DE2548254C3 - Device for injection molding of 180 degree pipe bends with subsequent cylindrical pipe section - Google Patents

Description

The invention relates to a device for injection molding of 180 ° pipe bend with subsequent cylindrical pipe section, comprising a shape with a die and a movable punch adapted to it, both of which correspond to one another Have recesses, which in turn, when the shape of the outer contour of the entire pipe section is closed correspond, as well as inside this, - recesses a two-part, consisting of a circularly curved and a cylindrical straight section Mold core, further means for pulling the mold core out of the recesses, the cylindrical straight section of the mold core in a straight line and the circularly curved section in the opposite direction Direction is rotatably guided according to its arc curvature.

Such a device is to a certain extent from the German Auslegeschrift 1114 027 known. There, however, it is a partly straight and partly curved tubular body part, its The footsteps are in two mutually perpendicular planes (cf. in the above-mentioned publication Column 1, lines 9-10 and column 7, lines 16-17). This means that there is a 90 ° bend with a straight section is present. The bow section can, as indicated in detail, by a simple rotary movement of the Arch core to be demolded. However, this is the case with a 180 ° bend followed by a cylindrical pipe section not possible because the pulled-out end due to the required large angle of rotation of almost 180 ° of the arc core would destroy the cylindrical gap in the pipe with its contour or a tarnishing of the 180 ° arch core to these two elements Demolding movement of the arch core well before it reaches its end position for demolding would prevent, so that a complete demolding of the arc core is not with a rotary movement

could take place.

In contrast, the invention is based on the object of providing a device of the type outlined at the outset Kind to improve so that the disadvantages mentioned do not occur, that the device is rather a combination from a turning, a lifting, a spiral and a tilting movement with a subsequent lifting and Tilt the I30 ° pipe bend connected to the cylindrical pipe section in front of the bend core enables ι ο

This object is achieved according to the invention in that the arcuate core part has a curvature of 180 ° and when demoulding first a relatively small rotational movement in its circular path and then a spiral movement of the outer contour of the pipe bend with it cylindrical straight piece in the tool on the side of the punch starting in the direction of the side of the Die executes, during this spiral movement of the arcuate core part of the cylindrical Core part and thus also the pipe bend with its cylindrical straight section a tilting movement is issued in such a way that the pipe bend is together his cylindrical straight piece pivots in front of the arcuate core part and this thus swivels during its spiral movement behind the pipe bend with its cylindrical straight section in a spiral shape turned past.

The solution according to the invention guarantees! - how immediately obvious - a considerable technological advance

This is because it enables a significantly increased intensification of the workflow during the injection molding process, and it also allows an automatic one Manufacture of the pipe elbows, which is what happens in the manufacture of Ji Pipe sections with a curvature of 180 ° with an adjoining cylindrical pipe section previously without, the use of manual labor was not possible. Another advantage of the device according to the invention is that when you open the mold of the cylindrical 4n Core part is inevitably pulled out of the pipe section.

The German Auslegeschrift 18 01 683 should also be referred to regarding the state of the art. The one specified there Solution (movement of one part of the body on one part Circular path and then away from the center of this path; Movement of the other core part also a circular path) is not for a 180 ° bend with an adjoining straight pipe section applicable, since the demolding of the cylindrical w Pipe part can not be made circular. The remaining arched core with the 180 ° arch with it subsequent cylindrical tubular part can therefore be used with those specified in the above-mentioned patent application Means are not demoulded, because here too the "arcuate core" is at a circular angle of 180 ° Always perform the required demoulding rotary movement of 180 ° ni '.- ht in the movement sequences described can because it can only move in one plane and thus with the injection molded part and its contour eo collides or prematurely to a standstill before the end of its required demoulding rotary movement comes.

The invention also allows a number of particularly advantageous embodiments, the fr / characteristic features are laid down in the subclaims.

In particular Äst provided (see. Claim 2) that the arcuate core part via a rotary arm a spindle is attached and on the side remote from this spindle a guide pin for engagement in has a recess of a cam connected to the die. Preferably there is the recess from a longitudinal groove parallel to the opening direction of the mold, one adjoining it inclined groove section and a funnel-shaped insertion groove (cf. claim 3). With these measures it is achieved that the arc-shaped attached to the rotary arm Core part is only set in rotation after a certain opening path of the mold. During this through the inclined groove section controlled rotary movement of the rotary arm is the arcuate core part of the Inner wall of the outwardly widening pipe section torn loose, v / o by the adjoining one Helical turning out of the arcuate core part from the pipe section is made much easier.

