SK642005A3 - Device for injection of moulding plastic shaped pieces - Google Patents

Abstract

Device for injection moulding of products from artificial material consists of an injection moulding machine (1) as well as corresponding tools (2), while an integral part of the tools (2) are at least two mould cavities (11, 12) corresponding in size with the products to be produced. The tool (2) consists of at least three parts (4, 5, 6) which are movable relatively one against the other, featuring at least one channel (13) for the supply of the molten man-made mass. On parts (4, 5, 6) of the tool (2) there is between two positions a position-adjustable locking means by which it is possible to lock only the central (5) and front (4) part of the tool in the first terminal position, while in the second one only the central (5) and the rear part (6) of the tool (2) can be locked. For this purpose, there is in the central part (5) there is at least one driving mean (19) with one slider piece (18) being movable toward the axis of the tool (2) and which is via its driving unit (19) shiftable in its longitudinal direction in two opposite sides between two terminal positions. Apart from that, there is on the tool (2) itself in the area of the current separating plane (9, 10) at least one clamping device (K) having one part always located in the central part (5) of the tool (2), while the other part is currently interacting with the first one, from one side, attached to the front part (4), of the tool (2), and on the other, at the rear part (6) of the tool (2) as the second part of the clamping device (K). Moreover, both the front part (4) and the rear part (6), of the tool (2) as the second part of the clamping device (4) have attached one slider (20, 21) reacing out in the axis of the tool (2) which at the position of the closed tool (2) with one of its ends goes into the suitable first part of the clamping device (K) and at the ending it has at least one clamping device (K) and at that end it has at least one pusher (R). The slider (18) in both of its terminal positions due to the snapping of the pusher (R) each time fits with the corresponding clamping device (K).

Description

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for injection molding of plastic fittings comprising an injection molding machine and a tool associated therewith, wherein at least two cavities are provided in the tool corresponding to the dimensions of the fittings produced. which, in the working position, adhere to one another along the dividing planes which extend through the cavities perpendicular to the direction of movement of the parts and run parallel to each other, each dividing plane extending through the at least one cavity and in which at least one channel is provided The material ends in cavities on the one hand and on the other hand at an entry point on the surface of the tool which, in the working position, is connected to an injection molding machine (German magazine "Kunststoffe 84" (1994) 10, pages 1375 to 1382).

BACKGROUND OF THE INVENTION

Injection molding machines are used for the production of fittings with almost any shape. Only cavities into which molten plastic may be injected shall be provided in the instrument concerned. The tool parts separated by a separating plane are compressed together, for example hydraulically, in the working position. After the plastic has been injected into the tool cavities, the tool remains closed in the prior art for as long as the molded parts in the cavities cool sufficiently and thus become stronger that they can be removed from the tool. To do this, the tool opens in the dividing plane, whereby its parts are separated from each other. The injection molding machine is not used during the time during which the molded plastic is cooled in the cavities. This disadvantage is particularly serious when relatively thick-walled fittings with a long cooling time are to be produced.

The performance of the injection molding machine can be increased when using a tandem working tool according to the above-mentioned German magazine "Kunststoffe 84". In an injection molding machine working with such a tool, the parts are opened alternately in two scraping planes. During the cooling period of the fittings of one separation plane, the fittings can be removed from the other separation plane from the mold. This method of operation is advantageous for fittings with a cooling time that is longer than the dosing time required to fill the cavities. Tandem injection molding machines are expensive special machines. They require a movable center plate located in a central position to which the injection unit is laterally connected. The molten plastic is injected through the channels arranged in the central plate into the respective cavities. This known tandem method cannot be used in conventional injection molding machines or can only be used after extensive conversions.

SUMMARY OF THE INVENTION It is an object of the present invention to provide the aforementioned device in such a way that the production of finished fittings can easily be increased even when using conventional injection molding machines, safely blocking those separating planes that are not to be opened.

