JP2000198699A - Velocity control device for high lift work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a velocity control device for a high lift work vehicle, which prevent an operator over a work stand from receiving a great impact when the work vehicle is suspended in running regardless of the developing quantity of its boom. SOLUTION: The output control of a hydraulic transmission 62 by a running control part 34 with its swash plate control valve actuated, thereby allows the running of a vehicle to be made. The velocity control part 33 of a controller 30 controls the running control part 34 in such a way that the running velocity of a car body falls in a running velocity range set in advance to correspond to the position of the work stand. And it is so determined that the narrower running velocity range is much more subject to the developing quantity of its boom 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for an aerial work vehicle in which a work platform for mounting a work vehicle is attached to the tip of a boom that can be raised, contracted, and turned.

[0002]

2. Description of the Related Art In general, an aerial work vehicle is a boom mounted on a vehicle body so as to be able to move up, down, extend, and turn, and a worker mounted on a tip of the boom so as to swing freely (horizontal turning). It is configured to have a work table, and by operating a boom operating device provided on the work table, the boom can be raised, contracted, and swiveled to move the work table to a desired position. Has become. In such a high-altitude work vehicle, the jack provided on the vehicle body is usually extended downward to fix the vehicle body to the ground before performing high-altitude work, but the vehicle is run with the worker on the work bench. In some cases, work is performed.

[0003]

However, in the case where the vehicle body is run with the worker on the work table, the worker on the work table has its own inertial force when the vehicle is stopped from running. It is shocked by such as. This impact is greater when the vehicle is running with the boom deployed (undulating, extending, turning), but the lateral bending stiffness of the boom is lower than the vertical bending stiffness, and the platform is at the boom tip. Since it is attached to the vertical axis (vertical post) of the section, it becomes the largest when the boom is deployed to the side of the vehicle body.

The present invention has been made in view of such a problem, and has a configuration in which a large impact is not applied to a worker on a workbench when the vehicle body stops running regardless of the amount of boom deployment. An object of the present invention is to provide a speed control device for a work vehicle.

[0005]

In order to achieve the above object, a first aspect of the present invention provides a speed control device for an aerial work vehicle,
As shown in FIG. 1 (A), a vehicle body, a boom provided on the vehicle body so as to be able to move up, down, extend, and turn, a workbench mounted on an end portion of the boom for a worker, and traveling of the vehicle body A traveling command unit 1 (in the embodiment, the traveling operation lever 24) for issuing a command, and a traveling unit 2 (in the embodiment, the traveling control unit 34 of the controller 30 and the swash plate control unit) for traveling the vehicle body in accordance with the operation of the traveling instruction unit. In an aerial work vehicle including the valve 54, the hydraulic transmission 62, and the like, the position detecting means 3 (in the embodiment, the up-and-down angle detector 41, the length detector 42, turning angle detector 43 and controller 3
0 worktable position calculation unit 32) and control for controlling the traveling means so that the traveling speed of the vehicle body is within a predetermined traveling speed range corresponding to the position of the worktable detected by the position detection means. Means 4 (in the embodiment, the controller 3
0 speed control unit 33). In such a configuration, since the traveling speed of the vehicle body is limited to a predetermined traveling speed range corresponding to the position of the worktable, the traveling speed range is determined by the boom deployment amount (particularly, the lateral deployment amount). )
Is set to be narrower (i.e., the maximum speed that can be output is smaller) as the size of the vehicle is larger, so that a large impact is not applied to the worker on the workbench when the vehicle body stops running, regardless of the amount of deployment of the boom. You can do so.
At the same time, since the load acting on the boom tip is reduced, the strength of the vehicle body and the boom can be prevented from lowering.

