JP2003129522A - Revolving frame of construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the dimensions of a base plate of a center frame and the like by using left and right side frames for a revolving frame, and improve workability in manufacture and workability. SOLUTION: This revolving frame 21 is composed of: the center frame 22 which is located in a central part and extended in a lengthwise direction; and the left and right side frames 31 and 34. The frame 31 is formed from a left arc-shaped frame 32 which his curved in an arc shape; and an overhanging beam 33 is provided between a bent frame part 32A of the frame 32 and the center frame 22. Additionally, the side frame 34 is formed from a right arc- shaped frame 35 which is curved in an arc shape; and overhanging beams 36 and 37 are provided between a bent frame part 35A of the frame 35 and the center frame 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing frame of a construction machine suitable for use in a hydraulic excavator for excavating earth and sand, etc., and particularly to a construction machine in which a swing radius of an upper swing body is made small. Of swivel frame.

[0002]

2. Description of the Related Art Generally, construction machines such as hydraulic excavators are
An undercarriage, an upper revolving structure rotatably mounted on the lower revolving structure, and a working device provided on the front part of the upper revolving structure so as to be able to move up and down, and operate the working device. By this, excavation work such as earth and sand is performed.

The upper revolving structure of such a hydraulic excavator includes a revolving frame mounted on a lower traveling structure via a revolving wheel, and a cab or a canopy provided on the revolving frame to define a driver's cab. An exterior cover which is located on the rear side of the cab or canopy and is provided on the revolving frame and accommodates a prime mover, a hydraulic pump and the like, and a rear cover which is located on the rear side of the exterior cover and is provided on the revolving frame. It is composed of a counterweight that balances the weight of the working device.

A medium-sized hydraulic excavator generally called a standard machine has a slewing frame having a skeleton structure. The slewing frame is mounted on a lower traveling body via a slewing wheel, and its front end side is mounted for a working device. A center frame, which serves as a bracket portion and whose rear end side serves as a weight mounting portion for mounting the counterweight, is joined to the left and right sides of the center frame by welding via a plurality of overhanging beams and extends in the front and rear directions. It consists of a left side frame and a right side frame.
No. 03867, etc.).

Since the swing frame of such a standard machine has a frame structure composed of the center frame and the left and right side frames, there is an advantage that the structure has a sturdy structure and the rigidity can be improved. However, on the other hand, the front and rear dimensions become long, and the counterweight provided at the weight mounting portion of the center frame greatly extends from the crawler belt of the lower traveling body.

For this reason, in the hydraulic excavator of the standard machine, when excavating work at a site where the work space is small, such as an urban area, when the upper revolving structure is driven to rotate on the lower traveling structure, the rear end side of the counterweight is surrounded. There is a possibility of collision with obstacles. Further, this increases the burden on the operator, and tends to be unsuitable for excavation work in a narrow site such as an urban area.

On the other hand, in a small hydraulic excavator, a small working device is adopted, and when the working device is folded, the working device together with the counterweight is housed within the vehicle width of the undercarriage. A small turning hydraulic excavator within a vehicle width is known. In addition, a working device close to the standard machine is used so as not to impair the working performance, and the counterweight is brought closer to the cab to shorten the front and rear dimensions (total length) of the revolving frame. Excavators are also known (for example, Japanese Patent Laid-Open No. 2000-27235).
JP-A-2000-291058, etc.).

In such a small swing hydraulic excavator, the swing frame of the upper swing body is formed into a substantially disc shape by using a relatively thick steel plate and the like, and before standing on the bottom plate, It is configured by left and right vertical plates extending in the rear direction, and a mounting bracket portion for a working device is integrally provided on the front side of each vertical plate.

Further, on the rear side of the bottom plate, a counterweight, which is formed by being curved in an arc shape with a predetermined curvature in advance, is attached to the bottom plate. The counterweight in this case can be accommodated in a circle with a predetermined turning radius, so that even in a narrow work site such as an urban area, the rear end side of the counterweight is surrounded by the surroundings when the upper turning body turns. Avoid contact with obstacles.

[0010]

In the small swing hydraulic excavator according to the above-mentioned prior art, the swing frame of the upper swing body has a substantially disc-shaped bottom plate made of one steel plate.
The left and right vertical plates are erected on the bottom plate and extend in the front and rear directions, and a mounting bracket for a working device is integrally provided on the front side of each vertical plate.

Therefore, in the prior art, it is necessary to use a thick steel plate having a single bottom plate in order to maintain the strength of the entire swivel frame, which increases the weight of the swivel frame as a whole and the material cost. There is a problem of being bulky.

Further, the left and right vertical plates are welded on the bottom plate made of one plate, and the cab or canopy covering the driver's seat and the operation are installed at positions on the bottom plate outside the vertical plates. It is necessary to install equipment mounts, etc., to which hydraulic equipment such as oil tanks and various directional control valves (multiple valves) are attached by welding.

Therefore, the bottom plate is apt to be distorted or deformed due to the heat effect during welding, and it is troublesome to remove the internal strain thereafter, and, for example, when the outer cover is attached, the weld distortion is not generated. There is a problem that a dimensional error or the like is likely to occur due to the influence of, and extra labor and time are spent.

Further, the disk-shaped bottom plate made of a single steel plate is struck by projections from the ground when the vehicle is traveling, or by rocks or flying stones excavated by the working device. In many cases, the bottom plate is partially damaged or damaged, which may reduce the durability and life of the revolving frame.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a frame having a frame structure so that the bottom plate of the center frame can be formed of a thin plate material, and It is an object of the present invention to provide a swing frame for a construction machine, which can reduce the weight and cost and can also reduce the swing radius so that excavation work can be performed easily even in a narrow work site.

Another object of the present invention is to reduce the size of the bottom plate of the center frame and the like by using the left and right side frames, and reduce the distortion and deformation due to the heat effect during welding. To provide a swing frame for a construction machine capable of improving the workability of a construction machine.

[0017]

In order to solve the above-mentioned problems, a swing frame for a construction machine according to the present invention comprises a center frame provided with a working device on the front side and a counterweight on the rear side, and the center frame. It is applied to the swing frame of construction machinery consisting of a left side frame and a right side frame provided on both the left and right sides of the frame.

The feature of the configuration adopted by the invention of claim 1 is that the left side frame and the right side frame are
It is configured by using left and right arcuate frames that are curved in an arcuate shape so as to fit within a circle having a predetermined turning radius R.

With this structure, both the left side frame and the right side frame, which are formed by using the arcuate frame, can be accommodated within the circle having the turning radius R, whereby the turning radius R of the upper revolving structure is set. Can be made smaller and the entire turning frame including the counterweight can be housed within a circle having a turning radius R. Further, the revolving frame can be formed into a frame structure by the center frame, the left side frame, and the right side frame, and the revolving frame can be reduced in size and weight.

According to the second aspect of the present invention, the arcuate frame includes a bending frame portion which is curved in an arcuate shape and extends forward and backward, and a center frame which extends leftward and rightward from the front end of the bending frame portion. A front frame part connected to the front end side, and a left side from the rear end of the bending frame part,
The rear frame portion extends rightward and is connected to the rear end side of the center frame.

Thus, the bending frame portion can be formed by curving in an arc shape, and the bending frame portion can be integrally connected to the center frame by using the front frame portion and the rear frame portion of the arc-shaped frame. The strength of can be increased.

Further, according to the invention of claim 3, the arcuate frame has a structure in which the bending frame portion, the front frame portion and the rear frame portion, which are separate members, are connected to each other by using welding means. Thereby, the bending frame portion, the front frame portion, and the rear frame portion of the arcuate frame can be formed in advance as separate members, and the bending frame portion, the front frame portion, and the rear frame portion can be subsequently joined to each other by welding means. Thus, the arcuate frame can be formed as an integral structure.

On the other hand, the invention of claim 4 is characterized in that the arcuate frame comprises a bending frame portion which is curved in an arcuate shape and extends forward and backward, and a center frame which extends leftward and rightward from the front end of the bending frame portion. The front frame portion is connected to the front end side.

Thus, the front frame portion of the arc-shaped frame can be connected to the front end side of the center frame, and in this state, the bent frame portion curved in an arc shape is arranged so as to extend rearward of the center frame. can do.

According to the invention of claim 5, the arcuate frame has a structure in which the bending frame part and the front frame part, which are separate members, are connected to each other using welding means. Thereby, the bending frame portion and the front frame portion of the arc-shaped frame can be formed in advance as separate members, and the bending frame portion and the front frame portion are then joined to each other by the welding means, whereby the arc-shaped frame is integrally structured. It can be formed as an object.

Further, in the invention of claim 6, a reinforcing member extending leftward and rightward is provided between the bending frame portion of the arcuate frame and the center frame. In this case, by using the reinforcing member, the joint strength between the bending frame portion of the arcuate frame and the center frame can be increased, and the reinforcing member can be used for hydraulic equipment (for example, multiple valves, hydraulic oil tanks), etc. The device mounting base can be configured.

Further, according to the invention of claim 7, the center frame is provided with a bottom plate provided on the lower traveling body via a slewing wheel, and is erected upward from the bottom plate and extends in the front and rear directions of the bottom plate. The left and right vertical plates are provided, and the reinforcing member is configured to connect the bending frame portion of the arc-shaped frame to the vertical plate of the center frame.

