JP2001187699A - Controller of vehicle for high lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an axial force detector (moment detection means) to be erroneously judged abnormal when a boom tip part or a working table is pressed against the ground. SOLUTION: A controller 50 of a vehicle for high lift work comprises at least a vertically movable boom, an elevating angle detector 22 detecting the elevating angle of the boom, an axial force detector 25 detecting a load moment acting from the boom to the working table, and a controller 30 judging the abnormality of the axial force detector and performing the operation limit of the boom, all mounted on a body. When the load moment detected by the axial force detector 25 becomes abnormal and the elevating angle of the boom is equal to or below a preset ground contact angle, the controller 30 does not judge the axial force detector 25 to be abnormal and allows the boom to move only in the boom raising direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an aerial work vehicle having a boom mounted at least on a vehicle body so as to be able to move up and down, and more particularly, to detecting a load moment acting on the vehicle body from the boom. The present invention relates to a control device for an aerial work vehicle provided with an abnormality determining means for determining an overload on a boom and an abnormality of a moment detecting means.

[0002]

2. Description of the Related Art Aerial work vehicles having the above-described control device have been widely used. It is equipped with a boom capable of swiveling, raising and lowering, and expanding and contracting on a movable vehicle body, and a work table attached to the end of the boom. This is a boom work vehicle that operates by operating a provided operating device to move the boom to a desired height by operating the boom such as turning, raising and lowering, and expanding and contracting. In such an aerial work vehicle, for example, when the boom is extended while the load on the work table exceeds the allowable load, the moment acting on the vehicle body from the boom becomes excessive, and the vehicle body falls. In order to prevent this from happening, a moment acting on the vehicle body from the boom (also referred to as a “falling moment”) is detected, and when this detected value exceeds a predetermined moment, the moment An overturn prevention device for regulating the operation of the boom is provided.

In such a fall prevention device, as means for detecting the moment acting on the vehicle body from the boom,
An axial force detector that detects an axial force acting in the cylinder axis direction is provided on a pivot pin of the undulating cylinder that raises and lowers the boom, and an axial force detection value detected by the axial force detector,
Means for calculating a moment acting on the boom from the boom undulation angle detected by the boom position detector and the like can be exemplified. In such a device, when an abnormality occurs in the axial force detector and the overturn prevention device does not operate, it may lead to a fall of the vehicle body. Therefore, an abnormality determination device for determining an abnormality in the axial force detector is provided. I have.

[0004] During normal operation of the boom, the axial force detector has at least an axial force of a moment corresponding to the weight of the boom itself and the weight of the worktable attached to the tip of the boom (hereinafter referred to as "zero load moment"). Must always be detected. Therefore, in the conventional abnormality determination device, when the axial force detected by the axial force detector falls below the zero load moment, it is determined that an abnormality has occurred in the axial force detector, and the axial force detector abnormality alarm is generated. And a boom operation restriction that immediately stops all operation of the boom was performed.

[0005]

However, in the above-mentioned conventional control device for an aerial work vehicle, the load moment detected by the moment detecting means (axial force detector) is set and stored in advance as described above. When the moment value becomes equal to or less than the set moment value (zero load moment), it is determined that there is an abnormality in the moment detecting means. Therefore, even when the boom or the workbench at the end of the boom gets on some obstacle, ( That is, it is determined that the moment detecting means is abnormal (in spite of the fact that the moment detecting means is not abnormal), an alarm for the moment detecting means abnormality is generated, and all operations of the boom are restricted.

For example, when a worker operates a boom to reciprocate a work table between the ground and a high place to transport materials to a high place, the tip of the boom or the work table is erroneously erroneously moved. May frequently come into contact with the ground. At this time, the conventional control device determines that the moment detecting means is abnormal and generates an alarm to restrict the operation of the boom. Therefore, the operator must release the alarm one by one to raise the boom and operate the boom. There was a problem in working efficiency that it was not done. Further, as described above, although it is not an abnormality of the original moment detecting means, it is erroneously determined that the moment detecting means is abnormal, and the content of the alarm occurrence (abnormal content) is stored as an error history. At the time of inspection and maintenance of a work vehicle, there is a problem in failure determination that it is difficult to determine whether an abnormality has actually occurred in the moment detecting means or whether the moment detection means has been pressed against the ground due to an erroneous operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for an aerial work vehicle that improves the accuracy of failure determination and improves work efficiency. Aim.

