JP4033573B2 - Hot runner mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a split coil for induction heating.The present invention relates to a mold for a hot runner type injection molding machine in which hot runner injection molding can be applied not only to a resin but also to a material that melts at a high temperature such as metal.
[0002]
[Prior art]
The hot runner injection molding method has a great advantage over the runner gate type injection molding because the product can be injection molded without discharging runners and sprues.
FIG. 10 is a cross-sectional view of a mold part of a hot runner type injection molding machine used for injection molding of resin or the like according to an example of an apparatus using induction heating.
The mold includes a fixed-side mold plate 46 to which the nozzle 42 and the manifold 45 are attached, and a movable-side mold plate 49 in which a cavity 49a having a shape corresponding to the product shape is formed.
A back plate 48 is attached behind the fixed side mold plate 46, and a manifold 45 is disposed in a space 47 between the back plate 48 and the fixed side mold plate 46. The manifold 45 is fixed to the back plate 48 by a manifold fixing member 44 that is detachably attached to the back plate 48 by bolts 44a. An induction heating coil 1 ′ is wound around a plurality of locations on the outer peripheral surface of the manifold 45.
[0003]
The coil 1 'is connected to a lead wire 12 passing through the inside of the back plate 48, and the lead wire 12 is connected to a voltage supply source (not shown). A predetermined voltage is applied to the coil 1 ′ via the lead wire 12 by this voltage supply source. When a predetermined voltage is applied to the coil 1 ′, the manifold 45 formed of a conductor is induction-heated to heat or keep the molten material of the runner 45 a and the sprue 45 b formed inside the manifold 45.
Such hot runner injection molding is suitable for injection molding of a resin or the like having a relatively low melting temperature of 200 ° C. to 300 ° C. and low thermal conductivity. Therefore, the hot runner injection molding method is widely used in resin injection molding.
By the way, with the rapid development of computers, audio, video equipment, etc., the demand for recording media such as CDs, MOs, and DVDs is rapidly increasing. In injection molding such a thin molded article, the surface of the mold in which the cavity is formed is rapidly heated to a predetermined temperature (preferably a temperature substantially equal to the molten material) immediately before injecting the molten material, It is preferable in terms of product quality to cool rapidly after completion of injection. In order to solve such problems, a spiral induction heating coil is inserted between the movable mold plate and the fixed mold plate before injection molding, and the induction heating coil is positioned near the surface of the cavity. After preheating the cavity by applying a voltage to this induction heating coil, the induction heating coil is moved away from the mold and clamped for injection molding, or an electric heater is embedded around the cavity and injected. Various methods have been proposed, such as a method in which an electric current is passed through the electric heater at the time of molding to heat and the current is stopped after injection molding is completed.
[0004]
However, in the former method, even if the mold is heated by induction heating, the temperature of the mold decreases until the injection molding is started. Therefore, the mold can be maintained at the predetermined temperature during the injection molding. Have difficulty. Further, in the latter method, it takes time until the mold is heated after an electric current is passed through the electric heater, and the cycle time becomes longer, and temperature unevenness occurs depending on each part of the mold. Therefore, even these conventional methods cannot sufficiently satisfy the requirement of rapidly heating and rapidly cooling the mold to obtain a high-quality thin product.
On the other hand, hot runner injection molding is a metal material having a high melting point of about 400 ° C. to about 700 ° C. and high thermal conductivity, such as magnesium (melting point: about 650 ° C.), aluminum (660 ° C.), zinc (same as above). Even at about 420 ° C., it can be applied theoretically.
[0005]
However,(1)The temperature difference between the molten material and the mold (usually around 200 ° C)If bigThe molten material injected into the cavity is rapidly deprived of heat and solidifies. For this reason, the molten material does not reach every corner of the cavity, and casting defects tend to occur.
(2)Since the timing at which the molten material solidifies in each part in the cavity is different, residual stress is likely to occur inside the product, and warpage defects are likely to occur.
