Hydraulic Valve Plug-in Locking Mechanism for Forklift Control Block

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Solution Overview

Problem

Hydraulic systems in industrial trucks face issues with leaks and loose valves due to improper torque application during assembly, which is not reliably detectable, leading to leakage and operational failures.

Innovation Solution

A control block with radially movable locking elements and a manually operable unlocking mechanism, combined with elastomeric rings and split rings, ensures secure engagement of hydraulic valves, preventing leaks and facilitating easy assembly and disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If threaded connections are used to fasten hydraulic valves to the control block, then assembly is simple and valves can be easily installed, but improper torque application causes leaks and valves becoming loose during operation

Engineering Contradiction:
Improveease of assemblyVSAvoidleak prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection system is divided into separate functional elements: a plug-in section with external threading, a receiving bore with internal threading, and a distinct locking element that can move radially. This segmentation allows the assembly process to be separated into insertion and locking stages, ensuring proper engagement without requiring precise torque control during initial assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking element is pre-positioned to engage with the plug-in section before the valve is fully tightened. This preliminary locking action ensures that the connection is secured at the correct position during assembly, preventing both over-tightening and under-tightening issues that lead to leaks and loose valves.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If threaded connections are used to fasten hydraulic valves, then valves can be installed with basic tools, but torque control cannot be reliably applied during assembly

Engineering Contradiction:
Improveassembly simplicityVSAvoidtorque application precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The locking element automatically engages and secures the valve in the correct position during the insertion process itself. The radial movement of the locking element provides self-aligning and self-securing functionality, eliminating the need for external torque control mechanisms or specialized assembly tools.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The locking element changes its radial position from a retracted state during insertion to an engaged state that locks the valve. This parameter change (radial movement) provides a clear mechanical indication of proper installation, replacing the need for torque measurement and control.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If threaded connections are used, then valves can be assembled with standard fastening methods, but assembly errors are not reliably detected

Engineering Contradiction:
Improveassembly process simplicityVSAvoidassembly error detection
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The locking element provides a visible mechanical indication of proper engagement. When the locking element is in its locked position, it presents a clear visual or tactile signal that the valve is correctly installed, allowing assembly errors to be immediately detected without requiring additional measurement or inspection steps.

Inventive Principle:
Principle #32Color changes

4Reliability

If radial locking elements are added to the control block, then leak-free connections are achieved, but device complexity increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidcontrol block structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking element is integrated into the control block structure, combining the functions of the control block and the locking mechanism into a single unified component. This merging approach adds minimal complexity while achieving the reliability goal, as the locking functionality is embedded within the existing control block geometry.

Inventive Principle:
Principle #5Merging (Combining)

5Ease of repair

If manual unlocking mechanisms are provided, then valve replacement is enabled, but assembly and disassembly procedures become more complex

Engineering Contradiction:
Improvevalve replacement capabilityVSAvoidunlocking mechanism structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The manually operable unlocking mechanism acts as an intermediary that temporarily disengages the locking element, allowing the plug-in section to be removed. This intermediary mechanism provides controlled access for maintenance while maintaining the secure locked state during normal operation, balancing ease of repair with operational reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The solution provides a leak-free connection, allows for quick and easy assembly, and enables reliable identification of assembly errors, enabling quick replacement of defective valves even in hard-to-reach places.

Implementation Method 1

An elastomeric ring or flange is provided on the valve body which, when the plug-in part is inserted into the control block, is energized by contacting the control block in order to arrange the valve in a fixed position in the control block.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

at least one radially movable locking element is arranged... wherein biasing means hold the locking element in the locking position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

a split ring made of resilient material is arranged in an annular groove in the receiving bore so that the split ring is temporarily expanded when the annular projection is inserted when the plug-in part is inserted The projection is pushed through the split ring. The ring groove in the mounting hole is designed so that the split ring can be temporarily widened to enable the plug-in part to be inserted. The ring then narrows again and thereby locks the plug-in part in the control block

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2913570B1Control block for a hydraulic system of an industrial truck with at least one hydraulic valve
Publication Date: 2018.07.25 JUNGHEINRICH AG
  • EP2913570B1 patent drawingFigure 1~2
  • EP2913570B1 patent drawingFigure 3
  • EP2913570B1 patent drawingFigure 4

AI summary

Control block for a hydraulic system of a forklift truck with at least one hydraulic valve, wherein the valve body of the hydraulic valve has a plug-in section with at least one radial bore, which can be inserted into a receiving bore of the control block, and wherein fastening means are provided for the detachable fastening of the hydraulic valve to the valve block, characterized in that at least one radially movable locking element is arranged on the outside of the plug-in section or in the receiving bore, which engages in a locking manner with an annular groove in the receiving bore or an annular groove on the outside of the plug-in section when the plug-in section is inserted into the receiving bore, wherein preload means hold the locking element in the locking position, and a release mechanism is associated with the plug-in section or the receiving bore by which the locking element can be disengaged from the annular groove of the receiving bore or the plug-in section.