JP7788928B2 - Excavation machine operating device and excavation machine - Google Patents

Description

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 equipped with a rotary drive device that rotates and drives an excavation tool, and an excavation machine.

Generally, construction machinery equipped with various working devices such as loading and unloading equipment and excavation equipment performs desired operations by tilting a control lever located in the driver's seat. These control levers are equipped with a fail-safe function; when the operator releases the lever from a designated operating position, the elastic force of a built-in spring returns the lever to a neutral position, stopping the machine's operation. Meanwhile, to meet the demand for maintaining a constant operating position of the control lever for convenience, a holding/release device has been proposed that can hydraulically hold the tilted position of the control lever (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2001-124010

Among various types of construction machinery, excavators used for underground work, for example, use Kelly drives for continuous rotational drive for long periods of time when removing obstacles. Therefore, being able to hold the rotational drive reduces the burden on the operator when operating the control lever. However, because the held state is not a fail-safe state, from a safety standpoint it is necessary that the held state not be entered easily. It is also necessary that it is easy to return from the held state, and that the rotational drive quickly stops when the return operation is performed.

The present invention therefore aims to provide an operating device for an excavator that can control the rotational drive of the rotary drive device and reduce the operating burden of the operating lever, as well as an excavator.

In order to achieve the above-mentioned object, the operating device for an excavating machine of the present invention is equipped to an excavating machine having a lower traveling body, an upper rotating body rotatably mounted on the upper traveling body, a cab mounted on the upper rotating body and defining an operator's cab therein, a leader erected at the front of the upper rotating body, and a rotary drive unit that can be raised and lowered along the leader, 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 located in the operator's cab, and is equipped with a controller, an operation detection unit that detects the tilting of the operating lever, and a rotation hold switch that is located in the operator's cab independently of the operating lever, The bar is provided with an elastic member that returns the lever shaft from the tilted position to the neutral position, and when detection signals from the operation detection unit and the rotation hold switch are simultaneously input, 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. With the alternative operation signal applied, the alternative operation signal is blocked based on tilting of the operating lever past the neutral position, and with both the lever operation signal and the alternative operation signal blocked, only the lever operation signal is returned from the blocked state based on tilting of the operating lever past the neutral position.

The lever operation signal is a lever operation pressure signal of hydraulic oil flowing through a pilot oil passage, and the pilot oil passage is equipped with a remote control valve that changes the lever operation pressure signal in accordance with the tilt of the operating lever and an electromagnetic control valve provided downstream of the remote control valve. The operation detection unit is a pressure transmitter that detects the lever operation pressure signal in the pilot oil passage between the remote control valve and the electromagnetic control valve. The electromagnetic control valve is composed of an oil passage shutoff valve that shuts off the flow of hydraulic oil from the remote control valve and an oil passage switching valve that switches the oil passage by connecting the pilot oil passage downstream of the oil passage shutoff valve to an attached supply pilot oil passage. The controller controls the pressure transmitter and the rotational When detection signals from the control switches are simultaneously input, the control unit controls the oil passage shutoff valve to shut off the flow of hydraulic oil, and controls the oil passage switching valve to introduce hydraulic oil flowing through the supply pilot oil passage into the downstream pilot oil passage, thereby applying an alternative operating pressure signal corresponding to the lever operating pressure signal to the rotary drive control valve. With the alternative operating pressure signal applied, the control unit controls the oil passage switching valve to shut off the alternative operating pressure signal based on the tilting of the operating lever past the neutral position. With the lever operating pressure signal and the alternative operating pressure signal cut off, only the lever operating pressure signal is restored from the cut-off state based on the tilting of the operating lever past the neutral position.

Furthermore, the interior of the cab is divided into two spaces in the left-right width direction by a vertical plane passing through the center of the driver's seat, and the operating lever is located in one space and the rotation hold switch is located in the other space, with the shortest distance between the operating lever and the rotation hold switch being greater than the left-right width dimension of the driver's seat. In addition, the excavator of the present invention is characterized by being equipped with the operating device.

