JP3142778U - Nozzle heater - Google Patents

Abstract

Provided is a nozzle heater that enables high-precision heating without increasing costs and that facilitates attachment to and removal from an injection nozzle.
A heater member in which a sheath heater wire formed by encapsulating a heating wire together with an insulator inside a metal tube is wound into a coil to form a cylindrical body, and a power supply connected to both ends of the heating wire. Wiring 30 and a heater cover 4 which is a fixing means for fastening the heater member 2A from the outside and fixing it to the injection nozzle 11 of the injection molding machine. The heater member 2A is provided on the outer peripheral surface of the injection nozzle 11. The nozzle heater 1A is mounted in a state of covering a predetermined range, and after the injection nozzle 11 is inserted, the heater member 2A is elastically deformed in the diameter-reducing direction by tightening the heater cover 4, whereby the inner peripheral surface is injected. The nozzle 11 was attached in close contact with the outer peripheral surface.
[Selection] Figure 1

Description

  The present invention relates to a nozzle heater, and more particularly to a nozzle heater that is attached to an injection nozzle of an injection molding machine and heats the injection nozzle by energizing an internal heating wire.

  In general, a nozzle heater is attached to an injection nozzle of an injection molding machine in order to heat the molten material inside the nozzle to ensure an appropriate temperature and to fill the mold with high accuracy. As such a nozzle heater, for example, a cylindrical nozzle heater 1B described in JP-A-8-281753 and mounted on the outer peripheral side of the injection nozzle 11 as shown in FIG. 4 is known.

  The nozzle heater 1B is provided with a heater member 3 for heating the nozzle by bringing the inner peripheral surface into close contact with the outer peripheral surface of the injection nozzle 11 as shown in FIG. 5 which is a sectional view taken along the line XX of FIG. ing. The heater member 3 is formed by forming a heating plate on a metal plate into a cylindrical shape and connecting wirings 32 for supplying power to both ends of the heating wire, and is generally called a mica system. It is.

  Further, in order to mount the heater member 3 in a state in which the inner peripheral surface is in close contact with the outer peripheral surface of the injection nozzle 11, a slit portion 34 having a predetermined width is provided along the cylindrical length direction, and the heater member 3 has a C-shaped cross section. Has been. The slit portion 34 reduces the diameter of the heater member 3 by tightly fixing the fixing screw 55 provided in the slit portion 54 of the cylindrical heater cover 5 that covers the outer peripheral surface of the heater member 3, so that the heater member 3 is in close contact with the outer peripheral surface of the nozzle 11. It is provided for.

  However, such a mica-type heater member 3 has a disadvantage that it has a press molding process in its production, is likely to be costly, and is not sufficiently high in thermal efficiency, and is likely to cause temperature unevenness. Yes. The injection nozzle 11 is frequently attached and detached by changing the filling material. However, since the fixing screw 55 is used as the fastening means of the heater cover 5, the work takes time and effort. It was.

Furthermore, although the heater member 3 is provided with a slit portion 34 as an adjustment allowance for tightly contacting the outer peripheral surface of the nozzle 11, it is made of a hard material as a whole and has poor deformability. There is also a drawback that it is likely to cause partial unevenness of heating.
JP-A-8-281753

  The present invention is intended to solve the above-described problems. A nozzle heater attached to an injection nozzle of an injection molding machine can be heated with high accuracy without increasing the cost, and the injection nozzle. It is an object of the present invention to facilitate the attaching / detaching operation to / from.

  In view of this, the present invention provides a heater member formed by winding a sheath heater wire in which a heating wire is enclosed with an insulator inside a metal tube into a coil shape, and power connected to both ends of the heating wire. Supply wiring and predetermined fixing means for tightening the heater member from the outside and fixing it to the injection nozzle of the injection molding machine, with the heater member covering a predetermined range of the outer peripheral surface of the injection nozzle A nozzle heater to be mounted, wherein the heater member is mounted in close contact with the outer peripheral surface of the injection nozzle in a state in which the heater member is elastically deformed in the direction of diameter reduction by tightening the fixing means. It was.

  In this way, by winding the sheath heater wire in a coil shape to form a cylindrical body, the heater member can be elastically deformed in the radial direction of the cylinder, so that the nozzle has a larger inner diameter than the nozzle heater outer diameter. The heater member is manufactured by press molding since the inner peripheral surface is fixed in close contact with the outer peripheral surface of the nozzle by tightening with a fixing means after being inserted and then elastically deformed in the reduced diameter direction. Such a process can be performed relatively easily without the need for such a process and can be easily attached and detached.

