JP4351841B2 - Construction machine swivel frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a swing frame that forms the base of an upper swing body in a construction machine such as a hydraulic excavator that swings an upper swing body with respect to a lower traveling body.
[0002]
[Prior art]
A self-propelled construction machine such as a hydraulic excavator includes a lower traveling body such as a crawler or a wheel that enables the self-propelled construction machine to travel, and an upper revolving body that is installed on the lower traveling body so as to be able to swivel. Provided and configured. The upper swing body is based on a swing frame, and is configured by installing various devices such as a driver's cab, a machine room, and a counterweight on the swing frame. The front end portion of the swing frame includes a boom that can tilt with respect to the swing frame, an arm that can swing with respect to the boom, and an attachment such as a bucket that can swing with respect to the arm and perform various operations. A working device (front) is usually installed.
[0003]
As this type of work apparatus, a work apparatus has been developed in which a tiltable boom can be swung in a horizontal direction. In a construction machine equipped with such a working device, a swing post on which a boom can be tilted is attached to the front end portion of a swing frame so as to be able to rotate around a vertical axis, and the swing post is driven to rotate. A swing cylinder for driving the swing post is attached to the swing frame. An example of such a construction machine is a swivel construction machine described in Patent Document 1. The present invention is intended to improve the turning frame in the construction machine described in Patent Document 1.
[0004]
Then, about the turning frame of the construction machine described in Patent Document 1, the technical contents of the portions related to the present invention will be outlined while adding the terms and symbols used in Patent Document 1 in parentheses.
[0005]
The turning frame described in Patent Document 1 includes a bottom plate (bottom plate 8) to which a turning wheel (turning wheel 3) is attached, and a pair of vertical plates (vertical plates 9, 10) erected on the bottom plate so as to extend in the front-rear direction. And a plurality of extended beams (16 to 19) protruding left and right from these vertical plates to constitute a frame portion. On the other hand, a swing post mounting portion (support bracket 13) for rotatably mounting the swing post (swing post 23) is provided at the front end portions (bending plate portions 9A, 10A) of the pair of vertical plates. Further, at the front end position of the left side of the pair of vertical plates, a cab bed (extension beam 16) that supports the cab (cab 4) in cooperation with the rear support member (extension beam 7) is disposed. A swing cylinder mounting portion (pin mounting hole 19A) for mounting a swing cylinder for driving the swing post (a swing cylinder using a hydraulic cylinder not shown) is disposed on the right side.
[0006]
The swing frame described in Patent Document 1 is an external force such as an excavation reaction force for the purpose of suppressing a large offset load between the bottom plate and the swing wheel in the swing frame having such a structure. Reinforcing plates (21, 51, 52) are provided so as to improve the strength against. In particular, in the example (third embodiment) shown in FIGS. 10 to 12 of Patent Document 1, the left vertical plate is used to increase the torsional rigidity in the welded portion between the bottom plate and the left vertical plate. In addition to providing a reinforcing plate (51) that is expanded obliquely rearward at an expansion angle θ to obliquely cross the turning wheel mounting portion (8A), the upper end side and the left vertical plate of the reinforcing plate A triangular reinforcing plate (52) having an apex angle of the expansion angle θ is provided between them. In that case, the reinforcing plate (51) welds the front end 51A to the left vertical plate and the bottom portion to the bottom plate, and the reinforcing plate (52) has both side portions between the reinforcing plate and the left vertical plate. Welded to close.
[0007]
By the way, in a revolving frame provided with a working device that can swing, a large torsional force in the left-right direction (lateral direction) acts on the swing post mounting portion of the revolving frame when the working device is swung. In addition, since the swing post mounting portion of the swing frame is supported by the cantilever in addition to the large gravity of the working device, the swing post mounting portion is vertically moved (vertical direction) to the swing post mounting portion in the process of swinging the working device. ) Large torsional force also acts. In this case, these large torsional forces are transmitted to the front end of the cab bed, which is the joint with the swing post mounting part, and may cause fatigue and damage to the cab bed. There is. Since this cab bed functions to support the cab and is a structural member that serves as the basis for the swivel frame, preventing damage to the cab bed is an extremely important theme in the production of the swivel frame. is there.
