JP2511075Y2 - Work vehicle safety equipment - Google Patents

Description

[Detailed Description of Device] a. The purpose of the invention (industrial application field) The invention is a crane vehicle, a digging column truck, an aerial work vehicle,
Regarding a work vehicle equipped with a boom that can be undulated, extended and retracted,
Furthermore, the present invention relates to a work vehicle including a work range limiting device that limits the work range of such a boom.

(Prior art) For work vehicles that perform work by elevating and retracting the boom,
Due to the weight of the boom and the suspension load at the tip of the boom, a moment is generated around the base end (fulcrum) of the boom in the direction of overturning the work vehicle. In order to prevent a fall due to such a moment, generally, for example, a fall moment (a moment of a size that causes a work vehicle to fall)
Set the rated moment by dividing by the specified safety factor, and when the moment reaches this rated moment, work to regulate the further movement of the boom in the falling direction (direction to increase the moment acting in the falling direction) Use range control equipment.

In such an apparatus, for example, the boom undulation angle, the extension amount, the turning angle, and the load applied to the boom are detected by the detector, and the moment is calculated by the calculator from these detected values. Further, when this moment reaches the rated moment, a restriction signal is sent from the computing unit to restrict the further operation of the boom toward the falling side.

However, if the detector or computing unit malfunctions, the computing unit may constantly send an incorrect regulation signal. In this case, the boom cannot be operated in either direction. .

Therefore, in such a case, the restriction signal is cut off to release the restriction by the restriction device, and the boom is temporarily operated without restriction so that the work can be continued or the boom can be retracted. I often do it.

(Problems to be solved by the invention) However, if the boom can be freely operated under such an unregulated condition, there is a problem that the moment may exceed the rated moment.

Also, if the operator operates a switch or the like to release the restriction by mistake while the restriction device is operating normally, the above moment may exceed the rated moment without the operator's knowledge. There is a problem.

In view of the above problems, it is an object of the present invention to provide a work vehicle safety device that allows a worker to recognize the operation of the boom in the falling direction when the regulation is released.

B. Configuration of the Invention (Means for Solving the Problem) In order to achieve the above-mentioned object, in the present invention, when the controller does not receive the restriction release signal from the restriction release operating means, the work range restricting device causes the boom moment. Restricts the boom operation beyond the specified work range (the allowable work range in which the boom operation is allowed by the work range control device), which is the range that does not exceed the rated moment, and the operating direction of the boom operating means within the specified work range. The boom operation according to the above, and when the restriction release signal is received from the restriction release means, the boom operation restriction by the work range restricting device is released, and in this case, the boom operation range is within the predetermined work range. Whether or not the operating direction of the boom operating means detected by the operating direction detector is
The alarm means is activated when it is determined that the boom is to be operated in the falling direction.

(Operation) In such a device, when the boom cannot be operated while the operation is restricted due to a malfunction of the work range restricting device, the operator operates the restriction releasing means to operate the boom. The regulation is released and the boom can be operated freely in either direction. However, when the operator operates the boom operating means under such an unregulated condition and the controller determines that the operation is the operation on the falling side based on the signal from the operation detecting means, the buzzer or the like is operated. The alarm means is activated to alert the operator. Also,
When the worker erroneously operates the regulation releasing means while the work range regulating device is operating normally, the alarm means is activated in the same manner as above.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows an aerial work vehicle equipped with the safety device according to the present invention.

Outriggers 3 are provided at four positions on the front, rear, left and right of the vehicle body 2 of the aerial work vehicle 1, and these outriggers 3 are used during work.
Are extended laterally and downwardly of the vehicle body 2 to stably support the vehicle body 2 on the road surface.

A swivel base 4 is attached to the rear portion of the vehicle body 2.
The swivel base 4 can be swung freely by rotating a swivel motor 5 which is hydraulically operated. Further, the swivel base 4 is pivotally attached to a base end portion of a boom 6 including a base end side member 6a, an intermediate member 6b, and a tip end side member 6c. The boom 6 can be freely lifted and retracted by the expansion and contraction operations of the undulation cylinder 7 and the expansion and contraction cylinder 8 that are hydraulically operated.

A workbench 9 is attached to the tip of the tip side member 6c. The work table 9 includes a swing motor 5 and a hoisting cylinder 7.
An operating lever 10 for controlling the operation of each of the telescopic cylinder 8 (hereinafter, collectively referred to as an actuator) is attached, and an operator on the workbench 9 operates the operating lever 10 to operate the boom 6. .

Next, the configuration of the safety device will be described with reference to FIG.

The safety device RE includes a work range regulation device ML, a regulation release switch RS, an operation direction detector OD, a main controller MC, and an alarm buzzer B.

The work range restricting device ML includes a hoisting angle sensor 21, an extension amount sensor 22, a turning angle sensor 23, a cylinder axial force sensor 24, and a calculator 25.

Lifting angle sensor 21, extension amount sensor 22, turning angle sensor 23
Detects the undulation angle, extension amount, and turning angle of the boom 6, respectively. In addition, the cylinder axial force sensor 24 detects the load acting in the axial direction on the cylinder rod of the undulating cylinder 7 due to the weight of the boom 6 and the workbench 9 and the weight of the worker on the workbench 9.

The computing unit 25 calculates the moment M acting in the direction of inclining the vehicle body 2 based on the detection signals from the sensors (21 to 24). Further, the calculator 25 outputs a regulation signal when the calculated moment M reaches the rated moment.

