JPH07196299A - Upper bucket travelling speed control device in vehicle for high lift work - Google Patents

Abstract

PURPOSE:To provide an upper bucket travelling speed control device in a high lift work vehicle on which length of a boom is reflected in up bucket move speed control, so that move speed of the up bucket is controlled within a specific speed range, regardless of length of a boom. CONSTITUTION:An upper bucket travelling speed control device has a controller for controlling a control valve device in a hydraulic circuit on the basis of a command from an up bucket 1. Accordingly, a detection data of length L (or a length Lx in horizontal direction) of a boom 2 supporting the up bucket is inputted in a controller. A maximum permissible opening of a raising/lowering valve (a valve for rotation) for the length L (the length Lx in horizontal direction) of the boom is obtained from a correlation stored in advance. The opening ratio of the raising/lowering valve (the valve for rotation) is altered for a command value from an operation unit on the basis of a maximum permissible opening, so that the travelling speed of the upper bucket portion is limited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement control device for an upper bucket portion of an aerial work vehicle, and more particularly to an upper bucket portion for limiting the moving speed of the upper bucket portion to improve work safety. The moving speed limiting device.

[0002]

2. Description of the Related Art This type of aerial work vehicle has an upper controller disposed in the upper bucket portion and a lower portion disposed on the vehicle, based on a command from an upper operation portion disposed in the upper bucket portion. In general, the control valve device of the hydraulic circuit is controlled via a controller to thereby control the position of the upper bucket and the like to obtain a predetermined working state. That is,
From the upper controller, upper information such as control data relating to position control of the upper bucket such as expansion / contraction, ups and downs, turning, etc., which are calculated based on the operation of the upper operation section, and, on the other hand, from the lower controller, related to the control result, The lower information is transmitted / received to / from each other, and various controls are appropriately performed based on these information. By the way, in the conventional movement control device for the upper bucket in the aerial work vehicle, when the crane operation is performed based on the command from the upper bucket unit, the boom moves at a predetermined angular velocity regardless of the length and the angle of the boom. . That is, as shown in FIG. 7, the operation amount of the operation lever by the operator, that is, the command value from the operation unit and the opening degree of each valve of the hydraulic circuit have a constant proportional relationship regardless of the state of the boom. Therefore, the operation amount of the operating lever and the operating speed of the undulating hydraulic cylinder or the turning hydraulic motor have a constant proportional relationship. Therefore, regardless of the amount of operation of the same operating lever, the moving speed of the upper bucket part increases as the boom extends in the up-and-down motion and as the horizontal length of the boom increases in the swivel motion. Is dangerous. In addition, if the operation is mistaken in such a state, the movement amount and the speed are large, which is dangerous. For this reason, especially when the boom is extended,
The operator needs to adjust the operation lever delicately and slowly move the upper bucket part.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to reflect the length of the boom in the control of the moving speed of the upper bucket so as to control the boom. An object of the present invention is to provide a moving speed limiting device for an upper bucket in an aerial work vehicle for limiting the moving speed of the upper bucket within a predetermined speed regardless of the length.

[0004]

The invention according to claim 1 is
In an upper bucket movement control device for an aerial work vehicle equipped with a controller composed of a microcomputer for controlling a control valve device of a hydraulic circuit based on a command from the upper bucket part, a length L of a boom supporting the upper bucket. While inputting the detection data to the controller, the allowable maximum opening degree of the undulation valve with respect to the boom length L is obtained from a previously stored correlation,
It is characterized in that the moving speed of the upper bucket portion is restricted by correcting the ratio of the opening degree of the undulating valve to the command value from the operating section based on the allowable maximum opening degree. Also,
According to a second aspect of the present invention, in the upper bucket movement control device for an aerial work vehicle, which includes a controller including a microcomputer that controls the control valve device of the hydraulic circuit based on a command from the upper bucket part, While inputting the detection data regarding the horizontal length Lx of the boom to be supported to the controller,
The allowable maximum opening degree of the turning valve with respect to the horizontal length Lx of the boom is obtained from a previously stored correlation, and the opening degree of the turning valve with respect to the command value from the operation unit is calculated based on the allowable maximum opening degree. The ratio may be modified to limit the moving speed of the upper bucket portion.

