DE102014201047B4 - Casting mold for pressure casting of castings - Google Patents

Abstract

Casting mold (1) for die-casting cast parts, consisting of a stationary mold half (2), a mold half (3) that can be moved in a direction of movement (5) from an open position to a closed position, and of at least one core (4) which, in the closed position delimit at least in sections a mold cavity for the casting that can be filled with a flowable molten metal, the core (4) detachably fixed to the movable mold half (3) being displaceable together with the movable mold half (3) into the closed position in which the core (4) rests against the stationary mold half (2) at least in sections, with a locking device (8) being provided which has a first locking element (6) arranged on the core (4) and a second locking element (7) arranged on the stationary mold half (2). which contact each other when the mold halves (2, 3) are in the closed position in such a way that a relative movement between the core (4) and the above-mentioned stationary mold half (2) perpendicular to the direction of movement (5) of the movable mold half (3), characterized in that the second blocking element (7) is movably mounted on the stationary mold half (2) and can be transferred from a release position to a blocking position, the two blocking elements (6, 7) not contacting each other when the mold halves (2, 3) are in the closed position and a second blocking element (7) is in the release position, while the two blocking elements (6, 7) are in the closed position mold halves (2, 3) and a second locking element (7) arranged in the locking position, preventing the relative movement between the core (4) and the fixed mold half (3) perpendicular to the direction of movement (5) of the movable mold half (2).

Description

The invention relates to a casting mold for die-casting castings, consisting of a stationary mold half, a movable mold half that can be displaced in a direction of movement from an open position to a closed position, and at least one core, which in the closed position has a mold cavity that can be filled with a free-flowing molten metal for the cast part at least limited in sections, with the core, which is detachably fixed to the movable mold half, being displaceable together with the movable mold half into the closed position, in which the core rests at least in sections on the stationary mold half, with a blocking device being provided which has a first blocking element arranged on the core and has a arranged on the stationary mold half second locking element, which contact arranged in the closed position mold halves such that a relative movement between the core and the stationary mold half and the movable Mold half is prevented perpendicular to the direction of movement of the movable mold half.

Die casting, the thixo process or injection molding are primary shaping processes in which a quantity of material tailored to the workpiece size is placed in an openable and closable metal shaping tool, a mold is filled with a flowable material and shaped under the influence of high pressure and the workpiece then left to solidify under the action of this pressure until the workpiece can be handled and removed from the mold. All shaping processes that can be subsumed under this definition are covered by the term "die casting".

A casting mold is a permanent metal mold for the production of castings on a die casting machine. The casting mold contains the mold cavity, i.e. the space that depicts the contour and dimensions of the cast part to be produced. A casting mold for die casting usually consists of at least two mold halves that can be moved relative to one another and from an open position to a closed position. Here, the sprue-side mold half is fixed to a stationary platen of the die-casting machine and the ejector-side mold half is fixed to a platen of the die-casting machine that is movable relative to the stationary platen. When ready for casting, the two halves of the mold are in the closed position and are held closed by a locking force on the machine side. In the case of castings with cavities or undercuts, hydraulically actuated slides, also referred to below as cores, are used.

When using cores or at least one core, this is releasably fixed to the movable mold half in the open position of the two mold halves or the die casting mold and is moved together with the movable mold half in a direction of movement relative to the stationary mold half into the closed position in which the core at least in sections rests against the stationary mold half. The mold cavity for the cast piece to be produced is formed between the two mold halves and the core. During a subsequent casting operation, a flowable molten metal is then introduced into the mold cavity at high speed and under high pressure. In order to prevent relative movement between the core and the two mold halves perpendicular to the direction of movement of the mold halves during the casting process, the core is locked to the stationary mold half during the movement of the movable mold half into the closed position. For this purpose, a locking device consisting of at least two locking elements is provided, with one of the locking elements being arranged on the core and the other locking element on the stationary mold half. The blocking elements are each fixed immovably or stationary on the core and on the stationary mold half. When the movable mold half and the core are displaced into the closed position, the blocking elements first make contact and then slide off one another as the movement into the closed position continues. When the closed position is reached, the blocking elements are then supported on or on one another in such a way that the relative movement between the core and the stationary mold halves is prevented during the subsequent casting process.

