JP3501876B2 - Backhoe working arm structure - Google Patents

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 boom, which is a working arm of a backhoe, an arm, and a boom bracket.

[0002]

2. Description of the Related Art Regarding the structure of a conventional backhoe, as disclosed in Japanese Utility Model Publication No. 62-7462 and Japanese Utility Model Publication No. 4-216722, and as shown in FIG. 44, the entire boom B'is a box type. However, the cylinder and the cylinder hose cannot be arranged inside the boom cylinder BC, and the boom cylinder BC is located at a portion closer to the base end than the bent portion of the boom in a side view (hereinafter, referred to as “base”). (Hereinafter referred to as "end portion"), and an arm cylinder bracket 47 is projectingly provided on the back side of the bent portion so as to pivotally support the base end of the arm cylinder AC. The cylinder AC was disposed on the back side of a portion closer to the tip portion than the bent portion (hereinafter, referred to as a “tip portion”). The belly side of the boom cylinder BC arranged on the belly side of the boom was covered with a cylinder cover 40. The arm A'is also box-shaped, and the bucket cylinder BTC for driving the bucket BT pivotally supported at the tip of the arm A'also has a cylinder bracket 49 projecting from the rear surface of the arm A'to provide the arm A '. Was placed on the back side of. Then, the cylinder hose CH for the arm cylinder AC and the bucket cylinder BTC is piped on the back side of the boom B ′, and in the arm A ′, the cylinder hose CH for the bucket cylinder is piped on the side surface of the arm A ′. Was there. Further, plate members 45 and 46 are attached to the outer side surface of the boom B ′ so as to maintain strength against stress concentration at the boss portion of the end portion, and the arm cylinder AC of the arm cylinder AC is attached to the base end portion of the arm A ′. A cylinder bracket 48 is provided so as to pivotally support the tip of the piston rod and to maintain the strength of the pivotal support portion.

In the backhoe having such a structure, each of the cylinders AC, BC, BTC and the cylinder hose CH is exposed to the outside and is unattractive. Therefore, for example, as shown in Japanese Utility Model Laid-Open No. 6-330538, in order to cover with the boom or arm, the boom or arm is made to have an H-shaped cross section, and a cylinder or a cylinder hose is provided between both side plates of the boom or arm. In some backhoes, the cylinders and the hydraulic hoses are arranged to cover the side plates of the boom, and the boom cylinder is arranged on the back side of the boom in order to further enhance the protection of the boom cylinder.

[0004]

However, when the boom cylinder is arranged on the rear side of the boom, even if the boom cylinder is arranged between both side plates of the boom, the raising angle of the boom is inevitably limited, and the backhoe is inevitably limited. The minimum turning radius of the main body also becomes large. Further, the boom cylinder and the cylinder hose arranged on the rear side of the boom are completely visible from the rear working seat, which is annoying to the operator. When the original configuration is restored as in the former case, the cylinder and the cylinder hose are exposed to the outside again. That is, conventionally, the boom structure has not been such that the boom cylinder is arranged on the ventral side of the boom and the cylinder and the hydraulic hose can be covered with the boom side plate. If a hydraulic hose is to be installed inside the box-shaped boom, a hole for passing the hose must be drilled, and the strength of this part is reduced.

Further, since the boom and the arm are provided with the cylinder pivot portion, the boom and the pivot portion of the arm itself at the tip end portion and the base end portion, stress concentration occurs. In order to strengthen this part, for example, as shown in Japanese Utility Model Publication No. 58-3904,
Plate members 45 and 46 in FIG. 44, and plate members having such bosses for pivotal support were welded and bonded like the cylinder bracket 48, but the bonding side was outside the boom side plate. Therefore, these plate materials were exposed to the outside and looked bad. Further, the boom side plate and the side plate portion of the boom bracket are made thicker in order to improve the strength, but this increases the weight, which is inconvenient for transportation and the fuel cost.

An object of the present invention is to reduce the weight of the working arm of the backhoe and to have sufficient strength.