[0008]

In order to achieve the above object, according to the present invention, there is provided a boom which is mounted on a vehicle body so as to be able to move up and down at least, and the tip of the boom is always kept horizontal regardless of the boom angle. A workbench mounted and mounted, an elevation angle detector for detecting the elevation angle of the boom, and moment detection means for detecting a load moment acting on the vehicle body from the boom (for example, the axial force detector 25 in the embodiment)
And abnormality determining means for determining abnormality of the moment detecting means based on the load moment detected by the moment detecting means (for example, the controller 3 in the embodiment).
0) and a boom operation restricting means (for example, the controller 30 and the boom operation controller 35 in the embodiment) for restricting the operation of the boom based on the judgment of the abnormality judging means, constitute a control device of the aerial work vehicle. This control device is provided when the value of the load moment detected by the moment detecting means is equal to or less than a preset moment value, and the angle of the boom detected by the angle detector is equal to or less than a predetermined angle. Means that the moment detecting means determines that the moment detecting means is not abnormal, and the boom operation restricting means permits only the boom operation in which the tip of the boom moves upward.

According to the control device for an aerial work vehicle having the above structure, even if the value of the load moment detected by the moment detecting means becomes equal to or less than a preset moment value, the undulation angle detector detects the load moment. When the detected angle of the boom is equal to or smaller than a predetermined angle, the abnormality determining means does not determine that the moment detecting means is abnormal, and the workbench (hereinafter referred to as the workbench attached to the boom tip or the boom tip). It is determined that these are referred to as “boom tip or the like”) against the ground or the like. The boom operation restricting means allows only the boom operation in which the tip of the boom moves upward based on the determination.

Here, the preset moment value is:
For example, a fixed value of several hundreds to several thousand Nm determined according to the boom type, the weight of the worktable, or the like, or should be detected according to the boom position in a state where nothing is loaded on the worktable as described above. It can be a moment value (zero load moment). In addition, the above-mentioned predetermined undulation angle refers to an undulation angle having a high probability of causing the boom tip or the like to abut an obstacle on the ground from the geometrical configuration of the boom and the workbench. Angle at which the tip of the boom can come into contact with the ground when the
Degree).

For this reason, according to the control device having the above configuration,
When the worker mistakenly operates the boom and touches the boom tip or the like to the ground, the abnormality determination means does not erroneously determine that the moment detection means is abnormal, and
The operator can perform a boom operation (for example, a boom raising operation or a lengthening operation) in which the tip of the boom moves upward without performing a complicated alarm releasing operation. Therefore, it is possible to provide a control device for an aerial work vehicle that improves the accuracy of the failure determination and improves the working efficiency.

In the case where the boom is extendable and retractable, and the control device has an extension detector for detecting the extension of the boom, the predetermined undulation angle is attached to the tip of the boom or the tip of the boom. The raised and lowered angle at which the work table is determined to be in contact with the ground can be set. In an aerial work vehicle in which the boom not only moves up and down but also expands and contracts, the angle at which the tip of the boom contacts the ground changes according to the extension state of the boom. In the control device having the above-described configuration, the up-and-down angle at which the boom tip or the like that changes in accordance with the amount of extension of the boom is determined to be in contact with the ground is set and stored as the predetermined up-and-down angle. The above-described determination is made based on a predetermined undulation angle. Accordingly, it is possible to further improve the accuracy of the failure determination, and to provide a control device for an aerial work vehicle with improved work efficiency.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a control device for an aerial work vehicle according to the present invention will be described below with reference to the drawings. FIG. 2 shows an aerial work vehicle equipped with the control device according to the present invention. First, the configuration of the aerial work vehicle will be described. The aerial work vehicle 1 is configured with a truck as a base, and a turning table 4 is attached to a rear portion of the vehicle body 2 having the driving cabin 3 so as to be horizontally turnable with respect to the vehicle body 2 by the operation of a turning motor 11. A boom 5 is pivotally mounted on the upper portion of the swivel 4 so as to be swingable, and is configured to be able to move up and down with respect to the swivel 4 by the operation of the up / down cylinder 12. The boom 5 includes a base boom 5a pivotally attached to the swivel 4 and a distal boom 5b inserted into the base boom 5a. The boom 5 is inserted into a telescope shape and arranged inside the boom 5. Telescopic work cylinder 13 installed
The distal end boom 5b with respect to the proximal end boom 5a
Are configured to be able to freely expand and contract.

