DE202005020812U1 - injection mold - Google Patents

Abstract

injection mold consisting of a mold core with an inner core and an outer core, preferably for the production of caps or the like, in particular screw caps, with an imaginary longitudinal axis , where the outer core is divided into a shaft and a, preferably a molding surface, Shank end, as well as a mold insert with a Vorkammerbuchse, the with the mold core a cavity form, characterized in that in the outer core (3) means (16, 28) for dissipation of heat from the shaft end (5) and / or in the mold insert and / or in the Vorkammerbuchse means are provided for the dissipation of heat.

Description

The The invention relates to an injection mold consisting of a Molded core, with an inner core and an outer core, preferably for the production of caps, lids, closures, Mugs, cans, pods or the like, in particular screw caps, with an imaginary Longitudinal axis, where the outer core it is divided into a shaft and a cavity-forming, preferably bearing a molding surface Shank end, as well as a mold insert with a Vorkammerbuchse, the with the mold core a cavity form.

Of the Mold core is made from a raw core. The raw core is different essentially from the finished mandrel characterized in that in the Outside surface of the Shank still none of the desired workpieces corresponding mold surface introduced is. Furthermore, the raw core, in contrast to the finished mandrel still no pinion, and no bearing for rotational movements. These will only when needed in the outer contour introduced the shaft, especially when with the finished Molded core screw caps or items with internal thread sprayed should be. For the production of such injection molded parts is a rotational movement of the mandrel necessary. The finished mold core is in the injection mold used on the ejector, wherein the outer molding surface of the shaft end with a Counter tool on the machine side forms a cavity, so the geometric Space, which is the negative equivalent of the finished injection molded part is. The injection molding machine The processed plastic compound injects under high pressure and high pressure Temperature in a certain time in the cavity. Then there is a cooling of the molded plastic mass, causing the plastic to solidify and the finished injection molded part, the is also called molding or molding is formed. The of the amount of heat released from the molding compound during solidification is transmitted via the inner core, in the helical, water-carrying cooling channels provided are, the mold core, provided in the absolutely konturnah arranged cooling channels are the ones provided with cooling channels Form insert and the antechamber socket, in which also absolutely konturnah arranged cooling channels provided are dissipated quickly and efficiently.

Of the Invention is therefore the object of the production capacity known injection molding tools to increase and the molded part quality to improve.

These Task is solved in a generic mold core in that in the outer core Means for dissipation of heat from the shaft end and / or in the mold insert and / or in the Vorkammerbuchse Means for dissipating heat are provided. Surprisingly, can already through one of these measures the shot sequence of the injection molding machine elevated become. Productivity rises accordingly. This effect can be particularly characterized to explain, that the heat energy transport can be done much faster, which alone on the spatial near outer core to the outer surface of the Stem end is due. Due to the sometimes considerable thickness of the outer core takes place in conventional injection molds the heat energy transport Delayed from the shaft end. The heat energy transport is also inhomogeneous. This is due to the different distances of individual Areas of the shaft end of the internal cooling and the poor thermal conductivity attributed to the previously used tool steels, resulting in different Temperature gradients between different areas of the outer surface of the Shank end and inner core cooling leads. Similar operating principles are assumed in the other measures.

Farther allows the provision of means for dissipating heat in the outer core a homogeneous dissipation of heat quantities, thereby the quality of the injection molded part because of the more even material cooling significantly increased becomes.

According to one advantageous embodiment of the invention it is provided that the Shank end is made of a high-quality copper alloy.

The thermal conductivity of high quality copper alloys is essential compared to tool steels higher and is preferably between 130 and 320 W / mK. This measure according to the invention accelerates the removal of heat from the cavity significantly, which in turn leads to an increase in production output leads.

It is appropriate that as a means of dissipating heat from the shaft end at least one heat dissipation in or on the shaft, preferably is provided at least partially along the shaft, wherein the Heat dissipation with the shaft end has at least one heat exchange surface. The amounts of heat are thus transported along the shaft, resulting in an accelerated Cooling the shaft end leads. The bigger the Heat exchange surface formed is, the faster the heat exchange takes place.

In order to provide a heat quantity removal without material transport, it is advantageously provided that the heat dissipation is solid, and in the Kavitätsbereich consists of a material, preferably of a high-quality copper alloy, which has a higher Wärmeleitfä ability as the shank end on the ejector side, preferably hardened tool steel. The amounts of heat are transported by the massive heat conduction along the shaft and can be removed at a location remote from the cavity-forming area to the shaft end of the ejector side.

In Embodiment of the invention is provided with advantage that the heat dissipation at least one second at a location remote from the shaft end Heat exchange surface with a fluidic coolant or with, preferably air-flowed, cooling fins having.