[0007]

The present invention uses the following means in order to solve the above problems. Claim
In the item 1, in the boom B of the backhoe, a portion closer to the base end than the bent portion having a V shape in a side view is formed into a box shape, and a cylinder hose CH is piped inside the bent portion, and the tip is formed from the bent portion. by cutting the back of the site of the part near the rib plate 6 in parallel to the ventral surface and arranged inside the <br/> rear end of the middle rib plate 6, bent in the vicinity of the arm cylinder boss 10a Then, it is connected to the back surface of the portion near the base end portion.

In claim 2, the boom of the backhoe
B, a cylinder hose CH is provided inside the boom B.
The inside is a reinforcing rib that is parallel to the ventral surface inside
A rib plate 6 is provided, and a cylinder hose CH is also inside.
Guide upper plate 9 and rubber clamp 17
And the mounting seat of the guide member is the middle rib plate 6
It is also used for both purposes .

According to a third aspect, the bag according to the first aspect is
In the work arm structure of Kuho, boom B and arm A
At the end, a boss that pivotally supports the rotation axis of the cylinder or work arm.
In a configuration in which the boss plates 5 having the
Stick the plates 5 and 5 inside the side plates of boom B and arm A.
It is a thing.

In claim 4, the boom of the backhoe
In the boom bracket BB that pivotally supports the base end of B, a convex portion 28b is formed on the outer surface.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. 1 is an overall side view of a backhoe according to the present invention, FIG. 2 is a side view of a boom B, and FIG. 3 is a- in FIG.
a view from the arrow a, FIG. 4 from the view b-b, and FIG. 5 from the same c
-C arrow view, FIG. 6 is a plan view of the front end portion of the boom B, FIG. 7 is the same bottom view of the front end portion, FIG. 8 is the same perspective view of the front end portion, and FIG. 9 is a plan view of the same proximal end portion. 10 is a bottom view of the base end portion, FIG. 11 is a view taken along the line dd in FIG.
12 is a view taken along the line ee, FIG. 13 is a plan view showing the configuration of the middle rib plate 6 of the boom B and the guide portion for hydraulic hose piping, and FIG. 14 is a view taken along the line ff in FIG. Similarly, FIG. 16 is a front view seen from the base end side, FIG. 16 is an internal side view showing the disposition of the arm cylinder AC and the piping structure of the hydraulic hose in the bent portion of the boom B, and FIG. 17 is the hydraulic hose in the bent portion of the boom B. FIG. 18 is a partial front sectional view showing the disposition structure of the pipe guide member, FIG. 18 is a front sectional view of the same as seen from the tip side, and FIG. 19 is a perspective view of the rubber clamp 17.
22 is a perspective view of the clamp 18, FIG. 21 is an internal side view showing the piping configuration of the hydraulic hose at the base end of the boom B, FIG.
Is a plan partial sectional view of the same, FIG. 23 is a plan view showing the disposition structure of the hydraulic hose pipe guide member at the base end of the boom B, FIG. 24 is a front sectional view of the same, and FIG. 25 is a side plate 1 of the boom B. The side view of the boom B which shows one form of the convex-shaped part comprised in an outer surface, FIG.
27 is a side view of the boom B, FIG. 28 is a side view of the boom B, FIG. 29 is a front sectional view of the boom B shown in FIG. 25, and FIG. 30 is a front sectional view of the boom B shown in FIG. 31 is a front sectional view of the boom B shown in FIG. 27, FIG. 32 is a front sectional view of the boom B shown in FIG. 28, and FIG. 33 is a right side view of the boom bracket BB.
4 is a left side view, FIG. 35 is a front view, FIG. 36 is a bottom view, and FIG. 37 (a) is a plan view of the arm A.
38B is a side view, FIG. 38 is a view taken along the line gg in FIG. 37B, FIG. 39 is a view taken along the line hh, FIG. 40 is a view taken along the line ii, and FIG. 41 is the same. j-j arrow view, FIG. 42 is the same k arrow view, FIG. 43 is the same l view, FIG.
4 is a side view of a conventional backhoe.

