JP3558112B2 - Safety equipment for aerial work vehicles - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a safety device that prevents a work table from interfering with another member of a high-altitude work vehicle during leveling adjustment of the work table.
[0002]
[Prior art]
The aerial work vehicle is configured based on a truck, and has a boom that can be freely raised and lowered on a vehicle body and a work platform for a worker to be mounted at the end of the boom so as to swing freely. The work table is moved to a desired height by operating the boom, and the work on the work table is performed by a worker on the work table. Generally, such an aerial work platform has a leveling device that always keeps the work table horizontal so that the work can be performed stably. This leveling device is configured to include a leveling cylinder provided between a worktable and a boom tip, which expands and contracts in accordance with the operation of raising and lowering the boom, and swings the worktable in accordance with the operation of raising and lowering the boom. Hold the table horizontally.
[0003]
By the way, a compressive load or a tensile load acts on the leveling cylinder due to the own weight of the work table or the weight of the load on the work table, and hydraulic pressure is generated in the oil chamber and the pipe connected to the oil chamber. The workbench may be gradually inclined from the horizontal position due to, for example, changes in piping or the like over time. For this reason, aerial work vehicles are usually provided with a leveling adjustment device, which supplies hydraulic oil to the bottom-side oil chamber or rod-side oil chamber of the leveling cylinder to adjust the amount of extension of the leveling cylinder, and to adjust the inclination angle. The leveling adjustment (correction of the posture) can be performed by swinging the worktable in a direction in which the distance becomes smaller.
[0004]
[Problems to be solved by the invention]
However, for example, when the leveling adjustment is performed with the boom in the retracted state, that is, the state in which the boom is laid down to the maximum, if the working table is erroneously swung in a direction in which the inclination angle increases, the working table is There is a problem that it may interfere with other members in the aerial work vehicle.
[0005]
In particular, this interference problem occurs when a large work table is used such as a heavy-load aerial work vehicle. In the case of heavy-load aerial work platforms, a large workbench is attached to the top of the boom, which is attached to the top of the boom so that it can swing back and forth. The front end is located on the driving cabin. For this reason, in the boom storage state, the rear end side is close to the boom, and the front end side is close to the driving cabin. Interfering with the driving cabin.
[0006]
The present invention has been made in view of such a problem, and it is an object of the present invention to provide a safety device that can prevent interference between a workbench and other members in an aerial work platform during leveling adjustment. I have.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a safety device according to the present invention includes a boom mounted on a vehicle body so as to be able to move up and down, a post mounted on a tip of the boom so as to swing back and forth, and a work mounted on the post. The table, a leveling cylinder that swings the post, a leveling mechanism that operates the leveling cylinder in response to the up and down of the boom to swing the post, and that always holds the worktable horizontally, and the worktable is inclined from the horizontal. In a case where the leveling cylinder is operated by a manual operation and the leveling adjustment means for adjusting the crossing angle of the post with respect to the boom and leveling the workbench is used for an aerial work vehicle, A workbench state detecting means for detecting whether or not the angle is within the allowable intersection angle range, and a workbench state detecting means for performing leveling adjustment Composed of the difference angle is detected that falls outside the allowable crossing angle range and alarm means for performing an alarm operation. Note that the alarm operation includes not only an alarm operation by an alarm buzzer but also an alarm operation that regulates the swing motion of the worktable.
[0008]
According to such a configuration, when performing the leveling adjustment, if the crossing angle exceeds the allowable crossing angle range due to excessive swinging of the worktable, a warning operation is performed by the alarm means, so that the worktable and the aerial work platform are used. Can be prevented from interfering with other members.
[0009]
In the safety device of the present invention, for example, a boom is mounted extending from the rear end side of the vehicle body to the front end side, the vehicle body is configured based on a truck, has a driving cabin in the front part of the vehicle body, and the work table is in a retracted state. The post extends from the upper end of the post to the front and rear of the vehicle body, the rear end is located on the boom, the front end is located on the driving cabin, and when the post is swung in the direction of decreasing the intersection angle, the rear end is boom This is particularly suitable for aerial work vehicles that are configured such that the front end side approaches the driving cabin when the post is swung in a direction in which the intersection angle increases. In this case, interference is prevented by the alarm operation because of interference between the rear end of the worktable and the boom and interference between the front end of the worktable and the driving cabin.
[0010]
Further, the safety device of the present invention is provided with a boom storage detector that detects whether the boom is in the retracted state, and the workbench state detecting means determines whether the intersection angle is equal to or greater than the minimum allowable intersection angle. A minimum intersection angle detector for detecting whether or not the intersection angle is less than or equal to an allowable maximum intersection angle.