As a result, the reinforcing member can be firmly joined between the bent frame portion of the arcuate frame and the vertical plate of the center frame, and the joint strength of the entire arcuate frame with respect to the center frame can be increased. It is also possible to increase the rigidity of the equipment mounting base formed by the reinforcing member.

On the other hand, according to the invention of claim 8, the reinforcing member is formed integrally with the bending frame portion of the arcuate frame. Accordingly, the reinforcing member can be formed with high strength with respect to the bending frame portion.

According to the invention of claim 9, the arcuate frame is formed by bending a hollow pipe material. As a result, it is possible to reduce the weight of the arcuate frame as a hollow structure and easily perform bending, and the arcuate frame is formed into a shape that is curved in an arc shape in accordance with a virtual circle having a turning radius R. it can.

Furthermore, according to the tenth aspect of the invention, the arcuate frame has an asymmetric cross section. As a result, the rigidity of the arcuate frame can be increased, and the hollow structure can reduce the weight. Then, for example, a D-shaped frame having a D-shaped cross section can be used as the arc-shaped frame.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the swing frame of a construction machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the swing frame is used as a swing frame of a small swing hydraulic excavator.

1 to 4 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a lower traveling body of the hydraulic excavator, and 2 denotes an upper revolving body mounted on the lower traveling body 1 so as to be capable of revolving via a revolving wheel 3 or the like.

The upper revolving structure 2 is provided with a revolving frame 21, which will be described later, a cab 4 which is mounted on the front left side of the revolving frame 21, and which defines a driver's cab, and a rear side of the cab 4. A building cover 5 which is provided in the revolving frame 21 and accommodates an engine, a hydraulic pump driven by the engine, a directional control valve such as a multiple valve (none of which is shown), and the like, and a rear of the building cover 5. And a counterweight 6 which is provided on the revolving frame 21 on the side and balances weight with respect to a working device 8 described later.

The cab 4 is formed as a so-called round cab, and a door 4A is provided on the front left side of the cab 4 so as to be openable and closable. And the cab 4 has a door 4A.
And the surrounding door frame portion 4B and the like are formed in an arc shape along an imaginary circle 7 having a turning radius R shown in FIG. 3, and have a turning radius R with respect to the turning center O of the upper turning body 2. It is configured so that it can be contained within the virtual circle 7.

The counterweight 6 is also formed so that its rear surface side has an arcuate shape and is housed within a virtual circle 7 having a turning radius R. The upper swing body 2 realizes a so-called small swing hydraulic excavator by housing the cab 4 and the counterweight 6 in such a virtual circle 7.

A working device 8 is provided on the front part of the upper revolving structure 2 so as to be able to move up and down. The working device 8 is, for example, an offset boom type working device, and includes a lower boom 9, an upper boom 10, a cylinder stay 11, The arm 12 and the bucket 13 are configured. The lower boom 9 of the working device 8 has vertical plates 24 and 25 whose base ends are described later.
Is rotatably mounted between the mounting brackets 24A and 25A, and is lifted up and down by the boom cylinder 9A.

Further, as shown in FIG. 1, the working device 8 takes a small turning posture by rotating the arm 12 and the bucket 13 so as to fold them while the lower boom 9 is largely lifted upward. In the turning posture, the working device 8 is housed in the virtual circle 7 having the turning radius R shown in FIG.

The vertical plates 24 and 25, to which the lower boom 9 of the working device 8 is attached, are arranged at positions offset to the right by a certain dimension with respect to the swing center O of the upper swing body 2 as shown in FIG. Has been done. As a result, the cab 4, which is a round cab, is arranged with a large mounting space on the left front part of the upper swing body 2 so as to enhance the habitability and operability for the operator in the cab 4.

Reference numeral 21 denotes a revolving frame which constitutes a frame of the upper revolving structure 2. The revolving frame 21 is located at a central portion as shown in FIGS. And the left side frame 31, which will be described later,
It is composed of the right side frame 34 and the like.

The center frame 22, the left side frame 31, and the right side frame 34 each have a skeleton structure to reduce the weight of the revolving frame 21 while ensuring sufficient rigidity. Also,
The swivel frame 21 is configured so that the left side frame 31 and the right side frame 34 are curved in an arc shape as described later, so that the swivel frame 21 is entirely housed within a virtual circle 7 having a swivel radius R shown in FIG.

Reference numeral 22 denotes a center frame which constitutes a central portion of the revolving frame 21, and the center frame 22 is constituted by a bottom plate 23, a right vertical plate 24, a left front vertical plate 25, a left rear vertical plate 26 and the like which will be described later. .

A bottom plate 23 is a base plate of the center frame 22. The bottom plate 23 is made of a thick steel plate or the like as shown in FIGS.
As shown in FIG. 3, it is formed in a substantially rectangular shape and extends in the front and rear directions with a predetermined length dimension. On the upper surface side of the bottom plate 23, a right vertical plate 24 and a left front vertical plate 25 extending in the front and rear directions.
The left rear vertical plate 26 and the horizontal plate 27 located on the rear end side of the left front vertical plate 25 and connecting the right vertical plate 24 and the left rear vertical plate 26 in the left and right directions use welding means. Has been set up.

Here, the bottom plate 23 of the center frame 22
Is formed with a width dimension slightly larger than the outer diameter of the swivel wheel 3 shown in FIG. 1, and the width dimension of the bottom plate 23 can be reduced to a range where it can be attached to the swivel wheel 3.

The right vertical plate 24 extends forward and rearward with a length substantially corresponding to the bottom plate 23, and the left front vertical plate 25 and the left rear vertical plate 26 are substantially parallel to the right vertical plate 24. ， Extended later. However, the left front vertical plate 25 and the left rear vertical plate 26
Are separated left and right (width direction) at the position of the horizontal plate 27, and the left front vertical plate 25 extends from the widthwise intermediate position of the horizontal plate 27 to the front end side of the bottom plate 23.

The left front vertical plate 25 constitutes, together with the front side of the right vertical plate 24, mounting brackets 24A, 25A to which the lower boom 9 of the working device 8 is pin-movable so that the lower boom 9 can be lifted and lowered. , 25A, a reinforcing plate 28 and the like are joined by welding in order to enhance the bending strength and the like of the mounting brackets 24A, 25A.

Further, a bracket portion 29 for the cylinder is provided on the front side of the right vertical plate 24 and the left front vertical plate 25, which is located on the front side of the reinforcing plate 28. The bracket portion 29 is shown in FIG. The base end side of the illustrated boom cylinder 9A is rotatably pin-connected.

On the other hand, the left rear vertical plate 26 is disposed so as to sandwich the horizontal plate 27 between the right vertical plate 24 and the left and right directions, and extends parallel to the right vertical plate 24 to the rear end side of the bottom plate 23. It is extended. And, the rear end sides of these right vertical plate 24 and left rear vertical plate 26 are
The weight mounting portion 30 is configured with the rear end portion of the bottom plate 23,
The counter weight 6 shown in FIG. 1 is removably attached to the weight attaching portion 30 using attachment bolts (not shown) or the like.

Reference numeral 31 is a left side frame which constitutes a part of the turning frame 21, and the left side frame 31 is shown in FIG.
The left side arcuate frame 32 curved in an arc shape so as to be housed in the virtual circle 7 having the turning radius R shown in FIG.
Is formed by bending a rectangular tube-shaped hollow frame member having a quadrangular cross section, similarly to the later-described arc-shaped frame 35 shown in FIG.

Here, the arcuate frame 32 is bent in the arcuate shape as shown in FIGS. 2 and 3 and extends in the front and rear directions.
2A, a front frame portion 32B that is bent and extends rightward from the front end of the bending frame portion 32A, and a rear frame portion 32C that is bent and extends rightward from the rear end of the bending frame portion 32A, The rear frame portion 32C extends toward the center frame 22 side substantially parallel to the front frame portion 32B.

The front end of the front frame portion 32B of the arc-shaped frame 32 is welded (joined) to the upper surface of the bottom plate 23 and the front end surface of the left front vertical plate 25 at the front end side of the center frame 22, and the rear frame portion 32C is welded. The front end is the rear end of the center frame 22 and the bottom plate 2
3 and the left side surface of the left rear vertical plate 26.
As a result, the arcuate frame 32 constitutes the left side frame 31 firmly connected to the center frame 22.

Reference numeral 33 denotes the center frame 22 and the bending frame portion 32.
A projecting beam serving as a reinforcing member provided between the projecting beam 33 and the projecting beam A. The projecting beam 33 is located between the front frame portion 32B and the rear frame portion 32C, and the base end side is on the inner surface of the bending frame portion 32A. Joined,
The front frame portion 3 is directed toward the left rear vertical plate 26 side of the center frame 22.
2B, extending substantially parallel to the rear frame portion 32C.

The tip side of the bulging beam 33 is joined to the upper surface of the bottom plate 23 and the left side surface of the left rear vertical plate 26 at the longitudinal middle portion of the center frame 22. The joining strength of the left side frame 31 (arc-shaped frame 32) to the center frame 22 is increased. Further, the overhanging beam 33 constitutes a cab mount together with the front frame portion 32B of the arcuate frame 32, and the cab 4 illustrated in FIG.
Is supported from below.

