Construction machinery

Abstract

To provide a hydraulic excavator that can achieve both improved stability in the front-to-back direction during operation and suppression of contact with surrounding objects. [Solution] The hydraulic excavator 1 comprises a self-propelled lower traveling body 2, an upper rotating body 3 rotatably mounted on the upper part of the lower traveling body 2, and a working device 5 rotatably mounted on the upper rotating body 3. The hydraulic excavator 1 also comprises an outrigger device 200 provided on the rear side of the lower traveling body 2 and having a ground contact portion 210 that contacts the ground surface GD of the hydraulic excavator 1. The outrigger device 200 has a support device 220 that supports the ground contact portion 210 so as to be movable between a working position where it protrudes further rearward than the lower traveling body 2 and contacts the ground surface GD, and a storage position where it is forward of the working position and spaced away from the ground surface GD.

Description

Technical Field

[0001] The present invention relates to a construction machine provided with a lower traveling body having crawler belts disposed on the left and right sides.

Background Art

[0002] For example, Patent Document 1 discloses a construction machine in which a dozer blade usable as an outrigger is provided on each of the front side and the rear side of a lower traveling body. In this conventional art, by additionally providing a dozer blade on the rear side in addition to the front side of the lower traveling body, even when an attachment heavier than a normal bucket is mounted on a work device, the back-and-forth swinging caused by driving the work device can be suppressed, and the stability in the front-rear direction during work can be improved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in the configuration of the above conventional art, the position of the rear end of the dozer blade provided on the rear side of the lower traveling body is further rearward than the positions of the rear ends of the left and right crawler belts. That is, the rear dozer blade protrudes beyond the rear end of the upper revolving structure and the rear end of the lower traveling body. Therefore, for example, when moving the construction machine in work in a narrow space, there is a problem that the rear dozer blade comes into contact with an object around the construction machine against the operator's intention.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a construction machine that can achieve both improvement of stability in the front-rear direction during work and suppression of contact with surrounding objects.

Means for Solving the Problem

[0006] To achieve the above objective, the present invention provides a construction machine comprising a self-propelled lower traveling body, an upper rotating body rotatably mounted on the upper part of the lower traveling body, and a work device rotatably mounted on the upper rotating body, wherein the outrigger device is provided on the rear side of the lower traveling body and has a ground contact portion that contacts the ground surface of the construction machine, and the outrigger device has a support device that supports the ground contact portion so as to be movable between a working position in which it protrudes further rearward than the lower traveling body and contacts the ground surface, and a storage position in front of the working position and spaced away from the ground surface. [Effects of the Invention]

[0007] According to the present invention, it is possible to achieve both improved stability in the front-to-back direction during operation and suppression of contact with surrounding objects. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing the overall external structure of a hydraulic excavator, an example of a construction machine according to one embodiment of the present invention. [Figure 2] These are a plan view and a side view showing the lower running body extracted from the structure shown in Figure 1. [Figure 3] Figure 2 shows a plan view and a side view illustrating the extended state of the support device for the outrigger system in the lower traveling body. [Figure 4] This is a circuit diagram showing the essential components of the hydraulic circuit of a hydraulic drive system installed in a hydraulic excavator. [Figure 5] This is an explanatory diagram illustrating a method for detecting wheel contact with the ground using an infrared sensor. [Figure 6] This is an explanatory diagram illustrating the command signals and the flow of pressurized oil when the hydraulic cylinder for vertical movement extends and the support frame tilts downward due to the operation of an operating switch by an operator. [Figure 7] This figure corresponds to the cross-sectional view of section AA in Figure 2(a), illustrating the behavior in which the support frame tilts downward, the extension hydraulic cylinder extends, and the elastically deformable member contacts the ground surface. [Figure 8] This figure corresponds to the cross-sectional view using the BB section in Figure 3(a), illustrating the behavior in which the support frame tilts downward, the extension hydraulic cylinder extends, and the elastically deformable member contacts the ground surface. [Figure 9] This is an explanatory diagram illustrating the command signal and the flow of pressurized oil when an expandable hydraulic cylinder extends and the elastically deformable member comes into contact with the ground surface. [Figure 10] This is an explanatory diagram illustrating the command signal and the flow of pressurized oil when the elastically deformable member has completed contact with the ground surface. [Figure 11] This is an explanatory diagram illustrating the flow of command signals and pressurized oil when the vehicle is being operated by an operator during normal operation when the outrigger device is not in use. [Figure 12] This is an explanatory diagram illustrating the command signal and the flow of pressurized oil when the telescopic hydraulic cylinder is extended and the elastic deformation member is in contact with the ground surface, and the operator operates the travel control lever, causing the telescopic hydraulic cylinder to retract and the elastic deformation member to move away from the ground surface. [Figure 13] This is an explanatory diagram illustrating the command signals and the flow of pressurized oil when the hydraulic cylinder for vertical movement is retracted and the support frame returns to its upward position. [Figure 14] This is an explanatory diagram illustrating the command signals and the flow of pressurized oil when the outrigger device returns to its unused state and the lower traveling body starts moving. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. In the following description, the vertical, horizontal, and front-to-back directions correspond to the directions of the arrows shown appropriately in each figure, such as Figure 1. That is, "up," "down," "left," "right," "front," and "rear" in the figures correspond to the vertical, horizontal, front-to-back directions as seen from the perspective of an operator seated in the driver's cab 9, which will be described later.

