JP4808594B2 - Injection molding equipment - Google Patents

Description

  The present invention relates to an injection molding apparatus that includes a sprue bush that constitutes a sprue that supplies molten resin injected from an injection molding machine into a cavity, and that is provided with a temperature control passage.

  As an injection molding apparatus in which a temperature control passage is provided in a conventional sprue bushing, a sprue bushing 1 as shown in FIG. 6 is constituted by two parts, and a flow passage constituted by a double helix on the outer periphery of the insertion side sprue bushing 3. In some cases, the temperature adjusting passage 2 is configured by incorporating the portion 4 provided in the fitting side sprue bush 5 (see, for example, Patent Document 1).

As another example, the outer periphery of the sprue bush 1 as shown in FIGS. 7 (a) and 7 (b) is provided with a flow path 4 composed of a double helix on the outer peripheral surface of the sprue bush 1. As described above, the outer cylinder 7 having the communication hole 6 for the flow path 4 is brazed or diffusion-bonded to the sprue bush 1 to constitute the temperature control passage 2 described above, or FIG. , (B), the flow path 4 has been processed into a meandering shape instead of a spiral shape (see, for example, Patent Document 2).
JP 2002-326266 A JP 2003-220633 A

  However, in the conventional configuration shown in FIG. 6, the sprue bush 1 is configured by two parts, and the temperature control medium also flows on the entire surface where each fits. Therefore, due to the generation of rust and scale (scale) Disassembly during maintenance has been difficult.

  In addition, since the flow path 4 has a double helix, the cross-sectional area of the flow path cannot be increased depending on the sprue length. Therefore, the flow rate is increased, but the temperature control effect cannot be sufficiently obtained due to the flow rate decrease due to pressure loss. . In addition, in the circuit from the temperature controller that reaches the inlet / outlet of the temperature adjusting medium of the sprue bushing 1, liquid tightness is required between the components forming this circuit. In the example shown in FIG. There has been a problem that the configuration for holding becomes very complicated.

  Further, in the conventional configuration shown in FIG. 7A, the flow path 4 has a double helix as described above. Therefore, depending on the sprue length, the cross-sectional area of the flow path cannot be increased, and the flow velocity is increased. However, the temperature control effect cannot be obtained sufficiently due to a decrease in flow rate due to pressure loss. Further, the two parts of the outer cylindrical body 7 covering the flow path 4 and the insertion side sprue bushing 3 are brazed or diffusion bonded, and cannot be disassembled.

  For this reason, even if rust and scale (scale) are generated, they cannot be removed, resulting in deterioration of the temperature control effect due to a decrease in the flow rate. As a result, the injected resin is not cooled sufficiently and the quality of the molded product is reduced. The influence on was inevitable. In addition, since the brazing or diffusion bonding is performed after the two parts are fitted, there is a problem that the cost is increased by the bonding means for performing these processes.

  The present invention is directed to solving the problems of the prior art, and an object of the present invention is to provide an injection molding apparatus that has a simple structure, high liquid tightness, and high-efficiency sprue temperature adjustment. .

In order to achieve the above object, an injection molding apparatus according to claim 1 of the present invention comprises a sprue bush that constitutes a sprue that supplies molten resin injected from an injection molding machine into a cavity, and a sprue bush. In an injection molding apparatus provided with a temperature adjustment passage for adjusting the temperature of the inner flow path component constituting a part of the temperature adjustment passage disposed on the outer periphery of the sprue, and injection molding for supplying a molten resin of the inner flow path component The upper sprue bush that fits with the machine end, the lower sprue bush that fits with the cavity end that injects the molten resin of the inner flow path component, and either the upper sprue bush or the lower sprue bush A communication hole connected to a part of the provided temperature control passage, and the inner flow path component is covered with an upper sprue bush and a lower sprue bush. With constituting a Mesh, a portion of said temperature adjusting passage in said flow path part, by the inner passage part of the upper sprue bushing is constituted by an inner peripheral surface contacting the inner passage for maintenance Parts can be easily disassembled, rust and scale (water scale) can be easily removed, and more efficient heat exchange is possible, thus shortening the molding cycle.