Reference numeral 34 is a right side frame forming a part of the turning frame 21, and the right side frame 34 is shown in FIG.
The right-side arcuate frame 35 curved in an arc shape so as to be accommodated in the virtual circle 7 having the turning radius R shown in FIG.
Is formed by bending a rectangular tubular hollow frame member having a quadrangular cross section as shown in FIG.

Here, the arcuate frame 35 is bent in the arcuate shape as shown in FIGS. 2 and 3 and extends in the front and rear directions.
5A, a front frame portion 35B bent and extended leftward from the front end of the bending frame portion 35A, and a rear frame portion 35C bent and extended leftward from the rear end of the bending frame portion 35A, The rear frame portion 35C extends toward the center frame 22 side substantially in parallel with the front frame portion 35B.

The front end portion of the front frame portion 35B of the arc-shaped frame 35 is welded (joined) to the upper surface of the bottom plate 23 and the front end surface of the right vertical plate 24 at the front end side of the center frame 22, and the rear frame portion 3 is formed.
The front end side of 5C is the rear end side of the center frame 22 and the bottom plate 23.
And the right side surface of the right vertical plate 24. As a result, the arcuate frame 35 constitutes the right side frame 34 that is firmly connected to the center frame 22.

Reference numerals 36 and 37 denote bulging beams as other reinforcing members which are disposed between the center frame 22 and the bending frame portion 35A with a front and a rear spacing, respectively.
Reference numerals 6 and 37 are located between the front frame portion 35B and the rear frame portion 35C, and the base end side is joined to the inner side surface of the bending frame portion 35A, and the front frame portion is directed toward the right vertical plate 24 side of the center frame 22. 35B,
It extends substantially parallel to the rear frame portion 35C.

Then, the tip ends of the projecting beams 36, 37 are joined to the upper surface of the bottom plate 23 and the right side surface of the right vertical plate 24 at the longitudinal middle portion of the center frame 22, whereby the projecting beams 36, 37 are formed. Numeral 37 increases the joint strength of the right side frame 34 (arc-shaped frame 35) to the center frame 22.

The projecting beams 36 and 37, together with the front frame portion 35B and the rear frame portion 35C of the arcuate frame 35, constitute an equipment mounting base and the like, on which multiple valves (direction control valves), A hydraulic device (not shown) such as a hydraulic oil tank is mounted.

Reference numerals 38A to 38E denote undercovers for covering the lower surface side of the revolving frame 21.
Among 38A to 38E, the under cover 38A is located between the left side arcuate frame 32 and the bottom plate 23 and is located between the front frame part 32B of the arcuate frame 32, the bending frame part 32A and the overhanging beam 33. It is fixed by using bolts. Further, the under cover 38B is fixed between the overhanging beam 33, the bending frame portion 32A of the arcuate frame 32, and the rear frame portion 32C from below using bolts or the like.

On the other hand, the under cover 38C is located between the right circular arc frame 35 and the bottom plate 23, and is located between the front frame portion 35B of the circular arc frame 35, the bending frame portion 35A and the projecting beam 36. It is fixed from the side using bolts. Further, the under cover 38D is fixed between the overhanging beams 36 and 37 from below by using bolts or the like, and the undercover 38E includes the overhanging beam 37, the bending frame portion 35A of the arcuate frame 35, and the rear frame portion 35C. It is fixed with a bolt or the like from the lower side between and.

The small turning hydraulic excavator according to the present embodiment has the above-mentioned structure. Next, a method of assembling the turning frame 21 will be described.

First, in the process of assembling the center frame 22, as shown in FIGS. 2 and 3, with respect to the bottom plate 23 formed of a thick steel plate or the like in a substantially rectangular shape, the right vertical plate 2 is provided on the upper surface side.
4, the left front vertical plate 25, the left rear vertical plate 26, the horizontal plate 27, etc. are respectively welded, and the lower boom 9 of the working device 8 is pin-joined to the front side of the right vertical plate 24 and the left front vertical plate 25. The mounting brackets 24A and 25A are provided by welding means or the like.

In this case, these mounting brackets 24
A reinforcing plate 28 or the like is welded between A and 25A to increase the bending strength and the like of the mounting brackets 24A and 25A.
Further, on the front side of the right vertical plate 24 and the left front vertical plate 25, the bracket portion 29 for the cylinder is located on the front side of the reinforcing plate 28.
The bracket 29 is provided so that the base end side of the boom cylinder 9A shown in FIG. 1 can be rotatably pin-connected.

On the rear side of the right vertical plate 24 and the left rear vertical plate 26, the weight mounting portion 3 is located at the rear end side of the bottom plate 23.
0 is provided, and the counter weight 6 shown in FIG. 1 is detachably attached to the weight attaching portion 30 by using a plurality of attaching bolts or the like.

On the other hand, the left side frame assembling process for assembling the left side frame 31 can be performed using an assembly line different from that for the center frame 22. In this case, as the left side frame 31, as shown in FIGS. 2 to 4, an arcuate frame 32 formed by bending a hollow frame material is used.

The arcuate frame 32 is bent into an arcuate shape and extends in the front and rear directions.
Front frame portion 32B bent and extended rightward from the front end of 2A
And a rear frame portion 32C that is bent and extends rightward from the rear end of the bending frame portion 32A. In addition, the arc-shaped frame 32
The bending beam portion 32A is provided between the front frame portion 32B and the rear frame portion 32C by welding the overhanging beam 33.

On the other hand, in the right side frame assembling process for assembling the right side frame 34, the center frame 22,
It can be performed using an assembly line different from that of the left side frame 31. Also in this case, as the right side frame 34, an arcuate frame 35 formed by bending a hollow frame material as shown in FIGS. 2 to 4 is used.

Then, the arcuate frame 35 is bent into an arcuate shape and extends in the front and rear directions.
Front frame portion 35B bent and extended leftward from the front end of 5A
And a rear frame portion 35C bent and extended leftward from the rear end of the bending frame portion 35A. In addition, the arc-shaped frame 35
The bending beams 35A are provided with welding beams 36 and 37 located between the front frame 35B and the rear frame 35C by welding.

Next, in the frame combining step, the left side frame 31 and the right side frame 34 assembled as described above are conveyed to the assembly line of the center frame 22, for example, and the side frames 31 and 34 are 2,
As shown in FIG. 3, the left and right sides of the center frame 22 are combined.

The left side frame 31 is welded to the bottom plate 23 of the center frame 22, the left front vertical plate 25, and the left rear vertical plate 26 by welding the front ends of the front frame portion 32B, the overhanging beam 33, and the rear frame portion 32C, respectively. By doing so, these are integrally joined to the center frame 22.

Also for the right side frame 34,
Front frame portion 35B, overhang beams 36 and 37, and rear frame portion 35
The front end side of C is the bottom plate 23 of the center frame 22 and the right vertical plate 2.
Center frame 2 by welding to 4 and
It is integrally joined to 2.

Thus, the revolving frame 21 according to this embodiment includes the center frame 22 and the left side frame 3.
1. The right side frame 34 and the right side frame 34 are assembled to form a skeleton structure. The side frames 31, 34 and the like use arcuate frames 32, 35 made of a hollow cylindrical hollow frame material. There is no need to secure the overall strength by using a single bottom plate as in the frame.

Further, it is possible to reduce the weight of the swivel frame 21 as a whole, and it is possible to efficiently increase the strength of the swivel frame 21 as a whole by using the frame structure. Further, the material cost of the entire swivel frame 21 can be reduced, and the cost can be reduced.

Further, the revolving frame 2 assembled in this way
1 can be used to manufacture a small turning hydraulic excavator as shown in FIGS. Then, in the hydraulic excavator, the counterweight 6 mounted on the rear end side of the revolving frame 21 via the weight mounting portion 30 can be housed within a virtual circle 7 having a revolving radius R as shown in FIG.

Regarding the left side frame 31,
As shown in FIG. 3, the bending frame portion 32A curved in an arc shape along the imaginary circle 7, the front frame portion 32B bent rightward from the front end of the bending frame portion 32A, and the bending frame portion 32A Since it is configured by using the arcuate frame 32 including the rear frame portion 32C that is bent and extends rightward from the rear end, the left side frame 31 is matched with the cab 4 that is a so-called round cab.
The bending frame portion 32A can be curved.

On the other hand, as for the right side frame 34,
As shown in FIG. 3, the bending frame portion 35A curved in an arc shape along the imaginary circle 7, the front frame portion 35B bent and extending leftward from the front end of the bending frame portion 35A, and the bending frame portion 35A It is configured by using an arcuate frame 35 including a rear frame portion 35C bent and extended leftward from the rear end.

Therefore, the turning radius R of the entire upper turning body 2 is
In addition to reducing the size, the entire turning frame 21 including the cab 4, the building cover 5, the counterweight 6 and the like can be housed within the virtual circle 7 having the turning radius R.

As a result, even in a narrow work site such as an urban area, the operator in the cab 4 may cause the rear end side of the counterweight 6 to collide with surrounding obstacles when the upper swing body 2 is turned. The number can be surely reduced, and it becomes unnecessary to pay special attention to the counterweight 6 located on the rear side of the cab 4.

Further, the center frame 22 and the bending frame portion 32
By the overhanging beam 33 provided between the left side frame 31 and the center frame 22, the left side frame 31 (arc-shaped frame 32)
The joint strength of can be increased. Then, a cab mount can be configured by the overhanging beam 33 and the front frame portion 32B of the arcuate frame 32, and the cab 4 shown in FIG. 1 can be stably supported from below.

