DE102020109197A1 - Channel system for the continuous injection of a plasticized molding compound into a molding tool, injection molding device and a method for controlling and regulating a continuous injection process of such an injection molding device - Google Patents

Abstract

The invention relates to a channel system (14) for continuously injecting a plasticized molding compound (12) into a molding tool (16) by means of an injection molding device (10) with at least two injection units (18, 20) and at least one plasticizing unit (22), having a first channel (36) which can be connected to a first injection unit (18), a second channel (38) which can be connected to a second injection unit (20), an injection channel (42) for injecting a plasticized molding compound (12) into a molding tool ( 16), which is connected to the first channel (36) and the second channel (38), and a filling channel (40) which is connected to the first channel (36) and the second channel (38) and with a plasticizing unit ( 22) can be connected in order to fill the first injection unit (18) with the plasticized molding compound (12) via the first channel (36) and the second injection unit (20) with the plasticized molding compound via the second channel (38), u nd wherein valve means (46, 48, 50, 52) are provided for the controlled supply of the plasticized molding compound (12) to the injection channel (42). The invention also relates to an injection molding device (10) and a method for controlling and regulating a continuous injection process of an injection molding device (10).

Description

The present invention relates to a channel system for continuously injecting a plasticized molding compound into a molding tool by means of an injection molding device with at least two injection units and at least one plasticizing unit. The invention further relates to an injection molding device for continuously injecting a plasticized molding compound into a molding tool with such a channel system and a method for controlling and regulating a continuous injection process of such an injection molding device.

To produce molded parts from plastic, for example from a thermoplastic or from an elastomer, the plastic is heated and plasticized in an extruder in an injection molding device and then injected into a mold cavity of a molding tool via an injection unit. The molding compound is heated under the influence of temperature, so that it changes into a solid state through crosslinking. After crosslinking, the molding tool can be opened and the hardened molding removed.

For the production of multi-layer objects, it is known to use two injection units which one after the other inject the plasticized molding compound into the mold cavity. Such injection molding devices are made of EP 0 657 268 A2 , DE 10 2014 002 728 B3 , DE 10 2014 207 591 B4 and DE 10 2015 012 747 A1 known.

In addition, two injection units can be used to produce large-volume objects by the injection units successively injecting the plasticized molding compound into the mold cavity.

The present invention is based on the object of creating a channel system, an injection molding device and a method for injecting a plasticized molding compound into a molding tool, which allow continuous injection of a plasticized molding compound into a molding tool.

To achieve the object, a channel system with the features of claim 1, an injection molding device with the features of claim 7 and a method with the features of claim 8 are proposed.

Advantageous configurations of the channel system and of the method are the subject matter of the respective dependent claims.

According to one aspect, a channel system for continuously injecting a plasticized molding compound into a molding tool by means of an injection molding device with at least two injection units and at least one plasticizing unit is proposed. The channel system has a first channel that can be connected to a first injection unit, a second channel that can be connected to a second injection unit, an injection channel for injecting the plasticized molding compound into the molding tool, which is connected to the first channel and the second channel, and a filling channel which is connected to the first channel and the second channel and can be connected to a plasticizing unit in order to fill the first injection unit with the plasticized molding compound via the first channel and the second injection unit with the plasticized molding compound via the second channel, and wherein valve means are provided for the controlled supply of the plasticized molding compound to the injection channel.

Through the combination of valve means and filling channel, the flow process of the plasticized molding compound can be controlled in such a way that the flow process is not interrupted. This enables continuous injection of a plasticized molding compound into a mold cavity of a molding tool. The flow process can be controlled via the valve means in such a way that one of the injection units is filled with the plasticized molding compound and the other injection unit injects the plasticized molding compound into the mold cavity without the flow process coming to a standstill. This allows large-volume components with a homogeneous structure to be created.

