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The composition and function of the valve group

  • Time of issue:2021-08-13

The composition and function of the valve group

(Summary description)The structure of the valve group is mainly composed of valves, valve sp₩rings, valve lock clips, etc. Under normal circumstances, the diameter of the inta×ke port is larger than the exhaust port, which is mainly to i™ncrease the intake volume to improve the combustion efficiency ♣and obtain a better Power output.

　　The intake and exhaust valves of the automobile engine are both mushroom-shaped valvesσ, which are composed of two parts: the valve head and the valve stem. The top surfac e of the valve has shapes such as flat top, concave top and convex top. At present, the ‌flat-top valve is the most widely used valve, which has a simple structure, is conven≤ient to manufacture, and has a small heating area. Both inta←ke and exhaust valves can be used.

　　 The valve and the valve seat or the valve seat ring are sealed by a conical surface. The angle αbetween the valve cone and the valve top surface is called the valve cone angle. The  valve cone angles of intake and exhaust valves are ge¶nerally 45 degrees, and only a few engines have intake valve cone angles of 30 degrees.

The function of the 　　 valve group is to control the intake and exhaust of each cyli nder through the ejector rod driven by the camshaft to realize the normal operation of the engine.

  • Time of issue:2021-08-13
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The structure of the valve group is mainly composed of valves, valve springs, val↕ve lock clips, etc. Under normal circumstances, the diameter of the intake port is larger than< the exhaust port, which is mainly to increase the i±ntake volume to improve the combustion efficiency and obtain a better Power outp¶ut.

　　The intake and exhaust valves of the automobile engine are both mushroom-shaped valves, which♥ are composed of two parts: the valve head and the valve stem☆. The top surface of the valve has shapes such as flat top, concave t&op and convex top. At present, the flat-top valve is the÷ most widely used valve, which has a simple structure, is con∞venient to manufacture, and has a small heating area. Both intake ↕and exhaust valves can be used.

　　 The valve and the valve seat or the valve seat ring are sealed by a conical₽ surface. The angle between the valve cone and the valve top surface' is called the valve cone angle. The valve cone angles of ∑intake and exhaust valves are generally 45 degrees, and only a few engines have intak™e valve cone angles of 30 degrees.

The function of the 　　 valve group is to control the intake and exhau‍st of each cylinder through the ejector rod driven by the ¶camshaft to realize the normal operation of the engine.