(3)The induction heating coil is formed by winding a conductor around the manifold. However, since the portion where the coil body can be formed is limited, the temperature of the molten material in the manifold is uneven, and the molten material injected into the cavity This will affect the cooling rate of each part of the lens and cause warpage defects.
[0006]
These issuesMainly related to product qualityEspecially when the molten material is metal.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems, so that rapid heating and rapid cooling of the cavity can be performed.CastingSo that stable factors can be obtained by reducing the factors causing defects such as defects and warpage as much as possible.MadeProviding molds that enable injection molding using hot runner injection molding machinesThatObjective.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is directed to a movable mold plate and a fixed mold plate, a cavity formed between the movable mold plate and the fixed mold plate, and a molten material. In a mold of a hot runner type injection molding machine comprising a manifold formed with a runner that performs and a nozzle that injects the molten material supplied via the manifold into the cavity, the movable mold plate has a movable side A fixed side core is attached to the fixed mold plate, and the cavity is formed at a boundary surface between the movable side core and the fixed side core, and the movable side core has an open end. A first holding body that holds a first conductor, a plurality of the first conductors, and that forms a first conductor row with the plurality of first conductors, and is held by the first holding body The first conductors are directly A conduction preventing means for preventing contact is provided, and the fixed core has a second conductor having an open end and a plurality of the second conductors to form a second conductor row, A second holding body detachably attached to the first holding body, and a conduction preventing means for preventing the second conductors held by the second holding body from directly contacting each other, Contact portions are formed at both ends of the first conductor, and contact portions that connect one contact portion and the other contact portion of the adjacent first conductor to both ends of the second conductor. The contact portion of the first conductor and the contact portion of the second conductor are in contact with each other when the mold is clamped, and the cavity is formed by the first conductor and the second conductor. Is formed so as to form a coil body. The molten material described above may be a resin or a metal.
According to this configuration, the movable mold plate side conductor and the fixed mold plate side conductor form a coil body by bringing the contact portions into contact with each other. By clamping the fixed side mold plate and the movable side mold plate, the contact portions of both conductors come into contact with each other to form a coil body around the cavity. This makes it possible to increase the temperature of the cavity during injection molding by induction heating, thereby reducing the temperature difference between the mold and the molten material, and preventing casting defects and warpage due to rapid cooling of the material being injected. Can do. In addition, this configuration enables rapid heating of the mold before injection and rapid cooling of the mold immediately after injection, and a high-quality thin product can be obtained.
[0012]
In the split coil described above, an end portion of a lead wire that connects the coil body and a voltage supply source that applies a voltage to the coil body is connected to the first conductor and the second holding body or the second holding body. It is good to sandwich between the conductor and the first holding body.
If it does in this way, the lead wire currently pinched | interposed between it only by isolate | separating a 1st holding body and a 2nd holding body can also be easily removed from the division | segmentation coil for induction heating.
The invention according to claim 7 is a movable side mold plate in which a cavity having a predetermined shape is formed, a manifold in which a runner through which the molten material flows is formed, and the molten material supplied through the manifold. In a mold of a hot runner type injection molding machine comprising a fixed mold plate having a nozzle for injection into a cavity, a plurality of conductors are held around the cavity of the movable mold plate, and each of the conductors is held. Correspondingly, a plurality of conductors are held on the fixed mold plate, contact portions are formed at the end portions of the respective conductors, and the conductors of the movable mold plate and the conductors of the fixed mold plate are clamped. May be connected at the contact portion, and a coil body may be formed around the cavity.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view of an induction heating split coil according to an embodiment of the present invention, FIG. 2 is a sectional view of the induction heating split coil of FIG. 1 in the XX direction, and FIG. 3 is a second view of a second holding body. It is a top view explaining arrangement | positioning of the conductor of this.
