Earth drill machine and display device for earth drill machine

Abstract

To provide an earth drill machine capable of hanging a cargo with a lager load.SOLUTION: An earth drill machine comprises bodies (2, 3), a leader (11) supported on the bodies through a front frame (32), and a sheave (15) attached on the leader on which a rope (17) is wound up, wherein the front frame can be raised and fallen with respect to the body, and the leader can be tilted to the front frame, to change an upper limit of a hanging load of the rope based on at least two of a rising / falling angle of the front frame, a tilting angle of the leader, and a work radius of the earth drill machine.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an earth drill machine and a display device for an earth drill machine.

Background Art

[0002] As background art in this technical field, for example, Patent Document 1 describes an earth drill machine provided with a moment limiter that performs overload prevention control based on a rated load curve. This rated load curve has the characteristic that the rated load decreases as the working radius increases. In Patent Document 1, a rated load curve for crane work and a rated load curve for earth drill rewinding work are stored in advance, and a rated load curve corresponding to the state of the front attachment is selected, and overload prevention control is performed based on that rated load curve.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, for example, during crane work, overload prevention control is performed based on one rated load curve in one working posture in a state where the front frame is held, so it is difficult to lift a heavier load.

[0005] The main object of the present invention is to provide an earth drill machine capable of lifting a heavier load.

Means for Solving the Problems

[0006] To achieve the above object, a typical invention of the present invention includes a main body, a leader supported by the main body via a front frame, and a sheave attached to the leader around which a rope is wound. Supplemental Volume The earth drill machine is provided with a sheave, and the front frame , which is a component constituting the front attachment, is capable of rising and falling with respect to the main body, and the leader is tiltable with respect to the front frame. When the angle of the center line of the front frame with respect to the horizontal axis in the side view of the earth drill machine is defined as the undulation angle, and the angle of the center line of the leader with respect to the vertical axis in the side view of the earth drill machine is defined as the tilting angle, at a predetermined working radius of the earth drill machine, the upper limit value of the suspension load of the rope at the predetermined working radius can be changed according to at least one of the undulation angle and the tilting angle, and when the suspension load exceeds the changed upper limit value, a part of the operation of the earth drill machine is stopped It is characterized by this.

[0007] According to the present invention, an earth drill machine capable of lifting a heavier load can be provided. In addition, problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] <First Embodiment> Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the earth drill 1 with the leader 11 in the drilling posture. FIG. 2 is a side view of the earth drill 1 with the leader 11 in the forward tilt posture.

[0010] The earth drill 1 according to the present embodiment mainly includes a traveling body 2, a slewing body 3 rotatably supported on the traveling body 2, and a leader-type front attachment 10 supported by the slewing body 3. The traveling body 2 and the slewing body 3 constitute an example of the main body. However, the main body is not limited to the combination of the traveling body 2 and the slewing body 3 as long as it can support the front attachment 10.

[0011] The traveling body 2 travels by the rotational drive of a traveling motor (not shown). The slewing body 3 slews with respect to the traveling body 2 by the rotational drive of a slewing motor (not shown). The slewing body 3 mainly includes a cab 4, a counterweight 5, a rear winch 6, and a front winch 7.

[0012] The cab 4 is provided at the front end of the slewing body 3. An internal space for the operator of the earth drill 1 to board is formed in the cab 4. Also, various operating devices (such as a lever 50, a switch 55, etc. / see FIG. 3) for operating the earth drill 1 are provided in the internal space of the cab 4. Then, when the operator boarding the internal space of the cab 4 operates the operating devices, the traveling body 2 travels, the slewing body 3 slews, and the front attachment 10 operates.

[0013] The counterweight 5 is provided at the rear end of the revolving body 3. The counterweight 5 is a heavy object that balances the weights of the front attachment 10 and the load M (Fig. 2). The rear winch 6 is rotationally driven by a rear winch drive motor (not shown) to wind up or unwind the Kelly rope 16. The front winch 7 is rotationally driven by a front winch drive motor (not shown) to wind up or unwind the supplementary winding rope 17. Thereby, the load M can be lifted or lowered. Note that the Kelly rope 16 does not necessarily have to be wound up or unwound by the rear winch 6 and may be wound up or unwound by the front winch 7.

[0014] The front attachment 10 is attached to the revolving body 3 via a connecting pin (not shown). The front attachment 10 performs operations according to the operations of the operating device. The operations of the front attachment 10 include an excavation operation of excavating the ground using the excavation tool 21 and a crane operation of raising and lowering the load M locked to the hook 22.