A work table (work floor) 8 is attached to the end of the end boom 5b via a vertical post 6 which is always maintained vertical by the operation of the leveling cylinder 14 irrespective of the elevation angle of the boom 5. . The workbench 8 is provided with an upper boom operation device 33a, and the vehicle body 2 is provided with a lower boom operation device 33b. An operator who is on the workbench or on the ground can use these boom operation devices 33 (33a). , 33b), the swing motor 1 is controlled via a boom operation controller 35 described later.
1. By operating the hoisting cylinder 12, the telescopic cylinder 13 and the like to turn, boom, and telescopically move the boom 5, the workbench 8 can be moved to a desired high place to perform high-place work. Is configured.

A boom receiver 18 erected on the vehicle body 2 is mounted in front of the vehicle body 2, and when the vehicle is moved after finishing work at a high place, the boom 5 is fully contracted and the boom 5 is retracted. It is configured so that it can be placed on the boom receiver 18. In addition, when the boom 5 is extended or turned, the body 2 acts against the moment in the overturning direction acting on the body 2.
Outrigger jacks 17 are attached to the front, rear, left and right of the vehicle body 2 (only the left jack of the vehicle body 2 is shown in the figure).

A turning angle detector 21 for detecting a turning angle of the turntable 4 with respect to the vehicle body 2 and a boom 5
A boom position detection device 20 including a undulation angle detector 22 for detecting the undulation angle of the boom 5, an extension amount detector 23 for detecting an extension amount of the boom 5, and the like is attached.
The position of the tip of the boom 5 with respect to the vehicle body 2 can be determined from the detected values 1, 2, and 23.

Further, in the swivel table 4, the undulating cylinder 12
An axial force detector 25 is provided on a connecting pin that pivotally pivots. The axial force detector 25 is a detector that detects an axial force that acts in the direction of the expansion and contraction axis of the up-and-down cylinder 12 that lifts the boom 5, and acts on the swivel 4 side from the boom 5 side around the pivot axis of the boom. Moment, that is,
This is a detector for detecting a total load moment M acting on the vehicle body side from the boom side including the work table 8.

The aerial work vehicle 1 is provided with a fall prevention device. This device raises and lowers the boom 5 as described above.
This is a device for preventing the vehicle from tipping over due to the moment acting on the vehicle body 2 from the boom 5 side when the extension movement or the like is operated. The load moment M detected by the axial force detector is determined by the boom position. when it is determined to exceed the predetermined moment M _L, which is determined in accordance with the boom tip position obtained by the detection device 20, to regulate the operation of the boom 5 in the direction moment increases.

The aerial work vehicle 1 is equipped with a control device 50 according to the present invention. This control device is roughly a device included in the above-mentioned overturn prevention device.
This is a control device that monitors the detection value of No. 5 to determine an abnormality of the axial force detector and controls the operation of the boom 5 based on the determination.

As shown in the block diagram of FIG. 1, the control device 50 includes an undulation angle detector 22, an extension amount detector 23, an axial force detector 25, a controller 30, a display device 40, and the like. Undulation angle detector 2
2 and the value of the load moment M detected by the axial force detector 25, the controller 30
An abnormality of the axial force detector 25 is determined according to a predetermined condition set and stored therein, and a restriction signal based on the abnormality is output to the boom operation controller 35. It regulates the operation of the boom operating device.

Here, the load moment M detected by the axial force detector 25 is the total load moment acting on the swivel 4 from the boom 5 including the worktable 8 to the pivot axis of the boom. Therefore, under normal boom operating conditions,
The axial force detector 25 always has at least the weight of the boom 5 itself and the weight of the workbench in a non-loaded state where no load is mounted on the workbench 8. moment corresponding to the derricking angle and elongation of 5 (zero load moment) M ₀ or more load moment must be always detected. Therefore, the axial force detector 25
Load moment M detected in that, when it becomes less than zero load moment M ₀ is some kind of anomaly, including the axial force detector 25 itself abnormality can be determined to have occurred.

On the other hand, for example, when the boom 5 or the work table 8 rides on some obstacle while the boom 5 is in the down position, the load moment M detected by the axial force detector 25 is the zero load moment. situation occurs below the M _0. However, at this time, the axial force detector 25
Is actually zero load moment M
The moment is ₀ or less, which does not mean that the axial force detector 25 is abnormal. Therefore, in such a case, the axial force detector 2
It is inherently undesirable to determine that No. 5 is abnormal before the record remains in the error history.

The riding of the boom or the like as described above is not limited to a specific boom position, but easily occurs between the vehicle and the ground. In particular, the aerial work vehicle 1 having a wide work table 8 as shown in FIG. 2 is used as a lifting device for transporting materials onto a construction structure by reciprocating between the ground and high places as shown in FIG. In many cases, the bottom end of the boom, which is the lowermost end when trying to approach the worktable 8 to the ground, is directly below the worktable 8 and is difficult to see. Cheap.