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　　 The neck height of the neck flange is low, which can improve th≠e rigidity and load-bearing capacity of the flange. Compared with the butt-welded flange, the weδlding workload is large, the electrode consumption is high, a₩nd it cannot withstand high temperature and high pressure, repeat♣ed bending and temperature fluctuations, but the on-s₹ite device is more convenient, and the process of welding seam sc✘ratching can be omitted, which is more popular. Butt welding flange with neck: neck flange weld✔ing is usually called "high hub" flange. Its purpose is ≥to transfer the pressure of the pipeline, thereby reducing the high stress concentration in →the flange base. Neck flange welding is a good design for butt welding those flanges that are ←provided due to their own constructive value. However, the price is relatively ←high because of the complicated production process of the product. Threaded (threaded ) flange: The threaded flange is connected by threaded fasteners. But the center of the prod​uct has a thread size corresponding to the pipe. Its main advantage is that it c€an be assembled without welding. Sliding flange: Sliding flange has a lower hub, because th e pipe enters the single flange before welding. This is to provide sufficient strength inside an♥d outside the welding to avoid leakage. Sliding flanges are matched> with boring pipes with slightly larger outer diameters. They are better λthan neck flange welding due to lower initial cost. flange Many users, but the cost of the la≠tter device will not be low, due to the increase in the number of ‌weld neck flanges, lap flange: in practice, the lap flange is the same complete sliding fl∑ange, unless it is in the hole and A radius between flange races. It is necessary for the radiu₩s to have the flange to contain the lap stub to complete. Usually, the lap flange and th±e lap stub end mating together will assemble the system. The socket welding flange is a similar sl§iding flange, unless it has a hole and a counter hole size. The mat®ching of the counter hole and the pipe allows the pipe t→o be inserted into a sliding flange similar to the flangeΩ. The diameter of the smaller hole is matched with the samγe pipe with the same ID. The restriction is a built-in hole that stays at the bottom as γa shoulder sleeve designed for pipes. This eliminates any flow restrictions when using socket ♥welding flanges.
　　1. In order to compact the sealing surface of the flat welding flange, only a small pressur×e is required. As the required pressure drops, the size of the bolt≥s and the number required are correspondingly reduced. After all, a plan is planned. A flat we₽lding flange product with a relatively small volume and a relativel←y light weight. 　　 2. The production of flat welded flanges can sav‌e data and reduce costs. When the raw material of the pipe is special and the prλice is high, the cost of welding the flange of the ↕same raw material will be high, and the use of this flange can ef±fectively save the cost of materials. Conducive to construction, when ‍connecting, the bolt holes of the flange are inconvenient to align or to ♦avoid replacing the flange bolt holes of the equipment, etc., the use of this flat wel"ded flange is very suitable.         3. The flat welding flange φcan save space and reduce weight in the process of use. The most importantΩ thing is to ensure that the head part will not leak. It has a very outstanding seali<ng function. The reason why the size of the compact flange ∏is reduced is because The diameter of the seal is reduced, which wi≤ll reduce the cross-section of the sealing surface. Also, the flange gasket has now been re÷placed by a sealing ring to ensure an outstanding ma♣tching of the flat welded flange seal facing the sealing surface. 　　 ✘flat welding flange 　　 But it also has some disadvantγages: 　　 Disadvantages of flat welding flange: 　　The main design disadvantage of flat welded flan≤ges is that it cannot ensure no leakage. This is the lack of its planning: the connectio$n is dynamic, and for example, thermal expansion and fluctuating cyclic load's will cause movement between the flange surfaces, which "will affect the function of the flange, which will damage the integrity o‌f the flange and eventually lead to leakage. It is impossible for any proαduct to be without shortcomings, just try to control the lack of ♦products to the minimum, so the company tries to perfect the functioπns of the products when producing flat welded flanges to ≤make them play the greatest role.
The principle and characteristics of the use of fla↕nges [ 2021-08-13 ]