According to this invention, the operating device provided on the excavator is equipped with a rotation hold switch that is positioned independently of the operating lever. When detection signals from the operation detector 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. This makes it possible to maintain the rotational state of the rotary drive device based on the alternative operation signal even when the operating lever is returned to the neutral position, thereby reducing the operating burden of the operating lever.

Furthermore, by emphasizing the independence of the rotation hold switches, simultaneous operation input from two locations can prevent unintentional transitions to the rotation hold state due to misoperation or other reasons. Meanwhile, after transitioning to the rotation hold state reflecting the operator's operational intentions, the lever's elastic return to neutral position is all that's required for lever operation to drive the rotation, eliminating the need for lever operation for rotation drive and making it possible to position the control lever appropriately in the operating position, ensuring stable operation that is not dependent on the operator's level of skill.

Furthermore, when the alternative operation signal is applied, the alternative operation signal is cut off based on the tilt of the operating lever past the neutral position, so the stop operation from the rotation-holding state can be performed easily and quickly with a single main operation input, providing excellent safety. In addition, when both the lever operation signal and the alternative operation signal are cut off, only the lever operation signal is returned from the cut-off state based on the tilt of the operating lever past the neutral position, so even if the operating lever is tilted at the time of the stop operation, it can be smoothly returned to the initial state while ensuring safety.

1 is a side view of a driver's cab equipped with an operating device according to an embodiment of the present invention; FIG. FIG. 10 is a diagram showing the arrangement of a rotation holding switch. FIG. FIG. 10 is a control circuit diagram showing a state in which the rotation control lever is tilted. FIG. 10 is a control circuit diagram showing a state in which detection signals from the operation detection unit and the rotation holding switch are simultaneously input to the controller. FIG. 10 is a control circuit diagram showing a state in which the rotation operation 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. FIG. 10 is a control circuit diagram showing a state in which the rotary operation lever is tilted from the neutral position and the alternative operation signal is cut off. FIG. 10 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. 1 is a side view of an excavator to which an operating device according to an embodiment of the present invention is applied;

Figures 1 to 10 show an example of an operating device according to the present invention applied to an excavation machine. As shown in Figure 10, the excavation machine 11 is a multipurpose excavation machine capable of various construction tasks, such as casing excavation and ground improvement work. It is equipped with a base machine 14 consisting of a crawler-equipped lower track body 12 and an upper rotating body 13 rotatably mounted on the lower track body 12, a leader 15 erected at the front of the upper rotating body 13, and a boom-raising cylinder 16 supporting the leader 15 from the rear. A leader support 17 is provided at the front of the upper rotating body 13 to support the leader 15 so that it can be raised or lowered, and a piping support member 18 is provided above the front of the upper rotating body 13 to support the piping. Furthermore, an operator's cab 19 is provided on 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 on the left side.

The leader 15 is made up of multiple interconnected leader components, each with 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 is attached to the upper end of the leader 15, around which the kelly rope 22 of the kelly bar 21 is wound. A kelly drive 24, 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 of the leader 15. A rack gear 26, a component of the rack and pinion lifting device, is attached to the center of the front of the leader 15, and a pair of left and right guide pipes 27, 27 are continuously attached to the front ends of both sides along the entire length of the leader 15, forming the mounting points for the kelly drive 24 and guide device 25.

The kelly drive 24 is constructed around a device body 24a that has a rotatable kelly bar 21 attached to it. A pair of left and right guide gibs 24b, 24b that slide against the guide pipes 27, 27 of the leader 15 protrude rearward, and a pair of left and right pinions that mesh with the rack gear 26 are driven to rotate by a hydraulic lifting motor (not shown), allowing the kelly drive 24 to rise and fall along the front of the leader 15.

The Kelly drive 24 also includes a rotary drive hydraulic motor 24c connected to a reduction mechanism within the device body 24a, and an associated electromagnetic proportional pressure reducing valve (not shown). 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 (amount of fluid discharged per motor rotation), is adjusted by a regulator. As a result, for a constant flow rate, the rotary drive hydraulic motor 24c will rotate faster as the displacement volume decreases, and although the rotation speed will decrease as the displacement volume increases, it will use more hydraulic oil to rotate and generate greater torque.

