CN201105498Y - A sequential injection mold device with internal vibration - Google Patents

Abstract

The utility model relates to an internal vibration sequential injection mold device. It includes the heating body (6) placed inside the hot runner plate (3) and the heating ring (1) placed outside the hot runner plate (3), the heating ring (1) passes through the hot nozzle (18), the hot nozzle gasket ( 2) Connect with the heating body (6), the heating body (6) is also equipped with a reciprocating linear motion mechanism (A), and the outside of the heating body (6) is equipped with a spacer (7). The utility model heats the plastic in the hot runner plate (3) through the heating body (6); the reciprocating linear motion mechanism (A) moves back and forth to realize the vibration of the molten high polymer; the spacer (7) makes the melting The high polymer is separated from the nozzle, and the frequency of the back and forth motion of the reciprocating linear motion mechanism (A) is controlled, so that the melt enters different positions of the cavity in order to achieve the effect of sequential pouring. The injection molding device of the utility model can effectively reduce product defects, improve product mechanical properties, increase product competitiveness, reduce production costs, and increase economic and social benefits.

Description

A sequential injection mold device with internal vibration

Technical field:

The utility model relates to an internal vibration sequential injection mold device, in particular to an internal vibration sequential injection mold device for injection molding large-scale mold products, which belongs to the transformation technology of the injection mold device.

Background technique:

Now large-scale molds use multiple gates, and the mold is heated outside the hot runner. The disadvantage is that it consumes a lot of power. In addition, when the traditional injection molding is filled with the melt, because the mold wall temperature (40 ° C ~ 50 ° C) is generally low, the injection molded parts always show the characteristics: the shape of the skin and the core layer. For amorphous polymers, it is common to form a thin layer of oriented material near the surface of the cold die, but for heterogeneous or crystalline polymers, three main regions often occur: skin, subskin, and core. There is a velocity gradient in the flow of the melt in the mold cavity, so that the two ends of the polymer chain are in different velocity fields, and the polymer chain is oriented. During the cooling stage, this orientation is frozen, forming a structure with a large orientation close to the epidermis and a small orientation in the center. For crystalline and non-crystalline polymers, the orientation effect has an important impact on the mechanical properties of the product, and the mechanical properties along the orientation direction are greatly improved. At the same time, due to the complexity of polymer molding, plastic parts are also prone to various defects: flashes, weld marks, air pockets, shrinkage, jetting, stagnation, etc.

Utility model content:

The purpose of the utility model is to consider the above problems and provide a built-in heating and reduce energy consumption internal vibration sequential injection mold device. The vibration sequence injection molding of the internal vibration sequence injection molding device of the utility model adopts a timing timer to control the gate, so that the melt in the mold enters different positions of the cavity in sequence, and the phenomenon of weld marks between the two gates can be eliminated, so The strength and apparent quality of the product are greatly improved.

The technical scheme of the internal vibration sequential injection mold device of the utility model is: it includes a heating body placed inside the hot runner plate and a heating ring placed outside the hot runner plate, and the heating ring is connected to the heating body through the hot nozzle and the hot nozzle pad cover , wherein the heating body is also equipped with a reciprocating linear motion mechanism, and the outer side of the heating body is equipped with a spacer that moves with it.

The above-mentioned reciprocating linear motion mechanism) includes an electromagnetic block and a stopper, the electromagnetic block is connected with the heating body through the stopper and the connector, and the electromagnetic block is placed on the side of the electromagnet that controls its attraction.

The above-mentioned reciprocating linear motion mechanism may include a cam driven by a motor, and the cam pushes the pulley connected with the heating body to move.

The spacer includes a chamber spacer for isolating the chamber and a stirring spacer for stirring and vibrating, the heating body includes a heating rod body and a heating element placed in the through hole in the middle of the heating rod body, the chamber spacer and the stirring spacer It is fixed on the outer wall of the heating rod body.

The chamber spacer and the stirring spacer are directly made on the outside of the heating rod body, and are made into an integral structure with the heating rod body.

A temperature-sensing ring is provided outside the heating ring.

The above hot runner plate is provided with nozzles, and the two sides of the nozzles are respectively connected with heat insulating gaskets through fixing parts and the central gasket through fasteners; the lower side of the hot runner plate is respectively connected with a second heat insulating The two fasteners are connected with a second washer.

