Pump Depression Head with Annular Piston for Back Suction
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Solution Overview
Problem
Existing pumps face challenges in achieving easy depression and effective shut-off of fluid leakage while maintaining a reliable back suction function, often compromising ease of operation due to excessive friction forces and inadequate negative pressure states.
Innovation Solution
The pump design incorporates a depression head with an annular piston and opening-closing valve member, featuring a resilient member system that allows for easy depression with reduced resistive force, ensuring effective back suction by maintaining a negative pressure state through a large stroke width and pressure-contact valve configuration, preventing unwanted piston displacement and ensuring leak-tight sliding contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional pump design with a stem and depression head is used, then the pump can be operated by depressing the head, but excessive friction forces make depression difficult and operation complex
Solution Approach 1:
The pump mechanism is segmented into functionally independent components: the depression head with opening-closing valve member operates independently from the stem, and the annular piston operates independently within the cylinder. This segmentation allows each component to perform its function with minimal interference, reducing the overall complexity of operation while maintaining ease of depression.
2Reliability
If the depression head is designed with multiple valve members and resilient members, then shut-off of fluid leakage is improved, but the resistive force against depression increases
Solution Approach 1:
Different resilient members are assigned to different functional locations with locally optimized properties. The first resilient member (coil spring) provides strong urging force for the opening-closing valve member to ensure reliable shut-off, while the second resilient member (leaf spring) provides gentler urging for the annular piston to maintain back suction. This local differentiation of resilient member properties achieves reliable shut-off without excessively increasing the resistive force against depression.
3Reliability
If the annular piston is designed to form a discharge valve with a valve seat, then back suction function is achieved, but piston displacement and misalignment may occur
Solution Approach 1:
The annular piston acts as an intermediary element that performs multiple functions: it forms the discharge valve with the valve seat to enable back suction, while simultaneously being urged by the second resilient member to maintain stable positioning. The piston mediates between the need for reliable shut-off and the need for position stability, preventing unwanted displacement while maintaining the negative pressure state required for back suction.
4Reliability
If the opening-closing valve member is urged toward the discharge opening with high resilience, then shut-off is improved, but the lever member operation becomes difficult
Solution Approach 1:
The resilience parameter of the first resilient member (coil spring) is optimized to provide sufficient urging force for reliable shut-off of the opening-closing valve member, while the geometric parameters of the lever member (length, pivot point position) are adjusted to provide mechanical advantage. This parameter optimization allows the valve to shut off reliably while keeping the lever member operation easy, resolving the contradiction between shut-off performance and operational ease.
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 enables easy operation with reduced friction, maintaining a reliable back suction effect and efficient fluid handling by ensuring a sufficient negative pressure state and preventing piston misalignment, thus addressing the limitations of existing pumps.
Implementation Method 1
a first resilient member (coil spring) urging the stem
Implementation Method 2
a second resilient member (leaf spring) urging the opening-closing valve member toward the discharge opening
Implementation Method 3
the annular piston has a lower end forming a discharge valve in cooperation with a discharge valve seat protruding from the outer circumference of the stem and is configured to be pressed against the valve seat to close the discharge valve
Implementation Method 4
a lever member connected at an upper end thereof to a rear end of the opening-closing valve member and is configured such that, when depressed, the lever member of the depression head operates to open the discharge opening by displacing the opening-closing valve member
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
The present invention proposes an improved pump that is capable of achieving excellent back suction function with use of characteristics of a depression head, without compromising the ease of depression operations of the head due to the additional function. The pump according to the present invention includes a depression head D5 and an annular piston D4. The depression head D5 is urged upward and also relatively displaceable with respect to the stem D1, and configured such that, when depressed, a lever member D7 of the depression head D5 operates to open a discharge opening 81 by displacing an opening-closing valve member D6 that is urged toward a discharge opening 81, and that a resistive force against the depression of the depression head D5 with respect to the stem is smaller than a resistive force against the depression of the stem itself. The annular piston D4 opens a discharge valve 73, which the annular piston D4 forms in cooperation with a discharge valve seat 40, in an uppermost displacement position and closes the discharge valve 73 in a lowermost displacement position. According to the pump, back suction is caused due to a negative pressure state occurring in the stem D1 until the discharge valve seat 40 is closed by the annular piston D4 during upward displacement of the stem D1.