Filter Device Backflow Prevention via Segmented Air Purge
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Solution Overview
Problem
Existing filter devices for internal combustion engines often discharge air along with liquid, leading to bubble formation in hydraulic systems, which can cause defects and damage due to increased temperature and pressure.
Innovation Solution
A filter device design that includes a back pressure valve and check valves to prevent backflow of liquid and purge air without generating bubbles, featuring a cylindrical portion with a bottomed shape and a lid body that covers the upper end, allowing air to be discharged while preventing hydraulic oil from being discharged, and check valves that ensure only air is released during low flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the check valve is opened to discharge air inside the filter device, then air can be purged effectively, but liquid may backflow and bubbles are generated in the liquid
Solution Approach 1:
The outflow portion is divided into two separate pathways: one for air discharge (through the lid body) and one for liquid discharge (through the cylindrical portion with back pressure valve). This segmentation allows air and liquid to be discharged through different routes, preventing bubble generation in the liquid while maintaining effective air purging capability.
Solution Approach 2:
The back pressure valve acts as an intermediary mechanism that controls liquid discharge. It allows liquid to flow out when necessary (during engine operation) but prevents liquid backflow when the engine stops, thereby preventing bubble formation in the hydraulic system without compromising air purging effectiveness.
2Object-generated harmful factors
If the outflow portion closes to prevent liquid backflow during engine operation, then liquid backflow is prevented, but air inside the filter device cannot be discharged
Solution Approach 1:
The discharge system is segmented into two independent pathways: the lid body with first hole for air discharge and the outflow portion with back pressure valve for liquid discharge. This allows the outflow portion to remain closed during engine operation (preventing liquid backflow) while the lid body pathway remains open for air discharge.
Solution Approach 2:
The back pressure valve provides dynamic control of the outflow portion, opening when liquid flow is present during engine operation and closing when the engine stops. This dynamic behavior prevents liquid backflow while the static open pathway in the lid body continuously allows air discharge.
3Device complexity
If a simple check valve is used to prevent backflow, then the device complexity is low, but air cannot be purged without disassembling the filter device
Solution Approach 1:
The lid body serves multiple functions: it seals the upper end of the case, provides structural support, and incorporates the first hole with check valve for air discharge. This multi-functionality allows air purging to be integrated into the existing lid structure, eliminating the need for disassembly while maintaining structural integrity.
Solution Approach 2:
The air discharge pathway through the lid body is pre-configured and always accessible, allowing air to be purged at any time during engine operation without requiring disassembly. This preliminary preparation of the air discharge route enables convenient maintenance and operation.
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 effectively prevents bubble formation in hydraulic oil, reducing the risk of defects and damage by ensuring air is purged without mixing with hydraulic oil, thus maintaining stable system operation and extending component lifespan.
Implementation Method 1
The first elastic member is provided between a bottom surface of the cylindrical portion and the valve body
Implementation Method 2
when a flow rate of the liquid increases and the back pressure valve opens (the valve body does not abut on the first valve seat), the space inside the filter element communicates with the space outside the case via the second through-hole
Implementation Method 3
check valves that ensure only air is released during low flow rates
Data Source
AI summary
A backflow of liquid inside a filter device during an operation of an internal combustion engine is allowed to be obviated while air inside the filter device is purged so as not to generate bubbles in the liquid. An outflow portion that includes a cylindrical portion having a substantially bottomed cylindrical shape and a back pressure valve provided inside the cylindrical portion is provided so as to penetrate a bottom surface of a case. In addition, a lid body provided on the case and an upper plate of a filter element so as to cover an upper end of the case has a first hole that communicates between a space inside the case and a space outside the case. When the back pressure valve opens (a valve body does not abut on a first valve seat), a space inside the filter element communicates with the space outside the case via a second through-hole formed in a side surface of the cylindrical portion.