The kelly bar 21 is a well-known locking kelly bar equipped with a locking mechanism capable of transmitting a strong pushing force in hard ground. It has a structure combining multiple kelly bar members (e.g., a four-stage structure) and is designed to expand and contract according to the excavation depth. The locking mechanism consists of a pair of plates attached to adjacent kelly bar members, which fit together and lock together to efficiently transmit the pushing force to the excavation tool attached to the tip (lower end) of the kelly bar 21.

When the excavating machine 11 is used for casing excavation, a casing (not shown) is used as the excavation tool. The casing is connected to the tip of the kelly bar 21 via a coupling. As a result, the cylindrical body of the casing is arranged concentrically with the rotation axis of the kelly drive 24 and rotates integrally with it. By lowering the kelly drive 24 while driving the kelly bar 21 to rotate, the excavation bit at the tip of the casing excavates the ground or cuts away obstacles such as old foundations.

To perform this type of casing drilling, an operator's compartment is defined within the cab 19, and devices such as control levers, control pedals, push button switches, and touch panel displays for driving, rotating, raising and lowering the kelly drive 24, etc. are concentrated near the operator's seat for ease of use. In addition, an operating device including a controller electrically connected to these operating devices is installed.

Figures 1 to 3 show the various operating units located in the driver's cab. To facilitate understanding, each figure is shown in the reverse orientation relative to the external view in Figure 10, with the right side in Figure 1 representing the front, the left side representing the rear, the far side of the page representing the left side, and the near side representing the right side. If the driver's cab is divided into two widthwise (vertical in Figure 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 across the driver's seat 28, with the left-hand operating input unit 29 operated with the left hand in the left space and the right-hand operating input unit 30 operated with the right hand in the right space.

The window frame corresponding to the driver's seat 28 in the left-hand space is equipped with a ceiling position operation input unit 31 and a support position operation input unit 32, which are typically operated with the left hand. 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 levers that activate the machine, they can easily be operated even while seated.

Furthermore, as will be described in more detail below, 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 support position operation input unit 32 is greater than the left-to-right width of the driver's seat 28. In other words, as can be seen in Figure 2, the operation lever 33 and the rotation hold switch 34, which is located independently of it, are spaced apart in the driver's cab outside the area of the driver's seat 28, which has a left-to-right width W. Although both hands are required to operate them simultaneously, they can be handled in a comfortable posture.

Incidentally, the excavating machine 11 continuously rotates the kelly drive 24 for long periods of time, for example, when drilling casing. Therefore, if the rotational drive can be held, the burden of operating the operating lever 33 can be reduced. Therefore, the operating device allows the operator to select a state in which the rotational drive of the kelly drive 24 is held.

The following describes the case where rotation hold operation is performed, with reference to Figures 4 to 9. Figure 4 shows the control circuit for the rotation operation system, which mainly comprises a controller 35 that executes a control program, an operation detection unit 36 that detects the tilt of the operating lever 33, and a rotation hold switch 34. In the state before the system is switched to rotation hold mode (lever mode), the system is configured to send a lever operation signal to the rotation drive control valve (rotation direction switching valve) 37 of the kelly drive 24 based on the tilt of the operating lever 33.

The lever operation signal is a pressure signal for hydraulic oil that selectively flows through the pilot oil passages 38, 39 on the forward and reverse sides of 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 located downstream of the remote control valve 40.

The operating lever 33 is configured using a remote control valve 40 for two-axis operation, with left-right tilting assigned to rotating the Kelly drive 24 and front-to-back tilting (not shown) assigned to raising and lowering the Kelly drive 24. Furthermore, by adjusting the tilting direction of the operating lever 33, combined rotation and raising and lowering operations are possible, i.e., pushing and pulling during casing drilling can be performed with one hand using a single lever. Furthermore, the operating lever 33 incorporates a coil spring 33b as an elastic member that returns the lever shaft 33a from the tilted position to the neutral position.

