JP2004345855A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scrap loader capable of loading scrap on a load-carrying platform of a trailer and a truck by running and moving in a scrap yard without damaging a concrete floor and obtaining a safety check. <P>SOLUTION: The center 4a of turn of an upper part turn body 4 of the scrap loader 1 provided with a long and bendable work arm 7 on which an attachment 9 for gripping and lifting scrap at a tip is mounted is positioned in a rear part more than the center of a wheel base L of a lower part running body 2. At running attitude, height on the ground of a driver's cab 5 is set to such dimension that clears height limit when running on a public thoroughfare. A front face of the driver's cab 5 agrees with a vertical line 14 passing through the center of a front axle 2b of the lower part running body 2 substantially. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a work vehicle, and more specifically, it is possible to move and travel in a scrap yard without damaging a concrete floor, efficiently load scraps on a bed such as a trailer or a truck, and obtain a vehicle inspection. It relates to a working vehicle adapted to be made possible.
[0002]
[Prior art]
In a scrap yard, scraps are loaded on a trailer or truck bed using a work vehicle in order to transport the scoops stacked on the concrete floor to an appropriate processing plant. Among such work vehicles, there is a two-axle construction machine that can travel between work sites by traveling at high speed on a public road or the like.
This construction machine moves the center of gravity to the rear of the vehicle body by folding a boom provided with an attachment for gripping scraps at the tip, and acts on the front-rear weight balance of the vehicle body (acts on the front axle and the rear axle). (Equalization of the shaft load), and a front view at the time of traveling can be secured. Hereinafter, the construction machine according to the conventional example will be described with reference to FIG.
[0003]
The construction machine according to the above-described conventional example is a wheel-type construction machine including a chassis 52 and wheels 53, 53,..., Which are attached to four front, rear, left, and right portions of the chassis 52 and are driven to rotate by hydraulic motors for traveling (not shown). A traveling body 51 is provided. An upper revolving unit 54 is mounted on the traveling unit 51 via a revolving unit 55, and is mounted on a revolving frame 56 of the upper revolving unit 54 via a cab elevating unit 58 which is elevated by an elevating cylinder 59. A cab 57 constituting the cab is provided, and a working device 60 having a configuration described later is mounted. The working device 60 includes a first boom 61, a second boom 62, an arm 63, and a grapple device (gripping means) 64. The hydraulic motor is supplied with pressure oil discharged from a hydraulic pump provided on the upper revolving unit 54 via a center joint 65 provided at the center of the revolving device 55. ing.
[0004]
More specifically, the first boom 61 pivots between a standing position and a falling position toward the rear of the vehicle body around a foot portion 61b by a first boom cylinder 61a whose bottom side is pivotally connected to a revolving frame 56. It is configured to be. The second boom 62 is configured such that the bottom side is vertically rotated by a second boom cylinder 62a pivotally attached to the first boom 61 with the mounting pin 62b at the tip of the first boom 61 serving as a fulcrum. The arm 63 is configured so that the bottom side is vertically rotated by an arm cylinder 63a pivotally attached to the second boom 62 with a mounting pin at the tip of the second boom as a fulcrum. Further, the grapple device 64 is configured such that the bottom side is vertically rotated about the tip of the arm 63 as a fulcrum by a working tool cylinder 64 a pivotally attached to the arm 63.
