WO2003080315A1 - Nozzle for use in hot runner mold - Google Patents

Nozzle for use in hot runner mold Download PDF

Info

Publication number
WO2003080315A1
WO2003080315A1 PCT/JP2003/002309 JP0302309W WO03080315A1 WO 2003080315 A1 WO2003080315 A1 WO 2003080315A1 JP 0302309 W JP0302309 W JP 0302309W WO 03080315 A1 WO03080315 A1 WO 03080315A1
Authority
WO
WIPO (PCT)
Prior art keywords
nozzle
mold
heat
distal end
end portion
Prior art date
Application number
PCT/JP2003/002309
Other languages
French (fr)
Inventor
Hirohide Nakano
Takeshi Koyama
Kouichi Odaka
Original Assignee
Honda Giken Kogyo Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Honda Giken Kogyo Kabushiki Kaisha filed Critical Honda Giken Kogyo Kabushiki Kaisha
Priority to GB0409749A priority Critical patent/GB2397796B/en
Priority to CA002467592A priority patent/CA2467592A1/en
Priority to KR10-2004-7006741A priority patent/KR20040093661A/en
Publication of WO2003080315A1 publication Critical patent/WO2003080315A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/20—Injection nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/72—Heating or cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/2701—Details not specific to hot or cold runner channels
    • B29C2045/2724—Preventing stringing of the moulding material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C2045/2777—Means for controlling heat flow or temperature distribution in the nozzle