SUMMARY OF THE INVENTION

This task is achieved in plastic injection molding machines consisting of an injection molding machine and a tool associated therewith, in which at least two cavities are available in the tool corresponding to the dimensions of the fittings produced, in which the tool consists of at least three relatively movable relative to each other. parts which, in the working position, adhere to one another along the parting planes, which extend through the cavities perpendicular to the direction of movement of the parts and run parallel to each other, each parting plane extending through the at least one cavity and in which at least one molten channel is provided In accordance with the invention, a plastics material which terminates on the one hand in the cavities and on the other hand at an entry point on the surface of the tool which is connected to the injection molding machine in a working position is provided by providing a channel in the tool. dividing plane and next extending to the second dividing plane from which the sub-channels extend up to the cavities and that a locking is provided on the tool parts, which is adjustable between two positions, whereby only the middle part and the front part of the tool comprising the channel entry point, and in the second position only the middle part and the rear part of the tool.

This device is usable without conversion and special additional modifications for conventional, usually sold injection molding machines. It only needs a simple tool, with two parts separated by a separation plane, to be replaced by a new tool consisting of three parts with two separation planes. Similar to the tandem method described, the production of fittings is increased with this tool, while the plastic injected into the cavities in the other separation plane is cooled during removal from the mold in the region of one separation plane. For this device, the blocking applied to the tool parts during the respective cooling phase is essential. It is easily adjustable between two positions. While two pieces of the tool are locked between each other while cooling the fittings, in the presence of a residual force that holds them firmly together, the separation plane to the third piece can be simultaneously opened to remove the finished pieces from the mold. After the closure plane is closed and the plastic is injected into its cavities, the locking is brought to its second position during the still tightly closed tool. The two parts of the tool with the newly filled cavities remain then locked to each other tightly on top of each other, while the previously locked separating plane can now be opened to remove between the cooled molds from the mold once the pressing force on the tool is canceled during the injection operation.

This blocking task is also solved by an injection molding device of plastic fittings consisting of an injection molding machine and a tool associated therewith, in which at least two cavities are provided in the tool, corresponding to the dimensions of the fittings produced, in which the tool consists of at least three relatively movable parts, the front part, the middle part and the rear part, which, under the action of a pressure exerting device in the working position, are adjacent to one another along the dividing planes which run parallel to each other in which at least one molten supply channel is formed plastic ending on one side in the cavities and on the other side at an entry point on the surface of the tool which is connected in the working position to an injection molding machine, in which the tool parts are locked, adjustable between the two end positions only the middle part and the front part of the tool provided with an entry point are locked in the first end position during the disconnected pressure generator and in the second end position only the middle part and the rear part of the tool, which according to the invention consists in providing at least one middle part of the tool drive with at least one slide switch (slide) extending in the direction of the tool axis, which is adjustable by drive in two opposing directions in its longitudinal direction between two end positions, and furthermore arranged on the tool in the region of each cutting plane one clamping device, of which the first part is always located on the middle part of the tool, while the second part, which cooperates with the corresponding first part, is fixed on one side to the front part of the tool and on the other side to the rear part of the tool; is on the front and rear of the rear At least one holder extending in the direction of the tool axis, which, when the tool is closed, engages one end in the corresponding first part of the clamping device and is provided with at least one clamping body at this end, and that the slide switch (slide) in each case from its end positions it interferes with the locking operation of the clamping body in the corresponding clamping device.

This blocking is particularly simple. It consists essentially of a drive with a slide switch (slide) and two clamping devices in which the slide switch (slide) alternately intervenes. In order to effect an effective locking between two tool parts in each case, the sliding switch (slide) needs to be pushed by the drive into only one of the clamping devices so that their clamping body is moved to the closing position. In the respective closing position, the slide switch (slide) is pulled out of the clamping device lying always in the region of the respective second cutting plane, so that the tool can be opened in this cutting plane.

