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
• • 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
  • B29C45/1782—Mounting or clamping means for heating elements or thermocouples
• • 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
  • B29C45/26—Moulds
  • B29C45/27—Sprue channels ; Runner channels or runner nozzles
  • B29C45/2737—Heating or cooling means therefor
• • 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
  • B29C45/76—Measuring, controlling or regulating
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
  • G01K1/14—Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• • 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
  • B29C45/2737—Heating or cooling means therefor
  • B29C2045/274—Thermocouples or heat sensors

Definitions

• the invention relates to a hot-runner nozzle for an injection mold according to the preamble of claim 1.
• Hot runner nozzles are used in injection molds to form a flowable mass, for.
• a plastic melt to supply a separable mold insert at a predetermined temperature under high pressure. They usually have a material tube with a flow channel that ends in a nozzle orifice. The latter forms a nozzle outlet opening at the end, which opens via a gate in the mold insert (mold cavity). So that the flowable mass does not cool prematurely within the material tube, a heater is provided, which has to ensure a uniform as possible temperature distribution into the nozzle mouthpiece. Thermal separation between the hot nozzle and the cold tool prevents the nozzle from freezing and heating the tool or mold insert.
• the requirements for the temperature control in a hot runner nozzle are very high, because the plastics to be processed often have a very narrow processing window and are extremely sensitive to temperature fluctuations. For example, a temperature change of only a few degrees can lead to spray defects and rejects. Precise temperature control is therefore important for a well-functioning and fully automatic hot runner tool.
• it is important that the temperature to be set for all mold cavities is the same for multiple tools with, for example, 24, 32 or 64 cavities. This requires that the set temperature must be very close to the actual temperature at the nozzle.
• Temperature sensors are usually used to monitor the actual temperature.
• the output signals of the temperature sensor can then be supplied to a corresponding control, which regulates the temperature based on a SolMst temperature compensation.
• a hot runner nozzle for an injection mold with such a temperature sensor is described for example in EP-A-1-623 810.
• a heat-conducting sleeve is pushed onto the material tube, which is provided with an axially extending slot in which a temperature sensor is arranged.
• a clamping sleeve is arranged, which has on its inner side a recess which is accessible by an access from the outside. The free end of the temperature sensor is guided through the access into the recess, whereupon the clamping sleeve is rotated on the material tube and the free end of the temperature sensor is clamped in the clamping sleeve.
• This embodiment is for example to the disadvantage that in addition to the politiciansleitdüse another component in the form of the clamping sleeve must be provided, which is not desirable in terms of the production of the hot runner nozzle and on their installation.
• the present invention provides a hot runner nozzle for an injection molding tool according to claim 1.
• the dependent claims relate to individual embodiments of the present invention.
• the hot runner nozzle comprises a material pipe, which is preferably made of a steel, wherein in the material pipe at least one flow channel for a flowable material is formed. Furthermore, the hot runner nozzle preferably comprises a thermally conductive material, for example copper or made of a copper alloy, produced sleeve which is pushed onto the material pipe. In addition, a heater for heating the material pipe and a temperature sensor for detecting a temperature are provided.
• the sleeve of the hot-runner nozzle near one of its end regions has a passage opening extending substantially radially through a wall of the sleeve, through which the material tube is visible or accessible from the outside when the sleeve is pushed onto the material tube.
• this passage opening serving as a measuring point of the temperature sensor free end of the temperature sensor or a corresponding portion of the temperature sensor extends near its free end in the state in which the sleeve is pushed onto the material pipe.
• the heat energy generated by the heater can not act directly on the temperature sensor or on the measuring point.
• the latter can thereby detect the temperature of the material tube and thus the temperature of the melt guided therein much more accurately, i. the outside temperature detected by the temperature sensor corresponds much more closely to the temperature of the melt guided in the material pipe.
• the above-described construction of the hot runner nozzle according to the present invention is further advantageous in that it is very simple and consists of only a few components. Furthermore, the temperature sensor in a simple manner - possibly together with the sleeve and the heater - be replaced.
• the sleeve Along an outer surface of the sleeve is preferably formed at least one groove in which the heating and / or the temperature sensor is receivable / are. According to a particularly preferred embodiment, both a groove for the heating and a further groove for the temperature sensor are formed in the outer surface of the sleeve. In this way, the heater and the temperature sensor are integrated into the sleeve, which is particularly advantageous during assembly of the hot runner nozzle according to the invention.
