JP2005082331A - Control device for high lift work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damaging stability of a car body of a high lift work vehicle due to increase of moment added to the car body. <P>SOLUTION: The high lift work vehicle comprises a boom 5 installed on the car body 2 having wheels 3a and 3a' at the front and rear, on the right and left, to be drivable to make it capable of hoisting, turning, and extending, and a working platform 10 installed on a tip part of the boom 5 to be capable of vertically moving. In the high lift work vehicle, this control device 60 comprises an inclination angle detector 21 to detect an inclination angle θ of a car body 2 generated in accordance with the moment added to the car body 2, an inclination limit angle memory circuit 31 for storing an inclination limit angle θ<SB>0</SB>preliminarily set as the upper limit value for the inclination angle θ for the car body 2 to be stably supported by wheels 3a and 3a', and a boom actuation regulating circuit 32 to regulate hoisting or the like of the boom 5 in directions in which the inclination angle θ of the car body 2 to a horizontal surface detected by the inclination angle detector 21 exceeds inclination limit angle θ<SB>0</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for an aerial work vehicle having an elevating device provided on a travelable vehicle body so as to be movable up and down, and a work table attached to the elevating device and on which an operator rides.

  Examples of the aerial work vehicle as described above include a boom type aerial work vehicle and a vertical lift type aerial work vehicle. These aerial work platforms are generally constructed on the basis of a truck chassis, and a boom type lifting device capable of turning and the like is mounted on the vehicle body behind the driving cabin, or a multistage type that moves up and down. A vertical post-type lifting device using a telescopic mast (extensible ladder) is attached, and a work table or the like is provided on the tip of the lifting device for an operator to work at a high place. Yes.

  Among the aerial work platforms as described above, for example, boom type aerial work vehicles generally have a telescopic jack provided on the side of the vehicle body at the lower side of the vehicle body. The vehicle body is extended and extended downward to stably support the vehicle body. However, when the boom moment acting from the boom side to the vehicle body side increases due to the boom turning motion or the loading load on the work table, the vehicle body tilts toward the boom turning side and the stability of the vehicle body deteriorates.

Therefore, for example, as described in Patent Document 1, a permissible work range such as a pivoting motion of the boom is preset and stored based on an inclination angle corresponding to a boom moment that the vehicle body can stably support. There is also an aerial work platform equipped with a work range regulating device that regulates the operation of the boom in a direction in which the position of the work table at the tip of the boom exceeds the allowable work range. Further, as described in Patent Document 2, when the inclination angle of the vehicle body with respect to the horizontal plane detected by the inclination angle detector provided on the vehicle body exceeds a predetermined value, the boom operation is restricted. In some cases, it is possible to ensure the stability of the vehicle body even in places such as sloping ground.
Japanese Patent Laid-Open No. 9-202598 Japanese Utility Model Publication No. 52-105230

  By the way, in an aerial work vehicle, each wheel supports the vehicle body via a telescopic suspension attached between each wheel and the vehicle body. Some jacks do not have a jack to do. However, in such an aerial work vehicle, when the lifting device is moved up and down to move the work table to a desired position, the moment of the vehicle body increases according to the operation of the lifting device, and one of the left and right sides of the vehicle body is increased. When the suspension on the other side expands and the suspension on the other side contracts, the vehicle body tilts toward the contraction side of the suspension, resulting in a problem that the stability of the vehicle body deteriorates.

  In this way, the tilt state of the vehicle body changes according to the expansion and contraction of the suspension due to the moment acting on the vehicle body, and in order to prevent an excessive moment from acting on the vehicle body and causing the vehicle body to become unstable, for example, a boom type In an aerial work vehicle, there is a method of maintaining the stability of the vehicle body by controlling the operation of the boom so that the moment of the vehicle body does not exceed a predetermined allowable moment that can stably support the vehicle body (moment limiter). However, such a method requires detection means such as a boom load detector that detects a boom load acting on the hoisting cylinder that moves the boom up and down, and an extension amount detector that detects the amount of expansion and contraction of the boom. There is a problem that the method of regulating the operation of the boom by the moment is expensive.