The induction heating split coil 1 (hereinafter referred to as split coil 1) includes a first holding body 2 formed with a manifold insertion portion 2c through which a manifold 45 having a substantially square cross section is inserted, and the first holding body 2. A plurality of (in this embodiment, five) first conductors 4 arranged at equal intervals along the axial direction (the direction perpendicular to the paper surface in FIG. 1)₁~ 4_FiveA second holding body 7 detachably attached to one side of the first holding body 2 (right side in FIG. 1), and a first conductor 4₁~ 4_FiveThe second conductor 6 disposed on the second holding body 7 at the same interval as₁~ 6_FiveAnd is roughly composed of
[0016]
The first holding body 2 is configured by arranging a pair of blocks 2a and 2b formed of a material having excellent non-conductivity and heat resistance, such as aluminum nitride and ceramic, on both sides of the manifold insertion portion 2c. . The blocks 2a and 2b are attached to the fixed mold plate 46 by bolts 3, respectively. On the side walls facing the blocks 2a and 2b, a conductor holding portion 5 is formed so as to project at a position where it does not interfere with the manifold 45.
The conductor holding portion 5 includes a first conductor 4₁~ 4_FiveA plurality of (in this embodiment, five) holes 5a through which can be inserted are formed in parallel at equal intervals from one side to the other side. Further, the first conductor 4 is provided on one side surface of the blocks 2a and 2b to which the second holding body 7 is attached.₁~ 4_FiveA plurality of grooves 2d for holding the end portions of the two are engraved in parallel. The groove 2d is a first conductor 4 fitted in the groove 2d.₁~ 4_FiveOf the first conductor 4 so that the end of the first protrusion slightly protrudes from one side surface of the first holding body 2.₁~ 4_FiveIt is formed slightly shallower than the wall thickness. First conductor 4 slightly protruding from one side surface of first holding body 2₁~ 4_FivePart of the second conductor 6 when the second holding body 7 is attached to the first holding body 2.₁~ 6_FiveContact portions 4a and 4b are formed in contact with each other.
[0017]
First conductor 4₁~ 4_FiveIs formed of a metal material such as iron, copper, or silver having excellent conductivity and at least a melting point higher than the heating temperature of the induction heating split coil. Also, the first conductor 4₁~ 4_FiveThe contact portions 4a and 4b are the second conductor 6₁~ 6_FiveIt is formed with a certain thickness or width so as to have a certain degree of elasticity so as to be pressed by the action of a spring.
Such a first conductor 4₁~ 4_FiveIs formed in a U-shaped cross-section with both ends open so as to surround the outer peripheral surface of the manifold 45. First conductor 4₁~ 4_FiveIs inserted through the hole 5a of the conductor holding portion 5 and bent at a right angle on one side of each of the blocks 2a and 2b, and is fitted into the groove 2d. In this embodiment, the hole 5a and the groove 2d are formed by the first conductor 4₁~ 4_FiveA conduction preventing means for preventing mutual contact is configured. First conductor 4₁~ 4_FiveBoth ends of the slab are pressed by a non-conductive presser plate 11 fixed to one side surface of each block 2a, 2b by a bolt 3. By the above procedure, the first conductor 4₁~ 4_FiveIs fixed to the first holding body 2 to form a first conductor row 4.
[0018]
The second holding body 7 is formed of a material excellent in non-conductivity, heat resistance, and heat insulation, such as aluminum nitride or ceramic, and is attached to the back plate 48 by bolts 8. Manifold 45, first holding body 2 and first conductor 4₁~ 4_FiveA convex portion 9 is formed at a midpoint portion on the other side of the second holding body 7 that does not interfere with the second holding body 7. Further, on the other side of the second holding body 7, there is a second conductor 6.₁~ 6_FiveA plurality of grooves 9 a that are fitted and held are formed through the protrusions 9. The groove 9a is formed by the first conductor 4₁~ 4_FiveAre formed in parallel with the same interval. In addition, the groove 9a takes into consideration the connection with the lead wire 12 for applying a voltage to the split coil 1, and the second conductor 6₁~ 6_FiveIt is desirable to form one more than the number (that is, six in this embodiment).
