DE102015220790A1 - Injection nozzle for a cold runner and a method for producing a corresponding injection nozzle - Google Patents

Abstract

The invention relates to an injection nozzle (1) for a cold runner (2) with a coolable nozzle body (3) in which a runner (16) for an injection molding material is formed, and a nozzle tip (4) inserted into the nozzle body (3). It is provided that the nozzle body (3) has a first nozzle body portion (8) and at least one second nozzle body portion (9, 10), wherein the nozzle body portions (8, 9, 10) in the axial direction with respect to a longitudinal center axis (11) of the nozzle body ( 3) adjoin one another and at least one cooling channel (21) extends both into the first nozzle body section (8) and into the second nozzle body section (9, 10) so that the cooling channel (21) at least one first one extending in the first nozzle body section (8) Cooling passage region (22, 25, 27, 28) and at least one in the second nozzle body portion (9,10) extending second cooling channel region (23, 24, 29, 30, 31), wherein the first cooling channel region (22, 25, 27, 28 ) extends straight over its entire extension and the second cooling channel region (23, 24, 29, 30, 31) is curved at least partially, and that the first nozzle body portion (8) as a solid component and de r at least one second nozzle body portion (9, 10) is present as a sintered component or that the first nozzle body portion (8) and / or the second nozzle body portion (9, 10) each present as a sintered component or together as a sintered component. The invention further relates to a method for producing an injection nozzle (1) for a cold runner (2).

Description

The invention relates to an injection nozzle for a cold runner, with a coolable nozzle body, in which a sprue for an injection molding material is formed, and a nozzle tip inserted into the nozzle body. The invention further relates to a method for producing an injection nozzle.

The injection nozzle is a component of the cold runner and can form such. The cold runner is used to produce injection molded parts from an injection molding material, in particular a polymer. As injection molding, for example, silicones or rubber come into question. However, for other injection molding materials, the use of the Kaltkanalgießvorrichtung for producing the Spritzgießformteile may be useful or necessary. The injection molding material is introduced through the injection nozzle in an injection mold of the cold runner and heated to its processing temperature. The injection mold can be heated for this purpose. For example, the processing temperature is the temperature at which crosslinking of the injection molding material takes place optimally. Alternatively, the processing temperature may also indicate the lowest temperature at which the crosslinking can take place at all.

The crosslinking denotes, for example, a vulcanization, in particular a hot vulcanization. Of course, however, the cold runner can also be used for cold vulcanization. It is preferably provided that the injection molding material is heated to the processing temperature only in the injection mold. If the injection molding material reaches or exceeds the processing temperature only in the injection mold, ie if it has a temperature below the processing temperature in the injection nozzle, the injection moldings can be manufactured without sprue or almost without sprue because no crosslinking takes place in the injection nozzle. Accordingly, a post-processing of the injection moldings can be omitted or at least necessary only to a reduced extent. Of course, the cold runner may also be referred to as a cold runner injection molding machine.

The injector has the sprue and the nozzle tip. The nozzle tip is fluidly connected to the injection mold on the side facing the sprue. The injection molding material is conveyed through the runner in the direction of the injection mold, so that it can escape through the nozzle tip into the injection mold. The nozzle tip is preferably inserted into the nozzle body in which the sprue is present. The nozzle body can be cooled in order to dissipate heat, which is introduced, for example, from the direction of the injection mold into the injection nozzle or the nozzle body, and consequently to keep the temperature of the injection molding material as long as possible, based on a flow direction of the injection molding material in the runner, below the processing temperature. For example, at least one cooling channel is formed in the nozzle body, which is flowed through by a coolant during operation of the cold channel casting device. For this purpose, the coolant preferably has a temperature which is below the processing temperature, in particular significantly below the processing temperature.

It is an object of the invention to provide an injection nozzle for a cold runner, which has advantages over known injectors, in particular allows more effective cooling of the nozzle body and thus the injection molding.

This is achieved according to the invention with an injection nozzle having the features of claim 1. It is provided that the nozzle body has a first nozzle body portion and at least a second nozzle body portion, wherein the nozzle body portions in the axial direction with respect to a longitudinal center axis of the nozzle body adjacent to each other and extends at least one cooling channel both in the first nozzle body portion and in the second nozzle body portion, so that the Cooling channel has at least one extending in the first nozzle body portion first cooling channel region and at least one extending in the second nozzle body portion second cooling channel region, wherein the first cooling channel region extends straight over its entire extent and the second cooling channel region is at least partially curved, and that the first nozzle body portion as a solid component and the at least one second nozzle body portion is present as a sintered component or that the first nozzle body portion and / or the second nozzle body erabschnitt each present as a sintered component or together as a sintered component.

The nozzle body is at least mentally divided into the plurality of nozzle body sections, namely the first nozzle body section and the at least one second nozzle body section. It may be provided that only exactly one first nozzle body section and only exactly one second nozzle body section are provided. However, in addition to the exactly one nozzle body section, a plurality of second nozzle body sections are provided, which adjoin the first nozzle body section. If only a second Nozzle body portion is received, so the respective embodiments can of course be transferred to a plurality of second nozzle body sections, in particular to each of the plurality of second nozzle body sections.

