JP5724566B2 - Casting equipment - Google Patents

Description

The present invention relates to casting equipment.

  Some casting apparatuses include a sleeve that temporarily stores molten metal before being injected into the cavity and a sprue core (a diverter) that opens and closes a gate that connects the cavity (for example, Patent Documents 1 and 2). . In the casting apparatuses of Patent Documents 1 and 2, the sprue core is moved by an actuator. Before injecting the molten metal, the gate is closed by the sprue core until a predetermined amount of molten metal is supplied into the sleeve. After the molten metal is supplied, the sprue core is opened, the plunger is advanced, and the molten metal is injected into the cavity.

JP 2004-17064 A Japanese Patent Laid-Open No. 6-31422

  The conventional casting apparatus has an actuator for moving the sprue core. The technology disclosed in this specification provides a casting apparatus that does not require an actuator for moving a sprue core.

  The technique disclosed in the present specification is characterized in that the sprue core is moved by a force when the plunger moves forward, and the communication port is opened. An aspect of the casting apparatus disclosed in the present specification includes a sleeve for temporarily storing molten metal, a plunger that pushes the molten metal in the sleeve into the cavity, and a sprue core that is disposed in the sleeve so as to be movable forward and backward. And a gate that communicates the cavity and the sleeve. The sprue core is disposed at a position where the space between the sprue core and the plunger tip (hereinafter referred to as “molten space”) and the gate are blocked when the molten metal is supplied. After the molten metal is supplied, the sprue core advances together with the molten metal as the plunger advances, and communicates the molten metal space with the gate. By placing the sprue core that does not have an actuator and slides passively as described above, the sprue core passively slides as the plunger advances, and the molten metal flows into the cavity when the gate and molten metal space are opened. Can do.

When a passively sliding sprue core is employed, a mechanism for retracting the sprue core that has advanced to the position where the gate is opened is required. Accordingly, in another aspect of the casting apparatus herein disclosed, the plunger tip (piston portion of the plunger tip), Ru with a magnet for attracting the Supurukoa. Because the magnet pulls the sprue core to the plunger tip, it retracts with the plunger tip when the plunger retracts. More preferably, the magnet is an electromagnet. If the power supply to the electromagnet is interrupted after the sprue core is retracted to the predetermined position together with the plunger tip, only the plunger tip can be further retracted while the sprue core remains at the predetermined position.

  In the casting apparatus of still another aspect disclosed in the present specification, the volume of the molten metal space (the space sandwiched between the plunger and the sprue core) when the plunger reaches a position for closing the molten metal supply port provided in the sleeve is the same. It is preferable to further include a melt supply means for supplying an amount of molten metal to the sleeve. When the plunger moves forward and reaches a position where the molten metal supply port is closed, the molten metal space becomes a closed space. If said structure is employ | adopted, when a fusion | melting space becomes a closed space, the fusion | melting space will be filled with a molten metal. That is, the molten space can be filled with the molten metal without containing air. Therefore, bubbles can be prevented from being mixed when the molten metal is injected into the cavity.

It is typical sectional drawing of a casting apparatus (at the time of molten metal supply). It is typical sectional drawing of a casting apparatus (state which advanced to the position where a plunger closes a molten metal supply port). It is typical sectional drawing of a casting apparatus (at the time of plunger advance). It is a fragmentary sectional view of the casting apparatus of 2nd Example. It is a fragmentary sectional view of the casting apparatus of 3rd Example. FIG. 6 is a cross-sectional view depicting a robot arm pulling out a sprue core. It is sectional drawing which drew a mode that the robot arm installed the sprue core in the original position.

  (First Embodiment) FIGS. 1 to 3 show sectional views (schematic diagrams) of a casting apparatus 100 of the first embodiment. In the figure, only parts necessary for explaining the invention are shown, and some of the parts included in a normal casting apparatus are not shown. The casting apparatus 100 includes a fixed mold 32 and a movable mold 14 and a set of molds. An actuator (not shown) is connected to the movable mold 14, and the movable mold 14 is brought into close contact with the fixed mold 32 or separated from the fixed mold 32. Forming a cavity CV that is a closed space into which the fixed mold 32 and the moving mold 14 are brought into close contact with each other and pouring molten metal is referred to as “closing the mold”. The opening of the cavity CV by separating the movable mold 14 from the fixed mold 32 is referred to as “opening the mold”.

