a and the boom 6
The hydraulic hoses 21 and 22 can always pass near the support portions 6a.

As described above, the hose guide 14 is fixed to the upper surface of the swing pin 13, and the hydraulic guides 21, 22, and 23 are guided by the hose guide 14 and then piped into the boom 6 to thereby provide a boom bracket. Since the hose guide 14 can be provided in a small space at the upper part of the boom 12 and the hydraulic hoses 21, 22, and 23 are not provided on the back of the boom 6, the amount of the boom bracket 12 protruding forward can be suppressed. As a result, the turning radius of the turning body 2 can be reduced, and the stability in the front-rear direction can be improved. The outer shape of the base plate 14b of the hose guide 14 is the same as the swing pin 13 in plan view.
Boom bracket 1
Since the swing pin 13 can be locked to the upper surface, the swing pin 13 can also function as a safety device for preventing the swing pin 13 from dropping downward. Further, since the hose guide 14, the swing pin 13, and the boom bracket 12 are integrally rotatable, the boom bracket 12
When the hydraulic hoses 21 are rotated left and right, the hydraulic hoses 21, 22, 23 by the hose guide 14 are adjusted in accordance with the rotational direction.
The guide direction of each hydraulic hose 2 also changes.
1, 22, 23 can be prevented from being damaged by contact with the boom bracket 12 or the boom 6.

Further, by forming the support portion 6a at the lower end of the boom 6 bifurcated, each of the hydraulic hoses 21 and 22 to be piped into the boom 6 can be piped in the vicinity of the support portion 6a serving as a rotation fulcrum of the boom 6. Thus, the bending allowance of each of the hydraulic hoses 21 and 22 can be reduced and the boom bracket 12 can be moved toward the cabin 8, and the turning radius of the revolving unit 2 can be reduced to improve the front-rear balance. it can.
Further, a guide hole 12c for penetrating the boom cylinder hydraulic hose 23 is provided below each support bracket 12a of the boom bracket 12 configured corresponding to each support portion 6a.
By forming the guide hole 12c, the hydraulic hose 23 for the boom cylinder can be guided by the guide hole 12c, the hose guide can be simplified, and the connection between the revolving unit 2 and the boom cylinder 11 can be made in a short distance. It is possible to optimize the piping of the hydraulic hose 23 for the boom cylinder.

Ribs 12d are formed on both sides of each support bracket 12a so as to extend downward.
By passing the boom cylinder hydraulic hose 23 passing through the guide hole 12c in the valley 12e between 2d, the boom cylinder hydraulic hose 23 can be guided without providing a special hose guide, The hose guide can be simplified and the boom cylinder hydraulic hose 23 can be prevented from being damaged.

Each of the hydraulic hoses 21, 22 and 23 extending from the front part of the revolving unit 2 is divided by a frame upper plate 2 a of the revolving unit 2. That is, each hydraulic hose 21
Of the parts 22 and 23, the part from the inside of the revolving superstructure 2 to the frame upper plate 2a and the part extending from the frame upper plate 2a to the work machine 7 side are divided, and the bulkhead connector 25 It is detachably connected via. Thus, each of the hydraulic hoses 21, 22 and 23 is connected to the frame upper plate 2a.
The hydraulic hoses 21, 22, and 23 are separately connected to the inside of the revolving unit 2 and to the revolving unit before the work unit 7 is attached to the revolving unit 2 at the time of assembling the revolving work vehicle or the like. 7, and after the working machine 7 is attached to the revolving structure 2, the hydraulic hoses 21 ・ 2 are connected to the frame upper plate 2a.
2 and 23 can be connected, so each hydraulic hose 2
It becomes possible to facilitate the assembly work of 1.22 / 23. In addition, each of the hydraulic hoses 21 of the portion piped to the working machine 7
-When replacing 22 and 23 for maintenance or the like, replacement work can be facilitated.

