JPH02100998A - Safety device for working vehicle with boom - Google Patents

Abstract

PURPOSE:To prevent the overturn of a working vehicle on the slope and the like by providing an angle sensor for detecting the inclination in the lateral direction of a body and actuating an elevating cylinder in the boom descending direction when the body is inclined more than the fixed angle. CONSTITUTION:When an operator gets in a boarding bucket 11 and a pedal 13 is operated in the ascending direction, a solenoid valve 28 is changed over to the ascending direction, an elevating cylinder is stretched, and a boom 7 ascends rotating around an axis 9. If a body 1 is inclined in the lateral direction on a slope, signals from an angle sensor 41 are sent to comparators 42, 43 and compared with + or - basic signals. For instance, if it is inclined in the + direction more than the fixed angle, a transistor 48 is turned on by the signal from the comparator 42, a relay 49 is magnetized, a contact 50 is switched on and a buzzer 52 emits an alarm. At the same time, a contact 51 is switched on, so that the solenoid valve 28' is changed over to the lower side and the elevating cylinder 10 is contracted. Accordingly, the boarding bucket is lowered down to the lowest position of the boom 7 so as to prevent a working vehicle from overturn.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a safety device for a work vehicle with a boom, and when the vehicle body is tilted in the left-right direction by a predetermined angle or more, the boom is forcibly lowered to prevent the vehicle from overturning. It was designed to prevent this.

(Prior art) A work vehicle with a boom for high-altitude work used for harvesting work, chemical spraying work, pruning work, etc. in orchards has a boom equipped with a work board at the tip that is pivoted on the vehicle body so that it can be raised and lowered. The boom is raised and lowered by expanding and contracting the lifting cylinder.

This type of work vehicle has a high center of gravity when the boom is raised, making it prone to tipping over from side to side, so use on slopes is prohibited.

(Problem to be solved by the invention) However, in the past, safety devices were not provided and the decision was left entirely to the worker, so there was no way to strictly prohibit use on slopes, and There was a risk of accidental falls.

The present invention aims to solve such conventional problems.

(Means for Solving the Problems) To achieve this, the present invention provides a work vehicle with a boom that is provided with a boom 7 on the vehicle body 1 that can be raised and lowered by expanding and contracting an elevating cylinder 10. An angle sensor 41 for detecting the angle is provided, and a control means 53 is provided for operating the lifting cylinder 10 in the boom lowering direction in conjunction with the angle sensor 41 when the vehicle body 1 is tilted by a predetermined angle or more in the left-right direction.

(Function) The angle of inclination of the vehicle body 1 in the left-right direction is detected by the angle sensor 41, and the (No. 3) from the angle sensor 41 is detected by the comparator 42.
43, it is compared with the standard signal.

When the signal from the angle sensor 41 exceeds the reference signal, the transistor 48 and relay 49 are activated by the signal from the comparator 42 or 43, and the solenoid valve 28 is switched to the lowering side, so that the lifting cylinder 10 is contracted. Boom 7 descends.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
In the figures and FIG. 3, l is a vehicle body, which has a main frame 2, a boom mounting frame 3, etc. A pair of left and right drive wheels 4L and 4R are supported at the front of the vehicle body 1, and support wheels are supported at the rear. A pair of left and right caster wheels 6L and 6R are supported via the frame 5. Reference numeral 7 denotes the boom of parallel link 2, which is pivotally attached to a bracket 8 on the boom mounting frame 3 of the vehicle body 1 via a horizontal shaft 9 so as to be freely raised and lowered.
It can be raised and lowered by expanding and contracting a lifting cylinder 10 interposed between the lower part and the lower part. Reference numeral 11 denotes a boarding bucket attached to the tip of the boom 7, which maintains substantially the same attitude even when the boom 7 is raised and lowered. The boarding bucket 11 is provided with a travel control lever 12 and a lifting pedal 13.

Reference numeral 14 denotes an engine, which is mounted at the rear of the vehicle body 1. As shown in FIG. 4, the engine 14 is interlocked with a relay shaft 16 via a heald 15, and from both left and right ends of the relay shaft 16, a pair of left and right forward hels I-17L, 17R, and reverse belts 18L, 18R are connected. , forward input shaft 19L, 19R3
Reverse input shaft 2OL, 2OR, gear mechanism 21L, 21R
, output shafts 22L, 22R, belts 23L, 23R, etc. to transmit power to left and right drive wheels 4L, 4R.

Forward belts 17L, 17R and reverse belts 18L,
18R has tension type forward clutches 24L, 24
R and reverse clutches 25L and 25R are provided, and by disengaging each of these clutches 24L, 24R, 25L, and 25R, the pair of left and right drive wheels 4L and 4R are rotated forward or reverse simultaneously or independently to move forward. , turning, going backwards, etc. are possible.

FIG. 6 shows a hydraulic circuit, where 26 is a hydraulic pump and 27 is a relief valve. Reference numeral 28 designates a solenoid valve for the lifting cylinder 10, which has a lifting solenoid 29 and a lowering solenoid 30, and each solenoid 29, 30 is connected to a switch (not shown) that is linked to the lifting pedal 13. 31L
, 31R, 32L, 32R are clutch 24L 24R1
25L, 25R human cutting cylinder, 33L, 33
R, 34L.