Further, an injection molding apparatus according to claim 2 is the injection molding apparatus of claim 1, a temperature controller communication path, a plurality of grooves forming a flow path meandering sprue axis direction inner passage part and It consists of a wall and the inner peripheral surface of the upper sprue bush or the lower sprue bush that engages with the inner flow path component that comes into contact with the wall. The wall in the direction is the contact surface of the upper sprue bush or the lower sprue bush that comes into contact with the inner flow path component, so that the inner flow having a vertically divided sprue bush and a groove that forms a flow path meandering in the sprue axial direction. In the configuration of the three parts of the road parts, the flow path is configured by contacting only the inner peripheral surface of the upper and lower sprue bushes fitted with the inner flow path parts, so that the flow length of the temperature control medium can be increased and high efficiency is achieved. of Enables the exchange and to, and degradation of the sprue bushing and the inner passage components forming the flow path is facilitated by the opening of the groove, rust can easily remove scale (water stain).

The injection molding apparatus according to claim 3 is the injection molding apparatus according to claim 1 or 2 , wherein the heat conductivity of the material of the inner flow path component is A, and the heat conductivity of the material of the upper sprue bush is Assuming that the thermal conductivity of the material of the lower sprue bush is C and that the following condition “A> B or A> C” is satisfied, the material of the inner flow path component is not only metallic but also heat Non-metallic materials with low conductivity can also be used, enabling highly efficient heat exchange and shortening the molding cycle.

An injection molding apparatus according to a fourth aspect of the present invention is the injection molding apparatus according to any one of the first to third aspects, wherein the end surface on the cavity side for injecting the molten resin of the inner flow path component is the same as the bottom surface of the lower sprue bushing. By reaching the position, the length of the sprue included in the inner flow path component can be expanded, the sprue temperature adjustment range can be expanded, the temperature of the most heat-storing sprue base can be adjusted, and more efficient heat exchange is possible. Thus, the molding cycle can be shortened.

  According to the present invention, the sprue bushing can be easily disassembled during maintenance, rust and scale (scale) can be easily removed, heat exchange can be performed with high efficiency, and the sprue temperature can be adjusted, thereby shortening the molding cycle. There is an effect that can be.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1A shows a sprue bushing of an injection molding apparatus according to Embodiment 1 of the present invention. FIG. 1A is a cross-sectional view, and FIG. 1B is a plan view taken along line AA ′. 2A and 2B show a schematic configuration of the sprue bush. FIG. 2A is a lower sprue bush side, FIG. 2B is a perspective view seen from the upper sprue bush side, and FIG. It is a figure explaining a wall.

  An injection molding apparatus in which a temperature control passage is provided in the sprue bushing according to the first embodiment will be described with reference to FIGS. As shown in FIGS. 1 and 2, the sprue bush is divided into an upper sprue bush 11 and a lower sprue bush 12, and an inner flow passage component 13 having a flow passage 4 meandering in the sprue axial direction is sandwiched between the sprue bushes. . The inner flow path component 13 has sprues that are continuous with the sprues of the upper and lower sprue bushes 11 and 12, and grooves 14 having a specific width forming the flow path 4 are arranged in eight equal parts along the outer periphery. Yes.

  With regard to the width and depth of the groove 14, the flow length of the temperature control medium can be increased as much as the number of divisions of the groove 14 is increased. However, since the width of the groove 14 is reduced, a decrease in flow rate due to pressure loss is avoided. Absent. In order to avoid this, the depth of the groove 14 must be further increased in order to ensure the cross-sectional area of the groove 14, but the surface of the inner flow path component 13 with the smaller sprue diameter on the side of the injection molding machine that supplies the molten resin. Therefore, the number of divisions of the groove 14 is basically eight.

  Further, the groove 14 does not penetrate in the sprue axis direction of the inner flow path component 13, and leaves 8 mm from the bottom surface which is the wider side of the sprue diameter on the cavity side where the molten resin of the inner flow path component 13 is injected. It stops at this side. Of the 8 mm, 5 mm is a fitting base to the lower sprue bush 12 (gate side). The remaining 3 mm is set so as to be positioned in the direction of the molding machine nozzle side from the divided surface when the inner flow path component 13 is assembled into the upper sprue bush 11 (molding machine nozzle side) divided in the vertical direction.