The second nozzle body portion adjoins the first nozzle body portion in the axial direction, in particular directly. This means that the second nozzle body portion preferably extends as far as the first nozzle body portion and abuts or merges therewith. The first nozzle body portion and the second nozzle body portion may be configured in one piece and / or of the same material. Of course, it can also be provided that the first nozzle body portion and the second nozzle body portion made of different materials or a differently processed material. In this case, the first nozzle body portion and the second nozzle body portion are preferably connected to one another in a material-locking manner.

As already indicated above, the at least one cooling channel is formed in the nozzle body. This is intended to extend both into the first nozzle body section and into the second nozzle body section, so that both the first nozzle body section and the second nozzle body section can be cooled by means of a coolant present in the cooling channel. In this respect, the cooling channel has the first cooling channel region and the second cooling channel region, wherein the first cooling channel region is completely present in the first nozzle body section and the second cooling channel region is present completely in the second nozzle body section. In this case, the first cooling channel region passes directly into the second cooling channel region, so far the two cooling channel regions directly adjoin one another in the flow direction of the coolant.

The two cooling channel areas differ in terms of their design. The first cooling channel region should extend straight over its entire extent, ie along its entire longitudinal center axis. Accordingly, the longitudinal center axis of the first cooling channel region is also completely straight. In addition, the flow cross-section of the first cooling channel region in the direction of its longitudinal central axis, in particular over its entire longitudinal central axis, can be constant; it is provided so far no extension or constriction of the first cooling channel area. The first cooling channel region or its longitudinal center axis preferably runs parallel to the longitudinal central axis of the nozzle body or parallel to a longitudinal central axis of the sprue. The first cooling channel region has, for example, a ratio of its dimensions in the axial direction to its dimensions in the radial direction, that is to say a length to diameter ratio of at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45 or at least 50 on.

By contrast, the second cooling channel region should be curved at least in regions. A longitudinal central axis of the second cooling channel region has at least one curvature or bend to that extent. It can be provided that the flow cross-section of the second cooling channel region is also constant, in particular along its entire longitudinal central axis. Of course, however, there can be an enlargement or a reduction of the flow cross-section of the second cooling channel region, in particular in the region of the curvature. The curvature is preferably understood not to be an abrupt change of direction of the second cooling channel region. Rather, the second cooling channel region should be continuous, its longitudinal central axis thus also in the region of the curvature have a steady course, to allow a low-turbulence as possible flow through the cooling channel and thus a low pressure drop. The second cooling channel region has, for example, a ratio of length to diameter, in particular to the largest diameter along the longitudinal central axis, of at least 1, at least 2, at least 3, at least 4 or at least 5 and / or at most 10 or at most 5.

With the aid of such an embodiment of the injection nozzle, in particular the division of the cooling channel into the straight first cooling channel region and the curved second cooling channel region, an excellent guidance of the coolant in the injection nozzle and thus a very effective cooling is made possible. For example, it can be provided that - seen in the axial direction or in longitudinal section - the cooling channel region is present overlapping with the nozzle tip, so that the nozzle body is effectively cooled even in the region of the nozzle tip. Preferably, in this case, a heat transfer connection between the nozzle tip and the nozzle body is ensured, for example, by surface contact between the nozzle body and the nozzle tip and / or by a suitable heat conduction.

In that regard, the nozzle tip and introduced by this injection molding in the injection molding material can be cooled so that the temperature of the injection molding material is below the processing temperature until it enters the injection mold. Of course, it can also be provided that - seen again in the axial direction or in longitudinal section - the cooling channel is present at a distance from the nozzle tip. In this case, however, the distance in the axial direction between the cooling channel and the nozzle tip is preferably at most 25%, at most 50%, at most 75% or at most 100% of the length of the nozzle tip in the axial direction, ie its extension in this direction.

It is preferably provided that the first nozzle body section is in the form of a solid component and the at least one second nozzle body section is in the form of a sintered component, or that the first nozzle body section and / or the second nozzle body section are each in the form of a sintered component or jointly as a sintered component. In principle, therefore, different embodiments of the injection nozzle can be distinguished. In a first embodiment, one of the nozzle body sections is solid, while the other is sintered. Here, the material of the first nozzle body portion and the second nozzle body portion may be the same or there may be different materials for the nozzle body portions. Preferably, however, if there are a plurality of second nozzle body sections, the same material is used for them.

In another embodiment, both nozzle body sections are sintered. They may each be configured as a sintered component and connected after sintering. However, the nozzle body sections can also be made together as a single and one-piece sintered component. The sintered component or the sintered components can in principle be sintered in any desired manner. For example, the sintered component or the sintered components are produced or formed by selective laser melting (laser cusing), electron beam melting or laser sintering or selective laser sintering. Particularly preferably, the sintered component or the sintered components are produced in layers, in particular by means of laser melting. In each case, a thin layer of, in particular powdery, material is applied in numerous successive steps and locally cured by means of a laser.

The former embodiment, in which the injection nozzle has both the solid component and the sintered component, has the advantage that a simple and inexpensive production is possible. For example, the first nozzle body portion, which is present in the solid component, is formed by drilling. The embodiment in which the first nozzle body portion is present as a sintered component, also in the region of the first nozzle body portion enables flexible guidance and precise production of the cooling channel, in particular of the first cooling channel region even in the case of large extensions of the nozzle body in the axial direction. In particular, a particularly contoured course of the cooling channel and a very small distance between the cooling channel and the nozzle tip are realized.

