DE20304841U1 - Fluid distribution system for temperature control of injection molding machines is built up of modular branch flow control valves - Google Patents

Abstract

Different parts of an injection molding machine are held at different temperature levels by a controlled flow of hot or cold fluid, e.g. water or oil. The control system is built up of a number of stacked modules that form the supply and return duct. Each module provides a branch supply and return and is fitted with a control valve , flow meter and temperature sensor. Different parts of an injection molding machine are held at different temperature levels by a controlled flow of hot or cold fluid, e.g. water or oil. The control system is built up of a number of stacked modules that form the supply and return duct (12, 14). Each module provides a branch supply and return (18, 20) and is fitted with a control valve (26), flow meter (34) and temperature sensor (40). The control valve can be operated by a hand knob (32) or a servo motor. The modules are held together by through bolts arranged round the supply and return ducts (12, 14). The end modules have covers that can be removed to add further modules.

Description

TER MEER STEINMEISTER & PARTNER GBR PATENT ATTORNEYS - EUROPEAN PATENT ATTORNEYS

Dr. Nicolaus ter Meer, Dipl.-Chem. Peter Urner, Dipl.-Phys. Gebhard Merkle, Dipl.-Ing. (FH) Mauerkircherstrasse 45 D-81 679 MUNICH Helmut Steinmeister, Dipl.-Ing. Manfred Wiebusch

Artur-Ladebeck-Strasse D-33617 BIELEFELD

TECP04 / 03

St/sc/zs

25.3.2003

Technotrans AG

Robert-Linnemann-Str. 48336 Sassenberg

TOOL TEMPERATURE CONTROL SYSTEM FOR PLASTIC INJECTION MOLDING

TOOLS

Technotrans AG · TECP04/03 March 25, 2003

TOOL TEMPERATURE CONTROL SYSTEM FOR PLASTIC INJECTION MOLDING

WITNESS

The invention relates to a distributor for tempering fluids in tempering systems for injection molding machines and to a tempering system with several such distributors.

In injection molding technology, tempering systems are used to temper the tools. In this context, "tempering" can mean both

IC) can mean both heating and cooling. Cooling of the tools is particularly important before a workpiece is removed from the mold. On the other hand, the tools must have a certain minimum temperature during the injection molding process so that the injected material does not solidify too quickly. When processing thermoplastics, for example, a temperature of 20 to 95°C is therefore possible, with the temperatures selected depending on the tool geometry, the material used and a number of other parameters. While open systems using water as the temperature control medium can be used in the temperature range up to 95°C, higher temperature control temperatures may be necessary when processing thermosets, elastomers and other more complex plastics. In this case, pressurized, closed systems must be used, and in extreme cases only oil can be used as the temperature control medium.

In practice, up to now, auxiliary devices have been used that have to be provided separately for the various positions of an injection molding machine that require temperature control. Therefore, a not inconsiderable number of temperature control devices are generally necessary for an injection molding machine, which require correspondingly complicated hose connections and control and regulating devices and make access to the machine difficult.

The object of the invention is to create a temperature control system for injection molding machines which has a relatively small space requirement, enables simple and clear hose and cable connections and can be controlled by a common control and regulating device.

Technotrans AG ·'''*''· t. i'i I, I TECP04/03 March 25, 2003

The object is achieved according to the invention by a temperature control system with a distributor for temperature control fluids, which can be assembled into the temperature control system in a modular design.

The distributor has a housing through which a flow channel and a return channel pass, and furthermore a branch line leading from the flow channel and the return channel for connection to a tempering channel of a tool, at least one of which is provided with a flow control valve.

The distributor according to the invention can be combined in a modular design with other distributors to form a unit of any size that can supply the various positions of an injection molding machine or several injection molding machines with freely adjustable temperatures.

If temperatures in the range of 15 to 20 ⁰ C are to be achieved simply by tempering, the tempering system can be connected to the existing cold water network on site. The fine adjustment of the temperature to be achieved can be determined by the flow rate. The larger the flow rate selected, the more the temperature achieved in the tempered position can be approached to the temperature of the cold water.