[0011]
The alarm means in the safety device of the present invention is configured such that when the boom storage detector detects that the boom is in the retracted state, it is allowed to perform leveling adjustment, and at the time of this leveling adjustment, or crossing angle by the minimum crossing angle detector is detected to be less than the allowable minimum angle of intersection, an alarm operation and it is detected larger than the allowable maximum angle of intersection crossing angle by the maximum crossing angle detector. Alternatively, the boom storage detector, boom when it is detected not in the storage state regulates the performing the leveling adjustment. Therefore, interference between the workbench and other members in the aerial work vehicle can be reliably prevented.
[0012]
According to such a configuration, when the boom is in the retracted state, the leveling adjustment can be performed, and during the leveling adjustment, the intersection angle becomes smaller than the allowable minimum intersection angle or the allowable intersection angle becomes smaller. When it becomes larger than the maximum intersection angle, an alarm is activated, and interference between the workbench and other members in the aerial work vehicle is prevented. In this case, the allowable intersection angle range is a range that is equal to or greater than the allowable minimum intersection angle and equal to or less than the allowable maximum intersection angle, and does not correspond to any state other than the boom storage state. Since the adjustment is regulated, interference is reliably prevented.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a heavy-load type aerial work vehicle (hereinafter, simply referred to as an aerial work vehicle) 1 having the safety device of the present invention. The aerial work vehicle 1 has a turntable 12 on a vehicle body 11 that can be turned by a turn motor (not shown). A boom 13 is attached to the turntable 12 so as to be able to move up and down. I have. The boom 13 includes a plurality of boom members, and these boom members are telescopically configured to be telescopic. The boom 13 expands and contracts by an expansion and contraction operation of a telescoping cylinder (not shown) provided therein, and operates by an expansion and contraction operation of a raising and lowering cylinder 14 disposed between the swivel 12 and the boom 13. It has become.
[0015]
A post 15a is attached to the tip of the boom 13 so as to be able to swing back and forth. A large work table 15 is attached to the post 15a, and a plurality of work vehicles can be mounted on the work table 15. The worktable 15 is attached so as to extend in the front-rear direction from the upper end of the post 15a, and when the boom 13 is placed on the boom receiver 19 and stored as shown in FIG. It is located on the boom 13 and is close to the boom 13, and the front end side is located on the driving cabin 10 and is close to the driving cabin 10.
[0016]
An upper operation device 17 is provided on the work table 15, and a lower operation device 18 is provided on the vehicle body 11 side. The operation of the operation devices 17, 18 causes the turning motor, the up / down cylinder 14, and the telescopic cylinder to operate. The supply and discharge of oil is controlled, and the turning, raising and lowering, and expansion and contraction operations of the boom 13 are controlled.
[0017]
As a result, the upper operating device 17 or the lower operating device 18 is operated to control the operation of the boom 13, and the work table 15 is moved to a desired height and the worker boarding the work table 15 performs work at a high place. You can do it. When the work is not performed, the boom 13 is placed on the boom receiver 19 and is in a stored state.
[0018]
A leveling cylinder 16 is provided between the bottom of the worktable 15 and the tip of the boom 13. The leveling cylinder 16 has a bottom-side oil chamber connected to a rod-side oil chamber of the up-and-down cylinder 14, and is operated to extend and contract in conjunction with the expansion and contraction operation of the up-and-down cylinder 14. That is, when raising the boom 13, the hydraulic oil is supplied to the bottom-side oil chamber of the up-and-down cylinder 14 and the hydraulic oil in the rod-side oil chamber of the up-and-down cylinder 14 enters the bottom-side oil chamber of the leveling cylinder 16. After the inflow, the up / down cylinder 16 is extended in conjunction with the extension operation of the up / down cylinder 14.
[0019]
When the boom 13 is caused to fall down, the operating oil is supplied to the rod-side oil chamber of the leveling cylinder 16 and the operating oil in the bottom-side oil chamber of the leveling cylinder 16 flows into the rod-side oil chamber of the undulating cylinder 14. The up-and-down cylinder 14 is reduced in conjunction with the reduction operation of the leveling cylinder 16.
[0020]
Therefore, the post 15a swings in the front-rear direction in conjunction with the up / down operation of the boom 13 due to the extension / retraction operation of the leveling cylinder 16 in conjunction with the extension / retraction operation of the up / down cylinder 14, and the post 15a is always held vertically. The work table 15 is always leveled so as to be kept horizontal.
