WO2003039835A1

WO2003039835A1 - Production line for die-casting of plastic products

Info

Publication number: WO2003039835A1
Application number: PCT/FI2002/000859
Authority: WO
Inventors: Nikke Petrola; Sauli RÄMÖ; Petri Virtanen; Martti MÄKIMATTILA; Ossi Wessman; Markku Ahokas; Heikki Marttinen; Jaakko Tuupanen; Matti Vitikainen
Original assignee: Eimo Oyj
Priority date: 2001-11-05
Filing date: 2002-11-05
Publication date: 2003-05-15
Also published as: FI20012133A0

Abstract

The invention relates to the production line for the die-casting of plastic products, the line comprising the die-casting cell (1) with the die-casting apparatus (2) of the product and the transfer apparatus (3) of the product, and the production apparatus is fitted onto a transferable transfer platform (6).

Description

Production ϊine for die-casting of plastic products

The present invention relates to a production line according to the preamble of claim 1 for the die-casting of plastic products.

Production lines intended for the die-casting of plastic products comprise the die- casting apparatus of the product and the transfer apparatus of the die-cast product with transfer lines. Before implementation, the production lines require that production goods, such as water, electricity and compressed air be joined to the production line via water and pneumatic pipelines and electric wirings. The implementation of product lines in production premises usually takes weeks, for example, due to the pipelines and electric lines and wirings having to be planned, drawn to the planned production site and connected to the production line. In this case, considerable investments have to be made in the planning of the wirings and pipelines of the production goods, and the implementation of the production line requires highly spe- cialised professionals. Because the arrangement for obtaining the production goods to the production line at present requires extensive planning and implementation preparations related with the wiring and piping of the production goods, expensive special personnel often has to be used in the implementation of production lines. Another factor complicating the transferability of production lines is the different distribution systems of electricity in different areas; in Europe, a voltage of 400V is mainly used as the voltage between phases for three-phase voltage, as in Japan and USA, among others, a voltage of 200V is used.

The basis for the invention is to achieve a transferable production apparatus intended for the die-casting of plastic products, which does not contain the drawbacks found in the state-of-the-art technology. Thus, it is the first object of the invention to achieve a production line for die-casting, which is possible to implement fast in production plants without having to invest extensively in the wiring of production goods and the planning of pipelines. The second object of the invention is to provide a production line for die-casting, the implementation of which does not require ex- pensive planning and implementation personnel that would have intimate knowledge of the planning and realisation of production lines, piping and wiring. The third object of the invention is to achieve a production line, which is, as far as possible, independent of the electricity supply voltage currently available. The above objects are achieved by the production line according to claim 1 for the die-casting of plastic products. The production line for the die-casting of plastic products comprises the die-casting apparatus of the product and the transfer apparatus of the product, and the production line has been fitted on a transferable transfer platform. Of the production goods of the production line, electricity is introduced to the production line via its electric assembly and compressed air via its pneumatic assembly.

In a second advantageous embodiment of the invention, water needed by the production line is brought to the cooling system of the die-casting apparatus of the pro- duction line through one water assembly. In yet another advantageous embodiment of the invention, the die-casting apparatus of the production line has an essentially closed water circulation.

In yet another advantageous embodiment of the invention, the electric system of the production lines includes a transformer and supply means for electricity, which can convert the voltages between phases of 200 volts and 400 volts so that the input voltage of the die-casting unit is 200V and that of the other devices used in the production line, such as the palletising unit, positioning unit and cooling system is 400V.

The invention is based on four basic ideas. The first basic idea of the invention is that the most important apparatuses and units of the production line for the die- casting of plastic products are arranged as one compact assembly onto an own transferable platform, and such key apparatuses and units are included in the assembly that the production line can be used for producing plastic products a very short time after the implementation of the production line. The production line of the invention is ready on a transfer platform that can be transferred by usual container transport to the desired place, such as another production plant. As the key apparatuses of the production line have been transferred to the production line along with the platform, the considerable advantage is achieved that it is possible to start the production fast, already in a few hours.

