Construction machinery

Abstract

To provide construction machinery with improved safety features. [Solution] A construction machine comprising: a drive unit that performs a predetermined movement by operating a plurality of actuators; a control device that transmits a control command signal to the engine and a control command signal to each solenoid valve for operating the plurality of actuators; and a plurality of operating devices that transmit an operating signal to the control device for operating the drive unit, wherein the control device is equipped with an operation start unit that, at the start of operation in any of the plurality of operating devices, restricts the control of the engine and the actuators based on an operating signal transmitted by a predetermined operating means in the selected operating device (S106, S107).

Description

Technical Field

[0001] The present invention relates to a construction machine in which operations by operation devices are collectively managed by a control device, the construction machine executing predetermined control at the start of operation.

Background Art

[0002] For construction machines, appropriate measures must be taken when an abnormality occurs. For example, the following Patent Document 1 discloses a conventional example regarding a case where a failure occurs in an accelerator volume or the like. That construction machine is provided with an engine control unit (ECU) that calculates a target engine speed based on a voltage signal from the accelerator volume and controls the engine speed. When any failure occurs in the accelerator volume itself or the wiring between the accelerator volume and the ECU, an arbitrary engine speed can be input and set by pressing a function button to switch a display device to an "engine speed setting screen". In the ECU, control of the engine speed for the engine is performed based on the engine speed command value input on the "engine speed setting screen" of the display device, with priority over the voltage signal from the accelerator volume.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As mentioned earlier, construction machinery is equipped with mechanisms to deal with malfunctions, but caution is necessary when restarting operation afterward, as sudden movements can occur. This is because some construction machinery controls can cause the machine to stop while maintaining its operating position. This caution applies not only when restarting operation after a malfunction, but also when starting operation after a certain period of time has passed or even across days since the construction machinery was properly stopped. Furthermore, the same precautions apply when operators take turns starting the machine.

[0005] Therefore, the present invention aims to provide construction machinery with improved safety in order to solve these problems. [Means for solving the problem]

[0006] The construction machine according to the present invention comprises a drive unit that performs a predetermined movement by operating a plurality of actuators, a control device that transmits control command signals to an engine and control command signals to each solenoid valve for operating the plurality of actuators, and a plurality of operating devices that transmit operation signals to the control device for operating the drive unit, wherein the control device includes an operation start unit that, at the start of operation in any of the plurality of operating devices, limits the control of the engine and the actuators based on an operation signal transmitted by a predetermined operating means in the selected operating device. [Effects of the Invention]

[0007] According to the above configuration, the construction machine has multiple operating devices that can be operated wirelessly or via a wired connection, and the control device controls the engine and actuators based on the operation signals transmitted from the selected operating device, thereby enabling the operation of predetermined movements of the construction machine. When the operator starts operation using the selected operating device, the control device can restrict the control of the engine and actuators if there is an operation signal transmitted as a predetermined operating means according to the operation start unit stored in the control device, thereby preventing the drive unit from suddenly starting to move without the operator's awareness. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing a pile driver as one embodiment of construction machinery. [Figure 2] This is a simplified diagram illustrating the control system of construction machinery. [Figure 3] This is a diagram showing a remote control operating device. [Figure 4] This is a flowchart illustrating the process of the operation start program. [Modes for carrying out the invention]

[0009] An embodiment of the construction machine according to the present invention will be described below with reference to the drawings. Figure 1 is a perspective view showing a pile driver with an auger device assembled as an example of a construction machine. In this embodiment, the pile driver 1 has a base machine 2, in which an upper rotating body 12 equipped with a driver's cab 15 is rotatably mounted on a lower traveling body 11 that can be traveled by crawlers. A leader 13 is swingably mounted in the center of the tip of the upper rotating body 12, and an auger device 3, which is a rotational output device, is attached to the leader 13. Furthermore, a lifting device 5 for strengthening the extraction of piles is attached to the auger device 3.