A further development of the invention provides that the first nozzle body section and the second nozzle body section are made of different materials or differently processed materials and are connected to one another in a material-locking manner. The first nozzle body portion and the second nozzle body portion may have different material properties insofar. In any case, however, they are materially connected to one another, so that overall the first nozzle body section and the second nozzle body section form the nozzle body in one piece.

For example, the first nozzle body portion consists of a first material and the second nozzle body portion of a second material different from the first material. Both materials are preferably steels. For example, the material for the first nozzle body portion and / or the second nozzle body portion of the material 1.2709, also referred to as X3NiOMoTi18-9-5 used. However, it can also be provided that the first nozzle body section and the second nozzle body section consist of the same material and, to that extent, are of the same material. The material may be processed differently to form the first nozzle body portion and the second nozzle body portion. By way of example, the first nozzle body section consists of solid material, while the second nozzle body section is sintered from the same, for example pulverulent material.

Prior to forming the injector, the material is preferably cured. The curing may be done separately or in common for the first nozzle body portion and the at least one second nozzle body portion. For example, the first nozzle body portion is cured and the at least one second nozzle body portion is sintered onto the already cured first nozzle body portion. The heat treatment during sintering causes hardening of the second nozzle body portion.

The hardening of the material of the first nozzle body section can therefore already take place before the actual formation of the first nozzle body section. In this case, the material is hardened and the first nozzle body section is formed from this material, for example by a machining or cutting process, in particular by turning or hard turning. Alternatively, of course, first of all the first Nozzle body portion formed, in particular by means of the machining process, and only then cured. Subsequently, the second nozzle body portion is sintered onto the first nozzle body portion.

After the second nozzle body section has been sintered onto the first nozzle body section, it is particularly preferred to rework, preferably by means of a machining process, wherein in particular an outer contour of the nozzle body is produced with a defined tolerance. For example, a geometrically defined cutting edge - for example in the case of turning or milling - or a geometrically undefined cutting edge - for example in the case of loops - is used for the machining process. Also, a thread can be introduced during the reworking in the first nozzle body portion and / or the second nozzle body portion or formed on them / him.

In the context of a further embodiment of the invention, it is provided that the first nozzle body portion is present as a nozzle receiving portion of the nozzle body, and has a nozzle tip receptacle for receiving the nozzle tip, and / or that the second nozzle body portion is formed as a connecting flange, which has a coolant inlet and / or a coolant outlet of the Has coolant channel. In principle, the second nozzle body section can thus be configured differently or be present at different locations of the injection nozzle. For example, the second nozzle body section has the nozzle tip receptacle in which the nozzle tip is arranged or can be arranged. In this case, the second nozzle body portion exists as a nozzle receiving portion. Additionally or alternatively, the second nozzle body section serves to supply and / or discharge the coolant present in the cooling passage. For this purpose, it has the coolant inlet and / or the coolant outlet. Through the coolant inlet coolant can be supplied to the coolant channel, while it can be removed from it by the coolant outlet. In such a configuration of the second nozzle body section, this is present as a connecting flange section.

A preferred further embodiment of the invention provides that there are a plurality of second nozzle body sections which are arranged on opposite sides of the first nozzle body section, one being designed as a nozzle receiving section and one as a connecting flange section. In this respect, the injection nozzle should have both the nozzle receiving section and the connecting flange section. For this purpose, the plurality of second nozzle body sections are present. Seen in the axial direction, the connection flange section is now present on a first side of the first nozzle body section, while the nozzle accommodating section is arranged on a first side of the first nozzle body section opposite to the first side. The first nozzle body portion is so far between the two second nozzle body sections. Each of the two second nozzle body sections in this case has a second cooling channel region according to the above explanations. Each of these second cooling channel regions is directly connected to the first cooling channel region, thus directly adjoining it.

A development of the invention provides that the second cooling channel region of the nozzle receiving section is in the form of a deflection region and fluidly connects one of a plurality of first cooling channel regions with an adjacent one of the first cooling channel regions. By means of the nozzle receiving portion, therefore, a deflection of the coolant is achieved, in particular a deflection by 180 °. It connects the adjacent first cooling channel areas fluidically with each other. The first cooling channel region described above is preferably part of this plurality of first cooling channel regions. For example, it is thus provided that the second cooling channel region of the nozzle receiving section fluidly connects the above-described first cooling channel region with a further first cooling channel region, wherein the further first cooling channel region is formed in the first nozzle body section, in particular analogous to the first cooling channel region already described. With such a configuration, the coolant in the axial direction or in longitudinal section seen can be performed up to the nozzle tip or at least almost up to the nozzle tip, so that this or the injection molding material located in it is effectively cooled.