When the mold halves are closed or when the blocking elements come into contact and slide onto one another during the closing movement, a height offset between the two mold halves, sheet metal underneath which increases the surface pressure on the sealing surfaces of the core, and/or thermal expansion of the core can lead to that the core is tilted and/or elastically deformed during the closing movement of the mold halves. The guide elements consisting of tongue and groove wedge and the core is then held in the tilted or elastically deformed and inclined position during the subsequent casting process. After the casting process and the opening of the mold, the core is first pulled and straightened again. Depending on the degree of the previous inclination of the core or the elastic deformation, forces are exerted on the cast part that has just been produced, which in extreme cases can lead to its destruction. There are often dimensional deviations in the cast parts. white The more serious consequences are an increased proportion of rejects and a reduction in the output of the die casting machine. Damage to the mold halves and/or the core can also occur. The necessary mold repairs then result in high repair costs in connection with long downtimes of the die casting machine.

From the DE 196 39 053 A1 a die-casting machine with a divisible die-casting mold consisting of two mold halves is known. In order to be able to die-cast large die-cast parts reliably beyond the limits of the machine design due to elasticity, the locking forces for the die-casting tool are transmitted by tie rods integrated in the die in a power flow circuit that remains within the die-casting tool.

The invention is based on the object of designing a die-casting mold of the type mentioned at the outset in such a way that dimensionally accurate castings can be produced, the proportion of rejects is reduced and downtimes of the die-casting machine can be minimized.

This object is achieved with a die-casting mold according to the features of patent claim 1. The subclaims relate to particularly useful developments of the invention.

According to the invention, a casting mold for die-casting castings is provided, in which the second blocking element is movably mounted on the stationary mold half and can be transferred from a release position to a blocking position, the two blocking elements moving when the mold halves are in the closed position and one is in the release position second blocking element does not contact or touch, while the two blocking elements contact each other when the mold halves are arranged in the closed position and a second blocking element is arranged in the blocking position, preventing the relative movement between the core and the fixed mold half and the movable mold half perpendicular to the direction of movement of the movable mold half or touch. The core is not moved into the closed position during the movement, as in the prior art mentioned at the outset, but only after the moveable mold half has been moved into the closed position, in which the core is initially only held in the desired position by the two mold halves , locked to the stationary mold half. As a result, no forces causing tilting or deformation act on the core during the shift into the closed position, and an inclined position of the core during the casting process can be effectively prevented. When the cast part is subsequently removed from the mold or when the core is pulled, no significant forces act on the cast part that has just been produced. The design of the casting mold according to the invention means that cast parts with increased requirements for dimensional accuracy can be produced and at the same time the proportion of rejects can be reduced and downtimes of the die casting machine can be minimized due to the lack of mold or core repairs.

A particularly advantageous embodiment of the invention provides that the second blocking element can be transferred from the release position to the blocking position by a translatory movement. This ensures, on the one hand, a process-reliable displacement of the second blocking element from the release position into the blocking position and, on the other hand, a secure locking of the core on the stationary mold half.

It proves to be particularly expedient here that a direction of movement of the second blocking element and the direction of movement of the movable mold half and the core are parallel to one another. As a result, the second blocking element can be transferred into the blocking position without forces being introduced into the core. In addition, a height offset between the two mold halves or between the movable core and the stationary mold half can be recognized by the fact that the second blocking element cannot be transferred, or not completely, into the blocking position. In this case, the mold halves must be readjusted.

The translational movement of the second blocking element is achieved in that the second blocking element is movably mounted on the stationary mold half by a linear guide, in particular a dovetail guide. This type of guide is particularly robust and can withstand the high forces and temperatures that occur during die casting.

A further advantageous embodiment of the present invention is also created in that a recess is formed between the core, the first blocking element and the stationary mold half when the mold halves are arranged in the closed position, in which the second blocking element engages positively in the blocking position. The form fit absorbs the forces occurring during the casting process and acting on the core in a process-reliable manner, thereby effectively preventing relative movement between the core and the stationary mold half during the casting process in all spatial directions perpendicular to the direction of movement of the movable mold half. The pressure peak at the end of the fill Development of the mold cavity and the forces resulting from the post-pressure are absorbed by the frame of the stationary mold half.

