JP2551248Y2 - Work vehicle safety devices - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a working vehicle in which a swivel having a telescopic boom that can be driven up and down is freely mounted on a vehicle.

[0002]

2. Description of the Related Art This type of work vehicle is widely used as an aerial work vehicle or a mobile crane. A conventional example of a safety device used for an aerial work vehicle will be described with reference to FIGS. FIG. 1 shows an aerial work vehicle. The aerial work vehicle mounts a swivel 3 having a telescopic boom 2 which can be driven up and down on a vehicle 1 so as to be able to be swiveled.
An operator's boarding bucket 4 is attached to the distal end of the telescopic boom 2. FIG. 2 shows a safety device mounted on an aerial work vehicle, and the safety device includes a telescopic boom 2.
Actual state detecting means A for detecting the actual value of the related operation, the operating direction detecting means B for detecting the direction of the related operation of the telescopic boom 2, and the actual state detecting means A and the operating direction detecting means B
To detect that the telescopic boom-related operation has reached a limit state based on the actual value from the actual state detecting means A, and in this limit state, detect the telescopic boom-related operation detected by the operation direction detecting means B. When the direction of operation is in the danger direction beyond the limit state (the relevant operation direction of the telescopic boom which becomes the operation state exceeding the current operation state in the limit state due to the relevant operation of the telescopic boom), an alarm or And limit signal generating means C for outputting a signal for regulating the telescopic boom-related operation.

In the case of this embodiment, actual state detection means A
Is a derricking angle detector A ₁ for detecting a derricking angle of the telescopic boom 2 theta, is composed of a telescopic boom length detector A ₂ for detecting the length L of the telescopic boom 2. Each detector A ₁ , A
Numeral ₂ is a conventional well-known potentiometer for outputting the displacement of the up-down angle and the length of the extension / contraction of the telescopic boom 2 as continuous electric signals. The operation direction detecting means B, controls the detecting and telescopic drive of the limit switch B ₁ and the telescopic boom 2 outputs an electric signal the operation on the telescopic boom lodging direction of the operation lever 5 for controlling the relief operation of the telescopic boom 2 Limit switch that detects the operation of the operating lever 6 in the telescopic boom extension direction and outputs an electric signal
It is composed of a B _2.

The limit signal generating means C stores a limit working radius Rmax (a working radius R allowable for the aerial work vehicle) of the aerial work vehicle, and stores each signal θ from the actual state detecting means A. , operating radius R is a limit state detection unit C ₁ for detecting that reaches the limit working radii Rmax according to this storage, the limit state detection unit C ₁ of the detection signal and the operation direction detecting means which is calculated based on the L An AND circuit that outputs a signal that regulates an alarm or a tilting movement of the telescopic boom 2 when both of the detection signals of the B limit switch B ₁ are input simultaneously.
And C _2, outputs a signal for restricting the extension movement of the alarm or the telescopic boom 2 when the two signals of the detection signal of the limit switch B ₂ of the detection signal and the operation direction detecting means B of limit state detection unit C ₁ is input at the same time It is constituted by an aND circuit C ₃ to.

The signals output from the limit signal generating means C, that is, the signals output from the AND circuits C ₂ and C ₃ , respectively, include an alarm device 7 and a falling motion stopping device 8 for stopping the telescopic boom 2 from falling, and an alarm. The extension movement stopping means 9 for stopping the extension movement of the device 7 and the telescopic boom 2 is operated.

[0006] The safety device used in the conventional aerial work vehicle configured as described above includes the telescopic boom 2 in the direction in which the operating state of the aerial work vehicle exceeds the current operating state when the operating state of the aerial work vehicle is in a limit state. Since only the related operation of the telescopic boom 2, that is, the falling operation and the extending operation of the telescopic boom 2 can be alarmed or restricted, it has been frequently used.