  In this case, the fixing means is a heater cover formed by bending a metal plate into a substantially cylindrical shape, and is a slit in which a slit whose interval changes like a taper is formed over the length direction of the cylinder. A folded portion is formed that is folded outward at a predetermined width on both side edges that constitute the slit portion, and both side edges that constitute the long side of the strip-shaped metal plate are inward at a predetermined width. A fixed plate having a folded portion that is folded and formed in a substantially similar shape that is narrower than the slit portion, and in a state where the injection nozzle is inserted through the nozzle heater, the fixed plate is widened. By inserting in the length direction of the slit portion parallel to the outer peripheral surface of the injection nozzle so that the short side is directed toward the narrow side of the slit portion of the heater cover, the two folded portions and the folded portion of the slit portion are engaged with each other while the slit portion is engaged. If the heater cover is deformed and the heater cover is deformed and the heater member is reduced in diameter to be in close contact with the injection nozzle, the coiled heater member can be reduced in diameter uniformly to ensure uniform adhesion. Compared with the case of a heater cover provided with a fixing screw, the labor at the time of attachment / detachment is greatly reduced.

  Furthermore, in the nozzle heater described above, the heater member is a coil spring that is elastically compressible and deformable in the length direction of the cylinder while the adjacent portions are spaced apart from each other by continuous winding of the sheath heater wire. In the normal state, the inner diameter is smaller than the outer diameter of the injection nozzle to be installed. By compressing and deforming it, the inner diameter becomes larger than the outer diameter of the injection nozzle. By inserting the injection nozzle and releasing the compression after releasing the compression, the diameter is reduced while the length is expanded by the elastic restoring force, and the inner peripheral surface is brought into close contact with the outer peripheral surface of the injection nozzle. If it features, even if it is a simple structure, while being excellent in the adhesiveness with respect to an injection nozzle, attachment and detachment work will become very easy.

  According to the present invention provided with a heater member formed in a cylindrical body by winding a sheath heater wire in a coil shape, it is possible to perform heating with high accuracy without increasing the cost and to be easily attached to and detached from the injection nozzle. It can be made.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a state in which a heater member 2A is fastened and fixed to an injection nozzle 11 by a heater cover 4 as a fixing means for a nozzle heater 1A according to a first embodiment of the present invention. 2 shows a state of the heater member 2A before the heater cover 4 is mounted. The heater member 2A provided in the nozzle heater 1A is characterized in that it is a micro type using a sheath heater wire in contrast to the mica type (heater member 3) in the conventional nozzle heater 1B. .

  The heater member 2A is a one-terminal type sheath heater in which a metal thin tube made of stainless steel or the like is filled with an insulator such as MgO, and a heating wire such as a built-in nichrome wire (NiCr wire) is folded at the tip side. The wire is wound into a coil shape and formed into a cylindrical shape, and power supply wirings 30 are connected to both ends of the heating wire.

  Further, the nozzle heater 1A includes a heater cover 4 formed as a substantially cylindrical body by bending a metal plate such as a stainless steel plate as a fixing means to the injection nozzle 11, and the heater member 2A is provided with the injection nozzle 11. The heater cover 4 is disposed so as to cover a predetermined range of the outer peripheral surface, and when the heater cover 4 is reduced in diameter, the coiled heater member 2A is elastically deformed in the reduced diameter direction tightened from the outside, and the inner peripheral surface is the outer periphery of the injection nozzle 11 It is characterized by being in close contact with the surface and firmly fixed and mounted.

  As shown in FIG. 1, the heater cover 4 is formed with slit portions 42 whose width changes in a taper shape along the length direction of the cylinder, and both end edges constituting the slit portion 42 have a predetermined width. Folded portions 42a and 42b are formed by folding outward. Then, the injection nozzle 11 is inserted inside the heater member 2A, and the outer periphery of the heater member 2A is covered with the heater cover 4 so that the long side of the strip-shaped metal plate is folded inward with a predetermined width, A fixed plate 43 having a width 43b having a narrower width than that of the slit portion 42 is inserted into the narrow side of the slit portion 42 in the direction of the arrow, whereby both folded portions 43a thereof are inserted. 43b and the folded-back portions 42a, 42b of the slit portion 42 are engaged, the heater cover 4 is deformed in the diameter reducing direction, and the heater member 2A is elastically reduced in diameter by the tightening, so that the injection nozzle 11 side It is designed to be fixed and attached.

  In the heater nozzle 1A of the present embodiment, since the heater member 2A is formed in a coil shape by winding the sheath heater wire, it is relatively easy and low-cost without requiring a large-scale apparatus and process such as press molding. It can be produced. Further, since the heater member 2A is formed in a coil shape, the heater member 2A can be fixed to the injection nozzle 11 without providing a slit as in a conventional mica heater.

  Since the fixing means is the heater cover 4 as described above, the attaching / detaching operation of the nozzle heater 1A to / from the injection nozzle 11 itself can be performed by an extremely simple procedure of sliding the fixing plate 43. In other words, the heater member 2A formed by forming the sheath heater wire in a coil shape is an injection nozzle because of its elastic deformability even if the fixing means is a slide diameter heater cover 4 in which the fastening force in the diameter reduction direction is not so strong. 11 can be firmly fixed, and a uniform contact state can be easily secured.