Definitions

  • the present invention relates generally to a hot runner mold for use in producing resin moldings and, in particular, to an injection nozzle provided in the hot runner mold.
  • BACKGROUND ART Fig.5 hereof shows a conventional hot runner mold 101 having a nozzle body 102 disposed therein.
  • the nozzle body 102 has flow passageways 104, 105 centrally positioned relative to a lateral directionthereof andformedto extendlongitudinallytherethrough. These flowpassageways 104 , 105 guidemoltenresin 103 therethrough.
  • the nozzle body 102 has a heating means 107 mounted around an outer peripheral surface 106 thereof. The heating means 107 maintains the resin 103 at a predetermined temperature andprevents the resin 103 from solidifying within the flow passageway 104.
  • a molded article 108 can cause a stringiness as will be next described in relation to Fig. 6.
  • An object of the present invention is to provide an injection nozzle forahotrunnermold.
  • Thenozzle is less costlytomanufacture, and is arranged such that the hot runner mold produces molded products without causing stringiness.
  • an injection nozzle for use in a hot runner mold having a cavity and a space formed therein, the space communicating with the cavity, saidnozzlebeingpositionedwithinthe space andhaving an outer peripheral surface having a heating means disposed thereon for heating said nozzle, characterized in that the outer peripheral surface of said nozzle has a heat transmitting ring disposed thereon for releasing heat of a distal end portion of saidnozzle to the hot runnermold, andhas a heat-insulating groove formed thereon for preventing heat generated by the heating means from being transferred to the distal end portion.
  • the heatingmeans, saidheat-insulating groove, and said heat transmitting ring are disposed in order along a direction of flow of resin within the hot runner mold.
  • the heat-insulating groove and the heat transmitting ring are provided on the outer peripheral surface of the nozzle and are disposed in order along the direction of the flow of resin.
  • the groove serves to prevent heat generated by the heating means from being transferred to the distal end portion of the nozzle while the ring serves to release heat of the distal end portion to the hot runner mold.
  • the resin lying in the distal end portion can thus be cooled with efficiency.
  • Fig.1 is a side elevation view of a hot runner mold, showing a stationary mold in cross-section, according to the present invention
  • Fig. 2 is a view showing on large scale a portion of the stationary mold encircled with an oval 2 of Fig. 1;
  • Fig. 3 is a cross-sectional view taken along line 3-3 of
  • Fig. 4 is a view showing how an injection nozzle disposed within the stationary mold is operated in accordance with the present invention
  • Fig.5 is aview showing a conventional nozzle of a hot runner mold.
  • Fig.6 is a view showing unwanted stringiness caused by the use of the nozzle of Fig. 5.
  • ahotrunnermold10 includes a stationary mold 12 and a movable mold 13 disposed to engage the stationary mold 12.
  • the mold 10 is mounted in an injection molding machine
  • the machine 14 includes a carrier 16, an injection device 17 positioned on the carrier 16, and a mold clamping mechanism
  • the mechanism 18 includes a stationary platen 21, tie bars
  • Themovable platen 23 is slidable in adirection as shown by an arrow al, to move the movable mold 13 mounted to the platen 23 to a closedposition as shownby a double-dot-and-dash line. In the closed position, the mold 13 is clamped to the stationary mold 12 with a predetermined pressure exerted thereon.
  • the movable platen 23 is also slidable in a direction as shown by an arrow a2, to move the mold 13 back to an opened position as indicated by a solid line.
  • the stationary mold 12 includes a body 24, a runner member
  • the body 24 has a runner 27 formed therein.
  • the runner 27 leads to the nozzle 26.
  • the body 24 also has a parting surface 28 to which the runner 27 leads through a gate (not shown) .
  • the parting surface 28 defines a cavity 29 in cooperation with the mold 13.
  • the nozzle 26 includes a nozzle body 31.
  • the nozzle 26 has a heating means 36 and a heat transmitting ring
  • heat releasingring (hereinafter referredto as "heat releasingring” ) 38 bothdisposed on an outer peripheral surface 35 thereof.
  • the nozzle 26 has a flange portion 32 formed at a proximal end portion 43b thereof.
  • the flange portion 32 is connected to the runner member 25.
  • the nozzle 26 has a flow passageway 33 and a runner 34 positioned centrally relative to a lateral direction thereof.
  • the passageway 33 andtherunner 34 communicatewitheachother.
  • the nozzle body 31 has the passageway 33 formed therethrough and extending longitudinally thereof.
  • the outer peripheral surface 35 has a heat-insulating groove 37 formed thereon.
  • the heating means 36, the groove 37, and the ring 38 are disposed in order alongadirectionas shownbyanarrowa3.
  • resin 51 flows in the direction of the arrow a3.
  • the flange portion 32 has a seat surface 41 held in contact with the runner member 25.
  • the nozzle 26 has a distal end portion 43a positioned opposite fromthe proximal end portion 43b.
  • the distal endportion43b has aseatsurface 42 formedthereat.
  • the stationary mold 12 has a nozzle mounting hole (space) 44 formed therein. The nozzle 26 is mounted within the hole 44.
  • the nozzle 26 is made from carbon steel such as S45C.
  • the flow passageway 33 has its diameter D.
  • the passageway 33 has a reduced portion 45 of diameter Ds formed distally thereof.
  • the diameter Ds is smaller than the diameter D.
  • the runner 34 communicateswiththeflowpassageway33throughthereducedportion 45 .
  • the runner 34 is taperedproviding an angle ⁇ between planes in which upper and lower inner surfaces of the runner 34 lie.
  • the runner 34 is continuous with the reduced portion 45. Forming the tapered runner 34 and the reduced portion 45 enables moldings to be removed from the reduced portion 45 when the hot runner mold
  • the heating means 36 is a band heater providing a power (a heat capacity) Q.
  • the heating means 36 heats a portion of the nozzle body 31 having the flow passageway 33 formed therein.