First, the arrangement of the boom cylinder and the arm cylinder in the backhoe according to the present invention will be described with reference to FIG. A main body 42 is rotatably mounted on the crawler traveling device 41, and the main body 42 includes an operation column 43, an engine base 44, and a seat 45.
Etc. are arranged. A boom bracket BB is horizontally rotatably disposed at the front end of the main body portion 42, and the base end of the boom B bent in a V shape in a side view is provided at the upper end of the boom bracket BB. The boom bracket BB is pivotally supported, and further, the base end of the boom cylinder BC is pivotally supported at the front end of the boom bracket BB. That is, in this backhoe, the boom cylinder BC is located at a portion closer to the base end than the bent portion of the boom B (hereinafter, “proximal end portion”).
It is arranged on the ventral side. The boom cylinder BC has a ventral surface covered with a cylinder cover 40 to prevent damage when the boom cylinder BC interferes with another object. Further, a portion closer to the tip end than the bent portion (hereinafter referred to as “tip tip end portion”)
In, the arm cylinder AC is arranged inside the boom 1, and the side thereof is covered with the side plate of the boom B. A bucket BT is pivotally supported at the tip of the arm A, and a bucket cylinder BTC is arranged on the back side of the arm A so as to be covered by a side plate.

The structure of the boom B will be described. As shown in FIG. 2, the two side plates 1 and 1 each having a “<” shape in side view and a “U” shape in cross section as shown in FIG. 3 are bonded together. Welding plate materials 2 and 3 for bonding are bonded to the upper and lower bonded portions. Note that, as will be described later, the bonded portion by the welding plate material 2 is notched on the rear surface side of the tip end portion, so only the rear surface side of the proximal end portion is formed, and the bonded portion by the welding plate material 3 is the boom B. Over the entire length of the abdomen.

Regarding the portion near the tip from the tip which is the arm pivot part to the bent portion of the V shape in side view,
This will be described with reference to FIGS. 2 and 6 to 8. A hole 1a for pivoting the arm base end is formed at the tip of each side plate 1.1, and a tip boss plate 5 is welded to the inside of each hole 1a hole. The tip boss plate 5 is provided with an arm boss 5a communicating with the hole 1a. The rear side of the tip end portion is notched from the base end to the tip end of the boom B as shown in FIG. Then, on the abdominal surface side, the above-mentioned welding plate material 3 for attachment is attached to the inside, and at the front end thereof, a reinforcing rib material 4 in the shape of "U" in a side view is provided on both end boss plates 5. It is arranged in a state of being laterally bridged between the five, and a drainage hole 4a is formed on the abdominal surface side of the reinforcing rib member 4 as shown in FIG.

Then, as shown in FIG. 2, a middle rib plate 6 is horizontally installed between the both side plates 1 and 1 behind the upper rear end of the reinforcing rib member 4 and in parallel with the abdominal surface of the boom B near the front end. It is arranged in the state where it does. The structure of the middle rib plate 6 will be described with reference to FIGS. 2, 6, and 13 to 15. As shown in FIG. 2, the rear end of the middle rib plate 6 is bent into an L shape at the bent portion of the "B" of the boom B, and the upper end thereof is the rear end portion of the cutout portion on the back surface of the front end portion. It is firmly attached to and is connected to the rear surface of the base end portion. Further, as shown in FIGS. 14 and 15, a hose fitting hole 6a is formed in the L-shaped bent portion, and female screws 6b and 6b are provided immediately above the hose fitting hole 6a. A guide side plate 8 bent in the shape of an “eight” in a plan view as shown in FIG. 13 is provided rearward from both side ends of 6a, and a guide upper plate 9 is also provided rearward from the upper end in a state of being sandwiched between the guide side plates 8. It is installed and used as a guide member for the cylinder hose. Further, a clamp stopper 7 is provided so as to project at a position slightly closer to the tip end than the hose fitting hole 6a in a portion of the middle rib plate 6 that is parallel to the abdominal surface of the tip end portion.