Next, a conventional example of a safety device used for a mobile crane will be described with reference to FIG. In the case of a mobile crane, instead of the bucket 4 of the aerial work vehicle shown in FIG. 1, a lifting tool is hung up and down freely from the distal end of the telescopic boom 2. Like the safety device of the aerial work vehicle shown in FIG. 2, the safety device of such a mobile crane includes an actual state detecting means A for detecting an actual value of a related operation of the telescopic boom 2, and a related device of the telescopic boom 2. The operation direction detecting means B for detecting the direction of the operation, and the signals from the actual state detecting means A and the operation direction detecting means B are received, and based on the actual value from the actual state detecting means A, the telescopic boom-related operation becomes the limit state. In this limit state, when the direction of the telescopic boom-related operation detected by the operation direction detecting means B is the danger direction exceeding the limit state, an alarm or a signal for restricting the telescopic boom-related operation is issued. And output limit signal generating means C.

In this embodiment, actual state detecting means A
Are the load detector A ₃ for detecting the weight of the suspended load or the actual value F of the load acting on the up / down cylinder, the length of the up / down angle detector A ₁ for detecting the up / down angle θ of the telescopic boom 2 and the length of the telescopic boom 2. It is composed of a telescopic boom length detector a ₂ which detect the L. Among derricking angle detector A ₁ and the telescopic boom length detector A ₂ are each stretchable Bed - constituted by a conventionally known potentiometer for outputting a hoisting angle displacement and stretching the length displacement of the arm 2 as a continuous electrical signal ing. The operation direction detecting means B, controls the detecting and telescopic drive of the limit switch B ₁ and the telescopic boom 2 outputs an electric signal the operation on the telescopic boom lodging direction of the operation lever 5 for controlling the relief operation of the telescopic boom 2 It is composed of a limit switch B ₂ for outputting an electric signal by detecting the operation of the telescopic boom extending direction of the operating lever 6.

The limit signal generating means C is provided for each combination of the up-and-down angle θ of the telescopic boom 2 and the length L of the telescopic boom 2
Allowable load on the telescopic boom 2 (the load suspended on the hanger,
Alternatively, a limit value Fmax of the load F) acting on the undulating cylinder of the telescopic boom 2 is stored, and the actual state detecting means A is stored.
Each signal from theta, reads the limit value Fmax corresponding to operating position of the telescopic boom 2 at that time the L as a read signal is detected by the actual value F (load detectors A ₃ and load the read-out limit Fmax and load of the suspended load, or by comparison actual value F) of the load acting on the derricking cylinder, a limit state detection unit C ₁ to detect that the actual value F becomes the limit state reaches the limit value Fmax, the The detection signal of the limit state detection section C ₁ and the limit switch B ₁ of the operation direction detection means B
AND that outputs a signal that regulates the tilting movement of the telescopic boom 2 when both of the detection signals are input simultaneously.
The circuit C ₂ , when both the detection signal of the limit state detection section C _{1 and} the detection signal of the limit switch B ₂ of the operation direction detection means B are simultaneously inputted, outputs an alarm or a signal for restricting the extension movement of the telescopic boom 2. It is constituted by an aND circuit C ₃ to output.

The signal generated by the limit signal generating means C, that is, the signal output from the AND circuits C ₂ and C _3, respectively, is an alarm 7 and a falling movement stopping means 8 for stopping the falling movement of the telescopic boom 2 and an alarm 7. The extension movement stopping means 9 for stopping the extension movement of the telescopic boom 2 is operated.

[0011] The conventional mobile crane constructed as described above.
The safety device used for the operation of the telescopic boom 2 in the direction in which the operating state of the mobile crane is in an operating state exceeding the current operating state when the operating state of the mobile crane is in a limit state, that is, the operation of falling down the telescopic boom 2 Since only the extension operation can be alarmed or restricted, it has been frequently used.

[0012]

In the conventional safety device for a work vehicle configured as described above, the operating direction detecting means B controls the operation lever 5 for controlling the up / down driving of the telescopic boom 2 in the telescopic boom falling direction. A limit switch B ₁ for detecting and outputting an electric signal, and a limit switch B ₂ for detecting an operation of the operating lever 6 in the extending direction of the telescopic boom for controlling the telescopic drive of the telescopic boom ₂ and outputting an electric signal. Therefore, the cost of the safety device is increased by the price of the limit switches B ₁ and B ₂ , and the work of adjusting the attachment of the limit switch to the operation lever is complicated and takes a long time.