[0008]
On the other hand, in the revolving frame shown in FIG. 10 to FIG. 12 of Patent Document 1, two reinforcing plates (51, 52) are provided to impart torsional rigidity to the vertical plate and the bottom plate. Even if a large torsional force acts on the front end portions (bent plate portions 9A and 10A) of the vertical plate that becomes the swing post mounting portion (support bracket 13), a large unbalanced load acts between the bottom plate and the swirling wheel. In addition to suppressing this, it is also possible to suppress the large torsional force from being transmitted to the front end portion of the cab bed (extending beam 16). Therefore, according to this conventional turning frame, damage to the cab bed can be prevented without increasing the strength of the cab bed.
[0009]
[Patent Document 1]
JP 2000-120107 A (page 3-6, FIG. 1-12)
[0010]
[Problems to be solved by the invention]
However, while this conventional swivel frame has such advantages, the structure is complicated because two reinforcing plates have to be provided. Further, since one reinforcing plate must be welded to the vertical plate or the bottom plate, and the other reinforcing plate must be welded to the one reinforcing plate and the vertical plate, the number of welding steps increases. Moreover, since these reinforcing plates are quite large, a great deal of labor is required for these welding operations.
[0011]
The present invention was created to solve these problems, and its technical problem is to prevent damage to the cab bed without increasing the strength of the cab bed even if a swing working device is installed. An object of the present invention is to provide a swivel frame for a construction machine that can be simplified and has a simpler structure than conventional techniques, and can reduce the number of welding steps.
[0012]
[Means for Solving the Problems]
In order to achieve these technical problems, the present invention
A bottom plate slewing ring is attached, a cab bed for supporting a pair of vertical plates erected on the bottom plate so as to extend in the longitudinal direction, one side is disposed to the front end position of the cab of the vertical plate of a pair, the pair A swing cylinder mounting portion for mounting a swing cylinder for driving a swing post disposed on the other side of the vertical plate, and a swing post provided at a front end portion of the pair of vertical plates protruding forward from the cab bed In a swing frame of a construction machine having a swing post mounting portion that can be mounted , a center frame having a bottom plate and a pair of vertical plates arranged in the center, the cab bed provided at a front end position, and a rear side of the cab bed And a projecting beam provided so as to partially overlap the center frame, and is disposed on one side of the pair of vertical plates. A first side frame which supports the cab by serial cab bed, as well as configuration by being divided into a plurality of frames and a second side frame which is arranged on the other side of the pair of vertical plates, the first the side frame, the cab bed so as not placed on the center frame, and the center gap is formed between the cab bed and the center frame as disconnected without welded to the center frame It is characterized by being installed on a frame.
[0013]
Since the cab bed is a basic structural member of the swivel frame that functions to support the cab, it is an important issue in the manufacture of the swivel frame to prevent damage. As described above, the turning frame of the construction machine according to the present invention is divided into a plurality of frames such as a first side frame disposed so as to partially overlap with the center frame. The first side is provided with a gap between the center frame and the cab bed so that the cab bed installed on the side frame is not placed on the center frame and is not welded to the center frame. Having established the frame to the center frame, there is no possibility that various forces acting on the swing post mounting portion of the center frame is directly transmitted to the cab bed. Therefore, even if a large torsional force in the left-right direction or the vertical direction acts on the swing post mounting portion of the swivel frame during the swing of the work device, these torsional forces are transmitted to the front end of the cabbed. There is no risk of damage.
[0014]
For this reason, as a measure for preventing damage to the cab bed, there is no need to provide a reinforcing plate or the like for imparting torsional rigidity to the vertical plate and bottom plate as found in conventional swivel frames. Furthermore, it is not necessary to increase the strength of the cab bed. Therefore, according to the swing frame of the construction machine of the present invention, even if a swing working device is installed, damage to the cab bed can be prevented without increasing the strength of the cab bed, and the structure is more than the conventional technology. Can be simplified, and the number of welding steps can be reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be clarified below by describing concrete examples showing how the present invention is actually embodied based on FIGS. 1 to 7.