The second basic idea of the invention is to introduce both electricity and compressed air to the production line through an own supply assembly. Such a production line comprising one supply assembly for each production good is effortless and simple to implement; electricity is supplied to the production line through the first electric assembly and compressed air through another pneumatic assembly, after which all apparatuses and machines of the production line are ready for use. This provides the considerable advantage that slow planning and realisation of pipelines and electric wirings requiring special personnel can be avoided. A further advantage is that the implementation of the production line does not require specialised personnel either, because the production line is ready to be taken into use immediately after compressed air and electricity have been connected to it by their own connecting plugs.

The third basic idea of the production line of the present invention is to provide the cooling system of the die-casting apparatus of the production line with closed water circulation and to also introduce the possibly required water to the production line through an own water assembly. Thus the advantage is achieved that no water is necessarily needed in the implementation of the production line, if the mould does not change. If the mould is changed, the necessary replacement water can be taken through one water assembly.

The fourth basic idea of the invention is to use a transformer in the electric system of the production line, which can convert the different voltages between phases of 200 volts and 400 volts used in different countries so that the apparatuses and units of the production line can operate irrespective of the operating voltage prevailing in the country in question. With this the considerable advantage is achieved that the production line can be moved from one country to another without changes having to be made in the electric system.

Such transferable production lines intended for the processing of plastic products are also known, for example, from the US patent specification 50214593, the patent document JP 90958 and the US patent specification 5251832. However, these take in no way into consideration the arrangement of production goods to said transfer- able production lines, so that their time of implementation at the production site is considerably longer, and the investments required by the implementation are considerably higher than in the present invention.

The following may be noted of other advantages to be achieved by the present invention: the production line does not require large investments in equipment and the planning of production lines, because the production line is pre-assembled to the transfer platform so that it can be used for producing plastic products all the way to palletising immediately after the implementation. Only part of the supply devices of raw materials and the apparatuses related with the transfer and storing of finished products have to be connected to the production apparatus. Of the production goods, the production line only requires the availability of electricity and compressed air; the production line has a closed water circulation so that the implementation of the production line requires replacement water only if the mould changes. The production line of the invention is an independent, compact assembly, which is located on a small area. This considerably reduces the floor area required by the production line compared with conventional production lines intended for die-casting, especially in the case that a mould elevator intended for the change and repair operations of moulds is connected to the production line, thus eliminating the need for a separate hall elevator in the production rooms. The transferable production line of the invention is especially applicable to situations, in which relatively small series of plastic products of a temporary nature have to be produced, such as test running a new product in premises in which the production itself will not necessarily be performed.

The invention is next described in more detail, referring to the enclosed drawings, in which

Figure 1 is a schematical view of the production line of the invention, seen from above,

Figure 2 is a schematical view of the electrification arrangement of the production line used in the invention, and

Figure 3 is side view of the transfer platform of the die-casting cell.

The production line in Figure 1 comprises the die-casting apparatus 2 and the trans- fer apparatus 3 of the product. The die-casting apparatus 2 comprises the die-casting unit 2; 21, the hydraulic aggregate 2; 22, and the two-piece mould 2; 23. The die- casting unit 21 used in the die-casting apparatus and its activity as such are of a conventional nature. The die-casting apparatus includes as an auxiliary device the mould core that, however, is not needed in the manufacture of all plastic products, and therefore, it has not been shown in the figure. The hydraulic aggregate 22 below the die-casting unit moves the mould core into and out of the mould 23; due to this, the hydraulic aggregate is only used in a case in which the said mould core is used in the die-casting of products.

The die-casting apparatus 2 also includes the feed equipment 4 of plastic material (granulate) and the mould guiding equipment of the die-casting unit (not shown in the figure). The feed equipment 4 of plastic material includes the feeding funnel 41 of the plastic granulate, the drying equipment (heating by an electric resistor) of the plastic granulate remaining inside the feeding funnel, and the vacuum unit 42, by which the plastic granulate is sucked from the storage to the feeding funnel 41. In addition, the feed equipment 4 of plastic material includes the transport equipment 43 of the granulate, shown schematically, and comprising the spiral conveyor 43 a inside the cylinder and the nozzle 43b in the front end of the cylinder. The spiral conveyor transfers the granulate to the nozzle, from which it is transferred to the heated hot channel of the front mould 23; 23 a. The feed equipment 4 further includes the heating apparatus 4; 44 of the hot channel (not shown in the figure), leading into the front mould; it is mould-specific and it is used for heating the input channel (hot channel) of the plastic raw material leading from the nozzle into the front part of the mould. The mould 2; 23 is a two-piece mould, and it comprises the front mould 23 a moving on guides and attached to the fastening plate, and the back mould 23b.

