JP2757955B2 - Safety device and automatic storage device for tip-extended telescopic boom - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic boom, and more particularly to a safety device for safely operating the telescopic boom and an automatic storage device for automatically storing the telescopic boom.

[0002] The tip-extended telescopic boom is a boom composed of a first boom member and a second boom member which is capable of extending and contracting in the longitudinal direction with respect to the first boom member. The portion from the middle part in the longitudinal direction to the tip side (hereinafter, referred to as a tip side part) can be bent and stretched from the middle part to the base side part (hereinafter, referred to as a base side part). . This telescopic boom is used as a working device by attaching a worktable or the like to the tip of the second boom member (that is, the tip of the tip side portion). If this telescopic boom is used, the workbench or the like can be moved using not only the up-and-down operation and the telescopic operation of the telescopic boom, but also the bending and elongating operation of the distal end portion, so that work can be performed efficiently.

Further, in this telescopic boom, the second boom member is reduced and stored (stored) in the first boom member in a state where the distal end portion is positioned linearly with respect to the proximal end portion. ing. In this case, even in the stored state, the work table or the like attached to the tip can be used immediately. For this reason, the retractable boom is stored in a folded state below the telescopic boom, and the retractable boom and a workbench or the like attached to the distal end of the retractable boom are moved out of the retracted boom to some extent in advance to extend the telescopic boom forward. It is easier to use than a type in which the work table or the like must be raised so as not to interfere with the ground or the like.

[0004]

However, in the above-described telescopic boom, the distal end portion (at least a part) of the second boom member is housed in the first boom member. However, if the distal end member is to be bent or the distal end portion is to be accommodated in the first boom member in spite of the distal end portion being bent relative to the base end portion, The part and the first boom member may interfere with each other and be damaged. Such interference accidents often occur due to misjudgment or misoperation by the operator. Therefore, it is necessary to provide a means for not only alerting the operator but also for surely preventing such an accident.

In order to store the second boom member with respect to the first boom member, the user operates the second boom after extending the distal end portion while visually confirming the bending state of the distal end portion. A plurality of operations are required, such as an operation of reducing the size of a member, which is troublesome and liable to cause errors.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a safety device for a flexure / extension type telescopic boom capable of reliably preventing interference between a distal end portion and a first boom member, and a simple second boom member. It is an object of the present invention to provide an automatic storage device capable of storing data.

[0007]

In order to achieve the above object, the present invention provides an extension amount detecting means for detecting an extension amount of a second boom member with respect to a first boom member;
Refraction angle detection means for detecting a refraction angle of the distal end portion with respect to the base end portion of the second boom member;
When it is determined that it is housed in the boom member, the bending operation of the distal portion is restricted, and the distal portion is bent relative to the proximal portion based on the refraction angle detected by the refraction angle detecting means. If it is determined that the
A safety device is constituted by a regulating means for regulating a reduction operation of the second boom member housed in the boom member.

According to such a safety device, when even a part of the distal end portion is housed in the first boom member,
The bending operation of the distal portion is automatically regulated. Further, when the distal end portion is bent relative to the proximal end portion, the retracting operation of the second boom member is automatically restricted.
For this reason, even if there is an operator's operation mistake etc., the collision accident between the tip end portion and the first boom member is reliably prevented.

Further, according to the present invention, there is provided a refraction angle detecting means for detecting a refraction angle of the distal portion with respect to a proximal portion,
When the operation means for controlling the reduction operation of the second boom member is operated, the distal end portion is bent relative to the base end portion based on the refraction angle detected by the refraction angle detection means. When it is determined that the first boom member is retracted, the distal end portion is actuated so as to be positioned linearly with respect to the proximal end portion, and then the second boom member is reduced so that the distal end portion is accommodated in the first boom member. The automatic storage device is constituted by the controller to be operated.

