Category Archives: Cnc Machining

Analysis of the corrosion resistance of carbon fiber composites


As an excellent structural material, carbon fiber has been used in many fields. In addition to the excellent properties of light weight and high strength, the corrosion resistance of carbon fiber composite materials is also more prominent than other structural materials. What makes carbon fiber have excellent performance? What about corrosion resistance? Let’s find out together.
It can be seen from the production process of carbon fiber that carbon fiber is a structure similar to graphite crystal formed by high temperature carbonization and graphitization at 2000-3000 °C. This structure itself has high resistance to medium corrosion. In some chemical media , its strength and modulus remain basically unchanged. However, in practical applications, carbon fiber is usually fused with matrix materials such as resin to form carbon fiber composite materials, so the corrosion resistance of carbon fiber products will be different from that of carbon fiber itself.
In different environments, carbon fiber products also have different corrosion resistance performance, because the comprehensive effect of ultraviolet rays, oxygen and moisture in the aging effect of the environment on epoxy resin composites is stronger than the unilateral effect, and the aging process Generally, it starts from the surface, and then gradually develops to the inside. With the development of carbon fiber composite product application technology, in many working scenarios with harsh environments, the good corrosion resistance of carbon fiber composite materials has won more and more application opportunities.
China Be-cu Prototype Material Technology Co., Ltd. is a professional manufacturer of carbon fiber products. The company has advanced fiber-reinforced composite material sheet, pipe, molding, autoclave, Cnc machining and other production lines. It has rich production experience and insists on bringing customers High quality carbon fiber products.
Analysis of the corrosion resistance of carbon fiber composites

ISO 9001 certified. BE-CU Prototype Offering CNC machining carbon fiber and other manufacturing services for carbon fiber marterial. Various capabilities include notching, labeling, drilling carbon fiber, grinding, laser cutting carbon fiber, finishing, plating, marking, CNC milling carbon fiber and turning carbon fiber.We stock high quality 3k carbon fiber sheet in a variety of thickness, types and finish. Its a great material used in applications where light weight and strength are needed such as drones. Unlike other workshops, we have no min order and are often filling orders with a single part. We also don’t make you pay for the full sheet and you only get charged for what is used. With a large selection of material, you should find everything you need to make your project come to life. We are also able to handle larger production runs and provide a competitive pricing. If we don’t have the material or finish you require, we are more the willing to look at bringing it in for you.

What Is Carbon Fiber?Carbon fiber is made of polyacrylonitrile (PAN) (or pitch, viscose) and other organic fibers by carbonization (removal of most elements except carbon) by pyrolysis method under inert gas at high temperature above 1,000 °C. Inorganic polymer fibers with a carbon content of more than 90%.

Spindle Components Of CNC Machining Centers


The role and function of the spindle The spindle component is one of the execution components of the forming movement of the machining center, and the spindle component of the machining center is required to have high running accuracy, long-term accuracy retention and long-term accuracy stability.

The machining center is usually used as a precision machine tool, and the running accuracy of the spindle components determines the machining accuracy of the machine tool. There are generally two methods for evaluating the running accuracy of machine tools: dynamic inspection and static inspection. Static inspection refers to the inspection of the runout of each positioning surface and working surface of the main shaft components under the condition of low speed or dynamic rotation of the main shaft. The dynamic inspection needs to use a certain instrument under the rated speed of the machine tool main shaft, and use a non-contact detection method to test the rotation accuracy of the main shaft.
 
Since the machining center usually has the function of automatic tool change, the tool is fastened by the tensioning mechanism installed inside the spindle of the machining center through the special tool holder, so the rotation accuracy of the spindle should consider the error caused by the machining error of the positioning surface of the tool holder. Machining center spindle bearings usually use C-class bearings. In the two-support spindle components, 41 and 22 are mostly used in combination, that is, four radial thrust bearings and one radial ball bearing are used for the front support and the rear support respectively. The supports use two radial thrust bearings to form the support system of the main shaft components. For light-duty high-precision machining centers, there is also a support system in which a radial thrust bearing is used for the front and rear supports to form the spindle components. This structure is suitable for high-precision and high-speed spindle components. The spindle accuracy is lost due to assembly errors and heat conduction, but the bearing capacity of the spindle will be greatly reduced.
 
When ordering the spindle bearings, you can choose single use order or paired use order. Paired use When ordering, the supplier will match the inner and outer rings of the paired bearings so that they have the specified axial interference after preloading on the main shaft. The optimal installation position of the paired bearings in the circumferential direction of the main shaft will also be marked by the supplier to meet the working performance requirements after the main shaft is installed.
 

