JPH10121505A - Working machine for hydraulic shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight working machine with improved durability without cracks, which can be produced easily by constituting the working machine by fixing with coupling members having boom and arm with two steel plates. SOLUTION: An arm 38 is fixed by providing predetermined intervals between two right and left steel plates 38a and 38b; and a first tubular coupling member 39a connected to a bucket 10, a second coupling member 39b coupled to a working machine link, and a boss portion 40a for coupling to the top portion of a boom and the bottom portion of a bucket cylinder is provided. Thus, the first coupling member 39a, the second coupling member 39b and the boss portion 40a are arranged on the neutral line La of the arm or near it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a working machine of a construction machine such as a hydraulic shovel or the like, and in particular, the structure of a boom and an arm is made of two steel plates to reduce the weight and improve the stability of the vehicle body. In addition, the present invention relates to a hydraulic shovel working machine that avoids stress concentration and has no cracks.

[0002]

2. Description of the Related Art A conventional hydraulic excavator will be described with reference to FIGS. Hydraulic excavator 1 undercarriage 2
An upper revolving superstructure 4 (hereinafter, referred to as a vehicle body 4) is disposed above the revolving circle 3 via a revolving circle 3. 5 is a cab.
The base end of the boom 6 is attached to a bracket (not shown) of the vehicle body 4. The phototom side of the boom cylinder 7 is the body 4
And a rod side is attached to a boom. The boom 6 can swing up and down by the expansion and contraction drive of the boom cylinder. The tip of the boom 6 is connected to the arm 8. The bottom part of the arm cylinder 9 is attached to a bracket 6 a fixed to the boom 6 by welding, and the rod side is attached to the arm 8. The arm 8 is swingable in the excavation / dumping direction by the expansion and contraction drive of the arm cylinder 9. Arm 8 is bucket 1
Connected to 0. The bottom of the bucket cylinder 11 is attached to a bracket 8a fixed to the arm 8 by welding, and the rod side is connected to the bucket 10 via working links 10a and 10b. The bucket 10 is rotatable by the expansion and contraction of the bucket cylinder. A perspective view of the boom 6 and the arm 8 will be described with reference to FIGS. The cross section of the boom 6 shown in FIG. 13 has a square box-like structure. A bracket 6a for attaching a bottom portion of the arm cylinder 9 is integrally fixed to an upper surface plate of the boom 6 by welding. The cross section of the arm 8 shown in FIG. 14 has a square box-like structure. A bracket 8a for attaching the bottom of the bucket cylinder 11 is integrally fixed to the upper surface plate of the arm 6 by welding.

[0003] In the current urban civil engineering work, hydraulic excavators provided with various attachments are used for demolition work of buildings and the like. In the demolition work of this building, etc., the work equipment can be operated upwards and work can be performed even at high places.In places where the buildings are densely packed, the refraction type A work machine equipped with a two-piece boom is used. This two-piece boom is also shown in FIG.
It has a box-shaped structure like the boom described in FIG.

[0004] Since the boom and arm of the hydraulic excavator have a box-shaped structure, the number of man-hours required for welding work is large and the cost is high. In addition, there is a problem that cracks occur because stress is easily concentrated on the welded portion. For this reason, measures have been taken such as increasing the thickness of the steel sheet to avoid stress concentration, or welding a reinforcing plate to a portion where stress concentration is likely to occur. In order to solve such a problem, the applicant has filed Japanese Utility Model Publication No. 4-49262. According to the publication, a boom and an arm that constitute a working machine body are
The arm cylinder and the bucket cylinder housed in the boom and the arm are formed by a tubular member and a bifurcated bracket fixed to the ends of these tubular members, and the through-hole opened in the bifurcated bracket projects the arm cylinder and the bucket cylinder. There is described a technique of a working machine of an excavating machine configured to rotate an arm and a bucket attached to a tip of the arm.

[0005] The applicant has filed Japanese Utility Model Application Laid-Open No. 3-2058. As shown in FIG. 15, the contents of this application are box-shaped members 21 and 31 formed by press working and having a protruding member 22 and a brim-like member 23; Are formed so that they face each other, and are spot-welded at their joints to form a boom body, and the boss 25 and the receiving plates 26a and 26b are welded to predetermined positions of the boom body. The technology is described.