[0021]
By the way, since the work table 15 is large, when a load is placed on the edge of the work table 15 or the like, a large tensile load or a compressive load acts on the leveling cylinder 16 and is connected to the oil chamber and the oil chamber. The hydraulic pressure in the piping becomes high. For this reason, the leveling may be shifted due to, for example, a change in piping with time, that is, the work table 15 may be gradually inclined from the horizontal position.
[0022]
For this reason, a leveling adjustment device is provided so that when the work table 15 is tilted in this way, the post 15a is swung in a direction in which the tilt angle is reduced to perform leveling adjustment (correction of the posture). I have. The leveling adjustment device is provided in the upper and lower operation devices 17 and 18 and outputs leveling adjustment operation signals in response to operations. The leveling adjustment operation devices 17a and 18a and an operation signal based on the leveling adjustment operation signals. And a leveling adjustment valve 21 (see FIG. 2). The leveling adjustment valve 21 controls supply of hydraulic oil to the leveling cylinder 16, and operates according to an operation signal output from the controller 20.
[0023]
According to such a configuration, when the leveling adjustment operating devices 17a and 18a are operated, the hydraulic oil is supplied to the leveling cylinder 16, and the leveling cylinder 16 expands and contracts. For this reason, the leveling adjustment can be performed by operating the leveling adjustment operation devices 17a and 18a to swing the post 15a in a direction in which the inclination angle of the worktable 15 decreases.
[0024]
However, when performing this leveling adjustment in a state where the boom 13 is laid down, particularly in a state where the boom 13 is retracted as shown in FIG. 1, the rear end side of the worktable 15 is close to the boom 13 and the front end side is connected to the driving cabin 10. Close. For this reason, if the post 15a is erroneously swung in a direction in which the inclination angle of the work table 15 increases, if the work table 15 is tilted too much backward (R direction in the figure), the rear end of the work table 15 The distance Cr between the side and the boom 13 becomes zero, and the workbench 15 may interfere with the boom 13.
[0025]
Further, if the worktable 15 is inclined forward (the direction F in the drawing) too much, the space Cf between the front end side of the worktable 15 and the cabin 10 becomes zero, and the worktable 15 may interfere with the operation cabin 10. . For this reason, the aerial work vehicle 1 is provided with the safety device of the present invention for preventing such interference.
[0026]
FIG. 2 shows the configuration of this safety device, which includes a boom receiving side limit switch 31, a first post side limit switch 32, and a second post side limit switch 33. The controller 20 also includes the above-described controller 20, and detection signals from these limit switches (hereinafter, referred to as L / S) 31 to 33 are input to the controller 20.
[0027]
The boom receiving side L / S 31 detects whether the boom 13 is in the stored state. The boom receiving side L / S 31 is provided in the boom receiver 19 as shown in FIG. 1, and when the boom 13 is in the retracted state, a switch is pushed in by the boom 13 to be turned on.
[0028]
The first and second post-side L / S 32, 33 are provided for detecting whether or not the intersection angle α of the post 15a with the boom 13 is within the allowable intersection angle range, as shown in FIG. Is attached to the post 15a. Here, the present safety device is to prevent interference when leveling adjustment is performed in the storage state of the boom 13, and the work table 15 is stored in the allowable intersection angle range in a state where the boom 13 is stored. The range of the intersection angle α that allows the post 15a to swing without interfering with the boom 13 or the driving cabin 10 is set.
[0029]
That is, in FIG. 1, a range of the intersection angle α that is equal to or more than αmin and equal to or less than αmax is set. αmin is the minimum value of the intersection angle α (allowable minimum intersection angle) at which the post 15a can be swung without causing the work table 15 to interfere with the boom 13, and αmax is the work value when the boom 13 is stored. This is the maximum value of the intersection angle α (allowable maximum intersection angle) at which the post 15a can be swung without causing the table 15 to interfere with the driving cabin 10.
[0030]
The first post-side L / S 32 detects whether the cross angle α has become smaller than the allowable minimum cross angle α min due to the post 15 a swinging too far backward, and the work table 15 is tilted too much. When the intersection angle α is larger than αmin, the switch is released and turned off as shown in FIG. When the post 15a is swung backward too much and the crossing angle α becomes smaller than αmin, the switch is pushed in by the boom 13 as shown in FIG.
[0031]
The second post-side L / S 33 detects whether the cross angle α is larger than the allowable maximum cross angle αmax by swinging the post 15a forward too much, and the work table 15 is tilted too much. When the intersection angle α is smaller than αmax, the switch is pushed in by the boom 13 as shown in FIG. When the post 15a swings forward too much and the crossing angle α becomes larger than αmax, the switch is released and turned off as shown in FIG. 4B.