The rotation hold switch 34 is an automatic reset push button switch that is turned on (pressed down), and when turned on, a button operation signal is input to the controller 35.

The operation detection unit 36 consists of a forward pressure transmitter 36a and a reverse pressure transmitter 36b that detect lever operation pressure signals in the detection pilot oil passages 38a and 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 electrical signal by the pressure transmitters 36a and 36b and input to the controller 35.

The solenoid control valve 41 is operated by control commands from the controller 35 and consists of forward and reverse oil passage shutoff valves (lever operation disabling solenoid valves) 42, 43 that shut off the flow of hydraulic oil from the remote control valve 40, and forward and reverse oil passage switching valves (rotation holding solenoid valves) 45, 46 that selectively connect the common pilot oil passages 38b, 39b downstream of the oil passage shutoff valves 42, 43 to the branch oil passages 44a, 44b of the attached supply pilot oil passage 44, thereby switching the intermediate pilot oil passages 38c, 39c between the oil passage shutoff valves 42, 43 to the supply pilot oil passage 44.

The hydraulic oil flowing through the supply pilot oil line 44 has the same hydraulic source as the hydraulic oil flowing through the remote control valve 40. In other words, the supply pilot oil line 44 is a branched oil line obtained by branching off the P line of the pilot pump, although this is not shown in the figure.

When operating the control circuit configured in this manner to perform rotation holding operation, the excavator 11 is first moved to the construction site, and after the necessary setup, the Kelly drive 24 is rotated and lowered. Focusing on the rotation operation, as shown in Figure 5, tilting the operating lever 33 in the forward direction sends a lever operation pressure signal to the rotation drive control valve 37, and excavation proceeds while obtaining pressurized oil from the main pump (not shown) and rotating the Kelly drive 24 in the forward direction.

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

When the operator simultaneously operates the control lever 33 and rotation hold switch 34 based on their intention to switch to rotation hold operation, as shown in FIG. 6, the controller 35 simultaneously receives "ON" detection signals from the forward rotation pressure transmitter 36a and rotation hold switch 34. The controller 35 then switches the forward rotation oil passage shutoff valve 42 to shut off the flow of hydraulic oil in the detection pilot oil passage 38a, and switches the forward rotation oil passage switching valve 45 to introduce hydraulic oil flowing through the supply pilot oil passage 44 (branch oil passage 44a) into the common pilot oil passage 38b, thereby providing the rotation drive control valve 37 with an alternative operating pressure signal corresponding to the lever operating pressure signal. At this time, the intermediate pilot oil passage 38c is connected to the T-line, which returns hydraulic oil to the tank, in accordance with the switching control of the forward rotation oil passage shutoff valve 42 and the forward rotation oil passage switching valve 45.

When this rotation hold mode is active, an alternative operating pressure signal is sent 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 Figure 7, if the tension on the lever operation (left/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, because an alternative operating pressure signal is sent to the rotation drive control valve 37, the rotation state of the Kelly drive 24 is maintained even when the operating lever 33 is returned to the neutral position. Furthermore, in this state, the controller 35 receives "off" detection signals from both the forward rotation pressure transmitter 36a and the rotation hold switch 34.

While the rotation hold mode is active, the operator can concentrate on the operation of lowering the kelly drive 24. However, there are times when it may be necessary to exit the rotation hold mode due to machine behavior, etc. In such cases, the operating lever 33 is tilted from the neutral position toward either the forward or reverse rotation side. For example, as shown in Figure 8, when the operating lever 33 is tilted toward the forward rotation side again (for example, 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.

At this time, the controller 35, which has received an "ON" lever operation detection signal, switches and controls the forward oil passage switching valve 45 based on the tilt of the operating lever 33 past the neutral position (Figure 7) while the alternative operating pressure signal is being applied (Figure 6), blocking the alternative operating pressure signal (Figure 8). 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 quickly stopped.