  A sleeve 26 is attached to the movable die 14. The sleeve 26 is a cylinder that temporarily stores the molten metal before flowing into the cavity CV. The inner space of the sleeve 26 and the cavity CV communicate with each other through the gate 16. The gate 16 is a flow path surrounded by the fixed mold 32 and the movable mold 14 and is formed when the mold is closed.

  A plunger 23 is provided inside the sleeve 26. The plunger 23 includes a plunger tip 24 and a rod 22. The plunger tip 24 corresponds to a so-called piston. A rod 22 is connected to the rear end of the plunger tip 24, and an actuator (not shown) is connected to the rear end of the rod 22. As the actuator advances / retracts the rod 22, the plunger tip 24 slides in the sleeve. In the present specification, the side facing the fixed mold 32 in the longitudinal direction of the sleeve 26 is defined as “front”, and the side far from the fixed mold 32 is defined as “rear”. The movement of the plunger 23 (plunger tip 24) toward the fixed mold 32 is referred to as “advance”, and the movement away from the fixed mold 32 is referred to as “retreat”.

  A sprue core 28 is disposed in front of the plunger 23 (plunger tip 24) in the sleeve. Note that a space inside the sleeve 26 and between the sprue core 28 and the plunger 23 is referred to as a molten metal space WS. The sprue core 28 is not connected to any other parts, and is merely placed in the sleeve 26 so as to be able to move forward and backward. The sprue core 28 will be described in detail. The sprue core 28 is slidably placed on the sleeve 26, but the peripheral surface of the sprue core 28 is in close contact with the inner peripheral surface of the sleeve 26 without a gap. The sprue core 28 is placed in front of the molten metal supply port 18 provided in the sleeve 26 before the molten metal is supplied. Further, the sprue core 28 is disposed at a position where the communication between the gate 16 and the molten metal space WS is blocked.

  FIG. 1 shows the position of the sprue core 28 when the molten metal is supplied. Reference numeral P <b> 1 is an initial position of the sprue core 28. As shown in FIG. 1, the sprue core 28 at the initial position P1 separates the gate 16 and the molten metal space WS. In this state, the molten metal W is supplied into the sleeve 26 from the ladle 20 (molten supply means) through the molten metal supply port 18. The molten metal W is poured into the molten metal space WS (the space between the plunger 23 and the sprue core 28). The sprue core 28 has a sliding resistance between the inner surface of the sleeve 26 so as not to move unless pressed strongly. That is, the sprue core 28 does not move as long as the molten metal W is poured, but when the plunger 23 moves forward, the sprue core 28 moves forward together with the molten metal W.

  FIG. 2 shows a state in which the plunger 23 moves forward halfway after supplying a predetermined amount of molten metal. Reference numeral P1 indicates the initial position of the sprue core 28 as in FIG. Reference numeral P <b> 2 indicates the position of the front edge of the molten metal supply port 18. The amount of the molten metal W supplied by the ladle 20 is the volume of the space (molten space WS) between the plunger 23 and the sprue core 28 when the plunger 23 (plunger tip 24) reaches the front edge position P2 of the molten metal supply port 18. equal. The front edge position P2 corresponds to a position where the plunger 23 closes the molten metal supply port 18. For example, when the distance between the position P1 and the position P2 is L1, and the cross-sectional area of the sleeve 26 is A1, the capacity of the molten space WS when the plunger 23 is positioned at the position P2 = the amount of supplied molten metal = L1 × A1. The In other words, the ladle 20 has the same amount as the volume of the melt space WS when the plunger 23 (plunger tip 24) reaches the position (front edge position P2) where the melt supply port 18 provided in the sleeve 26 is closed. Is supplied to the sleeve 26. By supplying such a molten metal amount to the sleeve 26, as shown in FIG. 2, when the plunger tip 24 reaches the position P2 where the molten metal supply port 18 is closed, the molten metal space WS contains bubbles. Filled with molten metal without any problems. Since there are no air bubbles in the space in the sleeve, when the plunger 23 is further advanced and the molten metal W is injected into the cavity CV, it is possible to prevent air bubbles from being mixed in the molten metal in the cavity CV.