Further, as shown in FIG. 1B, a second aspect of the present invention relates to a speed control device for an aerial work vehicle, and a boom provided on the vehicle body so as to be able to move up and down, extend and contract, and pivot freely. A workbench mounted on the end of the boom for the operator to board, travel command means 5 for issuing a travel command for the vehicle body (travel operation lever 24 in the embodiment), and a vehicle body in response to operation of the travel command means. Traveling means 6 (in the embodiment, the traveling control unit 34 of the controller 30 and the swash plate control valve 5
4, a hydraulic transmission 62, etc.), a turning angle detecting means 7 (turning angle detector 43 in the embodiment) for detecting a turning angle of the boom, and a traveling speed of the vehicle body. Control means 8 (in the embodiment, the speed control unit 33 of the controller 30) for controlling the traveling means so that the driving speed falls within a predetermined traveling speed range corresponding to the boom turning angle detected by the turning angle detection means. ). In such a configuration, the running speed of the vehicle body is limited to a predetermined running speed range corresponding to the turning angle of the boom, so that the running speed range becomes narrower as the turning amount of the boom to the side is larger. By setting it as such, the same effect as the speed control device for an aerial work vehicle according to the first aspect of the present invention can be obtained. Further, since the number of required detectors is smaller than that of the aerial work vehicle speed control device according to the first aspect of the present invention, the configuration can be simplified.

In the first and second speed control devices for aerial work vehicles according to the present invention, the travel instructing means includes not only a normal aerial work vehicle provided in a driver's seat of a vehicle body but also a travel instructor. The present invention can also be applied to an aerial work vehicle (self-propelled aerial work vehicle) provided with means on a workbench.

[0008]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a self-propelled aerial work vehicle (hereinafter referred to as an aerial work vehicle) 10 including the speed control device according to the first embodiment of the present invention. As shown in the figure, the vehicle body 11 has four running wheels 12, 1
.., And has a swivel 13 at the top. The swivel base 13 can horizontally turn with respect to the vehicle body 11 by a rotation motor 14 built in the vehicle body 11. A base end of a boom 15 having a base boom 15a, an intermediate boom 15b, and a distal end boom 15c nested on the swivel base 13 is pivotally connected to both the swivel base 13 and the base boom 15a. The boom 15 can be raised and lowered by the operation of the raising and lowering cylinder 16 provided over the straddle. A telescopic cylinder 17 is provided inside the boom 15,
By the operation of the telescopic cylinder 17, the boom 15 can be telescopically operated.

A vertical post 18 is provided at the tip of the boom 15, and a work table 19 for mounting a worker is attached to the vertical post 18. The work table 19 can be swung (horizontal turning) around the vertical post 18 by a swing motor (not shown) built in the work table 19. The vertical post 18 is attached to the boom 15 via a leveling device (not shown) so that the vertical position is maintained at all times. The head can be swung in a horizontal plane.

As shown in FIG. 3, a boom operation lever 22 and a swing operation lever 23 are erected on an operation box 21 provided on a work table 19. The boom operation lever 22 is manually operated so that it can be tilted from a neutral position (a position in a standing state) in any direction of 360 degrees including front, rear, left and right and an intermediate direction thereof, and is twisted around an axis. It is configured to be able to. Base of boom operation lever 22 (operation box 2
1), a potentiometer for detecting the amount of tilting of the operating lever 22 in the front-rear direction, a potentiometer for detecting the amount of tilting of the operating lever 22 in the left-right direction, and an operating lever 22.
And a potentiometer for detecting the amount of twisting is provided, and information detected by each potentiometer is output as an up / down cylinder drive signal, a telescopic cylinder drive signal, and a turning motor drive signal, respectively. The swing operation lever 23 is configured to be tiltable in the front-rear direction from a neutral position (a position in a standing state) by manual operation.

As shown in FIG. 4, the controller 30 has a boom operation control unit 31, a worktable position calculation unit 32, a speed control unit 33, and a traveling control unit 34, , The telescopic cylinder drive signal and the swing motor drive signal are both input to the boom operation control unit 31. In addition, the workbench position calculating section 32 includes an up-and-down angle detector 41 for detecting the up-and-down angle of the boom 15, a length detector 42 for detecting the length of the boom 15, and the turning angle of the swivel table 13 (that is, the turning of the boom 15). Angle), the detection information from the turning angle detector 43 is input, and the position of the workbench 19 with respect to the vehicle body 11 is constantly calculated. As shown in FIG. 2, the undulation angle detector 41 is located near the base end of the base boom 15a, the length detector 42 is located at the tip of the base boom 15a, and the turning angle detector 43 is connected to the turning motor 14. Is provided in the vicinity of.