  • the heat-insulating groove 37 is formed on the outer peripheral surface 35 of the nozzle 26. More specifically, the nozzle 26 has anintermediateportion 47 providedbetweenthe distal end portion 43a and the nozzle body 31. The distal end portion 43a and the intermediate portion 47 have the runner 34 formed to extend therethrough. The intermediate portion 47 has the groove 37 formed on an outer peripheral surface 35b thereof. In other words, the groove 37 extends circumferentially of the outer peripheral surface 35b of the intermediate portion 47.
  • the distal end portion 43a, the intermediate portion 47, the nozzle body 31, and the flange portion 32 are integral with each other.
  • the distal end portion 43a has the heat releasing ring 38 mounted around an outer peripheral surface 35a thereof.
  • the ring 38 extends circumferentiallyof the outerperipheral surface 35aof the distal endportion 43a.
  • Thenozzlebody 31 has theheatingmeans 36 mounted around an outer peripheral surface 35c thereof located adjacent or in the proximity of the groove 37. That is, the heating means 36 extends circumferentially of the outer peripheral surface 35c of the nozzle body 31.
  • the groove 37 is disposed in the vicinity of the reduced portion 45.
  • the groove 37 is of depth M and width
  • the groove 37 is disposed forwardly of the heating means 36.
  • the ring 38 is disposed forwardly of the groove 37.
  • the nozzle 26 has an external thread formed throughout the length of the outer peripheral surface 35.
  • the ring 38 has an internal thread formed on an inner peripheral surface thereof.
  • the internal thread of the ring 38 is formed to threadedly engage the external thread.
  • the ring 38 has a fitting surface 46 formed on an outerperipheral surface thereof. The surface 46 is designed to tightly or intimately contact an inner peripheral surface 24a of the body 24 defining the hole 44.
  • the ring 38 is made from, for example, aluminum, aluminum alloy, copper or copper alloys.
  • the nozzle body 31 has a temperature Tn.
  • the stationary mold 12 has a temperature Tf.
  • the distal end 43a has a temperature
  • the heat releasing ring 38 has a temperature Tr.
  • a relation between the temperatures Tn, Tf, Tt, and Tr can be shown by a mathematical expression Tf ⁇ Tr ⁇ Tt ⁇ Tn.
  • the nozzle 26 is mounted within the hole 44 as follows.
  • the heating means 36 is mounted around the outer peripheral surface 35c of the nozzle body 31.
  • the ring 38 is then threaded onto the distal end portion 43a.
  • the nozzle 26 having the ring 38 mounted on the distal end portion 43a is fitted into the nozzle mounting hole 44 of the mold 12.
  • the runner member 25 is mounted within the mold 12 into tight contact with the seat surface 41. This causes the seat surface 42 to be pressed against an inner wall surface 48 of the body 24 exposed or facing to the a space defined within the hole 44.
  • the ring 38 is shown as being fitted within the hole 44.
  • the heat releasing ring 38 increases in size or produces thermal expansion to bring the surface 46 into tight contactwith the inner peripheral surface
  • the resin 51 is injected from the injection nozzle 26 into the cavity 29 (see Fig. 1). More specifically, the resin 51 flows through the flow passageway 33 and the runners 34, 27 into the cavity 29, as shown by an arrow a4, to then fill the cavity 29.
  • the resin 51 lying within the runners 34, 27 and the cavity 29 starts to solidify.
  • the heating means 36 provided around the outer peripheral surface 35c of the nozzle body 31 heats a leading end portion 31a of the nozzle body 31 located adjacent the groove 37 or in the vicinity of the reduced portion 45, as shown by arrows a5, a5, to thereby transmit heat to the resin 51.
  • the resin 51 lying within the flow passageway33 canthusbemaintainedatapredeterminedtemperature. It thus becomes possible to prevent the resin 51 from decreasing in temperature.
  • the resin 51 is no longer solidified.
  • Providing the groove 37 increases surface area of the intermediate portion 47 positioned between the heating means 36 and the distal end portion 43a. This makes it possible to prevent the heat generated by the heating means 36 from being transferred from the leading end portion 31a to the distal end portion 43a. Consequently, the distal end portion 43a does not increase in temperature.
  • the distal end portion 43a is united with the stationary mold 12 by means of the ring 38.
  • heat of the distal end portion 43a is transmitted or released to the stationary mold 12, as indicated by arrows a6, a6.
  • the temperature Tt can be made lower than the temperature Tn.
  • the resin 51 melted within the runner 34 can thus be cooledwith efficiency.
  • the resin 51 thus cooled can produce no stringiness.
  • the nozzle 26 including the heating means 36, the groove 37, and the ring 38 as shown in Fig. 4 is simple in construction. This results in reduced cost for producing the mold 10.
  • the heat releasing ring 38 is made from aluminum, aluminum alloy, copper, or copper alloy all of which provide greater thermal conductivity than material from which the nozzle 26 is made. Using such a ring 38 achieves improved thermal conduction. More specifically, the ring 38 can release or transmit heat of the distal end portion 43a to the body 24 of the stationary mold 12 with improved efficiency.
  • the hot runnermold 10 has been described as having the runner 27 leading to the nozzle 26, however, it may be altered depending upon configuration of resin moldings.
  • the mold 10 is modified to provide a gate leading directly to the nozzle 26.
  • the groove 37 may take on any configuration.
  • the ring 38 which has been described as being threaded onto the distal end portion 43a, may not be threaded as long as it is mounted around the outer peripheral surface 35a of the distal end portion 43a.
  • Coolant may be provided in the vicinity of the ring 38 so as to cool the mold 12.
  • the inventive nozzle effectively cools the resin within the distal end thereof, thereby enabling removal of the molded product from the distal end without producing stringiness. Further, the nozzle is simple in construction and this leads to reduction in the cost of manufacture of the hot runner mold. Thus, the nozzle is useful particularly in resin molding using a hot runner mold.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)