[0016]
1 is a plan view of a swing frame of a construction machine embodying the present invention, FIG. 2 is a three-dimensional view of the swing frame of the construction machine of FIG. 1, and FIG. 3 is a front view of the swing frame of the construction machine of FIG. 4 is a rear view of the swing frame of the construction machine of FIG. 1, FIG. 5 is a side view of the swing frame of the construction machine of FIG. 1 viewed from the left side, and FIG. 6 is a swing frame of the construction machine of FIG. FIG. 7 is a side view seen from the right side, and FIG. 7 is a plan view of a turning frame of a standard construction machine in which a working device that does not swing is installed, and is a view for explaining the technical significance of the present invention in comparison with FIG. is there.
[0017]
The turning frame of this construction machine is provided at a bottom plate 2A to which a turning wheel is attached, a pair of vertical plates 2C and 2D erected on the bottom plate 2A so as to extend in the front-rear direction, and front ends of these vertical plates 2C and 2D. A boss 7 as a bracket for rotatably mounting the swing post 6, a cab bed 8 disposed at a front end position on one side of the pair of vertical plates 2C and 2D, and supporting the cab, and a pair of vertical plates 2C, A swing cylinder mounting portion which is disposed on the other side of 2D and mounts a swing cylinder 10 for driving a swing post, and the basic structure is the same as that of the conventional construction machine swing frame described in Patent Document 1. .
[0018]
1 to 6, reference numeral 1 denotes a steel-made revolving frame that serves as a base of the upper revolving structure, 2 denotes a center frame that is disposed at the center and includes a bottom plate 2A and a pair of vertical plates 2C and 2D, and 2A denotes points P ₁ to the bottom plate of the center frame 2 straight to the split by the curve passing through P _10, 2B a front end portion of the center frame 2 of the attachment portion of the swing post 6, 2C was erected on the bottom plate 2A so as to extend in the longitudinal direction The right vertical plate 2D is a left vertical plate that is erected on the bottom plate 2A so as to extend in the front-rear direction with a space on the left side of the right vertical plate 2C, and 3 indicates a pair of beams 3A and 3B. The tail frame is configured to stand upright on the side frames 4 and 5 so as to extend in the front-rear direction, 4 is a right side frame disposed on the right side of the vertical plates 2C and 2D, and 5 is on the center frame 2. To partially overlap Plate 2C, a left side frame which supports the cab is disposed on the left side of the 2D established the cab bed 8.
[0019]
Although not shown, on the revolving frame 1, a hydraulic pump for generating pressure oil for driving an actuator such as a traveling hydraulic motor, an oil tank for storing return oil of the actuator, and a revolving frame 1 are revolved. The upper revolving body is configured by installing various devices such as a slewing motor, a decelerator that decelerates the rotation of the revolving motor, a driver's cab, an engine, a fuel tank, and a counterweight. In this example, the swivel frame 1 is divided into four frames by providing a center frame 2, a tail frame 3, and left and right side frames 5, 4.
[0020]
In the center frame 2, a turning wheel for turning the turning frame 1 with respect to the lower traveling body is attached to the bottom plate 2A. Therefore, the bottom plate 2A is formed with a turning wheel attachment portion 2A ₁ (an outer ring attachment portion for the turning wheel) for attaching the outer ring of the turning wheel. A front working device (not shown) including a boom, an arm, and an attachment for performing various operations such as a bucket is installed on a front end 2B of the center frame 2 via a swing post 6 described later. ing. Vertical plates 2C, 2D extends to the vicinity of the rear end of the bottom plate 2A so as to cross the slewing ring mounting portion 2A ₁ at predetermined intervals, it is fixed by welding to the bottom plate 2A. The front end sides of the vertical plates 2C and 2D are bent inward so as to approach each other. An upper plate 2E is fixed to the upper portions of the vertical plates 2C and 2D so as to be bridged between them.