One even improved thermal energy transport is ensured by that the heat dissipation as inflow and outflow channel for a fluidic coolant formed and preferably part of a fluidic cooling circuit is. This measure has the advantage that the shaft end in the Kavitätsbereich absolutely konturnah of coolant is flowed through, resulting in accelerated cooling of the shaft end and therefore for cooling of the outer mold surfaces leads. there can the cooling channels in the be flowed through the simplest configuration with tap water. However, it is more economical that the cooling channels are part of a cooling circuit are.

One especially small distance between the cooling channels and the outer shaping surfaces of the contour-forming Tool parts is made by partially cooling the cooling channels are molded in a sheath of the shaft end.

In Development of the invention is provided that the cooling channels also partially integrated into the wall of the shank of the mold core. As a result, it is advantageously avoided that annoying cooling channels during production immediately on the outside of the shaft must be attached.

It is advantageous that the shaft preferably a pinion as well a warehouse for Having rotational movements about an imaginary longitudinal axis, wherein the Inlets and outlets the cooling channels between Pinion and the cavity-forming shaft end are arranged.

It is however according to a Another embodiment of the invention also provided that the Shank preferably a pinion and a bearing for rotary movements around an imaginary longitudinal axis having, wherein the inlet and outlet openings of the channels between Sprocket and a clamping end of the core are arranged to the ejector.

One particularly homogeneous heat transfer This ensures that the cooling channels in the cavity-forming shaft end formed helically are.

It is manufacturing technology of great Advantage that the shaft end and / or the shaft at least in each case are partially constructed of two concentrically arranged sleeves, which are radial with each other, preferably by electron beam welding, connected are. The cooling channels are as recesses in one of the two sleeves brought in. By this measure can axial bores in the sheath or shaft end with advantage be avoided.

It Is particularly advantageous that the end face of the shaft end with a stop surface the shaft end, preferably by electron beam welding radially connected is. This will be a particularly strong and tight connection between the shaft end of a high-grade copper alloy a high quality copper alloy and a high quality copper alloy and created to the shaft part of tool steel.

The Advantages of a material combination of hardened tool steel and high quality Copper alloy can also for the inner core are used when the inner core at least partially, preferably in the area of the shaft end, made of a high quality copper alloy is shaped.

The same thing applies mutatis mutandis to the measure that the mold insert at least in the area adjacent to the cavity, is molded from a high quality copper alloy.

The Measure, that the Vorkammerbuchse and / or any provided sprue bush in the area around the injector opening at least a cooling channel for a Having tempering and that the Vorkammerbuchse and / or a possibly provided sprue bushing at least two parts is formed, wherein a first part of the Nozzle, preferably made of hardened Tool steel consists, forms and a second part of a main body of the Prechamber bushing or any sprue bushing, preferably made of a high-quality copper alloy, serve a secure process management.

in the The following is a preferred embodiment of the invention based closer to examples explained.

The Figures of the drawing show:

1 an axial section of a mandrel, with inner core, mold insert with Vorkammerbuchse,

2 an axial section of a Rohkerns with Heat dissipation without fluid,

3 an axial section of a Rohkerns with fluidic cooling,

4 an axial section of a Rohkerns with fluidic cooling and other fluid management and

5 an axial section of a Vorkammerbuchse.

In 1 is a mold core 1 shown. The mold core 1 is part of an injection molding tool, not shown, and consists of an inner core 2 and an outer core 3 , The illustrated mandrel 1 is used for the production of screw caps. The outer core 3 is divided into a shaft 4 and one with the shaft 4 undetachably connected shaft end 5 , At the shaft end 5 opposite end 6 of the mold core 1 lies the chucking end 7 with threaded nut 8th for clamping the mold core 1 in the injection mold, not shown.

The shaft end 5 has an outer surface 9 on that as a molding surface 10 is trained. The mold surface 10 is formed in the mold core shown as a molding surface for an internal thread in a Schraubkappenspritzgießteil. The mold surface 10 makes with a counter tool 11 a cavity 12 , The injection molding machine, not shown, injects a processed plastic mass under high pressure and high temperature into the cavity in a certain time. This is through arrows 13 indicated. In 1 it can be seen that in the inner core 2 helical channels 14 are provided by the clamping end 7 Cooling water is passed to heat quantities from the shaft end 5 dissipate.

According to the invention, the heat conduction of the mandrel is thereby improved, that as an agent for dissipation of heat amounts an inflow channel 15 and a drainage channel 16 are provided for a fluidic coolant. inlet channel 15 as well as drainage channel 16 are in a coat 17 of the shaft end 5 as well as in the wall eighteen of the shaft 4 integrated. The coolant inlet opening 19 and the coolant outlet opening 20 connect inflow channel 15 and drainage channel 16 to a cooling circuit, not shown.

