Passive lock catch mechanism of three-plate die for die casting, three-plate die comprising passive lock catch mechanism and die casting equipment comprising passive lock catch mechanism

Abstract

The invention provides a passive lock catch mechanism of a three-plate die for die casting, the three-plate die comprising the passive lock catch mechanism and die casting equipment comprising the passive lock catch mechanism. The passive lock catch mechanism comprises a limiting block which is mounted on the movable mold and moves synchronously with the movable mold; the lock catch is installed on the middle plate through a lock catch support, the shape of one end of the lock catch is matched with that of the limiting block, a spring lifting pin is arranged on one side face of the other end of the lock catch, and a guide pin is arranged on the other side face adjacent to the other end of the lock catch; the guide block is mounted on the fixed mold, positioning platforms are arranged at the two ends of the guide block, and the guide block guides the guide pin to do curvilinear motion between the two positioning platforms; the curvilinear motion of the guide pin drives the lock catch to rotate with the rotating shaft on the lock catch support as the center, and meanwhile force is applied to the spring lifting pin. The three-plate die opening / closing mechanism is simple in structure, does not need to independently hydraulically drive the middle plate and can be matched with a die-casting machine to efficiently complete die opening / closing actions of a three-plate die.

Description

Technical Field

[0001] The present invention relates to the technical field of die-casting equipment, and in particular to a passive locking mechanism of a three-plate die for die-casting, and a three-plate die and die-casting equipment comprising the same. Background Art

[0002] Generally speaking, a casting mold consists of two parts, namely the movable mold and the fixed mold, also known as a two-plate mold. The molten aluminum is poured upward from the bottom of the product, and there is only one parting surface for the casting to separate from the mold. As die-casting products become more and more diverse, more and more die-casting mold structures adopt a three-plate mold structure design, that is, an intermediate plate (stripper plate) is added between the movable mold and the fixed mold to change the pouring direction of the molten aluminum, so that the molten aluminum is poured from the middle position behind the product. The three-plate mold has two parting surfaces: see Figure 1 The first parting is when the fixed mold and the middle plate separate from the fixed mold / middle plate interface 10, the gate is pulled off, and the material handle falls off. At this time, the middle plate and the movable mold remain relatively still to prevent the casting between them from being deformed; see Figure 2 The second parting is when the mold is opened to a certain distance, the middle plate stops moving, the movable mold continues to retreat, and the middle plate separates from the movable mold at the middle plate / movable mold interface 20 to eject the product.

[0003] In large-tonnage three-platen high-pressure vacuum casting production, the mold is generally heavy, and a spring mechanism cannot be used to drive the middle plate and the movable mold to follow. Currently, most molds use hydraulic cylinders to push / pull the middle plate to complete the set action, but this method has the following disadvantages: 1. Multiple hydraulic cylinders are required to be evenly distributed around the mold, and they need to be combined with circuit systems such as sensors. This is costly (the cost accounts for 5% of the total mold cost), has a complex structure, and is difficult to maintain; 2. The opening / closing speed needs to be coordinated with the hydraulic cylinder's push / pull of the middle plate, resulting in a longer production cycle (3s longer than the opening and closing cycle of a two-platen mold of the same size).

[0004] Therefore, how to improve the opening / closing efficiency of the three-plate mold while reducing the mold manufacturing and maintenance costs is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] Due to the defects of the existing technology, the present invention provides a passive locking mechanism for a three-plate mold for die casting, and a three-plate mold and die casting equipment containing the same. Through a new mechanical passive follow-up control locking mechanism, the structure is simplified and there is no need for a separate hydraulic drive intermediate plate, so that the opening / closing action of the three-plate mold can be efficiently completed in cooperation with the die casting machine.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a passive locking mechanism for a three-plate die for die casting, wherein the three-plate die comprises a movable die, a fixed die, and an intermediate plate therebetween; the passive locking mechanism comprises:

[0007] A limit block is installed on the movable mold and moves synchronously with the movable mold;

[0008] A lock catch is mounted on the middle plate through a lock catch bracket, one end of which is shaped to match the limit block, a spring ejector pin is provided on one side of the other end, and a guide pin is provided on the other adjacent side surface;

[0009] A guide block is mounted on the fixed die to guide the guide pin to move in a curve along the guide block;

[0010] The curved motion of the guide pin drives the lock to rotate around the rotation axis on the lock bracket, while exerting force on the spring ejector pin.

[0011] The components of the passive locking mechanism are mounted separately on the movable die, middle plate, and fixed die of a three-plate mold. As the movable die and middle plate move in tandem during mold opening and closing, the traditional hydraulically driven active control of the middle plate is transformed into mechanical passive follow-up control. Utilizing the curved trajectory of the guide block and the energy storage characteristics of the spring ejector pin, the middle plate achieves phased self-locking during mold closing and phased release during mold opening. The passive locking mechanism operates accurately, efficiently, and stably, significantly reducing production cycle times.

[0012] Furthermore, the spring ejector pin is subjected to a force that changes from an original state to a compressed state during the mold opening process, and returns from the compressed state to the original state during the mold closing process.