[0021]
The pair of beams 3A and 3B constituting the tail frame 3 are provided with a horizontal member and a vertical member forming flanges 3A ₁ and 3B ₁ , respectively, and are formed in, for example, an I-shaped or U-shaped cross section, respectively, Are connected to the rear ends of the vertical plates 2C, 2D by welding. In this case, since the left side of the upper plate 2E is larger load burden of the counterweight, by integrating connect the left rear end portion 2E ₁ of the upper plate 2E at flanges 3B ₁ and connecting member 9 of the beam 3B, upper The left side rigidity of the plate 2E is secured. The tail frame 3 is provided with, for example, an engine, a hydraulic pump and a counterweight associated therewith. In the case where the construction machine is a small machine having a small size in the front-rear direction, the function corresponding to the tail frame 3 can be replaced by the rear portion of the vertical plates 2C and 2D. It is not indispensable to materialize.
[0022]
The right side frame 4 is configured by providing projecting beams 4A, 4B, 4C projecting in the lateral direction and a D frame 12 described later. A part of the extended beams 4A, 4B, 4C of the right side frame 4 is placed on the bottom plate 2A of the center frame 2 and welded to the right vertical plate 2C. For example, an engine fuel tank or an oil tank is installed in the right side frame 4.
[0023]
The left side frame 5 is provided with a bottom plate 5A having a complex structure extending in the lateral direction, an extended beam 5B and an extended beam 5C for supporting the operator's cab extending in the horizontal direction, a cab bed 8 and a D frame 12 described later. Is configured. Part of the overhanging beams 5B and 5C of the left side frame 5 is placed on the bottom plate 2A of the center frame 2 and welded to the left vertical plate 2D. In that case, the cab bed 8 is not placed on the bottom plate 2A of the center frame 2 and is not welded to the bottom plate 2A or the left vertical plate 2D. In the left side frame 5, in addition to installing the cab, devices such as a radiator (heat radiator) and an air conditioner are appropriately installed using the space behind the cab.
[0024]
6 is a swing post for allowing the boom to be tilted and swinging the boom, and 7 is a bracket for attaching the swing post 6 to the front end 2B of the center frame 2 so that the swing post 6 can be rotated around a vertical axis. The boss 8 is a cab bed that forms the front end of the left side frame and supports the driver's cab, 9 is the connecting member described above, and 10 is expanded and contracted to drive the boom via the swing post 6. A swing cylinder 11 for supporting and pivotally supporting one end of the swing cylinder 10 so as to be pivotally supported, and 12 for reinforcing the outer side edges of the side frames 4 and 5 It is a D frame having a substantially D-shaped cross section as a reinforcing frame.
[0025]
The swing post 6 is pivotally mounted on a swing cylinder shaft mounting portion 6A for pivotally mounting the other end of the swing cylinder 10, a shaft mounting portion 6B of the boom cylinder, and a boom so that the boom can be tilted in the vertical direction. For this purpose, a boom shaft attaching portion 6C and a boss attachment portion 6D for attaching the swing post base portion to the boss 7 so that the swing post base portion can be rotated around the vertical axis are provided. The boss 7 is configured by providing a pair of holding pieces having pin holes at intervals in the vertical direction so that the swing post 6 can be held and attached to the boss 7.
[0026]
The support bracket 11 is provided with an upper plate and a pair of front and rear side plates hanging from the upper plate, is formed in a substantially U-shaped cross section, and is provided with a notch 11A through which the swing cylinder 10 is passed. The bracket 11 has a bottom portion of a pair of front and rear side plates coupled to the bottom plate 2A of the center frame 2, a base end portion welded to the right vertical plate 2C, and a distal end portion integrally joined to the D frame 12 by welding. A box structure is formed. With this configuration, the bracket 11 can stably support the swing cylinder 10, reinforce the front edge of the center frame 2, and further cooperate with the D frame 12 and the extended beams 4B and 4C. Thus, the right side of the revolving frame 1 can be made a strong structure.
[0027]
The cab bed 8 functions to support the cab in cooperation with the overhanging beam 5B, and is a basic structural member of the swivel frame 1. However, since the swivel frame 1 is provided with a working device that can swing, as described in the section of the prior art, the cab bed 8 has the center frame 2 in the process of swinging the working device. A large torsional force in the left-right direction or the vertical direction acts on the front end portion 2B. Such a large torsional force is strongly transmitted to the portion Q at the front end portion of the cab bed 8 which is a joint portion between the front end portion 2B of the center frame 2 and the left side frame 5 in the past. There is a risk of fatigue and damage to 8.
