Operation sensing system for construction machine

Abstract

To provide an operation sensing system for a construction machine using a joystick.SOLUTION: An operation sensing system for a construction machine includes a driving device (8) operated by an output from a power means (31), a joystick (28) for operating the power means (31), and a control device (33) for controlling the power means (31) based on an operation command signal transmitted according to an inclination operation of the joystick (28), wherein the joystick (28) is provided with a stimulation device (45,46,47) for stimulating a hand of an operator gripping a grip portion of the joystick, and the control device (33) controls the stimulation device (47) based on the operation command signal.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an operation sensing system for a construction machine that uses a joystick as an operation means. [Background technology]

[0002] Some construction machinery employs a joystick as an operating means for the operator. The joystick in Patent Document 1 listed below has a lever angle sensor that detects the operation angle, and a controller controls an electromagnetic pilot valve based on the detected value of the lever angle sensor and the detected value of the vehicle frame angle sensor. The electromagnetic pilot valve adjusts the pilot oil pressure supplied to the hydraulic valve, and the hydraulic valve adjusts the flow rate of hydraulic oil supplied to the steering cylinder according to the input pilot oil pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-154960 Summary of the Invention [Problem to be solved by the invention]

[0004] The driver's seat of a construction machine is equipped with an armrest, and the operator places his or her elbow on it to stabilize his or her arm and moves the wrist to operate the joystick. The operator operates the joystick intuitively, keeping their eyes forward without looking at their hands. However, joystick operation involves transmitting the detection value of a lever angle sensor, for example, as an operation command signal to the control device, and there is no resistance associated with the operation, making it difficult for the operator to grasp the operating status of the drive device being operated.

[0005] Therefore, when operating construction machinery with a joystick, the operator must acquire a certain degree of wrist sensation that corresponds to the operating status of the drive unit. Also, when the drive unit requires switching operations, switching lamps or other devices have been installed to indicate gradual changes, but this requires the operator to shift their gaze to check while operating, which makes it difficult for the operator to concentrate on the operation. Therefore, the operator must acquire a certain degree of operational sensation for these switching operations as well.

[0006] SUMMARY OF THE INVENTION In order to solve this problem, an object of the present invention is to provide an operation sensing system for a construction machine that uses a joystick. [Means for solving the problem]

[0007] The operation sensing system for a construction machine of the present invention is a construction machine having a drive unit operated by output from a power means, a joystick for operating the power means, and a control unit that controls the power means based on an operation command signal sent in response to tilting of the joystick, wherein the joystick is provided with a stimulation device for providing a stimulus to the operator's hand holding its grip, and the control unit controls the stimulation device based on the operation command signal. [Effects of the Invention]

[0008] According to the above configuration, when the operator tilts the joystick, the control device controls the power means based on an operation command signal transmitted in response to the tilt, and the drive device operates according to the output from the power means. During such a joystick tilt operation, the control device controls the stimulating device based on the operation command signal to stimulate the hand of the operator gripping the gripping portion. Therefore, the operator operating the joystick can easily grasp the operating status by feeling a stimulus in the gripping hand in response to the tilt operation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing one embodiment of a pile driver. [Figure 2] This is a view showing the inside of the operator's cab from the right side of the pile driver body. [Figure 3] FIG. 2 is a plan view showing the interior of the driver's cab of the pile driver. [Figure 4] FIG. 2 is a circuit diagram constituting an operation sensing system in a pile driver. [Figure 5] FIG. 2 is a simplified diagram illustrating a joystick that constitutes the operation sensing system. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the operation sensing system for a construction machine according to the present invention will be described below with reference to the drawings. In this embodiment, a pile driver will be described as an example of a construction machine. FIG. 1 is a side view of the pile driver. The pile driver 1 is a construction machine capable of performing tasks such as steel pipe pile installation and ground improvement work, and is configured as a base machine in which an upper rotating body 5 is rotatably mounted on a lower traveling body 3 equipped with crawlers 11. A collapsible leader 6 is attached to the upper rotating body 5, and as shown in the drawing, a driving device such as an auger can be attached in an upright position.