[0013] Furthermore, the guide block is provided with a reset block; when the mold is closed, the guide pin is limited by the reset block.

[0014] Furthermore, positioning platforms are provided at both ends of the guide block to guide the guide pin to move in a curve between the two positioning platforms.

[0015] Furthermore, the shape of the limiting block is a bar, and the shape of the lock buckle that cooperates with the limiting block is a hook.

[0016] In a second aspect, the present invention provides a three-plate mold for die-casting, comprising a movable mold, a fixed mold and an intermediate plate therebetween; the passive locking mechanism as described above is provided on the same side of the movable mold, the fixed mold and the intermediate plate.

[0017] Furthermore, the passive locking mechanism is provided in one group on the upper and lower sides of the left and right sides of the three-plate mold.

[0018] In a final aspect, the present invention provides a die-casting apparatus using the three-plate die for die-casting as a die.

[0019] Compared with the prior art, the present invention has the following advantages or beneficial effects:

[0020] (1) The present invention overcomes many shortcomings of previous related mechanisms in terms of structure and use. The middle plate moves along with the opening and closing process of the movable mold, and does not require a separate hydraulic drive, which reduces costs, simplifies the structure, is easy to manufacture, and is safe and reliable.

[0021] (2) The present invention can improve the production efficiency of a three-plate die-casting machine and reduce the cost of die manufacturing and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention and its features and advantages will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the three-plate mold for the first parting. The arrows in the figure indicate the movement direction of the movable mold and the middle plate.

[0024] Figure 2 This is a structural diagram of the second parting of the three-plate mold. The direction indicated by the arrow in the figure is the direction in which the movable mold continues to move;

[0025] Figure 3 Schematic diagram of the three-dimensional structure of a passive locking mechanism in one embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the structural changes of the passive locking mechanism during the opening and closing of a three-plate mold according to one embodiment of the present invention. The ground mark in the figure indicates that the component is fixed in position, the direction of the solid arrow indicates the driving movement direction of the component, and the direction of the dotted arrow indicates the driven movement direction of the component;

[0027] The figures are marked as follows: 10, fixed mold / middle plate interface; 20, middle plate / movable mold interface; 1, limit block; 2, lock; 3, lock bracket; 4, guide block; 41, first positioning platform; 42, second positioning platform; 5, guide pin; 6, reset block; 7, spring ejector pin. DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. It should be understood that all of the exemplary embodiments described are merely partial embodiments and examples of the present disclosure, and not exhaustive. Rather, these exemplary embodiments are provided to enable those skilled in the art to more thoroughly understand the present disclosure and to more fully convey the technical content of the present disclosure to those skilled in the art.

[0029] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "provided with", "installed", and "connected" should be understood in a broad sense. For example, the connection method can be welding, clamping, threaded connection, or binding connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the orientation or positional relationship indicated by the terms "front", "rear", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and does not require that the present invention must be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0030] See also Figure 1 and Figure 2 The three-plate mold structure is designed with an intermediate plate between the movable and fixed molds. During mold opening, the first parting is the separation of the fixed mold, the intermediate plate, and the movable mold at the fixed mold / intermediate plate interface 10. The second parting is the separation of the movable mold from the intermediate plate at the intermediate plate / movable mold interface 20. Traditionally, the intermediate plate is driven by a hydraulic cylinder to achieve the desired movement.

[0031] This embodiment provides a passive locking mechanism for a three-plate die for die casting, comprising a limit block 1, a lock 2, and a guide block 4. The limit block 1 is mounted on the movable die and moves synchronously with the movable die. The lock 2 is mounted on the intermediate plate via a lock bracket 3. One end of the lock 2 is shaped to match the limit block 1, and a spring ejector pin 7 is provided on one side of the other end, with a guide pin 5 provided on the adjacent side. The guide block 4 is mounted on the fixed die and guides the guide pin 5 to move in a curve along the guide block 4. The curve movement of the guide pin 5 causes the lock 2 to rotate about the rotation axis on the lock bracket 3, while simultaneously applying force to the spring ejector pin 7.

[0032] As a preferred embodiment, the shape of the limit block 1 is a bar, and the shape of the lock 2 that matches the limit block 1 is a hook. It is understandable that the matching shape of the limit block and the lock is only required to meet the requirements of matching and limiting, and is not limited to the above shapes.

[0033] See also Figure 4 The die-casting three-plate mold is opened by using the passive locking mechanism, which includes the following steps:

[0034] ① In the mold closing state, the lock buckle 2 and the limit block 1 are in a fastened state. At this time, the guide pin 5 is located on the first positioning platform 41 of the guide block 4.

[0035] ② In the early stage of mold opening, the lock buckle 2 and the limit block 1 are in a fastened state. During the retreat of the movable mold, the middle plate is driven to retreat together with the lock buckle 2.

