Tao Decai said: "I will give you a task, which is to process the mechanical casing of an electronic device. This electronic device is a small purifier."
The small purifier mainly detects the concentration of formaldehyde in the air. At the same time, the air is drawn by the fan and reaches the filter, which uses the filter to filter out the pollutants. Including sensors, fans, power supplies, displays, etc.
It seems quite simple, just make a shell and leave a hole to let in the air. Leave a hole to lead out communication wires and power wires. Leave a sensor port for detection. Leave a box to place the display so it can be stuck from the inside.
What you need to pay attention to in the mechanical casing is that there are some places where you need to place the battery or connect the power supply hole. There needs to be a place for the screen and holes for the communication lines. There needs to be handles and handles that can move this item. Inside the casing, there needs to be a place for batteries and power supplies, as well as a place for electronic devices. There may also be a cooling fan installed. The connections between the controller hardware and the screen, buttons, speakers, and power supply cannot be blocked by other mechanical components.
They have also been studying it for a while. I just made this casing, and then I found that the power hole was not provided, so I had to use the same hole as the communication line. The screen is placed from the inside out, but the connection wire is located too far away from the circuit board, resulting in relatively long communication wires.
It seems that there are many things to consider for a mechanical casing that is simple on the surface.
Some parts of the shell can be designed with reference to existing shells and programmed graphically.
They arrived at the processing workshop and learned from the master workers how to use several CNC machine tools in the factory. CNC machine tools are a type of machine tools that use digital control technology to automatically control the machining process of the machine tool. A CNC machine tool is an efficient automated machine tool equipped with a program control system and is an example of a typical application of CNC technology. Turning, milling, drilling, etc. can be performed.
"There are several existing shells here. How to obtain their shape data and process them?"
The master worker said, “The general process of graphical programming is processing parts and their process analysis, processing part modeling, process parameter input, tool path generation and editing, tool path verification and simulation, post-processing, and program output. "
Machining parts and their process analysis are the basis of CNC programming. The main tasks include approval of part geometric dimensions, tolerances and accuracy requirements; determination of processing methods, tool clamps, measuring tools and tools; determination of programming origin and programming coordinate system; determination of tool path and process parameters.
Processing part modeling is to accurately draw the geometric shape of the part to be processed on the computer screen by using the graphics drawing, editing and modification, curve surface and solid modeling functions of the integrated CNC programming software. At the same time, it uses a certain data structure inside the computer to Graphically recorded.
Tool path generation and editing. After completing the above operations, the programming system will analyze and judge based on these parameters, and automatically complete the calculation of the base point (the intersection or tangent point of different geometric lines that constitute the part outline) and the node (the intersection or tangent point of the interpolation fitting line segment). , and organize these data to form tool location data, and store them in the specified tool location file. After the tool path is generated, systems with tool path display and interactive editing functions can also display the tool path. If there is any inappropriate part, the tool path can be edited and modified appropriately in manual interaction mode.
They actually use a multi-axis CNC machining center for the housing processing.
Multi-axis CNC machining centers can be divided into two settings:
One is the rotary axis of the workbench. The advantages of this multi-axis CNC machining machine tool are: the spindle structure is relatively simple, the spindle rigidity is very good, and the manufacturing cost is relatively low. However, the general workbench cannot be designed to be too large and the load-bearing capacity is also small. Especially when the A-axis rotation angle is ≥90°, the workpiece will bring a large load-bearing moment to the workbench during cutting.
One is the vertical spindle head rotation. The advantage of a multi-axis CNC machining machine with this arrangement is that the spindle machining is very flexible and the workbench can also be designed to be very large. When using a spherical milling cutter to process a curved surface, when the tool center line is perpendicular to the processing surface, since the vertex linear velocity of the spherical milling cutter is zero, the surface quality of the workpiece cut out by the vertex will be very poor. However, the spindle rotation design makes the spindle Rotating an angle relative to the workpiece allows the spherical milling cutter to avoid apex cutting and ensure a certain linear speed, which can improve the surface processing quality, which is difficult to achieve with a table rotary machining center.
After the design is processed, it is handed over to Tao Decai for review. Tao Decai said: "Then we have to consider the appearance. It should be more beautiful and attract customers."
Duan Zhu said: "Okay. Let's find someone to modify it."
Tao Decai said: "Customers said there are some areas that need to be improved, such as the handles."
Wu Tian said: "This handle is installed from both sides. It blocks the line."
Duan Zhu said: "Let's do this for now. It's okay and we can find a solution."
Tao Decai said: "The customer said that the internal system should be kept confidential and sealed."
Duan Zhu said: "Then weld the outer shell. It won't open like this."
Wu Tian said: "Usually it is fixed with screws and can be opened. That's fine."
So the shell was welded shut.
The small purifier was displayed by the customer. But I found that there is still a sensor that has not been put in. But the electronic components have already been put in and fixed. The shell is welded on. Only the screen port can see inside.
"What other sensors should be put in?"
"A second formaldehyde sensor needs to be put in."
Formaldehyde sensor: semiconductor method: indoor formaldehyde content can be detected by measuring the resistance change of the sensor. long life. There are common deficiencies of low sensitivity and poor selectivity. Electrochemical method: easy to be interfered, it is almost impossible to distinguish the interference of VOC and other VOC, the authenticity must be removed during the test, and the life is short.
"This is troublesome. Do you want to do it again?"
"It will be displayed tomorrow. It's too late to buy electronic components."
"Yes, it will take three days to send it."
"Then you can't weld it from the beginning, and there's no way to modify it after it's sealed."
"Now I can only open the screen. How can I re-modify and fix the things inside?"
Duan Zhu thought of the gravity stone. Maybe this thing could come in handy.
Duan Zhu, Sun Shiji, and Wu Tian took the gravity stone to the factory workshop. Remove the screen from the outside, open the laser processing equipment, and use the gravity stone to change the direction of the laser. At this time, be careful not to cut other electronic components. Finally, process a few round holes, fix the sensor on it, screw it on with screws, put the screen on the outside, and screw on the screws. Fortunately, the screws of the screen are on the outside.
The sensor was successfully placed into the mechanical housing and the purifier was handed over to the customer.
