Automotive sensor bracket precision plastic mold design
Automotive sensor bracket precision plastic mold design nine steps
First, product analysis
This case is a stand on the sensor of the car. High precision, the material is POM, the product is small, the longest size is 38mm, and the metal insert (copper) is required for injection molding, which requires a small amount of deformation.
The difference between the upper and lower holes of the product is less than 0.02mm. Since the POM product is easily deformed, in order to minimize the internal stress of the product, the position of the glue point should be considered in the mold design. Moreover, the upper and lower holes are to be shaped after the mold is taken out.
In the middle neutral of the upper and lower holes, the crossing is made, and it is necessary to draw the core in two directions to release the mold, which brings certain difficulties to the design of the slider.
This direction should also be cored
When inserting an insert into a moving mold, the insert is a very flexible piece of copper.
In order to prevent the copper sheet from being offset by plastic during injection molding, two small holes are arranged on the copper sheet, and corresponding cores are arranged in the mold to position them.
Second, the design of the gate
After analysis, in order to reduce the profit of the product, try to reduce the deformation of the product, the best position of the glue point is in the position below.
In the form of a dispensing port
Mold flow analysis results
Due to the compact position of the space, the designed glue mouth interferes with the fixed mold insert, which is very difficult to handle. Therefore, the fixed mold insert is removed, and the core of the formed mold perforation is retained by the original body.
This will give the gate rod a reasonable position.
The overall structure of the mold is a simplified small nozzle structure, and the first reset device is adopted.
Arrangement of lower mold and three sliders
Hide the mold, but look at it like this.
The front mold is designed like this
Fourth, the design of the slider
This set of molds does not seem complicated, but the design of the slider is still a bit difficult, taking care of all aspects of the relationship.
Since the slider 1 and the slider 2 and their common boundary are the sealing faces, they are processed into a uniform plane with a draft angle, which is inserted into the mold, and the mating surface is very precise. To make the bond line on the surface of the product as small as possible
All the mating faces of the slider inserted into the mold must be beveled in the direction of motion to prevent the mating surface of the slider and the mold from being pulled by friction.
The cross section of the slider 3 is in contact with the movable mold to form a sealant position, and the mating surface of the mold insert is 3° in the moving direction to ensure that the slider does not pull due to friction during long-term operation.
Fifth, the design of the fixed mold
The power of the slider is derived from the three oblique guide columns. The slider is pulled out by the force of the mold opening of the injection molding machine. The inclined guide column is fixed on the fixed template by using the inclined guide column fixing block, and the fixed mold side is provided with the first reset structure. Plunger
Sixth, the layout of the dynamic model
The mold is very compact and uses a standard 1515 simplified small nozzle formwork
Seven, the design of the ejection mechanism
In order to reduce the internal profit of the product, the deformation is minimized, and more ejector rods are used, so that the ejection force of each part of the product is relatively balanced, and 10 pedestals are shared. For such a small product, it is rare
Since the five ejector pins interfere with the slider, the first reset structure must be set.
Eight, the design of the first reset mechanism
The first reset mechanism, also known as the pre-reset mechanism, is composed of a large part of the plunger, the swing rod, the roller and the baffle. When the mold is opened, the inclined guide column pulls out the slider.
Since the plunger has been pulled out, the plunger has a transmission space. When the plunger of the injection molding machine pushes the push plate, the swing lever rotates along the pin shaft due to the action of the roller, and here the rotation is 15°.
The reset mechanism is always on both sides of the mold and is completely symmetrical.
9. Design of cooling waterway
Because the product is relatively small, and the insert (copper) is placed in the gap of the injection molding, the injection molding cycle is relatively long, so the cooling water path of the mold is not high, and the most simplified design is adopted. It is directly from the template, and the mode is 2 straight waterways.
The same is true
The design point of this set of molds is the arrangement of the boundaries of the slider 1 and the slider 2 and the selection of the position of the glue feed point.
To sum up, these are automotive sensor bracket precision plastic mold design,finally plastic injection molding.