At the bent portion of the side plate 1.1 of the boom B, a hole 1b is provided for pivotally supporting the base end of the arm cylinder AC, and an intermediate boss is provided inside thereof. Plates 10 and 10 are welded together, and each intermediate boss plate 10 has an arm cylinder boss 10 communicating with the hole 1b.
a is provided. Further, as shown in FIG. 2, a boom cylinder bracket 11 for pivotally supporting the tip of the cylinder rod of the boom cylinder BC below the belly surface of the bent portion.
Is protruding.

Next, the base end portion of the boom B will be described with reference to FIGS. 2 and 9 to 12. As described above, the proximal portion is formed by bonding the side plates 1, 1 on the back surface and the abdominal surface by the welding plate materials 2, 3 for bonding, respectively, and has a box shape with a quadrangular cross section. The base ends of the side plates 1, 1 are notched in a semicircular shape, and hold a boss 12 that pivotally supports a rotating shaft 13 for pivotally supporting the boom bracket BB. On the ventral surface side of the base end portion, a water drainage hole 1c shown in FIG. 10 is cut out between the lower end of the boss 12 and the rear end portion of the welding plate material 3, and on the back surface side, As shown in FIG. 9, a hose fitting hole 1d is cut out between the rear end of the welding plate 2 and the upper end of the boss 12. Further, as shown in FIG. 12, side plate portions 14a and 14a to be welded and attached to the inner side surfaces of the both side plates 1.1.
The base end reinforcing member 14 formed by connecting a with the connecting portion 14b at the upper end is disposed inside the base end portion. The connecting portion 14b
11 is arranged immediately in front of the hose fitting hole 1d as shown in FIG. 11, and the hose retainer 15 is laterally arranged just after the connecting portion 14b (at the front end of the hose fitting hole 1d). It is set up. Further, below the hose fitting hole 1d, as shown in FIG. 11, it becomes a mounting seat for the rubber clamps 20 and 21, which will be described later, which is a guide member for the hydraulic hose, and has a shape inclined from the upper end of the boss 11 to the ventral side. Hose guide plate 16
Are installed. Both sides of the hose guide plate 16 are fixed to both sides of the base end reinforcing member 14, and the hose fitting hole 1d is attached.
It functions as a reinforcing rib for the base end that becomes weaker by notching.

In the boom B constructed as described above, conventionally, a plate member for reinforcing the tip end, the bent part, and the base end part having the boss of the arm base end part and the boss of the arm cylinder base end part, While it was pasted on the outer surface, side plate 1
Since the tip boss plate 5, the intermediate boss plate 10, and the base end reinforcing member 14 are attached to the inside of the side plate 1, the side plate 1 has an external appearance.
-It seems that it is composed of only one, and it gives a clean impression. Further, since the side plates 1 and 1 are press-molded, there is no welded portion at the bent portions at both ends of the back surface and the abdominal surface, and the appearance is even cleaner. By utilizing the press molding, by providing the convex portion 1e on the outer surface as shown in FIG. 2, the boom B can have a volume, and in addition to improving the appearance, the ribs due to the unevenness can be formed. You can also expect to work.

The shape of the convex portion can be various as shown in FIGS. 25 to 32. Since it is press-molded, it is easy to make various forms as described above. First, in the embodiment shown in FIGS. 25 and 29, the convex portion 1e is provided in a stepped shape, which gives a solid image. 26 and 3
In the example of No. 0, the outer side surface of the side plate is curved to give a rounded volume feeling. 27 and 3
In the first embodiment, the convex portion 1e 'is provided on the outer surface of the side plate 1 in an inclined shape from the back surface to the abdominal surface. 28 and 32 are examples in which the curved convex portion 1e ″ is partially provided, and give an impression like a force bump.

Further, the convex portion of the side plate portion of the boom bracket BB will be described with reference to FIGS. 33 to 36. Since the boom bracket BB is a member that supports the entire work arm such as the boom B and the arm A, it is integrally configured by a mold. On both sides, side plate portions 28, 28 having boss portions 28a, 28a for pivotally supporting the base end of the boom B are formed, and between the both side plate portions 28, 28, the base end of the boom cylinder BC is pivoted. Supporting bosses 29a, 29a
The boom cylinder base end bracket portion 29 having the structure is projected. Further, the both side plates 28, 28 have conventionally been constructed by thickening the entire plate in order to maintain the strength, but in the present embodiment, a method of partially thickening the plate, that is, the convex portion is used. The method of forming 28b and 28b is adopted. As a result, weight reduction and cost reduction can be brought about. Further, the shape of the convex portion 28b allows the bracket B to be formed.
The appearance of B is improved.