Further, the center frame 22 and the bending frame portion 3
The other overhanging beams 36 and 37, which are arranged at a distance from the front and rear of the right side frame 34 (arc-shaped frame 35) to the center frame 22, can be increased. Then, the projecting beams 36 and 37 and the arc-shaped frame 35
A device mounting base and the like can be configured by the front frame portion 35B and the rear frame portion 35C, and hydraulic devices such as multiple valves (directional control valves) and hydraulic oil tanks can be stably mounted on these. .

As a result, unlike the prior art, it is not necessary to separately provide an equipment mounting base or the like on the bottom plate of the revolving frame, and, for example, the bottom plate 23 of the center frame 22 is distorted or deformed due to the influence of heat during welding. Can be suppressed. Then, the building cover 5 is placed on the swivel frame 21.
It is possible to reduce the occurrence of dimensional error due to the effect of welding distortion even when mounting the same, and to improve workability during manufacturing and assembly.

Therefore, according to this embodiment, the revolving frame 21 is connected to the center frame 22 and the left side frame 3.
1. The bottom plate 23 of the center frame 21 is formed by forming a frame structure from the right side frame 34.
And the like can be formed of a thin plate material, and the overall weight can be reduced to reduce the manufacturing cost and the like.

Also, the left and right side frames 31, 34
Is formed by using the arcuate frames 32 and 35 that are curved in an arcuate shape, the bottom plate 23 of the center frame 22 and the like can be made small, and distortion, deformation, and the like due to the heat effect during welding can be reduced. Workability at the time of manufacturing and assembling can be improved.

Then, for example, the left side frame 3 is formed by using arcuate frames 32 and 35 formed by bending a hollow frame material.
1. By forming the right side frame 34, the weight of the revolving frame 21 as a whole can be reduced, and the bottom plate 23 of the center frame 22 can be formed with a width dimension slightly larger than the outer diameter of the revolving wheel 3 shown in FIG. The bottom plate 23 can be reduced to the extent that it can be attached to the turning wheel 3.

As a result, the bottom plate 23 collides with a protrusion from the ground when the vehicle is traveling, and the working device 8
It is possible to reliably reduce the possibility of collision of rocks, flying stones, etc. excavated in 1., and it is possible to improve the durability and life of the revolving frame 21.

In the first embodiment, as described in FIG. 4, the arcuate frames 32 and 35 are formed by using a hollow cylindrical hollow frame member having a quadrangular cross section. However, instead of this, for example, as in the first modification shown in FIG. 5, the arc-shaped frame 41 is formed by a hollow frame material having a substantially D-shaped cross section or a substantially triangular shape (asymmetrical shape), The left and right side frames 31 and 34 may be configured by using such an arcuate frame 41.

In this case, since the cross section of the arcuate frame 41 is formed in an asymmetrical shape having a substantially D-shape or a substantially triangular shape, the rigidity of the arcuate frame 41 can be increased and the hollow frame 41 can be hollow. The structure can be lightweight. And
For example, a D-shaped frame having a D-shaped cross section may be used as the arc-shaped frame 41.

Further, as in the second modified example shown in FIG. 6, the arc-shaped frame 4 is formed by using a frame material having a substantially U-shaped cross section.
2 may be formed. In addition, an arcuate frame 43 (third modification) having an asymmetrical horizontal cross section as shown in FIG. 7, an arcuate frame 44 (fourth modification) having a horizontal cross section having a gate shape as shown in FIG. The left and right side frames 31 and 34 may be configured by using an arcuate frame 45 (fifth modified example) having a gate shape whose cross section is asymmetrical as shown in FIG.

On the other hand, as in the sixth modification shown in FIG. 10, for example, a hollow frame member formed by welding two plate members 46A and 46B so as to have a substantially D-shaped or substantially triangular cross section. The arc-shaped frame 46 may be formed by, and the left and right side frames 31, 34 may be configured by the arc-shaped frame 46. In this case, two plate materials 46A and 46B
10 is in a state of being bent in advance so as to be curved in an arc shape along the virtual circle 7 having the turning radius R illustrated in FIG.
It is preferable to bond them to each other as shown in FIG.

Further, as in the seventh modified example shown in FIG. 11, two plate members 47A and 47B are welded to each other so that the cross section is substantially D.
The arcuate frame 47 may be configured by using a hollow frame material formed into a letter shape or a square shape. Further, as in the eighth modified example shown in FIG. 12, an arc-shaped frame 48 is formed by a hollow frame material having a circular cross section, and the left and right side frames 31 are formed by using such an arc-shaped frame. , 3
4 may be configured.

Next, FIG. 13 shows a second embodiment of the present invention. The feature of this embodiment is that a bending frame portion of an arc-shaped frame,
The front frame part and the rear frame part are formed as separate members, and the bending frame part, the front frame part and the rear frame part are connected by welding means. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 51 denotes a left side arcuate frame which constitutes the left side frame 31 of the turning frame 21, and the arcuate frame 51 is substantially the same as the arcuate frame 32 described in the first embodiment. In addition, the bending frame portion 51A, the front frame portion 51B, and the rear frame portion 51C are configured.

However, this arc-shaped frame 51 is
1A, the front frame portion 51B and the rear frame portion 51C are formed as separate members in advance, and the front frame portion 51 is provided on the front end side of the bending frame portion 51A.
B is connected using welding means or the like. Further, a rear frame portion 51C is similarly welded and provided on the rear end side of the bending frame portion 51A.

Reference numeral 52 denotes a right side arcuate frame which constitutes the right side frame 34 of the revolving frame 21, and the arcuate frame 5
2 is similar to the arcuate frame 35 described in the first embodiment, the bending frame portion 52A, the front frame portion 52B and the rear frame portion 52.
It is composed of C.

However, this arcuate frame 52 is
2A, the front frame portion 52B and the rear frame portion 52C are formed as separate members in advance, and the front frame portion 52 is provided on the front end side of the bending frame portion 52A.
B is connected using welding means or the like. Further, a rear frame portion 52C is similarly welded and provided on the rear end side of the bending frame portion 52A.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as those of the first embodiment, but particularly in this embodiment, the arc-shaped frames 51, 52 are provided. The bending frame parts 51A and 52 made of separate members.
A, front frame portions 51B and 52B and rear frame portions 51C and 52C
Are welded to each other.

Therefore, each of the arcuate frames 51 and 52 can be composed of three members, and each member can be easily manufactured and processed. Further, the work of bending the bending frame portions 51A and 52A along the virtual circle 7 or the like having the turning radius R can be performed relatively easily, and the manufacturing equipment and the like can be simplified and downsized.

The arcuate frame 51 has a bent frame portion 51A.
Alternatively, a welding joint or the like may be separately used to join the front frame portion 51B and the rear frame portion 51C. The same applies to the arcuate frame 52.

Next, FIG. 14 shows a third embodiment of the present invention, and the feature of this embodiment is that a reinforcing member is formed integrally with the bending frame portion of the arcuate frame. . In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 61 is a left side arcuate frame which constitutes the left side frame 31 of the revolving frame 21, and the arcuate frame 61 is substantially the same as the arcuate frame 32 described in the first embodiment. , Bending frame portion 61A, front frame portion 61B and rear frame portion 6
It is composed of 1C. However, this arc-shaped frame 61
Is different in that an overhanging beam 62 described later is integrally formed with the bending frame portion 61A.

Reference numeral 62 denotes an overhanging beam used as a reinforcing member in the present embodiment. Although the overhanging beam 62 is constructed in substantially the same manner as the overhanging beam 33 described in the first embodiment, The overhanging beam 62 is formed integrally with the arcuate frame 61 by using a press forming means such as hydroforming.

The bulging beam 62 is integrated with the inner side surface of the bending frame portion 61A with its base end side located between the front frame portion 61B and the rear frame portion 61C, and the tip end side of the center frame 22. The upper surface of the bottom plate 23 and the left rear vertical plate 26 at the middle portion in the length direction.
Is joined to the left side of the.

Reference numeral 63 denotes a right-side arcuate frame which constitutes the right side frame 34 of the revolving frame 21.
Also, similarly to the arcuate frame 35 described in the first embodiment, the bending frame portion 63A, the front frame portion 63B and the rear frame portion 63C are also provided.
It is composed by. However, this arcuate frame 63
The difference is that overhanging beams 64 and 65, which will be described later, are formed integrally with the bending frame portion 63A.

Reference numerals 64 and 65 are overhanging beams used as reinforcing members in the present embodiment.
Is substantially the same as the bulging beams 36 and 37 described in the first embodiment, but the bulging beams 64 and 65 are
Is integrally formed with the arcuate frame 63 by using a press forming means such as hydroforming.

The overhanging beams 64 and 65 are integrated with the inner side surface of the bending frame 63A with the base end located between the front frame 63B and the rear frame 63C, and the center frame 22 on the tip side. The upper surface of the bottom plate 23 and the right vertical plate 24 at the middle portion in the longitudinal direction of the
Is joined to the right side of each.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operational effects as those of the first embodiment, but particularly in this embodiment, the arcuate frames 61, 63 are provided. Bending beam 6 on bending frame portions 61A and 63A of
By integrally forming 2, 64 and 65, the welding work can be simplified and the strength of the swivel frame 21 as a whole can be further increased.