 


At Be-cu.com,we use advanced equipment to offer you Unparalleled precision for producing metal and plastic machining parts

  • We combine the latest CNC milling and turning processes with proprietary technology to deliver high quality, on-demand parts.
  • Our team of engineers and machinists program the equipment to optimize cutting time, surface finish, and final tolerance to meet your design specifications
  • We specialize in cnc precision machining, single part prototyping, short to medium production runs, manufacture parts on time, every time, so you can stay ahead of schedule
  • CNC machining can create very similar parts to series parts. It is often more efficient and faster than other rapid prototyping technologies for the manufacture of a quantity of prototypes between 1 and 10 parts . We also recommend CNC machining for parts with large sizes (greater than 600 mm).

Matters Needing Attention In Machining Center Programming


Designing the machining process of the machining center is actually designing the machining steps of each surface. When designing the working steps of the machining center, it is mainly considered from the two aspects of accuracy and efficiency. The following are the main principles for the design of machining steps in the machining center;
 
The machined surface is completed in the order of roughing, semi-finishing, and finishing, or all the machined surfaces are carried out separately according to roughing first, semi-finishing and fine-graining later. When the machining dimensional tolerance requirements are high, the former can be used considering factors such as part size, accuracy, and deformation of the rigidity of the parts; when the machining position tolerance requirements are high, the latter is used.
 
For parts with both milling surfaces and boring holes, you can mill first and then boring. Dividing the steps in this way can improve the machining accuracy of the hole. When milling, the cutting force is large, and the workpiece is easily deformed. Boring the hole after milling the surface to allow it to recover for a period of time, reducing the impact on the accuracy of the hole caused by deformation. On the contrary, if the hole is boring first and then the surface is milled, then during milling, burrs and burrs will inevitably be generated at the hole, thus destroying the accuracy of the hole.
 
When the positional accuracy of a design datum and hole machining is close to the machine tool positioning accuracy and profit positioning accuracy, the principle of centralized processing of the same design datum is adopted, which can solve the problem of machining accuracy when there are more than one design dimensional reference for the same station .
In the centralized processing of the same station, the processing should be done according to the nearest position as much as possible to shorten the moving distance of the tool and reduce the dry running time.
 
Divide the steps according to the tools used. For example, the rotation time of some machine tools is shorter than the tool change time, without affecting the accuracy, in order to reduce the number of tool changes, reduce the idle time, and reduce unnecessary positioning errors, the tool concentration process can be adopted, that is, the same tool is used. Finish machining the same parts on the knife handle part, and then change the second knife.
 
Considering the repeated positioning error in the processing, the principle cannot be adopted for the hole system with high coaxiality requirements. After one positioning, through sequential continuous tool change, after processing all the holes of the coaxial hole system continuously, add other coordinate position holes to improve the coaxiality of the hole system.
In one positioning set-up, complete as much as possible all surfaces that can be machined.

At Be-cu.com,we use advanced equipment to offer you Unparalleled precision for producing metal and plastic machining parts

  • We combine the latest Cnc milling and turning processes with proprietary technology to deliver high quality, on-demand parts.
  • Our team of engineers and machinists program the equipment to optimize cutting time, surface finish, and final tolerance to meet your design specifications
  • We specialize in cnc precision machining, single part prototyping, short to medium production runs, manufacture parts on time, every time, so you can stay ahead of schedule
  • CNC machining can create very similar parts to series parts. It is often more efficient and faster than other rapid prototyping technologies for the manufacture of a quantity of prototypes between 1 and 10 parts . We also recommend CNC machining for parts with large sizes (greater than 600 mm).

NC Tool Selection Points


The characteristics and requirements of Cnc tools (divided into two major systems: turning system and milling and boring system).CNC tools require high precision, good rigidity, convenient clamping and adjustment, strong cutting performance and high durability. Reasonable selection can not only improve processing efficiency but also improve product quality.

The main factors that should be considered in tool selection

  • 1. The material and performance of the workpiece to be processed: metal, non-metal, and its hardness, stiffness, plasticity, toughness and wear resistance.
    2. Processing technology categories; turning, drilling, milling, boring or roughing, semi-finishing, finishing and super-finishing, etc.
    3. The geometry of the workpiece, the machining allowance, and the technical and economic indicators of the parts.
    4. The cutting amount that the tool can bear.
    5. Auxiliary factor: operation interruption time, vibration, power fluctuation or sudden interruption, etc., how much does a CNC lathe cost.

