JP3958630B2 - Safety device for work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety device for a working vehicle, and more specifically, has a vehicle body support means for supporting a vehicle body having a rotatable roller at a lower end, and grounding the wheel and grounding a wheel. The present invention relates to a safety device for a working vehicle that performs work in a work running state.
[0002]
[Prior art]
Such a working vehicle is constructed based on a truck vehicle that has a front wheel and a rear wheel that are rotatably mounted on the front and rear of the vehicle body and can travel on the road. A front body support means and a rear body support means (hereinafter collectively referred to as “vehicle support means”) that support the vehicle body with a rotating roller are disposed, and a work device is mounted on the vehicle body, Generally, the front wheels are configured to be steerable, and the rear wheels are configured as drive wheels. Such a working vehicle is configured to be able to work while traveling in a working traveling state in which the front wheels and the rear wheels are grounded and the rotating roller is grounded. Here, when this working vehicle is in a working state, a part of the vehicle weight is supported by the vehicle body support means, so the front roller load and the rear wheel load acting on the grounded front and rear wheels are not subjected to rotation by the rotating roller. It will be less than when it is in the grounded state.
[0003]
This decrease in the front wheel load and the rear wheel load lowers the driving force necessary for traveling the vehicle, the braking force necessary for stopping the traveling vehicle, and the steering force for changing the traveling direction of the vehicle. Therefore, the extension amount of the vehicle body support means when the vehicle body support means extends and supports the vehicle is set to a predetermined value so that the driving force, the braking force, and the steering force are ensured in the work traveling state. .
[0004]
[Problems to be solved by the invention]
However, since the setting of the extension amount of the vehicle body support means is performed on a solid soil where the vehicle is placed, if the road surface is uneven when the vehicle is actually in a running state, the front wheel and the rear The load acting on the wheel will fluctuate. Also, when the diameters of the front wheels, the rear wheels, and the rotating rollers change due to wear or the like, the load acting on the front wheels and the rear wheels varies. Further, when the front wheels and the rear wheels are replaced with wheels having a diameter different from the diameter of the wheels at the time of setting (for example, studless tires), the load acting on the front wheels and the rear wheels varies. As described above, the load acting on the front wheels and the rear wheels fluctuates. In particular, when the load fluctuates in the decreasing direction, the driving, braking and steering performance of the vehicle deteriorates. In such a case, the conventional vehicle has no safety device that allows the operator to recognize such a state. For this reason, provision of such a safety device is desired.
[0005]
This invention is made in view of such a problem, and it aims at providing the safety device which can make an operator recognize the fluctuation | variation of the load which acts on a front wheel and a rear wheel.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a safety device for a working vehicle according to the present invention includes a vehicle body, front and rear wheels that are rotatably attached to the front and rear of the vehicle body and capable of traveling on a road, and left and right sides of the vehicle body. A front body support means (for example, in the embodiment) that has a rotation roller that is disposed and is rotatably attached to the lower end portion, can be vertically expanded and contracted, and can support the vehicle body with the rotation roller grounded. It has front jacks 20, 21) and rear body support means (for example, rear jacks 23, 24 in the embodiment), and can work in a working state where the front wheels and rear wheels are grounded and the rotating roller is grounded. A safety device for a working vehicle (for example, an aerial work vehicle 1 in the embodiment) for recognizing fluctuations in loads acting on the front wheels and the rear wheels , the front vehicle body support means and the rear vehicle body support means. Product Front reaction force detection means (for example, the first reaction force detection sensor 61 and the second reaction force detection sensor 62 in the embodiment) and rear reaction force detection means (for example, the third reaction force detection in the embodiment). The center of gravity position of the work vehicle is calculated from the detection values detected by the force detection sensor 63, the fourth reaction force detection sensor 64) and the front reaction force detection means and the rear reaction force detection means in the working travel state. Wheel load calculation means (for example, wheel load calculation circuit 69 in the embodiment) for calculating the front wheel load and the rear wheel load acting on the front and rear wheels in contact with the ground according to the position of the center of gravity , and wheel load calculation means Wheel load determination means (for example, wheel load determination circuit 71 in the embodiment) for determining whether or not the front wheel load value and the rear wheel load value calculated by the above are smaller than a preset wheel load value; Alarm means (for example, an alarm buzzer 79 in the embodiment) that operates when the wheel load determination means determines that at least one of the front wheel load value and the rear wheel load value is smaller than the wheel load value. Composed.