[0011] The leader 6 has its lower rear bracket journaled on a leader support 12 fixed to the front of the upper rotating body 5, and is supported by a hydraulically operated hoisting cylinder 13 connected between it and the upper rotating body 5. The leader 6 is made up of multiple leader members each having a rectangular cylindrical cross section, with flanges formed on both ends of each leader member overlapping and fastened together with bolts and nuts. In this embodiment, an auger 8, an example of a drive device, is attached to the leader 6 so that it can be raised and lowered by a rack and pinion lifting mechanism.

[0012] A pair of left and right guide pipes 14 are formed along the entire length on the front side of the erected leader 6, with a rack gear fixed between them along the same entire length. Meanwhile, a pair of left and right guide gibs 15 are attached to the auger 8 so that they slide against the guide pipes 14, and the pinion gear meshed with the rack gear is rotated by an elevation motor (hydraulic motor) 16, allowing the leader 6 to move up and down. An anti-vibration device 9 is attached to the bottom of the erected leader 6 so that it protrudes forward, in order to prevent the casing, which is rotated and pressed into the ground by the auger 8, from vibrating during construction.

[0013] The upper rotating body 5 of the pile driver 1 is provided with jacks 17 at four locations (front, rear, left and right), and a counterweight is mounted at the rear end to maintain balance. The upper rotating body 5 is also provided with a cab 18 where the operator sits. Since the leader 6 is located in the center of the machine's width, the cab 18 is located on the right side of the upper rotating body 5 to avoid it. Furthermore, on the left side, opposite the cab 18, a power unit (engine power unit) that generates hydraulic pressure is mounted.

[0014] Next, Fig. 2 is a view from the right side of the machine body showing the inside of the cab where the operator operates the pile driver, and Fig. 3 is a plan view of the same cab. The cab 18 is provided with various operating means so that operator A sitting in seat 21 can operate it with both hands. A monitor 23 is also placed in the front at eye level with operator A. The operating means include, for example, two travel operation levers 25 placed on the left and right in front of the seat 21, which can rotate the left and right crawlers 11, thereby enabling the pile driver 1 to travel straight ahead or turn.

[0015] To the left of seat 21 is a joystick 27 as an operating means, which allows for operation of the rotation of upper rotating body 5 and the raising and lowering of auger 8. To the right of seat 21 is a joystick 28, which allows for operation of the rotation of the winch that winds and unwinds the wire rope, as well as the forward and reverse rotation of auger 8. Joysticks 27 and 28 operate the target drive device by tilting the lever, and the operating state can be fixed according to the tilt.

[0016] The auger 8, which is the object of operation of the joystick 28, is equipped with a rotary motor 31 as a power source, and its rotation is output via a reducer. The rotary motor 31 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 is controlled by the control pressure output from an electromagnetic proportional pressure reducing valve 32 shown in Figure 4, which adjusts the displacement, or the amount of discharge per rotation of the rotary motor 31. Note that, for a constant flow rate, the smaller the displacement of the rotary motor 31, the faster the motor rotates, and the larger the displacement, the slower the rotation speed and the greater the torque generated.

[0017] 4 is a circuit diagram constituting the operation sensing system in the pile driver 1. A main hydraulic pump 35 is mounted on the upper rotating body 5 of the pile driver 1, and is connected to the rotation motor 31 via a hydraulic hose 36. A pilot hydraulic pump 39 is also mounted on the pile driver 1, and a hydraulic hose 38 is connected to it via an electromagnetic proportional pressure reducing valve 32 so that a control pressure acts on the rotation motor 31. Furthermore, hydraulic sensors 41 and 42 are connected to the hydraulic hoses 36 and 38, respectively, and detection signals related to the hydraulic pressure are sent to the control device 33.

[0018] The rotation of the auger 8 is controlled by the operator A by tilting the joystick 28. That is, the joystick 28 is provided with a lever angle sensor, and the detected value is sent to the control device 33 as an operation command signal. Then, the control command sent from the control device 33 continuously controls the secondary pressure of the electromagnetic proportional pressure reducing valve 32 and adjusts the displacement of the rotation motor 31. When burying a steel pipe pile with the pile driver 1, tilting the joystick 28 outputs rotation by the auger 8, and simultaneously performs a lowering operation, thereby pressing the steel pipe pile connected to the drive shaft 29 into the ground.