An object of the present invention is to solve the problems of the conventional safety device for a work vehicle by using a detection signal of an actual state detection means constituted by a potentiometer for an operation direction detection means. An object of the present invention is to provide a safety device for a work vehicle that is configured to calculate a direction and that does not require a limit switch.

[0014]

Means for Solving the Problems To achieve the above object, the safety device for a work vehicle according to the present invention is configured as follows.
That is, a swivel base with undulations drivable telescopic boom on the vehicle turning drive rotatably mounted, the actual state detecting means composed of a potentiometer for detecting the actual value of the telescopic boom related operation, the direction of the telescopic boom-related action Receiving the signals from the actual state detecting means and the operating direction detecting means, and detecting that the telescopic boom-related operation has reached the limit state based on the actual value from the actual state detecting means. In addition, when the direction of the telescopic boom-related operation detected by the operation direction detecting means in the limit state is a danger direction that exceeds the limit state, a limit signal generating means that outputs a signal that regulates an alarm or a telescopic boom-related operation, A safety device for a working vehicle, comprising: the operating direction detecting means receiving a signal from the actual state detecting means, and Safety device for a work vehicle, characterized in that phased time are constituted by computing means for obtaining a risk direction to calculate the front and rear of increase or decrease of the change.

[0015]

The safety device for a working vehicle according to the present invention having the above-described structure includes an operation direction detecting means for detecting the direction of a telescopic boom-related operation which has conventionally been constituted by a limit switch. When a signal from the state detecting means is received and the signal changes, the increase / decrease of the signal before and after the change is calculated to calculate the danger direction, so that all processing is performed by the actual state detecting means and the calculating means. This eliminates the need to separately provide a limit switch for detecting the direction of the extension-boom-related operation. For this reason, the cost of the safety device can be reduced by the amount that the limit switch is not required, and the complicated adjustment adjustment work of the limit switch can be eliminated.

[0016]

An embodiment of the safety device for a work vehicle according to the present invention will be described below with reference to FIGS. The safety device for a work vehicle according to the present invention stops using the limit switch as the operation direction detecting means B for detecting the direction of the telescopic boom-related operation in the conventional safety device. It has a feature in that it is obtained by calculation from the detection output. In the following description, the operation means is that the operation direction of the telescopic boom is driven in the dangerous direction from the detection output of the actual state detection means A. Only the means for detecting whether or not this is the case will be described.

[0017]C _Four Is a telescopic boom operating direction calculating means.
You. Telescopic boom operation direction calculating meansC _Four Is the actual state
Undulating angle detector of detection means AA ₁ Undulation angle signal detected by
No. θ and telescopic beam length detectorA _Two Telescopic boom detected by
Each of the length signals L is input. So
The telescopic boom operating direction calculating meansC _Four Is shown in FIG.
Calculation processing is performed according to the following calculation processing procedure.
Has become. In addition, the telescopic boom operation direction calculating meansC
_Four Constitutes the calculation means in the utility model registration claims
doing.

Next, the telescopic boom operating direction calculating means C ₄
Will be described. Stretch Bed - beam moving direction calculating means C _4, if started, the process proceeds to the first step, a derricking angle signal θ that derricking angle detector A ₁ detects the actual state detecting means A, stretchable Bed - arm length detector a ₂ is detected stretch Bed - arm length signal L reading each temporarily stored.

Next, proceeding to the second step,
Beam moving direction calculating means C ₄ determines whether immediately after startup.
Here stretchable Bed - for beam moving direction calculating means C ₄ has just started, without proceeding to the third step and returns to the first step of the next cycle. This is arithmetic means C
_This is because only the current up-and-down angle signal θ and the length signal L of the telescopic boom 2 have been read into 4 and the comparison operation cannot be performed even if the process proceeds to the third step.

