What does a camshaft do, and what does a camshaft do?

The function of the cam is to act as a moving element to transmit the motion to the roller moving close to its edge or to the needle bar that moves freely on the groove surface, or it bears the force from such a roller and the needle bar for constant velocity rotary motion or reciprocating linear motion. Cam mechanism.

It is widely used in light industry, textile, food, transportation, mechanical transmission and other fields.

When the displacement, velocity and acceleration of the follower.

It must be changed strictly according to the predetermined law, especially when the original moving part is in continuous motion and the driven part must be in intermittent motion, then the cam mechanism is the most simple.

The law of motion of the cam follower depends on the shape of the contour line or groove of the cam, and the cam can convert the continuous rotary motion into a reciprocating linear motion, which can achieve complex motion laws.

Cam mechanisms are widely used in a variety of automatic machinery, instrumentation and manipulation controls. The reason why the cam mechanism has been so widely used is mainly because the cam mechanism can realize a variety of complex motion requirements, and the structure is simple and compact, and the required motion law can be accurately realized. As long as the contour curve of the cam is properly designed, the actuator can get various expected motion laws.

Therefore, the design and manufacturing method of cam mechanism is of great significance to modern manufacturing industry.

The camshaft is a component of a piston engine. Its function is to control the opening and closing action of the valves. Although the speed of the camshaft in a four-stroke engine is half that of the crankshaft (in a two-stroke engine the camshaft rotates at the same speed as the crankshaft), it usually still rotates at a high speed and needs to withstand a lot of torque, so the design requires a high degree of strength and support for the camshaft, and its material is generally high-quality alloy steel or alloy steel.

Since the law of valve motion is related to the power and operation characteristics of an engine, camshaft design plays a very important role in the engine design process.

Cam bearings are subjected to periodic shock loads. The contact stress between the cam and the tappet is very large, and the relative sliding speed is also high, so the wear of the cam working surface is more serious. In view of this situation, the camshaft journal and cam working surface should have high wear resistance and good lubrication in addition to high dimensional accuracy, small surface roughness and sufficient stiffness.

Camshafts are usually forged from high-quality carbon or alloy steel, and can also be cast in alloy cast iron or ductile iron. The journal and cam working surfaces are heat-treated and polished.

Overhead single camshaft Overhead single camshaft in the cylinder head with a convex shaft, directly drive the intake and exhaust valves, it has a simple structure, suitable for high-speed engines, the lower camshaft generally used in the past, that is, the camshaft is on the side of the cylinder, directly driven by the timing gear. In order to convert the rotation of the camshaft into the reciprocating motion of the valves, the valve lifters must be used to transmit the power. In this way, there are more parts in reciprocating motion, and the inertia mass is large, which is not conducive to the high-speed movement of the engine.

Moreover, the slender tappet has a certain elasticity, which is easy to cause vibration, accelerate the wear of parts, and even make the valve out of control. 2 Overhead Twin Camshafts Overhead twin camshafts are two camshafts mounted on the cylinder head, one to drive the intake valve and the other to drive the exhaust valve, as shown in Figure 2. The use of overhead double camshafts does not require much on the design of camshafts and valve springs, and is especially suitable for hemispherical combustion chambers with V-shaped valve configurations, and is also easy to use with four-valve valve trains.

At present, the car engine is dominated by overhead camshafts, and overhead double camshafts are used in high-speed strengthened engines. Cam function: According to the number of camshafts, it can be divided into two types: single overhead camshaft (SOHC) and double overhead camshaft (DOHC).

A single overhead camshaft is one camshaft, and a double overhead camshaft is two, which is too straightforward to explain. The single overhead camshaft uses a convex shaft on the cylinder head to directly drive the intake and exhaust valves, which has a simple structure and is suitable for high-speed engines. In the past, side-mounted camshafts were generally used, that is, the camshafts were on the side of the cylinder and were directly driven by timing gears.

In order to convert the rotation of the camshaft into the reciprocating motion of the valves, the valve lifters must be used to transmit the power. In this way, there are more parts in reciprocating motion, and the inertia mass is large, which is not conducive to the high-speed movement of the engine. Moreover, the slender tappet has a certain elasticity, which is easy to cause vibration, accelerate the wear of parts, and even make the valve out of control.