[0019] Operator A's rotation of the auger 8 is controlled by adjusting the torque volume in accordance with the excavation resistance. Specifically, at the start of excavation, the rotation speed is increased to reduce the torque, and as the work progresses and the excavation resistance increases as the depth approaches the target, adjustments are made to gradually increase the torque in accordance with the decrease in the rotation speed of the auger 8. In other words, operator A increases the tilt of the joystick 28 and increases the displacement of the rotation motor 31, thereby outputting a large torque.

[0020] Incidentally, the rotation of the auger 8 is performed by changing the rotation speed in stages. However, the displacement of the rotation motor 31 changes continuously. Therefore, for example, when the first stage of operation is completed, the rotation speed can be fixed by pressing the set button, and when switching to the second stage, the joystick 28 is tilted to a considerable angle. However, previous joysticks did not have any operational resistance that would allow operator A to know when the stage had been switched, so the only way to determine whether the switch had been made was to check whether a lamp had illuminated. As a result, operator A sometimes overlooked the illumination of the lamp and was unable to operate the rotation motor 31 accurately.

[0021] In this regard, the pile driver 1 of this embodiment is provided with an operation sensing system that enables the operator A operating the joystick 28 to intuitively understand the change in the stages. As shown in Figure 4, the operation sensing system has an air hose 46 extending from a compressor 45 mounted on the pile driver 1 and connected to the joystick 28. An electromagnetic on-off valve 47 is connected to the air hose 46, and opening and closing control is performed by a control command from the control device 33. In other words, the supply and blocking of air sent from the compressor 45 to the joystick 28 can be switched on and off.

[0022] 5 is a simplified diagram of a joystick constituting the operation sensing system. Joystick 28 has a gripping cover 281 covering the gripping portion that operator A holds in his / her hand, and air supplied from air hose 46 is sent into the interior of the gripping cover. In addition, gripping cover 281 has an ejection hole 283 formed at a position where operator A's hand holding joystick 28 overlaps, and the sent air is ejected. Therefore, the operation sensing system of this embodiment is configured as a stimulation device that ejects air into the hand of operator A holding joystick 28.

[0023] The air is sprayed by controlling the electromagnetic on-off valve 47 in accordance with the tilt of the joystick 28. In this embodiment, an operation sensing process is executed to provide operator A with a spray of air in response to a tilt set as stepwise switching control for the rotation motor 31. Here, a case will be described in which the tilt of the joystick 28 is set to two stages. That is, one stage and two stages of rotation speed are set for the rotation motor 31. Conventionally, a lamp is provided for each stage, and operator A completes the operation by visually confirming that the lamp is lit. On the other hand, in this embodiment, the spray of air is transmitted to operator A as a switching signal.

[0024] In the operation detection process of the control device 33, a detection signal (operation command signal) is received from a lever angle sensor that detects the tilt of the joystick 28, and the opening and closing of the electromagnetic on-off valve 47 is controlled according to the tilt angle. For example, when the joystick 28 reaches a tilt corresponding to one stage, the electromagnetic on-off valve 47 is switched from a closed state to an open state for a certain period of time, and air supplied from the compressor 45 is sprayed from the spray hole 283. Because the air is sprayed toward the hand holding the joystick 28, operator A knows that one stage of operation has been completed, and can fix the rotation speed of the rotation motor 31 by pressing the set button. After the rotation speed is fixed, the rotation speed is maintained and the pile driving operation is carried out even if operator A releases his / her hand from the joystick 28.

[0025] When the joystick 28 is released, it returns to its original upright position. To switch the rotation speed of the rotation motor 31 between two levels, operator A tilts the joystick 28 again. When the joystick 28 exceeds the previously set tilt of the first level, the rotation speed is released, and tilting the joystick further causes the rotation speed of the rotation motor 31 to gradually change. When the joystick 28 reaches the tilt corresponding to the second level, the electromagnetic on-off valve 47 switches from a closed state to an open state for a certain period of time, and air supplied from the compressor 45 is sprayed from the nozzle 283. The air is sprayed into the hand holding the joystick 28, allowing operator A to know that the second-level operation has been completed. The rotation speed of the rotation motor 31 can be fixed again by pressing the set button.