Returning to the first step of the second cycle,
The undulation angle signal θ and the telescopic beam length signal L temporarily stored in the previous cycle are respectively stored in the internal memory (the undulating angle signal θ is stored in the memory as the storage value θm, and the telescopic beam is stored.
After beam length signal L is stored as a stored value Lm in memory), and a new relief and derricking angle signal θ the angle detector A ₁ detects, stretch Bed - stretching blanking the beam length detector A ₂ detects -
The system length signal L is read and temporarily stored.

Next, the process proceeds to a third step, where the undulation angle signal θ temporarily stored (the telescopic boom undulation angle signal θ detected in the current cycle) and the stored value θm stored in the memory (the previous cycle) (Corresponding to the expansion / contraction boom undulation angle signal θ detected in step (1)). If the comparison result indicates that the undulation angle signal θ is smaller than the stored value θm (θ <θm),
After outputting the signal to the AND circuit C _2, Meinru - and is reset to routine. If the comparison result is a condition other than the above (θ> = θm), the process proceeds to the next step as it is. In other words, in this step, the telescopic boom undulation angle (the stored value θm
Telescopic boom in this cycle after a very short time.
By comparing the hoisting angle (θ), the telescopic boom-related operation is in the direction of decreasing the hoisting angle of the telescopic boom 2 (the direction in which the telescopic boom 2 is driven to fall), or It is designed to calculate whether the direction is for increasing the undulation angle (direction for driving the telescopic boom 2 up or down). When the calculating means C ₄ determines from the calculation result that the telescopic boom-related operation is driving in the direction in which the telescopic boom 2 falls down, it determines that driving in the danger direction is AND. outputs a signal to the circuit C _2, it has become to actuate the relief movement stop means 8 and the alarm 7 in the limit state. If it is determined that the telescopic boom-related operation is driving in the direction in which the telescopic boom 2 is raised, it is determined that the driving is in the safe direction, and the AND circuit is operated.
It has become not to output a signal to the C _2.

When the process in the third step is completed, the process proceeds to a fourth step. Here, the telescopic beam length signal L temporarily stored (the telescopic beam length signal L detected in this cycle) and the stored value Lm stored in the memory (the telescopic beam detected in the previous cycle) (Corresponding to the length signal L), and the comparison result indicates that the telescopic beam length signal L is greater than the stored value Lm.
If the value becomes large (L> Lm), the AND circuit C
After outputting the signal to ₃ , the control returns to the main routine. Further, when the comparison result is a condition other than the above (L <= L
If m), the process proceeds to the next step as it is. In other words, in this step, the telescopic beam length (L) in the previous cycle is compared with the telescopic beam length (L) in this cycle after a lapse of a very short time, so that the telescopic beam length is calculated. Boom-related operation is telescopic
The direction in which the length of the telescopic boom 2 is increased (the direction in which the telescopic boom 2 is driven to extend) or the direction in which the length is reduced (the direction in which the telescopic boom 2 is driven to contract). Is calculated. When the calculating means C ₄ determines from the calculation result that the telescopic boom-related operation is driving in the direction in which the telescopic boom 2 is extended, it determines that driving in the dangerous direction is AND. outputs a signal in time <br/> path C _3, it has become to actuate the alarm 7 extension movement stop means 8 in the limit state. The stretch Bed - unrelated operations stretch Bed - when it is determined that the driving in the direction to reduce the beam 2, so as not to output a signal to the AND circuit C ₃ as a drive to safe direction It is.

When the fourth step is completed, the process returns to the first step of the next cycle, and thereafter, the above cycle is repeated.

The telescopic boom operating direction calculating means C of the present invention
₄ is to detect the actual state of the operation related to the telescopic boom toward the dangerous side, that is, the operation of the telescopic boom 2 in the falling direction and the operation of the telescopic boom 2 in the extending direction by repeating the above procedure. It can be detected by calculation based on the detection output of the means A.