• the heater and / or the temperature sensor are preferably held by means of a press connection in the respective groove.
• the heater and the temperature sensor can also be glued, soldered or otherwise secured in the grooves provided in the sleeve.
• the hot-runner nozzle according to the invention provided in the sleeve through opening on the outer surface of the sleeve has a groove or slot-like extension, which is designed such that serving as a measuring point of the temperature sensor free end of the temperature sensor is fastened in this, wherein the attachment can be produced by means of a press connection, a solder connection, an adhesive connection or the like.
• the free end of the temperature sensor is fixed, so that the position of the temperature-receiving portion of the temperature sensor near its free end is constant even under extreme external conditions due to the fixation. Due to the constant positioning of the temperature sensor and the heater relative to each other, the temperature of the material pipe can always be detected properly.
• a free end of the temperature sensor may protrude into the through-opening in a defined manner.
• the free end of the temperature sensor is advantageously fixed in such a way by a holding element, that in the installed state, a contact between the free end of the temperature sensor and the material tube is ensured.
• the holding element is preferably a clamp made of a temperature-resistant (up to about 500 0 C) spring steel.
• the free end of the temperature sensor can also be guided through the passage opening provided in the sleeve and received in a recess formed on an outer surface of the material tube and / or on an inner surface of the sleeve such that, when the sleeve pushed onto the material pipe, communicates with the through hole.
• the free end can then be fixed by means of a press connection, an adhesive bond, a solder joint or the like, so that here too a constant position of the temperature-receiving portion of the temperature sensor is ensured even under extreme external conditions.
• Figure 1 is a front view of a first embodiment of a sleeve of the hot runner nozzle according to the invention.
• Fig. 2 is a sectional view of the sleeve shown in Fig. 1;
• Fig. 3 is an enlarged partial view of the in Figs. 1 and 2 illustrated sleeve with inserted temperature sensor;
• FIG. 4 shows an enlarged partial view similar to FIG. 3 of an alternative embodiment of a sleeve of the hot-runner nozzle according to the invention with inserted temperature sensor;
• FIG. 5 shows an enlarged partial view similar to FIG. 3 of a further alternative embodiment of a sleeve of the hot-runner nozzle according to the invention with inserted temperature sensor;
• FIG. 6 shows an enlarged partial view similar to FIG. 3 of yet another alternative embodiment of a sleeve of the hot-runner nozzle according to the invention with inserted temperature sensor;
• FIG. 7 shows a partial cross-sectional view of the embodiment of a sleeve of the hot-runner nozzle according to the invention shown in FIG. 6 with inserted temperature sensor;
• FIG. 8 shows an enlarged partial view similar to FIG. 3 of yet another alternative embodiment of a sleeve of the hot-runner nozzle according to the invention with inserted temperature sensor;
• Fig. 9 is a sectional view of a hot runner nozzle according to the invention with the sleeve shown in Figs. 1 and 2.
• FIGS. 3 to 8 show alternative embodiments of a sleeve of the hot-runner nozzle according to the invention.
• the sleeve 10 is formed substantially tubular and made of a material having a good thermal conductivity, such as copper, a copper alloy or the like.
• a spiral-like groove 12 is formed in the axial direction of the sleeve 10 in the outer surface 14 of the sleeve 10 and serves to receive a wire-shaped heater 16, as shown in Fig. 9.
• the wire-shaped heater 16 is fixed in the groove 12 by means of a press connection, wherein the heater 16 may alternatively be attached by means of gluing, soldering or the like in the groove 12.
• a further groove 18 is formed in the outer surface 14 of the sleeve 10, which also extends in a spiral manner in the axial direction of the sleeve 10. This further groove 18 serves to receive a wire-shaped temperature sensor 20, as shown in Fig. 9.
• a through hole 24 is provided in the form of a bore which extends from the outer surface 14 of the sleeve 10 substantially radially inwardly through the wall of the sleeve 10. In this through hole 24 opens the temperature sensor 20 receiving groove 18th
• a groove-like extension 26 formed on the through hole 24, in which in the state in which the temperature sensor 20 is received in the groove 18, the free end of the temperature sensor 20 is inserted , as shown in the enlarged partial view of FIG. 3.
• the free end of the temperature sensor 20 is clamped in the extension 26.
• the free end of the temperature sensor 20 may also be fixed in the extension 26 by means of an adhesive bond, soldered connection or the like.
• a portion near the free end of the temperature sensor 20 extends through the through hole 24 when the temperature sensor 20 is inserted into the groove 18.
• sleeve 10 may also be provided in the figures, not shown, additional holes into which a puller or the like may engage, in particular to facilitate the disassembly of the sleeve 10 of the material tube 32.
• Figures 4 to 8 show alternative embodiments of the sleeve of the hot runner nozzle according to the invention.
• a groove-like extension 26 a is formed at the passage opening 24 opposite to the end opening in the passage opening 24 of the groove 18, which extends to the lower free end of the sleeve 10 a and in a free end of the Sleeve 10a formed recess 25 opens.
• the free end of the temperature sensor 20 is inserted, which is clamped in the extension 26a, wherein the free end of the temperature sensor protrudes into the recess 25.
