The so-called vibration grinding is to adhere the abrasive to the surface of the workpiece with a certain pressure. When the workpiece rotates and the abrasive vibrates along the axial direction of the workpiece with a certain amplitude and frequency, it can play a grinding role. During vibration grinding, the number of effective abrasive grains on the abrasive working surface and the number of effective grinding edges of the abrasive grains are significantly increased, the grinding ability is improved, and the grinding quality and efficiency are also improved. In addition, since the amplitude, frequency, and pressure are adjustable, it is possible to conveniently control the amount of grinding per unit time, so that the roughness can be effectively controlled.
In order to effectively control the roughness, the amplitude, vibration frequency, and pressure of the vibration grinding device must be adjustable depending on the object to be processed. Usually these three parameters are realized by mechanical means, and the structure is very complicated and the precision is high. In addition to the pressure to maintain the original spring pressure adjustment, the other two parameters are achieved by the NC method using a stepper motor. In vibration grinding, the amplitude of the reciprocating motion of the abrasive is its amplitude. Since the stepping motor can easily realize the angle control, and the commutation time of the forward and reverse is short, the amplitude modulation requirement of the low frequency vibration can be satisfied. In order to solve the motor vibration during commutation, the timing belt can be used to connect the motor to the eccentric shaft. Experiments show that the method is feasible within a certain range of vibration.
The rotational speed of the stepper motor is determined by the delay constant of the drive pulse, so the vibration frequency can be changed by changing the delay constant. Since the stepping motor has a certain step angle, the adjustment of the amplitude is actually discontinuous, but can be considered to be continuous. When the eccentric shaft does not swing but rotates in a circular motion, the vibration frequency can have a wide range. However, in practical applications, the vibration grinding frequency range is generally within 10 Hz, which is a low frequency vibration, and the forward and reverse response of the stepping motor. Within the speed, the vibration frequency is set to 0.10 Hz to any adjustment. When the processing object is determined, the frequency setting button can be used to change the delay constant of the driving pulse to determine a vibration frequency suitable for the processing object, and can be adjusted at any time according to the specific grinding effect.
Due to the small grinding force, the NC system uses a small stepper motor and a dedicated power drive circuit. First, the operator presets the vibration frequency and amplitude into the single-chip through the button, and then starts the grinding device, and the driving pulse is sent by the single-chip microcomputer, and the pulse signal is output to the stepping motor through the power amplifier to make it run. The forward and reverse rotation of the stepping motor, the rotation angle, etc. are all controlled by the CPU. The driving power supply adopts VMOS field effect transistor, which makes the whole circuit structure simple, easy to install and debug, and has a low failure rate. In order to improve the reliability of the system, the system uses photoelectric isolation circuit to isolate the strong electricity from the weak current, and adopts the semi-flow control technology in the drive circuit to output half current and full current during standby and operation, respectively, to reduce the heat generation. Improve reliability and extend life.
(Finish)
There are many grades of PVC. The viscosity or K value commonly used in the industry indicates the average molecular weight (or average degree of polymerization) of PVC, that is, the length of the PVC molecular chain, which determines the grade of the resin and the corresponding processing parameters. The molecular weight of the resin is related to the physical and mechanical properties of the product.
PVC Resin is a kind of non-crystalline linear polymer compound. The larger the relative molecular mass, the higher the viscosity, the higher the molecular weight, and the higher the tensile strength, impact strength, and elastic modulus of the product, but the flow of the resin melt Decline in sex and plasticity. The viscosity number is usually used to indicate the molecular weight of the polymer, and the polymer model is divided
PVC used to be the largest general-purpose plastic in the world, and it is widely used. It is widely used in construction materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foam materials, sealing materials, fibers, etc
SG3 (K-70, S1300): mostly used for soft products, hoses, wires and cables, films, shoe materials, toys, auto parts etc.
PVC RESIN SG3 has high purity, less fish eyes, easy to blister, high temperature resistance, insulation, soft product texture, etc. It is mainly used to produce soft products such as wires and cables, agricultural films, conveyor belts, and daily plastic products.
PVC RESIN SG3,Pvc Resin Sg3 Sg5 Sg8,Pvc Resin K70,Pvc Resin Powder Sg3,Suspension Pvc Resin Sg3
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