Abstract

A nozzle (26) for a hot runner mold (10) having a cavity (29) and a runner (27) formed in a body (24) thereof and communicating with the cavity. The nozzle leads to the runner and has a heating means (36), a heat-insulating groove (37), and a heat transmitting ring (38) provided on an outer peripheral surface (35) thereof. The nozzle has a f low passageway (33) formed therein. The heating means, the groove, and the ring are arranged in order along a direction of flow of resin (51) within the passageway. The groove serves to prevent heat generated by the heating means from being transferred to a distal end portion (43a) of the nozzle. The ring serves to release the heat of the distal end portion to the body. With this arrangement, the resulting molded product (11) can be removed from the mold without causing any stringiness between the runner and the distal end portion.

Description

DESCRIPTION
NOZZLE FOR USE IN HOT RUNNER MOLD
TECHNICAL FIELD
The present invention relates generally to a hot runner mold for use in producing resin moldings and, in particular, to an injection nozzle provided in the hot runner mold.
BACKGROUND ART Fig.5 hereof shows a conventional hot runner mold 101 having a nozzle body 102 disposed therein. The nozzle body 102 has flow passageways 104, 105 centrally positioned relative to a lateral directionthereof andformedto extendlongitudinallytherethrough. These flowpassageways 104 , 105 guidemoltenresin 103 therethrough. The nozzle body 102 has a heating means 107 mounted around an outer peripheral surface 106 thereof. The heating means 107 maintains the resin 103 at a predetermined temperature andprevents the resin 103 from solidifying within the flow passageway 104.
For the thus arranged runner mold 101, however, when removed from the mold 101, a molded article 108 can cause a stringiness as will be next described in relation to Fig. 6.
In Fig. 6, when removed from the mold 101 as indicated by an arrow, the article 108 produces a stringinessportion 111 leading to a runner portion 109 thereof. At the same time, the resin 103 causes a stringiness portion 113 leading to at a distal end 112 thereof. Such stringiness is developed by stretching of resin from the distal end 112 in the form of a string, which results in failed moldings .
In order to prevent production of unwanted stringiness, one may propose to precisely control temperature of the resin 103 or provide the hot runnermoldwith an additional valve for regulating orcontrollingthe flowof resin 103. iththis arrangement, however, the mold is inevitably complicated in construction. Such a complicated hot runner mold is undesirably costly to produce.
DISCLOSURE OF THE INVENTION An object of the present invention is to provide an injection nozzle forahotrunnermold. Thenozzle is less costlytomanufacture, and is arranged such that the hot runner mold produces molded products without causing stringiness.
According to an aspect of the present invention, there is provided an injection nozzle for use in a hot runner mold having a cavity and a space formed therein, the space communicating with the cavity, saidnozzlebeingpositionedwithinthe space andhaving an outer peripheral surface having a heating means disposed thereon for heating said nozzle, characterized in that the outer peripheral surface of said nozzle has a heat transmitting ring disposed thereon for releasing heat of a distal end portion of saidnozzle to the hot runnermold, andhas a heat-insulating groove formed thereon for preventing heat generated by the heating means from being transferred to the distal end portion.
Preferably, the heatingmeans, saidheat-insulating groove, and said heat transmitting ring are disposed in order along a direction of flow of resin within the hot runner mold.
The heat-insulating groove and the heat transmitting ring are provided on the outer peripheral surface of the nozzle and are disposed in order along the direction of the flow of resin.
The groove serves to prevent heat generated by the heating means from being transferred to the distal end portion of the nozzle while the ring serves to release heat of the distal end portion to the hot runner mold. The resin lying in the distal end portion can thus be cooled with efficiency. With this arrangement, there is developedno stringiness between amoldedproduct andthe distal end portion when the molded product is removed from the mold. The heating means, the groove, and the heat transmitting ring are provided in such a manner as to provide simplified construction of the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which:
Fig.1 is a side elevation view of a hot runner mold, showing a stationary mold in cross-section, according to the present invention; Fig. 2 is a view showing on large scale a portion of the stationary mold encircled with an oval 2 of Fig. 1;
Fig. 3 is a cross-sectional view taken along line 3-3 of
Fig. 2;
Fig. 4 is a view showing how an injection nozzle disposed within the stationary mold is operated in accordance with the present invention;
Fig.5 is aview showing a conventional nozzle of a hot runner mold; and
Fig.6 is a view showing unwanted stringiness caused by the use of the nozzle of Fig. 5.