Next, the piping structure of the hydraulic hose in the boom B will be described with reference to FIGS. 16 to 24. At the base end of the boom B, as shown in FIGS. 21 and 22, from the hose fitting hole 1d, a hydraulic hose, that is, a cylinder hose ACH for the arm cylinder AC and a cylinder hose BCH for the bucket cylinder BTC (generally referred to as a generic name). Cylinder hose CH) and hydraulic pressure take-out hose PH are fitted inside the portion near the base end. Further, as shown in FIG. 16, at the bent portion, the hydraulic hose is piped through the hose fitting hole 6a of the middle rib plate 6 to the tip end portion.
At the tip end portion, an arm cylinder AC is arranged above the middle rib plate 6 with its base end pivotally supported by the arm cylinder bosses 10a, 10a. The hydraulic hose is piped between the arm cylinder AC and the middle rib plate 6. Of these, the cylinder hose for the arm cylinder is connected to the arm cylinder AC at the tip end portion, and the cylinder hose for the bucket cylinder passes above the tip end and is pivotally supported by the arm A. It goes inside and is connected to the bucket cylinder. Furthermore, the hydraulic pressure extraction hose PH is
The end of the boom B is disposed in a hydraulic pressure take-out hole 1f formed near the tip of the boom B.

These hydraulic hoses are guided and piped at fixed locations in the boom B. First,
16 to 18 in the L-shaped bent portion of the middle rib plate 6.
As described above, the guide side plates 8 and the upper guide plate 9 guide the hydraulic hose to such an extent that the hose can be bent when the boom B is rotated up and down. Prevent the hydraulic hose from coming off. A rubber clamp 17 shown in FIG. 19 is fitted between the hose fitting hole 6 a and the clamp stopper 7 at the tip end portion. The rubber clamp 17 has two upper and lower hose fitting holes. The upper part of the rubber clamp 17 has large diameter fitting holes 17a, 17a for inserting the hydraulic pressure extraction hose PH, and the upper and lower parts thereof. Cylinder hoses CH (ACH / BCH) for arm cylinder AC and bucket cylinder BTC
.. with small diameter insertion holes 17b. From the outside of the rubber clamp 17, the respective fitting insertion holes 17a, 17
A notch is provided in b, a hose is embedded in the notch, and a hydraulic hose is fitted into each of the fitting insertion holes 17a and 17b, whereby the hydraulic hose piping to the tip end portion can be easily performed. Further, in order to fix the rubber clamp 17, the clamp 18 shown in FIG. 20 restrains the rubber clamp 17 from above. A screw hole 18a is provided above the clamp 18.
18a is bored, the bolts 19 and 19 are screwed into the screw holes 18a and 18a, and the female screws 6b and 6b of the middle rib plate 6 are formed.
The clamp 18 is fixed to the bent portion of the middle rib plate 6 by screwing. In this way, the hydraulic hose pipe guide member at the bent portion of the boom B is formed.

Next, at the base end, as shown in FIGS.
As described above, the rubber clamps 20 and 21 are arranged in two stages on the hose guide plate 16. The lower rubber clamp 20 has cylinder hose fitting holes 20a, 20a, ...
The upper rubber clamp 21 is provided with hydraulic pressure take-out hose fitting holes 21a. As shown in FIGS. 21 and 24, the rubber clamp 20 has a mounting plate member 22 fixedly mounted on the hose guide plate 16 fitted into a groove at the lower end thereof and mounted thereon, and a lower clamp 23 is placed thereon. The rubber clamp 21 is placed on the lower clamp 23,
The upper clamp 24 is stacked above it. Upper clamp 2
4. A bolt hole is bored at the upper end, and a female screw 25 is penetrated from the bolt hole to the mounting plate member 22 at the lower end. A bolt 26 is screwed into the female screw 25 to connect these hydraulic hose pipes. The guide member is fixed to the hose guide plate 16. The hydraulic hoses CH and PH are piped through the respective fitting insertion holes 20a and 21a of the rubber clamps 20 and 21, respectively.

