Figure 1 shows the frame of a CD-ROM movement. The material is SECC cold-rolled galvanized steel sheet with a material thickness of 1.2 mm. This part not only requires high dimensional accuracy, but also has a flatness of 0.04mm at the outer end of R15 mm (shaded in the figure), and the monthly demand is 3 million pieces. Therefore, the die design considers the progressive die, the blank is the coil, and the stamping process is shown in Figure 2.
Part 1. Part Structure <br> <br> high dimensional accuracy In addition, the requirements of flatness is high. The arc-shaped shadow part is mounted with a motor. When the motor is driven, the motor drives the disc to rotate at a high speed, and the flatness is too poor, which may cause the disc to be skewed and the reading of the disc is difficult. Install the head rails at A, B, C, and D (see Figure 1). The flatness is too poor, which will make the head movement difficult, or even read and write. The head hole is equipped with a head motor, and the size and flatness are out of tolerance, which may cause meshing and transmission difficulties. Therefore, based on the overall function of the pedestal, the overall flatness must be controlled within 0.5 mm.
2. Process analysis of parts
Based on the use of progressive die to punch the part, the instability of raw material properties, as well as the use of coil production, continuous radius change is the main factor causing flatness instability; the right side of the fold and the middle of the large hole pull, is caused Another factor in the change in flatness, and the change in flatness causes a change in positional accuracy. Therefore, whether the flatness of the punched product meets the requirements is the focus of the mold design. The original mold design scheme was continuous blanking → embossing block leveling → blanking, simple tooling leveling. An empty step is reserved in front of the embossing step of the progressive die, and the surface of the embossed block is ground into a trapezoidal tooth of 1 mm × 1 mm with a depth of 0.5 mm, as shown in Fig. 3. In the production process, the yield (the percentage of good output and the number of inputs) is about 70% in the production process, and the utilization rate (the percentage of the actual start time of the mold and the approved start-up time) is about 48%. After the mold is leveled, not only the flatness changes irregularly, but also the efficiency is very low. The trapezoidal tooth of the embossing block was changed to a pin point type, the needle point diameter was 0.5 mm, and the empty step of the progressive die was also loaded into the same pin point embossing block, and the situation remained unchanged. The analysis believes that the main cause is rebound, and the embossing block has limited resilience. Therefore, local rebound replenishment is the focus of the mold design.
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What is Bimetallic Thermometer ?
Bimetal thermometers are thermometers based on the functional principle that metals expand differently
depending on the change in temperature. A bimetal thermometer always consists of two different metal
strips that have a different thermal expansion coefficient.
Where is bimetallic thermometer used?
Bimetallic thermometers are used in residential devices like air conditioners, ovens, and industrial devices like heaters, hot wires, refineries, etc. They are a simple, durable, and cost-efficient way of temperature measurement.
How does a bimetallic strip thermometer work?
A liquid crystal thermometer, temperature strip or plastic strip thermometer is a type of thermometer that contains heat-sensitive (thermochromic) liquid crystals in a plastic strip that change colour to indicate different temperatures.
Wss Bimetallic Thermometer
Wss Bimetallic Thermometer,Working Of Bimetallic Thermomete,Bimetallic Temperature Sensor,Bimetallic Stemmed Thermometer
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