Additionally or alternatively, in a further embodiment of the invention, it may be provided that the second cooling channel region of the connecting flange section is present as a deflection region, which fluidly connects one of the first cooling channel regions with an adjacent one of the first cooling channel regions, or in that the second cooling channel region of the connecting flange section is formed as an inlet region or as an outlet region is, wherein the inlet region fluidly immediately between the coolant inlet and one of the first cooling channel regions and the outlet region fluidly present directly between the coolant outlet and one of the first cooling channel regions. The second cooling channel region can also be configured as a deflection region in this respect; Reference is made to the above statements.

Alternatively, the second cooling channel region may be present as an inlet region or as an outlet region. The inlet region is fluidically provided directly between the first cooling channel region and the coolant inlet. Through the inlet region, coolant entering through the coolant inlet can be supplied to the first cooling channel region. Alternatively, the second cooling channel region may be present as an outlet region and fluidically connect the coolant outlet directly to the first cooling channel region. Coolant present in the first cooling channel region can accordingly be supplied to the coolant outlet through the outlet region and exit therefrom.

A further preferred embodiment of the invention provides that the coolant inlet via several inlet regions and / or the coolant outlet are flow-connected via a plurality of outlet regions with a plurality of the first cooling channel regions. Thus, a branch can be provided between the coolant inlet or the coolant outlet on the one hand and the first cooling channel areas on the other hand. For this purpose, the plurality of inlet regions or the plurality of outlet regions are provided. Each of the inlet regions or outlet regions is fluidly connected on the one hand to the coolant inlet or the coolant outlet and on the other hand to one of the first cooling channel regions.

In a further embodiment of the invention can be provided that the nozzle body at least partially a coating, in particular a corrosion-resistant coating having. By means of the coating, the nozzle body is protected from external influences. The coating may be applied to an outside of the nozzle body. In addition or as an alternative, the coating can, of course, also be assigned to the first cooling channel region and / or the second cooling channel region, so that an inner side of the nozzle body is at least partially provided with the coating. Preferably, the entire cooling channel is provided with the coating. The coating has, for example, nickel, in particular it consists of nickel. The coating can be applied either chemically or electroplated, the former being preferred. The coating has, for example, a thickness of at most 10 μm, at most 20 μm, at most 30 μm, at most 40 μm or at most 50 μm.

Finally, in another embodiment, an embodiment of the injection nozzle may be provided as a needle valve nozzle, wherein a valve needle is arranged displaceably in the runner, which sealingly cooperates in a first position with a present in the nozzle tip valve seat for closing the sprue and in a second position, a flow connection through the sprue. The valve needle preferably extends completely through the runner and can be displaced by means of an actuator, in particular optionally in the first position or in the second position. The valve needle is preferably arranged coaxially with the sprue, in particular centrally in this. In the first position, the valve needle cooperates with the valve seat to seal the runner tightly so that the injection molding material can not escape through the nozzle tip into the injection mold. In the second position, however, the flow connection is released through the sprue. Accordingly, the injection molding material can pass from the nozzle tip into the injection mold. Preferably, it is provided that the valve needle in the first position is aligned with a side facing the injection mold of the nozzle tip, the valve needle thus completely fills a present on the side of the injection mold outlet opening of the nozzle tip.

In the context of a further preferred embodiment of the invention can also be provided that the nozzle tip is fixed by means of a holding element on the nozzle body, in particular the second nozzle body portion, wherein the holding element for changing the nozzle tip is non-destructive solvable. The nozzle tip is inserted into the nozzle body and is held there by means of the retaining element. In this respect, the holding element urges the nozzle tip against the nozzle body and / or into the nozzle tip receptacle. It can now be provided that the retaining element is non-destructive of the nozzle body solvable. In this way, a simple change of the nozzle tip is made possible. With advanced wear of the nozzle tip, it is not necessary to replace the entire injector. Rather, only the nozzle tip needs to be changed, which allows a cost-efficient operation of the cold runner. For example, the holding element with the nozzle body is positively and / or non-positively connected. As releasable positive connection, for example, a latching connection may be provided, as a releasable positive connection a screw. In the latter case, the holding element has a thread, in particular an internal thread, which engages in a thread, in particular an external thread, of the nozzle body.

The invention further relates to a method for producing an injection nozzle for a cold runner, in particular an injection nozzle according to the preceding embodiments, wherein the injection nozzle has a coolable nozzle body, in which a runner for an injection molding material is formed, and a nozzle tip inserted into the nozzle body. It is provided that the nozzle body has a first nozzle body portion and at least a second nozzle body portion, wherein the nozzle body portions in the axial direction with respect to a longitudinal center axis of the nozzle body adjacent to each other and extends at least one cooling channel both in the first nozzle body portion and in the second nozzle body portion, so that the Cooling channel is formed with at least one extending in the first nozzle body portion first cooling channel region and at least one extending in the second nozzle body portion second cooling channel region, wherein the first cooling channel region extends straight over its entire extent and the second cooling channel region is at least partially curved, and that the first nozzle body portion as a solid component and the at least one second nozzle body portion is formed as a sintered component or that the first nozzle body portion and / or de r second nozzle body portion are each formed as a sintered component or together as a sintered component.

The advantages of such an embodiment of the injection nozzle or such an approach has already been pointed out. Both the method for producing the injection nozzle and the injection nozzle itself can be developed according to the above statements, so that reference is made to this extent.

