JPH04130290U - Leveling device for aerial work vehicles - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] To perform accurate leveling control of a work platform in an aerial work vehicle, regardless of whether the boom is raised or lowered. [Configuration] Sensor 16 that detects the swing angular velocity of the workbench 6
, an arithmetic unit 41 that calculates the swing angle of the work platform by integrating the detected swing angular velocity, a gravity angle sensor 15 that detects the swing angle of the work platform with respect to the horizontal plane, and a raising/lowering operation of the boom 3, etc. It has a boom operation detection means 17 for detecting the presence or absence of the boom, a leveling cylinder 8 for the workbench 6, and a controller 40. When the boom operation detection means 17 detects the raising and lowering operation of the boom 3, the controller 40 controls the leveling cylinder 8 based on the swing angle of the work platform 6 calculated by the calculator 41. Boom operation detection means 1
7 detects that the boom 3 is stationary, the controller 40 resets the calculated value of the calculator 41 and adjusts the leveling cylinder 8 based on the swing angle of the work platform 6 detected by the gravity angle sensor 15. control.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a high-altitude work in which a workbench is attached to the tip of a boom that can be raised and lowered, expanded and contracted, etc. Regarding industrial vehicles, in more detail, this work platform must always be used regardless of whether the boom is raised or lowered. This invention relates to a leveling device that is held horizontally.

0002

[Conventional technology]

Conventional leveling devices detect the boom's heave angle, etc. Based on this, the operation of the leveling cylinder is controlled so that the workbench is level. equipment (for example, the equipment disclosed in Japanese Utility Model Publication No. 64-1352) or the slope of the workbench. It has a leveling detector and uses this detection signal to level the workbench. Controls the operation of the leveling valve and operates the leveling cylinder. There is a device (see, for example, Japanese Utility Model Application No. 61-78199).

0003

[Problem that the idea aims to solve]

When performing leveling control based on the boom angle, etc., the vehicle body is placed on a slope. If the vehicle is stationary, position the workbench so that it is parallel to this slope. Since leveling control is performed, there is a problem that correct leveling control cannot be performed. Ru. This problem can be avoided when using a leveling detector that detects the tilt of the workbench. do not have. However, leveling detectors use gravity to detect the inclination with respect to the horizontal plane. Therefore, when the boom is being hoisted, etc., Accurate leveling detection is difficult because the acceleration generated by the . Therefore, in this case, leveling control is inaccurate during boom hoisting operation. The problem is that it is easy to

0004 For this reason, the applicant uses a gyro etc. to detect the angular velocity of the workbench. At the same time, this angular velocity is integrated to calculate the swing angle of the workbench, and this calculated swing angle is We devised a method to control the leveling of the workbench based on the following. In this way, the block Accurately detects the swing angle of the workbench even when the workbench is in the process of raising and lowering, allowing for accurate leveling control. can be controlled. However, with this control, an error occurs in the calculation result of the swing angle of the workbench. This error is unavoidable and accumulates with each boom operation. For this reason, Even if this error is small, it accumulates with each boom operation and gradually There is a problem that the error becomes large and the leveling control becomes inaccurate.

[0005] This invention was developed in consideration of the above problems, and allows for accurate reading even when the boom is in operation. Work at heights with a configuration that allows belling to be carried out and does not cause problems with error accumulation. The purpose is to provide a car leveling device.

[0006]

[Means to solve the problem]

In order to achieve this purpose, the leveling device of the present invention is designed to control the swinging angular velocity of the workbench. An angular velocity detection sensor that detects the angular velocity detection sensor and a swing angle detected by this angular velocity detection sensor. A calculator that integrates the speed to calculate the swing angle of the workbench, and a calculator that uses gravity to calculate the water on the workbench. A gravity-type angle sensor that detects the swing angle with respect to a flat surface and whether or not the boom is raised or lowered. A boom operation detection means that detects the A controller that controls the operation of this leveling cylinder to control the swinging position of the workbench. controller.

[0007] The boom operation detection means indicates that the boom is being raised or lowered. When detected, the controller controls the workbench oscillation calculated by the calculator. Based on the movement angle, the leveling cylinder is controlled to keep the worktable level. control. On the other hand, the boom operation detection means detects that the boom is stationary. Sometimes, the controller resets the calculated value of the calculator to the reference value and The workbench is adjusted based on the swing angle of the workbench relative to the horizontal plane detected by the angle sensor. The operation of the leveling cylinder is controlled so that it is held horizontally.