[0006]

However, FIG.
3, boom and arm shown in FIG. 14, not shown 2
Since the piece boom has a box-shaped structure, a torsional load is applied during excavation work, and high stress is generated at a corner of the box, thereby causing a crack in a welded portion. Also, cracks are likely to occur in the welded portions of the brackets 6a, 8a due to the reaction force received from the arm cylinder 9 and the bucket cylinder 11. Although measures such as increasing the thickness of a steel plate or welding a reinforcing plate have been taken against such a problem, the weight of the boom and the arm increases, and the balance of the vehicle body becomes unstable.
For this reason, against the increase in the weight of the boom and the arm, the weight of the counterweight newly attached to the rear of the vehicle body is increased to stabilize the balance of the vehicle body.
As the total weight of the excavator increases, the driving force decreases. In order to compensate for this reduction in driving force, it is necessary to take measures such as increasing the output of the engine. As described above, in order to make the boom and the arm have a box-shaped structure, it is necessary to study the relationship between the weight of the vehicle and the engine output, and there are various problems.

In the technique disclosed in Japanese Utility Model Publication No. 4-49262, the boom and the arm are tubular members. By using the boom and the arm as tubular members, there is an effect that the number of cracks is reduced because the number of welds is smaller than that of the conventional box-shaped structure. The members need to be thick, and the boom and the arm cannot be reduced in weight.

The technique disclosed in Japanese Utility Model Application Laid-Open No. Hei 3-2058 is different from the conventional box-shaped structure having a rectangular cross section in that the box-shaped member formed by pressing, the protruding member and the flange-shaped member face each other. Since the boom main body is formed by spot welding at the joint, the structure is simplified and it is useful as a small-sized hydraulic excavator. However, a medium- to large-sized hydraulic excavator has sufficient strength. However, there is a problem that it is not possible to press a thick plate necessary for this, and it cannot be adopted.
As described above, the applicant has filed a prior art (Japanese Utility Model Publication No. 4-49262, Japanese Utility Model Application Laid-Open No. 3-2058) which solves the problems such as the occurrence of cracks in the conventional box-shaped boom and arm. However, the technique of this application also has various problems as a working machine of a hydraulic shovel.

The present invention focuses on the above-mentioned conventional problems, and has a construction in which a work machine for a boom and an arm is fixed to two steel plates with a connecting member. With a structure in which the mounting part and the mounting part are arranged on the same neutral line, the structure is durable against severe work of the hydraulic excavator, and is lightweight and easy to manufacture, and can be used for small to large hydraulic excavators. The purpose is to provide a machine.

[0010]

In order to achieve the above object, a first invention of a working machine for a hydraulic shovel according to the present invention comprises a boom which is sequentially rotatably connected to a vehicle body.
A hydraulic shovel including a working machine including an arm and a bucket, respective cylinders for swinging the working machine, and a working machine link rotatably attached to the arm and rotating the bucket by a bucket cylinder. In the working machine of the first embodiment, the arm 38 is fixed to the left and right two steel plates 38a and 38b with a predetermined space therebetween, and is connected to the bucket 10 by the first tubular connecting member 39a and the working machine link 10a.
And a boss portion 6a, 40a for connecting the tip of the boom 6 and the bottom portion of the bucket cylinder 11 together. The first connecting member 39a, The connecting member 39b and each boss 6a,
40a is disposed on or near the neutral line La of the arm. According to the above configuration,
The conventional box-shaped arm has a problem that a crack is generated at a welded portion at a corner of the box.
With left and right two steel plates 38a, 38b.
Since it is composed of the tubular first connecting member 39a and the second connecting member 39b to which the 8a and 38b are fixed, there is no welding at the corners of the conventional box-shaped arm and there is no problem of crack generation.
The left and right two steel plates 38a and 38b can be formed as arms capable of sufficiently withstanding the load during work if the welded portions with the tubular first connection member 39a and second connection member 39b are strengthened. Further, since the bottom portion of the bucket cylinder is sandwiched between the two left and right steel plates 38a and 38b, there is no bracket for attaching the bottom portion of the bucket cylinder which has been welded to the upper plate of the conventional box-shaped arm. And, according to the first invention, the left and right two steel plates 38a, 38
b, the first connecting member 39a, the second connecting member 39b, and the boss 40a are arranged on or near the neutral line La of the arm 38, so that the reaction force received from the bucket during excavation is Neutral line La of arm 38
The first connecting member 39 arranged above or in the vicinity thereof
a, pin 11 of second connecting member 39b and boss 40a
a, 11b, 11c. Further, the reaction force when the bucket cylinder 11 is driven is received by the pin 11a connected to the bottom portion of the bucket cylinder 11 and the boss portion 40a, so that a bending moment is not applied to the arm 38. Therefore, the arm is durable against severe work, is lightweight, does not deteriorate the balance of the vehicle, is easily manufactured, and is useful as a small to large hydraulic excavator arm.