In the channel system, the channels can be opened and / or closed via the valve means in such a way that one of the two injection units is filled with the plasticized molding compound via the filling channel and the channel connected to it and that at the same time the plasticized molding compound located in the other injection unit is filled via the channel and injecting the injection channel into the mold cavity of a molding tool. Valve means are advantageously provided for the controlled supply of the plasticized molding compound to the first channel, the second channel and / or the injection channel. In an advantageous embodiment, the valve means, in particular each valve means, control the supply of the plasticized molding compound from the filling channel via the first channel to the first injection unit, the supply of the plasticized molding compound from the filling channel via the second channel to the second injection unit, the supply of the plasticized molding compound from the first injection unit via the first channel to the injection channel and the supply of the plasticized molding compound from the second injection unit via the second channel to the injection channel.

In an advantageous embodiment, the channel system has a channel block in which the channels are introduced.

The molding compound can be plastic, which can be in the form of granules. The plastic can be a thermoplastic, thermosetting plastic or elastomer.

In an advantageous embodiment, the valve means are arranged within the channels.

In an advantageous embodiment, a first valve means is arranged between the first channel and the filling channel, a second valve means is arranged between the second channel and the filling channel, a third valve means is arranged between the first channel and the injection channel and a fourth valve means is between the second Channel and the injection channel arranged.

This has the technical advantage that the flow process of the plasticized molding compound can be controlled in such a way that it does not come to a standstill. The first valve means and the second valve means are advantageously arranged within the filling channel. The third valve means and the fourth valve means are also advantageously arranged within the injection channel. In an advantageous embodiment, the first valve means is arranged within the filling channel in front of a junction between the filling channel and the first channel. The second valve means is also advantageously arranged within the filling channel in front of a junction between the filling channel and the second channel. The third valve means is advantageously arranged within the injection channel after a junction between the first channel and the injection channel. The fourth valve means is advantageously arranged within the injection channel after a junction between the fourth channel and the injection channel. The node corresponds to a connection section or connection area between two channels.

In an advantageous embodiment, the valve means are designed as controllable valves.

This has the technical advantage that the channels can be opened and / or closed by activating the valves in order to enable one of the injection units to be filled and the plasticized molding compound located in the other injection unit to be injected into a molding tool at the same time. The controllable valves can be mechanically controllable valves, electrically controllable valves, hydraulically controllable valves, electromagnetically controllable valves and / or pneumatically controllable valves.

In an advantageous embodiment, the valves are designed as controllable needle shut-off nozzles.

This has the technical advantage that precise opening and closing behavior is achieved. In addition, a constant sprue quality is created over a longer period of time. In addition, needle valve nozzles are available as cost-effective standard components.

In an advantageous embodiment, the channel system has a channel block in which the channels are introduced.

This has the technical advantage that the channel system can be used universally. The channel block can be in one piece or in several pieces. In an advantageous embodiment, the injection units are connected to the channel block. The injection units can be connected to the channel block via connection nozzles. The connection nozzles can be connected to the duct block in a form-fitting and / or force-fitting manner. In particular, the connection nozzles can be screwed to the channel block. In addition, the channel block can be made of metal. The channel block can be a cold runner block or a hot runner block. A cold runner block is used to inject thermosets or elastomers, whereas a hot runner block is used to inject thermoplastics.

In an advantageous embodiment, the injection channel opens into a nozzle assembly.

This has the technical advantage that the temperature of the plasticized molding compound flowing through the nozzle assembly can be increased. The nozzle assembly advantageously has a nozzle body and a nozzle channel introduced into the nozzle body. The nozzle channel can have the same or a smaller diameter than the injection channel. In an advantageous embodiment, the cross section of the nozzle channel can be adjusted. The nozzle channel can be closed and opened by means of a closing needle. The nozzle assembly can be formed in one piece from the channel block of the channel system. Furthermore, the nozzle assembly can be a separate part that is connected to the channel system in a form-force and / or material-locking manner. The nozzle assembly can be screwed to the channel block.