[0008]

[Effect]

When leveling control is performed using the above leveling device, the raising and lowering operation of the boom, etc. If the oscillation angular velocity detected by the angular velocity detection sensor is integrated. Leveling control is performed based on the swing angle of the workbench determined by Angular velocity detection For example, the sensor is constructed using a gyro, and the detected value of this sensor is Since it is not affected by the acceleration associated with boom operation, boom raising and lowering operations etc. are not performed. Accurate leveling control is performed even when

[0009] On the other hand, when the boom is stationary, the movement detected by the gravity angle sensor Leveling control is performed based on the swing angle of the table with respect to the horizontal plane. This gravity type The angle sensor detects the swing angle with respect to the horizontal plane (absolute horizontal plane). Accurate leveling control is performed regardless of the slope of the Additionally, this control accelerates This is done when the boom is stationary and is not affected by gravity, and the detected value of the gravity angle sensor more accurate values can be detected. Note that when the boom is stationary, the swing angular velocity detected by the angular velocity detection sensor is integrated. The swing angle of the workbench determined by (value). Therefore, there may be an error in the swing angle calculated in this way. However, each time the boom operation is stopped, the calculation is reset and there is no error. Errors do not accumulate and leveling control during boom operation must be performed accurately. I can do it.

0010

【Example】

Hereinafter, preferred embodiments of the present invention will be described based on the drawings. Figure 1 shows an aerial work vehicle 1 equipped with a leveling device according to the present invention. An aerial work machine 2 is rotatably mounted on a vehicle body 1a of a vehicle 1. The aerial work machine 2 is A base 4 is rotatably attached to the vehicle body 1a, and a pin 5a is used to attach the base 4 to the base 4. A boom 3 is connected so that it can be lowered freely, and a pin 5b is attached to the tip of the boom 3 to swing it vertically. It has a workbench 6 which is movably connected. Note that the boom 3 is the first boom 3 a, and a second boom 3b that is extendable and retractable with respect to the first boom 3a, The base of the first boom 3a is connected to the base 4, and the workbench 6 is connected to the tip of the second boom 3b. Concatenated. A hoisting cylinder 7 is arranged between the first boom 3a and the base 4. By controlling the extension and contraction of the luffing cylinder 7, the boom 3 is centered around the pin 5a. It is possible to control the undulation angle.

[0011] A bracket 6a is integrally fixed to the workbench 6, and this bracket 6a is The work platform 6 is connected to the tip of the second boom 3b with a pin 5b. It is attached to the tip so that it can swing freely. The work platform 6 and the second boom 3b are leveled. Both ends of the cylinder 8 are pivotally connected, and the workbench 6 can be raised by expanding and contracting the leveling cylinder 8. It can be swung downwards. The workbench 6 uses gravity to detect the inclination of the workbench 6 with respect to the absolute horizontal plane. An angle that detects the swing angular velocity of the workbench 6 using a gravity angle sensor 15 and a gyro. A speed sensor 16 is attached. Detected by gravity angle sensor 15 The swing angle of the workbench 6 or the swing angular velocity detected by the angular velocity sensor 16 is The workbench 6 is held horizontally based on the swing angle of the workbench 6 determined by integration. The operation of the leveling cylinder 8 is controlled as follows. Note that this specific operating system Details will be explained later.

0012 The raising and lowering operation of the boom 3 is performed using an operating device provided on the vehicle body 1a side or on the workbench 6. This can be done by operating the up/down operation lever 21 (see Fig. 2) on the operating device provided in the be exposed. The base connection part of the boom 3 detects the up-and-down operation of the boom 3 and connects the boom 3 with the Boom operation detection sensor that detects whether the boom is activated or stationary. A sensor 17 is attached. In addition, in this example, the presence or absence of operation of the boom 3 is determined by directly detecting the raising and lowering operation of the boom 3. However, instead of this, the presence or absence of the operation of the luffing operation lever 21 is detected and the boot is activated. Alternatively, the presence or absence of operation of the system 3 may be detected.

[0013] Regarding the leveling control of the work platform 6 in the aerial work vehicle 1 configured in this way. This will be explained using FIG. In FIG. 2, the aerial work equipment 2 is schematically shown, and the hoisting operation of the boom 3 is shown schematically. The operation of the undulation cylinder 7 to be operated is controlled by the undulation control valve 60. Na Oh, this undulation operation corresponds to operating the undulation operation lever 21 of the operating device 20. It is something that is done. For this reason, the elevation operation lever 21 has its operating direction and A undulating operation detector 22 is attached to detect the amount. The actuation control signal detected by 2 is sent to the controller 40 via line 20a. It will be done. Based on this actuation control signal, the controller 40 operates via line 40b. and sends an activation signal to the left and right solenoids 60a, 60b of the elevation control valve 60. Controls the operation of the undulation control valve 60. Specifically, the left solenoid 60a is excited to cause the hydraulic fluid from the hydraulic source OP to rise and fall. The oil is supplied into the bottom side oil chamber 7a of the cylinder 7, and the luffing cylinder 7 is extended to create a boom. 3 or energize the right solenoid 60b to supply hydraulic fluid from the hydraulic source OP. The oil is supplied into the rod-side oil chamber 7b of the hoisting cylinder 7, and the luffing cylinder 7 is contracted to control such as laying down the arm 3.