Second conductor 6₁~ 6_FiveIs inserted into the groove 9a through the convex portion 9, and both ends thereof are folded up to the notches 10 on both sides of the second holding body 7, whereby the second conductor 6₁~ 6_FiveAre held by the second holding body 7 to form the second conductor row 6. In this embodiment, the groove 9a is formed by the second conductor 6₁~ 6_FiveA conduction preventing means for preventing contact between each other is configured.
[0019]
Second conductor 6₁~ 6_FiveIs formed of a metal material such as iron, copper, or silver having excellent conductivity and at least a melting point higher than the heating temperature by the induction heating split coil. Second conductor 6₁~ 6_FiveEach of the adjacent first conductors (4₁And 4₂, 4₂And 4_Three, 4_ThreeAnd 4_Four, 4_FourAnd 4_Five) Between the first conductor (eg 4₁) And a first conductor (for example, 4) adjacent to the contact portion 4a.₂) Is connected to the other contact portion 4b. In this embodiment, the second conductor 6 facing the first holding body 2 is used.₁~ 6_FiveThe surface of the first conductor 4₁~ 4_FiveIt is a contact part which contacts the contact parts 4a and 4b. When the second holding body 7 is attached to the first holding body 2, the first conductor row 4 and the second conductor row 6 form a coil body around the manifold 45.
The first conductor 4 of the first conductor row 4₁~ 4_FiveAnd the second conductor 6 of the second conductor row 6₁~ 6_FiveAre easily and accurately combined, it is preferable that the back plate 48 is always accurately positioned with respect to the fixed-side mold plate 46. Therefore, in this embodiment, a plurality of pins (not shown) are erected at predetermined positions on the back plate 48, and pin holes (not shown) into which the pins are inserted are provided in the fixed-side mold plate 46. ing. Of course, as long as the back plate 48 can always be accurately positioned with respect to the fixed side mold plate 46, the positioning means is not limited to the pin and the pin hole, but may be other means such as a key and a key groove. Good.
[0020]
A lead wire 12 for connecting a voltage supply source (not shown) and the coil body is connected to the second conductor 6.₁, 6_FiveIt is good also as what is connected to welding by the 2nd conductor 6₁, 6_FiveMay be formed at the end of the lead wire 12 as it is. In this embodiment, as illustrated, the end of the lead wire 12 is connected to the first conductor 4.₁, 4_FiveAnd the second holding body 7 or the second conductor 6₁, 6_FiveAnd the first holding body 2.
The split coil 1 configured as described above can be arranged as shown in FIG. 4, for example. In this arrangement example, one split coil 1 is arranged at the end of the manifold 45 and two between the sprue 45 b and the nozzle 20.
Next, the operation of the divided coil 1 having the above configuration will be described.
When a predetermined voltage is applied to the split coil 1 via the lead wires 12, 12, a current flows through the coil body constituted by the first conductor row 4 and the second conductor row 6 to inductively heat the manifold 4. . Therefore, the material in the runner 45a of the manifold 45 is heated or kept at a predetermined temperature.
[0021]
When the back plate 48 is removed from the fixed mold plate 46 in order to replace the manifold 45 or the like, the second holding body 7 attached to the back plate 48 is separated from the first holding body 2, and the split coil 1 has 2 Divided into two. Since the manifold 45 is separate from the second holding body 7 and the second conductor row 6, the second holding body 7 and the second conductor row 6 are removed from the back plate 48 and the lead wires 12 are connected. The manifold 45 can be removed from the back plate 48 without interruption.