The above-mentioned connecting piece and the second fastening piece are pins, and the fixing piece, the fastening piece and the second fastening piece are hexagon socket head cap screws.

Compared with the prior art, the utility model has the following advantages:

1) The internal vibration sequence injection mold device of the utility model is different from the existing multi-gate external heating hot runner mold, and adopts a built-in heating structure to reduce energy consumption, effectively use energy and reduce energy loss.

2) The scope of the vibration frequency of the vibration sequence injection mold device in the utility model is very large, the electromagnetic frequency may be 100 times/minute, and the frequency range of the mechanical-cam type can be expanded.

3) The internal vibration sequence injection mold device of the utility model makes the apparent viscosity of the melt in the vibration field related to the vibration frequency, amplitude, die temperature and injection screw speed. With the increase of the vibration frequency, the apparent viscosity first decreases to the lowest value, then rises to a certain level and remains basically unchanged, but is always lower than the apparent viscosity when no vibration is applied; the larger the amplitude, the greater the impact of the vibration field on the apparent viscosity; when the die temperature exceeds the melting point , the effect of the vibration field on the apparent viscosity increases; the greater the screw speed, the smaller the effect of the vibration field on the apparent viscosity.

4) The application of the internal vibration sequence injection mold device of the utility model also plays the role of a valve, changing the opening time of each gate, and adjusting the parameters of each injection molding process to achieve the quality of the injection molding product, the pressure and melt temperature during injection molding It can be set much lower, which can not only reduce the internal stress of the product, but also prevent the degradation threat brought by high temperature to the product. It can also effectively eliminate the weld line and air bubbles of the product, so that the strength and appearance quality of the product can be greatly improved. big boost.

5) The internal vibration sequence injection mold device of this utility model can not only improve the flow filling of high polymer in the injection stage of the product, but also effectively change the molding quality of the product in the pressure holding stage by using the pressure difference and frequency of multiple gates , Reduce product defects and improve mechanical properties.

6) The internal vibration sequence injection mold device of the utility model uses the principle of "frequency-temperature equivalence" to process heat-sensitive polymers, which can effectively reduce injection pressure and temperature, thereby reducing energy consumption and increasing productivity.

The new vibration sequence injection molding device of the utility model can effectively reduce product defects, improve product mechanical properties, increase product competitiveness, reduce production cost, and increase economic and social benefits.

Description of drawings:

Fig. 1 is the structural representation of the internal vibration sequence injection mold device of the utility model;

Fig. 2 is the structural representation that spacer (7) is contained on the heating body (6) in the utility model;

Fig. 3 is the structural representation of chamber partition (71) in the utility model;

Fig. 4 is the structural representation of stirring spacer (72) in the utility model;

Fig. 5 is the structure schematic diagram that partition (7) and heating body (6) are integrated in the utility model;

Fig. 6 is the sectional view of A-A in Fig. 5;

Fig. 7 is the sectional view of B-B in Fig. 5;;

Fig. 8 is a structural schematic diagram of the reciprocating linear motion mechanism (A) in the present invention.

Detailed ways:

Example:

The structural diagram of the internal vibration sequential injection mold device of the utility model is shown in Figure 1, including a heating body 6 placed in the hot runner plate 3 and a heating ring 1 placed outside the hot runner plate 3, and the heating ring 1 passes through the hot nozzle 18. The hot nozzle cushion cover 2 is connected with the heating body 6, wherein the heating body 6 is also equipped with a reciprocating linear motion mechanism A, and the outer side of the heating body 6 is equipped with a spacer 7 that moves together with it.

The above-mentioned reciprocating linear motion mechanism A includes an electromagnetic block 4 and a stopper 5. The electromagnetic block 4 is connected to the heating body 6 through the stopper 5 and the connector 8. The electromagnetic block 4 is placed beside the electromagnet that controls its attraction. The outer side of the heating coil 1 is provided with a temperature sensing coil 17 .

The hot runner plate 3 is provided with a nozzle 21, and the two sides of the nozzle 21 are respectively connected with a heat insulating gasket 9 through a fixing piece 10 and a central gasket 11 through a fastener 12; the lower side of the hot runner plate 3 is respectively connected with a The second heat insulating washer 13 is connected with the second washer 15 through the second fastening piece 16 .

The connecting piece 8 and the second fixing piece 16 are pins, and the fixing piece 10 , the fixing piece 12 and the second fixing piece 14 are hexagon socket head cap screws.