As part of a further embodiment of the invention can be provided that the nozzle body is at least partially produced as a sintered component. As already explained, at least the second nozzle body section should be present as a sintered component. In addition, this may also be true for the first nozzle body portion, so that preferably the first nozzle body portion and the second nozzle body portion are configured as a common sintered component. After the nozzle body has been produced as a sintered component, it is preferably post-processed, in particular mechanically or by post-machining. For example, at least one thread is formed on the first nozzle body section and / or the second nozzle body section, in particular on an outer circumference of the corresponding nozzle body section, during the post-processing. The thread can be provided, for example, for fastening the nozzle tip to the nozzle body, in particular for interaction with the holding element or an internal thread of the holding element.

A particularly advantageous embodiment of the invention provides that the nozzle body is at least partially provided with a coating, in particular a corrosion-resistant coating after the manufacture and / or the post-processing. This has already been discussed above. The application of the coating on the nozzle body is preferably carried out after manufacture and reworking, if the latter is provided. The coating is for example a nickel coating.

The invention further relates additionally or alternatively to an injection nozzle for a cold runner, with a coolable nozzle body, in which a sprue for an injection molding material is formed, and a nozzle tip inserted into the nozzle body. It is provided that the nozzle body is present at least partially, in particular completely, as a sintered component. The injection nozzle may be developed according to the above statements.

Likewise, the invention additionally or alternatively relates to a method for producing an injection nozzle for a cold runner, wherein the injection nozzle has a coolable nozzle body, in which a runner for an injection molding material is formed, and a nozzle tip inserted into the nozzle body. It is provided that the nozzle body is formed at least partially, in particular completely, as a sintered component. Again, for advantageous embodiments of the method and the injection nozzle to the above statements referenced.

The invention is also directed to an injector assembly having a plurality of the injectors described above.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings, without any limitation of the invention. Showing:

1 an injection nozzle for a cold runner,

2 a longitudinal section through a portion of a Kaltkanalgießvorrichtung, wherein the injection nozzle and an injection mold are shown,

3 a partial sectional view of the injection nozzle,

4 a partially sectioned view of a first portion of the injection nozzle,

5 a partially sectioned view of a second portion of the injector, as well

6 a multi-injector.

The 1 shows an injection nozzle 1 for a Kaltkanalgießvorrichtung not shown here 2 , The injector 2 has a nozzle body 3 on, in which a nozzle tip 4 is inserted, which has an outlet opening 5 for an injection molding material. The nozzle tip 4 can be permanently attached to the nozzle body 3 be attached. However, it is preferably, as shown here, by means of a holding element 6 on the nozzle body 3 attached, in particular releasably attached. For this example, the holding element 6 non-destructive of the nozzle body 3 removable, whereupon the nozzle tip 4 from the nozzle body 3 or a nozzle tip receptacle, not shown here 7 can be removed and subsequently replaced.

It can be clearly seen that the nozzle body 3 consists of different areas, namely a first nozzle body portion 8th and at least one second nozzle body portion. In the embodiment shown here are two second nozzle body sections 9 and 10 intended. In the axial direction with respect to a longitudinal central axis 11 of the nozzle body 3 take the second nozzle body sections 9 and 10 the first nozzle body portion 8th between them and each lie directly on this. The first nozzle body section 8th on the one hand and the second nozzle body sections 9 and 10 on the other hand may consist of different materials or materials processed differently. However, they can also consist of the same material, which can also be processed identically, or from the same, but differently processed material.

For example, the first nozzle body portion lies 8th as a solid component before, while at least one of the two nozzle body sections 9 and 10 , Preferably both nozzle body sections 9 and 10 are designed as a sintered component or sintered components. It can for the nozzle body sections 8th . 9 and 10 the same material may be provided, in particular a steel, for example the material 1.2709. In the case of the first nozzle body section 8th the material is massively used while it is for the nozzle body sections 9 and 10 is sintered. In particular, the material of the second nozzle body sections 9 and 10 directly on the first nozzle body section 8th sintered.

The 2 shows a longitudinal sectional view of the cold runner 2 next to the injector 1 an injection mold 12 having. It becomes clear that the nozzle tip 4 on their injection mold 12 facing side flush with an inner contour 13 the injection mold 12 concludes. The nozzle tip 4 so far extends to a mold cavity 14 the injection mold 12 , which at least partially from the inner contour 13 is limited, but not in this. Of course, the nozzle tip 4 in an alternative embodiment, however, also in the mold cavity 14 protrude.

The injector 1 is configured in the embodiment shown here as a needle valve nozzle. Accordingly, it has a valve needle 15 on that in a runner 16 the injector 1 is arranged. In particular, it sticks out into the nozzle tip 4 into it. It is designed such that it in a first position with a in the nozzle tip 4 present valve seat 17 sealingly cooperates to the sprue 16 from the injection mold 12 fluidically decouple or the flow connection through the runner 16 to interrupt. However, in a second position shown here, it is not in touching contact with the valve seat 17 but rather is at a distance from it. Accordingly, the flow connection through the sprue 16 released so that injection molding material through this into the injection mold 12 , in particular in the mold cavity 14 can flow in. The sprue 16 passes through the nozzle body 3 preferably completely in the axial direction. Through him, the nozzle tip 4 Injection molding material to be supplied. For this purpose, it has preferably in the radial direction with respect to its longitudinal central axis larger dimensions than the valve needle 15 ,