When it is determined based on the refraction angle detected by the refraction angle detecting means that the distal portion is refracted with respect to the proximal portion, the distal portion is accommodated in the first boom member. A restricting means for restricting the reduction operation of the second boom member to be operated, and a reduction operation of the second boom member by the restriction means when the operating means for controlling the reduction operation of the second boom member is operated. When is regulated, after the regulation state continues for a predetermined time, the distal end portion is operated to be positioned linearly with respect to the proximal end portion,
Then, the automatic storage device may be configured by using a controller for reducing the operation of the second boom member so that the front end side portion is accommodated in the first boom member.

In order to reduce and operate the second boom member with respect to the first boom member using such an automatic storage means, it is sufficient to continue the reduction operation in the operation means from the beginning to the end of storage. In addition, if the automatic storage device having the restricting means is used, the storage of the second boom member in a state where the distal end portion is bent is reliably prevented, and after the restriction of the reducing operation continues for a predetermined time, the automatic storage device is automatically retracted. The distal end portion is operated so as to be linearly positioned, and the reducing operation is automatically restarted, and the second boom member is retracted with respect to the first boom member.

[0012]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an aerial work vehicle equipped with a tip-extended telescopic boom. This aerial work vehicle 1 is configured based on a truck and has a vehicle body 1a.
Outrigger jacks 2 are attached to four front, rear, left and right sides of the vehicle body 1a to support the vehicle body 1a by projecting to the side of the vehicle body 1a and grounding the lower end thereof (only the rear left and right outrigger jacks 2 are shown in the figure). Shown). At the rear of the vehicle body 1a, a turntable 3 that can freely turn horizontally with respect to the vehicle body 1a is attached. The telescopic boom 4 is attached to an upper portion of the swivel base 3.

The telescopic boom 4 includes a base boom member 41 pivotally supported on the swivel base 3 so as to be able to move up and down.
An intermediate boom member (“first boom member” in the claims) 42 inserted into the intermediate boom 1 so as to be able to expand and contract in the longitudinal direction, and a tip boom member inserted into the intermediate boom 42 so as to be able to expand and contract in the longitudinal direction. (“The second boom member” in the claims) 43 to form a telescope. A hydraulic raising / lowering cylinder 5 is mounted between the base end boom member 41 and the swivel base 3, and the entire telescopic boom 4 is driven up and down by the expansion / contraction operation of the raising / lowering cylinder 5. Although not shown, the telescopic boom 4 has a first boom member 42 that drives the intermediate boom member 42 to expand and contract with respect to the base end boom member 41.
A hydraulic telescopic cylinder and a second hydraulic telescopic cylinder that drives the distal boom member 43 to expand and contract with respect to the intermediate boom member 42 are built in. For this reason, hydraulic oil is supplied to both telescopic cylinders so that the intermediate boom member 42 and the tip boom member 4
3 can be extended and retracted at the same time, while hydraulic fluid can be supplied only to the second telescopic cylinder to extend and retract only the tip boom member 43.

A portion 44 (hereinafter, referred to as a proximal member) of the distal end boom member 43 from a longitudinal middle portion to a proximal side is a tubular member having a rectangular cross section like the proximal boom member 41 and the intermediate boom member 42. Is formed. A portion 45 (hereinafter, referred to as a distal member) of the distal boom member 43 from an intermediate portion in the longitudinal direction is configured by two sets of parallel links attached to left and right sides of the proximal member 44, respectively. FIG. 1 shows only the left parallel link.

This parallel link (that is, the tip side member 45)
As shown in detail in FIG. 2, a first link 4 having a base end pivotally supported on the upper end of a base end member 44 so as to be vertically swingable.
5a, a second link 45b whose lower end is pivotally supported vertically in a lower portion of the proximal end member 44, and these distal ends are swung vertically in a state where they are extended in parallel. And a boom head 46 pivotably supported.
In addition, between the pin 47 which pivotally supports the second link 45b with respect to the proximal member 44 and the longitudinally intermediate portion of the first link 45a, the entire distal member 45 is vertically swung (that is, bent and stretched). ) Is mounted.