  FIG. 3 shows a state where the plunger 23 (plunger tip 24) is advanced to the most advanced position. A pocket 30 in which the sprue core 28 is accommodated is formed at a position facing the tip of the sleeve 26 of the fixed mold 32. Since the sprue core 28 cannot advance further when it fits in the pocket 30, the pocket 30 corresponds to a stopper that defines the most advanced position of the sprue core 28. Further, a gate 16 is provided at the tip of the sleeve 26 to communicate the internal space of the sleeve 26 with the cavity CV. As described above, the sprue core 28 is disposed at a position (position P1 in FIGS. 1 and 2) that blocks communication between the molten metal space WS (a space between the sprue core 28 and the plunger 23) and the gate 16 when the molten metal is supplied. The And after a molten metal supply, it advances with a molten metal with the advance of the plunger 23. FIG. When the sprue core 28 reaches the forefront position (position that fits in the pocket 30), the gate 16 and the molten metal space WS are opened. When the plunger 23 is further advanced, the molten metal W is pushed out into the cavity CV (FIG. 3). In other words, the opening on the sleeve side of the gate 16 is provided slightly behind the pocket 30 (in the longitudinal direction of the sleeve and far from the fixed mold 32), and when the sprue core 28 reaches the pocket 30, the gate 16 and the molten metal are provided. The space WS is opened.

  As described above, in the casting apparatus 100, the sprue core 28 is passively advanced by the pressing force accompanying the advance of the plunger 23 (plunger tip 24). The casting apparatus 100 does not include a dedicated actuator for moving the sprue core 28 and can reduce the cost.

  In addition, the casting apparatus 100 restricts a space for temporarily storing the molten metal by the sprue core 28. This can suppress the temperature drop of the molten metal in the sleeve. Further, as described above, when the plunger 23 reaches the position where the molten metal supply port is closed, the molten metal space WS is just filled with the molten metal. With such a structure, the casting apparatus 100 is less likely to generate bubbles in the cavity CV.

  (Second Embodiment) A casting apparatus 200 according to the second embodiment will be described with reference to FIG. FIG. 4 is a partial cross-sectional view of the casting apparatus 200. FIG. 4 shows the sprue core 28 and the plunger 23 (plunger tip 24 and rod 22). In the casting apparatus 200 of the second embodiment, an electromagnet 36 is embedded in the plunger tip 24. In the figure, illustration of a cable connected to the electromagnet, a switch for controlling the electromagnet 36, and the like is omitted. The sprue core 28 is made of a metal that is attracted by a magnetic force (a metal that exhibits ferromagnetism at room temperature). In the casting apparatus 200, the electromagnet is turned off until the plunger 23 pushes the molten metal into the cavity CV (the power supply to the electromagnet is cut off), and the electromagnet 36 is turned on when the plunger tip 24 is retracted after the molten metal is injected ( Energize). When the electromagnet 36 is turned on, the sprue core 28 is attracted to the electromagnet 36, and the sprue core 28 moves backward together with the plunger tip 24. When the sprue core 28 moves back to the initial position (position P1 in FIGS. 1 and 2), the electromagnet 36 is turned off. Thereafter, only the plunger tip 24 is further retracted to the initial position. The casting apparatus 200 can return the sprue core 28 to the initial position by magnetic force.

  (Third Embodiment) A casting apparatus 300 according to a third embodiment will be described with reference to FIGS. The casting apparatus 300 of the third embodiment is characterized by the shape of the sprue core. As shown in the figure, the sprue core 128 has the same shape at the front end and the rear end. The pocket 130 provided in the fixed mold 32 is also formed in the same shape as the front end (rear end) of the sprue core 128.