[0005]

[Operation] When controlling the boom up and down, the boom length L
Is reflected in the control of the hoisting valve, and when the boom is extended, the operating speed of the hoisting hydraulic cylinder relative to the operation amount is reduced to limit the moving speed of the upper bucket. Similarly, in the boom swing control, the horizontal length Lx of the boom is reflected in the control of the swing valve, and when the boom is extended, the operating speed of the swing hydraulic motor with respect to the operation amount is reduced. Limit the moving speed of the upper bucket.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are for explaining the operation in the embodiment of the present invention, FIG. 1 is an elevational view showing a undulating motion state, FIG. 2 is a plan view showing a turning motion state,
FIG. 3 is an elevational view showing the positional relationship of the upper buckets, FIG. 4 is an operation explanatory diagram relating to a position sensor for detecting boom extension / contraction,
FIG. 5 is a motion characteristic diagram relating to undulating motion, and FIG. 6 is a motion characteristic diagram relating to turning motion. In the figure, 1 is an upper bucket, 2 is a boom, an upper bucket 1a when the boom 2 is contracted before the operation, an upper bucket 1b when the boom 2 is extended, and an upper bucket after the undulating motion in each telescopic state. The buckets 1av and 1bv and the upper buckets 1ah and 1bh after the turning operation are illustrated.

Therefore, as shown in FIG. 1, when a hoisting hydraulic cylinder (not shown) is actuated on the boom 2 to perform hoisting operation at a rotation angle θv, if the operating speed is constant, The length L of the boom 2 is longer, the movement from the upper bucket 1b to 1bv when the boom 2 is extended is
Upper bucket 1a to 1av when the boom 2 is contracted
The moving speed is higher than that of moving to, and the above-mentioned drawbacks are involved. Therefore, in the present invention, as shown in FIG. 5, the undulating motion characteristic with respect to the length L of the boom 2 is devised. In this case, as for the length L of the boom 2, the position sensor 3 using a potentiometer or the like as shown in FIG. 4 is attached to an appropriate operating portion of the boom 2, and the operation amount of each position sensor 3, that is, the boom 2 The amount of expansion and contraction is input to the controller for calculation. Further, in the controller, for example, as shown in (a) of FIG. 5, the maximum allowable opening degree of the undulating valve is 100% until the length L of the boom 2 reaches a predetermined length La, If the length La is exceeded, the maximum allowable opening is gradually reduced to, for example, 70 at the maximum length.
For example, the correlation between the preset length L of the boom 2 and the maximum allowable opening degree of the undulation valve is stored such that the setting is made to be about%. In the controller, when the maximum allowable opening with respect to the length L of the boom 2 at that time is obtained by this correlation, based on the maximum allowable opening, for example, when the maximum allowable opening is 100%, (B) in 5
As indicated by the line A, the ratio of the opening / closing valve opening degree to the command value is set so that the opening / closing valve opening degree becomes 100% when the command value from the operating portion is 100%. Further, when the length L of the boom 2 is extended to the maximum length and the maximum allowable opening is 70%, the opening / closing valve opening is 70% when the command value is 100% as shown by the line B.
The ratio of the opening degree of the undulating valve to the command value from the operation unit is corrected so that it becomes%.

By downwardly modifying this ratio, specifically,
The undulating valve is formed via a solenoid valve that constitutes a hydraulic control circuit and is controlled to open and close by a known drive control circuit, a servo cylinder that is position-controlled by hydraulic control by the solenoid valve, and a spool connected to the servo cylinder. The opening operation command value is controlled downward when the opening degree is controlled. Therefore, the operating speed of the undulating hydraulic cylinder is moderately reduced according to the length L of the boom 2, and the moving speed of the upper bucket 1 is limited to an appropriate speed.

Next, as shown in FIG. 2, when a swing hydraulic motor (not shown) is actuated on the boom 2 to perform a swinging motion in the horizontal direction at a rotation angle θh, the operating speed is constant. If so, the horizontal length Lx of the boom 2 is long, and the upper buckets 1b to 1b when the boom 2 extends
The movement speed to bh is higher than the movement speed from the upper bucket 1a to 1ah when the boom 2 is contracted, and the above-mentioned drawbacks are involved. Regarding this turning operation, as shown in FIG. 6, the horizontal length L of the boom 2 is
The turning movement characteristic with respect to x is devised.
The horizontal length Lx of the boom 2 is detected by the length L of the boom 2 obtained from the amount of expansion and contraction of the boom 2 detected by the position sensor 3 of FIG. 4, and the angle sensor 4 of FIG. Based on the vertical rotation angle θv of the boom 2, the controller calculates Lx = LCOSθv. Further, the controller has, for example, a horizontal length L of the boom 2 as illustrated in (a) of FIG.
The maximum allowable opening of the turning valve is set to 100% until x reaches a predetermined length Lxa, and when the horizontal length Lxa is exceeded, the maximum allowable opening is gradually reduced to, for example, 7 at the maximum length.
The correlation between the preset horizontal length Lx of the boom 2 and the maximum allowable opening degree of the swing valve is stored, for example, the value is set to about 0%. In the controller,
When the allowable maximum opening degree with respect to the horizontal length Lx of the boom 2 at that time is obtained by this correlation, for example, the allowable maximum opening degree is 100% based on the allowable maximum opening degree.
In such a case, as shown by the line C in FIG. 6B, when the command value from the operating portion is 100%, the opening degree of the turning valve becomes 100%, and the turning valve corresponding to the command value is set to 100%. The opening ratio is set. Further, when the horizontal length Lx of the boom 2 extends to the maximum length and the maximum allowable opening is 70%, the command value is 10 as shown by the line D.
The ratio of the opening degree of the turning valve to the command value from the operation unit is corrected so that the opening degree of the turning valve becomes 70% at 0%. By downwardly adjusting the opening degree of the swing valve, the swing operation speed is appropriately reduced according to the horizontal length Lx of the boom 2 and the movement of the upper bucket 1 is performed, as in the case of the undulating motion described above. The speed will be limited to within a reasonable speed.