  In view of the above problems, in the present invention, in an aerial work vehicle equipped with a lifting device composed of a boom or the like, in order to prevent the stability of the vehicle body from being impaired due to an increase in the moment of the vehicle body, An object of the present invention is to provide a control device for an aerial work vehicle that restricts the lifting operation of the lifting device.

  In order to solve the above-described problems, a control device for an aerial work vehicle according to the present invention includes an elevating device (e.g., in the embodiment) that is provided on a vehicle body that can be traveled with wheels disposed on the front, rear, left, and right. Boom 5) and a work table that is attached to the tip of the lifting device and that can be moved up and down by the lifting device, and that detects the tilt angle of the vehicle body (for example, the tilt angle detector 21 in the embodiment). ), An inclination limit angle storage means (for example, an inclination limit angle storage circuit 31 in the embodiment) that stores the upper limit value of the inclination angle for stably supporting the vehicle body by the wheel as an inclination limit angle, and stores the inclination. And an operation restricting means (for example, a boom operation restricting circuit 32 in the embodiment) for restricting the lifting operation of the lifting device in a direction in which the tilt angle detected by the angle detecting means exceeds the tilt limit angle.

  Here, the “elevating device” is not limited to a boom type elevating device capable of moving up and down, but also includes a vertical post type elevating device including an extendable mast that moves up and down. In addition, the “lifting / lowering operation of the lifting device in a direction in which the tilt angle exceeds the tilt limit angle” means that in the boom type lifting device, the boom is tilted in the direction of the boom, the boom is extended, or the boom turns to the side of the vehicle body. In the vertical post type lifting device, this means that the multistage telescopic mast expands. Further, the “inclination angle” includes both an “absolute angle” that is an inclination angle with respect to the horizontal plane of the vehicle body and a “relative angle” that is an inclination angle with respect to the axle of the vehicle body.

  Further, in the control apparatus for an aerial work vehicle having the above-described configuration, each wheel is attached to the vehicle body via the suspension device, and the vehicle inclination angle that changes according to the operation of the suspension device is detected by the inclination angle detection means. .

  According to the control device for an aerial work vehicle having the above-described configuration, for example, in a boom-type aerial work vehicle equipped with a boom type lifting device, the boom changes according to the moment acting on the vehicle body when the boom turns. The operation restricting means restricts the operation of the boom in a direction in which the inclination angle of the vehicle body with respect to the horizontal plane exceeds a predetermined value set in advance. For this reason, it is possible to prevent the stability of the vehicle body from being deteriorated due to the boom moment that increases in accordance with the turning motion of the boom, and to ensure the stability of the vehicle body when working at a high place. Moreover, as long as the tilt angle in the left-right direction of the vehicle body does not exceed a predetermined value (tilt limit angle), it is possible to operate the boom in the direction in which the boom operation was restricted because it exceeded the allowable work range of the boom. Further, it is not necessary to provide an expensive turning angle detecting means for detecting whether or not the boom is positioned within the allowable work range.

  Further, according to the control device for an aerial work vehicle having the above-described configuration, for example, in a boom type aerial work vehicle equipped with a boom type lifting device, a boom load detector that detects a load acting on the hoisting cylinder from the boom is attached. The boom moment acting from the boom side to the vehicle body side is calculated, and the boom moment that changes according to the position of the boom tip and the load acting on the boom tip exceeds the predetermined allowable moment, making the vehicle body unstable. Compared with a method (moment limiter) that restricts the operation of the boom in the direction, it is not necessary to provide a boom load detector or the like, and therefore the boom operation control device can be configured at low cost.

  In addition, since each wheel supports the vehicle body via the suspension, the boom moment acting on the vehicle body changes according to the turning movement of the boom in the case of an aerial work vehicle where the vehicle body is not equipped with a jack. Even when the vehicle body tilts due to the expansion and contraction of the suspension device, it is possible to work at a high place by restricting the operation of the boom beyond the specified tilt limit angle corresponding to the boom moment that can be stably supported by the wheels. The stability of the vehicle body at the time can be ensured.