The up / down cylinder 16 is provided with the up / down cylinder drive valve 5.
By the operation of 1, the telescopic cylinder 17 is hydraulically driven by the operation of the telescopic cylinder drive valve 52, and the swing motor 14 is hydraulically driven by the operation of the swing motor drive valve 53. Each of these drive valves 51 to 53 is a controller 3
It is electromagnetically driven by the 0 boom operation control unit 31 to operate (see FIG. 4). The rotation direction and the rotation speed of the above-mentioned swinging motor change according to the tilting direction and the tilting amount of the swinging operation lever 23.

As described above, in the aerial work vehicle 10, the boom 15 is moved by operating the boom operation lever 22.
The work table 19 can be swung around the vertical post 18 by operating the swing operation lever 23. The operator himself / herself can operate the lever by operating the lever to move the workbench 19 to a desired position, and perform high-altitude work while adjusting the workbench 19 in a desired direction.

Further, as shown in FIG.
The first travel control lever 24 and the second travel control lever 2
5 are erected. First traveling operation lever 24
Can be tilted forward and backward from the neutral position (the position in the upright position). In addition to the neutral (neutral position), one forward speed (operating with a small amount of operation forward), and two forward speeds (Operating forward with a large operation amount), one reverse speed (operating backward with a small operation amount), and two reverse speeds (operating backward with a large operation amount) can be positioned at a total of five positions. The position of the first traveling operation lever 24 is detected by a potentiometer provided at the base of the operation lever 24 (inside the operation box 21), and is detected as a position signal by the controller 3.
0 is output to the travel control unit 34 (see FIG. 4). Also,
The second travel operation lever 25 can be tilted left and right from a neutral position (a position in an upright state), and the operation direction and operation amount of the second travel operation lever 25 are controlled by the operation lever. 25 is detected by a potentiometer provided at the base (inside the operation box 21) and output to the traveling control unit 34 of the controller 30 as an operation signal (including both information on the operation direction and the operation amount) (see FIG. 4). .

A hydraulic transmission 62 comprising a hydraulic pump 62a driven by an engine 61 and a hydraulic motor 62b receiving the oil discharged from the hydraulic pump 62a and outputting a rotational force is provided in the vehicle body 11. The traveling wheels 12a (the two rear wheels) are driven via the hydraulic transmission 62 (by the hydraulic motor 62b). Hydraulic pump 62a
The hydraulic motor 62b and the hydraulic motor 62b are both swash plate type variable displacement types. By tilting the respective swash plates (not shown) and changing the combination of the tilt angles of the two swash plates, the power of the engine 61 can be changed to a desired value. The rotation direction, the torque, and the number of rotations are converted into transmission to the drive-side traveling wheels 12a. Here, both swash plates of the hydraulic pump 62a and the hydraulic motor 62b are operated by hydraulic pressure adjusted by swash plate control valves 54 (provided on both swash plates) electromagnetically driven by the traveling control unit 34 of the controller 30. The tilting operation is performed through a link mechanism (not shown).

Here, the traveling control unit 34 controls the swash plate control valve so that the output of the hydraulic transmission 62 corresponds to the forward low speed when a first forward position signal is input by operating the first traveling operation lever 24. The swash plate control valve 54 is operated (the position of the swash plate control valve 54 at this time is set to a forward low speed position), and when a forward second speed position signal is input, the output of the hydraulic transmission 62 corresponds to the forward high speed. The valve 54 is operated (the position of the swash plate control valve 54 is set to the forward high-speed position). Further, when the reverse first speed position signal is input, the swash plate control valve 54 is operated so that the output of the hydraulic transmission 62 corresponds to the reverse low speed (the position of the swash plate control valve 54 is set to the reverse low speed position). When the second reverse speed position signal is input, the swash plate control valve 54 is operated so that the output of the hydraulic transmission 62 corresponds to the reverse high speed (the position of the swash plate control valve 54 is referred to as the reverse high speed position). When the neutral position signal is input, the hydraulic transmission 6
Swash plate control valve 5 so that the output of 2 corresponds to neutral.
Activate 4 When an operation signal from the operation of the second traveling operation lever 25 is input, the traveling control unit 34 electromagnetically drives the steering device operating valve 55 in accordance with both information (the operation direction and the operation amount) included in this signal, When the steering device 63 is hydraulically operated, the driven traveling wheels 12
b (two front wheels) is swung in the left-right direction with respect to its axle (not shown).