As in this embodiment, the end portion of the lead wire 12 is connected to the first conductor 4.₁, 4_FiveAnd the second holding body 7 or the second conductor 6₁, 6_FiveAnd the first holding body 2, the lead wire 12 is detached from the split coil 1 simply by separating the first holding body 2 and the second holding body 7. The holding body 2 and the second holding body 7 can be detached from the fixed-side mold plate 46 or the back plate 48 more easily.
[0022]
A new manifold 45 is attached to the back plate 48, and this back plate 48 is attached to the fixed-side mold plate 46. As described above, since the back plate 48 is positioned and attached to the fixed mold plate 46 by the positioning means described above, the second holding body 7 can always be accurately attached to the first holding body 2. . Also, the first conductor 4₁~ 4_FiveHas a certain degree of elasticity, so that the contact portions 4a and 4b are actuated by a spring to act as the second conductor 6.₁~ 6_FiveTo form a reliable contact state. Thereby, a coil body is formed by the first conductor row 4 and the second conductor row 6.
Next, another embodiment of the present invention will be described with reference to FIG.
This embodiment is different from the previous embodiment in that a coil body is provided around the manifold 45 in a double manner. That is, the first holding body 22 holds the inner first conductor row 23 and the outer first conductor row 24, and the second holding body 27 holds the first-stage second conductor row 26 and A second conductor row 28 in the second stage is held. The inner first conductor row 23 and the first-stage second conductor row 26 form an inner coil body, and the outer first conductor row 24 and the second-stage second conductor row 28 Forms the outer coil body.
[0023]
Specifically, the first holding body 22 attached to the fixed-side mold plate 46 by the bolt 20 has a plurality of holes 25 on the opposing wall surfaces of the blocks 22a and 22b constituting the first holding body 22. , 30 are formed in steps. First conductor 24₁~ 24_FiveAre inserted into the holes 30 to form the outer first conductor row 24. Inner first conductor 23₁~ 23_FourAre inserted into the holes 25 to form an inner first conductor row 23. In this embodiment, the holes 25 and 30 are formed on each conductor 23.₁~ 23_Four, 24₁~ 24_FiveIt is the conduction | electrical_connection prevention means which prevents conduction | electrical_connection of. Both conductors 23₁~ 23_Four, 24₁~ 24_FiveThe both ends of each of the two are bent to the inside of the manifold insertion portion 22a and the outside of the first holding body 22 to form contact portions 23a, 23b, 24a, 24b, and thereby both conductors 23₁~ 23_Four, 24₁~ 24_FiveIs fixed to the first holding body 22.
[0024]
The second holding body 27 holds the second conductor rows 26 and 28 so that the holding portions 29 and 29a do not contact each other. In this embodiment, the above-described holding portions 29 and 29a constitute a conduction preventing means. The second conductor rows 26 and 28 are provided in two stages so as to be in contact with the first conductor rows 23 and 24. Second conductor 28 constituting second-stage second conductor row 28₁~ 28_FiveAre the second conductors 26 constituting the second conductor row 26 in the first stage.₁~ 26_FourLonger than each other, and both ends of the second conductor 26 of the first stage.₁~ 26_FourOverhangs on both sides.
With the above configuration, when the second holding body 27 is attached to the first holding body 22, the outer first conductor row 24 and the second-stage second conductor row 28 form a coil body, and the inner side The first conductor row 23 and the first-stage second conductor row 26 form a coil body.
[0025]
In this way, it is possible to form two coil bodies on the pair of coil body holders 22 and 27. It is good also as what connects a lead wire (not shown) separately to two coil bodies, and applies a predetermined voltage to each, and connects two coil bodies to an outer coil body. (Or from the outer coil body to the inner coil body) a current may flow.