Next, FIGS. 15 and 16 show the fourth embodiment of the present invention.
The feature of this embodiment is that the swing frame is applied to a canopy type small swing hydraulic excavator using a swing post type working device.
In addition, in this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 71 is a lower traveling body, 72 is an upper revolving body mounted on the lower traveling body 71 by means of revolving wheels 73, and the upper revolving body 72 is a revolving frame 81 to be described later. An exterior cover 74, a driver's seat 75, a canopy 76, a counterweight 77, etc. are provided on the revolving frame 81. And the exterior cover 74
Defines a machine room in which an engine, a hydraulic pump (neither of which is shown), and the like are housed together with the counterweight 77.

Reference numeral 78 denotes a swing-post type working device provided on the front side of the upper swing body 72. The working device 78 is rotatably connected to a support bracket 87 of a swing frame 81 described later by using a connecting pin or the like. Swing post 78
A, a boom 78B movably connected to the upper end of the swing post 78A, an arm 78C movably connected to the tip of the boom 78B, and an arm 78C.
It is generally constituted by a bucket 78D that is rotatably connected to the tip end side of C.

In the working device 78, the swing post 78A is swung in the horizontal direction (left and right directions) with respect to the support bracket 87 of the revolving frame 81, for example, when performing a guttering work or the like. The entire device 78 is swung to the left and right with respect to the turning frame 81.

Reference numeral 81 is a swivel frame which constitutes the main frame of the upper swivel body 72, and the swivel frame 81 is shown in FIG.
As shown in FIG. 6, a center frame 82, which will be described later, located in the central portion and extends in the front and rear directions, and a left side frame 9 which will be described later.
2, the right side frame 95 and the like.

The center frame 82, the left side frame 92 and the right side frame 95 have a skeleton structure to reduce the weight of the revolving frame 81 and ensure sufficient rigidity. Further, the turning frame 81 is one in which the left side frame 92 and the right side frame 95 are curved in an arc shape as will be described later, so that the turning frame 81 can be entirely housed within the virtual circle 7 having the turning radius R illustrated in FIG. Is.

Reference numeral 82 denotes a center frame of the swivel frame 81. The center frame 82 has a bottom plate 83, a left vertical plate 84, a right vertical plate 85, a horizontal plate 86, a support bracket 87 and weight attachments, which will be described later, as shown in FIG. It is composed of a section 91 and the like.

Reference numeral 83 denotes a bottom plate which serves as a base plate of the center frame 82. The bottom plate 83 is formed of a flat plate material as shown in FIG. 16 and extends in the front and rear directions of the center frame 82. The bottom plate 83 has a central portion in the lengthwise direction (front and rear directions) rotatably mounted on the lower traveling body 71 via the slewing wheel 73, whereby the slewing frame 81.
Is driven to turn left and right about the turning center O.

Reference numerals 84 and 85 are a left vertical plate and a right vertical plate which are provided upright on the upper surface side of the bottom plate 83 and extend in the front and rear directions.
4, the right vertical plate 85 and the right vertical plate 85 are arranged so as to be spaced apart from each other on the left and right sides with respect to the turning center O and to extend in a substantially "C" shape, and the front end side thereof is a support bracket 87 described later. Extends to the position. The left vertical plate 84 and the right vertical plate 85 are
The rear end side extends to the rear end side of the bottom plate 83 and constitutes a part of a weight mounting portion 91 described later.

Reference numeral 86 denotes a horizontal plate which is positioned on the rear side of the left vertical plate 84 and the right vertical plate 85 and is erected on the bottom plate 83.
6 is formed using a steel plate or the like that is thinner than the bottom plate 83, the left vertical plate 84, and the right vertical plate 85, and is joined to the upper surface of the bottom plate 83 and the left vertical plate 84 and the right vertical plate 85 by welding means. Has been done. Then, the horizontal plate 86 is located on the bottom plate 83 and is located on the left vertical plate 8.
4 and the right vertical plate 85 are connected to each other.

Reference numeral 87 is a support bracket provided on the front end side of the left vertical plate 84 and the right vertical plate 85.
Is a lower plate 88 and an upper plate 89, which will be described later, as shown in FIG.
Etc., and has pin holes 87A, 87B, etc. extending through the lower plate 88 and the upper plate 89 in the upward and downward directions. The support bracket 87 has pin holes 87A and 8A.
Upward and downward connecting pins (not shown) inserted into 7B
Thus, the swing post 78A of the working device 78 described above
A bracket portion that rotatably supports is configured.

Reference numeral 88 is a lower plate welded to the front end of the bottom plate 83. The lower plate 88 is formed by using a substantially triangular plate member as shown in FIG. The bracket 87 is configured. And the lower plate 8
Reference numeral 8 projects forward from the bottom plate 83 and forms a part of the bottom plate 83.

Reference numeral 89 is an upper plate arranged so as to cover the front side of the left vertical plate 84 and the right vertical plate 85 from the upper side, and the upper plate 89 is
As shown in FIG. 16, it is formed by using a substantially triangular plate material, and is joined to the upper front ends of the left vertical plate 84 and the right vertical plate 85 by using welding means. The upper plate 89 constitutes the support bracket 87 together with the lower plate 88 by facing the lower plate 88 at the upper and lower sides.

Reference numeral 90 denotes a reinforcing plate for increasing the bending strength of the support bracket 87. The reinforcing plate 90 is located between the left vertical plate 84 and the right vertical plate 85 as shown in FIG. It is arranged between the bottom plate 83 and both left and right sides thereof are joined to the left vertical plate 84 and the right vertical plate 85 by welding.

Further, the reinforcing plate 90 includes a top plate 89 and a bottom plate 83.
And a slantingly extending portion between the upper end and the upper end of the upper plate 89, and the lower end is connected to the upper face of the bottom plate 83. The reinforcing plate 90 closes the bottom plate 83 between the left vertical plate 84 and the right vertical plate 85 between the lower plate 88 and the rear end side of the upper plate 89 so as to form a hollow box structure, and supports it. The entire bracket 87 is reinforced as a box structure.

91 is a bottom plate 83, a left vertical plate 84, and a right vertical plate 85.
15 is a weight mounting portion provided at the rear end portion, and the counter weight 77 shown in FIG. 15 is detachably mounted to the weight mounting portion 91 by using a bolt or the like.

Reference numeral 92 is a left side frame forming a part of the turning frame 81, and the left side frame 92 is the first side frame.
Similar to the left side frame 31 described in the above embodiment, the left side frame 31 is formed by using the arcuate frame 93 on the left side.

Here, as shown in FIG. 16, the arcuate frame 93 is bent in an arcuate shape and extends in the front and rear directions.
And a front frame portion 93B bent and extended rightward from the front end of the bending frame portion 93A, and a rear frame portion 93C bent and extended rightward from the rear end of the bending frame portion 93A. The frame portion 93C is substantially parallel to the front frame portion 93B and the center frame 82
It extends to the side.

The front end of the front frame portion 93B of the arc-shaped frame 93 is welded (joined) to the upper surface of the bottom plate 83 and the left side surface of the left vertical plate 84 at the front end side of the center frame 82, and the rear frame portion 9 is formed.
The front end side of 3C is the rear end side of the center frame 82 and the bottom plate 83.
And the left side surface of the left vertical plate 84. As a result, the arcuate frame 93 constitutes the left side frame 92 that is firmly connected to the center frame 82.

Reference numeral 94 denotes the center frame 82 and the bending frame portion 93.
A projecting beam serving as a reinforcing member provided between the projecting beam 94 and the front frame portion 93B is located between the front frame portion 93B and the rear frame portion 93C. Joined,
The front frame portion 93 is directed toward the left vertical plate 84 side of the center frame 82.
B, it extends substantially parallel to the rear frame portion 93C.

The tip side of the bulging beam 94 is joined to the upper surface of the bottom plate 83 and the left side surface of the left vertical plate 84 at the longitudinal middle portion of the center frame 82. The joint strength of the left side frame 92 (arc-shaped frame 93) to the frame 82 is increased. Further, the overhanging beam 94 constitutes a device mounting base or a cab mounting base together with the front frame portion 93B of the arcuate frame 93 and the like.

Reference numeral 95 denotes a right side frame which constitutes a part of the turning frame 81, and the right side frame 95 also includes the first side frame.
In the same manner as the right side frame 34 described in the embodiment, the right side arcuate frame 96 is used for the bending frame portion 96A,
It has a front frame portion 96B and a rear frame portion 96C.

The front end portion of the front frame portion 96B of the arc-shaped frame 96 is welded (joined) to the upper surface of the bottom plate 83 and the right side surface of the right vertical plate 85 at the front end side of the center frame 82, and the rear frame portion 9 is formed.
The front end side of 6C is the rear end side of the center frame 82 and the bottom plate 83.
Is joined to the right side surface of the right vertical plate 85. As a result, the arcuate frame 96 constitutes the right side frame 95 firmly connected to the center frame 82.

Reference numerals 97 and 98 denote bulging beams as other reinforcing members which are disposed between the center frame 82 and the bending frame portion 96A with a front and a rear space, respectively.
7, 98 are located between the front frame portion 96B and the rear frame portion 96C, the base end side of which is joined to the inner side surface of the bending frame portion 96A, and the front frame portion faces the right vertical plate 85 side of the center frame 82. 96B,
It extends substantially parallel to the rear frame portion 96C.