[0010] <Overall Configuration of a Hydraulic Excavator> The overall external appearance structure of the hydraulic excavator 1 is shown in Figure 1. Note that in Figure 1, the outrigger device 200, which will be described later, is stored between the left and right crawler belts 15L and 15R in a side view, so it does not appear in the drawing.

[0011] In Figure 1, the hydraulic excavator 1 is a construction machine used for, for example, excavation work. In addition to the hydraulic excavator 1, other machines having a configuration in which an upper revolving structure is mounted on a lower traveling body, such as a crawler crane, may be used as the construction machine. Hereinafter, in the present specification, description will be given taking the hydraulic excavator 1 as an example.

[0012] <Overall Schematic Configuration of Hydraulic Excavator> In this example, the hydraulic excavator 1 is a small-sized hydraulic excavator (mini excavator) used in a relatively narrow work site such as an urban area. The vehicle body of the hydraulic excavator 1 is constituted by a lower traveling body 2 capable of self-propelling by a traveling device 150, and an upper revolving structure 3 mounted on the lower traveling body 2 and capable of revolving by driving a revolving hydraulic motor (not shown). In this example, the traveling device 150 travels by driving the left and right crawler belts 15L and 15R (only the left crawler belt 15L is shown in the figure) by a pair of left and right traveling hydraulic motors 17L and 17R (only the left traveling hydraulic motor 17L is shown in the figure), respectively. In this example, the case of a so-called crawler-type excavator in which the lower traveling body 2 is provided with the crawler belts 15L and 15R will be described as an example, but the present invention is not limited to this, and a wheel-type excavator may be used.

[0013] In this example, the revolving radius of the upper revolving structure 3 is configured to be substantially within the vehicle width of the lower traveling body 2. On the front side of the upper revolving structure 3, there is provided a working device 5 supported via a swing post 4 so as to be swingable in the left-right direction and capable of being raised and lowered in the up-down direction. The working device 5 has an articulated structure, and includes a boom 61 driven by a boom cylinder 61A, an arm 62 driven by an arm cylinder 62A, and a bucket 63 driven by a bucket cylinder 63A.

[0014] The upper revolving structure 3 is provided with a revolving frame 6 serving as the base of the upper revolving structure 3, a cab 9, and a counterweight 10.

[0015] The cab 9 is mounted on the left side of the revolving frame 6, and an operator who operates the hydraulic excavator 1 boards the cab. Inside the cab 9, there are disposed an operator's seat 9A where the operator is seated, traveling operation levers 37L, 37R (traveling operation device, not shown, see Fig. 4 described later) for operating and driving the crawler belts 15L, 15R respectively to cause the lower traveling body 2 to travel, and an operation lever 9B for operating the work device 5. Note that, as the traveling operation device, an accelerator pedal may be provided in place of the traveling operation levers 37L, 37R.

[0016] The counterweight 10 is provided at the rear end portion of the revolving frame 6. The counterweight is constructed as a heavy object that balances the weight with the work device 5.

[0017] A revolving wheel 14 is disposed at the central portion of the lower traveling body 2, and the above-mentioned revolving hydraulic motor for causing the revolving frame 6 to revolve relative to the lower traveling body 2 is incorporated in the vicinity of the center of the revolving wheel 14. Further, the lower traveling body 2 includes a track frame 19 that supports the left and right crawler belts 15L, 15R.

[0018] <track frame> As shown in Figures 2(a), 2(b), and Figure 1 above, the lower running body 2 consists of a track frame 19 which is roughly H-shaped in plan view, drive wheels 18L and 18R rotatably supported on the left and right sides of the track frame 19 (however, only the left drive wheel 18L is shown in Figures 2(b) and 1), left and right hydraulic motors 17L and 17R which drive the drive wheels 18L and 18R respectively, and the left of the track frame 19 The vehicle is equipped with driven wheels 12L and 12R (however, only the left driven wheel 12L is shown in Figures 2(b) and 1) that are rotatably supported near the front end on both the right side and rotated by the driving force of the drive wheels 18L and 18R via the tracks 15L and 15R, respectively, and a dozer blade 13 that is vertically movable on the front side of the track frame 19, i.e., the front side of the lower running body 2, and moves up and down by a hydraulic cylinder 63 for the blade (see Figure 2(a)).

[0019] <Outrigger device> The most distinctive feature of the hydraulic excavator 1 of this embodiment is that it has an outrigger device 200 on the rear side of the lower traveling body 2, which is configured to be able to contact the ground contact surface GD (see Figure 1) of the hydraulic excavator 1 and whose rear end position 200A is configured to be able to move back and forth.

[0020] As shown in Figures 3(a), 3(b), and above in Figures 2(a) and 2(b), the outrigger device 200 has a ground contact portion 210 that contacts the ground surface GD, and a support device 220 that supports the ground contact portion 210 on the rear side of the track frame 19. The support device 220 supports the ground contact portion 210 so that it can move between a working position in which it protrudes rearward from the lower traveling body 2 and contacts the ground contact surface GD, and a retracted position in front of the working position and separated from the ground contact surface GD. Specifically, the support device 220 is extendable and retractable between an extended state in which the ground contact portion 210 contacts the ground contact surface GD and a retracted state in which the ground contact portion 210 is separated from the ground contact surface GD.