[0005]
In the traveling posture of the construction machine, as shown in FIG. 4, the first boom 61 falls down rearward due to the extension of the rod of the first boom cylinder 61a, and the second boom comes down due to the contraction of the rod of the second boom cylinder 62a. The boom 62 is folded so as to be directed forward. Then, the first boom 61 that has fallen rearward is configured to be accommodated in a space (not shown) provided in the upper swing body 54 (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-2000-335883 (pages 4-7, FIG. 1)
[0007]
[Problems to be solved by the invention]
According to the construction machine according to the above-described conventional example, the first boom is folded down rearward, and the first boom and the second boom are folded, so that the center of gravity of the working device is adjusted to be equal to or less than the regulation value and the center of gravity of the working device is adjusted to the body. To balance the weight balance between the front and rear of the vehicle body, and to secure a front view during traveling. Therefore, it is considered to be suitable for a waste material loading operation or the like at a building site in a city, a disaster site, or the like, which can only move on a public road. However, this construction machine has a configuration in which the boom constituting the working device is bent, and in addition to increasing the weight to secure the strength of the connecting portion, in addition to requiring more hydraulic cylinders, the working device requires It becomes heavy. In other words, the weight of the working device increases as the number of joints increases and the number of stages increases. On the other hand, when traveling on public roads, it is necessary to suppress the axle load applied to the axle within the regulation value, and the weight of the vehicle body is limited. As a result, it is difficult to make the working device sufficiently long. Therefore, as an original work vehicle mainly for cargo handling work in limited premises such as scrap yards and harbors, the work radius is short due to the short length of the work equipment, and the work capacity is insufficient due to the increase in the weight of the work equipment. In addition, it is difficult to secure required work performance.
[0008]
Therefore, an object of the present invention is to provide a work vehicle that can exhibit sufficient work ability even in a scrap yard, a harbor, and the like, and that can run on a public road by self-propelled driving.
[0009]
[Means for Solving the Problems]
Means adopted by the work vehicle according to claim 1 of the present invention to solve the above-mentioned problems include a lower traveling body provided with traveling wheels on a front axle and a rear axle disposed in front and rear of the vehicle body, An upper revolving structure rotatably mounted on the lower traveling structure, a working arm provided with a bendable portion on the upper revolving structure and having a bent portion, and a grip detachably provided at a tip of the working arm. In a working vehicle provided with a holding means and a driver's cab provided on a front side of the upper revolving structure for performing both traveling and work, the working arm is configured such that the bent portion is in the traveling posture when the bent portion is in the lower traveling position. It is located forward of the body and is configured to be able to fall down so that the uppermost surface of the working arm is substantially horizontal, and the center of rotation of the upper rotating body is the center between the axes of the front axle and the rear axle of the lower traveling body. More rearward, and the front part of the upper revolving structure It is characterized in that the front of the cab is located to be rearward of the center of the front axle.
[0010]
According to the working vehicle of the first aspect, the center of rotation of the upper revolving unit is located behind the center between the front axle and the rear axle of the lower traveling unit, and is the front front end of the upper revolving unit. The room is located behind the front axle. Therefore, although the bent part of the working arm is located in front of the lower traveling body during traveling, it is possible to make the axial load of the front axle and the rear axle almost equal, and this axial load can be run on a public road. By setting the weight near the critical limit value, the vehicle body weight can be set to the maximum weight within the regulation value, so that each structure can be set to the maximum capacity. Furthermore, a larger working arm configuration is possible within the limited overall vehicle length. Further, even though the center of gravity of the working arm is located forward of the vehicle body, the center of gravity of the vehicle can be positioned closer to the center between the front axle and the rear axle, and the axle load between the front axle and the rear axle can be substantially reduced. Since the same load can be applied, running stability is not impaired.
[0011]
Means adopted by the work vehicle according to the second aspect of the present invention is a lower traveling body provided with running wheels on a front axle and a rear axle disposed in front and rear of the vehicle body, and is capable of turning on the lower traveling body. An upper revolving unit mounted on the upper revolving unit, a work arm provided on the upper revolving unit so as to be able to undulate and bend, a gripping means detachably provided at a tip of the operation arm, and the upper revolving unit In a working vehicle provided with a driver's cab that is provided on the front side of the vehicle and performs both traveling and work, the working arm is such that the bending portion is located forward of the lower traveling body in a traveling posture, The work arm is configured to be able to fall down so that the uppermost surface thereof is substantially horizontal, and the center of rotation of the upper revolving unit is behind the center between the front axle and the rear axle of the lower traveling unit, and the upper revolving unit is turned. The front of the cab, which is the front end of the body, is the front axle. It is characterized in that a position where the substantially the same as the heart.