  Next, with respect to the flow path 4 formed by the groove 14 and the wall 14b of the inner flow path component 13, as shown in FIG. 2C, the wall 14b (i) between the two adjacent grooves 14a is used as a base axis. The height of the wall 14b (total of four locations: i to iv) at the position swung by 90 degrees is the same as the surface of the inner flow path component 13 where the sprue diameter is narrower, and the other adjacent grooves 14a About the wall 14b (v, viii) on both sides and the wall 14b (vi, vii) at a position swung by 90 degrees, a lowered open portion 14c is formed by the same dimension as the width of the groove 14.

  Further, the wall 14b (v to viii) is connected to the circumferential wall 14d on the surface side of the inner flow path component 13 having the larger sprue diameter. And the wall 14b (a total of three places: ii-iv) is arrange | positioned by opening the same dimension as the width of this circumferential wall 14d and the groove | channel 14. A series of meandering flow paths 4 is formed with the adjacent grooves 14a as the entrances and exits by the walls 14b (i to viii) and the grooves 14.

  Since the inner flow path component 13 is sandwiched between the upper and lower sprue bushes 11 and 12 and configured as the temperature control passage 2, the inner flow path component 13 2 is formed from the outer peripheral surface on the upper sprue bush 11 side (molding machine nozzle side). The communication hole 6 is opened by facing the adjacent groove 14a of the book. In the case of FIG. 1, the angle of the two communication holes 6 is 45 degrees. Further, a pipe parallel female thread 16 is erected in the communication hole 6 and a pipe 17 is inserted from the outside of the mounting plate 10 and incorporated into the pipe parallel female thread 16, so that a circuit capable of finally adjusting the sprue temperature is formed.

  In order to incorporate the inner flow path component 13 into the upper and lower sprue bushes 11 and 12 and make them liquid-tight, the inner flow path component 13 has one lower sprue bush 12 (gate side) on the narrower side of the sprue diameter. The seal material insertion grooves 15 are provided at one convenient place and three places on the side where the inner flow path component 13 is sandwiched between the upper and lower divided surfaces. By disposing the sealing material in this way, it is not on the surface where the inner flow path component 13 is fitted. Therefore, when the sealing material is assembled into the sprue bushing, the sealing material can be assembled without being broken by the edge of the fitting hole of the sprue bushing. It becomes possible, and liquid tightness can be surely maintained. Finally, the inner flow path component 13 is sandwiched between the upper and lower sprue bushings 11 and 12 and fastened with bolts 18 from the upper sprue bushing 11 (molding machine nozzle side).

  According to such a configuration, rust and scale (scale) are not generated on the entire fitting surface in the disassembly work during maintenance, so that the inner flow path component 13 can be easily disassembled and rust and scale (scale) can be easily removed. Become. Further, since the flow path 4 meanders in the sprue axis direction, a long flow length can be taken to enable highly efficient heat exchange, and the cross-sectional area of the flow path 4 also increases the outer shape of the inner flow path component 13. Since it can be expanded with a stable flow rate, the temperature control effect does not deteriorate. Furthermore, since the sealing material is in a direction compressed from the sprue shaft direction, the liquid tightness can be easily and reliably maintained.

  In the first embodiment, the example in which the flow path 4 is formed by a part of the inner flow path component 13 and the upper sprue bush 11 has been described. However, in the upper sprue bush 11 and the lower sprue bush 12 shown in FIG. The up and down length in the sprue axial direction is reversed, and the arrangement of the grooves 14 in the inner flow path component 13 is also reversed up and down, and the flow path 4 is formed by a part of the inner flow path component 13 and the lower sprue bush 12. You may make it do.