BEST MODE FOR CARRYING OUT THE INVENTION ReferringtoFig.1, ahotrunnermold10 includes a stationary mold 12 and a movable mold 13 disposed to engage the stationary mold 12. The mold 10 is mounted in an injection molding machine
14 for the purpose of producing a resin molded product 18.
The machine 14 includes a carrier 16, an injection device 17 positioned on the carrier 16, and a mold clamping mechanism
18.
The mechanism 18 includes a stationary platen 21, tie bars
22 mountedto theplaten 21, and amovableplaten 23 slidablymounted to the tie bars 22. Themovable platen 23 is slidable in adirection as shown by an arrow al, to move the movable mold 13 mounted to the platen 23 to a closedposition as shownby a double-dot-and-dash line. In the closed position, the mold 13 is clamped to the stationary mold 12 with a predetermined pressure exerted thereon.
The movable platen 23 is also slidable in a direction as shown by an arrow a2, to move the mold 13 back to an opened position as indicated by a solid line.
The stationary mold 12 includes a body 24, a runner member
25 provided in the body 24 and connected to the injection device
17, and an injection nozzle 26 connected to the runner member 25. The body 24 has a runner 27 formed therein. The runner 27 leads to the nozzle 26. The body 24 also has a parting surface 28 to which the runner 27 leads through a gate (not shown) . The parting surface 28 defines a cavity 29 in cooperation with the mold 13.
Turning to Fig.2, the nozzle 26 includes a nozzle body 31.
The nozzle 26 has a heating means 36 and a heat transmitting ring
(hereinafter referredto as "heat releasingring" ) 38 bothdisposed on an outer peripheral surface 35 thereof. The nozzle 26 has a flange portion 32 formed at a proximal end portion 43b thereof.
The flange portion 32 is connected to the runner member 25. The nozzle 26 has a flow passageway 33 and a runner 34 positioned centrally relative to a lateral direction thereof. The passageway 33 andtherunner 34 communicatewitheachother. More specifically, the nozzle body 31 has the passageway 33 formed therethrough and extending longitudinally thereof. The outer peripheral surface 35 has a heat-insulating groove 37 formed thereon. The heating means 36, the groove 37, and the ring 38 are disposed in order alongadirectionas shownbyanarrowa3. As describedhereinafter, resin 51 (see Fig.4) flows in the direction of the arrow a3. The flange portion 32 has a seat surface 41 held in contact with the runner member 25. The nozzle 26 has a distal end portion 43a positioned opposite fromthe proximal end portion 43b. The distal endportion43bhas aseatsurface 42 formedthereat. The stationary mold 12 has a nozzle mounting hole (space) 44 formed therein. The nozzle 26 is mounted within the hole 44.
The nozzle 26 is made from carbon steel such as S45C. The flow passageway 33 has its diameter D. The passageway 33 has a reduced portion 45 of diameter Ds formed distally thereof. The diameter Ds is smaller than the diameter D. The runner 34 communicateswiththeflowpassageway33throughthereducedportion 45 .
The runner 34 is taperedproviding an angle θ between planes in which upper and lower inner surfaces of the runner 34 lie. The runner 34 is continuous with the reduced portion 45. Forming the tapered runner 34 and the reduced portion 45 enables moldings to be removed from the reduced portion 45 when the hot runner mold
10 is in an opened position.
The heating means 36 is a band heater providing a power (a heat capacity) Q. The heating means 36 heats a portion of the nozzle body 31 having the flow passageway 33 formed therein.
The heat-insulating groove 37 is formed on the outer peripheral surface 35 of the nozzle 26. More specifically, the nozzle 26 has anintermediateportion 47 providedbetweenthe distal end portion 43a and the nozzle body 31. The distal end portion 43a and the intermediate portion 47 have the runner 34 formed to extend therethrough. The intermediate portion 47 has the groove 37 formed on an outer peripheral surface 35b thereof. In other words, the groove 37 extends circumferentially of the outer peripheral surface 35b of the intermediate portion 47. The distal end portion 43a, the intermediate portion 47, the nozzle body 31, and the flange portion 32 are integral with each other. The distal end portion 43a has the heat releasing ring 38 mounted around an outer peripheral surface 35a thereof. Namely, the ring 38 extends circumferentiallyof the outerperipheral surface 35aof the distal endportion 43a. Thenozzlebody 31 has theheatingmeans 36 mounted around an outer peripheral surface 35c thereof located adjacent or in the proximity of the groove 37. That is, the heating means 36 extends circumferentially of the outer peripheral surface 35c of the nozzle body 31. The groove 37 is disposed in the vicinity of the reduced portion 45. The groove 37 is of depth M and width
B. The groove 37 is disposed forwardly of the heating means 36. The ring 38 is disposed forwardly of the groove 37.
The nozzle 26 has an external thread formed throughout the length of the outer peripheral surface 35. The ring 38 has an internal thread formed on an inner peripheral surface thereof.