[0012]
According to the work vehicle according to the second aspect, the distribution of the axial load can be optimized and the maximum weight can be ensured without extending the body size forward, so that the mobility in the site and in a narrow place can be secured. Meanwhile, it is possible to set the working arm that secures the working radius to the maximum. Then, by keeping the shaft load within the specified value of the shaft load of the requirement for traveling on public roads, traveling on public roads becomes possible, so that both traveling performance and work performance can be achieved.
[0013]
The means employed by the work vehicle according to claim 3 of the present invention is the work vehicle according to any one of claims 1 and 2, wherein the driver's cab is connected to the upper revolving unit via an elevating means. Wherein the upper end of the lifting means is substantially the same as the overall height of the vehicle body in the running posture.
[0014]
According to the work vehicle of the third aspect, the upper end of the elevating means is substantially the same as the total height of the vehicle body in the running posture, so that even when the total height is limited, the height of the cab that can be raised by the elevating means is maximized. it can. Therefore, the driver's cab can be raised to a position higher than the total height of the vehicle body of the trailer or the truck, and the loading operation can be performed while checking the loading status.
[0015]
The means employed by the work vehicle according to claim 4 of the present invention is the work vehicle according to any one of claims 1 to 3, wherein a work arm folded forward on the front side of the lower traveling body. And an armrest provided with an inclined surface intersecting with the rotation locus of the tip of the armrest.
[0016]
According to the work vehicle according to the fourth aspect, the tip end of the folded work arm is held in the direction of the rotation locus by the armrest having the inclined surface intersecting the rotation locus of the tip of the folded work arm. Therefore, while having a simple and lightweight configuration, the work vehicle can be fixed in the running posture only by lowering the folded work arm when traveling and supporting the tip of the work arm with the armrest. . Then, in the running posture, the force generated by the shaking of the gripping means or the working arm during running or the like can be received closer to the body frame than the armrest having only a horizontal plane.
[0017]
The means employed by the work vehicle according to claim 5 of the present invention is the work vehicle according to any one of claims 1 to 4, wherein the steering device for steering wheels of the lower traveling body includes: A steering switching means for switching the steering signal to the opposite phase is provided.
[0018]
According to the work vehicle of the fifth aspect, by performing the switching operation of the steering switching means, the steering operation can be performed in the opposite phase, so that the steering handle is provided with the front of the cab facing the rear side of the vehicle body. The steering wheel can be steered in the direction to turn off.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a working vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings, taking as an example a case where the working vehicle is a scrap loader that loads scrap onto a bed of a trailer. FIG. 1 is a left side view of a scrap loader showing a running posture, FIG. 2 is a view showing a state where scraps are loaded on a bed of a trailer, and FIG. 3 is a configuration explanatory view of a steering switching means of a steering circuit.
[0020]
Reference numeral 1 shown in FIGS. 1 and 2 is a scrap loader according to an embodiment of the present invention. The scrap loader 1 includes a lower traveling body 2 driven by front and rear wheels. Front wheels (only one wheel is shown in the figure) 2a provided with rubber tires are provided at left and right ends of a front axle 2b of the lower traveling body 2, and rubber tires are provided at left and right ends of a rear axle 2d. Wheels (only one wheel is shown in the figure) 2c are provided. In addition, a flip-up type front outrigger (only one side is shown in the figure) is provided at a position in front of the front wheels 2a of the lower traveling body 2 so as to protrude left and right to support the lower traveling body 2 while loading the scrap. 2e is provided.
Further, a flip-up type rear outrigger (only one side is shown in the drawing) 2f is provided at the rear position of the rear wheel 2c of the lower traveling body 2 so as to extend left and right to support the lower traveling body 2 by floating. ing.