As already explained above, the nozzle tip is 4 in the nozzle tip holder 7 arranged the nozzle body. For example, the nozzle tip holder 7 in the second nozzle body portion 9 educated. The nozzle tip 4 is from the retaining element 6 in the nozzle tip holder 7 held. The holding element 6 can be removed non-destructively on the nozzle body 3 be attached, for example by means of a positive or non-positive connection. In the embodiment shown here is on the nozzle body 3 , in particular on the second nozzle body portion 9 an external thread 18 formed, in which an internal thread 19 of the holding element 6 intervenes. To seal the sprue 16 towards an external environment of the injection nozzle 1 To ensure a sealant 20 , For example, an O-ring, be provided, which on the one hand at the nozzle tip 4 and on the other hand on the nozzle body 3 sealingly rests. Preferably, the sealant surrounds 20 the nozzle tip 4 in the circumferential direction with respect to the longitudinal central axis 11 Completely.

The 3 shows a partial sectional view of the injection nozzle 1 , It can be clearly seen that in the nozzle body 3 at least one cooling channel 21 is trained. This extends both into the first nozzle body section 8th as well as in the two second nozzle body sections 9 and 10 , Accordingly, the cooling channel 21 one in the first nozzle body portion 8th present first cooling channel area 22 and two second cooling channel areas 23 and 24 in the second nozzle body section 9 and the second nozzle body portion 10 are formed. The first cooling channel area 22 preferably runs straight over its entire extent. The second cooling channel areas 23 and 24 However, at least partially curved.

The second cooling channel area 23 is available as deflection area. That means it's from the direction of the first cooling channel area 22 incoming coolant receives, deflects and subsequent to another first cooling channel area 25 supplies. The second cooling channel area 23 provides an immediate flow connection between the cooling channel areas so far 22 and 25 dar. The cooling channel area 25 is analogous to the cooling channel area 22 designed. In particular, it lies completely in the first nozzle body section 8th before and passes through this completely in the axial direction. In addition, he is straight, so has no curvature or the like. The cooling channel area 23 runs at least partially in the circumferential direction. In particular, it has a constant distance from the longitudinal central axis 11 on, so is also curved in the circumferential direction.

The cooling channel area 24 is available as an inlet area. Over him is an immediate flow connection between the cooling channel area 22 and a coolant inlet 26 of the cooling channel 21 produced. Fluidically, the cooling channel area is located 24 so far directly between the coolant inlet 26 and the cooling channel area 22 in front. Also the cooling channel area 24 can be circumferential and curved in the circumferential direction. This is purely optional. Additionally or alternatively, it runs from the coolant inlet 26 in the radial direction inwards, ie in the direction of the longitudinal central axis 11 ,

In this way he can the radially outward located coolant inlet 26 with the cooling channel area located further in the radial direction 22 fluidically connect. This allows a simple and easy supply of the coolant to the coolant inlet 26 and at the same time a positioning of the cooling channel area 22 with a small radial distance to the runner 16 , It can be provided that the coolant inlet 26 at least partially has a larger flow area than the cooling channel area 22 , Accordingly, through the cooling channel area 24 a reduction of the flow cross section, in particular a continuous reduction of the flow cross section, starting from the coolant inlet 26 in the direction of the cooling channel area 22 , Preferably far the cooling channel area 24 on its the cooling channel area 22 facing side the same dimensions as this.

It can be clearly seen that next to the first cooling channel areas 22 and 25 further first cooling channel areas 27 and 28 in the first nozzle body portion 8th are formed. In particular, the cooling channel areas are 22 . 25 . 27 and 28 with the same distances to the longitudinal central axis 11 before, so are at the same radial position. In addition to the cooling duct areas shown here 22 . 25 . 27 and 28 can further, not shown here first cooling channel areas, for example, a further cooling channel, in the first nozzle body portion 8th be educated. Preferably, all first cooling channel areas, so not only the cooling channel areas 22 . 25 . 27 and 28 evenly over the circumference of the nozzle body 3 distributed and are located at the same radial position. This ensures even cooling of the nozzle body 3 realized.

In addition, next to the second cooling channel areas 23 and 24 further second cooling channel areas 29 . 30 and 31 which are in the second nozzle body sections 9 and 10 are formed. The cooling channel area 29 is analogous to the cooling channel area 23 designed as a deflection. It connects the cooling channel areas 27 and 28 directly in fluidic terms. Also in the second nozzle body section 10 present cooling channel area 30 is designed as a deflection. Although this in the nozzle body section 10 and not in the nozzle body portion 9 is present, it preferably has the same properties as the cooling channel areas 23 and 29 , Over the cooling channel area 30 is a fluidic connection between the cooling channel areas 25 and 27 produced.

The cooling channel area 31 on the other hand, there is an outlet area. Above him is the cooling channel area 28 fluidically directly with a coolant outlet 32 flow-connected. Basically, the coolant outlet points 32 same properties as the coolant inlet 26 , so that reference is made to the above statements. Of course, from a functional point of view, the coolant outlet 32 as a coolant inlet and the coolant inlet 26 serve as a coolant outlet. In the cooling channel 21 over the coolant inlet 26 inflowing coolant passes over the cooling channel area 24 in the cooling channel area 22 , For this it flows into the cooling channel area 23 and is deflected by this in the axial direction and in the circumferential direction, so that it in the cooling channel area 25 can flow in.