[0015] The front attachment 10 includes a leader 11, a front frame 32, a triangular frame 31, a front stay 36, a pin 23, a leader head 13, a Kelly sheave 14, a supplementary winding sheave 15, a Kelly rope 16, a supplementary winding rope 17, a Kelly bar 18, a Kelly top guide 19, a rotary drive 20, a front frame lifting cylinder 38, a stay cylinder 34, a thruster cylinder 26, an excavation tool 21, a hook 22, and a rear guide sheave 25.

[0016] The leader 11 is a long tubular member. The leader 11 tilts between a drilling posture (Fig. 1) that is generally upright with respect to the ground and a forward-tilted posture (Fig. 2) that is more forward-tilted than this drilling posture. In the drilling posture, the tilting angle of the leader 11 (the angle of the tilt of the leader 11 with respect to the vertical axis) is approximately 0°. This drilling posture is the posture of the leader 11 when excavating the ground using the excavation tool 21. On the other hand, the forward-tilted posture is the posture of the leader 11 that is forward-tilted (the upper end of the leader 11 tilts forward) compared to the drilling posture. The forward-tilted posture is the posture of the leader 11 when raising and lowering the load M locked to the hook 22.

[0017] Also, a leader head 13 is attached to the upper end of the leader 11. Further, the leader 11 supports the kelly top guide 19 and the rotary drive 20 so that they can move up and down along the extending direction.

[0018] The front frame 32 is supported by the revolving body 3 so that it can rise and fall. A triangular frame 31 is provided at the tip of the front frame 32. This triangular frame 31 is supported by the front stay 36. The leader 11 is connected to the triangular frame 31 via a pin 23. Thus, the leader 11 is supported by the front frame 32, the front stay 36, and the triangular frame 31 so that it can rise and fall.

[0019] The front frame 32 and the revolving body 3 are connected via a front frame rising and falling cylinder 38. When the front frame rising and falling cylinder 38 extends, the front frame 32 stands up, and when the front frame rising and falling cylinder 38 contracts, the front frame 32 lies down. And in this embodiment, the front frame 32 rises and falls within a range where the angle with respect to the horizontal axis (rising and falling angle) is, for example, 40° to 78°. When the rising and falling angle is 40°, the front frame 32 lies down most forward, and when the rising and falling angle is 78°, the front frame 32 is in the most upright posture. That is, the front frame 32 stands up with respect to the revolving body 3 as the rising and falling angle increases.

[0020] In addition, the leader 11 and the triangular frame 31 are connected via a stationary cylinder 34. When the stationary cylinder 34 extends, the leader 11 falls down about the pin 23, and when the stationary cylinder 34 contracts, the leader 11 stands up about the pin 23. In this embodiment, the tilting angle of the leader 11 is at most 7°. That is, the leader 11 tilts within the range of tilting angles from 0° to 7°. And the leader 11 tilts forward more as the tilting angle increases.

[0021] Therefore, the earth drill 1 has the maximum working radius when the undulation angle of the front frame 32 is the minimum of 40° and the tilting angle of the leader 11 is the maximum of 7°, and has the minimum working radius when the undulation angle of the front frame 32 is the maximum of 78° and the tilting angle of the leader 11 is the minimum of 0°. Also, since the working radius is determined by the undulation angle of the front frame 32 and the tilting angle of the leader 11, even if the working radii are the same, the undulation angle of the front frame 32 and the tilting angle of the leader 11 may be different.

[0022] The leader head 13 is attached to the upper end (tip) of the leader 11. The leader head 13 rotatably supports the kelly sheave 14 and the compensating winding sheave 15.

[0023] The kelly rope 16 is paid out from the rear winch 6, wound around the kelly sheave 14, and hangs down downward from the front end of the kelly sheave 14. The compensating winding rope 17 is paid out from the front winch 7, wound around the compensating winding sheave 15, and hangs down downward from the front end of the compensating winding sheave 15.

[0024] The Kelly bar 18 is a long tubular member. The Kelly bar 18 is suspended from the lower end of the Kelly rope 16 that hangs down from the front end of the Kelly sheave 14. A Kelly top guide 19 is attached to the upper end of the Kelly bar 18. Also, the lower end of the Kelly bar 18 is inserted into the rotary drive 20. Further, a boring tool 21 is detachably attached to the lower end of the Kelly bar 18 that has passed through the rotary drive 20.

[0025] The Kelly top guide 19 is supported by the leader 11 so as to be movable up and down above the rotary drive 20. Also, the Kelly top guide 19 rotatably supports the Kelly bar 18. Note that "rotation of the Kelly bar 18" refers to rotation around the rotation axis extending in the extending direction of the Kelly bar 18 (the same shall apply hereinafter).