[0021]
In the present embodiment, a flip-up type outrigger is employed as described above. However, the structure is not limited to the flip-up type outrigger, and includes, for example, an expandable / contractible beam extending to the left and right of the vehicle body and a telescopic jack cylinder provided at the tip of the beam and extending downward to float the vehicle body. Outriggers can also be employed.
[0022]
On the lower traveling body 2, a slewing bearing 3 composed of an inner race having an internal gear and an outer race externally fitted to the inner race via a plurality of steel balls is provided at the rearmost portion. An upper revolving structure 4 having a counterweight 2g mounted thereon is rotatably mounted. The center 4a of rotation of the upper revolving structure 4 (corresponding to the center in the radial direction of the revolving bearing 3) is smaller than 1/2 of the wheel base L, which is the distance between the front axle 2b and the rear axle 2d. Is also located on the rear side. That is, when the distance between the front axle 2b and the turning center 4a is La and the distance between the turning center 4a and the rear axle 2d is Lb, the distance is set so that La> Lb. Incidentally, assuming that the total weight of the scrap loader 1 is 30 tons, the front axle 2b is set so that a shaft load of 15 tons is applied, and the rear axle 2d is set so that a shaft load of 15 tons is applied.
[0023]
That is, the turning center 4a of the upper turning body 4 is disposed behind the center between the front and rear axles of the lower traveling body 2, and the distance from the leading end of the vehicle to the turning center is increased.
On the other hand, by disposing the front shaft of the lower traveling body at a position forward of the driver's cab at the front end of the main body of the upper revolving structure, the weight of the vehicle body is adjusted, and the long working arm 7 that ensures workability is provided. Can be mounted.
[0024]
An operator cab 5 is provided at the front of the upper swing body 4 and on one side on the left side in FIG. The driver's cab 5 is in contact with the front side surface of the frame of the upper revolving superstructure 4 during traveling, and the ground height thereof is set to a dimension (3.8 meters) that can satisfy the height restriction when traveling on public roads. Have been. As shown in FIG. 1, the front surface of the cab 5 substantially coincides with a vertical line 14 passing through the center of the front axle 2b of the lower traveling unit 2. In this state, the operator's cab 5 is arranged such that the working arm 7 crosses the upper right side substantially horizontally.
[0025]
Further, a four-section parallel link type elevator mechanism 6 which is bendable by its lifting means is connected to the upper revolving superstructure 4 behind the operator cab 5. A power plant, such as an engine and a hydraulic pump, which is a driving source, is disposed behind the elevator mechanism 6 and between the counterweight 2g. In the elevator mechanism 6, a support portion is disposed so as to sandwich the turning center 4a in a side view. A support bracket provided with a rotation fulcrum of the parallel link mechanism is provided at an upper end of the support portion. Further, a parallel link mechanism is continuously provided between the support bracket and the lower rear end of the driver's seat 5. A hydraulic cylinder (not shown) is internally disposed in the parallel link mechanism, and the expansion and contraction operation causes the hydraulic cylinder to rotate around a center upper position of the vehicle body which is substantially the same as the vehicle body overall height in a side view and substantially coincides with the turning center. The cab 5 is configured to move up and down by moving.
[0026]
As shown in FIG. 2, the operator's cab 5 is lifted obliquely upward and forward by the operation of the elevator mechanism 6 during the scrap loading operation, and moves to a position higher than the full height of the body of the trailer or truck. It is configured to be possible. The front surface of the cab 5 is substantially coincident with the vertical line 14 passing through the center of the front axle 2b of the lower traveling body 2, but may be located behind the vertical line 14.
[0027]
On the upper revolving unit 4, for example, a long working arm 7 (for example, a long working arm 7 capable of loading scraps stacked in a scrap yard from the back side of a trailer bed having a length of 12 m in the front-rear direction) A total length of 15 m) is supported. The base end of the working arm 7 is supported by a foot pin 8 provided on the right side of the cab 5 and slightly behind the rear surface of the cab 5 in a side view near the center of rotation 4a of the upper swing body 4. The boom cylinder 7c is configured to be raised and lowered by expansion and contraction of the rod. The working arm 7 is boom 7a which is raised and lowered by a boom cylinder 7c whose bottom is pivotally attached to the upper revolving unit 4 side, and is pivotally attached to the tip of the boom 7a. And an arm 7b rotated by an arm cylinder 7d. The work arm 7 having such a long length is arranged so that the center of rotation of the upper swing body is offset rearward and the boom 7a is set to be as long as possible in order to secure workability and approach the limit range of the total length of the vehicle body as much as possible. It is configured.