According to a second aspect of the present invention, in the configuration of the first aspect, there is provided a two-piece boom composed of a first boom and a second boom which are sequentially rotatably connected to the vehicle body. Arm 3 made of sheet steels 38a and 38b
8 is connected. According to the above configuration, in addition to the operation and effect of the first invention, the arm 38 composed of the left and right two steel plates 38a and 38b can be mounted even in a working machine having a two-piece boom.
Since the weight of the piece boom and the arm are both box-shaped, the weight is reduced, the weight of the counterweight is not increased, and the balance of the vehicle is not deteriorated, so that the workability is improved.

According to a third aspect of the present invention, there is provided a working machine comprising a first boom, a second boom, an arm, and a bucket which are sequentially rotatably connected to a vehicle body, cylinders for swinging the working machine, and a rotatable arm. And a work machine link attached to the work boom and rotating the bucket by a bucket cylinder.
A is a pair of left and right two steel plates 36a, 36b separated by a predetermined distance. The rear end of the left and right two steel plates 36a, 36b, the front end of the first boom 36, and the bottom of the arm cylinder 9 are both joined. A first boss portion 6b to be connected, a second boss portion 36c to connect a second boom cylinder 37 for swinging the second boom 36A, and two left and right steel plates 36a, 3
6b and a third boss 6a for connecting the arm 38 and the bottom of the bucket cylinder 11 together. The first boss 6b, the second boss 36c and the third boss 6c
The boss 6a and the boss 6a are arranged on or near the neutral line Lb. According to the above configuration, the conventional second boom having a box-shaped structure has a problem that a crack is generated at a welded portion at a corner portion of the box. However, in the third invention, the second boom 36A is replaced with two left and right steel plates 36a. , 36b, the first boss portion 6b, the second boss portion 36c, and the third boss portion 6a of the left and right two steel plates 36a, 36b are respectively attached to the arms 3
8, since it is connected to the second boom cylinder 37 and the first boom 36, and the first boss 6b, the second boss 36c, and the third boss 6a are arranged on or near the neutral line Lb, There is no welding at the corner of the conventional box-shaped second boom, and there is no problem of crack generation. As described above, the second boom made of the two left and right steel plates 36a and 36b has a structure capable of sufficiently withstanding the load during operation. The bottom of the arm cylinder has two left and right steel plates 36a,
Since it is configured to be clamped by 36b, there is no bracket for attaching the bottom portion of the arm cylinder which has been welded to the upper surface plate of the conventional box-shaped second boom. Furthermore, according to the third aspect, the first boss portion 6b, the second boss portion 36c, and the third boss portion 6a are arranged on or near the neutral line Lb. The reaction force received on the neutral line Lb of the second boom 36A or
The first boss portion 6b and the second boss portion 36c arranged in the vicinity thereof
And the pins connected to the third boss 6a. The reaction force when the arm cylinder 9 is driven is determined by the bottom of the arm cylinder 9 and the first boss 6b.
The structure is such that a bending moment is not applied to the arm 38 because the arm 38 is supported by a pin connected thereto. Therefore, the second boom is durable for severe work, is lightweight, does not deteriorate the balance of the vehicle, is simple to manufacture, and has a small to large hydraulic excavator.
Useful as a boom.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the working machine of a hydraulic shovel according to the present invention will be described below with reference to FIGS. Note that the components denoted by the same reference numerals as those in FIG.
Here, the description is omitted. First, FIG. 1 and FIG.
The working machine of the embodiment will be described. The base end of the boom 6 is attached to a bracket (not shown) of the vehicle body 4 of the excavator 1. The tip of the boom 6 is connected to the arm 38. The arm 38 will be described with reference to FIGS. The arm 38 has two steel plates 38a and 38b. The two steel plates 38a and 38b are connected at one end (tip) to a bucket 10 and a tubular first connecting member 39a connected by a pin 11c, and near the bucket to a work link 10a and a tubular connected by a pin 11b. The second connecting member 39b is fixed by welding. The two steel plates 38a and 38b are provided with a boss 40a that is connected to the tip boss 6a of the boom 6 by a pin 11a at the other end (rear end). These two steel plates 38a, 38b
The rod end of the arm cylinder 9 and the pin 11
A boss 40b connected by d is provided. The first connection member 39a, the second connection member 39b, and the boss 40a are arranged on or near the neutral line La. As shown in FIGS. 1 and 2, the bucket cylinder 11
Is sandwiched between two steel plates 38a and 38b to form a bottom portion of the cylinder 11 and the two steel plates 38a and 38b.
a, 38b and the tip boss 6a of the boom 6
And are connected by a pin 11a.