A vertical post 6 is provided at the tip of the boom head 46 in the left-right direction in the drawing (that is, in the axial direction of the telescopic boom 4).
It is pivoted to be able to swing freely. An upper leveling cylinder 7a is mounted between the upper part of the vertical post 6 and the boom head 46. A hydraulic closed circuit is formed between the upper leveling cylinder 7a and a lower leveling cylinder 7b attached between the base end of the base end boom member 41 and the rear part of the swivel 3 as shown in FIG. ing. This hydraulic closed circuit extends the upper leveling cylinder 7a when the telescopic boom 4 is raised and the lower leveling cylinder 7b is contracted (the vertical post 6 swings to the left in the drawing), and the telescopic boom 4 When the lower leveling cylinder 7b is extended and the lower leveling cylinder 7b is extended, the upper leveling cylinder 7a is contracted (the vertical post 6 swings rightward in the figure) so that the two leveling cylinders 7
a and 7b are connected. For this reason, the vertical post 6
Irrespective of the up-and-down state of the telescopic boom 4, the telescopic boom is always maintained almost vertically.

Note that the posture of the boom head 46 with respect to the telescopic boom 4 does not change even if the distal member 45 bends and expands due to the parallel link action of the distal member 45 (FIG. 2).
reference). For this reason, it can be said that the vertical post 6 is always maintained almost vertically regardless of the undulating state and the bending state of the distal-side member 45.

A worktable bracket 8 is attached to the upper part of the vertical post 6 so that the worktable bracket 8 can swing horizontally about the vertical post 6. A work table 9 is attached to a side surface of the work table bracket 8. This workbench 9
An operator (not shown) can board the vehicle. Further, on the upper part of the work table 9, the swivel operation of the swivel table 3 and the up / down operation and expansion / contraction of the telescopic boom 4 (intermediate / tip boom member 4).
2, 43 expansion and contraction, and only the end boom member 43 expansion and contraction)
An operation device 10 for controlling the operation, the bending / extending operation of the tip boom 43 and the swinging operation of the work table 9 is attached. The operator boarding the work table 9 can move the work table 9 to an arbitrary height through the operation of the operation device 10 to perform a desired work at a high place.

At this time, as shown by an arrow A in FIG.
Can protrude from the intermediate boom member 42 to utilize the bending and stretching function of the distal boom member 43, and even when there is no such room, the distal boom member 43 is extended to extend the distal side member 45. By projecting from the intermediate boom member 42, the bending and stretching function can be used.

After the operation is completed, the telescopic boom 4 is fully contracted as shown by an arrow B in FIG. 1 while the distal end portion 45 is positioned linearly with respect to the proximal end portion 44. The telescopic boom 4 can be stored in the vehicle body 1a by lying down horizontally and further turning the swivel 3 toward the front of the vehicle body 1a. The retractable boom 4 is stored in a state in which the tip boom member 43 having the bending and stretching function is accommodated in the intermediate boom member 42 except for the boom head 46, and the work table 9 is located in front of the telescopic boom 4.
Next, even when the place where the aerial work vehicle 1 is used has little extra height, there is no problem (for example, as in the conventional aerial work vehicle shown in FIG. The worker can work at the workbench 9 without any problem.
You can get on board and work.

When the distal boom member 43 is to be bent, it is necessary to prevent the distal boom member 43 from interfering with the intermediate boom member 42 by projecting the distal side portion 45 from the intermediate boom member 42 as described above. Also, the tip boom member 4
3 is fully retracted in the intermediate boom member 42,
The distal portion 45 must be straightened with respect to the proximal portion 44 to prevent interference with the intermediate boom member 42. For this reason, the safety device according to the present invention (also including the automatic storage device according to the present invention) 30 is attached to the aerial work vehicle 1. Hereinafter, this safety device is shown in FIG.
This will be described with reference to FIG.

The safety device 30 includes a refraction angle sensor 31, an extension amount sensor 32, a main controller 33, a display 34, an alarm 35, and an automatic storage controller 36. As shown in FIG. 2, the refraction angle sensor 31 is attached around a pin 49 that pivotally supports the first link 45a to the base end portion 44.
The refraction angle θ with respect to the longitudinal direction of the base portion 44 of the (tip portion 45) is detected. As shown in FIG. 2, the extension amount sensor 32 is attached to the distal end of the intermediate boom member 42, and detects the length L of the distal boom member 43 protruding from the intermediate boom member 42. The display 34 is the operating device 1
0, indicating that the bending operation and the retracting operation of the tip boom member 43 are possible. Alarm 35
Comprises a buzzer and emits a predetermined alarm sound.