  Furthermore, in a vertical lift type aerial work platform equipped with a vertical post type lifting device using a multistage telescopic mast that moves up and down, in order to approach the work object, a work platform with a particularly large load is used. In order to prevent the stability of the car body from deteriorating due to the increase in the moment acting on the car body when it is slid horizontally to the left and right sides of the car body, the car body tilts in the left and right direction (lateral direction), With the control device according to the present invention, the operation restricting means can restrict the rise of the telescopic mast so that the inclination angle of the vehicle body in the left-right direction does not exceed a predetermined inclination limit angle.

  Hereinafter, a preferred embodiment of the control device for an aerial work vehicle according to the present invention, in particular, a boom type aerial work vehicle provided with a boom that can freely move up and down, turn, and extend as a lifting device on the vehicle body as an example. This will be described with reference to FIGS. As shown in FIGS. 1 and 2, the aerial work vehicle 1 has a driving cabin 2a in front of the vehicle body 2, and a chassis frame 6 extends in the front-rear direction of the vehicle body 2 behind the driving cabin 2a. The truck chassis is configured on the basis of a front wheel 3a (left front wheel 3a, right front wheel 3a ') and rear wheel 3b (left rear wheel 3b, right rear wheel 3b') disposed on the front, rear, left and right sides. The axle 9a is connected to the left front wheel 3a, and the axle 9a 'is connected to the right front wheel 3a' (the axles are also connected to the rear wheels 3b and 3b 'in the same manner). The vehicle body 2 can travel by being transmitted to the wheels 3a, 3a ′,. The front wheel 3a and the rear wheel 3b support the vehicle body 2 via suspensions 7a, 7a ', 7b, 7b' attached to the vehicle body 2, respectively.

  Further, as shown in FIG. 1, a base 4c is installed on the vehicle body 2 on the rear side of the driving cabin 2a. The swivel base 4 is mounted on the base 4c so as to be capable of swiveling. The turntable 4 is mounted on the base 4c so as to be capable of swiveling in the horizontal direction, and upward on the upper surface of the turntable 4a. And a projecting support member 4b. A turning motor 51 for turning the turntable 4a is built in the base 4c. When the turntable 4a is rotated by the turning motor 51, the support member 4b is turned in any direction. Yes.

  A base end portion of the boom 5 is pivotally connected to the upper end portion of the support member 4b so as to be swingable up and down, and can be raised and lowered by a raising and lowering cylinder 52. Further, the boom 5 is configured such that a plurality of boom members are combined in a nested manner, and the entire boom 5 can be expanded and contracted by a built-in telescopic cylinder 53. A vertical post (not shown) is provided at the tip of the boom 5, and a work table 10 configured to allow an operator to ride on the vertical post can be swiveled horizontally (necked) by a turning motor (not shown). Vibration). Since the vertical post is attached to the boom 5 via a leveling device including a leveling cylinder 55 and the like, and the vertical state is always maintained, the work table 10 is always maintained in a horizontal state regardless of the undulation angle of the boom 5. .

  Further, a boom operating device 11 for performing an operation for moving the boom 5 up and down and the like is disposed on the work table 10, and an operator on the work table 10 operates an operation lever of the boom operating device 11. By doing so, the boom 5 can freely move up and down, turn, and expand and contract, and the work table 10 can be vibrated to move the work table 10 to a desired high position.

  As shown in FIG. 3, the control device 60 for an aerial work vehicle according to the present invention receives an operation signal output from the boom operation device 11 when the operation lever of the boom operation device 11 is operated. A controller 30 that outputs a control signal to the hydraulic unit 40 to control the operation of the boom 5, and a hydraulic unit 40 that controls the supply and discharge of hydraulic oil to and from the hoisting cylinder 52 based on the control signal from the controller 30. Is provided. The controller 30 stores an operation history such as a turning motion of the boom 5 on the basis of an operation signal output from the boom operation device 11.

