Talking about the Application of Pneumatic Two-position Five-way Solenoid Valve Liu Guomin1, Chen Lei (1. Jinan Huaneng Pneumatic Components Co., Ltd., No. 63, Huanggong Road, Jinan, Shandong Province, China, 250100) 1 Introduction Pneumatic technology is called cheap automation technology. The application of pneumatic technology can be seen almost everywhere in modern equipment. With the combination of electronic technology, the application field of pneumatic technology has been rapidly broadened, in mechanical, chemical, electronic, electrical, textile, food, pharmaceutical, packaging, printing, light industry, Automobiles and other industries, especially in various automated production equipment and production lines, are widely used. In automation equipment and production lines, pneumatic technology plays an important role. Pneumatic two-position five-way electromagnetic reversing valve is the most widely used pneumatic control component, the most widely used, and the largest number of pneumatic components. This article takes the internal pilot two-position five-way electromagnetic reversing valve as an example. Some of the situations in the actual application are introduced.
2 2 five-way electromagnetic reversing valve working principle and general application 1 for the air inlets 2, 4 for the air outlets 3, 5 for the exhaust. In the initial state, the compressed air flows from the port through the small hole in the valve body into the reset chamber (the right end piston chamber), and under the action of the pressure of the reset chamber, the spool is pushed to the left side, and then the port 1 and the port 2 are connected, 2 The mouth has output, 4, 5 ports are connected, and 5 ports are exhausted. When the electromagnetic pilot valve is energized, the compressed air enters the left cavity of the control piston. Since the pressure acting area of ​​the control piston is larger than the right reset piston area, the valve core can be pushed to the right side against the reset force, and the 1 and 4 ports are connected, and the 4 ports have output. 2, 3 ports are connected, 3 ports are exhausted. This valve is often used in applications where the power-on time is short and the frequency of use is high.
The valve needs two electrical signals to control, 1 is the air inlet 2, 4 is the air outlet 3, 5 is the exhaust port.
State 1: Intake port 1 is in communication with outlet port 2, port 2 has output, 4 and 5 ports are connected, and 5 ports are exhausted. State 2: Intake port 1 communicates with outlet port 4, 4 ports have output, 2, 3 ports communicate, and 3 ports exhaust. When one of the electromagnetic pilot valves is energized, the compressed air flows from one port through the small hole in the valve body into the piston chamber at one end of the valve, and the piston pushes the spool to immediately reverse direction. After the signal is eliminated, the valve is not reset, only when another electromagnetic pilot valve is energized. The valve can be reset, that is, the commutation is performed when the power is turned on, and the original state is maintained when the power is off, so the double electric control valve has a memory function. Since the double electric control valve requires a pulse signal, the durability of the electromagnetic component can be prolonged. Both valves control the double-acting cylinder for reciprocating motion.
3 As a two-position three-way electromagnetic reversing valve application, if the air outlet 4 of Fig. 1a is blocked, it can be used as a normally open two-position three-way electromagnetic reversing valve to block the air outlet 2, which can be used as a normally closed two-position. Three-way electromagnetic reversing valve application. For the same reason, the two-electric two-position five-way electromagnetic reversing valve of Fig. 1b can be used as a double electric control two-position three-way electromagnetic reversing valve. The two-position three-way electromagnetic reversing valve can control the single-acting cylinder to reciprocate.
a) single electronically controlled internal pilot type b) dual electronically controlled internal pilot type 4 as a dual-intake, double-exhaust electromagnetic reversing valve application, such as changing the signal gas to the electromagnetic pilot valve in Figure 1a from 1 to 3 or 5 ports, 1 port as the exhaust port, 3 ports and 5 ports as the air inlet port, 2 ports and 4 ports as the air outlet port, so that the valve can be a single electronically controlled double-intake double-exhaust electromagnetic reversing valve, equivalent to two Only two three-way electromagnetic reversing valves (one is normally closed and the other is normally open) are used in parallel to enable different pressures to be applied to the front and rear chambers of the double-acting cylinder. The same principle is 5 ports, 1 port is used as the exhaust port, 3 ports and 5 ports are used as the air inlet ports, and 2 ports and 4 ports are the air outlet ports, so that the valve can be double electric control, double intake air, double exhaust air electromagnetic reversal valve.
5 As the application of high and low pressure double intake air reversing valve, the three ports and five ports in Fig. 1a are blocked, and the signal gas leading to the electromagnetic pilot valve is changed from one port to two ports, and two ports and four ports are air inlet ports. One port is the air outlet, so that the valve becomes a single electronically controlled high and low pressure double intake electromagnetic reversing valve. In the same way, the three ports and five ports in Fig. 1b are blocked, and the signal gas leading to the electromagnetic pilot valve is changed from one port to two ports and four ports, and the two electromagnetic pilot valves are respectively supplied with signal gas, so that the valve is Double electronically controlled high and low pressure double intake electromagnetic reversing valve. It can form a high and low voltage conversion circuit, so that the double-acting cylinder works self-locking hydraulic cylinder Wu Hao1, Li Hong Key words: hydraulic cylinder self-locking hydraulic control mechanical lock 1 Introduction When the hydraulic cylinder needs a long time to lock at a certain position, generally It is realized by providing a hydraulic lock circuit composed of a hydraulically controlled check valve on the oil passage.
Such a solution undoubtedly increases the number of hydraulic components, resulting in inconvenience in maintenance, large system footprint, and increased costs. If the hydraulic cylinder requires a long lock in only one extreme position, the self-locking hydraulic cylinder described below can be used. Such self-locking hydraulic cylinders are used in the manipulation of foreign aircraft fuselage doors.