Furthermore, it has proven to be particularly expedient for the first blocking element and the second blocking element to each have guide surfaces which are coordinated with one another and which in the blocking position rest against one another at least in sections to prevent relative movement, the guide surfaces being arranged parallel to one another and inclined to the direction of movement of the second blocking element. This results in guide surfaces designed inclined to the direction of movement or safety elements designed in the opposite direction in a wedge shape. The displacement of the second blocking element from the release position into the blocking position can take place without forces being introduced from the second blocking element into the first blocking element and thereby into the core during this displacement. The guide surfaces then ideally only contact one another when or after the blocking position has been reached in such a way that the second blocking element engages in a form-fitting manner in the recess formed when the movable mold half is transferred into the closed position. By wedging the two blocking elements in the blocking position, the temperature-related increase in length of the components can be compensated.

Since the two blocking elements of the blocking device are in the closed position of the mold halves inside the casting mold and cannot be accessed from the outside, and because the casting process must be able to be automated, it has proven to be advantageous for the second blocking element to be actuated by a motor, pneumatic or hydraulic drive device from the Release position can be converted into the blocking position. The translatory movement is introduced into the second blocking element by the drive device.

Furthermore, it proves to be particularly expedient that the drive device is connected to a deflection device, which deflects a translational movement generated by the drive device in the direction of movement of the second blocking element. Since the second locking element is mounted on the stationary mold half, which in turn is arranged on the sprue-side clamping plate of the die casting machine, the drive device is arranged on a side of the mold half facing away from the core for reasons of installation space and due to the prevailing temperatures in the area of the sprue on the stationary clamping plate not possible. By providing a deflection device, the drive device can be arranged at any point in the region of the stationary mold half. In this case, a deflection of 90° will preferably take place.

Another feature according to the invention is that the deflection device has a sliding block with an opening for receiving an actuating element of the drive device that can be moved translationally and relative to the sliding block, with a translational axis of the actuating element being arranged perpendicular to the direction of movement of the second blocking element and the translational axis of the actuating element and a Central axis of the opening enclose an acute angle.

Depending on the position at which the drive device or the deflection device is arranged, it can be advantageous for a coupling element to be provided between the deflection device and the second blocking element. In this way, construction-related distances between the second blocking element and the deflection device or the drive device can be bridged.

• 1 eine Prinzipdarstellung einer Gießform in einer Seitenansicht mit in einer Offenstellung angeordneten Formhälften;
• 2 die in 1 dargestellte Gießform mit in einer Schließstellung angeordneten Formhälften und mit einem in einer Freigabestellung angeordneten zweiten Sperrelement;
• 3 die in 2 dargestellte Gießform mit einem in einer Sperrstellung angeordneten zweiten Sperrelement;
• 4 eine Prinzipdarstellung der in 1 dargestellten ortsfesten Formhälfte in einer Seitenansicht;
• 5 eine Ansicht gemäß der Linie A-A in 4 mit einem in der Freigabestellung angeordneten zweiten Sperrelement;
• 6 eine Ansicht gemäß der Linie A-A in 4 mit einem in der Sperrstellung angeordneten zweiten Stellelement.

The invention permits numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in

• 1 a basic representation of a casting mold in a side view with mold halves arranged in an open position;
• 2 in the 1 Casting mold shown with mold halves arranged in a closed position and with a second locking element arranged in a release position;
• 3 in the 2 Casting mold shown with a second blocking element arranged in a blocking position;
• 4 a schematic diagram of the in 1 illustrated stationary mold half in a side view;
• 5 a view along line AA in 4 with a second locking element arranged in the release position;
• 6 a view along line AA in 4 with a second actuating element arranged in the blocking position.

1 shows a basic representation of a casting mold 1 for die casting of castings for a die casting machine, not shown, in a side view. The mold 1 consists of a stationary mold half 2, which is arranged on a stationary platen of the die casting machine, not shown, and a movable mold half 3, which is arranged on a movable platen of the die casting machine, also not shown. Furthermore, the casting mold 1 has at least one core 4 which is detachably fixed to the movable mold half 3 . the Movable mold half 3 can be moved in a direction of movement 5 relative to the stationary mold half 2 from an in 1 shown open position in a 2 and 3 shown closed position are shifted.