The aforementioned device is further preferably designed such that two separate clamping devices and two slide switches (slide valves) are formed on the tool in the region of each cutting plane.

In an even more preferred embodiment of the device, at the ends of the holders which engage the corresponding parts of the clamping devices in the locked position of the tool, at least one transversely clamping body extends beyond the tool axis direction and engages in the locked position beyond the stationary stopper forming the first part of the clamping device. mounted on the middle part of the tool.

In an even more preferred embodiment of the device, the clamping body is designed as a roller rotatable freely about its axis.

In an even more preferred embodiment of the device, a clamping body is arranged on two opposing sides of the holder and two corresponding stops are always attached to the central part of the tool.

The drive may advantageously be controlled automatically. This can be done by pneumatically or electrically operating drive. Preferably, however, a hydraulic drive is used.

The lock, consisting of a drive with a slide switch and a clamping device, can advantageously be positioned to save space inside the tool profile. Thus, the locking parts will not increase the external dimensions of the tool. Depending on the size of the tool, preferably at least two locks are located on two opposite sides of the tool.

Overview of the figures in the drawing

The subject matter of the invention will be explained in more detail by means of the exemplary embodiments shown in the drawings. The figures show the following:

Fig. 1 is a partial cross-sectional view of the device according to the invention in the closed position, FIG. 2 and 3 are two different open positions of the device of FIG. 1, FIG. 4 is a principle view of the blockage used in the apparatus; FIG. 5 in relation to FIG. 4 shows a supplementary embodiment of the device, FIG. 6 and 7 are the devices of FIG. 5, in the corresponding open positions of FIG. 2 and 3, FIG. Fig. 8 is an enlarged view of a holder usable in the apparatus; 9 is a cross-sectional view of the holder of FIG. 8 along the plane IX-IX.

In the drawings, only those parts of the injection molding device which are necessary for understanding the invention are shown. Essentially known elements of the device, such as an opening and closing mechanism or cooling channels or a heating device, are not shown. In FIG. 4 to 7, for greater clarity, the dashing of parts in cross-section is omitted.

DETAILED DESCRIPTION OF THE INVENTION

The injection device of FIG. 1 consists of an injection molding machine f and a tool 2 attachable thereto. The injection molding machine 1 can be a conventional, usually marketed machine without any special equipment. The machine is movable in the direction of the double arrow 3.

The tool 2 consists of three parts, a front part 4, a middle part 5 and a rear part 6. It is closed on the rear part 6 by a pressure plate 7, which is connected to the pressure generator 8. For example, pneumatic or hydraulic Es can be used as pressure generators. The three parts of the tool 2 are separated from each other by two mutually parallel dividing planes 9 and 10. In each dividing plane 9 and 10, at least one cavity 11 and 12, respectively, of the tool 2 can be formed, the clear dimensions of which correspond to the geometric shape of the fittings. In the embodiment shown, two cavities 11 and 12 are shown for each deflection plane 9 and 10, respectively.

In the embodiment shown, a channel 13 is centrally formed in the tool 2, which serves to supply molten plastic to the cavities 11 and 12. The channel 13 begins at an outwardly open entry point 14 lying on the surface of the tool 2. It first passes through the tool part 4 to the dividing plane 9 and then extends further through the central part 5 of the tool 2 to the dividing plane 10. In order to allow the plastic material referred to as a spout to be simply removed from the channel 13 after cooling and molding and removing it from the mold 13. correspondingly conical in both sections, as shown in the drawing. Partial channels 15 and 16, respectively, extend from the channel 13 and lead to the cavities 11 and 12, respectively. The partial channels 15 and 16 lie preferably in the separation planes 9 and 10.