[0021] <Support device> The support device 220 includes a base end 21a connected to the track frame 19 so as to be rotatable in the vertical direction and an extendable vertical hydraulic cylinder 21 (first hydraulic cylinder), a support frame 230 having a roughly U-shape and with a base end 230a supported to be rotatable in the vertical direction relative to the track frame 19, which moves up and down by the extension and retraction of the vertical hydraulic cylinder 21, and extendable telescopic hydraulic cylinders 20, 22 (second hydraulic cylinders) attached to the support frame 230 and moving up and down together with the support frame 230. As shown in Figures 2(a) and 2(b), the state in which the vertical hydraulic cylinder 21 and the telescopic hydraulic cylinders 20 and 22 are retracted corresponds to the retracted state of the support device 220, and as shown in Figures 3(a) and 3(b), the state in which the vertical hydraulic cylinder 21 and the telescopic hydraulic cylinders 20 and 22 are extended corresponds to the extended state of the support device 220.

[0022] <Grounding part> The ground contact portion 210 is attached to the tip of the telescopic hydraulic cylinders 20, 22 and includes an elastically deformable member 212 that contacts the ground contact surface GD when the telescopic hydraulic cylinders 20, 22 are extended (see Figures 3(a) and 3(b)). In this example, the elastically deformable member 212 is provided on a wheel 211 that is able to rotate in contact with the ground contact surface GD. In this embodiment, the rear end of the ground contact portion 210 in the aforementioned retracted position is positioned forward of the rear end of the lower running body 2. More specifically, the position of the wheel 211 in the longitudinal direction, in other words, the position of the elastically deformable member 212, is forward of the rear end position 15A of the left and right tracks 15L and 15R when the telescopic hydraulic cylinders 20, 22 are retracted (see Figures 2(a) and 2(b)).

[0023] <Hydraulic Circuit> Figure 4 is a circuit diagram showing the main parts of the hydraulic circuit of the hydraulic drive device provided in the hydraulic excavator 1 according to this embodiment.

[0024] As shown in Figure 4, the hydraulic drive system of this embodiment includes a hydraulic pump 41 driven by an engine located on the upper rotating body 3, the above-mentioned travel hydraulic motors 17L and 17R (actually there are two, but for simplicity's sake they are abbreviated as one) driven by the pressurized oil (hydraulic oil) discharged from the hydraulic pump 41, the above-mentioned extension and retraction hydraulic cylinders 20 and 22, the above-mentioned vertical movement hydraulic cylinder 21, a travel control valve 42 (pilot-operated control valve) that controls the flow rate of pressurized oil supplied from the hydraulic pump 41 to the travel hydraulic motors 17L and 17R, and a preliminary control valve 142 that controls the flow rate of pressurized oil supplied from the hydraulic pump 41 to the extension and retraction hydraulic cylinders 20 and 22 and the vertical movement hydraulic cylinder 21.

[0025] The hydraulic drive system also includes a pilot pump 38 as a pilot hydraulic power source driven by the engine, a hydraulic pilot type travel control lever device 46 equipped with travel control levers 37L and 37R for driving the tracks 15L and 15R to instruct the travel movement of the lower travel body 2, a controller 47, and an operation switch 162 provided, for example, on a touch panel (not shown) in the driver's cab 9, for operating the switching between the use position and the retracted position of the ground contact portion 210, in other words, the switching between the extended state (see Figure 3) and the retracted state (see Figure 2) of the support device 220. The controller 47 controls the supply and discharge of hydraulic fluid to the travel hydraulic motors 17L and 17R via the travel control valve 42, and controls the supply and discharge of hydraulic fluid to the vertical movement hydraulic cylinder 21 and the telescopic hydraulic cylinders 20 and 22 via the electromagnetic proportional valves 44 and 43, 45, which will be described later, based on the operation of the operation switch.

[0026] <Travel control lever device> The travel operation lever device 46 includes the travel operation levers 37L and 37R, and a pair of pressure reducing valves 49a and 49b that output an operating pilot pressure (secondary pilot pressure) obtained by reducing the primary pilot pressure from the pilot pump 38 according to the amount of operation of the travel operation levers 37L and 37R, respectively.

[0027] The travel control valve 42 is operated by pilot pressure guided to pilot operating sections 42a and 42b via pilot lines 51a and 51b. That is, when the travel operation lever 37L or 37R of the travel operation lever device 46 is operated to the front (or rear, the same correspondence applies in parentheses hereafter), the operating pilot pressure generated by the pressure reducing valve 49a (or 49b) is output to the pilot operating section 42a (or 42b) of the travel control valve 42 via pilot line 51a (or 51b) according to the amount of operation. As a result, the travel control valve 42 is switched to the left (or right) switching position shown in the figure, driving the travel hydraulic motors 17L and 17R to drive the tracks 15L and 15R in the forward (or reverse) direction, causing the lower travel body 2 to travel forward (or backward).

