JP2011520651A - Calibrator for casting method by projectile insertion (PIT) - Google Patents

Abstract

  A casting apparatus for producing a hollow casting product (24) comprising a cavity (14) and a filling apparatus (18) for filling a fluid casting material (16) into the cavity (14). And a displacement device (22, 30), wherein the displacement device (22, 30) causes a part of the casting material (16) filled in the cavity (14) to be moved by a fluid under pressure. In a type having a nozzle device (22) configured to be pushed away, the nozzle device (22) for discharging a fluid under pressure can enter and move into the cavity (14), and the cavity ( 14) and can be moved.

Description

  The present invention is a casting apparatus for producing a hollow casting product, comprising a cavity, a filling device for filling a fluid casting material into the cavity, and a displacement device, The displacement device relates to a type in which a part of the pouring material filled in the cavity is displaced by a fluid under pressure, and therefore the displacement device has a nozzle device.

  The present invention also provides a casting method for producing a hollow casting, a method step of filling a fluid casting material into a cavity, and a fluid under pressure at least partially in the casting material. The present invention relates to a method of the type having a method step for introducing a filling cavity and a method step thereby forcing the pouring material indirectly or directly into the cavity.

  Such a casting method is particularly suitable for carrying out in a casting apparatus of the type mentioned at the outset.

  A casting apparatus of the type mentioned at the beginning and a casting method of the type mentioned at the beginning are known from EP 0 757 936 as an injection molding device and an injection molding method.

  According to the injection molding apparatus and injection molding method known from the prior art, a projectile (projectile) is inserted into the projectile receiving part of the mold at one first longitudinal end of the cavity, The fluid under pressure pushes it through a plastic-filled cavity that is still partially fluid and into a subcavity provided at the other second longitudinal end of the cavity; As a result, a hollow tubular component is formed in the cavity. For this purpose, a supply line for supplying fluid under pressure leads to the projectile receptacle, where the flow of fluid under pressure is released under pressure by releasing the flow of fluid under pressure. A certain fluid acts on the projectile to drive the projectile.

  Furthermore, according to the prior art casting apparatus and casting method, a fluid under pressure, for example water as liquid or air as gas, is inserted into a cavity at least partially filled with plastic and directly In particular, the casting material is forced away from the cavity without mediating a geometrically defined projectile.

  In the casting apparatus and casting method described at the beginning of this type, the hollow casting product produced by this apparatus and method is directly directed to the fluid discharge opening of the nozzle device in the direction of fluid discharge into the cavity. It has been found that in subsequent regions it has an inner shape with insufficient definition of shape and / or dimensions and / or insufficient repeatability (same quality).

  According to the casting apparatus and the casting method of the type mentioned at the outset, in most cases the tube is produced as a hollow casting. Such a tube is such that at its longitudinal end, a fluid under pressure is introduced into the cavity in order to push away the core of the casting material filled in the cavity, which is still molten. At the longitudinal end of the tube, the tube needs to be matched with another component while assembled into one structure group or the entire device. Therefore, it is very important that the longitudinal end of such a hollow casting product is configured to have a well-defined, inner shape that can be repeatedly manufactured with the same quality.

  Therefore, the object of the present invention is to improve the casting apparatus and casting method described at the beginning, and compare the inner shape of at least the longitudinal end region of the hollow casting product with that of the prior art. Thus, it is possible to repeatedly manufacture with higher shape accuracy and / or dimensional accuracy.

  According to the means of the apparatus of the present invention which solves this problem, in the casting molding apparatus of the type described at the beginning, the nozzle apparatus for discharging the fluid under pressure can enter and move into the cavity and can be extracted from the cavity. It is characterized by being movable.

  Further, according to the means of the method of the present invention which has solved the above-mentioned problem, in the casting method of the type described at the beginning, further, a nozzle device configured to discharge a fluid under pressure is pushed into the cavity. It has a method step.

  By means of the solution proposed as described above, the part of the inner shape of the cast product is formed by the section of the nozzle device that enters the cavity. Thereby, the section of the inner shape of the cast product formed by the nozzle device with high dimensional accuracy and surface quality is repeatedly manufactured and managed.

  According to the basic idea of the present invention, a nozzle arrangement configured to introduce a fluid under pressure into a cavity at least partially filled with a flowable pouring material is, for example, a common plunger. In such a manner, it can move into the cavity and move out of the cavity. This means that the nozzle device at least partially has the function of shaping.

  Basically, when the nozzle device enters and moves into the cavity, the nozzle device can move into the cavity and exit from the cavity, regardless of whether the casting material is already filled in the cavity or not. It is movable.