  FIG. 3 shows a heater member 2B used in the nozzle heater according to the second embodiment of the present invention. As shown in FIG. 3A, in the present embodiment, the heater member 2B has a cylindrical shape in which adjacent portions formed by continuously winding the sheath heater wire have a predetermined distance from each other. The feature is that it is like a coil spring as a whole.

  That is, the heater member 2B is elastically compressible in the length direction of the cylinder in the same manner as the coil spring, and in the normal state of FIG. The inner diameter of the injection nozzle 12 is smaller than the diameter and is locked by the locking tool 70 or the like in a state where the length is reduced by compressing from both ends as shown in FIG. It becomes the state which can be inserted through the injection nozzle 12 in a state where the diameter is expanded to the same diameter or more.

  Then, as shown in FIG. 3C, the heater member 2B recovers its length by the elastic restoring force by removing the locking tool 70 in the state where the injection nozzle 12 is inserted and releasing the compressed state. However, the diameter is reduced, and the inner peripheral surface thereof is brought into close contact with the outer peripheral surface of the injection nozzle 12 and fixed. Therefore, this embodiment can be manufactured at a low cost similarly to the nozzle heater 1A of the first embodiment, and the heater member 2B itself can also serve as a part or all of the fixing means.

  Further, since the heater member 2B is reduced in diameter by itself, a more reliable and non-uniform contact state is ensured, so that uneven heating with respect to the injection nozzle 12 is further less likely to occur. It goes without saying that the heater cover 4 of FIG. 1 and the heater cover 5 of FIG. 4 can also be used in the present embodiment, thereby ensuring a more secure fixing state and preventing the heater member 2B from being damaged from the outside. It will be less susceptible to interference.

  As described above, with the present invention, the nozzle heater attached to the injection nozzle of the injection molding machine can be heated with high accuracy without increasing the cost and can be easily attached to and detached from the injection nozzle. It became a thing.

The side view which shows 1st Embodiment in this invention. The side view which shows the state before heater cover mounting | wearing of the nozzle heater of FIG. (A) is a side view showing the heater member of the second embodiment of the present invention, (B) is a side view showing a state where the injection nozzle is inserted in a state where the heater member of (A) is compressed, (C). (B) The side view which shows the state which removed the locking tool of (B) and extended the heater member. The side view which shows a prior art example. Sectional drawing which follows the XX line of the nozzle heater of FIG.

Explanation of symbols

  1A Nozzle heater, 2A, 2B Heater member, 4 Heater cover, 11, 12 Injection nozzle, 30 Wiring, 42 Slit part, 42a, 42b, 43a, 3b Folded part, 43 Fixed plate

Claims (3)

A heater member in which a sheath heater wire formed by encapsulating a heating wire together with an insulator inside a metal tube is wound in a coil shape, and a power supply wiring connected to both ends of the heating wire; And a predetermined fixing means for tightening the heater member from the outside and fixing the heater member to the injection nozzle of the injection molding machine, and the heater member is mounted in a state of covering a predetermined range of the outer peripheral surface of the injection nozzle. A nozzle heater,
A nozzle heater, wherein the heater member is mounted in close contact with the outer peripheral surface of the injection nozzle in a state where the heater member is elastically deformed in the diameter reducing direction by tightening the fixing means.   The fixing means is a heater cover formed by bending a metal plate into a substantially cylindrical shape, and is provided with a slit portion in which a slit that changes in a taper shape is formed over the length direction of the cylinder. A folded portion that is folded outward with a predetermined width is formed on both side edges constituting the slit, and both side edges that constitute the long side of the strip-shaped metal plate are folded inward with a predetermined width. A fixing plate having a folded portion and having a substantially similar shape narrower than the slit portion is provided, and the fixing plate is widened in a state where the injection nozzle is inserted through the heater member. By inserting in the length direction of the slit portion in parallel with the outer peripheral surface of the injection nozzle so that the short side is directed to the narrow side of the slit portion of the heater cover, the both folded portions and the folded portion of the slit portion are engaged. Together Nozzle heater according to claim 1, the reluctant slit width to shrink is in close contact with the injection nozzle reduced in diameter the heater member together with deforming the heater cover, characterized in that.   The heater member is a coil spring that is adjacent to each other by a predetermined winding of the sheath heater wire and is elastically compressible and deformable in the length direction of the cylinder. A state in which the inner diameter is smaller than the outer diameter of the injection nozzle to be mounted and is compressed and deformed and shortened in the length direction of the cylinder so that the inner diameter is larger than the outer diameter of the injection nozzle and can be inserted. Then, after releasing the compression after inserting the injection nozzle, the diameter is reduced while expanding the length by an elastic restoring force, and the inner peripheral surface is brought into close contact with the outer peripheral surface of the injection nozzle. A nozzle heater according to claim 1 or 2.

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