  The operation of the turning motor 51 for turning the boom 5 configured as described above, the raising / lowering cylinder 52 for raising / lowering, and the extending / contracting cylinder 53 for extending / contracting is performed by transmitting the rotational driving force of the engine disposed in the vehicle body 2. This is performed by controlling the supply and discharge of hydraulic oil discharged from a hydraulic pump (not shown) that is driven. In this supply / discharge control, the controller 30 controls the opening degree of each control valve including the swing control valve 41, the undulation control valve 42, and the expansion / contraction control valve 43 respectively corresponding to the swing motor 51, the undulation cylinder 52 and the expansion / contraction cylinder 53. Done in

  Further, as shown in FIG. 3, the control device 60 is mounted on the vehicle body 2 in addition to the boom operation device 11 and the like, and the loading load of the work table 10 provided at the tip of the boom 5 and the like. A tilt angle detector 21 that detects the tilt angle θ in the left-right direction of the vehicle body 2 generated in response thereto and outputs a detection signal is provided. The controller 30 includes an inclination limit angle storage circuit 31 and a boom operation restriction circuit 32.

The tilt limit angle storage circuit 31 corresponds to a boom moment that can be stably supported by the wheels 3a, 3a ′,... Even when the boom moment acting on the vehicle body 2 increases due to, for example, the boom 5 extending greatly. The inclination angle θ with respect to the horizontal plane of the vehicle body 2 in the left-right direction is preset and stored as the inclination limit angle θ ₀ . Further, the boom operation restriction circuit 32 is based on the left-right inclination angle θ of the vehicle body 2 detected by the inclination angle detector 21 and the predetermined inclination limit angle θ ₀ stored in the inclination limit angle storage circuit 31. Then, the turning motion of the boom 5 in the direction in which the tilt angle θ in the left-right direction of the vehicle body 2 exceeds the tilt limit angle θ ₀ is controlled. That is, as long as the relationship θ <| θ ₀ | is established, the boom 5 can be operated. Such operation restriction of the boom 5 is performed by the boom operation restriction circuit 32 restricting the output of the operation control signal from the controller 30 to the turning control valve 41, the undulation control valve 42 or the expansion / contraction control valve 43.

Note that the inclination angle θ detected by the inclination angle detector 21 is not limited to a so-called absolute angle with respect to the horizontal plane in the left-right direction of the vehicle body 2 as described above, but is an inclination angle with respect to the axles 9a, 9a 'in the left-right direction of the vehicle body 2. A so-called relative angle may be detected, and the operation of the boom 5 in a direction in which the relative angle exceeds the tilt limit angle θ ₀ stored in the tilt limit angle storage circuit 31 may be restricted.

  Hereinafter, the operation control of the control device 60 configured as described above will be described. Here, the boom 5 is turned by operating the operation lever of the boom operating device 11 from the state in which the boom 5 is stored in the fully contracted state as shown in FIG. When the substantially center portion of the work table 10 is located at the position of the point B, the boom operation device 11 is further operated to move the boom 5 in the direction of arrow A (in plan view, the work table 10 is the vehicle body). The case of turning (in the direction of the right side position 2) is described below.

  In this case, the more the boom 5 turns in the direction of the arrow A, the greater the working radius of the vehicle body 2 with respect to the left-right direction (lateral direction), so that the vehicle body 2 tends to tilt in the left-right direction (lateral direction). Boom moment increases. Then, as shown in FIG. 5, as the boom moment increases, the inclination angle θ with respect to the horizontal plane in the left-right direction (lateral direction) of the vehicle body 2 increases from a substantially horizontal state, and the vehicle body 2 is greatly inclined to the right. It becomes a state. In this state, among the suspensions 7a, 7a ′,... Provided between the wheels 3a, 3a ′,... And the vehicle body 2, the left suspensions 7a, 7b extend, and the right suspensions 7a ′,. 7b 'is contracted, and the wheels 3a, 3a', ... support the vehicle body 2 via these suspensions 7a, 7a ', ....

The inclination angle θ in the left-right direction of the vehicle body 2 detected by the inclination angle detector 21 is set in advance as an inclination angle corresponding to a boom moment that can stably support the vehicle body 2 stored in the inclination limit angle storage circuit 31. When the predetermined tilt limit angle θ ₀ is smaller, the boom operation restriction circuit 32 does not restrict the output of the operation control signal from the controller 30 to the turning control valve 41, and the turning motor 51 operates. . Therefore, as long as the tilt angle θ is smaller than the tilt limit angle θ ₀ , the work is performed by turning the boom 5 in the direction of arrow A from the state where the work table 10 is located at the position B in FIG. It is possible to move the base 10 in the lateral direction of the vehicle body 2.