The device according to the invention is shown in FIG. 1 in the operating position. For example, it works as follows:

The three parts 4, 5 and 6 of the tool 2 lie close together in the working position. They are pressed together by the data generator 8 and against the support plate 17 serving as a fixed support on which the front part 4 of the tool 2 is located. To produce the fittings in the cavities 11 and 12, the injection molding machine 1 extends up to the inlet 14 of the channel 13 on the tool 2. The molten plastic present in the injection molding machine 1 can then be pushed into the channel 13. Through the channel 13 both the partial channels 15 and 16 as well as the cavities 11 and 12 are filled. When the cavities 11 and 12 are filled using sufficient pressure, the machine 1 closes. The plastic present in the tool 2 is then cooled.

After a sufficient cooling time, the tool 2 opens, for example, in the screed plane 9. The parts 5 and 6 of the tool 2 remain locked together by means of a lock, which is explained below. After the pressure force exerted by the pressure generator 8 has been switched off, it can be brought to the position shown in FIG. 2. The locking is preferably carried out in such a way that, after the pressure extinguishing force 8 has ceased, a residual force remains that holds the two parts 5 and 6 of the tool 2. The fittings produced in the cavities 11 can now be removed from the tool. which remains in the channels 13 in the front part 4 of the tool 2 is removed, for example, by means of damp air, so that this part of the channel 13 is free again.

The tool 2 is then brought back to the closed or operating position, as shown in FIG. 1, in which its parts 4, 5 and 6 are firmly pressed against each other by a pressure generator 8. The cavities 11 are again filled with plastic. Subsequently, the locking is adjusted so that the tool parts 5 and 4 are locked together as described for the parts 5 and 6. The tool 2 is then opened in the dividing plane 10, with only its rear part 6 with the pressure plate 7 displaced to the position shown in FIG. 3. It is now possible to remove the finished fittings from the cavities 12. During this time, the plastic is cooled in the cavities 11 in the dividing plane 9. The inflow located in the part of the channel 13 which is in the central part 5 is removed for example using dak air.

The tool 2 is then brought back into its closing or operating position, as shown in FIG. 1. The cavities 12 are refilled with plastic and the parts 5 and 6 are locked together. In the meantime, the fittings in the cavities 11 have been cooled, so that the tool 2 can be opened in the separation plane 9 as described above. In this way, the cavities 11 and 12 are continuously filled alternately with plastic and after cooling the mold is removed.

In order to cool the plastics in the cavities 11 and 12, it is necessary, as already mentioned, that the two respective parts of the tool 2 always remain locked after the pressure force exerted by the vacuum generator 8 has ceased. For this purpose, the blocking containing the residual force according to FIG. 4 to 7, which is provided on at least one side of the tool 2, but preferably on at least two different sides of the tool 2. The construction of the locking and the manner of its operation are described below.

The blocking consists of the schematic representation in FIG. 4, in which the tool 2 of the device is shown in the cut-out in the closing or operating position, respectively, from a drive 19 equipped with a rod-shaped slide switch 18 and two two-part clamping devices K surrounded by a dashed line. The slide switch (slide) 18 extends in the direction of the tool axis 2. The slide switch (slide) is slidable in this direction between the two end positions. In each clamping device K, the first part comprises a holder 20 and 21, respectively, extending in the direction of the tool axis 2, of which the holder 20 is fixed to the front part 4 and the holder 21 is fixed to the rear part 6 of the tool 2.

As the second parts of the clamping devices K, they are fixed to the central part 5 of the tool 2 in each case in the region of the dividing planes 9 and 10 on one side of the stop 22 and 23, as well as the stops 24 and 25 on the other side.

At least one stop on the clamping device K should always be provided. The distance between the stops always corresponds to the width of the holder 20 and 21, respectively, which, as the first part in the respective locking position of the tool part, protrudes into the corresponding second part. slips between the two stops. Each holder 20 and 21, respectively, have at their free end two clamping bodies R, at least one clamping body R being to be provided, which are displaceable transversely to its respective longitudinal direction on or in the respective holder.