Also in this embodiment, the end portion of the lead wire 12 is connected to the first conductor 23.₁~ 23_FourAnd 24₁~ 24_Five(In the case of a double-winding integrated coil, the first conductor 23₁~ 23_FourOr 24₁~ 24_FiveAny one of these) and the second holding body 27 or the second conductor 26.₁~ 26_FourAnd 28₁~ 28_Five(In the case of a double-winding integrated coil, the second conductor 26₁~ 26_FourOr 28₁~ 28_Five1) and the first holding body 22, the lead wire 12 is detached from the split coil 1 simply by separating the first holding body 22 and the second holding body 27. Therefore, the first holding body 22 and the second holding body 27 can be detached from the fixed-side mold plate 46 or the back plate 48 more easily.
[0026]
Next, still another embodiment of the present invention will be described with reference to FIG.
In FIG. 6, the same members and the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, the first conductor 4 is divided so that the divided coil 1 can be divided into more parts.₁~ 4_FiveIs divided at the center along the axial direction of the conductor row 4 (direction orthogonal to the paper surface), and the conductor (reference numeral D4) on the lower side of the drawing.₁~ 4_FiveAnd the upper conductor (symbol U4)₁~ 4_FiveIt is divided into First conductor 4₁~ 4_FiveIs divided into conductors D4.₁~ 4_Five, U4₁~ 4_FiveAre bent to form contact portions 4c and 4d. Accordingly, the first conductor row 4 can be divided into two parts by removing the blocks 2a and 2b from the fixed mold plate 46, respectively. In addition, the 2nd holding body 7 and the 2nd conductor row | line | column 6 can also be divided into two by the same means, and the split coil 1 which can be divided into 3 or 4 can be obtained very easily.
[0027]
By using the multi-division divided coil for induction heating as in this embodiment, the induction heating coil can be easily provided at a predetermined portion of the heated member that has been difficult to provide up to now. . FIG. 7 is a sectional view of a mold of a hot runner type injection molding machine in which the divided coil of this embodiment is provided between the manifold 45 and the nozzle 42, and FIG. 8 is a view taken in the YY direction of FIG. As shown in the figure, the first holding body 4 and the first conductor 4 of the split coil 1.₁~ 4_FiveThe induction heating coil 1 can be easily provided between the manifold 45 and the base portion 42a of the nozzle 42, which has been difficult to provide conventionally. That is, the divided first conductor D4 is formed on the base portion 42a.₁~ 4_Five, U4₁~ 4_FiveAccordingly, a plurality of through holes 43 are formed, and the first conductor D4 divided into the through holes 43 from both sides of the base portion 42a is formed.₁~ 4_FiveAnd U4₁~ 4_FiveAnd the contact portions 4 c and 4 d are brought into contact with each other at the center inside the through hole 43.
[0028]
When the manifold 45 is removed, it is only necessary to remove the back plate 48 from the fixed mold plate 46 as described above, and when the nozzle 42 is further removed, the bolts 3 and 3 are loosened to block the blocks 2a and 2b. May be removed from the stationary mold plate 46.
Next, an embodiment in which the induction heating split coil is applied around the cavity 49a will be described with reference to FIG.
The cavity 49 a is formed in a core 50 made of a metal such as iron attached to the movable mold plate 49. A first holding body 32 made of a dielectric material such as ceramic is provided around the core 50. A plurality of grooves 32 a are formed in parallel on the outer peripheral surface of the first holding body 32, and the first conductor 34 is formed in the grooves 32 a.₁~ 34_FiveIs inserted. Each groove 32a has a first conductor 34.₁~ 34_FiveAppropriate conduction preventing means is provided so that each does not come into contact with the movable mold plate 48. Each first conductor 34₁~ 34_FiveAs shown in the drawing, both ends of the first and second ends are bent along the end surface of the first holding body 32 to form a contact portion 34a. First conductor 34₁~ 34_FiveIs fixed to the first holding body 32 by this bending. Thus, the plurality of first conductors 34₁~ 34_FiveThus, the first conductor row 34 is formed.