  To define the inner shape of the longitudinal end of the casting, the nozzle device can be introduced into the cavity from one longitudinal end of the cavity or from the longitudinal end of the cavity into the cavity. It can be introduced.

  Basically, according to the first embodiment of the invention, the nozzle device is used like a plunger, i.e. like a movable core, so that it already moves into the cavity before filling the cavity with the casting material. Can be made. This has the advantage that it only has to be filled into the cavity with a reduced amount of casting material that plunges into the cavity and is reduced by the volume of the section of the nozzle device.

  However, since the nozzle device is used as it is to push away the pouring material filled in the cavity, according to an advantageous embodiment of the invention, the pouring material is first filled into the cavity and then the nozzle device is penetrated into the cavity. It is possible to move it. The nozzle device then pushes away the casting material in the cavity as it moves into the cavity. This ensures that the nozzle device is surrounded by the pouring material over the entire depth of penetration of the nozzle device at its end position that has entered the cavity.

  In this case, since the cavity is not completely filled with the casting material, a residual volume is provided in the cavity to accommodate the casting material displaced by the nozzle device and / or by the fluid under pressure.

  Additionally or alternatively, the pouring device has a subcavity that is fluidly connected or fluidly connectable to the cavity and contains a pouring material that is pushed away from the cavity. It is configured as follows.

  Such a subcavity is fluidly connected to the cavity via a constantly open flow-through passage, or fluidly connected to the cavity at a predetermined or predefinable time point via a valve means. Yes.

  Basically, the nozzle device is first moved from the retracted position to the position where it enters the cavity without discharging the fluid under pressure, and then the nozzle device reaches its end position in the cavity. Starting from this point, the fluid under pressure is started to be discharged in order to further push away the casting material in the cavity.

  Prior to the movement of the nozzle device into the cavity from the retracted position, if the discharge of fluid under pressure has been started in advance, it will be at least partially into the cavity filled with the flowing casting material. The pushing of the nozzle device can be done with a small force, so that until the start of the movement of the nozzle device, at least the pouring material in the area near the fluid discharge opening of the cavity is already under pressure and under pressure Since it is displaced by the fluid, such a displacement operation no longer needs to be performed by the nozzle device.

  Furthermore, when the nozzle device is in motion to penetrate into a cavity which is at least partially filled with a pouring material and before the discharge of the fluid under pressure is started before reaching one end position of the nozzle device In addition, an operation mode combining the above two operation modes is also conceivable.

  In order to control the operation of the nozzle device as accurately as possible, in particular to select as precisely as possible when the fluid should be discharged from the nozzle device, the nozzle device has a movable closure member, It is movable between a closed position for closing the fluid discharge opening of the nozzle device and an open position for opening the fluid discharge opening for allowing the fluid to flow therethrough.

  This type of closure member prevents the pouring material from reaching into the fluid supply passage of the nozzle device when the nozzle device is pushed into a cavity that is at least partially filled with the pouring material. In addition, care should be taken so that the casting material does not undesirably solidify early and clog the fluid supply passage.

  Due to the mode of operation in which the nozzle device penetrates into the cavity, which is at least partially filled with casting material, thereby performing a powerful displacement operation, the high driving force required to move the nozzle device into the cavity is increased. can get.

  The driving force required to move the nozzle device into the cavity is such that the nozzle device having the closing member moves into the cavity when the nozzle device moves along the nozzle device longitudinal axis in the closed position. It can be reduced in an advantageous manner by tapering at least partly towards the longitudinally penetrating end that penetrates in advance. Since the nozzle device tapers continuously toward the longitudinal entry end, that is, in a substantially stepless manner, the required driving force can be further reduced. In this case, the longitudinal entry end may be of any shape, for example conical, hemispherical or ellipsoidal.

  According to an advantageous embodiment of the invention, the closing member of the nozzle device forms at least part of the longitudinal entry end of the nozzle device. This type of closure member is pulled back like a needle valve from its closed position into its open position to introduce fluid under pressure into the cavity, into its open position. ing. As a result, a hollow chamber is formed in front of the fluid discharge opening in advance, and the fluid under pressure penetrates into the hollow chamber without the need to perform the displacement operation.