When the operating lever 33 is tilted (Figure 8), the flow of hydraulic oil from the remote control valve 40 to the forward pilot oil passage 38 is blocked by the closed forward oil passage shutoff valve 42, so rotation of the Kelly drive 24 remains stopped even when the operating lever 33 is in the tilted position. Then, when the operating lever 33 is returned to the neutral position almost simultaneously with or immediately after rotation of the Kelly drive 24 stops, the flow of hydraulic oil to the detection pilot oil passage 38a is blocked by the closed remote control valve 40, as shown in Figure 9.

When the forward rotation pressure transmitter 36a inputs an "off" lever operation detection signal to the controller 35, it controls the forward rotation oil line shutoff valve 42 to maintain the forward rotation pilot oil line 38 in a connected state. The system thus exits rotation hold mode and transitions (returns) to the initial state, lever mode. At this time, with the lever operation pressure signal and alternative operation pressure signal in a cut-off state (Figure 8), the controller 35 returns only the lever operation pressure signal from the cut-off state (Figure 8) based on the tilt of the operation lever 33 through the neutral position (Figure 9), as shown in Figure 5. This allows casing drilling to proceed with any lever operation by the operator.

As such, according to the present invention, the operating device provided on the excavator 11 is equipped with a rotation hold switch 34 arranged independently of the operating lever 33. When detection signals from the operation detector 36 and the rotation hold switch 34 are simultaneously input to the controller 35, the lever operation signal is blocked and an alternative operation signal corresponding to the lever operation signal is provided to the rotation 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 rotation drive device 24 based on the alternative operation signal, thereby reducing the operating burden of the operating lever 33.

Furthermore, by emphasizing the independence of the rotation hold switch 34, simultaneous operation input from two locations can prevent unintentional transition to the rotation hold state due to erroneous operation, etc. On the other hand, after transitioning to the rotation hold state reflecting the operator's operating intention, the operation lever 33 can simply be left to elastically return to neutral, eliminating the need for lever operation for rotation drive, and making it possible to appropriately position the operation lever 33 in the driving position, allowing for stable driving operations that are not dependent on the operator's level of skill.

Furthermore, when the alternative operation signal is applied, the alternative operation signal is cut off based on the tilting of the operating lever 33 past the neutral position, so the stop operation from the rotation-holding state can be performed easily and quickly with a single main operation input, providing excellent safety. In addition, when both the lever operation signal and the alternative operation signal are cut off, 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, so even if the operating lever is tilted at the time of the stop operation, it can be smoothly returned to the initial state while ensuring safety.

In addition, because the lever operation signal is the lever operation pressure signal (pilot secondary pressure) of the hydraulic oil flowing through the pilot oil passage, it can be easily incorporated into existing hydraulic pilot operated operating devices as a new or retrofit, resulting in an operating device that is inexpensive, simple to control, and highly robust.

Furthermore, the interior space is divided into two widthwise spaces by a vertical plane S passing through the center of the driver's seat 28. The operating lever 33 is located in one space, and the rotation hold switch 34 is located in the other space. Because the shortest distance between the operating lever 33 and the rotation hold switch 34 is greater than the width W of the driver's seat 28, the rotation hold state is not easily entered. In other words, rotation hold operation against the operator's will can be restricted.

Furthermore, the operating lever 33 is configured for two-axis operation, with left-right tilting assigned to rotating the kelly drive 24 and forward-backward tilting assigned to raising and lowering the kelly drive 24. This allows for efficient input of operations during 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 during excavation with a single lever operated with one hand, and can easily be coordinated with rotation holding operation.

The present invention is not limited to the above-described exemplary embodiments, and the configuration and layout of the operating device can be modified as appropriate depending on the specifications of the driver's cab. Furthermore, while the embodiment uses a hydraulic pilot-operated operating lever, an electrically operated operating lever may also be used. In this case, the rotary drive control valve is electrically controlled by a controller, and the lever operation signal from a potentiometer acting as an operation detection unit can be input directly to the controller. Furthermore, the number of axes of the operating lever can be arbitrary. Additionally, while casing excavation (obstacle removal work) has been used as an example, the present invention is not limited to this and can be applied to other construction methods such as ground improvement.