Furthermore, the casting mold 1 has a locking device 8 consisting of a first locking element 6 and a second locking element 7 . The first locking element 6 is arranged in a stationary manner on the core 4 , while the second locking element 7 is movably mounted on a projection 9 of the stationary mold half 2 . The second blocking element 7 can be moved in a direction of movement 10 from an in 1 illustrated release position in an in 3 shown locking position are moved, wherein the direction of movement 10 of the second locking element 7 and the direction of movement 5 of the movable mold half 3 are parallel to each other. During a displacement of the second blocking element 7 from the release position to the blocking position, it moves translationally and relative to the stationary mold half 2 or the projection 9 of the stationary mold half 2. The two locking elements 6, 7 of the locking device 8 each have a guide surface 11, 12 on which are arranged parallel to each other and each inclined to the direction of movement 10 of the second blocking element 7 and to the direction of movement 5 of the movable mold half 3 . With a movable mold half 3 arranged in the closed position and a second locking element 7 ( 3 ) the two blocking elements 6, 7 or the guide surfaces 11, 12 of the two blocking elements 6, 7 make contact or lie against one another in such a way that a relative movement between the core 4 and the stationary mold half 2 or the movable mold half 3 is perpendicular to the direction of movement 5 of the movable mold half 3 is prevented. In contrast, in the open position and during the displacement of the movable mold half 3 into the closed position, the two blocking elements 6, 7 do not make contact ( 1 and 2 ).

The procedure for die casting castings with the casting mold 1 according to the invention is shown below with reference to FIG 1 until 3 summarized briefly. First, the movable mold half 3 is in the open position at a defined distance from the stationary mold half 2. The core 4 is already fixed to the movable mold half 3 and the second locking element 7, which is movably mounted on the stationary mold half 2, is in the release position ( 1 ).

The movable mold half 3 is then displaced together with the core 4 in the direction of movement 5 and relative to the stationary mold half 2 until the mold halves 2, 3 are in the closed position ( 2 ). In the course of the displacement of the movable mold half 3 and the core 4 in the direction of the stationary mold half 2 , the projection 9 of the stationary mold half 2 supporting the second blocking element 7 enters a correspondingly formed free space 13 arranged in the core 4 . In the closed position, the core 4 rests at least in sections on the stationary mold half 2 and the second blocking element 7 arranged in the release position is, without contacting the first blocking element 6, in one of the core 4, the first blocking element 6 and the stationary mold half 3 or the projection 9 limited recess 14 is arranged.

To transfer the second blocking element 7, which is arranged in the release position, into the blocking position, the second blocking element 7 is then moved in the direction of movement 10, namely in the direction of the core 4, with the second blocking element 7 in the blocking position engaging in a form-fitting manner in the recess 14, so that the contact surfaces 11, 12 of the blocking elements 6, 7 bear against one another and support one another ( 3 ). This causes a relative movement between the core 4 and the two mold halves 2, 3 perpendicular to the direction of movement 5 of the movable mold half 3 or to the direction of movement 10 of the second blocking element 4 during a subsequent casting process, in which a flowable molten metal is poured at a high speed and under a high Pressure is introduced into a mold cavity that is not shown in the figures and is at least partially delimited by the two mold halves 2, 3 and the core 4.

The second blocking element 7 is, as in 4 shown, supported by a linear guide 15 designed as a dovetail guide on the stationary mold half 2 or on the projection 9 of the stationary mold half 2, so that the second locking element 7 can be moved by a translatory movement relative to the stationary mold half 2 or the projection 9.

To initiate the movement and to shift the second blocking element 7 from the in 5 shown release position in 6 In the blocking position shown, the second blocking element 7 is connected to a drive device 18 with the interposition of a coupling element 16 and a deflection device 17 ( 5 and 6 ).

As in 5 shown, the second blocking element 7 is connected directly to a coupling element 16 designed as a push/pull rod. A sliding block 19 with an oblique opening 20 and a central guide 21 is provided as the deflection device 17 . Trained as a hydraulic cylinder drive device 18 is with an actuating element 22 arranged in the opening 20 of the sliding block 19 and designed as an angle piece. Here, a translational axis 27 of the actuating element 22 and a central axis 28 of the opening 20 enclose an acute angle α. If the second blocking element 7 arranged in the release position is to be shifted into the blocking position, then the actuating element 22 is actuated in the direction of the arrow 23 ( 5 ) moved forward. As a result, the sliding block 19 and thus also the coupling element 16 and the second locking element 7 are moved in the direction of the arrow 24 in the direction of movement 10 to the left in the in 6 blocking position shown moved. If the second blocking element 7 is to be moved from the blocking position back into the release position, then the actuating element 22 is pushed backwards by the drive device 18 in the direction of the arrow 25 ( 6 ) emotional. As a result, the sliding block 19, the coupling element 16 and the second blocking element 7 also move in the direction of the arrow 26 in the direction of movement 10 to the right, namely until the second blocking element 7 is again arranged in the release position.