Further, since a large load is applied to the support portion 6a at the lower end of the boom 6 which is a pivotal support point of the boom 6, the support portion 6a is formed by a cast member, and the load is not applied as much as the support portion 6a. The boom main body 6b above the support portion 6a is formed of a plate-like member such as a steel plate in order to reduce the weight of the boom 6. The support portion 6a and the boom main body 6b are connected by welding or the like, and a reinforcing plate 19 formed of a plate-like member is attached to the connection portion from the inside to reinforce strength. . The reinforcing plate 19
Is formed such that the lower part, which is in contact with the support part 6a, is made thicker, and becomes thinner toward the upper part in contact with the boom body 6b. As described above, the reinforcing plate 19 is formed so as to become thinner from the lower portion to the upper portion, so that the rigidity of the upper portion of the reinforcing plate 19 in contact with the boom main body 6b is reduced. Therefore, the support 6
When stress is applied to a, the boom main body 6b formed of a plate-shaped member can release and relieve the stress by bending, even at the portion where the reinforcing plate 19 is attached. Accordingly, it is possible to prevent stress applied to the boom 6 from being concentrated on the boundary between the upper end of the reinforcing plate 19 and the boom main body 6b, and the boom including the joint between the boom main body 6b and the support portion 6a is provided. 6, and the load resistance can be improved. In addition, by forming the upper portion of the reinforcing plate 19 to be thin, the weight and cost of the reinforcing plate 19 can be reduced.

Next, as the structure of the working machine 7, the structure in the middle of the boom 6 will be described with reference to FIGS.
As described above, the boom 6 is bent forward in the middle and is formed in a substantially “U” shape in side view. The arm cylinder bottom bracket 31 is provided on the back of the middle of the boom 6 and the base end of the arm 5. The arm cylinder bottom bracket 31
Between the arm and the bucket cylinder bracket 30
The arm cylinder 10 for rotating the arm is interposed.
The upper end of the arm cylinder 10 is supported by a bucket cylinder bracket 30, and the lower end of the arm cylinder 10 is supported by an arm cylinder bottom bracket 31.

The arm cylinder bottom bracket 31
Are provided on the back surface of the boom 6 in a pair on the left and right sides and are disposed near the bent portion 6d. I have. The hose outlet 6c has a bent portion 6
upper back surface 6 which is located above d and is formed in a planar shape
e, an arm cylinder hydraulic hose 22 extending from the revolving structure 2 and housed in the boom 6 is taken out through the hose outlet 6c and connected to the arm cylinder 10.

Further, a cover mounting seat 32 formed of a thick plate-like member is fixedly provided at a peripheral portion of the hose outlet 6c. A mounting plate 33 protruding toward the inside of the boom 6 is fixed to the cover mounting seat 32, and the arm plate hydraulic hose 22 is supported by the mounting plate 33. The arm cylinder hydraulic hose 22 is divided into the revolving unit 2 side and the arm cylinder 10 side at a portion supported by the mounting plate 33, and the revolving unit 2 side and the arm cylinder 10
The side is connected to each other at the portion of the mounting plate 33 using the partition wall connector 25 to form the divided connection portion 26.
Further, a hydraulic hose support bracket 34 protruding toward the inside of the boom 6 is fixed to the cover mounting seat 32, and the hydraulic hose support bracket 34 is provided with a hydraulic hose for a bucket cylinder piped in the boom 6. 2
1 is supported.

The mounting plate 33 is provided on the upper back surface 6 of the boom 6.
The arm cylinder hydraulic hose 22 is supported in a direction substantially perpendicular to the surface direction of the mounting plate 33. And mounting plate 3
The angle θ1 formed by the upper back surface 3e and the upper back surface 6e is substantially the same as the angle θ2 formed by the lower back surface 6f located below the bent portion 6d of the boom 6 and the mounting plate 33. That is, the angle θ1 between the mounting plate 33 and the upper back surface 6e is the bending angle of the boom 6 and the upper back surface 6e.
And approximately half the angle formed by the lower back surface 6f.

A cover body 35 is attached to the cover mounting seat 32 from the outside, and the cover body 35 closes the hose outlet 6c. The cover body 35 is fixed to a cover mounting seat 32 with bolts or the like.
And a cover 35a for closing the hose outlet 6c. The cover 35a is formed so as to enter the inside of the boom 6 obliquely from the upper end to the lower end of the cover mounting seat 32. Have been. The cover portion 35a is connected to the external hose 22 of the arm cylinder hydraulic hose 22 extending from the mounting plate 33 to the outside.
a, and is located on the inner side of the boom 6 with respect to the external hose 22a.