[0026] The rotary drive 20 is supported by the leader 11 so as to be movable up and down below the Kelly top guide 19. Specifically, the rotary drive 20 moves up and down along with the telescopic operation of the thruster cylinder 26. Also, the rotary drive 20 rotatably supports the Kelly bar 18. Also, the rotary drive 20 moves up and down by the expansion and contraction of the thruster cylinder 26. Further, the rotary drive 20 is equipped with a Kelly rotation drive motor (not shown) that rotationally drives the Kelly bar 18.

[0027] Thereby, when the leader 11 is in the boring posture, the Kelly bar 18 is extended in the vertical direction by the Kelly top guide 19 and the rotary drive 20. Then, when the rear winch 6 winds up the Kelly rope 16, the Kelly bar 18 rises. Also, when the rear winch 6 winds down the Kelly rope 16, the Kelly bar 18 descends. Thereby, the boring tool 21 attached to the lower end of the Kelly bar 18 moves up and down. Also, the Kelly top guide 19 moves up and down integrally with the Kelly bar 18.

[0028] Also, by driving the Kelly rotation drive motor mounted on the rotary drive 20, the Kelly bar 18 and the excavation tool 21 attached to the Kelly bar 18 rotate. The rotary drive 20 is an example of a drive device that drives the Kelly bar 18 and the excavation tool 21.

[0029] The excavation tool 21 is, for example, an auger that excavates the ground by rotating while being pressed against the ground. However, the specific example of the excavation tool 21 is not limited to the auger as long as it has a function of excavating the ground, and a drilling bucket or the like may be used.

[0030] The hook 22 is suspended from the lower end of the compensating rope 17 hanging down from the front end of the compensating sheave 15. The hook 22 is configured to be able to lock the load M. When the compensating rope 17 is wound up by the front winch 7, the hook 22 rises. When the compensating rope 17 is wound down by the front winch 7, the hook 22 descends. Thereby, the load M locked to the hook 22 moves up and down. Although any load M can be locked to the hook 22, typical examples of the load M include a steel bar cage to be inserted into the hole excavated by the excavation tool 21.

[0031] (Hydraulic Circuit Configuration) Next, the hydraulic circuit configuration of the earth drill 1 will be described. FIG. 3 is a diagram showing a part of the hydraulic circuit configuration of the earth drill 1.

[0032] As shown in FIG. 3, the earth drill 1 includes, for example, three variable displacement or fixed displacement hydraulic pumps P1 to P3. The hydraulic pump P1 is connected to the front winch drive motor, which is a hydraulic actuator, via a control valve 60. When the operator operates the front winch lever 50, the pilot pressure acts on the pressure receiving portion of the control valve 60 from the remote control valve 64, and the position of the control valve 60 is switched. Thereby, the pressure oil from the hydraulic pump P1 is supplied to the front winch drive motor, and the front winch drive motor rotates in the winding-up direction or the winding-down direction.

[0033] The hydraulic pump P2 is connected to the front frame lifting cylinder 38, which is a hydraulic actuator, via the control valve 61. When the operator operates the front frame lifting operation lever 56, the pilot pressure acts on the pressure receiving part of the control valve 61 from the remote control valve 67, and the position of the control valve 61 is switched. As a result, the pressure oil from the hydraulic pump P2 is supplied to the front frame lifting cylinder 38, and the front frame lifting cylinder 38 extends or contracts. As described above, when the front frame lifting cylinder 38 extends, the front frame 32 rises, and when the front frame lifting cylinder 38 contracts, the front frame 32 falls.

[0034] The hydraulic pump P3 is connected to a pair of left and right stay cylinders 34, which are hydraulic actuators, via the control valves 68 and 69. When the operator operates a stay cylinder operation switch (not shown), the control valves 68 and 69 are excited, and the positions of the control valves 68 and 69 are switched. As a result, the pressure oil from the hydraulic pump P3 is supplied to the pair of stay cylinders 34, and the pair of stay cylinders 34 extends or contracts. As described above, when the pair of stay cylinders 34 extends, the leader 11 falls, and when the pair of stay cylinders 34 contracts, the leader 11 rises.

[0035] In addition, in FIG. 3, reference numerals 62, 63, 65, and 66 are solenoid valves, which operate when an automatic stop signal is output from the controller 80.

[0036] (Input / Output of Controller 80) Next, the input / output of the controller 80 will be described with reference to FIG. 3 as well.