The main controller 33 has a built-in refraction control program shown by the flowchart shown in FIG. 4 and a reduction control program shown by the flowchart shown in FIG. Further, the main controller 33 includes a refraction operation signal output when an operation for causing the distal boom member 43 to perform the bending operation is performed by the operating device 10 and a reduction operation of the distal boom member 43 (the bending operation of the distal boom member 43). A reduction operation signal that is output when an operation for performing a single reduction operation or a reduction operation together with the intermediate boom member 42 is performed is input.

Step S1 in the refraction control program
Then, the refraction operation signal and the detection signal from the extension amount sensor 32 are read. In step S2, the operation device 10
It is determined whether or not a refraction operation has been performed, that is, whether or not there is a refraction operation signal. When it is determined that the refraction operation has been performed, the process proceeds to step S3, and when it is determined that the refraction operation has not been performed, the current flow is ended as it is.

In step S3, based on the detection signal from the extension amount sensor 32, it is determined whether or not the protrusion length L is equal to or longer than a predetermined length L1. Here, as shown in FIG. 2, L1 is a length at which the distal end portion 45 is completely and sufficiently protruded from the inside of the intermediate boom member 42, and more specifically, the distal end portion 45 is bent. Also the intermediate boom member 42
Length that does not interfere with When it is determined that L ≧ L1, the process proceeds to step S4, and when it is determined that L <L1, the process proceeds to step S5.

In step S4, a switching signal corresponding to the bending / extension operation signal is output to a bending / extension valve 51 (see FIG. 3) for controlling the supply of hydraulic oil to the bending / extension cylinder 48.
The refraction operation of the tip boom member 43 is permitted, and the display 34 displays an indication that the refraction operation is possible (after that, the current flow is ended). On the other hand, in step S5, the tip boom member 43 is not output in the state where the bending signal is output from the operating device 10 without outputting the switching signal.
The refraction operation is restricted, and when the display 34 indicates that refraction operation is possible, this is erased (the flow is terminated thereafter).

By the operation of the main controller 33 based on such a refraction control program, the refraction operation in a state where the distal end portion 45 is not sufficiently (more than L1) protruded forward from the intermediate boom member 42 is automatically prevented. As a result, it is possible to reliably prevent interference between the two due to an operator's determination error or the like. Conversely, as long as the tip boom member 43 can perform the bending operation, there is no fear of interference with the intermediate boom member 42, so that the burden on the operator can be reduced.

Next, the reduction control program will be described. In step S11 in this program, the reduction operation signal, the detection signal from the refraction angle sensor 31, and the detection signal from the extension amount sensor 32 are read. In step S12, it is determined whether or not a reduction operation has been performed on the operation device 10, that is, whether or not there is a reduction operation signal. When it is determined that the reduction operation has been performed, the process proceeds to step S13,
If it is determined that the reduction operation has not been performed, the current flow is terminated.

In step S13, it is determined based on the detection signal from the extension amount sensor 32 whether the protrusion length L is equal to or less than L1. When it is determined that L> L1, the process proceeds to step S14, and when it is determined that L ≦ L1, the process proceeds to step S15. In step S14, a switching signal corresponding to the contraction operation signal is output to the telescopic valve 52 (see FIG. 3) that controls the supply of the hydraulic oil to the second telescopic cylinder, and the tip boom member 43 is contracted to the intermediate boom member 42. The operation is permitted, and a display indicating that the reduction operation is possible is performed on the display 34 (the current flow is terminated). On the other hand, in step S15, the refraction angle θ is set to 0 based on the detection signal from the refraction angle sensor 31.
It is determined whether or not (zero). When it is determined that θ = 0, the process proceeds to step S16, and when it is determined that θ ≠ 0, the process proceeds to step S17.

