Basic knowledge of auto mechanics continued

Commonly used composite materials are: fiber reinforced composite materials, laminated composite materials, particle composite materials and so on.
According to the different carbon content in the iron-carbon alloy phase diagram and the room temperature structure, it can be divided into industrial pure iron F (C). Commonly used heat treatment methods include annealing, normalizing, quenching, tempering, etc. The properties after tempering are strength and hardness , Plasticity and toughness are good comprehensive mechanical properties. Usually the heat treatment combined with quenching and high temperature tempering is called quenching and tempering treatment.
Metal materials commonly used in industry are divided into two categories: iron-based (ferrous metals) and non-ferrous-based (non-ferrous metals) metal materials.
Carbon tool steel such as T8 represents a carbon tool steel with an average carbon mass fraction of 0.8%. If A is added to the end of the grade, it means high-grade high-quality steel, such as T10A.
Alloy steel is divided into low-alloy steel and alloy steel according to the mass fraction of alloying elements; according to the purpose, it is divided into structural steel, tool steel and special performance steel. Q345 is the most produced and used low-alloy structural steel in China. Commonly used high-speed steels are W18Cr4v, W6Mo5Cr4v2 and 9W18Cr4v.
Macromolecular compounds have a huge relative molecular mass, have long chains, and each molecule constituting the macromolecule compound is not exactly the same size and has a simple chemical composition.
Several common types of restraints: flexible cable restraint, smooth contact surface restraint, cylindrical hinge restraint, living hinge support restraint.
The classification of the shaft: according to the function and load capacity of the shaft, it can be divided intotransmission shaft, Shaft, mandrel; according to the geometric shape of the axis can be divided into straight shaft andCrankshaft.
The main failure mode of the shaft is fatigue failure, so the material of the shaft requires high strength and grace. The shaft material is mainly carbon structural steel and alloy structural steel. Commonly used carbon steels are 35, 40, and 45 steel, with 45 steel being the most widely used. In order to improve its mechanical properties, it can be normalized or quenched and tempered (ie quenching + high temperature tempering).
Bearings can be divided into sliding bearings and rolling bearings.
bushIt is the part of the sliding bearing that directly contacts the journal, and is the main component of the sliding bearing. The material is required to have sufficient strength, wear resistance, corrosion resistance, good thermal conductivity and wear resistance.
Commonly used lubricants for bearings arelubricating oilAnd grease. Lubrication methods include oil lubrication and grease lubrication. Oil lubrication has two types: intermittent oil supply and continuous oil supply. Continuous oil supply mainly includes: drip lubrication, oil ring lubrication, splash lubrication, pressure cycle lubrication.
The general-purpose rolling bearing code is composed of basic code, pre-code and post-code.
There are two types of parts: general-purpose parts and special-purpose parts.
The cam mechanism is mainly composed of a cam, a follower and a frame.
The hinged four-bar mechanism can be divided into three forms: crank-rocker mechanism, double-crank mechanism and double-rocker mechanism.
The cam mechanism is mainly composed of a cam, a follower and a frame. The driving part usually rotates at a constant speed, but there are also reciprocating linear movements. The cam mechanism has a simple and compact structure and convenient design; however, the cam and the follower are in point or line contact, which is a high pair, so it is easy to wear, so it is generally used in occasions where the transmission of power is not large.
The type of mechanical transmission can be divided into friction belt transmission and meshing belt transmission. The friction belt transmission relies on the friction on the contact surface between the belt and the pulley to transmit movement and power; the meshing belt transmission relies on the meshing between the belt teeth and the pulley teeth to transmit movement and power. This kind of belt transmission is called synchronous belt transmission.
carThe marking content and order of the V-belt are: model number, nominal value of effective length, and standard number. For example, AV15 type V belt, the nominal value of effective length is 1000MM, and its mark is AV15*1000.
Automobile V-ribbed belts are marked in numerical and alphabetical order: number of wedges, model, and effective length. For example, 6PK1150 means that the number of wedge is 6, and the effective length is 1150mm.
The condition to ensure that a pair of gears can continuously mesh and drive is: the length of the actual meshing line should be greater than or equal to the normal tooth pitch of the gear.
Cutting processing can be divided into profiling method and generative method.
HydraulicmotorAccording to the structure, it is divided into three categories: gear type, vane type and plunger type.
The flow control valve relies on changing the size of the flow area of ​​the valve port or the length of the flow passage to control the flow through the valve to achieve the purpose of adjusting the movement speed of the actuator. Commonly used flow control valves include throttle valves and speed control valves.