Reference List

1

mold

2

stationary mold half

3

movable mold half

4

core

5

direction of movement

6

first blocking element

7

second blocking element

8th

locking device

9

head Start

10

direction of movement

11

guide surface

12

guide surface

13

free space

14

recess

15

linear guide

16

coupling element

17

deflection device

18

drive device

19

sliding block

20

breakthrough

21

center guide

22

actuator

23

Arrow

24

Arrow

25

Arrow

26

Arrow

27

axis of translation

28

central axis

Claims (10)

Casting mold (1) for die-casting cast parts, consisting of a stationary mold half (2), a mold half (3) that can be moved in a direction of movement (5) from an open position to a closed position, and of at least one core (4) which, in the closed position delimit at least in sections a mold cavity for the casting that can be filled with a flowable molten metal, the core (4) detachably fixed to the movable mold half (3) being displaceable together with the movable mold half (3) into the closed position in which the core (4) rests against the stationary mold half (2) at least in sections, with a locking device (8) being provided which has a first locking element (6) arranged on the core (4) and a second locking element (7) arranged on the stationary mold half (2). , which contact each other when the mold halves (2, 3) are in the closed position in such a way that a relative movement between the core (4) and the above-mentioned stationary mold half (2) perpendicular to the direction of movement (5) of the movable mold half (3), characterized in that the second blocking element (7) is movably mounted on the stationary mold half (2) and can be transferred from a release position to a blocking position, the two blocking elements (6, 7) not contacting each other when the mold halves (2, 3) are in the closed position and a second blocking element (7) is in the release position, while the two blocking elements (6, 7) are in the closed position mold halves (2, 3) and a second locking element (7) arranged in the locking position, preventing the relative movement between the core (4) and the fixed mold half (3) perpendicular to the direction of movement (5) of the movable mold half (2). Casting mold (1) according to claim 1 , characterized in that the second blocking element (7) can be converted from the release position into the blocking position by a translatory movement. Casting mold (1) according to claims 1 or 2 , characterized in that a direction of movement (10) of the second locking element (7) and the direction of movement (5) of the movable mold half (3) are parallel to each other. Casting mold (1) according to at least one of the preceding claims, characterized in that the second locking element (7) is movably mounted on the stationary mold half (2) by a linear guide (15), in particular a dovetail guide. Casting mold (1) according to at least one of the preceding claims, characterized in that there is a recess ( 14), in which the second blocking element (7) engages in a form-fitting manner in the blocking position. Casting mold (1) according to at least one of the preceding claims, characterized in that the first blocking element (6) and the second blocking element (7) each have coordinated guide surfaces (11, 12) which in the blocking position rest against one another at least in sections to prevent relative movement , wherein the guide surfaces (11, 12) are arranged parallel to one another and inclined to the direction of movement (10) of the second blocking element (7). Casting mold (1) according to at least one of the preceding claims, characterized in that the second locking element (7) can be transferred from the release position to the locking position by a motor, pneumatic or hydraulic drive device (18). Casting mold (1) according to at least one of the preceding claims, characterized in that the drive device (18) is connected to a deflection device (17) which causes a translational movement (arrows 23, 25) generated by the drive device (18) in the direction of movement (10th ) of the second locking element (7) deflects. Casting mold (1) according to at least one of the preceding claims, characterized in that the deflection device (17) has a sliding block (19) with an opening (20) for receiving an actuating element (22) of the drive device ( 18), wherein a translational axis (27) of the actuating element (22) is arranged perpendicular to the direction of movement (10) of the second blocking element (7) and the translational axis (27) of the actuating element (22) and a central axis (28) of the opening (20 ) enclose an acute angle (a). Casting mold (1) according to at least one of the preceding claims, characterized in that a coupling element (16) is provided between the deflection device (17) and the second blocking element (7).

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