Next, as shown in FIG. 5, in the working machine shown in FIGS. 1 and 2, the bottom portion of the bucket cylinder 11 connects the arm 38 and the tip boss portion 6a of the boom 6 by a pin 11a. The reaction force F1a of the bucket cylinder 11 when a load F1 during work is applied to the bucket 10 shown in FIG.
Has a structure to be covered by the pin 11a of the boss 6a.

Next, the operation of FIGS. 1, 2 and 5 will be described with reference to FIG. The arm 38 composed of the left and right two steel plates 38a and 38b is provided with a first connecting member 39a and a second connecting member 39b.
And the boss portion 40a are disposed on or near the neutral line La of the arm 38, so that the reaction force received from the bucket during excavation is reduced by the first connection disposed on or near the neutral line La of the arm 38. Each pin 11a, 11 of the member 39a, the second connecting member 39b, and the boss 40a
The structure is taken over by b and 11c. According to the structure shown in FIG. 5, the conventional bracket provided on the upper plate of the arm receives a reaction force when driving the bucket cylinder 11 to apply a bending moment. The force F1a is applied to the pin 11a connected to the bottom portion of the bucket cylinder 11 and the boss portion 40a, so that a bending moment is not applied to the arm 38. As a result, the arm 38 is durable against severe work, and since it is made of two steel plates, it is lightweight, does not deteriorate the balance of the vehicle, and is easily manufactured. This arm 38 is attached to a box-shaped boom.
Alternatively, it can be mounted on the tip of a two-piece boom.

Another embodiment of the arm will be described with reference to FIG. 3 and FIG. The arm 48 is composed of two steel plates 48a and 48b. These two steel plates 48
a, 48b are a plurality of tubular connecting members 49a, 49b, 4
9c by welding. Two steel plates 48a,
48b is a first boss 50a, a second boss 50b, and a third boss 50b.
The boss 50c and the fourth boss 50d are fixed by welding. The first boss portion 50a is connected to the bucket 10 shown in FIG.
And a pin 48A. The second boss 50b is connected to the work link 10a shown in FIG. 1 by a pin 48B. The third boss 50c is connected to the tip boss 6a of the boom 6 shown in FIG. 1 by a pin 48C. The fourth boss 50d is connected to the rod of the arm cylinder 9 shown in FIG. 1 by a pin 48D. The first boss 50a, the second boss 50b, the third boss 50c, and the fourth boss 50d are arranged on or near the neutral line La. The arm 48 shown in FIGS. 3 and 4 is configured by connecting two steel plates 49 a and 49 b to the tubular connecting member 4.
9a, 49b, 49c, and the first to fourth boss portions 50a to 50c.
Since it is connected at 0d, it is a reinforced type as compared with the first embodiment shown in FIG. The arm 48 having such a configuration has the same operation and effect as the arm 38 shown in FIGS. 1 and 2 of the first embodiment.