(Embodiment 2)
In the second embodiment, the thermal conductivity of the material of the inner flow path component 13 shown in the first embodiment is A, the thermal conductivity of the material of the divided upper and lower sprue bushes 11 and 12 is B, respectively. When C, the material having thermal conductivity “A> B” and “A> C” is used. As an example, the material of the inner flow path component 13 is copper (thermal conductivity at 20 ° C. is 372 W / mk), and the material of the divided upper and lower sprue bushes 11 and 12 is carbon steel (thermal conductivity at 20 ° C. is 53 W / mk). ), A cooling effect of about 7 times can be obtained. In this way, by adopting such a configuration in which a material having a thermal conductivity relationship is selected, the molding cycle is remarkably shortened by high-efficiency heat exchange.

  Here, instead of the configuration comprising the upper and lower sprue bushes 11 and 12 and the inner flow passage component 13 shown in the first embodiment, as an application example thereof, as shown in FIG. In the case of a sprue bush having a structure in which the nozzle side) and the inner flow path component 13 are integrated, if the inner flow path component 13 is a metal material having a thermal conductivity higher than that of the upper sprue bush 11, brazing or diffusion bonding is used. By integrating, high-efficiency heat exchange can be expected. However, even if the structure shown in FIG. 3 is used to improve the assemblability, it is impossible to integrate with non-metals.

  On the other hand, in the configuration in which the inner flow path component 13 is sandwiched between the upper and lower sprue bushes 11 and 12 in the first embodiment, the inner flow path component 13, the upper, By appropriately selecting a material that takes heat conductivity into consideration for the material of the lower sprue bushes 11 and 12, it is possible to adopt a non-metal for the inner flow path component 13, and furthermore, a highly efficient heat exchange becomes possible and a molding cycle. Can be significantly improved.

(Embodiment 3)
4 (a) to 4 (c) are cross-sectional views showing a sprue bushing of an injection molding apparatus according to Embodiment 3 of the present invention, and FIG. 5 (a) shows a schematic configuration of the sprue bushing. (B) is the perspective view seen from the upper sprue bush side.

  The third embodiment has three patterns shown in FIGS. 4A to 4C in which the cross-sectional shape of the outer contour of the inner flow path component 13 in the first and second embodiments is different. Will be described.

  First, as shown in FIG. 4A, in the inner flow path component 13 in the first and second embodiments, the cross-sectional shape of the outer contour is a quadrangle (rectangular) with respect to the sprue axis direction. In the third aspect, protrusions that are quadrangular (rectangular) having a small cross-sectional shape of the outer contour are respectively added above and below the inner flow path component 13a in the sprue axis direction.

  Furthermore, in order to be liquid-tight with respect to the nozzle direction of the molding machine, a standing wall that enters at least 2 mm inside one side of the inner diameter of the sealing material insertion groove 15 provided on the narrower surface of the inner flow path component 13a. 19 and the fitting tolerance with the upper sprue bush 11 (on the molding machine nozzle side) is a clearance fit of 10 to 20 μm on one side. Further, the height of the standing wall 19 is limited to a minimum of 5 mm as a predetermined position in consideration of the buckling strength due to the nozzle touch of the molding machine before the nozzle touch surface 8.

  On the other hand, the surface with the larger sprue diameter is provided on the bottom surface where the inner flow path component 13a of the lower sprue bush 12 (gate side) described in the first and second embodiments is sandwiched as described above. Further, a standing wall 20 is provided at least 2 mm inside on one side of the inner diameter of the sealing material insertion groove 15, and the fitting tolerance with the lower sprue bush 12 (gate side) is a clearance fit of 0 to 5 μm on one side. The height of the standing wall 20 is the same position that reaches the bottom surface of the lower sprue bush 12 (gate side).

  FIG. 4B shows an inner flow path component 13b by adding a projecting portion that is a rectangle (rectangular shape) having a small cross-sectional shape of the outer contour on the molding machine nozzle direction side in FIG. FIG. 4 (c) is a plan view in which a protrusion having a rectangular (rectangular) shape with a small cross-sectional shape of the outer contour with respect to the sprue axial direction is added on the surface side with the large sprue diameter in FIG. The component 13c is used.