[0028]
The tip of the arm 7b of the working arm 7 is rotated by an attachment cylinder 7e pivotally attached to the abdominal surface of the arm 7b, grips the scrap by opening and closing operations, and loads the scrap onto a loading platform such as a trailer. An attachment 9 as a holding means is mounted. The attachment 9 is connected to the tip of the arm 7b by a hydraulically operated automatic connection mechanism provided at the tip of the arm 7b.
[0029]
In this way, by arranging the arm cylinder 7d on the side, in addition to avoiding interference at the time of work, it is also possible to improve the front view when traveling in the boom lying state.
In this embodiment, as described above, the attachment 9 for holding the scrap by opening and closing is attached to the tip of the arm 7b. However, the present invention is not limited to the attachment having such a configuration. For example, a lifting magnet, a clam cell , Grapples and the like can also be attached.
[0030]
An armrest 10 is provided on the front surface of the center portion of the lower traveling body 2 in the width direction to receive and support the distal end of the arm 7b of the working arm 7 folded during traveling. The armrest 10 includes an inclined receiving surface portion extending from an inclined surface that intersects the rotation locus of the tip of the arm, and a lower surface of the inclined receiving surface portion that extends in the horizontal direction and is held from below when the arm descends. An arm holding bracket 10a having a surface portion and an arm receiving member 10b made of hard rubber having a rectangular cross section and screwed to the horizontal receiving surface portion.
[0031]
The inclined receiving surface of the bracket 10a is configured so that only the outer periphery of the pivot boss at the center of the automatic coupling mechanism at the tip of the arm 7b abuts. Further, the horizontal receiving surface portion is configured to abut only on the edge side of the outer periphery of the pivot boss portion (outer surface on the distal end side of the arm 7b).
[0032]
As described above, since the inclined receiving surface portion of the arm holding bracket 10a is inclined forward and downward so as to intersect with the rotation locus 15 of the tip of the arm 7b of the folded working arm 7, the working arm 7 When supported by a receiving surface orthogonal to the rotation locus 15 of the arm rest, the moment acting on the mounting portion of the armrest 10 due to the acting force from the arm can be reduced, and the vertical movement of the arm 7b can be suppressed. Therefore, the contact portion of the receiving surface portion may be in a narrow range, and the weight can be reduced as compared with a conventional armrest having a horizontal receiving surface.
[0033]
According to the armrest 10, when the folded working arm 7 is folded down and the tip of the arm 7b is received and supported by the receiving surface, the scrap loader 1 is in the running posture. The height of the boom 7a, which is substantially horizontal, up to the rear surface is set to a dimension (3.8 m or less) that can satisfy the height restriction when traveling on a public road. The armrest 10 is simpler than a conventional armrest, and can efficiently receive the force caused by the swing of the arm 7b and the attachment 9 during traveling. In addition, the fixing work associated with the storage is performed only by the turning operation of the working arm, and the mobility and workability of the working vehicle can be further improved.
In addition, by providing the horizontal receiving surface portion, when the arm 7b is hydraulically held by the arm cylinder 7d in the running posture for a long time, there is a problem that the arm 7b descends due to oil circulation in the hydraulic equipment, but this is also prevented. it can.
[0034]
In this embodiment, the boom 7a is set to be substantially horizontal when the work arm 7 is folded down in the running posture, but in the running posture, the back surface of the tip of the boom 7a is set to be the full height of the vehicle body. Is set. This is a consideration to make it easier to confirm interference with a preceding obstacle during traveling. For example, if the upper end of the elevator mechanism 6 provided on the upper swing body 4 or the upper end of the cab 5 is set to the full height of the vehicle body, interference with a forward obstacle cannot be confirmed from inside the cab 5. It is.