[0010] A leader support 21 is provided at the center of the tip of the upper rotating body 12, and a swing crank 25 is formed on the leader 13 so as to protrude to the rear. The leader 13 is configured to tilt in the front-rear direction, with the swing crank 25 pivotally supported by a support pin parallel to the width direction of the machine body relative to the leader support 21. The leader support 21 and the swing crank 25 are connected by a front-rear swing cylinder 26. Furthermore, the lower side of the leader support 21 is pivotally supported by a support shaft in the front-rear direction relative to the upper rotating body 12, and the leader 13 can swing in the left-right direction together with the swing crank 25 and the front-rear swing cylinder 26. A left-right swing cylinder 27 is pivotally attached to the leader support 21 between it and the upper rotating body 12.

[0011] In this embodiment, the pile driver 1 has an auger device 3 attached to a leader 13 that can swing in the forward / backward and left / right directions. The auger device 3 is a working device for imparting rotation to the gripped casing K. The auger device 3 is assembled vertically from a base frame 31, a chuck frame 32, and a work table 33, and through holes 34 are formed in each of them through which the casing K can pass. The base frame 31 is provided with four hydraulic motors 35 for the auger that rotate the casing K, and the rotational output is transmitted to a cone, which is a cylindrical gear member that passes through the casing K.

[0012] The chuck frame 32 has a wedge-shaped chuck that fits between the cone and the casing, mounted on a rotatable annular rotating body. The base frame 31 is provided with four chuck cylinders 36, which connect to the chuck frame 32. As a result, the chuck frame 32 moves up and down relative to the base frame 31 as the chuck cylinders 36 extend and retract, and as it moves down, multiple chucks are firmly inserted between the casing K and the cone. The gripped casing K is then rotated by the output of the auger hydraulic motor 35 transmitted through the cone.

[0013] The auger device 3 has a guide block fixed to the base frame 31 that is slidably attached to the rail section 23 of the leader 13. The leader 13 is equipped with a lifting cylinder 24 between the two rail sections 23, and is configured so that the auger device 3 descends when it is retracted and rises when it is extended. Furthermore, the pile driver 1 is configured so that an auger lifting device 5 can be attached to and detached from the underside of the auger device 3 in order to increase the pulling force of the casing K. The auger lifting device 5 has a horizontal jack 37 that is in contact with the ground, and the auger device 3 can be lifted by the extension of a thrust jack 38.

[0014] As mentioned above, the pile driver 1 uses actuators such as hydraulic cylinders including a lifting cylinder 24, a forward / backward oscillating cylinder 26, and a left / right oscillating cylinder 27, as well as hydraulic motors such as an auger hydraulic motor 35, and a hydraulic circuit incorporating solenoid valves for hydraulic control. While conventional construction machinery was configured to switch solenoid valves by operator operation using levers or pedals, the pile driver 1 of this embodiment has removed such operating means such as levers and pedals from inside the operator's cab 15, and is configured to be operated both inside and outside the cab using a handheld operating device.

[0015] The pile driver 1 has a dual control system that allows switching between wireless radio control and wired remote control. Figure 2 is a simplified diagram illustrating the control system of the pile driver 1. The pile driver 1's drive control is electronically controlled by a controller (control device) 51, and it is possible to drive, turn, and push out piles using a radio control device 52 (wireless operation device) and a remote control device 54 (wired operation device). The controller 51 is connected to a display 55 and several lamps 56 to show the operator the operating status, and several solenoid valves 58 that operate the engine 57 and various actuators are connected to the controller via a drive circuit (not shown).

[0016] The controller 51 is centered around a CPU that performs various calculations such as data processing and judgment, and is composed of a ROM that stores a drive control program for executing predetermined construction work, and a RAM that temporarily stores various data during processing. In the pile driver 1, the drive control can be centrally managed by the controller 51 by electronic control, and by having a dual operating system of radio control and remote control, remote operation by radio control is particularly possible. All operation signals from the radio control device 52 and the remote control device 54 are transmitted to the controller 51, and the controller 51 creates and transmits drive command signals to the engine 57 and solenoid valve 58, etc., and predetermined drive control is performed. In particular, the pile driver 1 of this embodiment has a program incorporated into the main drive control program to support safe operation by the operator.