  Protrusions (128a, 128b) having the same shape are formed at the front and rear ends of the sprue core 128. The protrusions 128a and 128b are gripping portions for the robot arm to grip. In FIG. 5, the protrusion 128a is located on the front side, and the protrusion 128b is located on the rear side. In the casting apparatus 300, the molten metal is injected as in the casting apparatus 100 of the first embodiment, and then the mold is opened to expose the sprue core 128 whose front side is fitted in the pocket 130. At this time, the front protrusion 128a is housed in the pocket 30, and the rear protrusion 128b is exposed. Thereafter, as shown in FIG. 6, the protrusion 128 b is gripped by the robot arm 40, and the sprue core 128 is pulled out from the pocket 30. Next, as shown in FIG. 7, the robot arm 40 rotates the sprue core 128 while holding the protrusion 128 b, inserts the sprue core 128 from the tip of the sleeve 26, and moves it to the initial position. When the mold is closed again in this state, the next casting is ready. Next, when the casting process is performed, the protrusion 128a is now exposed from the pocket 130, contrary to the previous time. The robot arm 40 now grips the protrusion 128a and returns the sprue core 128 to its original position. The robot arm 40 can move the sprue core 128 from the pocket 130 to the initial position in the sleeve without changing the sprue core 128.

  As described above, in the casting apparatus 300, the sprue core 128 having the same shape at the front end and the rear end and having the protrusions 128a and 128b (gripping portions) having the same shape on both sides is adopted. Easy position reset.

  Points to be noted regarding the casting apparatus described in the embodiment will be described. The casting apparatus 200 of the second embodiment includes an electromagnet 36 for pulling back the sprue core 28. The casting apparatus may include a permanent magnet instead of the electromagnet. In the casting apparatus 300 of the third embodiment, the sprue core 128 has grips on both the front side and the rear side. A configuration may be provided in which only one of both ends of the sprue core 128 is provided with a gripping portion (protrusion) for the robot arm to grip. In this case, the side having the grip portion corresponds to the rear end of the sprue core.

  The casting apparatus described above includes the gate 16 that communicates the sleeve 26 and the cavity CV in front of the sleeve 26. Summarizing the above description, a casting method using such a casting apparatus can be expressed as follows. In the casting method, the sprue core 28 is disposed at a position P1 in the sleeve where the gap between the molten metal space WS between the sprue core 28 and the plunger 23 and the gate 16 is blocked. Next, the molten metal is supplied to the molten metal space WS. Next, the plunger 23 is advanced to advance the sprue core 28 together with the molten metal. The sprue core 28 is advanced to a position where the gate 16 is opened. In other words, the plunger 23 is advanced until the sprue core 28 reaches the most advanced position where it abuts against the stopper (pocket 30). When the sprue core 28 reaches the pocket 30, the gate 16 and the molten metal space WS communicate with each other, and the molten metal is injected into the cavity CV.

  In the above-described method, in the step of supplying the molten metal, the molten metal having the same volume as the volume of the molten metal space WS when the plunger 23 reaches the position for closing the molten metal supply port 18 provided in the sleeve 26 is supplied to the sleeve. Is preferred. The reason is as described above.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

14: movable type 16: gate 18: molten metal supply port 20: ladle 22: rod 23: plunger 24: plunger tip 26: sleeve 28, 128: sprue core 30, 130: pocket (stopper)
32: Fixed mold 36: Electromagnet 40: Robot arm 100, 200, 300: Casting device 128a, 128b: Projection (gripping part)
CV: cavity W: molten metal WS: molten metal space

Claims (2)

A sleeve for temporarily storing molten metal,
A plunger for pushing out the molten metal in the sleeve;
A sprue core that is arranged to move forward and backward in front of the plunger in the sleeve;
A gate communicating with the cavity and the sleeve ,
A magnet that attracts the sprue core to the plunger tip is provided.
Sprue core
Casting, which is located at a position where the molten metal space between the sprue core and the plunger is blocked from the gate when the molten metal is supplied, and moves forward with the molten metal as the plunger moves forward to communicate the molten metal space with the gate. apparatus. Plunger according to claim 1, further comprising a melt supply means for supplying the same amount of molten metal to the volume in the sleeve of the molten metal space when it reaches the position for closing the melt feed port provided in the sleeve Casting equipment.

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