JP3265545B2 - Adjustment control device for work vehicle state detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to calibration of a sensor of an overload prevention device for a working vehicle such as a crane.

[0002]

2. Description of the Related Art A work vehicle such as a crane is provided with an overload prevention device to prevent the work vehicle body from overturning or being damaged by an overload. The overload prevention device can apply a load to a work machine. The rated load that defines the limit load is compared with the actual load that actually acts on the work equipment.If the actual load becomes the rated load, an alarm or the operation of the work equipment is restricted, and the work vehicle may fall or be damaged. It is necessary to keep the operation accuracy within a certain range. However, due to errors caused by variations in the production and assembly of work vehicles,
Adjustment was required to ensure the accuracy of the overload prevention device. As a conventional technique, as described in JP-A-1-299199 and JP-A-1-299200,
The actual value detected by the detecting means is compared with a design value corresponding to the detecting means, and a zero point and a gradient coefficient are calculated and obtained.

[0003]

However, in the above-mentioned prior art, the deviation of the zero value and the span value caused by the characteristic difference of the mounting state of each detecting means is automatically calibrated.
In order to calibrate the characteristic difference with respect to the design value fixedly stored in advance as the reference value, if there is a difference between the actual physical state of the working machine and the design value as the reference value at the time of adjustment,
It will not be possible to calibrate accurately, but as a practical matter,
It is extremely difficult to match the conditions of the boom length, boom angle, working radius, hanging load, etc. of the working equipment to the conditions of the design values, it takes a lot of man-hours, it is not easy, and the calibration of the detector is basically not the design value However, there is a problem that the operation must be performed on the physical state of the working machine.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in an overload prevention device for a crane working vehicle, a plurality of operating states of a sensor are commonly detected. An adjustment object selecting means for arbitrarily selecting an adjustment object in the adjustment processing unit, a first initial value and a second initial value changing means for selecting and displaying a plurality of detected values, and an initial value based on an actually measured value; Means for changing a first initial value and a second initial value, and a storage command for the first A / D conversion value, the second A / D conversion value, the first initial value after the change, and the second initial value after the change. Storage command means, a first A / D converted value, a second A / D
And a storage unit for storing the converted value, the changed first initial value, and the changed second initial value.

[0005]

With the above arrangement, the initial values based on the design reference values are replaced with the actual physical state of the working machine, that is, the numerical values calculated from the actually measured values, so that each detector can be calibrated and the actually measured values can be adjusted. Since it can be used, it is only necessary to bring the working machine near the state that is the reference state for adjustment, and it is not necessary to set the work state accurately to the reference state.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the embodiment, FIG. 2 is a flowchart at the time of sensor adjustment, and FIG. 3 is a layout diagram of a monitor panel. In FIG. 1, a detection value Vi obtained through A / D conversion 1d from a selected sensor 9 is converted into a physical quantity Pi by a physical quantity conversion unit 1b by an adjustment target selection unit 2 that can arbitrarily select an adjustment target.

[0007]

(Equation 1)

In the calculation of the conversion formula, when the sensor has already been adjusted, the adjustment values S and V stored in the storage unit 6 at the time of sensor adjustment are substituted for the physical quantities Pmin and Pmax and the data Dmin and Dmax. That is, the adjustment value S, that is, the first initial value and the second initial value converted by the actually measured values are substituted for Pmin and Pmax, and Dmin and Dmax
The adjustment value V, that is, the first A / D conversion value and the second A / D conversion value of the sensor detection value corresponding to the first initial value and the second initial value are substituted. Then, the physical quantity Pi corresponding to the current sensor detection value is calculated by substituting the A / D conversion value of the current sensor detection value for Vi. A / Ds corresponding to the design reference value S _0, ie, the first initial value and the second initial value, and V _0, ie, the first initial value and the second initial value, stored in the initial value storage unit 1 c when the sensor is not adjusted. The calculation can be performed by substituting the design reference value of the conversion value, and it is possible to use either the measured value or the design reference value. Initially, the design reference value is used as the initial value. When the actual measurement value is detected, the initial value is changed by the change unit 4 and the actual measurement value is stored in the storage unit 6 by using the storage command unit 5. Can be stored. The A / D-converted detection values and actual measurement values, design reference values, or adjustment values are displayed on the display unit 3.