2 structure and working principle The structure of the self-locking hydraulic cylinder is shown in Figure 1.
1. Cylinder 2. Hollow rod piston 3. Fan lock link 4. Sector lock block 5. Positioning cylinder 6. Positioning cylinder spring 7. Lock rod piston 8. Lock spring 2. 1 unlocking process as shown in Figure 2. When the piston rod is required to be unlocked by the left limit position, the F port enters the pressure oil, the A port returns to the oil (the same as the general hydraulic cylinder), and the pressure oil flows to the right end of the lock rod piston 7 and the piston rod 2 through the in-cylinder passage respectively. At the beginning of the left end, since the piston rod 2 is locked by the sector lock block 4, the piston rod is temporarily moved and the lock rod piston 7 is moved to the left against the force of the lock spring 8 under the action of the pressure oil, thereby making the fan lock The rod 3 is disengaged from the dead point position, and is contracted inwardly under the action of the lip of the piston end, and the piston rod 2 is released and protruded. At the same time, the positioning cylinder 5 is moved to the right with the piston under the action of the positioning cylinder spring 6, and remains fan-shaped. The locking block 4 is in the retracted position, thus avoiding the phenomenon that the piston does not interfere with the sector lock block when the next retraction occurs.
2. 2 The locking process is shown in Figure 1. When the piston rod is retracted and locked, the A port passes the pressure oil, the F port passes the oil back, and the piston moves to the left under the action of the pressure oil. When the left end of the piston and the positioning cylinder When contacting, push the positioning cylinder to the left together. When the lip of the piston passes over the sector lock block, the sector lock block is released. Under the action of the lock spring 8, the lock rod piston moves to the right and reaches the right limit position. When the fan lock block is opened, it is erected to the dead point position. At this time, no matter how much force acts on the sector lock, since the link is at the dead point position, the sector lock block will not be retracted, thereby ensuring reliable locking of the piston. The oil port H is connected to the oil tank, so that the oil in the piston of the lock rod piston can be discharged in time without causing the hydraulic oil lock. The positioning cylinder spring also functions as a hydraulic cylinder buffering device during the working process, and the steel cable can be placed in the hollow portion of the locking rod. In an emergency situation, the locking rod can be pulled back and unlocked by an artificial method.
3 Conclusion From the above introduction, the self-locking hydraulic cylinder is unlocked and locked reliably, and the structure is simple and compact. This hydraulic cylinder is used when the hydraulic cylinder requires only a long lock in one extreme position, which simplifies the work. The cavity is subjected to different pressures, so that the cylinder can obtain two kinds of thrust or pulling force according to the working condition during work.
6 Conclusions The above application can be seen that the pneumatic two-position five-way electromagnetic reversing valve can be used for general applications, or it can change the intake direction or intake position of the internal pilot gas according to the different pipe connection mode. Other types of valves can be used in a variety of special occasions. Valves for different applications can also be stacked by stacking plates, which saves installation space and can meet the requirements of valve mixing for different purposes. The valve is external to the valve and other components are interchangeable, saving maintenance costs. â–¡
Alnico (AlNiCo) is the first developed a permanent magnet is made of aluminum, nickel, cobalt, iron and other trace metals composition of an alloy.According to different production process is divided into sintered Alnico (Sintered AlNiCo), and cast aluminum nickel and cobalt (Cast AlNiCo).Product shape of the round and square. Sintered products limited to the small size, their production out of rough tolerance is better than the rough cast product can be better workability.
Alnico alloys can be magnetised to produce strong magnetic fields and have a high coercivity (resistance to demagnetization), thus making strong permanent magnets. Of the more commonly available magnets, only rare-earth magnets such as neodymium and samarium-cobalt are stronger. Alnico Magnets produce magnetic field strength at their poles as high as 1500 gausses (0.15 teslas), or about 3000 times the strength of Earth's magnetic field. Some brands of alnico are isotropic and can be efficiently magnetized in any direction. Other types, such as Alnico 5 and alnico 8, are anisotropic, with each having a preferred direction of magnetization, or orientation. Anisotropic alloys generally have greater magnetic capacity in a preferred orientation than isotropic types. Alnico's remanence (Br) may exceed 12,000 G (1.2 T), its coercivity (Hc) can be up to 1000 oersteds (80 kA/m), its energy product ((BH)max) can be up to 5.5 MG·Oe (44 T·A/m). This means that alnico can produce a strong magnetic flux in closed magnetic circuits, but has relatively small resistance against demagnetization. The field strength at the poles of any permanent magnet depends very much on the shape and is usually well below the remanence strength of the material.
Alnico alloys have some of the highest Curie temperatures of any magnetic material, around 800 °C (1,470 °F), although the maximal working temperature is normally limited to around 538 °C (1,000 °F).[4] They are the only magnets that have useful magnetism even when heated red-hot.[5] This property, as well as its brittleness and high melting point, is the result of the strong tendency toward order due to intermetallic bonding between aluminium and other constituents. They are also one of the most stable magnets if they are handled properly. Alnico magnets are electrically conductive, unlike ceramic magnets.
Alnico magnets are widely used in industrial and consumer applications where strong permanent magnets are needed; examples are electric motors, electric guitar pickups, microphones, sensors, loudspeakers, magnetron tubes, and cow magnets. In many applications they are being superseded by rare-earth magnets, whose stronger fields (Br) and larger energy products (BHmax) allow smaller-size magnets to be used for a given application.
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