For this reason, the worker on the work table 19 can operate the aerial work vehicle 10 by operating the lever, and when the first travel operation lever 24 is positioned at the first forward speed, the low speed range is attained. (For example, about 2 km / h or less), and when it is positioned at the second forward speed, the vehicle can travel forward within a high-speed range (for example, about 4 km / h or less). Also, the first traveling operation lever 2
When the vehicle 4 is positioned at the first reverse speed, it is possible to travel backward within the low speed range, and when it is positioned at the second reverse speed, it is possible to travel backward within the high speed range. It should be noted that the right or left turn during traveling is the second traveling operation lever 25.
Can be performed.

Here, the operation of the boom 15 causes the work table 1 to move.
An area where the vehicle body 9 can be located is an area where it is recognized that the worker on the workbench 19 does not receive a large impact when the vehicle body 11 stops running within the high-speed range (when the vehicle body 11 travels within the high-speed range). A region D1 and a region D2 where the worker is recognized to receive a large impact when the vehicle body 11 stops from traveling in the high-speed range (a region where the vehicle body 11 cannot travel in the high-speed range). Therefore, the traveling speed range of the vehicle body 11 corresponding to the position of the work table 19 in the area D1 is determined in the above-described high-speed range.
The traveling speed range of the vehicle body 11 corresponding to the position of the workbench 19 located inside is set to the low speed range. For this reason, the speed control unit 33 of the controller 30
When it is recognized that the work table 19 calculated in Step 2 is in the area D2, the swash plate control valve 5 is controlled even if a position signal of two steps forward or two steps is input to the travel control unit 34.
The travel control unit 34 is restricted so that the vehicle body 4 is not located at the forward high-speed position or the reverse high-speed position (prohibiting the vehicle body 11 from traveling within the high-speed range). That is, the speed control unit 33 controls the traveling control unit 33 so that the traveling speed of the vehicle body 11 falls within the traveling speed range determined according to the position of the workbench 19.

For this reason, when the working amount of the boom 15 is small and the workbench 19 is positioned in the area D1, the first forward speed (running in the low speed range) and the high speed second speed (running in the high speed range). ) Can be selected to travel, but the deployment amount of the boom 15 is large and the workbench 19 is located in the area D2.
When the vehicle is located within the range, traveling at the second forward speed is not possible, and the traveling is limited to traveling at the first forward speed only (the same applies to reverse traveling).

As described above, in the aerial work vehicle speed control apparatus according to the first aspect of the present invention, the traveling speed of the vehicle body 11 is controlled by the work table 1.
Since the travel speed range is limited to a predetermined travel speed range corresponding to the position 9, the travel speed range is narrowed (that is, extended) as the amount of deployment of the boom 15 (particularly, the amount of lateral deployment) increases. By setting the maximum speed to be small), it is possible to prevent a large impact on the worker on the work table 19 when the running of the vehicle body 11 is stopped irrespective of the amount of deployment of the boom 15. At the same time, the load acting on the end of the boom 15 is reduced, so that the strength of the vehicle body 11 and the boom 15 can be prevented from lowering.

Next, a second embodiment of the present invention will be described. The configuration of this speed control device is substantially the same as the configuration of the high-place worker speed control device according to the first invention shown in FIG. 4, but the travel speed is limited only for the turning amount of the boom 15. It has a configuration. This is because the bending stiffness in the horizontal direction of the boom 15 is smaller than the bending stiffness in the vertical direction, and the work table 19 is attached to the vertical axis (vertical post 18) at the end of the boom 15; This is because it is the largest when it is deployed to the side of the. Therefore, the undulation angle detector 41 and the length detector 42 are not required.