34R is a solenoid valve that controls the cylinders 31L, 31R, 32L, and 32R, and has a solenoid. 35 is a pressure reducing valve;
36 is an unload solenoid valve, and its solenoid is the solenoid valve 3.
3L, 33R, 34!1, 34R is excited at the same time as any one of them is excited.

As shown in FIG. 5, the operating lever 12 has a joystick structure that can be operated forward, backward, left, and right, and on the base side of the operating lever 12 are provided electromagnetic valves 33L, 33R, and 34L.
, 34R, four switches 37 for giving command signals to
~40 are arranged. Each switch 37 to 40 is turned on and issues a command signal when the operating lever 12 is operated, and the operating direction A-F and switch 3 are
7 to 40 and the command signal have the following relationship.

FIG. 1 shows an electric circuit, and numeral 41 is an angle sensor for detecting the inclination angle of the vehicle body 1 in the left-right direction, and is composed of a potentiometer and the like. . A comparator 12.43 compares the signal from the angle sensor 41 with a predetermined reference signal set by a resistor 44.45, and when the signal exceeds the ± reference signal, the comparator 42.43 outputs a diode 46. .47 to drive the transistor 48 and turn it on. Note that the main reference signal is set in accordance with a predetermined angle within a range that does not cause the vehicle body 1 to overturn. 49 is a relay which is energized when the transistor 48 is turned on and contacts 50.
51 is turned on, a buzzer 52 is activated to issue an alarm, and the lowering solenoid 30 of the solenoid valve 28 is energized to switch the solenoid valve 28 in the lowering direction. In addition, the comparator 4243.1 resistors 44, 45 and the diode 46.
47, an I-transistor 48, a relay 49, and the like constitute a control means 53.

During work, when a worker gets on the boarding brush 11 and operates the pedal 13 in the upward direction, the solenoid valve 28 is switched to the upward direction, and the elevating cylinder 10 is extended, so that the boom 7 rises around the shaft 9. At this time, if the vehicle body 1 is tilted in the left-right direction on a slope, the signal from the angle sensor 41 is sent to the comparators 42 and 43 and compared with the ± base signal. For example, if the tilt angle is greater than a predetermined angle in the child direction, the transistor 48 is turned on by a signal from the comparator 42, and the relay 49 is energized, so that the contact 50 is turned on and the buzzer 52 issues an alarm. On the other hand, since the contact 51 is turned on at the same time, the solenoid valve 28 is switched to the lowering side, and the elevating cylinder 10 is contracted. Therefore, the boom 7 is lowered and the work vehicle can be prevented from falling over. Note that the boom 7 is lowered to the lowest position.

When the operating lever 12 is operated forward (arrow A) during work, the switch 37.40 is turned on and the solenoid valves 33L, 33 are turned on.
Since R opens, the cylinders 31L and 31R operate, and the left and right forward clutches 24L and 24R engage. Therefore, the left and right drive wheels 4L and 4R simultaneously rotate and move forward.

When the operating lever 12 is operated in the direction of arrow B, the switch 3
7 is turned on and the left forward clutch 24L is engaged via the electromagnetic valve 33L and the cylinder 31L, so only the left drive wheel 4 rotates and the vehicle can turn to the right using the right drive wheel 4R as a fulcrum.

Similarly, the vehicle can run or turn in the direction in which the operating lever 12 is operated, and the movement of the operating lever 12 coincides with the traveling direction, making it easy to use. Furthermore, since the operating section is compact and requires only wiring, there is a great deal of freedom in designing the fulcrum of the boom 7.

Note that the angle sensor 41 and the control means 53 may be constructed mechanically.

Further, the working vehicle may be equipped with a crane or the like at the tip of the boom 7, and is not limited to a working vehicle for orchards.

(Effects of the Invention) The present invention includes an angle sensor 41 that detects the tilt angle of the vehicle body 1 in the left-right direction, and when the vehicle body 1 tilts in the left-right direction by a predetermined angle or more, the lifting cylinder 10 is activated in conjunction with the angle sensor 41. Since the control means 53 is provided to operate the boom in the lowering direction, it is possible to prevent the boom from overturning in the left and right directions when working on a slope or the like.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an electric circuit diagram;
Figure 2 is a side view of the work vehicle, Figure 3 is a plan view of the same, Figure 4 is a configuration diagram of the power transmission system, Figure 5 is an explanatory diagram of the relationship between levers and switches, and Figure 6 is a hydraulic circuit diagram. be. ■... Vehicle body, 7... Boom, 10... Lifting cylinder, 11... Boarding brush, 28... Solenoid valve, 41
...Angle sensor 42.43...Comparator, 48...
- Transistor, 49... Relay 53... Control means. Patent applicant Kubota Iron Works Co., Ltd. Figure 5

Claims (1)

[Claims] (1) In a work vehicle with a boom, which is equipped with a boom (7) on the vehicle body (1) that can be raised and lowered by expanding and contracting the lifting cylinder (10), an angle sensor ( 41), and a control means (53) for operating the lifting cylinder (10) in the boom lowering direction in conjunction with the angle sensor (41) when the vehicle body (1) is tilted by a predetermined angle or more in the left-right direction. A safety device for work vehicles with booms.