The mold core is a mold insert 11 assigned to the mold core with the cavity 12 forms, which is filled with plastic at each shot of the injection molding machine. Also this mold insert 11 is cooled by a fluid. The fluid used is usually water. However, it may also be advantageous for certain plastics, the use of oil. The fluid flows through cooling channels 38 inside the mold insert 11 are provided. The area 39 , the cavity 12 is made of a high quality copper alloy. The cylindrical seam 40 between area 39 and base material 41 of the mold insert 11 is manufactured by electron beam welding. In 1 is the mold insert 11 in an inner mold insert 43a and an outer mold insert 43b divided.

On the finished mold core is a pinion 21 intended. Through the thread nut 8th can do the same around its longitudinal axis 22 to be turned around. Next to the pinion 21 in the direction of the shaft end 4 is a warehouse 23 consisting of a storage area 24 and a bearing bush 25 intended. The designed as a plain bearing 23 serves to guide the mold core 1 during axial movement while rotating. The rotational movement is necessary in particular in the manufacture of injection-molded parts with an internal thread in order to be able to unscrew the mold core after completion of the injection-molded part. For this movement is also an axial movement of the mandrel 1 in the direction of the end of the chuck 7 necessary. For storage, the corresponding slide bearing is used 26 ,

In the 2 to 4 is not the finished mold core 1 but the raw part of an outer core 3 shown. This is mainly due to the fact that the outer surface 9 of the shaft end 5 has no contours, that is not formed as a molding surface. The formation of the geometric contours has yet to take place. The raw core already consists of an outer core 3 and a hole 27 for receiving an inner core, not shown. In the embodiment shown, the heat transfer is carried along the heat dissipation 28 that are inside the sleeve 33 of the shaft 4 is arranged without fluid. The heat dissipation 28 consists of a high quality copper alloy. The heat dissipation 28 is solid and has a first heat exchange surface 29 with the shaft end 5 on and a second heat exchange surface 30 which, for example, is in contact with a cooling circuit or with air-flowed cooling fins.

The in 3 illustrated raw core 1 has an inflow channel 15 and a drainage channel 16 for a fluidic coolant. The entrance opening 19 , as well as the outlet opening 20 are between clamping ends 7 and pinion 21 arranged. The pinion 21 is at the raw core 1 not yet completely formed, but consists only of an enlarged diameter portion of the shaft 4 because the pinion 21 is introduced into the raw core only when needed. The same is true of the camp 23 , The cooling channels 15 . 16 are inside the coat 17 of the shaft end 5 and inside the wall eighteen of the shaft 4 arranged. In the shaft end 5 are the cooling channels 15 . 16 formed helically, whereby a uniform amounts of heat transport distributed over the entire shaft end 5 is reached.

The shaft end 5 is made of two concentrically arranged sleeves 31 . 32 constructed, with the cooling channels 15 . 16 helical in the inner sleeve 31 are introduced. With the inner sleeve 31 is the concentrically arranged sleeve 32 connected by electron beam welding. The shaft 4 also consists of two concentrically arranged sleeves 33 . 34 , The cooling channels 15 . 16 are in the inner sleeve 33 introduced, whereupon the concentrically arranged outer sleeve 34 also by electron beam welding with the inner sleeve 33 connected is.

The in 4 illustrated raw core 1 is different from the one in 3 shown raw core in that the inlet opening 19 and the exit opening 20 the inflow channel 15 and the drainage channel 16 between pinions 21 and shank end 5 are arranged. To recognize is also in 4 in that the shaft end 5 from pods 31 and 32 is constructed and that analogous to a part of the shaft 4 from the concentric pods 33 and 34 is constructed, with all sleeves are connected to each other by electron beam welding. Furthermore, in 4 to recognize that the frontal area 35 of the shaft 4 with a radial abutment surface of the shaft end 5 connected by electron beam welding.

5 shows an axial section through a Vorkammerbuchse. Unlike the in 1 shown prechamber bushing she is in 5 tempered. A heating / cooling medium flows through one or more channels 44 , The nozzle 46 with nozzle opening 37 is made of hardened tool steel, while the surrounding base body 45 consists of a high-quality copper alloy and is tempered via medium-flow channels. To make the channels of the main body is divided and with the outer main body part in the area 49 assembled by electron beam welding. The nozzle 46 is preferably by electron beam welding to the body 42 inextricably linked.

For the injection molding process The machine nozzle (not shown) attaches itself to the collar. A principled analogue design is also for sprue bushings advantageous, as in hot runner system are present at mold cavities.

