JP2000086194A - Automatic jack projecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide constitution capable of easily and rapidly causing projecting of jacks so that a vehicle body is horizontally supported even on inclined surfaces or rugged road surfaces. SOLUTION: A controller 35 controls a jack actuation valve 34, thereby actuating jacks 30 for expansion or contraction. The controller 35 first causes all of the jacks 30 to project from storage positions, and after the grounding of all of the jacks 30 has been detected by a grounding detector 33, the tilt angle of a vehicle body detected by a tilt angle detector 32 is compared with a preset allowable tilt angle. When the tilt angle of the vehicle body is detected to exceed the allowable tilt angle, only those jacks needed to be actuated for expansion in order to keep the tilt angle of the vehicle body at or below the allowable tilt angle are actuated for expansion; when the tilt angle of the vehicle body is detected to be equal to or less than the allowable tilt angle, all of the jacks 30 are actuated for expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic jack extension device for automatically extending a jack for supporting a vehicle body provided in an aerial work vehicle or the like.

[0002]

2. Description of the Related Art A work vehicle such as an aerial work vehicle or a crane vehicle having a boom that can be raised and lowered freely on a vehicle body has jacks for supporting the vehicle body at front, rear, left and right of the vehicle body. By protruding downward and lifting and supporting the vehicle body, it is possible to obtain stability against a moment acting on the vehicle body in the direction of tipping over due to its own weight or tip load (hereinafter referred to as “falling moment”). I have.

When working at a high place or the like with a work vehicle equipped with such a jack, the vehicle body is usually stopped at a horizontal place and jacks are extended so that the vehicle body is supported horizontally. The reason why the vehicle body is horizontally supported in this way is that when the vehicle body is tilted, the above-mentioned overturning moment may act greatly depending on the turning direction of the boom.

[0004]

However, it is easy to overhang the jack for supporting the vehicle body in a horizontal state when the road surface is almost horizontal, but it is very difficult on a slope or uneven road surface. Was. For this reason, much time is required, and the working efficiency is reduced. In addition, when the vehicle body is not sufficiently horizontally supported, there is a possibility that the vehicle body may fall when the boom or the like is operated. There is also an automatic overhanging device for automatically extending the jack, but the conventional automatic overhanging device does not extend the jack while controlling the vehicle body to be horizontally supported.

[0005] The present invention has been made in view of such a problem, and can be easily applied to an inclined surface or an uneven road surface.
It is another object of the present invention to provide an automatic jack extension device capable of promptly extending a jack so that a vehicle body is horizontally supported.

[0006]

In order to achieve the above object, an automatic jack extension device according to the present invention comprises a plurality of jacks which extend downward from a stored state to lift and support a vehicle body. Work vehicles arranged on the left and right (for example,
A jack-operated valve, a ground detection unit (for example, the ground detectors 33, 33,... In the embodiment), and a tilt angle detection unit (for example, in the embodiment) An inclination angle detector 32), an overhang start signal output unit (for example, the overhang start switch 31 in the embodiment), and a control unit (for example, the controller 35 in the embodiment) are configured. The jack operating valve adjusts the supply of hydraulic oil to the jack to control the extension operation of the jack, and the ground detecting means is provided in each of the jacks, and determines whether or not the lower end of the jack is in contact with the ground. The inclination angle detection means detects the inclination angle of the vehicle body, the overhang start signal output means is externally operated and outputs an overhang start signal, and the control means outputs the overhang start signal. When the jack operating valve is operated so that all the jacks extend from the retracted state when the jacks are in contact with the ground based on the detection result from the ground detecting means, the inclination angle detecting means When the inclination angle of the vehicle body is detected to be greater than the allowable inclination angle, and the inclination angle of the vehicle body is detected to be greater than the allowable inclination angle, the inclination angle of the body of the jack is set to the allowable inclination angle. Below the corner When a jack that requires extension operation is selected and the jack actuation valve is controlled so that only the selected jack is extended, control is performed to detect that the vehicle body inclination angle is less than the allowable inclination angle. Performs control to operate the jack operating valve so that all jacks extend.

