A brief discussion on the application of CONTRINEX high-voltage switches in the water jet industry

1. Overview

CONTRINEX Industrial Electronics is a Swiss company specializing in the development, production and sales of sensors. Its main products include proximity switches, photoelectric switches, ultrasonic switches, laser photoelectric switches, rotary encoders, capacitive switches, identification systems, safety products, etc.

2. CONTRINEX featured products

CONTRINEX proximity switches have the characteristics of miniaturization, long distance, impact resistance, high and low temperature resistance, waterproofness, high pressure resistance, analog output, etc. Here we mainly talk about the application of high-pressure resistant switches in the water jet industry.

3. CONTRINEX high voltage switch products

The main problem of high-voltage switches is that in order to withstand the pressure, the sensing surface must have a thick mask (usually magnetic). However, the thickness of the mask reduces the detection distance of the product, so the effective detection distance is very short, and sometimes even non-existent. Therefore, some products on the market install an oscillating coil on the side that bears the high pressure, so that the sensing surface is partially made of plastic, but this cannot guarantee the stability of work in some working environments (hydraulic oil, high temperature, cyclic pressure, etc.).

In contrast, the CONTRINEX high-voltage switch has a completely different product structure and will not have similar problems. The CONTRINEX high-voltage switch uses Condist technology to insert the electronic components into the thick sensing surface shell, so that the product does not need to use any auxiliary equipment or other methods, and can achieve a long detection distance even if a thick magnetic shell is installed. Since the entire electronic component (core and coil) is installed on the non-pressurized side, the effective detection distance is far greater than required. [page]

The advantages of CONTRINEX high-voltage switches are: a variety of installation sizes, pressure resistance up to 500BAR, impact-resistant stainless steel housing, protection level IP68, can work in an oil-immersed environment, and the effective detection distance can reach 3MM.

The CONTRINEX high-voltage switch housing uses heat shrink technology to compress the disk, and can achieve a good sealing effect without taking additional sealing measures. Therefore, it is also suitable for dynamic high-pressure environments, especially in the water jet industry.

4. Origin of water jet

"Dripping water wears away a stone" reflects the potential eternal power of water, which is weak in people's eyes. However, with the continuous discovery of science and technology, people have given water drops a magical striking energy greater than that of free fall; the long phenomenon of dripping water wearing away a stone can be completed in an instant, that is, water jet. As an independent and complete processing technology, the emergence of high-pressure water jet (WJ) and abrasive water jet (AWJ) has only been in the past thirty years. The use of high-pressure water for people's production services began around the 1870s, mainly used to mine gold and peel off bark. It was not until World War II that the phenomenon of "rain erosion" during aircraft operation causing damage to radar cabins inspired people's thinking. It was not until the 1950s that the possibility of high-pressure water jet cutting originated from the Soviet Union, but the first cutting technology patent was produced in the United States, that is, in 1968 by Dr. Norman Franz, a professor of forestry at the University of Missouri. In the past decade, water jet (WJ, AWJ) cutting technology and equipment have made great progress, and its application has spread to all aspects of industrial production and people's lives. Many universities, companies and factories competed in research and development, and new ideas, new theories and new technologies continued to emerge, forming a trend of catching up with each other. At present, more than 3,000 sets of water jet cutting equipment have been used in dozens of industries in dozens of countries, especially in high-tech, cutting-edge and difficult technologies such as aerospace, ships, military industry and nuclear energy. It can cut more than 500 kinds of materials, and its annual growth rate of equipment exceeds 20%.

5. The principle of water jet

The basic principle of high-pressure water jet is: using the principle of liquid boosting, through a specific device (boosting port or high-pressure pump), the mechanical energy of the power source (motor) is converted into pressure energy. The water with huge pressure energy passes through a small hole nozzle (another energy conversion device), and then converts the pressure energy into kinetic energy, thus forming a high-speed jet (WJ). Therefore, it is often called high-speed water jet. The high-pressure water jet system is shown in Figure 1.

It is mainly composed of a booster system, a water supply system, a booster constant pressure system, a nozzle pipeline system, a CNC workbench system, a water collection system and a water circulation treatment system. The low-pressure oil (10-30MPa) of the hydraulic system pushes the large piston to move back and forth, and its direction is automatically controlled by the reversing valve. The water supply system first purifies the water and adds anti-rust additives, etc., and then the water supply pump pumps out low-pressure water from the one-way valve into the high-pressure cylinder. The booster constant pressure system includes a booster and an accumulator. The boost ratio is the ratio of the area of ​​the large piston to the area of ​​the small piston, which is usually 10:1-25:1. Therefore, the high-pressure water pressure output by the booster can reach 100MPa-750MPa. Since the compression rate of water at 400Mpa is 12%, the piston rod will only output high-pressure water after it has traveled one-eighth of its entire stroke. When the piston reaches the end of the stroke, the reversing valve automatically changes the direction of the oil circuit (as shown by the dotted arrow in the figure), thereby pushing the large piston to move in the opposite direction, and the high-pressure water is output at the other end. If this high-pressure water is sent directly to the nozzle, the jet pressure coming out of the nozzle will be pulsating; and this will cause periodic oscillations in the pipeline system. In order to obtain a stable high-pressure water jet, an accumulator (constant pressure) device is often set between the booster and the nozzle circuit to eliminate water pressure pulsation and achieve the purpose of constant pressure; if the water pressure can exceed the breaking strength of the material, the material can be cut off and the purpose of material removal can be achieved. [page]

This is the traditional application; the detection of the piston depends on 15 parts such as the reversing valve; if there is a problem in one part, it will be paralyzed, and maintenance is very inconvenient. Nowadays, the CONTRINEX high-pressure switch can be fixed on the wall of the high-pressure cylinder and immersed in oil to directly detect the position of the piston. The effect is very good, maintenance is convenient, and the cost is reduced. It has been widely promoted and applied since the beginning.

6. Outlook of CONTRINEX high-voltage switch products in the water jet industry

High-pressure water jet cutting is carried out using a high-speed jet with very high kinetic energy (sometimes also called high-speed water jet processing). Like laser, ion beam, and electron beam, it belongs to the category of high-energy beam processing. It has been successfully applied in the following industries: automobile manufacturing and repair, aerospace, mechanical processing, national defense, military industry, weapons, electronic power, petroleum, mining, light industry, construction and building materials, nuclear industry, chemical industry, shipbuilding, food, medical treatment, forestry, agriculture, municipal engineering, etc. CONTRINEX high-voltage switches have been used in Shanghai Gaojie Jiliu, Huai'an Fluid Equipment, Ningbo Shunma Cleaning Machine, Shanghai Port Machinery, etc., and have won high praise from customers. We believe that with our technological innovation and new technology application, CONTRINEX high-voltage switches will be more deeply and widely used in the water jet industry.