Note that the specific operating characteristics between the command value from the operating section and the opening of the undulating or turning valve illustrated in FIGS. 5 and 6 are changed according to the specific conditions of the crane mechanism. It is a matter of design to select a specific structure for both valves. Further, as the detecting means for directly detecting the variation in the length L of the boom 2, a configuration as shown in FIG. 8 may be used. This detecting means fixes the other end of the cable 6 wound on the drum 5 for winding the cable urged in the winding direction to the boom member at the most distal end, and the drum due to the displacement of the cable 6 is fixed. The amount of expansion and contraction of the boom 2 is detected by the rotation angle of 5. The rotation angle is the output voltage Vo of the variable resistance circuit formed through the contactor 9 attached to the shaft portion 7 of the drum 5 and having the other end slidably contacting the spiral resistance wire 8. To be detected. The idea of the present invention is also effective when applied to a crane or the like.

[0011]

According to the present invention, as described above, according to the length L of the boom or the length Lx in the horizontal direction, the opening / closing valve or the swing valve for the specified value from the operating portion is opened. As a result, the operating speeds of the undulating hydraulic cylinder and the slewing hydraulic motor, which are actuators for the upper bucket, are adjusted so that the transfer speed of the upper bucket can be limited within a predetermined speed. it can. Moreover, since the adjustment is performed according to the length L of the boom or the length Lx in the horizontal direction, the difference in the lengths between them is excluded. Therefore, regardless of the length of the boom, the operation of the operation unit is performed. The responsiveness between the amount and the moving speed of the upper bucket can be averaged. Therefore, when the boom is in the extended state, the delicate operation conventionally required is also released, so that the work safety can be further improved.

[Brief description of drawings]

FIG. 1 is an elevational view showing an undulating operation state in an example of the present invention.

FIG. 2 is a plan view showing a turning motion state in the embodiment.

FIG. 3 is an elevational view showing the positional relationship of the upper buckets.

FIG. 4 is an operation explanatory diagram relating to a position sensor for detecting boom extension / contraction.

FIG. 5 is an operational characteristic diagram relating to the undulating motion according to the embodiment of the present invention.

FIG. 6 is a motion characteristic diagram relating to the turning motion of the embodiment of the present invention.

FIG. 7 is an operation characteristic diagram of a conventional example.

FIG. 8 is an explanatory view showing a means for detecting the length L of the boom.

[Explanation of symbols]

 1 ... Upper bucket 2 ... Boom 3 ... Position sensor 4 ... Angle sensor 5 ... Drum 6 ... Cable 7 ... Shaft part 8 ... Resistance wire 9 ... Contact L ... Boom length Lx ... Boom horizontal direction

Claims (2)

[Claims] 1. An upper bucket movement control device for an aerial work vehicle equipped with a controller comprising a microcomputer for controlling a control valve device of a hydraulic circuit based on a command from the upper bucket part. A boom supporting the upper bucket. The detection data relating to the length L of the boom is input to the controller, and the maximum allowable opening of the undulation valve with respect to the length L of the boom is obtained from the previously stored correlation, and based on the maximum allowable opening, the operation unit is operated. The opening bucket valve opening ratio is corrected with respect to the command value to limit the moving speed of the upper bucket portion. 2. An upper bucket movement control device for an aerial work vehicle equipped with a controller comprising a microcomputer for controlling a control valve device of a hydraulic circuit based on a command from the upper bucket part. A boom supporting the upper bucket. Detection data regarding the horizontal length Lx of the swing valve is input to the controller, and the maximum allowable opening of the swing valve with respect to the horizontal length Lx of the boom is obtained from a previously stored correlation, and the maximum allowable opening is calculated. A moving speed limiting device for an aerial work vehicle, wherein the moving speed of the upper bucket part is restricted by correcting the ratio of the opening degree of the turning valve to the command value from the operating part based on .