[0007]
According to the safety device having the above configuration, the front side vehicle support means and the rear side vehicle support means are provided with the front reaction force detection means and the rear reaction force detection means, and according to the detection values detected from these reaction force detection hands. A front wheel load value and a rear wheel load value acting on the front wheel and the rear wheel are calculated, and if it is determined that at least one of the front wheel load value and the rear wheel load value is smaller than a preset wheel load value, an alarm is issued. Since the means operates as an alarm, the operator can surely recognize that the load acting on the front wheel and the rear wheel is reduced as the alarm means operates as an alarm. In this specification, the alarm operation includes an operation that performs an alarm using an alarm buzzer, an alarm lamp, etc., an operation that stops the traveling vehicle, and an operation that regulates the operation of the work device mounted on the vehicle body. Operation.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. The present embodiment is a high place having a boom that is provided on a vehicle body so as to be swivelable and movable up and down, and that can be expanded and contracted, and a workbench that is attached to the tip of the boom so as to be swingable up and down. The aspect of a work vehicle is shown. Before describing a safety device according to the present invention, an aerial work vehicle equipped with this safety device will be described.
[0009]
As shown in FIG. 1, the aerial work vehicle 1 is disposed on a pair of front wheels 5 rotatably disposed on the left and right side portions on the front side of the vehicle body 3 extending in the front-rear direction and on the left and right side portions on the rear side of the vehicle body. The vehicle has a pair of rear wheels 7 that rotate by receiving a driving force of an engine (not shown). The vehicle can travel on the road, and is based on a truck vehicle 11 having a driving cabin 9 at the front. The pair of front wheels 5 and rear wheels 7 are held by suspension mechanisms 13 disposed on the left and right sides of the vehicle body 3. As shown in FIG. 2, an axle tube 14 extending in the left-right direction of the vehicle is attached between the pair of left and right suspension mechanisms 13 on the rear side of the vehicle, and the rear wheel 7 is rotatably attached to both left and right ends of the axle tube 14. It has been. The suspension mechanism 13 includes a laminated leaf spring 15 disposed in a lower portion of the vehicle body 3 so as to be elastically deformable up and down in a state of extending in the longitudinal direction of the vehicle, and the axle 8 of the rear wheel 7 is provided at both ends of the axle tube 14. Is rotatably inserted. Both end portions of the axle tube 14 are attached to the middle upper portion of the laminated leaf spring 15 via U bolts 16. For this reason, the rear wheel 7 is suspended from the vehicle body 3 via the suspension mechanism 13. A pair of front wheels 5 shown in FIG. 1 is also suspended from the vehicle body 3 via a pair of suspension mechanisms 13 disposed on the front side of the vehicle body 3, as with the rear wheel 7.
[0010]
As shown in FIG. 1, the left and right side portions on the front side of the vehicle body extending to the rear side of the vehicle from the pair of front wheels 5 and the left and right side portions of the rear portion of the vehicle body extending to the rear side of the vehicle from the pair of rear wheels 7 A pair of front jacks 20, 21 and rear jacks 23, 24 configured to be freely projecting in the direction are provided. The front jacks 20 and 21 and the rear jacks 23 and 24 are provided with rotatable rollers 22 and 25 at the bottom. The aerial work vehicle 1 configured as described above is configured to be able to travel in a working state in which the front wheels 5 and the rear wheels 7 are grounded and the rotary rollers 22 and 25 are grounded. A jack operating device 30 for operating the front jacks 20 and 21 and the rear jacks 23 and 24 is disposed at the rear of the vehicle body 3. The jack operating device 30 drives the front jacks 20 and 21 and the rear jacks 23 and 24. A plurality of operation levers 31 to be operated are provided. When the operation lever 31 is operated, the jack operation device 30 is configured to extend / contract one of the front jacks 20 and 21 and the rear jacks 23 and 24 corresponding to the operated operation lever 31. More specifically, when the operation lever 31 is operated, the jack operating device 30 has the front jacks 20 and 21 so that the extension amounts of the front jacks 20 and 21 and the rear jacks 23 and 24 corresponding to the operation lever 31 become a predetermined value. And the rear jacks 23 and 24 are extended. The predetermined value of the jack extension amount will be described later.