[0029]
The tip of the nozzle 42 is supported by a core 51 made of a metal such as iron attached to the fixed mold plate 46. A second holding body 37 made of a dielectric material such as ceramic is provided around the core 51. Also in the second holding body 37, a plurality of grooves 37 a are formed in parallel like the first holding body 32, and the second conductor 36 is formed in the groove 37 a.₁~ 36_FiveIs inserted. Also for each groove 37a, the second conductor 36 is provided.₁~ 36_FiveAppropriate conduction preventing means is provided so that each does not come into contact with the fixed mold plate 46. Second conductor 36₁~ 36_FiveAnd the first conductor 34₁~ 34_FiveIs the same as in the above-described embodiment. Each second conductor 36₁~ 36_FiveAs shown in the drawing, both ends of the first and second members are bent along the end surface of the second holding body 37 to form a contact portion 36a. Second conductor 36₁~ 36_FiveIs fixed to the second holding body 37 by this bending. In this way, the plurality of second conductors 36₁~ 36_FiveFrom this, a second conductor row 36 is formed.
[0030]
The split coil 1 configured as described above is provided on both sides of the nozzles 42 of the cores 50 and 51 so as to surround the cavity 49a. Each of the conductor rows 34 and 36 is brought into contact with the contact portions 34a and 36a during mold clamping to form a coil body. When a voltage is applied to the coil body via a lead wire (not shown), the cores 50 and 51 are heated to a predetermined temperature by induction heating. In this case, it is preferable that the on / off of the voltage applied to the split coil 1 and the heating temperature can be controlled by a known means such as a heating control device. If the temperature of the cavity 49a is maintained at a temperature substantially equal to that of the molten material at the time of injection of the molten material and the application voltage is set to be turned off at the same time as the injection is completed, the cavity 49a can be heated and cooled quickly. And a high-quality thin product can be obtained.
[0031]
Although preferred embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments.
For example, in the above description, the first conductor 4₁~ 4_FiveBetween the second conductor 6₁~ 6_FiveIs diagonally crossed, but the opposite, that is, the second conductor 6₁~ 6_FiveBetween the first conductor 4₁~ 4_FiveMay be configured to cross diagonally.
The first conductor row 4₁~ 4_FiveHas been described as being U-shaped in accordance with the cross-sectional shape of the manifold 45, but the first conductor 4₁~ 4_FiveAnd the second conductor 6₁~ 6_FiveThe shape can be formed in any shape such as a circle, an ellipse, a polygon, and an indeterminate shape in accordance with the cross-sectional shape of the member to be heated.
Furthermore, although it has been described that the conduction preventing means is the hole 5a or the like, a non-conductive member may be wound around each conductor.
[0032]
Further, in the hot runner mold of the present invention using the split coil for induction heating, the first holding body is attached to the fixed side mold plate 46, the second holding body is attached to the back plate 48, and the back plate 48 is attached. Although it has been described that the divided coil is divided by one operation of detaching, the first holding body and the second holding body may be directly attached to the manifold 45 or the like.
Furthermore, in the above embodiment, the induction heating split coil of the present invention has been described as being provided around the manifold 45 and the cavity 49a. However, if the induction heating split coil of the present invention has the same action, Other induction heating split coils may be used.
Further, the induction heating split coil of the present invention of the present invention can be widely applied not only to hot runner type injection molding machines but also to other fields where induction heating is required.
[0033]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects.
According to the present invention, a coil body is formed around a cavity during injection molding, and the cavity can be rapidly heated to a predetermined temperature, and the cavity can be rapidly cooled after completion of injection. A thin product with high quality can be obtained. In addition, according to the present invention, it is possible to obtain a split coil for induction heating that is less likely to fail even when mold clamping and mold opening are repeated, and that has high reliability.
Further, the induction heating split coil according to the present invention is arranged in the coil body because the coil body is held by the coil body holder separate from the member to be heated and can be divided into two or more. Heated members such as manifolds can be easily removed. In addition, it is possible to provide a coil body at a desired part of the member to be heated, for example, a part where it is difficult to provide an induction heating coil conventionally, such as a joint between a manifold and a nozzle. Therefore, an induction heating coil body excellent in workability and productivity can be obtained.