However, in the process of turning the boom 5 to the side of the vehicle body 2 in the direction of arrow A, when the inclination angle θ with respect to the horizontal plane of the vehicle body 2 in the left-right direction (lateral direction) reaches a predetermined inclination limit angle θ ₀ , boom actuation restricting circuit 32 regulates the output of the operation control signal from the controller 30 to the swing control valve 41, pivotal movement in the arrow a direction of the boom 5 from the time of reaching the inclination limit angle theta ₀ is restricted . In this way, the operation of the boom 5 in the direction in which the inclination angle θ of the vehicle body 2 exceeds the predetermined inclination limit angle θ ₀ is restricted, and the risk that the stability of the vehicle body 2 deteriorates and the danger increases is prevented. can do.

As described above, the controller 30 stores an operation history such as the turning motion of the boom 5 based on the operation signal output from the boom operation device 11. Therefore, when the inclination angle of the boom 5 theta is pivotal movement of the boom 5 to reach the limit angle theta ₀ is stopped midway, performs boom operation and inverse operation immediately before the operation of the boom 5 is restricted Thus, the operation control signal is output from the controller 30 to the turning control valve 41 based on the operation signal from the boom operation device 11, and the boom 5 operation restriction by the boom operation restriction circuit 32 is released. Can be operated in a direction opposite to that immediately before the regulation.

  Further, as shown by a chain line in FIG. 4, when the boom 5 extends from the retracted state to the rear of the vehicle body 2 and the substantially central portion of the work table 10 is located at the position of the point C, the boom A case where the operating device 11 is operated to extend the boom 5 further rearwardly in the direction of arrow D in the direction of the vehicle body 2 so that the substantially center portion of the work table 10 at the tip of the boom 5 is positioned at the position of point E. This will be described below.

  At this time, when the allowable work range of the boom 5 is set in advance as in the prior art, and the work range restriction device for restricting the operation of the boom 5 in the direction exceeding the allowable work range is provided in the aerial work vehicle 1. When the work table 10 is moved to the position of the point E and the allowable work range is exceeded, the extension movement of the boom 5 is restricted, and the work table 10 stops moving halfway. It cannot be moved to position E.

However, according to the control apparatus for an aerial work vehicle according to the present invention, the allowable work range of the boom 5 is not set in advance, and the horizontal inclination angle θ of the vehicle body 2 detected by the inclination angle detector 21 is determined. As long as it is smaller than the predetermined inclination limit angle θ ₀ stored in the inclination limit angle storage circuit 31, the boom operation restriction circuit 32 does not restrict the output of the operation control signal from the controller 30 to the expansion / contraction control valve 43. The telescopic cylinder 53 operates. For this reason, the movement of the work table 10 can be moved to the point E without being regulated in the middle.

  Although the preferred embodiments of the present invention have been described so far, the scope of the present invention is not limited to the above-described embodiments. For example, in the above-described embodiment, the left-right direction inclination angle θ of the vehicle body 2 detected by the inclination angle detector 21 is detected, but the vehicle body 2 is provided with an inclination angle detector that detects the front-rear direction inclination angle. You may comprise so that the action | operation of the boom 5 may be controlled based on the inclination | limit inclination angle with respect to 2 front-back directions. Alternatively, an inclination angle detector that detects an inclination angle in all directions (360 °) with respect to the vehicle body 2 is provided, and an inclination limit angle corresponding to a limit moment in each direction is set. You may comprise so that the action | operation of the boom 5 to a direction in which an inclination angle exceeds the predetermined inclination limit angle in the direction can be controlled.