[0011]
A swivel base 35 that is driven by a turning motor (not shown) and configured to be horizontally turnable is attached to the rear of the vehicle body of the truck vehicle 11. A boom 37 pivotally connected to the base is attached to the swivel base 35 so that the boom 37 can swing up and down. The boom 37 includes a base end boom 37a, an intermediate boom 37b, and a front end boom 37c which are combined in a telescopic manner and are not shown. The cylinder is configured to be extendable and retractable. The boom 37 is raised and lowered by a raising and lowering cylinder 39.
[0012]
A support member 41 is attached to the tip of the boom 37 so as to be swingable up and down, and a work table 45 is attached to the support member 41 via a swing device 43 so as to be able to swing horizontally (swing). ing. A leveling device (not shown) is disposed between the tip boom 37c and the support member 41, and the work table 45 is always held in a horizontal state by the leveling device regardless of the raising / lowering angle of the boom 37. The work table 45 is provided with an operation device 47 for operating the raising / lowering motion, turning motion, telescopic motion of the boom 37 and the swinging motion of the work table 45.
[0013]
The aerial work vehicle 1 configured in this way sounds an alarm buzzer when the load acting on the front wheels 5 and the rear wheels 7 in the grounded state is lower than a predetermined value when the vehicle is in a working running state. Safety devices are installed. As shown in FIG. 3, the safety device 60 includes a first reaction force detection that detects a ground reaction force acting on the front jack 20 disposed on the left side of the vehicle among the pair of front jacks 20, 21 shown in FIG. 1. The sensor 61, the second reaction force detection sensor 62 for detecting the ground reaction force acting on the front jack 21 disposed on the right side of the pair of front jacks 20, 21, and the pair of rear jacks 23, 24 shown in FIG. Among them, a third reaction force detection sensor 63 for detecting a grounding reaction force acting on the rear jack 23 disposed on the left side of the vehicle, and a grounding acting on the rear jack 24 disposed on the right side of the rear jacks 23, 24. A fourth reaction force detection sensor 64 that detects the reaction force, a controller 67 that operates according to detection values from these sensors, and an alarm buzzer 79 are provided.
[0014]
The controller 67 includes a wheel load calculation circuit 69, a wheel load determination circuit 71, and an alarm drive circuit 73. The controller 67 operates a travel work switch (not shown) that is operated when the operation of the operation device 47 shown in FIG. Then, power is supplied from a power source (not shown) to enable operation. The wheel load calculation circuit 69 determines the center of gravity of the vehicle according to the detection values detected by the first reaction force detection sensor 61, the second reaction force detection sensor 62, the third reaction force detection sensor 63, and the fourth reaction force detection sensor 64. The position is calculated, and the front wheel load value and the rear wheel load value acting on the pair of front wheels 5 and the pair of rear wheels 7 are calculated from the vehicle weight set in advance according to the calculated center of gravity position.
[0015]
More specifically, the wheel load calculation circuit 69 calculates the front wheel load value and the rear wheel load value based on the following equations 1 and 3. In addition, Formula 1 is a formula which shows the balance of force, Formula 2 and Formula 3 are formulas which show the balance of the moment of the vehicle front-back direction shown in FIG.
[0016]
[Expression 1]
Wf + Wr + Ff + Fr = W
However, Wf shows the reaction force of the front wheel load value which acts on a pair of front wheels 5 as shown in FIG.
Wr represents the reaction force of the rear wheel load value acting on the pair of rear wheels 7,
Ff represents the sum of the detection values detected by the first reaction force detection sensor 61 and the second reaction force detection sensor 62 shown in FIG.
Fr represents the sum of the detection values detected by the third reaction force detection sensor 63 and the fourth reaction force detection sensor 64 shown in FIG.
W represents the vehicle weight.
[0017]
[Expression 2]
(Wf1 × Xwf1) + (Wf2 × Xwf2) + (Wr1 × Xwr1)
+ (Wr2 × Xwr2) + (Ff1 × Xf1) + (Ff2 × Xf2)
+ (Fr1 × Xr1) + (Fr2 × Xr2) = W × Xw
However, Wf1 shows the reaction force of the load which acts on the front wheel 5 on the left side of the vehicle, as shown in FIG.