Further, from both sides of the lower clamp 23, a hose retainer 27 having a U-shape in plan view as shown in FIGS. 22 and 23.
21 is provided so as to project rearward, and the lower-stage cylinder hose CH that is piped on the hose guide plate 16 is pressed from above as shown in FIG. On the other hand, the hose holder 15 is
Hydraulic pressure hose PH that has passed through the rubber clamp 21
21 is pressed from above as shown in FIG. Thus, in the vicinity of the rubber clamps 20 and 21, the hydraulic hoses are curved more than necessary, and the fitting holes 20a and 21 of the rubber clamps are inserted.
I try not to get out of a.

The construction of the boom B has been described above. Next, the construction of the arm A will be described with reference to FIGS. 37 to 43. The arm A is a side plate 3 having a U-shape when viewed from the front.
0 and 30 are bonded by welding from both sides as shown in FIG. As shown in FIG. 37 (a), the back side is cut out to connect the bucket cylinder and the cylinder hose from a portion slightly closer to the base end to the base end, and the abdominal base end is a boom B. A pivot shaft 35 for pivotally supporting the arm bosses 5a, 5a at the tip is welded to a boss 34 for pivotally supporting it. Further, the side surface base end portions of the side plates 30 are projected rearward to form pivot support holes 30a for supporting the piston rod of the arm cylinder AC. Further, the tip ends of the side plates 30, 30 are welded to a boss 38 that pivotally supports a rotating shaft 39 of the bucket. A boss 36 that laterally supports the rotating shaft 37 is provided laterally.

Cylinder brackets 31, 31 are welded and attached to the inside of each of the base ends of the side plates 30, 30. The front end of the cylinder bracket 31 on the back side is the side plate 30.
It is fitted into the groove portion of the bracket fitting portion 30b formed at the rear end portion of the rear surface of the to improve the assembling strength. The cylinder bracket 31 is bent in a V shape when viewed from the side, and a rib member 31c is provided so as to connect the upper protruding portion and the lower protruding portion in order to enhance the strength.
Arm cylinder tip bosses 31a and 31a communicating with pivotal support holes 30a and 30a of the side plates 30 and 30 are formed at the rear ends of the cylinder brackets 31 and 31, and a bucket cylinder is provided on the back side. Bucket cylinder base end bosses 31b, 31b for pivotally supporting the BTC base end
Is formed. Conventionally, the cylinder bracket at the base end of the arm is attached to the outer surface of the side plate, and the cylinder bracket is exposed to the outside. However, in the arm A of this embodiment, the cylinder bracket 31 is Since it is attached to the inside of the side plate 30 and the pivotal support portion of the piston rod tip of the arm cylinder, which is conventionally formed only on the cylinder bracket 31, is also provided on the side plate 30 (the pivotal support hole 30a). The pivot portion is also covered with the side plate 30, and from the outside, as shown in FIG. 37 (b), the bucket cylinder base end bosses 31b, 31b only appear to project, and the arm is formed almost entirely by the side plate 30. The impression is that A is configured, and it looks neat.

Incidentally, between the side plates 30 and 30, as shown in FIG.
As shown in (b), a middle rib plate 33 is installed so as to extend from the front end of the notch on the back side to the boss 34, and between the cylinder brackets 31, 31, the arm cylinder tip boss 31a and the bucket cylinder base end are provided. Boss 31
A rib plate 32 is provided between the rib plate 32 and b. The boss 34 and the arm cylinder tip boss 31a between the cylinder brackets 31 and 31 are notched so as to communicate with the space between the side plates 30 and 30 on the middle rib plate 33. Like 16, bucket cylinder hose BC
H is fitted into the arm A and is piped on the middle rib plate 33. The bucket cylinder BTC and the bucket cylinder hose BCH are covered by the side plates 30 and 30,
Most of the appearance is invisible, and the movable space of the working arm is widened as much as it does not project to the back side.