• the free end of the temperature sensor 20 or the like by means of an adhesive bond, solder joint. be fixed in the extension 26a.
• the temperature sensor 20 is arranged closer to the free end of the material tube 32, without extending the subsystem consisting of the sleeve 10 and the heater 16 and without the free end of the temperature sensor 20 protrudes from the sleeve and projects from this.
• the free end of the temperature sensor 20 projects from the end of the groove 18 opening into the passage opening 24 into the passage opening 24 and ends there.
• the free end of the temperature sensor 20 protrudes from the opening in the passage opening 24 opening end of the groove 18 defined in the through hole 24 and ends there, wherein the free end of the temperature sensor 20 by means of a clamp 27 is held such that a Contact the free end of the temperature sensor 20 with the material tube 32 is ensured.
• a clamp 27 pushes the temperature sensor 20 in the manner of a hold down in the direction of the material tube, not shown.
• the free ends of the bracket 27 engage in corresponding expansion areas 29 of the through hole 24 to set the bracket 27 in the recess 24.
• the bracket 27 is made of a temperature resistant (up to about 500 0 C and higher) spring steel to produce the force required to press the free end of the temperature sensor 20 to the material pipe.
• Fig. 8 shows a further embodiment similar to that shown in Fig. 4, except that in the present case, the free end of the temperature sensor 20 as in the in Figs. 6 and 7 embodiment is pressed with a bracket 27 in the direction of the material tube to make contact between the temperature sensor 20 and the material tube.
• the principle of the determination of the clip 27 in the recess 25 corresponds in this case to that which is shown in Fig. 7.
• Fig. 9 shows a hot runner nozzle 30, in which the sleeve 10 shown in Figs. 1 and 2 is installed.
• the hot runner nozzle 30 is for use in an injection mold intended. It comprises a material tube 32, which is provided at its upper end with a flange-like connection head 34. This sits detachably in a housing 36 which can be fixed from below to a distributor plate (not shown). A radially formed step 38 centers the housing 36 and thus the hot runner nozzle 30 in the tool.
• a flow channel 40 for a molten material is centrally introduced.
• the preferably formed as a bore flow channel 40 has in the connection head 34, a material supply port 42 and opens at its lower end in a nozzle orifice 44, which is formed for example as a nozzle tip.
• the latter has a material outlet opening 46, so that the flowable material melt can get into a (not shown) mold cavity.
• the nozzle mouthpiece 44 preferably made of highly heat-conductive material is inserted into the material tube 32 at the end, preferably screwed in. But it can also - depending on the application - axially displaceably mounted with the same operation or formed integrally with the material tube 32.
• a sealing ring 48 is provided concentrically with the material feed opening 42 in the connection head 34 of the material tube 32. It is also conceivable the formation of an additional (not shown) annular centering approach, which can facilitate the installation of the hot runner nozzle 30 on the tool.
• the sleeve 10 shown in FIGS. 1 and 2 is placed on the outer circumference 50 of the material tube 32, with the wire-shaped heater 16 and the wire-shaped temperature sensor 20 being correspondingly fixed in the grooves 12, 18 of the sleeve 10.
• the respective connections of the heater 16 and the temperature sensor 20 are led out laterally from the housing 36, which is not shown here, however.
• the entire sleeve 10 is enclosed by a protective tube 52 which is pushed onto the sleeve 10.
• the passage opening 24 provided in the sleeve 10 is arranged in the end region 54 of the material tube 32, where the temperature of the material tube 32 is to be detected.
• the passage opening 24 generates a direct connection between the outer circumference 50 of the material tube 32 and a section 56 of the temperature sensor 20, which is arranged near the free end of the temperature sensor 20 defined in the extension 26 of the passage opening 24. Thanks to this direct connection, the temperature detected by the temperature sensor 20 is not or only insignificantly influenced by the temperature of the sleeve 10, which differs from that of the material tube 32. reduces or falsifies, so that the temperature sensor 20 can detect the exact temperature of the material tube 32 and thus that of the melt located therein.
• the extension 26 which is provided on the outer surface 14 of the sleeve 10 in the embodiment shown in FIGS. 1 to 3, also optionally on the inner surface of the sleeve or on the outer periphery of Material tube are formed, which is not shown in Figs. 1 to 3. Accordingly, the end portion of the temperature sensor is first passed through the through hole before the free end of the temperature sensor is inserted into the correspondingly arranged extension of the through hole. The temperature sensor can then be fixed in the extension and / or between the sleeve and the material tube.
• the fixing of the free end of the temperature sensor between these components can likewise be effected by pressing. In this way, the relative position between the heater and the material tube is fixed at the same time.
• the structure of the sleeve of the hot runner nozzle according to the invention is characterized by its simple construction. In particular, no additional components are required to set the temperature sensor or the heater to the sleeve. Due to the exact and permanent positioning of the temperature sensor relative to the heater optimal reproducibility of the data detected by the temperature sensor is also achieved.
• Extension 52 Protective tube a extension 54 end area