  Particular preference is given to using the casting apparatus described above for the so-called projectile insertion technique (Projektil-injektionstechnik). In this projectile insertion technique, as mentioned at the outset, the nozzle device is a cavity in which the projectile is at least partially filled with a flowable pouring material by the fluid under pressure discharged from the nozzle device. Used to drive into the interior (preferably through this cavity). With these types of projectiles, based on the prescribed shape of the projectile, a hollow cast product having a wider variety of inner contour shapes of the cast product and a higher shape quality and dimensional quality. Can be mass produced. Moreover, even in the conventional casting apparatus using a projectile as a displacement device, the inner shape of the generated hollow casting product in the longitudinal end region near the fluid discharge opening is defined as the casting molding product. And it has been found to improve in relation to repeatability. Such an improvement is obtained by the present invention. Accordingly, all the above descriptions, advantageous embodiments and modes of operation of the casting apparatus according to the invention apply in particular for casting apparatuses having the following projectiles. That is, the nozzle device is used to drive an intrusive movement (preferably through the casting material) into the casting material filled in the cavity by the fluid under pressure discharged by the nozzle device. This is also the case for casting machines with such projectiles.

  Therefore, according to an embodiment of the method according to the invention, it further comprises another method step of inserting the projectile into the projectile receiving part of the nozzle device and closing the mold in the open mold. Yes.

  In an advantageous manner, the projectile is actuated to be driven by a nozzle device, since at least the longitudinal end leading in the direction of movement of the projectile has as little flow resistance as possible. Located in front of the fluid discharge opening of the nozzle device in position, a pre-configured group of projectiles and nozzle devices can penetrate and move into the cavity using the good flow characteristics of the projectile Or moved into the cavity.

  In an advantageous manner, the nozzle device can slide into and out of the cavity along with the projectile along the length of the nozzle device.

  The advantage of low flow resistance for pre-configured structures consisting of projectiles and nozzle devices is that such structures penetrate into the casting material filled in the cavity over as long a path as possible. Although most effective when moving, this type of pre-configured structure has already been intruded into the termination position that has entered the cavity before filling the casting material into the cavity. Except that, as in the case of the plunger, a part of the outer contour shape of the structural group defines the inner contour shape of the section surrounding the structural group of the hollow cast product manufactured by the casting technique. Not what you want.

  Known sealing means for sealing plungers and other movable cores by pouring techniques can be used to seal the nozzle device movable relative to the cavity.

  Basically, the proposed casting apparatus and casting method as described above can use any casting material. However, it is particularly advantageous to use an injection molding device using a thermoplastic casting material as the casting device.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

1 is a schematic cross-sectional view of a portion of a casting apparatus according to the present invention configured as an injection molding apparatus.

  In the drawing, an embodiment of a casting apparatus according to the present invention configured as an injection molding apparatus 10 is shown.

  In the drawing, a portion of the mold 12 having a cavity 14 is shown, in which a thermoplastic 16 as a casting material is filled by a filling device 18.

  The nozzle device 22 extending along the longitudinal axis 20 of the nozzle device projects into the cavity 14 over the length a in the longitudinal end region of the cavity 14 in the illustrated embodiment and has a length b. In the meantime, it comes into contact with the casting material 16 filled in the cavity 14. At least over this length b, the outer contour 22a of the nozzle device 22 forms the inner shape of the tube 24 formed in the mold 12, for example as a hollow cast product.

  A nozzle device 22 that tapers at least partially towards the fluid extrusion opening 26 has a fluid extrusion opening and projects at a longitudinal end 28 that projects into the cavity 14 (Projektil). 30. The outer contour shape 30a of the projectile 30 has shifted to the outer contour shape 22a of the nozzle device 22 in the same plane, whereby the projectile 30 and the nozzle device 22 in the inner contour shape 24a of the tube 24 to be formed. The separation surface 32 between the two is avoided as much as possible.

  When the projectile 30 is loaded with fluid under pressure through the fluid supply passage 34 in the illustrated release position, the projectile 30 still moves to move away from the nozzle device 22 in the direction of arrow P. It is driven through the casting material 16 remaining in the cavity 14. When the projectile 30 is moved along the arrow P, when the projectile 30 is projected, the projection 30 is viewed in the direction of motion of the projectile 30 and before the projection surface of the projectile 30, with respect to the plane of motion of the projectile 30. The meltable casting material 16 located on the orthogonal projection planes is automatically within the cavity 14 (if the cavity 14 is only partially filled with the casting material 16) and / or of the cavity 14 (shown in FIG. It is pushed away into a subcavity (not shown) provided at the longitudinal end (located opposite to the cavity longitudinal end). At this time, in the illustrated embodiment, the filling is located in the boundary surface 24b indicated by the broken line in the radial direction relative to the tube longitudinal axis 36 of the tube 24, which coincides with the nozzle device longitudinal axis 20. A portion of the cast material 16 is pushed away. A portion of the casting material 16 located radially outward of the interface 24b is caused by the projectile 30 located radially inward of the interface 24b in the cavity after the projectile 30 has passed. It remains as a tube 24 having a hollow chamber.