11...Excavation machine, 12...Lower traveling body, 13...Upper rotating body, 14...Base machine, 15...Leader, 16...Drilling cylinder, 17...Leader support, 18...Pipe support member, 19...Driver'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 rotational drive, 25...Guide device, 26...Rack gear, 27...Guide pipe, 28...Driver's seat, 29...Left-hand side operation input unit, 30...Right-hand side operation input unit, 31...Ceiling position operation input unit, 32...Support position operation input unit, 33...Operation lever, 33a...Lever shaft, 33b...Coil spring, 3 4...Rotation hold switch, 35...Controller, 36...Operation detection unit, 36a...Forward pressure transmitter, 36b...Reverse pressure transmitter, 37...Rotation drive control valve, 38...Forward pilot oil line, 38a...Detection pilot oil line, 38b...Common pilot oil line, 38c...Intermediate pilot oil line, 39...Reverse pilot oil line, 39a...Detection pilot oil line, 39b...Common pilot oil line, 39c...Intermediate pilot oil line, 40...Remote control valve, 41...Solenoid control valve, 42...Forward oil line shutoff valve, 43...Reverse oil line shutoff valve, 44...Supplementary pilot oil line, 44a, 44b...Branch oil line, 45...Forward oil line switching valve, 46...Reverse oil line switching valve

Claims (4)

The excavator is equipped 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 cabin therein, a leader erected at the front of the upper rotating body, and a rotary drive device that can rise and fall along the leader,
an operating device that applies a lever operation signal to a rotary drive control valve of the rotary drive device based on tilting of an operating lever arranged in the driver's cab,
A controller;
an operation detection unit that detects tilting of the operation lever;
a rotation holding switch disposed in the driver's cab independently of the operation lever,
The operating lever is provided with an elastic member that returns the lever shaft from the tilted position to the neutral position,
when detection signals are simultaneously input from the operation detection unit and the rotation hold 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;
In a state where the alternative operation signal is applied, the alternative operation signal is cut off based on the tilting of the operating lever past the neutral position,
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 tilting of the operating lever past a neutral position. the lever operation signal is a lever operation pressure signal of hydraulic oil flowing through a pilot oil passage,
the pilot oil passage includes a remote control valve that changes the lever operation pressure signal in accordance with tilting of the operating lever, and an electromagnetic control valve provided downstream of the remote control valve,
the operation detection unit is a pressure transmitter that detects the lever operation pressure signal in the pilot oil passage between the remote control valve and the electromagnetic control valve,
The electromagnetic control valve comprises an oil passage shutoff valve that shuts off the flow of hydraulic oil from the remote control valve, and an oil passage switching valve that switches the oil passage by connecting a pilot oil passage downstream of the oil passage shutoff valve to an attached supply pilot oil passage,
when detection signals from the pressure transmitter and the rotation hold switch are simultaneously input, the controller controls the oil passage shutoff valve to shut off the flow of hydraulic oil, and controls the oil passage switching valve to introduce the hydraulic oil flowing through the supply pilot oil passage into the downstream pilot oil passage, thereby applying an alternative operating pressure signal corresponding to the lever operating pressure signal to the rotation drive control valve;
In a state where the alternative operating pressure signal is applied, the oil passage switching valve is controlled based on the tilting of the operating lever past the neutral position to cut off the alternative operating pressure signal,
2. The operating device according to claim 1, wherein, when the lever operating pressure signal and the alternative operating pressure signal are in a cut-off state, only the lever operating pressure signal is restored from the cut-off state based on tilting of the operating lever past the neutral position. The interior of the driver's cab is divided into two spaces in the left-right width direction by a vertical plane passing through the center of the driver's seat, and the operation lever is disposed in one space of the divided interior spaces, and the rotation holding switch is disposed in the other space,
3. The operating device according to claim 1, wherein the shortest distance between the operating lever and the rotation holding switch is greater than the left-right width of the driver's seat. An excavation machine equipped with the operating device described in claim 1 or 2.