[0014] The work platform 6 tilts in response to the raising and lowering of the boom 3, so it is necessary to keep it horizontal. Therefore, the operation of the leveling cylinder 8 is controlled by the leveling valve 50. Ru. The operation of this leveling valve 50 is controlled via the line 40a. For excitation control of the left and right solenoids 50a and 50b by control signals sent from the controller 40. It is done more. Specifically, the left solenoid 50a is energized to level the hydraulic oil from the hydraulic source OP. Supply into the bottom side oil chamber 8a of the ring cylinder 8, and extend the leveling cylinder 8. to swing the workbench 6 upward (in the direction of arrow A), or to turn the right solenoid 50b. Excite the hydraulic oil from the hydraulic source OP to the rod side oil chamber 8b of the leveling cylinder 8. The leveling cylinder 8 is contracted and the workbench 6 is moved downward (in the direction of arrow B). ).

[0015] Such rocking control of the work platform 6 is performed by controlling the work platform 6 according to the raising and lowering operations of the boom 3, etc. This is done to keep it horizontal if it is tilted from the horizontal position. Regarding this control This will be explained using FIG. 3 as well. This control is to hold the workbench 6 in a horizontal position, so first, the workbench 6 is It is necessary to accurately detect the swing angle. For this reason, the workbench 6 is equipped with a gravity angle sensor. A sensor 15 and an angular velocity sensor 16 are provided. Detection of both these sensors 15 and 16 The output signals are sent to controller 40 via lines 15a, 16a. In addition, This is because the detected value of the gravity angle sensor 15 indicates the swing angle with respect to the horizontal plane. It can be used as is for leveling control. However, the detection of the angular velocity sensor 16 Since the value indicates the swinging angular velocity of the workbench 6, the detection signal of the angular velocity sensor 16 is sent to the arithmetic unit 41 in the controller 40, and is integrated by this arithmetic unit 41. The swing angle of the workbench 6 is calculated.

[0016] As described above, the swing angle of the workbench 6 can be determined from the detection values of the two sensors 15 and 16. However, in this leveling control, the fluctuations obtained from both sensors 15 and 16 are The moving angle is controlled depending on the operating state of the boom 3. This angel In order to perform the separation, the detection from the boom operation detection means 17 is performed via the line 17a. The signal is input to the input switching/resetting means 42 of the controller 40. This input switching/resetting means 42 receives the swing angle signal from the calculator 41 and the gravity A swing angle signal from the type angle sensor 15 is also input, and the boom operation detection means 17 The control section 43 selects either one of the two swing angle signals according to the detection signal from the control section 43. send to

[0017] This selection will be specifically explained. First, the detection signal of the boom operation detection means 17 indicates that the boom 3 is in the raising/lowering operation. , the swing angle signal from the calculator 41 is selected and this signal is controlled. Send it to section 43. When the boom 3 is raised and lowered, the work platform 6 is swung accordingly. However, this swing angular velocity is detected by the angular velocity sensor 16 using a gyro. At the same time, this detection signal is integrated by the calculator 41 to determine the swing angle of the workbench 6. is required. In this way, the angular velocity sensor 16 detects the rocking of the workbench 6. Therefore, the accurate swing angle can be calculated when the boom 3 is being operated to raise and lower. The signal from the arithmetic unit 41 is selected. Note that when the boom 3 is operated, this occurs in the case of the gravity angle sensor 15. Accurate angle detection becomes difficult due to the influence of acceleration associated with the operation of boom 3. , at this time, the detection signal of the gravity angle sensor 15 is not used.

[0018] Next, the detection signal of the boom operation detection means 17 indicates that the boom 3 is stationary. When the oscillation angle signal from the gravity angle sensor 15 is selected, contrary to the above, and sends this signal to the control section 43. When boom 3 is stationary, gravity type Since the angle sensor 15 can detect the accurate swing angle of the workbench 6 with respect to the horizontal plane, this select the correct signal.