[0026] Thus, with the pile driver 1 equipped with the operation sensing system, even if the joystick 28 is an operating means that makes it difficult to grasp the operating status, the operator can accurately grasp the operating status by feeling the stimulation of the sprayed air in the operating hand. Moreover, unlike lamps, the operator does not have to move his or her eyes while operating, so the operating status can be accurately grasped even while looking at the work area. Furthermore, the air-based stimulation device can use the compressor 45 already installed in the pile driver 1, and the above effect can be achieved with a simple modification, such as connecting an air circuit equipped with an electromagnetic shut-off valve 47 to the joystick 28.

[0027] In the above embodiment, air is simply sprayed to notify the switching angle of the joystick 28, but the air spray pattern may be changed to improve operability. For example, the electromagnetic on-off valve 47 may be repeatedly turned on and off before the tilt of the joystick 28 reaches the set angle, and the interval between on and off may be shortened as the set angle is approached. Also, in the above embodiment, the switching angle is notified to the operator A by spraying air, but as a modified example of the stimulation device, for example, the shape of a part of the grip cover 281 may be changed so that the area where the fingertip comes into contact is inflated with air.

[0028] The stimulation device of the operation sensing system may not only use air, but also be one that applies electrical stimulation to the fingertips of operator A holding joystick 28. This stimulation device, for example, applies a weak electric current to stimulate by electric shock, similar to a commercially available low-frequency therapy device. Operator A operates joystick 28 with the electrical stimulation means in contact with his fingertips, and receives an electric shock when the joystick reaches one or two tilt levels. Operator A knows that the operation is complete by the electric shock stimulation, and can fix the rotation speed of rotation motor 31 by pressing the set button. To improve operability, the electric shock stimulation may also be varied in various patterns.

[0029] Furthermore, the stimulation device of the operation sensing system may be not only air or electricity, but also impact. For example, the stimulation device may incorporate an iron rod as an impact transmission rod inside the joystick 28, and the plunger of the solenoid may be brought into contact with the impact transmission rod. This impact device is configured such that the solenoid is attached to the impact transmission rod extending out from the joystick 28, since there is no space inside the joystick 28 to incorporate a solenoid.

[0030] By operating the joystick 28 containing the impact transmission rod, operator A receives a vibration from the plunger striking the impact transmission rod when the rod reaches a tilt corresponding to one or two stages. Operator A is informed by the vibration stimulus that the operation is complete, and can fix the rotation speed of the rotation motor 31 by pressing the set button. To improve operability, the vibration stimulus may also be varied in various patterns.

[0031] Although one embodiment of the present invention has been described above, the present invention is not limited to this and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiment, a pile driver is used as an example of construction machinery, and the auger 8 is used as an example of a drive device, but other construction machinery and drive devices may also be used. [Explanation of symbols]

[0032] 1...Pile driver 3...Lower traveling body 5...Upper rotating body 6...Leader 8...Auger 18...Operator's cab 28...Joystick 31...Rotation motor 33...Control device 35...Main hydraulic pump 39...Pilot hydraulic pump 45...Compressor 47...Electromagnetic opening / closing valve 281...Gripping cover 283...Injection hole

Claims

1. a drive device operated by output from the power means; a joystick for operating the power means; a control device that controls the power means based on an operation command signal transmitted in response to a tilt operation of the joystick; A construction machine having The joystick is provided with a stimulation device for applying a stimulus to the hand of the operator holding the grip portion, and the control device controls the stimulation device based on the operation command signal.

2. 2. A construction machinery operation sensing system as described in claim 1, wherein the drive device performs a stepwise switching operation of the power means using the joystick, and the control device controls the stimulation device based on an operation command signal corresponding to the tilt of the joystick, which is the switching operation.

3. the drive device is an auger using a drive motor as the power means to output rotation, and the construction machine is a pile driver that controls the rotation speed of the drive motor for the mounted auger by operating the joystick, 3. The operation sensing system for a construction machine according to claim 2, wherein the control device controls the stimulating device based on the operation command signal corresponding to stepwise switching of the rotation speed.

4. 4. An operation sensing system for a construction machine according to any one of claims 1 to 3, wherein the stimulation device comprises a gripping cover having an injection hole formed therein that covers the gripping portion of the joystick, and an air hose connected from a compressor mounted on the construction machine to the inside of the gripping cover is provided with an electromagnetic valve controlled by the control device.

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