The tip ends of the bulging beams 97 and 98 are joined to the upper surface of the bottom plate 83 and the right side surface of the right vertical plate 85 at the longitudinal middle portion of the center frame 82, whereby the bulging beams 97 and 98 are joined. The reference numeral 98 increases the joint strength of the right side frame 95 (arc-shaped frame 96) to the center frame 82. Further, the overhanging beams 97 and 98 form a device mounting base together with the front frame portion 96B and the rear frame portion 96C of the arcuate frame 96.

Reference numerals 99A to 99E are undercovers for covering the lower surface side of the revolving frame 81.
To 99E are undercovers 3 described in the first embodiment.
8A to 38E, and the bulging beams 94,
It is fixed to 97, 98, etc. from below by using bolts or the like.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same operational effects as those of the first embodiment. In addition, in the present embodiment, FIG.
In the canopy type small swing type hydraulic excavator in which the swing post type working device 78 is provided as illustrated in FIG. 5, the swing frame 81 can be configured from a center frame 82, a left side frame 92 and a right side frame 95 into a frame structure. It is possible to secure sufficient rigidity while reducing the weight of the revolving frame 81.

Next, FIGS. 17 to 20 show a fifth embodiment of the present invention.
The present embodiment is characterized in that the swing frame is applied to a cab-type small swing hydraulic excavator using a swing post type working device. In addition, in this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 101 is an undercarriage, 102 is an upper revolving superstructure mounted on the lower traveling car 101 by means of revolving wheels 103, and the upper revolving superstructure 102 is a revolving frame 110 described later. have.

In the upper swing body 102, the cab 104 and the exterior cover 10 are located on the swing frame 110.
5, the counterweight 106 and the like are provided, and the exterior cover 105 defines a machine room in which the engine, the hydraulic pump (neither is shown) and the like are housed together with the counterweight 106.

Here, the cab 104 is formed as a so-called round cab almost like the cab 4 described in the first embodiment, and is housed within a virtual circle 7 having a turning radius R shown in FIG. Has become.

Further, the counterweight 106 is also formed such that the rear surface side has an arc shape as shown in FIG. 20, and is housed within the virtual circle 7 having the turning radius R. The upper swing body 102 realizes a so-called small swing hydraulic excavator by housing the cab 104 and the counterweight 106 in such a virtual circle 7.

Reference numeral 107 denotes a swing-post type working device provided on the front side of the upper swing body 102. The working device 1
Reference numeral 07 denotes a swing post 107A that is rotatably connected to a support bracket 120 of a revolving frame 110, which will be described later, using a connecting pin or the like, and a boom 107B that is movably connected to the upper end of the swing post 107A. The arm 107C is connected to the tip side of the boom 107B so as to be able to move up and down, and the bucket 107D is rotatably connected to the tip side of the arm 107C.

In the working device 107, for example, when performing a gutter work or the like, the swing post 107A is oscillated in the horizontal direction (left and right directions) with respect to the support bracket 120 of the turning frame 110, whereby the work is performed. Device 107
The whole is swung to the left and right with respect to the turning frame 110.

Reference numeral 110 denotes a revolving frame which constitutes the main frame of the upper revolving structure 102.
18 to 20, a center frame 111, which will be described later, located in the central portion and extending in the front and rear directions, a left side frame 124, and a right side frame 127, which will be described later.
Etc.

The center frames 111,
Left side frame 124 and right side frame 127
The frame structure makes it possible to reduce the weight of the revolving frame 110 and ensure sufficient rigidity. Also,
The turning frame 110 has a turning radius R shown in FIG. 19 as a whole by forming the left side frame 124 and the right side frame 127 into an arc shape as described later.
Is contained in the virtual circle 7 of.

Reference numeral 111 denotes a center frame of the revolving frame 110, and the center frame 111 is a bottom plate 1 described later.
12, a left vertical plate 113, a right vertical plate 114, a horizontal plate 115, a weight mounting plate 118, a support bracket 120, and the like.

Reference numeral 112 denotes a bottom plate which serves as a base plate of the center frame 111, and the bottom plate 112 is formed of a flat plate material and extends in the front and rear directions of the center frame 111. The center of the bottom plate 112 in the longitudinal direction (front and rear) is rotatably mounted on the lower traveling body 101 via the slewing wheel 103, and is driven to slew left and right around the slewing center O. It is something.

Reference numerals 113 and 114 denote a left vertical plate and a right vertical plate which are provided upright on the upper surface side of the bottom plate 112 and extend in the front and rear directions. The left vertical plate 113 and the right vertical plate 114 are as shown in FIG. It is arranged so as to be spaced apart from the turning center O on both the left and right sides and extend in a substantially "C" shape, and its front end side is joined to a boss tube 122 described later from both the left and right sides, as shown in FIG. ing.

As shown in FIG. 19, the left vertical plate 113 extends obliquely in a straight line between a later-described upper plate 121 and a horizontal plate 115. The right vertical plate 114 is the bottom plate 1.
Although it extends in the front and rear directions on the upper part 12, the front part side is bent and extends obliquely in a substantially V shape at a position of an upper plate 121 described later.

Reference numeral 115 denotes a horizontal plate which is positioned on the rear end side of the left vertical plate 113 and the right vertical plate 114 and is erected on the bottom plate 112. Board 1
The bottom plate 112 is formed by using a steel plate or the like that is thinner than 14
Are joined to the upper surface of the left vertical plate 113 and the right vertical plate 114 by welding means or the like. Then, the horizontal plate 115
On the bottom plate 112, the left vertical plate 113 and the right vertical plate 114 are connected to each other.

116 and 117 are on the rear side of the horizontal plate 115 on the left,
Left and right rear vertical plates that are spaced apart to the right, and the rear vertical plates 1
16 and 117, the lower surface side is joined to the rear portion side of the bottom plate 112, and the rear end side is joined to a weight mounting plate 118 described later. Further, the rear vertical plates 116 and 117 are joined at their front end sides to the left and right end sides of the horizontal plate 115, respectively.
A horizontal plate 115 in front between the rear end and the rear end of the right vertical plate 114,
It is arranged so as to be sandwiched from the rear direction.

Reference numeral 118 denotes a weight mounting plate fixed to the rear end side of the bottom plate 112 by means such as welding. The weight mounting plate 118 is composed of a plate material extending in the left and right directions, and the upper surface and the rear side of the bottom plate 112. It is provided so as to be joined to the rear ends of the vertical plates 116 and 117. Then, as shown in FIG. 20, the counter weight 1 is attached to the weight attaching plate 118.
06 is detachably attached using a bolt or the like.

Reference numeral 119 denotes a mounting bracket provided on the left rear vertical plate 116. The mounting bracket 119 projects from the rear vertical plate 116 toward the left outside, and a hydraulic cylinder 132 to be described later shown in FIG. 20 is mounted thereto. Is.

Reference numeral 120 denotes a support bracket provided on the front side of the left vertical plate 113 and the right vertical plate 114. The support bracket 120 is a bottom plate 11 as shown in FIGS.
It is configured to include the front side of the second plate 2 and an upper plate 121 described later, and has a pin hole 120A and the like extending through the bottom plate 112 and the upper plate 121 in the upper and lower directions.

Here, the support bracket 120 has a boss tube 122 whose front ends of the left vertical plate 113 and the right vertical plate 114 will be described later.
The outer peripheral surface of is joined by welding. The support bracket 120 is a bracket that rotatably supports the swing post 107A of the working device 107 described above by means of upper and lower connecting pins (not shown) that are inserted into the pin hole 120A and the boss cylinder 122. It constitutes a section.

Reference numeral 121 denotes an upper plate which covers the front sides of the left vertical plate 113 and the right vertical plate 114 from above, and the upper plate 121 is shown in FIG.
8 to 20, it is formed by using a substantially triangular flat plate material, and is joined to the upper ends of the left vertical plate 113 and the right vertical plate 114 on the front side by welding means. And the upper plate 121
The support bracket 120 is configured with the bottom plate 112 by facing the front side of the bottom plate 112 above and below.

Reference numeral 122 denotes a boss cylinder which is provided by welding between the bottom plate 112 and the upper plate 121 and constitutes a part of the support bracket 120. The boss cylinder 122 is the support bracket 12.
It is arranged coaxially with the 0 pin hole 120A and extends upward and downward between the bottom plate 112 and the upper plate 121.

Reference numeral 123 is a reinforcing plate for increasing the bending strength of the support bracket 120. The reinforcing plate 123 is shown in FIG.
8, located between the left vertical plate 113 and the right vertical plate 114 as shown in FIG. 19, and disposed between the upper plate 121 and the bottom plate 112,
Both left and right sides thereof are joined to the left vertical plate 113 and the right vertical plate 114 by welding.

The reinforcing plate 123 extends obliquely between the upper plate 121 and the bottom plate 112, and the upper end of the reinforcing plate 123 has the upper plate 1.
21 is joined to the rear end side portion, and the lower end side is joined to the upper surface of the bottom plate 112. The reinforcing plate 123 closes between the left vertical plate 113 and the right vertical plate 114 between the bottom plate 112 and the rear end side of the upper plate 121 so as to form a hollow box structure.
As a result, the entire support bracket 120 is reinforced as a box structure.