Wf2 indicates the reaction force of the load acting on the front wheel 5 on the right side of the vehicle,
Wr1 represents the reaction force of the load acting on the rear wheel 7 on the left side of the vehicle,
Wr2 represents the reaction force of the load acting on the rear wheel 7 on the right side of the vehicle,
Xwf1 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the operating position of Wf1,
Xwf2 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the operating position of Wf2,
Xwr1 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the action position of Wr1,
Xwr2 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the action position of Wr2,
Xf1 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the action position of Ff1,
Xf2 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the operating position of Ff2,
Xr1 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the action position of Fr1,
Xr2 indicates the distance in the vehicle front-rear direction between an arbitrary reference position and the action position of Fr2.
[0018]
Here, in Equation 2, Xwf1 = Xwf2, Wf1 + Wf2 = Wf, Xwr1 = Xwr2, Wr1 + Wr2 = Wr, Xf1 = Xf2, Ff1 + Ff2 = Ff, Xr1 = Xr2, and Fr1 + Fr2 = Fr. 2 is converted into Equation 3.
[0019]
[Equation 3]
(Wf × Xwf) + (Wr × Xwr) + (Ff × XFf) + (Fr × XFr) = W × Xw
[0020]
Here, in Equations 1 and 3, W and Xw are known values, Ff and Fr are detected values, and Xwf, Xwr, XFf, and XFr are known values. Therefore, the wheel load calculation circuit 69 shown in FIG. 3 can calculate Wf and Wr by solving the two simultaneous equations of Equations 1 and 3.
[0021]
Now, the front wheel load value and the rear wheel load value calculated in this way are sent to the wheel load determination circuit 71 as shown in FIG. The wheel load determination circuit 71 determines whether or not the calculated front wheel load value and rear wheel load value are smaller than preset wheel load values. Here, there are two types of wheel load values, a front wheel side load value corresponding to the front wheel load and a rear wheel side load value corresponding to the rear wheel load value. The front wheel side load value stops the traveling vehicle by the front wheel 5 shown in FIG. The rear wheel side load value is set to a value that takes into account the braking force required to change the vehicle's state and the steering force that can change the traveling direction of the vehicle. It is set to a value that takes into account the braking force required to achieve this. The front wheel side load value and the rear wheel side load value may be set to one value necessary for securing the braking force, the steering force, and the driving force.
[0022]
Here, the extension amounts of the front jacks 20 and 21 and the rear jacks 23 and 24 when the vehicle body 3 is supported by the front jacks 20 and 21 and the rear jacks 23 and 24 shown in FIG. As described above, the front jacks 20 and 21 and the rear jacks 23 and 24 support the vehicle body 3 in a state where the extension amount reaches a predetermined value. When the vehicle body 3 is supported by these, the pair of front wheels in a grounded state is supported. 5 and the front jacks 20 and 21 so that the load acting on the pair of rear wheels 7 in contact with the ground is approximately the same as the load value on the rear wheel side. The extension amount of the rear jacks 23 and 24 is set.
[0023]
As shown in FIG. 3, the alarm driving circuit 73 is electrically connected to the alarm buzzer 79, and the wheel load determination circuit 71 determines that at least one of the front wheel load value and the rear wheel load value is smaller than the wheel load value. Then, the alarm buzzer 79 is sounded. The alarm buzzer 79 is a speaker and is installed in the driving cabin 9 shown in FIG.
[0024]
Next, the operation of the safety device 60 configured as described above will be described. First, as shown in FIG. 1, after the front jacks 20, 21 and the rear jacks 23, 24 are stored in the vehicle, the rear wheel 7 is rotationally driven to move the vehicle to the work site, and then the jack operating device 30. The front jacks 20, 21 and the rear jacks 23, 24 are grounded in a state where the operation lever 31 is operated and the front wheels 5 and the rear wheels 7 are grounded. Subsequently, an operator (not shown) who has boarded the work table 45 operates the operation device 47 to drive the boom 37 to move the work table 45 to a desired work position. Subsequently, the driving switch described above is operated to drive the boom 37 in a restricted state. For this reason, the boom 37 and the work table 45 will not be driven (turning, extending / contracting, raising / lowering, swinging) even if an operator on the work table 45 operates the operating device 47 by mistake.
[0025]
When the traveling work switch is operated so as to restrict the boom drive, electric power is supplied to the controller 67 shown in FIG. That is, the controller 67 is based on detection values from the first reaction force detection sensor 61, the second reaction force detection sensor 62, the third reaction force detection sensor 63, and the fourth reaction force detection sensor 64, as shown in FIG. Then, the wheel load calculation circuit 69 calculates the front wheel load value acting on the pair of front wheels 5 and the rear wheel load value acting on the pair of rear wheels 7 using the above-described equations 1 and 3. Subsequently, based on the front wheel load value and the rear wheel load value, the wheel load determination circuit 71 determines whether the front wheel load value is smaller than the front wheel side load value, and the rear wheel load value is smaller than the rear wheel side load value. It is determined whether or not it is small.