Overhead twin camshafts are equipped with two camshafts on the cylinder head, one to drive the intake valve and the other to drive the exhaust valve. The use of double overhead camshafts does not require much on the design of camshafts and valve springs, especially suitable for hemispherical combustion chambers with V-shaped valve configurations, and is also convenient for use with four-valve valve mechanisms. There is also a cam concept on the software:

According to the new concept of software machinery, a new concept of software cam machinery is proposed, and the concept of software cam is to use software to realize the function and function of mechanical cam. This paper describes the design method and working process of mechanical cam, introduces the software convex theory and its application, compares the software cam and the mechanical cam, and makes it easy to understand the similarities and differences between the design methods of the software cam and the mechanical cam. Thus it is possible to get a clearer idea that the software cam has:

No machining error, no wear error, stable curve shape and convenient design, flexible parameter modification, fast speed response and other advantages. The implementation process of the software cam is also introduced with examples.

The main function of the cam mechanism is to make the driven rod complete various complex movements according to the work requirements, including linear motion, swing, constant velocity motion and unequal velocity motion.

A rotating or sliding part of a machine (e.g. a wheel or a protruding part of a wheel) that transmits motion to a roller moving close to its edge or to a needle bar that moves freely on the grooved surface, or from which it receives the force.

Circular motion becomes linear motion.

How to say this, simply put, the cam is to make the follower make another regular action through its own regular action, which is the role of the cam. Don't underestimate this role, a lot of mechanical automation can be realized.

Camshaft is an important part of the vehicle engine, its role is to control the opening and closing of the intake valve and exhaust valve, and the regular movement of the valve is directly related to the output and operation characteristics of the engine power, and it is also the key component of the engine to work stably, so the camshaft occupies a very important position in the design of the entire engine.

Mechanically, the function of the camshaft mechanism is to convert the circular motion into reciprocating linear motion. And because the rotation of the camshaft moves at a certain rate and angle, it is also commonly used as a structural component that needs to control the movement regularly.

For example, the movement of crankshafts and pistons on automobiles; the connection between the camshaft and the oil supply and power supply system in the timing mechanism; The camshaft drives the movement of the valve feet, and so on.

The role of the camshaft is to turn the rotary motion into reciprocating motion.

Question 1: What is the general cam and the material that stands up? 10 points The materials used to make cams can generally be made of 45 gauge steel and 38 crmoai.

1. The cam can be defined as a mechanical part with a curved surface or a curved groove, and by using its swing or rotation, the follower of another component can provide a pre-set motion. The path of the follower is mostly confined to a chute to obtain reciprocating motion.

2. In its recovery stroke, it sometimes relies on its own weight, but some mechanisms often use springs as the recovery force in order to obtain accurate movements, and some use guide troughs to make them move on a specific path.

Question 2: What materials are used to make cams now Alloy structural steel carburizing and quenching, ductile iron carburizing and quenching, quenching cast iron and other cams are more manufactured.

The cam is generally made of alloy steel, and the surface is generally nitrided or carburized to ensure that the cam is not deformed after heat treatment and to ensure high wear resistance.

The cam must not be quenched, the deformation is very large, and it is troublesome to repair the cam, or it cannot be used after treatment.

Question 4: The material requirements of the camshaft are 20 points It is required to have high fatigue resistance characteristics and meet the mechanical properties of the load strength.

Question 5: What is the general material of the textile machinery cam, and the specific material for the cam can generally be made of 45 steel and 38crmoai. However, it is important to pay attention not only to the material, but also to the heat treatment.

For example, 38crmoai uses ion nitriding to obtain high hardness, thereby improving the wear resistance of the cam.

Question 6: What is the purpose of the cam mechanism? Thank you! It is mainly used to control the intake and exhaust air.

It is also used to control the ignition time.

Question 7: What is the material of the camshaft of the car engine The camshaft material is generally ductile iron.