Next, a second embodiment of the working machine of a hydraulic shovel according to the present invention will be described with reference to FIGS. The first
The same reference numerals as in FIGS. 1, 2 and 12 of the embodiment denote the same parts, and a description thereof will not be repeated. FIG. 6 illustrates a working machine including a two-piece boom including a first boom 36 and a second boom 36A instead of the boom 6 of the first embodiment. As shown in FIGS. 6 and 7, the base end of the first boom 36 is attached to a bracket of the vehicle body 4.
The bottom of the first boom cylinder 7 is attached to the bracket of the vehicle body 4, and the rod side is the tip boss 6 b of the first boom 36.
And the bottom part of the arm cylinder 9 and the second boom 36A
And a pin 36d. The bottom of the arm cylinder 9 is sandwiched between two steel plates 36a and 36b. This second boom 36A is 2
It consists of a number of steel plates 36a, 36b. The rod side of the second boom cylinder 37 that swings the second boom 36A is sandwiched between two steel plates 36a and 36b.
Bosses 36c fixed to 6a and 36b are connected to each other by pins 36e. The bottom of the second boom cylinder 37 is attached to the first boom 36. A boss 6a for connecting the arm 38 and the second boom 36A by a pin 11a, and the bosses 6b and 36c are arranged on or near the neutral line Lb.

The work load F is applied to the bucket 10 shown in FIG.
The reaction force F1a of the bucket cylinder 11 when 1 is applied is
The arm cylinder 9 is held by the pin 11a of the boss 6a.
The reaction force F2a is supported by the pin 36d of the boss 6b.

Next, the operation of FIGS. 6 to 8 will be described. The conventional second boom having a box-shaped structure has a problem that a crack is generated at a welding portion at a corner of the box. However, in the third invention, the second boom 36A is formed by using left and right two steel plates 36a and 36b. The first boss portion 6 of the left and right two steel plates 36a, 36b
b, the second boss portion 36c and the third boss portion 6a are connected to the first boom 36, the second boom cylinder 37 and the arm 38, respectively, and the first boss portion 6b, the second boss portion 36c and the third boss portion are respectively connected. 6a is disposed on or near the neutral line Lb, so that there is no welding at the corners of the conventional box-shaped second boom, and there is no problem of crack generation. Also,
The bottom part of the arm cylinder 9 is divided into two left and right steel plates 36a, 3
6b, the bracket for attaching the bottom portion of the arm cylinder, which has been welded to the upper surface plate of the conventional box-shaped second boom, is eliminated. Thus, the first boss 6
b, since the second boss portion 36c and the third boss portion 6a are arranged on or near the neutral line Lb, the reaction force received from the bucket 10 via the arm 38 during excavation is equal to the neutral force of the second boom 36A. The first boss portion 6b, the second boss portion 36c, and the third boss portion 36b disposed on or near the line Lb.
Each of the pins 36d, 36e connected to the boss 6a,
11a. Therefore, the reaction force at the time of driving the arm cylinder 9 is received by the pin 36d connecting the bottom portion of the arm cylinder 9 and the first boss portion 6b, and no bending moment is applied to the arm 38. Thereby, the second boom 36A is durable against severe work,
Moreover, it is lightweight and does not deteriorate the balance of the vehicle,
It is easy to manufacture, and is useful as the second boom of a small to large hydraulic excavator.

FIGS. 9 to 11 show another working machine of a boom made of two steel plates. The arms, cylinders, etc. are omitted. One end of a work link 61 is attached to a bracket of the vehicle body 4 shown in FIG. The other end of the work link 61 connects the boss 62d of the boom 60 with a pin 60D. The boss 62c of the boom 60 is connected to one end of the rod 62 by a pin 60C. The other end of the rod 62 is connected to the bracket of the work link 61 by a pin 60E. This boom 60 will be described with reference to FIG. Boom 60 is 2
It is composed of two steel plates 60a and 60b. The two steel plates 60a and 60b are connected to a plurality of tubular connecting members 61a and 61b.
b and is fixed by welding. Two steel plates 60a, 6
Reference numeral 0b indicates that the first boss 62a, the second boss 62b, and the third boss 62d are fixed by welding. First boss 62
a is connected to the arm 38 shown in FIG. 8 by a pin 60A. The second boss portion 62b connects both the bottom portion of the arm cylinder (not shown) and the rod side of the boom cylinder with a pin 60B. The boss 62c of the boom 60
It is connected to one end of the rod 62. The first boss portion 62a, the second boss portion 62b, and the connecting members 61a, 61b are arranged on or near the neutral line Lc. The work link 61 shown in FIG. 11 is formed integrally.
The boom 60 having such a configuration has the same operation and effect as the second boom 36A of the second embodiment shown in FIGS.