Turning System (Integral Tool System)

1. Composition: It consists of a blade (tool), a tool body, a handle (or handle body), a cutter head, etc.
2. Codes and parameters of indexable inserts
3. The chip breaker geometry of the indexable insert: free chip breaking and smooth chip evacuation
4. Clamping methods of indexable inserts: wedge-up type, lever type, screw-up type Requirements: reliable clamping, accurate positioning, smooth chip removal, simple structure, and easy operation

5. Selection of indexable inserts

  • 1), blade material selection: high speed steel, cemented carbide, coated cemented carbide, ceramics, cubic boron carbide or diamond
  • 2), blade size selection: effective cutting toughness length, the amount of the knife to be eaten, the main declination angle, etc.
  • 3), insert shape selection: according to surface shape, cutting method, tool life, number of indexing, etc.
  • 4), the choice of the nose radius of the blade:
  • A. When roughing, the workpiece diameter is large, the strength of the blade is required to be high, and the rigidity of the machine tool is large, and the large tool nose arc is selected.
  • B. Finishing, small depth of cut, slender shaft machining, small machine tool stiffness, small tool nose arc

Tool system (modular tool system)

1. Composition; blade (tool), tool holder (or handle body), spindle or blade (tool), working head, connecting rod, main handle, and spindle

2. Selection of CNC milling tools

1), the choice of milling cutter type:

  • A. Select face milling cutter for processing larger plane,
    B. Machining bosses, grooves, facet end mills,
    C. Select the carbide corn milling cutter for machining the rough surface and roughing holes.
    D. Select ball end milling cutter for surface processing,
    E. Select the mold milling cutter for the surface of the mold cavity and the punch surface in the processing space,
    F. Select keyway milling cutter for machining closed keyway, etc.

2), the selection of milling cutter parameters

  • A. Main parameter selection of face milling cutter
    a) The diameter of the standard indexable face milling cutter is Φ16-Φ630): choose a small diameter for rough milling, and choose a large diameter for fine milling.
    b) Determine its geometric parameters according to the workpiece material, tool material and processing properties: milling cutters with small rake angle are usually selected, materials with high strength and hardness are selected with negative rake angle, and workpiece material hardness is not large. Small clearance angle, small clearance angle for coarse-tooth milling cutters, and large clearance angle for fine-tooth milling cutters. The edge inclination angle of the milling cutter is usually -5–15 degrees, and the main declination angle is 45-90 degrees.

B. Selection of main parameters of end mills

  • a), the tool radius r should be less than the minimum curvature radius ρ of the inner contour of the part
    b), the processing height of the part
    c), no through hole or deep groove selection
    d), select when processing shape and through groove
    e), the tool diameter when machining ribs is
    f) When roughing the inner contour surface, the maximum diameter of the milling cutter

3. Selection of machining center tools

The machining center tool is usually composed of two parts: cutting tool and tool holder. The cutting edge has various milling cutters for surface processing and various drill bits, reaming drills, boring tools, reamers and taps for hole processing. The tool holder should meet the requirements of the machine tool. The spindle is automatically loosened and clamped for positioning, and can accurately install various cutting tools and adapt to the clamping requirements of the tool changing manipulator.
1), the basic requirements for machining center tools
A. The tool should have high rigidity
B, high repeat positioning accuracy

 


At Be-cu.com,we use advanced equipment to offer you Unparalleled precision for producing metal and plastic machining parts

  • We combine the latest CNC milling and turning processes with proprietary technology to deliver high quality, on-demand parts.
  • Our team of engineers and machinists program the equipment to optimize cutting time, surface finish, and final tolerance to meet your design specifications
  • We specialize in cnc precision machining, single part prototyping, short to medium production runs, manufacture parts on time, every time, so you can stay ahead of schedule
  • CNC machining can create very similar parts to series parts. It is often more efficient and faster than other rapid prototyping technologies for the manufacture of a quantity of prototypes between 1 and 10 parts . We also recommend CNC machining for parts with large sizes (greater than 600 mm).

Overview Of Carbon Fiber Pultrusion


Pultrusion and winding are both important forming processes for fiber materials. The pultrusion process can produce products with light weight, corrosion resistance and low conductivity, which are suitable for mass production. It was originally used to produce glass fiber composite materials. With the development of technology, it is gradually used in carbon fiber and Kevlar fiber. Now, both civilian and industrial products of carbon fiber can be manufactured by this method. It has penetrated into many fields such as transportation, sporting goods, medical equipment and so on.
 
