Operation device of excavation device, and excavation device

Abstract

To provide an operation device of an excavation device and an excavation device that are capable of controlling rotation drive of a rotation drive device to reduce operation burden of an operation lever while also ensuring safety.SOLUTION: In an operation device that applies a lever operation signal to a rotation drive control valve 37 based on tilting of an operation lever 33, a controller 35: cuts off a lever operation signal when detection signals from an operation detection portion 36 and a rotation holding switch 34 are input simultaneously, and applies an alternative operation signal corresponding to the lever operation signal to the rotation drive control valve; cuts off the alternative operation signal when the operation lever is tilted past a neutral position in a state where the alternative operation signal is applied, or when a detection signal from a rotation lock detection portion 52 is input continuously for more than a predetermined time; and restores only the lever operation signal from a cut-off state based on that the operation lever is tilted past the neutral position in a state where the lever operation signal and the alternative operation signal are cut off.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an operating device for an excavation machine and an excavation machine, and more particularly to an operating device for an excavation machine provided with a rotary drive device that rotates an excavation tool, and an excavation machine. [Background technology]

[0002] In general, construction machines equipped with various working devices such as loading and unloading equipment and excavation equipment perform desired operations by tilting the control lever at the driver's seat. Such control levers are equipped with a fail-safe function, and when the driver's hand is released from a specified operating position, the elastic force of a built-in spring returns the control lever to a neutral position, stopping the operation of the machine. Meanwhile, in order to meet the demand for maintaining the operating position of the control lever in a constant position from the viewpoint of convenience, a holding / release device capable of holding the tilted position of the control lever with hydraulic pressure has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-124010 A Summary of the Invention [Problem to be solved by the invention]

[0004] Among various construction machines, excavation machines that work underground perform the rotational drive of the Kelly drive continuously for a long time, for example, when removing obstacles, so if the rotational drive is held, the burden of operating the operation lever can be reduced. However, since the held state is a state that does not follow the concept of fail-safe, it is necessary from a safety standpoint that the held state is not entered easily, and it is also required that it is easy to return from the held state, and that the rotational drive is quickly stopped when a return operation is performed. Furthermore, the stopped state of the rotational drive may be in a rotation lock state (insufficient drive torque of the excavation tool against friction with the underground obstacle) caused by an underground obstacle, and in such a case, there is a misunderstanding between the operator and the worker as to whether or not the machine is in operation (rotation is continuing), so how to ensure the safety of the work site after the rotational drive is held is an issue.

[0005] Therefore, an object of the present invention is to provide an operating device for an excavation machine and an excavation machine that can control the rotational drive of the rotary drive device, thereby achieving both a reduction in the operating burden of the operating lever and safety. [Means for solving the problem]

[0006] In order to achieve the above object, the operating device for an excavating machine of the present invention is equipped to an excavating machine which includes a lower traveling body, an upper rotating body rotatably provided on the upper part of the lower traveling body, a cab mounted on the upper rotating body and defining an operator's cab therein, a leader provided upright at the front of the upper rotating body, a rotary drive unit which can rise and fall along the leader, and an excavating tool which is rotated by obtaining the rotary drive force of the rotary drive unit, and the operating device applies a lever operation signal to a rotary drive control valve of the rotary drive unit based on the tilting of an operating lever arranged in the operator's cab, the operating device comprising: a controller; an operation detection unit which detects the tilting of the operating lever; a rotation hold switch which is arranged in the operator's cab independent of the operating lever; and a rotation lock detection unit which detects when the rotation of the excavating tool is locked, is provided with an elastic member that returns the lever shaft from a tilted position to a neutral position, and the controller, when detection signals from the operation detection unit and the rotation hold switch are input simultaneously, cuts off the lever operation signal and applies an alternative operation signal corresponding to the lever operation signal to the rotation drive control valve, cuts off the alternative operation signal based on either when the operating lever has tilted past the neutral position while the alternative operation signal is being applied or when a detection signal from the rotation lock detection unit is continuously input for more than a predetermined time period, and returns only the lever operation signal from the cut-off state based on the operating lever having tilted past the neutral position while the lever operation signal and the alternative operation signal are cut off.