[0028] <Electromagnetic shutoff valve> An electromagnetic shut-off valve 57 is provided in the pilot conduit 51a connecting the pressure reducing valve 49a of the travel operation lever device 46 and the pilot operating section 42a of the travel control valve 42 to prevent travel operation while the outrigger device 200 is in motion (details will be described later). The electromagnetic shut-off valve 57 is, for example, always in a communicative state, and when a command signal Ss is transmitted from the controller 47 to the solenoid section 57a, it shuts off the pilot conduit 51a, thereby shutting off the pilot pressure led to the travel control valve 42 and returning the travel control valve 42 to the neutral position.

[0029] <Solenoid proportional valves and solenoid switching valves> Furthermore, the hydraulic drive system shown in Figure 4 is equipped with an electromagnetic proportional valve 44 (first electromagnetic valve), electromagnetic proportional valves 43 and 45 (second electromagnetic valves), and an electromagnetic switching valve 34. These electromagnetic proportional valves 43, 45, and 44 control the flow of hydraulic fluid supplied to and discharged from the vertical hydraulic cylinder 21, which is the first hydraulic cylinder, and the telescopic hydraulic cylinders 20 and 22, which are the second hydraulic cylinders. Note that if electromagnetic proportional valves 43, 45, and 44 are provided, the placement of the electromagnetic switching valve 34 is not essential, so the electromagnetic switching valve 34 may be omitted.

[0030] The electromagnetic proportional valve 44 controls the flow of hydraulic fluid supplied to and discharged from the vertical hydraulic cylinder 21 via the pipeline 144 (first pipeline) based on a command signal Sa (first command signal) from the controller 47 to the solenoid units 44a and 44b, which is based on the operation of the operating switch 162. The electromagnetic proportional valves 43 and 45 control the flow of hydraulic fluid supplied to and discharged from the expansion and contraction hydraulic cylinders 20 and 22 via the pipelines 143 and 145 (second pipelines) based on command signals Sb and Sc (second command signals) sent from the controller 47 to the solenoid units 43a, 43b and 45a, 45b, which are based on the operation of the operating switch 162. The electromagnetic switching valve 34 is switched to either a first switching position 34A, which directs hydraulic fluid to pipeline 144, or a second switching position 34B, which directs hydraulic fluid to pipelines 143 and 145, based on a command signal Sw (switching command signal) output from the controller 47.

[0031] <Various Sensors> To detect that the elastic deformation member 212 is in the aforementioned operating position, pressure sensors 80a, 80b and 82a, 82b are provided in the conduits 70a, 70b and 72a, 72b leading to the bottom and rod sides of the telescopic hydraulic cylinders 20, 22, respectively. These sensors are not limited to detecting that the elastic deformation member 212 is in contact with the ground surface GD, but are also configured to detect that it is in the aforementioned operating position. This is because it is important to accurately identify that the elastic deformation member 212 is in the operating position even if, for example, the elastic deformation member 212 is floating due to unevenness in the ground surface GD. The controller 47 identifies, for example, when the telescopic hydraulic cylinders 20 and 22 are extended and the wheels 211 are in contact with the ground, based on the detection results of the pressure sensors 80a and 82a in the bottom-side conduits 70a and 72a. The controller 47 can also identify when the telescopic hydraulic cylinders 20 and 22 are retracted, based on the detection results of the pressure sensors 80b and 82b in the rod-side conduits 70b and 72b.

[0032] On the other hand, for example, an angle sensor 91 (see Figure 11, etc., described later) capable of detecting the rotation angle of the support frame 230 relative to the track frame 19 by a known method is provided at the base end 230a of the support frame 230, and the controller 47 can identify whether the vertical hydraulic cylinder 21 has been extended or retracted based on the detection result of the angle sensor 91.

[0033] The aforementioned pressure sensors 80a, 80b and 82a, 82b, along with the angle sensor 91, constitute a grounding sensor.

[0034] Alternatively, instead of the pressure sensors 80a, 80b and 82a, 82b, an infrared sensor SE that optically measures the distance to the ground surface GD may be provided on the wheel 211, as conceptually shown in Figures 5(a) and 5(b), and the elastic deformation member 212 may be detected to be in contact with the ground surface GD based on the detection result. In this case, the infrared sensor SE constitutes part of the ground sensor.

[0035] <Basic operation of outrigger devices> In the above configuration, if the operator intends to switch the support device 220 from the retracted state to the extended state and bring the elastic deformation member 212 of the wheel 211 into contact with the ground surface GD, they operate the "1" button or the "2" button on the operation switch 162 (while no driving operation as described later is being performed).

[0036] Then, as shown in Figure 6, the controller 47 outputs a command signal Ss to the solenoid unit 57a to set the electromagnetic shut-off valve 57 to the shut-off position, and switches the auxiliary control valve 142 to the left-side switching position in Figure 4 by an appropriate method, and further outputs a command signal Sw to switch the electromagnetic switching valve 34 to the first switching position 34A, and outputs a command signal Sa to the solenoid unit 44a to drive the electromagnetic proportional valve 44 to the left-side switching position in Figure 4. As a result, pressurized oil from the hydraulic pump 41 is supplied to the bottom side of the vertical hydraulic cylinder 21, and as shown in Figures 7(a) and 7(b), and Figures 8(a) and 8(b), the vertical hydraulic cylinder 21 extends and the support frame 230 tilts downward. Furthermore, by providing the electromagnetic switching valve 34 in addition to the electromagnetic proportional valves 44, 43, and 45, it is possible to concentrate the supply of hydraulic fluid and move the cylinder quickly, thereby improving responsiveness. Therefore, if the perspective of improving responsiveness does not need to be considered, the placement of the electromagnetic switching valve 34 is not essential if the electromagnetic proportional valves 44, 43, and 45 are provided. Note that in Figure 6, to avoid complexity in the illustration, the electromagnetic proportional valves 44, 43, and 45 and the electromagnetic switching valve 34 are collectively abbreviated as "solenoid valves 34, 43, 44, and 45".