Pultrusion consists of three sequential, continuous automated processes, preforming of reinforcement material, resin infusion of the molded body and conversion of the preform into a solid layer and board peak resin curing. These three processes can be seen as three independent technical steps. The first stage is the formation of carbon fiber bundles with a properly oriented structure, and the second stage is the impregnation of the resin into the fiber preform. These two stages can be performed in parallel, saving time. The third stage is to complete the setting, curing and forming the final solid part in the heat setting mold. The whole process is affected by conditions such as tensile force, thermal expansion coefficient, and temperature. The pultrusion equipment itself is not an important factor in determining the success of machining and forming, it can be any kind of machinery that can realize clamping and drawing to make the material pass through the above three processes.
 
This article is just about telling you about the pultrusion technology of carbon fiber. China Be-cu official website will continue to update other content about carbon fiber, you can always pay attention to our website to check, if you need carbon fiber materials, you can find China Be-cu Carbon Fiber Composite Materials Co., Ltd.

 

ISO 9001 certified. BE-CU Prototype Offering CNC machining carbon fiber and other manufacturing services for carbon fiber marterial. Various capabilities include notching, labeling, drilling carbon fiber, grinding, laser cutting carbon fiber, finishing, plating, marking, CNC milling carbon fiber and turning carbon fiber.We stock high quality 3k carbon fiber sheet in a variety of thickness, types and finish. Its a great material used in applications where light weight and strength are needed such as drones. Unlike other workshops, we have no min order and are often filling orders with a single part. We also don’t make you pay for the full sheet and you only get charged for what is used. With a large selection of material, you should find everything you need to make your project come to life. We are also able to handle larger production runs and provide a competitive pricing. If we don’t have the material or finish you require, we are more the willing to look at bringing it in for you.

What Is Carbon Fiber?Carbon fiber is made of polyacrylonitrile (PAN) (or pitch, viscose) and other organic fibers by carbonization (removal of most elements except carbon) by pyrolysis method under inert gas at high temperature above 1,000 °C. Inorganic polymer fibers with a carbon content of more than 90%.

What Are The Carbon Fiber Connection Methods?


Carbon fiber composite materials are usually used in the manufacture of automobiles, rail vehicles and various mechanical equipment in the form of parts. Glue connection. Different connection methods have their own advantages and disadvantages. Let’s take a look at them together in this article.
 
For components whose thickness, length or overall volume account for a large proportion of the entire equipment, mechanical connection is usually used, because heavier or larger mechanical equipment tends to generate greater vibration and friction during operation. The mechanical connection is more conducive to the transmission of larger concentrated loads, and this method is more reliable. Moreover, if the parts need to be disassembled and replaced, it is more convenient to use a mechanical connection.
 
For components with light weight and small volume, they can be connected by gluing, because compared with mechanical connection, gluing is not only easy to obtain a smooth transition shape that meets the requirements of aerodynamics, but more importantly, it will not significantly increase the size of the body. Self-weight, and self-weight has a great influence on small, especially precision equipment, but because the bonding strength changes with environmental changes such as temperature and humidity, the reliability is reduced compared to mechanical connections. Not suitable for parts with high strength requirements.
 
China Be-cu Prototype Material Technology Co., Ltd. is a private technology enterprise engaged in the research and development of carbon fiber-based high-performance fiber-reinforced composite materials and the development and manufacture of advanced equipment parts such as rail transit, automobile industry, medical equipment, robots, etc. Rich production experience and multiple machining equipment are committed to bringing high-quality carbon fiber products to customers.

 

ISO 9001 certified. BE-CU Prototype Offering CNC machining carbon fiber and other manufacturing services for carbon fiber marterial. Various capabilities include notching, labeling, drilling carbon fiber, grinding, laser cutting carbon fiber, finishing, plating, marking, CNC milling carbon fiber and turning carbon fiber.We stock high quality 3k carbon fiber sheet in a variety of thickness, types and finish. Its a great material used in applications where light weight and strength are needed such as drones. Unlike other workshops, we have no min order and are often filling orders with a single part. We also don’t make you pay for the full sheet and you only get charged for what is used. With a large selection of material, you should find everything you need to make your project come to life. We are also able to handle larger production runs and provide a competitive pricing. If we don’t have the material or finish you require, we are more the willing to look at bringing it in for you.

What Is Carbon Fiber?Carbon fiber is made of polyacrylonitrile (PAN) (or pitch, viscose) and other organic fibers by carbonization (removal of most elements except carbon) by pyrolysis method under inert gas at high temperature above 1,000 °C. Inorganic polymer fibers with a carbon content of more than 90%.