[0007] The present invention is also characterized in that it includes a relief valve that opens when the pressure of the hydraulic oil supplied to the rotary drive device reaches a preset relief pressure, and the rotation lock detection unit is a pressure transmitter that detects the relief pressure. Effect of the Invention

[0008] According to the present invention, the operating device provided on the excavating machine is equipped with a rotation hold switch that is arranged independently of the operating lever, and when detection signals from the operation detection unit and the rotation hold switch are simultaneously input to the controller, the lever operation signal is blocked and an alternative operation signal corresponding to the lever operation signal is applied to the rotary drive control valve.Therefore, even when the operating lever is returned to the neutral position, it is possible to maintain the rotational state of the rotary drive device based on the alternative operation signal, thereby reducing the operating burden of the operating lever.

[0009] Also, by placing importance on the independence of the rotation hold switch, unintentional transition to the rotation hold state due to erroneous operation can be prevented by simultaneous operation input from two places. On the other hand, after transition to the rotation hold state reflecting the operator's operating intention, it is possible to eliminate the involvement of lever operation for rotation drive by simply leaving it to the elastic return of the control lever to neutral, and to appropriately position the control lever in the driving posture, allowing for stable driving operation that is not dependent on the operator's level of skill.

[0010] Furthermore, since the alternative operation signal is cut off based on either the tilting of the operating lever past the neutral position while the alternative operation signal is being applied, or the input of a detection signal from the rotation lock detection unit for a period of time or longer that is set in advance, the stop operation from the rotation hold state can be easily and quickly performed by inputting the main operation from one point, while the rotation state of the drilling tool is monitored, and the rotation drive of the rotation drive device can be automatically stopped when a rotation lock state occurs due to an underground obstacle, so that it is also excellent in terms of safety. In addition, since only the lever operation signal is returned from the cut-off state based on the tilting of the operating lever past the neutral position while the lever operation signal and the alternative operation signal are cut off, the initial state can be smoothly returned to while ensuring safety based on the operator's intention to operate. [Brief description of the drawings]

[0011] [Figure 1] 1 is a side view of a driver's cab equipped with an operating device according to an embodiment of the present invention; [Diagram 2] FIG. [Diagram 3] FIG. 13 is a diagram showing the arrangement of a rotation holding switch. [Figure 4] FIG. [Diagram 5] FIG. 11 is a control circuit diagram showing a state in which the rotary operation lever is tilted. [Figure 6] FIG. 11 is a control circuit diagram showing a state in which detection signals from an operation detection unit and a rotation holding switch are simultaneously input to the controller. [Figure 7] FIG. 13 is a control circuit diagram showing a state in which the rotation operating lever is returned to the neutral position in a rotation holding state in which an alternative operation signal is applied to the rotation drive control valve. [Figure 8] FIG. 11 is a control circuit diagram showing a state in which the rotary operation lever is tilted from the neutral position to cut off the alternative operation signal. [Figure 9] FIG. 11 is a control circuit diagram showing a state in which the rotary operation lever is returned to the neutral position with the alternative operation signal being cut off. [Figure 10] FIG. 11 is a control circuit diagram showing a state in which the rotation of the excavation tool is locked in a rotation holding state in which an alternative operation signal is applied to the rotary drive control valve. [Figure 11] FIG. 13 is a control circuit diagram showing a state in which a detection signal from a rotation lock detection unit is input and an alternative operation signal is blocked. [Figure 12] 1 is a side view of an excavation machine to which an operating device in one embodiment of the present invention is applied; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1 to 12 are diagrams showing an operating device according to an embodiment of the present invention applied to an excavation machine. As shown in FIG. 12, the excavation machine 11 is a multipurpose excavation machine capable of various construction works such as casing excavation and ground improvement work, and is equipped with a base machine 14 consisting of a lower traveling body 12 equipped with crawlers and an upper rotating body 13 rotatably installed on the lower traveling body 12, a leader 15 erected at the front of the upper rotating body 13, and a hoisting cylinder 16 supporting the leader 15 from the rear. In addition, a leader support 17 supporting the leader 15 so that it can be raised and lowered is provided at the front of the upper rotating body 13, and a piping support member 18 supporting piping is provided above the front of the upper rotating body 13. In addition, a cab 19 for operation is provided at the right side of the upper rotating body 13, and a power unit 20 equipped with an engine and a hydraulic pump serving as a hydraulic source is provided at the left side.