According to a further aspect, an injection molding device for continuously injecting a plasticized molding compound into a molding tool with at least two injection units, proposed at least one plasticizing unit and the channel system.

By means of the injection molding device and the channel system, it is thus possible to continuously inject plasticized molding compound into a mold cavity of a molding tool.

The injection molding device can have a plasticizing unit, an injection unit, an operating unit and a closing unit for closing and holding the molding tool closed. The plasticizing unit can have a screw or extruder arranged within a cylinder, a screw drive device, a funnel for pouring in the molding compound to be processed, a heating device for plasticizing the poured molding compound and a nozzle for filling the injection unit with the plasticized molding compound. The injection unit can have a cylinder with a nozzle and an injection piston movable within the cylinder. By moving the injection piston, the plasticized molding compound in the cylinder is injected through the nozzle into the mold cavity of a molding tool. In an advantageous embodiment, the injection molding device heats the molding tool during injection.

In an advantageous embodiment, the injection molding device has a control device which is designed to open and / or close the valve means on the basis of detected operating parameters. To record the operating parameters, the control device can be connected to sensors that record the injection pressure of the respective injection unit, the position of the injection piston of the respective injection unit, the fill level of the plasticized molding compound within the respective injection unit, the pressure within the channels and the temperature within the channels. Furthermore, the control device for detecting the operating parameters can be connected to sensors which measure the speed and the torque of the extruder of the plasticizing unit.

According to a further aspect, a method for controlling and regulating a continuous injection process of an injection molding device is proposed. For this purpose, the first injection unit is first filled with a plasticized molding compound via the filling channel connected to the plasticizing unit and the first channel by opening the first valve means and closing the second valve means and the third valve means. The molding compound located in the first injection unit is then injected into the molding tool by closing the first valve means and opening the third valve means, with the second injection unit being filled at the same time via the filling channel connected to the plasticizing unit and the first channel by the second valve means is opened and the fourth valve means is closed. The molding compound located in the second injection unit is then injected into the molding tool by closing the second valve means and opening the fourth valve means.

In an advantageous embodiment, the closing and opening of the valve means is controlled via a control device. The control device can open and / or close the valve means as a function of detected operating parameters. For this purpose, the control device can be connected to sensors that measure the injection pressure of the respective injection unit, the position of the piston of the respective injection unit, the fill level of the plasticized molding compound within the respective injection unit, the pressure within the channels, the temperature within the channels, and the speed and record the torque of the extruder of the plasticizing unit. Furthermore, the control device for detecting the operating parameters can be connected to sensors which measure the speed and the torque of the extruder of the plasticizing unit.

In an advantageous embodiment, the second valve means is closed during the injection process of the first injection unit and after a filling quantity of the second injection unit has been reached, and a predetermined injection pressure is built up against the closed fourth valve means.

This has the technical advantage that the actual injection pressure of the first injection unit for the second injection unit is built up as a target value against the fourth valve means that is still closed.

In an advantageous embodiment, the fourth valve means is opened before the end of the injection process of the first injection unit, so that both injection units inject the plasticized molding compound into the molding tool.

This has the technical advantage that an injection speed that is as uniform as possible is achieved even while the injection units are being switched over.

In an advantageous embodiment, the third valve means is closed after a delay time has elapsed or after a predetermined position of an injection piston of the first injection unit has been reached.

In an advantageous embodiment, the first valve means is opened during the injection of the plasticized molding compound by the second injection unit in order to fill the first injection unit with the plasticized molding compound via the filling channel.

This has the technical advantage that the first injection unit can be filled again with the plasticized molding compound in order to be available for a further injection process.

After filling the first injection unit, the same is available again for injection in that the first injection unit first builds pressure against the closed third valve means before the end of the injection process of the second injection unit and shortly before the end of the injection process of the second injection unit, the third valve means is opened, see above that both injection units inject the plasticized molding compound into the molding tool, as described above for the second injection unit. The fourth valve means is then closed and the second injection unit is refilled by opening the second valve means.