As described above, on the back of the boom 6 between the left and right bottom brackets 31 supporting the lower end of the arm cylinder 10, a hose outlet for taking out the arm cylinder hydraulic hose 22 built in the boom 6 to the outside. By forming the hose outlet 6c, the hose outlet 6c has a structure surrounded by a strong bottom bracket 31, so that the strength of the back surface of the boom 6 where the hose outlet 6c is formed can be secured, and It is also possible to apply to the working machine. Further, since the strength of the back surface of the boom 6 can be ensured, the hose outlet 6c can be largely opened, and the hydraulic hose 22 for the arm cylinder can be opened.
Etc. and the maintainability can be improved. further,
Since the bottom brackets 31 are erected on both left and right sides of the portion where the hose outlet 6c is formed, the hose outlet 6c is hidden by the bottom bracket 31 and cannot be seen, thereby preventing the appearance design from being damaged. In addition, by installing a hydraulic hose such as the arm cylinder hydraulic hose 22 in the boom, a large boom rising angle can be obtained,
It is possible to reduce the turning radius.

Further, the bottom bracket 31 is disposed near the bent portion 6d of the boom 6, and the hose outlet 6c is formed in the upper back surface 6e, which is a flat portion above the bent portion on the back of the boom 6. A cover mounting seat 32 for reinforcing the hose outlet 6c and attaching a cover body 35 that closes the hose outlet 6c is fixed to the periphery of the outlet 6c, so that the hose outlet 6c is provided.
And the cover body 35 can be easily formed and attached, and the hose outlet 6 on the back of the boom 6 can be formed.
The strength of the c-formed portion can be further improved.

Further, the cover body 35 is formed so as to be located inside the arm cylinder hydraulic hose 22a and to enter the inside of the boom 6, and the cover body 35 is attached to the hose outlet 6c forming portion to form the cover body 35. By closing the hose outlet 6c, it is possible to prevent earth and sand, dust and the like from entering the boom 6 from the hose outlet 6c.

In the vicinity of the bent portion 6d of the boom 6, a divided connecting portion 26 for dividing and connecting the hydraulic hoses 22 and 22a provided in the boom 6 is formed, and a mounting plate 33 for supporting the divided connecting portion 26 is provided. The angle θ between the mounting plate 33 and the boom back surface 6e above the bent portion 6d.
1 and the angle θ2 between the mounting plate 33 and the boom back surface 6f below the bent portion 6d are arranged to be substantially the same angle, so that the lower portion of the boom 6 passes through the bent portion 6d and Hydraulic hoses 22 and 2 for arm cylinders that are taken out of the hose outlet 6c above the bent portion 6d and are supported by the mounting plate 33 near the bent portion 6d.
2a can be prevented from being sharply bent or bent into an unnatural shape in the vicinity of the bent portion 6d, and the hydraulic hoses 22 and 22a for the arm cylinder can be smoothly and smoothly piped. Becomes

Next, as the structure of the working machine 7, the structure of the tip of the boom 6 will be described with reference to FIGS. An angle rib 50 and a pair of left and right arm fulcrum brackets 51 are fixedly provided at the distal end of the boom 6. The angle rib 50 is formed by bending a plate-like member, and is attached so as to connect the tip of the upper front face 6g and the tip of the upper back face 6e in the boom 6. The attachment side of the angle rib 50 to the upper back surface 6e extends toward the base end of the boom 6 along the inner surface of the upper back surface 6e to form an extension 50a. Also,
The portion connecting the upper front surface 6g and the upper rear surface 6e is formed in a convex shape protruding forward from the end of the boom 6 toward the center in a side view, and the portion from the substantially center to the rear side is inclined upward. It is formed as a surface 50c.

A substantially circular opening 50b is formed in the extending portion 50a of the angle rib 50 for communicating between the inside and the outside of the boom 6, and a bucket cylinder piped into the boom 6 from the opening 50b. The maintenance of the hydraulic hose 21 can be performed. In addition, the angle rib 5 at the tip of the upper back surface 6e of the boom 6
The portion where the opening 50b is formed is cut out to form a notch 6
h. The cover body 55 is detachably attached to the opening hole 50b from the outside so that the opening hole 50b is closed when the working machine 7 that does not perform maintenance or the like is used, so that earth and sand, dust and the like do not enter the boom 6. ing.