[0028]
In response to such a problem, the swivel frame 1 firstly splits the center frame 2 and the left side frame 5 by dividing the left frame of the swivel frame 1 into a central frame, The left side frame 5 was disposed so as to partially overlap the bottom plate 2A of the center frame 2. Along with this, the right and rear frames of the revolving frame 1 are also divided from the center frame 2 so that the revolving frame 1 is divided into four frames including the center frame 2 and the left side frame 5. Second, the left side frame 5 is divided and arranged with respect to the center frame 2 as described above, and the cab bed 8 installed in the left side frame 5 is not placed on the center frame 2. And it installed so that it might cut | disconnect with the center frame 2 without welding. In order to realize this, a gap R is formed between the bottom plate 2 </ b> A of the center frame 2 and the cab bed 8.
[0029]
In this revolving frame 1, by adopting such a structure, it is possible to prevent various forces acting on the front end 2 </ b> B of the center frame 2 from being directly transmitted to the cab bed 8. Even if a large torsional force in the left-right direction or the up-down direction acts on the front end 2B of the frame 2, these torsional forces are transmitted to the point Q at the front end of the cab bed 8 to damage the cab bed 8. There is no fear. Therefore, as a measure for preventing damage to the cab bed 8, it is no longer necessary to provide a reinforcing plate or the like for imparting torsional rigidity to the vertical plate and the bottom plate as found in conventional swivel frames, Furthermore, it is not necessary to particularly increase the strength of the cab bed 8. Therefore, even if the swing post 6 and the swing cylinder 10 are provided and a swing working device is installed, the cab bed 8 can be prevented from being damaged without increasing the strength of the cab bed 8, and moreover than the conventional technique. The structure can be simplified and the number of welding steps can be reduced.
[0030]
Since this revolving frame 1 exhibits such a remarkable effect and also exhibits an excellent effect in product production, the technical significance of this point will be described with reference to FIG. A turning frame 1 ′ of the construction machine shown in FIG. 7 is a standard type turning frame provided with a non-swinging working device developed by the applicant. In FIG. 7, the parts denoted by the same reference numerals as those in FIGS. 1 to 6 described above represent the same parts as those in FIG.
[0031]
1 ′ is a standard-type swivel frame with a working device that does not swing, 2 ′ is a center frame of a standard-type swivel frame 1 ′ having a bottom plate 2A ′ and a pair of vertical plates 2C ′, 2D ′, 2A is a bottom plate of the center frame 2 ′, 2C ′ is a right vertical plate standing on the bottom plate 2A ′ so as to extend in the front-rear direction, and 2D ′ is spaced in the front-rear direction on the left side of the right vertical plate 2C ′. A left vertical plate standing on the bottom plate 2A 'so as to extend, 4' is a right side frame of a revolving frame 1 'of a standard type arranged on the right side of the vertical plates 2C' and 2D ', and 6' is a boom. It is a bracket for axial mounting so that it can tilt in the vertical direction.
[0032]
The center frame 2 ′ has the same basic structure as the center frame 2 of FIG. 1, but the front end 2B ′ is located behind the cab bed 8 and the lateral direction of the bottom plate 2A ′. There is a difference in that there is not as much spread as the bottom plate 2. Further, there is a difference in that the right side frame 4 ′ protrudes slightly forward from the right side frame 4 of FIG. However, the tail frame 3 and the left side frame 5 are not different from those in FIG.
[0033]
Therefore, when the structure as described above is adopted for the swing frame for installing the swing working device, at least the left side frame 5 and the tail frame 3 on which the cab bed 8 is installed are of the standard type for installing the work device that does not swing. Since these can be shared with the swivel frame 1 ', when the swivel frames 1 and 1' are manufactured, the left side frame 5 and the tail frame 3 can be manufactured in a uniform manner and efficiently. Can do. When a swing working device is installed on the revolving frame, the cab bed 8 is not damaged even if a large torsional force in the left-right direction or the up-down direction is transmitted to the front end of the cab bed 8, particularly with respect to the left side frame 5. As usual, the strength should be increased. On the other hand, in the revolving frame 1 according to the present invention, the torsional force is not directly transmitted to the cab bed 8 by adopting the first and second structures described above. Can be shared with the left side frame 5 of the swivel frame 1 '. Furthermore, the revolving frame 1 according to the present invention can be easily remodeled even when it is desired to remodel an already-made standard type revolving frame 1 ′.