When the operation in the sensor adjustment mode is performed, specifically, the display mode switch 21 is set to a check on the monitor panel shown in FIG. 3, and the switch key 21 is pressed for 2 seconds to switch to the sensor adjustment mode. In the sensor adjustment mode, the sensor to be adjusted can be selected by the upper operation mode switch 22. For example, “boom” is a boom length sensor, and “single top” is a boom angle sensor. The operation menu for adjustment is displayed on the display device 23.
Will be displayed on the screen. The sensor adjustment operation according to the flowchart shown in FIG. 2 can be performed using the functions of the following switches shown in FIG. 51 is a setting (memory command: used for adjusting value setting), 52 is selection (memory command: used for adjusting value canceling), 53 is an upper limit angle (actual measured value setting: used as an increment key), 5
4 is used for the lower limit angle (actual value setting: used as a decrement key). In FIG. 2, first, it is checked whether or not the mode has been switched to the sensor adjustment mode in step 1, and then the operation proceeds to step 2, where a sensor to be adjusted is selected. 2
Move to 1. Thereafter, while operating the selected working machine, the detected values of the sensors are input and stored as measured values, and the adjustment operation is performed.

FIG. 4 shows a screen of the display device 23 during the operation of adjusting the boom length sensor. The operation is performed in the following procedure.
To set the boom length MIN, first set the boom to the boom length MI.
A known length near N is set. Next, after inputting the boom length at that time with the “upper limit” or “lower limit” key, confirm with the “set” key. At this time, the input actual measured value of the boom length near the boom length MIN and the A / D converted value of the sensor detected value at that time are temporarily held (latched) in the memory. Boom length MAX
Is set to a known length near the boom length MAX. Enter the boom length at that time with the “upper limit” or “lower limit” key and confirm with the “set” key. At this time, the input actual measured value of the boom length near the boom length MAX and the A / D converted value of the sensor detected value at that time are temporarily held (latched) in the memory. If the sensor A / D conversion value latched by the above operation is appropriate, it is stored as an adjustment value and "Adjustment completed!"
Is displayed for 3 seconds. If NO, "Please reset" is displayed for 3 seconds and the buzzer sounds. When the sensor has not been adjusted, the actual measurement value displays the default value of the boom length MIN and MAX. However, when the sensor has been adjusted, the adjusted value is displayed. Is canceled, and the transfer operation is started when no adjustment is made.

FIG. 5 shows a screen of the display device 23 during the operation of adjusting the boom angle sensor. Since the operation is performed in the same procedure as in the case of the boom length, the description is omitted. FIG. 6 shows the relationship between the detected value Vi and the physical quantity Pi.

As described above, the sensor can be adjusted on the basis of the actually measured value, and it is only necessary to bring the working machine near the reference state, and it is not necessary to accurately set the design value. Work can be performed accurately and easily.

[0013]

As described in detail above, the present invention can calibrate each of the detectors with respect to the actual physical state of the working machine, that is, the measured value, and can set the measured value. The sensor need only be brought to the vicinity of the reference state, and it is not necessary to set the reference state accurately, so that the adjustment work of the sensor can be performed accurately and easily.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment according to the present invention.

FIG. 2 is a flowchart of a sensor adjustment operation.

FIG. 3 is an explanatory diagram of functions of an overload prevention device monitor panel in a sensor adjustment mode.

FIG. 4 is a display example when adjusting a boom length sensor.

FIG. 5 is a display example at the time of adjusting a boom angle sensor.

FIG. 6 is a relationship diagram between a sensor detection value V and a physical quantity P.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Overload prevention device 1a Adjustment processing part 2 Adjustment target selection means 3 Display means 4 Changing means 5 Storage command means 6 Storage part 9 Sensor

Claims (1)

(57) [Claims] 1. In an overload prevention device 1 for a working vehicle such as a crane, an adjustment target in an adjustment processing unit 1a for commonly processing detection values of a sensor 9 as a plurality of operation state detection means can be selected. The first and second initial value display means 3 for selecting and displaying a plurality of detection values, and the first and second initial values for changing the initial values based on actual measurement values are provided. Changing means 4, the first A / D converted value, the second A / D
Storage command means 5 for storing and commanding the D-converted value, the changed first initial value, and the changed second initial value; a first A / D converted value, a second A / D converted value, and a changed first initial value And a storage unit 6 for storing a second initial value after the change.