[0037] Subsequently, as shown in Figure 9, the controller 47 outputs (or stops outputting) a command signal Sw to switch the electromagnetic switching valve 34 to the second switching position 34B, and outputs command signals Sb and Sc to the solenoid units 43a and 45a to drive the electromagnetic proportional valves 43 and 45 to the left switching position in Figure 4. As a result, pressurized oil from the hydraulic pump 41 is supplied to the bottom side of the telescopic hydraulic cylinders 20 and 22, and as shown in Figures 7(c) and 8(c), the telescopic hydraulic cylinders 20 and 22 extend, and the elastic deformation member 212 of the grounding portion 210 comes into contact with the grounding surface GD.

[0038] Based on the detection results from the pressure sensors 80a and 82a, when the controller 47 identifies that the elastic deformation member 212 of the wheel 211 has made contact with the ground surface GD, the controller 47 returns the auxiliary control valve 142 to the neutral position by an appropriate method, as shown in Figure 10. The elastic deformation member 212 of the ground contact portion 210 is held in contact with the ground surface GD (as shown in Figures 7(c) and 8(c)).

[0039] In this embodiment, the grounding position of the elastic deformation member 212 can be selected in two stages by the number on the operating switch 162 button (the larger the number, the further the wheel 211 is grounded). That is, for example, when the operator presses the "2" button, the current value of the command signal Sa to the solenoid unit 44a is smaller than when the "1" button is pressed, resulting in a smaller switching amount of the electromagnetic proportional valve 44 to the left in Figure 4, while the current values ​​of the command signals Sb and Sc to the solenoid units 43a and 45a are larger, resulting in a larger switching amount of the electromagnetic proportional valves 43 and 45 to the left in Figure 4. For example, operating the "1" button corresponds to the change behavior from Figures 2(a) and 2(b) to Figures 3(a) and 3(b), while operating the "2" button corresponds to the change behavior from Figures 7(a) and 8(a) to Figures 7(c) and 8(c).

[0040] For example, in a work site involving confined spaces where workers move around behind the machine, pressing the "1" button on the operation switch 162 to move the contact point of the wheels 211 slightly forward can stabilize the posture of the hydraulic excavator 1 while preventing it from obstructing the passage of other workers. On the other hand, for example, in a spacious work area where there are no people or objects behind the aircraft, pressing the "2" button on the operation switch 162 to move the wheel 211 to the rearward side can provide greater attitude stability.

[0041] Furthermore, if the operator intends to switch the support device 220 from the extended state to the retracted state and move the elastic deformation member 212 of the wheel 211 away from the ground surface GD, they operate the "OFF" button on the operation switch 162. This causes the processes to be executed in the reverse order of the above, returning the system to the state shown in Figures 2(a) and 2(b) (or the state shown in Figures 7(a) and 8(a)).

[0042] <Operation when driving is performed while the vehicle is extended> As described above, when the support device 220 is in the extended state and the wheels 211 are in contact with the ground, the rearward visibility of the operator from the cab 9 is not very good due to the structure of the hydraulic excavator 1. Therefore, there is a possibility that the operator may forget that the excavator is in the extended state and attempt to operate it. In this embodiment, to prepare for such a situation, the controller 47 performs the process of "automatically retracting the outrigger device 200 before starting to travel when a travel operation is performed" in order to prevent the hydraulic excavator 1 from traveling with the support device 220 in the extended state. Specifically, when the aforementioned ground sensor detects that the elastic deformation member 212 is in the above-mentioned use position, and when a travel operation is performed by the travel operation device 50, the controller 47 drives the electromagnetic proportional valves 43 and 45 to retract the extension hydraulic cylinders 20 and 22, moving the elastic deformation member 212 to a position forward of the above-mentioned use position. Then, the controller 47 drives the electromagnetic proportional valve 44 to retract the vertical movement hydraulic cylinder 21, tilting the support frame 230 upward, and after the elastic deformation member 212 is positioned in the above-mentioned storage position, it starts supplying hydraulic fluid to the travel hydraulic motors 17L and 17R. The details are explained below with reference to Figures 11 to 14.

[0043] Figure 11 is an explanatory diagram illustrating the flow of command signals and pressurized oil when the operator is performing travel operations under normal circumstances when the outrigger device 200 is not in use. Under normal circumstances, the controller 47 does not output a command signal Ss to the solenoid unit 57a (or outputs an appropriate command signal Ss), and the electromagnetic shut-off valve 57 is in the communication position. In this state, when the operator operates the travel operation levers 37L and 37R with the intention of moving the hydraulic excavator 1, the travel control valve 42 is switched to the left (or right, the same correspondence in parentheses thereafter) position in Figure 4, the travel hydraulic motors 17L and 17R are driven, the tracks 15L and 15R are driven in the forward (or reverse) direction, and the lower travel body 2 moves forward (or backward).