[0035]
The rear of the tip of the working arm 7, which is slightly easier to repair than the elevator mechanism 6 and the cab 5, is strong, and can be retracted by lowering the tip when there is a possibility of interference, This is because it is preferable to make the total height of
As described above, in the traveling posture, the scrap loader 1 is configured such that the upper surface of the working arm 7 is substantially horizontal and projects forward of the vehicle body, and the upper end of the operator cab 5 and the elevator mechanism 6 serving as an elevating means of the operator cab 5. Is configured to substantially coincide with the upper end of.
It is sufficient that any one of these three places is the height of the vehicle body. Normally, guards, security devices such as headlights are protruded and mounted on the upper part of the driver's cab, so that the height of the work vehicle becomes full. This is because there are many cases.
[0036]
In addition, it is good to provide the camera which functions for visual recognition of the front and side at the time of driving | running | working, and for the visual recognition of the load at the time of work at the front-end | tip part of the boom 7a. In this case, the camera can be tilted (remotely operated) from the driver's cab, and images of the traveling time and the working time are displayed on the monitor. This can greatly contribute to the improvement of loading efficiency.
[0037]
By the way, in the case of the scrap loader 1, as shown in FIG. 2, the loading of the scrap is performed in a state where the upper swing body 4 is swiveled by 180 ° and the rear side of the lower running body 2 is opposed to the bed of the trailer. May work. In this case, naturally, the front and rear outriggers 2e and 2f are extended to lift the vehicle body, and the scrap is loaded. However, in the scrap yard, since there are many piles of scraps, it is often necessary to store the front and rear outriggers 2e and 2f and travel in the scrap yard with the upper swing body 4 turned 180 °. . In this case, since the upper revolving superstructure 4 is turning by 180 ° and the front of the driver's cab 5 is facing the rear of the vehicle body, the front wheels 2a are operated in the opposite direction to the operation direction of the steering handle, which hinders safe driving. There is fear.
[0038]
For this reason, the steering device for operating the front wheels 2a of the scrap loader 1 is switched so that the front wheels 2a can be operated in the operating direction of the steering wheel even when the front surface of the cab 5 faces the rear side of the vehicle body. , A steering switching means described later is provided.
[0039]
As shown in FIG. 3, in this steering switching means, an electromagnetic switching valve 13 at 4 ports and 2 positions is interposed in steering pipes 11 and 12 communicating with a steering cylinder (not shown). The solenoid-operated directional control valve 13 includes a solenoid 13a which is energized by a switch operation (not shown) and is de-energized, and a return spring 13b for returning a spool (not shown) when the excitation of the solenoid 13a is released. It has. Therefore, the operation with the front wheels 2a can be easily switched by switching the flow direction of the pressure oil by the switch operation, and the vehicle can be driven by the normal operation even when the front of the cab 5 is directed to the rear side. can do.
[0040]
In the above-described embodiment, the case where the front wheels 2a are used has been described. However, a case where a two-wheel steering mechanism having only the rear wheels 2c may be used. Further, in the case of a work vehicle with a four-wheel steering mechanism (4WS), a control structure for switching between the front wheel and the rear wheel may be employed, or a centralized control according to the mode may be performed.
[0041]
Hereinafter, an operation mode of the scrap loader 1 according to the embodiment of the present invention will be described. That is, in the running posture of the scrap loader 1 according to the present embodiment, the working arm 7 in which the arm 7b is folded by the contraction of the arm cylinder 7 projects forward of the vehicle body, and the center of gravity of the working arm 7 is lower. It is located ahead of the traveling body 2. However, the turning center 4 a of the upper revolving unit 2 is located behind the center of the wheel base L of the lower traveling unit 2, and the vertical line 14 passing through the center of the front axle 2 b of the lower traveling unit 2 is It almost matches the front.