The turning angle range that can be taken by the boom 15 is defined as the turning angle range in which the worker on the work table 19 is not likely to receive a large impact when the vehicle body 11 is stopped from traveling within the high-speed range (the vehicle body 11). Is a turning angle range in which the operator can travel within the high-speed range) D1 ', and a turning angle range in which the worker is recognized to receive a large impact when the vehicle body 11 stops traveling in the high-speed range (the (A turning angle range in which the vehicle cannot travel within the range) D2 ′ (this is because the boom 15 is closest to the horizontal state,
In addition, the evaluation is preferably performed in the most extended state), so that the traveling speed range of the vehicle body 11 corresponding to the turning angle of the boom 15 within the turning angle range D1 'is determined in the high speed range, and the turning angle range D2 The traveling speed range of the vehicle body 11 corresponding to the turning angle of the boom 15 within the 'is set to the low speed range. For this reason, when the speed control unit 33 of the controller 30 recognizes that the turning angle of the boom 15 detected by the turning angle detector 43 is within the turning angle range D2 ′, the traveling control unit 34 outputs Alternatively, even if the position signal of the rear two stages is input, the swash plate control valve 5
The travel control unit 34 is restricted so that the vehicle body 4 is not located at the forward high-speed position or the reverse high-speed position (prohibiting the vehicle body 11 from traveling within the high-speed range). That is, the speed control unit 33 controls the traveling control unit 33 so that the traveling speed of the vehicle body 11 falls within the traveling speed range determined according to the turning angle of the boom 15.

For this reason, when the turning amount of the boom 15 to the side is small and the turning angle of the boom 15 is within the turning angle region D1 ', the first forward speed (running in a low speed range) and the second high speed ( (Running in a high speed range) can be selected to run, but when the turning amount of the boom 15 to the side is large and the turning angle of the boom 15 is within the turning angle range D2 '. Becomes impossible to travel in the second forward speed, and is limited to traveling only in the first forward speed (the same applies to reverse travel). FIG. 5 shows the turning angle ranges D1 ′ and D2 ′ when the turning angle range D1 ′ is within 30 degrees of the side turning of the boom 15.
Here is a setting example.

As described above, in the second aspect of the present invention, the traveling speed of the vehicle body 11 is controlled by the boom 1.
Since the traveling speed range is limited to a predetermined traveling speed range corresponding to the turning angle of 5, the traveling speed range is set so as to be narrower as the turning amount of the boom 15 to the side is larger. The same effects as those of the first aspect of the invention can be obtained. Further, since the number of required detectors is smaller than that of the aerial work vehicle speed control device according to the first aspect of the present invention, the configuration can be simplified.
Also, the process of calculating and obtaining the position of the work table 19 is omitted,
Since the detected turning angle of the boom 15 can be used directly, it is also possible to use a limit switch instead of the turning angle detector 43.

Although the first and second embodiments of the speed control device for an aerial work vehicle according to the present invention have been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made. For example, in the above embodiment, the first travel operation lever 24
There are two types of traveling speed ranges (low-speed range and high-speed range) that can be selected, and therefore, two types of traveling speed ranges (regions D1, D2, or turning) determined in accordance with the position of the workbench 19 or the turning angle of the boom 15 are provided. Angle range D1 ', D
2 '), but when the selectable traveling speed ranges are three or more (including continuous changes), three traveling speed ranges determined in accordance with the position of the work table 19 or the turning angle of the boom 15 are set. It is also possible to make the above (including continuous changes).