  Further, as the tilt angle detecting means, the tilt angle detector 21 that is mounted on the vehicle body 2 and detects the tilt angle θ with respect to the horizontal plane in the left-right direction of the vehicle body 2 and outputs a detection signal is used. Instead of using the tilt angle detector 21, for example, a non-contact type length measuring device such as a laser displacement meter for measuring the distance between the chassis frame 6 and the left and right axles 9a, 9a 'is used. From the difference in the distance between the chassis frame 6 and the left and right axles 9a, 9a 'that occurs when the vehicle body 2 is inclined (as shown in FIG. 5), the vehicle body 2 is inclined in the horizontal direction (lateral direction). You may comprise so that (theta) may be detected.

  Also, the aerial work vehicle 1 in the above embodiment lifts the vehicle body 2 during work at a high altitude, because the wheels 3a, 3a ', ... support the vehicle body 2 via suspensions 7a, 7a', .... Although the supporting jack is not provided, as shown in FIG. 6, on the left and right side portions on the front side of the chassis frame 6 extending from the driving cabin 2 a to the rear side of the vehicle body 2, outward in the left-right direction of the vehicle body 2. When the work is performed at a high place, the jack 8 is widened to the left and right of the vehicle body 2 by operating a jack operation device 12 disposed at the rear of the vehicle body 2. Alternatively, the aerial work vehicle 1 may be configured so that the operation of the jack 8 is stopped in a state where it is extended and extended downward and brought into contact with the ground (the ground contact is stopped) so that the vehicle body 2 can be stably supported.

Further, in the above embodiment, a boom type aerial work vehicle using a boom type lifting device capable of turning motion as a lifting device on the vehicle body behind the driving cabin has been described. Even if the vertical lift type aerial work vehicle using the vertical post type lift device provided with a possible multistage telescopic mast as the lift device is provided with the control device 60 for an aerial work vehicle according to the present invention. Good. When such a control device 60 is used, for example, when the load on the work bench is large, the moment acting on the vehicle body increases, and the vehicle body tilts in the left-right direction (lateral direction), so that the inclination angle θ is set. If the configuration is such that the rise of the expansion / contraction mast is restricted when the predetermined inclination limit angle θ ₀ is exceeded, the stability of the vehicle body can be guaranteed.

It is a left view of an aerial work vehicle provided with a control device for an aerial work vehicle according to the present invention. It is the fragmentary sectional view which looked at the aerial work vehicle from the back. It is a block diagram which shows the control apparatus of an aerial work vehicle which concerns on this invention. It is a top view which shows the action | operation of the boom provided in the said aerial work vehicle. It is the fragmentary sectional view which looked at the aerial work vehicle where the vehicle body inclined, from the back. It is a left view which shows the working state of the said high-altitude work vehicle in which the jack was provided as one Embodiment.

Explanation of symbols

1 High-altitude work vehicle 2 Car body 3a Left front wheel (wheel)
3a 'Right front wheel (wheel)
3b Right front wheel (wheel)
3b 'Right rear wheel (wheel)
5 Boom (elevating device)
7a Suspension (suspension device)
7a 'suspension (suspension device)
7b Suspension (suspension device)
7b 'suspension (suspension device)
10 Work table 21 Tilt angle detector (Tilt angle detecting means)
31 Inclination limit angle storage circuit (Inclination limit angle storage means)
32 Boom operation restriction circuit (operation restriction means)
60 Control device

Claims (2)

A lifting device provided with wheels on the front, rear, left and right and capable of moving up and down on a travelable vehicle body, and a work table attached to a tip of the lifting device and movable up and down by the lifting device A work vehicle control device,
An inclination angle detecting means for detecting an inclination angle of the vehicle body;
An inclination limit angle storage means for presetting and storing an upper limit value of the inclination angle for stably supporting the vehicle body by the wheels as an inclination limit angle;
A control apparatus for an aerial work vehicle, comprising: an operation restricting means for restricting an ascending / descending operation of the elevating apparatus in a direction in which the inclination angle detected by the inclination angle detecting means exceeds the inclination limit angle. 2. The vehicle according to claim 1, wherein each of the wheels is attached to the vehicle body via a suspension device, and the inclination angle detection unit detects the inclination angle of the vehicle body that changes according to the operation of the suspension device. The control device for an aerial work vehicle described in 1.

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