The die-casting apparatus 2 also includes the water-circulated cooling system 6. The water- circulated cooling system 6 is a closed two-piece system comprising the tempering system 6; 6a of the front mould, and the cooling system 6; 6b of the back mould and the hydraulic aggregate. The cooling system 6 has the heating and cooling equipment 61; 61a, 61b and the pipeline 62; 62a; 62b. Of these, the tempering system 6; 6a of the front mould consists of the heating and cooling equipment 61; 61a and the pipeline 62; 62a. The cooling system 6; 6b of the back mould and the hydraulic aggregate again consists of the heating and cooling equipment 61; 61b and the pipeline 62; 62b. The water circulation of the tempering system of the front mould is separate from the cooling system of the back mould and the hydraulic aggregate. Water is heated by a conventional heating resistor and cooled by a compressor. The pipeline contains two separate water circulations, water circulating in which is not mixed; the heating and cooling pipeline 62; 62a tempering the front mould and the pipeline 62; 62b cooling the back mould. The heating and cooling pipeline tempering the front mould keeps the temperature of the front mould on a desired level by adjusting the water temperature of the water chamber in the front mould in a desired way. It is usually not necessary to add water to the water- circulated cooling system 6, because it is a closed, compact water circulation. Water is added to the water circulation only in a case in which the mould is changed; upon changing the mould as much water has to be added to the water circulation as is the volume of the water chamber in the front mould of the new mould. Water is added to the water circulation through the water assembly 6c, which is located in a suitable part of the heating and cooling pipeline 62; 62a of the tempering system 6; 6a.

The transfer apparatus 3 of the product again contains the robot manipulator 31 used as the positioning unit of the product and the palletising apparatus 32. The robot manipulator 31 receives the finished plastic products coming from the die-casting unit and transfers them to the palletising apparatus 32. The palletising apparatus has an assembly line transporting the pallets, to which the plastic products are placed, and the pallet-handling means used for removing the product from the pallet to the product stack and for taking the empty pallet back to the starting end of the assembly line. In the solution shown in the figure, the pallet-handling means are manual. The transfer equipment 3 of the product also includes the control apparatus 33, which controls and synchronises the operation of the die-casting apparatus 2, robot manipulator 3; 31 and palletising apparatus 3; 32.

The production line also includes the transfer line 7 of compressed air, to which compressed air is supplied via the pneumatic assembly 7a. The transfer line of compressed air transfers compressed air to the parts needed by the production line. In the embodiment in the figure, the line network 7' of the transfer line is used for transferring compressed air to the hydraulic aggregate 72 and the mould cleaner (not shown in the figure) and to the vacuum extractor 42 of the transfer apparatus, and to the robot manipulator 31 and the palletising apparatus 32 along the line network 7".

The electric system 8 of the production apparatus is shown in Figure 2. The electric system is provided with the necessary electricity to the transformer 8c either through the electric assembly 8a (input line of 200 volts) or the electric assembly 8b (line of 400 volts), depending on the operating voltage available at the given time. The transformer always supplies electricity to the part 81 of the network electrifying the die-casting unit with a voltage of 200 volts and to the parts 82, 85 of the network electrifying other devices and apparatuses with the voltage of 400 volts. The network part 82 electrifies the hydraulic aggregate 22, the part 83 the water cooling and heating equipment 61 used in the cooling system, the part 84 the heating device 4;44 of the hot channel of the mould, and the part 85 the feeding and drying equipment 4;42 of the plastic granulate.

The above disclosed apparatuses and units of the production apparatus 1 are placed onto a rectangular steel element used as the transfer platform 9, which is described in more detail in Figure 3. Thus, all key apparatuses and units needed in the die- casting of a plastic product are located in one compact space.