[0017] The operator's cab 15 is equipped with a radio control device 52 and a remote control device 54. The radio control device 52 can communicate wirelessly with the receiver 511 of the controller 51, allowing operation from a seat in the operator's cab 15, as well as remote control of the pile driver 1 from a distance outside the operator's cab 15. The radio control device 52 is also equipped with a radio control slave unit 53, which is small and lightweight, allowing for operation of limited functions. On the other hand, the remote control device 54 is connected to the controller 51 via a cable 59, so its basic use is from inside the operator's cab 15. However, the cable 59 connected to the controller 51 is of a certain length, allowing the remote control device 54 to be pulled out from the operator's cab 15, making it possible to operate the pile driver 1 while monitoring its operation from the outside.

[0018] Figure 3 shows the remote control device 54. The remote control device 54 is equipped with several operating means such as operating switches and buttons, among which is a selector switch 61 that allows selection of the operating system mode. In other words, by switching the selector switch 61, control rights are given to either the radio control device 52 (including the radio control slave unit 53) or the remote control device 54, and the drive control of the pile driver 1 is possible only by operation from the corresponding operating device. The radio control device 52 is not shown in detail, but it is configured similarly except for the selector switch 61, and control rights are confirmed by pressing the confirm button on the radio control device 52 after the radio control mode is selected.

[0019] The remote control device 54 is equipped with multiple operating switches and buttons. For example, there are three travel levers 62 for operating the rotation, left travel, and right travel of the lower travel body 11, as well as an auger rotation switch 63, a pull-out / push-in switch 64, and a chuck opening / closing switch 65 for the auger device 3. In addition, there are jack extension / retraction switches 66 for each jack, as well as a rotation brake switch 67 and an engine stop button 68. Furthermore, the remote control device 54 is equipped with volume switches 71, 72, 73, 74, 75, and 76 for torque adjustment, speed adjustment, push-in speed, push-in force, pull-out force, and chuck force. There is also a volume switch 77 for adjusting the rotational speed of the engine 57, which is the power source.

[0020] In the pile driver 1 of the present embodiment, an operator operates the radio remote control operation device 52, the radio remote control handset 53 or the remote control operation device 54 to perform, for example, removal work of embedded concrete. In the pile driver 1, the traveling hydraulic motor is driven by the traveling operation of the lower traveling body 11, the auger device 3 is moved to a predetermined working position, and adjustments such as alignment with the driving position of the casing K are performed. Then, the inclination of the leader 13 is adjusted by extension and retraction control of the front-rear swing cylinder 26 and the left-right swing cylinder 27. In addition, the pile driver 1 performs extension and retraction control of the front jack 28 and the leader jack 29 located at the front, and the unillustrated outrigger jack located at the rear, and the weight mounted at the rear stabilizes the machine body during the removal work.

[0021] In the pile driver 1, the auger device 3 moves to the raised position in accordance with the extension control of the lifting cylinder 24, and in particular, the casing K is pushed in by the contraction operation. Further, in the auger device 3, rotation is applied to the gripped casing K by drive control of the auger hydraulic motor 35. Then, by applying a pushing force downward while applying rotation to the casing K, the cemented carbide bit at the tip cuts and advances in a circular shape through concrete and the like present in the ground. Such drive control for pushing and rotating the casing K is executed based on arithmetic processing according to the drive control program in the controller 51.

[0022] In the pushing of the casing K, arithmetic processing such as the rotation speed and pushing pressure of the casing K is performed in the controller 51 in accordance with an operation command signal transmitted from, for example, the remote control operation device 54, and drive control of the lifting cylinder 24 and the auger device 3 is performed. In the arithmetic processing, the values of the volume switches 71-76 of the remote control operation device 54 are converted, and torque adjustment, speed adjustment, or pushing speed, pushing force and the like are calculated. Then, a drive control signal for the drive circuit is output in accordance with the calculated value, and drive control for the actuator 58 and the like of each drive unit is performed.

[0023] Incidentally, the pile driver 1 may need to temporarily stop its drive during operation. One such instance is when an emergency stop button, such as one provided on the radio control device 52, is pressed by the operator. Furthermore, the pile driver 1 is equipped with various detection sensors on the base machine 2 and the auger device 3, etc., to monitor the operating status of each device. Therefore, if an excessive load is placed on the casing K during the pile pushing or pulling operation (hereinafter referred to as "pushing operation") performed by the auger device 3, an abnormality is determined when the detected value from the pressure sensor exceeds a threshold, and drive stop control is performed on the lifting cylinder 24 and the hydraulic motor 35 for the auger.