As described above, since the extending portion 50a of the angle rib 50 formed of a thick plate-like member extends at the distal end of the boom 6, the notch 6h is formed in the upper back surface 6e. Even if the opening 50b is formed, the strength of the boom 6 can be secured. Accordingly, it is not necessary to provide a reinforcing member such as a reinforcing patch around the opening 50b, and the number of components can be reduced.
Further, since the strength of the boom 6 can be ensured, the opening 50b can be formed large, and the workability of assembling and maintenance such as piping work of the hydraulic hose 21 for the bucket cylinder can be improved. it can.

On the other hand, the arm fulcrum bracket 51 is composed of a bracket 52 formed of a thin plate-like member and a reinforcing plate 53, and the bracket 52 is fixed to the tip of the boom 6, Extends to the other side. A reinforcing plate 53 is attached inside a portion of the bracket 52 extending from the end of the boom 6. In addition, only the bracket 52 is joined to the boom 6 at the joint between the arm fulcrum bracket 51 and the tip of the boom 6. Further, an arm 5 is supported at the front end of the arm fulcrum bracket 51 and is configured to be rotatable around an arm fulcrum 54.

As described above, at the joint between the arm fulcrum bracket 51 and the boom 6, the thin plate-shaped bracket 5 is provided.
Since only 2 is joined to the boom 6, it is possible to prevent stress from being concentrated on the joint due to bending of the bracket 52 or the like. This eliminates the need for milling or the like for the bracket 52 or the reinforcing plate 53, thereby reducing the number of processing steps for the arm fulcrum bracket 51.

The hydraulic hose 21 for the bucket cylinder, which is provided in the boom 6, is connected to the upper inclined surface 5 of the angle rib 50.
The bucket cylinder hydraulic hose 21 is taken out to the outside through a take-out hole 50d formed in the outside cylinder 0c and connected to the bucket cylinder 9, and the bucket cylinder hydraulic hose 21 is moved by the upper slope 50c in a direction substantially perpendicular to the plane direction of the upper slope 50c. Supported. The bucket cylinder hydraulic hose 21 has an upwardly inclined surface 50c on the side of the revolving superstructure 2 provided inside the boom 6 and on the side of the bucket cylinder 9 taken out.
The revolving unit 2 side and the bucket cylinder 9 side are connected to each other using a partition wall connector 25 at the upper inclined surface 50c. The portion taken out of the bucket cylinder hydraulic hose 21 is configured as an external hose 21a.

As described above, the hydraulic hoses 21 and 21a for the bucket cylinder are connected to the upper inclined surface 50c of the angle rib 50.
When supported by the bucket cylinder hydraulic hose 2
At the tip of the boom 6, the pipes 1 and 21 a are arranged so as to be inclined more upward than when they are piped to the back of the boom 6. The external hose 21a of the bucket cylinder hydraulic hose 21 turns the arm 5 having the largest connection length from the upper inclined surface 50c to the bucket cylinder 9 to the lowest position in order to follow the turning operation of the arm 5. Because the piping is adjusted to the required length when it is moved,
When the arm cylinder 10 is contracted and the arm is rotated upward, the external hose 21a bends.

Since the outer hose 21a is piped so as to incline upward when the bucket cylinder hydraulic hose 21 is piped to the back of the boom 6, the outer hose 21a is bent when the outer hose 21a is bent. The degree of bending of the hose 21a is smaller than in the case where piping is provided on the back of the boom 6.
This reduces the amount of deflection of the outer hose 21a,
The space required when the outer hose 21a bends can be reduced, and even when the outer hose 21a bends, the outer hose 21a can be installed between the pair of left and right bucket cylinder brackets 30.

[0039]

As described above, the present invention has the following advantages. That is, as in claim 1,
Hydraulic hoses for driving the work equipment extending from the revolving structure are piped into the boom, and an angle rib fixed to the end of the boom is extended toward the base end of the boom along the back surface of the boom. Since the opening for communicating the outside and the inside of the boom is formed in the extension of the boom, the strength of the boom can be secured even if the opening is formed at the tip of the boom. Accordingly, it is not necessary to provide a reinforcing member such as a reinforcing patch around the opening hole, and the number of components can be reduced. In addition, since the strength of the boom can be secured,
The opening hole can be formed large, so that assembling workability such as piping work of the hydraulic hose and maintenance performance can be improved.