[0013] The leader 15 is formed by connecting a plurality of leader members each having a rectangular cylindrical cross section, and is rotatably attached to a support shaft in the vehicle width direction provided on the leader support 17. A top sheave 23 around which the kelly rope 22 of the kelly bar 21 and the like are wound is attached to the upper end of the leader 15, and a kelly drive 24, which is an example of a rotary drive device that rotates the kelly bar 21, and a guide device 25 for the kelly bar 21 are attached to the front surface of the leader 15. A rack gear 26 is attached to the center of the front surface of the leader 15 as a component of the rack and pinion type lifting device, and a pair of left and right guide pipes 27, 27 are provided continuously over the entire length of the leader 15 at the front ends of both sides, and serve as the mounting parts for the kelly drive 24 and the guide device 25.

[0014] The kelly drive 24 is configured around a device body 24a having a rotatable kelly bar 21, and has a pair of left and right guide gibs 24b, 24b that slide against the guide pipes 27, 27 of the leader 15 and protrude rearward. A pair of left and right pinions that mesh with the rack gear 26 are rotated by a lifting hydraulic motor (not shown), causing the kelly drive 24 to rise and fall along the front surface of the leader 15.

[0015] The Kelly drive 24 also includes a rotary drive hydraulic motor 24c connected to a speed reducing mechanism in the device body 24a, and an electromagnetic proportional pressure reducing valve (not shown) attached thereto. The rotary drive hydraulic motor 24c is a swash plate type variable displacement hydraulic motor whose capacity can be changed by changing the tilt angle of the swash plate. The tilt angle of the swash plate, i.e., the displacement volume (the amount of discharge per rotation of the motor), is adjusted by a regulator. As a result, if the flow rate is constant, the rotary drive hydraulic motor 24c will rotate faster as the displacement volume decreases, and the rotation speed will decrease as the displacement volume increases, but it will generate a large torque because it uses a large amount of hydraulic oil to rotate.

[0016] The kelly bar 21 is a well-known locking kelly bar equipped with a locking means capable of transmitting a strong pressing force in hard ground, has a structure (for example, a four-stage structure) in which multiple kelly bar members are combined, and is formed so as to expand and contract according to the excavation depth. The locking means is made up of a pair of plate structures provided between adjacent kelly bar members, which are fitted together and locked to efficiently transmit the pressing force to the excavation tool attached to the tip (lower end) of the kelly bar 21.

[0017] Here, when the excavating machine 11 is used for the purpose of casing excavation, a casing is used as the excavating tool. The casing 47 is connected to the tip of the Kelly bar 21 or to the device body (reduction mechanism output part) 24a of the Kelly drive 24 via a coupling 48. As a result, the cylindrical body of the casing 47 is provided concentrically with the rotation axis of the Kelly drive 24 and rotates integrally with it, and by lowering the Kelly drive 24 while driving it to rotate, the excavation bit 47a at the tip of the casing 47 excavates the ground or cuts obstacles such as old foundations.

[0018] To perform such casing drilling, a driver's compartment is defined within the cab 19 for the operator to sit in, and devices such as operating levers and pedals for driving, turning, raising and lowering the Kelly drive 24, push button switches, and a touch panel display are concentrated near the driver's seat for ease of operability, and an operating device including a controller electrically connected to these operating devices is also installed.

[0019] 1 to 3 show various operating units arranged in the cab. Here, in order to facilitate understanding of the explanation, each figure is shown in the front-reverse direction with respect to the orientation of the external view in Fig. 12, and in Fig. 1, the right side is the front, the left side is the rear, the back side in the paper direction is the left side part, and the front side is the right side part. When the cab is divided into two in the left-right width direction (the up-down direction in Fig. 2) by a vertical plane S passing through the center of the driver's seat 28, the various operating units are arranged side by side with the driver's seat 28 between them, with the left-hand side operating input unit 29 operated with the left hand in the left space and the right-hand side operating input unit 30 operated with the right hand in the right space.

