Glass lift handle injection mold design

 

  Abstract lift handle on the structural characteristics of glass and molding process were analyzed, focusing on the mold structure and design ideas for a systematic analysis. Cattle production plastic products quality and stability, to the design and use requirements.

 

  Keywords lift handle bevel pillar slider injection mold casting system

 

A process analysis products

 

    The handle is used to lift the elevator car glass handle, so the part requires sufficient strength and rigidity to transfer certain torque, required surface finishing, the product should be minimized after forming the auxiliary work. Lifting the handle consists of a modified ABS material injection molding, the size and shape shown in Figure 1.

 

    Lift one end of the handle for the stepped bore, with the handle head coordination to ensure load lever handle after the first head can rotate but can not swing, lift the other end of the handle embossed with door hole, and automotive glass with the lifting mechanism, the product has two 1.6mmx9.6mm square hole, used for loading retainer.

 

    Characterized by lifting the handle the production of large quantities, although small size products, but the sub-surface is not a plane, the other two 1.6mmx9.6mm because the square hole, thus forming the core-pulling mechanism to order products from mold release, the third point is the product of the big end is nowhere hole tactile, so the design must be used in the mold core portfolio, making it easy for core processing, easy to mold maintenance.

 

2 die mold structure analysis and work process

 

2.1 Analysis of the mold structure

 

    According to the process of plastic injection molding thread configuration shown in Figure 2, the analysis structure in Figure 2 shows the mold, lifting the handle main functional structure of the injection mold by the molded parts, mold guide mechanism, gating system, the ejection mechanism, temperature control system, side core institutions and supporting component parts.

 

2.1.1 Forming Parts

 

    Molded parts primarily by the geometry and size of products, precision, surface roughness and some special requirements of the decision. Molded parts processing thus requiring better performance, ease of assembly, ease of maintenance, the economy is good. From Figure 2 Tomoyo molded parts from the fixed mold 16 and the movable mold 13 consisting door molding mold; appearance core 14, the inner core 15 and lower mold core 18, the mold core 19 composed molding punch. The fixed mold 16 and the movable mold 13 consisting of mold gate determines the size and shape accuracy of the shape of products; shape the core 14, the inner core 15, the mold core 18, the mold core 19 is composed of the punch determined by the shape size precision and The inner shape and size of product accuracy.

 

2 .1.2 Clamping guide mechanism

 

    Clamping guide mechanism is mainly used to ensure the movable die, the fixed mold, the inner core, core shape, the mold core, the mold: Xue exact mutual position between, in order to ensure the dimensional accuracy and shape of the product, and to avoid mold parts collision and interference. Guide sleeve 22, the guide post 23 is mold-oriented components, bushings column with the H7/f7, guide pillar and guide suit with concentricity requirements of less than O.Olmm. Guide column with 20 steel carburizing 50 ~ 55HRC. Guide sleeve with 45 hardened steel 45 ~ 45HRC. Guide housing bore surface hardness should be less than the hardness of the surface of the guide post work, which can improve both the lack of friction between the situation and prevent the guide post or guide sleeve is napping.

 

2 .1.3 gating system

 

    According to the structure of plastic, can be known from Figure 2, the injection mold is a mold used in a two-chamber structure, gating system means the plastic melt from the injection machine nozzle out, to reach the cavity in the mold prior to the flow through the channel. Its role is to convey melt from the nozzle firmly into the mold cavity and mold filling and solidification shaping process, the injection pressure and holding pressure fully transmitted to the various parts of the cavity in order to obtain dense and form clear, surface finish and dimensional precision plastic products. Therefore, in a multi-cavity molding die, if the melt reaches the mold cavity of the time there are differences, namely that it melts the first to reach the cavity will soon be filled completely, but the other has not yet fill the cavity, then acting on the melt flow only to overcome the resistance of the melt pressure necessary, i.e. filling in the melt, the melt pressure is not high, only up to the end of the cavity fill, the molding pressure will rise sharply, when Once you stop the melt into the cavity, the gate began to condense, the first cavity filled with finished yet reaches a predetermined molding pressure, hardening of the gate had been condensed, so do not get the correct size of the physical properties of good products. To prevent this phenomenon, the gate must be balanced, so that each gate start and end at the same time the filling of the cavity. This is the balance of injection mold gating system design, to determine whether the gating system balance, equilibrium values ​​can be used to gate BGV rough estimates. If the calculated BGV each gate of equal value, it is judged that the gate system is substantially balanced, whereas the gate system is unbalanced. In order to balance the gating system, according to the actual situation on the gate and runner cross-sectional area and length of the design is adjusted until the gating system gates BGV value exactly equal, the gating system reached equilibrium.