[0042]
Therefore, according to the scrap loader 1 according to the present embodiment, since the weight of the upper swing body 4 acts rearward from the center of the wheel base L, the axial loads acting on the front axle 2b and the rear axle 2d are balanced. Thus, the value of the shaft load acting on the front axle 2b and the rear axle 2d can be set within a range in which traveling on a public road is possible, and pitching during traveling can be reduced. Also, since the scrap loading operation can be performed by the work arm 7 having a large working radius by freely moving, the loading efficiency is superior to the conventional example.
[0043]
Further, according to the scrap loader 1 according to the present embodiment, as shown in FIG. 2, in the scrap loading operation in which the front surface of the cab 5 is directed to the rear side of the lower traveling body 2, the cab 5 In addition to approaching a loading platform such as a trailer, the cab 5 is lifted obliquely upward and forward by a link type elevator mechanism. For this reason, the situation on the cargo yard such as a scrap yard or a trailer can be visually recognized from the operator's cab 5 appropriately, and it is easy to check the loading status of the scrap on the cargo bed. be able to.
[0044]
Further, according to the scrap loader 1 according to the present embodiment, the armrest having the inclined surface almost intersecting with the turning locus 15 of the tip of the arm 7 b of the folded working arm 7 is provided on the front side of the lower traveling body 2. The scrap loader 10 can be set to the running posture only by bringing the tip of the arm 7b of the folded working arm 7 into contact with the inclined surface. The height of the driver's cab 5 above the ground and the height of the working arm 7 that is folded and the tip of the arm 7d is supported by the armrest 10 to the back of the boom 7a are dimensions that can clear the height limitation when traveling on public roads. Is set to Therefore, the vehicle inspection can be acquired in combination with the shaft loads acting on the front axle 2b and the rear axle 2d, and the vehicle can be moved to another scrap yard by traveling on a public road.
[0045]
Further, according to the scrap loader 1 according to the present embodiment, the electromagnetic switching valve 13 which is a steering switching means of the steering device for operating the front wheels 2a of the lower traveling body 2 is switched, so that the driver's cab 5 is controlled. The wheels can be steered in a direction in which the steering wheel is turned with the front surface facing the rear side of the vehicle body. Therefore, it is possible to easily operate the scrap loader 1 with the front surface of the cab 5 facing the rear side of the lower traveling body 2.
[0046]
【The invention's effect】
As described above, in the working vehicle according to claim 1 or 2 of the present invention, in the running posture, the folded working arm protrudes forward of the vehicle body, and the center of gravity of the working arm is forward of the lower traveling body. It is located in. However, the center of rotation of the upper revolving unit is located behind the center of the wheel base of the lower traveling unit, and the front surface of the cab is behind or substantially coincident with a vertical line passing through the center of the front axle of the lower traveling unit. I have.
[0047]
Therefore, according to the work vehicle according to claim 1 or 2 of the present invention, the weight of the upper revolving structure acts rearward from the center of the wheel base, so that the vehicle inspection can be acquired even if the long work arm is arranged to protrude forward. Thus, the shaft loads acting on the front axle and the rear axle can be balanced. In addition, since the yard is of a wheel traveling type, the yard can be moved freely without damaging the yard, and the loading operation of the scrap on the bed such as a truck can be efficiently performed by the working arm having a large working radius. Further, within the limited overall length of the vehicle body, a larger work arm can be configured, and work efficiency can be improved.
[0048]
According to the working vehicle according to the third aspect of the present invention, the loading operation can be performed while raising the driver's cab to a position higher than the full height position of the trailer or the truck by the lifting / lowering means while checking the loading status. Work efficiency is improved.
[0049]
According to the working vehicle according to the fourth aspect of the present invention, when traveling, the working vehicle can be brought to the running posture only by lowering the folded working arm and supporting the tip of the working arm with the armrest. it can. Then, in the running posture, the working arm can be efficiently fixed by the armrest having a lightweight configuration.
