Tandem Pneumatic-Hydraulic Pressure Generator for 500 Bar Output
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Solution Overview
Problem
Existing pressure generators for hand-held riveting, stamping, and drawing tools face limitations in generating high pressures efficiently while maintaining compactness and reducing wear on seals, especially when working with high-strength materials.
Innovation Solution
A pressure generator with a pneumatic-hydraulic pump design featuring a tandem piston arrangement and a self-closing hydraulic coupling, allowing for a high transmission ratio and efficient hydraulic fluid conveyance, along with a bypass valve for automatic reset and reduced wear, and a piston control mechanism for optimized compressed air usage and noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a single pneumatic piston is used in the pressure intensifier, then the device structure remains simple, but the generated hydraulic pressure is insufficient for processing high-strength materials
Solution Approach 1:
The single pneumatic piston is divided into multiple segments (first, second, and third pneumatic pistons) arranged in series. Each piston has its own working chamber and contributes to the overall pressure generation, allowing the system to achieve higher hydraulic pressures by combining the effects of multiple pneumatic pistons acting on a single hydraulic piston.
Solution Approach 2:
Multiple pneumatic pistons are combined in a series arrangement where their working chambers are connected through channels. The pneumatic pressure acts on each piston sequentially, and their combined effect is transmitted through the rod to the hydraulic piston, merging their individual pressure contributions into a unified high-pressure output.
2Productivity
If compressed air is continuously supplied to the pneumatic piston working chambers, then the pistons can maintain continuous motion, but compressed air consumption increases
Solution Approach 1:
The pneumatic pistons operate through periodic cycles of pressurization and decompression. Compressed air is supplied to the working chambers in periodic pulses rather than continuously. During each cycle, air enters the chambers to drive the pistons forward, then is discharged to allow reset, creating a rhythmic operation that reduces overall air consumption while maintaining continuous productivity.
Solution Approach 2:
The system discards compressed air from the working chambers after it has performed its useful work of driving the pistons. The exhaust air from one piston's working chamber is discharged to the environment rather than being recovered, but the periodic nature of this discarding allows the system to maintain operation with reduced total consumption compared to continuous supply.
3Speed
If the pneumatic piston working chambers are kept pressurized, then the pistons remain in the forward position for rapid tool activation, but noise from air discharge increases
Solution Approach 1:
The harmful noise-generating process of compressed air discharge is extracted and separated from the useful function of piston actuation. The system takes out the air discharge function and provides it through dedicated exhaust channels and silencers, allowing the useful pressurization function to proceed quietly while the harmful discharge function is handled separately with noise mitigation.
Solution Approach 2:
The harmful noise from compressed air discharge is converted into a beneficial silent operation during the pressurization phase. By designing the system to discharge air through silencers and controlled channels, the harmful noise is transformed into a manageable exhaust process that does not compromise the rapid activation capability while actually reducing overall noise emissions.
4Stress or pressure
If a large pneumatic piston area is used to generate high pressure, then the transmission ratio increases, but the device dimensions increase
Solution Approach 1:
The system transitions from using a single large-area piston to multiple smaller-area pistons arranged in series along the longitudinal dimension. By distributing the pressure-generating function across multiple pistons in the series direction rather than concentrating it in a single large piston, the system achieves the same or higher pressure multiplication ratio while reducing the lateral footprint and overall device dimensions.
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 the generation of pressures over 500 bar with reduced wear on seals and improved performance, allowing for efficient processing of high-strength materials while minimizing noise and compressed air consumption.
Implementation Method 1
Air pressure is converted into hydraulic pressure via the pressure intensifier. The pressure intensifier is designed as an oscillating pump, i.e. during a pulling or pushing process, the pressure intensifier works as a pneumatic-hydraulic pump
Implementation Method 2
The transmission ratio of the pressure intensifier is determined by the ratio of the area of the pneumatic piston and the area of the hydraulic piston. Pressures of several 100 bar can be generated on a standard compressed air connection with a pressure of less than 10 bar
Implementation Method 3
During each work cycle, hydraulic fluid is drawn in from a buffer volume and conveyed at high pressure via the hydraulic piston of the pressure intensifier in the direction of a hydraulic connection for a tool application
Implementation Method 4
a sufficient quantity of hydraulic fluid can be moved at the same time in order to be able to drive riveting, stamping, pressing or drawing tools that include a hydraulic working piston
Implementation Method 5
The pressure generator also includes a self-closing hydraulic coupling for connecting a hydraulically operated tool application
Implementation Method 6
The pressure generator includes a bypass valve, via which hydraulic fluid can flow back to a working chamber of a membrane or a piston
Data Source
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AI summary
The invention relates to a pressure generator, comprising a compressed air connection, a pressure booster working as a pneumatic-hydraulic pump with a pneumatic area and a hydraulic area, the pressure generator being designed as a hand-held device and having a self-locking hydraulic coupling for connecting a hydraulically operated tool application. According to the invention, the pressure intensifier has a pneumatic area with two pistons arranged in series, which are connected to a hydraulic piston.