[0037] Although not shown, the controller 80 is composed of hardware including a CPU that performs various operations and the like, a storage device such as a ROM or HDD that stores programs for the CPU to execute operations, a RAM that serves as a work area when the CPU executes programs, and a communication interface that is an interface for transmitting and receiving data to and from other devices, and software stored in the storage device and executed by the CPU. Each function of the controller 80 is realized by the CPU loading various programs stored in the storage device into the RAM and executing them.

[0038] Operation signals from various operation levers and operation switches provided in the cab 4 are input to the controller 80. Specifically, operation signals from a travel lever, a swivel lever, a front winch lever 50, a rear winch lever, a Kelly rotation lever, a thruster switch, a front frame undulation lever 56, a leader tilt lever 57, an operation mode changeover switch 55, etc. are input to the controller 80. Here, the operation mode changeover switch 55 is a switch for switching between an excavation mode for performing excavation and a crane work mode for lifting the load M.

[0039] In addition, detection signals from a leader angle detector 41 that detects the tilt angle of the leader 11, a front frame angle detector 42 that detects the undulation angle of the front frame 32, and a load detector 43 that detects the weight of the load M are input to the controller 80. The leader angle detector 41 and the front frame angle detector 42 are, for example, potentiometers and are provided on the leader 11 and the front frame, respectively. The load detector 43 is, for example, a pin type load cell and is provided on the compensating sheave 15 (see FIGS. 1 and 2). In FIG. 3, reference numeral 44 is a pressure detector for detecting the operation of the front winch lever 50, reference numeral 45 is a limit switch for detecting winch overwinding, and reference numeral 46 is a pressure detector for detecting the operation of the front frame undulation lever 56.

[0040] Based on the detection signals from the leader angle detector 41 and the front frame angle detector 42, the controller 80 calculates the upper limit value (rated total load) of the suspended load and outputs the calculation result to the moment limiter 85. The moment limiter 85 displays on the display screen the tilting angle of the leader 11 detected by the leader angle detector 41, the undulating angle of the front frame 32 detected by the front frame angle detector 42, the weight of the load M detected by the load detector 43, the information on the calculated rated total load, and alarms, etc.

[0041] Figure 4 is a diagram showing an example of the display screen of the moment limiter 85. As shown in Figure 4, a design imitating an earth drill machine is displayed on the display screen of the moment limiter 85, and various numerical information V1~V8 is displayed around the earth drill machine. V1 is the value (measured value) of the actual load detected by the load detector 43. V2 is the value of the working radius of the earth drill machine 1 calculated from the tilting angle of the leader 11, the undulating angle of the front frame 32, and the dimensional data of the front attachment 10. V3 is the upper limit value (rated total load) of the suspended load at the working radius displayed as V2. V4 is the maximum value of the working radius at which the load M can be suspended as V1. V5 is the undulating angle of the front frame 32. V6 is the tilting angle of the leader 11.

[0042] Here, in this embodiment, the rated total load displayed as V3 changes based on the tilting angle of the leader 11 and the undulating angle of the front frame 32. Therefore, the value of V3 (rated total load) displayed on the moment limiter 85 changes with the changes in the values of V5 (undulating angle of the front frame 32) and V6 (tilting angle of the leader 11).

[0043] (Overload prevention control) Next, the overload prevention control during crane operation will be described. When the load M exceeds the rated total load, the controller 80 performs control to stop the crane operation. Specifically, the controller 80 refers to the rated load curve (upper limit value table) based on the tilting angle of the leader 11 and the lifting angle of the front frame 32, and calculates the rated total load. Then, when the load M exceeds the rated total load, the crane operation is stopped.

[0044] FIG. 5 is a diagram showing an example of the rated load curve. In FIG. 5, the horizontal axis represents the working radius (m), and the vertical axis represents the rated total load (t), that is, the upper limit value of the suspended load. In this embodiment, rated load curves defined in advance are defined for tilting angles of 0°, 3°, 5°, and 7°, respectively. Each rated load curve has the characteristic that the rated total load decreases as the working radius increases. And the rated total load has the characteristic of decreasing as the tilting angle of the leader 11 increases.

[0045] For example, in the case of a tilting angle of 3°, the rated total load varies in the range of 13.0 t to 5.1 t according to the working radius. Also, in the case of a tilting angle of 7°, the rated total load varies in the range of 9.9 t to 3.4 t according to the working radius. And the maximum value of the rated total load in the cases of tilting angles of 0° and 3° is 13.0 t, but as the tilting angles become 5° and 7°, the maximum value of the rated total load becomes smaller, 11.4 t and 9.9 t. Thus, the greater the leader 11 tilts forward, the smaller the load that can be lifted.