1

injection mold

2

inner core

3

outer core

4

shaft

5

shank end

6

The End of the mold core

7

clamping end

8th

Gewindeleitmutter

9

outer surface

10

form surface

11

mold insert

12

cavity

13

Injection direction

14

Cooling channels in the inner core

15

inlet channel

16

spillway

17

coat of the shaft end

18

wall of the shaft

19

inlet opening

20

outlet opening

21

pinions

22

longitudinal axis

23

camp

24

storage area

25

bearing bush

26

bearings

27

drilling

28

heat dissipation

29

First Heat exchange surface

30

second Heat exchange surface

31

shell

32

shell

33

shell

34

shell

35

face

36

stop surface

37

Injection port

38

cooling channels

39

Area

40

seam

41

Parent material

42

Gate bushing

43a

internal mold insert

43b

outer From insert

44

channels

45

channels

46

jet

47

body

48

Outer body part

49

area

50

Retaining compound

51

Federation

Claims (15)

Injection mold consisting of a mold core with an inner core and an outer core, preferably for the production of caps or the like, in particular screw caps, with an imaginary longitudinal axis, wherein the outer core is divided into a shaft and a preferably bearing a mold surface, shaft end, and a mold insert with a Vorkammerbuchse which form a cavity with the mold core, characterized in that in the outer core ( 3 ) Medium ( 16 . 28 ) for the removal of heat from the shaft end ( 5 ) and / or provided in the mold insert and / or in the prechamber bushing means for the discharge of heat. Injection mold according to claim 1, characterized in that the shank end ( 5 ) is made of a high quality copper alloy. Injection mold according to one of the preceding claims, characterized in that as means ( 16 . 28 ) for the removal of heat from the shaft end ( 5 ) at least one heat dissipation ( 28 ) in or on the shaft ( 4 ), preferably at least partially along the shaft ( 4 ), the heat dissipation ( 28 ) with the shaft end ( 5 ) at least one first heat exchange surface ( 29 ) having. Injection mold according to one of the preceding claims, characterized in that the heat dissipation ( 28 ) is solid and made of a material, preferably a high-quality copper alloy, which has a higher thermal conductivity than the shaft material, preferably hardened tool steel. Injection mold according to one of the preceding claims, characterized in that the heat dissipation ( 28 ) at one of the shaft end ( 5 ) remote location at least a second heat exchange surface ( 30 ) having a fluidic coolant or preferably, with air flows, cooling fins. Injection mold according to claim 3, characterized in that the heat dissipation ( 28 ) as inflow ( 15 ) and drainage channel ( 16 ) is formed for a fluidic coolant and is preferably part of a fluidic cooling circuit and / or the channels ( 14 ) are partially formed in a shell of the shaft end and / or the channels ( 14 ) partially in the wall of the shaft ( 4 ) are integrated. Injection mold according to claim 6, characterized in that the shaft ( 4 ) preferably a pinion ( 21 ) as well as a warehouse ( 23 ) for rotational movements around its imaginary longitudinal axis and the input ( 19 ) and outlet openings ( 29 ) of the channels ( 14 ) are arranged between the pinion and the shaft end or between the pinion and a clamping end of the core. Injection mold according to one of claims 6 or 7, characterized in that the channels ( 14 ) in the shaft end ( 5 ) are helically formed. injection mold according to one of the preceding claims, characterized that the shaft end and / or the shaft at least partially in each case are constructed of two concentrically arranged sleeves, the radial with each other, preferably inextricably linked by means of electron beam welding are. Injection mold according to one of the preceding claims, characterized in that the end face of the shank ( 4 ) with a stop surface of the shaft end ( 5 ), preferably inextricably linked by electron beam welding. injection mold according to one of the preceding claims, characterized in that the inner core at least partially, preferably in the region of Shank end to the cavity out, made of a high quality copper alloy. Injection mold according to one of the preceding claims, characterized in that the mold insert ( 43 ) at least in the area ( 39 ) attached to the cavity ( 12 ) is formed of a high-quality copper alloy and / or cooling channels ( 44 ) for a cooling medium. Injection mold according to one of the preceding claims, characterized in that the prechamber bushing ( 42 ) and / or a possibly provided sprue bush in the region around the injection nozzle opening ( 37 ) at least one channel ( 45 ) for a tempering medium. Injection mold according to one of the preceding claims, characterized in that the prechamber bushing ( 42 ) and / or a possibly provided sprue bush is formed at least in two parts, wherein a first part of the nozzle ( 46 ), preferably made of hardened tool steel, forms and a second part ( 47 ) a main body of the antechamber socket ( 42 ) or any provided sprue bushing, preferably made of a high quality copper alloy. Injection mold according to claim 2, characterized in that the shaft end ( 5 ) is made of hardened tool steel for processing GF reinforced plastics.