      Flange work characteristics: 　　Flange work characteristics: 　　 1. A self-control ♣butterfly valve that can be remotely controlled, which♠ also has the characteristics of a flanged butterfly valve, and can be equipp↑ed with a wide range of butterfly valves; 　　2. The power supply is< the driving energy of the butterfly valve, with a wide range of power sourc•es, wide application range, saving human resources, and having work efficiency; 　　3. C♦onvenient operation and easy to meet various control requirem‌ents. It can be realized by selecting different actuators, signal feedback, flow adjustment, explos‌ion-proof and other functions; 　　4. Ultra-miniaturization can be realαized, mechanical self-locking can be realized, and different sealing rings can be c∞hanged to meet different working conditions. 　　The working principle of flange: 　　Using the ®actuator to input a standard signal of 0-10 mA, the motor group drives the gear,  worm, and torque to drive the disc to rotate. When the valve is in the fully open position, ©the thickness of the butterfly plate is the resistance of the πmedium flowing through the valve body, so the pressure drop generated by the valve is small, soΩ it has better flow control characteristics. 　　Butte>rfly valve has two sealing types: elastic seal and metal seal. For elastic sealing ©valves, the sealing ring can be embedded on the valve body or attached to the periphery of the but£terfly plate. The valve with metal seal generally has a longer life than§ the valve with elastic seal, but it is difficult to achieve a complete seal. M₽etal seals can adapt to higher operating temperatures, ​while elastic seals have the defect of temperature limitation. If flanged butterfly valves are re≤quired to be used as flow control, the main thing is to correctly select the &size and type of the valve.
The role and use of the valve [ 2021-08-13 ]
　The valve is an accessory of the pipeline, used to control t↑he flow, pressure, and direction of the fluid. The fluid to be co<ntrolled can be liquid, gas, gas-liquid mixture or solid-liquid mixture.   one. Basic p≤arameters of valve 　　The basic parameters of the valve include working pressure (PN€), working temperature (T) and nominal diameter (DN). For various valves equipped on pipelines©, nominal pressure and nominal diameter are commonly used as basic param₩eters. Nominal pressure refers to the maximum working pressure that a valve ®of a certain material can withstand at a specified temperature. The nominal diamete®r refers to the nominal inner diameter of the connecting end of the valve body and th€e pipeline. Valves, pipelines and pipeline accessories o€f the same nominal diameter can be connected to each other, which is interchangeaφble.   two. Valve classification 　　 1. According to function ®and purpose 　　 According to the different functions of the va±lve, it can be divided into the following five types: 　　①Shutoff valve 　　 shut-§off valve is also called closed-circuit valve, its func↓tion is to connect or cut off the medium in the pipeline. Block valves include gate valves, ♣globe valves, plug valves, ball valves, butterfly valves, and diaphragm valves. 　　②Che↓ck valve 　　 Check valve is also called one-way valve or check valve, its function i s to prevent the back flow of the medium in the pipeline. For example, the suction valv&e of the water pump belongs to the non-return valve category. 　　③Safety valve 　　 The role of∑ safety valves is to prevent the pressure of the medium in the p>ipeline or device from exceeding the specified value to protect the safe opera>tion of subsequent equipment. 　　④Regulating valve 　　The< function of the regulating valve is to regulate the pressure, flow and other ¶parameters of the medium. The regulating valve has different cla₽ssification methods. According to the purpose and function, the regulating valve can be divi↔ded into: 　　 (1) Two-position valve. The two-posi•tion valve is mainly used to close or connect the medium. 　　 (2) Regulating₹ valve. The regulating valve is mainly used for regulating the coeff icient. When selecting the valve, the flow characteristics of the regulating valve need t€o be determined; the regulating valve can be divided into the following forms according to the≥ structure: single-seat regulating valve; double-seat regula ting valve; sleeve regulating valve; angle regulating Valve; t≈hree-way regulating valve; diaphragm valve; butterfly valve; ball valve; eccentric✘ rotary valve. 　　 (3) Shut-off valve. Usually refers to a valve with a÷ leakage rate of less than one part in 100,000. 　　⑤Divert valve 　α　 The diverter valve includes various distribution valves and flow valve∑s, etc., whose function is to distribute, separate ←or mix the medium in the pipeline. 　　2. According to the valve  drive mode 　　According to the valve drive mode, it can be divided into the following three types : 　　①Automatic valve 　　 refers to valves that do not require external drive, but rely on t÷he energy of the medium to actuate the valve, such as safety valves, pressure reducing valvesα, traps, check valves, automatic control valves, etc. 　　②Power driven valve 　　The power-¶driven valve can be driven by various power sources. Including electric valves driven by electric∑ity, pneumatic valves driven by compressed air, hydraul‌ic valves driven by hydraulic pressure such as oil, and combinations of various driving met∞hods, such as pneumatic-electric valves. 　　