[0046] The controller 80 calculates the working radius of the earth drill 1 from the tilting angle of the leader 11 and the undulating angle of the front frame 32. Various dimensions of the front attachment 10, such as the length of the leader 11, the length of the front frame 32, etc., are stored in advance in the ROM of the controller 80. The controller 80 calculates the working radius of the earth drill 1 from the angle data respectively obtained from the leader angle detector 41 and the front frame angle detector 42 and the dimensions of the front attachment 10. Then, the controller 80 refers to the rated load curve corresponding to the tilting angle of the leader 11 and determines the rated total load corresponding to the calculated working radius.

[0047] For example, when the calculation result of the working radius is 5.50 m and the tilting angle of the leader 11 input from the leader angle detector 41 is 3°, the controller 80 refers to the rated load curve of the tilting angle of 3° and determines the rated total load to be 8.5 t.

[0048] On the other hand, even when the working radius is 5.50 m, when the tilting angle of the leader 11 is 5°, the controller 80 refers to the rated load curve of the tilting angle of 5° and determines the rated total load to be 10.3 t.

[0049] This is because even when the undulating angle of the front frame 32 and the tilting angle of the leader 11 are different, the calculation result of the working radius may be the same. For example, the calculation result of the working radius may be 5.50 m when the tilting angle of the leader 11 is 3° (the first angle) and the undulating angle of the front frame 32 is 60°, and when the tilting angle of the leader 11 is 5° (the second angle) and the undulating angle of the front frame 32 is 70°. In this case, since the controller 80 refers to the rated load curve corresponding to the tilting angle of the leader 11 to obtain the rated total load, different rated total loads will be determined even for the same working radius.

[0050] And in this embodiment, in the case of the same working radius, the larger the tilting angle of the leader 11, the larger the value of the rated total load. That is, it is configured to be able to lift a heavier load M.

[0051] In addition, when there is no rated load curve corresponding to the tilting angle of the leader 11, the controller 80 determines the rated total load by calculation using a rated load curve close to the detected tilting angle of the leader 11 from among the rated load curves stored in advance. For example, when the tilting angle of the leader 11 is 3.5°, the controller 80 calculates a value between the rated load curve with a tilting angle of 3° and the rated load curve with a tilting angle of 5° to obtain the rated total load.

[0052] Then, when the weight of the load M detected by the load detector 43 exceeds the calculated rated total load (upper limit value), the controller 80 outputs an automatic stop signal A (see FIG. 3) to control to stop part of the operation of the earth drill 1 in order to prevent overload and tipping.

[0053] Specifically, as shown in FIG. 3, the controller 80 cuts off the power supply to the solenoid valve 65 and switches the control valve 60 to the neutral position. Thereby, the rotation of the front winch drive motor in the winding-up direction is prohibited. That is, even if the front winch lever 50 is operated in the winding-up direction, the lifting operation (crane operation) of the load M cannot be performed.

[0054] In addition, the controller 80 de-energizes the extension side solenoid valves 62 and 63 of the control valves 68 and 69. Thereby, the extension operation of the stay cylinder 34 is prohibited. That is, the tilting operation of the leader 11 in the direction in which the working radius increases becomes impossible.

[0055] Furthermore, the controller 80 cuts off the power supply to the solenoid valve 66 and switches the control valve 61 to the neutral position. Thereby, the contraction operation of the front frame lifting cylinder 38 is prohibited. That is, the lifting operation of the front frame 32 in the direction in which the working radius increases becomes impossible.

[0056] As described above, according to the first embodiment, the following operational effects are achieved.

[0057] The controller 80 calculates the upper limit value (rated total load) of the suspension load of the compensating winding rope 17 based on the undulation angle of the front frame 32 and the tilting angle of the leader 11. Therefore, the upper limit value of the suspension load is changed to a desired value according to the undulation angle of the front frame 32 and the tilting angle of the leader 11 (that is, according to the posture of the front attachment 10). Therefore, a heavier load M can be suspended compared with the conventional case.

[0058] Referring to FIG. 5 for a detailed description, conventionally, since the rated load curve was determined only according to the working radius regardless of the tilting angle of the leader 11, for example, when the working radius was 5.50 m, the rated total load was 6.2 t. On the other hand, in the present embodiment, since a plurality of rated load curves are provided according to the tilting angle of the leader 11, even if the working radius is the same, a larger rated total load can be determined according to the tilting angle of the leader 11. Even when the working radius is 5.50 m, when the tilting angle of the leader 11 is 3°, the rated total load becomes 8.5 t. That is, the load M can be suspended up to 8.5 t. Further, even when the working radius is the same 5.50 m, when the tilting angle of the leader 11 is 5°, the load M can be suspended up to 10.3 t.