The internal thread of the ring 38 is formed to threadedly engage the external thread. The ring 38 has a fitting surface 46 formed on an outerperipheral surface thereof. The surface 46 is designed to tightly or intimately contact an inner peripheral surface 24a of the body 24 defining the hole 44.
The ring 38 is made from, for example, aluminum, aluminum alloy, copper or copper alloys.
The nozzle body 31 has a temperature Tn. The stationary mold 12 has a temperature Tf. The distal end 43a has a temperature
Tt. The heat releasing ring 38 has a temperature Tr. A relation between the temperatures Tn, Tf, Tt, and Tr can be shown by a mathematical expression Tf < Tr < Tt < Tn.
The nozzle 26 is mounted within the hole 44 as follows.
First, the heating means 36 is mounted around the outer peripheral surface 35c of the nozzle body 31. The ring 38 is then threaded onto the distal end portion 43a. Second, the nozzle 26 having the ring 38 mounted on the distal end portion 43a is fitted into the nozzle mounting hole 44 of the mold 12. Finally, the runner member 25 is mounted within the mold 12 into tight contact with the seat surface 41. This causes the seat surface 42 to be pressed against an inner wall surface 48 of the body 24 exposed or facing to the a space defined within the hole 44.
With respect to Fig.3, the ring 38 is shown as being fitted within the hole 44. During molding operation, the heat releasing ring 38 increases in size or produces thermal expansion to bring the surface 46 into tight contactwith the inner peripheral surface
24a of the body 24. Thus , no gap can be formed between the surface
46 and the inner peripheral surface 24a of the body 24. Discussion will be made in relation to Fig.4 as to how the injection nozzle 26 disposed within the hot runner mold 10 is operated according to the present invention.
During the molding operation, the resin 51 is injected from the injection nozzle 26 into the cavity 29 (see Fig. 1). More specifically, the resin 51 flows through the flow passageway 33 and the runners 34, 27 into the cavity 29, as shown by an arrow a4, to then fill the cavity 29. The resin 51 lying within the runners 34, 27 and the cavity 29 starts to solidify. At this time, the heating means 36 provided around the outer peripheral surface 35c of the nozzle body 31 heats a leading end portion 31a of the nozzle body 31 located adjacent the groove 37 or in the vicinity of the reduced portion 45, as shown by arrows a5, a5, to thereby transmit heat to the resin 51. The resin 51 lying within the flow passageway33canthusbemaintainedatapredeterminedtemperature. It thus becomes possible to prevent the resin 51 from decreasing in temperature. The resin 51 is no longer solidified.
Providing the groove 37 increases surface area of the intermediate portion 47 positioned between the heating means 36 and the distal end portion 43a. This makes it possible to prevent the heat generated by the heating means 36 from being transferred from the leading end portion 31a to the distal end portion 43a. Consequently, the distal end portion 43a does not increase in temperature.
Because the ring 38 provided around the outer peripheral surface 35a of the distal end portion 43a is held in tight contact with the inner peripheral surface 24a of the body 24, the distal end portion 43a is united with the stationary mold 12 by means of the ring 38. With this arrangement, heat of the distal end portion 43a is transmitted or released to the stationary mold 12, as indicated by arrows a6, a6. As a result, the temperature Tt can be made lower than the temperature Tn. The resin 51 melted within the runner 34 can thus be cooledwith efficiency. The resin 51 thus cooled can produce no stringiness.
The nozzle 26 including the heating means 36, the groove 37, and the ring 38 as shown in Fig. 4 is simple in construction. This results in reduced cost for producing the mold 10. As described hereinbefore, the heat releasing ring 38 is made from aluminum, aluminum alloy, copper, or copper alloy all of which provide greater thermal conductivity than material from which the nozzle 26 is made. Using such a ring 38 achieves improved thermal conduction. More specifically, the ring 38 can release or transmit heat of the distal end portion 43a to the body 24 of the stationary mold 12 with improved efficiency.
The hot runnermold 10 has been described as having the runner 27 leading to the nozzle 26, however, it may be altered depending upon configuration of resin moldings. For example, the mold 10 is modified to provide a gate leading directly to the nozzle 26.
The groove 37 may take on any configuration. The ring 38 , which has been described as being threaded onto the distal end portion 43a, may not be threaded as long as it is mounted around the outer peripheral surface 35a of the distal end portion 43a.
Coolant may be provided in the vicinity of the ring 38 so as to cool the mold 12.
INDUSTRIAL APPLICABLITY
With the arrangements as explained above, the inventive nozzle effectively cools the resin within the distal end thereof, thereby enabling removal of the molded product from the distal end without producing stringiness. Further, the nozzle is simple in construction and this leads to reduction in the cost of manufacture of the hot runner mold. Thus, the nozzle is useful particularly in resin molding using a hot runner mold.