In step S16, a switching signal corresponding to the contraction operation signal is output to the telescopic valve 52 to permit the contraction operation in which the protruding length L of the tip boom member 43 is equal to or less than L1. A display indicating that the reduction operation is possible is performed (the current flow is terminated thereafter). On the other hand, in step S17, it is determined whether or not the restriction of the reduction operation described later has continued for a predetermined time (for example, 5 seconds). When it is determined that the predetermined time has not yet elapsed, the process proceeds to step S18, and when it is determined that the predetermined time has elapsed, the process proceeds to step S20.

In step S18, a switching operation for the telescopic valve 52 is not output, and the reducing operation in which the protruding length L of the tip boom member 43 becomes L1 or less while the reducing operation signal is output from the operating device 10 is performed. Regulate and
If the display 34 indicates that the reduction operation is possible, this is erased (the current flow is terminated). As a result, it is possible to reliably prevent interference between the two boom members 42 and 43 due to an operator's misjudgment or the like.
Conversely, as long as the tip boom member 43 can be contracted, there is no need to worry about interference between the two boom members 42, 43, so that the burden on the operator can be reduced.

In step S20, the alarm device 35 is operated, and an automatic storage program represented by a flowchart shown in FIG. In step S21 in the automatic storage program, a detection signal from the refraction angle sensor 31 and a detection signal from the extension amount sensor 32 are read.
In step S22, based on the detection signal from the refraction angle sensor 31, it is determined whether or not the refraction angle θ is 0 (zero). When it is determined that θ ≠ 0, the process proceeds to step S23, and when it is determined that θ = 0, the process proceeds to step S24. In step S23, the refraction valve 51 is switched and controlled so that the distal end boom member 43 in the refraction state is extended.

On the other hand, in step S24, based on the detection signal from the extension sensor 32, the protrusion length L is set to 0.
(Zero), that is, the end boom member 43 is
It is determined whether or not 2 is in the fully contracted state. When it is determined that L ≠ 0, the process proceeds to step S25, and when it is determined that L = 0, the process proceeds to step S26. Step S25
Then, switching control of the telescopic valve 52 is performed so that the distal end boom member 43 operates to contract (retract) with respect to the intermediate boom member 42 (the flow is terminated thereafter). On the other hand, in step S26, the expansion / contraction valve 52 is controlled so as to stop the contraction operation of the tip boom member 42 (after that, the current flow is ended).

Such an automatic storage program is automatically executed by continuing the reduction operation of the operating device 10 while the restriction of the reduction operation of the tip boom member 43 in step S18 in the reduction restriction program continues for a predetermined time. . Then, after the tip boom member 43 is linearly extended (step S23), the contraction operation is restarted (step S25), and the contraction operation is automatically stopped at the time when the retracted state is reached (step S25). S26). For this reason, the tip boom member 43 used by being bent can be stored quickly and easily (only by performing a reduction operation), and the work efficiency can be improved and the burden on the operator can be reduced.

Although the telescopic boom of the above embodiment is a three-stage telescopic boom composed of three boom members, the telescopic boom using the safety device of the present invention is not limited to this. Telescopic boom. Also,
In the above embodiment, the safety device of the telescopic boom including the tip boom member that can be bent only in the vertical direction has been described, but the safety device of the present invention is not limited to this.
The invention can also be applied to a telescopic boom provided with a tip boom member that can be bent in the left-right direction.

[0036]

As described above, according to the safety device of the present invention, the second boom member can be extended and contracted with respect to the first boom member, and the distal end portion of the second boom member bends and extends. In the bending / extension type telescopic boom, when at least a part of the distal end portion of the second boom member is accommodated in the first boom member, the bending operation of the distal end portion can be restricted. Further, when the distal end portion is bent with respect to the proximal end portion, the reduction operation of the second boom member that accommodates the distal end portion in the first boom member can be restricted. For this reason, even if the operator who controls the operation of the telescopic boom as described above makes an operation error or the like, it is possible to reliably prevent the first boom member from interfering with the bent second boom member.