Furthermore (see. Claim 6) a.i stamp is one the Rotary arm during the through the slant ,. Groove section caused rotational movement holding guide member attached This development grants the Advantage that, despite greater demolding forces when the arcuate core part is torn away, there are no strong Bending moments or other forces are exerted on the rotary arm, which is only fixed in one spindle. So will prevents premature wear of the nut placed on the spindle

As far as the spindle carrying the rotating arm is concerned in detail, the ejector plate is (cf. claim 8) by means of an ejector rod after the guide pin has emerged from the inclined groove section of the Cam and can be moved towards the stationary die when the nut is locked.

Tilting of the pipe section between the rotary arm and the punch when the arcuate core part is pulled out can be prevented in a development of the invention by an ejector pin on the Ejector plate is arranged and acted upon by compressed air or springs (see. Claim 10). This However, the ejector pin initiates the tilting movement into the free space between the arcuate one Core part and the die. With these measures, the arcuate core part is turned out when unscrewing the pipe section, which is prevented from rotating by a stripper (see. Claim 9), the arc-shaped core part a spiral movement and the pipe section itself given a tilting movement, so that the pulled out end of the arcuate core part passes next to the pipe section, which in the Manufacture of pipe sections with a curved curve «Όπ 180 °, which is also an adjoining Have cylindrical pipe section, is very advantageous.

The invention is illustrated below using a particularly advantageous exemplary embodiment with reference to the drawing explained in more detail. It shows

F i g. 1 shows a section through a device along the line If of FIG. 2,

F i g. 2 a view in partial section of the stamp with the mold open (section plane H-II in

G)

3 is a view in partial section of the die with the mold open (section plane I1I-III in Fig. 1),

F i g. 4 shows a section along the line IV-IV in FIG. 2,

F i g. 5 in the developed representation, the curve plate in the direction of the arrow V in FIG. 3 seen

F i g. 6 shows a section along the line V! -VI in FIG. 2 to show the core lock,

F i g. 7 shows an enlarged illustration of a rotary arm corresponding to the sectional illustration in FIG. 2,

8 shows a section along the line ViIi-ViII of Fig. 7,

F i g. 9 is a view of the arcuate core part;

FIG. 10 shows an enlarged illustration of that in FIG. 1 only partially shown ejector rod,

F i g. 11 is an enlarged sectional view of the FIG Fig. 1 indicated ejector pin, and

Fig. 12 is a manufactured with the device Annular pipe section with an adjoining cylindrical pipe section.

The injection molding tool shown in the figures consists essentially of a die 10 and a corresponding punch 12 having form 14. The die 10 is by means of a screw iS attached to a GcScfikpiäiic io, which in turn with a fixed platen 20 is screwed.

When the mold 14 is closed, the die 10 rests on the corresponding punch 12, which is on a Stamp plate 22 is screwed tight. This is attached to a mounting plate 26 by means of a plurality of screws 24 Both are fixed by spacers 28, which are penetrated by the screws 24, at a distance held.

The mold 14 is used for the simultaneous production of two pipe bends 30 with a curvature of 180 ° and an adjoining cylindrical straight piece 112 (see. Fig. 12), so that the die 10 and the Stamp 12 have two mirror-symmetrically designed cavities 32 into which the plasticized Material can be pressed. For this purpose, the two cavities 32 are provided with a common sprue bushing 34 connected, via which the plasticized material is pressed into the cavities 32. In the cavities 32 is furthermore a core is provided, which consists of an arcuate core part 36 and an adjoining, serving as a slide, substantially rectilinear cylindrical core part 38 consists. When closed Form i4 HeEt the cylindrical core part 38 with a The end face fits snugly on the opposite end face of the arcuate core part 36. For centering serves a centering bolt 40, which is screwed in the cylindrical core part 38 and with its protruding The end protrudes into a centering bore 42 of the arcuate core part 36. To be able to pull out the To facilitate arcuate core part 36 from the finished molded pipe bend 30, the tapers arcuate knobs "36, so that the center hole 32 having end has a smaller diameter than the opposite end.

In Fig. 12 it is indicated that the pipe bend 30 its free end has a thread +4 To produce this thread 44 are both on the die 10 as well as two threaded half-shells 46 attached to the punch 12, as shown in particular in FIGS. 1 and 4 can be seen. These threaded half-shells 46 fit tightly around the cylindrical core part 38.