[0026]
Here, when it is determined that at least one of the front wheel load value and the rear wheel load value is small, the alarm driving circuit 73 sounds the alarm buzzer 79. As a result, the driver riding in the driving cabin 9 shown in FIG. 1 can recognize that the load acting on the front wheels 5 and the rear wheels 7 is small, and the front wheels 5 and the rear wheels 7 before the vehicle travels. In addition, the rotating rollers 22 and 25 can be reliably inspected.
[0027]
Further, if the alarm buzzer 79 is generated when the vehicle is traveling in a working state, the driver can recognize that the load acting on the front wheels 5 and the rear wheels 7 is small. For this reason, the driver can recognize that the driving, braking, and steering performance of the vehicle while the vehicle is running are in a state of being lowered.
[0028]
In the above-described embodiment, the safety device 60 performs an alarm operation using the alarm buzzer 79. However, the safety device 60 may be configured to stop a traveling vehicle.
[0029]
【The invention's effect】
As described above, according to the safety device of the present invention, the front vehicle body support means and the rear vehicle body support means are provided with the front reaction force detection means and the rear reaction force detection means, and are detected from these reaction force detection means. The center of gravity position of the work vehicle is calculated from the detected values, the front wheel load value and the rear wheel load value acting on the front wheels and the rear wheels are calculated according to the calculated center of gravity position, and these front wheel load value and rear wheel load value are calculated. When it is determined that at least one of the values is smaller than the preset wheel load value, the alarm means is activated, so that the operator operates the alarm means to activate the load acting on the front wheels and the rear wheels. It can be recognized with certainty that it is decreasing.
[Brief description of the drawings]
FIG. 1 is a left side view of an aerial work vehicle equipped with a safety device according to an embodiment of the present invention.
FIG. 2 is a front view of a suspension mechanism that holds a rear wheel in an embodiment of the present invention.
FIG. 3 is a block diagram of a safety device according to an embodiment of the present invention.
FIG. 4 is a schematic plan view of an aerial work vehicle for explaining the operation of the safety device according to the embodiment of the present invention.
[Explanation of symbols]
1 Aerial work vehicle (work vehicle)
3 body 5 front wheel 7 rear wheels 20 and 21 front jack (front body support means)
22, 25 Rotating rollers 23, 24 Rear jacks (rear body support means)
60 safety device 61 first reaction force detection sensor (front reaction force detection means)
62 Second reaction force detection sensor (front reaction force detection means)
63 Third reaction force detection sensor (rear reaction force detection means)
64 Fourth reaction force detection sensor (rear reaction force detection means)
69 Wheel load calculation circuit (wheel load calculation means)
71 Wheel load judgment circuit (wheel load judgment means)
79 Alarm buzzer (alarm means)

Claims (1)

The car body,
Front and rear wheels that are rotatably attached to the front and rear of the vehicle body and capable of traveling on roads;
It is arranged on both the left and right sides of the front and rear of the vehicle body, and has a rotation roller that is rotatably attached to the lower end portion, and can be expanded and contracted up and down, and can support the vehicle body with the rotation roller grounded Front vehicle body support means and rear vehicle body support means,
A working vehicle safety device for recognizing fluctuations in load acting on the front wheels and the rear wheels , which can be operated in a working state in which the front wheels and the rear wheels are grounded and the rotating roller is grounded. There,
Front reaction force detection means and rear reaction force detection means for detecting a ground reaction force acting on the front vehicle body support means and the rear vehicle body support means;
In the work travel state, the center of gravity position of the working vehicle is calculated from the detection values detected by the front reaction force detection unit and the rear reaction force detection unit , and the ground state is determined according to the calculated center of gravity position. Wheel load calculating means for calculating a front wheel load and a rear wheel load acting on the front wheel and the rear wheel,
Wheel load determination means for determining whether the front wheel load value and the rear wheel load value calculated by the wheel load calculation means are smaller than a preset wheel load value;
Alarm means that operates when the wheel load determination means determines that at least one of the front wheel load value and the rear wheel load value is smaller than the wheel load value. A working vehicle safety device.

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