Through this it reaches the cooling channel area 30 from which it is in turn deflected in the axial direction and circumferential direction, so that it in the cooling channel area 27 entry. At these closes the cooling channel area 29 on, so again a deflection in the axial direction and circumferential direction is made and accordingly the coolant through the cooling channel area 28 in the direction of the coolant outlet 32 can flow. For this it comes out of the cooling channel area 28 through the cooling channel area 31 , From the cooling channel area 31 the coolant is deflected at least in the radial direction, optionally additionally in the circumferential direction.

Overall, it becomes clear that the curved cooling channel areas 23 . 24 . 29 and 31 in the second nozzle body sections 9 and 10 present, while the completely straight cooling channel areas 22 . 25 . 27 and 28 in the first nozzle body portion 8th available. This embodiment is in particular by a specific method for producing the injection nozzle 1 realized in which the nozzle body portion 8th exists as a solid component, while the nozzle body sections 9 and 10 present as sintered components and during their manufacture on the first nozzle body portion 8th be sintered, in particular in layers. In this way, an extremely flexible design of the cooling channel 21 will be realized.

It should again be noted that the cooling duct areas shown here 22 to 25 and 27 to 31 not the only cooling channel areas are or have to be. Preferably, a further cooling channel in the nozzle body 3 formed, which also to the coolant inlet 26 and the coolant outlet 32 connected. Of this further cooling channel, however, only the cooling channel areas 33 and 34 approach to recognize, with the cooling channel area 33 as inlet area and the cooling channel area 34 is designed as an outlet region of the further cooling channel. The further cooling channel is for example symmetrical, in particular axially symmetrical, to the cooling channel 21 educated.

The 4 shows a partial sectional view of a portion of the injection nozzle 1 , Here is the cooling channel again 21 on his second nozzle body section 10 clearly visible side facing. On the nozzle body 3 , in particular on the nozzle body portion 10 , is a connection flange 35 provided via which a flow connection to the runner 16 can be produced. The connection flange 35 is ahead. At least one seal, in particular an O-ring seal, can be arranged on it. In particular, the connection flange 35 provided for attaching a connecting line, via which the sprue 16 Injection molding material can be fed. The connection flange 35 engages in this respect after attaching the connection line in this one. Furthermore, in the nozzle body 3 mounting holes 36 provided, which serve, for example, the inclusion of screws, bolts or the like to the injection nozzle 1 at other facilities of the cold runner 2 to fix. It becomes clear that the mounting holes 36 both the nozzle body section 10 as well as the nozzle body section 8th succeed.

The 5 shows a partial sectional view of the injection nozzle 1 on the part of the nozzle body section 9 , Approach here are now Kühlkanalbereiche 37 and 38 to recognize the above-mentioned further cooling channel. Full reference is made to the foregoing. It becomes clear that the cooling channel areas 23 and 29 in the axial direction only a part of the nozzle body portion 9 succeed. Preferably, the cooling channel regions pass through 23 and 29 at least 25%, at least 30%, at least 35%, at least 40%, at least 45% or at least 50% of the nozzle body portion 9 in the axial direction. The cooling channel areas 23 and 29 are identical and arranged only offset in the circumferential direction to each other.

The 6 shows an injection nozzle assembly 39 containing several injectors 1 has, in the embodiment shown here four injectors. Accordingly, the injector assembly 39 four valve pins 15 on. The injectors 1 the injection nozzle assembly 39 are basically constructed analogously to the preceding embodiments, so reference is made to the corresponding statements. The only difference is that the nozzle body sections not shown in detail here 8th . 9 and 10 the injectors 1 are each configured as a sintered component or together present as a sintered component. Here are the nozzle body 3 the four injectors 1 integral with each other, so that the configuration shown here results. Each injector 1 is each a coolant inlet 26 and a coolant outlet 32 assigned, the both sides of the respective valve needle 15 are arranged. Also injector arrangements 39 with several injectors 1 , in particular with any number of injectors 1 , Can in this respect the curved cooling channel areas and thus the flexible design of the cooling channel 21 exhibit.

Claims (10)