The cylindrical core part 38 is, as shown in FIG. 1 shows, screwed to a slide 48. 1 drawn in arrow Z is guided longitudinally in the punch 12. The slide 48 is provided with an inclined bore through which an inclined pin 50 penetrates. This inclined pin 50 is fastened in the die plate 18

As can also be seen from FIG. 1, a cam disk 52 is fastened in the die plate 18 and has a partially cylindrical shape (cf. FIG. 3). With its part protruding from the die 10, the cam disk 52 engages in an opposite recess 54 of the punch plate 22 for guidance. Like F i g. 5 shows, a recess 56 is incorporated into this cam disk 52. This consists of a longitudinal groove 58, an adjoining inclined groove section 60 and a funnel-shaped adjoining insertion groove 62. The longitudinal groove 53 runs parallel to the opening direction of the mold 14 (direction X in FIG Longitudinal groove 58 preferably has an angle of 30 °

Β includes.

A guide pin 64 of a rotary arm 66 engages in the recess 56 of the cam disk 52. This Rotary arm 66, which is shown in FIG. 7, is in the recess of a spindle 68 by means of a screw 70

attached. The spindle 68 is, as FIGS. 1 and 4 show, stored in an ejector plate 72, which by means of an evaluation rod 74 in the direction of the stationary Die 10 is movable.

A nut 76 is placed on the spindle 68 and is rotatably supported within the punch plate 22 Plastic-coated plain bearing sleeves 78 are preferably used for storage.

In the f i g. 2, 7 and 8 as well as in FIG. 4 it is indicated that the rotary arm 66 is connected to the arcuate core part 36. For this purpose, the rotary arm 66 has a recess 80 which is adapted to the shape of the arched core part 36 and which receives the arched core part 36. 9, from which the upper exit of the recess 80 protrudes in FIG. 2 and 7, the arrow Y and the arc-shaped core member 36 taken along in this direction.

.e;, t a

Guide member 84 is fastened, which engages with a finger 86 in a corresponding recess of the rotary arm 66. This ensures that the rotary arm 66 cannot bend in the event of a movement controlled by the recess 56 in the cam disk 52.
On the ejector plate 72, as in particular FIG. 2 and 4 show a stripper 88 attached which acts with a semicircular recess 90 on the thread-free side of the pipe bend 30 and prevents its rotation when the arc-shaped core part 36 is pulled out

The device works as follows:

After the cavities 32 is filled via the Angußbruchse 34 platischem material and thus two identical pipe sections have been prepared, the mold 14 is opened for removal of the two pipe pieces For this purpose, the clamping plate 26 with the punch plate 22 and the attached punch 12 in the direction X (see Fig. 1). During this opening movement, the oblique pin 30 pulls the slide 48 with the cylindrical core part 38 attached to it out of the end of the injection-molded pipe section containing the thread 44. The slide 48 with the cylindrical core part 38 performs a movement in the Z direction relative to the punch 12

(see Fig. 1). By the above-mentioned guidance of the slide 48 in the punch 12 is only one Longitudinal movement possible in the specified direction. At the end of this stroke in the Z direction are the Slide 48 and the cylindrical core part 38 attached to it out of the movement path of the rotary arm 66 pulled out. During this first opening movement, the one attached to the pivot arm 66 moves Guide pin 64 in the longitudinal groove 58 of the cam disk 52, so that a rotary movement of the rotary arm 66 in this phase is not yet taking place.

When the ram 12 is moved further in the X direction, the guide pin 64 of the rotary arm 66 then enters the inclined groove section 60 of the cam disk 52, so that a rotation of the rotary arm 66 is initiated. The arcuate core part 36 fastened to the rotary arm 66 is thus - in the exemplary embodiment by about 24 ° - from the finished C7pcnrit7t «> n Rr» hrcti * ir * L · horaiiccrAHriHt OaV \ «> t \ sot \ rt Aar _o -, - o --.-.... """.........." _.

Rotary arm 66 only perform a circular movement because the guide member 84 has a different direction of movement does not allow. Without the guide member 84, there would be a pull-out due to the tensile force component exerted on the guide pin 64 by the inclined groove section 60 or a bending stress on the rotating arm 66 fastened in the spindle 68 is possible.

During the rotary movement of the rotary arm 66 through the aforementioned angle, the nut 76 Rotate because you have a backlash of the same extent - in the embodiment of 24 ° - available This torsional backlash of the nut 76 is limited by a pin 92 attached to it, which is in a correspondingly milled-out rotary chamber 94 in the punch plate 22 is movable (see. Fig.2). One in Fi g. 4 indicated ball catch% ensures that the nut 76 at the end of its torsional backlash on the Stamp plate 22 is determined.