The calculator 25 is connected to the valve controller VC via the regulation signal line 30. Valve controller VC
Is the switching valve (5a, 7a, 8a) based on the operation signal sent from the operation lever 10 when the regulation signal is not input.
To send an activation signal. These switching valves (5a, 7a, 8
A) is operated by this operation signal and controls the supply / discharge of the hydraulic oil from the hydraulic pressure source OP to each actuator (5, 7, 8). In addition, above the regulation signal line 30, this line 30
A restriction signal cut-off switch 31 for opening and closing is provided. The switch 31 shuts off (closes) the line 30 when the solenoid 31a is excited, and opens the line 30 when it is not excited.

The restriction release switch RS is a switch that is turned on / off by a worker who is on the workbench 9. For example, when the worker pushes the switch by hand to turn it on, a restriction release signal is output, and when the hand is released, it is turned off. It is a momentary switch.

The operation direction detector OD includes each actuator (5, 7,
8) corresponding to the operating direction of the operating lever 10 (for example, in the case of a hoisting cylinder operating lever, whether the boom 6 is upright or lying down, and in the case of a telescopic cylinder operating lever, it is the boom shortening side). Is it the extension side?).

The alarm buzzer B is attached to the workbench 9 and generates an alarm sound to the operator in response to a signal from the main controller MC.

The main controller MC is connected to the restriction release switch RS and the operation direction detector OD via a restriction signal line 32 and an operation direction signal line 33, respectively. Also the controller
MC is the solenoid 31a of the regulation signal cutoff switch 31 described above.
The alarm buzzer B is connected to the alarm buzzer B via the shutoff signal line 31b and the alarm signal line 34.

 Next, the operation of the safety device RE will be described.

Normally, the boom 6 is operated by an operation signal from the operation lever 10.
When the calculated moment M reaches the rated moment while undulating, expanding and contracting, etc., the calculator 25 sends a regulation signal to the valve controller VC. At this time, the solenoid of the restriction signal cutoff switch 31 is in the non-excited state. The valve controller VC receiving the regulation signal prohibits the switching operation of the switching valves (5a, 7a, 8a) that actuate the boom 6 in the falling direction of the vehicle body 2 (direction in which the moment acting in the falling direction increases). However, the operation of the boom 6 that increases the moment M further is restricted.

However, due to a malfunction of each sensor (21 to 24) in the regulation device ML or the calculator 25, the regulation signal is still sent from the calculator 25 to the valve controller VC regardless of the operation of the operation lever 10. , The boom 6 cannot be operated in either direction.

In such a case, the operator turns on the restriction release switch RS and inputs the restriction release signal to the main controller MC. The main controller MC receiving the restriction release signal sends a cutoff signal to the solenoid 31a of the restriction signal cutoff switch 31 to excite the solenoid 31a to cut off the restriction signal line 30.
In this way, the regulation signal is not input to the valve controller VC, and the boom 6 can be freely operated according to the operation of the operation lever 10.

On the other hand, while the operation lever 10 is being operated, the operation direction detector OD detects the operation direction of the operation lever 10 and sends it as an operation direction signal to the main controller MC. When the restriction release signal from the restriction release switch RS is input as described above, the controller MC determines whether or not the operation direction of the operation lever 10 is the overturn side based on the operation direction signal. When it is determined that the operation direction is the falling side, an alarm signal is sent to the alarm buzzer B and an alarm sound is generated. Here, the transmission of the alarm signal is performed even within the predetermined operating range in the state where the restriction release signal is not input.
Thereby, the operator hears this alarm sound, recognizes that the current boom operation is an operation in the falling side direction, and can exercise caution in operating the boom.

Instead of the alarm buzzer B, a light such as an alarm lamp that gives an alarm may be used.

The safety device can also be used for crane trucks, digging column trucks, and the like.

C. Effect of the Invention As described above, if the safety device is used, if the operation range regulating device does not normally regulate the boom operation due to malfunction of sensors, etc. It is possible to operate the boom by releasing the restriction, but in this case, when the boom is operated to operate in the falling side direction of the work vehicle (direction that increases the moment acting in the falling direction), the boom operation Even within the predetermined operating range at the time of regulation, a warning such as a buzzer is issued. Therefore, the worker can recognize that the current boom operation is an operation in the falling side direction, and can perform the work safely while paying careful attention to the boom operation. Also, even if the operator accidentally operates the deregulation operation means to prevent the boom from being regulated by the regulating device that operates normally, an alarm will be issued when the boom is actuated in the falling direction in the same manner as above. Since it is emitted, the operator can notice the erroneous operation.

[Brief description of drawings]

FIG. 1 is a schematic view showing the construction of a work vehicle safety device according to the present invention, and FIG. 2 is a side view showing an aerial work vehicle equipped with the above device. 6 ... Boom, 10 ... Operating lever ML ... Work range control device MC ... Main controller OD ... Operating direction detector RS ... Regulation release switch B ... Alarm buzzer

Claims (1)

(57) [Scope of utility model registration request] 1. A work range restricting device for restricting a work range of a boom, a restriction releasing operation means for sending a restriction releasing signal by an operator, and a boom operating means for controlling the operation of the boom by an operator. An operation direction detector for detecting the operation direction of the, an alarm means for issuing an alarm to the worker, when the restriction release signal is not input from the restriction release operation means, by the work range restriction device The boom operation exceeding the predetermined work range is restricted, and the boom is operated according to the operation direction of the boom operating means within the predetermined work range, and the work range restriction is performed when the restriction release signal is input. The operation direction of the boom is released by the device, and the operation direction is set regardless of whether the operation range of the boom is within the predetermined work range. And a controller that activates the alarm means when it is determined that the operation direction of the boom operation means detected by the ejector is a direction in which the boom is operated in the falling direction of the work vehicle. Work vehicle safety device.