Since the arm, the second boom of the two-piece boom, and the boom of the standard specification are composed of two steel plates, cracks at the welded portion and weight of the working machine, which are problems of the conventional working machine, are increased. Therefore, it is possible to solve all problems such as deterioration of the balance of the vehicle body and difficulty in manufacturing due to the box-shaped structure, and thus it is useful for small to large hydraulic excavators.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a working machine of a hydraulic shovel according to the present invention.

FIG. 2 is an explanatory diagram of an arm made of two steel plates.

FIG. 3 is an explanatory view of an arm made of another two steel plates.

FIG. 4 is an X view of FIG. 3;

FIG. 5 is an explanatory diagram of an action point of a reaction force of the bucket cylinder.

FIG. 6 is an explanatory view of a second embodiment of the working machine of the hydraulic shovel.

FIG. 7 is a perspective view showing a second embodiment having a second boom made of two steel plates.
It is explanatory drawing of a peace boom.

FIG. 8 is an explanatory view of an action point of a reaction force of the arm cylinder.

FIG. 9 is an explanatory diagram of a boom made of another two steel plates.

FIG. 10 is a Y view of FIG. 9;

FIG. 11 is a Z view of FIG. 9;

FIG. 12 is a side view of the hydraulic excavator.

FIG. 13 is an explanatory diagram of a conventional box-shaped boom.

FIG. 14 is an explanatory view of a conventional box-shaped arm.

FIG. 15 is an explanatory diagram of a prior art boom structure.

[Explanation of symbols]

 6 Boom 7 Boom cylinder 9 Arm cylinder 10 Bucket 10a Work implement link 11 Bucket cylinder 11a, 11b, 11c, 36e, 36d Pin 36 First boom 36A Second boom 36a, 36b Two steel plates (second boom) 38 Arm 38a 38b Two steel plates (arms) 39a First connecting member 39b Second connecting member 6a, 6b, 36c, 40a, 40b Boss parts La, Lb, Lc Neutral wire

Claims (3)

[Claims] 1. A work machine comprising a boom, an arm, and a bucket sequentially rotatably connected to a vehicle body, respective cylinders for swinging the work machine, and a bucket cylinder rotatably attached to the arm. And a work machine link for rotating the bucket by the arm, wherein the arm is fixedly attached to the left and right two steel plates at a predetermined interval, and is connected to the bucket by the first tubular connecting member. And a second tubular connecting member connected to the working machine link;
A first connecting member having a tip end of the boom, and each boss for connecting the bottom of the bucket cylinder together;
The second connecting member and each boss are connected to the neutral line La of the arm.
A working machine for a hydraulic shovel, wherein the working machine is disposed above or in the vicinity thereof. 2. The work machine for a hydraulic shovel according to claim 1, further comprising a two-piece boom composed of a first boom and a second boom sequentially connected from a vehicle body, wherein a tip of the second boom and the left and right two steel plates are provided. A working machine for a hydraulic shovel, wherein the working machine is connected to an arm composed of: 3. A work machine comprising a first boom, a second boom, an arm, and a bucket which are sequentially rotatably connected to a vehicle body, cylinders for swinging the work machine, and rotatably attached to the arm. And a working machine link for rotating a bucket by a bucket cylinder, wherein the second boom is formed by separating two left and right steel plates by a predetermined distance. A first boss connecting the rear end of the first boom and the bottom of the arm cylinder together, and a second boss connecting a second boom cylinder that swings the second boom. A third boss portion for connecting the distal end portions of the two left and right steel plates and the bottom portion of the arm and the bucket cylinder together, and neutralizing the first boss portion, the second boss portion, and the third boss portion. On the line Lb There is, the working machine of a hydraulic shovel, characterized in that arranged in the vicinity.