[0028]

Since the present invention is configured as described above, it has the following effects. Since it is configured as in claim 1,
By making the part nearer to the base end from the bent part of the V shape in side view into a box shape and piping the cylinder hose inside it, the piping part of the cylinder hose becomes invisible, especially from the operator. As you can see, there is no cylinder hose on the back of the boom, so you can work comfortably without giving you a troublesome appearance. Also, if the cylinder hose is installed on the rear side of the boom, there is no freedom to bend and the raising angle of the boom is limited.However, in the box-shaped part of the boom, the flexibility of bending the cylinder hose is increased, and the boom can be raised. You can raise the angle.

Further, by cutting out the rear surface of the portion closer to the tip end than the bent portion and disposing the middle rib plate parallel to the abdominal surface inside, the arm cylinder and the cylinder hose are arranged above the middle rib plate. When the piping is done, the arm cylinder and the cylinder hose are covered from the side with the side plate of the boom. Therefore, in terms of appearance, the arm cylinder and the cylinder hose are not exposed, and the appearance is neat. Moreover, since it is not necessary to project the bracket for the arm cylinder on the back side, the movable space of the boom becomes wider, which leads to cost reduction. Further, the rear end portion of the middle rib plate is bent and connected to the back surface of the box-shaped portion, so that the vicinity of the proximal end pivotal support portion of the arm cylinder AC is reinforced by the bent portion of the middle rib plate. Further, the bent portion of the middle rib plate can be used as a mounting portion for the guide member of the cylinder hose at the bent portion.

According to the second aspect of the present invention, by assembling the cylinder hose in the box-shaped portion of the boom through the guide member and the rubber clamp , it is possible to easily assemble and assemble the cylinder hose, which is appropriately positioned. . In addition, a through hole must be formed when the cylinder hose is passed through the box-shaped boom, but this portion is reinforced by the mounting seat of the guide member, and there is no need to install a rib member separately. The cost can be reduced.

According to a third aspect of the present invention, a member having a boss that pivotally supports the rotation shaft of the cylinder or the working arm is attached to the inside of the side plate of the boom and arm, so that the member can be seen on the outer surface of the side plate. Instead, only the outer surface of one side plate can be seen, which gives a cleaner impression than what was pasted on the outer surface of the conventional side plate. Further, since it is not necessary to care about the appearance, the shape can be freely considered in consideration of the stress concentration in the boss portion.

Further, according to the fourth aspect, the strength can be secured by the convex portion having the effect of partially increasing the plate thickness, without thickening the entire side plate portions of the boom and the boom bracket. . Then, the form of the convex portion can be devised to give a design, and a backhoe that gives various impressions in appearance can be provided.

[Brief description of drawings]

FIG. 1 is an overall side view of a backhoe according to the present invention.

FIG. 2 is a side view of a boom B.

FIG. 3 is a view on arrow aa in FIG.

FIG. 4 is also a view taken along the line bb.

FIG. 5 is likewise a view taken along the line cc.

FIG. 6 is a plan view of a portion of the boom B near the tip.

FIG. 7 is a bottom view of the tip portion of the same.

FIG. 8 is a perspective view of the tip portion of the same.

FIG. 9 is a plan view of a portion near the base end.

FIG. 10 is a bottom view of the base end portion of the same.

FIG. 11 is a view on arrow d-d in FIG. 9.

FIG. 12 is a view likewise seen from the arrow ee.

FIG. 13 is a plan view showing a configuration of a middle rib plate 6 of the boom B and a guide portion for hydraulic hose piping.

FIG. 14 is a view on arrow f-f in FIG. 13.

FIG. 15 is a front view of the same as seen from the base end side.

16 is an internal side view showing the arrangement of arm cylinders AC in the bent portion of boom B and the piping configuration of the hydraulic hose. FIG.

17 is a plan partial cross-sectional view showing the disposition structure of the hydraulic hose pipe guide member in the bent portion of the boom B. FIG.