[0059] Also, as shown in FIG. 4, various information is displayed on the moment limiter 85. When the undulation operation of the front frame 32 and the tilting operation of the leader 11 are performed, the values of the undulation angle V5 of the front frame 32 and the tilting angle V6 of the leader 11 change according to these operations. Then, as the values of V5 and V6 change, the values of the working radius V2 and the rated total load V3 also change. Therefore, the operator can efficiently perform the crane operation while checking the display screen of the moment limiter 85.

[0060] <Second Embodiment> Next, the earth drill machine according to the second embodiment will be described. In the second embodiment, the configuration is different from the first embodiment in that the rated load curve is set according to the presence or absence of the excavation attachment attached to the leader 11. In the second embodiment, a hose reel can be attached to the leader 11 in addition to the kelly bar 18 as an excavation attachment. Here, the hose reel is a device for winding or unwinding a hydraulic hose that transmits the hydraulic pressure for expanding the expanding wings of the underreaming bucket.

[0061] Since the kelly bar 18 and the hose reel are heavy objects, the presence or absence of these excavation attachments is an important factor for determining the rated total load. Therefore, in this embodiment, different rated load curves are preset according to the following four states: (a) the state where the kelly bar 18 and the hose reel are attached to the leader 11, (b) the state where the hose reel is attached to the leader 11, (c) the state where neither the kelly bar nor the hose reel is attached to the leader 11, and (d) the state where the kelly bar 18 is attached to the leader 11 (the same as the first embodiment). When the operator operates the display screen of the moment limiter 85 to select one of these four states, the controller 80 determines the rated total load by referring to the rated load curve corresponding to the selected state.

[0062] Figs. 6 to 8 are diagrams showing an example of the display screen of the moment limiter according to the state of the earth drill machine. Fig. 6 shows an example of the display screen of the moment limiter 85 in the state where the kelly bar 18 and the hose reel are attached to the leader 11. Fig. 7 shows an example of the display screen of the moment limiter 85 in the state where the hose reel is attached to the leader 11. Fig. 8 shows an example of the display screen of the moment limiter 85 in the state where neither the kelly bar nor the hose reel is attached to the leader 11.

[0063] As shown in FIGS. 6 to 8, in the second embodiment, the presence or absence of the Kelly bar 18 and the hose reel is visually displayed on the display screen of the moment limiter 85. Therefore, the operator can efficiently perform the crane operation while looking at the display screen of the moment limiter 85. Moreover, since the rated load curve is determined according to the presence or absence of the Kelly bar 18 and the hose reel which are excavation attachments, a heavier load M can be lifted according to the presence or absence of the excavation attachments.

[0064] Note that the controller 80 may determine the presence or absence of the excavation attachment by a sensor or the like and automatically switch the display screen of the moment limiter 85 based on the determination result.

[0065] <Third Embodiment> Next, a third embodiment of the present invention will be described. In the earth drill according to the third embodiment, at least one of the raising and lowering operation of the front frame 32 and the tilting operation of the leader 11 is restricted based on the working radius. Specifically, when the working radius of the earth drill is less than a predetermined value (for example, 5.9 m), the front frame 32 is fixed at a predetermined raising and lowering angle (for example, 78°), and only the tilting operation of the leader 11 is enabled. On the other hand, when the working radius of the earth drill is equal to or more than a predetermined value (for example, 5.9 m), the leader 11 is fixed at a predetermined tilting angle (for example, 7°), and only the raising and lowering operation of the front frame 32 is enabled.

[0066] That is, when the working radius is less than 5.9 m, the controller 80 controls to fix the raising and lowering angle of the front frame 32 and permit only the tilting operation of the leader 11. Therefore, until the working radius reaches 5.9 m, the operator can only operate the leader tilting lever 57 (see FIG. 3).

[0067] Furthermore, when the working radius reaches 5.9 m, the controller 80 maintains the tilt angle of the leader 11 at its maximum (tilt angle of 7°).The controller 80 then fixes the tilt angle of the leader 11 and controls to permit only the hoisting operation of the front frame 32. Therefore, when the working radius is in the range of 5.9 m or more, the operator can only operate the front frame hoisting lever 56 (see FIG. 3).

[0068] Due to this configuration, in the third embodiment, the method of calculating the total rated load by the controller 80 differs from that in the first and second embodiments. Fig. 9 is a diagram showing a rated load curve according to the third embodiment. As shown in Fig. 9, in the third embodiment, a rated load curve is defined in advance for the tilt angle of the leader 11 from 0° to 7° in 1° increments. Each rated load curve has a characteristic that the larger the working radius, the smaller the rated load becomes.