A lower temperature below the network temperature can be achieved by exchanging heat between the water used for temperature control and a cooling device or, if necessary, a refrigeration machine via a heat exchanger. On the other hand, for higher temperatures, a heating device can be connected to the temperature control circuit, which can consist of an electric flow heater or a suitable heat exchanger and can be connected to a circulation pump and a control valve to form a circuit. Here, too, the temperature of the target area can be adjusted to that of the temperature control fluid using the flow rate. This means that with the help of one and the same temperature control network, different temperatures can be set in the different positions of one or more injection molding machines by adjusting the temperature control flow to bring the position to be tempered into more or less intensive heat exchange with the temperature control medium.

Technotrans AG! . &Idigr; TEC P04/03 March 25, 2003

The distributors according to the invention have, as shown, a flow channel and a return channel that penetrate the housing of the distributor and, if several distributors are joined together, form a combined, continuous flow and return channel. The individual branch lines branch off from the flow and return channels, at least one of which is provided with a flow control valve with which the flow rate of the tempering medium branched off at the respective point is adjusted. The distributors can be made of plastic.

Further advantages and features of the invention emerge from the subclaims and the following description of embodiments.

Fig. 1 is a partially sectioned perspective view

a distributor according to the invention with a manually adjustable flow control valve;

Fig. 2 is a corresponding representation with electrical actuator

motor for the control valve;

Fig. 3 shows a distributor according to the invention in a similar

perspective view with side wall omitted;

Fig. 4 shows a combined unit of six distributors

according to Figure 3, which are assembled in a modular construction;

Fig. 5 is a schematic diagram of an inventive

Tempering system with extraction of the tempering medium from the on-site cold water network;
30

Fig. 6 illustrates the setting of the temperature of the Tempe

ration medium via a heat exchanger;

Fig. 7 shows a two-circuit system comprising a heater, a

Circulation pump and a control valve.

Technotrans AG ·* » ! '&iacgr;&iacgr;·&iacgr; * &iacgr; I. I TECP04/03 March 25, 2003

Figure 1 shows a distributor according to the invention in a perspective, partially cutaway view. The housing of the distributor, designated 10, is passed through by a flow channel 12 and a return channel 14, which are arranged one above the other and emerge from the housing on opposite sides.

5' housing. The function of the flow channel and the return channel can basically be interchanged, provided that a check valve 16 shown in the drawing is moved or removed. From the two channels 12, 14 branch lines 18, 20 extend to the right in Figure 1, which lead to connections 22, 24 on the right side 1 in Figure 1, which allow a connection to

KD to produce the tempering medium channels of an injection molding machine (not shown).

The upper branch line 18 has a step 26, in the upper level of which a rotatable valve disc 28 is arranged. The valve disc 28 is connected via a shaft 30, which leads upwards out of the housing 10, to a rotary knob 32, which makes it possible to adjust the flow rate in the upper branch line 18 with the aid of the valve disc 28.

The tempering fluid is introduced from the upper channel, the feed channel, into the upper branch line and passes through the upper connection 22 into the tempering channel system of the injection molding machine (not shown). From this tempering channel system, the tempering fluid returns to the connection 24 and thus into the lower branch line 20 and from there into the return channel 14.

2i5 In the upper branch line 18 there is also an impeller 34 which is connected to a flow meter 36 placed on the housing 10. A receptacle 38 on the left side in Figure 1 allows the insertion of a temperature sensor or other measuring device into the flow channel 12. A receptacle 40 on the lower side of the housing 10 also allows the accommodation of corresponding measuring devices, in particular a temperature sensor in the lower branch line 20.

Figure 2 largely corresponds to Figure 1 and the parts already explained have been provided with the reference numbers of those parts.
35

In addition, temperature sensors 42 and 44 are installed in the housings 38 and 40

Technotrans AG **·..* · ·· · ^# · »· · TECP04/03 March 25, 2003

Furthermore, an actuator 46, for example an electric actuator, is located on top of the housing 10 and is connected to the shaft 30 of the valve disk 28. This actuator enables remote-controlled actuation of the flow control valve 28, 30 from a control and regulating device which is not shown in the drawing.

Figure 3 shows a distributor according to the invention in a position similar to Figure 1, but is not cut open, but is shown with a front end wall omitted. It can be seen that on the circumference of the flow and return channels 12, 14 there are a number of tension anchor channels 48 running parallel to the axes of the channels 12, 14.

These tension anchor channels allow several distributors according to Figures 1 to 3 to be clamped together in a modular manner to form a coherent unit, as will be explained below with reference to Figure 4.