The twisting motion described, that of the length of the inclined groove section 60 in the cam disk 52 corresponds, serves to remove the arcuate core part 36 from the inner wall of the finished molded pipe section to tear away. In this case, despite greater demolding forces, there are no strong bending moments or other disadvantageous forces on the rotating arm 66, which is only held in the spindle 68, with the arm attached to it arcuate core portion 36 exerted. Such stresses would lead to premature wear of the Nut 76 and lead to damage to the rotary arm 66 in the area of its clamping point. These dangers are prevented by the guide member 84, which with its finger 86 into a recess of the rotary arm 66 engages and guides it safely during the described rotary movement.

In order to reduce the friction of the guide pin 64 during its movement in the recess 56, it is possible to put a roller bearing, for example a needle bearing, on the guide pin 64 The outer ring rolls on the wall of the recess 56.

At the end of the rotary movement of the rotary arm 66, the guide pin 64 connected to it emerges from the Recess 56 of the cam 52 out. This is followed by a not shown further Control actuates a machine ejector. This pushes over an ejector pin indicated in FIG. 10 98 the ejector rod 74 guided in the clamping plate 26 to the front. The ejector pin 98 is connected to the piston rod of a hydraulic cylinder via a screw fastening 100. By moving of the ejector rod 74 in the direction of FIG The ejector plate 72 fastened to this ejector rod 74 is also shown in FIG Moved towards the now stationary stamp plate 22 of the open mold 14. Moved in the same way The spindle 68 mounted on the ejector plate 72 also moves and at the same time performs a rotary movement off because the nut 76 is now rotating

ίο is prevented. With the spindle 68 also rotates Rotary arm 66 with the attached arcuate core member 36, so that this further from the injection molded Pipe section is pulled out. A Mitdrch the pipe section is prevented by the stripper 88, the moves forward with ejector plate 72 and retains the pipe section at its end

Since, as described, the rotary arm 66 is no longer in the cam disk 52 in this phase of the movement "s leads, the described Drehbsv / s" runs Rotary arm 66 with the arcuate core part 36 from a spiral. Because of this spiral Rotational movement is excluded that the rotary arm 66 in the contour of the thread 44 on the pipe section in the with the threaded shell 46 provided punch 12 runs in because of the spiral-shaped movement becomes during the rotary movement of the rotary arm 66 with the arcuate core part attached thereto 36 in the direction of the arrow III drawn in FIG. 1, the pipe section together with the ejector a Tilting movement granted so that the pivot arm 66 passes next to the thread 44 of the pipe section. At the end this movement is the pivot arm 66 in the space between the thread 44 and the Dividing the stamp IZ At the end of its path, the rotary arm 66 hits the now almost free Pipe section that sits only with a small part on the arched core part 36. This creates a caused slight elongation of the neutral center line of the injected pipe gap, in which case the pipe section falls completely from the arcuate core part 36

The mentioned short-term expansion of the pipe section can with smaller dimensions of the rotary arm 66 fall away. In this case it is advisable to attach two ejector pins 102 to the ejector plate 72, which press continuously on the pipe section during the forward movement of the ejector plate 72. Because of the conical design of the arcuate Kernteüs 36 can be the injected pipe section with increasing Tilt the demolding path of the arcuate core part 36 forward. A tilt behind the curved one Curve part 36 is prevented by the ejector pins 102 constantly acting on the pipe section. As shown in FIG. II, the ejector pins are 102 constantly loaded by a compression spring 104

When, at the end of the demolding movement, the arcuate core part 36 is almost completely out of the pipe section is unscrewed, then the rotary arm 66, as already mentioned, abuts slightly with an inclined edge

so the outside of the pipe section, preventing it from tipping is reinforced until the pipe section finally falls and can be removed from below the open form 14 can.

After the ready-molded pipe sections have become free, the above-mentioned does not illustrated control of the ejector pin 98 and thus also the spindle 68 in the direction of the Clamping plate 26 withdrawn. The rotates

Spindle 68 in the opposite direction, pulling the arcuate core portion 36 over the Rotary arm 66 back to its original position. As a result of this backward movement of the rotary arm 66 is through the funnel-shaped opening insertion groove 62 in the cam disk 52 the insertion of the guide pin 64 in the recess 56 facilitated. When the mold 14 is closed, the punch 12 is again in the direction of the die 10 is moved, so is the slide 48 with the cylindrical core part 38 attached thereto returned to its original position by the angled pin 50. At the end of this movement then runs the slide 48 with an inclined guide surface on a corresponding locking surface 106, which on a locking piece 108 fastened to the die plate 18 is provided (see FIG. I). This achieves that the cylindrical core part 38 is fixed in its central starting position.