[0007] In the jack automatic overhanging device having such a configuration, after all the jacks have touched the ground, the vehicle body is first adjusted to a horizontal state, and then the jacks are extended while maintaining this horizontal state to thereby extend the vehicle body. Lift up. For this reason, the vehicle body can be easily and quickly horizontally supported even on an inclined surface or an uneven surface, and the time required for the jack overhang operation can be reduced to improve the operation efficiency.

In addition to this configuration, the control means measures an elapsed time from when it is detected that all jacks have contacted the ground based on the ground signal, and the elapsed time is calculated as follows:
A configuration in which a jack operating valve is operated so that the entire expansion operation of the jack is stopped when the jack exceeds a predetermined time limit within a time required for the jack to extend from the retracted state to the fully extended state. It is preferable that With such a configuration, when the vehicle is being lifted in a horizontal state, the other jacks continue to extend while the extending operation of one jack is completely extended. The situation can be prevented, thereby avoiding the inconvenience that the horizontal state of the vehicle body collapses or the vehicle body falls down depending on the situation.

Further, the control means outputs an alarm signal when detecting that the inclination angle of the vehicle body is equal to or less than the allowable inclination angle when the elapsed time exceeds the time limit. It is preferable to have a configuration having an alarm unit (for example, the alarm lamp 37 and the alarm buzzer 38 in the embodiment) that performs an alarm operation in response to a signal. With such a configuration, the worker can check whether or not the vehicle body is in a horizontal state at the time when the automatic extension operation of the jack ends, so that the worker starts working while the vehicle body is tilted. This ensures safety.

[0010]

Preferred embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 shows an aerial work vehicle equipped with the automatic jack extension device according to the present invention. The aerial work vehicle 1 is configured based on a truck, and a driver's seat 11 is provided in front of a vehicle body 10.
On four front, rear, left and right sides of the vehicle body 10, running wheels 12, 12,
Are arranged. A swivel 13 is mounted on the vehicle body 10 so that the vehicle can be horizontally rotated by a rotation motor 14 built in the vehicle body 10. A base end of a boom 15 is pivotally connected to the swivel base 13, and the boom 15 is raised and lowered by an expansion and contraction operation of an up-and-down cylinder 16 attached to both the swivel base 13 and the boom 15. Is available. A telescopic cylinder 17 is provided inside the boom 15, and the boom 15 can be telescopically operated by the telescopic operation of the telescopic cylinder 17.

A vertical post 18 is provided at the tip of the boom 14, and a work table 19 for an operator to board is mounted on the vertical post 18 so as to be pivotable. Here, since the vertical post 18 is attached to the boom 15 via a leveling device (not shown) and is always kept in a vertical state, the work table 19 is always in a horizontal plane regardless of the elevation angle of the boom 15. Can be turned.

The vehicle body 10 and the workbench 19 are provided with boom operating devices 20 and 21, respectively. The operating lever L attached to these boom operating devices 20 and 21 is manually operated to raise and lower the cylinder 16 and the telescopic cylinder 16. The work table 19 can be moved to a desired position by operating the boom 15 up and down, expanding and contracting, and turning by operating the 17 and the turning motor 13.

Also, jacks 30, 30,... Are provided at four front, rear, right, and left sides of the vehicle body 10, and can be expanded and contracted by hydraulic pressure. Are capable of lifting and supporting the vehicle body 11 by extending downward from the stowed state, whereby the vehicle body 11 can be stably supported. Each jack 30 is shown in FIG.
It is possible to protrude to the side of the vehicle body 11 as shown in FIG. 1, whereby the vehicle body 11 can be supported in a more stable state. The jack automatic extension device according to the present invention is characterized by a device for extending the jacks 30, 30,..., And the configuration and operation will be described in detail below.

FIG. 1 shows the configuration of an automatic jack extension device according to the present invention. The overhang start switch 31 is attached to a jack operating device (not shown) provided behind the vehicle body 11, and outputs an overhang start signal when manually operated (ie, externally operated). Tilt angle detector 32
Is built in the vicinity of the center of the vehicle body 11,
And outputs a tilt angle signal by detecting the tilt angle from the horizontal state. The tilt angle detector 32 includes a tilt angle θx in the front-rear direction of the vehicle body 11 (for example, when the forward lifting of the vehicle body 11 is positive) and a tilt angle θy in the left-right direction of the vehicle body 11 (for example, Both positive and negative) can be detected at the same time. The grounding detector 33 is provided in each jack 30, and outputs a grounding signal when the jack 30 comes into contact with the ground (hereinafter referred to as "grounded"). The jack operating valve 34 is provided in a hydraulic circuit system formed in the vehicle body 11, and the jack 30,
Adjust the supply of hydraulic oil to each jack 3
0 is extended and retracted. Then, the controller 35 receives the overhang start signal, the inclination angle signal, and the ground signal, and operates the jack operating valve 34.