Further, according to the automatic storage device of the present invention, after the second boom member is contracted, the distal end portion is first actuated so as to be positioned linearly with respect to the proximal end portion. , The second boom member is retracted relative to the first boom member. Therefore, the process from the start of storage to the end of storage can be easily controlled only by the above-described reduction operation.
For this reason, the burden on the worker when storing the telescopic boom can be reduced, and the time required for storage can be reduced.

In the state where the second boom member has been reduced, the automatic storage described above is performed after the restriction of the second boom member by the restricting means has continued for a predetermined period of time. In this case, the interference between the two boom members can be reliably prevented, and the storage operation can be automatically shifted to the storage operation only by continuing the reduction operation even in the regulated state.

[Brief description of the drawings]

FIG. 1 is a rear view of an aerial work vehicle equipped with a safety device for a tip-extended telescopic boom according to the present invention.

FIG. 2 is a partially enlarged view of the telescopic boom.

FIG. 3 is a block diagram of the safety device.

FIG. 4 is a flowchart of refraction restriction control used in the safety device.

FIG. 5 is a flowchart of a reduction regulation control used in the safety device.

FIG. 6 is a flowchart of automatic storage control used in the safety device.

[Explanation of symbols]

 Reference Signs List 1 aerial work platform 4 telescopic boom 41 proximal boom member 42 intermediate boom member (first boom member) 43 distal boom member (second boom member) 44 proximal member (of distal boom member) 45 (of distal boom member) ) Tip side member 9 Workbench

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B66F 9/24 B66F 9/06

Claims (3)

(57) [Claims] 1. A first boom member and at least a second boom member capable of extending and contracting in the longitudinal direction with respect to the first boom member, wherein the second boom member has a distal end side from a longitudinal middle portion. Portion is bendable and extendable from the intermediate portion to a portion on the proximal side, and the first portion of the second boom member is in a state where the distal portion is linearly positioned with respect to the proximal portion. A safety device for an extension-bend-type telescopic boom capable of being reduced and accommodated in a boom member, comprising: an extension amount detection unit configured to detect an extension amount of the second boom member with respect to the first boom member; Refraction angle detecting means for detecting a refraction angle of a side portion with respect to the base end portion, and the distal end portion is housed in the first boom member based on the extension amount detected by the extension amount detection means. Judge When, the refraction operation of the distal portion is regulated, and based on the refraction angle detected by the refraction angle detecting means, the distal portion is refracted with respect to the proximal portion. And a restricting means for restricting a contraction operation of the second boom member for accommodating the distal end portion in the first boom member when the judgment is made. . 2. A first boom member, and at least a second boom member that is capable of extending and contracting in the longitudinal direction with respect to the first boom member, wherein the second boom member has a distal end side from a middle portion in the longitudinal direction. Portion is bendable and extendable from the intermediate portion to a portion on the proximal side, and the first portion of the second boom member is in a state where the distal portion is linearly positioned with respect to the proximal portion. An automatic storage device for a tip-end bending type telescopic boom capable of being reduced and accommodated in a boom member, comprising: a refraction angle detecting means for detecting a refraction angle of the distal end portion with respect to the base end portion; (2) When the operating means for controlling the reduction operation of the boom member is operated, the distal end portion is bent relative to the base end portion based on the refraction angle detected by the refraction angle detection means. When doing When disconnected, the second boom is actuated to position the distal end portion linearly with respect to the proximal end portion, and then to accommodate the distal end portion in the first boom member. An automatic retractable device for a bending-extendable telescopic boom, comprising: a controller configured to reduce and operate a member. 3. When it is determined that the distal end portion is refracted with respect to the base end portion based on the refraction angle detected by the refraction angle detection means, the distal end portion is moved to the second position. The controller has a restricting means for restricting a reduction operation of the second boom member to be accommodated in the one boom member, and the controller is configured to control an operation means for controlling the reduction operation of the second boom member. When the restricting means restricts the reduction operation of the second boom member, after the restriction state has continued for a predetermined time, the operation is performed so as to linearly position the distal end portion with respect to the proximal end portion. 3. The extension / retraction hood according to claim 2, wherein the second boom member is contracted to accommodate the distal end portion in the first boom member. Automatic storage device.