  To release the completed tube 24 from the mold 12, the nozzle device 22 is withdrawn from the cavity 14 in any manner. On the other hand, it is conceivable that the nozzle device 22 is pulled out of the cavity 14 in the direction opposite to the arrow P along the nozzle device longitudinal axis 20. Similarly, the nozzle device 22 together with the tube 24 is lifted from the mold 12 in a direction perpendicular to the drawing plane of the drawing (matching the mold release surface of the mold 12) and then along the nozzle device 20 You may make it pull out from the completed pipe | tube 24. FIG.

  The nozzle device 22 can enter the cavity 14 in any manner. That is, the nozzle device 22 is moved in the direction of the arrow P along the nozzle device longitudinal axis 20, or by the movement of the mold 12 perpendicular to the mold release plane that matches the drawing plane, or The mixed movement of these movements can also enter the cavity 14.

  DESCRIPTION OF SYMBOLS 10 Injection molding device, 12 Formwork, 14 Cavity, 16 Thermoplastic as fluid pouring material, 18 Filling device, 20 Nozzle device longitudinal axis, 22 Nozzle device, 22a Outer contour of nozzle device 22, 24 tube ( Casting product), 24a inner profile of tube 24, 24b boundary surface, 26 fluid discharge opening, 28 longitudinal end, 30 projectile (projectile), 32 separation surface, 22, 30 displacement device, 34 fluid supply passage 36 Pipe longitudinal axis

Claims (10)

A casting apparatus for producing a hollow casting product (24) comprising a cavity (14) and a filling apparatus (18) for filling a fluid casting material (16) into the cavity (14). And a displacement device (22, 30), wherein the displacement device (22, 30) causes a part of the casting material (16) filled in the cavity (14) to be moved by a fluid under pressure. In the type having a nozzle device (22) configured to be pushed away,
The casting apparatus, characterized in that the nozzle device (22) for discharging a fluid under pressure can move into and out of the cavity (14) and move out of the cavity (14).   Having a subcavity, wherein the subcavity is fluidly connected or fluidly connectable to the cavity (14) and contains a pouring material (16) displaced away from the cavity (14). The casting apparatus according to claim 1, which is configured.   The nozzle device (22) has a movable closing member, the closing member closing a fluid discharge opening (26) of the nozzle device (22), and a fluid discharge for allowing fluid to flow therethrough. 3. A casting apparatus according to claim 1 or 2, which is movable between an open position for opening the opening (26).   Longitudinal entry end where the nozzle device (22) with a closing member enters in advance into the cavity (14) during movement of the nozzle device (22) along the nozzle device longitudinal axis (20) in the closed position. Tapering at least partially towards the part (28), preferably continuously tapering, particularly preferably forming part of the longitudinal entry end (28) of the nozzle arrangement (22) The casting apparatus according to claim 3.   A casting material (16) having a projectile (30), wherein the projectile (30) is filled into the cavity (14) by a fluid under pressure discharged from a nozzle device (22). 4. The casting apparatus according to claim 1, wherein the casting apparatus is drivable by a nozzle device (22) for intrusion movement through the casting material (16).   The projectile (30) is located in front of the fluid discharge opening (26) of the nozzle device (22) in its operating position, and is composed in advance of the projectile (30) and the nozzle device (22). 6. A casting apparatus according to claim 5, wherein said structure group is capable of penetrating movement into the cavity (14).   The casting apparatus according to any one of claims 1 to 6, wherein the casting apparatus is an injection molding apparatus using a thermoplastic as a casting material. A casting method for producing a hollow casting product (24), comprising:
Filling the flowable casting material (16) into the cavity (14);
Introducing a fluid under pressure into a cavity (14) at least partially filled with a casting material (16);
Thereby indirectly or directly pushing the casting material (16) into the cavity (14);
In a method of the type having method steps,
As yet another method step,
Pushing a nozzle device (22) configured to discharge fluid under pressure into the cavity (14);
A casting method, characterized in that it comprises a method step.   9. The casting method according to claim 8, wherein the pushing of the nozzle device (22) is carried out after filling the casting material (16) into the cavity (14). As yet another method step,
Inserting the projectile (30) into the projectile receiver (28) of the nozzle device (22) in the open mold (12);
Closing the formwork (12),
10. A casting method according to claim 8 or 9, comprising a method step.

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