[0050]
According to the work vehicle according to the fifth aspect of the present invention, by switching the steering switching means of the steering device for steering the wheels of the lower traveling body, the front of the cab is directed toward the rear side of the vehicle body. The wheels can be steered to turn the steering wheel. Therefore, the traveling operation can be easily performed with the front surface of the cab facing the rear side of the lower traveling body.
[Brief description of the drawings]
FIG. 1 is a left side view of a scrap loader showing a running posture according to an embodiment of the present invention.
FIG. 2 is a diagram showing a state in which scrap is loaded on a bed of a trailer according to the embodiment of the present invention.
FIG. 3 is an explanatory diagram of a configuration of a steering switching means of a stearin circuit according to the embodiment of the present invention.
FIG. 4 is a side view of a construction machine showing a running posture according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Scrap loader, 2 ... Lower traveling body, 2a ... Front wheel, 2b ... Front axle, 2c ... Rear wheel, 2d ... Rear axle, 2e ... Front outrigger, 2f ... Rear outrigger, 2g ... Counterweight, 3 ... Turning Bearing 4 Upper revolving structure 4a Revolving center 5 Driver's cab 6 Elevator mechanism 7 Working arm 7a Boom 7b Arm 7c Boom cylinder 7d Arm cylinder 7e Attachment cylinder , 8 ... foot pin, 9 ... attachment, 10 ... arm rest, 10a ... arm holding bracket, 10b ... arm receiving member, 11, 12 ... steering pipe, 13 ... electromagnetic switching valve, 13a ... solenoid, 13b ... return spring, 14 ... Vertical line passing through the center of the front axle, 15: rotation locus, L: wheel base.

Claims (5)

A lower traveling body having traveling wheels provided on a front axle and a rear axle disposed in front of and behind the vehicle body, an upper revolving body pivotally mounted on the lower traveling body, and an up-and-down movable on the upper revolving body A work arm provided with a bent portion, a gripping means detachably provided at a tip of the work arm, and a front side of the upper revolving unit, which is used for both traveling and work. In the working vehicle having a driver's cab, the working arm is capable of falling down so that the bent portion is located forward of the lower running body in a running posture and the uppermost surface of the working arm is in a substantially horizontal state. The turning center of the upper revolving structure is behind the center between the front axle and the rear axle of the lower traveling structure, and the front of the driver's cab, which is the front front end of the upper revolving structure, is the front axle. Work characterized by a position behind the center of the work Both. A lower traveling body having traveling wheels provided on a front axle and a rear axle disposed in front of and behind the vehicle body, an upper revolving body pivotally mounted on the lower traveling body, and an up-and-down movable on the upper revolving body A work arm provided with a bent portion, a gripping means detachably provided at a tip of the work arm, and a front side of the upper revolving unit, which is used for both traveling and work. In the working vehicle having a driver's cab, the working arm is capable of falling down so that the bent portion is located forward of the lower running body in a running posture and the uppermost surface of the working arm is in a substantially horizontal state. The front center of the driver's cab, wherein the center of rotation of the upper revolving unit is behind the center between the front axle and the rear axle of the lower traveling unit, and the front axle is the front axle of the upper revolving unit. Characterized by a position that is approximately the same as the center of the Both. 3. The work vehicle according to claim 1, wherein the driver's cab is arranged on the upper revolving unit so as to be movable in a vertical direction via a lifting / lowering unit. 4. A work vehicle, wherein an upper end portion is substantially the same as the overall height of the vehicle body in a running posture. The work vehicle according to any one of claims 1 to 3, further comprising an armrest provided on a front side of the lower traveling body and having an inclined surface that intersects a rotation locus of a tip end of the folded work arm. A work vehicle provided with: 5. The work vehicle according to claim 1, wherein a steering device that steers wheels of the lower traveling body is provided with a steering switching unit that switches a steering signal to an opposite phase. 6. A work vehicle characterized by:

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