[0032]
When the boom 13 is in the retracted state and the ON signal is input from the boom receiving side L / S 31, the controller 20 is based on the leveling adjustment operation signals from the leveling adjustment operation devices 17 a and 18 a as described above. Then, an operation signal is output to the leveling adjustment valve 21 to perform leveling adjustment. At the time of this leveling adjustment, the intersection angle α becomes smaller than the allowable minimum intersection angle αmin, and an ON signal is input from the first post-side L / S 32, or the intersection angle α becomes larger than the allowable maximum intersection angle αmax. When an off signal is input from the second post-side L / S 33, an alarm operation is performed.
[0033]
Here, the alarm operation is to stop the output of the operation signal to the leveling adjustment valve 21 to restrict the swinging movement of the post 15a in the direction in which the inclination angle of the worktable 15 increases, and to sound the alarm buzzer 22. And so on. After that, when an operation signal for leveling adjustment for swinging the post 15a in a direction in which the inclination angle of the worktable 15 becomes smaller is input, an operation signal is sent to the leveling adjustment valve 21 in accordance with the operation signal. Output, and swing the post 15a.
[0034]
In a state where the boom 13 is raised and is not in the retracted state and the OFF signal is input from the boom receiving side L / S31, the leveling adjustment operation devices 17a and 18a are operated to perform the leveling adjustment, and the leveling adjustment is performed. When an operation signal is input, an alarm is activated and leveling adjustment is not performed.
[0035]
According to such an alarm operation, when the leveling adjustment is performed in a state where the boom 13 is stored, it is possible to prevent the work table 15 from interfering with the boom 13 or the driving cabin 10 and to prevent the boom 13 from operating. Leveling adjustment in a state where 13 is not stored can be restricted.
[0036]
As described above, in the present safety device, the boom receiving side L / S31 is detected in order to detect whether the boom 13 is in the retracted state, and whether the intersection angle α is within the allowable intersection angle range. For this purpose, the first and second post side L / Ss 32 and 33 are used, respectively. Since these L / Ss 31 to 33 are inexpensive, this safety device has a demerit that the leveling adjustment is limited to the boom storage state, but has a merit in cost.
[0037]
The safety device capable of preventing interference only when the boom 13 is in the retracted state has been described above. Next, a second example in which interference can be prevented regardless of the up-and-down state of the boom 13 will be described. The safety device will be described. FIG. 5 shows the configuration of such a safety device. This safety device has an undulation angle detector 41 for detecting the undulation angle of the boom 13, an intersection angle detector 42 for detecting the intersection angle α (both refer to FIG. 1), and a controller 30. The detection signals from the devices 41 and 42 are input to the controller 30.
[0038]
The controller 30 outputs an operation signal to the leveling adjustment valve 21 based on the leveling adjustment operation signals from the leveling adjustment operation devices 17a and 18a regardless of the up-and-down state of the boom 13, and performs leveling adjustment in the same manner as in the above example. Let it do. On the other hand, the allowable intersection angle range in the undulation angle detected by the undulation angle detector 41 is calculated. At the time of this leveling adjustment, when the intersection angle α detected by the intersection angle detector 42 is out of the calculated allowable intersection angle range, an alarm operation is performed in the same manner as in the above example.
[0039]
Here, the allowable intersection angle range is equal to or greater than the allowable minimum intersection angle (same as the allowable minimum intersection angle αmin in the above example) at which the work table 15 can swing without interfering with the boom 13 at the undulation angle. The range of the intersection angle α is equal to or less than the allowable maximum intersection angle at which the work table 15 can be swung without interfering with the driving cabin 10. In this case, the allowable maximum intersection angle changes according to the undulation angle.
[0040]
According to such a configuration, an allowable intersection angle range according to the elevation angle is set, and the alarm operation is performed when the intersection angle α exceeds the allowable intersection angle range. Even if the leveling adjustment is performed in the state, the interference can be prevented.
[0041]
The crossing angle α is not directly detected by the crossing angle detector 42 as described above, but is calculated, for example, by providing a stroke sensor on the leveling cylinder 16 and elongating the leveling cylinder 16 detected by the stroke sensor. It can also be detected in this way.
[0042]
【The invention's effect】
As described above, according to the safety device of the present invention, when performing the leveling adjustment, if the intersection angle exceeds the allowable intersection angle range due to excessive swinging of the worktable, an alarm operation is performed by the alarm unit. Interference between the workbench and other members in the aerial work vehicle can be prevented. Therefore, leveling adjustment work can be performed without concern for interference.