[0069] As shown in Fig. 9, the rated load curve is defined as the broken line L1. Specifically, when the working radius is less than 4.8 m, the total rated load is constant at 13.00 t, which is the design value of the earth drill machine 1, regardless of the size of the working radius.

[0070] When the working radius is 4.8 m or more and less than 5.9 m, the rated load decreases linearly as the working radius increases. The value of the rated load for the working radius is defined as a straight line connecting the maximum values ​​of the rated load for each tilt angle of the leader 11. Specifically, when the working radius is 4.8 m or more and less than 5.9 m, the straight line connects the maximum value of the rated load for a tilt angle of 4°, 12.33 t, the maximum value of the rated load for a tilt angle of 5°, 10.61 t, and the maximum value of the rated load for a tilt angle of 7°. For example, the rated load for a working radius of 5.3 m is 11.43 t, referring to the broken line L1. It is not necessary to connect the points with straight lines, and each point may be connected with a curved line.

[0071] When the working radius is 5.9 m or more, since the tilting angle of the leader 11 is fixed at 7°, the value of the rated total load with respect to the working radius follows the rated load curve for the case of a tilting angle of 7° of the leader 11. Therefore, for example, when the working radius is 6.2 m, the rated total load is calculated by referring to the rated load curve for a tilting angle of 7° and is 8.00 t.

[0072] In this way, depending on whether the working radius is less than a predetermined value (for example, 5.9 m) or not, by restricting the tilting operation of the leader 11 and the heaving operation of the front frame 32, it is possible to set the value of the maximum rated total load for each tilting angle of the leader 11 as the upper limit of the suspended load according to the working radius. Therefore, a heavier load M can be suspended.

[0073] Incidentally, when the configuration is such that the heaving operation of the front frame 32 and the tilting operation of the leader 11 are not restricted depending on whether the working radius is less than a predetermined value or not as in the third embodiment, and each operation can be freely performed, that is, in the case of a configuration in which the rated total load is calculated only based on the working radius, the rated load curve needs to be defined like the broken line L2.

[0074] To explain the reason, for example, even when the working radius is the same, the rated total load is smaller in the case where the heaving angle of the front frame 32 is A2 (for example, 50°) and the tilting angle of the leader 11 is B2 (for example, 3°) than in the case where the heaving angle of the front frame 32 is A1 (for example, 70°) and the tilting angle of the leader 11 is B1 (for example, 7°) due to the structure of the earth drill machine. Therefore, when the operation of the front attachment 10 is not restricted, it is necessary to determine the value of the rated total load on the safer side. Thus, the rated load curve is defined as a line connecting the minimum values of the rated load curves for each tilting angle like the broken line L2.

[0075] Therefore, according to the earth drill machine according to the third embodiment, a load M with a weight greater by the difference between the broken line L1 and the broken line L2 can be suspended for a certain working radius. For example, when the working radius is 5.3 m, referring to the broken line L1, the rated total load is 11.43 t, and compared with the rated total load of 6.90 t when referring to the broken line L2, a load M with a weight greater by 4.53 t (11.43 - 6.90 = 4.53) can be suspended.

[0076] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. All technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments show preferred examples, but those skilled in the art can realize various alternative examples, modified examples, deformed examples, or improved examples from the content disclosed in this specification, and these are included in the technical scope described in the appended claims.

[0077] In the above-described embodiment, the controller 80 has been exemplified as having a configuration for calculating the rated total load from the tilting angle of the leader 11 and the undulating angle of the front frame 32. However, the controller 80 may calculate the rated total load based on at least two pieces of information among the tilting angle of the leader 11, the undulating angle of the front frame 32, and the working radius of the earth drill machine 1, and may control to stop the crane operation when the load M exceeds the rated total load.

[0078] That is, the controller 80 may calculate the rated total load based on the tilting angle of the leader 11 and the working radius of the earth drill machine 1, or may calculate the rated total load based on the undulating angle of the front frame 32 and the working radius of the earth drill machine 1. Of course, the controller 80 may calculate the rated total load based on the tilting angle of the leader 11, the undulating angle of the front frame 32, and the working radius of the earth drill machine 1. In any case, a load M with a greater weight than in the conventional case can be suspended.

[0079] Also, the value of the rated total load V3 displayed on the moment limiter 85 (see Fig. 4) will be changed accordingly when at least two of the values of the tilting angle V5 of the front frame 32, the tilting angle V6 of the leader 11, and the working radius V2 are changed.