According to Figure 4, six distributors according to Figure 3 are combined to form a unit. It can be seen that in the combined position the supply and return channels 12, 14 of all distributors are aligned with one another and form a continuous channel. The same applies to the tension anchor channels 48, so that tension anchors can be introduced through the tension anchor channels of all distributors, which hold the unit shown in Figure 4 together.

While at one end of this unit a supply line (not shown) and a return line (not shown) are connected to the two channels 12, 14, these channels 12, 14 can be closed off by a closing plate on the opposite side, which is not visible in Figure 4.

Furthermore, the representation according to Figure 4 should be easily understandable when taking into account the representations according to Figures 1 to 3.

Figure 5 is a circuit diagram and shows a schematic of an injection molding tool 50 of an injection molding machine. The two mold halves of the injection molding tool 50 are each assigned to combined groups of distributors, as shown in Figures 1 to 4. The individual distributors are symbolized in the drawing by their two connections 22, 24. Figure 5 is about the simple

Technotrans AG ·* '' * J &Idigr;. J*i!. J TECP04/03 March 25, 2003

st case, in which the temperature is always in the range of 15 to 20 ⁰ C. Here, cold water can be taken directly from the cold water network via a supply line 52, which can then be used for other purposes via a return line 54. Valves in the two lines 52, 54 are designated 56, 58.

According to Figure 6, the tempering medium water runs through a flow line 60 and a return line 62 in a closed circuit through the individual distributors and, on the other hand, through a heat exchanger. On the other hand, this heat exchanger can be supplied with a tempering medium from a refrigeration machine 66, the temperature of which is below the temperature of the cold water network. On the other hand, the refrigerating medium water can be heated in the heat exchanger according to the same principle. In Figure 6, 68 designates a pump and 70 a temperature sensor.

Figure 7 is a circuit diagram of an embodiment in which a first distribution group 72 operates in the range of 15 to 20 ⁰ C and a second distribution group 74 operates in the temperature range of 60 to 80 ⁰ C. The two distribution groups are separated by a partition 76, but are combined into an overall group across this partition.

The distributor group 72, which operates at temperatures of around 15 to 20 ⁰ C, is supplied directly via a flow line 78 and a return line 80, as has already been described in connection with Figure 5. The distributors, which operate in the temperature range of 60 to 80 ⁰ C, are supplied via a flow line 82 and a return line 84. In the flow line 82 there is a control valve 86 and a circulation pump 88. In the return line 84 there is a heating device 90. A connecting line 92 allows the tempering fluid heated in the heating device 90 to be fed directly via the

3Ci connecting line 92 and the circulation pump 88 to feed the flow again. If the temperature becomes too high, the control valve 86 can be opened and colder tempering fluid can be admitted into the circuit. In this case, the excess medium is returned from this circuit to the return line 80.

In Figures 5 to 7, all control lines, connecting hoses, etc. have been omitted for the sake of simplicity.

Claims (6)

1. Distributor for tempering fluids in tempering systems for injection molding machines, with a housing ( 10 ) through which a supply and a return channel ( 12 , 14 ) pass, and with a branch line ( 18 , 20 ) leading from the supply and the return channel ( 12 , 14 ) for connection to a tempering channel of a tool, at least one of which is provided with a flow control valve ( 26 , 28 , 30 ) and that a flow meter ( 34 , 36 ) is provided in one of the branch lines ( 18 , 20 ) and a temperature sensor ( 42 , 44 ) is also provided in one of the branch lines ( 18 , 20 ). 2. Distributor according to claims 1 to 3, characterized in that a ring of tension anchor channels ( 48 ) directed parallel to the axes of the channels ( 12 , 14 ) is provided around the flow and return channels (12, 14). 3. Distributor according to one of claims 1 to 4, characterized in that a handwheel ( 32 ) for adjusting the flow control valve ( 26 , 28 , 30 ) is provided on the housing ( 10 ). 4. Distributor according to one of claims 1 to 4, characterized in that an actuator ( 46 ) for adjusting the flow control valve ( 26 , 28 , 30 ) is provided on the housing ( 10 ). 5. Distributor according to one of claims 1 to 6, characterized in that the distributors have a detachable cover on the opposite sides on which the flow and return channels ( 12 , 14 ) exit and can be directly joined to further distributors after removal of the cover. 6. Temperature control system for injection molding machines with a number of distributors according to one of claims 1 to 7, which are connected to form a composite unit such that the feed and return channels ( 12 , 14 ) are continuously connected to one another.