Reference numeral 124 denotes a left side frame which constitutes a part of the turning frame 110.
Are formed by using the arcuate frame 125 on the left side in substantially the same manner as the left side frame 31 described in the first embodiment.

Here, the arcuate frame 125 is curved in an arcuate shape as shown in FIG. 18 and extends in the front and rear directions.
5A and a front frame portion 125B that is bent and extends rightward from the front end of the bending frame portion 125A.
The rear end of 25A is a free end 125C.

The arcuate frame 125 is the front frame portion 125.
The front end side of B is the front end side of the center frame 111 and the bottom plate 11
2 and the left side surface of the left vertical plate 113 are welded (joined). As a result, the arc-shaped frame 125 constitutes the left side frame 124 connected to the center frame 111.

Reference numeral 126 is an overhanging beam serving as a reinforcing member provided between the center frame 111 and the bending frame portion 125A. The overhanging beam 126 is located on the rear side of the arcuate frame 125 and is bent on the base end side. It is joined to the inner side surface of the frame portion 125A and extends substantially parallel to the front frame portion 125B toward the rear vertical plate 116 side of the center frame 111.

The tip end side of the bulging beam 126 is joined to the upper surface of the bottom plate 112 and the left side surface of the rear vertical plate 116 at the longitudinal middle portion of the center frame 111. The joining strength of the left side frame 124 (arc-shaped frame 125) to the frame 111 is increased. Further, the overhanging beam 126 is formed by the arc-shaped frame 12
5 together with the front frame portion 125B of No. 5 and the like, constitutes an equipment mounting base or a cab mounting base.

Reference numeral 127 denotes a right side frame which constitutes a part of the turning frame 110.
Also, similarly to the right side frame 34 described in the first embodiment, the right side frame 34 is formed using the right circular arc frame 128.

Here, the arcuate frame 128 is bent in the arcuate shape as shown in FIG. 19 and extends in the front and rear directions.
8A and a front frame portion 128B bent and extended leftward from the front end of the bending frame portion 128A.
The rear end of 28A is a free end 128C.

The arcuate frame 128 is the front frame portion 128.
The front end side of B is the front end side of the center frame 111 and the bottom plate 11
2 and the right side surface of the right vertical plate 114 are welded (joined). As a result, the arc-shaped frame 128 constitutes the right side frame 127 connected to the center frame 111.

Reference numerals 129 and 130 denote bulging beams as other reinforcing members which are arranged between the center frame 111 and the bending frame portion 128A with a front and a back, respectively, and the bulging beams 129 and 130 have a front portion. Frame part 128B and free end 128
The base end side is located between C and C, is joined to the inner side surface of the bending frame portion 128A, and extends substantially parallel to the front frame portion 128B toward the right vertical plate 114 side of the center frame 111.

The tip ends of the overhanging beams 129 and 130 are located at the middle portion in the length direction of the center frame 111 at the bottom plate 1.
12 is joined to the upper surface of the right vertical plate 114 and the right side surface of the right vertical plate 114.
11 to the right side frame 127 (arc-shaped frame 12
It is intended to increase the bonding strength of 8). Further, the overhanging beams 129 and 130 have the front frame portion 128 of the arc-shaped frame 128.
A device mounting base and the like are configured together with B.

Reference numerals 131A, 131B and 131C denote undercovers for covering the lower surface side of the revolving frame 110, and these undercovers 131A to 131C are constructed in substantially the same manner as the undercovers 38A to 38E described in the first embodiment. , The overhang beams 126, 129, 13 as shown in FIG.
It is removably fixed to 0 or the like from below by using bolts or the like.

Further, 132 is a hydraulic cylinder which serves as a swing actuator. The hydraulic cylinder 132 is mounted at its base end side to a mounting bracket 119 as shown in FIG.
The tip side is attached to the swing post 107A shown in FIG. Then, this hydraulic cylinder 132
Is for swinging the working device 107 shown in FIG. 17 as a whole to the left and right together with the swing post 107A.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same operational effects as those of the first embodiment. In addition, in the present embodiment, FIG.
As illustrated in FIG. 7, a swing post type working device 107
In the cab type small swing type hydraulic excavator provided with, the swing frame 110 can be configured in a frame structure by the center frame 111, the left side frame 124 and the right side frame 127, and the swing frame 110 can be made lightweight and secure sufficient rigidity. can do.

Next, FIG. 21 shows a sixth embodiment of the present invention. The feature of the present embodiment is that the bending frame portion and the front frame portion of the arcuate frame are formed as separate members, respectively. The bending frame portion and the front frame portion are connected by welding means. In this embodiment, the same components as those in the fifth embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 141 denotes a left-side arcuate frame which constitutes the left side frame 124 of the turning frame 110,
The arc-shaped frame 141 is similar to the arc-shaped frame 125 described in the fifth embodiment, and the bending frame portion 141A and the front frame portion 14 are substantially the same.
1B and.

However, in this arcuate frame 141, the bending frame portion 141A and the front frame portion 141B are previously formed as separate members, and the front frame portion 141B is formed on the front end side of the bending frame portion 141A by using welding means or the like. It is connected.

Reference numeral 142 denotes a right-side arcuate frame which constitutes the right side frame 127 of the revolving frame 110, and the arcuate frame 142 is the arcuate frame 12 described in the fifth embodiment.
The bending frame portion 142A and the front frame portion 142B are formed in substantially the same manner as in No. 8.

However, in this arcuate frame 142, the bending frame portion 142A and the front frame portion 142B are previously formed as separate members, and the front frame portion 142B is formed on the front end side of the bending frame portion 142A by using welding means or the like. It is connected.

Thus, in the present embodiment having such a configuration, it is possible to obtain substantially the same operational effect as in the fifth embodiment, but particularly in the present embodiment, the arcuate frames 141, 142 are provided. Is a bending frame portion 141 formed of a separate member.
A and 142A and front frame parts 141B and 142B are welded to each other.

Therefore, each of the arcuate frames 141 and 142 can be composed of two members, and each member can be easily manufactured and processed. In addition, the bending frame portions 141A and 142A
The work of bending along the virtual circle 7 having the turning radius R and the like can be performed relatively easily, and the manufacturing equipment and the like can be simplified and downsized.

The arcuate frame 141 has a bent frame portion 141.
A configuration may be employed in which a welded joint or the like is separately used to join between A and the front frame portion 141B. This also applies to the arcuate frame 142.

On the other hand, in the fifth embodiment, the arcuate frames 125 and 128 and the projecting beams 126, 129 and 130 are used.
However, the present invention is not limited to this. For example, as described in the third embodiment, the arc-shaped frame and the overhanging beam are formed by hydroforming or the like. You may form integrally using a press molding means. In this respect, the same applies to the fourth embodiment shown in FIG.

In the first embodiment, one overhanging beam 33 is provided between the bending frame portion 32A of the arcuate frame 32 and the center frame 22, and the bending frame portion 35A of the arcuate frame 35 is provided. The case where the two projecting beams 36 and 37 are provided between the center frame 22 and the center frame 22 has been described as an example, but the present invention is not limited to this. For example, the bending frame portion 32A of the arcuate frame 32 is provided. Two or more projecting beams may be provided as a reinforcing member between the center frame 22 and the center frame 22.

On the other hand, one or three or more projecting beams may be provided as a reinforcing member between the bending frame portion 35A of the arcuate frame 35 and the center frame 22. This point is the same for the second to sixth embodiments.

In the first embodiment, the case where a so-called round cab is used in which the left side portion (door 4A, etc.) of the cab 4 is curved so as to be housed within the virtual circle 7 having the turning radius R is taken as an example. However, the present invention is not limited to this, and for example, a cab similar to a medium-sized construction machine called a standard machine may be mounted on the cab mount of the revolving frame 21.

Furthermore, also in the first and fifth embodiments, etc., the cab 4 (104) is not necessarily limited to the type in which the door 4A for getting in and out is provided, and for example, the upper part of the driver's seat is partially used. Needless to say, a canopy type cover which is covered with a light may be adopted.

Further, in each of the above-mentioned embodiments, the small swing hydraulic excavator has been described as an example of the construction machine.
The present invention is not limited to this, and may be applied to a swing frame of a construction machine including an upper swing body such as a wheel type hydraulic excavator or a hydraulic crane.

[0185]

As described in detail above, according to the invention described in claim 1, the swing frame of the construction machine comprises the center frame, the left side frame, and the right side frame, and the left side frame and the right side frame. Since the side frames are each configured to use an arcuate frame that is curved in an arc shape so as to be housed within a circle having a predetermined turning radius R, the turning radius of the upper revolving structure is reduced and the turning including the counterweight is performed. The entire frame can be housed within a circle having a turning radius R, and the turning frame can be formed in a frame structure, so that the turning frame can be reduced in size and weight.

Therefore, the bottom plate of the center frame and the like can be formed of a thin plate material, the overall weight can be reduced, and the cost can be reduced. By reducing the turning radius of the upper swing body, excavation work can be easily performed even in a narrow work site. Further, by using the left and right side frames, the bottom plate of the center frame and the like can be made small, distortion and deformation due to the heat effect during welding can be reduced, and workability during manufacturing and assembly can be improved.