Further, in the above embodiment, the traveling control unit 34 of the controller 30, the swash plate control valve 54, the hydraulic transmission 62 and the like are provided as means for traveling the vehicle body 11, and the operation of the swash plate control valve 54 is performed by the traveling control unit 34. Controlling the operation of the swash plate of the hydraulic pump 62a and the hydraulic motor 62b to control the running of the vehicle body 11 was performed.
The traveling control of the vehicle body 11 does not necessarily need to be performed by such a configuration. For example, the traveling of the vehicle body 11 may be controlled by controlling the flow rate of hydraulic oil supplied to the hydraulic motor 62b, or an electric motor controlled by the traveling control unit 34 may be configured by the swash plate control valve 54 and the hydraulic transmission 62. Instead of the motor, the driving-side traveling wheels 12a may be driven thereby. In these cases, the speed control described above can be performed by detecting the position of the work table 19 or the turning angle of the boom 15 as described in the above embodiment.

In the above embodiment, a self-propelled aerial work vehicle has been described as an example. However, the present invention is also applicable to an aerial work vehicle of a type in which a vehicle travels from a driver's seat on the vehicle.

[0028]

As described above, in the aerial work vehicle speed control device according to the first aspect of the present invention, the traveling speed of the vehicle body is within the traveling speed range predetermined in accordance with the position of the workbench. Since the travel speed range is limited, the travel speed range is determined so as to be narrower as the deployment amount of the boom (particularly, the deployment amount to the side) is larger (that is, the maximum speed that can be output becomes smaller). Irrespective of the deployment amount, it is possible to prevent a large shock from being applied to the worker on the work table when the vehicle body stops running. At the same time, since the load acting on the boom tip is reduced, the strength of the vehicle body and the boom can be prevented from lowering.

In the second aspect of the present invention, the traveling speed of the vehicle body is limited to a predetermined traveling speed range corresponding to the turning angle of the boom. By defining the traveling speed range so as to be narrower as the turning amount of the boom to the side is larger, the same effect as the first aspect of the invention can be obtained. Further, since the number of required detectors is smaller than that of the aerial work vehicle speed control device according to the first aspect of the present invention, the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a speed control device for an aerial work vehicle according to the present invention, and FIG. 1 (A) shows a configuration of a speed control device for an aerial work vehicle according to a first present invention; ,
(B) shows the configuration of the speed control device for an aerial work vehicle according to the second invention.

FIG. 2 is a side view of an aerial work vehicle provided with the aerial work vehicle speed control device according to the present invention.

FIG. 3 is a perspective view showing a workbench of the aerial work vehicle of FIG. 2;

FIG. 4 is a block diagram showing a configuration of the first embodiment of the speed control device for an aerial work vehicle according to the present invention.

FIG. 5 is a plan view of an aerial worker showing a setting example of a turning angle range D1 ′ and a turning angle range D2 ′ in the second embodiment of the speed control device for an aerial work vehicle according to the present invention.

[Explanation of symbols]

Reference Signs List 10 work platform aerial platform 11 body 15 boom 19 work platform 24 first travel operating lever (travel command means) 30 controller 32 work platform position calculation unit (position detection means) 33 speed control unit (control means) 34 travel control unit (travel) Means) 41 Undulating angle detector (Position detecting means) 42 Length detector (Position detecting means) 43 Turning angle detector (Position detecting means, Turning angle detecting means) 54 Swash plate control valve (Running means) 62 Hydraulic transmission ( Running means)

Claims (2)

[Claims] 1. A vehicle body, a boom provided on the vehicle body so as to be able to move up, down, expand and contract, and pivot; a workbench mounted on an end of the boom for an operator to board; A speed control device for an aerial work vehicle, comprising: travel command means for performing; and travel means for causing the vehicle body to travel in accordance with an operation of the travel command means. And a control unit that controls the traveling unit so that the traveling speed of the vehicle body is within a traveling speed range that is predetermined according to the position of the worktable detected by the position detection unit. A speed control device for an aerial work vehicle, comprising: control means. 2. A vehicle body, a boom provided on the vehicle body so as to be able to move up, down, extend, and turn, a workbench mounted on an end of the boom for a worker, and a traveling command of the vehicle body is provided. And a traveling means for traveling the vehicle body in accordance with an operation of the traveling instruction means. Turning angle detecting means, and control for controlling the running means such that the running speed of the vehicle body is within a predetermined running speed range corresponding to the turning angle of the boom detected by the turning angle detecting means. And a means for controlling the speed of an aerial work vehicle.