The steps described above can be repeated as often as required. This enables a plasticized molding compound to be continuously injected into a molding tool.

• 1 einen Ausschnitt eines Querschnitts durch eine Spritzgussvorrichtung mit einem Kanalsystem und einem Formgebungswerkzeug, wobei eine erste Spritzeinheit eine plastifizierte Formmasse in das Formgebungswerkzeug einspritzt und eine zweite Spritzeinheit mit der plastifizierten Formmasse befüllt wird;
• 2 einen Ausschnitt eines Querschnitts durch die Spritzgussvorrichtung von 1, wobei beide Spritzeinheiten die plastifizierte Formmasse in das Formgebungswerkzeug einspritzen;
• 3 einen Ausschnitt eines Querschnitts durch die Spritzgussvorrichtung von 1, wobei die erste Spritzeinheit befüllt und die zweite Spritzeinheit die plastifizierte Formmasse in das Formgebungswerkzeug einspritzt; und
• 4 einen Querschnitt durch die Spritzgussvorrichtung von 3 entlang der Linie IV-IV.

A channel system, an injection molding device, a method for injecting a plasticized molding compound into a molding tool and further features and advantages are explained in more detail below using an exemplary embodiment that is shown schematically in the figures. Here shows:

• 1 a section of a cross section through an injection molding device with a channel system and a molding tool, a first injection unit injecting a plasticized molding compound into the molding tool and a second injection unit being filled with the plasticized molding compound;
• 2 a section of a cross section through the injection molding device from FIG 1 Both injection units inject the plasticized molding compound into the molding tool;
• 3 a section of a cross section through the injection molding device from FIG 1 wherein the first injection unit fills and the second injection unit injects the plasticized molding compound into the molding tool; and
• 4th a cross section through the injection molding device of 3 along the line IV-IV.

In the 1 until 4th is an injection molding device 10 shown for injecting a plasticized molding compound 12th into a shaping tool 16 serves.

The injection molding machine 10 has a first injection unit 18th , a second injection unit 20th , a plasticizing unit 22nd and a canal system 14th on.

The first and the second injection unit 18th , 20th have a housing 24 , one inside the case 24 movable injection piston 26th and a connection nozzle 28 to connect the injection units 18th , 20th with the sewer system 14th on.

As in 4th can be seen, has the plasticizing unit 22nd an extruder housing 30th and one inside the extruder barrel 30th rotationally and / or translationally movable extruder screw 32 on. In the present case, the extruder screw is rotated 32 a plastic granulate (not shown) for the molding compound 12th plasticized and in a connecting channel 33 pressed.

The sewer system 14th has a channel block 34 , a first channel 36 , a second channel 38 , a filling channel 40 and an injection port 42 on. The channel block 34 is in the present case designed as a cold runner block. The channel block 34 however, it can also be designed as a heat channel block.

As in the 1 until 3 can be seen is the first channel 36 with the first injection unit 18th and the second channel 38 with the second injection unit 20th tied together. Both the first channel 36 as well as the second channel 38 are with the filling channel 40 connected via the connection channel 33 with the plasticizing unit 22nd related, as in 4th can be seen. In addition, the first canal open 36 and the second channel 38 into the injection port 42 going into a nozzle assembly 44 flows out.

The nozzle assembly 44 has a nozzle body 45 and one in the nozzle body 45 introduced nozzle channel 47 on. The nozzle assembly 45 is is form-fitting, force-fitting and / or cohesive with the duct block 34 tied together. Via the injection port 42 and the nozzle assembly 44 becomes the plasticized molding compound 12th into the forming tool 16 injected.