The same applies to the central locking of the arcuate core part 36 of the latter at its end protruding from the rotary arm 66 with bevels Guide surfaces 110 provided, which when the mold 14 closes on corresponding locking surfaces of the Die 10 and Viempels 12 run up (see FIG. 6).

As you can see, a 180 ° pipe bend is obtained 30 with an adjoining cylindrical pipe section 112 serving, for example, as an immersion pipe possible because when unscrewing the arcuate core part 36 from the pipe section, the latter in the described way tilts and the pivot arm 66 with the arcuate core part 36 at the end of the Demolding movement passes behind the pipe section.

ίο This means that the curved one runs during the demoulding movement Core part 36 also passes behind the cylindrical pipe section 112.

When making a tube gap here In the open type, it may finally be useful not to have the cylindrical core part 38 over a To pull the oblique pin 50 out of the cylindrical pipe section 112, but to provide a hydraulic cylinder, which removes the cylindrical core portion 38 from the cylindrical pipe section 112.

In addition to the described actuation of the spindle 68, this can also be done via a hydraulic, pneumatic or an electric motor drive.

In addition 6 sheets of drawings

Claims (11)

Patent claims: 1. Device for injection molding 180 ° pipe bends with a subsequent cylindrical pipe section, comprising a mold with a die and a movable punch adapted to it, both of which have corresponding recesses which in turn correspond to the outer contour of the entire pipe section when the mold is closed, as well as within this Recesses a two-part mold core consisting of a circularly curved and a cylindrical straight section, further means for pulling the mold core out of the recesses, the cylindrical straight section of the mold core being guided in a straight line and the circularly curved section being guided rotatably in the opposite direction according to its arcuate curvature, thereby It is shown that the arcuate core part (36) has a curvature of! 80 ° and, when demoulding, first a relatively small rotational movement in its circular path and then a spiral movement from the outer contour of the tube ogens (30) with a cylindrical straight piece (1 12) (cf. Fig. 12) executes in the tool on the side of the punch (12) starting in the direction of the side of the die (10), during this spiral movement of the arcuate core part (36) the cylindrical core part (38) and thus also the tube sheet (30) together with its cylindrical straight piece (112) a tilting movement is given in such a way that the Rohi Dogen (30) with its cylindrical straight piece (112) swings in front of the arched core part (36) and this thus swings behind the pipe bend during its spiral movement ( 30) with its cylindrical straight piece (112) turns past in a spiral. 2. Device according to claim 1, characterized in that that the arcuate core part (36) is attached to a spindle (68) via a rotary arm (66)! is and on the side remote from this spindle (68) a guide pin (64) for engagement with a Has recess (56) of a cam (52) connected to the die (10). 3. Apparatus according to claim 2, characterized in that the recess (56) from a to Opening direction of the mold (14) parallel longitudinal groove (58), an adjoining oblique Groove section (60) and an insertion groove (62) adjoining it in a funnel shape. 4. Device according to one of claims 2 and 3, characterized in that on the spindle (58) a nut (76) is put on, which inside a punch plate (22) receiving the punch (12) is rotatably mounted, and that the nut (76) has a length of the longitudinal groove (58) corresponding Has torsional backlash within the punch plate (22). 5. Apparatus according to claim 4, characterized in that the nut (76) at the end of its Torsional backlash can be locked into place by a ball catch (96) on the punch plate (22). 6. Device according to one of claims 3 biii 5, characterized in that on the punch (12) a rotary arm (66) during the rotary movement caused by the inclined groove portion (60) holding the guide member (84) is attached. 7. The device according to claim 4, characterized in that the spindle (68) at a relative to Nut (76) is mounted movable ejector plate (72) in the direction of the spindle axis 8. Apparatus according to claim 7, characterized in that the ejector plate (72) by means of a Ejector rod (74) after the guide pin (64) emerges from the inclined groove section (60) of the cam (52) and with the nut (76) locked in the direction of the stationary die (10) is movable 9. Apparatus according to claim 8, characterized in that on the ejector plate (72) a Wiper (88) holding the pipe bend (30) when the arcuate core part (36) is pulled out is 10. The device according to claims, characterized in that on the ejector plate (72) at least one with compressed air or springs (104) acted upon, the pipe bend (30) touching Aiiswerferstift (102) is arranged 11. The device according to claim 2, characterized in that the arcuate core part (36) at its end protruding from the rotary arm (66) has inclined guide surfaces (110) which when closing the mold (14) on corresponding locking surfaces of the die (10) and of the stamp (12) run up.