The transfer platform 9 shown in Figure 3 has the fastening lugs 9b, to which ropes and/or pulleys can be attached, which can be used for fastening the devices that are most susceptible to be damaged during the transport of the production line, such as the die-casting unit, to the walls of the transport unit and to the platform. The die- casting unit is attached to the platform by elastic fastening organs for the duration of the transport. All apparatuses and units of the die-casting cell are detachably attached to the platform by bolts or L pieces. For facilitating the lifting, the transfer platform contains recesses 9; 96, for example, for transport by forklifts. The width of the transfer platform 9 is less than 8 feet so that it can be transported in a marine container.

As the production line is transferred from one place to another on the transfer platform, it is possible to start the production almost immediately: for starting the production, it is only needed to connect the compressed air via the pneumatic assembly 7a, connect the transformer to the electrical network via the electric assembly 8a or 8b, in the manner described above, and to possibly add water via the water assembly 6c, if it is desired to change the mould.

Only one embodiment of the transferable production line of the invention is presented above, and it is obvious for one skilled in the art that it is possible to realise the invention in many other ways within the scope of the inventional idea disclosed in the patent claims.

Thus, the transfer platform can have other fasteners and lugs for fastening the units and apparatuses of the die-casting cell and for facilitating the lifting; likewise, the shape of the transfer platform can differ from the shape of a rectangle. The length and width dimensions of the transfer platform are selected so that it is possible to transport the transfer platform together with its die-casting cells by a chosen form of transport, which can be either train, car or marine transport. The dimensions of the transfer platform are preferably selected so that the transfer platform with its die- casting cells can be transported in a standard container using any of the above men- tioned forms of transport.

The apparatuses and units included in the production line can also vary somewhat, depending on the plastic products to be manufactured. However, the die-casting cell always comprises the die-casting unit for manufacturing the products and the transfer apparatus of the product, by which the products are transported to a suitable place for storing and/or further processing. It is also possible to provide the production line of the invention, for example, with a mould hoisting apparatus for the mould changing and repair operations so that no separate hall elevator is needed for these operations in the production premises.

Claims

1. Production line (1) for the die-casting of plastic products, comprising the die- casting apparatus (2) and the transfer apparatus (3) of the product, the production line (1) being fitted on a transferable transfer platform (9), characterised in that, of the production goods needed by the production line, compressed air is brought to the production line via the first compressed air assembly (7a) and electricity is brought to the production line via the second electric assembly (8a or 8b).

2. Production line (1) according to claim 1, characterised in that water required by the production line is brought to the cooling system (6) of the die-casting appara- tus (2) via one water assembly (6c).

3. Production line (1) according to any of the preceding claims, characterised in that the water circulation of the cooling system (6) of the die-casting apparatus (2) is substantially closed.

4. Production line (1) according to any of the preceding claims, in which the die- casting apparatus (2) comprises the die-casting unit (2; 21), to which the mould (2;

23) can be fitted, and the feed equipment (4) for plastic raw-material, characterised in that the cooling system (6) of the die-casting unit (2) comprises the cooling system (6; 6b) for the back mould (23; 23b) of the die-casting unit, and the tempering system (6; 6a) for the front mould (23; 23a), the water circulations of which are sub- stantially closed.

5. Production line according to claim 4, in which the transfer apparatus (3) of the product comprises the product positioning unit (31) and the palletising unit (32), characterised in that the electric system of the production line has a transformer and power supply equipment that can convert the input voltage of the electric units (8a, 8b) of 200 volts or 400 volts to the supply voltage of 200V to the die-casting unit (2; 21) and to the supply voltage of 400V to the palletising unit (32) and the positioning unit (31).

6. Production line according to claim 5, characterised in that also the supply voltage of the hydraulic aggregate (22) and the heating apparatus (4; 44) of the hot channel is converted to 400 V.

7. Production line according to any of the preceding claims, characterised in that compressed air comes to the production line from the pneumatic assembly (7; 7a), after which it is distributed to the die-casting apparatus (6) by the first line network (7; 7') and to the product transfer apparatus (3) by the second line network (7; 7").

8. Production line according to any of the preceding claims, characterised in that the transfer platform (9) is a steel or cavity slab, which comprises transport supports (9b), such as fastening lugs, and lift supports (9a), such as lifting recesses.

9. Production line according to claim 4, characterised in that the transfer platform (9) can be fitted to a transport container.

10. Production line according to any of the preceding claims, characterised in that the die-casting apparatus (2) and the product transfer apparatus (3) are detachably attached to the transfer platform (9) .