According to the 1 until 3 is between the first channel 36 and the filling channel 40 a first valve means 46 arranged between the second channel 38 and the filling channel 40 is a second valve means 48 arranged between the first channel 36 and the injection port 42 is a third valve means 50 arranged, and between the second channel 38 and the injection port 42 is a fourth valve means 52 arranged. The valve means 46 , 48 , 50 , 52 are presently designed as controllable valves, in particular as controllable needle shut-off nozzles.

For controlling the valve means 46 , 48 , 50 , 52 has the injection molding device 10 a control device, not shown, which the valve means 46 , 48 , 50 , 52 opens and / or closes.

The following is a method for injecting the plasticized molding compound 12th in the Shaping tool 16 by means of the injection molding device 10 and the sewer system 14th described. First the first injection unit 18th about the one with the plasticizing unit 22nd connected filling channel 40 filled by the first valve means 46 is opened and the second valve means 48 and the third valve means 50 getting closed. This causes the to flow in the plasticizing unit 22nd plasticized molding compound produced 12th via the filling channel 40 and the first channel 36 into the first injection unit 18th and fills them up.

After filling the first injection unit 18th becomes the first valve means 46 closed and the third valve means 50 opened so that the plasticized molding compound 12th by means of the first injection unit 18th over the first channel 36 , the injection port 42 and the nozzle channel 47 into the forming tool 16 is injected by the injection plunger 26th inside the case 24 is moved down as in 1 can be seen. At the same time, the second injection unit 20th via the filling channel 40 and the second channel 38 with the one in the plasticizing unit 22nd produced plasticized molding compound 12th filled by the second valve means 48 opened and the fourth valve means 52 is closed.

After the filling quantity of the second injection unit has been reached 20th and before the end of the injection process of the first injection unit 18th , for example with a residual volume of plasticized molding compound 12th of 100 cm ³ , the second valve means becomes 48 closed and a predetermined injection pressure against the closed fourth valve means 52 built up by the injection plunger 26th inside the case 24 the second injection unit 20th is moved down.

Shortly before the end of the injection process for the first injection unit 18th if there is only a small residual volume of injectable plasticized molding compound in this 12th is present, for example 40 cm ³ , becomes the fourth valve means 52 opened so that both injection units 18th , 20th the plasticized molding compound 12th into the forming tool 16 inject as in 2 can be seen. This ensures that the injection speed is as uniform as possible, even while the injection units are being switched over 18th , 20th achieved.

After a delay time or a specified position of the injection piston 26th the first injection unit 18th is on the second injection unit 20th switched by the third valve means 50 is closed. From this point on, the second injection unit injects 20th the plasticized molding compound 12th over the second channel 38 and the injection port 42 into the forming tool 16 a. At the same time, the first injection unit 18th refilled by the first valve means 46 opens like in 3 can be seen.

After filling the first injection unit 18th the same is available again for injection by the second injection unit before the end of the injection process 20th first a pressure against the closed third valve means 50 built up and shortly before the end of the injection process of the second injection unit 20th the third valve means 50 is opened so that both injection units 18th , 20th the plasticized molding compound 12th into the forming tool 16 inject as before for the second injection unit 20th described. Then the fourth valve means 52 closed and the second injection unit 20th is refilled by the second valve means 48 is opened.

The method described above, or the steps described above, can be repeated as often as desired in order to continuously inject a plasticized molding compound 12th into a shaping tool 16 to enable.

By providing valve means 46 , 48 , 50 , 52 in a sewer system 14th and their targeted control, the flow process is not interrupted, so that continuously a plasticized molding compound 12th into a shaping tool 16 can be injected. This allows large-volume components with a homogeneous structure to be created.