According to the second aspect of the invention, since the arcuate frame is composed of the bending frame part, the front frame part and the rear frame part, the bending frame part of the arcuate frame is curved in an arc shape. Formed,
The turning radius can be reduced, and the bending frame part can be integrally connected to the center frame by using the front frame part and the rear frame part of the arcuate frame, and the strength of the arcuate frame can be reliably increased.

According to the third aspect of the invention, the arcuate frame has a structure in which the bending frame part, the front frame part and the rear frame part, which are separate members, are connected to each other by welding means. The arc-shaped frame can be composed of three members, and each member can be easily manufactured and processed. Further, the work of bending the bending frame portion into an arc shape along a circle having a turning radius R or the like can be relatively easily performed, and the manufacturing equipment and the like can be simplified.
The size can be reduced.

On the other hand, according to the fourth aspect of the invention, since the arcuate frame is composed of the bending frame part and the front frame part, when the front frame part of the arcuate frame is connected to the front end side of the center frame, The bending frame portion curved in an arc shape can be arranged so as to extend rearward of the center frame, and the turning radius of the turning frame can be reduced.

According to the fifth aspect of the present invention, the arcuate frame has a structure in which the bending frame part and the front frame part, which are separate members, are connected to each other by welding means. Can be composed of two members, and each member can be easily manufactured and processed, and the work of bending the bending frame into an arc along a circle having a turning radius R can be performed relatively easily. Therefore, the manufacturing equipment and the like can be simplified and downsized.

According to the sixth aspect of the invention, since the reinforcing member extending leftward and rightward is provided between the bending frame portion of the arcuate frame and the center frame, the reinforcing member is used. The joining strength between the bending frame portion of the arcuate frame and the center frame can be increased, and a device mounting base for hydraulic devices and the like can be configured by this reinforcing member.

According to the invention described in claim 7, the center frame includes a bottom plate and left and right vertical plates, and the reinforcing member connects the bending frame portion of the arc-shaped frame to the vertical plates of the center frame. With this configuration, the reinforcing member can be firmly joined between the bending frame portion of the arc-shaped frame and the vertical plate of the center frame, and the joint strength of the arc-shaped frame as a whole to the center frame can be increased, and It is also possible to increase the rigidity of the equipment mounting base formed by the reinforcing member.

On the other hand, according to the invention as set forth in claim 8, since the reinforcing member is formed integrally with the bending frame portion of the arcuate frame, the reinforcing member can be formed with high strength with respect to the bending frame portion, and welding work can be performed. Can be simplified.

Further, according to the invention of claim 9, since the arcuate frame is formed by bending a hollow pipe material, the arcuate frame can have a hollow structure to reduce the weight. The bending process can be easily performed, and the arcuate frame can be formed into a shape curved in an arcuate shape in accordance with the virtual circle having the turning radius R.

Further, according to the tenth aspect of the invention, since the arcuate frame has an asymmetric cross section, the rigidity of the arcuate frame can be increased and the hollow structure can reduce the weight. Can be planned. Then, for example, a D-shaped frame having a D-shaped cross section can be used as the arc-shaped frame.

[Brief description of drawings]

FIG. 1 is an external view showing a small turning hydraulic excavator to which a turning frame according to a first embodiment of the present invention is applied.

FIG. 2 is an enlarged perspective view showing a swivel frame in FIG.

3 is a plan view of the swivel frame shown in FIG. 2. FIG.

FIG. 4 is a cross-sectional view of the arcuate frame viewed from the direction of arrows IV-IV in FIG.

FIG. 5 is a cross-sectional view showing an arcuate frame according to a first modification at substantially the same position as in FIG.

FIG. 6 is a cross-sectional view showing an arcuate frame according to a second modification at substantially the same position as in FIG.

FIG. 7 is a cross-sectional view showing an arcuate frame according to a third modification at substantially the same position as in FIG.

FIG. 8 is a cross-sectional view showing an arcuate frame according to a fourth modification at substantially the same position as in FIG.

FIG. 9 is a cross-sectional view showing an arcuate frame according to a fifth modification at substantially the same position as in FIG.

FIG. 10 is a cross-sectional view showing an arcuate frame according to a sixth modification at substantially the same position as in FIG.

FIG. 11 is a cross-sectional view showing an arcuate frame according to a seventh modification at substantially the same position as in FIG.

FIG. 12 is a cross-sectional view showing an arcuate frame according to an eighth modification at substantially the same position as in FIG.

FIG. 13 is a plan view showing a revolving frame according to a second embodiment.

FIG. 14 is a plan view showing a swivel frame according to a third embodiment.

FIG. 15 is an external view showing a small turning hydraulic excavator to which a turning frame according to a fourth embodiment is applied.

16 is an enlarged perspective view showing a swivel frame in FIG. 15. FIG.

FIG. 17 is an external view showing a small turning hydraulic excavator to which a turning frame according to a fifth embodiment is applied.

FIG. 18 is an enlarged perspective view showing a swivel frame in FIG. 17.

19 is a plan view of the swivel frame shown in FIG. 18. FIG.

20 is a plan view similar to FIG. 19 showing a revolving frame to which a counterweight or the like is attached.

FIG. 21 is a plan view showing a swivel frame according to a sixth embodiment.

[Explanation of symbols]

1, 71, 101 Lower traveling body 2, 72, 102 Upper revolving structure 3, 73, 103 Revolving wheel 4, 104 Cab 6, 77, 106 Counterweight 7 Virtual circle 8, 78, 107 Working device 21, 81, 110 Revolving Frame 22, 82, 111 Center frame 23, 83, 112 Bottom plate 24, 85, 114 Right vertical plate 24A, 25A Mounting bracket 25 Left front vertical plate 26 Left rear vertical plate 30, 91 Weight mounting part 31, 92, 124 Left side frame 32, 51, 61, 93, 125, 141 Arc-shaped frame 32A, 51A, 61A, 93A, 125A, 141A
Bending frame portions 32B, 51B, 61B, 93B, 125B, 141B
Front frame part 32C, 51C, 61C, 93C Rear frame part 33, 62, 94, 126 Overhanging beam (reinforcing member) 34, 95, 127 Right side frame 35, 41-48, 52, 63, 96, 128, 142
Arc-shaped frames 35A, 52A, 63A, 96A, 128A, 142A
Bending frame parts 35B, 52B, 63B, 96B, 128B, 142B
Front frame portion 35C, 52C, 63C, 96C Rear frame portion 36, 37, 64, 65, 97, 98, 129, 130
Overhanging beam (reinforcing member) 84,113 Left vertical plate 87,120 Support bracket 118 Weight mounting plate O Turning center R Turning radius

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunori Yamada             1-2, Sasagaoka, Mizuguchi Town, Koga District, Shiga Prefecture             Hitachi Construction Machinery Tierra Shiga Factory (72) Inventor Makoto Sugaya             Hitachi Construction Machinery Co., Ltd.             Ceremony Company Tsuchiura Factory (72) Inventor Naohiro Ishikawa             1-2, Sasagaoka, Mizuguchi Town, Koga District, Shiga Prefecture             Hitachi Construction Machinery Tierra Shiga Factory

Claims (10)

[Claims] 1. A construction machine comprising a center frame provided with a working device on the front side and counter weights provided on the rear side, and a left side frame and a right side frame provided on both left and right sides of the center frame. In the revolving frame, the left side frame and the right side frame are configured by using left and right arcuate frames that are curved in an arc shape so as to be accommodated in a circle having a predetermined revolving radius R. Slewing frame of construction machinery. 2. The arcuate frame is curved in an arcuate shape to the front,
A bending frame portion extending rearward, and a left side from a front end of the bending frame portion,
A front frame portion extending rightward and connected to the front end side of the center frame, and a rear frame portion extending leftward and rightward from the rear end of the bending frame portion and connected to the rear end side of the center frame. A swivel frame for a construction machine according to claim 1. 3. The turning of the construction machine according to claim 2, wherein the arcuate frame is configured such that the bending frame part, the front frame part and the rear frame part which are separate members are connected to each other by welding means. flame. 4. The arcuate frame is curved in an arcuate shape to the front,
A bending frame portion extending rearward, and a left side from a front end of the bending frame portion,
The swivel frame for a construction machine according to claim 1, wherein the swivel frame includes a front frame portion that extends rightward and is connected to a front end side of the center frame. 5. The swing frame for a construction machine according to claim 4, wherein the arcuate frame is configured to connect the bending frame portion and the front frame portion, which are separate members, to each other by using welding means. 6. The swivel frame for a construction machine according to claim 2, wherein a reinforcing member extending in the left and right directions is provided between the bending frame portion of the arcuate frame and the center frame. . 7. The center frame includes a bottom plate provided on the lower traveling body via a slewing wheel, and left and right vertical plates standing upright from the bottom plate and extending in the front and rear directions of the bottom plate. 7. The reinforcing member is configured to connect the bending frame portion of the arc-shaped frame to the vertical plate of the center frame.
Slewing frame of construction machine described in. 8. The swing frame for a construction machine according to claim 6, wherein the reinforcing member is formed integrally with a bending frame portion of an arc-shaped frame. 9. The arc-shaped frame is formed by bending a hollow pipe material.
A swing frame for a construction machine according to 5, 6, 7 or 8. 10. The arc-shaped frame has a cross-section formed in an asymmetrical shape, as claimed in any one of claims 1, 2, 3, 4, 5, 6, 7, 8.
Or the swing frame of the construction machine according to item 9.