[0034]
According to the mold of the hot runner type injection molding machine of the present invention, a split coil for induction heating is provided around the cavity, and the temperature of the mold at the time of injection is increased to a predetermined temperature by induction heating. Can be spread to every corner of the cavity, and casting defects can be prevented. Moreover, the difference in the cooling rate of the molten material in each part in the cavity can be alleviated to prevent warping.
In addition, by providing an induction dividing coil at the joint between the manifold and the nozzle, the temperature variation of the molten material flowing through the runner can be reduced, and the temperature unevenness of the molten material injected into the cavity can be reduced. Generation of warpage can be prevented.
[Brief description of the drawings]
FIG. 1 is a front view of an induction heating split coil according to an embodiment of the present invention.
2 is a cross-sectional view of the induction heating divided coil of FIG.
FIG. 3 is a plan view for explaining the arrangement of second conductors in a second holding body.
FIG. 4 is a sectional view of a mold of a hot runner type injection molding machine in which divided coils are arranged around a manifold.
FIG. 5 is another embodiment of the split coil for induction heating according to the present invention.
FIG. 6 is still another embodiment of the split coil for induction heating according to the present invention.
7 is a cross-sectional view of a mold in which the split coil of FIG. 5 is provided between a manifold and a nozzle of a hot runner type injection molding machine.
8 is a cross-sectional view in the YY direction of FIG.
FIG. 9 is a partial cross-sectional view of a mold of a hot runner type injection molding machine showing an arrangement example in which divided coils are arranged around a cavity.
FIG. 10 is a cross-sectional view illustrating a general configuration of a mold of a hot runner type injection molding machine.
[Explanation of symbols]
1 Split coil
2,22 first holding body
2a, 2b block
2c Manifold insertion part
2d groove
4 First conductor row
4₁~ 4_Five        First conductor
4a, 4b contact part
4c, 4d contact area
6,27 Second conductor row
6₁~ 6_Five        Second conductor
7 Second holder
12 Lead wire
23 First conductor row (inside)
23a, 23b contact part
24 First conductor row (outside)
24a, 24b contact part
26 Second conductor row (inside)
28 Second conductor row (outside)
32 First holding body
34 First conductor row
36 Second conductor row
37 Second holder
42 nozzles
45 Manifold
46 Fixed mold plate
47 Space
48 Back plate
49 Movable mold plate
49a cavity
50, 51 cores

Claims (2)

A movable mold plate and a fixed mold plate, a cavity formed between the movable side mold plate and the fixed mold plate, a manifold formed with a runner through which a molten material flows, and the manifold In a mold of a hot runner type injection molding machine comprising a nozzle for injecting the supplied molten material into the cavity,
A movable core is attached to the movable mold plate and a fixed core is attached to the fixed mold plate.
The cavity is formed at a boundary surface between the movable core and the fixed core,
The movable core includes a first conductor having an open end, a first holding body that holds the plurality of first conductors, and forms a first conductor row with the plurality of first conductors. And a conduction preventing means for preventing the first conductors held by the first holding body from directly contacting each other,
The fixed core has a second conductor having an open end and a plurality of the second conductors to form a second conductor row, and is detachably attached to the first holding body. A second holding body and conduction preventing means for preventing the second conductors held by the second holding body from directly contacting each other;
Contact portions are formed at both ends of the first conductor, and contacts that connect one contact portion and the other contact portion of the adjacent first conductor to both ends of the second conductor. A contact portion of the first conductor and the contact portion of the second conductor are in contact with each other at the time of clamping, and the first conductor and the second conductor Forming a coil body surrounding the cavity;
Hot runner type injection molding machine mold characterized by. The mold of the hot runner type injection molding machine according to claim 1, wherein the molten material is a molten metal.

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