  According to such a configuration, the inner flow path components 13a to 13c are long in the sprue axial direction and have the meandering flow path 4, and can be temperature-controlled at a position close to the sprue. In this way, the sprue length included in the inner flow path components 13a to 13c is expanded, the sprue temperature adjustment range can be expanded, and in particular, the temperature can be adjusted even in the vicinity of the sprue root where the heat is stored most and the molding machine nozzle touch surface. Become. This significantly improves the shortening of the molding cycle.

  The injection molding device according to the present invention can be easily disassembled during maintenance of the sprue bushing, can easily remove rust and scale (scale), can perform high-efficiency heat exchange, and can adjust the sprue temperature, thereby reducing the molding cycle. It can be shortened, and is useful for an injection molding apparatus provided with a sprue bushing and a temperature control passage constituting the sprue.

(A) which shows the sprue bush of the injection molding apparatus in Embodiment 1 of this invention is sectional drawing, (b) is a top view of A-A '. (A) which shows schematic structure of a sprue bush, (b) is the perspective view seen from the upper sprue bush side, (c) demonstrates the groove | channel and wall which form the flow path of an internal flow-path component. Figure Sectional view showing the sprue bushing with the upper sprue bushing and the inner flow path parts formed integrally Sectional drawing which shows three structural examples of inner flow-path components (a)-(c) of the sprue bush in Embodiment 3 of this invention. (A) shows a schematic configuration of a sprue bush, (b) is a perspective view seen from the upper sprue bush side Schematic with conventional sprue bushing and temperature control passage (A) is a schematic view, and (b) is a cross-sectional view provided with a temperature control passage composed of a conventional sprue bush and an outer cylinder. (A) is a schematic view, and (b) is a cross-sectional view in which a temperature control passage having a different configuration is provided by a conventional sprue bushing and an outer cylinder

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sprue bush 2 Temperature control path 3 Insertion side sprue bushing 4 Flow path 5 Fitting side sprue bushing 6 Communication hole 7 Outer cylindrical body 8 Nozzle touch surface 10 Mounting plate 11, 11a Upper sprue bushing 12, 12a Lower sprue bushing 13, 13a , 13b, 13c Inner flow path component 14 Groove 14a Adjacent groove 14b Wall 14c Opening portion 14d Circumferential wall 15 Sealing material insertion groove 16 Pipe parallel female thread 17 Pipe 18 Bolts 19, 20 Standing wall

Claims (4)

In an injection molding apparatus provided with a sprue bush that constitutes a sprue that supplies molten resin injected from an injection molding machine into a cavity, and a temperature adjustment passage that adjusts the temperature of the sprue bush,
An inner flow path component constituting a part of the temperature control passage disposed on the outer periphery of the sprue;
An upper sprue bush fitted to an end of the inner flow path component on the injection molding machine side for supplying the molten resin;
A lower sprue bush fitted to an end of the inner flow path part on the cavity side for injecting the molten resin;
A communication hole connected to a part of the temperature control passage provided in either the upper sprue bush or the lower sprue bush, and the inner flow path component is covered by the upper sprue bush and the lower sprue bush. And the temperature control passage is configured by a part of the inner flow path component and an inner peripheral surface of the upper sprue bush which is in contact with the inner flow path component . The temperature control passage includes a plurality of grooves and walls that form a flow path meandering in the sprue axis direction with an inner flow path component, and an upper sprue bush or lower portion that fits with the inner flow path component that contacts the wall section. The inner circumferential surface of the sprue bushing, and the circumferential wall portion at the end of the inner flow passage component on the side mating with the sprue bushing is in contact with the inner flow passage component of the upper sprue bush or the lower sprue bushing. The injection molding apparatus according to claim 1 , wherein the injection molding apparatus is a contact surface. When the thermal conductivity of the material of the inner flow path component is A, the thermal conductivity of the material of the upper sprue bush is B, and the thermal conductivity of the material of the lower sprue bush is C, the following condition “A > B or A> C "
The injection molding apparatus according to claim 1 or 2 , wherein: The injection according to any one of claims 1 to 3 , wherein an end surface on a cavity side for injecting molten resin of the inner flow path component reaches the same position as a bottom surface of the lower sprue bush. Molding equipment.

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