[0020] A ceiling position operation input unit 31 and a pillar position operation input unit 32, which are usually operated with the left hand, are arranged on the window frame corresponding to the driver's seat 28 in the left-hand space. These operation input units 31, 32 consist of a group of switches aligned in a horizontal or vertical row along the wall surface, and although they are operated less frequently than main operations such as lever operations that cause the machine to operate, they can be easily operated even while seated.

[0021] Further, as will be described in detail later, the shortest distance between the Kelly drive lift / rotation operation lever (two-axis operation lever) 33 belonging to the right-hand operation input unit 30 and the rotation hold switch 34 belonging to the pillar position operation input unit 32 is greater than the left-right width dimension of the driver's seat 28. In other words, as can be seen from Fig. 2, the operation lever 33 and the rotation hold switch 34 arranged independently therefrom are spaced apart from each other in the outside area of ​​the area of ​​the driver's seat 28 having the left-right width dimension W in the driver's cab, and although both hands are required to operate them simultaneously, they can be handled in a natural posture.

[0022] Incidentally, since the drilling machine 11 performs rotational drive of the Kelly drive 24 continuously for a long period of time, for example, when drilling a casing, if the rotational drive can be held, the burden of operating the control lever 33 can be reduced. Therefore, the control device allows the operator to select a state in which the rotational drive of the Kelly drive 24 is held.

[0023] The case where rotation holding operation is performed will be described below with reference to Figures 4 to 11. Figure 4 shows a control circuit for the rotation operation system, which mainly comprises a controller 35 that executes a control program, an operation detector 36 that detects the tilt of the operating lever 33, and a rotation holding switch 34, and is configured to give a lever operation signal to a rotation drive control valve (rotation direction switching valve) 37 of the Kelly drive 24 based on the tilt of the operating lever 33 in the state before the system is switched to the rotation holding mode (lever mode).

[0024] The lever operation signal is a pressure signal of hydraulic oil selectively flowing through each of pilot oil passages 38, 39 on the forward and reverse rotation sides in the rotation drive. The pilot oil passages 38, 39 are equipped with a remote control valve 40 that changes the lever operation pressure signal (pilot secondary pressure) in response to the tilt of the operating lever 33, and an electromagnetic control valve 41 provided downstream of the remote control valve 40.

[0025] The operating lever 33 is constructed using a two-axis remote control valve 40, with left and right tilting being assigned to the rotation of the Kelly drive 24 and front and rear tilting (not shown) being assigned to the elevation of the Kelly drive 24. Furthermore, by adjusting the tilting direction of the operating lever 33, combined operations of rotation and elevation are possible, i.e., pushing and pulling in casing drilling can be performed with one hand operation of a single lever. Furthermore, a coil spring 33b is built into the operating lever 33 as an elastic member that returns the lever shaft 33a from the tilted position to the neutral position.

[0026] The rotation holding switch 34 is an automatic return type push button switch that is turned on (pushed down), and a button operation signal is input to the controller 35 when the switch is turned on.

[0027] The operation detection unit 36 ​​is a forward pressure transmitter 36a and a reverse pressure transmitter 36b that detect a lever operation pressure signal in detection pilot oil passages 38a, 39a between the remote control valve 40 and the solenoid control valve 41. The lever operation pressure signal generated based on the tilt of the operating lever 33 is converted into an electric signal by the pressure transmitters 36a, 36b and input to the controller 35.

[0028] The solenoid control valve 41 is operated by a control command from the controller 35, and comprises forward and reverse side oil passage shut-off valves (lever operation disable solenoid valves) 42, 43 that shut off the flow of hydraulic oil from the remote control valve 40, and forward and reverse side oil passage switching valves (rotation holding solenoid valves) 45, 46 that are provided downstream of the oil passage shut-off valves 42, 43 and can selectively connect the intermediate pilot oil passages 38c, 39c output from the oil passage shut-off valves 42, 43 to branch oil passages 44a, 44b of an attached supply pilot oil passage 44, thereby switching the intermediate pilot oil passages 38c, 39c to the supply pilot oil passage 44, and common pilot oil passages 38b, 39b output from the oil passage switching valves 45, 46.