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Basic Maintenance Steps And Methods Of Shenyang Machine Tools


2. The main circuit structures of Siemens AC drives are similar

3. The drive of Shenyang machine tool is the core of the power part, and more than 70% of its failures are power part failures. First, check whether the intermediate DC voltage is normal. If it is not normal, check the rectifier or filter circuit. If it is rectified by a thyristor, there may be a fault in the trigger control circuit. This can be detected with the help of an oscilloscope. If the intermediate DC voltage is normal, you can check the inverter power part. In the early products, most of the devices were Darlington power modules with freewheeling tubes. The multimeter makes a preliminary judgment like measuring a transistor. Further, it can be judged by a transistor characteristic grapher. If each power module is normal, further check whether the signal sent to the base of each module is normal.

4. You can add power to each channel separately. In the absence of an enable signal, the base voltage of each base should be the corresponding negative reverse bias voltage, so that the power module is in a cut-off state. If a certain channel is found to have no reverse bias voltage or If the voltage deviation is large, it can be determined that there is a problem with the path.

5. For further inspection, the inverter control device (pre-amplification link) of Shenyang machine tool should be overhauled, and the failure rate of this part is relatively high. One is the fault caused by this part itself; the other is that if the inverter power part is damaged, most of the pre-amplifier parts are also damaged, which is the key to repairing the driver.

6. The preamplifier part of Shenyang machine tool consists of 6 identical circuits. It is easy to find the optocoupler and the output terminal of the preamplifier, add the required source, and measure the voltage at the output terminal, which should be all negative values ​​(the B terminal is measured based on the E terminal), generally about -5v , If a certain circuit cannot generate a negative bias voltage, the power module will be damaged as soon as the drive circuit is turned on, and the fault will be further expanded. Then add an artificial positive signal to the optocoupler to make the optocoupler turn on. At this time, the output voltage should be positive, generally about 8v. At this time, if you can clearly see the presence or absence of the optocoupler input signal, If the voltage at the output varies between positive and negative, the channel is already normal. Use this method to test the 6-way preamplifier channels respectively. If the Shenyang machine tool test is normal, it can be basically determined that the control loop is normal. However, if it is found that a certain circuit is different from the basic normal circuit, it is certain that the circuit is faulty, and the comparison method (measurement of resistance or voltage) can be used to compare it with the normal circuit point by point, and finally find the damaged components and replace them. until the test result is the same as the normal path.

Note: It must be added here that the positive and negative bias voltages in Shenyang machine tools are different due to the different designs of various drivers. The test should be based on the same positive and negative bias voltages of each channel.

 


At Be-cu.com,we use advanced equipment to offer you Unparalleled precision for producing metal and plastic machining parts

  • We combine the latest Cnc milling and turning processes with proprietary technology to deliver high quality, on-demand parts.
  • Our team of engineers and machinists program the equipment to optimize cutting time, surface finish, and final tolerance to meet your design specifications
  • We specialize in cnc precision machining, single part prototyping, short to medium production runs, manufacture parts on time, every time, so you can stay ahead of schedule
  • CNC machining can create very similar parts to series parts. It is often more efficient and faster than other rapid prototyping technologies for the manufacture of a quantity of prototypes between 1 and 10 parts . We also recommend CNC machining for parts with large sizes (greater than 600 mm).

What Are The Types Of Carbon Fiber?


In 1959, the United Carbide Corporation produced carbon fiber with a modulus of 40GPa and a strength of 0.7GPa, which opened a new era of carbon fiber. With the continuous deepening of research, various specifications and models of carbon fibers have been developed, with a wide variety. In this article, I will talk about the types of carbon fiber.
 
According to different manufacturing materials, it can be divided into polyacrylonitrile -based carbon fiber, pitch-based carbon fiber and viscose-based carbon fiber. The vast majority are PAN-based carbon fibers. Among the 85 large-scale carbon fiber production companies in the world, there are 9 companies that use PAN as raw material to produce carbon fiber, including Japan’s Toray, Toho Tenax, and Mitsubishi Rayon, and the United States’ Zoltek, Hexel, and Sutec. , Aldira, SGL in Germany and Formosa Plastics in Taiwan.
PAN-based carbon fiber is divided into two types: small tow and large tow according to the size of the tow. Small tow refers to carbon fibers with fiber tows between 1-24K , which are mostly used in high-end technical fields; large tow carbon fiber refers to carbon fibers with a tow number of 48K and above, and its performance is low. As a general-purpose fiber, it is mainly used in civil and general industries.
 