[0025] In summary, stretch blanking in the safety device for a work vehicle of the present invention - beam moving direction calculating means C _4, the arithmetic means C ₄ is a monitor detection signal detected actual state detecting means A within a predetermined time interval Subsequently, if the signal from the actual state detecting means A changes due to the telescopic boom-related operation, the detection value of the actual state detecting means A after the change (after the telescopic boom-related operation) is changed before (the telescopic boom). The driving direction of the telescopic boom is determined as follows by calculating how the detected value of the actual state detecting means A changes (before the related operation). Stretch Bed - after unrelated operation, if the detection value of the undulation angle detector A ₁ of the actual state detecting means A is reduced with respect to the detection value of the before-related operation, the telescopic Bed - related direction of movement of the arm 2 is A signal is output when it is determined that the telescopic boom is in the danger direction beyond the limit state of the work vehicle. Stretch Bed - after unrelated operation, if the detection value of the undulation angle detector A ₁ of the actual state detecting means A is increased relative to the value detected before the relevant operation, the telescopic Bed - related direction of movement of the arm 2 is It does not output a signal because it is determined that it is a telescopic boom raising drive in a safe direction that does not exceed the limit state of the work vehicle. Stretch Bed - if the increase in the detected value of the beam length detector A ₂ is the detected value of the front-related operation, the telescopic Bed - - unrelated operation after the actual state detecting means A telescopic blanking related arm 2 A signal is output when it is determined that the extension of the telescopic boom is performed in the danger direction in which the operation direction exceeds the limit state of the work vehicle. Stretch Bed - if decrease detection value of the arm length detector A ₂ is the detected value of the front-related operation, the telescopic Bed - - unrelated operation after the actual state detecting means A telescopic blanking related arm 2 It is determined that the retractable boom is driven to the safe side where the operation direction does not exceed the limit state of the work vehicle, and no signal is output.

In the above embodiment described with reference to FIG. 4, the telescopic beam operating direction calculating means C ₄ has been described as a circuit configuration in which the limit signal generating means C is incorporated. Of course, it may be incorporated in the arithmetic processing program described above to function as a part of the processing program of the limit signal generating means C. Further, in the above-described embodiment, the embodiment has been described in which the retractable operation of the telescopic boom and the extension operation of the telescopic boom are respectively detected.
Of course, it may be used as an operation direction detecting means for detecting a direction of a turning drive direction to a danger side in a safety device of a work vehicle having a different limit state according to a turning direction of the turntable.

[0027]

The safety device for a work vehicle according to the present invention, which is constructed and operates as described above, detects an operation direction of a telescopic boom-related operation which has conventionally been constituted by a limit switch of this type of safety device. Since the means is configured to be operated by using the actual state detecting means and the calculating means conventionally provided in this type of safety device, there is no need to separately provide a limit switch, and the cost of the safety device can be reduced. This has the effect of eliminating the need for complicated installation and adjustment work of limit switches.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a work vehicle to which the safety device for a work vehicle of the present invention is applied.

FIG. 2 is an explanatory view of a conventional safety device for an aerial work vehicle.

FIG. 3 is an explanatory view of a conventional safety device for a mobile crane.

FIG. 4 is an explanatory view of the safety device for a work vehicle according to the present invention.

FIG. 5 is an explanatory diagram of an operation procedure of the safety device for a work vehicle according to the present invention.

[Explanation of symbols]

Reference Signs List 1 vehicle 2 telescopic boom 3 turntable A actual state detecting means B operating direction detecting means C limit signal generating means C ₄ calculating means (telescopic boom operating direction calculating means)

Claims (1)

(57) [Scope of request for utility model registration] 1. An actual state detecting means comprising a potentiometer mounted on a vehicle and provided with a swivel base provided with a telescopic boom that can be driven up and down so as to be capable of turning, and detecting an actual value of a telescopic boom- related operation. Operation direction detection means for detecting the direction of operation, and receiving signals from the actual state detection means and the operation direction detection means, and that the telescopic boom-related operation has reached a limit state based on the actual value from the actual state detection means. And a limit signal for outputting a warning or a signal for restricting the telescopic boom-related operation when the direction of the telescopic boom-related operation detected by the operation direction detecting means in the limit state is a danger direction exceeding the limit state. Generating means, comprising: a working vehicle safety device comprising: an operating direction detecting means for receiving a signal from the actual state detecting means; No. work vehicle safety device, wherein a are constituted by computing means for obtaining a risk direction to calculate the front and rear of increase or decrease of the change when the change.