[0029] The hydraulic oil flowing through the supply pilot oil passage 44 has the same hydraulic pressure source as the hydraulic oil flowing through the remote control valve 40. That is, although not shown in the figure, the supply pilot oil passage 44 is a branch oil passage obtained by branching off the P line of the pilot pump.

[0030] A relief valve 51 and a rotary pressure transmitter 52 are provided in a discharge oil passage 50 between the main pump (swash plate pump) 49 and the rotary drive control valve 37. The relief valve 51 is normally provided for protecting the hydraulic circuit, and when the discharge pressure of the main pump 49, i.e., the pressure of the hydraulic oil supplied to the Kelly drive 24, reaches a preset relief pressure, it opens (opens the valve) and relieves excess pressure to the hydraulic oil tank side. The rotary pressure transmitter 52 detects the discharge pressure of the main pump 49, and is capable of detecting the relief pressure by interacting with the relief valve 51. The rotary pressure transmitter 52 serves as a rotation lock detection unit that detects that the rotation of the drilling tool (e.g., the casing 47) is locked when the Kelly drive 24 is in the rotary drive state. The discharge pressure signal generated based on the operation of the main pump 49 is converted into an electric signal by the rotary pressure transmitter 52 and input to the controller 35.

[0031] When the control circuit configured in this manner is operated to perform rotation holding operation, first, the excavator 11 is moved to the construction site, and after going through the necessary setup, the rotation and lowering operation of the Kelly drive 24 is performed. Focusing on the rotation operation, as shown in Figure 5, tilting the operating lever 33 to the forward rotation side applies a lever operation pressure signal to the forward rotation side port of the rotation drive control valve 37, and excavation proceeds while obtaining pressure oil from the main pump 49 and rotating the Kelly drive 24 in the forward direction.

[0032] When such a lever mode is executed, the controller 35 detects the tilt state of the operating lever 33 by a signal from the forward rotation pressure transmitter 36a, but does not give a control command to the solenoid control valve 41. As a result, both the oil passage shutoff valve 42 and the oil passage switching valve 45 are held in a state in which the forward rotation side pilot oil passage 38 is communicated (de-energized state), and therefore the flow of hydraulic oil from the supply pilot oil passage 44 is blocked by the oil passage switching valves 45, 46 in the closed state.

[0033] Here, when the operation lever 33 and the rotation holding switch 34 are simultaneously operated based on the operator's intention to switch to the rotation holding operation, the detection signals "ON" from the forward rotation pressure transmitter 36a and the rotation holding switch 34 are simultaneously input to the controller 35 as shown in Fig. 6. Then, the controller 35 switches and controls the forward rotation side oil passage shutoff valve 42 to shut off the flow of hydraulic oil in the detection pilot oil passage 38a, and switches and controls the forward rotation side oil passage switching valve 45 to introduce the hydraulic oil flowing in the supply pilot oil passage 44 (branch oil passage 44a) into the common pilot oil passage 38b, thereby applying an alternative operation pressure signal corresponding to the lever operation pressure signal to the rotation drive control valve 37. At this time, the intermediate pilot oil passage 38c is connected to the T line that returns the hydraulic oil to the tank according to the switching control of the forward rotation side oil passage shutoff valve 42 and the forward rotation side oil passage switching valve 45.

[0034] When the rotation hold mode is executed, an alternative operating pressure signal is given as a control command to the rotation drive control valve 37, and the rotation drive of the Kelly drive 24 continues. Here, as shown in FIG. 7, when the tension in the lever operation (left and right direction) is released and the operating lever 33 is returned to the neutral position, the flow of hydraulic oil to the detection pilot oil passage 38a is blocked by the closed remote control valve 40. However, since an alternative operating pressure signal is given to the rotation drive control valve 37, the rotation state of the Kelly drive 24 is maintained even if the operating lever 33 is returned to the neutral position. Also, in this state, the detection signals "OFF" are input to the controller 35 from both the forward rotation pressure transmitter 36a and the rotation hold switch 34.