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=39108101

Family Applications (1)

Country Status (11)

Families Citing this family (14)

Family Cites Families (15)

• 2006
  • 2006-12-06 DE DE202006018576U patent/DE202006018576U1/de not_active Expired - Lifetime
• 2007
  • 2007-10-31 KR KR1020097011593A patent/KR20090097154A/ko not_active Application Discontinuation
  • 2007-10-31 JP JP2009539624A patent/JP2010511535A/ja not_active Withdrawn
  • 2007-10-31 EP EP07819520A patent/EP2091714A1/de not_active Withdrawn
  • 2007-10-31 MX MX2009004544A patent/MX2009004544A/es not_active Application Discontinuation
  • 2007-10-31 WO PCT/EP2007/009491 patent/WO2008067883A1/de active Application Filing
  • 2007-10-31 BR BRPI0716310-0A patent/BRPI0716310A2/pt not_active IP Right Cessation
  • 2007-10-31 CN CNA2007800418097A patent/CN101535025A/zh active Pending
  • 2007-10-31 CA CA 2670785 patent/CA2670785A1/en not_active Abandoned
  • 2007-10-31 US US12/448,063 patent/US20100092595A1/en not_active Abandoned
  • 2007-11-02 TW TW096141276A patent/TW200916297A/zh unknown

Non-Patent Citations (1)

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