[0019] In this case, the signal from the calculator 41 is The swing angle of the work platform 6 is detected when the boom 3 is stopped. 41 and the swing angle detected by the gravity angle sensor 15. should theoretically match. However, the detection of the angular velocity detection sensor 16 Due to the influence of errors, etc., a certain amount of error occurs in the swing angle calculated by the calculator 41. is inevitable. Therefore, in the input switching/resetting means 42, the boom operation detecting means 17 When the detection signal indicates that the boom 3 is stationary, the calculator 41 In addition to not using the swing angle signals from the (a value corresponding to the horizontal position of the table 6). By resetting in this way, the calculation result will be updated every time the boom 3 stops operating. Since the error of The calculation (integration) of the swing angle in step 6 will start from the reset reference value. , the accumulation of errors is prevented.

[0020] As described above, the selection is made in accordance with whether or not the boom 3 is activated, and the control unit 43 When the swing angle signal is sent, the control unit 43 performs the following based on the swing angle signal. The operating direction and direction of the leveling cylinder 8 necessary to hold the workbench 6 horizontally. The leveling valve 50 sends an operating signal to perform such operating control. Output to. The leveling valve 50 is actuated in response to this actuation signal, and the leveling valve 50 is A swing control system that controls the expansion and contraction of the cylinder 8 to maintain the workbench 6 horizontally. control (leveling control) is performed.

[0021]

[Effect of the idea]

As explained above, according to the present invention, when the boom is being hoisted, etc. In this case, the operation determined by integrating the swing angular velocity detected by the angular velocity sensor Leveling control is performed based on the swing angle of the platform, and when the boom is stationary is based on the swing angle of the worktable relative to the horizontal plane detected by the gravity angle sensor. leveling control is performed. Here, the angular velocity detection sensor is configured using a gyro, for example. The detected value of this sensor is not affected by the acceleration associated with boom operation, so the value detected by this sensor is Accurate level can be obtained by using the detection value of the angular velocity sensor when undulating operations are being performed. Ring control can be performed. In addition, the gravity angle sensor detects the swing angle with respect to the horizontal plane (absolute horizontal plane). Therefore, when the boom is stationary and is not affected by acceleration, the detected value of this gravity angle sensor is By using It is possible.

[0022] Furthermore, in this invention, when the boom is stationary, the angular velocity detection sensor The swing angle of the workbench obtained by integrating the detected swinging angular velocity is the reference value (when the workbench is The boot is reset to the value corresponding to the horizontal swing angle. Even if there is an error in the swing angle calculated during boom operation, the Calculation errors are accumulated because the calculation results are reset and the errors are canceled. This ensures accurate leveling control even when the boom is operated next time. be able to.

[Brief explanation of drawings]

FIG. 1 is a front view showing an aerial work vehicle equipped with a leveling device according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a leveling device according to the present invention.

FIG. 3 is a control block diagram showing control details of the leveling device according to the present invention.

[Explanation of symbols]

1 Aerial work vehicle 3 Boom 6 Workbench 7 Lifting cylinder 8 Leveling cylinder 15 Gravity angle sensor 16 Angular velocity detection sensor 17 Boom operation detection means 21 Lifting operation lever 40 controller 50 Leveling valve 60 Elevation control valve

Claims (1)

[Scope of utility model registration request] Claim 1: An aerial work vehicle in which a work platform is attached to the tip of a boom that can freely raise and lower, expand and contract, etc. so as to be able to swing up and down, and the work platform is always kept horizontal regardless of the raising and lowering operation of the boom. A leveling device for holding,
an angular velocity detection sensor that detects the oscillating angular velocity of the workbench; an arithmetic unit that integrates the angular angular velocity detected by the angular velocity detection sensor to calculate the oscillation angle of the workbench; A gravity-type angle sensor that detects the swing angle of the workbench with respect to a horizontal plane; a boom operation detection means that detects whether the boom is in the up-and-down operation; a leveling cylinder that swings the workbench up and down; and the leveling cylinder. a controller for controlling the swinging position of the work platform by controlling the operation of the workbench, and the controller detects that the boom is being raised or lowered by the boom operation detection means. Sometimes, the operation of the leveling cylinder is controlled to hold the workbench horizontally based on the swing angle of the workbench calculated by the calculator, and the boom is stopped by the boom operation detection means. If it is detected that the workbench is on the horizontal plane, the calculated value of the calculator is reset to the reference value, and the workbench is horizontally adjusted based on the swing angle of the workbench with respect to the horizontal plane detected by the gravity angle sensor. A leveling device for an elevated work vehicle, characterized in that the leveling cylinder is controlled to maintain the leveling cylinder.