[0044] On the other hand, when the operating levers 37L and 37R are operated while the pressure sensors 80a and 82a detect contact between the elastic deformation member 212 and the ground contact surface GD in the extended state of the ground contact portion 210 by operating the operating switch 162 as described above, the controller 47 first outputs a command signal Ss as shown in Figure 12 to shut off the electromagnetic shut-off valve 57 and stop the supply of hydraulic fluid to the travel hydraulic motors 17L and 17R via the travel control valve 42.

[0045] Subsequently, the controller 47 outputs a command signal Sw to switch the electromagnetic switching valve 34 to the second switching position 34B, and also outputs command signals Sb and Sc to drive the electromagnetic proportional valves 43 and 45 to the right-hand switching position shown in Figure 4, thereby shortening the telescopic hydraulic cylinders 20 and 22 and moving the elastic deformation member 212 away from the ground surface GD.

[0046] Subsequently, as shown in Figure 13, the controller 47 outputs a command signal Sw to switch the electromagnetic switching valve 34 to the first switching position 34A, and also outputs a command signal Sa to drive the electromagnetic proportional valve 44 to the right switching position shown in Figure 4, thereby shortening the vertical hydraulic cylinder 21 and rotating the support frame 230 upward to return it to its original position.

[0047] Then, the angle sensor 91 detects that the vertical hydraulic cylinder 21 has been retracted, and after the ground contact portion 210 is in the retracted state, as shown in Figure 14, the controller 47 outputs a command signal Ss to de-shut off the electromagnetic shut-off valve 57 (open state). As a result, hydraulic fluid corresponding to the amount of operation of the travel operation levers 37L and 37R is supplied to the travel hydraulic motors 17L and 17R via the travel control valve 42, and the travel of the lower travel body 2 begins.

[0048] <Effects of the Embodiment> In this embodiment configured as described above, the outrigger device 200 is provided on the rear side of the lower traveling body 2. The outrigger device 200 has a support device 220 that supports the ground contact portion 210 so that it can move between a working position where it protrudes further rearward than the lower traveling body 2 and contacts the ground surface GD, and a stored position where it is forward of the working position and separated from the ground surface GD. This allows the outrigger device to contact the ground surface GD of the hydraulic excavator 1, and also allows the rear end position 200A to move back and forth. When in use, as shown in Figures 3(a) and 3(b), the ground contact portion 210 of the outrigger device 200 is brought into contact with the ground contact surface GD of the hydraulic excavator 1. This suppresses swaying at the rear of the lower traveling body 2, even when, for example, an attachment heavier than a normal bucket 63 is attached to the working device 5, thereby improving longitudinal stability and stabilizing the posture. On the other hand, when not in use, as shown in Figures 2(a) and 2(b), the rear end position 200A of the outrigger device 200 can be advanced to a position, for example, in front of the rear end position 15A of the left and right tracks 15L and 15R. This prevents situations such as the conventional dozer blade 13 described above, where, for example, when moving the hydraulic excavator 1, the outrigger device may come into contact with surrounding objects against the operator's intention. As a result of the above, this embodiment makes it possible to achieve both improved stability in the front-to-back direction during operation and suppression of contact with surrounding objects.

[0049] Furthermore, in this embodiment, by extending the support device 220 and bringing the ground contact portion 210 into contact with the ground surface GD, the swaying of the hydraulic excavator 1 is reliably suppressed, and stability in the longitudinal direction during operation is reliably improved. Also, the rear end of the ground contact portion 210 in the retracted position is located in front of the rear end of the lower traveling body 2. Specifically, when the support device 220 is retracted to separate the ground contact portion 210 from the ground surface GD, the rear end position is located in front of the rear end positions of the left and right tracks 15L and 15R. This ensures that the hydraulic excavator 1 does not come into contact with surrounding objects when it is moved.

[0050] Furthermore, in this embodiment in particular, as the vertically moving hydraulic cylinder 21, whose base end 21a is supported to be rotatable vertically relative to the track frame 19, extends and retracts, the support frame 230 moves up and down relative to the track frame 19, and as the telescopic hydraulic cylinders 20 and 22 attached to the support frame 230 extend, the elastically deformable members 212 of the ground contact portion 210 attached to the tip of the telescopic hydraulic cylinders 20 and 22 come into contact with the ground contact surface GD (see Figure 3(b)). In this case, the presence of an elastically deformable member 212 in the ground contact portion 210 makes it possible to mitigate the impact during ground contact, and it can be used without problems even if the area of ​​the ground contact surface GD where the elastically deformable member 212 makes contact is not flat. In particular, by using a circular object such as a wheel 211 or a U-shaped object such as a sled as the ground contact portion 210, it is possible to configure it so that it contacts the ground contact surface GD at only one point at its lower end.

[0051] Furthermore, in this embodiment, when the extension and retraction hydraulic cylinders 20 and 22 are in the retracted state (see Figure 2(a)), the elastic deformation member 212 is positioned in front of the rear end position 15A of the left and right tracks 15L and 15R. This allows the outrigger device 200 to be housed within the longitudinal dimension range of the tracks 15L and 15R when not in use.