Therefore, the control device 50 according to the present invention uses the load moment M detected by the axial force detector 25 during the operation of the boom 5 as the zero load stored in the controller 30 corresponding to the position of the end of the boom. when a moment M ₀ or less, the controller 30 outputs an operation stop signal to the boom operation controller 35 causes the first immediately once stops the operation of the boom 5. Then, the controller 30
Is a contact angle θ preset in the controller 30 as an undulation angle at which the boom tip can contact the ground in accordance with the extension L from the extension L of the boom 5 detected by the extension detector 23. _{Read L.}

The undulation angle α at which the boom tip contacts the ground
Is calculated based on the geometrical configuration of the boom 5 on the vehicle body, and changes according to the extension amount L of the boom 5. This situation is shown in FIG. 4. When the boom 5 extends at a small length L ₁ , the elevation angle at which the boom tip abuts is α ₁ (when the horizontal is 0 degree and the raising direction is plus, and a negative value) in manner, a relief angle of the boom tip abuts when the extension amount is large L ₂ of the boom 5 alpha
₂ (same as above), they have a relationship of | α ₁ |> | α ₂ |.

The contact angle θ _L is determined by adding a predetermined spare angle to the contact angle α obtained in this way in consideration of the effects of irregular terrain and obstacles on the ground. It is determined as the undulation angle to be obtained. Controller 3
0, the contact angle θ _L corresponding to the extension amount L of the boom,
For example, the controller 30 is set and stored in a map form as a function having L as a variable or as a step value corresponding to the range of L, and the controller 30 uses the detected extension amount L of the boom 5 as an argument to correspond to the contact angle θ corresponding to the extension amount. _{Read L.}

The controller 30 compares the read-out ground angle θ _L with the up-and-down angle of the boom 5 detected by the up-and-down angle detector 22, and detects the detected up-and-down angle at the pre-set and stored ground angle θ. _L or less (ie, boom 5
Is determined, it is determined that the axial force detector 25 is not abnormal and the boom tip has contacted the ground. Then, a display indicating that the boom tip is in contact with the display device 40 is made, and the boom operation in which the boom tip is raised relative to the boom operation controller 35, ie, the boom
Only the raising operation and the lengthening operation are permitted, and a restriction signal for restricting other boom operations is output to regulate the operation of the boom.

At this time, since it is not determined that the axial force detector 25 is abnormal, the occurrence of an abnormality in the device is not automatically recorded in the error history which is automatically stored as the axial force detector abnormality.
It should be noted that, for example, an error number different from the axial force detector abnormality may be separately provided, and recording may be performed based on the above determination.

On the other hand, if relief angle detected in derricking angle detector 22 is beyond the ground angle theta _L which is previously set and stored (i.e. Okoshiossha direction of the boom 5), contact with the ground Since it is difficult to consider, it is determined that an abnormality has occurred in the axial force detector 25. Then, an alarm display (alarm display) indicating that an abnormality has occurred in the axial force detector is displayed on the display device 40.
And a restriction signal for restricting all the boom operations is output to the boom operation controller 35 to regulate all the boom operations. At this time, the axial force detector 2
5 is recorded in the error history and stored.

Therefore, in the determination of the abnormality of the axial force detector 25, the erroneous determination that the axial force detector 25 is abnormal although the detector is normally in a normal detection state rather than the detector abnormality is reduced. Accordingly, the accuracy of the failure determination at the time of vehicle inspection and maintenance can be improved. Also, when the controller 30 determines that the boom has come into contact with the ground, the boom operation for moving the boom upward without performing a complicated operation such as an alarm reset is allowed, so that the work at a high place where the working efficiency is improved is improved. A control device for a vehicle can be provided.

In the above-described embodiment, an aerial work vehicle in which the boom tip abuts on the ground has been described as an example of a boom structure. Needless to say, the same configuration can be applied to the above.

The above-mentioned ground contact angle θ can be determined in consideration of the case where the vehicle body 2 is jacked on an inclined ground, and for example, the inclination angle of the ground road surface is determined by detecting the vehicle body inclination angle immediately before the jack installation. Or by calculating from the amount of extension of the front and rear jacks 17, 17 after the jack is touched, and correcting the touching angle θ based on the obtained inclination angle. According to the control device that performs such correction processing, the axial force detector 25
Can be more accurately determined.