The clamping bodies R are preferably cylindrical and are freely rotatable as well as adjustable laterally, transversely to the direction of the tool axis 2, and positioned on the respective holder 20 and 21 respectively. In the rest position they lie in the profile of the holders as shown in Fig. 4 on the right side for the holder 20 and are moved outwardly by the slide switch 18 so that, in the locked position of the tool 2, they engage the stops as shown in FIG. 4 on the left for holder 21 and stops 24 and 25.

The slide switch 18 is slidable in the directions of the double arrow 26, i.e. in opposite directions between the two end positions. In one, in FIG. 4, the slide switch 18 slides into the clamping device K in the region of the dividing plane 10 so that the middle part 5 and the rear part 6 of the tool 2 are locked together. In addition, the slide switch (slide) 18, as already mentioned, has moved the rollers R out of the bracket 21 so that they now lie behind the stops 24 and 25. Since the rollers R are mounted in the bracket 21 as freely rotatable and movable laterally, For example, when the slide 21 is pulled out of the stops 24 and 25, the slide slide switches 18 are moved back to their rest position in the respective holder as shown for the holder 20.

The interaction of the clamping devices K and the slide switch 18 will be explained by way of example with reference to FIG. 8 and 9, in which the end of the holder 20 is enlarged.

At the end intended to interfere with the clamping device K, the bracket 20 has a slotted cutout 27 extending in its longitudinal direction, approximately in the middle, into which a sliding switch (slide) 18 engages in the locked position of the clamping device 18. The cutout 27 is shown open outwards at two opposite locations. Two freely rotatable clamping bodies are provided at these points, designed as rollers and movable transversely to the longitudinal direction of the bracket 20. They may also be provided, on the front surfaces, with circular recesses in which the pins 28 which are attached to the bracket 20 engage. In the drawing above, it is integrated into the profile of the holder 20 so that it can move around the stop 22. The lower roller is pushed out of the holder 20 by a slider 18 indicated by a broken line so that it lies in a locked position behind the stop 23.

In principle, each holder 20 and 21 requires only one clamping body R. Then only one stop is required on the tool part 5 at a time. However, because of the symmetry, the described embodiment is always advantageous with two clamping bodies R and two respective stops. The clamping bodies R may have a different geometric shape from the roller shape mentioned above.

In a preferred embodiment, two separate clamping devices K are provided on each side of the tool 2, as shown in FIG. 5 for one side of the tool 2. Thus, unwanted opening of the tool 2 in the separation planes 9 and 10 during the locking phase is avoided with greater certainty. In this embodiment, the actuator 19 is provided with two slide switches (sliders) 18, which are mounted on a common carrier 29, and therefore the actuator 19 adjusts them synchronously.

The blocking described above operates from the operating position of the device of FIG. 5, for example as follows:

As long as the pressure generator 8 is switched off, it will be as shown in FIG. 5 to lock the two tool parts 5 and 6 together. For this purpose, the two slide switches 18 have been moved by the drive 19 between the rollers R of the two holders 21. The tool parts 5 and 6 are thus held together with sufficient residual force. . To remove the fittings from the cavities 11, the tool 2 can now be opened in the separation plane 9, as was analogous to FIG. 2 shown in FIG. 6th

After the fittings have been removed from the cavities 11, the tool 2 is closed again and the plastics are again injected into the cavities 11 under the active pressure generator 8. Before removal of the fittings from the cavities 12 of the separating plane 10, a locking is provided for the front part 4 and the middle part 5 of the tool 2. To this end, the drive 19 shifts the slide switches 18 to the second end position in which the slide switches 18 push the rollers R This locking position of the tool 2 results in an analogous manner to FIG. 3 of FIG. 7th

Claims (6)