Further, a hydraulic hose for driving a working machine, which is extended from the revolving unit, is piped into the boom, and the hydraulic hose is connected to the angled rib fixed to the end of the boom from the upper inclined surface of the angle rib. Take out to the outside, divide the hydraulic hose at the part of the upper inclined surface, and detachably connect the hydraulic hose that is piped inside the boom and the hydraulic hose that is taken out to the outside with the upper inclined surface Therefore, the degree of bending of the hydraulic hose when the hydraulic hose is bent can be made smaller than when the hydraulic hose is piped to the back of the boom.
This makes it possible to reduce the amount of deflection of the hydraulic hose and reduce the space required when the hydraulic hose bends. Even when the hydraulic hose bends, it is provided at the connection between the boom and the arm. An external hose can be provided between the pair of left and right bucket cylinder brackets.

Further, a plurality of thin plate-like members are attached to a portion of the arm fulcrum bracket fixed to the end of the boom and supporting the arm, which protrudes forward from the end of the boom. With this configuration, when stress is applied to the arm fulcrum bracket, it is possible to prevent the stress from concentrating on the joint between the arm fulcrum bracket and the boom due to bending of the arm fulcrum bracket. Accordingly, it is not necessary to perform processing by the fly or the like on the arm fulcrum bracket, and the number of processing steps of the arm fulcrum bracket can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a turning work vehicle having a working machine structure of the present invention.

FIG. 2 is a side view showing a support portion of the boom by a swing body.

FIG. 3 is a plan view of the same.

FIG. 4 is a side view showing a boom bracket.

FIG. 5 is a front view showing a boom bracket and a support portion of the boom.

FIG. 6 is a side view showing a hose guide mounting structure and a swing pin position fixing structure.

FIG. 7 is a side view showing a piping structure of a hydraulic hose for an arm cylinder in a middle part of the boom.

FIG. 8 is a plan view of the same.

FIG. 9 is a side view showing a connecting portion between the boom and the arm.

FIG. 10 is a plan view of the same.

[Explanation of symbols]

 2 Revolving body 5 Arm 6 Boom 6e Upper back 6g Upper front 6h Notch 7 Work implement 9 Bucket cylinder 10 Arm cylinder 21 Hydraulic hose for bucket cylinder 21a External hose 25 Partition wall connector 30 Bucket cylinder bracket 50 Angle rib 50a Extension 50b Opening Hole 50c Upper inclined surface 51 Arm fulcrum bracket 52 Bracket 53 Reinforcement plate 54 Arm fulcrum

Claims (3)

[Claims] 1. A boom rotatably mounted on a revolving structure that is configured to be rotatable, an arm rotatably mounted on the boom, and a work implement attachment rotatably mounted on the arm. In a turning work vehicle equipped with a working machine, a hydraulic hose for driving the working machine extending from the revolving structure is piped into the boom, and an angle rib fixed to the end of the boom is provided along the back of the boom at the base end of the boom. A working machine structure for a turning work vehicle, characterized in that the opening portion extends in the direction of the part, and an opening hole communicating between the outside and the inside of the boom is formed in the extending portion of the angle rib. 2. A boom that is rotatably attached to a revolving body that is configured to be pivotable, an arm that is pivotally attached to the boom, and a work implement attachment that is pivotally attached to the arm. In a turning work vehicle equipped with a working machine, a hydraulic hose for driving the working machine, which is extended from the revolving unit, is piped into the boom, and the hydraulic hose is externally connected from an upper inclined surface of an angle rib fixed to a tip of the boom. And the hydraulic hose was divided at the portion of the upper inclined surface, and the hydraulic hose on the side piped in the boom and the hydraulic hose on the side taken out were detachably connected at the upper inclined surface. A working machine structure for a turning work vehicle, characterized in that: 3. A boom that is rotatably attached to a revolving body that is configured to be pivotable, an arm that is rotatably attached to the boom, and a work implement attachment that is rotatably attached to the arm. In a turning work vehicle equipped with a working machine, a portion of an arm fulcrum bracket fixed to a boom tip and supporting an arm, which protrudes beyond the boom tip, is configured by attaching a plurality of thin plate members to each other. A working machine structure of a turning work vehicle, characterized in that: