JP5774569B2 - Hot runner nozzle assembly structure and injection molding machine - Google Patents

Description

  The present invention relates to an assembly structure of a hot runner nozzle and an injection molding machine, and in particular, a structure for advantageously assembling a hot runner nozzle to a mold, a hot runner nozzle, and a hot runner nozzle are advantageously assembled. The present invention relates to an injection molding machine having a mold.

  As is well known, injection molding is roughly classified into a molding method that employs a hot runner system and a molding method that employs a cold runner system. Among them, the injection molding method that employs a hot runner system can realize runner-less operation, thereby providing a great merit that leads to cost reduction such as reduction of molding material and shortening of the molding cycle.

  Therefore, in recent years, the development of an injection apparatus, a hot runner type, or a hot runner nozzle to be assembled to the hot runner type, which is used when implementing an injection molding method employing such a hot runner system, has been variously proposed. It is coming. For example, Japanese Patent Laying-Open No. 2012-20472 (Patent Document 1) discloses a structure for advantageously assembling a hot runner nozzle to a mold.

  A hot runner nozzle that is assembled to a mold by the assembly structure disclosed in this publication has a nozzle body and a nozzle tip. The nozzle body has a resin flow path through which molten resin injected from an injection device of an injection molding machine is provided, and is provided with heating means for heating the molten resin in the resin flow path. ing. The nozzle tip is made of a material having higher thermal conductivity than the nozzle body, and is configured such that a nozzle hole for discharging molten resin flowing in the resin flow path of the nozzle body is provided at the tip portion. Then, the base end portion of the nozzle tip opposite to the tip portion where the nozzle hole is formed is screwed into the screw hole provided in the tip surface of the nozzle body, so that the nozzle tip can The tip having the tip is protruded from the tip of the nozzle body and is fixed to the nozzle body. On the other hand, the mold is provided with an insertion hole into which a hot runner nozzle can be inserted. In addition, one opening of the insertion hole has a smaller diameter than the other opening, and the small-diameter opening serves as a gate port communicating with a molding cavity formed in the molding die. Then, the hot runner nozzle is inserted into such an insertion hole from the opening opposite to the gate port, so that the nozzle hole provided at the tip of the nozzle tip is positioned corresponding to the gate port. In this state, the hot runner nozzle 40 is assembled to the mold.

  An insertion amount regulating means for regulating the amount of insertion of the hot runner nozzle into the insertion hole is provided between the hot runner nozzle inserted into the insertion hole and the mold. That is, a stepped surface on the outer peripheral surface of the base end side portion of the hot runner nozzle opposite to the tip end to which the nozzle tip is fixed is larger in diameter than the tip end portion of the nozzle body. Is provided. In addition, a spacer ring is inserted on the tip side of the stepped surface of the nozzle body. And the end surface located in the base end side of the nozzle main body in this spacer ring engages with the stepped surface of the nozzle main body, and the movement to the base end side of a nozzle main body is prevented. Furthermore, an annular outer flange portion is integrally formed at the proximal end of the nozzle body in the spacer ring, and this outer flange portion engages with the opening peripheral edge of the recess in the mold. ing. Thereby, the insertion amount regulating means is configured by the outer flange portion and the opening peripheral edge portion of the recess of the mold, and the insertion amount into the recess of the hot runner nozzle is regulated. is there.

  According to such a structure for assembling the hot runner nozzle to the mold, the insertion amount of the hot runner nozzle into the insertion hole is restricted, so that the outer peripheral surface of the tip portion of the nozzle tip and the gate port of the insertion hole The heat insulation space which makes them non-contact is reliably provided between the inner peripheral surfaces on the side. For this reason, although the nozzle tip is made of a material having high thermal conductivity, the heat conduction from the tip of the nozzle tip to the mold is suppressed by the presence of the heat insulating space. As a result, due to the temperature drop of the nozzle tip due to heat conduction from the tip of the nozzle tip to the mold, the molten resin is solidified in the fine nozzle holes provided at the tip of the nozzle tip, and smooth. It is prevented as much as possible that the situation where the injection molding is hindered. In this way, high cycle molding is realized.

  However, when the present inventor has made various studies on the conventional assembly structure of the hot runner nozzle as described above, it has been found that the following problems are inherent therein.

  That is, in general, both the nozzle body and the nozzle tip constituting the hot runner nozzle have a certain dimensional tolerance in the axial length. For this reason, when adopting the conventional assembly structure of the hot runner nozzle as described above, the heat insulation space becomes a nozzle by engaging the base end of the nozzle body with the opening peripheral edge of the insertion hole of the mold. From the place formed between the tip of the nozzle tip protruding from the tip of the main body and the inner peripheral surface of the insertion hole, the width of such heat insulation space (the inner peripheral surface of the insertion hole and the tip of the nozzle tip The distance between the two is greater than the predesigned size by adding the dimensional tolerance of the axial length of the nozzle body and the dimensional tolerance of the axial length of the nozzle tip, or There was a possibility of getting smaller. If the width of the heat insulation space becomes smaller than the predesigned size, the amount of heat conduction from the tip of the nozzle tip to the mold inevitably increases, and resin clogging in the nozzle hole is likely to occur. As a result, it has been found that there is a risk that it may be difficult to stably perform a smooth injection molding and further a repeated operation of injection molding. In addition, it has also been found that the possibility of such a problem is remarkably increased when injection molding is performed using a resin material having a very high melting point such as a super engineering plastic.

JP 2012-20472 A

  Here, the present invention has been made against the background described above, and the problem to be solved is the tip of the nozzle tip of the hot runner nozzle and the insertion hole into which the hot runner nozzle is inserted. The hot runner nozzle can be assembled to the mold so that the width of the heat insulating space formed between the inner peripheral surface and the inner peripheral surface of the hot runner nozzle is as large as possible. It is an object of the present invention to provide a hot runner nozzle assembly structure which is improved so that injection molding using a molding die assembled with can be repeatedly performed smoothly and at high cycles regardless of the type of resin material. Further, according to the present invention, the width of the heat insulating space formed between the tip portion of the nozzle tip of the hot runner nozzle and the inner peripheral surface of the insertion hole into which the hot runner nozzle is inserted is as much as possible from the design value. The mold has a structure in which a hot runner nozzle is assembled so as to match the size, and the injection molding is improved so that it can be repeatedly performed smoothly and at high cycles regardless of the type of resin material. Another problem to be solved is to provide an injection molding machine.