[0035] Incidentally, while the rotation hold mode is being executed, one can concentrate on the driving operation of lowering the kelly drive 24, but there are cases when one wishes to exit the rotation hold mode due to the behavior of the machine, etc. In such cases, the operating lever 33 is tilted from the neutral position to either the forward rotation side or the reverse rotation side. For example, as shown in Fig. 8, when the operating lever 33 is tilted again to the forward rotation side (for example, tilted by 3 degrees or more), a lever operating pressure signal generated based on this is input to the controller 35 via the forward rotation pressure transmitter 36a.

[0036] At this time, the controller 35 to which the lever operation detection signal "ON" has been input controls the forward rotation oil passage switching valve 45 to cut off the alternative operating pressure signal (FIG. 8) based on the tilt of the operating lever 33 through the neutral position (FIG. 7) in the applied state of the alternative operating pressure signal (FIG. 6). As a result, no control command is sent to the rotation drive control valve 37, and the rotation (hydraulic drive) of the kelly drive 24 is promptly stopped.

[0037] With the operating lever 33 in a tilted state (FIG. 8), the flow of hydraulic oil from the remote control valve 40 in the forward pilot oil passage 38 is blocked by the closed forward oil passage shutoff valve 42, so the rotation of the Kelly drive 24 is maintained stopped even when the operating lever 33 is in a tilted position. Then, when the operating lever 33 is returned to the neutral position almost simultaneously with the stopping of rotation of the Kelly drive 24 or immediately after the stopping of rotation, the flow of hydraulic oil to the detection pilot oil passage 38a is blocked by the closed remote control valve 40, as shown in FIG.

[0038] Here, the controller 35, to which the lever operation detection signal "OFF" has been input from the forward rotation pressure transmitter 36a, switches and controls the forward rotation oil passage shutoff valve 42 to maintain the forward rotation pilot oil passage 38 in a communicated state. In this way, the system leaves the rotation holding mode and transitions (returns) to the lever mode, which is the initial state. At this time, the controller 35 returns to the lever mode, which is the initial state shown in FIG. 5, from a state in which only the lever operation pressure signal is shut off (FIG. 8) based on the tilt of the operating lever 33 through the neutral position (FIG. 9) in a state in which the lever operation pressure signal and the alternative operation pressure signal are shut off (FIG. 8). This allows the operator to proceed with casing drilling by operating the lever as desired.

[0039] Here, if the excavation machine 11 stops rotating (rotation lock) due to an underground obstacle during execution of the rotation hold mode (FIG. 7), workers around the excavation machine 11 cannot determine whether the operator intentionally stopped the rotation or the rotation stop occurred due to insufficient driving torque of the Kelly drive 24, and may approach the casing 47 by mistake. In this case, it is possible to provide an indicator light to inform the outside of the operation state of the excavation machine 11, but depending on the situation at the work site, the indicator light may be overlooked. Therefore, as shown in FIG. 10, when the casing 47 is in a rotation lock state during execution of the rotation hold mode (neutral position of the operation lever 33) and the discharge oil passage 50 reaches the relief pressure (main relief pressure), the rotation pressure transmitter 52 generates a detection signal (relief pressure signal) corresponding to the relief pressure.

[0040] At this time, if the relief pressure signal is continuously input from the rotation pressure transmitter 52 for a preset time (e.g., 10 seconds) or more, the controller 35 switches the forward rotation side oil passage switching valve 45 from the state in which the alternative operating pressure signal is being applied (Fig. 10) to the state in which the alternative operating pressure signal is being applied, as shown in Fig. 11. As a result, no control command is issued to the rotation drive control valve 37, and the hydraulic drive of the kelly drive 24 is quickly stopped.