FIG. 18 is a front sectional view of the same seen from the tip side.

FIG. 19 is a perspective view of a rubber clamp 17.

20 is a perspective view of the clamp 18. FIG.

FIG. 21 is an internal side view showing the piping configuration of the hydraulic hose at the base end of the boom B.

FIG. 22 is a partial cross-sectional view of the same plane.

FIG. 23 is a plan view showing an arrangement structure of a hydraulic hose pipe guide member at the base end of the boom B.

FIG. 24 is a front sectional view of the same.

FIG. 25 is a side view of the boom B showing one form of a convex portion formed on the outer surface of the side plate 1 of the boom B.

FIG. 26 is a side view of the boom B of the same.

FIG. 27 is a side view of the boom B of the same.

FIG. 28 is a side view of the boom B of the same.

FIG. 29 is a front sectional view of the boom B similarly shown in FIG. 25.

FIG. 30 is a front sectional view of the boom B shown in FIG. 26.

FIG. 31 is a front sectional view of the boom B shown in FIG. 27.

32 is a front sectional view of the boom B shown in FIG. 28.

FIG. 33 is a right side view of the boom bracket BB.

FIG. 34 is a left side view of the same.

FIG. 35 is a front view of the same.

FIG. 36 is a bottom view of the same.

37A is a plan view of the arm A, and FIG. 37B is a side view of the same.

38 is a gg arrow view in FIG. 37 (b). FIG.

FIG. 39 is also a view from the arrow hh.

FIG. 40 is also a view from the arrow ii.

FIG. 41 is also a view from the arrow jj.

FIG. 42 is also a view from the direction of the arrow k.

FIG. 43 is also a view from the arrow l.

FIG. 44 is a side view of a conventional backhoe.

[Explanation of symbols]

B boom A arm BB boom bracket AC arm cylinder BTC bucket cylinder CH cylinder hose Cylinder hose for ACH arm cylinder Cylinder hose for BCH bucket cylinder PH hydraulic pressure hose 1 side plate 1d hose fitting hole 1e (1e ′ · 1e ″) convex portion 5 Tip boss plate 6 Middle rib plate 6a Hose fitting hole 7 Clamp stopper 8 Guide side plate 9 Guide upper plate 10 Intermediate boss plate 14 Base end reinforcing member 15 Hose holder 16 Hose guide plate 17 rubber clamp 18 clamps 20 rubber clamp 21 rubber clamp 23 Lower clamp 24 Upper clamp 27 Hose holder 28 Side plate 28b convex portion 30 side plate 31 cylinder bracket 32 rib material 33 Middle rib plate

Claims (4)

(57) [Claims] 1. In the boom B of the backhoe, a portion closer to the base end than a bent portion having a V shape in a side view is formed into a box shape, and a cylinder hose CH is piped inside the bent portion, and a tip end is formed from the bent portion. The rear face of the part closer to the part is cut out, the inner rib plate 6 parallel to the abdominal face is arranged inside, and the rear end portion of the middle rib plate 6 is bent near the arm cylinder boss 10a , A backhoe work arm structure characterized in that it is connected to the back surface of the part near the base end. 2. The boom in the backhoe at the boom B.
Cylinder hose CH is connected to the inside of B and further inside
The middle rib plate 6 which is a reinforcing rib is arranged in parallel to the abdominal surface,
Similarly, as a guide member for the cylinder hose CH inside
The guide upper plate 9 and the rubber clamp 17, and
The working arm structure of the backhoe, wherein the mounting seat of the door member is also used as the middle rib plate 6 . 3. A working arm structure for a backhoe according to claim 1.
At the end of boom B and arm A,
Or a boss plate 5 having a boss that pivotally supports the rotation axis of the working arm.
5 is attached, the boss plate 5
And a working arm structure of a backhoe, which is attached to the inside of the side plate of the arm A. 4. A boom bracket BB pivotally supporting a base end of a boom B of a backhoe, wherein a convex portion 28b is formed on an outer surface of the boom bracket BB .
The work arm structure of the backhoe, which is characterized in that