Claims

1. An injection nozzle for use in a hot runner mold having a cavity anda space formedtherein, the space communicatingwiththe cavity, said nozzle being positioned within the space and having an outer peripheral surface having a heating means disposed thereon for heating said nozzle, characterized in that the outer peripheral surface of said nozzle has a heat transmitting ring disposed thereon for releasing heat of a distal end portion of said nozzle to the hot runner mold, and has a heat-insulating groove formed thereon for preventing heat generatedbythe heatingmeans frombeingtransferredto the distal end portion.
2. An injection nozzle as claimed in claim 1, wherein the heating means, said heat-insulating groove, and said heat transmitting ring are disposed in order along a direction of flow of resinwithin the hot runner mold.
PCT/JP2003/002309 2002-03-26 2003-02-28 Nozzle for use in hot runner mold WO2003080315A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB0409749A GB2397796B (en) 2002-03-26 2003-02-28 Nozzle for use in hot runner mold
CA002467592A CA2467592A1 (en) 2002-03-26 2003-02-28 Nozzle for use in hot runner mold
KR10-2004-7006741A KR20040093661A (en) 2002-03-26 2003-02-28 Nozzle for use in hot runner mold

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2002-087077 2002-03-26
JP2002087077A JP3813527B2 (en) 2002-03-26 2002-03-26 In-mold nozzle structure of hot runner mold

Publications (1)

Publication Number Publication Date
WO2003080315A1 true WO2003080315A1 (en) 2003-10-02

Family

ID=28449354

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2003/002309 WO2003080315A1 (en) 2002-03-26 2003-02-28 Nozzle for use in hot runner mold

Country Status (6)

Country Link
JP (1) JP3813527B2 (en)
KR (1) KR20040093661A (en)
CN (1) CN1325245C (en)
CA (1) CA2467592A1 (en)
GB (1) GB2397796B (en)
WO (1) WO2003080315A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7105123B2 (en) 2003-02-20 2006-09-12 Mold-Masters Limited Heat dissipation device for and method of dissipating heat from a manifold
EP1785256A1 (en) * 2005-11-14 2007-05-16 Plastic Engineering & Technical Services, Inc. Injection nozzle tip
DE102006029097A1 (en) * 2006-06-24 2008-01-03 Witosa Gmbh Hot channel nozzle for introducing plasticized plastic into the form of an injection moulding tool, comprises a nozzle shank having a nozzle channel end-laterally arranged with a nozzle tip, heating unit for the nozzle channel, and a slit
US7458804B2 (en) 2004-11-04 2008-12-02 Plastic Engineering & Technical Services, Inc. Injection molding drop tip
USRE41536E1 (en) 2004-01-06 2010-08-17 Mold-Masters (2007) Limited Injection molding apparatus having an elongated nozzle incorporating multiple nozzle bodies in tandem
EP2015917B2 (en) † 2006-05-06 2016-01-27 MHT Mold & Hotrunner Technology AG Bottom insert with heat insulation

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2482254A1 (en) 2004-04-07 2005-10-07 Mold-Masters Limited Modular injection nozzle having a thermal barrier
US7780433B2 (en) 2007-03-27 2010-08-24 Mold-Masters (2007) Limited Hot runner nozzle having thermal insert at downstream end
KR200461215Y1 (en) * 2007-07-05 2012-06-28 주식회사우리엠텍 Mold for molding comprising cartridge heater
KR101306051B1 (en) 2011-09-06 2013-09-09 김진기 Hot runner nozzle of injection molding for string prevention
CN107877790A (en) * 2017-10-23 2018-04-06 广东泰安模塑科技股份有限公司 A kind of hot mouth device of anti-wire drawing

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02112919A (en) * 1988-10-22 1990-04-25 Mitsuhiro Kanao Nozzle with valve
WO1995005930A1 (en) * 1993-08-26 1995-03-02 Fill Robert J Nozzle for injection moulder
JP2002331552A (en) * 2001-05-09 2002-11-19 Mitsubishi Materials Corp Valve gate type die device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5820900A (en) * 1996-08-21 1998-10-13 Mcgrevy; Alan N. Heating device for an injection mold apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02112919A (en) * 1988-10-22 1990-04-25 Mitsuhiro Kanao Nozzle with valve
WO1995005930A1 (en) * 1993-08-26 1995-03-02 Fill Robert J Nozzle for injection moulder
JP2002331552A (en) * 2001-05-09 2002-11-19 Mitsubishi Materials Corp Valve gate type die device

