Hydraulic Valve Connection Path for Travel Speed Continuity
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Solution Overview
Problem
Hydraulic controlling devices in working machines like hydraulic excavators face pressure interference issues during combined operational processes at low engine rotational speeds, leading to slow or halted operations due to insufficient oil supply to actuators, especially when performing tasks requiring higher operating pressures.
Innovation Solution
The hydraulic controlling device dynamically adjusts the opening amount of the connection path between pump lines based on engine rotational speed by introducing an intermediate position in the straight travel valve or an external communication valve, ensuring reliable prevention of pressure interference by controlling the valve's position to maintain smooth operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the connection path between pump lines is opened during combined operational process, then travel speed continuity is improved, but pressure interference occurs at low engine speeds
Solution Approach 1:
The connection path opening amount is made dynamically adjustable based on engine rotational speed. The control unit increases the opening amount when engine speed is high (where pressure interference is less problematic) and reduces the opening amount when engine speed is low (where pressure interference is severe), thereby maintaining travel speed continuity while preventing operational reliability issues.
Solution Approach 2:
The opening amount of the connection path is changed as a control parameter based on engine rotational speed conditions. By adjusting this parameter dynamically, the system optimizes the balance between maintaining travel speed and preventing pressure interference that would compromise operational reliability.
2Quantity of substance
If the opening amount of connection path is increased, then oil supply to actuators is improved, but pressure interference worsens
Solution Approach 1:
The opening amount of the connection path is dynamically adjusted as a controllable parameter based on engine rotational speed. At high engine speeds, a larger opening supplies sufficient oil to actuators without causing severe pressure interference. At low engine speeds, the opening is reduced to prevent pressure interference while still providing necessary oil supply.
Solution Approach 2:
The system transitions from a static fixed opening connection path to a dynamic adjustable opening path that responds to engine speed conditions, optimizing the balance between oil supply quantity and pressure interference prevention in real-time.
3Device complexity
If a fixed opening connection path is used, then device complexity is reduced, but adaptability to different engine speeds is insufficient
Solution Approach 1:
The connection path is transformed from a fixed-structure element to a dynamically controllable element. The control unit adjusts the opening amount based on engine rotational speed signals, enabling the system to adapt to varying engine speed conditions while maintaining reasonable structural complexity through electronic control rather than complex mechanical mechanisms.
Solution Approach 2:
The patent replaces complex mechanical adjustment mechanisms with electronic control. The control unit receives engine speed signals and electronically adjusts the connection path opening amount, substituting intricate mechanical adaptability systems with a simpler electronically-controlled system that achieves the same adaptability goal.
Data Source
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AI summary
A hydraulic controlling device in which, when performing a combined operational process, a position of a straight travel valve (25) is switched to a straight travel position (C) to drive both a travel motor (13) and a working actuator (12,7) by separate pumps (19,20). In this case, to prevent a sudden reduction in travel speed resulting from a reduction in a flow amount at a travel side, pump lines (P1,P2) of both pumps (19,20) are connected to each other at an intermediate position (B) by a connection path (27), so that a portion of oil at a working side is sent towards the travel side. With such a structure, when a rotational speed of an engine is less than a set rotational speed, an opening amount of the connection path (27) is reduced through a straight travel proportional valve (23) by a controller (26), thereby preventing pressure interference causing, for example, the working actuator (12,7) to no longer move.