PATENT CLAIMS Apparatus for injection molding of plastic fittings, consisting of an injection molding machine (1) and a tool (2) corresponding thereto, in which at least two cavities (11, 12) are provided in the tool (2) corresponding to the dimensions of the fittings produced in which the tool (2) is comprised of at least three relatively movable parts (4, 5, 6) which are fixed to one another in the working position along the dividing planes (9, 10) which extend through the cavities (11, 12) perpendicular to the direction of movement of the parts and running parallel to each other, each division plane (9, 10) extending through at least one cavity (11, 12) and having at least one molten plastic channel (13) in the tool (2), which terminates on the one hand in the cavities (11, 12) and on the other hand at an entry point (14) on the surface of the tool (2) which is connected in the working position to the injection molding machine (1) (2) formed by can a channel (13) extending from the entry point (14) to the first partition plane (9) and further extending to the second partition plane (10) from which the individual channels (15, 16) extend, extending to the cavities (11), 12), and that there is a lock on the tool portions (4, 5, 6) which is adjustable between two positions, whereby only the middle portion (5) and the front tool portion (4) are locked together in the first position (4). 2), comprising an entry point (14) of the channel (13), and in the second position only the middle part (5) and the rear part (6) of the tool (2). An apparatus for injecting plastic fittings, consisting of an injection molding machine (1) and a tool (2), in which at least two cavities (11, 12) are provided in the tool (2) corresponding to the dimensions of the fittings produced. , in which the tool (2) comprises at least three relatively movable parts (4, 5, 6), a front part (4), a middle part (5) and a rear part (6), which interact with each other during the action of the data generator (2). 8) in the working position they are fixed to one another along the dividing planes which run parallel to each other, in which at least one molten plastic supply channel (13) is formed in the tool (2), which terminates on one side in the cavities (11, 12) and, on the other hand, at an entry point (14) on the surface of the tool (2), which in the working position is connected to the injection molding machine (1), in which a blocking is formed on the tool parts (2). positions in which only the middle part (5) and the front part (4) of the tool (2) provided with an entry point (14) are locked together in the first end position with the generator (8) disconnected, and in the second end position only the middle part (5) ) and a rear part (6) of the tool (2), characterized in that at least one actuator (19) with at least one slide switch (18) extending in the direction of the tool axis (2) is arranged on the middle part (5) of the tool (2). ), which is Λ / adjustable by drive (19) in two opposite directions in its longitudinal direction between two end positions, furthermore, in that at least one clamping device (2) is also provided on the tool (2) in the region of each cutting plane (9, 10) K), of which the first part is always located on the middle part (5) of the tool (2), while the second part, which cooperates with the corresponding first part, is fixed on one side to the front part (4) of the tool (2) and on the other hand on the rear part (6) of the tool (2), in that at least one holder (20) is fastened to the front part (4) and the rear part (6) of the tool (2) as a second part of the clamping device (K). 21) extending in the direction of the tool axis (2) which, when the tool (2) is closed, engages one end in the corresponding first part of the clamping device (K) and is provided at this end with at least one clamping body (R); ) always in poison from its end positions, it interlocks to lock the clamping body (R) into the corresponding clamping device (K). Device according to claim 2, characterized in that two separate clamping devices (K) and two slide switches (18) are formed on the tool (2) in the region of each cutting plane (9, 10). Device according to claim 2 or 3, characterized in that at the ends of the holders (20, 21) which, in the locked position of the tool (2), engage corresponding parts of the clamping devices (K), at least one transverse to the tool axis (2) a movable clamping body (R) which, in the locked position, engages a fixed stop (22, 23, 24, 25) forming the first part of the respective clamping device (K) and fastened to the middle part (5) of the tool (2). Device according to claim 4, characterized in that the clamping body (R) is designed as a roller rotatable freely about its axis. Device according to claim 4 or 5, characterized in that a clamping body (R) is arranged on two opposing sides of the holder (20, 21) and two corresponding parts are always fastened to the central part (5) of the tool (2). stops (22, 23 and 24, 25, respectively).