[0041] The return operation from the rotation lock state is, for example, to raise the Kelly drive 24 to weaken the pressing force of the casing 47 after safety confirmation. When it is desired to enable the rotation operation, that is, when it is desired to release the restriction in the rotation holding mode, it is necessary to tilt the operation lever 33 from the neutral position to either the forward rotation side or the reverse rotation side, and then return it to the neutral position again for safety reasons. Here, the controller 35, to which the lever operation detection signals "ON" and "OFF" are sequentially input from the forward rotation pressure transmitter 36a or the reverse rotation pressure transmitter 36b based on the tilt operation of the operation lever 33, switches and controls the forward rotation side oil passage cutoff valve 42 to maintain the forward rotation side pilot oil passage 38 in a communicated state. That is, the controller 35 returns to the lever mode, which is the initial state shown in FIG. 5, from the state in which only the lever operation pressure signal is cut off (FIG. 11) based on the tilt of the operation lever 33 through the neutral position in the state in which the lever operation pressure signal and the alternative operation pressure signal are cut off (FIG. 11). In this way, the system escapes from the restricted state of the rotation holding mode and transitions (returns) to the initial state, that is, the lever mode, whereby casing drilling can be carried out by any lever operation by the operator.

[0042] Thus, according to the present invention, the operating device provided on the excavating machine 11 is equipped with the rotation hold switch 34 arranged independently of the operating lever 33, and when detection signals from the operation detection unit 36 ​​and the rotation hold switch 34 are simultaneously input to the controller 35, the lever operation signal is cut off and an alternative operation signal corresponding to the lever operation signal is applied to the rotary drive control valve 37. Therefore, even when the operating lever 33 is returned to the neutral position, it is possible to maintain the rotational state of the rotary drive device 24 based on the alternative operation signal, thereby reducing the operating burden of the operating lever 33.

[0043] Also, by placing importance on the independence of the rotation hold switch 34, unintentional transition to the rotation hold state due to erroneous operation or the like can be prevented by simultaneous operation input from two places. On the other hand, after transition to the rotation hold state reflecting the operator's operating intention, it is possible to eliminate the involvement of lever operation for rotation drive by simply leaving it to the elastic return of the control lever 33 to neutral, and to appropriately position the control lever 33 in the driving posture, allowing for stable driving operation that is not dependent on the operator's level of skill.

[0044] Furthermore, since the alternative operation signal is cut off based on either the tilting of the operating lever 33 past the neutral position while the alternative operation signal is being applied, or the input of a detection signal from the rotation lock detector 52 for a period of time or longer that is set in advance, the stop operation from the rotation hold state can be easily and quickly performed by inputting the main operation from one point, while the rotation state of the excavator 47 is monitored, and the rotation drive of the rotation drive device 24 can be automatically stopped when a rotation lock state occurs due to an underground obstacle, providing excellent safety. In addition, since only the lever operation signal is returned from the cut-off state based on the tilting of the operating lever 33 past the neutral position while the lever operation signal and the alternative operation signal are cut off, the initial state can be smoothly returned to while ensuring safety based on the operator's intention to operate.

[0045] In addition, when a rotation lock state occurs, the rotation drive of the rotation drive device 24 can be stopped based on a detection signal corresponding to the relief pressure of the hydraulic circuit. This means that the device can be easily incorporated into or retrofitted to a conventional operating device using a hydraulic pilot operation method, resulting in an operating device that is inexpensive, has simple control, and is highly robust.

[0046] In addition, the interior space is divided into two in the left-right width direction by a vertical plane S passing through the center of the driver's seat 28, and the operation lever 33 is disposed in one space and the rotation hold switch 34 is disposed in the other space, and since the shortest distance between the operation lever 33 and the rotation hold switch 34 is greater than the left-right width dimension W of the driver's seat 28, the rotation hold state is not easily entered. In other words, it is possible to avoid rotation hold operation against the operator's will.

[0047] Furthermore, the operating lever 33 is configured for two-axis operation, with left and right tilting assigned to rotating the Kelly drive 24 and front and rear tilting assigned to raising and lowering the Kelly drive 24, allowing efficient operation input for the construction of the excavation machine 11. Even when performing combined operations by adjusting the tilt direction of the operating lever 33, casing can be pushed in and pulled out by single-handed operation of a single lever, and coordination with rotation holding operation can be easily achieved.