As shown in FIG. 1, the jack operating valve 34 includes four solenoid valves 34a, 3a corresponding to each jack 30.
4a,... Open or close an oil passage of hydraulic oil flowing from the hydraulic pressure source P into each jack 30. The solenoid valve 34a shown in FIG.
Only the first switching position P1 at which the extension operation of 0 is stopped and the second switching position P2 at which the jack 30 is extended are shown (actually, there are also switching positions at which the jack 30 is contracted). Do).

Each solenoid valve 34a is located at the first switching position P1 when not excited by the controller 35, closes an oil passage of hydraulic oil flowing from the hydraulic pressure source P into the jack 30, and is excited by the controller 35. Sometimes, it is located at the second switching position P2 and opens the oil passage flowing from the hydraulic pressure source P to the jack 30. When all of the solenoid valves 34a are located at the first switching position P1, the hydraulic oil from the hydraulic pressure source P is returned from the relief valve to the tank T. In other cases, that is, at the second switching position P2. Are operated, the jacks 30, 30,... Corresponding to those solenoid valves are extended (however, the hydraulic pressure restricted by the relief valve R in the hydraulic circuit is limited). When actuated, the hydraulic oil is returned from the relief valve R to the tank T, and no jacks 30 extend further). For this reason, the expansion / contraction (and stop) operation of each jack 30 can be controlled only by switching each switching position by operating each electromagnetic valve 34a by the controller 35.

The operation of the automatic jack extension device having the above-described configuration will be described. The operator sets the overhang start switch 31
Is operated, the overhang start signal is output to the controller 35, whereby the jack operating valves 34 are operated (all the solenoid valves 34a are located at the second switching position P2), and the hydraulic oil is supplied to all the jacks 30. Supplied. .. Start the extension operation from the retracted state. The extension operation of the grounded jack 30 is stopped until all the other jacks 30, 30,. This is because the hydraulic oil supplied to the jack 30 flows preferentially into the one with the smaller load.

Here, a ground signal is output from the ground detector 33 to the grounded jack 30, and is input to the controller 35. Further, when the jack 30 is grounded, a lamp (not shown) corresponding to each jack 30 provided in the above-mentioned jack operating device is illuminated and displayed, and the operator can determine which jack 30 is grounded. You can check if it is.

The controller 35 controls all jacks 30
Is detected, the inclination angles θx and θy of the vehicle body 11 detected by the inclination angle detector 32 are compared with predetermined allowable inclination angles θxo and θyo (both are positive values) ( (For example, at predetermined time intervals), (1) that the inclination angle of the vehicle body 11 exceeds the allowable inclination angle (that is, | θ
If x |> θxo and / or | θy |> θyo) is detected, the inclination angle of the vehicle body 11 of the four jacks 30 is set to be equal to or less than the allowable inclination angle (that is, | θx | ≦ θxo and | θy | ≦ θyo), and select the jack 30 that requires the extension operation, and operate the jack operation valve 34 so that only the selected jack 30 performs the extension operation (selected). Only the solenoid valve 34a corresponding to the jack 30 is moved to the second switching position P.
2 and the other solenoid valve 34a is in the first switching position P
1), and (2) when it is detected that the inclination angle of the vehicle body 11 is equal to or smaller than the allowable inclination angle (that is, | θx | ≦ θxo and | θy | ≦ θyo).
Is detected), all jacks 30
The control is performed such that the jack operating valves 34 are operated such that all the solenoid valves 34a are extended (the solenoid valves 34a are all positioned at the second switching position P2).