According to the mechanical properties of carbon fiber and can be divided into general-purpose and high-performance. The strength of general-purpose carbon fiber is 1000MPa and the modulus is about 100GPa. High-performance carbon fiber is divided into high-strength type and high model . With the development of and industry, high-strength and high-elongation carbon fibers have also appeared, and their elongation is greater than 2%.
 
There are various types of carbon fibers and a wide range of applications, involving automobiles, high-speed rail, medical equipment, sporting goods and other fields. China Be-cu Prototype Material Technology Co., Ltd. relies on integrity and quality to survive, rely on scientific and technological innovation for development, and is highly competitive in the market. It can customize various carbon fiber products according to customers’ drawings.

ISO 9001 certified. BE-CU Prototype Offering CNC machining carbon fiber and other manufacturing services for carbon fiber marterial. Various capabilities include notching, labeling, drilling carbon fiber, grinding, laser cutting carbon fiber, finishing, plating, marking, CNC milling carbon fiber and turning carbon fiber.We stock high quality 3k carbon fiber sheet in a variety of thickness, types and finish. Its a great material used in applications where light weight and strength are needed such as drones. Unlike other workshops, we have no min order and are often filling orders with a single part. We also don’t make you pay for the full sheet and you only get charged for what is used. With a large selection of material, you should find everything you need to make your project come to life. We are also able to handle larger production runs and provide a competitive pricing. If we don’t have the material or finish you require, we are more the willing to look at bringing it in for you.

What Is Carbon Fiber?Carbon fiber is made of polyacrylonitrile (PAN) (or pitch, viscose) and other organic fibers by carbonization (removal of most elements except carbon) by pyrolysis method under inert gas at high temperature above 1,000 °C. Inorganic polymer fibers with a carbon content of more than 90%.

Research On The Design Of Automatic Transmission For Electric Vehicles


introduction

Electric vehicles are powered by renewable and clean electric energy, which overcomes the problems of environmental pollution and resource shortage of traditional internal combustion engine vehicles; electric vehicle traction motors have a wider working range than traditional internal combustion engines, and the motor has constant torque at low speed and constant power at high speed. The characteristics are more suitable for vehicle operation requirements. However, the fixed ratio reducer has only one gear, so that the electric vehicle motor is often in the low-efficiency area, which not only wastes precious battery energy and reduces the driving range, but also increases the requirements for the traction motor.

The electric vehicle traction motor must provide high instantaneous torque in the constant torque area and high operating speed in the constant power area in order to meet the vehicle performance requirements such as high speed, climbing and acceleration. In order to give full play to the advantages of electric vehicles and reduce the requirements for power batteries and traction motors of electric vehicles, the transmission system of electric vehicles should be multi-speed.

The complicated shifting operation of manual transmission and the need to cut off the power source during the shifting process affect the driving performance and comfort of electric vehicles. Automatic transmission is the development trend of vehicle transmission. Compared with manual transmission, automatic transmission has higher vehicle safety and comfort performance. The dual-clutch automatic transmission based on the parallel shaft manual transmission not only inherits many advantages such as high transmission efficiency, compact structure and low price of the manual transmission; The advantages of good shifting quality such as automatic transmissions. Therefore, electric vehicles with two-speed dual-clutch automatic transmission have better vehicle performance.

1. Structural principle of electric vehicle automatic transmission

1.1 System structure schematic diagram

Figure 1 shows the schematic diagram of the system structure of the two-speed dual-clutch automatic transmission. It is centered on the transmission electronic control unit and receives signals from sensors such as brake pedal, selector switch, accelerator pedal, etc., and can use CAN bus technology to receive signals from the whole system. Signals from the vehicle controller, such as vehicle speed, motor speed and other signals. The transmission electronic control unit collects the current road condition information, sends out signal commands through a certain shifting rule, and controls the clutch actuator to operate the clutch separation and combination.

1.2 The principle of transmission structure

According to the driving performance of the vehicle, it is determined that the ideal Ⅱ pure electric vehicle transmission design adopts a two-speed transmission to meet the power and economic requirements of the whole vehicle. Figure 2 is the transmission structure diagram of the two-speed dual-clutch automatic transmission. The output shaft of the clutch CL1 is a solid shaft, and a hollow shaft is sleeved outside the solid shaft, that is, the output shaft of the clutch CL2. The concentricity of the two output shafts makes the structure more compact. Through the motor and the deceleration and distance-increasing structure, the engagement and analysis of the two clutches realizes two-speed automatic transmission, and there is no need to add a shifting mechanism, which simplifies the structure of the system.