 

    The above equation indicates the flow channel to achieve balance, it is easy to balance the gate. Therefore, when considering the gate balanced design, should be considered first runner balance. Here the injection mold gate lift handle system balance is calculated as follows: From Figure 2 shows the mold in the same shape and dimensions with two cavities, each gate are rectangular slits.

 

2 .1.4 ejection mechanism

 

    The ejection mechanism is made of plastic extrusion mold cavity means, a lot of its structure, the structure of the mold is used to push the top of the stalk. Member 4, member 5, the push rod member 24, a total of 16, are fixed to the top plate 9, the fixing plate 11 which is fixed to the board than the rod diameter large 0.3 ~ 0.5mm. Roof 9 and the fixed plate 11 through Ejector Leader Pins 8, guide sleeve 10 to ensure its exact location in the mold. While the fixed plate 11 is also provided with the return lever 3 and the pulling rod 25. Reset lever 3 is the role of the mold is closed mold cavity to avoid collision with the putter so that the pusher in advance before the collision with the mold cavity is reset. The role of pulling rod 25 is in the mold opens, the products remain in the dynamic model, and finally by putting the products out.

 

2 .1.5 temperature control system

 

    Set in the mold temperature control system is designed to meet the mold plastic molding temperature requirements, to ensure filling of the plastic melt shaping and curing. The mold temperature adjusting structure 27 through the spout, seal 26 and the opening in the fixed mold 16, the movable die 13 to achieve the waterway.

 

2 .1.6 lateral pulling mechanism

 

    Side core institutions of many types, mold structure in Figure 2 is used in the lateral oblique guide pillar pulling mechanism. Bevel column side parting mechanism is the use of angle pin, sliders and other transmission parts, the vertical motion to the slide mold, thus producing lateral movement to finish typing and core-pulling action. The agency is characterized by compact structure, safe and reliable operation, easy fabrication, and low cost. Therefore bevel pillar core-pulling mechanism design of injection mold is most commonly used as a side parting and pulling mechanism.

 

    The injection mold side parting and core-pulling mechanism is composed of the slider 2, the spring 29, the limit ruthenium 30, slide 31, the fixed pin 32, the angle pin 33 integral with the guide rail 1. Figure 3 by the pulling mechanism calculated the parameters.

 

    (3) slider design.

 

    Bevel pillar side slider is pulling mechanism in one of the main parts, which will connect with the skateboard, complete side core movement. Injection molded parts of the sides of the square hole by its shape and size to ensure the precision of movement. Because skateboarding is a flake core, so the use of the pin insertion and fixation. Pulling the slide in motion, always chute member 14 moving in shape without departing from the core, so the groove of the slider fixing slide down major 0.2mm, purpose of doing so is to avoid slide in motion by the assembly and processing Accuracy of the force.

 

    (4) pressing block design.

 

    Clamping block face is inclined wedge, wedge angle 3 = ce +3. = 15. +3. = 180, chosen to ensure that the wedge angle of the surface can be pressed in the mold when the slide, and in the mold can be quickly disengaged when the slider to avoid pinching blocks affect inclined guide post for the slider drive , pressed blocks in various forms, is used in the injection molding integral, ie the fixed mold 16 Tops 4 clamping block, so pressing reliable, able to withstand greater lateral forces. But workability uneconomical.

 

    (5) Design of the positioning device.

 

    Positioning device is in an open mold process is used to ensure the slider stay just out of position angle pin, any movement does not occur, in order to avoid re-clamping angle pin when the collision with the slider, and can accurately be able Bevel column inserted into the slider oblique hole. The injection mold is of the springs, the slide stopper nails remain in a predetermined position.

 

2.2 die working process

 

    Mold opening rearward movement of the movable die 13 mounted on the stationary platen guide posts 33 are inclined Stubbs 4 slide outward movement of the slide block 31 in the Wei driven outward movement of the side core-pulling action is completed. Following the rearward movement of the movable die, from the inclined guide post and the slider, the slider 30 moves to the position limiting nails, nail stopper under the action of the spring 29 defining the slider position, and finally the plastic product ejecting pusher movable die .

 

    Fixed mold 16 when the mold first with the reset lever contacts so that the pusher resets the forward movement of the movable mold continues, accurate angle pin 33 inserted into the hole in the slider of the ramp, pull the slider movement, will bring to the exact location of skateboarding , final pressing block will slide clamp, injection molding with injection conditions.

 

3 Conclusion

 

    Lift the handle after several months of production injection mold, injection plastic products in full compliance with the product drawings and assembly requirements, changing the stairs into the fixed end of the long length of the mold, the product pieces left in the fixed mold problems, improve production efficiency and quality of plastic products.