The above-mentioned reciprocating linear motion mechanism A can also be the structure shown in FIG. 8 , including a cam 19 driven by a motor, and the cam 19 pushes the pulley 20 connected to the heating body 6 to move.

The structural representation of above-mentioned spacer 7 is as shown in Figure 2,3,4, comprises the chamber spacer 71 of isolated chamber and the stirring spacer 72 of agitation vibration, and heating body 6 comprises heating rod body 61 and is placed in heating The heating element in the through hole in the middle of the rod body 61 , the chamber spacer 71 and the stirring spacer 72 are fixed on the outer wall of the heating rod body 61 .

In addition, the chamber spacer 71 and the stirring spacer 72 can also be made directly on the outside of the heating rod body 61, and made into an integral structure with the heating rod body 61, as shown in Figures 5, 6 and 7,

Injection molding is carried out with the vibration sequence injection mold device in the utility model, which comprises the following process steps:

1) The heating ring 1 is powered on and transfers heat to the heating body 6 to heat the plastic in the hot runner plate 3;

2) The reciprocating linear motion mechanism A on the heating body 6 moves back and forth to realize the vibration of the molten high polymer in the hot runner plate 3;

3) The spacer 7 installed on the heating body 6 separates the molten high polymer from the nozzle, and controls the frequency of the back and forth motion of the reciprocating linear motion mechanism A, so that the spacer 7 controls the opening and closing of the gate according to the specified time , so that the melt in the mold hot runner plate 3 enters different positions of the cavity in order to achieve the effect of sequential pouring.

The frequency of the back and forth motion of the above-mentioned reciprocating linear motion mechanism A is controlled by an electromagnetic switch or a timing timer to control the injection sequence of the gates.

When the utility model works, the action of the electromagnetic block 4 can be controlled to make the heating body 6 reciprocate. It can also be driven by a mechanical cam. The track of the cam is designed according to the time of the injection molding circuit, and the vibration frequency is controlled by the rotation rate of the motor. .

The apparent viscosity of the melt in the vibration field is related to the vibration frequency, amplitude, die temperature and injection screw speed. As the vibration frequency increases, the apparent viscosity first drops to the lowest value, and then rises to a certain level and then basically maintains constant, but always lower than the apparent viscosity without vibration; the greater the amplitude, the greater the effect of the vibration field on the apparent viscosity; when the die temperature exceeds the melting point, the effect of the vibration field on the apparent viscosity increases Large, using the reduction of viscosity, the injection temperature and injection pressure can be reduced, which is beneficial to the molding of high polymer plastics, and good products can be injection molded. Plastic parts also reduce various defects: flash, weld lines, air pockets, sinking, jetting, stagnation, etc.

By changing the vibration frequency, the sharp change of the physical and chemical state of the polymer polymer during the injection molding process and the change of the flow direction of the plastic melt will cause regular shearing, orientation, and crystallization of the plastic melt during the molding process. Phenomenon, eliminate weld marks and residual internal stress, which are beneficial to the strength of injection molded parts. Under the action of shear force, the bond angles and bond lengths of polymer macromolecules change and are forced to produce tensile deformation. When the shear action is enhanced and the energy exceeds the bond energy of the macromolecules, it will cause the macromolecules to break and degrade, thereby reducing the mechanical properties of the injection molded parts. And regular vibration can prevent the mechanical properties of injection molded parts from declining. The orientation of the polymer macromolecules makes the molecular chains align along the direction of the force, resulting in anisotropic characteristics. The orientation of the polymer polymer is affected by the filling speed, processing technology and material properties, as well as fillers such as fibers. For fiber-reinforced plastics, the influence of fiber orientation is greater and cannot be ignored. The use of vibration injection molding is conducive to the orientation of polymers and the improvement of mechanical properties of products. According to the free volume theory, the movement of polymer chains gradually reaches the overall movement through the movement and diffusion of chain segments. The polymer chains are very large and easy to form a network, while the intertwined nodes form cavities. When the vibration force field is introduced, on the one hand, the vibration increases the mutual shear friction between the polymer chains, generates a large amount of heat dissipation, increases the thermal kinetic energy of the polymer, and the holes also increase and expand, and the molecules On the other hand, the vibration continuously squeezes and releases the polymer melt, which increases the orientation of the molecules, increases the intermolecular cavities, and shifts the center of gravity of the molecular chains. The shift also reduces the interaction force between molecules, thereby increasing the fluidity of the polymer melt. Macroscopically, it shows that the viscosity of the polymer melt decreases, the flow rate increases, the elasticity decreases, the extrusion pressure decreases, and the energy consumption decreases. As a result, the extrusion process of the plastic is improved, and the performance of the product is improved to a certain extent.