Injector ( 1 ) for a cold runner ( 2 ), with a coolable nozzle body ( 3 ), in which a sprue ( 16 ) is formed for an injection molding material, and one in the nozzle body ( 3 ) inserted nozzle tip ( 4 ), characterized in that the nozzle body ( 3 ) a first nozzle body portion ( 8th ) and at least one second nozzle body portion ( 9 . 10 ), wherein the nozzle body sections ( 8th . 9 . 10 ) in the axial direction with respect to a longitudinal central axis ( 11 ) of the nozzle body ( 3 ) adjoin one another and at least one cooling channel ( 21 ) in both the first nozzle body section ( 8th ) as well as in the second nozzle body section ( 9 . 10 ), so that the cooling channel ( 21 ) at least one in the first nozzle body portion ( 8th ) extending first cooling channel area ( 22 . 25 . 27 . 28 ) and at least one in the second nozzle body portion ( 9 . 10 ) extending second cooling channel area ( 23 . 24 . 29 . 30 . 31 ), wherein the first cooling channel area ( 22 . 25 . 27 . 28 ) runs straight over its entire extent and the second cooling channel area ( 23 . 24 . 29 . 30 . 31 ) is curved at least in regions, and that the first nozzle body portion ( 8th ) as a solid component and the at least one second nozzle body portion ( 9 . 10 ) is present as a sintered component or that the first nozzle body section ( 8th ) and / or the second nozzle body section ( 9 . 10 ) are each present as a sintered component or together as a sintered component. Injection nozzle according to claim 1, characterized in that the first nozzle body portion ( 8th ) and the second nozzle body portion ( 9 . 10 ) consist of different materials or differently processed materials and are materially interconnected. Injection nozzle according to one of the preceding claims, characterized in that the second nozzle body portion ( 9 . 10 ) as a nozzle receiving portion of the nozzle body ( 3 ) and a nozzle tip receptacle ( 7 ) for receiving the nozzle tip ( 4 ) and / or that the second nozzle body portion ( 9 . 10 ) is formed as a connecting flange portion having a coolant inlet ( 26 ) and / or a coolant outlet ( 32 ) of the coolant channel ( 21 ) having. Injection nozzle according to one of the preceding claims, characterized in that a plurality of second nozzle body sections ( 9 . 10 ) located on opposite sides of the first nozzle body section ( 8th ) are arranged, wherein a nozzle receiving portion ( 9 ) and a connecting flange section ( 10 ) is trained. Injection nozzle according to one of the preceding claims, characterized in that the second cooling channel region ( 23 . 29 ) of the nozzle receiving portion (FIG. 9 ) is present as a deflection region and one of a plurality of first cooling channel regions ( 22 . 25 . 27 . 28 ) with an adjacent one of the first cooling channel areas ( 22 . 25 . 27 . 28 ) fluidically connects. Injection nozzle according to one of the preceding claims, characterized in that the second cooling channel region ( 30 ) of the connecting flange section ( 10 ) is present as a deflection region, one of the first cooling channel areas ( 22 . 25 . 27 . 28 ) with an adjacent one of the first cooling channel areas ( 22 . 25 . 27 . 28 ) fluidically connects, or that the second cooling channel area ( 24 . 31 is formed as an inlet region or as an outlet region, wherein the inlet region is fluidically directly between the coolant inlet ( 26 ) and one of the first cooling channel areas ( 22 . 25 . 27 . 28 ) and the outlet area fluidically directly between the coolant outlet ( 32 ) and one of the first cooling channel areas ( 22 . 25 . 27 . 28 ) is present. Injection nozzle according to one of the preceding claims, characterized in that the coolant inlet ( 26 ) over several inlet areas ( 24 . 33 ) and / or the coolant outlet ( 32 ) over several outlet areas ( 31 . 34 ) with a plurality of the first cooling channel regions ( 22 . 25 . 27 . 28 ) are fluidly connected. Injection nozzle according to one of the preceding claims, characterized in that the nozzle body ( 3 ) at least partially a coating, in particular a corrosion-resistant coating having. Injection nozzle according to one of the preceding claims, characterized by a configuration as a needle valve nozzle, wherein in the runner ( 16 ) a valve needle ( 15 ) is arranged displaceably, which in a first position with a in the nozzle tip ( 4 ) present valve seat ( 17 ) for closing the sprue ( 16 ) cooperates sealingly and in a second position, a flow connection through the runner ( 16 ) releases. Method for producing an injection nozzle ( 1 ) for a cold runner ( 2 ), in particular an injection nozzle ( 1 ) according to one or more of the preceding claims, wherein the injection nozzle ( 1 ) a coolable nozzle body ( 3 ), in which a sprue ( 16 ) is formed for an injection molding material, and one in the nozzle body ( 3 ) inserted nozzle tip ( 4 ), characterized in that the nozzle body ( 3 ) a first nozzle body portion ( 8th ) and at least one second nozzle body portion ( 9 . 10 ), wherein the nozzle body sections ( 8th . 9 . 10 ) in the axial direction with respect to a longitudinal central axis ( 11 ) of the nozzle body ( 3 ) adjoin one another and at least one cooling channel ( 21 ) in both the first nozzle body section ( 8th ) as well as in the second nozzle body section ( 9 . 10 ), so that the cooling channel ( 21 ) with at least one in the first Nozzle body section ( 8th ) extending first cooling channel area ( 22 . 25 . 27 . 28 ) and at least one in the second nozzle body portion ( 9 . 10 ) extending second cooling channel area ( 23 . 24 . 29 . 30 . 31 ), wherein the first cooling channel area ( 22 . 25 . 27 . 28 ) over its entire extent straight and the second cooling channel area ( 23 . 24 . 29 . 30 . 31 ) is curved at least in regions, and that the first nozzle body portion ( 8th ) as a solid component and the at least one second nozzle body portion ( 9 . 10 ) is formed as a sintered component or that the first nozzle body portion ( 8th ) and / or the second nozzle body section ( 9 . 10 ) are each formed as a sintered component or together as a sintered component.

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