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
GOLDBACH HUBERT: "Heisskanal-Werkzeuge fuer die Verarbeitung technischer Thermoplaste (wie ABS, PA, PBT, PC)", PLASTVERARBEITER, ZECHNER UND HUETHIG VERLAG GMBH. SPEYER/RHEIN, DE, vol. 29, no. 11, November 1978 (1978-11-01), pages 591 - 598, XP002177041, ISSN: 0032-1338 *
PATENT ABSTRACTS OF JAPAN vol. 014, no. 331 (M - 0999) 17 July 1990 (1990-07-17) *
PATENT ABSTRACTS OF JAPAN vol. 2003, no. 03 5 May 2003 (2003-05-05) *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7105123B2 (en) 2003-02-20 2006-09-12 Mold-Masters Limited Heat dissipation device for and method of dissipating heat from a manifold
US7118703B2 (en) 2003-02-20 2006-10-10 Mold-Masters Limited Heat dissipation device for and method of dissipating heat from a nozzle
USRE41536E1 (en) 2004-01-06 2010-08-17 Mold-Masters (2007) Limited Injection molding apparatus having an elongated nozzle incorporating multiple nozzle bodies in tandem
US7458804B2 (en) 2004-11-04 2008-12-02 Plastic Engineering & Technical Services, Inc. Injection molding drop tip
EP1785256A1 (en) * 2005-11-14 2007-05-16 Plastic Engineering & Technical Services, Inc. Injection nozzle tip
EP2015917B2 (en) † 2006-05-06 2016-01-27 MHT Mold & Hotrunner Technology AG Bottom insert with heat insulation
DE102006029097A1 (en) * 2006-06-24 2008-01-03 Witosa Gmbh Hot channel nozzle for introducing plasticized plastic into the form of an injection moulding tool, comprises a nozzle shank having a nozzle channel end-laterally arranged with a nozzle tip, heating unit for the nozzle channel, and a slit
DE102006029097B4 (en) * 2006-06-24 2009-11-26 Witosa Gmbh hot runner nozzle

Also Published As

Publication number Publication date
GB2397796B (en) 2005-11-02
CA2467592A1 (en) 2003-10-02
GB0409749D0 (en) 2004-06-09
GB2397796A (en) 2004-08-04
CN1596183A (en) 2005-03-16
JP3813527B2 (en) 2006-08-23
KR20040093661A (en) 2004-11-06
JP2003276057A (en) 2003-09-30
CN1325245C (en) 2007-07-11

Similar Documents

Publication Publication Date Title
JP4233616B2 (en) Torpedo for injection molding
WO2003080315A1 (en) Nozzle for use in hot runner mold
WO2012076008A3 (en) Diecasting die and diecasting method
JPH0773867B2 (en) Injection molding equipment
JPH06285920A (en) Injection molding torpedo provided with fixed ring gate
CN102126010A (en) Casting method
JPH0628248Y2 (en) Heat insulation structure of molten resin in molten resin pressure molding equipment
GB2311240A (en) Sprue for a hot-chamber metal die-casting machine
JP4038491B2 (en) Contact structure between mold and nozzle member
JP3571281B2 (en) Aluminum Wheel Mold
JP2009262215A (en) Die device and injection molding method
JP2000006198A (en) Injection molding die
JP2011098512A (en) Mold assembly for injection molding machine and injection molding machine
US20080086866A1 (en) Molding system including body overlapping and sealing conduits, amongst other things
JP3713707B2 (en) Mold equipment for molding
KR200412705Y1 (en) nozzle for injection molding machine
JP4296285B2 (en) Mold for metal injection molding machine
CN212285810U (en) Sprue gate injection device and gating system
JP2599292B2 (en) Injection mold
JP3950011B2 (en) Method and apparatus for injection molding of molten metal
JP2007111733A (en) Injection molding device
JP4160431B2 (en) Injection nozzle
JP2566779Y2 (en) Blow molding machine dies
JP3281231B2 (en) Die casting nozzle device
JP3041811B2 (en) Nozzle structure in hot runner type injection mold

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA CN GB KR

ENP Entry into the national phase

Ref document number: 0409749

Country of ref document: GB

Kind code of ref document: A

Free format text: PCT FILING DATE = 20030228

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 1020047006741

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 2467592

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 20038016958

Country of ref document: CN