Here, the allowable inclination angles θxo and θyo can be set to any angles. However, the smaller these values are, the closer the vehicle body 11 when lifted and supported is to a horizontal state. In addition, the jack 30 to be extended is
Specifically, the selection is made according to the data shown in the table of FIG. 3 (stored in the controller 35 in advance). here,
The “inclination state of the vehicle body” in the table of FIG. 3 is defined as the allowable inclination angle θxo, where θx is positive for forward raising and θy is positive for rightward raising.
It is detected by a magnitude comparison with θyo, for example, θx>
When θxo and θy> θyo, it is required that the vehicle body 11 be in the rear left lowering state. Also, "left front",
“Front right”, “rear left”, and “rear right” indicate the positions of the respective jacks 30. The mark を indicates the jack 30 to be extended, and the mark X indicates the jack 30 not to be extended.

The controller 35 measures an elapsed time t from when all the jacks 30, 30,... Have been touched, and the elapsed time t is determined by a predetermined limit. When the time T is exceeded, the jack operation valves 34 are operated (all the solenoid valves 34a are located at the first switching position P1), and all the jacks 30, 30,.
・ Stop the extension operation. Here, the above time limit T
Is set within the time To required for the jack 30 to extend from the stored state to the completely extended state.

As described above, in the automatic jack extension device according to the present invention, after all the jacks 30, 30,... Are in contact with the ground, the body 11 is first adjusted to a horizontal state, and then the horizontal state is maintained. The vehicle body 11 is lifted by projecting the jacks 30 while keeping the state (the vehicle body 11 is restored to the horizontal state even if the vehicle body 11 is tilted during the lifting). Therefore, even on an inclined surface or an uneven surface,
In addition, the vehicle body 11 can be quickly horizontally supported,
The time required for the overhang work of the jacks 30, 30,... Can be reduced, and the work efficiency can be improved. Also, since the time limit as described above is provided for the time when the jacks 30, 30,... Can be extended, when the jacks 30, 30,. Despite the extension operation of one jack 30 being completely extended, the other jacks 30,
.. Can be prevented from continuing to extend, thereby avoiding the inconvenience of the horizontal state of the vehicle body 11 being collapsed or the vehicle body 11 falling down depending on the situation. .

When the extension operation of all jacks 30, 30,... Is stopped when the elapsed time t exceeds the time limit T, the lifting operation of the vehicle body 11 by the jacks 30, 30,. . When the vehicle body 11 is kept horizontal when the elapsed time t exceeds the time limit T, that is, | θx | ≦ θxo and | θy | ≦ θ
When yo is detected, the controller 35 outputs a normal end signal and turns on and displays a normal end indicator lamp 36 provided on the jack operating device (see FIG. 1).

On the other hand, when the vehicle body 11 is not kept horizontal when the elapsed time t exceeds the time limit T, that is, when | θx |> θxo and / or | θy |> θyo , The controller 35 outputs an alarm signal,
An alarm lamp 37 provided on the jack operating device is lit and displayed, and an alarm sound is emitted from an alarm buzzer 38 (see FIG. 1). In this way, the worker can use the jacks 30, 3
When the automatic overhang operation of 0,... Is completed, it is possible to check whether or not the vehicle body 11 is in a horizontal state, so that work does not start while the vehicle body 11 is tilted. , Safety is ensured.

In this automatic jacking device, not only the above-mentioned automatic extension but also each jack 30 is provided.
Can be individually extended. For this reason,
If the vehicle body 11 is not in a horizontal state at the time when the automatic overhang operation is completed, the worker operates the inclinometer (the vehicle body 11 detected by the inclination angle detector 32) provided in the jack operating device described above. The individual jacks 30 are extended while viewing the tilt state visually (not shown).
The vehicle body 11 can be adjusted to a horizontal state.

Note that, depending on the positional relationship between the slope and the vehicle body 11, when a specific jack 30 is extended, another jack 30 may be separated from the ground. For this reason, when the controller 35 detects the jack 30 separated from the ground based on the grounding detector 33, the controller 35 determines the inclination angles θx and θy of the vehicle body 11 and the allowable inclination angle θxo,
Before performing the comparison with θyo, first, the jack 30 that is separated from the ground is extended until the ground is grounded (the solenoid valve 34a is operated), and it is detected that all the jacks 30, 30,. It is preferable that the comparison be performed after that. With such a configuration, the vehicle body 11 can always be kept in a stable state.