[0052] Furthermore, in this embodiment in particular, the elastic deformation member 212 is provided on a wheel 211 that is in contact with the ground surface GD and capable of rotating. This has the effect of allowing fine adjustment of the height position at ground contact as the wheel 211 provided on the ground contact portion 210 rotates. In addition, rotation has the advantage of preventing wear and tear on the elastic material (such as rubber) of the elastic engagement member.

[0053] Furthermore, in this embodiment, the system includes electromagnetic proportional valves 44, 43, and 45 that control the flow of hydraulic fluid supplied to and discharged from the vertical hydraulic cylinder 21 and the telescopic hydraulic cylinders 20 and 22, an operation switch 162 for switching between the operating position and the stored position, and a controller 47 that controls the electromagnetic proportional valves 44, 43, and 45 based on the operation of the operation switch 162. In detail, an electromagnetic proportional valve 44 is provided in the pipeline 144 that supplies pressurized oil to the vertical hydraulic cylinder 21 that swings the support frame 230, and electromagnetic proportional valves 43 and 45 are provided in the pipelines 143 and 145 that supply pressurized oil to the telescopic hydraulic cylinders 20 and 22 that move the grounding portion 210 forward and backward. Electromagnetic proportional valves 44 and 43 and 45 are opened and closed based on command signals Sa and Sb and Sc from the controller 47. This makes it possible to vary the swing angle of the support frame 230 and the amount of movement of the ground contact portion 210 by adjusting the current values ​​of the command signals Sa and Sb,Sc, for example. This allows for adjustment in multiple stages of the position where the ground contact portion 210 makes contact with the ground at the rear of the lower traveling body 2, depending on the working conditions.

[0054] Furthermore, when the aforementioned operating position is selected by the operation switch 162, in other words, when the operator operates the operation switch 162 with the intention of extending the support device 220 from the retracted state, the controller 47 first switches the electromagnetic switching valve 34 to the first switching position 34A to supply pressurized oil to the vertical hydraulic cylinder 21 via the pipeline 144 to extend it, and then switches the electromagnetic switching valve 34 to the second switching position 34B to supply pressurized oil to the telescopic hydraulic cylinders 20 and 22 via the pipelines 143 and 145 to extend them. This allows the support frame 230 to be tilted downward first, and then the elastic deformation member 212 to make stable contact with the ground surface GD.

[0055] Furthermore, in this embodiment in particular, when the aforementioned grounding sensor detects that the elastic deformation member 212 is in the above-mentioned usage position, and when a travel operation is performed by the travel operation device 50, the controller 47 drives the electromagnetic proportional valves 43 and 45 to retract the telescopic hydraulic cylinders 20 and 22, thereby moving the elastic deformation member 212 forward of the above-mentioned usage position. Then, the controller 47 drives the electromagnetic proportional valve 44 to retract the vertical hydraulic cylinder 21, tilting the support frame 230 upward, and after the elastic deformation member 212 is positioned in the above-mentioned storage position, it starts supplying hydraulic fluid to the travel hydraulic motors 17L and 17R. Specifically, when the elastic deformation member 212 is in contact with the ground surface GD and the operator operates the travel operation levers 37L and 37R, the controller 47 controls the electromagnetic shut-off valve 57 to shut off, ensuring that the supply of hydraulic fluid to the travel hydraulic motors 17L and 17R is stopped. Then, the electromagnetic switching valve 34 is switched to the second switching position 34B and the electromagnetic proportional valves 43 and 45 are driven to the right-hand switching position shown in Figure 4 to retract the telescopic hydraulic cylinders 20 and 22. Subsequently, the electromagnetic switching valve 34 is switched to the first switching position 34A and the electromagnetic proportional valve 44 is driven to the right-hand switching position shown in Figure 4 to retract the vertical hydraulic cylinder 21. When the ground portion 210 is completely retracted, the electromagnetic shut-off valve 57 is switched to the non-shut-off (connected) state to start supplying hydraulic fluid to the travel hydraulic motors 17L and 17R. As a result, the elastic deformation member 212 first moves forward and separates from the ground surface GD, and then the support frame 230 rotates upward (moves upward to become nearly horizontal and returns to its original position), after which the left and right tracks 15L and 15R are driven to move the lower running body 2. As a result, the running operation starts after the longitudinal dimension of the outrigger device 200 has been shortened, so that the outrigger device 200 does not interfere with the running operation. In addition to the above, it also has the following effects: In other words, as described above, the overall length of the outrigger device 200 is shortened, and then it is lifted upwards. By following this sequence, when retracting the outrigger device 200, it is possible to avoid the elastic deformation member 212 located at the tip of the outrigger device 200 hitting obstacles around the vehicle body. In other words, if the tip of the outrigger device 200 is raised upward while protruding from other parts, there is a risk of interference with obstacles that were not in contact with the vehicle when it was lowered. Therefore, by first shortening the longitudinal dimension of the entire outrigger device 200 (so that it fits between the left and right tracks 15L and 15R in a side view) and then raising it upward, interference with obstacles around the vehicle body can be avoided.