When the electric vehicle is stopped, the clutch CL1 and the clutch CL2 are both in the disengaged state, so no power is transmitted. When the electric vehicle starts, the automatic transmission electronic control unit controls the clutch CL1 motor to engage the clutch CL1. When the clutch CL1 is fully engaged, the electric vehicle enters the 1st gear. At this time, the clutch CL2 is still disengaged and does not transmit power. When the electric vehicle accelerates and reaches the shift speed value of 2nd gear, the clutch motor is controlled by the transmission electronic control unit so that the clutch CL1 starts to be disengaged, and the clutch CL2 starts to be engaged.

The two clutches are switched alternately until the clutch CL1 is completely disengaged and the clutch CL2 is fully engaged, and the electric vehicle upshifting process ends. When the electric vehicle enters the 2nd gear speed operation, the transmission electronic control unit collects relevant signals and judges whether the gear that the electric vehicle is about to run in is downshifted. The downshift process only needs to disengage the positive clutch CL2 and engage the disengaged clutch CL1 at the same time. Cooperate with the switching sequence of the two clutches, and shift according to a certain shifting pattern, and the entire shifting can be completed in an orderly manner.

1.3 Principle of control system

1.3.1 The hardware principle of the control system

The automatic transmission electronic control unit TCU is the control core of the entire dual-clutch automatic transmission system. The design of the TCU is directly related to the quality and performance of the entire dual-clutch automatic transmission. This design selects Freescale’s 16-bit MC9S12C64 microcontroller. MC9S12C64 has high-speed digital signal processing capability, strong real-time performance, low power consumption, and high integration performance. Its working environment temperature can be between -40 ~ 125, which can overcome the impact of the harsh working environment of the car on the performance of the single-chip microcomputer.

MC9S12C64 adopts 16-bit microprocessor S12CPU, which has high computing and processing capabilities. MC9S12C64 has 2KB internal RAM, 64KB internal FLASH; an 8-channel 16-bit TIM (timer) module, which has the ability to efficiently process multiple time events, and meets the multi-channel speed signal acquisition requirements in the automatic transmission control system of electric vehicles; 8 channels 10-bit AD (analog-to-digital conversion) module, which meets the requirements of multi-channel analog signal conversion accuracy; 6-channel 8-bit PWM (pulse width modulation) module, which can meet the multi-channel motor drive signal output requirements of electric vehicles; CAN bus module for communication. Other available resources: The 80-pin package has 60 general-purpose I/O ports, two 8-bit bidirectional digital I/O ports, an internal watchdog, and more.

Taking MC9S12C64 as the core TCU system is mainly composed of main Controller module, input module, motor drive module, Display and CAN communication module. Signal input includes analog signal, switch signal and pulse signal input. Among them, the motor speed adopts a Hall pulse sensor, and the pulse signal output by the speed sensor is input to the pin of the single-chip microcomputer for speed measurement after photoelectric isolation and level conversion. The motor drive module uses PWM to control the speed and steering of the two clutch control motors. PWM has the advantages of high speed regulation accuracy, fast response speed, wide speed regulation range and low consumption.

The CAN communication module can transmit data between the TCU and the vehicle motor controller and anti-lock braking system, thus realizing the control of the motor speed and torque by the dual-clutch automatic transmission system, which not only simplifies the design, but also reduces the system manufacturing cost , while improving the integration and reliability of the TCU, improving the quality of shifting and the power and comfort of the vehicle. The display module adopts two digital tubes to display the gear position and fault code respectively. The fault alarm is realized by light-emitting diode and buzzer.

MC9S12C64 does not have internal EEPROM and clock, so it needs to add clock circuit and power-down memory. 

1.3.2 Software principle of conrol system software

The dual-clutch automatic transmission software system adopts the modular programming method, which is composed of main program, signal processing, shifting decision-making, execution and other modules. The main program is a cyclic program, which continuously reads the vehicle status by collecting signals, calls the corresponding subroutines for shifting decision-making, shifting and fault diagnosis according to the driver’s operation in real time, and displays the gear position and fault code. Call the police.

The main program of the TCU system consists of the power-on initialization subroutine, the parking gear processing subroutine, the neutral gear processing subroutine, the forward gear processing subroutine, the reverse gear processing subroutine, and the online fault diagnosis and display program. The power-on initialization subroutine is mainly to initialize the software operating environment. Subroutines such as parking gear processing subroutine, neutral gear processing subroutine, forward gear processing subroutine and reverse gear processing subroutine respectively form their own loops according to their respective gear processing characteristics and functions. The fault diagnosis and display function handles the abnormal or unhandled situation of the program, and displays the fault code. 