[0034]
【The invention's effect】
As is clear from the above description, the turning frame of the construction machine according to the present invention employs the means shown in the means for solving the problem, so even if a swing working device is installed, the cab Damage to the cab bed can be prevented without increasing the strength of the bed, the structure can be simplified as compared with the conventional technique, and the number of welding steps can be reduced. In addition, since the first side frame on which the cab bed is installed can be shared by the revolving frame on which the swing working device is installed and the revolving frame on which the non-swing work device is installed, a plurality of types of revolving frames are manufactured. In this case, the first side frame can be manufactured in a uniform manner and can be manufactured efficiently. In addition, when it is desired to remodel a standard standard swivel frame, the remodeling can be easily performed.
[0035]
When the present invention is embodied, particularly when embodied as in claim 2 of the claims, the swing cylinder can be stably supported and the front edge of the center frame can be reinforced. Further, in cooperation with the reinforcing frame, the other side of the pair of vertical plates in the revolving frame can be made a strong structure.
[Brief description of the drawings]
FIG. 1 is a plan view of a turning frame of a construction machine embodying the present invention.
FIG. 2 is a three-dimensional view of a turning frame of the construction machine of FIG.
FIG. 3 is a front view of a turning frame of the construction machine of FIG. 1;
4 is a rear view of a turning frame of the construction machine of FIG. 1;
5 is a side view of the turning frame of the construction machine shown in FIG. 1 as viewed from the left side. FIG.
6 is a side view of the turning frame of the construction machine of FIG. 1 as viewed from the right side.
7 is a plan view of a turning frame of a standard construction machine on which a working device that does not swing is installed, and is a view for explaining the technical significance of the present invention in comparison with FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Revolving frame 2 Center frame 2A Bottom plate 2C, 2D Vertical plate 2E Top plate 3 Tail frame 3A, 3B Beam 4 Right side frame 4A, 4B, 4C Overhanging beam 5 (right side frame 4) Left side frame 5A (Left side frame 5) Bottom plate 5B, 5C Overhanging beam 6 (left side frame 5) Swing post 6A Swing cylinder shaft mounting portion 6B Boom cylinder shaft mounting portion 6C Boom shaft mounting portion 6D Boss mounting portion 7 Boss 8 Cab bed 9 Connecting member 10 Swing cylinder 11 Support bracket 12 D-type frame

Claims (2)

A bottom plate to which a swivel wheel is attached;
A pair of vertical plates standing on the bottom plate so as to extend in the front-rear direction ;
A cab bed for supporting the one side are disposed in the front end position of the cab of the vertical plate of a pair,
A swing cylinder mounting portion disposed on the other side of the pair of vertical plates and mounting a swing post driving swing cylinder ;
In a swing frame of a construction machine provided with a swing post mounting portion that protrudes forward from the cab bed and is provided at a front end portion of the pair of vertical plates and rotatably mounts a swing post ,
A center frame disposed at the center and having a bottom plate and a pair of vertical plates;
And a projecting beam that is provided so as to partially overlap the cab bed provided at the front end position and the rear side of the cab bed on said center frame, by the cab bed is disposed on one side of the pair of vertical plates A first side frame that supports the cab;
While being divided into a plurality of frames including a second side frame disposed on the other side of the pair of vertical plates,
Said first side frame, said cab bed so as not placed on the center frame, and a gap is formed between the cab bed and the center frame as disconnected without welded to the center frame A swing frame for a construction machine, wherein the swing frame is installed on the center frame.   2. A revolving frame for a construction machine according to claim 1, wherein a reinforcing frame is provided on the outer side of the second side frame, and the swing cylinder mounting portion is provided with an upper plate and a pair of front and rear side plates depending from the upper plate. A box structure is formed by connecting the bottom of a pair of front and rear side plates of the bracket to the center frame and connecting the tip of the bracket to a reinforcing frame. A swing frame for a construction machine.

Images