Vibration sequential injection molding uses a timing timer to control the gate, so that the melt in the mold enters different positions in the cavity in sequence, which can eliminate the weld line between the two gates, so the strength and apparent quality of the product are greatly improved. At the same time, due to the application of the program control valve, the melt running in the cavity is rarely affected by the cold material factor, so compared with ordinary injection molding, the pressure and melt temperature during injection molding can be set lower than ordinary gates This also reduces the existence of internal stress in the product and prevents the degradation of the product caused by high temperature. In addition, because the application of the program control valve can reduce the injection pressure, for the same product, the same shape, the same projected area, and different injection pressures require different clamping forces, so the mold of the program control valve is used to manufacture The requirements of the product on the clamping force of the injection molding machine are much lower than that of the ordinary gate mold on the injection molding machine.

Taking the injection molding that the utility model is used for bumper as an example, the results of its analysis are compared as follows:

1) The injection time of sequential injection molding is 0.136s less than that of ordinary injection molding;

2) Sequential injection molding has significantly fewer weld lines than ordinary injection molding. The two very long weld lines in ordinary injection molding do not appear in sequential injection molding, indicating that sequential injection molding has a significant effect on eliminating weld lines.

3) Sequential injection molding has significantly fewer bubbles than ordinary injection molding. Especially in ordinary injection molding, the bubbles produced when two melts meet do not appear in sequential injection molding.

Claims (8)

1. An internal vibration sequence injection mold device, including a heating body (6) placed inside the hot runner plate (3) and a heating ring (1) placed outside the hot runner plate (3), the heating ring (1) It is connected with the heating body (6) through the hot nozzle (18) and the hot nozzle cushion cover (2), and it is characterized in that a reciprocating linear motion mechanism (A) is also installed on the heating body (6), A spacer (7) that moves with it is installed. 2. The internal vibration sequence injection mold device according to claim 1, characterized in that the above-mentioned reciprocating linear motion mechanism (A) includes an electromagnetic block (4) and a stopper (5), and the electromagnetic block (4) passes through the stopper ( 5) and the connector (8) are connected with the heating body (6), and the electromagnetic block (4) is placed on the side of the electromagnet that controls its suction. 3. The internal vibration sequence injection mold device according to claim 1, characterized in that the above-mentioned reciprocating linear motion mechanism (A) includes a cam (19) driven by a motor, and the cam (19) pushes to connect with the heating body (6) The pulley (20) moves. 4. The internal vibration sequence injection mold device according to claim 1, characterized in that the spacer (7) includes a chamber spacer (71) for isolating the chamber and a stirring spacer (72) for stirring and vibrating, heating The body (6) includes a heating rod body (61) and a heating element placed in the through hole in the middle part of the heating rod body (61), and the chamber spacer (71) and the stirring spacer (72) are fixed on the heating rod body (61 ) on the outer wall. 5. The internal vibration sequence injection mold device according to claim 1, characterized in that the above-mentioned cavity spacer (71) and stirring spacer (72) are directly made on the outside of the heating rod body (61), and are connected with the heating rod Body (61) is made into an integral structure. 6. The internal vibration sequential injection mold device according to claim 1, characterized in that a temperature-sensitive coil (17) is provided outside the heating coil (1). 7. The internal vibration sequential injection mold device according to any one of claims 1 to 6, characterized in that the above-mentioned hot runner plate (3) is provided with a nozzle (21), and the two sides of the nozzle (21) respectively pass through the fixing parts (10) The heat insulation gasket (9) is connected with the central gasket (11) through the adapter (12); the lower side of the hot runner plate (3) is respectively connected with the second heat insulation gasket (13), The second fastener (16) is connected with a second washer (15). 8. The internal vibration sequence injection mold device according to claim 7, characterized in that the above-mentioned connecting piece (8) and the second fastening piece (16) are pins, and the fixing piece (10), the fastening piece (12), The second fixing member (14) is a hexagon socket head cap screw.

Images