[0036] ③ When the mold is opened and the middle plate is about to be in place, the lock 2 gradually rotates with the lock bracket 3 as the fulcrum and moves along the curve of the guide block 4 with the guide pin 5, and releases the limit block 1. Before it is completely released, it still drives the middle plate to continue moving. At this time, as the lock 2 moves, the spring push pin 7 is compressed.

[0037] ④ Open the mold until the middle plate is in place, the lock 2 is completely released, and the guide pin 5 reaches the second positioning platform 42 of the guide block 4. At this time, the middle plate stops, and the limit block 1 continues to open with the movable mold to complete the mold opening action.

[0038] See also Figure 4 The three-plate die for die casting is closed by using the passive locking mechanism, which includes the following steps:

[0039] ⑤ In the early stage of mold closing, the middle plate does not move, the lock 2 remains fully open, the spring ejector pin 7 is still in a compressed state, and the movable mold begins to move forward.

[0040] ⑥ After the movable mold reaches the middle plate position, it moves forward with the middle plate to close the mold. At this time, the spring ejector pin 7 causes the guide pin 5 to move forward along the curve of the guide block 4, gradually tightening the lock catch 2 and the limit block 1. Preferably, the guide block 4 can also be equipped with a reset block 6. The reset block 6 serves as a redundant device in case the spring ejector pin 7 fails during mold closing. When the spring ejector pin 7 fails during mold closing, the reset block 6 mechanically forces the lock catch 2 to reset.

[0041] ⑦ After the lock buckle 2 is fastened to the limit block 1, continue to close the mold.

[0042] ⑧The middle plate moves to fit the fixed mold, and the movable mold also fits closely to the middle plate to start building up the clamping force.

[0043] As an example, the lock 2 can rotate within a range of ±15° around the rotation axis on the lock bracket 3. The range of the lock rotation angle can be adjusted appropriately according to the size of different molds. The purpose is only to make the lock 2 just disengage the limit block 1 and release the restriction.

[0044] Currently, the passive locking mechanism has been tested in production on a three-plate mold on a 44,000 KN die-casting machine. The mechanism operates accurately, efficiently, and stably, and the production cycle has been significantly reduced.

[0045] This embodiment also provides a three-plate die for die casting, comprising a movable die, a fixed die, and an intermediate plate therebetween. The movable die, fixed die, and intermediate plate are provided with the aforementioned passive locking mechanism on the same side. To ensure parallelism during mold opening, four sets of these passive locking mechanisms are provided on the three-plate die, one set on each of the upper and lower sides of the left and right sides of the die.

[0046] Finally, this embodiment also provides a die-casting device, which uses the three-plate mold for die-casting as described above as a mold.

[0047] It should be noted that the die-casting machine or die-casting equipment in this application document is an existing three-plate die-casting machine or die-casting equipment, especially a high-pressure vacuum die-casting machine, and the driving mode of its movable mold can be electric drive, hydraulic drive or mechanical drive, etc., which are existing technologies known to technical personnel in this field.

[0048] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A passive locking mechanism for a three-plate die for die casting, the three-plate die comprising a movable die, a fixed die, and an intermediate plate therebetween; characterized in that: The passive locking mechanism comprises: A limit block (1) is mounted on the movable mold and moves synchronously with the movable mold; A lock catch (2) is mounted on the intermediate plate via a lock catch bracket (3), one end of which is shaped to match the limit block (1), a spring ejector pin (7) is provided on one side of the other end, and a guide pin (5) is provided on the other adjacent side surface; A guide block (4) is mounted on the fixed die to guide the guide pin (5) to move in a curve along the guide block (4); The curved motion of the guide pin (5) drives the lock catch (2) to rotate around the rotation axis on the lock catch bracket (3), while exerting force on the spring ejector pin (7).

2. The passive locking mechanism of a three-plate die for die casting according to claim 1, characterized in that: The spring ejector pin (7) is subjected to a force that changes from an original state to a compressed state during the mold opening process, and returns from the compressed state to the original state during the mold closing process.

3. The passive locking mechanism of a three-plate die for die casting according to claim 1, characterized in that: The guide block (4) is provided with a reset block (6); when the mold is closed, the guide pin (5) is limited by the reset block (6).

4. A passive locking mechanism for a three-plate die for die casting according to claim 1 or 3, characterized in that: Positioning platforms are provided at both ends of the guide block (4) to guide the guide pin (5) to move in a curve between the two positioning platforms.

5. A passive locking mechanism for a three-plate die for die casting according to claim 1 or 3, characterized in that: The shape of the limiting block (1) is a bar, and the shape of the lock buckle (2) matched with the limiting block (1) is a hook.

6. A three-plate die for die casting, comprising a movable die, a fixed die, and an intermediate plate therebetween; characterized in that: The passive locking mechanism according to any one of claims 1 to 5 is provided on the same side of the movable mold, the fixed mold and the middle plate.

7. The three-plate mold for die casting according to claim 6, characterized in that: The passive locking mechanism is provided in one group on the left and right sides and one group on the upper and lower sides of the three-plate mold.

8. A die-casting device, characterized in that: The three-plate die for die casting as claimed in claim 6 or 7 is used as the die.

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