List of reference symbols

10

Injection molding device

12th

plasticized molding compound

14th

Sewer system

16

Shaping tool

18th

first injection unit

20th

second injection unit

22nd

Plasticizing unit

24

casing

26th

Injection plunger

28

Connection nozzle

30th

Extruder housing

32

Extruder screw

33

Connection channel

34

Channel block

36

first channel

38

second channel

40

Filling channel

42

Injection port

44

Nozzle holder

45

Nozzle body

46

first valve means

47

Nozzle channel

48

second valve means

50

third valve means

52

fourth valve means

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0657268 A2 [0003]
• DE 102014002728 B3 [0003]
• DE 102014207591 B4 [0003]
• DE 102015012747 A1 [0003]

Claims (12)

Channel system (14) for continuously injecting a plasticized molding compound (12) into a molding tool (16) by means of an injection molding device (10) with at least two injection units (18, 20) and at least one plasticizing unit (22), having a first channel (36), which can be connected to a first injection unit (18), a second channel (38) which can be connected to a second injection unit (20), an injection channel (42) for injecting a plasticized molding compound (12) into a molding tool (16), the is connected to the first channel (36) and the second channel (38), and a filling channel (40) which is connected to the first channel (36) and the second channel (38) and can be connected to a plasticizing unit (22) in order to fill the first injection unit (18) with the plasticized molding compound (12) via the first channel (36) and the second injection unit (20) with the plasticized molding compound via the second channel (38), and valve means (46, 48, 50, 52) are provided for the controlled supply of the plasticized molding compound (12) to the injection channel (42). Canal system according to Claim 1 , characterized in that a first valve means (46) is arranged between the first channel (36) and the filling channel (40), a second valve means (48) being arranged between the second channel (38) and the filling channel (40), wherein a third valve means (50) is arranged between the first channel (36) and the injection channel (42), and wherein a fourth valve means (52) is arranged between the second channel (38) and the injection channel (42). Channel system (14) according to Claim 1 or 2 , characterized in that the valve means (46, 48, 50, 52) are designed as controllable valves. Channel system (14) according to Claim 3 , characterized in that the valves are designed as controllable needle shut-off nozzles. Channel system (14) according to one of the preceding claims, characterized by a channel block (34) in which the channels (36, 38, 40, 42) are introduced. Channel system (14) according to one of the preceding claims, characterized in that the injection channel (42) opens into a nozzle assembly (44). Injection molding device (10) for continuously injecting a plasticized molding compound (12) into a molding tool (16) with at least two injection units (18, 20), at least one plasticizing unit (22) and a channel system (14) according to one of the Claims 1 until 6th . Method for controlling and regulating a continuous injection process of an injection molding device (10) according to Claim 7 , which comprises the following steps: a. Filling the first injection unit (18) with a plasticized molding compound (12) via the filling channel (40) connected to the plasticizing unit (22) and the first channel (36) by opening the first valve means (46) and the second valve means (48) and closing the third valve means (50); b. Injection of the plasticized molding compound (12) located in the first injection unit (18) into the molding tool (16) by closing the first valve means (46) and opening the third valve means (50), with the second injection unit (20) at the same time the filling channel (40) connected to the plasticizing unit (22) and the first channel (36) are filled by opening the second valve means (48) and closing the fourth valve means (52); c. Injection of the molding compound (12) located in the second injection unit (20) into the molding tool (16) by closing the second valve means (48) and opening the fourth valve means (52). Procedure according to Claim 8 , characterized in that the second valve means (48) is closed during the injection process of the first injection unit (18) and after a filling quantity of the second injection unit (20) has been reached and a predetermined injection pressure is built up against the closed fourth valve means (52). Procedure according to Claim 8 or 9 , characterized in that the fourth valve means (52) is opened before the end of the injection process of the first injection unit (18) so that both injection units (18, 20) inject the plasticized molding compound (12) into the molding tool (16). Method according to one of the Claims 8 until 10 , characterized in that the third valve means (50) is closed after a delay time has elapsed or after an injection piston (26) of the first injection unit (18) has reached a predetermined position. Method according to one of the Claims 8 until 11 , characterized in that the first valve means (46) is opened during step c) in order to fill the first injection unit (18) with the plasticized molding compound (12) via the filling channel (40).

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