[0056] Furthermore, in this embodiment in particular, by having the dozer blade 13 on the front side of the lower traveling body 2, the outrigger device 200 can be brought into contact with the ground surface GD on the rear side of the lower traveling body 2 to suppress shaking, while the dozer blade 13 can be brought into contact with the ground surface GD on the front side of the lower traveling body 2 to suppress shaking, thereby further ensuring stability of the vehicle's posture. [Explanation of Symbols]

[0057] 1. Hydraulic excavator (construction machinery) 2 Lower running body 3. Upper rotating body 5. Working equipment 9. Driver's cab 13 Earth removal plate 15A Rear end position 15L, 15R tracks 17L, 17R Hydraulic Motor for Travel 19 Track Frames 20. Telescopic hydraulic cylinder (2nd hydraulic cylinder) 21. Hydraulic cylinder for vertical movement (first hydraulic cylinder) 21a Proximal end 34 Solenoid switching valve 34A First switching position 34B Second switching position 37L, 37R Driving control lever 42. Travel control valve (pilot-operated control valve) 42a, 42b Pilot control section 43. Solenoid proportional valve (2nd solenoid proportional valve) 44. Solenoid proportional valve (first solenoid proportional valve) 45. Solenoid proportional valve (2nd solenoid proportional valve) 47 Controllers 50 Traveling device 51a Pilot conduit 51b Pilot conduit 57 Electromagnetic shutoff valve 62 Operating switches 80a Pressure Sensor (Grounding Sensor) 80b Pressure sensor (ground sensor) 82a Pressure sensor (ground sensor) 82b Pressure sensor (ground sensor) 91 Angle sensor (ground sensor) 143 Pipeline (Second Pipeline) 144 Pipeline (1st Pipeline) 145 Pipeline (Second Pipeline) 200 Outrigger device 200A rear end position 210 Grounding part 211 Wheels 212 Elastic deformation member 220 Support device 230 Support Frame 230a Proximal end Sa command signal (1st command signal) Sb command signal (second command signal) Sc command signal (second command signal) Sw command signal (switching command signal)

Claims

1. A self-propelled lower vehicle, An upper rotating body is provided on the upper part of the lower traveling body so as to be rotatable, A work device is provided on the upper rotating body so as to be able to move up and down, In construction machinery equipped with, The outrigger device is provided on the rear side of the lower traveling body and has a ground contact portion that contacts the ground surface of the construction machine, The outrigger device has a support device that supports the ground contact portion so that it can move between a usage position in which it protrudes rearward from the lower traveling body and contacts the ground contact surface, and a storage position in front of the usage position and separated from the ground contact surface. A construction machine characterized by the following features.

2. In the construction machine described in claim 1, The rear end of the grounding portion in the aforementioned storage position is It is positioned in front of the rear end of the lower traveling body. A construction machine characterized by the following features.

3. In the construction machine described in claim 1, The aforementioned lower running body is equipped with a track frame that supports the left and right tracks, The aforementioned support device is A first hydraulic cylinder, whose base end is connected to the track frame so as to be rotatable in the vertical direction and is extendable and retractable, A support frame whose base end is supported so as to be rotatable in the vertical direction relative to the track frame, and which moves up and down by the extension and retraction of the first hydraulic cylinder, Includes a second hydraulic cylinder that is attached to the support frame and is extendable, The aforementioned grounding portion is Includes an elastically deformable member attached to the tip of the second hydraulic cylinder, which contacts the ground surface when the second hydraulic cylinder is extended. A construction machine characterized by the following features.

4. In the construction machine described in claim 3, The elastically deformable member is It is provided on a wheel that is capable of rotating in contact with the aforementioned ground surface. A construction machine characterized by the following features.

5. In the construction machine described in claim 3, A solenoid valve that controls the flow of hydraulic fluid supplied to and discharged from the first hydraulic cylinder and the second hydraulic cylinder, An operating switch for switching between the aforementioned usage position and the aforementioned storage position, A controller that controls the solenoid valve based on the operation of the aforementioned operating switch, A construction machine characterized by having the following features.

6. In the construction machine described in claim 5, The solenoid valve is A first solenoid valve controls the flow of hydraulic fluid supplied to and discharged from the first hydraulic cylinder, Includes a second solenoid valve that controls the flow of hydraulic fluid supplied to and discharged from the second hydraulic cylinder, The aforementioned controller, When the operating switch selects the usage position, By driving the first solenoid valve, the first hydraulic cylinder is extended and the support frame is tilted downward. Then, by driving the second solenoid valve, the second hydraulic cylinder is extended and the elastic deformation member is brought into contact with the ground surface. A construction machine characterized by the following features.

7. In the construction machine according to claim 6, A traveling device having a traveling hydraulic motor provided on the lower traveling body, The driver's cab provided in the upper rotating body, A running control device is provided in the driver's cab for operating the running gear, The system includes a grounding sensor that detects whether the elastically deformable member is in the position of use, The aforementioned controller, When the grounding sensor detects that the elastic deformation member is in the usage position, and the vehicle is operated by the travel operation device, the second solenoid valve is driven to shorten the second hydraulic cylinder, moving the elastic deformation member forward of the usage position, and then the first solenoid valve is driven to shorten the first hydraulic cylinder, tilting the support frame upward. After the elastic deformation member is positioned in the storage position, the supply of hydraulic fluid to the travel hydraulic motor is started. A construction machine characterized by the following features.

8. In the construction machine according to any one of claims 1 to 7, The lower traveling body is equipped with a dozer blade located on the front side. A construction machine characterized by the following features.

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