2. Advantages of automatic transmission for electric vehicles

According to the structural characteristics of pure electric vehicle two-speed dual-clutch automatic transmission, it has the following advantages:

(1) The structure is simple. The pure electric vehicle motor can steplessly adjust the speed within a certain range, so the transmission system can meet the dynamic performance and economy of the vehicle as long as it adopts two forward gears, and simplifies the transmission structure; Combination and separation control can meet the requirements of automatic transmission without shifting actuators.

(2) Cost saving. The dual-clutch automatic transmission has a good inheritance of the original automatic transmission production line, and the investment in technical transformation is low; the complex mechanism such as the hydraulic system has been cancelled, and the manufacturing cost has been reduced; the battery and motor of pure electric vehicles are relatively expensive, and the two-speed dual-clutch automatic transmission can be used. Save battery power and reduce motor performance requirements, thereby saving vehicle manufacturing costs.

(3) The shifting quality is high. The dual-clutch automatic transmission is simple in structure, stable in operation, does not cut off power during shifting, and has good shifting quality and transmission efficiency.

(4) Easy maintenance and low cost. There is no hydraulic system, and complex structures such as shift actuators are eliminated, reducing maintenance difficulty and costs.

3. Summary

Under the social background of energy saving and emission reduction, electric vehicles will have good development prospects. Limited by battery technology and vehicle motor technology, electric vehicles need to use and will still need to use more than two-speed transmissions for a period of time in the future to meet the power and economy of the whole vehicle. The two-speed dual-clutch automatic transmission for electric vehicles not only reduces the requirements of electric vehicles for batteries and motors, but also overcomes the problems of poor shifting quality of manual transmissions and the power source interruption of AMT shifting. Therefore, the two-speed dual-clutch automatic transmission has better performance. application prospects.

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The Production And Advantages Of Carbon Fiber Board


Carbon fiber board is a basic and commonly used carbon fiber product. It is the main application form of carbon fiber prepreg. It is currently used in many structural parts. In this article, we will learn about the production and performance advantages of carbon fiber board.
 
Carbon fiber prepreg is an important raw material for carbon fiber board. Before making carbon fiber board, the prepreg is cut according to the specifications of the required board. The thicker the carbon fiber board, the more prepreg layers that need to be superimposed. A reasonable layup angle can optimize the mechanical properties. Common layup angles are 0°, ±45°, and 90°. After the prepreg is laid, it needs to be cured. The prepreg is placed in a press and cured and formed under the dual action of temperature and pressure.
 
The significant advantage of carbon fiber material is light weight and high strength, its density is only 1.7g/cm3, the density of common structural materials aluminum and steel are 2.7g/cm3 and 7.85g/cm3 respectively, in comparison, the weight reduction performance of carbon fiber material more prominent. At the same time, its mechanical properties are very outstanding, with excellent tensile strength, bending strength and shear strength, which can effectively meet the needs of use strength. Carbon fiber materials also have excellent X-ray transmission properties and are also used in the medical field. Carbon fiber board also has performance advantages such as high temperature resistance, corrosion resistance and aging resistance.
 
China Be-cu Prototype Material Technology Co., Ltd. is a professional manufacturer of carbon fiber products. The company has large-scale hot presses, autoclaves, hydraulic forming tables, Cnc high-speed milling machines and other machining equipment. The carbon fiber products produced by the company all use Made of raw materials from well-known brands such as Taiwan and Japan, the quality is guaranteed.

 

ISO 9001 certified. BE-CU Prototype Offering CNC machining carbon fiber and other manufacturing services for carbon fiber marterial. Various capabilities include notching, labeling, drilling carbon fiber, grinding, laser cutting carbon fiber, finishing, plating, marking, CNC milling carbon fiber and turning carbon fiber.We stock high quality 3k carbon fiber sheet in a variety of thickness, types and finish. Its a great material used in applications where light weight and strength are needed such as drones. Unlike other workshops, we have no min order and are often filling orders with a single part. We also don’t make you pay for the full sheet and you only get charged for what is used. With a large selection of material, you should find everything you need to make your project come to life. We are also able to handle larger production runs and provide a competitive pricing. If we don’t have the material or finish you require, we are more the willing to look at bringing it in for you.

What Is Carbon Fiber?Carbon fiber is made of polyacrylonitrile (PAN) (or pitch, viscose) and other organic fibers by carbonization (removal of most elements except carbon) by pyrolysis method under inert gas at high temperature above 1,000 °C. Inorganic polymer fibers with a carbon content of more than 90%.