Hydraulic Valve End Wall Positioning in Rock Drilling Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic rock drilling machines require precise machining for reliable valve function, especially at increased percussive frequencies, leading to high production costs.
Innovation Solution
A distribution valve design where at least one valve end wall is movable and pressed against an abutment by a pressing device, eliminating the need for precise axial positioning of the valve body, and utilizing an existing hydraulic pressure source to define end positions, allowing for simpler and more economical production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precision machining is used to guarantee reliable valve function, then valve reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces the traditional mechanical positioning system (relying on precision-machined bottom holes in the valve housing) with a hydraulic positioning system. A pressing device with a piston uses hydraulic pressure to push the valve body against a precisely positioned abutment, thereby defining the valve body's end position. This substitution allows the use of less precise machining for the valve housing while maintaining reliable valve function through hydraulic force.
2Manufacturing precision
If precision machining of bottom hole is performed to define valve body position, then positioning accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces complex precision machining operations (drilling and positioning bottom holes in the valve housing) with a hydraulic pressing mechanism. The pressing device uses hydraulic pressure to automatically position the valve body against a simple abutment, eliminating the need for complex bottom hole machining while achieving the same positioning accuracy.
Solution Approach 2:
The patent introduces an intermediary element - the abutment - that serves as a simple positioning reference. Instead of machining complex cavities and bottom holes in the valve housing, a simple abutment is provided that the hydraulic pressing device uses to define the valve body's end position. This intermediary simplifies the overall manufacturing process while maintaining precision.
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 design reduces production costs and allows for accurate positioning of valve elements, enhancing the operational efficiency and reliability of the rock drilling machine while maintaining high precision.
Implementation Method 1
an end wall piston portion arranged on said at least one of the valve end walls and being received in a cylinder portion to be pressurized in order to drive the valve end wall against said abutment during pressurizing
Data Source
Figure 1~2
Figure 3~4
AI summary
A device in a hydraulic rock drilling machine (1) including a distribution valve (7,7', 7") arranged in connection with the rock drilling machine for controlling hydraulic flows to different parts of the rock drilling machine, wherein the distribution valve includes a valve body (8, 8', 8"), which is arranged movable to and fro in axial directions inside a valve chamber (33) and wherein the valve chamber is limited in axial direction by two valve end walls (10,11; 10 ',11'; 10",11"). One of the valve end walls is movable in an axial direction against an abutment (12,12") in such a way that it defines an end position for the valve body, and a pressing device (13,13 ',13") is arranged for pressing said at least one of the valve end walls against said abutment. The invention also relates to a rock drilling machine.