[0024] Furthermore, in radio-controlled mode operation using the radio control device 52, if wireless communication between the radio control device 52 and the receiver 511 is interrupted, or if communication between the receiver 511 and the controller 51 is interrupted, the system will recognize this as an abnormality and stop the drive of the pile driver 1. In addition, since the pile driver 1 has multiple control devices, the system will also stop temporarily when switching modes for each control device. For example, if the operation mode is switched from radio control mode to remote control mode during pile extraction, the system will stop the pile driver 1 at the time the control device is changed.

[0025] Therefore, the drive control program for properly operating the pile driver 1 incorporates a stop control program as a subroutine. This stop control program is executed when the controller 51 receives a stop signal, such as from an emergency stop button, as a stop trigger. Other stop triggers include flags set in the drive control program based on the determination of detected values ​​transmitted from various detection sensors, and flags based on the determination of wireless communication interruption. Furthermore, the mode transition signal transmitted from the selector switch 61 to the controller 51 as a switch in the operation mode also serves as a stop trigger for stop control.

[0026] For example, the stop control program during pile extraction operations performs drive stop control for the lifting cylinder 24 and the hydraulic motor 35 for the auger, and idle control that minimizes the rotational speed of the engine 57, regardless of the state of the operating means, such as whether the operating device switch is ON. The stop control program targets actuators for drive parts that are in motion, and depending on the work, it may also target thrust jacks 38, for example, not just the lifting cylinder 24, and controls are performed to return the solenoid valve 58 to neutral in order to stop each of them. In addition, although the rotational speed of the engine 57 is controlled by an engine control unit (ECU) (not shown), idle control is performed by sending a control command from the controller 51 to the ECU to minimize the rotational speed.

[0027] Next, we will explain the process of starting operation on the pile driver 1. Starting operation on the pile driver 1 includes not only resuming operation after it has been stopped by the stop control program as described above, but also starting operation after a certain period of time has elapsed since the engine 57 of the pile driver 1 was stopped (including cases where the operation spans across days). At the start of operation, it is important to note that the alternate-type switches and buttons on the radio control device 52, radio control slave unit 53, and remote control device 54, which are the operating devices of the pile driver 1, remain in the ON state. Furthermore, the volume value remains above a certain value. This is because the corresponding drive unit will suddenly start moving as soon as communication with the controller 51 becomes possible when starting operation.

[0028] For example, in the remote control device 54 shown in Figure 3, the auger rotation switch 63 and the pull-out / push-in switch 64 are composed of alternate-type lever switches (toggle switches). When the machine is forcibly stopped by the stop control program, the alternate-type lever switches may be left in the ON position. Therefore, as mentioned above, when the system transitions to remote control mode, if the controller 51 receives a signal indicating that the corresponding lever switch is ON and sends a control signal without applying any control, the lifting cylinder 24 and other components may start moving even if the operator is not aware of the operation. The same applies to the volume switch 77 of the engine 57, and depending on the adjustment position, the rotation speed may be high from the start. Therefore, the drive control program incorporates an operation start program as a subroutine.

[0029] Figure 4 is a flowchart showing the processing of the operation start program. The controller 51 identifies the operating device from which to acquire control rights from the radio control device 52, the radio control slave unit 53, and the remote control device 54 (S101). Here, we will explain assuming that the remote control device 54 has control rights. For the remote control device 54, first, the state of the alternate switch is checked (S102). This is because if the target auger rotation switch 63 or pull-out / push-in switch 64 is in the ON state, those targets will be driven simultaneously with the start of the operation.

[0030] If the controller 51 receives the appropriate operation signal from the selected remote control device 54 (S102: NO), it determines that the operation signal is an NG signal and does not perform drive control based on the operation of the remote control device 54 (S106). On the other hand, if the auger rotation switch 63 or the like that is subject to restriction is in the OFF state (S102: YES), it is then checked whether the volume value of the volume switch in question exceeds a preset threshold (S103). For example, if the volume value of the volume switch 77 of the engine 57 does not exceed the threshold (S103: YES), it permits drive control in response to the operation signal from the control device (S104), and an operation permission notification is given, such as the illumination of the operation permission light (S105).