③Manual valve 　　∞Manual valves use handwheels, handles, levers, sprockets and other components to maεnipulate the valve action by manpower. When the valve closing torque is large, a gear or tu€rbo reducer can be set between the handwheel and the valve stem. If necessary, universal↓ joints and drive shafts can also be used for long-distance operatio↕n. 　　3. Press the connection method 　　 can be divided into the following six types aσccording to the connection method: 　　①Threaded conne¶ction valve: The valve body has an internal thread or an exte±rnal thread to connect with the pipe thread; 　　②Flange c♠onnection valve: the valve body has a flange to connect§ with the pipeline flange; 　　③Welding connection valve: The ∞valve body has a welding groove and is welded to the pipeline; 　　④Clamp-₽connected valve: the valve body has a clamp to connect with the pipe clamp; 　　⑤ Ca≈rd sleeve connection valve: It is connected with the pipeline by a card© sleeve; 　　⑥Wafer connection valve: a connection form in which the valve an'd the two pipes are directly clamped together with bolts. 　　4. According to the valve b™ody material 　　①Metal material valve 　　The valve body and other parts are made λof metal materials, such as cast iron valves, carbon steel valves, alloy ✘steel valves, copper alloy valves, aluminum alloy valves, lead alloy valves, titanium alloy va​lves, Monel alloy valves, etc. 　　②Non-metallic valve 　　The valve body and other parts ♠are m
The caliper can also be called a brake cylinder. There areδ a lot of pistons inside the caliper. The function o↑f the caliper is to push the brake pads to clamp the brake disc, so that the car c♠an slow down. After the brake pads clamp the brake disc, the kinetic energy ±can be converted into heat energy. The brake system is a v ital system in a car. The brake system is related to the driving stability and drivin€g safety factor of the car. The key components of the brake system include vacuum b'ooster pump, brake master cylinder, brake cylinder, brake pads,© and brake discs. Brake pads and brake discs are basically wearing★ parts that need to be replaced on a regular basis. As the driving distance of the c®ar increases, the brake pads and brake discs will basically cont★inue to wear. After the brake pads and brake discs are worn to a certain degree , they need to be replaced. If they are not replaced, the braki↕ng distance will be affected. After the driver steps on the brake p∞edal, the master cylinder can push the brake cylinder through the brake fluid. At this time, t•he brake cylinder can push the brake pads to clamp the br↕ake disc. The vacuum booster pump provides power assistance, and the vacuum booster pump allows αthe driver to easily step on the brake pedal. The brake fluid in ↔the brake system needs to be replaced regularly. If it is not replaced for a long✔ time, it will affect the braking force and braking distance. Brake fluid is a kind of f¶luid that is easier to absorb water. When the wate↓r content of the brake fluid reaches 3%, it needs to be replaced. After replacin☆g the brake fluid, the air in the brake system pipeline needs to be emptied, otherwise the braki÷ng force and braking distance may also be affected.
What are the functions of gears [ 2021-08-13 ]
　　 We have seen many products using gears in our lives, b×ut do you know what principle they use gears? Accoεrding to its working principle, 　　 gear has the following f∞unctions: First, gears can transmit mechanical power, such as¶ automobile gear shifting devices, industrial gearboxes, etc.; second, gears can change the ¥direction of movement, such as mechanical watches, shaking head devices in electric fans, etc.; th←ird, gears can reduce speed and Improve torque, such as motor reducer, various speed change mechan≥isms, etc. 　　Gear transmission mechanism 　　 Here> are two interesting applications of gears in auto₩mobiles and aviation, let's take a look at the role of gears in them. 　　 There is a mechanical stδructure in a car called a differential, which is an extremely important part. W÷hen a car turns, the speeds of the inner and outer wheels are different.™ If there is no differential, the speeds of the inner and outer wheels are t©he same. The wheels slip and roll over. Moreover, the speed of the car is very fas$t, and it is absolutely impossible to have no differential at high speeds. The gear‍ here is on the differential, which can not only transmit the power of the engine, but als✘o reduce the speed through the different speed ratios of the gear device, a☆nd at the same time can achieve a very cool "differential" function. 　　 three-dimensiβonal model of differential 　　In aviation, helicopters u☆sing coaxial reversal technology are favored by many countries because of their excell§ent performance. This helicopter has two propellers ≈on the same shaft. When the plane is flying, the rotation direction of the two propeller≤s must be opposite to ensure the power balance of the plane. 　　Helicopter using coaxial r∑eversal technology 　　 From the three-dimensional mo®del of the coaxial reversal structure, it can be seen that after two transformat✔ions of the gear, the mechanical transmission direction is smoothly changed, and two different "rotation directions are realized on the same shaft.
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