Work Vehicle Hydraulic Control for Arm-Bucket Flow Priority
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Solution Overview
Problem
In work vehicles with parallel hydraulic circuit systems, the arm drive is interrupted when the bucket is engaged in rotating operation, leading to difficulties in resetting the bucket's angular position and ensuring smooth movement, as the pressure oil supply prioritizes the arm over the bucket, causing the bucket to struggle in resuming its predetermined position.
Innovation Solution
A hydraulic control device with a flow control valve that restricts pressure oil supply to the arm drive actuator when both the arm and bucket are in combined operation, ensuring that pressure oil is prioritized for the bucket drive actuator, and includes an angle detection unit to manage oil flow based on the arm's position, preventing pressure oil from being diverted to the arm until it reaches a set angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a parallel hydraulic circuit system is used to drive the arm and bucket concurrently, then the bucket can rotate simultaneously with the arm, but the arm drive is interrupted when the bucket rotates, causing the bucket to struggle in resuming its predetermined position
Solution Approach 1:
The patent extracts the priority control function from the normal parallel hydraulic circuit by introducing a separate priority valve. This priority valve is specifically dedicated to ensuring the bucket drive receives sufficient pressure oil during rotation operations, independent from the arm bucket concurrent operation control. The priority valve extracts the critical function of pressure guarantee from the overall hydraulic system.
Solution Approach 2:
The priority valve acts as an intermediary component between the hydraulic pump and the bucket drive actuator. It mediates the pressure oil distribution by selectively prioritizing the bucket circuit when rotation operations are detected, ensuring that the bucket receives adequate pressure oil supply even during concurrent arm operations or when the arm weight creates pressure imbalances.
2Ease of operation
If pressure oil is supplied with priority to the arm drive actuator, then the arm can move smoothly, but the bucket will not be allowed to resume a predetermined position with ease
Solution Approach 1:
The priority valve dynamically adjusts pressure oil distribution based on operational conditions. When the bucket operation unit detects bucket rotation operations, the priority valve automatically shifts to prioritize the bucket circuit, ensuring sufficient pressure oil supply for rapid bucket rotation. This dynamic switching resolves the contradiction by adapting pressure allocation to the current operational phase rather than maintaining a fixed priority scheme.
Solution Approach 2:
The system changes the pressure distribution parameters dynamically based on operational mode. During bucket rotation operations, the priority valve modifies the pressure oil flow parameters to favor the bucket circuit, increasing pressure and flow rate to the bucket actuator. This parameter change enables the bucket to rotate at required speeds without being hindered by arm weight effects that would otherwise dominate in a static priority system.
3Force
If the arm is subjected to downward force of gravity during lowering, then the pressure in the arm drive hydraulic cylinder decreases, but pressure oil will be supplied into this oil chamber with priority, causing the bucket to fail in resuming position
Solution Approach 1:
The priority valve implements preliminary anti-action by preemptively counteracting the pressure imbalance caused by arm gravity. When bucket rotation operations are detected, the priority valve activates before the arm gravity effect can fully disrupt the pressure balance. It creates a compensating pressure effect in the bucket circuit that opposes and neutralizes the detrimental pressure reduction caused by arm weight during concurrent operations.
Solution Approach 2:
The priority valve applies local quality control by focusing pressure optimization specifically on the bucket circuit during rotation operations, without uniformly affecting the entire hydraulic system. It creates a localized pressure enhancement in the bucket actuator circuit while allowing the arm circuit to operate under its own pressure conditions determined by arm position and gravity. This localized intervention resolves the contradiction by addressing only the bucket position control issue without disrupting arm lowering operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows the bucket to rotate without reduced speed relative to the arm, ensuring smooth concurrent operation and preventing the bucket from being hindered by the arm's weight, thereby improving operational efficiency and ease of position resetting.
Implementation Method 1
a hydraulic pump that supplies pressure oil
Implementation Method 2
a flow control valve that restricts pressure oil to be supplied to the arm drive actuator
Data Source
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AI summary
A hydraulic control device for a work vehicle includes: a hydraulic pump that supplies pressure oil; an arm drive actuator that drives, with pressure oil supplied from the hydraulic pump, an arm attached to the work vehicle so as to swing the arm; a bucket drive actuator that drives, with pressure oil supplied from the hydraulic pump, a bucket attached to a front end of the arm, so as to swing the bucket; an arm drive pressure oil control valve that controls drive of the arm drive actuator by controlling pressure oil supplied from the hydraulic pump to the arm drive actuator; a bucket drive pressure oil control valve that controls drive of the bucket drive actuator by controlling pressure oil supplied from the hydraulic pump to the bucket drive actuator; an arm operation unit that controls the arm drive pressure oil control valve; a bucket operation unit that controls the bucket drive pressure oil control valve; an operating state detection unit that detects operating states of the arm drive actuator and the bucket drive actuator; and a flow control valve that restricts pressure oil to be supplied to the arm drive actuator as combined operation of the arm drive actuator and the bucket drive actuator is detected via the operating state detection unit.