[0043]
In addition, a boom storage detector for detecting whether the boom is in the retracted state is provided, and the workbench state detecting means is used to detect whether or not the intersection angle is equal to or more than the allowable minimum intersection angle. And a maximum crossing angle detector for detecting whether or not the crossing angle is equal to or smaller than an allowable maximum crossing angle. When the boom is in the retracted state, the leveling adjustment is permitted. In addition, at the time of this leveling adjustment, an alarm is activated when the intersection angle is smaller than the allowable minimum intersection angle or larger than the allowable maximum intersection angle, and when the boom is in the retracted state, the leveling adjustment is performed. Leveling adjustment is limited to the boom retracted state, but the boom retract detector, the minimum crossing angle detector, and the maximum crossing angle detector have simple functions, and Luo, since it is possible to use a configuration inexpensive simple, cost-is advantageous.
[0044]
In addition, an undulation angle detector that detects the undulation angle of the boom is provided, and the allowable crossing angle range in the undulation angle detected by the undulation angle detector is calculated by the workbench state detecting means, and the allowable intersection angle according to the undulation angle is calculated. If the range is set, the allowable intersection angle range according to the undulation angle is set, so that interference can be prevented even if the boom is in any undulation state and leveling adjustment is performed. be able to.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of an aerial work vehicle 1 including a safety device of the present invention.
FIG. 2 is a block diagram showing a configuration of a safety device of the present invention.
FIGS. 3A and 3B are schematic diagrams illustrating the on / off operation of a first post-side L / S 32, where FIG. 3A shows an off state and FIG. 3B shows an on state.
FIGS. 4A and 4B are schematic diagrams illustrating an on / off operation of a second post-side L / S 33, wherein FIG. 4A shows an ON state and FIG. 4B shows an OFF state.
FIG. 5 is a block diagram showing a configuration of a safety device of a second example.
[Explanation of symbols]
Reference Signs List 10 Operating cabin 11 Body 13 Boom 15 Workbench 15a Post 20 Controller 22 Alarm buzzer 31 Boom receiving side detector (Boom storage detector)
32 1st post side L / S (minimum crossing angle detector)
33 2nd post side L / S (maximum crossing angle detector)
α intersection angle αmax allowable maximum intersection angle αmin allowable minimum intersection angle

Claims (2)

A boom mounted on the vehicle body so as to be able to move up and down, a post mounted on the end of the boom so as to be swingable back and forth, a work table mounted on the post, a leveling cylinder for swinging the post, and the boom The leveling cylinder is operated by operating the leveling cylinder in response to the ups and downs, and the post is swung, and the leveling mechanism that constantly holds the work table horizontally, and the leveling cylinder is manually operated when the work table is inclined from horizontal. Actuation, leveling adjustment means for adjusting the crossing angle of the post with respect to the boom and leveling the workbench horizontally, comprising:
A minimum intersection angle detector for detecting whether the intersection angle is equal to or greater than an allowable minimum intersection angle and a maximum intersection angle detector for detecting whether the intersection angle is equal to or less than an allowable maximum intersection angle; Worktable state detection means for detecting whether or not the intersection angle is within an allowable intersection angle range,
A boom storage detector that detects whether the boom is in a stored state;
When performing the leveling adjustment by manual operation, the worktable state detection means is configured to include an alarm unit that performs an alarm operation when it is detected that the intersection angle is out of the allowable intersection angle range ,
The alarm means,
When the boom storage detector detects that the boom is in the retracted state, the leveling adjustment is allowed to be performed, and at the time of the leveling adjustment, the minimum intersection angle detector detects the intersection. When the angle is detected to be smaller than the allowable minimum crossing angle, or when the maximum crossing angle detector detects that the crossing angle is larger than the maximum allowable crossing angle, the alarm operation is performed.
When the boom storage detector detects that the boom is not in the retracted state, the leveling adjustment is restricted from being performed . The boom is attached extending from a rear end side of the vehicle body to a front end side,
The vehicle body is configured based on a truck and has a driving cabin in a vehicle body front portion,
The workbench is mounted in a retracted state, extending from the upper end of the post to the front and rear of the vehicle body, the rear end is located on the boom, the front end is located on the driving cabin, and the intersection angle is small. When the post is swung in a direction, the rear end approaches the boom, and when the post is swung in a direction in which the intersection angle increases, the front end is located at a position approaching the driving cabin. The safety device for an aerial work vehicle according to claim 1, wherein

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