[0048] The present invention is not limited to the above-mentioned embodiment, and the configuration and arrangement of the operating device can be appropriately changed according to the specifications of the cab. In the embodiment, a hydraulic pilot operation type operating lever is used, but an electrically operated operating lever may be used. In this case, the rotation drive control valve is electrically controlled by a controller, and a lever operation signal from a potentiometer as an operation detection unit can be directly input to the controller. Furthermore, the number of axes of the operating lever is also arbitrary. In addition, the rotation lock detection unit may determine whether or not the drilling tool is rotating based on a detection signal from a camera or a sensor, and the input time of the detection signal can be appropriately changed taking into consideration the grace period from when the rotation lock state occurs until the rotation naturally returns. In addition, the casing excavation (obstacle removal work) has been described as an example, but the present invention is not limited to this, and can be applied to other construction methods such as ground improvement. [Explanation of symbols]

[0049] 11...excavation machine, 12...lower running body, 13...upper rotating body, 14...base machine, 15...leader, 16...derailing cylinder, 17...leader support, 18...piping support member, 19...operator's cab, 20...power unit, 21...kelly bar, 22...kelly rope, 23...top sheave, 24...kelly drive, 24a...device main body, 24b...guide gib, 24c...hydraulic motor for rotation drive, 25...guide device, 26...rack gear, 27...guide pipe, 28...operator's seat, 29...left hand side operation input unit, 30...right hand side operation input unit, 31...ceiling position operation input unit, 32...pillar position operation input unit, 33...operation lever, 33a...lever shaft, 33b...coil spring, 34...rotation hold switch, 35...controller, 36...operation detection unit, 36a...positive Rotation pressure transmitter, 36b...reverse pressure transmitter, 37...rotation drive control valve, 38...forward rotation pilot oil passage, 38a...detection pilot oil passage, 38b...common pilot oil passage, 38c...intermediate pilot oil passage, 39...reverse rotation pilot oil passage, 39a...detection pilot oil passage, 39b...common pilot oil passage, 39c...intermediate pilot oil passage, 40...remote control valve, 41...electromagnetic control valve, 42...forward rotation oil passage shutoff valve, 43...reverse rotation oil passage shutoff valve, 44...supply pilot oil passage, 44a, 44b...branch oil passage, 45...forward rotation oil passage switching valve, 46...reverse rotation oil passage switching valve, 47...casing, 47a...drilling bit, 48...coupling, 49...main pump, 50...discharge oil passage, 51...relief valve, 52...rotation pressure transmitter

Claims

1. The excavation machine is provided with a lower traveling body, an upper rotating body rotatably provided on the upper part of the lower traveling body, a cab mounted on the upper rotating body and defining an operator's room therein, a leader erected at the front part of the upper rotating body, a rotary drive device capable of ascending and descending along the leader, and an excavation tool rotated by obtaining a rotary drive force of the rotary drive device, an operating device that applies a lever operation signal to a rotary drive control valve of the rotary drive device based on a tilt of an operating lever arranged in the driver's cab, A controller; an operation detection unit that detects a tilting movement of the operation lever; A rotation holding switch arranged in the cab independently of the operating lever; a rotation lock detection unit for detecting that the rotation of the drilling tool is locked, The operating lever is provided with an elastic member that returns the lever shaft from a tilted position to a neutral position, when detection signals are simultaneously input from the operation detection unit and the rotation holding switch, the controller blocks the lever operation signal and applies an alternative operation signal corresponding to the lever operation signal to the rotation drive control valve; When the operating lever is tilted past a neutral position while the alternative operation signal is being applied, or when a detection signal from the rotation lock detection unit is continuously input for a predetermined period of time or longer, the alternative operation signal is cut off, An operating device characterized in that, when the lever operation signal and the alternative operation signal are in a cut-off state, only the lever operation signal is restored from the cut-off state based on a tilt of the operating lever through a neutral position.

2. a relief valve that opens when the pressure of the hydraulic oil supplied to the rotary drive device reaches a preset relief pressure; 2. The operating device according to claim 1, wherein the rotation lock detector is a pressure transmitter that detects the relief pressure.

3. An excavating machine comprising the operating device according to claim 1 or 2.

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