JP2001132703A - Vehicle for work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To almost equalize a velocity variable amount corresponding to velocity adjusting operation, independently of the velocity region in adjusting to enhance operational capability in velocity adjusting in a car for work in which the hydraulic velocity, such as working machine elevation velocity is adjustable according to the kinds of working machines or taste of an operator. SOLUTION: The valve control function for determining a valve driving control value according to a target flow rate or target velocity is set in a control part 9 for controlling a hydraulic valve 7, and the inclinations of valve control functions f0-f10 to be switched in the change-over of valve control functions to be used according to the operation of a set operation part 16 are made the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a working vehicle such as a tractor having a hydraulic speed adjusting function.

[0002]

2. Description of the Related Art Recently, a working traveling vehicle such as a tractor of this kind is provided with a hydraulic speed adjusting function for adjusting a hydraulic speed such as a lifting / lowering speed of a working machine according to a type of the working machine and an operator's preference. It has been proposed that this function applies a valve control function that determines a valve drive control value (valve drive current value, valve drive duty value, etc.) according to the target flow rate or target speed to the operation of the hydraulic speed adjuster. This can be realized by providing a means for changing accordingly.

[0003]

However, when the inclination of the valve control function is changed according to the operation of the hydraulic speed adjuster, the amount of speed change accompanying the speed adjustment operation depends on the speed range at the time of adjustment. Therefore, even if the hydraulic speed is adjusted while driving the hydraulic valve, the hydraulic speed may not be adjusted to the desired hydraulic speed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made in order to solve these problems. In a working vehicle in which a valve control function that determines a valve drive control value according to a target speed is set, the control unit includes a hydraulic speed adjusting unit that switches a valve control function to be used in accordance with an operation of a hydraulic speed adjuster. In addition, the inclination of each of the valve control functions to be switched is set to be substantially the same. That is,
Since the amount of speed change accompanying the speed adjustment operation is substantially uniform regardless of the speed range at the time of the adjustment, if the hydraulic speed is adjusted while driving the hydraulic valve, the desired hydraulic speed can be easily adjusted.

[0005]

Next, one embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling body of a tractor, and a working machine 3 is connected to a rear portion of the traveling body 1 via a lifting link mechanism 2. The working machine 3 moves up and down in response to the hydraulic operation of a lift arm 5 (lift arm cylinder) that suspends the lifting link mechanism 2 via a pair of left and right lift rods 4. Inclination in the left and right directions according to the hydraulic operation of the interposed lift rod cylinder 6, but these basic configurations are all conventional.

Numerals 7 and 8 denote electromagnetically operated hydraulic valves for operating the respective cylinders, and solenoid operated solenoids 7a, 7b, 8a, incorporated in the hydraulic valves 7, 8 respectively.
8b are connected to the control unit 9 via valve drive circuits, respectively, and are driven in accordance with a valve drive signal output from the control unit 9. The cylinder operation speed (hydraulic speed) accompanying this drive is: It changes according to a valve drive control value (valve drive current value, valve drive duty value, etc.) determined by the control unit 9.

A front panel 10 is provided in front of a driver's seat 11. A meter panel 12 incorporated in the front panel 10 includes meters such as an engine tachometer 13 and monitor lamps such as a charge lamp 14. In addition, a setting display unit 15 capable of displaying various setting states of the control unit 9 is provided at the lower right end of the meter panel 12. That is, the setting display unit 15 displays n
It is composed of a liquid crystal panel provided with display dots of m columns in a row, and can display various setting states as arbitrary character strings or figures according to a display drive signal from the control unit 9.

Reference numeral 16 denotes a setting operation unit (hydraulic speed adjuster) provided at the lower right end of the front panel 12,
The setting operation unit 16 includes a menu switch 17 for switching setting items displayed on the setting display unit 15,
Selection switch 1 for increasing or decreasing the set value of each setting item
8 and 19 and a decision switch 20 for storing the changed set value are arranged. That is, the setting display unit 1
By operating the setting operation section 16 while viewing the setting 5, various setting states of the control section 9 can be confirmed or changed. For example, the ascending speed (basic ascending speed) of the lift arm 5 is adjusted. In this case, after the “hydraulic speed increase” screen is displayed by operating the menu switch 17, the speed level (0 to 0) is operated by operating the selection switches 18 and 19.
10) is changed, and thereafter, when the decision switch 20 is operated, the changed speed level is stored and held.
The setting values of other setting items can be changed by substantially the same operation.