Further, since the height position of the boom tip and the like from the ground is determined by the up-and-down angle and the amount of extension of the boom 5, the description of the boom turning angle direction is omitted. The angle can be changed in the same direction, or can be changed in combination with a conventionally used so-called boom working range restricting device. For example, the driving cabin 3 is located in front of the vehicle body, and the boom tip or the like cannot contact the ground in this turning angle range. Further, when the boom 5 is placed and stored in the boom receiver 18 on the vehicle body, a negative axial force acts on the axial force detector 25 because a constant retraction force is required. Therefore, such a configuration that the boom turning angle range is excluded from the determination range of the control device 50 does not reduce the effect of the present invention at all.

[0034] When implementing the present invention with a simple configuration, in place of the zero load moment M ₀ of the aforementioned changes in accordance with the angular position of the boom, example, several hundred Nm and several thousand Nm
For example, instead of the contact angle θ that changes according to the amount of extension of the boom, a constant undulation angle such as -5 degrees or -10 degrees may be set. Is also possible.

[0035]

As described above, the control device according to the present invention comprises an elevation angle detector, a moment detecting means, an abnormality judging means for judging an abnormality of the moment detecting means, a boom operation restricting means for restricting the operation of the boom. Consists of In addition, the abnormality determining means of the control device is configured to perform the operation when the value of the load moment detected by the moment detecting means is equal to or less than a preset moment value and the boom angle is equal to or less than a predetermined angle. The moment detecting means determines that the tip of the boom or the workbench is pressed against the ground or the like without any abnormality, and the boom operation restricting means permits only the boom operation in which the tip of the boom moves upward.

Therefore, according to the control device having the above-described configuration, when the operator mistakenly operates the boom to bring the boom tip or the like into contact with the ground, the abnormality determining means determines that the moment detecting means has an abnormality. The operator can perform the boom operation in which the tip of the boom moves upward without making an erroneous determination and without performing a troublesome alarm releasing operation. Therefore, it is possible to provide a control device for an aerial work vehicle that improves the accuracy of the failure determination and improves the working efficiency.

In the case where the boom is extendable and retractable and the control device has an extension amount detector for detecting the extension amount of the boom, the predetermined undulation angle is attached to the tip of the boom or the tip of the boom. The raised and lowered angle at which the work table is determined to be in contact with the ground can be set. According to the above configuration, the up-and-down angle at which the boom tip or the like that changes according to the amount of extension of the boom is determined to be in contact with the ground is set and stored as the above-mentioned predetermined up-and-down angle. The above determination is made based on the above. Accordingly, it is possible to further improve the accuracy of the failure determination, and to provide a control device for an aerial work vehicle with improved work efficiency.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control device for an aerial work vehicle according to the present invention.

FIG. 2 is a side view of an aerial work vehicle equipped with the control device.

FIG. 3 is an explanatory diagram for explaining a working situation of the aerial work vehicle.

FIG. 4 is an explanatory diagram for explaining a relationship between a boom extension amount and an up-and-down angle at which a boom tip portion abuts on the aerial work vehicle.

[Explanation of symbols]

Reference Signs List 1 aerial work platform 5 boom (5a base end boom, 5b end boom) 8 workbench 22 undulation angle detector 23 extension amount detector 25 axial force detector (moment detection means) 30 controller (abnormality judgment means, boom operation regulation) Means) 35 Boom operation controller (Boom operation restriction means)

Claims (2)

[Claims] 1. A boom mounted on a vehicle body so as to be able to move up and down at least, a work table mounted to a tip end of the boom so as to be constantly horizontal regardless of the boom angle, and the boom is raised and lowered. An up-and-down angle detector for detecting an angle; a moment detecting means for detecting a load moment acting on the vehicle body side from the boom; and determining an abnormality of the moment detecting means based on the load moment detected by the moment detecting means. Abnormality determination means, and boom operation restriction means for restricting operation of the boom based on the determination of the abnormality determination means, wherein the value of the load moment detected by the moment detection means is equal to or less than a preset moment value. And
When the up-down angle of the boom detected by the up-down angle detector is equal to or less than a predetermined up-down angle, the abnormality determination unit determines that the moment detection unit is not abnormal,
And a control device for the aerial work vehicle, wherein the boom operation restricting means allows only a boom operation in which a tip end of the boom moves upward. 2. The boom is extendable and retractable, the control device has an extension amount detector for detecting an extension amount of the boom, and the predetermined undulation angle is a tip of the boom or the work table. 2. The control device for an aerial work vehicle according to claim 1, wherein is an undulating angle determined to be in contact with the ground. 3.