[0080] For example, in the third embodiment, when the front frame 32 is tilted within the range where the working radius is less than 5.9 m, the controller 80 may determine the rated total load according to the straight line L3. Similarly, when the leader 11 is tilted within the range where the working radius is 5.9 m or more, the controller 80 may also determine the rated total load according to the straight line L3. Here, the straight line L3 is the minimum value of the rated total load. With this configuration, since the rated total load becomes the minimum value regardless of the working radius, the crane operation can be performed safely.

[0081] In addition, as an example of the display device for the earth drill, the configuration of the moment limiter 85 provided in the cab 4 of the earth drill 1 has been described, but the display device for the earth drill according to the present invention is not limited to this embodiment. For example, a portable terminal or an external terminal such as a tablet that displays all or part of the information displayed by the moment limiter 85 is also an aspect of the display device according to the present invention. In this case, it is convenient because on-site workers and on-site managers who are away from the cab 4 of the earth drill 1 can use the terminal to check the same information as the information displayed on the moment limiter 85.

Explanation of symbols

[0082] 1 Earth drill 2 Traveling body (main body) 3 Slewing body (main body) 4 Cab 5 Counterweight 6 Rear winch 7 Front winch 10 Front attachment 11 Leader 13 Leader head 14 Kelly sheave 15 Supplementary winding sheave (sheave) 16 Kelly rope 17 Supplementary winding rope (rope) 18 Kelly bar (excavation attachment) 19 Kelly top guide 20 Rotary drive 21 Excavation tool 22 Hook 25 Rear guide sheave 26 Thruster cylinder 31 Triangle frame 32 Front frame 34 Stay cylinder 36 Front stay 38 Front frame undulating cylinder 41 Leader angle detector 42 Front frame angle detector 43 Load detector 44 Pressure detector 45 Limit switch 46 Pressure detector 50 Front winch lever 55 Operation mode changeover switch 56 Front frame undulating lever 57 Leader tilting lever 60,61,68,69 Control valve 62,63,65,66 Solenoid valve 80 Controller 85 Moment limiter (display unit, display device)

Claims

1. A main body, a leader supported by the main body via a front frame, and a supplementary winding sheave attached to the leader around which a rope is wound, wherein the earth drill machine: the front frame is a component constituting a front attachment and is capable of tilting with respect to the main body; the leader is tiltable with respect to the front frame; when the angle of the center line of the front frame with respect to the horizontal axis in a side view of the earth drill machine is defined as the tilting angle, and the angle of the center line of the leader with respect to the vertical axis in a side view of the earth drill machine is defined as the tilting angle, when the earth drill machine is at a predetermined working radius, the upper limit value of the suspension load of the rope at the predetermined working radius can be changed according to at least one of the tilting angle and the tilting angle; when the suspension load exceeds the changed upper limit value, a part of the operation of the earth drill machine is stopped. An earth drill machine characterized by this.

2. In the earth drill machine according to claim 1, it has a display unit for displaying the upper limit value of the suspension load of the rope, and the upper limit value displayed on the display unit is changed based on at least one of the tilting angle and the tilting angle and the predetermined working radius. An earth drill machine characterized by this.

3. In the earth drill machine according to claim 1 or 2, as the tilting angle increases, the front frame stands up with respect to the main body, and as the tilting angle increases, the leader tilts forward with respect to the front frame. It is configured, when the tilting angle is constant, the upper limit value is changed so as to decrease as the tilting angle increases. An earth drill machine characterized by this.

4. In the earth drill machine according to claim 3, when the working radius of the earth drill machine is the same, the upper limit value at the second angle where the tilting angle is larger than the first angle is larger than the upper limit value at the first angle where the tilting angle is the first angle. An earth drill machine characterized by this.

5. In the earth drill machine according to any one of claims 1 to 4, a drilling attachment can be attached to the leader, and the upper limit value is changed according to the presence or absence of the drilling attachment. An earth drill machine characterized by this.

6. In the earth drill according to claim 1 or 2, at least one of the undulating operation of the front frame and the tilting operation of the leader is restricted based on the predetermined working radius, and the earth drill is characterized by this.

7. In the earth drill according to claim 6, when the working radius of the earth drill is less than a predetermined value, the front frame is fixed at the predetermined undulating angle and only the tilting operation of the leader is enabled, and the earth drill is characterized by this.

8. In the earth drill according to claim 6 or 7, when the working radius of the earth drill is greater than or equal to a predetermined value, the leader is fixed at the predetermined tilting angle and only the undulating operation of the front frame is enabled, and the earth drill is characterized by this.

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