The control section 9 is constituted by using a microcomputer (including a CPU, a ROM, a RAM, etc.), and has, on its input side, the above-described menu switch 17, selection switches 18, 19, While input devices such as the switch 20 are connected via a predetermined input interface, the output side includes the above-described solenoids 7a and 7a.
Output devices such as b, 8a, 8b and a setting display unit 15 are connected via a predetermined output interface circuit. Then, the control unit 9 controls the display of the setting display unit 15 in accordance with the operation of the setting operation unit 16, “setting display”, and the setting operation unit 16.
"Setting change" to change various setting values according to the operation of
A control routine such as "control function switching" for switching a control function to be used according to various setting value changes is provided. That is, the "control function switching" includes a control routine such as "lift arm raising speed adjustment" for switching the valve control function for lift arm raising control according to the set level of the hydraulic pressure raising speed described above. The main part of the present invention will be described by taking "lift arm lifting speed adjustment" as an example.

The "lift arm lifting speed adjustment" is a valve control function for determining a valve driving control value (valve driving current value, valve driving duty value, etc.) for lifting the lift arm according to a target flow rate or a target speed. Is switched in accordance with the above-mentioned set level of the hydraulic pressure rising speed, and the basic rising speed of the lift arm 5 is set to be adjusted stepwise based on the function switching process. In other words, in the “lift arm rising speed adjustment”, when it is determined that the set level of the hydraulic pressure rising speed is 5, the standard speed valve control function f5 (a linear function that matches the actual flow rate / current characteristics) is used. But the setting level is 6-10
Is determined to be within the range, the valve drive control value for the target flow rate or target speed is increased (A-
If the set level is determined to be in the range of 0 to 4 while using the valve control functions f6 to f10 (C range), the valve drive control value for the target flow rate or target speed is decreased (A-B). Range) valve control function f0
To f4.

The valve control functions f0 to f10
Is set based on the standard speed valve control function f5 so that the valve drive control value with respect to the target flow rate or the target speed increases or decreases stepwise. However, the slopes of the valve control functions f0 to f10 are the same. Is set to a linear function. That is, since the amount of speed change accompanying the speed adjustment operation is uniform regardless of the speed range at the time of adjustment, if the hydraulic speed is adjusted while driving the hydraulic valve 7, the desired hydraulic speed can be easily adjusted. It has become.

In the apparatus configured as described above, a valve control function for determining a valve drive control value in accordance with a target flow rate or a target speed is set in a control section 9 for driving and controlling the hydraulic valve 7 and a setting operation section. In providing the “lift arm raising speed adjustment” means for switching the valve control function to be used in accordance with the operation of No. 16, the inclination of each of the switched valve control functions f0 to f10 is made the same, so that the speed change amount accompanying the speed adjustment operation is reduced. It becomes uniform regardless of the speed range at the time of adjustment. As a result, if the hydraulic speed is adjusted while driving the hydraulic valve 7, the desired hydraulic speed can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor.

FIG. 2 is a front view of a front panel.

FIG. 3 is a block diagram showing input and output of a control unit.

FIG. 4 is a flowchart showing “lift arm lifting speed adjustment”.

FIG. 5 is an explanatory diagram showing a hydraulic speed adjustment procedure (display screen).

FIG. 6 is a graph showing a valve control function.

[Explanation of symbols]

 Reference Signs List 1 traveling machine body 3 work machine 5 lift arm 6 lift rod cylinder 7 hydraulic valve 8 hydraulic valve 9 control section 15 setting display section 16 setting operation section 17 menu switch 18 selection switch 19 selection switch 20 determination switch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toyoharu Endo 667 Idaicho, Oji, Higashi-Izumo-cho, Yatsuka-gun, Shimane 1 Inside Mitsubishi Agricultural Machinery Co., Ltd. Address 1 Inside Mitsubishi Agricultural Machinery Co., Ltd. (72) Inventor Masaki Uyama 667 Iidacho, Oji-machi, Higashi-Izumo-machi, Yatsuka-gun, Shimane Prefecture Address 1 Mitsubishi Agricultural Machinery Co., Ltd. (72) Inventor Shigeharu Kimura 667 Iida-cho, Ojimo-cho, Higashi-Izumo-cho, Yatsuka-gun, Shimane 1 F-term in Mitsubishi Agricultural Machinery Co., Ltd. (Reference) 2B304 KA07 LA02 LA06 LB05 LB15 LC04 MA02 MB01 MB02 MB03 MB04 MC02 MC08 MD02 MD03 PB02 PB06 PD14 PD24 QA12 QA22 QA25 QA26 QB12 QB15 RB01 3H089 AA21 BB15 DB63 EE34 FF04 FF23 GG02 JJ17

Claims (1)

[Claims] 1. A work vehicle in which a control unit for driving and controlling a hydraulic valve is provided with a valve control function for determining a valve drive control value according to a target flow rate or a target speed.
The control unit further comprises a hydraulic speed adjusting means for switching a valve control function to be used in accordance with an operation of a hydraulic speed adjusting tool, and a gradient of each of the switched valve control functions is set to be substantially the same. Traveling car.