[0031] On the other hand, if the volume value exceeds the threshold (S103: NO), limited drive control is performed with a limit of the value up to the threshold (for example, the rotation speed for idling) (S107). However, at this point, the operation permission light is not illuminated, and the remote control device 54 is not yet in a state where it can be operated. This is because, if NO is determined in step S103, not only the operation signals of the target auger rotation switch 63, but also the operation signals of other switches are similarly processed as NG. In other words, as in step S106, drive control by operating the remote control device 54 is not performed.

[0032] The operation start program is repeatedly executed within the main flow, and the decisions in steps S106 and S107 result in the pile driver 1 remaining in an unoperable state. The operator can understand the situation from the fact that the controls are unresponsive and the operation permission light is not illuminated, and will correct the state of the affected lever switches and volume switches (i.e., return all affected lever switches to their initial state, such as the neutral position, and set all affected volume switches below the threshold). As a result, the controller 51 switches to a drive control permission state in which the control restrictions of the various switches are released (S104), and operation permission is indicated by the illumination of the operation permission light (S105).

[0033] Therefore, in the pile driver 1 of this embodiment, even if operation is initiated using the remote control device 54 or the like, which is not in the OFF state, it is possible to avoid the drive unit suddenly starting to move without the operator's awareness. Even if the operator is unable to operate the pile driver 1 due to the operation start program's determination, they can easily return to an operable state by correcting the state of the operating means, such as turning the switch of the operating device OFF. Furthermore, when the controller 51 receives a stop trigger, regardless of the state of the operating means, it can perform a safe stopping process by stopping the drive to predetermined actuators such as the lifting cylinder 24 or by performing limit control of the engine 57.

[0034] Although one embodiment of the present invention has been described above, the present invention is not limited thereto, and various modifications are possible without departing from its spirit. For example, although the above embodiment described a pile driver 1 as an example, the construction machinery can also be applied to other construction machines such as obstacle removal machines and ground improvement machines, as well as cranes. Furthermore, although the processing of the operation start program was explained using the remote control device 54 as an example in the above embodiment, the same applies to the radio control device 52 and the radio control slave unit 53. [Explanation of symbols]

[0035] 1…Pile driver 2…Base machine 11…Lower vehicle 13…Leader 24…Lifting cylinder 24…Lifting cylinder 35…Auger hydraulic motor 52…Radio control device 53…Radio control sub-unit 54…Remote control device 57…Engine

Claims

1. A drive unit that performs a predetermined movement through the operation of multiple actuators, A control device that transmits control command signals to the engine and control command signals to each solenoid valve for operating the plurality of actuators, A plurality of operating devices that transmit operating signals to the control device for operating the drive unit, It has, The control device is a construction machine comprising an operation start unit that, at the start of operation in any of the plurality of operating devices, limits the control of the engine and the actuator based on an operation signal transmitted by a predetermined operating means in the selected operating device.

2. The construction machine according to claim 1, wherein the operation start unit of the control device restricts the control of the actuator when the operation is started while the operating means, which is an alternate lever switch, is in the ON state.

3. The construction machine according to claim 1, wherein the operation start unit of the control device limits the control of the engine based on the threshold when operation is started with respect to the engine while the operating means, which is a volume switch, is in a state where the volume value exceeds the threshold.

4. The construction machine according to any one of claims 1 to 3, wherein the operation start unit of the control device releases the control restriction by the selected operation device when the state of the operation means that transmits an operation signal at the start of operation is corrected.

5. The construction machine according to claim 4, wherein the operation start unit of the control device activates the operation permission notification means when the control restriction on the operation means is released.

6. The control device includes a stop control unit that controls the stopping of the drive to the target actuator in accordance with a predetermined stop trigger, and a stop control unit that controls the engine speed to the minimum. The construction machine according to claim 1, wherein the operation start unit, in the start of operation after stop control by the stop control unit, restricts control based on an operation signal transmitted by the operation means corresponding to the actuator that was the subject of stop control.

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