Then, in the present invention, in order to solve the above problems, a resin flow path of the molten resin injected from the injection device flows together with provided inside, to heat the molten resin of the resin flow path a nozzle body provided with a heating means, a nozzle hole for ejecting molten resin you flowing resin passage of the nozzle body and a nozzle tip disposed at the distal end, the distal end portion of the nozzle tip A hot runner nozzle, in which the nozzle tip is fixed to the nozzle body, is fixed to the tip of the heating cylinder of the injection device so that the nozzle protrudes from the tip of the nozzle body, thereby forming a desired injection molded product. a structure for allowing abutment against the mold is, the gate port communicating with the molding cavity provided in forming die as one opening, into the insertion hole formed in the forming die, the other From the opening of the By inserting a runner nozzle and restricting the insertion amount of the hot runner nozzle into the insertion hole by an insertion amount regulating means provided between the hot runner nozzle and the mold, the gate port The nozzle hole of the nozzle tip is positioned correspondingly, and a heat insulating space is formed between the tip portion of the nozzle tip and the inner peripheral surface of the insertion hole, so that the hot runner nozzle is formed in the mold. in those in so that to contact, extrapolated to the nozzle tip, covering the proximal portion except for the tip of the nozzle tip, tip cover made material having lower thermal conductivity than the nozzle tip Is attached and fixed to the nozzle body so that it protrudes from the tip of the nozzle body and the tip of the nozzle tip protrudes from the tip of the tip cover. While the annular shoulder surface of the stationary extending around the tip of the tip cover, you formed in the outer flange portion provided on the projecting portion from the nozzle body tip of the tip cover, the insertion of the mold An annular stepped surface is provided on the inner peripheral surface of the hole to narrow the gate port side portion of the insertion hole than the opening side portion opposite to the gate port, and the shoulder surface and the stepped surface are provided. The insertion amount regulating means, and the insertion of the hot runner nozzle by bringing the shoulder surface into contact with the stepped surface under the insertion state of the hot runner nozzle into the insertion hole. The gist of the contact structure of the hot runner nozzle is characterized in that the amount of insertion into the hole is regulated.

  According to one advantageous aspect of the present invention, based on the pressing force exerted from the injection device to the hot runner nozzle or based on the fastening force for fastening the hot runner nozzle to the mold, The shoulder surface is configured to be sealed between the shoulder surface and the stepped surface by being brought into contact with the shoulder surface while being pressed against the stepped surface over the entire circumference.

  Furthermore, according to one of the preferred embodiments of the present invention, an annular protrusion is integrally formed on at least one of the shoulder surface and the stepped surface.

Then, in the present invention, (a) an injection device, (b) together with the resin flow path injection-molten resin injected from the device flows is provided inside, molten resin of the resin flow path has a nozzle body heating means is provided for heating, nozzle holes for ejecting molten resin you flowing resin passage of the nozzle body and a nozzle tip provided at a distal end portion, said nozzle tip A hot runner nozzle in which the nozzle tip is fixed to the nozzle body so that the tip of the nozzle body protrudes from the tip of the nozzle body, and (c) one opening is a gate port communicating with the molding cavity. The hot runner nozzle has an insertion hole into which the hot runner nozzle can be inserted, and an insertion amount restricting means for restricting the insertion amount of the hot runner nozzle into the insertion hole, and the hot runner nozzle is inserted into the insertion hole. The insertion amount restriction hand By restricting the amount of insertion of the hot runner nozzle into the insertion hole, the nozzle hole of the nozzle tip is positioned corresponding to the gate port, and the tip of the nozzle tip and An injection molding machine configured to include a molding die in which a heat insulating space is formed between the inner peripheral surface of the insertion hole, and is inserted into the nozzle tip to remove a tip portion of the nozzle tip A tip cover made of a material having a lower thermal conductivity than the nozzle tip, covering the proximal end portion, protrudes from the tip of the nozzle body, and the tip of the nozzle tip is the tip. so as to protrude from the tip of the cover, attached, along with being fixed, the shoulder surface of the stationary ring extending around the tip of the tip cover, or the nozzle body tip of the tip cover Inner peripheral surface, an opposite opening side portion of the said gate opening side portion of the insertion hole the gate port of the projecting one that will be formed in the outer flange portion provided so as to be positioned in part, the insertion hole of An annular stepped surface that is narrower than that is provided, the shoulder surface and the stepped surface constitute the insertion amount restricting means, and the hot runner nozzle is inserted into the insertion hole, An injection molding machine characterized in that the amount of insertion of the hot runner nozzle into the insertion hole is regulated by bringing the shoulder surface into contact with the stepped surface. This is the gist.

  In such an injection molding machine, the hot runner nozzle is advantageously fixed to the tip of the heating cylinder of the injection device.

  That is, in the assembly structure of the hot runner nozzle according to the present invention, a shoulder surface provided to be positioned at the tip of the nozzle body, and a stepped surface provided on the inner peripheral surface of the insertion hole of the mold The amount of insertion of the hot runner nozzle into the insertion hole is regulated by this contact. Therefore, the width of the heat insulation space formed between the tip of the nozzle tip and the inner peripheral surface of the insertion hole is smaller than the dimension designed in advance, and the dimensional tolerance of the axial length of the tip of the nozzle tip is smaller. The amount of increase / decrease is advantageously smaller than the sum of the dimensional tolerance of the axial length of the nozzle body and the dimensional tolerance of the axial length of the tip of the nozzle tip. Can be done. Moreover, since the axial length of the tip of the nozzle tip is sufficiently smaller than the axial length of the nozzle body, the dimensional tolerance of the axial length of the tip of the nozzle tip is extremely small. Value.

  Therefore, according to the assembly structure of the hot runner nozzle according to the present invention, the heat insulating space formed between the tip of the nozzle tip of the hot runner nozzle and the inner peripheral surface of the insertion hole into which the hot runner nozzle is inserted. The hot runner nozzle can be assembled to the mold so that the width is as large as possible with the design value. As a result, the injection molding using the molding die with the hot runner nozzle assembled can be smoothly and repeatedly performed regardless of the type of the resin material.

  In the injection molding machine according to the present invention, since the hot runner nozzle is assembled to the molding die by the above-described assembly structure, the hot runner nozzle according to the present invention is exhibited in the assembly structure. The actions and effects substantially the same as the actions and effects can be enjoyed effectively.

It is a fragmentary sectional view showing one embodiment of an injection molding machine which has a structure according to the present invention. It is the II section expansion explanatory drawing of FIG. It is a figure corresponding to FIG. 1 which shows another embodiment of the injection molding machine which has a structure according to this invention. It is a figure corresponding to FIG. 1 which shows another embodiment of the injection molding machine which has a structure according to this invention. It is a figure corresponding to FIG. 1 which shows other embodiment of the injection molding machine which has a structure according to this invention. It is a figure corresponding to FIG. 2 which shows other embodiment of the injection molding machine which has a structure according to this invention.

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

  First, in FIG. 1, a part of an embodiment of an injection molding machine having a structure according to the present invention is shown in its cross-sectional form. As apparent from FIG. 1, the injection molding machine 10 of this embodiment has an injection device 12 and a molding die 14. Both the injection device 12 and the mold 14 have the same basic structure as the conventional one.

  That is, the injection device 12 has a heating cylinder 16 having an inline screw type structure and having a screw (not shown) inserted therein. Although not shown, a band heater is attached to the outer peripheral surface of the heating cylinder 16. As in the prior art, the resin material put into the heating cylinder 16 through a hopper (not shown) is plasticized and melted by the shearing action by the heating by the band heater and the rotation of the screw, and by the advance operation of the screw. From the injection hole 18 at the front end of the heating cylinder 16, it is injected in a molten state.

  On the other hand, the mold 14 has a fixed mold 20 and a movable mold 22. Although not clearly shown in FIG. 1, in this mold 14, the movable mold 22 is moved close to or away from the fixed mold 20 by a mold opening / closing device having the same structure as the conventional one. As a result, the movable mold 22 and the fixed mold 20 are closed or opened.

  In addition, the movable mold 22 is provided with a cavity forming recess 26 that opens in the mold mating surface 28 with the fixed mold 20. When the movable mold 22 and the fixed mold 20 are closed, the opening of the cavity forming recess 26 is closed by the mold-matching surface 24 of the fixed mold 20 to correspond to the target injection-molded product. A molding cavity 30 having the above-described shape is formed between the fixed mold 20 and the movable mold 22.

  On the other hand, the fixed mold 20 is formed with an insertion hole 32 extending through the fixed mold 20 in a direction facing the movable mold 22 (vertical direction in FIG. 1). The insertion hole 32 has an opening on the surface opposite to the mold mating surface 24 of the fixed mold 20, a first opening 33 as the other opening, and an opening on the mold mating surface 24. The second opening 34 is provided. The insertion hole 32 communicates with the outside through the first opening 33, while the second opening is formed in the molding cavity 30 formed in the molding die 14 by closing the fixed die 20 and the movable die 22. It communicates through part 34. Thus, the second opening 34 is a gate port 35.

  Further, a portion of the inner peripheral surface of the insertion hole 32 that is proximal to the gate port 35 (second opening 34) has a portion on the gate port 35 side of the insertion hole 32, and the other portion (of the insertion hole 32. A stepped surface 36 having a smaller diameter than a portion located in the middle of the extending direction and a portion located on the first opening 33 side opposite to the gate port 35 of the insertion hole 32 is formed. The stepped surface 36 is configured by a flat annular surface that extends in a direction perpendicular to the extending direction of the insertion hole 32.

  In the insertion hole 32, a portion closer to the first opening 33 than the stepped surface 36 is a first insertion portion 37, while a portion closer to the gate port 35 than the stepped surface 36 is the first insertion portion 37. Two insertion portions 38 are provided. The first insertion portion 37 has a cylindrical shape whose inner peripheral surface extends with a constant inner diameter. In addition, the second insertion portion 38 has an inner peripheral surface portion on the stepped surface 36 side having a cylindrical surface shape with a smaller diameter than the inner peripheral surface of the first insertion portion 37, while the inner peripheral surface on the gate port 35 side. The surface portion has a tapered surface shape that gradually decreases in diameter toward the gate port 35. Thereby, the diameter of the gate opening 35 is made sufficiently smaller than the diameter of the first opening 33.

  As shown in FIG. 1, in the injection molding machine 10 of the present embodiment, the hot runner nozzle 40 is fixed to the tip of the heating cylinder 16 of the injection device 12, and the hot runner nozzle 40 is The mold 14 is assembled in a special structure not seen in the past.

  More specifically, the hot runner nozzle 40 includes a nozzle main body 42 and a nozzle tip 44 fixed to the tip of the nozzle main body 42 (the lower end in FIG. 1). The nozzle body 42 is made of, for example, a substantially thick cylindrical body 46 formed using a metal material such as iron or an iron alloy, and a metal such as iron or iron alloy that covers the entire outer peripheral surface of the cylindrical portion 46. The main body cover 48 is further provided.

  In the nozzle main body 42, the inner peripheral surface portion on the distal end side of the inner peripheral surface of the inner hole 50 is shifted to the inner peripheral surface portion that is deviated by a predetermined dimension from the axial center of the cylindrical body 46. Is formed with a stepped surface 51 made of a flat annular surface extending in a direction perpendicular to the axis and having a larger diameter than the inner peripheral surface portion on the base end side (upper end side in FIG. 1). As a result, the inner hole 50 portion located on the proximal end side of the nozzle main body 42 with respect to the stepped surface 51 serves as a main body side resin flow path 52 extending with substantially the same diameter as the injection hole 18. Further, the inner hole 50 portion located on the tip end side of the nozzle main body with respect to the step surface 51 is an accommodation hole portion 54 having a larger diameter than the main body side resin flow path 52. A female screw 56 is formed on the inner peripheral surface of the accommodation hole 54 from the opening of the inner hole 50 on the tip end side of the nozzle body 42 to a predetermined depth.

  A coil heater 58 serving as a heating unit is wound around the outer circumferential surface of the cylindrical body 46 over substantially the entire length of the cylindrical body 46. The coil heater 58 is fixed to the nozzle body 42 by being sandwiched between the outer peripheral surface of the cylindrical body 46 and the inner peripheral surface of the main body cover 48 covering the cylindrical body 46. The coil heater 58 is connected to a power supply device (both not shown) via a feeder line. Thus, the entire nozzle main body 42 is heated by the heat generated by the coil heater 58 by the power supply from the power supply device, and as a result, the molten resin flowing in the main body side resin flow path 52 and the accommodation hole portion 54 as will be described later. The nozzle chip 44 accommodated therein is heated together.

  Further, in the nozzle body 42, it protrudes outward in the direction perpendicular to the axis and continuously extends in the circumferential direction at an outer peripheral surface portion that is deviated by a predetermined dimension from the center in the axial direction (length direction). An extending annular step portion 60 is provided. As a result, the base end side portion of the nozzle main body 42 with respect to the stepped portion 60 is a large diameter portion 62, while the tip end portion of the nozzle main body 42 with respect to the stepped portion 60 is a small diameter portion 64. Here, the outer diameter of the small diameter portion 64 of the nozzle main body 42 is set to be slightly smaller than the diameter of the first insertion portion 37 of the insertion hole 32 provided in the fixed mold 20.

  On the other hand, the nozzle tip 44 is formed using a metal material having higher thermal conductivity than the forming material of the cylindrical body 46 and the body cover 48 of the nozzle body 42 such as titanium alloy, tungsten, aluminum, or aluminum alloy. It consists of a cylinder. The nozzle tip 44 made of this cylindrical body has a tapered portion 66 having a tapered shape in which the tip portion located on one side in the axial direction (the lower side in FIG. 1) gradually decreases in diameter toward the tip. . Further, of the nozzle tip 44 portion excluding the tapered portion 66, one side portion in the axial direction adjacent to the tapered portion 66 is a small diameter portion 68 having the same outer diameter as the maximum diameter of the tapered portion 66, The axially intermediate portion is a medium diameter portion 70 having an outer diameter larger than that of the small diameter portion 68, and a base end side (upper side in FIG. 1) opposite to the taper portion 66 side is further than the medium diameter portion 70. Is a large-diameter portion 72 having a larger outer diameter. Here, the outer diameter of the large diameter portion 72 of the nozzle tip 44 is made smaller than the inner diameter of the accommodation hole portion 54 of the nozzle main body 42 by a predetermined dimension, and the axial length of the nozzle tip 44 is accommodated. The hole 54 is larger than the axial length by a predetermined dimension.

  As is clear from FIGS. 1 and 2, in the nozzle tip 44, the inner hole has a tip-side resin having substantially the same diameter as the body-side resin flow path 52 provided in the nozzle body 42. A flow path 76 is provided. Further, the tip-side resin flow path 76 is branched into two in the tip portion of the nozzle chip 44, and the two branch flow paths of the tip-side resin flow path 76 are tapered portions 66 of the nozzle chip 44. The two are opened to the outside through two nozzle holes 78, 78 formed respectively. As a result, as will be described later, the molten resin that has flowed into the chip side resin flow path 76 from the main body side resin flow path 52 is discharged from the chip side resin flow path 76 through the two nozzle holes 78 and 78. -ing

  Here, the tip cover 74 is extrapolated with respect to the nozzle tip 44, and most of the nozzle tip 44 excluding the tip portion of the tapered portion 66 where the two nozzle holes 78, 78 are provided is the tip cover 74. It is covered with. The tip cover 74 is formed of a cylinder formed using a material having lower thermal conductivity than the metal material forming the nozzle tip 44, for example, a metal material such as iron or an iron alloy. The cylindrical tip cover 74 has an axial length shorter by a predetermined dimension than the total axial length of the medium diameter portion 70, the small diameter portion 68 and the taper portion 66 of the nozzle tip 44. . The inner diameter of the tip cover 74 is slightly larger than the outer diameter of the middle diameter portion 70 of the nozzle tip 44 and smaller than the outer diameter of the large diameter portion 72 of the nozzle tip 44 by a predetermined dimension.

  Accordingly, the tip portion of the taper portion 66 of the nozzle tip 44 is exposed to the outside in the state where the tip cover 74 is externally attached to the nozzle tip 44, so that the two nozzle holes 78, 78 provided therein are exposed to the outside. The cover 74 is protruded from the opening on the front end side on one side in the axial direction. Further, the large-diameter portion 72 of the nozzle tip 44 protrudes to the outside through the base end side opening opposite to the tip side of the tip cover 74. Under such an arrangement, the step surface formed between the large-diameter portion 72 and the medium-diameter portion 70 of the nozzle tip 74, which is a flat annular surface extending in the direction perpendicular to the axis, is the base of the tip cover 74. It is in contact with the end face.

  Further, in the tip cover 74, the tip portion that is extrapolated to (covers the taper portion 66) the tip portion taper portion 66 of the nozzle tip 44 is the second insertion portion of the insertion hole 32 provided in the fixed mold 20. 38. A shape corresponding to the shape of the inner peripheral surface of 38, that is, a shape that has an outer peripheral surface in which the proximal end side is a cylindrical surface and the distal end side is a tapered surface and can be inserted into the second insertion portion 38. It is said that. The tip end portion of the chip cover 74 having an outer peripheral surface corresponding to the inner peripheral surface of the second insertion portion 38 has a length shorter in the axial direction than the axial length of the second insertion portion 38 by a predetermined dimension. It is said.

  Further, a male screw 80 is formed on the outer peripheral surface of the base end side portion that is externally inserted into (covers the medium diameter part 70) the nozzle chip 44. Further, the outer peripheral surface of the tip cover 74 that is extrapolated to (covers the small diameter portion 68) of the nozzle tip 44 protrudes outward in a direction perpendicular to the axis at a predetermined height, and An annular plate-like outer flange portion 82 extending continuously in the direction is integrally formed. Of the both end surfaces in the thickness direction of the outer flange portion 82, the end surface located on the tip side of the tip cover 74 extends around the tip portion of the nozzle tip 44 in the circumferential direction of the tip portion. The shoulder surface 84 is a flat annular surface extending in a perpendicular direction.

  Then, the nozzle tip 44 with such a tip cover 74 is inserted together with the tip cover 74 into the accommodation hole portion 54 of the inner hole 50 of the cylindrical body 46 in the nozzle body 42, on the tip opening side of the inner hole 50. Inserted and housed. Further, under such an accommodation state, a male screw 80 formed on the outer peripheral surface of the base end side portion of the chip cover 74 is screwed into a female screw 56 formed on the inner peripheral surface of the accommodation hole portion 54. Then, by fastening the male screw 80 to the female screw 56, the large-diameter portion 72 of the nozzle tip 44 is in a state where the tip-side resin flow passage 76 of the nozzle tip 44 communicates with the main body-side resin flow passage 52 of the nozzle main body 42. The nozzle tip 44 is sandwiched between the base end side end surface of the tip cover 74 and the step surface 51 provided at the axially intermediate portion of the inner peripheral surface of the inner hole 50 of the nozzle body 42, It is fixed to the tip.

  Thus, under the state in which the nozzle tip 44 is fixed to the tip of the nozzle body 42, the outer flange portion 82 of the tip cover 74 and the tip side portion of the outer flange portion 82 are from the inner hole 50 of the nozzle body 42. It protrudes through the tip opening. As a result, a shoulder surface 84 formed by the end surface of the outer flange portion 82 is disposed at the tip of the nozzle body 42 so as to spread around the tip of the nozzle tip 44 in the direction perpendicular to the axis. Further, two nozzle holes 78, 78 provided at the tip of the nozzle tip 44 are exposed to the outside at the tip of the nozzle body 42.

  In this embodiment, the hot runner nozzle 40 having such a structure is fixed to the tip of the heating cylinder 16 of the injection apparatus 12 as follows and assembled to the mold 14. Yes.

  That is, as shown in FIG. 1, at the tip of the heating cylinder 16 of the injection device 12, a plurality of injection hole forming blocks 86 having a low-profile columnar shape are positioned coaxially with the heating cylinder 16. It is fixed with mounting bolts 88 (only one is shown in FIG. 1). The injection hole forming block 86 is provided with a recess 90 that opens on the end surface opposite to the side fixed to the heating cylinder 16. The recess 90 has a size that can accommodate the large-diameter portion 62 of the nozzle body 42.

  A through hole 92 is formed in the center of the injection hole forming block 86 and extends in the axial direction and opens at the bottom surface of the recess 90 and the end surface on the side fixed to the heating cylinder 16. In the through hole 92, the diameter of one opening that opens on the end surface on the side fixed to the heating cylinder 16 is the same as the diameter of the inner hole of the heating cylinder 16, and the heating cylinder passes through the one opening. It communicates with 16 inner holes. Further, in the through-hole 92, an inner peripheral surface portion located in the middle in the extending direction has a tapered surface that gradually becomes smaller in diameter from the end surface on the fixing side to the heating cylinder 16 toward the bottom surface of the recess 90. Has been. As a result, the other opening that opens at the bottom surface of the recess 90 is made sufficiently smaller in diameter than the one opening that has the same diameter as the inner hole of the heating cylinder 16, and the other opening is injected. It is a hole 18. As is clear from FIG. 1, here, the diameter of the injection hole 18 is the same as the diameter of the main body side resin flow path 52 of the nozzle main body 42.

  On the other hand, a mounting plate 94 is externally attached to the small diameter portion 64 of the nozzle body 42 in the hot runner nozzle 40. The mounting plate 94 is formed of a thick annular plate, and has an insertion hole 96 through which the small diameter portion 64 is inserted at the center. The insertion hole 96 has an inner diameter that is slightly larger than the outer diameter of the small diameter portion 64 of the nozzle body 42 and smaller than the outer diameter of the large diameter portion 62 of the nozzle body 42. An engagement portion 98 is provided on the inner peripheral surface portion on the opening side that is located on the large diameter portion 62 side of the nozzle body 42 among the two openings of the insertion hole 96. The engaging portion 98 is a stepped surface extending in a direction perpendicular to the axis that steps the opening on the large-diameter portion 62 side of the nozzle body 42 so as to have a larger diameter than the opening opposite to the opening. have.

  The large-diameter portion 62 of the nozzle body 42 is accommodated in the recess 90 of the injection hole forming block 86 fixed to the tip of the heating cylinder 16 under such an extrapolation state of the mounting plate 94 to the small-diameter portion 64. In addition, the mounting plate 94 is positioned so as to cover the concave portion 90 and is overlapped with the distal end surface of the injection hole forming block 90. In such a state, the nozzle body 42 is coaxial with the injection hole forming block 86 and the heating cylinder 16, the end surface of the large diameter portion 62 is brought into contact with the bottom surface of the recess 90, and the body side resin of the nozzle body 42 is The flow path 52 is disposed in communication with the injection hole 18 of the injection hole forming block 86. Furthermore, the stepped portion 60 that steps the large-diameter portion 62 and the small-diameter portion 64 of the nozzle main body 42 is provided with respect to the engaging portion 98 provided on the inner peripheral surface of the insertion hole 96 of the mounting plate 94. Are in contact with each other in the axial direction. The mounting plate 94 is fixed to the injection hole forming block 86 with a plurality of mounting bolts 100 (only two are shown in FIG. 1).

  Thus, the large diameter portion 62 of the nozzle main body 42 is sandwiched between the engaging portion 98 of the mounting plate 94 and the bottom surface of the recess 90 of the injection hole forming block 86, and the hot runner nozzle 40 is heated by the injection device 12. It is fixed to the tip of the tube 16. As a result, the molten resin injected from the injection hole 18 of the heating cylinder 16 flows into the main body side resin flow path 52 of the nozzle main body 42 of the hot runner nozzle 40 and is heated by the coil heater 58 while being heated by the main body side resin. The fluid flows in the flow path 52 and further flows in the chip-side resin flow path 76 of the nozzle chip 44 heated by the coil heater 58 and is discharged from the two nozzle holes 78 and 78.

  In this embodiment, the hot runner nozzle 40 fixed to the tip of the heating cylinder 16 is coaxially inserted through the first opening 33 into the insertion hole 32 provided in the fixed mold 20. Specifically, the portion from the tip of the hot runner nozzle 40 to the axially intermediate portion of the small diameter portion 64 of the nozzle body 42 is slidably in contact with the inner peripheral surface of the first insertion portion 37 of the insertion hole 32 and guided. The first insertion portion 37 of the insertion hole 32 is inserted and arranged. At the same time, a small-diameter portion 68 of the nozzle tip 44 protruding from the tip of the small-diameter portion 64 of the nozzle body 42 and an outer flange portion 82 formed integrally with the tip cover 74 portion that is externally inserted into the small-diameter portion 68 are also inserted. The first insertion portion 37 of the hole 32 is inserted and arranged.

  As shown in FIG. 2, under such a state that the hot runner nozzle 40 is inserted into the insertion hole 32, the entire surface of the shoulder surface 84 of the outer flange portion 82 of the chip cover 74 is covered with the insertion hole 32. In contact with the stepped surface 36, the shoulder surface 84 is engaged with the stepped surface 36 in the axial direction of the hot runner nozzle 40 (in the insertion direction of the hot runner nozzle 40 into the insertion hole 32). . This prevents further insertion of the hot runner nozzle 40 into the insertion hole 32 and restricts the amount of insertion of the hot runner nozzle 40 into the insertion hole 32.

  Further, in such a state where the insertion of the hot runner nozzle 40 into the insertion hole 32 is restricted, the tapered portion 66 of the nozzle tip 44 and the tip cover 74 that is extrapolated to the proximal end portion of the tapered portion 66 are provided. Only the portion on the front end side of the shoulder surface 84 is inserted into the second insertion portion 38 of the insertion hole 32 and is spaced apart from the inner peripheral surface of the second insertion portion 38.

  Thus, between the outer peripheral surface of the tip end portion of the tip cover 74 and the tip end portion of the tapered portion 66 of the nozzle tip 44 protruding from the tip end portion, and the inner peripheral surface of the second insertion portion 38, the heat insulating space 102 is provided. Is formed. This prevents the nozzle tip 44 having high thermal conductivity from coming into direct contact with the fixed die 20 (molding die 14), and the tip cover 74 covering most of the nozzle tip 44 is also The fixed portion 20 is not in contact with the outer flange portion 82 except for the limited portion of the shoulder surface 84 alone. Thus, heat conduction from the nozzle tip 44 to the fixed mold 20 is prevented as much as possible.

  Further, here, the axial length (the length indicated by L in FIG. 1) of the tapered portion 66 of the nozzle tip 44 inserted into the second insertion portion 38 and the tip portion of the tip cover 74 is the second length. The tip edge of the tapered portion 66 of the nozzle tip 44 is disposed in the gate port 35 so as to have the same length as the axial length of the insertion portion 38. Thus, the two nozzle holes 78 and 78 provided at the tip of the tapered portion 66 of the nozzle tip 44 are arranged corresponding to the gate port 35 so as to communicate with the gate port 35 through the heat insulating space 102. . As is apparent from these, in the present embodiment, the shoulder amount 84 of the chip cover 74 and the stepped surface 36 of the insertion hole 32 constitute an insertion amount regulating means.

  In the injection molding machine 10 of the present embodiment, the heating cylinder 46 is fixed to the hot runner nozzle 40 from the injection device 12 with the hot runner nozzle 40 inserted into the insertion hole 32 as described above. A pressing torque is applied toward the direction approaching 20.

  Thus, the shoulder surface 84 of the outer flange portion 82 is pressed against the stepped surface 36 of the insertion hole 32 with a force corresponding to the magnitude of the pressing torque applied from the injection device 12. As a result, the hot runner nozzle 40 is fixedly assembled to the fixed mold 20 while being sandwiched between the injection device 12 and the fixed mold 20. At the same time, the gap between the shoulder surface 84 of the outer flange portion 82 and the stepped surface 36 of the insertion hole 32 is fluid-tightly sealed based on the pressing force of the shoulder surface 84 against the stepped surface 36. It has become.

  As is clear from the above description, in the injection molding machine 10 of the present embodiment, the front end side of the hot runner nozzle 40 is in contact with the shoulder surface 84 that contacts and engages the stepped surface 36 of the fixed mold 20. Only the taper portion 66 of the nozzle tip 44 and the tip end portion of the tip cover 74 are located in the position. The axial length L of the portion (tapered portion 66 of the nozzle tip 44) located on the tip side of the hot runner nozzle 40 relative to the shoulder surface 84 is sufficiently small.

  For this reason, in this embodiment, the minimum width of the heat insulating space 102 formed between the tapered portion 66 of the nozzle tip 44 or the tip of the tip cover 74 and the inner peripheral surface of the second insertion portion 37 of the insertion hole 32. (The dimension indicated by W in FIG. 2) is an axial length of the tapered portion 66 of the nozzle tip 44; an error corresponding to the dimensional tolerance of L, as compared with the previously designed size. . However, since the axial length L of the tapered portion 66 is sufficiently small, the dimensional tolerance of such a tapered portion 66 is extremely small. Therefore, the minimum width W of the heat insulating space 102 is set to a value substantially as designed.

  Therefore, in the injection molding machine 10 of the present embodiment as described above, the minimum width W of the heat insulating space 102 is narrower than the design value, so that the nozzle tip 44 having a high thermal conductivity and the molding die 14 ( It can be effectively avoided that the amount of heat conduction to the fixed mold 20) becomes larger than the designed amount. As a result, not only injection molding using a general-purpose resin, but also injection molding using a resin material having a very high melting point, such as super engineering plastic, is repeated extremely smoothly and stably. It is possible.

  In the present embodiment, the shoulder surface 84 of the outer flange portion 82 formed integrally with the chip cover 74 is pressed against the stepped surface 36 of the insertion hole 32 by the pressing torque exerted from the injection device 12. The shoulder surface 84 and the stepped surface 36 are sealed. This ensures that the molten resin leaks into the insertion hole 32 other than the heat insulating space 102 formed between the tapered portion 66 of the nozzle tip 44 and the inner peripheral surface of the second insertion portion 37 of the insertion hole 32. Can be prevented.

  Furthermore, in this embodiment, the shoulder surface 84 that contacts the stepped surface 36 is not provided in the nozzle tip 44, and has a lower thermal conductivity than the nozzle tip 44 that is extrapolated to the nozzle tip 44. A chip cover 74 made of a material is integrally formed. As a result, the amount of heat conduction from the shoulder surface 84 to the stepped surface 36 is effectively reduced, and as a result, smooth injection molding can be realized more advantageously.

  In the present embodiment, the hot runner nozzle 40 is fixed to the tip of the heating cylinder 16 of the injection device 12. Therefore, it is not necessary to attach the hot runner nozzle 40 to the mold 14, and the structure of the mold 14 can be simplified accordingly.

  The specific configuration of the present invention has been described in detail above. However, this is merely an example, and the present invention is not limited by the above description.

  For example, in the above embodiment, the hot runner nozzle 40 is fixed to the tip of the heating cylinder 16, but the hot runner nozzle 40 may be configured as a member independent of the heating cylinder 16. In that case, for example, the hot runner nozzle 40 is fixedly assembled to the mold 14 as follows.

  That is, as shown in FIG. 3, the hot runner nozzle 40 in which the spherical touch surface 104 is provided on the end surface on the base end side of the nozzle body 42, that is, on the end surface opposite to the fixed side of the nozzle tip 44, is provided. And inserted into the insertion hole 32. In addition, the shoulder surface 84 of the outer flange portion 82 provided at the tip end portion of the tip cover 74 protruding from the tip end of the nozzle body 42 in the inserted state is a stepped surface provided on the inner peripheral surface of the insertion hole 32. 36. The heating cylinder 16 is pressed against the nozzle body 42 in a state where the spherical tip surface provided in the injection hole forming block 86 fixed to the tip of the heating cylinder 16 is in contact with the touch surface 104 of the nozzle body 42. As a result, the hot runner nozzle 40 is sandwiched between the heating cylinder 16 and the fixed mold 20 and is fixedly assembled to the mold 14.

  When the hot runner nozzle 40 is not fixed to the heating cylinder 16, for example, as shown in FIG. 4, a plurality of hot runner nozzles 40 (only two are shown in FIG. 4). The bracket 106 can be fixed to the forming die 14 (here, the fixed die 20).

  That is, as shown in FIG. 4, the bracket 106 is made of a substantially L-shaped thick plate material formed using a metal material such as iron. The L-shaped leg portion is bolted to the surface of the fixed die 20 opposite to the die-matching surface 24 so as to be positioned around the insertion hole 32. In addition, a plate-like protrusion 108 is integrally projected from the upper end portion of the bracket 106 toward the central axis side of the insertion hole 32. On the other hand, the hot runner nozzle 40 is integrally formed with the large-diameter portion 64 of the nozzle body 42 with an outer flange portion 110 protruding at a predetermined height in the direction perpendicular to the axis and continuously extending in the circumferential direction.

  Here, the hot runner nozzle 40 has an outer flange portion 110 provided in the large-diameter portion 64 of the nozzle body 42 with respect to the plate-like protrusion 108 of each bracket 106 fixed around the insertion hole 32. The insertion hole 32 is inserted in a state of being opposed to the lower side. In addition, between the outer flange portion 110 of the hot runner nozzle 40 and the plate-like protrusions 108 of the brackets 106 that are opposed to each other, an elastic member or a biasing member such as a compression coil spring 112 is a predetermined amount. It is inserted in a compressed state.

  Thus, in the injection molding machine 10 of the present embodiment, the hot runner nozzle 40 is moved by the biasing force of each compression coil spring 112 interposed between the hot runner nozzle 40 inserted into the insertion hole 32 and each bracket 106. In addition, it is assembled to the fixed mold 20 while being sandwiched between the fixed mold 20 and each bracket 106.

  In the present embodiment, the tip surface of the injection hole forming block 86 of the heating cylinder 16 is pressed and brought into contact with the touch surface 104 of the large diameter portion 62 of the nozzle main body 42 in the hot runner nozzle 40, so that such heating is performed. Based on the pressing force exerted from the cylinder 16 and the urging force of each compression coil spring 112, the shoulder surface 84 of the outer flange portion 82 provided at the tip end portion of the tip cover 74 in the hot runner nozzle 40 is inserted into the insertion hole 32. The amount of insertion of the hot runner nozzle 40 into the insertion hole 32 is regulated by being pressed against a stepped surface 36 provided on the inner peripheral surface of the nozzle. Therefore, in this embodiment as well, the same actions and effects as those in the first embodiment can be enjoyed effectively.

  Further, as shown in FIG. 5, the hot runner nozzle 40 may be bolted to the fixed mold 20 with the mounting bolts 114 in a state where the hot runner nozzle 40 is inserted into the insertion hole 32.

  In this case, as shown in FIG. 5, the outer flange portion 110 is formed integrally with the large-diameter portion 62 of the nozzle body 42 of the hot runner nozzle 40 that protrudes to the outside through the first opening 33 of the insertion hole 32. The outer flange portion 110 is fixed to the fixed mold 20 with the mounting bolts 114. In addition, an elastic member or a biasing member such as the compression coil spring 112 is interposed between the outer flange portion 110 and the mating surface 24 of the fixed die 20. Accordingly, when the mounting bolt 114 is fastened to the fixed mold 20, the non-contact between the outer flange portion 110 and the die mating surface 24 of the fixed mold 20 is maintained, while the outer portion provided at the tip portion of the chip cover 74. The shoulder surface 84 of the flange portion 82 is pressed against the stepped surface 36 provided on the inner peripheral surface of the insertion hole 32 based on the fastening force (tightening force) of the mounting bolt 114. Thus, the insertion amount of the hot runner nozzle 40 in the insertion hole 32 is restricted, and the shoulder surface 84 and the stepped surface 36 are sealed based on the fastening force of the mounting bolt 114, and the hot runner nozzle 40 is hot. The runner nozzle 40 is fixed to the fixed mold 20. Therefore, in this embodiment as well, the same actions and effects as those in the first embodiment can be enjoyed effectively.

  Further, as shown in FIG. 6, an annular protrusion 116 having a tip surface having a smaller area than the shoulder surface 84 is formed integrally with the shoulder surface 84 of the outer flange portion 82 provided at the tip portion of the chip cover 74. Then, the tip end surface of the annular protrusion 116 may be pressed against the stepped surface 36. Thereby, the contact area of the shoulder surface 84 with respect to the stepped surface 36 can be sufficiently reduced, and the amount of heat conduction from the shoulder surface 84 to the stepped surface 36 can be advantageously reduced.

  In addition, as long as such an annular protrusion 116 has a protrusion shape extending continuously in the circumferential direction of the nozzle tip 44, the overall shape and cross-sectional shape thereof are not limited at all. Further, instead of the shoulder surface 84 or in addition to the shoulder surface 84, it is possible to form the stepped surface 36. In the case where the shoulder surface 84 and the stepped surface 36 are formed, the shoulder surface 84 and the stepped surface 36 are respectively formed on the shoulder surface 84 and the stepped surface 36 in order to reduce the mutual contact area between the shoulder surface 84 and the stepped surface 36. It is desirable that the tip surfaces of the annular protrusions 116 and 116 come into contact with each other.

  Further, in some of the embodiments, the shoulder surface 84 is pressed against the stepped surface 36 to realize the sealing of the heat insulating space 102. However, for example, of the tip end portion of the chip cover 74 inserted into the second insert portion 38 of the insertion hole 32, the cylindrical outer peripheral surface portion is changed into the second insert portion by the thermal expansion of the tip end portion of the chip cover 74. Even if the heat insulating space 102 is sealed by bringing it into contact with the 38 cylindrical inner peripheral surface, there is no problem. That is, the shoulder surface 84 only needs to be in contact with the stepped surface 36 so that the insertion amount of the hot runner nozzle 40 in the insertion hole 32 can be regulated.

  In the above-described embodiments, the shoulder surface 84 and the stepped surface 36 are flat surfaces extending in the direction perpendicular to the axis of the hot runner nozzle 40 and the insertion hole 32. However, the shoulder surface 84 and the stepped surface 36 are stepped. The surface 36 only needs to have a shape that engages with each other in the axial direction of the hot runner nozzle 40 and the insertion hole 32. Therefore, the shoulder surface 84 and the stepped surface 36 can be formed as an inclined surface or a curved surface that extends in a direction intersecting the direction perpendicular to the axis of the hot runner nozzle 40 or the insertion hole 32.

  In addition, even when the hot runner nozzle 40 is fixed to the tip of the heating cylinder 16 or when the hot runner nozzle 40 is fixed to the mold 14, those fixing structures are the same as those described above. Of course, it is not limited to what is shown in the embodiment.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Injection molding machine 12 Injection apparatus 14 Mold 16 Heating cylinder 32 Insertion hole 33 1st opening part 34 2nd opening part 35 Gate port 36 Stepped surface 40 Hot runner nozzle 42 Nozzle main body 44 Nozzle chip 52 Main body side resin flow path 58 Coil heater 74 Chip cover 76 Chip-side resin flow path 78 Nozzle hole 82 Outer flange 84 Shoulder surface 102 Thermal insulation space 116 Annular projection

Claims (4)

Together with the resin flow path of the molten resin injected from the injection device flows is provided inside a nozzle body heating means is provided for heating the molten resin of the resin passage, resin flow path of the nozzle body nozzle holes for ejecting molten resin you circulating inside it and a nozzle tip provided at a distal end portion, such that the tip portion of the nozzle tip protrudes from the tip of the nozzle body, the nozzle tip is the the hot runner nozzle comprising fixed to the nozzle body, said fixed to the tip of the heating cylinder of the injection apparatus, a structure for allowing abutment against the mold the injection molded article is formed for the purpose, Using the gate port communicating with the molding cavity provided in the mold as one opening, the hot runner nozzle is inserted into the insertion hole formed in the mold from the other opening, and the hot run nanos By restricting the insertion amount of the hot runner nozzle into the insertion hole by an insertion amount regulating means provided between the nozzle tip and the mold, the nozzle hole of the nozzle tip is formed in the gate port. causes the corresponding positions, to form a heat-insulating space between the tip and the inner peripheral surface of the insertion hole of said nozzle tip, in that the so that to contact the hot runner nozzle into the molding mold,
A tip cover made of a material having a lower thermal conductivity than the nozzle tip, which is extrapolated to the nozzle tip and covers the base end side portion excluding the tip portion of the nozzle tip, A fixed position annular ring that is mounted and fixed so that it protrudes from the tip and the tip of the nozzle tip protrudes from the tip of the tip cover and extends around the tip of the tip cover the shoulder surface, while you formed on the outer flange portion provided on the projecting portion from the nozzle body tip of the tip cover, the inner peripheral surface of the insertion hole of the mold, the gate opening side of said insertion hole An annular stepped surface is provided that narrows the portion smaller than the opening side portion opposite to the gate opening, and the shoulder amount and the stepped surface constitute the insertion amount restricting means, and the hot run nano The amount of insertion of the hot runner nozzle into the insertion hole is regulated by bringing the shoulder surface into contact with the stepped surface in a state where the rod is inserted into the insertion hole. The hot runner nozzle contact structure. Based on the pressing force exerted on the hot runner nozzle from the injection device, or on the basis of the fastening force for fastening the hot runner nozzle to the mold, the shoulder surface is stepped over the entire circumference. The contact structure of a hot runner nozzle according to claim 1, wherein the shoulder surface and the stepped surface are sealed by being brought into contact with each other while being pressed against the surface. In at least one of said stepped surface and the shoulder surface, the annular projection is integrally formed, and the shoulder surface and the stepped with surfaces adapted to be brought into contact via the annular projection The contact structure of the hot runner nozzle according to claim 1 or 2 . (A) an injection device, and is mounted within the resin flow path of the molten resin to flow emitted from the (b) injection-device, a heating means for heating the molten resin of the resin passage is provided includes a nozzle body, a nozzle hole for ejecting molten resin you flowing resin passage of the nozzle body and a nozzle tip disposed at the distal end, the distal end portion of the nozzle tip of the nozzle body tip A hot runner nozzle in which the nozzle tip is fixed to the nozzle body so as to protrude from the nozzle body, and (c) the hot runner nozzle in which one opening portion is a gate port communicating with the molding cavity can be inserted. An insertion amount regulating means for regulating the amount of insertion of the hot runner nozzle into the insertion hole, and the hot runner nozzle is inserted into the insertion hole, The hot run nanos By restricting the amount of insertion of the nozzle tip into the insertion hole, the nozzle hole of the nozzle tip is positioned corresponding to the gate port, and the tip portion of the nozzle tip and the inner peripheral surface of the insertion hole An injection molding machine configured to include a mold in which a heat insulating space is formed between
A tip cover made of a material having a lower thermal conductivity than the nozzle tip, which is extrapolated to the nozzle tip and covers the base end side portion excluding the tip portion of the nozzle tip, A fixed position annular ring that is mounted and fixed so that it protrudes from the tip and the tip of the nozzle tip protrudes from the tip of the tip cover and extends around the tip of the tip cover shoulder surface, while that will be formed in the outer flange portion provided so as to be positioned protruding portion from the nozzle body tip of the tip cover, the inner peripheral surface of the insertion hole, said gate opening of said insertion hole An annular stepped surface that narrows the side portion than the opening side portion opposite to the gate port is provided, and the insertion amount restricting means is constituted by the shoulder surface and the stepped surface. The amount of insertion of the hot runner nozzle into the insertion hole is regulated by bringing the shoulder surface into contact with the stepped surface under the insertion state of the runner nozzle into the insertion hole. An injection molding machine.

Images