Question 8: What kind of heat treatment does the cam need to undergo? Buy a new one, heat treatment is very troublesome, first annealing, then surface fire or nitriding or carburizing, and then and regret Hui finishing...

Question 9: What materials are good for cams before making alloy structural steel carburizing and quenching, ductile iron carburizing and quenching, quenching cast iron and other cams are manufactured.

Question 10: How to choose cam materials, how to process the profile, and how to process the heat treatment process Cam material: generally forgings No. 45 steel, now there are ductile iron.

How to process the profile: use the mold processing.

The practice of relying on the mold: past tense: 1. Scribing, milling, fitter refinement.

2. Scribing, milling, tool grinding and tool fine grinding.

Now it is: cut with wire.

The camshaft is a key component in driving the valve movement, and its role is to control the opening and closing of the valve. The working principle of the camshaft is: the continuous rotation of the automobile camshaft pushes the valve ejector rod to move up and down, and then controls the opening and closing of the valve.

By changing the curve of the camshaft, the opening and closing times of the valves can be precisely adjusted. The symptoms of engine camshaft damage are as follows: the vehicle has a high-pressure fire, but the starting time is long, and the vehicle can eventually operate; During starting, the engine crankshaft will turn and the intake manifold will be quenched.

The idle speed of the vehicle is serious, similar to the common fault of the vehicle missing cylinder; The vehicle does not accelerate enough, the vehicle cannot run, and the speed ratio exceeds 2500 rpm; When the car consumes high gasoline and diesel, the industrial exhaust gas exceeds the standard, and the exhaust pipe will form black smoke from the exhaust pipe. Camshaft Position: There are three types of camshaft positions:

Bottom, middle, top. The camshaft of the lower valve train is located in the crankcase, the camshaft of the middle valve train is located in the upper part of the engine block, and the camshaft of the upper valve train is located in the cylinder head. Most of today's production cars are equipped with overhead camshafts.

The function of the camshaft is to transmit the force generated during the transfer process to the individual components.

The function of the camshaft is to extend the opening time of the valve, increase the lift of the valve, make the intake and exhaust valves open early and close late, and let more air enter the cylinder, thereby improving the power output of the engine at high speeds.

The camshaft is a component of a piston engine. Its function is to control the opening and closing action of the valves.

The main body of the camshaft is a cylindrical rod body of approximately the same length as the cylinder block. It is covered with several cams that are used to actuate the valves. The camshaft is supported in the camshaft bearing bore by the camshaft journal, so the number of camshaft journals is an important factor affecting the camshaft support stiffness.

If the camshaft stiffness is insufficient, bending deformation will occur during operation, which will affect the timing of the gas valve.

The sides of the cam are egg-shaped. It is designed to ensure adequate intake and exhaust of the cylinder. In addition, considering the durability of the engine and the smooth operation, the valve should not have too much impact due to the acceleration and deceleration process during the opening and closing action, otherwise it will cause serious wear of the valve, increase noise or other serious consequences.

Therefore, the cam is directly related to the power and torque output of the engine, as well as the smoothness of the operation.

Generally, the cam is a component that obtains a certain periodic motion search through the cam surface at different radii; The camshaft is on the same shaft, fixed (or processed) a plurality of cams, these cams rotate synchronously, so that the periodic movement of each cam can be strictly synchronized, or to achieve strict repeated work in a certain order. For example, the camshaft of the mechanical "music box" in the toy is cyclically and synchronously plucked, and the reeds corresponding to different tones can cycle to produce a sound that brightens a certain piece of music; The camshaft inside the sewing machine makes the needle maintain a certain sequence with the push plate and the stitch; The working sequence of each cylinder of the multi-cylinder internal combustion engine is carried out sequentially, and so on is due to the mechanical control of the camshaft and the synchronous effect of the cyclic work.

The function of the camshaft is to control the opening or closing of the intake and exhaust valves.

Hello, the shaft is a component in the piston engine, which is used to control the opening of the valve and the closing of the source;

Although in a four-stroke engine, the speed of the convex axle is half that of the crankshaft (in a two-stroke engine, the speed of the camshaft is the same as that of the crankshaft.