While the embodiment of the automatic jack extension device according to the present invention has been described above, the present invention is not limited to the configuration shown in the above embodiment, and various design changes are possible. For example, the tilt angle detector 32 only needs to detect the tilt state of the vehicle body 11 from a horizontal state, and does not necessarily need to detect the front-back direction tilt angle and the left-right direction tilt angle.

[0028]

As described above, in the automatic jack extension device according to the present invention, after all jacks have touched down, the vehicle body is first adjusted to a horizontal state, and then the horizontal state is maintained. Each jack is overhanging and the body is lifted, so even on inclined or uneven surfaces,
In addition, the vehicle body can be quickly horizontally supported, and the time required for the jack overhang operation can be reduced, thereby improving the operation efficiency.

Also, the elapsed time from when all jacks have contacted the ground is measured, and this elapsed time is determined in advance within the time required for the jack to extend from the retracted state to the completely extended state ground. The extension operation of one jack is completely extended when the body is lifted in a horizontal state by adopting a configuration in which the extension operation of all jacks stops when a predetermined time limit is exceeded. This prevents the situation where the other jacks continue to extend in spite of the fact that it has become inconvenient, thereby avoiding the inconvenience that the horizontal state of the vehicle body collapses and the vehicle body falls over in some situations be able to.

Further, when the elapsed time exceeds the time limit, the alarm is activated when the inclination angle of the vehicle body is equal to or smaller than the allowable inclination angle. Is completed, it is possible to check whether or not the vehicle body is in a horizontal state, so that work does not start while the vehicle body is tilted, and safety is ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a jack automatic extension device according to the present invention.

FIG. 2 is a perspective view showing a configuration of an aerial work vehicle equipped with the automatic jack extension device.

FIG. 3 is a table showing data used by the controller to select which jack should be extended based on the inclination angle of the vehicle body.

[Description of Signs] 1 Aerial work platform 30 Jack 31 Projection start switch (Projection start signal output means) 32 Tilt angle detector (Tilt angle detecting means) 33 Grounding detector (Grounding detecting means) 34 Jack operating valve 35 Controller (control means) 37 Alarm lamp (alarm means) 38 Alarm buzzer (alarm means)

Claims (3)

[Claims] 1. A plurality of jacks disposed on the front, rear, left and right sides of a vehicle body and extending downward from a retracted state to lift and support the vehicle body, and adjusting supply of hydraulic oil to the jack to extend the jack. A jack operating valve for performing operation control; a plurality of grounding detecting means provided on each of the jacks for detecting whether a lower end portion of the jack is in contact with the ground; and an inclination for detecting an inclination angle of the vehicle body. Angle detection means, overhang start signal output means for outputting an overhang start signal by external operation, and when the overhang start signal is output, the jacks all extend from the storage state. After actuating a jack actuation valve and detecting that all of the jacks have come into contact with the ground based on the detection result from the contact detection means, the inclination of the vehicle body detected by the inclination angle detection means is detected. The angle is compared with a predetermined allowable inclination angle, and when it is detected that the inclination angle of the vehicle body exceeds the allowable inclination angle, the inclination angle of the vehicle body of the jack is equal to or less than the allowable inclination angle. In order to make the extension operation necessary, a jack that requires extension operation is selected, and control is performed to operate the jack operating valve so that only the selected jack performs extension operation, and the inclination angle of the vehicle body is equal to or less than the allowable inclination angle. Control means for controlling the operation of the jack operation valve so that all of the jacks extend when detected. 2. The method according to claim 1, wherein the control unit measures an elapsed time from when the jack detects that all of the jacks are in contact with the ground based on the ground signal, and measures the elapsed time from when the jack is completely retracted from the stored state. The jack operating valve is operated so that the extending operation of all the jacks is stopped when a predetermined time limit exceeds a predetermined time within a time required to extend until reaching the overhang state. The automatic jack extension device according to claim 1. 3. An alarm signal is output when the control means detects that the inclination angle of the vehicle body is equal to or less than the allowable inclination angle when the elapsed time exceeds the time limit. 3. An automatic jack extension device according to claim 2, further comprising alarm means for performing an alarm operation upon receipt of the alarm.